Matrilineal inheritance of complex I dysfunction in a multigenerational Parkinson's disease family

Recent data suggesting complex I dysfunction in Parkinson's disease (PD) arises from mitochondrial DNA (mtDNA) mutation does not conclusively answer whether the responsible genetic lesion is inherited (primary) or somatic (secondary). To address this question, we identified a family in which multiple members over three generations are affected with PD through exclusively maternal lines. Cytoplasmic hybrids (cybrids) were created for 15 family members over two generations by transferring each individual's mtDNA to mtDNA-depleted human neuroblastoma cells. Eight of the 15 cybrid lines contained mtDNA obtained from maternally descended family members and seven contained mtDNA from paternally descended family members. After 6 weeks of culture, cybrid cell lines were assayed for complex I activity and oxidative stress, and mitochondrial morphology was analyzed by electron microscopy. Compared with the cybrid lines containing mtDNA from paternal descendants, cybrid lines containing mtDNA from maternal descendants had lower complex I activity, increased reactive oxygen species production, increased radical scavenging enzyme activities, and more abnormal mitochondrial morphologic features. These findings were present in cybrid lines containing mtDNA from maternal descendants with PD as well as in currently asymptomatic young maternal descendants, and support a precedent for inherited mtDNA mutation in some persons with PD.     

Regulated nucleo/cytoplasmic exchange of HOG1 MAPK requires the importin beta homologs NMD5 and XPO1

MAP kinase signaling modules serve to transduce extracellular signals to the nucleus of eukaryotic cells, but little is known about how signals cross the nuclear envelope. Exposure of yeast cells to increases in extracellular osmolarity activates the HOG1 MAP kinase cascade, which is composed of three tiers of protein kinases, namely the SSK2, SSK22 and STE11 MAPKKKs, the PBS2 MAPKK, and the HOG1 MAPK. Using green fluorescent protein (GFP) fusions of these kinases, we found that HOG1, PBS2 and STE11 localize to the cytoplasm of unstressed cells. Following osmotic stress, HOG1, but neither PBS2 nor STE11, translocates into the nucleus. HOG1 translocation occurs very rapidly, is transient, and correlates with the phosphorylation and activation of the MAP kinase by its MAPKK. HOG1 phosphorylation is necessary and sufficient for nuclear translocation, because a catalytically inactive kinase when phosphorylated is translocated to the nucleus as efficiently as the wild-type. Nuclear import of the MAPK under stress conditions requires the activity of the small GTP binding protein Ran-GSP1, but not the NLS-binding importin alpha/beta heterodimer. Rather, HOG1 import requires the activity of a gene, NMD5, that encodes a novel importin beta homolog. Similarly, export of dephosphorylated HOG1 from the nucleus requires the activity of the NES receptor XPO1/CRM1. Our findings define the requirements for the regulated nuclear transport of a stress-activated MAP kinase.     

Using focus groups to identify psychosocial issues of urban black individuals with diabetes

BACKGROUND: Human serum represents an important barrier to the entry of most mucosal organisms into tissues and to the systemic circulation. If at all present, Helicobacter pylori within gastric tissue is rare, and bacteremia for this organism has been described only once. METHODS: To assess the susceptibility of H. pylori to the bactericidal activity present in normal human serum (NHS), we examined 13 H. pylori isolates. To assess the contributions of the classical and alternative complement pathways to killing, we added either C2-deficient or factor B-deficient serum, respectively, to heat-inactivated NHS. Also we assessed the ability of the strains to bind 125I-C3. RESULTS: After incubation for 60 minutes at 37 degrees C, all 13 H. pylori strains were killed by NHS; heating to 56 degrees C for 30 minutes ablated killing, indicating complement dependence for this phenomenon. In the absence of an antibody source, there was no killing when either an alternative or classical complement pathway source was used. Adding B-deficient serum to heat-inactivated normal human serum did not restore killing, but adding C2-deficient serum permitted partial killing. All of the 13 strains bound 125I-C3. Although the kinetics varied from strain to strain, C3 bound was significantly correlated (r = 0.61, p = 0.03) with serum susceptibility. CONCLUSIONS: H. pylori are susceptible to complement, alternative pathway activation appears critical, and C3 binding is a major locus of variability.     

Association of MSX1 and TGFB3 with nonsyndromic clefting in humans

Nonsyndromic cleft lip with or without cleft palate (CL/P) and nonsyndromic cleft palate only (CPO) are common congenital anomalies with significant medical, psychological, social, and economic ramifications. Both CL/P and CPO are examples of complex genetic traits. There exists sufficient evidence to hypothesize that disease loci for CL/P and CPO can be identified by a candidate-gene linkage-disequilibrium (LD) strategy. Candidate genes for clefting, including TGFA, BCL3, DLX2, MSX1, and TGFB3, were screened for LD with either CL/P or CPO in a predominantly Caucasian population, with both case-control- and nuclear-family-based approaches. Previously reported LD for TGFA with both CL/P and CPO could not be confirmed, except in CL/P patients with a positive family history. Also, in contrast to previous studies, no LD was found between BCL3 and either CL/P or CPO. Significant LD was found between CL/P and both MSX1 and TGFB3 and between CPO and MSX1, suggesting that these genes are involved in the pathogenesis of clefting. In addition, a mutation search in the genes DLX2, MSX1, and TGFB3 was performed in 69 CPO patients and in a subset of the CL/P patients. No common mutations were found in the coding regions of these genes; however, several rare variants of MSX1 and TGFB3 were found that may alter the latters' normal function. These results form the basis for future research, including (a) mutation searches in the MSX1 and TGFB3 genes in Caucasian CL/P patients and (b) extension of the search for MSX1 mutations in CPO patients to the noncoding regions.     

Mechanism of triazolo-benzodiazepine and benzodiazepine action in anxiety and depression: behavioral studies with concomitant in vivo CA1 hippocampal norepinephrine and serotonin release detection in the behaving animal

1. Real time, in vivo microvoltammetric studies were performed, using miniature carbon-based sensors, to concurrently detect norepinephrine (NE) release and serotonin (5-HT) release, in 2 separate electrochemical signals, within CA1 region of hippocampus in the freely moving and behaving, male, Sprague Dawley laboratory rat. 2. Concurrently, four parameters of open-field behavior, i.e. Ambulations, Rearing, Fine Movements and Central Ambulatory behavior (a measure of anxiety reduction behavior), were assayed by infrared photobeam detection. 3. Time course studies showed that the mechanism of action of the triazolobenzodiazepine (TBZD), adinazolam, (Deracyn) is dramatically different from that of the classical benzodiazepine (BZD), diazepam (Valium, i.e., adinazolam increased, whereas diazepam decreased, 5-HT release within CA1 region of hippocampus in the freely moving and behaving rat. 4. Adinazolam initially increased NE release and then decreased NE release in CA1 region of hippocampus in the freely moving and behaving rat whereas diazepam only decreased the electrochemical signal for NE; the decrease in NE produced by adinazolam was greater than the decrease in NE release produced by diazepam. 5. The Behavioral Activity Patterns, derived from same animal controls, simultaneously with detection of in vivo microvoltammetric signals for NE release and 5-HT release, showed that the BZD, diazepam, exhibited more potent sedative properties than did the TBZD adinazolam. 6. Hippocampal 5-HT and NE release effects of the TBZD, adinazolam, concomitant with behavioral effects lends explanation to the dual anxiolytic/antidepressant properties of the TBZDs.     

Intervention with PTCA and CABG following thrombolysis for acute myocardial infarction. Australian data from GUSTO 1 (1991-3) and International Study Group r-TPA-Streptokinase Mortality (1989) trials. Global Utilisation of Streptokinase and Tissue

Genotoxic stress triggers signalling pathways that either mediate cell killing or protection of affected cells. While induction of p53 is observed for most of the genotoxins, activation of MAPK/SAPK cascades is not a general response. The role of MAPK/SAPK activation on cell fate, seems to be dependent, in some systems, on the balanced response among both cascades. We have here examined the effect of cis and trans-DDP on the activation of ERK and JNK activities. While no significant induction of ERK was observed with the compounds, both of them are able to strongly activate JNK. Trans-DDP response is rapid and transient while the cis-DDP one is slow and persistent. In contrast with the observed nuclear translocation of JNK in response to U.V. light, none of the platinum compounds induces translocation, on the contrary, activation of JNK occurs in both the nuclear and cytoplasmic compartments. Inhibition of tyrosine phosphatases by orthovanadate pretreatment prolongs the time of JNK induction in response to both platinum compounds. The positive modulation of JNK activation correlates with an increase in toxicity that, for cis-DDP corresponds to a tenfold decrease in the IC50. A strong increase in MKP-1 levels was observed only in response to trans-DDP suggesting the involvement of this activity in the downregulation of JNK activity in response to this compound. Altogether the results suggest that the prolonged activation of JNK in response to cis-DDP contributes to cell death induction.     

Deconditioning reduces mineral content of the third metacarpal bone in horses

Diet and exercise are two management factors that affect bone density and strength. We proposed that bone density and calcium status would be affected by deconditioning for 12 wk and by dietary Ca concentration. Eleven highly conditioned Arabian horses were taken out of training and placed in stalls for 12 wk. Horses were walked on a mechanical walker in two 30-min sessions, 7 d/wk. Diets were designated CC (.36% Ca) and HC (.62% Ca). Data were collected every 21 d. Serum or plasma were analyzed for total and ionized Ca, parathyroid hormone, osteocalcin, hydroxyproline, electrolytes, and blood gases. Bone mineral content (BMC) of the left third metacarpal bone was estimated by radiographic photometry using an aluminum step wedge, which was exposed in each radiograph, as a reference standard for an image analysis system. During deconditioning, BMC decreased by approximately 1.1 g/2 cm, or .45% per week. This decrease was unaffected by dietary Ca. Serum Ca concentration increased with deconditioning. The results suggest that dietary Ca at twice the currently recommended level did not prevent the loss of BMC in response to deconditioning. Loss of BMC during 12 wk of stall confinement may weaken bones, increasing the risk of skeletal injuries when training is resumed.