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Biomedical subjects

H Baldwin

Publications and source records attributed to H Baldwin.

18 recordsLinked to original sources
PubMed1998

Mast cells in pathological and surgical scars.

AIM: To investigate the role of mast cells in surgical and pathological scar reactions by their identification and quantification using immunohistochemistry. METHODS: Surgical scars and pathological scar reactions were stained immunohistochemically for tryptase to identify mast cells. These were quantified in the scar tissue and surrounding dermis. Statistical analyses were performed to test the hypothesis that mast cell numbers were different in the varying types of scar reaction. RESULTS: A significant difference was found between the mean number of mast cells in periocular scars compared with keloids, hypertrophic scars, and surgical scars from other sites (p < 0.05). No significant difference was found in mast cell numbers between the other scar types either within the lesions or surrounding dermis. There were significantly more mast cells in the dermis than in the scar tissue itself, except for the small group of periocular scars. The ratio of mast cells in the lesion compared with the dermis was not significantly different between the scar types, except for the periocular scars. CONCLUSIONS: Mast cell numbers are similar in and around keloid, hypertrophic, and surgical scars. The increased number of mast cells at periocular scar sites was contrary to expectation since keloids are rare at this site. Absolute mast cell numbers may not be an accurate measure of tissue concentrations of active mast cell products. Further comparisons between immunological characteristics of keloid and periocular scars may elucidate specific immunological abnormalities of keloid scars, and this has implications for the development of immunotherapy.

Adult↗
PubMed1994

The role of corticotropin-releasing factor in the anxiogenic effects of ethanol withdrawal.

In summary, endogenous CRF has been demonstrated to play an important role in the endocrine but also autonomic and behavioral responses to a stressor and to mediate some of the signs and symptoms observed in human affective and anxiety disorders. These findings led to the hypothesis that the anxiety that characterizes drug withdrawal, such as ethanol withdrawal in humans, may be related in part to the action of CRF-producing neurons in the CNS. Indeed, rats made dependent on an ethanol liquid diet showed significant signs of enhanced stress responsiveness that was blocked by intracerebral administration of a CRF antagonist. At this time little is known about the specific site of action for endogenous CRF. However, recent studies using local administration of CRF antagonist and in vivo CRF microdialysis suggest that the central nucleus of the amygdala may be an important site for the increases in CRF activity associated with the anxiogenic effects of ethanol withdrawal. Although preliminary, these results propound that ethanol dependence may involve a prolonged dysregulation of the CRF system in the basal forebrain that may contribute to the increased motivational effect of ethanol withdrawal.

Alcoholism↗
PubMed1994

High plasma vitamin C associated with high plasma HDL- and HDL2 cholesterol.

High plasma vitamin C may lower risk of cardiovascular disease as indicated by direct association with plasma high-density-lipoprotein (HDL) cholesterol and HDL2 cholesterol. Plasma lipids and vitamin C were determined in 316 women and 511 men (aged 19-95 y). After adjustment for age, sex, obesity, and smoking, plasma vitamin C was directly associated with HDL- (P = 0.01) and HDL2 cholesterol (P = 0.0002). When men and women with diseases that might affect lipids were excluded, associations between plasma vitamin C and HDL- and HDL2 cholesterol persisted, though the relationships were strongest in older men. Comparisons of diets in a subset (n = 485) who completed 7-d diet records were made. Total fat, saturated fatty acids, energy from fat, and cholesterol intakes were not associated with plasma vitamin C. Mean intakes of vitamin C were well above recommended dietary allowances. These findings suggest that high plasma concentrations of vitamin C may lower atherogenic risk.

Adult↗
PubMed1994

Relapsing polychondritis: case report and review of the literature.

A 65-year-old man who experienced the acute onset of pain, redness, and swelling of his right ear was treated with antibiotics for erysipelas. Subsequently, the other ear and both eyes became inflammed. Relapsing polychondritis was diagnosed and treatment with prednisone was successful. Relapsing polychondritis, a rare multisystem disease, presents most commonly with auricular chondritis. Other clinical manifestations include arthritis, nasal chondritis, scleritis, damage to tracheal and bronchial cartilage, and aortic, cardiac, and renal involvement. The cause is autoimmune. Recurrent episodes of progressive inflammation result in destruction of cartilage. Treatment consists of administration of corticosteroids and other anti-inflammatory and immunosuppressive drugs.

Aged↗
PubMed1993

The role of corticotropin-releasing factor in behavioural responses to stress.

Corticotropin-releasing factor (CRF), when administered directly into the CNS, can have activating properties on behaviour and can enhance behavioural responses to stress. CRF injected intraventricularly produces a dose-dependent increase in locomotor activity and increased responsiveness to an acoustic startle stimulus. However, this profile of activation changes to enhanced suppression of behaviour in stressful situations and includes increased freezing, increased conditioned suppression, increased conflict, decreased feeding and decreased behaviour in a novel open field. These effects of CRF are independent of the pituitary-adrenal axis and can be reversed by the CRF antagonist alpha-helical CRF(9-41). More importantly, the CRF antagonist can also reverse many behavioural responses to stressors. alpha-Helical CRF(9-41) reverses stress-induced fighting behaviour, stress-induced freezing, stress-induced suppression of feeding, stress-induced decreases in exploration of an elevated plus maze, fear-potentiated startle and the development of conditioned suppression. Intracerebral microinjections suggest that the amygdala may be an important site for the anti-stress effects of alpha-helical CRF(9-41). These results suggest that endogenous CRF systems in the CNS may have a role in mediating behavioural responses to stress and further suggest that CRF in the brain may function as a fundamental behavioural activating system. This CRF system may be particularly important in situations where an organism must mobilize not only the pituitary-adrenal system but also the CNS in response to environmental challenge.

Animals↗
PubMed1992

Long-term longitudinal measurements of plasma dehydroepiandrosterone sulfate in normal men.

Dehydroepiandrosterone sulfate (DS) was measured by direct tritium RIA in longitudinal plasma specimens from 97 normal healthy male participants in the Baltimore Longitudinal Study of Aging. Fasting blood was collected at regular visits (approximately 1.5 yr apart) over an average 13 yr of adulthood (cumulative age range: 32-83 yr). DS was measured in 3-4 widely spaced specimens from each subject. A decline in DS was found in 65 (67%) subjects, 13 subjects (13%) showed no change, and increases were found in the 19 remaining subjects during the study period. A plot of individual data points revealed the same pattern we had obtained previously from a cross-sectional study of a different normal male population. A plot of DS values vs. age among subjects whose DS increased during the study also revealed an age-related decline. Thus, the longitudinal decrease in circulating DS, long inferred from cross-sectional data, is confirmed for normal men in the present study. A more detailed study of every specimen collected during the study period from 12 of the Baltimore Longitudinal Study of Aging subjects (4 whose values tended to be low, 4 whose values tended to be high, and 4 whose values were near the mean) failed to reveal any patterns of variation that could be correlated with changes in life circumstances, health status, or any other discernible factors. Hence, the wide variability seen in DS among individuals within normal populations remains unexplained.

Adult↗
PubMed1991

Anxiolytic activity of steroid anesthetic alphaxalone.

The synthetic steroid anesthetic alphaxalone (3 alpha-hydroxy-5 alpha-pregnane-11,20-dione) was studied in two behavioral paradigms known to be sensitive to anxiolytic drugs. In an elevated plus maze, alphaxalone produced an anxiolytic profile, significantly increasing the percentage of entries made into the open arms as well as the percentage of time spent on the open arms. In the conflict test, alphaxalone (6 and 8 mg/kg) produced a significant dose-dependent increase in punished responding and a decrease (8 mg/kg) in unpunished responding. The pattern of responding was similar to that observed with the benzodiazepine agonist chlordiazepoxide (2-8 mg/kg). The increase in punished responding was not altered by the benzodiazepine antagonist Ro 15-1788 and only partially blocked by the picrotoxinin receptor ligand isopropylbicyclophospate (10 and 15 micrograms/kg). The gamma-aminobutyric acid agonists picrotoxin (1 mg/kg) and bicuculline (1 mg/kg) also failed to suppress the rate-increasing effects of alphaxalone in the conflict test. Chronic administration of alphaxalone for 1 week produced no tolerance to the anxiolytic behavioral effects. In addition, no changes in pain threshold were noted with alphaxalone (8 mg/kg) in the tail-flick analgesia test. These results suggest that the pharmacologic substrates for the anxiolytic actions of alphaxalone may be independent of either the benzodiazepine or picrotoxinin binding sites of the gamma-aminobutyric acid/benzodiazepine receptor complex.

Anesthetics↗
PubMed1989

Gadolinium-DTPA enhancement of a recurrent intramedullary ependymoma: a case report.

Magnetic resonance images enhanced with the paramagnetic contrast agent gadolinium-DTPA accurately differentiated a recurrent intramedullary spinal cord ependymoma from surrounding postoperative and postirradiation spinal cord tissue changes, thereby facilitating total excision of the lesion. The illustrative case and the merits of enhanced magnetic resonance imaging are presented.

Contrast Media↗
PubMed1982

Combined trimipramine/phenelzine treatment of depression: case report.

Trimipramine was found safe, effective, and free of complications when used in combination with the MAOI phenelzine in the treatment of a case of refractory depression. Trimipramine co-administration with phenelzine may be an efficacious alternative pharmacotherapy for selected cases when synergistic antidepressant therapies are indicated.

Adult↗