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Biomedical subjects

A Klein

Publications and source records attributed to A Klein.

At least 253 records · Page 14Linked to original sources
PubMed1992

[Cardiac morbidity and fatalities in patients with vascular surgery. Identification of risk groups].

Incidence and type of cardiac complications in 701 patients undergoing arterial vascular surgery were prospectively investigated to identify high-risk groups. Cardiac morbidity was 10.1%. Cardiac complications were responsible for 28 deaths (57%). Using logistic regression analysis, age (cardiac morbidity greater than 7017.3%), impaired renal function (19.8%), and congestive heart failure (17.3%) were the main independent risk factors. In addition, 4 risk factors (arrhythmia, coronary artery disease, anemia, emergency surgery) showed significant individual association with cardiac complications. Cardiac morbidity increased to 27.8% in patients with more than 2 of these 7 risk factors. A further association could be demonstrated between the degree of peripheral vascular disease and cardiac morbidity, but not with the extent of the operation. Based on our results a distinction between three groups of different cardiac risk can be made. A clinical algorithm for further cardiac assessment in high-risk patients is presented.

Adolescent↗
PubMed1992

Naked megakaryocyte nuclei as an indicator of human immunodeficiency virus infection.

Compact, lobulated megakaryocyte nuclei, apparently denuded of cytoplasm (naked nuclei), have been reported to be markedly increased in the bone marrow of persons infected with human immunodeficiency virus (HIV). We have confirmed this observation and have developed a useful diagnostic index, the naked nucleus ratio, to characterize the bone marrow of individuals who are infected with HIV. The naked nucleus ratio, calculated as the average number of naked nuclei per high-power field divided by the average number of intact megakaryocytes per high-power field, has a sensitivity of 97.9% and a specificity of 96.4% for patients with HIV infection. In our patients with a 62.6% prevalence of HIV infection, the predictive value of a positive test was 97.9% and the predictive value of a negative test was 96.4%. An increase in the naked nucleus ratio above 10%, without specific changes in the bone marrow, should raise or may confirm the suspicion of HIV infection.

Biopsy↗
PubMed1992

[Spectrometry for determining hematoma duration in vivo].

Spectroreflectometric measurements in the range of 430 to 700 nm were carried out in order to check this new method with regard to its application to determine time of haematomas in living humans. For this purpose 52 cases with artificial superficial skin haematomas and 40 patients with pure "monocle-haematomas" were investigated. Wavelengths of 560 and 580 nm indicate the best results. There are significant differences in cases with "monocle-haematomas" if the age difference of the haematomas is more than two days.

Adult↗
PubMed1992

[Salvaging a mass grave from 1945--Lieberose Labor Camp of the Sachsenhausen concentration camp].

It is reported about a recovering a common grave of 577 skeletons from 1945. Investigations of the age of the victims, the cause of death etc. were carried out. There were gunshot fractures at 541 skeletons. In 93.7% out of all cases there were gunshot fractures of the skull and the cervical vertebra. Difficulties arose from root interpretations in addition to intertwinings owing to the location of the skeletons. Indications to belonging to nationality of the victims are discussed by means the results from AB0-analysis and denture works.

Burial↗
PubMed1992

[Preoperative risk assessment with the ASA classification. A prospective study of morbidity and mortality in various ASA classes in 2,937 patients in general surgery].

The value of ASA classification in assessment of perioperative risk, i.e. especially postoperative morbidity, was analyzed prospectively using the data of 2937 patients. The analysis took into account the criteria validity, reliability, and sensitivity. The incidence of post-operative morbidity after elective surgery rose from 3.9% in ASA class I to 36% in ASA class IV. Mortality was 0.6% in ASA class II, whereas 9.3% died in ASA class IV. Morbidity, mortality respectively, after emergency surgery was 10.2% in ASA class II compared to 69% in class IV, mortality 1.4% compared to 21.5%. Differences between the ASA classes were confirmed (p-value < 0.05) considering separate kinds of complications and different periods. Furthermore, ASA classification was a valuable reference to length of stay and severity of necessary therapy at the ICU.

Adult↗
PubMed1992

[Pulmonary complications following surgical abdominal interventions. Identification of various risk groups].

Incidence and type of postoperative complications were prospectively analyzed in 2280 patients undergoing gastrointestinal surgery. 6.6% had one or more pulmonary complications requiring therapeutic intervention (2.3% pneumonia, 1.6% drained pleural effusions, 1.2% atelectases). Based on univariate and logistic regression analyses, the following parameters constitute high-risk patients with regard to pulmonary complications: Elective surgery (4.3%, 61/1428): anemia (7.2% pulmonary complications), pathological blood gas analysis (9.8%), preoperative hospitalization greater than 1 week (6.3%), blood loss under operations greater than 1000 ml (10.5%), length of the operation greater than 3 h (9.7%); emergency surgery (10.4%, 89/852): upper gastrointestinal operation (16.2%), age greater than 75 (19.9%), ASA IV/V (28%), anemia (19.6%), chronic bronchitis (19%), pathological blood gas analysis (26.6%), diabetes (16.5%), heart failure (18.2%), blood loss under operation greater than 1000 ml (24.3%), length of the operation greater than 2 h (15.4%). These results allow to distinguish between different levels of pulmonary risk.

Adolescent↗
PubMed1992

Human respiratory mucins.

Human respiratory mucins are secreted by goblet cells and mucous glands of the respiratory mucosa. They consist of a broad family of complex glycoproteins with different peptides, or apomucins, corresponding to several genes located on at least three different chromosomes. Glycosylation, the major posttranslational phenomenon, is responsible for about 70-80% of the weight of mucins: it produces an extraordinary diversity of O-glycosidically linked carbohydrate chains which are expressed as several hundreds of different chains in the mucins of a single individual. The variety of mucin peptides and the diversity of carbohydrate chains probably allows many interactions, especially with microorganisms: this may be an essential factor in the defence of the underlying respiratory mucosa.

Animals↗
PubMed1991

Hydrogen-forming and coenzyme-F420-reducing methylene tetrahydromethanopterin dehydrogenase are genetically distinct enzymes in Methanobacterium thermoautotrophicum (Marburg).

A coenzyme-F420-reducing and an H2-forming methylenetetrahydromethanopterin dehydrogenase have been isolated from Methanobacterium thermoautotrophicum (Marburg). Indirect evidence suggested that the former enzyme (32 kDa) might be derived from the latter enzyme (42 kDa) by proteolysis. To test this hypothesis the gene sequence of the H2-forming dehydrogenase was determined and compared with the N-terminal amino acid sequence of the F420-reducing dehydrogenase. No corresponding sequences were found indicating that the two dehydrogenases are genetically distinct enzymes. With purified enzyme preparations it is shown that the activity of the F420-reducing dehydrogenase is inhibited in the presence of the H2-forming enzyme. This finding is discussed in terms of substrate competition.

Amino Acid Sequence↗
PubMed1991

Factor XI deficiency acquired by liver transplantation.

Factor XI deficiency (the Rosenthal syndrome), an autosomal recessive genetic defect, was transmitted to a patient after orthotopic liver transplantation. The deficiency was manifested by an isolated prolonged activated partial thromboplastin time (aPTT) after surgery. Hematologic evaluation using specific factor analysis revealed an absolute deficiency of factor XI. Stored serum obtained from the organ recipient before transplantation showed normal factor XI levels. When the liver donor's family was questioned, it was discovered that he was of Ashkenazi Jewish descent and that he had a history of bleeding after dental procedures. Before his death from intracerebral bleeding, he was documented to have an isolated prolonged aPTT value. This case shows that potentially morbid genetic defects can be transmitted by organ transplantation. It also provides evidence confirming that the liver is the only site of factor XI production.

Factor XI Deficiency↗
PubMed1991

Release of [3H]acetylcholine from the isolated rat or guinea-pig trachea evoked by preganglionic nerve stimulation; a comparison with transmural stimulation.

Basal and stimulated outflow of radioactive acetylcholine, phosphorylcholine and choline from rat and guinea-pig isolated tracheae were measured by reverse phase HPLC followed by liquid-scintillation-spectrometry. Tracheae were stimulated either by an electrical field (transmural stimulation) or by a local stimulation of the innervating parasympathetic nerves (preganglionic stimulation). Epithelium was removed in most experiments, as the epithelium inhibits acetylcholine release. The basal tritium efflux (1,600 dpm/3 min) from rat isolated tracheae incubated with [3H]choline consisted of 56% [3H]phosphorylcholine and 38% [3H]choline. Preganglionic stimulation (15 Hz, 1,200 pulses) caused a 2-fold increase in tritium outflow that was abolished by the removal of extracellular calcium or by the addition of tetrodotoxin. The stimulated outflow of tritium induced by preganglionic nerve stimulation was caused by an exclusive release of [3H]acetylcholine, whereas the efflux of [3H]phosphorylcholine and [3H]choline remained unaffected by this stimulation mode. Transmural stimulation of the rat or guinea-pig trachea, however, caused, in addition to the release of [3H]acetylcholine, the outflow of [3H]phosphorylcholine. Hexamethonium (300 mumol/l) or tubocurarine (100 mumol/l) inhibited (80%) the increase in tritium outflow evoked by preganglionic stimulation, but did not affect tritium outflow evoked by transmural stimulation. Oxotremorine reduced [3H]acetylcholine release evoked by both stimulation modes, but oxotremorine was less potent with transmural stimulation. Scopolamine (0.3 mumol/l) enhanced (120%) the release of [3H]acetylcholine evoked by preganglionic nerve stimulation indicating the blockade of an endogenous negative muscarinic feedback mechanism. Epithelium-dependent inhibition of [3H]acetylcholine release was evident with both preganglionic and transmural stimulation. The present experiments demonstrate that release of [3H]acetylcholine evoked from the isolated trachea by stimulation of the preganglionic trunk of the parasympathetic cholinergic nerves.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗