Comparative studies of the activity of disaccharidases in the mucosa of the small intestines in dystrophic, formerly hypotrophic-born young children and of patients with flat mucosa of various etiology

The disaccharidase activities of the mucous membrane of the small intestine were determined in formerly hypotrophic children who showing a dystrophy with a morphological normal mucosa (n = 36), patients with a flat mucosa caused by enteral protein intolerances of different genesis (n = 27), patients with a morphologically and functionally normal mucosa (n = 51). In about half of the former small-for-date children were shown activities lower than the simple standard deviation of the normal value, for lactase n = 17, for sucrase n = 14, for maltase n = 12. Some children showed pathologically reduced activities even below the double standard deviation for the normal value: lactase n = 8, sucrase n = 5, maltase n = 3.     

Histological comparison of implanted cadaveric and porcine dermal matrix grafts.

OBJECTIVES: Histological comparison of human-based (AlloDerm) and porcine-based (ENDURAGen) dermal matrices regarding tissue incorporation and neovascularization as potential soft tissue augmentation materials. STUDY DESIGN: In vivo, rat model. METHODS: Subcutaneous implantation of 1-mm thick, 1 cm x 1 cm pieces of AlloDerm, ENDURAGen, and meshed ENDURAGen was performed in 24 Sprague Dawley rats. Implant materials were harvested at 4 (n = 12) and 8 weeks (n = 12). Histological quantification of soft tissue ingrowth and microvascular density was performed following hematoxylin-eosin staining and CD34 immunohistochemistry, respectively. RESULTS: AlloDerm showed significantly greater soft tissue ingrowth and microvascular density compared with both ENDURAGen and meshed ENDURAGen at 4 and 8 weeks (P < 0.001). CONCLUSIONS: Although these results may differ in human host tissues, AlloDerm seems to be a more suitable dermal matrix implant than ENDURAGen for cases in which tissue incorporation and neovascularization are sought for the optimal outcome based on this animal model.     

Intestinal first-pass metabolism of nitrosamines. 2. Metabolism of N-nitrosodibutylamine in isolated perfused rat small intestinal segments

In a previous study a high first-pass metabolism of N-nitrosodi-[1-¹⁴C]butylamine(NDBA, O.32–730p.µM) has been shown in isolatedperfused rat small intestinal segments. In the present workthe identification and quantitation of metabolitesin samplesof perfusate and absorbed fluid (absorbate) is reported. AfterHPLC enrichment and purification five metabolites could be identifiedby GLC-MS: N-nitrosobutyl-(3-hydroxybutyl)amine (NB3HBA), N-nitrosobutyl-(4-hydroxybutyl)amine(NB4HBA), N-nitrosobutyl-(3-carboxypropyl)amine (NB3CPA), N-nitrosobutyl-(2-hydroxy-3-carboxypropyl)amine(NB2H3CPA) and N-nitrosobutylcarboxymethylamine (NBCMA), representing> 95% of total metabolites. -hydroxylatlon leading to NB4HBAand NB3CPA accounted for 75–95% of total metabolites.The formation of their follow-up products NB2H3CPA and NBCMAwas too small for quantitative analysis. In absorbate NB3CPAwas by far the most important metabolite. The hydroxylationof NB4HBA to NB3CPA was more efficient in jejunal as comparedto ileal segments.-1-hydroxylation to NB3HBA and, as reportedpreviously, -hydroxylation were only minor metabolic pathways.In conclusion, a high first-pass metabolism of NDBA to the proximatebladder carcinogen NB3CPA takes place during its absorptionin rat small intestine. This is in contrast to the observationin rat liver preparations, where - and -1-hydroxylation arethe predominant pathways. The intestinal first-pass metabolismmay play a key role explaining the increased incidence of bladdertumors in rats after low oral doses of NDBA.     

Impaired tactile pattern recognition in the early stage of primary degenerative dementia compared with normal aging

Tactile pattern recognition of ten different patterns which were engraved upon 4 x 4 cm plastic plaquettes with one hand and thereafter drawing with the other or the same hand was tested in 21 patients with a mild stage primary degenerative presenile onset dementia of Alzheimer type (DAT) and in 14 patients with a questionable dementia on the background of a chronic cardiovascular disease (CVD) in comparison to 15 healthy subjects of the same age (51 years old, elder controls, (EC)) and 16 younger subjects (22 years old, younger controls, (YC)). Patients made about four times more errors than the EC group. Duration from the begin of touching to the end of drawing was significantly longer in patients than in controls. In a second task the subjects had to recognize four subsequent patterns, then to perform a standard multiplication task and afterwards to draw all four patterns in their correct sequence. Patients made about ten times more errors in pattern recognition and series reproduction than age-matched controls.     

Persistent infection of human lymphoid and myeloid cell lines with herpes simplex virus.

Herpes simplex virus (HSV) type 1 replicated and persisted in human T, B, and myeloid cell lines with different patterns of viral replication and various effects on cell growth. T cell line CEM supported the replication of HSV for over 400 days without detectable differences in cell growth as compared with uninfected cells. HSV persisted in B cell line NC37 and myeloid cell line K562 for up to 222 and 374 days, respectively, but led to a significant decrease in the number of viable cells by 7 weeks of infection. The average number of cells producing infectious virus was very low in these cell lines (range, 0.5 to 2.7+) compared with a larger proportion of cells exhibiting HSV antigens by immunofluorescence (range, 24 to 58%). In contrast, null cell line LAZ 221 failed to replicate HSV even though the viral infection led to a cessation of cell growth.     

Serum-induced chronic pancreatitis

Summary Clinical research into patients with idiopathic chronic pancreatitis points to a possible immunopathogenetic process in a number of cases.In order to examine the behaviour between the exocrine pancreas under the influence of anti-rat-pancreas immune serum produced in rabbits, a 1.00 ml immune serum is administered once a week over a maximum 26 week period into Wistar-rats by intraperitoneal injection. By electrone-microscopy a much reduced production of enzymes apparently takes place, though to differing extent. There is also destruction of the basal membrane of acinocytes; the production of interstitial oedema, the new formation of collagen fibres and the proliferation of connective tissue cells. Under a conventional light microscope the first changes become noticeable after 8-12 weeks of study. These take the form of localised cell decay, deterioration and lysis of acinocytes; and an increasing non-specific inflammation. There is also the new formation of connective tissue. After 20–26 weeks the exocrine pancreas is characterised by reduction of parenchyma, acino-ductal metaplasia, chronic inflammatory infiltrates of differing density, fibrous and irregular calibres of the smaller and larger ducts.The findings are almost identical to the structural changes of chronic idiopathic pancreatitis in human beings. The results support the view of an immuno-pathologic aetiology for human chronic idiopathic pancreatitis.Supported by Deutsche Forschungsgemeinschaft     

Frequency of rpoB mutations inside and outside the cluster I region in rifampin-resistant clinical Mycobacterium tuberculosis isolates

The prevalence of recently described mutation V176F, located in the beginning of the rpoB gene and associated with rifampin resistance and the wild-type cluster I sequence, was determined by analyzing the distribution of rpoB mutations among 80 rifampin (RIF)-resistant Mycobacterium tuberculosis strains isolated in Germany during 1997. The most frequent rpoB mutations were changes in codon 456 (52 isolates, 65%), followed by changes in codon 441 (13 isolates, 16%) and codon 451 (11 isolates, 14%). The V176F mutation was detected in one isolate of the study population and in 5 of 18 RIF-resistant strains with no cluster I mutation from six previously published studies. In three isolates, a mixture of resistant and susceptible subpopulations (heteroresistance) prohibited the detection of rpoB mutations in the initial analysis; however, in these isolates, cluster I mutations could be verified after a passage on RIF-containing medium. IS6110 DNA fingerprinting of 76 strains revealed eight clusters comprising 27 strains with identical restriction fragment length polymorphism patterns that mainly also show identical rpoB mutations and identical or similar drug resistance patterns. In conclusion, our results indicate that the V176F mutation should be included in molecular tests for prediction of RIF resistance in M. tuberculosis. We further demonstrated that heteroresistance caused by a mixture of mycobacterial subpopulations with different susceptibilities to RIF may influence the sensitivity of molecular tests for detection of resistance.