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Biomedical subjects

J Hendriks

Publications and source records attributed to J Hendriks.

At least 19 recordsLinked to original sources
PubMed1995

Granulocyte-macrophage colony-stimulating factor (GM-CSF) counteracts the inhibiting effect of monocytes on natural killer (NK) cells.

GM-CSF is known to accelerate haematopoietic recovery following allogeneic bone marrow transplantation (BMT). In addition, it may restore and enhance both granulocyte and monocyte functions. Stimulation of monocyte functions may induce a direct or an indirect anti-leukaemic activity due to an increase of cellular cytotoxicity and production of cytokines which may result in a reduction of the relapse rate after BMT. NK cells may play a crucial role in this activity. Therefore we studied the influence of monocytes on NK activity in combination with GM-CSF. Lymphocytes and monocytes were isolated from buffy coats of healthy individuals by counterflow centrifugation elutriation (CCE). NK activity was exerted by CD3-CD56+ cell populations and could be enhanced by IL-2 incubation overnight. Incubation of CD3-CD56+ cells with GM-CSF in the presence or absence of IL-2 hardly influenced NK activity of the lymphocyte population. Low amounts of monocytes enhanced NK activity. NK activity in lymphocyte population in the presence of equivalent numbers of monocytes with or without IL-2 was strongly decreased irrespective of the effector:target ratio (ETR). This appeared not to result from sterical hindrance effects of the present number of cells. However, addition of GM-CSF abrogated the inhibition of NK activity by monocytes in the presence of IL-2. In monocyte fractions neither IL-2 nor GM-CSF yielded NK activity. Our findings indicate that GM-CSF can affect NK activity by counteracting the suppressing effects of monocytes, and hence may improve the outcome after BMT.

Cell Communication↗
PubMed1991

[Favorable effects of rehabilitation in patients with CARA].

OBJECTIVE: To examine the effects of a rehabilitation programme in patients with asthma or COPD who have major complaints despite the fact that their pulmonary function is not severely disturbed. SETTING: Medical Centre Dekkerswald, Groesbeek. DESIGN: Prospective clinical trial. PATIENTS AND METHODS: The treated group consisted of 44 patients with an obstructive lung disease, FEV1 68.3% of predicted value. This group was compared with 43 patients in a control group. These were volunteers, who were comparable for pulmonary function, reversibility, age, sex, Quetelet index, pulmonary medication and educational level. These groups were examined for 2 years by means of tests and questionnaires. Changes from baseline values were analysed by covariance analysis. Patients followed a rehabilitation programme which consisted of an optimal medical treatment in combination with training of physical endurance, health education and psychological and social support. The duration of the programme was 3 months, 38 hours a week. RESULTS: Pulmonary rehabilitation had a long-term beneficial effect on endurance, several psychological valuables, consumption of medical care, attitude towards way of life, skills, coordination and smoking habits. Bronchial hyperresponsiveness, need of pulmonary drugs and complaints of cough and sputum production did not change after rehabilitation. Airway obstruction and subjective feelings of dyspnoea, allergy and hyperresponsiveness only decreased in the short term (less than I year). CONCLUSION: This study shows that pulmonary rehabilitation improves many variables in the short as well as in the long run. When COPD patients do not improve on conventional treatment, pulmonary rehabilitation should be considered.

Adaptation, Psychological↗
PubMed1988

Incidence of retroviruses in some Brazilian groups.

The prevalence of human T lymphotropic virus type I (HTLV-I) and human immunodeficiency virus (HIV) antibodies was evaluated in Brazil among 116 aboriginal Indians living in a pre-Amazonian region, and in 44 patients with haematological malignant disorders being treated in Rio de Janeiro. Screening for the presence of antibodies to HIV was performed routinely for 17,224 blood donors at the National Cancer Institute, Rio de Janeiro, from January 1986 to May 1987. The results demonstrated that HIV infection was not endemic among Brazilian Indians, as none of them had antibodies to HIV, in contrast with the population of Rio de Janeiro, which showed a high prevalence (0.34%) of positivity among normal individuals. In a small group of patients with haematological disease only one with acute lymphoblastic leukaemia proved to be HIV-positive, the infection having been acquired through previous blood transfusion. None of the serum samples reacted with HTLV-I, including those of 17 non-Hodgkin's lymphoma patients. HTLV-I infection does not seem to be endemic in this country, but further large scale studies are necessary, especially in patients with haematological disorders, homosexual individuals and drug users.

Adolescent↗
PubMed1988

Epidemiology of root surface caries in patients treated for periodontal diseases.

The prevalence of root surface caries was estimated in 83 patients surgically treated for periodontal disease and some relating factors were analyzed. The overall root caries index (RCI) was 6.28%. Anterior teeth in the mandible were significantly less affected than other groups of teeth. Root surfaces, divided into subgroups according to surgical treatment and length of exposure, showed no significant differences in RCI. No correlation was found between DFS-index and RCI. RCI increased with age. Concomitantly in older people more time had elapsed between the periodontal treatment and the present clinical examination. Salivary S. mutans counts and a combination of higher salivary S. mutans and lactobacilli counts were good indicators for the presence of root surface caries.

Adult↗
PubMed1988

Quantification of Leishmania-specific T cells in human American cutaneous leishmaniasis (Leishmania braziliensis braziliensis) by limiting dilution analysis.

Limiting dilution analysis was used to estimate the frequency of Leishmania-specific T cells from the peripheral blood of 18 human cases of American Cutaneous Leishmaniasis (ACL). Sixteen patients had localized cutaneous leishmaniasis (LCL) and two were recovered LCL patients. In 10 patients with active disease and in two with healed lesions the Leishmania-specific T cell frequencies ranged from 1/10(5) to 1/10(3). In six patients no proliferation was detected after 21 days of cell culture. This finding points to very low precursor frequencies in the peripheral blood of these patients. A significant correlation was found between the two groups with low or high Leishmania-specific T cell frequencies and the lymphoproliferative responses to leishmanial antigens. The majority of the blast-like Leishmania-specific T cells showed a helper/inducer (CD4) phenotype.

Adolescent↗
PubMed1987

Non-Hodgkin lymphoma in Jamaica and its relation to adult T-cell leukemia-lymphoma.

Of 95 patients consecutively diagnosed with non-Hodgkin lymphoma, 52 (55%) had antibodies to human T-cell leukemia-lymphoma virus, type I. Antibody positivity was strongly associated with skin involvement, leukemia, and hypercalcemia (p less than 0.02). Two patients had systemic opportunistic infections. Neither meningeal nor lung infiltration was detected, and lymph node infiltration was diffuse in all patients. Of 36 patients who received immunophenotypic classifications, 30 had diseases that affected the T-cell system, and the cells of all tested patients with these diseases showed the helper/inducer (T4) phenotype. Twenty-seven of these thirty-six patients were found to have adult T-cell leukemia-lymphoma, and of the 27, 24 had antibodies to HTLV-I. The median duration of survival in patients with adult T-cell leukemia-lymphoma was 17 weeks, but a subgroup of 9 patients had indolent courses and a median survival of 81 weeks, which suggests that the disease has differing expression with courses that range from smoldering and indolent to acute and rapidly fatal. Hypercalcemia was the most important prognostic determinant of adult T-cell leukemia-lymphoma.

Adolescent↗
PubMed1986

The residual effect of treatment with ivermectin after experimental reinfection with nematodes in calves.

The residual effect of treatment with ivermectin after experimental reinfection in calves was tested. Twenty-four calves were divided into 6 groups of 4 calves each. All calves received a primary infection of 50,000 larvae of both Ostertagia ostertagi and Cooperia oncophora and 1000 Dictyocaulus viviparus larvae. Calves of group 1 remained untreated, and all other calves were treated 21 days after primary infection (0.2 mg/kg injected subcutaneously). Calves of groups 1 and 2 were slaughtered 7 days later. Calves of groups 3-6 were reinfected with the same number of larvae 3 days, 1, 3 and 6 weeks after treatment respectively. Slaughter was 21 days after reinfection. Based on post-mortem worm counts the efficacy of ivermectin after primary infection was 99.7% for O. ostertagi, 95.1% for C. oncophora and 100% for D. viviparus. A residual effect was present for at least one week, but could not be observed 3 weeks after treatment.

Animals↗
PubMed1986

A simple method to deplete human interleukin 2-containing medium of phytohemagglutinin by filtration through a concanavalin A sepharose 4B column.

A method is presented to deplete human interleukin 2 (IL-2) containing conditioned medium of phytohemagglutinin (PHA) by filtration through a concanavalin A Sepharose 4B (Con A Seph 4B) column. The presence of residual PHA was determined by measuring the mitogenic effect of treated medium on freshly isolated blood mononuclear cells as well as by counter-immunoelectrophoresis using an anti-PHA serum. A one-step passage over a Con A Seph 4B column removes 80% or more of the PHA present in conditioned medium without a significant loss of IL-2 activity. These data show that the use of a Con A Seph 4B column is a simple, fast and economical method for the preparation of IL-2-containing medium for use on long-term human T cell cultures.

Chromatography, Agarose↗
PubMed1985

A possible association between HTLV-I and B-cell chronic lymphocytic leukemia in Jamaica.

Cell surface markers were determined in 10 patients with chronic lymphocytic leukemia (CLL) in Jamaica, an area endemic for the human T-cell leukemia/lymphoma virus (HTLV-I) and with a high positivity for HTLV-I antibody titers in CLL patients. The results demonstrated that the predominant cell phenotype in all patients was of B-cell origin. When surveyed for HTLV-I antibody, 3 out of 5 patients with B-CLL from this series were found positive. A possible association between HTLV-I and B-CLL is discussed.

Adult↗
PubMed1984

Mononuclear cells in sickle cell disease: subpopulations and in vitro response to mitogens.

The subpopulations of mononuclear cells and the lymphocyte proliferative capacity following mitogen stimulation were studied in 22 patients with homozygous sickle cell (SS) disease and 25 controls with a normal haemoglobin (AA) genotype. The total number of lymphocytes in peripheral blood samples was higher in SS patients compared to controls. Expressed as a percentage of total lymphocytes, the number of B lymphocytes (detected by membrane immunoglobulin fluorescence) was normal and of T lymphocytes (identified by sheep erythrocyte rosetting) was slightly reduced in SS disease. Expressed in absolute numbers, both B and T lymphocytes were increased. Lymphocyte proliferation measured by tritium labelled thymidine incorporation following stimulation with phytohemagglutinin A, and concanavalin A was normal. Following pokeweed mitogen stimulation, thymidine incorporation was significantly increased in SS disease although normal when expressed as a stimulation index. These results do not suggest a major defect in cell mediated immunity in sickle cell disease. The number of circulating monocytes was increased in SS disease and correlated inversely with the number of reticulocytes (r = -0.58, p less than 0.005).

Adolescent↗
PubMed1983

[Lungworm disease in cattle, a persistent problem?].

From the results of a number of studies it is concluded that: (1) Cattle of a large proportion (approximately 80 per cent) of the dairy farms in the Netherlands were infected with L3 larvae of Dictyocaulus viviparus during the grazing season in 1981. (2) Experiments showed a significant negative cubic effect on the level of infection with L3 larvae of D. viviparus on the growth of calves. (3) Sporangia of Pilobolus kleinii harbouring L3 larvae were shot significantly further away than sporangia not harbouring L3 larvae.

Animals↗
PubMed1983

[The prophylactic effect of a morantel sustained release bolus (Paratect) on lungworm infections in vaccinated and non-vaccinated calves].

Groups of four calves received a vaccination, a vaccination combined with a morantel sustained release bolus (Paratect) together with the second vaccination dose, a vaccination combined with a Paratect bolus 14 days after the second dose, a Paratect bolus alone or remained untreated. From the faecal, serological and clinical observations it was concluded that the larval output, the course of the antibody titers against lungworm and the clinical picture of the calves which had received a bolus after or together with the vaccination did not differ from the observations in the only vaccinated calves. Calves provided with a Paratect bolus were excreting lungworm larvae in the faeces and showed mild symptoms of parasitic bronchitis. It was not necessary to treat these calves in contrast with the untreated controls.

Animals↗
PubMed1982

Circadian rhythms in electrical discharge of rat suprachiasmatic neurones recorded in vitro.

The discharge of suprachiasmatic (SCN), retrochiasmatic (RCA) and arcuate (ARC) neurones was recorded in brain slices incubated for periods up to 30 h. The firing rate of cells in the SCN, but not in the RCA and ARC, exhibited a circadian rhythm similar to that reported for the SCN in freely moving animals. This rhythm cannot be ascribed to subtle exogenous diurnal variations in the incubation conditions. It is concluded that the SCN explant is capable of endogenous generation of at least one circadian cycle in vitro.

Animals↗
PubMed1982

Melnick-Needles syndrome: indication for an autosomal recessive form.

We describe three patients with bone changes and the facial characteristics of the Melnick-Needles syndrome (MNS). Associated anomalies (once bilateral glaucoma, twice congenital heart defect) were the reason for referral. The MNS literature also suggests a high frequency of associated anomalies, especially cardiopulmonary malformations. The distribution of the affected relatives, consanguinity of one pair of parents, and absence of similar symptoms in parents and other relatives makes autosomal recessive inheritance of the trait in this family a definite possibility. This is of great importance in genetic counseling, particularly of sporadic cases.

Abnormalities, Multiple↗
PubMed1980

[The value of lungworm vaccination in calves (author's transl)].

Although the lungworm vaccine was found to be useful under field conditions, some questions remain, particularly epidemiological ones. Experiments with housed and grazing calves were carried out to elucidate a number of these problems. From these experiments in which vaccinated and unvaccinated calves were challenged, it was apparent: 1. that the immunity developed by vaccinated calves could resist a heavy challenge without clinical symptoms; 2. that vaccinated calves exposed to a heavy challenge could produce small numbers of lungworm larvae. It was shown that, despite the hard winter of 1978/1979, infectious lungworm larvae were present on the pasture in the spring of 1979.

Animals↗
PubMed1979

Regularly firing neurones in the rat suprachiasmatic nucleus.

The spontaneous discharge of some suprachiasmatic neurones in vivo and in vitro was found to exhibit a very constant interspike interval. In vivo these cells were comparatively rare and appeared to be mutually coupled. The findings are discussed in relation to coupled oscillator theories of circadian rhythm generation.

Animals↗