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Biomedical subjects

S Richter

Publications and source records attributed to S Richter.

At least 127 records · Page 7Linked to original sources
PubMed1994

A new CCK-B/gastrin receptor antagonist acts as an agonist on the rat pancreas.

The new CCK-B/gastrin receptor antagonist PD 136450 is of potential value in treating neurologic and psychiatric disorders. We investigated possible side effects on the rat pancreas using acute and chronic administration schedules. In chronic experiments, four groups of rats were given either PD 136450, the proton pump inhibitor BY 308 (in order to induce hypergastrinemia), a combination of both, or control solutions over 14 d. Pancreatic growth, DNA, and protein content were significantly increased in rats given PD 136450 irrespective of circulating gastrin levels. Furthermore, an anticoordinate shift in pancreatic enzyme content in favor of trypsin and chymotrypsin at the expense of amylase and lipase was observed. Plasma CCK levels remained unchanged in this group making a role of circulating hormone unlikely. In order to investigate a possible direct agonist effect of the CCK-B/gastrin receptor antagonist, we studied amylase release from isolated rat pancreatic acini in response to PD 136450 and sulfated CCK8 alone and in combination with the specific CCK-A receptor antagonist MK 329. Increasing concentrations of PD 136450 caused a monophasic dose-response curve in contrast to the well-known biphasic amylase release in response to CCK8. Addition of increasing doses of PD 136450 to a concentration of CCK causing maximal stimulation of amylase release (0.1 nM) further enhanced amylase release from pancreatic acini. The specific CCK-A receptor antagonist MK 329 dose-dependently inhibited CCK8- and PD 136450-induced amylase release. In conclusion, the new CCK-B/gastrin receptor antagonist PD 136450 exhibited profound agonist actions on the rat pancreas mediated via CCK-A receptors.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1994

Betacyanins from bracts of Bougainvillea glabra.

Betacyanins from the bracts of Bougainvillea glabra were isolated and characterized by a combination of spectroscopic techniques (DAD-HPLC, NMR, LC-MS, GC-MS, electrospray MS, tandem MS) as gomphrenin I (betanidin 6-O-beta-glucoside) and various derivatives of bougainvillein-v (betanidin 6-O-beta-sophoroside), i.e. mono- and diglucosylsophorosides which are acylated with 4-coumaric and caffeic acid (mono- and diesters). Besides the betacyanins, B. glabra bracts accumulated large amounts of flavonols (kaempferol and quercetin conjugates) reaching ratios of flavonol to betacyanin of 1:1.

Betalains↗
PubMed1993

[Is it possible to establish a constant physician/nurse team at an emergency department of internal medicine?].

In order to obtain better continuity in the contact between the patient and doctors/nurses during hospitalization in a medical department, small teams of nurses and doctors were established, so that the patients were attached to their personal doctor and nurse. In nearly three-fourth of the weekdays the patients saw their personal doctor and nurse. We conclude, that within the Danish public health care system and according to the contractual agreements it is possible to establish small doctor/nurse teams and by this to obtain a high continuity during daytime.

Continuity of Patient Care↗
PubMed1993

[Does the patient obtain close contact with the hospital physician when a physician/nurse team is established?].

The contact between patients and doctors was examined having established smaller doctor/nurse teams to take care of the same seven to eight patients during the weekdays of their stay at hospital. Ten weekdays after their admission to hospital 63% of the patients had not had contact with any other doctor(s) than their personal doctor(s), and 70% of the patients had seen only two different doctors. During the same period the doctors saw their patients three times on an average. We conclude that organizing the hospital doctors in small teams is a way to obtain good continuity in the contact between the patient and the hospital doctor.

Communication↗
PubMed1993

Proximal and distal reaction times (RTs) are not differentially affected in Parkinson's disease.

The hypothesis was tested that proximal and distal reaction times (RTs) might be differentially affected in Parkinson's disease (PD). Twelve patients with PD were compared with 12 age-matched healthy controls on tests of finger-, hand-, leg-, and torso-RTs. Patients were significantly slower in initiating all movements and were slower in executing all movements except for the leg (stepping) task. Choice- versus simple-RTs were also not differentially affected in the PD group. In the healthy subjects, age was significantly positively correlated with response initiation times (RITs) but not with movement times (MTs).

Aged↗
PubMed1993

Changes of natural killer cells during acute psychological stress.

Emotional stress is often followed by increased susceptibility to infections. One major role in the immediate immune response to infection is played by natural killer (NK) cells. This study was designed to establish whether acute psychological stress influences cellular immune functions and to elucidate the role of endocrine parameters as potent mediators of stress induced alterations of the immune system. Forty-five first-time tandem parachutists were examined continuously for their plasma concentrations of cortisol and catecholamines from 120 min before to 60 min after jumping. Lymphocyte subsets, NK activity, and ADCC were determined 2 hr before, immediately after, and 1 hr after jumping. There was a significant increase in sympathetic-adrenal hormones during (adrenaline, noradrenaline) and shortly after jumping (cortisol). Lymphocyte subsets and the functional capacity of NK cells revealed an increase immediately after jumping followed by a decrease significantly below starting values 1 hr later. These changes were significantly correlated to plasma concentrations of noradrenaline. Thus, quick mobilization of NK cells is suggested as one major mechanism for this effective adaptation of the immune system to stress situations.

Acute Disease↗
PubMed1993

Efficacy of transurethral hyperthermia in benign prostatic hyperplasia.

From February 1990 through May 1991, 37 patients with benign prostatic hyperplasia were treated by transurethral hyperthermia according to two different protocols. In group I, 10 patients with an indwelling catheter underwent six one-hour sessions twice a week for three weeks, at a temperature of 43 degrees C. The 27 patients from group II (11 with indwelling catheter) had two sessions of two hours each for one week, at a temperature of 44.5 degrees C. Prostatic volume, Madsen symptom score, two estimates of peak flow, average flow, and residual urine measurements were recorded before treatment and one week, one month, six months, and one year after completing the sessions. Hyperthermia was applied through a metal ring, which was used both for heating and temperature control, mounted on a 16-F Foley-Tieman-like catheter. The follow-up period was five to fifteen months. From those who had an indwelling catheter, 5 of 10 patients (50%) from group I and 8 of 11 patients (72.7%) from group II regained spontaneous micturition and continued to void satisfactorily throughout the follow-up period. Nine of 16 patients without catheter (56.3%), showed objective and subjective improvement. Transurethral hyperthermia is a new, simple, noninvasive, and well-tolerated method for the treatment of benign prostatic hyperplasia.

Aged↗
PubMed1993

[Life expectancy of clinically occult breast cancer. Study of a comparative patient sample since 1975].

We have been observing 2 groups of 50 female patients with occult or clinical breast cancer each of whom was initially treated at the Gynaecologic Hospital of the University of Erlangen-Nürnberg between 1975 and 1978. During the follow-up period, 2 patients out of the group of occult cancer and 13 out of the group of clinical carcinoma died of their primary disease. Four women out of the group of occult cancer and 3 from the group of "clinical carcinoma" have developed recurrences. The differences in survival times according to Kaplan-Meier are immense, even if they are not significant owing to the small number of patients. But it is difficult to obtain and to evaluate larger groups of patients and longer follow-up periods due to the low percentage of occult cancer (7.7 to 10.5% only). There are 30 women out of the group of occult breast cancer living without relapse after an observation period up to 15 years. 27 patients out of the group of "clinical cancer" have not shown any evidence of recurrence up to now. This small difference after such a long follow-up period can be explained by the general life expectancy and by the age at initial treatment.

Adult↗
PubMed1993

Psychophysiological, neuroendocrine and cellular immune reactions under psychological stress.

Emotional stress is often followed by increased susceptibility to infections. Natural killer (NK) cells play a major role in the immediate immune response controlling this susceptibility. In this study on 45 first-time parachutists, it is demonstrated that highly controlled psychological stress increased psychophysiological variables, enhanced the secretion of sympathetic-adrenal hormones and also led to a significant increase of NK cells and their cytotoxic activity followed by a decrease below starting values. This immunological alteration is correlated with the secretion of noradrenaline during the emotional strain. Quick mobilization of these cytotoxic effector cells is suggested as a major mechanism for the effective adaptation of the immune system to stress situations.

Adult↗
PubMed1993

Expression of engrailed can be lost and regained in cells of one clone in crustacean embryos.

In three species of higher crustaceans (Malacostraca) the expression of engrailed has been analysed in relation to the development of the cell division pattern in the germ band. The species differ in the timing of initial en expression. Compared to Cherax destructor and Neomysis integer the onset of en expression in Orchestia cavimana is delayed and appears one cell cycle later. In Cherax and Neomysis cells of the posterior margin of early en stripes lose en expression. This phenomenon does not occur in Orchestia. In a second step the en stripes widen both by division of en positive cells and de novo expression at the posterior margin of the en stripes. The widening phase is similar among all investigated species. In Cherax and Neomysis the cells with de novo en expression are derivatives of cells, which have ceased to express en one cell cycle before. The results in higher crustaceans suggest that neither initiation nor maintenance of en expression is controlled by lineage restrictions and that early en expression is not clonally transmitted. Furthermore, some aspects of boundaries and fields in embryos are discussed.

Animals↗
PubMed1992

Safety of transrectal prostatic biopsy through double-glove technique without antibiotic prophylaxis.

We studied 143 men who underwent transrectal prostatic biopsies using the double-glove technique. No patient received any antimicrobial therapy before the procedure. Clean catch urine cultures were obtained at admission and two, four, and twenty-four hours, and two weeks after biopsy. Aerobic and anaerobic blood cultures were performed at admission, and at thirty minutes and four hours after the procedure. In addition, clinical parameters were monitored closely in the hospital for twenty-four hours after the biopsy. A total of 132 patients were considered evaluable. Temperatures of 37.6 degrees C or higher occurred in 3.8 percent of the patients. In no case was rigors recorded. In 4 of the patients studied (3%) post-biopsy urine cultures were infected with Escherichia coli. All post-biopsy blood cultures, both aerobic and anaerobic, were negative. Our data indicate that with the use of the double-glove technique, prophylactic administration of antibiotics is not necessary to prevent the infectious complications following transrectal biopsy of the prostate.

Aged↗
PubMed1992

Treatment of benign prostatic hyperplasia causing complete urinary retention through local transurethral hyperthermia.

A new technique is described for the treatment of benign prostatic hyperplasia with local hyperthermia applied transurethrally by an electromagnetic wave generator. A series of 72 treatment sessions given to 16 patients sustaining an indwelling catheter is reported. The patients were divided into two groups. Group 1 consisted of 10 patients who received 60 treatment sessions (six 60-min sessions each with 43 degrees C during 3 weeks). In group 2 there were 6 patients who received a total of 12 treatment sessions (two 120-min sessions each with a temperature of up to 44.5 degrees C for 1 week). Five of the 10 patients from group 1 (50%) and 4 of 6 patients from group 2 (67%) were relieved of the catheter and have been able to void satisfactorily during the 7- to 14-month (mean 10.1 +/- 2.8) follow-up period. The overall success rate in this series of 16 patients was 56.3%.

Aged↗
PubMed1991

Identification of a silent point mutation in the LDL-receptor gene by direct DNA sequencing.

To study the allelic variation at the human LDL-receptor gene locus in a number of individuals with familial hypercholesterolemia, a protocol was applied for direct sequence analysis of genomic DNA. The asymmetric polymerase chain reaction (PCR) was used to synthesize single-stranded DNA. Sequencing was carried out with modified T7 DNA polymerase (Sequenase version 2.0, United States Biochemical) after purification of the amplification product with a glass powder adhesion method. The method is sensitive enough to identify the heterozygous state of allelic variation and bypasses cumbersome cloning and subcloning procedures. Here we report the occurrence of a guaninine-to-adenine change in the codon for amino acid 655. However, the glycine residue is not replaced by the base change at this position, and the mutation observed here does not represent the underlying genetic defect of the LDL-receptor defect in this individual. Preliminary data suggest that this mutation represents a rare genetic variation.

Amino Acid Sequence↗
PubMed1991

Heterogeneity in antigenic expression and radiosensitivity in human colon carcinoma cell lines.

A panel of human colon carcinoma cell lines were characterized regarding both antigenic heterogeneity and variations in radiosensitivity. Monoclonal antibodies were used to study the expression of carcinoembryonic antigen (CEA), gastrointestinal cancer antigen (GICA or CA 19-9) and carcinoma-associated antigen (CA-50). Radiosensitivity was studied with the clonogenic survival technique. Three cell lines, LS 174T, HCTC, and SW 1116 stained positive for all three antigens. HT-29 was positive for CA 19-9 and CA-50 whereas Caco-2 was positive for CEA and CA 19-9. The cell lines SW 620 and LIM 1215 only stained positive for one of the antigens, CA-50 and CEA, respectively. In nearly all positive cases the stainings were very heterogeneous with mixtures of positive and negative cells. One exception was the HCTC cells which stained homogeneously for the CA 19-9 and CA-50 antigens. The neuroendocrinelike COLO 320 cells were negative in all cases. The radiosensitivity varied strongly between the cell lines with Dq-values between 0.8 and 1.9, extrapolation numbers between 2.0 and 4.7, Do-values between 1.1 and 2.8. The surviving fraction at 2 Gy varied between 0.3 and 0.7 with HCTC as the most radiosensitive and HT-29 as the most radioresistant cell line. Thus, there were differences in antigenic expression and intrinsic radiosensitivity between the cell-lines and antigenic heterogeneities within each cell line. The analyzed panel of cell lines will be valuable in studies of dose-effect relations for monoclonal antibodies labeled with toxic radionuclides simulating both antigenic heterogeneity and variations in radiosensitivity.

Adenocarcinoma↗
PubMed1991

Transperineal ultrasound examination in the evaluation of prostatic size.

Eighty patients with benign prostatic hyperplasia underwent transperineal ultrasonographic evaluation of prostatic size and calculation of prostatic volume. In 10 patients transabdominal prostatic ultrasonography was also performed and the findings compared with those of transperineal examination. The estimated prostatic volume measured by transperineal ultrasonography was compared to the actual weight of the surgically removed gland. The correlation coefficient was 0.89 (P less than 0.0001). The transperineal and transabdominal ultrasonographic estimated volumes were also compared. The correlation coefficient was 0.92 (P less than 0.0001). No pain or discomfort were reported by the patients. Transperineal ultrasonography appears to be an accurate, fast and easy method to evaluate prostatic volume.

Humans↗