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Biomedical subjects

R Silver

Publications and source records attributed to R Silver.

At least 91 records · Page 5Linked to original sources
PubMed1990

Vasoactive intestinal polypeptide-like immunoreactivity during reproduction in doves: influence of experience and number of offspring.

To assess the possibility that vasoactive intestinal polypeptide (VIP) plays a role in naturally occurring changes in prolactin secretion in ring doves, we used immunohistochemical techniques to measure VIP-like immunoreactivity in the brain as a function of stage of the reproductive cycle. Differences between parental and nonparental birds in VIP profiles were detected in the ventral portion of the infundibular region. More specifically, there is an increase in cell size and staining intensity in the ventral infundibulum of breeding birds compared to simultaneously processed tissue taken from control animals. In both sexes, an increase in size of VIP-like immunoreactive cells is detectable during courtship and early incubation, anticipating the increase in plasma prolactin levels. VIP cell size remains elevated from about Incubation Day 14 to Brooding Day 14, and a steady decrease is observed during the remaining posthatching period, as squab begin to feed independently. Compared to parents rearing one squab, those with two young have a prolonged interval of increased infundibular VIP immunoreactivity. Furthermore, doves with no previous experience of a breeding cycle exhibit prolonged VIP-like immunoreactivity compared to experienced parents, paralleling previously described differences between these groups in parental behavior.

Animals↗
PubMed1990

A feasibility study of intensive CAF as outpatient adjuvant therapy for stage II breast cancer in a cooperative group: CALGB 8443.

In preparation for a national Phase III study of dose and dose intensity in the treatment of node-positive, Stage II adenocarcinoma of the female breast, CALGB instituted a pilot study of intensive intravenous outpatient CAF (cyclophosphamide, Adriamycin, 5-fluorouracil) for four months. This study was designed to give full doses of drugs without dose reduction for hematologic toxicity. In order to evaluate the feasibility of physician and patient compliance with a potentially toxic therapy, a multi-institution pilot study was performed. This protocol demonstrated that a cooperative group could deliver toxic drug doses to outpatients with a median of 98% of cyclophosphamide, 97% of Adriamycin (doxorubicin), and 91% of 5-fluorouracil administered on schedule. Major side effects, as expected, were leukopenia, nausea, and vomiting. Disease-free survival is at least equivalent to that observed in previous studies.

Adenocarcinoma↗
PubMed1990

Adrenal failure and the primary antiphospholipid syndrome.

We describe a 32-year-old woman with the primary antiphospholipid syndrome given anticoagulation therapy for a second pulmonary embolus. During this therapy, she developed bilateral adrenal hemorrhage and adrenal insufficiency. We discuss the potential association between adrenal failure and the primary antiphospholipid syndrome, and briefly review anticoagulant induced adrenal hemorrhage.

Adrenal Gland Diseases↗
PubMed1989

Retinal projections in quail (Coturnix coturnix).

The trajectory of retinal projections and the location of retinorecipient nuclei in the quail brain was examined after application of horseradish peroxidase (HRP) either to the cut end of the optic nerve or following intraocular injection of HRP. Retinal projections to the hypothalamus, dorsalateral anterior thalamus (rostralateral part, magnocellular part, and lateral part), lateral anterior thalamus, lateroventral geniculate nucleus, lateral geniculate intercalated nuclei (rostral and caudal parts), ventrolateral thalamus, superficial synencephalic nucleus, external nucleus, tectal gray, diffuse pretectal area, pretectal optic area, ectomammillary nucleus, and optic tectum were revealed. Retinal projections observed in quail were compared with results obtained in other avian species and considered in relation to possible anatomic pathways underlying photoperiodism and circadian rhythms.

Animals↗
PubMed1989

Retinohypothalamic projections and the suprachiasmatic nucleus in birds.

Although many investigators have examined retinal projections in birds, there is uncertainty as to the location and identity of a retinorecipient nucleus in the hypothalamus of Aves. A direct retinohypothalamic projection to the medial hypothalamic suprachiasmatic nucleus in mammals is believed to play a role in the entrainment of circadian rhythms. A direct retinohypothalamic projection could subserve a similar function in birds. In the present experiment, horseradish peroxidase, injected intravitreously or applied to the cut optic nerve, consistently labeled a retinorecipient nucleus in the lateral hypothalamus in ringdoves, budgerigars, quails, starlings, and song sparrows, while a significant retinal input to a medial hypothalamic nucleus was absent in these species. These results are interpreted in the light of reports of two retinorecipient nuclei, one in the medial and the other in the lateral hypothalamus, in several classes of vertebrates.

Animals↗
PubMed1988

Clonal immunoglobulin gene rearrangements in chronic lymphocytic leukemia: a correlative study.

Forty-two patients with chronic lymphocytic leukemia (CLL) were studied for immunoglobulin gene and T-cell receptor gene rearrangements. Immunoglobulin heavy chain gene rearrangements were demonstrable in 41 cases. One rearrangement of the T-cell receptor beta chain gene was detected. Quantification of the relative intensities of germline and rearranged DNA bands suggests that a significant component of the lymphocytosis may be due to cell populations other than the malignant clonal population, particularly in earlier stages of the disease. A direct relationship was found between severity of disease and the relative amount of clonal immunoglobulin heavy chain gene rearrangement. Preliminary data for 12 patients followed sequentially indicated that clinical deteriorations or improvements are reflected in an increase or decrease, respectively, in the proportion of cells with rearranged immunoglobulin genes. Change in the relative proportion of cells with germline versus rearranged genes may provide an additional useful criterion for staging CLL, for more precisely defining the abnormal lymphocyte population, and for monitoring progression of the disease and efficacy of treatment.

Adult↗
PubMed1988

Coexpression of opsin- and VIP-like-immunoreactivity in CSF-contacting neurons of the avian brain.

Cerebrospinal fluid-contacting (CSF) cells in both the septal and the tuberal areas in the brain of the ring dove are labeled by RET-P1, a monoclonal antibody to opsin that reacts with inner and outer segment membranes of rod photoreceptors in a variety of vertebrates. Immunoblot analysis of proteins from diverse brain regions, however, revealed bands of anti-RET-P1 immunoreactivity that did not correspond to opsin. Binding of RET-P1 to opsin-containing membranes, was not inhibited by membranes rich in muscarinic and beta-adrenergic receptor proteins (red blood cells, heart, lung) taken from doves. RET-P1-immunoreactive CSF-contacting cells emit a dendritic process that penetrates the ependyma and ends in a knob-like terminal suspended in the ventricle. These cells also possess other processes that penetrate more or less deeply into the neuropil. Additionally, a band of labeled fibers occurs in the external layer of the median eminence. A double-label technique demonstrated that RET-P1-positive cells coexpress VIP-like immunoreactivity. VIP-positive cells in other brain areas are not RET-P1-positive.

Animals↗
PubMed1988

Depression by Fc gamma receptor ligands of SRBC-induced IgM-PFC generation in human blood mononuclear cell cultures.

A tissue-culture system to stimulate human peripheral blood mononuclear cells (PBMC) has been employed in which IgM plaque-forming cell (IgM PFC) generation in response to sheep erythrocytes (SRBC) is dependent on macrophages and T suppressor and helper lymphocytes. In this system PBMC from normal subjects give IgM PFC responses ranging from 26 to 938 PFC/culture. Heat-aggregated human IgG or immune complexes present for the duration of culture induce a significant depression of PFC. Unaggregated IgG has no effect on the response or only a moderate stimulatory effect at the highest dose. The results of these experiments are compatible with previous results in a murine system, which indicated that Fc gamma receptor-positive (Fc gamma R+) cells in the suppressor subset are the target for aggregated IgG and induce depression of the PFC response. A similar mechanism may be operating in the human system described here, although the target cell has not been identified. These results may reflect a mechanism of immunomodulation dependent on interaction of Fc receptor (FcR) ligands with FcR, which may play a role in the pathogenesis of immune complex disorders.

Antibody-Producing Cells↗
PubMed1988

The location of breakpoints within the breakpoint cluster region (bcr) of chromosome 22 in chronic myeloid leukemia.

Rearrangement of the breakpoint cluster region (bcr) was demonstrated by Southern blot analysis in the DNA in each of 68 patients with Ph chromosome-positive CML and in 3 of 7 patients with apparent Ph chromosome-negative CML. In contrast, no bcr rearrangement could be found in DNA from 17 normal individuals and 28 patients with various hematologic disorders other than CML or ALL. An analysis of the location of the breakpoints within the bcr indicated that 3' breakpoints were significantly more common in patients in blast crisis or accelerated phase disease compared to those with chronic phase disease. Patients with chronic phase disease and 3' breakpoints had shorter average disease duration than that for chronic phase patients with 5' breakpoints, although the difference between these two groups of patients was not statistically significant. For patients who had progressed to accelerated disease or blast crisis, a statistically significant difference in chronic phase disease duration could be demonstrated between 11 patients with 3' breakpoints (average chronic phase 30.2 months) and 15 patients with 5' breakpoints (average chronic phase 50.6 months). For 8 patients studied in both chronic phase and accelerated or blast crisis, the location of the breakpoint did not change. We suggest that the bcr-abl fusion protein associated with a 3' breakpoint could result in more rapid progression to acute disease, and this may account for differences in the relative frequency of 3' and 5' breakpoints at different disease stages. Although more studies are required, identifying CML patients with a higher propensity for early blast transformation may eventually prove to be of some clinical value.

Blast Crisis↗
PubMed1988

Mononuclear cells from rheumatoid arthritis patients exhibit a depressed IgM response to sheep erythrocyte stimulation in vitro.

Human peripheral blood mononuclear cells when cultured for the short term (11 days) produce an optimal IgM plaque-forming cell (PFC) response to sheep erythrocytes, which is dependent on macrophages and T suppressor and helper lymphocytes. With this system we have investigated the PFC response of individuals with rheumatoid arthritis and compared this to the response of normal sex- and age-matched controls and of patients with osteoarthritis. The response of rheumatoid arthritis patients was significantly lower than that of subjects in the other two categories.

Animals↗
PubMed1987

Unemployment and mortality: a small area analysis.

It has been claimed that unemployment affects the health and thus the mortality of the unemployed, their families, and other members of their communities. This paper examines the relation between mortality and the unemployment experiences of small areas which vary in the extent to which their unemployment levels have changed in recent years. Quarterly numbers of unemployed, classified by age, sex, duration of unemployment, and unemployment office for 1977-81, have been aggregated to correspond to Family Practitioner Committee areas (FPCs), for which population and mortality data had been collected for a different study. There was little variation in long term (greater than 6 months) unemployment trends prior to July 1980, but subsequently there were large variations between FPCs in the rate of increase in unemployment rates. Mortality data for suicide, ischaemic heart disease, cerebrovascular disease, and all causes were examined for the period 1975-83. When the mortality trends of FPCs with different unemployment experiences were compared, no statistically significant differences in trends were found, although areas with greater increases in unemployment appeared to have slightly worse mortality trends for suicide, ischaemic heart disease, cerebrovascular disease, and total mortality for men in the younger age groups. If changes in the level of unemployment do have an effect on changes in trends in mortality levels, this effect is not of sufficient magnitude to be statistically significant with the sample available, in spite of the fact that it included the whole of England and Wales.

Adult↗
PubMed1987

Circadian rhythmicity restored by neural transplant. Immunocytochemical characterization of the graft and its integration with the host brain.

It is well established that overt circadian rhythms are permanently disrupted following lesions of the hamster hypothalamic suprachiasmatic nucleus (SCN). In the present study, we show that implantations of brain grafts containing the fetal SCN reestablish circadian rhythms of locomotor activity in adult hamsters previously made arrhythmic by SCN lesions. The restoration of free-running rhythms in conditions of constant darkness is correlated with the presence in the graft of neuropeptides normally present in the SCN of unlesioned hamsters, including vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and vasopressin (VP). In several recipients, grafts were found to receive retinal input, and appeared to send efferents into the host brain. Not all functions of the SCN were reinstated by the graft: animals with restored locomotor rhythms did not show gonadal regression in the absence of light, and failed to synchronize (entrain) to light intensities to which SCN-intact animals responded.

Animals↗
PubMed1987

Laryngeal manifestations of drug induced lupus.

Respiratory stridor and hoarseness were the predominant presenting symptoms in a 63-year-old woman with an hydralazine induced lupus syndrome. Laryngeal tomograms and direct laryngoscopy were consistent with cricoarytenoid arthritis. Proteinuria, anemia, arthritis, and leukocytoclastic vasculitis, as well as the laryngeal findings, all resolved after withdrawal of hydralazine. Laryngeal manifestations of systemic lupus erythematosus are reviewed.

Female↗
PubMed1986

Immunologic response in an elderly population with a mean age of 85.

Previous studies of changes in immune responses in the elderly have been limited in both number and age of elderly subjects and have produced conflicting results. Using 260 subjects, mean age 84.6, the present study conclusively demonstrates that T cell response is decreased in the elderly. Decreases in response to phytohemagglutinin and concanavalin A were demonstrated in groups aged 70 to 79, 80 to 84, and 85 to 89, although a group 90 to 106 years old showed a decreased response only to phytohemagglutinin. None of the groups had a decreased response to pokeweed mitogen. No response to all three mitogens was observed in 13 percent of the group aged 70 to 89, but in none of the group aged 90 to 106 or in the young groups. No differences in natural killer cell cytotoxicity were observed among the elderly groups. In contrast to previous studies, these results suggest that: the decreased immune response of the elderly is not directly related to age, over age 70; and there may be a selection process in which subjects who live to the age of 90 are those in whom the least decrease in immune response is demonstrated.

Adult↗
PubMed1986

Limb swelling after release of a tourniquet.

Using a water displacement method the authors found that an exsanguinated human limb will swell immediately by approximately 10% of its original volume after release of a pneumatic tourniquet. Exsanguination reduces limb volume by forcing blood from it. Approximately one-half of the post-tourniquet swelling is due to the return of the exsanguinated blood volume to the limb. Reactive hyperemia accounts for the remainder of the swelling the authors measured. Subsequently, additional swelling can occur from both hematoma formation and the accumulation of postanoxic edema fluid. In some cases, the placement of a circumferential postoperative plaster on a limb prior to tourniquet release may be a hazardous procedure.

Casts, Surgical↗