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Biomedical subjects

M Kessler

Publications and source records attributed to M Kessler.

At least 55 records · Page 3Linked to original sources
PubMed2000

Early increase of peripheral B cell levels in kidney transplant recipients with CMV infection or reactivation.

BACKGROUND: Cytomegalovirus (CMV) infection or reactivation is a frequent complication of renal transplantation. Diagnosis of these conditions relies on the detection of circulating antigen, or of specific IgM and/or IgG, which develop over several weeks. Evocative clinical features may be detected earlier, but lack specificity. Rapid and early changes in the partition of lymphocyte subsets could be an additional indication of pending CMV infection. METHODS: A systematic follow-up of peripheral B lymphocytes identified immunophenotypically by the determination of surface immunoglobulins (sIg), performed in 97 kidney transplant recipients, allowed to identify transient increases apparently predictive of CMV primo-infection or reactivation over the next 3 months. To better define the nature of these B cells, an extended investigation was performed for 14 prospective patients. In addition to surface Ig, membrane CD19, HLA-DR, and CD80 expression were explored. The cytoplasmic presence of mu, kappa, and lambda chains was also examined. B cell function was investigated using the ELISPOT technique, which allows an enumeration of the populations of IgG, IgA, and IgM secreting B cells. RESULTS: Retrospective analysis of the clinical outcome of the cohort of 97 patients evidenced that early transient increases in B cell levels were significantly (P<0.0001) associated with CMV infection. The same trend was noted in the smaller series of patients who benefited from a more extensive investigation of B cells, 10 of whom presented clinical or biological signs of CMV infection. Mature B cells, expressing surface Ig, CD19, DR, and CD80 are those presenting transient increases. No significant variation of preB (cmu+/kappalambda-) or activated (spot-forming) cells was evidenced in these patients. CONCLUSION: Individual examination of each patient's immune reconstitution profile allows to detect transient peaks of mature B cell during the initial immunosuppressive therapy, that appear to be predictive of oncoming CMV infection or reactivation.

Adult↗
PubMed2000

Poor clinical outcome of patients with Hodgkin's disease and elevated interleukin-10 serum levels. Clinical significance of interleukin-10 serum levels for Hodgkin's disease.

Interleukin (IL)-10 is a pleiotropic cytokine with potent inhibitory effects towards T(H)-1 cells. IL-10 inhibits secretion of IL-2 and interferon (IFN)gamma by T cells and downregulates major histocompatibility complex antigens. A variety of tumor cells secrete IL-10, which can inhibit growth of tumor-specific cytotoxic T cells. IL-10 expression has also been detected in B-cell lymphomas and Hodgkin's disease (HD), and it has been suggested that the cytokine is involved in the pathogenesis of these tumors. We analyzed levels of IL-10 in pretreatment sera of 64 patients with HD and healthy controls using a sensitive enzyme-linked immunosorbent assay. Patients with biopsy-proven HD were enrolled in trials of the German Hodgkin Study Group (GHSG). Elevated IL-10 levels were detected in the sera of nine patients with HD (14.1%) (range 4.5-225.6 pg/ml with a mean of 61.5 pg/ml). IL-10 was not detectable in a control population of healthy volunteers (n =90). Multivariate analyses revealed a significant correlation between elevated IL-10 levels and higher age (over 45 years) but not with any other factors defined by the international prognostic factor score. Patients with elevated IL-10 levels had a significantly lower freedom from treatment failure rate as detected in univariate and multivariate tests. Thus, IL-10 may serve as an independent prognostic factor for HD patients.

Adolescent↗
PubMed2000

Electrical impedance measurement of the breast: effect of hormonal changes associated with the menstrual cycle.

The purpose of this study was to evaluate the influence of hormonal factors on electrical impedance measurement with a new device TS2000, which is a new method in diagnosis of breast disease. Twenty-one healthy pre-menopausal women volunteers (aged 24-39 years) were examined with the TS2000 once/week for two menstrual cycles. On average, at least one spot was present in 47% of images of women not taking oral contraceptives and in 44% of women taking oral contraceptives (OC). The number of spots varied over the menstrual cycle and had a maximum in week 3 and week 5. We found that after 1 week only 15% of spots were present and no spots persisted for three consecutive weeks. These data, if further supported by observations on other populations of women, show that false-positive results are common in pre-menopausal women; however, these false-positive spots do not persist for long periods of time. This information may provide a basis for discrimination between true-positive and false-positive spots on the TS2000 image, since the latter would be expected to disappear on short-term follow up.

Adult↗
PubMed2000

Impact of virtual reality imaging on hepatic liver tumor resection: calculation of risk.

The risk involved in partial liver resections depends mainly on tumor localization, invasion of central vascular structures, and parenchymal function. The imaging techniques available today (computed tomography, magnetic resonance imaging) allow us to detect precisely the extent of tumor invasion and their relationship to central vessels. The various three-dimensional reconstruction techniques are helpful with regard to a virtual planning of liver resections. The calculation of remaining liver volumes subsequent to partial hepatectomies are considered to be an essential predictive parameter in terms for the development of postoperative liver failure. In a retrospective and a later consecutive, prospective clinical study we analyzed the postoperative risk in a series of 570 patients. In an univariate analysis 13 of 31 parameters showed significant values. In multivariate analysis only three parameters (partial hepatic resection rate, PHRR), gamma-glutamyltranspeptidase, and prothrombin activity) were independent parameters for predicting liver failure, generating the most significant values for the PHRR. In our experience the most comfortable and precise technique for evaluating PHRR is the b-spline technique.

Female↗
PubMed2000

Successful surgical thrombectomy of renal allograft vein thrombosis in the early postoperative period.

We report the successful surgical treatment of two cases of renal vein thrombosis, each occurring early after kidney transplantation. Prompt intervention was a result of accurate diagnosis by color Doppler ultrasonography. Invasive radiological procedures were not useful. Although recent advances in thrombolytic therapy have created several alternatives to open surgery, the rationale for surgical exploration in these cases was to remove the thrombus quickly, to avoid the postoperative bleeding complications of thrombolytic therapy, and to correct any technical or anatomic problems.

Adult↗
PubMed2000

[Quality control in patient education. Results of a patient survey about the patient education protocol of the Swiss Society of Surgery in 6 Swiss hospitals].

In the past years the number of malpractice suits due to lack of patient information has increased. Because there have been no generally accepted guidelines for preoperative patient information, the Swiss Society of Surgery has decided to work out an informative brochure tailored to the needs of patients. It takes into account that the need to know beforehand is increasing rapidly. In collaboration with the judiciary service of the Swiss Medical Federation all the items and points of legal relevance have been compiled to establish an informative brochure. Based on this protocol, patients in surgical departments of 6 Swiss community hospitals were asked before discharge to qualify the preoperative information offered to them. 2660 questionnaires were evaluated. The majority of patients considered the information regarding their diagnosis, the complications, risks, treatment and postoperative care, the sketches describing the operation and the overall degree of information as good or very good. Almost 60% of all patients stated that no alternative treatment had been discussed with them other than the planned procedure. In most of these patients operative procedures were chosen and carried out for which there were few or no other acceptable options. 2/3 of the patients asked for immediate preoperative written information, especially if they had malignant disease. Barely 4% of the patients were not reassured by the information provided to them. The fact that 2/3 of all patients re-read the informative protocol before the operation underlines how important it is to hand out a copy of the protocol to satisfy the informative needs of the patients. To our surprise the vast majority of patients uttered little concern about giving their signature to forms that were presented to them. Only 2% of the patients felt that giving a signature would cause them grave reservations. The informative protocol devised by the Swiss Society of Surgery is well adapted to the informative needs of the patients and allows for a structured conversation. It facilitates documentation and offers valid legal proof for the physician that he/she has provided adequate information.

Adult↗
PubMed2000

Effects of the potent ampakine CX614 on hippocampal and recombinant AMPA receptors: interactions with cyclothiazide and GYKI 52466.

R,S-alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor up-modulators of the benzamide type ("ampakines") have previously been shown to enhance excitatory synaptic transmission in vivo and in vitro and AMPA receptor currents in excised patches. The present study analyzed the effects of an ampakine (CX614; 2H,3H, 6aH-pyrrolidino[2",1"-3',2']1,3-oxazino[6',5'-5,4]benz o[e]1, 4-dioxan-10-one) that belongs to a benzoxazine subgroup characterized by greater structural rigidity and higher potency. CX614 enhanced the size (amplitude and duration) of field excitatory postsynaptic potentials in hippocampal slices and autaptically evoked excitatory postsynaptic currents in neuronal cultures with EC(50) values of 20 to 40 microM. The compound blocked desensitization (EC(50) = 44 microM) and slowed deactivation of responses to glutamate by a factor of 8.4 in excised patches. Currents through homomeric, recombinant AMPA receptors were enhanced with EC(50) values that did not differ greatly across GluR1-3 flop subunits (19-37 microM) but revealed slightly lower potency at corresponding flip variants. Competition experiments using modulation of [(3)H]fluorowillardiine binding suggested that CX614 and cyclothiazide share a common binding site but cyclothiazide seems to bind to an additional site not recognized by the ampakine. CX614 did not reverse the effect of GYKI 52466 on responses to brief glutamate pulses, which indicates that they act through separate sites, a conclusion that was confirmed in binding experiments. In sum, these results extend prior evidence that ampakines are effective in enhancing synaptic responses, most likely by slowing deactivation, and that their effects are exerted through sites that are only in part shared with other modulators.

Alanine↗
PubMed2000

A conservative femoral replacement for total hip arthroplasty. A prospective study.

Between 1985 and 1993, 146 patients (162 hips) had total hip replacement (THR) using a conservative uncemented femoral component. The mean age of the patients was 50.8 years and the mean follow-up was 6.2 years (2 to 13). One patient was lost to follow-up, one died within two years of surgery and one had a revision procedure after a fracture sustained in a road-traffic accident. For the remaining 159, Kaplan-Meier survival analysis was calculated for the incidence of revision because of mechanical loosening or osteolysis. Survival without mechanical loosening at both five and ten years was 98.2%. Survival without osteolysis was 99% at five and 91% at ten years. The Harris hip score improved from a mean of 66.3 before to 90.4 at follow-up. Of particular note is the lack of thigh pain in this group. Radiological analysis showed that 139 stems (88%) had no measurable subsidence, 8 (5%) had less than 2 mm and 12 (7%) had more than 2 mm. Two of the eight and one of the 12 were revised for mechanical loosening. Nine hips were revised for late loosening associated with osteolysis. No reaming of the femoral canal was associated with statistically significant less blood loss compared with a comparable control group of uncemented implants (p < 0.0001). Our study suggests that using a conservative femoral implant does not protect against wear debris but the reliable mechanical stability (98.2%) makes this an attractive design of implant particularly for young patients.

Adult↗
PubMed2000

[Bladder candidosis after renal transplantation: contribution of ultrasonography].

Candidosis of the ureter and the bladder is an infrequent complication after renal transplantation. A case occurring early after kidney transplantation is reported in a patient presenting with candiduria. Ultrasound examination detected several fungal bezoars, presenting as a proliferating, avascular lesions, located within the ureter and the bladder. It allowed to demonstrate the rapid extension of lesions, in spite of a medical treatment, leading to a successful endoscopic removal of fungus balls.

Aged↗
PubMed2000

Targeting exposed RNA regions in crystals of the small ribosomal subunits at medium resolution.

Within the framework of ribosomal crystallography, the small subunits are being analyzed, using crystals diffracting to 3 A resolution. The medium resolution electron density map of this subunit, obtained by multiple isomorphous replacement, show recognizable morphologies, strikingly similar to the functional active conformer of the small ribosomal subunit. It contains elongated dense features, traceable as RNA chains as well as globular regions into which the structures determined for isolated ribosomal proteins, or other known structural motifs were fitted. To facilitate unbiased map interpretation, metal clusters are being covalently attached either to the surface of the subunits or to DNA oligomers complementary to exposed ribosomal RNA. Two surface cysteines and the 3' end of the 16S ribosomal RNA have been localized. Targeting several additional RNA regions shed light on their relative exposure and confirmed previous studies concerning their functional relevance.

Crystallography, X-Ray↗