[Biologic material for closure of abdominal wall defects]

A new preparation process was studied which should allow the implantation of collagen type I in its native structure in reconstructive surgery, in this special case for closure of incisional hernias. As experimental animals we used 30 female Lewis rats. A defect of the anterior abdominal wall - measuring 3 X 4 cm - was closed with our collagen substitute. Biopsies were taken after 4, 6 and 8 weeks and examined morphologically. As criteria for revitalization and revascularisation we used type of immigrated cells, depth and density of immigration and formation of new blood vessels. After 4 weeks the implants were immigrated by fibroblasts, density diminishing towards the centre. On the muscle-implant-interface good revascularisation could be seen. After 6 weeks density of immigrated cells has distinctly increased even in the centre of the collagen implant. Sporadically small vessels could be seen. Eight weeks after implantation density of immigrated cells was at the same high level, and capillary bundles could be seen within the whole implant. We think that the studied collagen implant is suitable for the closure of hernias as shown by its physical and morphological properties. Especially it seems to guarantee an earlier and tighter closure of hernias in comparison to other materials.

[Ossification of the collagen implant]

Native collagen type I was studied morphologically and fluorescent-histologically after implantation in bony defects. As criteria for revitalisation we used depth and density of immigration, type of immigrated cells, revascularisation, formation of new cartilage and bone. Furthermore the deposition of fluorochromes was studied. The maximum of cellular immigration was reached after 8 weeks and remained at this level for the period of observation. The implants were impregnated only with fibroblasts and fibrocytes, developing into chondroblasts, chondrocytes, osteoblasts and osteocytes. Only in one case basophilic round-cells could be seen. The centres of the implants were after 6 weeks rarely, after 8 weeks fully revascularized. Formation of new cartilage and bone could be seen after 6 weeks, increasing in number and extension during the observation-period. Osteoneogenesis was performed both by desmal and enchondral ossification, enchondral ossification much more in evidence. The deposition of fluorochromes could be seen in each implant. After 8 weeks fluorochromes could only be seen at the bone-implant interface, after 12 and 16 weeks even the centres were well impregnated. In a single case reossification in a control-rib could be seen as well morphologically as fluorescent-histologically.

[Changes in plasma amino acid level as a possible tumor marker in cancers of the gastrointestinal tract]

We evaluated the free-plasma amino acid pattern in 73 healthy volunteers and 156 patients with gastrointestinal carcinomas after an overnight fast. None of the examined persons showed a sign of malnutrition or metabolic illness. Differences of more than +/- 40% in the concentrations of methionine, phenylalanine, glutamic acid, ornithine, taurine, and phosphoserine were found in cancer patients compaired to healthy volunteers. Tumorstage but not localization or grading correlated significantly with most amino acids. From our results we were able to compute a linear model of seven amino acids using computer-based stepwise discriminant analysis. This formula in the form of a tumor-index can be used as a prognostic indicator for the presence or absence of a gastrointestinal carcinoma.

A catheter system for long-term intravenous infusion in unrestrained rats

An intravenous catheter system for long-term (at least 6-8 weeks) parenteral nutrition of unrestrained rats is described. The apparatus is inexpensive and can be constructed from commonly available materials.

[Plasma amino acid pattern in gastrointestinal carcinoma]

We evaluated the free-plasma amino acid patterns of 156 patients with various gastrointestinal carcinomas at different tumor stages. As a control group, the plasma amino acid pattern of 73 healthy volunteers at different ages was determined. From out results we were able to compute a linear model of seven amino acids using computer-based stepwise discriminant analysis. This formula in the form of a Tumor-Index can be used as a prognostic indicator for the presence or absence of a gastrointestinal carcinoma.

Influence of native collagen on the cell cycle

The influence of native collagen-solutions on the cell cycle of human-fibroblasts was investigated. The results point out that the phase of cell-specific function is distinctly lengthened to the debit of a reduced rate of mitosis. That seems to be desirable, because the cells of the implantation-layer would produce more rapidly and augmentedly their cell-specific product--usually collagen--and incorporation of the implanted material would occur quite earlier. This effect seems also to be responsible for the promotion of granulation of "Dermodress", a fleece of collagen I for temporary covering of debrided areas (5).

[Treatment of non-small cell bronchial cancer with high-dosage cisplatin and vindesine. Results of a prospective study]

Thirty-seven patients with advanced, histologically confirmed non-small-cell lung cancer received combination chemotherapy with high-dose (120 mg/m2, day 1 and 29, thereafter every 6 weeks) cisplatin and vindesine (3 mg/m2, day 1, 8, 15, 22, and 29, thereafter every two weeks). All patients had measurable disease and had not previously received chemotherapy. 20 out of 37 patients responded to therapy. Two patients with adenocarcinoma, and one patient with squamous carcinoma of the lung experienced complete remission, 11 out of 37 patients partial remission, three patients a minor response, while in three patients the tumour neither remitted nor progressed. Despite chemotherapy cancer progressed in 17 out of 37 patients. Under supportive care including prehydratation, diuresis, administration of high-dose metoclopramide this aggressive chemotherapy was well tolerated. The response rate was similar to that of other chemotherapeutic regimens. The remission duration (9.5 months) and the survival time (16.5 months) are, however, somewhat better.

Stimulant and blocking effects of optical isomers of pindolol on the sinoatrial node and trachea of guinea pig. Role of beta-adrenoceptor subtypes in the dissociation between blockade and stimulation

The blocking and stimulant potencies of (-)-pindolol and (+)-pindolol were estimated on right atria and tracheae of guinea pig. Blocking affinities were estimated for beta-adrenoceptor subtypes by using several agonists. Binding affinities of (-)-pindolol and (+)-pindolol were also estimated for beta-adrenoceptors labelled with 3H-(-)-bupranolol in membranes of ventricular myocardium and lung of guinea pig. Both (-)-pindolol and (+)-pindolol caused tracheal relaxation with intrinsic activities of 0.3. The concentration-effect curve for (-)-pindolol exhibits a high-sensitivity and a low-sensitivity relaxant component; the curve for (+)-pindolol was nearly monophasic. The EC50's were (-log mol/l) 9.2 and 6.1 for (-)-pindolol and 7.6 for (+)-pindolol. Using subtype-selective blockers it was found that the relaxant effects of (+)-pindolol and those of the high-sensitivity component of (-)-pindolol are mediated through beta 2-adrenoceptors. The low-sensitivity component of relaxation of (-)-pindolol was antagonized by beta-blockers less than expected from their affinities for beta-adrenoceptors. Both (-)-pindolol and (+)-pindolol caused an increase of atrial beating rate with an intrinsic activity of 0.2. The concentration-effect curve of (-)-pindolol was biphasic; the curve of (+)-pindolol was monophasic. The EC50's were (-log mol/l) 9.1 and 7.0 for (-)-pindolol and 7.5 for (+)-pindolol. From the use of subtype-selective antagonists we conclude that the positive chronotropic effects of (+)-pindolol are mediated predominantly by beta 2-adrenoceptors. On the other hand, the high-sensitivity component of the positive chronotropic effects of (-)-pindolol appears to be mediated predominantly through beta 1-adrenoceptors, although beta 2-adrenoceptors may also participate. The low-sensitivity component of the positive chronotropic effects of (-)-pindolol is resistant to blockade by subtype-selective antagonists at concentrations causing at least 98% beta-adrenoceptor occupancy. Only high but non-depressant concentrations of non-selective (-)-bupranolol antagonized the low-sensitivity component of (-)-pindolol. (-)-Pindolol antagonized the effects of several agonists to similar extent in both trachea and right atrium. (+)-Pindolol was less potent as antagonist of the relaxant effects of (-)-noradrenaline on trachea than against those of (-)-adrenaline, (-)-isoprenaline and (+/-)-salbutamol.(ABSTRACT TRUNCATED AT 400 WORDS)

[A model for long-term parenteral feeding in the rat]

A model has been developed for the intravenous feeding in unrestrained rats, with use of simple technique and nutritional solutions, available in every hospital. The major survival time is 6-8 weeks. During the parenteral nutrition the rats gain weight and are in a excellent general health. The cumulative nitrogen balance is with a 95% retention highly positive.

[Catheter-related complications in long-term or ambulatory parenteral feeding]

Catheter-related complications represent the major risk in parenteral nutrition. The evaluation of 115 patients with a total of 16 836 days of mainly home parenteral nutrition showed 19 infected and 21 noninfected complications. Among these were two thromboses of the superior vena cava which had to be cleared surgically. Related to one year of parenteral nutrition the rate of infected and non-infected complications was 0.87 cases. There was no correlation between the duration of parenteral nutrition and the frequency of catheter-related septicaemia. Apart from the material used for catheters and a standardised technique of implantation and care the meticulous selection of patients is decisive for a low rate of complications.

[Metabolic consequences of parenteral nutrition in tumor patients]

Between 30 and 60% of all carcinoma patients are already in deficient nutritional status at the time when diagnosis of the disease is established. The pathogenesis of this deficit is multifactorial. Increased caloric needs as caused by the malignoma as well as loss of adaptability of the tumor patient to reduced nutritional intake may be decisive factors. Effective parenteral nutrition is possible before, but only rarely during oncological therapy. Prospective studies have shown up to now only in tumor surgery but not in patients treated only with chemotherapy or with radiation therapy of malignoma that adjuvant parenteral nutrition may improve the results of treatment as determined by prolongation of life. The role of parenteral nutrition as an adjuvant therapeutic step in oncology has to be defined more clearly in the future, as is the case with most other adjuvant therapeutic measures.

[Life-threatening infections after splenectomy--the overwhelming post- splenectomy infection syndrome]

About 2.5% of the patients, on whom splenectomy is done, die later from fulminant bacterial infection. This particular late sequelae usually occurs within 5 years after surgery, however, - especially in adults, - it has been observed also decades after splenectomy. Pneumococci have been identified as infectious agents in about 70% of the cases concerned. This syndrome is caused by deficient clearance of bacteria, which is due to reduced phagocytosis, decreased IgM-production, disturbances of the complement system and lack of tuftsin. Prevention of this syndrome may be achieved by using surgical procedures saving part of the spleen, by appropriate use of antibiotics and by vaccination against pneumococci.

Vitamin A effects on hepatic Golgi apparatus architecture

Effects of dietary vitamin A deficiency and excess on Golgi apparatus architecture were determined for livers of male CDF rats. In deficient animals, Golgi apparatus stacks were reduced in diameter and characterized by small, often highly fenestrated, saccules. Total membrane surface occupied by Golgi apparatus membranes also was less. Golgi apparatus of livers of animals receiving vitamin A in excess were more variable ranging from nearly normal appearance to much larger than normal. Saccules were larger and lacked the numerous fenestrations shown by Gol;gi apparatus of vitamin A deficient animals. Numbers and appearance of secretory vesicles and total number of small vesicular profiles were unaffected by vitamin A status of the animal. Unusual cisternal configurations were encountered much more frequent at the mature face of Golgi apparatus of animals fed vitamin A excess than in animals receiving adequate vitamin A and were absent from Golgi apparatus of animals receiving no vitamin A. Except for slightly swollen mitochondria and a loss of the "zone of exclusion" surrounding the nucleus, both observed in vitamin A excess, the Golgi apparatus response was the only ultrastructural alteration in liver that responded consistently to changes in vitamin A status.

Psychophysical tuning functions for brief stimuli: preliminary report

Observations from clinical and research applications of brain stem evoked response audiometry and electrocochleography have suggested that tone bursts of only a few milliseconds' duration can elicit frequency specific responses. Because such brief stimuli are not perceived as being total, the extent to which the auditory system can "tune" to such stimuli was questioned. In order to investigate this question, psychophysical tuning functions were determined for brief tone bursts (i.e., 1. to 2 msec. duration). The results suggest that in working near normal thresholds (and therefore at relatively low sound pressure levels), brief tone bursts do yield rather frequency specific information. However, the range of sound pressure levels of the stimulus for which the tuning is resonably sharp is limited. the tuning functions show signs of deterioration, particularly in the "tip region," with only modest increases in the sound pressure level above threshold (i.e., typically with 20 dB.). Differences also may be seen between tuning functions for these very brief tone bursts, which in turn are characterized by a so-called click pitch, and those of stimuli long enough to have tonal pitch (i.e., 20 msec.). Finally, tuning functions also were examined for click stimulation, which also revealed some degree of tuning at relatively low levels of stimulation.