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Biomedical subjects

W Klein

Publications and source records attributed to W Klein.

At least 343 records · Page 19Linked to original sources

Long-term treatment of hypertension with the calcium channel blocker diltiazem.

A group of 48 patients with essential mild to moderate hypertension were treated with the calcium-channel blocker diltiazem (90-270 mg/day) for one year. Adequate blood pressure control was achieved in all patients. No tolerance developed during the one-year treatment period. The drug is almost free from side effects. Very few patients develop fluid retention, which can be controlled by adding a diuretic.

Diltiazem↗

Comparative trial of lisinopril and nifedipine in mild to severe essential hypertension.

A total of 136 patients with mild to severe uncomplicated essential hypertension were evaluated in a multicenter, randomized, double-blind, double-placebo, parallel study to compare the effect of lisinopril, a new angiotensin-converting enzyme inhibitor, with that of nifedipine. Following a 2-week placebo control period the patients were treated with either 20-80 mg/day of lisinopril (n = 89) or with 40-80 mg/day of nifedipine (n = 47). Blood pressure was significantly reduced in both groups after 4, 8, and 12 weeks of treatment. There was no difference in the effect of lisinopril compared to nifedipine. No serious clinical or laboratory adverse experiences were observed during the study. The incidence of clinical side effects was significantly lower in the lisinopril group than in the nifedipine group (21.3 vs. 48.9%, p less than or equal to 0.01). There were no significant changes in laboratory data in either group. The results indicate that lisinopril is as effective as nifedipine in the treatment of uncomplicated essential hypertension and that lisinopril is well tolerated and has an acceptable safety profile.

Angiotensin-Converting Enzyme Inhibitors↗

[Diagnosis of susceptibility to malignant hyperthermia using the in vitro contracture test].

Though a malignant hyperthermia (MH) crisis is still a critical event during general anesthesia, recent developments in prophylaxis and treatment should help in avoiding fatal episodes. The best means to avoid MH episodes would be early recognition of MH susceptibility. Today the only reliable test to identify MH susceptibility is the in vitro contracture test. Thus, to diagnose MH susceptibility we performed this test on muscle biopsies from 26 individuals who: (1) had an event during general anesthesia that may have been indicative of MH (4 patients); (2) had a family member with a medical history of MH (20 patients); or (3) had unexplained elevated CK levels (1 patient). The criteria according to which patients were submitted to the testing are shown in detail in Table 1. We used the standardized version of the contracture test that has been proposed by the European Malignant Hyperpyrexia Group. Muscle biopsies (20-30 mm long, 8 mm diameter) were dissected into 8-10 small bundles (2-3 mm diameter) and tested within 3 h post-biopsy in four independent tissue baths with various concentrations of caffeine or halothane. According to the concentration of caffeine or halothane necessary to elicit contractures exceeding a predefined force threshold (20 mN), it was possible to classify the patients as MHS (MH-susceptible), MHE (equivocal), or MHN (negative). In addition to the in vitro test, clinical, laboratory, and neurophysiological data were collected from these patients and correlated with the individual test results (Table 2). Thirteen patients were classified as MHS, five were MHE, and seven patients MHN (Fig. 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Arthroscopic and surgical ligament-plasty of the knee joint].

The introduction of artificial augmentation grafts in conventional reconstruction and replacement of the anterior cruciate ligament led to work on the technique of arthroscopic implantation without arthrotomy. The advantages of this new technique are evident: less severe postoperative pain, rapid recovery, shorter stay in hospital, preservation of proprioceptive innervation and the superficial cutaneous nerves, less extensive surgery to the knee, and the availability of all options for correction if further surgery is needed. This is a preliminary report of the author's own arthroscopic surgical technique and his first experiences with the new procedure using a Dacron graft.

Arthroscopy↗

[Pharmacologic modification of diastolic ventricular function in patients with coronary heart disease].

The influence of 2 different cardiac pharmaceutics on the diastolic ventricular function (VF) in patients with ischaemic heart disease was examined. Diltiazem, a calcium antagonist, and k-strophanthine led to a reduction of time constant T of the isovolumic relaxation from 49 +/- 9 to 39 +/- 7 msec (p less than 0.005), to an increase of the quotient dt/T from 2.4 +/- 0.5 to 3.0 +/- 0.6 msec (p less than 0.01), to an increase of the peak filling rate (PFR) from 2.08 +/- 0.65 EDV/sec to 2.34 +/- 0.67 EDV/sec (p less than 0.001), to an increase of the filling fraction (FF) from 30 +/- 12% to 33 +/- 15% (p less than 0.001). The ejection fraction (EF) and the maximum rise of pressure dp/dt did not change significantly. After k-strophanthine T was reduced from 49 +/- 7 to 46 +/- 11 msec (p less than 0.05). The increase of dt/T from 2.5 +/- 0.4 to 2.7 +/- 0.4 msec was not significant. The PFR with 2.16 +/- 0.7 and 2.08 +/- 0.8 EDV/sec and the FF with 32 +/- 14 and 34 +/- 18% did not show any significant changes. The EF rose from 52 +/- 15 to 55 +/- 16 (p less than 0.05) and dp/dt rose from 1855 +/- 468 to 2124 +/- 591 (p less than 0.05). Diltiazem improves the diastolic VF without deteriorating the systolic VF in patients with ischaemic heart disease. K-strophanthine improves the systolic VF and the velocity of the isovolumic relaxation. The other variables of the diastolic VF did not show any directed changes.

Adult↗

[Acute coronary heart disease. Current status of diagnostic and therapeutic possibilities in the intensive care station].

The paper presents an overview of the recent diagnostic and therapeutic feasibilities in acute coronary heart disease. In unstable angina the leading symptoms are new onset or increasing anginal pain or resting pain as well as ST-T-changes in the ecg without a rise in enzymes. Coronary arteriography shows double or triple vessel disease (70%), a left main stenosis (10 to 15%) or normal coronary arteries (10 to 15%). The treatment of unstable angina in the CCU consists of Nitroglycerin-infusion together with calcium channel blockers and/or betablockers. With this regimen, 80% of patients may be stabilized within 24 to 48 hours. Thereafter coronary arteriography is performed to settle the further therapeutic regimen (PTCA, CABG, medical therapy). Acute myocardial infarction is characterized by persisting (more than 30 min) pain, ST-T-changes in the ecg with or without development of Q-waves indicating irreversible myocardial damage. Angiographically, usually a subtotal or total occlusion of the corresponding artery is found. Aims of therapy in acute myocardial infarction is-besides treatment of complications like arrhythmias and left ventricular failure-reperfusion of the myocardium with reopening of the occluded vessels by intracoronary or systemic thrombolysis. Recently, also clot-specific streptokinase derivates and plasminogen activators are used with fewer bleeding complications. After recanalization of the vessel a persisting stenosis should be relieved either by PTCA or CABG to avoid reocclusion. However, these active forms of treatment can only be performed, if the patient reaches the hospital within 4 to 6 hours after the onset of ischemia.

Angina Pectoris↗

Arthroscopic arthropathy: iatrogenic arthroscopic joint lesions in animals.

Damage to the articular cartilage does occur, on occasion, during the course of diagnostic arthroscopy and arthroscopic surgery. Because of this, we decided to do an arthroscopic gross and histologic study of the alterations in the articular cartilage and the underlying bone that we produced in the joints of dogs. Depending upon the instruments used and the depth of the lesion created, various types of lesions were produced in the cartilage, including track-like fissures, patch-like defects, and even superficial damage to the subchondral bone. Superficial lesions reaching only to the transitional zone were repaired by a smoothing of the edges of the defects. In the deeper lesions, repair consisted of a flat fibrous covering with sclerosis of the subchondral bone. These defects were followed for a period of 6 months, and in no case did a complete filling in occur. We realize that this animal experimental study is not a model for human osteoarthritis, but it casts some light on the importance of iatrogenic lesions of the joint. This study was carried out for the purpose of drawing attention to damage of the articular cartilage that can occur during arthroscopic surgery, especially in narrow joint spaces. These findings underline the need for responsible and effective education in the field of diagnostic and therapeutic arthroscopy.

Animals↗

Increased metachromatic cells and lymphocytes in bronchoalveolar lavage fluid of dogs with airway hyperreactivity.

Bronchoalveolar lavage (BAL) was performed in 11 basenji greyhound (BG) dogs, which showed persistent airway hyperreactivity to methacholine and citric acid aerosols, and in 15 non-BG dogs, which were significantly less reactive to these challenges. Five of the BG dogs had never received any aerosols prior to BAL, and 3 of the non-BG dogs were allergic to Ascaris suum. No dog received aerosols for 2 wk prior to BAL. Fluid recovered was centrifuged, and aliquots were taken for histamine content and cell identification. Total cell numbers were similar in BG and non-BG dogs. The BG dogs had increased percentages of lymphocytes and metachromatic cells in BAL fluid compared with those in non-BG dogs. Lymphocytes averaged 35.5 +/- 2.3% (mean +/- SEM) and 17.2 +/- 1.2% (p less than 0.005) in BG and non-BG dogs, respectively. The BG dogs that had received previous aerosol challenge and the BG dogs never challenged had 6.2 +/- 0.4% (mean +/- SEM) and 4.6 +/- 0.6% metachromatic cells in BAL. Nonallergic non-BG dogs had 0.91 +/- 0.2% and allergic non-BG dogs had 2.6 +/- 0.5% metachromatic cells in BAL (p less than 0.05 from BG). Total histamine closely correlated with numbers of metachromatic cells in BAL (r = 0.86). Forty-nine percent fewer mast cells were detected in cell preparations fixed in formalin than in cell preparations fixed in basic lead acetate. Electron micrographs revealed 2 mast cell types on the basis of structural characteristics of the granules.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Results of emergency aortocoronary bypass surgery in patients with acute myocardial ischemia after percutaneous transluminal coronary angioplasty].

From April 1980 to June 1985 7.3% (15) of 205 PTCA-treated patients required emergency operations. The spectrum of PTCA-induced ischemia included anginal pain alone (2/1, 13%) or transmural infarction (13/15, 87%) with hypotension (8/15), cardiac arrest (4/15), and severe cardiogenic shock (3/15, 20%). 14 patients underwent saphenous-vein-bypass-graft operation (ACBG) with a mean of 1.7 grafts performed per patient. The average time from onset of symptoms to completed revascularisation was 166.5 (110 to 290) minutes. Inspite of the use of IABP one hospital death (6.6%) occurred prior to the institution of ECC in a patient with previous ACBG surgery. No late death was observed during a mean follow up of 11.1 (1 to 33) months with 13/14 patients free of anginal symptoms. Retrospective assessment of postoperative serum enzyme levels of CPK and CK-MB showed evidence of myocardial infarctions in 7/14 (50%) patient. The incidence on ECG of Q-wave infarctions was 35,7% (5/14). With the exception of one patient, IABP was not used pre- or postoperatively. In patients with acute myocardial ischemia following PTCA-attempts immediate restoration of myocardial blood flow can stabilize left ventricular function and reduce the incidence and size of myocardial infarctions. The availability of emergency ACBG-surgery and facilities remain an important prerequisite of PTCA-programs due to the unpredictable natural course of PTCA-induced myocardial ischemia.

Adult↗

Long-term recording of core temperatures with chronically implanted silicon diodes.

An electronic circuit for measurement of temperatures is described utilizing silicon diodes as temperature sensors and the feature that the reverse current flow of a diode is linearly related to temperature. Once calibrated and implanted into various sites of the body core of rabbits, the diodes preserved their precise temperature sensing qualities for periods longer than a year. Temperature changes of the atlanto-occipital membrane were found to be close to simultaneously measured intracisternal temperature, both temperatures being some 0.3 degree C higher than rectal temperature. This temperature-relationship persisted under conditions with different states of cutaneous vasoconstriction and thermal panting as observed in fever and during defervescence. These results indicate that extrahypothalamic brain regions as the cerebellum and the medulla oblongata do not benefit from the proposed protective function of brain cooling during stimulation of heat dissipating effector mechanisms.

Animals↗