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Biomedical subjects

H Klein

Publications and source records attributed to H Klein.

At least 181 records · Page 10Linked to original sources
PubMed1991

Lack of efficacy of tranexamic acid in thrombocytopenic bleeding.

A controlled, randomized, double-blind study was performed to assess the effect of the oral antifibrinolytic agent tranexamic acid in patients with amegakaryocytic thrombocytopenia as regards their need for platelet transfusions and the number of bleeding episodes experienced. Each patient served as his or her own control and received sequential, randomized courses of either tranexamic acid or an identical placebo. The need for platelet transfusions due to bleeding and the total number of bleeding episodes were compared for tranexamic acid and placebo courses. Patients received platelet transfusions at the discretion of their personal physician and kept detailed records of bleeding episodes. Of three patients who completed the full study, none had a reduction in the need for platelet transfusions. Moreover, in the eight patients who participated in the study, there was no reduction in number of bleeding episodes during tranexamic acid treatment as compared to the number with placebo. Our data indicate that the prophylactic administration of tranexamic acid does not decrease dependence on platelet transfusions or decrease bleeding episodes in patients with bleeding due to amegakaryocytic thrombocytopenia.

Anemia, Aplastic↗
PubMed1991

Regulation of nitric oxide production by stimulated rat Kupffer cells.

Macrophages have been described to release nitric oxide (NO) as a cytotoxic radical. This highly unstable substance is as well known as endothelium-derived relaxing factor produced by vascular endothelial cells. Because of its cytotoxic activity the synthesis of NO by rat Kupffer cells, the liver macrophages, upon stimulation with endotoxin (lipopolysaccharide; LPS) and tumor necrosis factor-alpha (TNF-alpha) in combination with prostaglandin E2 (PGE2) and dibutyryl cAMP (dBcAMP) was studied. Kupffer cells were stimulated after 48 h of primary culture. NO was quantified as NO2- in the cell medium 24 h after stimulation. LPS stimulated NO generation 5- to 10-fold over the basal level. This increase could be further enhanced by PGE2 and dBcAMP, especially when added 1 h after LPS. NO generation after stimulation with LPS or LPS + PGE2 depended on the simultaneous production of PGE2 by the stimulated Kupffer cells. It could be partly inhibited by anti-PGE2 antibody or acetylsalicylic acid. While murine TNF-alpha did not stimulate NO synthesis significantly, added PGE2 raised NO synthesis about 6-fold. The addition of dBcAMP to TNF-alpha in the same concentration as with LPS, however, had no effect. Thus, stimulation by LPS + PGE2 equals that of LPS + dBcAMP whereas TNF-alpha + PGE2 does not equal TNF-alpha + dBcAMP, indicating differences in the mode of action of PGE2 on LPS- or TNF-alpha-treated Kupffer cells.

Animals↗
PubMed1991

Couvade syndrome: male counterpart to pregnancy.

Couvade is the common but poorly understood phenomenon whereby the expectant father experiences somatic symptoms during the pregnancy for which there is no recognized physiological basis. Symptoms commonly include indigestion, increased or decreased appetite, weight gain, diarrhea or constipation, headache, and toothache. Onset is usually during the third gestational month with a secondary rise in the late third trimester. Symptoms generally resolve with childbirth. Couvade has been seen as an expression of somatized anxiety, pseudo-sibling rivalry, identification with the fetus, ambivalence about fatherhood, a statement of paternity, or parturition envy. It is likely that the dynamics of couvade may vary between individuals and may be multidetermined.

Ceremonial Behavior↗
PubMed1991

[Significance of catheter ablation as emergency intervention in patients with sustained monomorphic ventricular tachycardia].

Treatment of incessant ventricular tachycardia (VT) refractory to antiarrhythmic drugs and DC cardioversion is difficult and still debated. We performed catheter ablation (CA) of sustained monomorphic ventricular tachycardias (VT) with high-energy DC shock (360-400 Joule) in 11 patients (pts) with incessant VT (duration greater than 24 h), refractory to antiarrhythmic drugs and DC cardioversion. Ten pts suffered from coronary disease and one pt from dilated cardiomyopathy. DC energy was delivered either at the site of the earliest endocardial activation (EEA) (six pts) or at the area of slow conduction (ASC) (five pts). In nine pts incessant VT could be terminated by DC ablation; two pts had to undergo emergency endocardial resection. During the mean follow-up of 31 +/- 26 (1-66) months nonfatal VT recurrences occurred in five pts with CA at the EEA and in one pt with CA at the ASC. We conclude that CA of incessant VT is an effective approach to terminate VT. However, there is a high incidence of nonfatal recurrence after CA, particularly when DC energy is delivered at the earliest site of endocardial activation.

Adult↗
PubMed1991

[Anti-tachycardia stimulation in supraventricular and ventricular tachycardia with and without cardioverter/defibrillator].

Reentry is the underlying electrophysiologic mechanism in most of the clinically occurring tachycardias. It has been known for 25 years that a reentrant circuit can be interrupted by correctly timed stimuli during programmed stimulation. Although there has been a continuous technological progress in pacemaker technology in the last ten years, application of pacemaker therapy for the treatment of atrial as well as of ventricular tachyarrhythmias did not increase significantly. Prophylactic permanent pacing preventing the onset of tachyarrhythmias has not become an accepted therapeutic approach and is still a matter of research. Antitachycardia pacing designed to interrupt a reentrant circuit uses single or multiple extrastimuli which invade the excitable gap of the reentrant circuit so that antegrade and retrograde conduction within the circuit becomes impossible. The excitable gap, however, is not a fixed electrophysiological parameter, but its width depends mainly on the influence of the sympathetic and parasympathetic nervous system. Therefore, a variety of stimulation programs delivered by the implanted pacemaker had to be invented in order to adapt to the constantly changing electrophysiologic parameters. It becomes obvious that application of burst stimulation is more effective than delivery of single or double extra stimuli and that tachycardia rate-related pacing is more reliable than fixed-rate pacing for tachycardia interruption. The most effective termination mode seems to be self-adaptive auto-decremental pacing with constantly decreasing intervals between multiple stimuli and addition of further impulses for each new termination attempt. The risk of acceleration of tachycardia or induction of non-clinical tachyarrhythmias is higher with burst-stimulation than with single or double extra stimuli. Fast tachycardia rates are more prone to acceleration than slower ones. Tachycardia detection algorithms are based mainly on rate, sudden onset and rate stability of the tachycardia. In order to reliably distinguish pathologic tachycardias from sinus or physiologic tachycardias, other than rate-detection parameters will be applied in the future. These are endocardial electrogram signal-analysis, frequency content of the endocardial signals as well as biological sensors. A prerequisite for successful permanent antitachycardia pacing is a thoroughly performed preoperative electrophysiologic study in order to identify the most reliable and effective tachycardia termination mode. This requires multiple induction of the clinical tachycardia under various conditions, different activity or posture states as well as under the influence of antiarrhythmic drugs.(ABSTRACT TRUNCATED AT 400 WORDS)

Electric Countershock↗
PubMed1990

[Serology and culture diagnosis of Campylobacter jejuni infections].

Campylobacter jejuni is known today as one of the most common pathogens in acute infectious enteritis. In 77 patients serological testing by complement fixation as well as stool cultures were performed. A campylobacter jejuni infection was identified in 53% by culture and in 64% by serology, only in 17% the diagnosis was made with both methods. We conclude, that because of these data stool culture and serological testing should be used simultaneously. The complement fixation technique shows an increase in serum titer one to three weeks after beginning of the illness and a decrease in serum titer after four to eight weeks. For this reason it is an appropriate method for the identification of acute infections.

Antibodies, Bacterial↗
PubMed1990

Synthesis of granulocyte colony-stimulating factor and its requirement for terminal divisions in chronic myelogenous leukemia.

In this paper we demonstrate that maturing neoplastic cells from patients with chronic myelogenous leukemia (CML) constitutively produce G-CSF and are also receptive for this molecule. G-CSF functions as an autocrine growth factor in stable phase CML, and thus is responsible for divisions of maturing leukemic cells leading to an expansion of the compartment of mature cells. This observation is well in line with in vivo features of CML in stable phase, i.e., the hyperplasia of the mature granulocyte compartment. In acute blastic phase of CML expression of the G-CSF gene seems to be less common and not related to autonomous blast growth.

Antigens, CD↗
PubMed1990

[Treatment of chronic hepatitis B with interferon alpha-2b].

In a prospective randomized trial 58 patients (46 men, 12 women; mean age 41 [18-65] years) with histologically proven chronic hepatitis B and demonstration of HBs antigen and hepatitis B virus DNA in serum were randomly divided into two groups: 30 patients were treated with recombinant alpha 2b interferon. The interferon was administered subcutaneously, 3 x 10(6) IU, three times weekly for four months. 28 patients served as untreated controls. There was a six-month post-treatment follow-up. Two patients in the treatment group and one in the control group had to be excluded later. In the treatment group one patient responded completely (HBs antigen, HBe antigen and HBV-DNA negative) and eight partially (HBe antigen and HBV-DNA negative). In three patients of the control group, HBe antigen and HBV DNA were no longer demonstrated (P less than 0.05). The loss of HBV features was associated with normalization of serum transaminases activity. Reactivation of liver inflammation after seroconversion was not observed.

Adolescent↗
PubMed1990

Sotalol in patients with life-threatening ventricular tachyarrhythmias.

To assess the antiarrhythmic efficacy of oral d,l-sotalol, 68 patients with sustained monomorphic ventricular tachycardia (SMVT) (n = 62) or ventricular fibrillation (VF) (n = 6) were studied by programmed ventricular stimulation (PVS). Fifty-one patients had coronary artery disease with a previous myocardial infarction and there were 17 patients without coronary disease: 11 patients had right and/or left ventricular dysplasia, one patient an aortic-valve replacement, and five patients had no visible heart disease. Prior to sotalol patients were treated with a mean of 3.6 +/- 1.3 antiarrhythmic class I drugs. None of these drugs prevented SMVT or VF. During control PVS (PVS 1), VF was induced in 8 patients (12%), SMVT in 47 patients (69%), and nonsustained ventricular tachycardia (NSVT) in 13 patients (19%). After loading with oral d,l-sotalol (320 mg/day), PVS (PVS 2) was repeated 4.2 +/- 3.3 weeks after PVS 1. In one of the patients (1%) VF was inducible, in 15 patients (22%) SMVT was induced, and in 18 patients (26%) NSVT was induced. In 34 patients (50%) either no or a short ventricular response was inducible. Our data show that oral d,l-sotalol is an effective antiarrhythmic agent in patients with SMVT or VF.

Adult↗
PubMed1990

Treatment of chronic hepatitis B with interferon alfa-2b.

A total of 58 patients with histologically confirmed chronic viral hepatitis B and presence of hepatitis B surface antigen and hepatitis B virus DNA (HBV DNA) in the serum were randomized in a prospectively controlled trial. Thirty patients were treated with 3 megaunits of recombinant interferon alfa-2b (INTRON A, R Schering-Plough, Essex Corporation) subcutaneously thrice weekly for 4 months. Twenty-eight controls received no treatment. The post-treatment follow-up period consisted of 6 months. Twenty-eight treated patients and 27 controls completed the protocol. One female patient of the treatment group showed a complete response, and eight other treated patients (32%) showed a partial response to therapy. Three patients in the control group (11%) lost hepatitis B e antigen and HBV DNA spontaneously. This finding is statistically significant (p less than 0.05). The elimination of hepatitis B virus markers from the serum was associated with a normalization of aminotransferase activities in the serum. Reactivation of hepatitis was not observed after seroconversion.

Adult↗
PubMed1990

Drinker prototypes in American society.

Based on a national probability sample of 2,401 Americans age 21 and over (1,069 of whom were deemed "drinkers" on the basis of having consumed at least one alcoholic beverage in the past 7 days), this study develops profiles of the drinker and heavier drinking prototypes for beer, distilled spirits, wine, and wine cooler drinkers. Both beer-drinking prototypes are mainly composed of less well-educated males who drink beer in circumstances unconnected with any mealtime setting. Wine drinkers are more often women (although the heavy drinking prototype is more likely to be a man), usually with education at or beyond the "some college" level, who typically drink wine in moderation with a meal such as dinner. Both prototypes of the distilled spirits drinkers are likely to be men, age 45 or over, who are not currently married, who usually drink in a bar, before a meal, when they feel somewhat happy or calm. Wine cooler drinkers are much more heterogeneous, and hence less distinguishable than the other drinking prototypes. The heavier wine cooler drinker, however, is likely to be single, with 12 or 13 years of schooling. This person usually drinks when feeling very stimulated, very happy, very romantic, or else very bored, and often does so at bars or in friends' homes.

Adult↗
PubMed1990

Effect of different body-exercise modes on the rate response of the temperature-controlled pacemaker Nova MR.

In order to evaluate the effect of different modes of physical exercise on the rate response of the temperature-controlled Nova MR, parameters such as temperature behaviour and correlation of work load to pacing rate were investigated using different types and protocols of stress testing. This study considered 21 patients (age: 66 +/- 12 y). The indications for the Nova MR were AV block (n: 14) and sick sinus syndrome (n: 7). The patients performed two different types of exercise (treadmill n: 13, bicycle n: 14) based on different protocols. We registered the surface ECG, pacing rate, exercise time, and (via data transmission by the RX 2000 programmer) blood temperature and pacing rate. An adequate rate response could be achieved with all the different types of exercise and protocols using more sensitive program settings. The type of stress testing used to adjust or evaluate the Nova MR seems to be secondary, although cycling as compared with treadmill exercise resulted in a slightly weakened reaction of temperature and pacing rate. Our investigations revealed a good correlation between work load and pacing rate independent of the type of stress testing. The initial DIP (48%) is not a constant phenomenon and showed inter- and intraindividual variations. Impressive psychological influences also exhibited an effect on temperature and pacing rate, sometimes preventing a DIP response. During exercise at lower work loads (under 50 watts, shorter than 3-4 min) the rate response of the Nova MR--without any detected DIP--is often delayed due either to a decrease or to a late and flat increase in temperature. An additional fast-reacting sensor could be advantageous in triggering the initial rate response in such cases.

Aged↗
PubMed1990

Automatic implantable cardioverter defibrillator implantation after previous open heart surgery: subcostal incision and small left anterior thoracotomy.

In order to avoid the risk of major bleeding with redo sternotomy, an alternative surgical approach for the implantation of an automatic implantable cardioverter defibrillation (AICD) is presented. A subcostal incision in combination with a small left anterior thoracotomy was used in three patients. The procedure was easy to perform, considerably shorter than a redo sternotomy and well tolerated by the patient. We recommend this approach for AICD implantation in cases with previous heart operation.

Coronary Artery Bypass↗
PubMed1990

Intraventricular migration of an ICD patch.

A 42-year-old man presented with fever and weight loss 12 months after ICD replacement. After unsuccessful search for an infected focus and a specific antibiotic treatment ICD pocket was explored and Staphylococcus epidermidis was cultured. Following generator explanation fever recurred and at a second operation one ICD patch was found to have perforated in the right ventricular cavity. Explanation of the patches was performed on cardiopulmonary bypass, the patient survived the operation and infection was eradicated.

Adult↗
PubMed1990

Late-onset globoid cell leukodystrophy: unusual ultrastructural pathology and subtotal beta-galactocerebrosidase deficiency.

An 11-year-old girl was found to have severely reduced beta-galactocerebrosidase activity as evidence of late-onset globoid cell leukodystrophy, while her mother had almost normal enzyme activity in circulating white blood cells. Clinically, the patient showed a remitting course marked by seizures, ataxia, white-matter disease on computed tomographic scan, and reduced conduction velocities of peripheral nerves. Symptoms improved somewhat around the age of 10 years. Two sural nerve biopsies, performed 6 years apart, disclosed a demyelinating neuropathy. By electron microscopy, membrane-bound vacuolar lysosomes in Schwann cells of myelinated axons, unlike the typical needlelike inclusions seen in classic infantile globoid cell leukodystrophy, were present in both specimens. Thus, clinical, morphologic, and biochemical data in this patient--and her mother--emphasize, compared with past reports on late-onset globoid cell leukodystrophy, considerable variation in the nosologic spectrum of late-onset globoid cell leukodystrophy and conspicuous differences from classic infantile globoid cell leukodystrophy.

Adolescent↗
PubMed1990

Social occasions and the perceived appropriateness of consuming different alcoholic beverages.

Based on a national probability sample of 2,401 Americans aged 21 and over (1,069 of whom were deemed "drinkers" on the basis of having drunk at least one alcoholic beverage within the previous 7 days), this study looks at differences in the perceived situational appropriateness of drinking beer, distilled spirits, wine and wine coolers in each of six social occasions. It was found that wine is usually deemed appropriate in integrative, social enjoyment-enhancing situations. Beer use tends to be viewed ambivalently, with a sort of "cross-situational neutrality"; its use is neither strongly condoned nor strongly condemned in any of the six social contexts under study. People's attitudes toward the use of distilled spirits are best described as allowing for a "cautious indulgence" in this beverage. The respondents tend to favor drinking distilled spirits during integrative social occasions, feel ambivalently toward drinking in social contexts that are simultaneously integrative and disintegrative and disfavor drinking during disintegrative and anxiety-reductive social occasions. Wine cooler use is viewed inconsistently, perhaps with a tendency toward being seen as appropriate for consumption during integrative social occasions that involve having a good time. Sex, income and marital status differences were found to be minimal. Age, though, was found to be a discerning variable in many of these relationships, such that people aged 65 or older were less likely than their younger counterparts to endorse drinking in all of the social contexts under study, except for drinking as a perfect complement to a nice dinner.

Adult↗