Hemodynamic responses to alfentanil in halothane-anesthetized dogs

Alfentanil is an opioid that has been used both as a sole anesthetic and in conjunction with other inhalation anesthetics. However, its effects on myocardial performance and regional blood flow are not clearly known. Using sonomicrometry and radioactive microsphere techniques, we examined the hemodynamic responses to alfentanil when given as a loading dose (45 micrograms/kg) followed by continuous infusion (3 micrograms X kg-1 X min-1) in dogs anesthetized with halothane. Similar plasma levels of alfentanil were observed after the loading and infusion doses, and both techniques of administration produced a significant reduction in arterial pressure without change in global or regional function of the left ventricle. Although cardiac output and left ventricular end-diastolic pressure remained unchanged, heart rate and systemic vascular resistance decreased significantly after the loading dose and recovered slightly when alfentanil was infused continuously. Despite the systemic hypotension, alfentanil did not alter perfusion to the heart, brain, muscle, and skin; however, blood flow to the renal cortex and the arterial supply to the liver decreased by 25 and 60%, respectively. Reduction in blood flow to the kidneys and the liver suggests that alfentanil should be used with caution when normal function of these organs is in question.     

Investigations on the biology,epidemiology, pathology and control of<Emphasis Type="Italic"> Tunga penetrans</Emphasis> in Brazil: I. Natural history of tungiasis in man

Tungiasis is an important health problem in poor communities in Brazil and is associated with severe morbidity, particularly in children. The causative agent, the female flea Tunga penetrans, burrows into the skin of its host, where it develops, produces eggs and eventually dies. From the beginning of the penetration to the elimination of the carcass of the ectoparasite by skin repair mechanisms, the whole process takes 4-6 weeks. The present study is based on specimens from 86 patients, for some of whom the exact time of penetration was known. Lesions were photographed, described in detail and biopsied. Biopsies were examined histologically and by means of scanning electron microscopy (SEM). Based on clinical, SEM and histological findings, the "Fortaleza classification" was elaborated. This allows the natural history of tungiasis to be divided into five stages: (1) the penetration phase, (2) the phase of beginning hypertrophy, (3) the white halo phase, (4) the involution phase and (5) residues in the host's skin. Based on morphological and functional criteria, stages 3 and 4 are divided into further substages. The proposed Fortaleza classification can be used for clinical and epidemiological purposes. It allows a more precise diagnosis, enables the assessment of chemotherapeutic approaches and helps to evaluate control measures at the community level.     

The control of sodium excretion by reflexes from the low pressure system independent of adrenal activity

An experimental increase in left atrial pressure (eLAP↗) leads to an increase in sodium excretion (UNa \(\dot V\) ). This ‘atrial natriuresis’ is probably involved in the adjustment of sodium balance, but the mechanism is not well understood. The present studies were undertaken to examine

1. the influence of eLAP↗ on plasma renin activity (PRA) and UNa \(\dot V\) in conscious dogs, and
2. the influence of eLAP↗ on UNa \(\dot V\) with and without the presence of adrenal glands.

Twenty-three female beagle dogs were kept under controlled environmental conditions. They had chronically implanted instruments (purse string around the mitral annulus, catheter in the left atrium, carotid loop; 5 dogs were adrenalectomized). PRA waselevated by a chronic low sodium intake (LSI). When eLAP↗ was performed (+1.0 kPa), PRA decreased by about 50% within at least 60 min. PRA was chronicallylowered by a high sodium intake (HSI). Even under HSI conditions a decrease of PRA could be demonstrated if eLAP↗ was performed (by about 50%). However both HSI and LSI dogs showed a marked increase in UNa \(\dot V\) if eLAP↗ was performed. After the removal of the adrenals a decrease in glomerular filtration rate was observed (40% of the control values), but eLAP↗ led to a similar increase in UNa \(\dot V\) to that found in intact dogs (Δ mean 110%). These results indicate that stretching of the left atrium leads to a reduction of tubular sodium reabsorption in a twofold manner: 1st by reduction of PRA, possibly followed by a reduction in aldosterone secretion and 2nd by activating an adrenal independent mechanism of unknown origin. This could be a direct influence of angiotensin II on the tubular reabsorption of sodium. These results are compatible with the hypothesis that reflexes out of the low pressure system are important for the adjustment of sodium balance independent of changes in mineralocorticoid activity.     

Prospective randomized clinical study in general surgery comparing a new low molecular weight heparin with unfractionated heparin in the prevention of thrombosis

A prospective, randomized, controlled clinical trial was performed comparing the antithrombotic efficacy of the low molecular weight heparin LMWH 21–23, (Braun) with an unfractionated heparin in elective general surgical patients over an observation period of 7 postoperative days. A total of 230 patients were admitted: 103 (group I) received low molecular weight heparin and 100 (group II) low-dose unfractionated heparin treatment given subcutaneously. In group I 41 patients (46%) were operated on for malignant disease and in group II 54 patients (54%). Due to the large amount of great abdominal procedures the intra- and perioperative application of hydroxyethyl starch was allowed for volume substitution. None of the patients died due to fatal pulmonary embolism. In group I four patients revealed positive ¹²⁵I-labeled fibrinogen uptake (3.9%); two patients belonged to the hydroxyethyl starch subgroup. In group II five patients displayed a positive fibrinogen uptake (5%); two belonged to the hydroxyethyl starch subgroup. The results of the hemostaseological investigations (e.g., prothrombin time, activated partial thromboplastin time, thrombin clotting time, fibrinogen, antithrombin III, protein C, plasminogen, ₂-antiplasmin , tissue-type plasminogen activator, plasminogen activator inhibitor) revealed no statistically significant differences between groups I and II or their subgroups, although a tendency to prolonged clotting times was observed. The antifactor Xa activity values, however, displayed a statistically significant difference between the two groups (P < 0.05). The antifactor Xa activity measured up to 0.16 U/ml for the low molecular weight heparin (group I) and 0.05 U/ml for the unfractionated heparin (group II) in the postoperative period. Major bleeding complications were not encountered in this study. Fundamental for the low incidence of thrombosis, the additive administration of hydroxyethyl starch appeared in almost one-third of the patients in both study groups.Abbreviations APTT activated partial thromboplastin time - aXa anti-factor Xa - DVT deep venous thrombosis - FUT ¹²⁵I-labeled fibrinogen uptake test - HES hydroxyethyl starch - LMWH low molecular weight heparin - PE pulmonary embolism - UFH unfractioned heparin     

Influence of age,comorbidity, type of operation and other variables on lethality and duration of post-operative hospital stay in patients with peptic ulcer

Three hundred and three consecutive patients operated on for peptic ulcer for the first time between 1 January 1984 and 31 December 1993 were evaluated in this retrospective study. Eleven variables (Period when operation took place, gender, smoking behaviour, history of former ulcers, ulcerogenic drug intake, ulcer location, epigastric pain, number of blood units substituted, patient's age, type of operation, comorbidity) were investigated regarding their influence on peri- and post-operative mortality and on the length of hospital stay after operation. We found that a high comorbidity score (>2) and the indication emergency operation (vs elective operation) had an adverse impact on survival. The importance of age was marginal. The duration of post-operative hospital stay in survivors was negatively influenced by age higher than 60 years, more than two red cell units substituted and a high comorbidity score according to Charlson.

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Einfluß von alter, komorbidität, art der operation und anderen variablen auf die letalität und die dauer des postoperativen krankenhausaufenthalts bei patienten mit peptischem ulkus. Eine analyse von 303 chirurgisch behandelten patienten

Zusammenfassung In dieser retrospektiven Studie wurden im Zeitraum zwischen dem 1.1.1984 und dem 31.12.1993 303 operativ behandelte Ulkuspatienten erfaßt. Elf potentielle Einflugröen (Zeitraum der Operation, Geschlecht, Raucherverhalten, Ulkusanamnese, Einnahme ulzerogener Medikamente, Ulkuslokalisation, Magenschmerz, Anzahl der substituierten Blutkonserven, Alter der Patienten, Operationsindikation, Komorbidität) wurden hinsichtlich ihres Einflußes auf die peri- und postoperative Sterblichkeit sowie die Krankenhausverweildauer untersucht. Hohe Komorbidität (>2) und die Indikation Notfalloperation (gegen elektive Operation) zeigten einen negativen Einfluß hinsichtlich des Überlebens. Dem Alter kam nur eine geringe Bedeutung zu. Die postoperative Aufenthaltsdauer wurde hauptsächlich durch hohes Alter (>60 Jahre), eine hohe Anzahl (>2) substituierter Blutkonserven und einen hohen Komorbiditätsscore nach Charlson negativ beeinflußt.

The paper contains major parts of R. J. Ricker's thesis at the University of Ulm     

Biophysical studies and anti‐growth activities of a peptide,a certain analog and a fragment peptide derived from α‐fetoprotein

Abstract: A chemically synthesized 34‐amino acid peptide, an analog, and a fragment of the peptide have been purified and studied. Biophysical studies were carried out to determine some of the metal ion binding properties of the original peptide and an analog of this parent peptide, in which the two histidine residues were replaced by alanines. As shown by visible absorption spectroscopy, Co (II) forms a complex with the parent peptide, but not with the analog peptide, and one or two histidines in the parent peptide are ligands for Co (II) ion binding. The effects on disulfide bond formation in the peptide by Zn (II) and Co (II) ions were also examined for this analog. Anti‐growth assays were performed using the original cysteine‐containing peptide with Zn (II) ion complexed to the peptide through the two cysteine residues. These rat uterine growth assays showed that the complexing of Zn (II) ion to the peptide maintained the anti‐growth activity of the peptide, while gel‐filtration experiments showed the zinc ions maintained the peptide in its anti‐growth form indefinitely in solution. A saliently important part of this research was the discovery that a fragment of the peptide consisting of a middle sequence of 14 amino acids was found to have significant anti‐growth activity in the rat uterine assay. Its activity suggested that this fragment might be considered a viable candidate for testing in anti‐cancer protocols.