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Biomedical subjects

V Lee

Publications and source records attributed to V Lee.

At least 109 records · Page 6Linked to original sources
PubMed1990

Manipulation of the acute inflammatory response by dietary polyunsaturated fatty acid modulation.

Dietary polyunsaturated fatty acid modulation has been used as an anti-inflammatory strategy in experimental models of disease as well as in clinical trials. To elucidate the mechanisms underlying the anti-inflammatory effects of manipulating dietary polyunsaturated fatty acids, the in vivo effects of essential fatty acid (EFA) deficiency and (n-3) fatty acid supplementation were contrasted using a model of acute inflammation induced by the i.p. injection of zymosan into mice. Both diets led to a substantial decrease in tissue (n-6) fatty acid content. EFA deficiency was also characterized by the accumulation of (n-9) fatty acids, particularly 20:3 (n-9), the fatty acid that uniquely characterizes the deficiency state. Dietary (n-3) fatty acid supplementation led instead to marked increases in (n-3) fatty acids, especially 20:5 (n-3). With respect to the antiinflammatory effects of the two diets, EFA deficiency, but not (n-3) fatty acid supplementation, depleted levels of resident peritoneal macrophages. EFA deficiency was also more effective than (n-3) fatty acid supplementation in inhibiting the influx of polymorphonuclear neutrophils in response to zymosan. The effect of the two diets on the in vivo generation of leukotriene(LT)B also differed markedly. EFA deficiency completely inhibited the synthesis of LTB. Dietary (n-3) fatty acid supplementation, in contrast, reduced the production of LTB4 by only 50%. With (n-3) fatty acid supplementation LTB5 was produced. The more modest effect of (n-3) fatty acid supplementation in decreasing LTB4 generation was not due to blockade of the cyclooxygenase pathway. EFA deficiency, but not (n-3) fatty acid supplementation, was associated with the decreased synthesis of thromboxane. Although dietary fatty acid modulation has been shown to diminish platelet activating factor (PAF) synthesis, studies using the PAF receptor blocker, L659989, established that PAF was not a significant factor in the elicitation of leukocytes in this model of inflammation. In summary, the anti-inflammatory effect of EFA deficiency was more marked that that of dietary (n-3) fatty acid supplementation in acute inflammation. This difference in anti-inflammatory potential appeared to be due to either the greater effect of EFA deficiency in decreasing levels of resident peritoneal macrophages or in suppressing the in vivo generation of LTB4.

Acute Disease↗
PubMed1989

Neuronal modulation of Schwann cell glial fibrillary acidic protein (GFAP).

Adult rat sciatic nerves contain cytoskeletal peptides that resemble CNS glial fibrillary acidic protein (GFAP) in immunoreactivity and molecular weight. Immunohistological examination of teased nerve fascicles indicated that these peptides are expressed selectively by Schwann cells related to small axons. Radiolabelled mouse and rat CNS GFAP cDNA probes hybridized with a single, 2.7 kb RNA band in Northern blots prepared from total RNA from both rat sciatic nerve and rat brain. Sciatic nerve GFAP mRNA was detectable by this means in adult, 2 month, or 21 day postnatal rats, but not in 3,6, or 10 day postnatal rats. Sciatic nerve transection caused a marked reduction in the level of GFAP mRNA in the axotomized distal stump. We conclude that Schwann cell synthesis of GFAP is developmentally regulated and that Schwann cells, unlike astroglia, require continued trophic input from small axons in order to express GFAP.

Aging↗
PubMed1989

Differential role of protein kinase C in the action of luteinizing hormone-releasing hormone on hormone production in rat ovarian cells.

This study was undertaken to determine the involvement of arachidonic acid and protein kinase C in the actions of luteinizing hormone-releasing hormone on steroid and prostaglandin formation in the ovary. In primary culture of rat granulosa cells, treatment with 3 x 10(-7) mol/L melittin stimulates progesterone and prostaglandin E2 accumulation after a 5-hour culture period. Concomitant treatment of the cells with melittin and luteinizing hormone-releasing hormone or 12-0-tetradecanoylphorbol 13-acetate further enhances the stimulatory action of either luteinizing hormone-releasing hormone or 12-0-tetradecanoylphorbol 13-acetate by itself on prostaglandin E2 production. In contrast, no synergistic effects are observed on progesterone production by the same treatments. Treatment with luteinizing hormone-releasing hormone for 24 hours significantly decreases follicle-stimulating hormone-induced progesterone production by approximately 50%. Treatment of the cells with either follicle-stimulating hormone or luteinizing hormone-releasing hormone stimulates prostaglandin E2 production at least tenfold in the same cultures. When follicle-stimulating hormone and luteinizing hormone-releasing hormone are present concomitantly, they synergistically enhance prostaglandin E2 formation (p less than 0.01). Similar effects are observed with the phorbol ester, 12-0-tetradecanoylphorbol 13-acetate, which causes a dose-dependent inhibition of progesterone production by follicle-stimulating hormone whereas follicle-stimulating hormone-stimulated prostaglandin E2 formation is enhanced. Thus luteinizing hormone-releasing hormone-induced activation of protein kinase C may play multiple roles (stimulatory or inhibitory) in hormone production in the ovary.

Animals↗
PubMed1989

The treatment of breast engorgement with Serrapeptase (Danzen): a randomised double-blind controlled trial.

We evaluated an anti-inflammatory enzyme drug Danzen (Serrapeptase: Takeda Chemical Industries, Ltd.) on 70 patients complaining of breast engorgement. These patients were randomly divided into 2 groups, a treatment group and a placebo group. A single observer, unaware of the group the patients were in, assessed the severity of each of the symptoms and signs of breast engorgement before treatment was commenced, and daily for 3 days, during which therapy was administered. Danzen was noted to be superior to placebo for improvement of breast pain, breast swelling and induration and while 85.7% of the patients receiving Danzen had "Moderate to Marked" improvement, only 60.0% of the patients receiving placebo had a similar degree of improvement. "Marked" improvement was found in 22.9% of the treatment group and 2.9% of the placebo group. These differences were statistically significant (P less than 0.05). No adverse reactions were reported with the use of Danzen. Danzen is a safe and effective method for the treatment of breast engorgement.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1988

Neonatal neurobehavioral examination. A new instrument for quantitative analysis of neonatal neurological status.

A new neonatal neurobehavioral examination (NNE) was designed in response to the need for a more quantitative assessment of neonatal neurological status. The NNE consists of 27 items divided into three sections: 1) tone and motor patterns, 2) primitive reflexes, and 3) behavioral responses. Each section consists of 9 items scored on a three-point scale. Fifty-four healthy full-term infants were examined at 2 days of age and demonstrated total NNE scores ranging from 70 to a maximum possible score of 81 (X = 76, s = 1.03). Mean section scores for these infants ranged from 25.3 to 26.6 (s = .59-1.79). Intertester agreement was 88% by item and 95% by total score in each section. Two hundred ninety-eight high-risk infants were then examined at 37 to 40 weeks conceptional age (gestational age plus chronological age) or at discharge from the neonatal intensive care unit, whichever occurred first. Total NNE mean scores for high-risk infants fell into discrete clusters by conceptional age at the time of examination (37-42 weeks, mean score = 66.5; 34-36 weeks, mean score = 60.7; less than 34 weeks, mean score = 51.1). Similar clustering occurred for the three section scores. Highly significant differences existed between the three conceptional age groups for total scores and section scores. No clinically significant score differences were associated with severity of illness or gestational age at birth. The results of this study suggest that the NNE easily and reliably assesses infants' neonatal neurobehavioral status at a given conceptional age. Additional studies are in progress to determine the value of the NNE in predicting subsequent developmental disabilities.

Child Behavior↗
PubMed1987

AF-DX 116 discriminates between muscarinic M2 receptors of the heart and vasculature.

The newly developed muscarinic antagonist, AF-DX 116, has been reported to have a higher affinity in vivo for muscarinic receptors in the heart than in the vasculature. Therefore two in vitro preparations, the rabbit ear artery and spontaneously beating right atrium, were compared. AF-DX 116 had a 29 times greater affinity for muscarinic receptors in the cardiac preparation than in the ear artery, with a pA2 in the heart of 7.42 compared to a value of 5.95 in the ear artery. Thus AF-DX 116 shows promise as an approach to differentiating sub-classes of muscarinic M2 receptors.

Animals↗
PubMed1986

Enhanced survival of rat neonatal cerebral cortical neurons at subatmospheric oxygen tensions in vitro.

In vitro tissue culture experiments are routinely performed at atmospheric oxygen tension (21%), although most cells experience lower oxygen tensions in vivo. The optimal oxygen tension for the survival of neurons and synthesis of neurofilament (NF) was determined using dissociated neonatal rat cerebral cortex and monoclonal antibodies to the 68 kDa and 200 kDa subunits of NF. Maximum production of each subunit determined by Enzyme-Linked Immunosorbant Assay occurred at 9% O2. Neuronal survival determined by immunohistochemistry was also maximal at 9% O2. CNS neurons are highly sensitive to oxygen tension and grow best at levels approximating capillary rather than atmospheric pO2.

Animals↗
PubMed1986

Neuroimmunology of gangliosides in human neurons and glial cells in culture.

Gangliosides (sialic-acid-bearing glycolipids) have received attention in recent years because of their role in cell recognition phenomena, synaptic transmission, memory generation, and nerve regeneration in the fields of neurosciences. It is suggested that each brain region or each neural cell type may contain a specific and characteristic set of gangliosides. We have investigated the immunocytochemical localization of several classes of gangliosides that include GM1, GM4, GD3, and GQ gangliosides on the cell surface of various cell types found in human neural cell cultures with antibodies specific for these gangliosides. Cell cultures were obtained from adult human brains and fetal human dorsal root ganglia and spinal cord and cultured in vitro for the period up to 6 months and utilized for the ganglioside immunocytochemistry. It was demonstrated that GM1 ganglioside was present in all galactocerebroside-positive oligodendrocytes and most of glial fibrillary acid protein (GFAP)-positive astrocytes (80%), most of neurofilament-positive neurons (80%), 50-70% of Schwann cells, and 5-10% of fibronectin-positive fibroblasts; GM4 ganglioside could be detected in all oligodendrocytes, 80% of astrocytes, and 50% of Schwann cells, while no staining was found in neurons or fibroblasts; GD3 ganglioside was present in all oligodendrocytes and 5-10% of astrocytes but not in neurons, Schwann cells, or fibroblasts; and all of fetal CNS neurons and approximately 80-90% of fetal dorsal root ganglia (DRG) neurons and a small percentage of astrocytes (10-20% in fetal and less than 1% in adult astrocytes) was labeled by A2B5 antibody which is specific for GQ ganglioside, while this antibody did not stain cell surface of oligodendrocytes, Schwann cells, or fibroblasts. Three classes of gangliosides, GM1, GM4, and GD3 were found to be definite components of fetal and adult human oligodendroglial plasma membrane, while GM1 and GM4 gangliosides were detected on the surface of most astrocytes. Only a minor population of astrocytes from both fetal and adult human CNS contained GD3 and GQ gangliosides. Two classes of gangliosides, GM1 and GQ, were detected on the surface of fetal human neurons. More than half of fetal Schwann cells reacted to GM1 and GM4 antibodies but did not to GD3 or GQ antibodies. We recognized the presence of a specific and characteristic set of gangliosides on the cell surface of different human neural cell types and these findings should facilitate further investigation of the precise biological activity of these gangliosides.

Aged↗
PubMed1986

Neuronal intranuclear hyaline inclusion disease in a nine year old.

Thirteen previous cases have been reported as neuronal intranuclear hyaline inclusion disease. The majority of patients have presented with movement disorders at less than 12 years of age followed by a progressive worsening of symptoms and, frequently, loss of cognitive function. Death has usually occurred by the second or third decade. Three have presented in the fifth through seventh decade with either movement disorders or dementia. These cases have been linked by the presence of eosinophilic neuronal intranuclear inclusions diffusely within the CNS and in peripheral ganglion cells. The patient in this case report also presented with a rapidly progressive movement disorder and at autopsy showed the characteristic intranuclear inclusions. Investigation of these inclusions did not reveal shared epitopes with neurofilaments or other intermediate filaments.

Brain↗
PubMed1986

Immunohistochemical co-localization of S-100b and the glial fibrillary acidic protein in rat brain.

A rabbit antiserum against purified bovine brain S-100b protein was produced and characterized by immunoassay and immunoblot analysis of electrophoretically resolved soluble brain proteins. Fluorescent immunohistochemistry was conducted in order to determine the cellular localization of the S-100b immunoreactivity. Double immunohistofluorescent experiments on adult rat brain tissue sections with the rabbit antiserum to S-100b and a rat monoclonal antibody to the glial fibrillary acidic protein resulted in immunolabelling of the same cells. This finding determines a strict astroglial localization of the S-100b immunoreactivity. In addition, the immunolabelling of astrocyte perikarya and processes by the S-100b immunohistochemistry is consistent with a cytoplasmic location of S-100b. In contrast, the glial fibrillary acidic protein immunohistochemistry predominantly labeled the fine fibrillary processes of the cells. The present report suggests that S-100b immunohistochemistry is of use for the specific identification and morphological description of astrocytes in the rat brain.

Animals↗
PubMed1985

Combined immunostaining of neurofilaments, neuron specific enolase, GFAP and S-100. A possible means for assessing the morphological and functional status of the enteric nervous system.

Neurofilaments, part of the cytoskeletal network, and neuron specific enolase, a major enzyme in glycolysis, are both present in central and peripheral neurons. Glial fibrillary acidic protein and S-100, on the other hand, are soluble proteins which are found exclusively in the supportive cells of the nervous system, i.e. the glial cells. Examination was made, using immunocytochemistry, of all main areas of the gastrointestinal tract of three mammalian species, rat, pig and man. By applying serial tissue sectioning, it was possible to study the relative occurrences of the two neuronal markers in the same cell bodies and to examine the relationships of the neurons with the glial cells as revealed by the antibodies to glial fibrillary acidic protein and S-100. Both neurofilaments and neuron specific enolase were localised to an extensive system of enteric nerves, with the level of neuron specific enolase-immunoreactivity showing greater variability than that observed using antibodies to neurofilaments. Comparison of the occurrence of neuron specific enolase and neurofilament immunoreactivity in serially sectioned neuronal cell bodies revealed that a minor population stained only with antibodies to neurofilaments. The equivocal or absent neuron specific enolase-immunoreactivity in some perikarya may reflect variations in functional status within the nervous system. Glial fibrillary acidic protein- and S-100-immunoreactivities were confined to glial cells which, in this normal tissue, were always in close association with the neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Immunohistochemical application of monoclonal antibodies against myelin basic protein and neurofilament triple protein subunits: advantages over antisera and technical limitations.

Four monoclonal antibodies against guinea pig myelin basic protein (MBP), and four against subunits of bovine neurofilament triplet proteins (NF) were produced and their activity determined by enzyme-linked immunosorbant assay. The specificity and cross-reactivity of these eight monoclonal antibodies and one heterologous antiserum against each of the two central nervous system (CNS) antigens were examined in a histological study using the immunoperoxidase, antibody sandwich technique in rat and human brain tissue. Tissue sections were prepared from paraffin-embedded or fresh brain tissue that had been fixed with one of five different fixatives. The resulting immunoperoxidase labeling was then graded for intensity and examined for artifacts. One monoclonal antibody against MBP and one against NF resulted in labeling that was superior to that given by each of the antisera against their respective antigens. Of the five fixatives tested, a mercuric chloride-formalin solution gave the best preservation of these two antigens in rat and human brain tissue. The mercuric chloride-formalin solution was found to be superior to the other fixatives when immersion fixation was used, and was especially optimal when brains were perfused fixed. Three artifacts were encountered among the various antibody-fixative combinations that produced erroneous, but seemingly specific staining of Purkinje cells, neurons and axons, or astrocytes.

Animals↗
PubMed1982

Induction of neurofilament triplet proteins in PC12 cells by nerve growth factor.

The localization of neurofilament triplet proteins in PC12 cells grown in the absence of (PC12-) or maintained in the presence of (PC12+) nerve growth factor (NGF) was studied using indirect immunofluorescence and monospecific, immunosorbent purified antibodies to 68,000 (P68), 150,000 (P150) and 200,000 (P200) dalton neurofilament proteins. The intensity of immunofluorescent staining of the triplet proteins was always greater in PC12+ compared with PC12-cells. Neuritic staining was seen in PC12+ cells with all 3 monospecific antibodies to neurofilament proteins. However, the perikaryal distribution of each of the neurofilament proteins differed in both PC12+ and PC12-cells. Monospecific antibodies to P68 protein yielded a 'ball-like' cytoplasmic staining pattern whereas monospecific antibodies by P150 protein stained in a stippled pattern. Monospecific antibodies to P200 on the other hand diffusely stained the perikaryal cytoplasm with very faint but detectable foci of 'ball-like' configurations and stippling. Electron microscopic study of PC12+ and PC12-cells revealed intermediate filaments in the cell bodies of both as well as in the processes of the former. 'Ball-like' clusters of such filaments were rarely seen. However, these filaments lacked the three-dimensional organization typical of intact neurofilaments. It is concluded that PC12 cells contain dissociated or incompletely assembled immunoreactive neurofilament triplet proteins and that these proteins can be induced by NGF. The PC12 cells are therefore an attractive model system not only for studies of neuronal differentiation but also for studies of neurofilament metabolism and disorders thereof.

Adrenal Gland Neoplasms↗
PubMed1982

Monoclonal antibodies recognize individual neurofilament triplet proteins.

A series of 12 monoclonal antibodies has been prepared against crude or purified individual bovine neurofilament (NF) triplet proteins (designated as P68, P150, and P200). Six of the antibodies recognized unique determinants on individual NF subunits. The other six recognized shared determinants on at least two NF triplet proteins. Six of the antibodies recognized separated, immobilized individual NF in nitrocellulose paper. By the peroxidase-antiperoxidase technique, all of the antibodies stained neurons and their processes in a manner identical to the well-known distribution of NF in both the central and peripheral nervous system. These results strongly suggest that the NF subunits are distinct but related proteins and that the smaller NF subunits (P68 and P150) are not derived from larger NF proteins.

Animals↗