Biomedical subjects
Publications and source records attributed to H Meier.
Mice given quercetin per os at concentrations that were about 10(3) times greater than the estimated average human intake of total flavonols were tested for mutagenicity with 2 complementary in vivo mutagenicity/carcinogenicity screening tests--the micronucleus test and the host-mediated assay employing the Ames Salmonella tester strain TA 98 as indicator organism. No mutagenic effect was detected with either test.
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Performing a gastrostomy is an easy operative procedure. Indications for this procedure include neonates and children with congenital deformities of the oesophagus, dysphagia for different reasons, small bowel atresias, exomphalos and diaphragmatic hernias. The gastrostomy is performed in the left upper abdomen through a small vertical midline incision. Between 1970 and 1979, gastrostomy has been performed in 143 newborns and children. In none of these cases did a serious complication occur. The main advantages are: decompression of the abdomen, improvement of the ventilation and early enteral quantitative feeding.
In experiments with fattening pigs peas and lupines were used, both pealed and unpealed, in order to investigate the influence of native crude fibres on the true digestibility of nitrogen and the amino acids in pigs. The results of the experiments allow the conclusion that native crude fibres, as long as they remain in the normal range between 3 and 7% in the ration does not cause a depression in the true digestibility of nitrogen and the amino acids in the feeding of fattening pigs. Only the increased content of native crude fibres in the ration has a negative effect on true digestibility.
Among 12 recombinant inbred strains of mice derived from crossing two strains, C57BL/6J and C3H/HeJ, which have a low incidence of neoplastic disease, one strain (BXH-2) has been found to have a high incidence of lymphoma, of non-T-cell origin, at an early age. The BXH-2 strain carries the Fv-1b allele and spontaneously expresses a B-tropic murine leukemia virus beginning at as early as 10 days of gestation and continuing throughout their life. No significant differences in ecotropic virus titers were observed at any age tested (16 to 17 days of gestation through 7 months), whereas xenotropic virus was first detected in lymphoid tissues of 2-month-old mice and virus titers increased with age. Dual tropic virus(es), which induced cytopathic changes on mink lung cells, was isolated from BXH-2 lymphomatous tissues. Unlike AKR mink lung focus-forming virus (N-tropic recombinant), BXH-2 dual tropic virus is B tropic and induces cytopathic changes in mouse fibroblast cultures as well. The BXH-2 mouse provides a model system for studying the role of replication-competent viruses in spontaneously occurring leukemias of non-T-cell lineage and neurological disease.
HRS/J, hr/hr and hr/+ mice were evaluated for their ability to resist challenge with a syngeneic tumor, HTU, and for their ability to mount a protective immune response when immunized in vivo with inactivated HTU cells previous to challenge with viable tumors. The heterozygous (hr/+) mice responded more strongly than the homozygous (hr/hr) mice. This response was characterized by the presence of an enhanced ability of spleen cells from immunized mice to form blasts in vitro when incubated with purified murine leukemia viruses (MuLV). We conclude that the in vivo response of HRS/J mice against this tumor is directed, in part, against MuLV antigens expressed on the tumor cells and that the relatively weak response of hr/hr spleen cells to these antigens may be mechanistically linked to their tumor susceptibility.
The prognosis of exocrine carcinoma of the pancreas is still quite bad; because of that, total duodenopancreatectomy following the procedure by Fortner has been our surgical approach since January 1978. Since that time surgery of periampullary carcinoma was extended as well in such a way, that first and second order lymph nodes were excised systematically. Following the introduction of these procedures the percentage of patients with exocrine pancreatic carcinoma operated upon rose from 12 to 35%, - the percentage of patients operated upon because of periampullary carcinoma correspondingly rose from 61 to 91% of all patients carrying these tumors. The incidence of lymphogenous metastases was 88% in 17 patients, which had surgery because of ductal pancreatic carcinoma, and 27% in 22 patients with periampullary carcinoma. 29% of patients with pT1-3 tumors and 71% of patients with pT4 tumors did have already lymphogenous metastases. In 22% of the cases, who would have been operated upon by conventional total duodenopancreatectomy metastases were found in the second order lymph nodes which were taken out according to the new more radical surgical approach; the corresponding figure for patients, who were operated upon by partial duodenopancreatectomy was 5%. Mortality of regional partial duodenopancreatectomy was 4% in our series, and mortality after regional total duodenopancreatectomy was similar to that of conventional pancreatectomy without dissection of lymph nodes.
With B-scan sonography a method of investigation is available which is characterized by simple, rapid and painless application, no side effects and which can be repeated as often as desired, thus enabling investigation to be performed in outpatients. In a mass echographic examination of 305 infants, a pathologic finding in the abdominal and retroperitoneal region was detected in 5% of them. A result of our investigations and literature search we believe that B-scan echography in experienced hands is a necessary extension of the preventive program as a method of screening in infancy.
76 children were treated with clindamycin at a dosage of 40 mg/kg/day for postsurgical wound infections, sepsis, phlegmon, peritonitis, osteomyelitis, pneumonia, mediastinitis, pyoderma and urinary tract infections. Frequency distribution of individual infectious agents: Staphylococci, 94,7%; Streptococci, 59,2%; Pneumococci, 5,3%; Enteroccocci, 25%; Escherichia coli, 10,5%; Pseudomonas, 14,5%; Proteus, 7,9%; Bacteroides, 6,6%; Clostridia, 7,9%. Therapy was successful in 83% of cases. Results were poor in 2 children treated for phlegmona, one case of mediastinitis and one of urinary tract infection, since organisms were predominantly gram-negative.
In this study we examined the leukemia incidence, ectropic and xenotropic murine leukemia virus expression, and immune responsiveness of congenic AKR/J mice differing at the H locus. Congenic AKR.L-H-2b/1 mice, bearing the H-2b haplotype derived from C57L/J, were found to have a significant delay in time of death due to leukemia relative to that of AKR/J (H-2k) mice. The expression of ecotropic murine leukemia virus was found to be identical in both strains. The expression of xenotropic murine leukemia virus did vary, however, with the AKR.L-H-2b/1 mice showing a significantly reduced level of virus expression relative to AKR/J mice. In addition to these observations, we found that the AKR.L-H-2b/1 mice have an enhanced blastogenic responsiveness to phytohemagglutinin and to specific antigen to which they had previously been sensitized. Concomitant enhanced antibody response was not found. We suggest that the stronger cellular response, relative to AKR/J, may contribute to the delay in leukemia onset and to reduced xenotropic virus expression observed with the congenic mice.
Pregnant rabbits of two partially inbred strains, WH/J and IIIVO/J, were given ten consecutive daily ip injections of 10 mg N-ethyl-N-nitrosourea (ENU)/kg dissolved in trioctanoin starting on either day 10, 15, or 18 of gestation. Of 7 WH/J progeny weaned, 3 developed primary renal tumors at 6.8 +/- 0.6 months of age (mean +/- SE). Similarly, of 12 IIIVO/J progeny weaned, 10 developed primary renal tumors at 6.3 +/- 0.6 months of age (mean +/- SE); in addition, 1 fibroblastic osteosarcoma and 5 neurofibromas, some associated with neurilemma cysts, were observed. Renal tumors were nephroblastomas , which appeared to develop within small renal cortical cysts. The frequency of tumor induction for each strain was similar to that in our previous experiments with acute administration of ENU and ethyl-urea plus NaNO2, but the latency period (6.4 +/- 0.5 mo) was almost doubled. In addition, chronic treatment of ENU induced teratogenic effects. In a number of these progeny, a disproportionate stunting or miniaturization was evident, the frequency of which increased with the age of the treated fetuses. In contrast, holes were found in the parietal bones at birth, but with a frequency that decreased with increasing fetal age at time of treatment. No teratogenic effects were observed in the controls.
MICE of the AKR/J strain show high rates of spontaneous thymic lymphoma and are chronically infected with murine leukaemia viruses. Total thymectomy in young mice of this strain results in a marked decrease in the incidence of leukaemia. The finding of athymic mutant mice on the AKR/J background (referred to as streaker mice) is of importance in the study of genetic factors which influence virus expression and leukaemogenesis. Here we report that mice of both normal and mutant genotypes vary in the expression of a particular class of murine leukaemia virus. This lower virus expression in conjunction with the absence of a thymus leads to a lower tumour incidence in streaker mice.
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In several test series with rats, the influence of native crude fibres (straw meal and pea hulls) on the amount of metabolic fecal nitrogen (MFN) was tested. It could be ascertained that native crude fibres increase MFN. The influence of the increased MFN on the true digestibility of nitrogen and the amino acids was investigated in test series with casein diets. The casein diets were supplemented with native crude fibres. Generalising, we can state that native crude fibres--due to their structure (lignin)--fix amino acids and thus withhold them from absorption. They do not, however, increase the MFN by mechanical action (increase of the scraping off of intestinal epithelium).
It is to be proved in model experiments with rats that calculations with true digestible amino acids are more exact than calculations with the gross amount of amino acids and therefore are advantageous. 7 resp. 6 rations were tested whose gross contents of lysin, methionine and cystin were balanced. Their content of actually digestible lysin differed, however. The results of the two test series show distinctly that the prediction resp. assessment of the animals' performance in dependence on the amino acid content of the rations is most safely based on the actually digestible amino acids.
Available operative procedures to reduce incontinence are gracilis transplant, levator plastic, free muscle transplantation and pacemakers. Further procedures being tested in clinical trials are electronic cuffs, modified Scott's sphincters, and implantation of cuffs of unstriated muscle. The magnetic anal ring, which has been developed in Erlangen, consists of two halves. Using a sacral approach both parts can be placed around the rectum without opening the bowels. An anal tampon consisting of a magnetic tampon and a tampon covering is responsible for occlusion. The tampon covering consists of polyvinylformalfoam, which guarantees an excellent plugging. Application is similar to tampons for menstruation; tampons can be changed three times a day and the bowel can be emptied normally when a change is made. In order to work successfully the tampon is pressure adapted to the pressure profile of the large bowel. Histologic investigations of the mucosa did not show any alterations. Megacolon or megarectum proximal to the anal ring did not occur.
Complications of pulmonary surgery in childhood which should be prevented are: 1. Wrong indication for thoracotomy. An exact preoperative diagnosis including angiography is necessary to diagnose exactly the morphological abnormalities (i.e. arteriovenous fistulae). 2. Technical mistakes: Identifying vascular connections in cases of sequestrations of the lung which may transverse the diaphragm; priority of ligation of the vessels in pulmonary resections carried out for arterio-venous fistulae, i.e. the artery must be ligated first then the vein. If haemorrhage will occur from the vena cava, longitudinal clamps must be applied. Blindly carried out punctures of the lung are contraindicated. Pleural drainage catheters should be placed one intercostal space higher than the hole where they pass through the skin. In cases with cysts of the lung (i.e. echinococcus) where there is a danger of a rupture of the cyst into a bronchus, unilateral intubation is indicated.
The length of the infant, the weight of the infant, the weight of the placenta, and the correlation between the weight of the placenta and the weight of the infant are coarse parameters for the estimation of the maturity of an infant. We plotted these parameters of 20,000 deliveries in relationship to the stated length of gestation from 23--46 weeks. Our results correspond to those quoted in the literature. The values of the parameters show a marked variation which is accentuated by the small number of cases with very short or very prolonged gestation. These parameters are only of limited value in the determination of the paternity. The mean values including the first standard deviations are of some importance.