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Biomedical subjects

J Hendriks

Publications and source records attributed to J Hendriks.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1979

[Studies on the epizootiology of maedi/visna in sheep (author's transl)].

The transmission of maedi/visna from a severely infected flock to their progeny was studied. At birth, the lambs were divided at random in four groups of approximately forty animals each, which were exposed to the parent flock for zero hours, ten hours, six weeks and one year respectively. Although more than 80 percent of the ewes were affected with maedi, lambs which were separated from the ewes immediately after birth continued to be free from maedi/visna virus infection during an eight years period of observation. In addition, antibodies to the virus were not detected in this group. It is therefore concluded that congenital infection, if any, is of minor importance in the epizootiology of the disease. The number of sheep in which serological, virological and histopathological studies were positive, the onset of the disease and the severity of the lesions in the three other flocks increased with the period for which they had been exposed to the ewes. A separate trial did not supply any evidence to suggest that larvae of Muellerius capillaris are capable of transmitting infection with maedi/visna virus.

Animals↗
PubMed1979

Operational diagnostics of lungworm infections in cattle. Preliminary investigation into the usefulness of the indirect haemagglutination.

To give an impression of the usefulness of indirect haemagglutination (IHA) in the diagnosis of lungworm infections in cattle under practical conditions, five calves vaccinated against Dictyocaulus viviparus and five unvaccinated calves were periodically subjected to clinical, parasitological, and serological examinations over a period of seven months. All calves grazed on a lungworm-infected plot. 82% of the observations in unvaccinated calves, which were positive with respect to one or more of the used parameters, concerned IHA-positive animals which, however, showed negative results with the parasitic parameters. The titre variation of the serological examination was a further indication of the fact that the IHA detected antibodies against lungworm antigens. No indications of false positive reactions were obtained. An investigation carried out on 46 farms on the correlation between serological and clinical findings on lungworm infections revealed a positive correlation in 80% of the groups between results obtained with both methods. The authors consider that IHA offers good prospects for the diagnosis of lungworm infections.

Animals↗
PubMed1979

Experimental infections with Cooperia oncophora (Railliet, 1918) in calves. Results of single infections with two graded dose levels of larvae.

Two experiments were carried out in which calves reared parasite-free were infected with a single dose of 3rd-stage larvae of Cooperia oncophora. In the first experiment the calves received 20 000 or 200 000 infective larvae and they were autopsied 28 or 56 days after the infection. In the second experiment the doses were the same but the animals were killed 14, 84 or 140 days after infection. If a dose of 20 000 was given, clinical signs were never observed, while at a dose level of 200 000 the weight gain was less on 56 and 84 days after the infection compared with the low-infected groups or the control animals. After 170 days the differences in weight gain were compensated. Faecal egg output was higher in the 200 000 groups only in the first period of patency, thereafter the calves in the 20 000 groups produced more. No obvious differences between the two infection levels were observed with regard to the haematological data. In the low-infected groups worm counts were only slightly lower when the results after 28 days were compared with those after 56 days. Also, the worm numbers after 14 days were almost equal to those after 84 days, while at 140 days 1 animal still had the same number, the other one had lost its worm burden. In the high-infected groups the worm loss was much quicker. After 28 days a great part of the population had already been lost. Obviously, at the 200 000 level the reaction of the host against the parasite was much stronger. Adult worms were expelled at a higher rate than early 4th-larval stages. In the first experiment worm measurements revealed differences between the length of females, males and spicules of males, these being significantly longer in the low-infected groups. Analysis of the distribution of worms over the small intestine showed that in the low-infected groups worms were mainly restricted to the first 6 metres. In the high-infected groups the worm population was distributed more evenly over the whole small intestine.

Animals↗
PubMed1979

Studies in epidemiology of maedi/visna in sheep.

Lambs born to ewes from flocks with a high incidence of maedi/visna were separated from their dams at birth (group 1), or after 10 h (group 2), six weeks (group 3) or one year (group 4) and were observed for periods of up to eight years. Group 1 lambs remained free of infection while 28 per cent, 76 per cent and 81 per cent respectively of lambs in the other groups developed clinical, serological or histopathological evidence of infection during the observation period. It is therefore concluded that vertical transmission, if it occurs at all, is of little significance in the epidemiology of the disease. The number of serologically, virologically and histopathologically maedi/visna positive sheep, the time of onset of disease and the severity of lesions were related to the duration of exposure to the parent flock. In a separate trial no evidence was obtained for the transmission of maedi/visna by Muellerius capillaris larvae.

Animals↗
PubMed1978

The effect of diet on the establishment and growth of Ostertagia ostertagi in calves.

Three groups of four calves were raised parasite-free. Each group received a different diet. At the moment of infection one group was fed with milk equivalent artificially dried grass, and concentrates, the second with water, grass pellets (16 mm), and concentrates, while the third was fed with water, artificially dried grass, and concentrates. Each animal was infected at an age of 8 weeks with 10,000 larvae of Ostertagia ostertagi and necropsied 28 days later, No significant differences between the groups were observed with regard to the number of worms post-mortem, length of worms, number of eggs per female, or gain of weight of the calves.

Animal Feed↗
PubMedDate not supplied

Generation of Leishmania-specific short-term T-cell lines derived from peripheral blood of cured American cutaneous leishmaniasis patients.

The putative protective immune response in localized cutaneous leishmaniasis caused by Leishmania braziliensis braziliensis (Lbb) was analysed by generation of short term T-cell lines from peripheral blood lymphocytes (PBL) of three patients. All had had active skin lesions but were clinically cured at the time of study. PBL were stimulated in vitro with sonicated Lbb promastigotes; blasts were isolated after 5 days and propagated for 9 to 16 days before being tested for proliferative capacity. The majority of propagated cells were T4-positive and reacted with Leishmania antigens. An apparent cross-reactivity with Trypanosoma cruzi (T. cruzi) soluble antigen was recorded. Although preliminary, these data indicate that immune T cells derived from cured LCL patients can recognize antigens common to Lbb and T. cruzi.

Adult↗