Biomedical subjects
Publications and source records attributed to J Baumann.
Specific binding of ATP to bovine serum albumin (BSA) is demonstrated employing ATP derivatives spin-labeled at either N6 or C8 of adenine ring or at the ribose moiety. Based on a 1:1 stoichiometry binding constants are in the 50-100 microM range. Binding is largely competitive with ATP or stearic acid. A small fraction of the labeled nucleotides could not be liberated by these ligands. Binding of AMP is in the millimolar range, only.
BACKGROUND: Surgery for Dukes' Stage B2 or C rectal carcinoma has a locoregional recurrence rate of 15-67%; this rate is significantly reduced when postoperative radiation therapy (RT) is given. However, RT contributes to radiation-associated small bowel injury in a dose-dependent manner. METHODS: Polyglycolic acid mesh used as an intestinal sling is able to keep the small bowel out of the pelvis during RT, thereby preventing radiation-associated small bowel injury. RESULTS: The authors reviewed the perioperative experiences and acute toxic effects of RT in 53 patients in whom the polyglycolic sling was placed from May 1985 through May 1990 during laparotomy for rectal malignancies (47 primary and 6 recurrent). There were 26 men and 27 women whose ages ranged from 34 to 88 years (mean, 64.7 years). Mild postoperative ileus occurred in most patients, and one patient had an anastomotic leak with a pelvic abscess. Bowel displacement from RT portals was confirmed using radiologic contrast studies. Forty-three patients with primary tumors have completed postoperative RT, and a mean of 5174 cGy has been administered. CONCLUSIONS: After 1-6 years of follow-up (mean, 2.1 years), eight patients have died of systemic disease. There were no cases of radiation-associated small bowel injury and only two cases of pelvic recurrence from primary rectal adenocarcinoma (5%).
Progesterone (P) facilitation of sexual receptivity in rodents has been achieved by intracranial administration to the ventral hypothalamus; the preoptic area; and midbrain areas such as central gray, mesencephalic reticular formation, and ventral tegmental nucleus. In our laboratory, by far the most effective site in rats has been the ventromedial nucleus of the hypothalamus (VMN). However, several reports of sensitivity to P in the midbrain of rats and other rodent species led us to investigate whether stimulation of the ventral midbrain of female rats might contribute to facilitation of sexual receptivity. Ovariectomized Long-Evans rats received one cannula aimed at the VMN, and another aimed at the contralateral ventral mesencephalon. P in both cannulae, following a priming dose of estradiol, caused significantly higher lordosis quotients (LQ) than blank tubes. Controls with bilateral cannulae in the VMN responded when both tubes were filled with P, but did not respond to unilateral VMN P stimulation. P in the VMN and contralateral anterior preoptic area did not result in a greater degree of receptivity than did the empty tubes. These studies indicate that although progesterone stimulation in the midbrain alone is not sufficient to facilitate receptivity in female rats with our methods, the midbrain may play an auxiliary role. P implants in the midbrain appear to facilitate receptivity in the case of VMN implant treatments that are subthreshold for stimulating lordosis. The results are discussed in light of similar studies in other rodent species, and in the context that more than one brain site may be important in the natural stimulation of sexual receptivity by gonadal hormones.
We were able reproduce typical morphological and laboratory changes of endotoxinemia in dogs and small experimental animals by administration of E. coli = 111 K58 endotoxin labelled with 99m Tc. Contrary to the literature our distribution studies in rats showed a high concentration of endotoxin in the kidney. An effective endotoxin elimination was possible by extracorporal hemoperfusion in vitro and vivo. Optimal results were achieved using immunoabsorption in combination with plasmapheresis. However, further experimental studies are necessary to clarify the problem fully.
The influence of fixation time on the ultrasound damping was investigated in vitro in both normal and altered formalin-fixed testicular tissue. By means of ultrasound spectroscopy the ultrasound damping coefficient alpha is estimated. The results of measurements in different time intervals after onset of fixation did show that in both normal and altered testicular tissue only slight changes of ultrasound damping was found. Therefore, the influence of fixation time could be neglected.
In normal and pathological testicular tissue the influence of various fixing agents (Formalin solution, Bouins solution, Hellys solution, Carnoys solution) concerning the acoustical properties of testicular tissue was examined. By means of an ultrasound spectroscopic measurement technique the ultrasound damping was registered by calculation of the ultrasound damping coefficient alpha. The results show that the most lower alpha values were obtained by fixation with formalin solution as well in normal as in altered testicular tissue. The results of fixation according to Helly, Carnoy and Bouin did show markedly differences. Therefore, the fixation of testicular tissue using formalin solution is the best way for experimental examinations of the ultrasound damping behaviour.
A phase I study with recombinant human tumor necrosis factor alpha (rhuTNF-alpha; Knoll AG, Ludwigshafen, FRG) in patients with advanced malignant disease was undertaken to evaluate drug toxicity (organ specificity, time course, predictability, reversibility, maximal tolerated dose), effectiveness, antigenicity and pharmacokinetics. TNF was administered as a test dose followed by daily i.v. infusions for 5 days, every 3 weeks (single i.v. infusion lasting 10 min, TNF dissolved in 50 ml 5% human albumin). Dosage was increased in groups of 3 or 4 patients from 0.04 mg/m2 to 0.28 mg/m2. A total of 19 patients with different cancers, including seven large-bowel carcinomas, three chronic myelogenous leukemias, three hypernephromas, two small-cell lung cancers, one malignant melanoma, one malignant lymphoma, one rhabdomyosarcoma and one fibrosarcoma were treated. Major side-effects were chills and fever (maximum 40.4 degrees C, median 38.7 degrees C, 19/19), headache (12/19), nausea and vomiting (12/19) and pronounced (greater than 20%) hypotension (4/19). Acute side-effects could be diminished by paracetamol or indomethacin pretreatment, and with one possible exception no tachyphylaxis to TNF was noted. Mild renal toxicity was seen during TNF treatment. Pharmacokinetic studies showed a serum half-life (t1/2) ranging from 11 min to 17 min for doses from 0.04 mg/m2 to 0.16 mg/m2 and prolonged clearance with t1/2 ranging from 54 min to 70 min in the 0.20-0.28 mg/m2 dose range. No objective antitumor effects were observed in this phase I study.
Measurements of the ultrasound attenuation were carried out in 10 normal testes and 20 pathologically changed testicular tissue biopsies in vitro after formalin fixation. The ultrasound attenuation as function of the frequency was recorded ultrasound-spectroscopically about the complete frequency spectrum of the ultrasound-broad range transformer (3-8 MHz). The frequency dependence of the attenuation behaviour differed in the 10 normal testes from the 20 pathologically changed biopsies by smaller values of the ultrasound attenuation coefficient a (linear regression analysis). The ultrasound attenuation in a characteristic measuring point allows the differentiation between normal and pathologically changed testicular tissue. The following comparison with the histologic evidences showed the correspondence of the results.
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One hundred seven consecutive new cases of Hodgkin disease were evaluated with chest radiography and computed tomography (CT) for initial staging. The data were evaluated with regard to five popular treatment protocols for Hodgkin disease. Thoracic CT scans were normal in 30 of 31 patients who had normal radiographs. In the remaining 76 patients, CT demonstrated 194 new sites of disease and disproved 25 suspected sites of disease. The use of CT scans changed the staging of disease in 20 patients, 16 of whom had extranodal extension. The effect of using CT findings on treatment depended on whether radiation therapy was used, and, if so, which treatment protocol was followed. The use of CT findings would have changed the treatment in 6.5%-62.7% of new cases of Hodgkin disease. The authors recommend that CT scans be obtained in all patients with Hodgkin disease, especially those with abnormal chest radiographs.
Chronic methamphetamine (MA) administration via the drinking water not only induced hyperactivity, but phase delayed the rat rest-activity cycle under entrained conditions. The minimum and/or maximum of the rhythms in eating, drinking, body weight, core body temperature and plasma/urine corticosterone were delayed. The different phase shifts of peak and trough values can also be a result of modulation in the wave form of the rhythms. The fall, but not the rise, of nocturnal pineal melatonin secretion occurred 4 hours earlier in MA-treated rats than in controls: this pattern was still present 1 week after withdrawal, but no longer after 4 weeks withdrawal. Neither chronic MA nor its withdrawal had any effect on plasma thyrotropin. These patterns after chronic MA intake fall into two groups: those rhythms whose peak and/or trough are delayed and those that are not. We thus interpret chronic MA application as modulating the eating rhythm (though not directly through rhythmic MA levels in the CNS), and that this in turn changes all food-dependent rhythms. In contrast, the circadian rhythms of melatonin and thyrotropin remain independent.
In 1984 was detected a 5 cm long worm in the eyelid of a 49 year old woman. This worm was classified as Dirofilaria conjunctivae. The woman had spent her holidays previously in Italy, Spain and Yugoslavia and in one of these countries she might be worm-infected by a mosquito bite. No further nodules were seen in the subskin after the operation and the blood control parameters remained normal. Only the persistent antibodies convey the idea of a previous worm infection. Today the patient is considered to be healthy.
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The nutritional status of 41 male patients with carcinoma of the stomach was recorded, right after admission to hospital, and was related to tumour-specific operability. The nutritional condition of most of the patients was moderately impaired. Significant differences between operable and non-operable patients were recorded from the following parameters: upper-arm circumference, haemoglobin concentration, serum albumin, pseudocholinesterase, intradermal testing, E-rosette count. The findings thus obtained provided some limited information on operability.
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Transplantation of 2 chemically (DMBA, MCA)-induced tumors into syngeneic female or male DA strain rats elicited hormonal changes during tumor growth. Plasma levels of 7 different hormones were studied. Tumor cells in syngeneic recipients produced a biphasic decrease in insulin, an early increase in prolactin, and a late-phase decrease in thyroxine. Corticosterone decreased in female tumor bearers but increased in males. This difference may reflect differences in the tumors transplanted. Male rats had a decrease in testosterone during the late phase of tumor growth, while females had a biphasic decrease in progesterone and a late-phase increase in growth hormone. The tumors used were moderately immunogenic in syngeneic recipients. However, tumor transplantation to allogeneic recipients produced an early decrease in growth hormone and no change in insulin, corticosterone or thyroxine. Further, transplantation of normal liver cells to syngeneic or allogeneic recipients produced no hormonal abnormalities. This study demonstrates that hormonal changes which are not observed with normal cells or allogeneic tumor transplantation can occur within 2 days of syngeneic tumor transplantation. Progressive tumor growth is characterized by a worsening endocrine imbalance which involves multiple hormone systems.
Studies on the combined effects of a variety of lipoxygenase inhibitors and cyclo-oxygenase inhibitors revealed strong evidence for the existence of supplementary binding sites on lipoxygenases which modify the reactions of inhibitors with the catalytic site of the enzyme. Independent of their low or non-existent inhibitory reaction at the catalytic site, compounds which interact more effectively with this putative supplementary site are capable of blunting the inhibitory efficacy of potent lipoxygenase inhibitors. Although the degree of interaction with the catalytic site determines the potency of inhibitors, an additional reaction at the supplementary site is also obligatory for inhibitory efficacy. We found that potent lipoxygenase inhibitors possess high affinities for both sites, whereas weak inhibitors and suitable cyclo-oxygenase inhibitors interact predominantly with the supplementary site on the lipoxygenase and possess low or negligible affinities for its catalytic site.
We examined a patient with advanced keratoconus and a fixed and dilated pupil prior to keratoplasty. Local iris ischemia to the sphincter muscle appears to be the most likely etiology of this abnormality.