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Biomedical subjects

S Springer

Publications and source records attributed to S Springer.

50 records · Page 3Linked to original sources

Experimental pancreatic carcinogenesis. II. Lifetime carcinogenesis studies in the outbred Syrian golden hamster with N-nitroso-bis(2-hydroxypropyl)amine.

A high incidence of pancreatic duct neoplasms was induced in outbred male Syrian golden hamsters following weekly sc injection of N-nitroso-bis(2-hydroxypropyl)amine for life. The first such tumors appeared as early as 16 experimental weeks; the maximum incidence reached 100% by the termination of the study. Tumors in the respiratory tracts and angiosarcomas of the livers of the hamsters were also observed in high frequency. Latency of the induced neoplasms was significantly decreased by the substitution of distilled water for olive oil as the vehicle for the carcinogen.

Animals↗

13-cis-retinoic acid: inhibition of bladder carcinogenesis in the rat.

Transitional cell and squamous cell cancer of the bladder was induced in Wistar/Lewis female rats by direct instillation of N-methyl-N-nitrosourea into the bladder. Feeding of the synthetic retinoid, 13-cis-retinoid acid, inhibited the incidence and extent of bladder cancer in these rats, even when 13-cis-retinoic acid administration was begun after completion of the carcinogen treatment.

Animals↗

Experimental pancreatic carcinogenesis. I. Morphogenesis of pancreatic adenocarcinoma in the Syrian golden hamster induced by N-nitroso-bis(2-hydroxypropyl)amine.

In serial sacrifice experiment, outbred male Syrian golden hamsters were treated once weekly for life with subcutaneous injections of N-nitroso-bis(2-hydroxypropyl) amine (DIPN). The pancreas was examined by high resolution light (1-micro sections) and transmission electron microscopy. Early nonspecific changes in all pancreatic epithelial cellular elements were followed by a progressive proliferation of intra- and interlobular duct cells, with the development of multicentric foci of cystic and papillary cystic adenomas, intraductal carcinomas, and invasive ductal neoplasms. These observations were consistent with multistage morphogenesis of pancreatic adenocarcinoma of ductal origin.

Adenocarcinoma↗

Histopathological evaluation of the inhibition of rat bladder carcinogenesis by 13-cis-retinoic acid.

An objective system for histopathological and statistical evaluation of rat bladder lesions induced by the carcinogen, N-methyl-N-nitrosourea, is described. This system has been used to measure the inhibitory effects of 13-cis-retinoic acid on the development of bladder cancer in female Wistar/Lewis rats. 13-cis-Retinoic acid caused significant inhibition of development of both preneoplastic and neoplastic lesions in bladder epithelium.

Animals↗

[Effects of prepartum infusion solutions on glucose and bilirubin metabolism of mother and child in the prepartum and postpartum period].

BACKGROUND: Administration of glucose 5% infusion is regularly used in obstetrics. The purpose of the study was to investigate the effects of glucose as compared to xylose and electrolyte solutions on parameters of maternal and fetal glucose and bilirubin metabolism during labour and after delivery. PATIENTS AND METHODS: 53 pregnant women (> or = 37 weeks of gestation, uncomplicated pregnancies) were randomised by entering the delivery ward. Under labour either glucose 5%, xylose 5% or electrolyte infusions were administered. Maternal serum glucose, serum osmolarity, insulin and glucagon were analysed before administration and 20 minutes after delivery. In the newborn blood osmolarity and serum glucose levels were analysed in the umbilical cord directly after birth and in capillary blood samplings 2 hours after birth. RESULTS: Maternal blood glucose levels 20 min. post partum were significantly different (p < 0.05). Maternal insulin and glucagon concentrations 20 min. pp showed similar trends with glucose levels but were not significantly different. Glucose levels in the umbilical cord were significantly higher in the glucose than in the electrolyte group, but not higher than in the Xylit group. In contrast, the glucose-levels in the newborns after 2 h were significantly higher in the glucose group compared with both other groups. No significant differences were observed in bilirubin levels. Osmolarity in the umbilical cord between groups differed significantly. CONCLUSIONS AND DISCUSSION: In conclusion, the administration of different solutions showed a distinct influence on the maternal and neonatal glucose metabolism. A significant impact on the bilirubin levels could not be shown in this study.

Adult↗

Psychosocial effects of enhanced external counterpulsation in the angina patient: a second study.

Enhanced external counterpulsation (EECP) is a noninvasive technique that has shown promise in the treatment of ischemic coronary artery disease. Patients undergoing EECP were tested for alterations in psychosocial state associated with treatment. Overall perception of health and quality of life improved with EECP. There was also significant improvement in levels of depression, anxiety, and somatization but no change in levels of anger or hostility. On most measures, change was more significant for subjects who showed objective evidence of resolution of ischemia. Given the known predictive relationship between depression and mortality from cardiac disease, the improvement in depression scores through EECP indicates a finding of potential importance that may warrant further study in future research.

Aged↗

Arthroscopic treatment of synovial impingement of the ankle.

Twenty-nine cases of operative arthroscopy of the ankle were done between 1985 and 1989 for synovial impingement of the ankle. The average age of the patients was 37 years. All patients (17 men, 12 women) reported an earlier history of injury, with 24 of the patients (83%) noting chronic ankle pain after an inversion injury and 5 of the patients (17%) reporting a previous ankle fracture. Physical examination elicited anterolateral tenderness at the ankle in all cases with associated anteromedial pain in 4 patients. A demonstrable "click" was evident in 6 of the patients (21%) on forced dorsiflexion of the ankle. All patients failed conservative treatment including physical therapy and nonsteroidal antiinflammatory drugs. Surgery was performed at an average of 36 months postinjury. Ankle arthroscopy revealed extensive hypertrophic synovial thickening and scar tissue anterolaterally, indicating synovial impingement in all patients. Associated chondromalacia of the distal tibia was seen in 21% of the patients. Operative arthroscopy included partial synovectomy and debridement of the hypertrophic tissue and partial shaving chondroplasty of the tibia when indicated. Postoperatively, patients were weightbearing as tolerated. Results were assessed subjectively and objectively. At 25-month followup 26 patients had excellent or good results and 3 had fair results; there were no poor results. There were no major complications, including infection or neurovascular compromise. The 3 patients with associated ankle instability comprised the "fair" result group and eventually required lateral ankle reconstruction. Thus, chronic ankle pain due to synovial impingement can be safely, predictably, and effectively treated by operative ankle arthroscopy.

Adolescent↗

Investigation of the efficacy of a genetically-stabile live Salmonella typhimurium vaccine for use in swine.

Hybrid swine (Landrace x Pietrain) aged 3-4 weeks were immunized twice at an interval of 3 weeks solely by the oral route and by the oral/parenteral route to evaluate the efficacy of a live S. Typhimurium vaccine. In each experiment a control group was run without vaccination. The animals were challenged at the age of 8-10 weeks by oral test infection with a labelled S. Typhimurium DT 104 strain. An ELISA was used to establish the presence of antibodies to S. Typhimurium in serum samples, coupled with clinical investigation. The presence of the challenge strain in the ileal and caecal mucosa and in the ileocolic lymph nodes was investigated quantitatively using the Koch plating method to determine the degree of colonization of those organs at the time of slaughter. The clinical course of disease was used to assess the success of vaccination. However, it was not possible to trigger, in a reproducible manner, clinical signs of disease in unvaccinated animals through infection. The vaccinated animals had a significantly lower (p < 0.05) colonization of the ileal and caecal mucosa than the unvaccinated animals. This was also seen to a lesser degree for the ileocolic lymph nodes.

Animals↗