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Biomedical subjects

W Thomas

Publications and source records attributed to W Thomas.

At least 145 records · Page 8Linked to original sources
PubMed1986

Pavlovian conditioning and addictive behavior: relapse to oral self-administration of morphine.

The effect of conditional environmental stimuli on morphine consumption in rats was examined. Rats were first trained to consume a morphine solution (increased from 0.5 mg/ml to 1.2 mg/ml) by a forced drinking procedure spanning 235 days. Then, a period of abstinence of 81 days was given. They next received injections of morphine in one environment and injections of saline in a different environment (30 injections of morphine, dose increased from 5 mg/kg to 40 mg/kg). At the end of this phase, the effects of conditional environmental stimuli on tolerance to the analgesic effect of 40 mg/kg morphine were examined. Consistent with previous results, analgesic tolerance was most pronounced in the context of the cues previously associated with subcutaneous morphine injections. Finally, the effects of the different environments on consumption of morphine were determined in one-bottle and two-bottle tests. In a two-bottle test, there was almost no consumption of the morphine solution regardless of environment. In a one-bottle test, significantly more morphine was consumed in the drug environment than in the saline environment. The results are discussed in relation to theoretical views of the role of environmental stimuli in tolerance and drug dependence.

Administration, Oral↗
PubMed1984

Behaviour of protein C inhibitor in intravascular coagulation and liver disease.

We measured levels of protein C inhibitor in patients with disseminated intravascular coagulation (DIC) and liver disease using a functional assay. Levels in 24 normal subjects averaged 93% of the amount in normal pooled plasma, giving a normal range of 65 to 121%. Levels were below normal in 8 of 17 patients with DIC, in 4 of 19 patients with liver cirrhosis, and in 3 patients with acute hepatic necrosis. Levels were normal or elevated in 9 of 10 patients with cirrhosis and accelerated fibrinolysis, and in 6 patients receiving warfarin. We conclude that protein C inhibitor may be involved in regulation of protein C activity during pathologic activation of the hemostatic system (DIC). Decreased protein C inhibitor does not appear to contribute to the pathogenesis of accelerated fibrinolysis in liver disease. The liver may be the site of synthesis of protein C inhibitor.

Disseminated Intravascular Coagulation↗
PubMed1984

Reduction in risk of hepatitis transmission by heat-treatment of a human Factor VIII concentrate.

A human Factor VIII concentrate containing both a non-A, non-B hepatitis agent and 300 or 30,000 chimpanzee infectious doses of added hepatitis B virus (HBV) was heated to 60 C in the lyophilized state for more than 10 hr. None of the four test chimpanzees that received the heated concentrate developed biochemical or ultrastructural evidence of non-A, non-B hepatitis, whereas both control animals receiving unheated product acquired the disease four to five weeks after infusion. In one of these animals the alanine aminotransferase level remained elevated, a finding indicating unresolved or persistent liver disease. Challenge inoculations with unheated Factor VIII base product (without HBV) resulted in the development of non-A, non-B hepatitis in one of two chimpanzees that previously received the heated product. Hepatitis B infection developed in the control animal that resolved its non-A, non-B hepatitis infection but not in the non-A, non-B hepatitis carrier chimpanzee. Both chimpanzees receiving the heated Factor VIII containing 300 chimpanzee infectious doses of HBV failed to develop hepatitis B until 32 and 40 weeks postinoculation, whereas the two chimpanzees that received heated concentrate containing 30,000 infectious doses of HBV became infected within the expected time. Product characterization and human safety trials have revealed no significant difference between the heated and unheated Factor VIII lots and recovery of product has been exceptionally good.

Alanine Transaminase↗
PubMed1983

Myositis of chronic graft versus host disease.

A 13-year-old girl with chronic graft versus host disease (GVHD) developed severe proximal weakness. Muscle biopsy showed necrotic fibers with anti-IgG deposits and interstitial inflammation. Steroid treatment helped, but her weakness recurred. Repeat biopsy showed persistent inflammation and possible steroid myotoxicity. Numerical ratio of capillaries to myofibers and capillary numerical density were higher than childhood dermatomyositis (CD), and capillaries had no tubuloreticular inclusions. Absence of quantitative histologic, ultrastructural, or immunocytochemical abnormalities of capillaries differentiated our patient from CD. We conclude that myositis of chronic GVHD can present as a severe myopathy that responds to steroids and differs from CD.

Adolescent↗
PubMed1983

[Value of computed tomography in congenital hip dysplasia and hip luxation].

A lot of methods of measurement have been developed to record precisely the degrees of luxation and the deviations from the normal form in the hip joints of the child and adult. The orthopaedic surgeon needs those data for a preoperative "coxometric program" before performing acetabuloplastic operations with osteotomy, osteotomy of the pelvis and combined operations. Computed tomography yields a series of informations and of possibilities of measurements which can determine the operative procedure in particular. These informations concern among other things the dimensions of the dysplasia of the acetabulum in the horizontal plane with the extension of the posterior lip and the angle of the acetabular opening, furthermore the physiological or pathological congruence between the head of the femur and the acetabulum, the angle of antetorsion of the neck of the femur and, in the small infant, the direct noninvasive imaging of the tube of the capsule with imaging of possible obstacles to reposition.

Acetabulum↗
PubMed1982

Ultrasonic evaluation of echinococcosis in four lowland gorillas.

Four captive lowland gorillas (Gorilla gorilla gorilla) were subjected to abdominal ultrasonic scanning. Evidence of progressive infection by the enzootic parasite Echinococcus vogeli was observed in all 4 of them. Ultrasonic scanning revealed abdominal disease, with evidence of both hepatic and bowel involvement. Three gorillas subsequently died. Necropsy results validated the ultrasonic diagnoses.

Animals↗
PubMed1982

[The Anatomical sliding-axis knee-joint prosthesis (author's transl)].

In order to avoid the disadvantages of a fixed axis the newly-designed knee-joint prosthesis was equipped with a sliding one. This is not a load-bearing component; its main purpose is to guide the movement of the endoprosthesis. The design permits almost physiological movement, thus diminishing the detrimental forces at the anchor points. To further improve anchoring the shafts of the prosthesis were designed with an anatomical cross-section. The design of the anatomical sliding-axis prosthesis is described and the results of the first 36 implantations are presented.

Biomechanical Phenomena↗