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Biomedical subjects

K Scholz

Publications and source records attributed to K Scholz.

At least 37 records · Page 2Linked to original sources
PubMed1994

Structure of hydrated layers on silicate electrode glasses.

The structural changes of the silicate framework in hydrated layers of silicate electrode glasses compared with untreated glasses as well as the quality and quantity of water and its ionic species stored in the layer have been investigated by high-resolution solid-state nuclear magnetic resonance (NMR) techniques [29Si magic-angle spinning (MAS), 29Si cross-polarization (CP) MAS, 1H high-speed MAS, 1H CRAMPS and 1H Echo NMR]. To support the results, infrared (IR) spectroscopy, thermal analysis and sodium ion concentration analyses were used. It was found that at least two different water species exist in the hydrated layer: SiOH groups and not very mobile hydrogen-bonded molecular water. Concerning the framework modified, Q3 groups [(SiO)3SiOH] were formed in the hydrated glass. During the swelling process a condensation of silanol groups formed took place to a great extent.

Electrodes↗
PubMed1993

[The effect of different autotransfusion procedures on the antibiotic picture. A study on cephalosporin cefamandole].

Infection after open heart surgery is a serious complication since eradication of infection in these cases is difficult even with appropriate antibiotic therapy. In the attempt to avoid this problem, prophylactic administration of antibiotics is common. Their relative safety and their broad spectrum of activity make cephalosporin antibiotics popular choices for prophylaxis prior to and during operations, including cardiovascular procedures. METHODS. Preoperative antibiotic prophylaxis with 2 g cefamandole was performed in a prospective randomized study including 62 male patients divided into three groups. All patients gave informed consent, and the study was approved by the ethics committee of the hospital. Patients in group 1 (n = 21) and group 2 (n = 21) underwent aortocoronary bypass (ACVB) with extracorporeal circulation (ECC), while patients in group 3 (n = 20) had carotid surgery. Anaesthesia, coronary-bypass procedures and infusion regime were standardized. The flow rate during ECC was maintained at 2.41/min/m2 and the rectal temperature between 33 degrees and 34 degrees C. Arterial and urine specimens for the determination of plasma and urine levels of cefamandole were taken at definite times. Autologous blood salvage during operation was performed with haemofiltration techniques (HF) in group 1 (HF 80, Fresenius, Bad Homburg, Germany) and with cell separation techniques (CS) in group 2 (Hemonetics III, Hemonetics). Plasma and urine cefamandole levels were measured by high-pressure liquid chromatography (HPLC). RESULTS. After administration of 2 g cefamandole mean peak levels of 404.6 +/- 141.7 micrograms/ml were seen. Because of haemodilution at the beginning of extracorporeal circulation, group 1 and 2 showed much lower cefamandole plasma levels, 22.1 +/- 11.6 micrograms/ml and 24.3 +/- 14.4 micrograms/ml, than group 3 (after the same time course), with 47.4 +/- 19.1 micrograms/ml. For all patients in group 1 and 2 prebypass time (70.3 +/- 22.4 min) and the duration of the ECC (72.3 +/- 17.7 min) were comparable. There was a significant correlation between prebypass time and cefamandole plasma levels at the beginning of extracorporeal circulation (P < 0.001). No correlation could be seen for the plasma concentration after discontinuation of the extracorporeal circulation and the duration of extracorporeal circulation. The volume of autologous red packed cells and the enclosed amount of cefamandole showed a significant difference (P < 0.001) between group 1 (1120.0 +/- 296.8 ml, 27.5 +/- 17.1 mg) and group 2 (734.3 +/- 186.6 ml, 2.9 +/- 3.2 mg). The plasma cefamandole level after transfusion of autologous blood displayed a significant correlation (p < 0.01) with cefamandole concentration in the autologous red packed cells. Transfusion of the autologous blood produced no significant increase in plasma cefamandole levels. With an operation time of more than 2.5 h during ECC the cefamandole plasma level decreased below the necessary minimal inhibitory concentration (MIC90), particularly for gram-negative bacteria. CONCLUSION. Additional administration of 1 g cefamandole shortly before the beginning of cardiopulmonary bypass is recommended, particularly for surgical procedures with ECC of more than 2.5 h. Adjustment of drug dosage prior to or during surgery may be required to optimize therapy, but before this can be achieved precisely, more information on drug disposition during the operative procedures is needed.

Aged↗
PubMed1988

Serotonergic and serotonin-accumulating neurons in the goldfish retina.

Autoradiography of goldfish retinas incubated in micromolar levels of 3H-serotonin displayed 3 kinds of labeled somas in the inner nuclear layer: S1 amacrine cells with heavy labeling, large somas, and a sparse distribution (approximately 93/mm2); S2 amacrine cells with moderate labeling, smaller somas, and a denser distribution (approximately 500/mm2); and a subset of bipolar cells with light labeling, small somas, and a very dense distribution (approximately 4000/mm2). Serotonin-like immunoreactivity was observed only in S1 amacrine cells and their synaptic terminals. Radiolabeled terminals in the inner plexiform layer formed 4 strata that were differentially assigned to the 3 cell types. S1 amacrine cells arborized in sublayers 1 and 5, received inputs from type a1 bipolar cells and amacrine cells, and made synapses on other amacrine cells, type a1 bipolar cells and unidentified processes. Thus, S1 amacrine cells seem to receive significant input from "off-center" pathways. S2 amacrine cells arborized in sublayer 3 and made synapses onto amacrine cells. Labeled bipolar cell terminals were exclusively located in sublayer 2 and were identified as type a2 mixed rod-cone bipolar cells. We conclude that the S1 amacrine cell is truly serotonergic and that radiolabeling of S2 amacrine cells and type a2 bipolar cells is due to cross-specificity for another carrier or processes unrelated to their neurochemical identities. These observations partially reconcile many previous observations on the types, numbers, and synaptologies of teleost retinal neurons identified by different markers for indoleaminergic transmission.

Animals↗
PubMed1987

The nervus terminalis ganglion in Anguilla rostrata: an immunocytochemical and HRP histochemical analysis.

Immunocytochemistry and retrograde horseradish peroxidase (HRP) transport were used to study the ganglion of the nervus terminalis in the American eel, Anguilla rostrata. Luteinizing hormone releasing hormone (LHRH) like immunoreactivity was found in large, ganglion-like cells located ventromedially at the junction of the telencephalon and olfactory bulb and in fibers within the retina and olfactory epithelium. HRP transport from the retina demonstrated direct connections with both the ipsi- and contralateral populations of these ganglion-like cells. Given the well-documented role of both olfaction and vision during migratory and reproductive phases of the life cycle of eels, the robust nature of a nervus terminalis system in these fish may present a unique opportunity to study the behavioral correlates of structure-function organization in a discrete population of ganglion-like cells.

Anguilla↗
PubMed1987

A case of pneumonia caused by Legionella pneumophila serogroup 8 in West Germany. Etiological diagnosis by immunofluorescence, enzyme immunoassay, and immunoblot.

The severe and complicated course of a Legionella pneumonia in an 18-year-old female patient is reported. The serogroup 8 of Legionella pneumophila was identified as the infecting agent for the first time in West Germany. The etiological diagnosis was confirmed by immunofluorescence, enzyme immunoassay, and immunoblot. We emphasize the importance of serological testing of all Legionella pneumophila serogroups available.

Adolescent↗
PubMed1980

Unusual behaviour of SPO1 DNA with respect to restriction and modification enzymes recognizing the sequence 5'-G-G-C-C.

SPO1 DNA contains only 5 cleavage sites for restriction enzymes which recognize and cleave the sequence 5'-G-G-C-C (HaeIII or BsuR). Fragments of SPO1 DNA cloned in E. coli to substitute 5'-hydroxymethyluracil (HMU) by thymine (T) remain resistant to HaeIII indicating that this unexpectedly small number of cleavages by HaeIII is not correlated with the presence of HMU in the normal phage DNA. It was previously shown that SPO1 is neither subject to B. subtilis R restriction (Trautner et al., 1974) nor modification in vivo (Günthert et al., 1975). We now show that SPO1 DNA can however be restricted and modified in vitro.

Bacteriophage lambda↗
PubMed1978

[Assessment of the proteins in crill meal and lucerne meal extract].

In a feed test with rats lucerne meal extract and crill meal were used as protein sources in order to test their quality in comparison to casein. On the basis of the applied criteria, feed conversion, protein efficiency ratio productive protein value and efficiency of the gross energy we can conclude that lucerne meal extract alone is unsuitable to cover the protein requirement of growing rats. Lucerne meal extract can be supplied particularly on a higher protein level if casein is given in addition. Crill meal as protein source proves to be superior to casein concerning feed conversion and inferior concerning protein accumulation. In this case, complementary doses of casein did not lead to better results.

Animals↗
PubMed1977

[Influence of the age of old primiparae on the perinatal infant morbidity and mortility (author's transl)].

157 old primiparae (greater than 30 a) have been compared to a randomised control group of primiparae between the 16th and 30th year of age. In addition to the perinatal infant mortality rate, the number of children with malnutrition, the frequency of premature babies, the presence of a low Apgar score (less than or equal to 7) and pathological pH-values in the umbilical artery (pH less than or equal to 7,10) were cheked. Moreover the frequency of early neonatal morbidity (presence of one of the following criteria: 1 minute Apgar score less than or equal to 7, pH of the umbilical artery less than or equal to 7, 10, a transitoric or severe RDS and neurological complications during the newborn period) was investigated in both groups. In the group of the old primiparae a significantly higher perinatal infant mortality rate was found compared to the control group (3,8% versus 0,6%, p less than 0.05). The rate of small for date babies was remarcably higher than in the control group (14,6% versus 6,4%, p less than 0.05). There was no difference in the prematurity rate in both groups. The children of old primiparae had more frequently a low Apgar score (less than or equal to 7) than infants of the randomised control group (18,5% versus 11,5%), but the difference is statistically not significant. Furthermore no difference in the number of pathological pH values in the umbilical arteries (pH less than or equal to 7, 10) were found in the both groups. The children of old primiparae show a higher early neonatal morbidity rate compared to the control group (21.7% versus 14.0%); however, the difference is statistically not significant. According to our results the risk for the newborns is increased already with primiparae over 30 rather than 35 years of age.

Adult↗
PubMed1977

[Cold preservation of human sperm].

The authors report the development and investigation of a new technique for freezing and storage of human spermatozoa. Utilizing isolated container of different kind the average rate of freezing was between 1,3 grd/min and 14 grd/min in the sphere from 5 degrees C to--10 degrees C and between 2,9 grd/min to 55 grd/min in the sphere from--10 degrees C to--60 degrees C. The technical expense was low. Semen specime were provided by 33 andrological patients. A total of 53 samples of human semen were frozen and stored for periods of time up to 25 days. The authors used the cryoprotective medium from Behrman and Sawada. The best results were obtained in the mode of freezing at 2,8 grd/min respectively 12 grd/min in ejaculates of original motility about 80%. The recovery of motility and fertilizability of spermatozoa was 50% of original motility, in cases of oligospermia only 34%. The results of this new technique of freezing and storage of human spermatozoa are similar to other new reports in literature.

Freezing↗
PubMed1975

[Vitamin b6 depletion in women with hyperemesis gravidarum (author's transl)].

The serum pyridoxal 5-phosphate (vitamin B6) level was measured in 20 women with hyperemesis gravidarum before and after therapy with vitamin B6. Control specimens were obtained from 22 healthy pregnant, women during the first trimester, 18 healthy prgnant women during the last trimester and from 29 healthy non-pregnant women of comparable age. The determinations were performed by means of decarboxylation of L-tyrosine-1-14 C.

Female↗
PubMed1975

[The significance of radioimmunological HPL determination in obstetrics (author's transl)].

The serum HPL level was studied in normal and high-risk pregnancies. 30 patients with premature labour showed significantly decreased levels. In 24 patients with monosymptomatic toxaemia, HPL patterns showed a statistically significant deviation from the normal standard curve; a highly significant decrease was observed in 23 cases of polysymptomatic gestoses. As opposed to the results of other authors, no significant difference from the normal distribution of HPL was found in cases of Rh sensitisation (13 patients) and diabetes mellitus (16 patients). A noteworthy results was seen in 19 cases of cervix insufficiency: after purse-string suturing of the cervix (original method of Shirodkar), the previously low plasma HPL level rapidly rose to normal levels. Because of the small number of cases without an adequate control group this phenomenon cannot be attributed with certainly, as yet, to the cerclage procedure.

Blood Group Incompatibility↗