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Biomedical subjects

K Roth

Publications and source records attributed to K Roth.

At least 37 records · Page 2Linked to original sources
PubMed1996

Cross talk between cell death and cell cycle progression: BCL-2 regulates NFAT-mediated activation.

BCL-2-deficient T cells demonstrate accelerated cell cycle progression and increased apoptosis following activation. Increasing the levels of BCL-2 retarded the G0-->S transition, sustained the levels of cyclin-dependent kinase inhibitor p27Kip1, and repressed postactivation death. Proximal signal transduction events and immediate early gene transcription were unaffected. However, the transcription and synthesis of interleukin 2 and other delayed early cytokines were markedly attenuated by BCL-2. In contrast, a cysteine protease inhibitor that also blocks apoptosis had no substantial affect upon cytokine production. InterleUkin 2 expression requires several transcription factors of which nuclear translocation of NFAT (nuclear factor of activated T cells) and NFAT-mediated transactivation were impaired by BCL-2. Thus, select genetic aberrations in the apoptotic pathway reveal a cell autonomous coregulation of activation.

Apoptosis↗
PubMed1996

Noninvasive temperature measurement in vivo using a temperature-sensitive lanthanide complex and 1H magnetic resonance spectroscopy.

A new lanthanide complex, praseodymium-2-methoxyethyl-DO3A, was tested as a temperature indicator for 1H magnetic resonance spectroscopy under in vivo conditions, using a 2-T imaging system. The chemical shift of the methoxy group of the compound is strongly temperature dependent. In vitro, a shift change of -0.131 ppm/degree C was found. The signal was shifted by about -24 ppm relative to the water signal, allowing easy water suppression and signal identification in vivo. The body temperatures of eight anesthetized rats were measured in the liver after intravenous administration of 1 mmol/kg of the praseodymium complex under different heating conditions of the animal. The temperatures calculated from the spectra were in good agreement (deviation < +/- 1 degree C) with values obtained simultaneously with a thermocouple placed in the rectum of the animals.

Anesthesia↗
PubMed1996

[Analysis program for quantitative detection of chromosome aberrations using comparative genomic hybridization].

Comparative genomic hybridization (CGH) is a molecular cytogenetic method for the detection of chromosomal imbalances between a tumor and a normal genome. In order to produce quantitative and reproducible results, we developed an image analysis program that allows the detection and mapping of the genetic alterations. The result is represented as a CGH sum karyogram in which the genetic changes are documented as color coded-chromosomes. The aim of our investigation is to correlate the genotype with the phenotype on the basis of CGH sum karyograms and thus to achieve a genetic characterization that will supplement the morphological tumor description.

Cell Transformation, Neoplastic↗
PubMed1995

Endoscopically controlled trocar and cannula insertion.

One of the keys to safe laparoscopic or thoracoscopic surgery is an expeditious and reliable access to the region of interest. To minimise the risk of accidental injury to major vessels, lung, intestine and other important structures the principle of controlled visualised access has been advocated. This has led to several developments in the field of trocars, cannulae and puncture techniques. Examples are the insertion of a needle scope into a Veress needle, complex access cannulae and our new principle of using an "optical scalpel". The direct visualisation of an active, controllable penetration of the abdominal wall is expected to become indispensable. A selected variety of endoscopically assisted trocar and cannula systems such as the "windowed trocar", the "optical trocar", the "Visiport" and the "optical scalpel" are described.

Catheterization↗
PubMed1994

The correlation between HIV seropositivity, cervical dysplasia, and HPV subtypes 6/11, 16/18, 31/33/35.

Twenty-one human immunodeficiency virus (HIV) seropositive patients were studied to determine the prevalence of cervical dysplasia, the distribution of human papilloma virus (HPV) subtypes, and the utility of cytologic diagnosis in this population. The patients ranged in age from 18 to 41 years. HIV infection was diagnosed in all patients by ELISA method and confirmed by Western blot. Patients were interviewed to document risk factors for HIV infection and cervical dysplasia. All were examined colposcopically and identifiable lesions were biopsied. In patients with normal colposcopic findings four quadrant biopsies were performed. Cervical and endocervical smears were obtained on all patients at the time of colposcopy and blood was collected for T-cell studies. Eighteen patients (86%) had abnormal cytologic findings. The Pap smear was able to identify 10 of 13 biopsy-proven epithelial abnormalities. In 14 patients there was sufficient tissue for HPV typing by in situ hybridization; the HPV subtypes identified were 6/11 (10 patients), 16/18 (9 patients), and 31/33/35 (9 patients). Dysplasia was present in 11/14 (79%) of the specimens submitted for subtyping. The absolute CD4 cell counts were 342 per mm3 for the dysplasia group and 281 per mm3 for the patients without dysplasia. Patients with dysplasia did not differ significantly from patients without dysplasia in regard to risk factors for cervical dysplasia, including history of STD, tobacco use, multiple sexual partners, age at first coitus, and parity. In addition, history of medication use and risk factors associated with HIV infection were similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Nucleolar organizer regions (AgNORs) in astrocytic tumors.

79 astrocytic tumors classified according to the WHO classification and stained with a modified AgNOR staining technique were analysed with the help of an automatic image analysing system. The number and area of AgNORs were determined. The mean AgNOR number per nucleus was 1.28 in pilocytic, 1.98 in differentiated, 2.84 in anaplastic astrocytomas, 3.33 in small cell glioblastomas and 4.24 in multiforme glioblastomas. The area of all AgNORs per cell ranged from 0.95 microns2 (pilocytic astrocytomas), 1.53 microns2 (differentiated astrocytomas), 2.73 microns2 (anaplastic astrocytomas), 3.1 microns2 (small cell glioblastomas) to 4.12 microns2 (multiforme glioblastomas). With regard to AgNORs there are little differences between anaplastic astrocytomas and small cell glioblastomas.

Astrocytoma↗
PubMed1994

Automated processing of endoscopic surgical instruments.

This paper deals with the requirements for automated processing of endoscopic surgical instruments. After a brief analysis of the current problems, solutions are discussed. Test-procedures have been developed to validate the automated processing, so that the cleaning results are guaranteed and reproducable. Also a device for testing and cleaning was designed together with Netzsch Newamatic and PCI, called TC-MIC, to automate processing and reduce manual work.

Automation↗
PubMed1993

Operation for gastro-oesophageal reflux associated with severe mental retardation.

One hundred and seventy six children with severe mental retardation underwent a fundoplication for considerable gastro-oesophageal reflux. There were six 'early' (3%) deaths and five 'late' deaths. Major complications developed in 17 (10%) children whereas 86 (49%) had 'minor' complications. A revision operation was required in 27 patients. Overall 142 (81%) children achieved a good result. In spite of the high complication rate and the need for a secondary operation in 15% of the patients, the quality of life for these children and their parents and carers is greatly improved by antireflux surgery.

Age Factors↗
PubMed1993

Visually controlled trocar insertion by means of the "optical scalpel".

The importance of a safer approach to the abdominal cavity has led to several developments in the field of trocars, cannulae and puncture techniques. Examples are the insertion of a needle scope into a Veress needle, complex access cannulae and our new principle of using an "optical scalpel". In our view, direct optical visualization and actively controllable penetration of the abdominal wall are mandatory. First experimental and clinical applications indicate the newly developed "optical scalpel" (Olympus Winter & Ibe, Hamburg, Germany) as a reliable and useful instrument for a safe approach to the endoscopic operative field. This instrument was successfully used in 10 endoscopic operations and is currently undergoing further clinical testing.

Abdomen↗
PubMed1992

Surgical management of duplex ureteroceles.

We reviewed the cases of 95 children with duplex ureteroceles treated in this department over an 18-year period. There were 101 ureteroceles (6 bilateral). Diagnosis and treatment were analyzed. Special attention was paid to newborns screened in utero. We always strove to preserve functional renal tissue whenever possible. In keeping with this goal, three surgical techniques were used: (1) upper pole heminephrectomy; (2) ureterocele excision, bladder neck reconstruction, and ureter reimplantation with or without cutaneous ureterostomy of the upper pole ureter; and (3) endoscopic ureterocele incision. Follow-up studies using x-ray and radionuclide imaging demonstrated satisfactory renal function in 86.6% of patients. These findings support a conservative approach to ureteroceles using endoscopic ureterocele incision as the primary treatment. Lower urinary tract reconstruction may be associated in cases involving urinary tract infection, obstruction or incontinence. Upper pole heminephrectomy should be performed only after functional evaluation following ureterocele incision or cutaneous ureterostomy.

Adolescent↗
PubMed1992

[Sexual addiction in alcohol abuse and dependence. Clinical, nosologic and psychoanalytic aspects].

DSM-III-R names sexual addiction for the first time as a sexual disorder. In this study a group of alcoholics was examined who described their own sexual behavior as being addictive and self-destructive. In this nearly all male patient group sexual addiction manifested itself mostly in excessive masturbation and obsessional sexual fantasies often in combination with use of pornography. Promiscuity, prostitute contacts and excessive sexual demands on a steady partner and sexually deviant behavior, were less often reported in this population. The addictive sexual behavior was said to be usually provoked by emotional distress and unresolved conflicts. More than 80% of these patients were dependent upon at least one other substance beside alcohol. Two-thirds considered their sexual addictive behavior to be their primary and earliest dependency. The nosology of this disorder seems to be unspecific, since a number of forms of neurosis and personality disorder are diagnosed. A psychodynamic interpretation of sexual addiction points to defence mechanisms against inner psychic conflicts, as seen both in addiction and sexual perversion. Aspects of differential diagnosis and classification are also discussed.

Adult↗
PubMed1991

Determination of cytosolic ADP and AMP concentrations and the free energy of ATP hydrolysis in human muscle and brain tissues with 31P NMR spectroscopy.

Based on experimentally determined concentrations of PCr, Pi, ATP, and H+, the ADP and AMP concentrations and the free energy for the ATP hydrolysis in normal human brain and muscle were calculated assuming that the creatine kinase- and the myokinase-catalyzed reactions were in equilibrium, accounting for changes in pH and free Mg2+ ion concentration.

Adenosine Diphosphate↗
PubMed1990

P-31 MR spectroscopy of normal human brain and brain tumors.

Image-guided phosphorus-31 magnetic resonance (MR)-localized image-selected in vivo spectroscopy was performed on normal human brain and brain tumors. Peak area ratios, absolute molar concentrations of metabolites, and pH were determined. T1 values in normal brain were measured. The most important finding was that the metabolite concentrations detectable with MR spectroscopy in brain tumors were reduced from 20% to 70%. Phosphomonoesters, phosphodiesters, and phosphocreatine (PCr) showed the greatest decreases, while inorganic phosphate (Pi) showed the least change. The PCr-Pi ratio was significantly reduced in tumors. The pH of brain tumors (7.12 +/- 0.03) was more alkaline than that of normal brain (6.99 +/- 0.01). The authors conclude that the metabolite concentrations and pH in human brain tumors differ significantly from those in normal brain. These differences may be ultimately useful in characterizing tumors in man.

Adolescent↗
PubMed1990

[Statistical study of alcohol intoxicated female victims of sex offenses].

Comparing 133 presumable rape victims who underwent blood sampling after the event with 2446 alcoholized female traffic offenders it was found that both groups had a delinquency maximum between midnight and 2 a. m. and a delinquency minimum between 6 a. m. and 6 p. m. Most of the rape victims, however, were approximately 5 years younger than the traffic offenders, most of whom were about 25 years old. The time intervals between blood sampling and the event were longer in the case of the rape victims (4 to 20 hours) whereas most traffic offenders underwent blood sampling 1 to 2 hours after the event. At comparable maxima of the distribution curves of blood alcohol concentration (between 1.5% and 2%) that of the rape victims showed a shift to higher values. This is also illustrated by the mean values of blood alcohol concentration at the time of the event: the blood alcohol concentration of the rape victims was 2.24% and thus 0.45% higher than that of the traffic offenders, who averaged only 1.97%. The reason for this is probably to be seen in the different modes of back computation. By assigning 38 offenders to 35 victims it was possible to set up and compare 35 pairs. Comparing the blood alcohol concentrations of all 35 pairs it was found that the blood of the victims contained on average 0.4% more ethanol than the blood of the offenders (1.41% vs. 1.01%).

Accidents, Traffic↗
PubMed1989

[Using drugs: experiences with a slide show program and patient questionnaires].

200 patients were surveyed by questionnaire while attending the medical outpatient service at the university hospital of Zürich. Questions related to a slide show on the usage of prescribed drugs presented at the same time in the attending room but also to general personal habits and attitudes regarding pharmacotherapy. Appreciation of the slide show was remarkable. This was substantiated by the observation that next to the physician media such as news papers, television and broadcast serve as source of information on drugs. Patient-compliance was in part related to lack of correct information. While older patients discontinued treatment because of side-effects, younger patients stopped drugs often because of improvement under therapy. In depth information could improve compliance in the latter population since particularly these individuals complained about insufficient instruction. The personal preference of "natural" over "chemical" drugs was surprisingly at variance with the admission of regular intake of prescription drugs--possibly a sign of an ultimately greater confidence in "chemical" drugs.

Audiovisual Aids↗
PubMed1989

Phosphorus-31 magnetic resonance spectroscopy in humans by spectroscopic imaging: localized spectroscopy and metabolite imaging.

In in vivo phosphorus magnetic resonance spectroscopy (MRS), spectroscopic imaging (SI) can be used as a flexible localization technique, producing spectra from multiple volumes in a single examination. Presented here are phosphorus SI studies of human organs in which a selective-volume SI reconstruction was used rather than the usual array-format SI reconstruction. A linear predictor technique was used to estimate the initial points of the free induction decay missing because of the delay needed for phase-encoding gradients, significantly reducing the baseline artifacts which commonly complicate interpretation of SI spectra. In studies of heart, brain, liver, and kidney, the performance of SI was found to compare favorably with that of ISIS. SI phosphorus metabolite intensity images from a brain tumor patient were obtained at 2 X 2-cm in-plane resolution (with "slice" thickness of roughly 16 cm, determined by coil sensitivity) in 34 min, demonstrating the feasibility of obtaining clinically useful metabolite images in clinically reasonable examination times.

Astrocytoma↗