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T de Vries

Publications and source records attributed to T de Vries.

29 records · Page 2Linked to original sources
PubMed1988

Comparison of heart rate as a non-invasive determinant of anaerobic threshold with the lactate threshold when cycling.

In 9 trained athletes and 4 sedentary subjects the anaerobic threshold was assessed on a cycle ergometer, using the deflection point of heart rate in a protocol in which the workload increased by 10 W every 45 s. The workload at which plasma lactate concentration equalled 4 mmol.l-1 was assessed under steady state conditions on separate occasions. In addition, in 3 subjects the non-invasive anaerobic threshold and the 4 mmol.l-1 lactate level under steady state conditions were assessed on a treadmill. On the cycle ergometer 6 subjects demonstrated a deflection point in the heart rate record, whereas the others failed to do so. The workload at which heart rate departed from linearity in the progressive protocol did not coincide with the steady state 4 mmol.l-1 workload but occurred at a higher workload. On the treadmill no deflection in heart rate was observed. It is concluded that in cyclists a deflection in heart rate does not always occur, and when it does, it does not coincide with the anaerobic threshold determined under steady state conditions.

Adult↗
PubMed1985

Carcinogenicity study in rats with a mixture of eleven volatile halogenated hydrocarbon drinking water contaminants.

A lifetime carcinogenicity study was carried out in Wistar rats, with a mixture of the following halogenated hydrocarbons: trichloromethane, tetrachloromethane, monobromodichloromethane, trichloroethylene, tetrachloroethylene, 1,2-dichlorobenzene, 1,3,-dichlorobenzene, 1,4,-dichlorobenzene, 1,2,3,-trichlorobenzene, 1,2,4,-trichlorobenzene, 1,3,5-trichlorobenzene. From this mixture 0.22, 2.2, or 22 mg was added per liter drinking water representing concentrations being three orders of magnitude higher than found in several water wells. Most of the changes found in body weight, hematology and pathology correlated with intercurrent diseases or were in accordance with background pathology. With respect to incidence and time of occurrence of tumors, no significant differences were found between the control and the high dose group when lifespan correction was applied. Thus it is concluded that in the present study no significant toxic or carcinogenic effects are induced by lifetime exposure of rats to a mixture of volatile halogenated hydrocarbons in the drinking water.

Animals↗
PubMed1981

Histopathological profile of a Wistar rat stock including a survey of the literature.

This study is concerned with the histopathological changes and tumors and their incidences in the Wistar SPF Tox rat. Also included are data on survival, growth and haematology. The animals were untreated and were investigated for 30 months. The data are compared with those from two Wistar substocks, which had been used in the same laboratory: the Wistar CPB and the Wistar Conv. The results are summarized in tables and figures and are compared with data from the literature. A survey of studies dealing with spontaneous lesions and tumors in rats is given. A wide variety of tumor types and a relatively high tumor incidence were found in the Wistar SPF Tox rats. Since most of the tumors were found after 24 months, this high incidence was correlated with the life expectancy.

Animals↗
PubMedDate not supplied

ANCA seropositivity in HIV: a serological pitfall.

In systemic vasculitis, cytoplasmic staining in ethanol-fixed neutrophilic granulocytes, i.e. cytoplasmic antineutrophilic cytoplasmic antibody (c-ANCA), is generally considered a highly significant serological marker. When a patient presents with upper airway or renal symptomatology and seropositivity to c-ANCA, a Wegener's granulomatosis is usually easily diagnosed by performing a biopsy of the diseased organ. However, not every ANCA-positive patient with pulmonary inflammation is suffering from Wegener's disease. In some cases of upper airway or pulmonary symptomatology, the a priori chance of having Wegener's disease is low despite a positive ANCA. A coincidental positivity of ANCA may then lead to clinicians jumping to conclusions. We present a 40-year-old man who was falsely suspected of having Wegener's disease because of upper airway symptomatology and c-ANCA positivity. Specificity analysis revealed that he was negative to antibodies for proteinase-3, but positive to myeloperoxidase. The potential serological pitfall of the supposedly specific c-ANCA is discussed.

Adult↗