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Biomedical subjects

M Schultz

Publications and source records attributed to M Schultz.

At least 91 records · Page 5Linked to original sources
PubMed1993

[Results of surgical treatment and prognosis of colonic neoplasms complicated by perforation].

Twenty two patients (13 males), whose ages ranged between 25 and 94 years, were subjected to surgical treatment for perforative carcinoma of the colon in a period of 10 years. Seventy three percent of tumors were localized in rectum and sigmoid colon. The perforation lied within the tumor in half of the patients and proximal to the tumor, specially in the cecum, in the rest. The perforation produced a local abscess in 5 patients and a diffuse peritonitis in 17 patients. Fifteen patients were subjected to segmental resections with a 40% operative mortality rate and 5 to a fecal diversion procedure with a 57% operative mortality. Tumor staging was similar to that of patients subjected to elective surgery. Crude 5 year survival was 18% and, excluding operative mortality, 57%.

Adult↗
PubMed1992

Structure of the major oligosaccharide of cobra venom factor.

Cobra venom factor (CVF), the complement-activating glycoprotein in cobra venom, contains three or possibly four N-linked oligosaccharide chains per molecule and is devoid of O-linked saccharides. Analysis by lectin-affinity staining revealed the presence of complex-type oligosaccharides containing non-reducing terminal alpha-galactosyl residues and fucose residues linked to the proximal N-acetylglucosamine. Sialic acid residues could not be detected. For their structural analysis, the oligosaccharides were released by hydrazinolysis and fractionated on Bio-Gel P-4. Approximately 80% of the eluted oligosaccharides have a size equivalent of 17 +/- 2 glucose units. The major oligosaccharide representing about 45% of the total carbohydrate present in CVF was purified to homogeneity by MicroPak AX-5 HPLC and its structure was analyzed by sequential exoglycosidase digestion. The positions of the glycosidic linkages of the sugar residues were established by methylation analysis of CVF-derived glycopeptides. The data of these analyses indicated that the major oligosaccharide has a symmetrical fucosylated biantennary complex-type structure terminating with unusual alpha-galactosyl residues.

Animals↗
PubMed1992

[Colon and rectum cancer complicated with obstruction: immediate results and long-term follow-up].

Colorectal cancer is the leading cause of large bowel obstruction in Chile. The aim of this work was to assess the immediate results and long term survival of the surgical treatment of this complication. The clinical features of 113 patients (48 male and 65 female) with a mean age of 65 years, operated in a period of 10 years, were reviewed. The follow up was made by clinic appointments or home visits. The tumor was localized in the right colon in 30 cases, transverse colon in 20, splenic angle in 14, left colon in 39 and rectum in 10. Operative mortality was 34% for tumors of the right colon and 14% form tumors of the left colon. The follow up of the 89 survivors was accomplished in 97% with a mean follow up of 54 months (range 6 months-10 years). The principal prognostic factor was the initial stage of the tumor; survival was 87% for Dukes-Turnbull stage A, 70% for stage B and 32% for stage C1. The maximal survival period for stages D was 28 months. Patients subjected to an initial resective surgical procedure fared better, although not significantly, than colostomized patients. Present tendency is to perform one surgical procedure, avoiding colostomies that worsen patients quality of life and require a second intervention that increases surgical morbidity.

Adult↗
PubMed1992

[The problems of early diagnosis of diffuse malignant mesothelioma from the pathologo-anatomic view].

An account is given in this paper of particular problems associated with early detection of mesotheliomatous alterations and differential diagnosis for their distinction from reactive mesothelial cell proliferations. Reference is made, in that context, to pathologico-anatomic experience obtained from postmortem and biopsy samples of human malignant mesotheliomas and animal experiments, following exposure to various asbestos-containing dusts. Diagnoses, such as "premesotheliomatous alteration" or "early mesothelioma", in other words, differentiation between benign and malignant, consequently, appear to be unjustified.

Animals↗
PubMed1991

Patterns of early lexical and cognitive development in premature and full-term infants.

The linguistic and cognitive development of 26 premature and 27 full-term infants was studied longitudinally over the first 3 years of life. Infants in the premature population included 12 who were below 1500 g in birthweight and an even larger number with "at risk" signs. Language samples were collected in the home approximately every other month, the children were given experimenter-designed tests periodically, and mothers were asked to keep diaries of their children's lexical development. The children were given standardized tests as they exited the study. Cognitive development was also measured periodically. The patterns of lexical and cognitive development of the prematures did not differ markedly from those of full-term infants. There were no significant differences between the prematures as a whole and the full-term infants on standard language test measures as they exited from the study. There were significant differences between the very low birthweight and full-term infants on two of the exit measures. However, the performance of the very low birthweight infants was well within the range of normal on these two measures. The nature of the study and the factors that might have led to lack of differences between the two groups are discussed.

Cognition↗
PubMed1991

Parvovirus B19 infection of the fetus. Histology and in situ hybridization.

Fetal tissues from 16 spontaneous abortions, two terminations, and one perinatal death, 18 of which were associated with maternal human parvovirus B19 infection, were examined for B19 infection by histology and in situ hybridization using a digoxigenin-labeled B19-DNA probe. In 15 spontaneous abortions and one termination, erythroblasts with intranuclear inclusions (lantern cells) reacted with B19-DNA by in situ hybridization. No internal or external fetal malformations were observed. Because 13 (86.7%) spontaneous abortions with lantern cells occurred between the 20th and 28th weeks of gestation, it is postulated that B19 infection may be a particular threat to the fetus during this stage of gestation.

Adult↗
PubMed1990

Site-specific mutagenesis of PRD1 DNA polymerase: mutations in highly conserved regions of the family B DNA polymerase.

The PRD1 DNA polymerase is a small multifunctional enzyme containing three major conserved amino acid sequences shared by family B DNA polymerases. Thus, the PRD1 DNA polymerase provides an useful model system with which to study structure-function relationships of DNA polymerase molecules. In order to investigate the functional and structural roles of the highly conserved amino acid sequences, we have introduced mutations into each of the 3 conserved regions of the PRD1 DNA polymerase. Genetic complementation study as well as DNA polymerase assay indicated that each mutation inactivated DNA polymerase catalytic activity, but not the 3' to 5' exonuclease activity.

Amino Acid Sequence↗
PubMed1990

Giant axonal neuropathy (GAN): an immunohistochemical and ultrastructural study report of a Latin American case.

Giant axonal neuropathy (GAN), a progressive childhood disorder of intermediate filaments (IF), is characterized by a peripheral neuropathy and central nervous system involvement. Twenty-eight cases have been reported while several pathogenic hypotheses have been proposed. Sural nerve biopsy of a 10-year-old Argentinian girl showed a reduced number of myelinated fibers as well as several enlarged axons up to 30 microns in diameter, thinly myelinated or devoid of myelin sheath, displaying accumulation of neurofilaments (NF), but few microtubules (MT) beneath the axolemmal membrane. There was IF accumulation in Schwann and perineural cells as well as in melanocytes, fibroblasts, pericytes, endothelial and epithelial cells in both nerve and skin biopsy. Our findings strongly support GAN as a generalized IF disorder with MT segregation from NF in giant axons. Abnormal NF phosphorylation is suggested by heavy immunostaining of enlarged axons by a monoclonal antibody to NF phosphorylated determinants (SMI 31-Sternberger's) and lack of reaction with a monoclonal antibody with different phosphoepitopes affinity (SMI 34-Sternberger's).

Axons↗
PubMed1990

Phenomenological kinetics of pharmacological response.

The evaluation and quantitative analysis of the time course of drug response are difficult tasks even in uncomplicated fields of pharmacology. In an attempt to assist the analysis of the pharmacological effect, a procedure is presented which incorporates widely used intuitive-experimental practices of evaluation, and descriptive kinetic functions. The aim is to find a simple function which can approximate the time course of the response curves at different doses. Having estimated the values of parameters for each curve, valuable information can be drawn by examining the dose-parameter relationships. The method is illustrated by one possible evaluation and interpretation of the blood pressure-time curves of a drug.

Animals↗
PubMed1990

Induction of heterotypic virus resistance in adult inbred mice immunized with a variant of Coxsackievirus B3.

Infection of adult male C3H/HeJ mice with a host range variant of Coxsackievirus B3 (CB3W-RD) induced resistance in these mice to an otherwise lethal dose of Coxsackievirus B1 (CB1). The protective effect induced by CB3W-RD was detectable as early as 1 day post-vaccination and was still present 10 weeks later. While untreated mice infected with CB1 died within 5 days because of massive hepatic necrosis, the liver was spared in mice immunized with CB3W-RD and then challenged with CB1. In general, CB1 titers in heart, liver, and pancreas of CB3W-RD-vaccinated animals were lower than that found in unvaccinated animals. Virus neutralizing antibody was not a mediator of this heterotypic, virus-induced protective effect. In addition, the outcome of CB1 infection could be modified if superinfection with CB3W-RD took place within 1-4 days following CB1 infection. In this regard, maximum therapeutic efficacy was observed when CB1 infected mice were superinfected 2 days after CB1 infection. CB1-infected mice that survived as a result of treatment with CB3W-RD exhibited liver regeneration but did develop myocardial necrosis.

Animals↗
PubMed1989

[Results of osteologic studies of medieval pediatric skeletons with special reference to the population of Anatolia].

Causes and frequency of diseases during childhood in populations of the Middle Ages were studied. The infant skeletons of ten populations from Central Europe and Anatolia were examined by macroscopical, radiological, endoscopical, histological, and scanning-electron microscopical techniques. Because only little is known about Anatolian populations, more attention was paid to the Byzantine populations. The infant skeletons are very well preserved. Therefore, the morbidity and the mortality could be studied in detail. The following disorders were diagnosed: anemia, C-avitaminosis, D-avitaminosis, osteomyelitis, meningitis-meningoencephalitis, otitis media and mastoiditis, perisinusitis, inflammation of the cavum nasi, inflammation of the paranasal sinuses, stomatitis, periodontal diseases, caries, pleuritis, trauma, and malformations. The frequency of diseases and the mortality depended on the type and the intensity of particular external life conditions. These may have been quite different in several social groups of the same population. In summary, these studies provide new information on the etiology and the epidemiology of diseases during childhood in the Middle Ages.

Age Determination by Skeleton↗
PubMed1988

Pathogenesis of acute myocardial necrosis in inbred mice infected with coxsackievirus B3.

The pathogenesis of myocardial necrosis due to CB3W infection was studied in BALB/c and C3H/HeJ mice. BALB/c mice infected with 5 x 10(4) pfu were found to die of massive hepatic coagulative necrosis before myocardial changes occurred. Reducing the inoculum size to 5 x 10(2) pfu resulted in sublethal hepatic involvement and multifocal myocardial coagulative necrosis by day 7 p.i. In contrast, C3H/HeJ mice survived infection and developed multifocal myocardial coagulative necrosis, but not liver disease following inoculation with as much as 5 x 10(6) pfu of CB3W. As with BALB/c mice infected with 5 x 10(2) pfu, myocardial lesions became apparent in C3H/HeJ mice a few days after peak cardiac virus titer was attained. Minimal inflammatory infiltrate was seen following development of cellular necrosis and was restricted to the areas of virus-induced pathologic change. However, no evidence was found for virus-specific cytotoxic T cell activity or for delayed type hypersensitivity responses. Furthermore, myocardial necrosis in CB3W-infected, T cell-depleted C3H/HeJ mice was as severe as in CB3W-infected, immunocompetent mice. These data have led us to conclude that cardiac lesions were due to virus-induced cytopathology rather than immunopathogenic mechanisms.

Animals↗