Experimentelle Untersuchungen über Resorption und Abbau von Benzpyren

Zusammenfassung Untersucht wurden die Resorptions- und Abbauvorgänge nach intraperitonealer Injektion von Benzpyren in verschiedenen Lösungsmitteln bei Ratten und Goldhamstern. Es fand sich eine deutliche Unterschiedlichkeit der Verweildauer des Benzpyrens abhängig vom Lösungsmittel und erhebliche Unterschiede der Abbauleistung bei den beiden Tierarten. Die Bedeutung der einzelnen Faktoren für die cancerogene Wirkung wird diskutiert.

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Experimental studies of the absorption and decomposition of benzpyrene

Summary The absorption and catabolism of benzpyrene in different solvents in rats and golden hamsters was investigated after intraperitoneal injection. A significant difference was found for the stay-period of benzpyrene depending on solvents as well as for the catabolism of animal species examined. The importance of particular factors for the carcinogenic activity is discussed.

     

Anthropometric study of the hip joint in Northeastern region population with computed tomography scan

Background:

Anthropometric study of the hip joint has important clinical implications and is largely unknown for the northeastern region of India. The purpose of this study is to determine the anatomic variation of the normal hip joint among the people of the northeastern region and to statistically compare them with the available data worldwide.

Materials and Methods:

We evaluated 104 individuals with normal hip joints and of different ethnic backgrounds (Caucasoid and Mongoloids) clinically and by plain x- ray. One topogram of the hip joint, one axial section of the femoral head and femoral condyles of the individual was taken on CT scan. Twelve cases had center edge angle (CE) angle less than 20° (unilateral/bilateral), were considered to be dysplastic and were excluded from the study. Thus the present study includes 92 individuals (184 normal hips, Mongoloids = 45; Caucasoid = 47) between 20-70 years of age. We calculated the mean of the CE angle, acetabular angle, neck shaft angle, acetabular version, femoral neck anteversion, acetabular depth and joint space width in both sexes.

Results:

The mean parameters observed were as follows: acetabular angle 39.2°, centre edge angle 32.7°, neck shaft angle 139.5°, acetabular version 18.2°, femoral neck anteversion 20.4°, acetabular depth 2.5 cm and joint space width 4.5 mm.

Conclusion:

The parameter and its values in our series shows differences when compared to the other western literatures. The neck shaft angle and the femoral neck anteversion in our individuals was 5-6° more than the western literature. The remaining parameters were less or equal to the western literature.     

Calcium phosphate ceramics as bone graft substitutes in filling bone tumor defects

Background:

Synthetic bio-inert materials are currently used as an alternative to autogenous bone graft. Calcium hydroxyapatite (HA) and Beta tri-calcium phosphate (β-TCP), which belong to the calcium phosphate ceramics group, are biocompatible and osteo-conductive. The purpose of this study is to analyse the use of HA and β-TCP in their ceramic forms as a bone graft substitute in filling bone voids after curettage of benign bone tumors.

Materials and Methods:

Twenty-four patients in the age range of 3.5-55 years (mean 14.3 years) having benign bone tumors with bone defects were filled with bone graft substitute following curettage. In 20 patients bone defects were filled with block/granules of HA ceramic and in four with β-TCP. Fibular strut graft was packed with HA in four patients. The patients were followed up for an average of 18 months (range 12-36 months).

Results:

The functional status of the patients at follow-up was evaluated and compared with preoperative functional status. Early incorporation of graft substitutes became evident radiologically between 6 and 10 weeks (Stage I). Complete incorporation (Stage III) was observed in an average of nine months (6-18 months). Clinical healing was observed before radiological healing. The average time taken to return to preoperative function was 14 weeks. There was no recurrence of lesion or growth retardation.

Conclusion:

Calcium hydroxyapatite and β-TCP are excellent bone graft substitutes for autogenous bone graft in filling voids after curettage of benign bone tumors.     

Elevated adenosine deaminase and purine nucleoside phosphorylase activity in peripheral blood null lymphocytes from patients with acquired immune deficiency syndrome

The purine metabolic enzymes adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) are important in lymphocyte differentiation, and genetic deficiencies of either enzyme have been associated with hereditary immunodeficiency states. Both ADA and PNP activity were measured in null cell-enriched and T cell-enriched peripheral blood lymphocytes from 16 patients with the acquired immune deficiency syndrome (AIDS), seven patients with the AIDS-related symptom complex (ARC), and seven asymptomatic homosexuals. ADA activity in nmol/10(6) lymphocytes/h was significantly elevated in null lymphocytes from AIDS (161 +/- 12) as compared with 23 healthy heterosexual controls (127 +/- 8;P less than .025). PNP activity was also significantly increased in null lymphocytes from AIDS patients (96 +/- 10;P less than .005) as well as those from ARC patients (84 +/- 11:P less than .025) relative to controls (61 +/- 5). No significant differences in enzyme activity were noted in T cell-enriched cells in any group. Along with elevated enzyme activity, AIDS patients had small yet significant increases in the percentages of HLA-DR (P less than .025), terminal deoxynucleotidyl transferase (TdT) (P less than .0001), and peanut agglutinin receptor (P less than .0001) positive lymphocytes in the null fraction compared with controls. TdT-positive cells appeared morphologically as large lymphoblasts with irregular nuclei. The data imply that the cellular immune deficiency in AIDS is not a result of deficiencies in lymphocyte ADA or PNP activity, but is more likely associated with an increase in an immature and/or activated lymphocyte subset.     

The transport of 125I-labeled human high molecular weight urokinase across the intestinal tract in a dog model with stimulation of synthesis and/or release of plasminogen activators

In an attempt to elucidate the mechanism of fibrinolytic enhancement by orally administered urokinase, studies on the intestinal transport of urokinase were carried out, using 125I-labeled human high mol wt urokinase, administered intraduodenally in the experimental dog model with a saphenous vein thrombus. Using the plasma sample obtained from blood 45 minutes after intraduodenal administration of the urokinase, protein fractions were isolated by a sequential two-step affinity chromatography method, first with [N alpha-(epsilon-aminocaproyl)-DL- homoarginine hexylester]-Sepharose followed by a specific anti-human low mol wt urokinase rabbit IgG-Sepharose (adsorbed-eluted and unadsorbed). Each of the isolated protein fractions was further purified by gel filtration on Sephacryl S-300. The proteins isolated by the two-step affinity chromatography method were transported human urokinase with radioactivity in the adsorbed-eluted fraction, and newly synthesized and/or released dog plasminogen activators, probably urokinase-type and tissue-activator type, without radioactivity. In an antibody quenching assay, dog urokinase and the immuno-affinity unadsorbed fraction were not neutralized, but the immuno-affinity adsorbed-eluted fraction was completely neutralized by the specific anti-urokinase IgG antibody. Proteins isolated from control plasma (after administration of saline) by the two-step affinity chromatography method in the unadsorbed fraction had negligible amounts of activator activity. In these studies, we were able to show that synthesis of plasminogen activators was stimulated, with the activators being released, from either the liver or the vascular endothelium. Also we showed that urokinase is transported across the intestinal tract in the dog model.     

Self-expanding metallic stents: preliminary evaluation in an atherosclerotic model

The performance of the self-expanding stainless steel (Gianturco) stent in atherosclerotic arteries was examined in a rabbit model. Atherosclerosis was induced by supplementing rabbit chow with 6% peanut oil and 2% cholesterol followed by endothelial disruption of the abdominal aorta with a balloon catheter and continuation on the atherogenic diet for the remainder of the study. Eighteen stents, 1 cm in length and 4 or 5 mm in diameter when fully expanded, were placed in atherosclerotic stenotic lesions in six rabbits. Luminal distention was consistently achieved. At 8 weeks follow-up, no luminal narrowing, stent migration, thrombus formation or branch vessel occlusion had occurred. Atherosclerotic neointimal proliferation occurred around the stent wires following placement, but did not cause significant luminal narrowing.     

Qualitätsvergleich von modifizierter Neurolept-, balancierter und intravenöser Anästhesie Teil 2. Ergebnisse der Krefelder Studie 1992*

The safety and tolerance of neuroleptanaesthesia (NLA), balanced anaesthesia (BAL), and intravenous anaesthesia with propofol (IVA) were analysed for the first time in a prospective, randomised clinical trial. Methods. In all, 1318 surgical patients received either NLA, BAL, or IVA. Patients who had regional anaesthesia, were aged under 18?years, or were nonco-operative or vitally threatened (ASA class?IV to V) did not participate in the study. Premedication and anaesthetic course were set up at a standard of 30% oxygen and 70% nitrous oxide. Incidents, events, and complications due to anaesthesia were obtained (IEC key of the German Society of Anaesthesia and Critical Care Medicine, DGAI). Furthermore, postanaesthetic alertness based on specific recovery tests and the quality of anaesthesia from the patient's viewpoint, rated by patient questionnaires from the DGAI were evaluated. All parameters were calculated and checked for statistical significance using the chi-square test. Results and discussion. The groups were broadly comparable with respect to age (P=0.91), ASA class (P=0.42), preoperative blood pressure (P=0.36), and length of anaesthesia (P=0.82). The anaesthesia, which averaged 103?min, comprised the following regimens: (1) NLA: 7.1?mg droperidol and 0.008?mg/kg body weight fentanyl, (2) IVA: 493.4?mg propofol and 0.004?mg/kg body weight fentanyl, and (3) BAL: 2.6?mg droperidol and 0.004?mg/kg body weight fentanyl with 0.4?vol.% isoflurane. With respect to anaesthetic risk, the following reactions were observed: the use of NLA led to a high incidence of tachycardia (P=0.001), arrhythmias (P=0.05), and hypertensive reactions (P= 0.001), whereas in the IVA group only hypotension (P=0.0001) occurred. However, after the use of BAL none of the aforementioned complications were detectable to any considerable degree. Similarly, patients who had cardiac disease showed greater IEC changes after the use of NLA than after BAL or IVA (P=0.02) (Tables?1 and 2). The heart rates and blood pressures during BAL and IVA were extremely stable, and therefore, vasoactive therapy was required considerably less in comparison to NLA (P=0.001) (Table?4). Recovery after the use of IVA was strikingly rapid: the patient's responsiveness, orientation, and ability to concentrate was significantly better than after the other anaesthetic regimen (P=0.01) (Table?5). With regard to the typical discomforts after anaesthesia, IVA was highly superior to BAL and NLA: nausea (P=0.0003) and retching (P=0.03) hardly ever occurred (Table?6). Due to the tolerable manner of waking up and rapid return of orientation and the ability to concentrate, IVA was highly favoured by the patients (P=<0.01) (Table?7). Conclusion. The present results show clear clinical advantages of BAL and IVA in contrast to neuroleptanaesthesia. Due to the very low incidence of side effects such as nausea and vomiting IVA was highly recommended by the patients, at least in part because of the rapid recovery time.     

Experimental studies on the rumorigenic activity of cigarette smoke condensate on mouse skin. VI. Fractionation of cigarette smoke condensate (author's transl)]

This experiment has been performed to clarify the question to which extent fractions containing polycyclic aromatic hydrocarbons (PAH) or other carcinogenic compounds are responsible for the biological activity of cigarette smoke condensate. With chromatographic procedures using organic gels it was possible to separate quantitatively polar compounds from the PAH-fraction and to obtain fraction IX representing 0.4% of the whole condensate. In this fraction the PAH were enriched 250fold. Significant losses of tumorigenic effects by this fractionation method could not be observed. This PAH-containing fraction showed 50% of activity compared with the overall activity of whole smoke condensate of a reference cigarette. A so-called PAH-free fraction showed with 7% of the overall activity of the whole smoke condensate a weak carcinogenic effect. The importance of PAH for the tumorigenic effect of cigarette smoke is emphasized by these results.