Identification and functional analysis of novel mutations of the CLCNKB gene in Chinese patients with classic Bartter syndrome

Mutations in the gene CLCNKB encoding the ClC-Kb chloride channel causes classic Bartter syndrome, which is characterized by hypokalaemic metabolic alkalosis, renal salt loss, hyper-reninaemic hyperaldosteronism and normal blood pressure. We aimed to investigate the underlying mutations in CLCNKB in two Chinese patients with classic Bartter syndrome and then test the effect of the mutations on ClC-Kb chloride channel activity. Mutation analysis of CLCNKB was performed by polymerase chain reaction (PCR) direct sequencing. Expression of the wild-type and mutant ClC-Kb was heterologous in Xenopus laevis oocytes. We identified three novel CLCNKB gene mutations, including one homozygous missense mutation (R351W) in one patient and two compound heterozygous mutations (R30X and A210V) in the other. As determined by two-electrode voltage-clamp analysis of ClC-Kb channel activity, R30X abolished the current amplitude; A210V and R351W significantly reduced the current amplitude. A210V was almost as sensitive as the wild type to extracellular pH and calcium, whereas R351W removed extracellular calcium activation and markedly reduced alkaline pH activation of ClC-Kb. The three novel CLCNKB mutations we identified in two Chinese patients with classic Bartter syndrome have a role in altering the functional properties of ClC-Kb channels.

Diabetes, pre-diabetes and associated risks on Minnesota code-indicated major electrocardiogram abnormality among Chinese: a cross-sectional diabetic study in Fujian province, southeast China

The goal of this study was to determine the prevalence of diabetes mellitus (DM), impaired glucose regulation (IGR) and related metabolic disorders (overweight, obesity and hypertension) in a Chinese population (20-74 years old). An additional goal was to investigate the relationship between glucose metabolism and the Minnesota code-indicated major abnormal electrocardiogram (MA-ECG). There were 3960 individuals selected from urban and rural areas of Fujian, China from July 2007 to May 2008 by multistage-stratified sampling. Ultimately, data from 3208 subjects (20-74 years old) were analysed (including physical measurements, blood biochemical analysis, oral glucose tolerance test and 12-lead resting ECG). According to World Health Organization diagnostic criteria, the prevalence rates of DM and IGR were 9.51% (male, 10.08%; female, 9.14%) and 14.40% (male, 14.48%; female, 14.35%) respectively. Newly diagnosed DM was found in 53.44% of the diabetic subjects. Based on the 2000 China census, the age-standardized prevalence rates of DM and IGR were 7.19% (male, 7.74%; female, 6.61%) and 11.96 % (male, 12.35%; female, 11.56%) respectively. The age-standardized prevalence rates of DM and IGR in urban areas (7.74% and 12.97% respectively) were slightly but no significantly higher than in rural areas (6.67%, 10.86%). The prevalence rates of overweight, obesity and hypertension were 25.50%, 3.52% and 28.52% respectively (age- and sex- standardized rates: 23.69%, 3.02 % and 22.45 %). After adjusting for other confounding risk factors, multiple logistic regression analysis showed that DM and impaired glucose tolerance were independent risk factors for MA-ECG. Non-diabetic subjects with increased 30-min plasma glucose (PG) after an oral glucose load had a higher risk of MA-ECG after adjusting for other risk factors, especially in those with normal glucose tolerance but with 30-min PG >or= 7.8 mmol L(-1) (odds ratio = 1.371 [1.055-1.780]). The prevalence rates of DM and IGR as well as other metabolic disorders have increased dramatically in the last decade in China, especially in rural areas, with many undiagnosed cases of DM. Even slightly elevated PG levels may predict early cardiovascular events.

First Report of Choke Disease Caused by Epichloë typhina on Orchardgrass (Dactylis glomerata) in China

Orchardgrass or cocksfoot (Dactylis glomerata L.) has been widely cultivated as a forage crop in many provinces of China (1). It is also a native perennial forage grass, which grows at the edge of forests, shrubs, and mountainous grasslands in Xinjiang and Sichuan (2). In September of 2007, signs of choke disease on orchardgrass were observed in a native grassland under birch woodland near Altai City, Xinjiang, China. Stromata, which formed on culms of diseased grass, enclosing the inflorescence and leaf sheath, were 4.5 to 5.5 mm long, smooth or wrinkled, white and later becoming yellowish or yellow, tuberculate, dry, and covered with perithecia. Inflorescences surrounded by fungal stromata were choked and failed to mature, thus restricting seed production. Pure cultures were obtained by directly scraping stromata from the surface and incubating it on antibiotic potato dextrose agar (PDA). The colonies were cottony, white on the upper surface, and white to yellow on the reverse. The growth rate was 13 to 21 mm per week at 25°C on PDA. Conidia were hyaline, lunate to reniform, and measured 4.1 ± 0.5 × 2.2 ± 0.5 μm. They accumulated in small globose heads at the tips of conidiogenous cells and were produced singly on conidiophores of 13 to 33 μm long and 2.7 to 4.1 μm wide at the base. Internal transcribed spacer (ITS) sequence by BLAST search had 99% similarity with an Epichloë typhina isolate of orchardgrass in Spain (GenBank Accession No. AM262420.1). Cultural characteristics, microscopic examination, and phylogenetic analysis showed that this choke disease on D. glomerata was caused by the fungus E. typhina (Pers.) Tul. & C. Tul. as described by White (4). To our knowledge, this is the first report of E. typhina causing choke disease on orchardgrass in China. The pathogen has been identified in France, England, Germany, Sweden, Switzerland, and the United States (3,4) with the same symptoms as those reported here. In 1997, choke disease was found in 70% of the fields in the Willamette Valley of Oregon, with disease incidences ranging from 0.05 to 28%. It was predicted to increase and spread under the prevailing climatic conditions (3). This new disease report is to provide observational and diagnostic information to help with recognition and prevention of disease spread in orchardgrass cultivation regions of China. References: (1) X. R. Chao et al. Shandong Agric. Sci. 1:7, 2005. (2) S. X. Jia, ed. China Forage Plant Flora. China Agriculture Press, Beijing, 1987. (3) W. F. Pfender and S. C. Alderman. Plant Dis. 83:754, 1999. (4) J. W. White. Mycologia 85:444, 1993.

Investigation of the neural substrates of voice recognition in Chinese schizophrenic patients with auditory verbal hallucinations: an event-related functional MRI study

OBJECTIVE

Auditory hallucinations (AVHs), like real auditory perceptions, are often perceived as familiar voices. Given that neural correlates of AVHs involve the auditory cortex, it is likely that those brain regions responsible for recognition of voice identity are invoked during AVHs.

METHOD

Schizophrenic patients with (n = 13) and without (n = 13) auditory hallucinations, and 13 healthy subjects performed a voice recognition task during functional magnetic resonance imaging at 1.5 T. In the task using prerecorded vocal stimuli, they classified voice as familiar and unfamiliar.

RESULTS

Under the familiar minus unfamiliar contrasts, cerebral activation pattern is different in the three groups and patients with auditory hallucinations showed less activation in the right temporal lobe than controls.

CONCLUSION

Voice recognition was impaired in patients with AVHs. Our results support that auditory association cortices play a role in the perception of AVHs.

Cerebral White Matter Lesions and Cognitive Function in a Non-demented Chinese Veteran Cohort

This study examined the association between cerebral white matter lesions (WMLs) and cognitive function in a male, non-demented Chinese veteran cohort. A total of 662 participants underwent CT scan and cognitive function assessments; 51 were excluded from the analysis because they exhibited non-lacunar infarcts or suspected dementia. Subjects were allocated to one of four groups according to WML status and between-group comparisons were made for seven cognitive function tests. Logistic regression was used to assess odds ratios for impaired performance associated with WML status. In all cognitive tests, subjects with severe WMLs differed significantly from those without WMLs or with mild WMLs, and in three tests subjects with severe WMLs differed significantly from those with moderate WMLs. For each cognitive test severe WMLs were strongly associated with increased risk of impaired performance. Severe WMLs were associated with greater diminished cognitive function and there may be a WML threshold after which, in elderly Chinese subjects, an impact on cognitive function occurs.

Omega-3 polyunsaturated fatty acid supplementation reduces hypertension in TGR(mRen-2)27 rats

To establish the effect of dietary omega-3 PUFA on angiotensin II (ANG II)-mediated hypertension, male TGR (mRen-2)27 (Ren-2) rats (animals with high ANG II activity) were maintained on a diet either deficient or sufficient in omega-3 PUFA from conception. Half the animals on each diet were treated with the angiotensin-converting enzyme inhibitor, perindopril, from birth. Ren-2 rats fed the omega-3 PUFA deficient diet were significantly more hypertensive than those fed the omega-3 PUFA sufficient diet. Perindopril reduced the blood pressure of both omega-3 PUFA-deficient and omega-3 PUFA-sufficient diet-fed Ren-2 rats. Body weight, body fat and plasma leptin were reduced by perindopril treatment but not affected by omega-3 PUFA supply. Given that the elevated blood pressure of the Ren-2 rat is mediated by ANG II, the data suggest that omega-3 PUFA may reduce hypertension via the renin-angiotensin system.

Pharmacokinetics of lenalidomide in subjects with various degrees of renal function

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Background: Lenalidomide is a novel oral immunomodulatory drug approved for treating myelodysplastic syndrome (MDS) and multiple myeloma (MM). As unchanged lenalidomide is eliminated predominantly by urinary excretion, the present study investigated the effect of renal impairment (RI) on pharmacokinetics (PK) of lenalidomide. Results were used to refine initial dosing recommendations based on a subject’s estimated creatinine clearance. Methods: The study was conducted at 3 clinical centers. Thirty male and female subjects aged 39–76 years were stratified into 5 groups based on their creatinine clearance (CLCr) values: normal renal function (NRF) (CLCr > 80 mL/min; N = 7), mild RI (50 = CLCr = 80 mL/min; N = 5), moderate RI (30 = CLCr < 50 mL/min; N = 6), severe RI (CLCr < 30 mL/min, but not on dialysis; N = 6), and end stage renal disease (ESRD, requiring dialysis; N = 6). Subjects with NRF, mild, moderate or severe RI received a single 25-mg oral dose of lenalidomide. Subjects with ESRD received 2 single 25 mg doses which were separated by 7–10 days: one dose on a non-dialysis day and the other dose 3 hours before a 4-hour haemodialysis. Assessments included PK and safety parameters. Results: All subjects completed the study. Total and renal clearance of lenalidomide were strongly correlated with CLCr (R > 0.9, p < 0.01). As a result, AUC8 increased with decreasing CLCr. The mean difference in AUC8 between NRF and mild RI was < 20%. Compared with the pooled data from NRF and mild RI groups, mean AUC8 increased approximately 140% in moderate RI, 240% in severe RI, and 360% in ESRD (off dialysis). There was no correlation between Cmax or Tmax and CLCr. Approximately 10% of the dose was recovered in the dialysate of subjects with ESRD. Protein binding of lenalidomide was not markedly affected by RI (∼35 - 44%). The drug was well tolerated. On the basis of these data, recommendations for initial starting doses were made ( Table below). Conclusions: Lenalidomide dosage adjustment should be considered for patients with CLCr < 50 mL/min.

[Table: see text]

No significant financial relationships to disclose.

The importance of company: Na+ and Cl- influence substrate interaction with SLC6 transporters and other proteins

SLC6 transporters, which include transporters for gamma-aminobutyric acid (GABA), norepinephrine, dopamine, serotonin, glycine, taurine, L-proline, creatine, betaine, and neutral cationic amino acids, require Na+ and Cl- for their function, and this review covers the interaction between transporters of this family with Na+ and Cl- from a structure-function standpoint. Because detailed structure-function information regarding ion interactions with SLC6 transporters is limited, we cover other proteins cotransporting Na+ or Cl- with substrate (SLClA2, PutP, SLC5A1, melB), or ion binding to proteins in general (rhodanese, ATPase, LacY, thermolysine, angiotensin-converting enzyme, halorhodopsin, CFTR). Residues can be involved in directly binding Na+ or Cl-, in coupling ion binding to conformational changes in transporter, in coupling Na+ or Cl- movement to transport, or in conferring ion selectivity. Coordination of ions can involve a number of residues, and portions of the substrate and coupling ion binding sites can be distal in space in the tertiary structure of the transporter, with other portions that are close in space thought to be crucial for the coupling process. The reactivity with methanethiosulfonate reagents of cysteines placed in strategic positions in the transporter provides a readout for conformational changes upon ion or substrate binding. More work is needed to establish the relationships between ion interactions and oligomerization of SLC6 transporters.

Somatic cell nuclear transfer using transported in vitro-matured oocytes in cynomolgus monkey

Somatic cell nuclear transfer (SCNT) is not successful so far in non-human primates. The objective of this study was to investigate the effects of stimulation cycles (first and repeat) on oocyte retrieval and in vitro maturation (IVM) and to evaluate the effects of stimulation cycles and donor cell type (cumulus and fetal skin fibroblasts) on efficiency of SCNT with transported IVM oocytes. In this study, 369 immature oocytes were collected laparoscopically at 24 h following human chorionic gonadotrophin (hCG) treatment from 12 cynomolgus macaque (Macaca fascicularis) in 24 stimulation cycles, and shipped in pre-equilibrated IVM medium for a 5 h journey, placed in a dry portable incubator (37 °C) without CO2 supplement. A total of 70.6% (247/350) of immature oocytes reached metaphase II (MII) stage at 36 h after hCG administration, MII spindle could be seen clearly in 80.6% (104/129) of matured IVM oocytes under polarized microscopy. A total of 50.0% (37/74) of reconstructive SCNT embryos cleaved after activation; after cleavage, 37.8% (14/37) developed to the 8-cell stage and 8.1% (3/37) developed to morula, but unfortunately none developed to the blastocyst stage. Many more oocytes could be retrieved per cycle from monkeys in the first cycle than in repeated cycles (19.1 vs. 11.7, p < 0.05). There were no significant differences in the maturation rate (70.0 vs. 71.4%, p > 0.05) and MII spindle rate under polarized microscopy (76.4 vs. 86.0%, p > 0.05) between the first and repeat cycles. There were also no significant differences in the cleavage rate, and the 4-cell, 8-cell and morula development rate of SCNT embryos between the first and repeat cycles. When fibroblast cells and cumulus cells were used as the donor cells for SCNT, first cleavage rate was not significantly different, but 4-cell (50.0 vs. 88.9%, p < 0.05) and 8-cell (0 vs. 51.9%, p < 0.01) development rate were significantly lower for the former. In conclusion, the number of stimulation cycles has a significant effect on oocyte retrieval, but has no effect on maturation and SCNT embryo development; however, different donor cell types (cumulus and fibroblast) resulted in different developmental potentials of SCNT embryos.

Effects of immunisation against leptin on feed intake, weight gain, fat deposition and laying performance in chickens

1. Three experiments were conducted to study the effects of leptin on weight gain and body composition in laying hens. 2. The effects of immunisation against chicken leptin on feed intake (FI), fat deposition and laying rate were observed in laying Guangdong yellow-feathered hens. Ten hens were inoculated with leptin immunogen on d 3, 31, 63 and 84, together with 10 control hens immunised with bovine serum albumin (BSA). In the 100-d experiment, immunisation against leptin increased blood anti-leptin antibody titres, slightly reduced plasma T3 concentrations, slightly decreased FI and increased live weight; however, laying rate was significantly depressed and abdominal fat mass was increased by the end of the 100-d experiment. 3. Passive immunisation of 50-d-old pullets with yolk extract containing anti-leptin antibody IgY significantly increased FI within 6 h of treatment compared with physiological saline treated controls. 4. In growing 70-d-old pullets, inoculation with 0.5 (group 1) or 1 (group 2) ml leptin immunogen on d 1 and 28 of the experiment slightly increased FI and significantly increased daily gain compared with BSA-immunised control pullets. Abdominal fat mass on d 49 increased from 48+/-4.5 g in controls to 66+/-3.5 and 80+/-3.1 g in groups 1 and 2, respectively. 5. It was suggested that immunisation against leptin mimicked loss of leptin bioactivity and might become a novel technique to stimulate fat growth in certain types of animal production.

A genomic view of the sea urchin nervous system

The sequencing of the Strongylocentrotus purpuratus genome provides a unique opportunity to investigate the function and evolution of neural genes. The neurobiology of sea urchins is of particular interest because they have a close phylogenetic relationship with chordates, yet a distinctive pentaradiate body plan and unusual neural organization. Orthologues of transcription factors that regulate neurogenesis in other animals have been identified and several are expressed in neurogenic domains before gastrulation indicating that they may operate near the top of a conserved neural gene regulatory network. A family of genes encoding voltage-gated ion channels is present but, surprisingly, genes encoding gap junction proteins (connexins and pannexins) appear to be absent. Genes required for synapse formation and function have been identified and genes for synthesis and transport of neurotransmitters are present. There is a large family of G-protein-coupled receptors, including 874 rhodopsin-type receptors, 28 metabotropic glutamate-like receptors and a remarkably expanded group of 161 secretin receptor-like proteins. Absence of cannabinoid, lysophospholipid and melanocortin receptors indicates that this group may be unique to chordates. There are at least 37 putative G-protein-coupled peptide receptors and precursors for several neuropeptides and peptide hormones have been identified, including SALMFamides, NGFFFamide, a vasotocin-like peptide, glycoprotein hormones and insulin/insulin-like growth factors. Identification of a neurotrophin-like gene and Trk receptor in sea urchin indicates that this neural signaling system is not unique to chordates. Several hundred chemoreceptor genes have been predicted using several approaches, a number similar to that for other animals. Intriguingly, genes encoding homologues of rhodopsin, Pax6 and several other key mammalian retinal transcription factors are expressed in tube feet, suggesting tube feet function as photosensory organs. Analysis of the sea urchin genome presents a unique perspective on the evolutionary history of deuterostome nervous systems and reveals new approaches to investigate the development and neurobiology of sea urchins.

Weekly paclitaxel, oxaliplatin, 5-FU and leucovorin in the treatment of metastatic pancreatic cancer

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Background: Patients with metastatic PC have poor prognosis due to lack of effective treatment options. We did a pilot study on weekly chemotherapy with TOFL in the treatment of patients with advanced PC associated with severe clinical symptoms. Methods: 4 patients age 35 to 56 with biopsy proven metastatic PC were treated with weekly T: 50 mg/m2, O: 60 mg/m2, L: 20 mg/m2 and F: 425 mg/m2. One patient (A.B.) also received intermittent Cetuximab. Pre-medication with I.V. Glutathione and calcium magnesium was routinely used to prevent Oxaliplatin-related sensory neuropathy. Patients were seen every week. Sequential CA19–9 levels and CT scans were obtained for followup. Results: After 12 weeks of treatments, all 4 patients had dramatic reduction of CA 19–9 levels (see table) and improvement of cancer-related symptoms. 3 patients now have normalization of CA19–9 levels. Patient D.P. had bilirubin of 27 and severe abdominal pain after disease progression following first-line chemotherapy. His bilirubin returned to normal range and abdominal pain resolved after 6 weeks on the protocol. Patient A.B. was severely debilitated (ECOG 4) following progression of disease after 2 prior lines of chemotherapy. He is now alive over a year with PR and ECOG 1. Patient L.C. presented with bilirubin of 9.6, nausea and abdominal pain. Her total bilirubin normalized and GI symptoms resolved after 12 weeks. Patient I.S. had disease progression with liver metastasis and worsening abdominal pain after failing 2 lines of prior chemotherapy. Her CA 19–9 decreased by over 80% and abdominal pain resolved after 12 weeks. The regimen was well tolerated with only one grade 3 neurotoxicity. Conclusions: Weekly combination of Paclitaxel, Oxaliplatin, 5-Fu and Leucovorin has significant activity against advanced PC with manageable side effects. Phase II study is underway. [Table: see text]

No significant financial relationships to disclose.

Atomic force microscopy studies of conditioner thickness distribution and binding interactions on the hair surface

The way in which common hair care products, such as conditioner, deposit onto and change hair properties is of interest in beauty care science, as these properties are closely tied to product performance. The binding interaction between conditioner and the hair surface is one of the important factors in determining the conditioner thickness distribution and consequently the proper functions of conditioner. In this study, atomic force microscopy was used to obtain the local conditioner thickness distribution, adhesive forces and effective Young's modulus mapping of various hair surfaces. The conditioner thickness was extracted by measuring the forces on the atomic force microscopy tip as it approached, contacted and pushed through the conditioner layer. The effective Young's moduli of various hair surfaces were calculated from the force distance curves using Hertz analysis. The intrinsic binding interactions between different silicones and the hair surface on the microscopic scale, as well as their effect on the effective Young's modulus of the hair, are also discussed. It was found that the effective Young's modulus of the hair is strongly affected by the binding of conditioner molecules on the hair surface.

Complete coding sequences of the rabbitpox virus genome

Rabbitpox virus (RPXV) is highly virulent for rabbits and it has long been suspected to be a close relative of vaccinia virus. To explore these questions, the complete coding region of the rabbitpox virus genome was sequenced to permit comparison with sequenced strains of vaccinia virus and other orthopoxviruses. The genome of RPXV strain Utrecht (RPXV-UTR) is 197 731 nucleotides long, excluding the terminal hairpin structures at each end of the genome. The RPXV-UTR genome has 66.5 % A + T content, 184 putative functional genes and 12 fragmented ORF regions that are intact in other orthopoxviruses. The sequence of the RPXV-UTR genome reveals that two RPXV-UTR genes have orthologues in variola virus (VARV; the causative agent of smallpox), but not in vaccinia virus (VACV) strains. These genes are a zinc RING finger protein gene (RPXV-UTR-008) and an ankyrin repeat family protein gene (RPXV-UTR-180). A third gene, encoding a chemokine-binding protein (RPXV-UTR-001/184), is complete in VARV but functional only in some VACV strains. Examination of the evolutionary relationship between RPXV and other orthopoxviruses was carried out using the central 143 kb DNA sequence conserved among all completely sequenced orthopoxviruses and also the protein sequences of 49 gene products present in all completely sequenced chordopoxviruses. The results of these analyses both confirm that RPXV-UTR is most closely related to VACV and suggest that RPXV has not evolved directly from any of the sequenced VACV strains, since RPXV contains a 719 bp region not previously identified in any VACV.