Heat induced male sterility in Drosophila melanogaster: adaptive genetic variations among geographic populations and role of the Y chromosome.

We analyzed genetic variation among geographically diverse populations of Drosophila and showed that tropical flies are more tolerant than temperate ones to heat-induced male sterility, as assessed by the presence of both motile sperm and progeny production. In tropical populations, the temperature inducing 50% sterility (median threshold) is 1 degrees C above the value for temperate populations (30.4 vs.

The distribution of Echinococcus granulosus in moose: evidence for parasite-induced vulnerability to predation by wolves?

The role of parasites in influencing the trophic dynamics of hosts is becoming increasingly recognized in the ecological literature. Echinococcus granulosus is a tapeworm that relies on the predator-prey relationship between the definitive host (wolf, Canis lupus) and the intermediate host, (moose, Alces alces) to complete its life cycle. Heavy infection by E.

Photosystem II inhibition by moderate light under low temperature in intact leaves of chilling-sensitive and -tolerant plants.

Photosystem II (PSII) activity was examsined in leaves of chilling-sensitive cucumber (Cucumis sativus L.), tomato (Lycopersicum esculentum L.), and maize (Zea mays L.

Sperm size evolution in Drosophila: inter- and intraspecific analysis.

Numerous reports were devoted to the variation of sperm length in relation to sperm competition amongst species. However, studies on intraspecific variations of sperm size are very scarce and the number of sperm measured, very limited. This paper investigates within-individual, between-individual and between-population variation of sperm length in the two cosmopolitan species, D.

Characterization of Pasteurella multocida isolates from wetland ecosystems during 1996 to 1999.

We cultured 126 Pasteurella multocida isolates, 92 from water and 34 from sediment samples collected from wetlands in the Pacific and Central flyways of the United States between 1996 and 1999. Most (121) of the isolates were P. multocida serotype 1, but serotypes 3, 3/4, 10, and 11 were also found.

Enhanced rates of P700(+) dark-reduction in leaves of Cucumis sativus L photoinhibited at chilling temperature.

The changes in electron transport within photosystem I (PSI) were studied in detached leaves of Cucumis sativus L. during the course of irradiation with moderate white light (300 micromol photons m(-2) s(-1)) at 4 degrees C. When intact leaves were exposed to the combination of moderate light and low temperature, the amplitude of far-red light-induced P700 absorbance changes at 820 nm (deltaA(820)), a relative measure of PSI, progressively decreased as the light treatment time increased.

N,N,N',N'-tetramethyl-p-phenylenediamine initiates the appearance of a well-resolved I peak in the kinetics of chlorophyll fluorescence rise in isolated thylakoids.

Addition of N,N,N',N'-tetramethyl-p-phenylendiamine (TMPD) to thylakoid membranes isolated from pea leaves initiates the appearance of peak I in the polyphasic rise of chlorophyll (Chl) fluorescence observed during strong illumination, making it similar to that observed in leaves or intact chloroplasts. This effect depends on TMPD concentration and incubation period of isolated thylakoids with TMPD. The resolution of I-peak in the presence of weak concentrations of TMPD which reduced the overlap between I- and P-peaks, resulted from a decreased reduction of both fast and slow plastoquinone (PQ) pools of the granal and stromal thylakoids, respectively, as TMPD effectively accepts electrons from reduced PQ.

Phosphorylation-dependent paxillin-ERK association mediates hepatocyte growth factor-stimulated epithelial morphogenesis.

Activation of the hepatocyte growth factor (HGF) receptor c-met results in the regulation of cell-matrix interactions, including the MAPK-dependent stimulation of epithelial cell morphogenesis. In the present study we demonstrate that HGF stimulates the localization of ERK to sites of cell-matrix interactions and that this is mediated by the tyrosine phosphorylation-dependent association of inactive ERK and the focal adhesion complex protein paxillin. In addition, paxillin was found to associate with the upstream MAP kinases Raf and MEK, resulting in a complex that can mediate localized ERK activation.

Beta4 integrin and laminin 5 are aberrantly expressed in polycystic kidney disease: role in increased cell adhesion and migration.

Extracellular matrix alterations have been suggested to be part of the early events occurring in Autosomal Dominant Polycystic Kidney Disease (ADPKD), a disease characterized by formation of renal cysts and progressive renal failure. Here we report that cDNA array analysis identified beta(4) integrin aberrant expression in ADPKD cells. Furthermore, laminin 5 (Ln-5), the main alpha(6)beta(4) integrin ligand, was also found to be abnormally expressed in ADPKD.

The sperm roller: a modified testicular duct linked to giant sperm transport within the male reproductive tract.

The male reproductive tracts of Drosophila display considerable variation in the relative size of their components, notably of the testes, but there are few structural differences between species. Here we report a remarkable coiled structure separating the testes from the seminal vesicles in the giant sperm species Drosophila bifurca. This evolutionary novelty, known as the 'sperm roller', seems to be an exaggeration in the size of the testicular duct as revealed by light and electron microscopic observations.

Differentiation of dialects and courtship strategies in allopatric populations of Drosophila teissieri.

Intra-specific differentiation has been investigated between two geographically isolated populations of D. teissieri, one from Brazzaville (Congo) and the other from Silinda (Zimbabwe). Courtship songs were analyzed on 23 parameters.

Chronic wasting disease in free-ranging Wisconsin White-tailed Deer.

Three White-tailed Deer shot within 5 km during the 2001 hunting season in Wisconsin tested positive for chronic wasting disease, a prion disease of cervids. Subsequent sampling within 18 km showed a 3% prevalence (n=476). This discovery represents an important range extension for chronic wasting disease into the eastern United States.

Octogenarians reaching end-stage renal disease: cohort study of decision-making and clinical outcomes.

The fate of octogenarians reaching end-stage renal disease (ESRD) is poorly defined, and implicit dialysis rationing may be practiced in this age group. The main objectives of this study were to analyze the characteristics of pre-ESRD octogenarians offered dialysis or not and to identify factors influencing mortality while on dialysis, to improve prognosis assessment and decision-making. In this single-center cohort, 146 consecutive pre-ESRD octogenarians were referred to a nephrology unit over a 12-yr period (1989 to 2000).

[Frequency of anaemia and indications for treatment with epoetin in chronic renal failure at the pre-dialysis stage].

Objectives: To determine the degree of anaemia corresponding to the decreasing levels of renal function in patients with chronic renal failure (CRF) and not yet on dialysis, and to assess the indications for treatment with recombinant erythropoeitin (epoetin).

Methods: We studied the relationship between haemoglobin (Hb) concentration and creatinine clearance (Ccr) in 403 consecutive patients with CRF regularly monitored in nephrology consultations between January 1 and June 30, 1999, and who received appropriate iron and vitamin supplementation. These patients were then followed-up until June 30, 2000 or until maintenance dialysis was initiated.

Multiple parameter cytotoxicity index on dental alloys and pure metals.

Palladium (Pd) is a metal frequently used for dental alloys. In order to elucidate controversial options about Pd concerning its biological performances, our study consists in the evaluation of commercial and experimental PFM and C&B precious and semi-precious dental alloys. This investigation was also designated to the establishment of a cytotoxicity index (CI) such as it was described for hemocompatibility testing.

[Fabry disease in adulthood: clinical aspects and therapeutic progress].

Introduction: Fabry disease is an X-linked recessive abnormality of glycosphingolipid metabolism that is due to deficiency of the lysosomal enzyme alpha-galactosidase A.

Current Knowledge And Key Points: A majority of hemizygous men develop severe multisystemic disease (classic form), dominated by renal failure, progressive neurological and cardiac involvement. Nevertheless, some affected men retain sufficient enzyme activity and long remain asymptomatic (atypical form); their main manifestation is hypertrophic cardiomyopathy.

Renal disease in Fabry patients.

Renal dysfunction is a major complication in hemizygous males with Fabry disease. This often results in end-stage renal failure (ESRF), requiring dialysis or transplantation, on average 10 years after the start of renal impairment. ESRF usually occurs between 40 and 50 years of age, but may occur much earlier.

Pathogenesis of twin-twin transfusion syndrome: the renin-angiotensin system hypothesis.

In spite of active perinatal management, twin-twin transfusion syndrome (TTTS) remains a severe disease with a high risk of neonatal mortality and morbidity. TTTS initially results from an unbalanced blood flow from a donor to a recipient twin. However, its pathogenesis remains unclear, although cardiovascular disturbances and regulation of fetal volemia and diuresis seem central in this syndrome.

Medical treatment of cystinuria: critical reappraisal of long-term results.

Purpose: We evaluated long-term results of a contemporary medical therapeutic regimen in patients with cystinuria and analyzed factors predictive of therapeutic success.

Materials And Methods: A total of 27 adults with cystine urolithiasis were treated at our institution for 1.3 to 32 years (mean 11.

[Prevention of renal carcinoma: the nutri-genetic approach].

The development of renal cell carcinoma (RCC) has been associated with both genetic and environmental factors, with somatic and germline mutations in the von Hippel-Lindau (VHL) tumor suppressor gene and with tobacco smoking, obesity, long term exposure to some nutrients, pollutants, and industrial solvents such as trichloroethylene. Intra and interfamilial variability of expression of germline mutations in the VHL gene and variable susceptibility to carcinogens in the sporadic forms strongly suggest the involvement of conditional modifier genes. In order to identify sub groups of individuals at increased risk because of susceptibility genotypes, we have collected a series of 460 patients who developed an RCC and 79 families with the von Hippel Lindau disease.

PAX2 mutations in renal-coloboma syndrome: mutational hotspot and germline mosaicism.

The renal-coloboma syndrome (RCS, MIM 120330) is an autosomal dominant disorder caused by PAX2 gene mutations. We screened the entire coding sequence of the PAX2 gene for mutations in nine patients with RCS. We found five heterozygous PAX2 gene mutations: a dinucleotide insertion (2G) at position 619 in one sporadic RCS case, a single nucleotide insertion (619 + G) in three unrelated cases, and a single nucleotide deletion in a familial case.