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Biomedical subjects

S Pollack

Publications and source records attributed to S Pollack.

At least 181 records · Page 10Linked to original sources
PubMed1988

Clinical evaluation of computerized functional electrical stimulation after spinal cord injury: a multicenter pilot study.

This study investigated the safety and effects of computerized functional electrical stimulation (FES) on spinal cord injured individuals. Nineteen subjects two to ten years postinjury, with clinically complete motor and sensory lesions between C4 and T10, participated. All subjects met the specific selection criteria. None had received lower extremity electrical stimulation before. In phase I, subjects received surface electrical stimulation to the quadriceps muscle bilaterally for resistive knee extension 3 times a week for four weeks. The resistance and number of completed lifts was recorded daily. In phase II, 36 sessions provided sequential surface electrical stimulation to the quadriceps, hamstrings, and gluteus muscles bilaterally in order for subjects to pedal a lower extremity ergometer with resistance varied depending on completed run time. For each session, heart rate, blood pressure, temperature, and work performance were recorded. Tests done before and after the training program included fasting blood chemistries, 24-hour urinalysis, arm-crank ergometer stress testing, and midthigh girth measurement. Results indicate that this form of FES is safe, that quadriceps strength and endurance is increased, that endurance for ergometer pedaling is increased, and that there may be a training effect as more work is done at a similar heart rate and systolic blood pressure and as muscle bulk is increased. The FES effect on cardiovascular conditioning and general health requires further research to precisely determine its benefits.

Adult↗
PubMed1987

Defective humoral and cellular immune functions associated with veno-occlusive disease of the liver.

We describe veno-occlusive disease of the liver associated with humoral and cellular immune defects in two siblings. Another child, with aplastic anemia, died before the age of 1 year. No consanguinity was found in the family. Both infants had lymphopenia and hypogammaglobulinemia; the surviving infant has defective in vitro immunoglobulin production after stimulation of lymphocytes with pokeweed mitogen, increased proportions of OKT8 positive cells, defective proliferative responses to phytomitogens, and decreased help for immunoglobulin production. A therapeutic trial with cimetidine, an H2 receptor antagonist, has not changed the immunologic status of the surviving child.

Agammaglobulinemia↗
PubMed1987

Desferrioxamine suppresses Plasmodium falciparum in Aotus monkeys.

Clinical observation has suggested that iron deficiency may be protective in malaria, and we have found that desferrioxamine (DF), an iron-specific chelating agent, inhibited Plasmodium falciparum growth in vitro. It was difficult to be confident that DF would be effective in an intact animal, however, because continuous exposure to DF was required in vitro and, in vivo, DF is rapidly excreted. Also, the in vitro effect of DF was overcome by addition of iron to the culture and in vivo there are potentially high local iron concentrations when iron is absorbed from the diet or released from reticuloendothelial cells. We now show that DF given by constant subcutaneous infusion does suppress parasitemia in P. falciparum-infected Aotus monkeys.

Animals↗
PubMed1987

Immunological studies in children with type I diabetes mellitus and their healthy relatives: in vitro antigen stimulated IgM production, T-cell subsets and islet-cell antibodies.

Several defects in immunoregulation have been described in patients with insulin dependent diabetes mellitus (IDDM). We have looked at immunoregulatory T-cell subsets autoantibodies and in vitro IgM production in IDDM patients and their healthy first degree relatives. The proportions of total T-cells (OKT11+), helper/inducer (OKT4+), suppressor/cytotoxic T-cells (OKT8+) and OKT4/OKT8 ratio were normal in 8 patients as well as in their 26 family members and in 40 age-matched controls. Anti islet-cell antibodies (ICA) were found in sera of 6 out of 17 patients (35%) in 1 out of 62 (1.6%) family members and in none of the age-matched healthy controls. A significant increase of in vitro IgM production was found in 8 patients (130 +/- 10 PFC/10(6) cultured cells, mean +/- S.E.) as compared to 21 healthy controls (57 +/- 5.0) (p less than 0.01). In vitro IgM production by B-cells of 22 family members was also increased compared to controls (83 +/- 8.0) (p greater than 0.05). This increased antibody production is characteristic for clinical states associated with impaired immunoregulation, and reflects perturbation of immunoregulatory mechanisms in IDDM.

Adolescent↗
PubMed1987

Immune basis for cimetidine-induced pancytopenia.

We report a case of a female patient with chronic myelogenous leukemia who presented, 8 yr after initial diagnosis, with pancytopenia, encephalopathy, and myalgia. The tentative diagnosis was accelerated phase of chronic myelogenous leukemia. However, because the patient had been treated with cimetidine for 7 months we first omitted this drug. When cimetidine was stopped, bone marrow recovered, and myalgia and encephalopathy subsided. Immunological studies showed stimulation of the patient's lymphocyte blastogenesis by cimetidine and a marked increase in the proportion of cytotoxic/suppressor T lymphocytes after incubation of peripheral blood lymphocytes with cimetidine for 6 days. These findings indicate a role for cell-mediated immunity in the pathogenesis of cimetidine-induced pancytopenia in this patient.

Aged↗
PubMed1987

MRI of the normal orbit and optic pathway.

In recent years MRI has made increasingly important contributions to the evaluation of the orbit and optic pathway. The unique ability of MRI to demonstrate soft tissue contrast allows exquisite demonstration of anatomic detail. MRI technique and normal anatomy are reviewed. Today, optimal ophthalmologic work-up is often incomplete without the critical input of the radiologist.

Aqueous Humor↗
PubMed1986

Natural killer cell activity in post-necrotic cirrhotic patients as related to hepatitis-B virus infection and plasma zinc levels.

In view of the suggested physiological role of natural killer (NK) cells in immunosurveillance and defence against viral infections, we have investigated the relationship between hepatitis B virus (HBV) infection and NK activity against K-562 cells in patients with post-necrotic cirrhosis. Overall, the NK activity in cirrhotic patients did not differ from age- and sex-matched controls. However, cirrhotic males with evidence of HBV infection with or without HBs antigenemia tend to have lower NK activity than controls. Cirrhotic males without evidence of HBV infection do not differ from controls. Such a trend was not observed in the female cirrhotic patients examined. In addition significantly reduced NK activity was observed in cirrhotic patients with low plasma zinc levels. This relationship is of interest because of the known association between zinc deficiency and various immunodeficiencies.

Adolescent↗
PubMed1986

Complete recovery of pure red cell aplasia by intramuscular gammaglobulin therapy in a child with hypoparathyroidism.

A 10-year-old girl with multiple endocrinopathies, hypoparathyroidism, and pernicious anemia subsequently developed pure red cell aplasia, which responded only temporarily to cytotoxic therapy. Because of transfusion dependency, resistance to steroids, plasmapheresis, and Cytoxan, she was given injections of intramuscular gammaglobulin. The injections caused a prompt and sustained rise in the child's erythropoiesis.

Child↗
PubMed1986

Eosinophilic fibrohistiocytic lesion of bone marrow associated with monoclonal gammopathy and osteolytic lesions.

We describe a 63-year-old male patient with severe osteoporosis, multiple lytic bone lesions, and monoclonal gammopathy (IgG lambda). Whereas the tentative diagnosis in this case was multiple myeloma, bone marrow trephine biopsies of the iliac crest and from an osteolytic lesion of the tibia both showed a peculiar infiltrate consisting of numerous elongated mast cells, eosinophils, and some plasma cells and lymphocytes. The bone marrow lesions fit the diagnosis of eosinophilic fibrohistiocytic lesion of bone marrow (EFHBM). The patient had no abnormality that could be related to a known allergic disease, and no relationship to drug hypersensitivity could be established. The features of the bone marrow infiltrate and its association with monoclonal gammopathy may suggest a linkage between EFHBM and the monoclonal gammopathy.

Bone Marrow Diseases↗
PubMed1986

Factors affecting recurrence following resection for Crohn's disease.

The records of 187 patients with Crohn's disease who underwent resectional surgery were analyzed to evaluate the effect of several clinical and histologic features on the recurrence rate. Recurrence was defined as the need for re-resection. The data were analyzed by the life-table method. Age, sex, age at onset of disease and at time of resection, family history, presence of granuloma, and microscopic involvement at the line of resection did not affect the recurrence rate. The distribution of the disease and duration of symptoms before primary resection did influence the rate of re-resection. Patients with predominantly large bowel disease (N = 56) were found to have a higher rate of re-resection (45 percent) when compared with 32 percent in patients with small bowel involvement (N = 94) and with 35 percent in patients with both small and large bowel involvement (N = 37) (P = 0.04). A detailed review, an analysis of the literature, and a comparison with our results are made.

Adolescent↗
PubMed1986

Reconstitution of in vitro humoral immune function in bone marrow transplant recipients.

The process by which humoral immune function is re-established following bone marrow transplantation was investigated in 50 transplant recipients. The recovery of in vitro-specific antibody production directed at sheep red blood cells was found to proceed through three phases. B cell function and helper T cell function were undetectable in the first phase (encompassing the first 5 months after transplantation), in which only suppressor cells reached functional maturity. Suppressor cells controlled responsiveness in the second phase (encompassing the period 5 to 15 months postgrafting). During this period, B cells and helper T cells became fully responsive; their activity became measurable, however, only after removal of Sephadex G-10-adherent suppressor cells. Normal responsiveness (associated with the loss of excessive suppressor cell activity) was characteristic of the third phase (over 15 months posttransplantation). Particular attention was paid to the role of suppressor cells in the recovery of humoral immune function. Their activity was positively correlated with graft-versus-host disease (GVHD), particularly of the chronic type. Suppressor cell activity in the early posttransplant period was predominantly mediated by OKT8-positive T lymphocytes, whereas suppressor cell activity in chronic GVHD patients was predominantly mediated by peripheral blood mononuclear cells that were retained on Sephadex G-10 columns, but did not express OKT8 antigen.

Acute Disease↗