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PubMed1975

[Studies on the relationship of temperent phages and bacteriocines of streptococcus faecium (author's transl)].

Two bacteriocins (enterocin E1A and E1B) as well as a complete bacteriophage (PE1) were produced by Streptococcus faecium strain E1. Although the phage could be demonstrated by electron microscopy it was not possible to observe phages or phage-like particles in the purified preparation of the large enterocin E1B. Phage PE1 had a much smaller activity spectrum than that of enterocin E1A and E1B, inhibiting only one strain of Streptococcus faecium and one strain of Streptococcus salivarius. The enterocins were not neutralized by antiphage sera, thereby suggesting that the enterocins and the phage are chemically unrelated.

Animals↗
PubMed1975

[Clostridium novyi type A bacteriophages (author's transl)].

In the culture fluids and on the cells of two toxigenic strains of Clostridium novyi type A, bacteriophages were detected and confirmed by electron microscopy (Fig. 1 and 2). The heads of the bacteriophages are hexagonal and 500 A in diameter. The tails have a length of 1400 A and a diameter of 60 A. Reproduction of the bacteriophages was not yet possible owing to the lack of sensitive indicator strains.

Bacteriophages↗
PubMed2003

[Effect of human hair keratin implant on oligodendrocyte proliferation and differentiation in rats with acute spinal cord injury].

OBJECTIVE: To investigate the changes of oligodendrocyte proliferation and differentiation in response to implantation of degradable human hair keratin (HHK) into the spinal cord with acute injury in adult rats. METHOD: Rat models of acute spinal cord injury were established by direct impact of the exposed spinal cord with a weight-dropping device, 12 of which received immediate HHK implant into the injured spinal cord. The rats of control injury group (n=12) were subjected to the injury but did not receive subsequent implant, and those in sham operation group (n=12) only had the spinal cord exposure without injury. Another 8 rats were used as the normal control group. Samples of the spinal cord were obtained 1, 4, 12, and 26 weeks respectively after the operations and serial sections were prepared for examination with light and electron microscope. RESULTS: One week after the injury, few oligodendrocytes were observed among the large number of the infiltrating leukocytes in the injured spinal cord with HHK implants. Staining with hematoxylin eosin and Mallory's phosphotungstic acid-hematoxylin at the fourth week revealed oligodendrocyte proliferation around the HHK implant. The period from the 12th to 26th week was characterized by nerve regeneration and myelin sheath reconstruction, in the course of which empty cavity occurred within the sheath of the oligodendrocytes, and lamellar separation of the myelin sheath were observed. Phagocytized myelin sheath and axone fragment were detected in oligodendrocytes, with the newly generated oligodendrocytes scattering abound the rebuilt myelin sheath. CONCLUSION: HHK can be beneficial for the proliferation and differentiation of oligodendrocytes and myelin sheath rebuilding and repair in the course of neuronal regeneration after acute spinal cord injury.

Animals↗
PubMed1999

Morphological changes of rats muscles at various postmortem intervals by scanning electron microscopy.

The aim of this study was to observe the morphological changes of muscle in the process of rigor mortis. The quadriceps of 40 rats at various postmortem intervals were observed under the scanning electron microscope (SEM) and the light microscope by phosphotungstic acid-haematoxylin (PTAH) stain. The results showed that the striations of muscle were blurred within 4 h, but they became apparent from 6 h to 24 h after death. The authors suggest that this phenomenon be associated with the increased resistance of muscle against the postmortal changes. The observations by scanning electron microscopy and light microscopy have revealed that the muscles do contract in the process of rigor mortis because the distance between two Z lines shortens and the 1 band narrows, compared with those in anaesthetised animals. The basic biochemical process for the formation of rigor mortis is the same as that of muscle contraction except that the former happens postmortem and the latter antemortem.

Animals↗
PubMedDate not supplied

Cytologic study of the tissue repair cells of the uterine cervix. With special reference to their origin.

In order to characterize tissue repair cells (TR) of the uterine cervix and clarify their origin, exfoliated cells obtained after laser conization for early cervical lesions were examined. One specimen was first examined by Papanicolaou staining and then examined for epithelial membrane antigen (EMA) and vimentin by immunocytochemical staining, using a restaining method. The other specimen was observed by phosphotungstic acid-hematoxylin (PTAH) staining. Morphologic findings on TR were investigated together with the histologic findings on the wound healing process. TR were classified morphologically into three groups: stromal (STR), epithelial (ETR) and of unknown origin (UTR). Validity of this classification was confirmed by the findings of immunocytochemical staining with EMA and vimentin. These cells appeared one to eight weeks after laser conization. TR with relatively large nuclei, or atypical TR (ATR), appeared when each type of TR was most plentiful, at two to five weeks. Regarding the origins of each TR, cytologic and histologic findings could be considered to offer evidence that ETR originated with hyperplasia of immature cells of the squamous epithelium or reserve cells below the columnar epithelium. The presence of myofibrils in cytoplasm, demonstrated by PTAH staining for STR and some UTR, strongly suggested the possibility that these cells were myofibroblasts in granulation tissue.

Carcinoma in Situ↗
PubMed1991

In situ oncocytic change in association with multiple renal cell adenocarcinomas.

We report a case of in situ oncocytic change in association with two low-grade renal cell adenocarcinomas and one contralateral low-grade oncocytic adenocarcinoma. The in situ oncocytic change showed abundant cytoplasmic mitochondria confirmed by ultrastructural examination and phosphotungstic acid-hemotoxylin staining. In addition, this in situ oncocytic change expressed cytokeratin CAM 5.2 in the absence of cytokeratin AE1/AE3, as reported in oncocytic renal cell adenocarcinomas. Further study of in situ oncocytic change identified in kidneys resected for adenocarcinomas with regard to follow-up and management of the contralateral kidney seems indicated.

Carcinoma↗
PubMed1977

Cholesterol determination in high-density lipoproteins separated by three different methods.

We describe a simplified method for measuring high-density lipoprotein cholesterol in serum after very-low- and low-density lipoproteins have been precipitated from the specimen with sodium phosphotungstate and Mg2+. Values so obtained correlate well with values obtained with the heparin-Mn2+ precipitation technique (r = 0.95, CV less than 5% in 66% of the subjects studied and between 5 and 10% in the remaining ones) or by ultracentrifugal separation (r = 0.82, CV less than 5% in 80% of the subjects studied and between 5 and 10% in the remaining ones). Our precipitation technique is more appropriate for routine clinical laboratory use.

Adult↗
PubMed1990

Developmental changes in synapses of the retino-recipient layers of the opossum superior colliculus.

Changes in synaptic structure were examined in junctions of the retino-recipient layers of the opossum superior colliculus (SC) at critical developmental stages (30, 40 and 61 day-old pouch young and adult controls). Criteria of classification were the presence and direction of curvature (smile, flat, frown and irregular) and the degree of aggregation of paramembranous components (immature, intermediate and mature). The results favor the aggregation of dense components vis-a-vis curvature in the assessment of maturational changes.

Animals↗
PubMed1979

Comparison of current methods for high-density lipoprotein cholesterol quantitation.

We compared six precipitation methods for high-density-lipoprotein cholesterol quantitation with an ultracentrifugation method, the accuracy of which was improved by correcting for 4% manipulative loss in the d greater than 1.063 fractions. For purposes of comparison, the apoprotein B-associated cholesterol (average 56 mg/L) measured by immunoassay in the d greater than 1.063 fractions was subtracted. In 65 plasma samples from men, women, and children, a heparin-Mn2+ procedure with Mn2+ at 46 mmol/L produced results slightly higher (+16 mg/L), while results with Mn2+ at 92 mmol/L averaged slightly lower (-8 mg/L) than the comparison ultracentrifuge method. Results that were about 5% low were obtained by the dextran sulfate 500-Mg2+ (-25 mg/L) and phosphotungstate-Mg2+ (-31 mg/L) methods. A heparin-Ca2+ method produced results 10% high (+58 mg/L). Results by a polyethylene glycol-6000 precipitation method were 12% low (-64 mg/L). Precision was better with the two heparin-Mn2+ and the dextran sulfate 500-Mg2+ procedures, with CVs of 4%, intermediate with phosphotungstate-Mg2+ and polyethylene glycol-6000 (CV 6-7%), and poorest with heparin-Ca2+ (CV 10%). Precipitation by phosphotungate-Mg2+ appeared more sensitive to reagent concentration and temperature variations than either the heparin-Mn2+ or dextran sulfate 500-Mg2+ methods. We conclude that these precipitation methods are not equivalent, but give rise to significant systematic differences in high-density-lipoprotein cholesterol quantitation.

Adult↗
PubMedDate not supplied

Further evidence for the heterogeneity of high density lipoprotein isolates: HDL2:HDL3 cholesterol ratios and the presence of apolipoprotein B.

The ratios were compared of HDL2 to HDL3 cholesterol and the quantitation of apo B in high density lipoprotein (HDL) isolated by the heparin manganese, dextran sulfate, and phosphotungstate precipitation procedures. Thirty-two sera with varied HDL cholesterol concentration were analyzed. Heparin manganese isolates had the highest HDL cholesterol concentrations and the lowest HLD2:HDL3 cholesterol ratios, which differed further from the other isolates at higher HDL concentrations. The corresponding values for dextran sulfate isolates did not differ significantly from phosphotungstate isolates. Heparin manganese and phosphotungstate isolates did not contain apo B, but dextran sulfate isolates contained an average of nine percent of the corresponding serum concentrations of apo B, with no dependence on HDL cholesterol concentration. These differences in HDL2:HDL3 cholesterol and apolipoprotein concentrations are further evidence for the marked heterogeneity of the lipid fraction isolated by various precipitation procedures.

Apolipoproteins B↗
PubMed1985

Comparison of improved precipitation methods for quantification of high-density lipoprotein cholesterol.

We compared the standard Lipid Research Clinics heparin-Mn2+ (46 mmol/L) method and five improved precipitation methods for quantification of high-density lipoprotein (HDL) cholesterol. Three of these methods--a dextran sulfate-Mg2+ procedure, reported as a Selected Method, a modified heparin-Mn2+ (92 mmol/L) method, and a modified phosphotungstate-Mg2+ procedure--all gave similar results. Three other methods--the standard heparin-Mn2+ (46 mmol/L) method and two polyethylene glycol methods (75 g/L or pH 10 reagent at 100 g/L final concentrations)--gave slightly higher values for HDL cholesterol. Addition of NaCl or glucose to specimens did not significantly change protein precipitation. In terms of sedimentation effectiveness with hypertriglyceridemic specimens, the methods were ranked in the following order: polyethylene glycol (pH 10, 100 g/L) greater than dextran sulfate-Mg2+ greater than heparin-Mn2+ (92 mmol/L) = polyethylene glycol (75 g/L) greater than phosphotungstate-Mg2+ greater than heparin-Mn2+ (46 mmol/L).

Adolescent↗
PubMed1989

The determination of high density lipoprotein cholesterol separated by electrophoresis and sodium phosphotungstate/Mg2+ precipitation: a physical evaluation.

Epidemiologic studies show that the risk of clinically evident atherosclerosis correlates negatively with concentrations of high density lipoprotein (HDL) and the influence of different factors on variations in the concentration of HDL cholesterol. We measured HDL cholesterol by both the electrophoresis and the precipitation method, and then proposed reference intervals for HDL cholesterol, adjusted for age and sex. Our findings show that the HIDL cholesterol concentration was lowest in cord blood. The concentration increased between the ages of 1 to 15 years, but lowered between the ages of 16 to 20 years. After this age period our study shows that the HDL cholesterol levels began to rise again before leveling off between the ages of 21-30 years. There was a significant difference in concentrations of HDL cholesterol between males and females. Our findings also show that the precision of the precipitation method is better than that of the electrophoresis method. The C.V. of the within-run analysis was 4.8% vs. 10.7%, while the C.V. of the between-run analysis was 4.3% vs. 14.6%. However, a significant correlation (r = 0.77) was noted between the precipitation method and electrophoresis. The electrophoresis method can be recommended as an aid in lipoprotein phenotyping, so we suggest it as a routine clinical method for HDL cholesterol analysis.

Adolescent↗