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Biomedical subjects

D L Hoffman

Publications and source records attributed to D L Hoffman.

At least 37 records · Page 2Linked to original sources
PubMed1980

Vasoactive intestinal polypeptide (VIP) in mouse and rat brain: an immunocytochemical study.

Immunoperoxidase technique and light microscopy were used to investigate the distribution of vasoactive intestinal polypeptide (VIP) in mouse and rat brain. Both 50 micrometers unmounted cryostat and 6 micrometers deparaffinized sections were studied in coronal or sagittal plane. At least 4 different major VIP systems were found: (1) an intracerebral cortical system; (2) one innervating the central amygdala and nucleus of the stria terminalis; (3) a pathway originating in the suprachiasmatic nucleus of the hypo thalamus; and (4) another originating in the central grey of the midbrain. Specific cell body staining was seen in the limbic and neocortex, in the basal-caudal portion of the suprachiasmatic nucleus of the hypothalamus, and in the central grey of the midbrain. Heavy terminal field patterns were noted in the suprachiasmatic nucleus, central amygdaloid nucleus, bed nucleus of the stria terminalis and nucleus accumbens. Fiber density was moderate in the tuberculum olfactoriu, anterior hypothalamus including the medial preoptic area, mediobasal hypothalamus (especially dorsomedial region), periventricular thalamus, lateral lemniscal system, parabrachial nucleus, nucleus solitarius, and area postrema. Fibers could be traced dorsally from the suprachiasmatic nucleus to the dorsomedial and paraventricular nuclei of the hypothalamus and the periventricular nucleus of the thalamus. Scattered cell bodies and fibers were found in a number of other forebrain and brain stem areas with only a rare fiber seen in median eminence.

Amygdala↗
PubMed1980

Treatment of primary osteoporosis with fluoride and calcium. Clinical tolerance and fracture occurrence.

Thirty-six patients with primary osteoporosis were treated for up to six years with sodium fluoride, calcium supplements, and, in 24 patients, vitamin D. Major adverse reactions (synovitis, painful plantar fascial syndrome, recurrent vomiting, or anemia) occurred in 15 patients (42%). New vertebral fractures occurred at a rate of 329 fractures per 1,000 years of observation. Almost half of them occurred during the first year of therapy, and they were only one sixth as frequent in 12 patients who had fluoride-induced increased trabeculation on vertebral roentogenograms. Nevertheless, until long-term safety and antifracture efficacy are better established, this regimen should continue to be restricted to investigational use.

Adult↗
PubMed1980

Immunocytochemical localization of angiotensin II and vasopressin in rat hypothalamus: evidence for production in the same neuron.

1. By immunoperoxidase technique, immunoreactive angiotensin II (ANG II) was located in the cell bodies of many magnocellular neurons in the supraoptic and paraventricular nuclei of the hypothalamus and their pathways to median eminence and posterior pituitary gland in the rat. 2. Like vasopressin and its neurophysin, but not oxytocin, ANG II was also found in parvocellular neurons in the suprachiasmatic nucleus. 3. Analysis of these peptides in the same magnocellular neurons reveals that ANG II is localized primarily in vasopressin cells. 4. Like vasopressin and its precursor, ANG II is deficient in homozygous Brattleboro rats with diabetes insipidus. 5. In adrenalectomized rats increases in vasopressin and its neurophysin in median eminence are associated with increases in ANG II. 6. The data suggest that the ANG II demonstrated shares antigenic determinants with the vasopressin precursor, or is regulated in a similar way to vasopressin in the same neurons.

Adrenalectomy↗
PubMed1980

Gasoline-induced mucositis.

Gasoline-induced mucositis may become more common because of fuel shortages or increased fuel cost. Dentists should, therefore, consider this oral irritant in the differential diagnosis of oral lesions.

Adult↗
PubMed1978

Calcium and salmon calcitonin in treatment of osteoporosis.

Calcitonin has been considered of therapeutic value in osteoporosis because of its effects in tissue culture. In the whole animal, however, the predominant result seems to be hypocalcemia, which might be expected to have the opposite effect of stimulating parathyroid hormone secretion and therefore resorption of bone. Indeed, in a short term study of 3- and 4-month duration in osteoporotic women, this was found to be so. A combination of calcium and calcitonin was therefore considered a more promising therapeutic alternative for this disease. Calcium was given to 26 patients, alone or with vitamin D, for a period of 15 months, and the effects on serum and urine calcium and phosphorus and on bone resorption and formation were evaluated. Calcium and vitamin D decreased serum parathyroid hormone levels, reduced bone resorption, and increased urinary calcium. The addition of calcitonin to the calcium and vitamin D did not seem to change these effects. Neither form of treatment resulted in change of bone mass. Calcium, with or without vitamin D supplements, may prevent the development of osteoporosis, but it seems unlikely that calcitonin has any additional desirable effect in the disease.

Aged↗
PubMed1977

Adrenergic control of hypothalamic function during osmotic stress in the mallard duck (Anas platyrhynchos).

The role of the paraventricular nucleus (PVN) and biogenic amines (BA) in regulating the level of corticoids in the serum of osmotically stressed mallard ducks (Anas platyrhynchos) was analyzed employing three experimental approaches: 1) pharmacologic alteration of central BA levels, 2) microscopic evaluation of BA distribution, and 3) placement of electrolytic lesions into the PVN. Reserpine and alpha-methyl-p-tyrosine (alphampt), agents that decrease the amount of BA's in the central nervous system, produced a fivefold increase in the concentration of serum corticoids. Conversely, pargyline and amphetamine, agents that increase the functional pool of BA's, prevented the rise in serum corticoid concentration normally observed in birds challenged with an intraperitoneal injection of hypertonic saline. When the topographic distribution of BA's was analyzed in the brains of osmotically stressed and nonstressed ducks distinct changes in the intensity of catecholamine (CA) fluorescence were observed in only bone location, the PVN of the hypothalamus. Additionally, electrolytic lesions stereotaxically placed in the PVN blocked the osmotic stress-induced rise in serum corticoid concentration. These data therefore indicate that the PVN in the mallard duck plays some role in regulating the observed stress-induced rise in serum corticoid concentration, and that this regulatory function is probably inhibited by catecholamines.

Adrenal Cortex Hormones↗
PubMed1977

Correlative fluorescence-immunocytochemical technique for the localization of monoamines and neurophysin (NP).

A correlative fluorescence-immunocytochemical technique for the localization of monoamines and neurophysin on sections of freeze-dried tissues is described. An extensive network of monoamine-containing perikarya and terminals was found throughout the hypothalamus and median eminence. Immunocytochemical localization of antisera for neurophysin was found in the supraoptic and paraventricular nuclei of the hypothalamus and in both the zona interna and zona externa of the median eminence. This correlative demonstration of both catecholamines and neuropeptides within the same tissue provides a new approach to the study of neurotransmitters and neurohormones and their role in the regulation of the peripheral endocrine system.

Animals↗
PubMed1976

Effects of oral therapy with calcium and vitamin D in primary osteoporosis.

Eighteen patients (17 women and 1 man) with primary osteoporosis were divided into two groups of 9 patients each. Group A received 2.0 to 2.5 g of calcium and 400 units of vitamin D per day orally and was studied before and after short-term (3 to 4 months) treatment; group B received 1.5 to 2.0 g of calcium per day and 50,000 units of vitamin D twice weekly and was studied before, after short-term, and after long-term (1 year) treatment. In group A there was a decrease (P is less than 0.01) in bone-resorbing surfaces (microradiography of bone biopsy samples) after short-term treatment. In group B there was a decrease (P is less than 0.01) in bone-forming and bone-resorbing surfaces after both short-tern and long-term treatment. Fasting-state (morning) serum immunoreactive parathyroid hormone (iPTH) concentrations decreased after short-term treatment (combined data of groups A and B) and after long-term treatment (group B). We conclude that the principal effect of the oral calcium and vitamin D therapy in primary osteoporosis is to decrease bone turnover. The most probable mechanism for this effect on bone is a partial inhibition of PTH secretion.

Administration, Oral↗