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Biomedical subjects

D Wahl

Publications and source records attributed to D Wahl.

At least 55 records · Page 3Linked to original sources
PubMed1995

Effects of cyclosporine A on the rat liver and kidney protein pattern, and the influence of vitamin E and C coadministration.

The effects of cyclosporine A (CsA), a potent immunosuppressive drug, were examined in rat liver and kidney samples using two-dimensional electrophoretic protein analysis. Of a total of 370 liver and 336 kidney spots analyzed, 8% (29 spots) and 6% (19 spots), respectively, showed a significant drug-induced change (p < 0.01), which was predominantly reflected in increased protein abundance (62% and 74% of the changes, respectively). Of the 48 proteins changed in either organ, 14 were most probably common to both tissues and one of these was significantly increased in both the liver and the kidney. Most of the other 13 showed similar trends (either increases or decreases) in both organs. However, the most striking drug effect seen in this study concerned an unidentified protein present only in the kidney, which completely disappeared upon CsA treatment. It was also investigated whether the drug-induced changes could be prevented by the coadministration of the radical scavengers vitamin E and C with CsA. Spots changed by the administration of the drug were classified according to three different categories, based on their response profiles in rats treated with CsA in combination with the vitamins: (i) spots which were changed by CsA as well as by CsA in combination with the vitamins (12 liver and 4 kidney spots), (ii) spots which were changed by CsA and showed an additional increase of this change by CsA plus the vitamins (no liver and 4 kidney spots), and (iii) spots which were changed by CsA but not by CsA in combination with the vitamins (8 liver and 6 kidney spots). These results showed that in both organs the vitamins were able to prevent around 30% of the effects caused by CsA, and that two-dimensional gel electrophoresis is an excellent tool to demonstrate such drug interactions at the molecular level.

Animals↗
PubMed1995

Protein variability in male and female Wistar rat liver proteins.

In the emerging field of mechanistic toxicology, growing attention is being paid to the interpretation of sex-related toxic responses. The Wistar rat outbred stock is a frequently used rodent for toxicity testing. Outbred strains, which display a relatively high degree of genetic variability between the individual animals are often used in risk assessment, as they are considered to best approximate the variability present in a human population. In this study two-dimensional (2-D) protein gel electrophoresis was applied to investigate the liver protein patterns of male and female Wistar rats and to search for (i) sex-related and (ii) interindividual qualitative and quantitative differences in protein expression. Among the sexes, six proteins were detected that were shown to be exclusively present in male rats and one that was present only in females. A male-specific protein was tentatively assigned to alpha 2u globulin. Seven protein spots showed statistically significant abundance changes (p < 0.001) between males and females, one was tentatively assigned to heme oxygenase 1 and another to the 23 kDa morphin-binding protein. Four sets of protein spots were detected that showed positional shifts in the individual patterns and are likely to represent polymorphic proteins inherent in the Wistar rat. These results form a valuable basis for future investigations of drug-induced changes in the male and female Wistar rat liver pattern.

Alpha-Globulins↗
PubMed1994

Detection and volume estimation of embolic air in the middle cerebral artery using transcranial Doppler sonography.

BACKGROUND AND PURPOSE: Cerebral embolism has been implicated in the development of cognitive and neurological deficits following bypass surgery. This study proposes methodology for estimating cerebral air embolus volume using transcranial Doppler sonography. METHODS: Transcranial Doppler audio signals of air bubbles in the middle cerebral artery obtained from in vivo experiments were subjected to a fast-Fourier transform analysis. Audio segments when no air was present as well as artifact resulting from electrocautery and sensor movement were also subjected to fast-Fourier transform analysis. Spectra were compared, and frequency and power differences were noted and used for development of audio band-pass filters for isolation of frequencies associated with air emboli. In a bench model of the middle cerebral artery circulation, repetitive injections of various air volumes between 0.5 and 500 microL were made. Transcranial Doppler audio output was band-pass filtered, acquired digitally, then subjected to a fast-Fourier transform power spectrum analysis and power spectrum integration. A linear least-squares correlation was performed on the data. RESULTS: Fast-Fourier transform analysis of audio segments indicated that frequencies between 250 and 500 Hz are consistently dominant in the spectrum when air emboli are present. Background frequencies appear to be below 240 Hz, and artifact resulting from sensor movement and electrocautery appears to be below 300 Hz. Data from the middle cerebral artery model filtered through a 307- to 450-Hz band-pass filter yielded a linear relation between emboli volume and the integrated value of the power spectrum near 40 microL. Detection of emboli less than 0.5 microL was inconsistent, and embolus volumes greater than 40 microL were indistinguishable from one another. CONCLUSIONS: The preliminary technique described in this study may represent a starting point from which automated detection and volume estimation of cerebral emboli might be approached.

Animals↗
PubMed1993

Osteogenic activity of bone morphogenetic protein and hydroxyapatite composite implants.

In an experimental study in rats hydroxyapatite (HA) ceramics of characteristics and inactive rat bone matrix were investigated comparatively for their suitability as carriers for osteoinductive factors. Bone morphogenetic protein was extracted from long bones of pigs under dissociative conditions and partially purified by gel filtration. The resulting pBMP was combined with the granular hydroxyapatite ceramics Osprovit, Algipore, Frialit and inactive rat bone matrix (IBM) by precipitation of aliquots of this pBMP fraction onto pellets of each carrier material. The osteogenic activity of these composite implants and of corresponding controls was bioassayed by implantation into muscle pouches of immunodeficient rats. All pBMP-HA ceramic implants elicited ectopic bone formation within 25 days after implantation, whereas control implants did not show any osteoinductive ability. Alkaline phosphatase (AP) activity of the explant tissues was determined for quantitation of bone formation. Due to the high incidence of bone formation found in each pBMP group all HA ceramics tested seem to be basically suitable as carriers for osteoinductive factors. Algipore, a highly porous phycogen HA ceramic, was found to be quantitatively superior to all other materials investigated due to its very large surface available for protein binding.

Animals↗
PubMed1992

Self-limited primary cytomegalovirus colitis in an immunocompetent individual.

Cytomegalovirus colitis in immunocompetent patients has rarely been reported without another severe illness. The prognosis is usually bad, leading to toxic megacolon or death due to multi-organ system failure. We report a case of a self-limited cytomegalovirus colitis in a young patient with no risk factor for CMV infection or associated disease. This suggests that self-limiting CMV colitis may be more frequent than is usually believed, and its prognosis may be better in young patients with normal immune functions. Therefore it should be sought systematically even in immunocompetent young patients.

Adult↗
PubMed1991

Outcome of treatment in alcoholic women.

One hundred and seventy-eight females (mean age 40.6 +/- 10.2 years) were retrospectively studied by questionnaires for a mean duration of 46 (17-75) months. Sixty-two percent were married or living maritally. One third were working. The mean alcohol intake was 157 +/- 76 g/day and 57.3% had alcohol dependence for less than 5 years. Twenty-seven patients (15%) were lost to follow-up; out of the 151 remaining patients, 7 (4%) refused to answer and 18 (12%) died. Suicide and alcoholism complications were a frequent cause of death. One hundred and twenty-six questionnaires were obtained. Twenty-eight women (22%) were abstinent. A good outcome determined by the state of alcoholization (abstinence or moderate consumption) and the improvement of quality of life, was found in 44% of patients. Absence of marital life and greater alcohol intake were related to a poor outcome, whereas enrollment in a fellowship of recovering alcoholics was more frequent in abstinent patients. The mortality rate was important in alcoholic females. A number of factors were related to the outcome.

Adolescent↗
PubMed1991

Angiofollicular lymph node hyperplasia (Castleman's disease) in an adolescent female. Clinical and immunologic findings.

Angiofollicular lymph node hyperplasia is a heterogeneous disorder of unclear etiology and has a wide spectrum of systemic symptoms. This report describes a case of this disorder in a 15-year-old girl and examines the response of the primary mass, systemic symptoms, and alterations of selected immune parameters at diagnosis, as a result of steroid therapy and radiation therapy (RT). The patient had a 1-year history of growth failure, delayed puberty, and refractory iron deficiency anemia. Computed tomography scan showed a posterior mediastinal mass. Biopsy revealed angiofollicular lymph node hyperplasia of mixed hyaline-vascular and plasma cell type histologic type. Immunoperoxidase studies showed polyclonal B-cells, predominance of T-helper cells (CD4) over cytotoxic/suppressor T-cells (CD8), and the presence of natural killer (NK) cells. Southern blot analysis demonstrated germ line gene configuration for the T-cell antigen receptor and Ig heavy chain. The patient clinically improved with RT after failing to respond to steroids. Immunophenotyping of peripheral blood lymphocytes before therapy revealed a CD4:CD8 ratio of 0.8 with decreased numbers of circulating T-cells; this increased to 1.4 after steroid therapy. The patient's T-lymphocytes had no proliferative response to phytohemagglutinin (PHA) or concanavalin A (Con A) before RT. After RT, a small but significant mitogenic response to these reagents was noticed. The proliferative response to recombinant interleukin-2 (rIL-2) remained similar to that of control lymphocytes. Induction of second messenger signals by activation of protein kinase C (PKC) and elevation of free cytosolic calcium through the use of the phorbol ester, phorbol 12, 13-dibutyrate (PDBu), and ionomycin (Io) resulted in a strong proliferative response at diagnosis and after RT. In vitro cytotoxicity assays revealed diminished NK activity before and after therapy. Lymphokine-activated killer (LAK) activity remained comparable with that of control cells and was not affected by therapy. Before RT patient lymphocytes maintained cytotoxic capabilities after coincubation with rIL-2 and PDBu plus Io, whereas coincubation with these reagents abrogated cytotoxic function of normal cells. This case demonstrates a clinical response to RT as well as improvement in immune parameters. Intact signal transduction mechanisms through PKC activation and elevation of cytosolic calcium were also demonstrated in the circulating lymphocytes.

Adolescent↗
PubMed1991

[Sedation with intranasal midazolam for endoscopy of the upper digestive tract].

Twenty-nine patients, ranked ASA 1 or 2, scheduled for diagnostic gastroduodenal fibroscopy were randomly allocated into three treatment groups: intranasal midazolam (IN) 0.15 mg.kg-1; intramuscular midazolam (IM) 0.15 mg.kg-1, and placebo (P). Sedation and the fibroscopy were all carried out by the same anaesthetist and fibroscopist. Efficiency and tolerance of the method were assessed by monitoring the heart rate, systolic and diastolic arterial blood pressure, arterial oxygen saturation (pulse oximetry), the degrees of sedation, anxiety, and anterograde as well as retrograde amnesia. The patient's and endoscopist's reactions were also considered. Patients in group P were older than those of the other two groups (p less than 0.01). Sedation was more important and patients less anxious in groups IN and IM than in group P. Three patients in group IM had retrograde amnesia. There were no significant differences between the degrees of anterograde amnesia in the three groups. At no time during the study were there any significant differences in SpO2 between and within groups. Four out of the 9 patients in group P had a bad opinion of their experience, as compared with two out of the 20 in the midazolam groups; the difference was not statistically significant. Three hours after the procedure, all patients were fully awake. Intranasal administration of midazolam therefore seemed to be an interesting alternative for gastroduodenal fibroscopy, because it was simple, non traumatic, well tolerated, and did not result in arterial desaturation.

Administration, Intranasal↗
PubMed1991

[Treatment of Monteggia fracture in children].

Described in this paper is a therapeutic concept by which to cope with Monteggia's fracture in childhood. It is based on experience obtained from 72 cases with injuries of that kind and their evaluation in a group study. Therapeutic approach to the individual case was determined by the following criteria: age of infant, localisation and shape of ulnar fracture, reducibility of capitulum radii, and accompanying injuries requiring treatment on the same arm. The need for surgical stabilisation of ulnar fracture was found to increase along with growing age of the affected child. High-stability anatomic reduction of the ulnar fracture proved to be a prerequisite for safe stabilisation of the radial capitulum. Close reduction has proved to be sufficient in many instances. Open reduction and internal fixation were found to be necessary in cases in which an ulnar fracture was irreducible or instable and/or a radial head was not reducible. Minimal osteosynthesis and plaster cast is considered to be an optional therapy for younger children, whereas ulnar stabilisation by means of plates is preferred for children in somewhat advanced age of childhood. The radial head may be fixed by trans-articular Kirschner's wire (WITT) or primary reconstruction of the annular ligament, using a strip of biceps or triceps tendon, or adaptation around the collum radii and ulna of the proximal radio-ulnar joint by means of a sling of Dexon or Vicryl suture.

Child↗
PubMed1989

[Acute thrombosis of mitral Starr prosthesis. Value of color coded two-dimensional doppler echocardiography].

In a case of acute thrombosis on mitral Starr valve two-dimensional doppler-echocardiography rapidly showed that parts of the transprosthetic jets had disappeared, while conventional continuous wave doppler ultrasound confirmed the presence of a severe haemodynamic obstacle. With colour-coded doppler ultrasound, there only remained a jet that was parallel to the posterior wall of the left ventricle. This jet was of unusual pattern, with the presence of turbulence and high velocities in aliasing colour. The effectiveness of a thrombolytic treatment was demonstrated by the reappearance of the missing diastolic jets with return to normal velocities. Comparison between a post-thrombolysis colour-coded doppler examination and a reference examination confirmed that the valve was now functioning normally. Thus, while conventional doppler recordings accurately quantify prosthetic dysfunctions leading to stenosis, two-dimensional doppler recordings rapidly provide an anatomical information. By showing changes in the transprosthetic jets they indicate the precise location and extent of valve obstruction.

Echocardiography, Doppler↗
PubMed1989

[Post-infarction anterior septal rupture. Aspects of the IVC flux on bidimensional Doppler with color coding].

In a case of anterior septal rupture complicating a transeptal myocardial infarction, the diagnosis of IVC is immediately confirmed by bidimensional Doppler with color coding. The abnormal flow and its three components are studied in multiple section planes. Incidences permitting the best visualization of the shunt are the longitudinal sections: left parasternal and apical-long axis. The parasternal short axis section only visualizes an abnormal intraventricular flow. Sweeping of the septum by caudal tilting of the probe, from an apical section of the 4 cavities, successively studies the three portions: left intraventricular, trans-septal, and right intraventricular of the abnormal flow. The size of the defect seems underestimated on bidimensional ultrasonograms as well as color Doppler. Speed, sensitivity and reliability of the color coded bidimensional Doppler, places it as the reference diagnostic test in this type of pathology. Catheterization still has a place in evaluating the severity of the shunt.

Aged↗
PubMed1988

[Physical therapy within the scope of fracture treatment in children. Recommendations of the Traumatology in Childhood Study Group].

Physiotherapeutic follow-up treatment is required only in exceptional cases of fractures in childhood. Physiotherapeutic indications are justified for fractures with months of immobilisation, multiple fractures, fractures accompanied by soft-tissue defects and nerve injuries, vertebral fractures, fractures and craniocerebral trauma, and fractures entailing the risk of bone necrosis. Passive exercises are not at all indicated.

Child↗