Decreased β2-adrenoceptor density and decreased isoproterenol induced c-AMP increase in juvenile type I diabetes mellitus: An additional cause of severe hypoglycaemia in childhood diabetes?

Little is known about the receptor and post receptor mechanisms of sympathoadrenal signal transmission in type I diabetes mellitus. Therefore, we examined the maximum binding of granulocyte ₂-adrenoceptors and the in vitro c-AMP accumulation in lymphocytes of 24 children and adolescents with diabetes mellitus and 14 similarly aged healthy subjects. The number of high affinity ₂-adrenoceptors on granulocytes correlated significantly with unstimulated (r=0.6,P<0.004) and with isoproterenol stimulated c-AMP values in lymphocytes (r=0.68,P<0.0007) showing the proportional changes of ₂-adrenoceptors and c-AMP in two different cells. The number of ₂-adrenoceptors on granulocytes was significantly reduced in diabetic as compared to healthy children (median 1397, range 599–3405 vs. 2205, 825–3200 ₂-adrenoceptors per granulocyte,P=0.014). Moreover, the percentage in vitro stimulation of c-AMP by isoproterenol in lymphocytes was significantly reduced in diabetic children as compared to healthy individuals (120%, 39%–278% vs. 225%, 66%–500%,P=0.012). These results indicate a decreased sympathoadrenergic signal transmission in peripheral blood cells as a model for the liver probably contributing to severe hypoglycaemia in diabetic children.     

Serotonin transporter gene and schizophrenia: evidence for association/linkage disequilibrium in families with affected siblings

The serotonergic (5-HT) system has been implicated in the etiopathogenesis of psychoses. Since the 5-HT transporter plays an important role in regulation of 5-HT transmission, its gene can be considered as a candidate for vulnerability to psychiatric disorders. Two polymorphic sites of the 5-HT transporter gene-5-HTTLPR, a VNTR in the 5' regulatory region, and a VNTR in the second intron-were studied in a sample of 61 families with schizophrenia for transmission disequilibrium. Each family contained at least two siblings affected with schizophrenia or schizoaffective disorder (mainly schizophrenic). One hundred and thirty-nine affected offspring with parental information for genotyping, were available for analysis. No preferential transmission of either short or long alleles of the promoter polymorphism was observed. However, a transmission distortion was detected for alleles of the intronic VNTR polymorphism (chi2TDT max =14.33; P = 0.0002; corrected P value = 0.0003) resulting in more frequent than expected transmission of the 12 repeat allele. This finding adds additional evidence to the idea that the serotonergic system may be involved in development of psychoses. Molecular Psychiatry (2000) 5, 91-95.     

Molekulare und phänotypische Charakterisierung von Methicillin-resistenten Staphylococcus-aureus-Isolaten Untersuchungen an einer Unfallchirurgischen Klinik von 1994–1997

Methicillin resistant Staphylococcus aureus-strains, isolated from 1994 to 1997 from patients of the traumatic surgery hospital Tübingen, were compared using lysotyping and pulsed-field gel electrophoresis. Both typing methods detected two clones causing an outbreak 1994 in 6 patients and a third endemic clone of MRSA, which was isolated from 5 patients (1995), 4 patients (1996), and 6 patients (1997). Additionally other MRSA-types were found in 6 cases of which transmissions occurred in up to three patients. An epidemiological connection to MRSA isolated from patients of the university hospital of Tübingen was made. Possible consequences for patient management and antibiotic strategies in MRSA-infections were discussed.     

Safety, pharmacokinetics, and activity of ABX-EGF, a fully human anti-epidermal growth factor receptor monoclonal antibody in patients with metastatic renal cell cancer.

PURPOSE: To determine the antitumor activity of ABX-EGF, a fully human monoclonal antibody to the epidermal growth factor receptor (EGFr), in previously treated patients with metastatic renal cell carcinoma, and to characterize its toxicity, immunogenicity, pharmacokinetics, and pharmacodynamics. PATIENTS AND METHODS: The antitumor activity, as well as the toxicity, pharmacokinetics, pharmacodynamics, and immunogenicity of ABX-EGF, were assessed. RESULTS: Eighty-eight patients were treated with ABX-EGF doses of 1.0, 1.5, 2.0, or 2.5 mg/kg weekly with no loading dose. EGFr immunostaining was performed on 76 tumor biopsy specimens (86%), and 69 (91%) scored positive. Major responses occurred in three patients, and two patients had minor responses. Forty-four patients (50%) also had stable disease at their first 8-week assessment, and the median progression-free survival (PFS) was 100 days (95% CI, 58 to 140 days). Low hemoglobin and high alkaline phosphatase predicted for short PFS. The principal toxicity, an acneiform rash, occurred in 68%, 95%, 87%, and 100% of patients who received at least three doses of ABX-EGF at 1.0, 1.5, 2.0, and 2.5 mg/kg/wk, respectively. A trend indicated that the severity of the rash may relate to PFS. No human antihuman antibodies were detected. ABX-EGF pharmacokinetics fit a model that incorporated both linear and saturable EGFr-mediated clearance mechanisms, and interindividual variability was low. At 2.5 mg/kg/wk, ABX-EGF concentrations throughout treatment exceeded those estimated to saturate nonlinear clearance and inhibit xenograft growth by 90%. CONCLUSION: ABX-EGF was generally well tolerated. The objective response rate was low in previously treated patients with metastatic renal cell carcinoma. Although skin rash may be a pharmacodynamic marker of drug action, its potential as a surrogate marker of clinical benefit requires further evaluation.     

A longitudinal investigation of the concordance between individuals with traumatic brain injury and family or friend ratings on the Katz adjustment scale

Changes in the level of agreement (concordance) between self and family or friend reporting on the Katz Adjustment Scale (KAS) from 6 to 12 months postinjury were assessed in 55 individuals with traumatic brain injury (IwTBI). Although the concordance between self and family/friend reports significantly increased over the course of recovery, possibly reflecting improvements in awareness, the concordance showed limited relationship to measures of injury severity and neuropsychological functioning. Concordance did not significantly relate to clinicians' ratings of inaccurate insight and self-appraisal on the awareness item from the Neurobehavioral Rating Scale (NBRS). Clinicians' ratings of awareness demonstrated only limited relationship to measures of injury severity and neuropsychological functioning, as well. Although similar results in the literature have been interpreted as demonstrating that awareness, defined as concordance, is possibly a unique construct separate from injury severity and neuropsychological functioning, an alternative hypothesis is presented concerning other, noninjury factors that may affect the level of agreement in problem reporting between IwTBI and family/friend informants.     

Mycophenolate mofetil increases cytomegalovirus invasive organ disease in renal transplant patients

The impact of cytomegalovirus (CMV) infection post-transplantation is in part influenced by the degree of immunosuppression. While mycophenolate mofetil (MMF) does not increase the overall incidence of CMV infection, we have questioned whether or not it increases its severity. Using a case control study design in which 29 renal transplant patients developed CMV disease [17 (59%) of which received azathioprine (AZA) and 12 (41%) received MMF], increases in the frequency of organ involvement with CMV (58 vs. 18%; p = 0.03) and in the number of organs involved with CMV were noted in the MMF versus the AZA group (2.0 vs. 1.0; p = 0.015). These results indicate that the increased immunosuppressive activity of MMF impacts the morbidity of CMV infection, thus warranting the use of effective anti-CMV preventive regimens while patients are treated with MMF.     

Exacerbation of radiocontrast nephrotoxicity by endothelin receptor antagonism

BACKGROUND: Endothelin is a potent vasoconstrictor that has been implicated in the pathogenesis of radiocontrast nephrotoxicity. Endothelin antagonists may reduce the renal hemodynamic abnormalities following radiocontrast administration. METHODS: One hundred fifty-eight patients with chronic renal insufficiency [mean serum creatinine +/- SD = 2.7 +/- 1.0 mg/dL (242. 3 to +/- 92.8 micromol/L)] and undergoing cardiac angiography were randomized to receive either a mixed endothelin A and B receptor antagonist, SB 290670, or placebo. All patients received intravenous hydration with 0.45% saline before and after radiocontrast administration. Serum creatinine concentrations were measured at baseline, 24 hours, 48 hours, and 3 to 5 days after radiocontrast administration. The primary end point was the mean change in serum creatinine concentration from baseline at 48 hours; the secondary end point was the incidence of radiocontrast nephrotoxicity, defined as an increase in serum creatinine of > or =0.5 mg/dL (44 micromol/L) or > or = 25% from baseline within 48 hours of radiocontrast administration. RESULTS: The mean increase in serum creatinine 48 hours after angiography was higher in the SB 209670 group [0.7 +/- 0. 7 mg/dL (63.5 +/- 58.6 micromol/L)] than in the placebo group [0.4 +/- 0.6 mg/dL (33.6 +/- 55.1 micromol/L), P = 0.002]. The incidence of radiocontrast nephrotoxicity was also higher in the SB 209670 group (56%) compared with placebo (29%, P = 0.002). This negative effect of SB 209670 was apparent in both diabetic and nondiabetic patients. Adverse effects, especially hypotension or decreased blood pressure, were more common in the SB 209670 group. CONCLUSIONS: In patients with chronic renal insufficiency who were undergoing cardiac angiography, endothelin receptor antagonism with SB 209670 and intravenous hydration exacerbate radiocontrast nephrotoxicity compared with hydration alone.