<p>Platelet aggregation plays an important role in both the formation of a hemostatic plug and in the generation of thrombus. The mechanism of platelet aggregation has not been fully elucidated. It is conceivable that changes in the synthesis, breakdown or rate of turnover of some of the constituents of the platelet membrane may be important in the mechanisms of aggregation. Recent experimental evidence in other mammalian tissues has implicated the closed circle conversion between MPI and PA as part of the membrane receptor-effector interaction process, and a possible role permeability toward of TPI-DPI interconversion in the regulation of membrane permeability toward Na⁺ and K⁺. Platelets have been recognized to be a useful model for these studies because of its abundance in phosphoinositides and easiness of obtaining pure platelet suspensions. Previous studies showed that addition of ADP to ³²P-labeled washed platelets caused an increase in radioactivity in PA in 2 sec, DPI in 30 sec and MPI in 2-3 min. TPI-DPI interconversion was suspected but consistent changes in ³²P-radioactivity in TPI was not detected. Similar changes were observed in platelets in response to thrombin stimulation. In none of the studies in other tissues all the metabolic pathways for inositol lipids were studied simultaneously. The aims of the present experiments were to investigate TPI-DPI interconversion and MPI metabolism during platelet aggregation and the release reaction caused by ADP, ionophore A23,187 and thrombin. Since these stimuli are considered to act on platelets by different mechanisms, their effects on the platelet phosphoinositide metabolism were compared. Furthermore, experiments were carried out with unstimulated platelets labeled with ³²PO₄ to find out if there vere differences in the patterns of ³²PO₄ incorporation into the major platelet phospholipids (PC, PE, PS) under in vitro and in vivo conditions, as claimed by former investigators.</p> <p>Using improved methods for separation of phosphoinositides, it was found that the pattern of ³²P-incorporation into the major phospholipids in platelet suspension was similar to that of in vivo platelets when the incubation was carried out for many hours. Therefore, the phosphate moiety in all phospholipids turn over; but the phosphate in the major phospholipids turn over much more slowly than that in the phosphoinositides.</p> <p>During ADP-induced platelet aggregation, hydrolysis of TPI to DPI was measurable at 60 sec, with a loss of ³²PO₄, ¹⁴C-arachidonic acid and ³H-inositol from TPI. This hydrolysis was abolished by AMP, an inhibitor of ADP-induced aggregation. Resynthesis of TPI occurred during platelet deaggregation, with the ³²PO₄ radioactivity of this compound being restored to the control level. With A23,187-induced aggregation and release, hydrolysis of TPI did not occur. While there was a significant amount of MPI converted into PA, the majority of MPI appeared to be hydrolysed to fatty acid and lyso MPI. Using platelets labelled with ¹⁴C-arachidonic acid, ³H-glycerol, ³H-inositol, ³²PO₄ and phosphorus assay, it was found that thrombin caused a decrease in TPI (-5.64 ± 1.55%, P < 0.005) as early as 9 sec when platelet shape change was maximal, ³²P-content was also decreased. Resynthesis of TPI was measurable at 60 sec. Most of the MPI was metabolised via the 1,2-diacylglycerol pathway. The the amount of PA was increased. A small amount of the MPI was converted to polyphosphoinositides or lyso MPI and free fatty acid. These experiments have shown a close relationship between changes in phosphoinositide metabolism and platelet aggregation and the release reaction.</p> <p>These principal changes are: (1) increased TPI- DPI interconversion; (2) increased conversion of MPI to l,2-diacylglycerol PA and MPI; (3) with the release reaction conversion of MPI to lyso MH and free fatty acids.</p> / Doctor of Philosophy (PhD)

<p>The goal was to determine the physiological significance of pyruvate dehydrogenase (PDH) activation in muscle. The PDH activity was measured in small samples of muscle obtained by needle biopsy from normal volunteers. In heart PDH was measured using an isolated perfused rat heart preparation. The PDH activity was measured by determining ¹⁴Co₂ production from pyruvate-1-¹⁴C using whole tissue homogenates.</p> <p>The total PDH (PDHt) activity in human skeletal muscle was 302 ± 10 nmol/g/min. with about 40 ± 3% in the active form (PDHa). With aerobic exercise (60% VO₂max) more than 88% of PDH was converted to PDHa within 5 min. Aerobic training did not increase the resting muscle PDHt activity (untrained 304 ± 4, trained 309 ± 8 nmol/g/min,) but it increased the PDHa from 124 ± 9 nmol/g/min. to 215 ± 15 nmol/g/min.</p> <p>Muscle immobilization by arm cast for 6 weeks decreased the PDHa from 112 ± 4 to 28 ± 4 nmol/g/min. but it had no effect on the PDHt activity. Exercise following immobilization decreased the rate and the extent of PDH activation while exercise after weight training increased the extent of PDH activation.</p> <p>Starvation for 24 and 48 hr. in rat heart decreased PDHa from 2768 ± 73 to 1286 ± 109 and 920 ± 149 nmol/g/min. respectively.</p> <p>In the perfused heart PDH was fully activated by epinephrine (1.3 μg/ml), insulin (1 mU/ml) and high (>0.2 mM) pyruvate concentration. PDH activation was not mediated by cyclic AMP since insulin activated PDH but did not change the heart cyclic AMP concentration. Propranolol prevented epinephrine from activating PDH. Octanoic acid decreased the proportion of PDH in the active form.</p> <p>In the heart a detailed study of the relationship between the rate of heart pyruvate oxidation and PDH activation was undertaken. In all experimental conditions where the rate of pyruvate oxidation was changed, parallel changes in the PDHa activity was seen. The correlation between PDH activation and rate of heart pyruvate oxidation was greater than 0.92. These findings suggest that interconversion of PDHa and PDHɨ probably control the rate of heart pyruvate oxidation. A similar correlation was not seen in skeletal muscle during exercise. The calculated rate of muscle pyruvate oxidation was several fold greater than the extent of PDH activation. Although the activation of PDH regulates pyruvate oxidation in both heart and skeletal muscle, in heart this is achieved through the interconversion of active and inactive PDH whereas in skeletal muscle allosteric conversion of the active form of PDH plays a greater part.</p> / Doctor of Philosophy (PhD)

<p>Proteolysis of short-lived cellular proteins was investigated in early- and late-passage cells from normal donors and in cells from donors with the premature aging diseases of progeria and the Werner syndrome. Studies were conducted using intact cells or crude cell extracts to measure the degradation of cellular proteins pre-labeled for 1 hour with ³H- and ¹⁴C-Iabeled phenylalanine.</p> <p>The purpose of these studies was:</p> <p>1. To determine whether aging cells (late-passage normal, progeria and Werner) show increased proteolysis compared to early-passage normals as would be predicted from the Orgel hypothesis.</p> <p>2. To investigate the effect of growth state and inhibitors on proteolysis in these cells.</p> <p>3. To identify specific cell fractions or proteins which undergo increased proteolysis in aging cells.</p> <p>4. To measure proteolysis of cellular proteins in extracts of cells, using both endogenous cellular proteases and added exogenous proteases. This was to probe the role of cellular proteins as substrates for prot eases in elevated proteolysis in aging cells.</p> <p>Proteolysis was increased in late-passage normal, progeria and Werner cells compared to early-passage normal cells. This was found in growth and at confluence. The chymotrypsin inhibitor TPCK reduced the elevated proteolysis in freshly plated late-passage and progeria cells but did not have this effect on cultures growing logarithmically or those at confluence. Increased proteolysis of soluble (post-microsomal) proteins may be occurring in progeria cells but SDS-polyacrylamide gels failed to show increased turnover of any protein bands.</p> <p>Protease activity in cell extracts could only be demonstrated at acid pH with endogenous cellular proteases. This proteolysis did not preferentially degrade proteins which have short half-lives in vivo including those containing the amino acid analogue canavanine. Proteins from early- and late-passage normal cells showed no difference in acid optimum proteolysis. However, proteins from progeria cells showed less proteolysis than normal controls. This was observed for labeled progeria proteins with proteases from extracts of normal or progeria cells. Paradoxically, proteins from progeria cells were more susceptible to labeled in the trypsin than normal controls but when proteins were labeled in the presence of TPCK no difference in trypsin susceptibility was observed.</p> <p>The finding indicate:</p> <p>1. Increased proteolysis is a feature of cellular aging.</p> <p>2. Proteolysis in aging cells during growth shows greater elevation compared to early-passage normals, than that seen at confluence.</p> <p>3. In progeria, cellular proteins have altered susceptibility to both endogenous and exogenous proteases.</p> <p>4. The inhibitor TPCK can, under certain conditions, reduce increased proteolysis in late-passage normal and progeria cells.</p> <p>Therefore, it is concluded that increased proteolysis occurs in aging cells and that increased activity of TPCK-sensitive proteases may in some circumstances be responsible. Thus, altered control of the proteolytic apparatus and not abnormal proteins may be causing increased proteolysis in aging cells.</p> / Doctor of Philosophy (PhD)

<p>Nature mammalian myofibres are multinucleated elongate cells in which the nuclei are regularly distributed along the entire length of the cell. The multinucleated condition arises by the fusion of mononucleated myoblasts to form myotubes during primary development. A fundamental and essentially unexplored problem in muscle cell biology is the question of the nuclear-cytoplasmic relationship in muscle fibres. Although local membrane specializations occur, most notably in the region of innervation, it is not known if each myonucleus controls the biochemical functions of a local territory comprised of the immediately adjacent muscle cytoplasm, organelles, and membrane, or if the gene products of every myonucleus are uniformly distributed in the fibre. An understanding of this aspect of the organization of muscle cells could help solve other problems in the biology of skeletal muscle; for example, what is the significance of X-chromosome mosaicism in the expression of muscle disease problems in the biology of skeletal muscle; for example, what is the significance of X-chromosome mosaicism in the expression of muscle disease in carriers of X-linked myopathies? Which myonuclei are the targets of neurotrophic influences on muscle?</p> <p>In this study I have taken advantage of the fact that in mouse chimaeras two genotypically distinct types of myonuclei are often incorporated into single myofibres skeletal muscle cells in vivo. Mouse chimaeras were produced by the aggregation of embryos homozygous for different alleles for both the monomers of the cytoplasmic enzyme glucosephosphate isomerase (GPI-1) and the monomers of the nuclear-coded mitochondrial matrix protein malic enzyme (MOD-2). Therefore, mosaic myofibres contained both Gpi-1ª/Gpi-1ª, Mod-2ª/Mod-2ª myonuclei and Gpi-1ᵇ/Gpi-1ᵇ, Mod-2ᵇ/Mod-2ᵇ myonuclei.</p> <p>The distribution of the electrophoretic variants of GPI-1 was measured at various points along the length of mosaic muscle fibres. Changes in the isozyme composition along the length of a cell would indicate that the enzyme remains localized in cytoplasmic territories. A uniform isozyme profile would result if the products of individual myonuclei are homogeneously distributed. The results presented here indicate that the intracellular distribution of GPI-1 isozymes does not change along the length of mosaic myofibres in both adult and young mouse chimaeras. Therefore, the products of each myonucleus are widely distributed in skeletal myofibres.</p> <p>Functional GPI-I is an oligomeric enzyme composed of two monomers. Analyses of the proportions of GPI-I dimer types in mosaic myofibres reveal that the homogenous distributions of GPI-I isozymes arise by the widespread distribution of precursors of GPI-I (monomers or monomer precursors such as messenger RNA) before dimer formation; dimers are not initially assembled in local territories around each myonucleus and then widely distributed.</p> <p>The investigation was extended to the question of whether individual mitochondrion in skeletal myofibres have access to nuclear-toded proteins encoded by one or by multiple myonuclei. Evidence was obtained that indicates that both types of monomers of nuclear-coded mitochondrial malic enzyme (MOD-2) are present in an individual mitochondrion of a mosaic myofibre.</p> <p>The results indicate that the gene predicts of different myonuclei are widely distributed both before the assembly of cytoplasmic oligomeric proteins and before the incorporation of proteins into mitochondria.</p> <p>Taken together, the results obtained in this study constitute direct evidence that mammalian skeletal myofibres are functional syneitia in which the gene products of many myonuclei are distributed throughout each cell. Problems and possibilities regarding the mechanisms of distribution and the nature of the gene products distributed are discussed.</p> / Doctor of Philosophy (PhD)

<p>A broad overview of the irritable bowel syndrome (IBS), with an emphasis on theoretical problems, is followed by a comparative psychophysiological study of normal subjects, psychoneurotic patients and patients with IBS. All subjects had a psychiatric interview and psychometric testing followed by measurement of activity in the rectosigmoid colon during baseline, neutral interview, stressful interview and following a meal or neostigmine (0.5 mg I.M.). Myoelectrical activity was recorded from two intraluminal bipolar suction electrodes (4 cm apart); motor activity was recorded from two intraluminal strain gauges at the same sites. The number and duration of contractions per minute were determined by inspection of the motor activity record; the frequency content of both the motor and myoelectrical records was determined using a Fast Fourier Transform (FFT) computer assisted method. Measurements were also made of severity of pain following varying degrees of distension of the rectosigmoid colon, serum gastrin and motilin levels and heart rate responses. The two patient groups were psychologically similar to each other and more disturbed than normals both at psychiatric interview and on psychometric measures of anxiety, depression and neuroticism. The IBS patients were significantly different from the neurotics only on the lie scale of Eysenck Personality Inventory (p < .05). The ratings of pain to distension of the sigmoid colon were not significantly different in the three groups (p >.05). The ISS group did not differ significantly from the neurotic group on any of the physiological measures (p >.05); during baseline the ISS group had a greater number and duration of contractions than the normals at one recording site (p <.05). We conclude that previous reports of physiological characteristics unique to ISS have resulted from a failure to control for relevant psychological characteristics and from recording and analysis deficiences. A behavioral model, capable of accounting for both the experimental findings and observed clinical features, is described.</p> / Doctor of Philosophy (PhD)

<p>The differentiation of any cell leads to the synthesis of certain proteins which are responsible for its specific function. In the nervous system this includes such functions as the conductance of action potentials, synaptic transmission and the establishment of specific connections. The developmental biology of proteins unique to the nervous system is therefore of great importance when studying the relationship of proteins to physiological function.</p> <p>Although some neural specific components of adult chicken brain and their ontogeny in the chicken embryo have been previously described by others, they have not been extensively characterized. The present investigation was undertaken in order to enumerate, characterize and study the embryological appearance of antigens specific to the adult chicken brain that can be demonstrated by rabbit anti-brain sera. Particular interest was given to the isolation and purification of one such neural specific antigen in hopes of further elucidating its role in adult function and embryonic development.</p> <p>Antiserum produced in response to a saline soluble extract of adult chicken brain (ABE), when absorbed with adult liver, serum and kidney extracts, yielded a neural specific antiserum (AABS). This polyvalent antiserum was capable of demonstrating at least eight adult neural specific antigens within ABE during immunoelectrophoret analysis. The sequential appearance of seven of these antigens during embryonic development (D2 to D11 of incubation) was established. An eighth antigen could not be detected within the embryonic brain extracts and was assumed to be associated with posthatching neural development. By immunochemical criteria, the majority of the neural specific antigens, but not all, were demonstrated to be restricted to avian brain. Similarly the majority of these antigens, but not all, were demonstrated to be protein in nature since reactions with trypsin and chymotrypsin resulted in loss of antigenicity.</p> <p>Separation of the antigens within ABE, based on their net ionic charge and molecular weight, was attempted with each resulting fraction being analyzed by immunoelectrophoresis. One neural antigen (CNA-1), possessing alpha-1 globulin mobility was isolated from the other neural specific antigens. This thesis further describes a procedure developed for the purification of CNA-1, utilizing ammonium sulphate fractionation, ion exchange chromatography, gel filtration chromatography and preparative polyacrylamide gel electrophoresis. Highly sensitive and quantitative immunochemical techniques (crossed and fused rocket immunoelectrophoresis) were employed in monitoring the purification steps.</p> <p>Studies on the purified antigen revealed it to be homogeneous by a number of criteria, having a native molecular weight of 65,000 daltons as determined by molecular exclusion chromatography and possessing two identical subunits (MW 30,000) as determined by SDS polyacrylamide gel electrophoresis. The structure of CNA-1 was concluded to be protein on the basis of its sensitivity to trypsin and chymotrypsin.</p> <p>Immunochemical studies utilizing a monovalent antiserum to CNA-1 revealed the protein to be avian specific and not present in brain extracts of mammalian species. Also both a high (> 1,500,000 daltons) and low (65,000 daltons) molecular weight component which shared the CNA-1 antigenic determinant were observed, indicating possible aggregation of the protein during the isolation procedure.</p> <p>CNA-1 was first detectable by the seventh day of incubation and continued to accumulate during the period of embryonic neural development in which both neurogenesis and synaptogenesis are known to occur. Within the adult chicken cerebellum, CNA-1 was specifically localized to the cell surfaces of particular neuronal cell types (i.e. Purkinje cells, granule cells and neurons of the deep cerebellar nuclei) by immunohistochemical techniques. Glial elements were not labelled.</p> <p>Organ specific brain antigens have been described by different investigators. The antigen described within this thesis appears to be completely different from all others described in the literature as revealed by a study of its physical and chemical properties. The function and role of CNA-1 on the cell surface remains to be elucidated. Its localization on specific cell types suggests that it may be associated with inhibitory synaptic function. For this reason, further study of CNA-1 may prove to be important in unravelling some of the questions concerning cell-cell interaction and neuronal specificity during development of the central nervous system.</p> / Doctor of Philosophy (PhD)

<p>There are some data human epidemiological studies which suggest that radiation has a small but significant effect in causing aneuploid gametes. Alberman et al. (1972) suggested that much of this radiation occurred more than ten years before the conception of the abnormal child. Mice have been used to study experimentally radiation effects on chromosome segregation. Radiation induces nondisjunction in several strains, including (C₃HxICR/Swiss)F₁ females. The present study was designed to investigate the possibility of repair of the mechanisms which results in nondisjunction following irradiation. Female (C₃HxICR/Swiss)F₁ mice were randomized into 4 experimental groups at 6-8 weeks of age. Some were irradiated at 3 months with 20R gamma rays from a ¹³⁷Cs source. Young mice were sacrificed at 3 months of age, within 24-48 hours of irradiation. Others were irradiated then housed until 9 months old. At the time of sacrifice ovaries were removed and the oocytes obtained were cultured to the metaphase II stage. Chromosomes were then analyzed. Oocytes from 974 mice were studied. The frequency of spontaneous nondisjunction in oocytes from young mice was quite low (0.2%) and this increased significantly after irradiation to 1.6% (p=0.001). The spontaneous frequency of nondisjunction in oocytes increased with age from 0.2% to 1.2%. In contrast the nondisjunction frequency in oocytes from irradiated-aged animals was 0.0%. In other words, following irradiation at a young age, no aneuploid oocytes were recovered. This is significant different from the frequency in control aged animals, p=0.002. The mechanism by which radiation causes nondisjunction is not known. Possibilities include damage to the centromere region or radiaton could act by causing premature or accelerated terminalization of chiasma. The disappearance of aneuploid oocytes in irradiated-aged animals in this study suggests that in addition to causing nondisjunction immediately there is a delayed effect somewhere between 48 hours and 6 months which results in an elimination of abnormal cells. This experimental finding in mice is quite different from epidemiological information from humans. It provides an avenue for further research into agents causing chromosome abnormalities and the factors involved in germ cell selection and survival.</p> / Doctor of Philosophy (PhD)

<p>Part 1 of the present investigation was designed to examine Sternberg's model of information retrieval. In particular, Experiments 1 through 3 focused on the confounding between frequency of occurrences, P, and positive set size, s. These experiments were designed to examine the possibility that the increase in RT with increases in s is, in whole or in part, an effect of variations in the frequency of occurrences of individual positive items. In shot, each experiment examined the memory scanning stage of the linear additive model.</p> <p>In Experiment 1, the two variables, s and P, were unconfounded for some trials by holding constant the frequency of occurrences for one item in each set size. Here, it was found that when P was unconfounded by s, there remained a small but significant effect of s, supporting the conclusion that increases in mean RTs are largely accounted for by the associated decreases in P.</p> <p>To determine whether or not the variable P has additive or interacting effects in the scanning stage, the additive-factors method was employed in the subsequent experiments. Mean RTs were obtained where at least two positive items within each memory set were assigned different P values and these particular values of P were found in all set sizes. In Experiment 2, it was found that P had additive effects when values of P were held constant across s at .25 and . 15. In contrast, in Experiment 3 when P was held constant across s at .25 and .05, it was found that P had interacting effects on the scanning stage, strongly suggesting that the serial and exhaustive scanning model, as proposed by Sternberg, is unable to handle the effects of P.</p> <p>In an attempt to explain some of the features of the data, Stanovich and Pachella's temporal overlap model, Theios et al. 's self-terminating model, and Atkinson and Juola's familiarity model were examined separately. The general features of the data reconciled best with the familiarity model where it is hypothesized that subjects do not always serially and exhaustively scan the memorized list on every trial. The supposition is that repetitions of an item as a probe will result in an increase in its familiarity value, and thereby increase the likelihood of a fast positive response.</p> <p>Working within the basic concepts underlying the familiarity model, Part 2 of this Thesis describes an experiment which examined aspects of repetition that affect the memory scanning stage of the item recognition process. In general, the data revealed that repetition is an important variable since scanning of the memory list seems to be influenced by how often a positive item is probed and by the number of intervening items occurring between consecutive tests of positive item (lag length).</p> / Doctor of Philosophy (PhD)

<p>Extremely low birth weight infants who develop severe chronic lung disease, known as bronchopulmonary dysplasia (BPD), commonly experience long term growth failure. A randomized, blinded study was designed with the objective to enhance growth in this population using aggressive nutritional intervention. Growth and body composition were assessed during four months of formula feeding that was either: (1) enriched in energy, protein and minerals (EF) or (2) enriched in energy (isoenergetic to EF) but with standard concentrations of protein and minerals (SF). We hypothesized that between randomization (37 weeks post-menstrual age) and 3 months corrected age (CA) the EF group would demonstrate a faster rate of growth with greater lean (versus fat) mass deposition, and greater bone mineral accretion. In addition, higher energy expenditure (EE) as determined by the doubly labelled water method (DLW) would accompany the enhanced rate of growth. The measurements continued after the intervention ended to determine if any growth benefits derived from the enhanced nutrition up to 3 mo CA would be sustained to 12 mo CA. Body composition of the infants was measured with dual energy x-ray absorptiometry (DXA), which was validated against the reference method of chemical analysis. Repeated measures and carcass analysis of infant pigs identified that DXA was accurate and precise in determining bone and lean masses of piglets weighing 6 kg; thus, validating the methodology for use in infants of post-term age. At the end of the nutrition intervention (3 mo CA) infants in the EF group were longer, with greater absolute amounts of lean and bone mass compared to the SF group. The highest velocity of growth occurred between 37 wk PMA and 1 mo CA. No differences in EE were detected, but the high variability within treatment groups (for undetermined reasons) likely precluded our ability to detect significant results. Thus, the DLW method requires further validation for use in BPD infants. Nine months after the intervention ended (12 mo CA), EF and SF groups were similar in weight, length and body composition. When plotted on standard reference growth curves, both groups became significantly more negative in weight-for-length between 3 and 12 mo CA, despite energy and protein intakes deemed adequate by current recommendations for term infants. A longer nutritional intervention study would determine whether growth benefits provided by EF are sustainable, such that catch-up is inducible. Alternatively, catch-up growth may not be possible in infants of such extremely low birth weights under the influence of nutrition alone, and investigations of other factors such as the disease process may be warranted.</p> / Doctor of Philosophy (PhD)

<p>The focus of my research has been to identify cellular proteins which facilitate herpes simplex virus (HSV) entry and cell-to-cell spread. Previous research had demonstrated that HSV glycoprotein gD bound to a cell surface protein which was required by the virus for entry into cells. I began efforts to identify and characterize cellular proteins which bound to a soluble form of gD which lacked the transmembrane domain and cytoplasmic tail. I demonstrated that both the 275 kDa and 46 kDa mannose 6-phosphate receptors (MPRs) bound to soluble and full-length gD. The interaction between gD and the 275 kDa MPR was mediated primarily through mannose 6-phosphate (M6P) residues present on N-linked oligosaccharides. There was evidence that interactions between HSV and MPRs were important for virus entry. When the interaction between HSV and MPRs was blocked, HSV entry into cells was inhibited by 60% to 80%. However, HSV was able to enter into a mouse cell line that did not express MPRs. In addition to functioning during entry, there was evidence that MPRs also played a role in HSV egress or cell-to-cell spread. Blocking MPRs or preventing the addition of M6P residues to HSV glycoproteins resulted in inefficient viral egress and cell-to-cell spread. Therefore blocking the ability of HSV to interact with MPRs renders the virus less efficient at entry, cell-to-cell spread, and egress. To determine whether MPRs functioned during HSV egress from cells, I examined the intracellular localization of HSV gD by indirect immunofluorescence. I demonstrated that the HSV proteins gD, gI, and HSV capsids localized to the same compartment as the 275 kDa MPR. However, the intracellular retention of gD was not dependent on M6P residues. These data provide evidence that HSV proteins accumulate in intracellular compartments. These intracellular compartments represent a site involved in HSV exit from cells.</p> / Doctor of Philosophy (PhD)