Localization of bumetanide- and thiazide-sensitive Na-K-Cl cotransporters along the rat nephron

The present study was undertaken to investigate the mRNA localization of the two major kidney-specific Na-K-Cl transport proteins, the bumetanide-sensitive cotransporter (NKCC2 in rabbit and BSC1 in rat) and the thiazide-sensitive cotransporter (TSC). NKCC2 from rabbit and mouse has been shown to exist in three isoforms (designated A, B, and F) that differ only in a 96-bp region. The divergent region of each of the three NKCC2 isoforms was cloned from rat kidney by a polymerase chain reaction (PCR)-based strategy, and isoform-specific primers were chosen. RNA and cDNA were prepared from renal cortex and medulla and from microdissected nephron segments. Using reverse transcription (RT)-PCR, the B isoform was detected only in cortex and the F isoform only in medulla, whereas the A from was found in both. In dissected nephron segments, the B form was found exclusively in cortical thick ascending limb (CTAL) and macula densa-containing segment (MDCS), the F form only in medullary thick ascending limb (MTAL) and outer medullary collecting duct, and the A form in CTAL, MDCS, and MTAL. An additional isoform including both A and F exons was identified by direct sequencing of a 592-bp product from medulla. The AF product was found only in the medulla and was localized exclusively in MTAL. TSC mRNA was detected exclusively in the distal convoluted tubule. Differential nephron localization of NKCC2 isoforms suggests that Na-K-Cl cotransporters may differ in their transport characteristics to explain regulation of salt transport along the nephron.

Tubuloglomerular feedback: new concepts and developments

Luminal [NaCl] at the macula densa (MD) has two established effects: regulation of glomerular arteriolar resistance through tubuloglomerular feedback (TGF) and control of renin secretion. TGF acts as a minute-to-minute stabilizer of distal salt delivery, thereby minimizing the impact of random perturbations in filtration and absorption forces on NaCl excretion. During long-lasting perturbations of MD [NaCl], control of renin secretion becomes the dominant function of the MD. The potentially maladaptive effect of TGF under chronic conditions is prevented by TGF adaptations permitting adjustments in glomerular filtration rate to occur. TGF adaptation is mechanistically coupled to the endpoint targeted by chronic deviations in MD [NaCl], the rate of local and systemic angiotensin II generation. Studies of TGF in transgenic mice are expected to provide further insights into the mechanisms mediating between luminal [NaCl] and afferent arterioles. TGF responses are virtually abolished in mice in which either the AT1A gene or the angiotensin converting enzyme gene is rendered nonfunctional by homologous recombination. In contrast, TGF responses are unaltered in nitric oxide synthase I knockout mice. Thus, an intact renin-angiotensin system appears to be critical for the TGF signaling pathway.

Comparison of 0.25 mg and 0.1 mg intrathecal morphine for analgesia after Cesarean section

PURPOSE

To test the hypothesis that 0.1 mg intrathecal morphine plus NSAIDs provides satisfactory analgesia post-Cesarean section with fewer side effects than 0.25 mg intrathecal morphine.

METHODS

Sixty women, scheduled for elective Cesarean section under spinal anesthesia, were randomized to receive either 0.1 mg or 0.25 mg intrathecal morphine combined with hyperbaric bupivacaine 0.75% and 20 microg fentanyl. All patients received a 100 mg indomethacin suppository at the end of surgery and 500 mg naproxen p.o. b.i.d. was started the evening of surgery and continued until discharge. A blinded researcher recorded the pain, pruritus, and nausea scores, the time to first request for additional analgesics, a visual analogue scale (VAS) satisfaction score, and the use of additional opioids, antipruritics, and/or antiemetics.

RESULTS

Of the 60 patients enrolled, two were not included in the data analysis because of protocol violations leaving 30 patients in the 0.1 mg group and 28 in the 0.25 mg group. There were no differences in the VAS pain scores or the number of women requesting an opioid other than codeine between the two groups. The VAS pruritus scores in the 0.1 mg group were lower throughout the 24 hr (P < 0.001). Fewer women in the 0.1 mg group (4/30 vs 12/28) requested nalbuphine to treat itching (P = 0.018). Nausea scores were lower in the 0.1 mg group (P < 0.001).

CONCLUSION

The use of 0.1 mg intrathecal morphine plus NSAIDs provides analgesia of similar quality to 0.25 mg but with fewer undesirable side effects following Cesarean section.

Nicotine inhibits voltage-dependent sodium channels and sensitizes vanilloid receptors

Nicotine is an alkaloid that is used by large numbers of people. When taken into the body, it produces a myriad of physiological actions that occur primarily through the activation of neuronal nicotinic acetylcholine receptors (nAChRs). We have explored its ability to modulate TRPV1 receptors and voltage-gated sodium channels. The reason for investigating nicotine's effect on sodium channels is to obtain a better understanding of its anti-nociceptive properties. The reasons for investigating its effects on capsaicin-activated TRPV1 channels are to understand how it may modulate this channel that is involved in pain, inflammation, and gustatory physiology. Whole cell patch-clamp recordings from rat trigeminal ganglion (TG) nociceptors revealed that nicotine exhibited anesthetic properties by decreasing the number of evoked action potentials and by inhibiting tetrodotoxin-resistant sodium currents. This anesthetic property can be produced without the necessity of activating nAChRs. Nicotine also modulates TRPV1 receptors inducing a several-fold increase in capsaicin-activated currents in both TG neurons and in cells with heterologously expressed TRPV1 receptors. This sensitizing effect does not require the activation of nAChRs. Nicotine did not alter the threshold temperature (approximately 41 degrees C) of heat-activated currents in TG neurons that were attributed to arise from the activation of TRPV1 receptors. In this regard, its effect on TRPV1 receptors differs from those of ethanol that has been shown to increase the capsaicin-activated current but decrease the threshold temperature. These studies document several new effects of nicotine on channels involved in nociception and indicate how they may impact physiological processes involving pain and gustation.

Partial hepatectomy for ruptured hepatocellular carcinoma

BACKGROUND

Improvements in surgical technique and perioperative care have made partial hepatectomy a safe and effective treatment for hepatocellular carcinoma (HCC), even in the event of spontaneous HCC rupture.

METHODS

A consecutive cohort of patients who underwent partial hepatectomy for HCC between 2000 and 2009 was divided into a ruptured group and a non-ruptured group. Patients with ruptured HCC were further divided into emergency and staged hepatectomy subgroups. Mortality and morbidity, overall survival and recurrence-free survival (RFS) were compared. Prognostic factors for overall survival and RFS were identified by univariable and multivariable analyses.

RESULTS

A total of 1233 patients underwent partial hepatectomy for HCC, of whom 143 had a ruptured tumour. The morbidity and mortality rates were similar in the ruptured and non-ruptured groups, as well as in the emergency and staged subgroups. In univariable analyses, overall survival and RFS were lower in the ruptured group than in the non-ruptured group (both P < 0·001), and also in the emergency subgroup compared with the staged subgroup (P = 0·016 and P = 0·025 respectively). In multivariable analysis, spontaneous rupture independently predicted poor overall survival after hepatectomy (hazard ratio 1·54, 95 per cent confidence interval 1·24 to 1·93) and RFS (HR 1·75, 1·39 to 2·22). Overall survival and RFS after hepatectomy for ruptured HCC in the emergency and staged subgroups were not significantly different in multivariable analyses.

CONCLUSION

Spontaneous rupture predicted poor long-term survival after hepatectomy for HCC, but surgical treatment seems possible, safe and appropriate in selected patients.

Anti-minK antisense decreases the amplitude of the rapidly activating cardiac delayed rectifier K+ current

The rapidly and slowly activating delayed rectifier K+ currents (IKr and IKs, respectively), which have different physiological properties have been identified in cardiac cells from several species, including humans. Although expression of the minimal K+ channel protein (minK) cDNA in some systems results in a current resembling IKs, the role of this gene product in channel function remains controversial. In atrial tumor myocytes (AT-1 cells), no IKs is recorded, but minK mRNA is detected, raising the possibility that expression of the minK gene serves an as-yet-unidentified function. In these experiments, AT-1 cells were exposed to antisense oligonucleotides targeting the 5' translation start site of the minK cDNA cloned from an AT-1 library. Cell size, IKr, and L-type and T-type Ca2+ currents were measured 24 to 48 hours after exposure and compared with data in cells exposed to the corresponding sense oligonucleotide or grown in medium only. Antisense oligonucleotide significantly reduced IKr compared with sense and medium-only control cells in 0 of 2 experiments (n = 3 to 6 cells per treatment in each experiment) at 50 nmol/L, 1 of 2 at 250 nmol/L, 6 of 6 at 1000 nmol/L, and 2 of 2 at 10,000 nmol/L. At 1000 nmol/L, maximum tail current in antisense-exposed cells was 2.5 +/- 0.1 pA/pF (mean +/- SEM, n = 28, 6 separate experiment), 6.6 +/- 0.4 pA/pF in sense-exposed cells (n = 27), 5.4 +/- 0.6 pA/pF in medium-only cells (n = 21), and 5.8 +/- 0.7 pA/pF in cells exposed to a random oligonucleotide (n = 9).(ABSTRACT TRUNCATED AT 250 WORDS)

Sex chromosome positions in human interphase nuclei as studied by in situ hybridization with chromosome specific DNA probes

Two cloned repetitive DNA probes, pXBR and CY1, which bind preferentially to specific regions of the human X and Y chromosome, respectively, were used to study the distribution of the sex chromosomes in human lymphocyte nuclei by in situ hybridization experiments. Our data indicate a large variability of the distances between the sex chromosomes in male and female interphase nuclei. However, the mean distance observed between the X and Y chromosome was significantly smaller than the mean distance observed between the two X-chromosomes. The distribution of distances determined experimentally is compared with three model distributions of distances, and the question of a non-random distribution of sex chromosomes is discussed. Mathematical details of these model distributions are provided in an Appendix to this paper. In the case of a human translocation chromosome (Xqter----Xp22.2::Yq11----Yqter) contained in the Chinese hamster X human hybrid cell line 445 X 393, the binding sites of pXBR and CY1 were found close to each other in most interphase nuclei. These data demonstrate the potential use of chromosome-specific repetitive DNA probes to study the problem of interphase chromosome topography.

Bevacizumab (Bev) in combination with XELOX or FOLFOX4: Updated efficacy results from XELOX-1/ NO16966, a randomized phase III trial in first-line metastatic colorectal cancer

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Background: NO16966 is the first phase III trial to evaluate the combination of Bev with oxaliplatin-based chemotherapy (FOLFOX4 or the XELOX regimen) in the first-line setting. Methods: 1401 pts were randomized to receive FOLFOX4 (oxaliplatin, 5-FU, leucovorin as described previously) or XELOX (oxaliplatin 130mg/m2 iv, capecitabine 1000mg/m2 bid oral d1–14, q3w) plus Bev (5mg/kg q 2 weeks for FOLFOX, 7.5mg/kg q 3 weeks for XELOX) or Placebo in a 2x2 factorial design. Results: The addition of Bev to oxaliplatin-based chemotherapy demonstrated a significant benefit in terms of PFS in the primary analysis (HR 0.83; 97.5% CI 0.72- 0.95, p=0.0023). Prespecified analysis of PFS on treatment (defined as progressive disease or death within 28 days from the last dose of study treatment) and PFS analysis based on tumor assessments by an independent review committee (IRC) were consistent with the benefit observed in the primary analysis. PFS results are shown in Table 1 . 34% of patients have died and the median follow-up for survival at this time is 18.6 months. Mature overall survival data will be presented at the meeting. Conclusions: This large, international phase III trial demonstrates that the addition of Bev to oxaliplatin-based chemotherapy regimens significantly improves PFS.

[Table: see text]

[Table: see text]

Effectiveness of continuous and pulsed ultrasound for the management of knee osteoarthritis: a systematic review and network meta-analysis

BACKGROUND

To investigate the efficacy of continuous and pulsed ultrasound (US) in the management of knee osteoarthritis (OA).

DESIGN

This systematic review and network meta-analysis covered 12 trials in total. Electronic databases including MEDLINE, Embase and Cochrane Library were searched through to identify randomized controlled trials comparing the two modes of US with control interventions (sham or blank) or with each other. Bayesian network meta-analysis was used to integrate both the direct and indirect evidences on treatment effectiveness.

RESULTS

Pulsed US (PUS) is more effective in both pain relief and function improvement when compared with the control group; but for continuous US (CUS), there is only a significant difference in pain relief in comparison with the control group. In addition, no matter in terms of pain intensity or function at the last follow-up time point, PUS always exhibited a greater probability of being the preferred mode. However, the evidence of heterogeneity and the limitation in sample size of some studies could be a potential threat to the validity of results.

CONCLUSIONS

Our findings indicated that PUS, with a greater probability of being the preferred mode, is more effective in both pain relief and function improvement when compared with the control group. However, CUS could only be considered as a pain relief treatment in the management of knee OA. The findings also confirmed that none of these modes is dangerous.

LEVEL OF EVIDENCE

Level II, systematic review and network meta-analysis of randomized controlled trials.

An improved version of embolic model of brain ischemic injury in the rat

A modified version of focal embolic stroke model has been developed in rats. Ischemic injury was induced by injection of a pre-formed clot into the middle cerebral artery (MCA). In the first series of experiments, the model was validated. Embolizing a pre-formed clot resulted in an infarction in the territory irrigated by the MCA. At 48 h after embolization, 2,3,5-triphenyltetrazolium chloride (TTC) staining showed that infarction volume was 42.1+/-15.6% (mean+/-S.D.) when 5 microl clot was injected (n=8) and 28.4+/-8.6% in the animals received 3.5 microl clot (n=8). The infarction volume between these two groups showed a significant difference (P<0.05). In the second series of experiments, the natural dissolution of the clot in the MCA was studied. Five min after embolization (n=6), clots were observed in the MCA of all the animals. Clots in the MCA were seen in 68 and 29% of the animals at 1 and 3 h, respectively, after embolization. These results suggest that the procedure described here produces a reliable and reproducible ischemic injury. The clots injected were dissolved in the MCA in relatively short period of time. The model shows a close similarity to thromboembolic stroke in human, and it provides a useful tool to investigate mechanisms and test thrombolytic agents in ischemic brain injury.

Coordinate regulation of renal expression of nitric oxide synthase, renin, and angiotensinogen mRNA by dietary salt

Experiments were performed to examine the effect of changes in dietary salt intake on the neuronal form of the constitutive nitric oxide synthase (ncNOS, type I NOS), renin, and angiotensinogen mRNA expression in the kidney. Three groups of Sprague-Dawley rats were studied as follows: rats maintained on a 3% Na diet plus 0.45% NaCl in the drinking fluid for 7 days (high salt), rats given a single injection of furosemide (2 mg/kg i.p.) and a 0.03% Na diet for 7 days (low salt), and rats on a diet containing 0.2% Na (control). mRNA expression was assessed with reverse transcription-polymerase chain reaction (RT-PCR) methods using cDNA prepared from samples of renal cortex and microdissected tubular segments. ncNOS PCR products were quantified by comparison with a dilution series of a mutant deletion template. Compared with their respective control, ncNOS mRNA levels in renal cortical tissue were elevated in rats on a low-salt diet and reduced in rats on a high-salt diet. Similar changes were seen in the expression of renin and angiotensinogen mRNA. Dietary salt intake did not alter the mRNA levels for ncNOS from the inner medulla or for endothelial constitutive NOS (ecNOS, type III NOS) and inducible NOS (iNOS, type II NOS) in the renal cortex. ncNOS mRNA was found in glomeruli dissected with the macula densa-containing segment (MDCS), but only at marginal levels in glomeruli without MDCS. Furthermore, a low-salt diet stimulated ncNOS mRNA in glomeruli with MDCS by 6.2-fold compared with a high-salt diet. There was no effect of salt diet on ncNOS mRNA in glomeruli without MDCS or in inner medullary collecting ducts. These results suggest that ncNOS expression in macula densa cells is inversely regulated by salt intake, thus following the known response of the renin-angiotensin system to changes in salt balance.

Expression of peroxisomal proliferator-activated receptors and retinoid X receptors in the kidney

The discovery that 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) is a ligand for the gamma-isoform of peroxisome proliferator-activated receptor (PPAR) suggests nuclear signaling by prostaglandins. Studies were undertaken to determine the nephron localization of PPAR isoforms and their heterodimer partners, retinoid X receptors (RXR), and to evaluate the function of this system in the kidney. PPARalpha mRNA, determined by RT-PCR, was found predominately in cortex and further localized to proximal convoluted tubule (PCT); PPARgamma was abundant in renal inner medulla, localized to inner medullary collecting duct (IMCD) and renal medullary interstitial cells (RMIC); PPARbeta, the ubiquitous form of PPAR, was abundant in all nephron segments examined. RXRalpha was localized to PCT and IMCD, whereas RXRbeta was expressed in almost all nephron segments examined. mRNA expression of acyl-CoA synthase (ACS), a known PPAR target gene, was stimulated in renal cortex of rats fed with fenofibrate, but the expression was not significantly altered in either cortex or inner medulla of rats fed with troglitazone. In cultured RMIC cells, both troglitazone and 15d-PGJ2 significantly inhibited cell proliferation and dramatically altered cell shape by induction of cell process formation. We conclude that PPAR and RXR isoforms are expressed in a nephron segment-specific manner, suggesting distinct functions, with PPARalpha being involved in energy metabolism through regulating ACS in PCT and with PPARgamma being involved in modulating RMIC growth and differentiation.

Assessing symptom change in Southeast Asian refugee survivors of mass violence and torture

The authors evaluated changes in symptoms and levels of perceived distress of 21 Cambodian, 13 Hmong/Laotian, and 18 Vietnamese patients before and after a 6-month treatment period. Most of the patients improved significantly. Cambodians had the greatest and Hmong/Laotians had the least reductions in depressive symptoms. Although psychological symptoms improved, many somatic symptoms worsened. The authors conclude that refugee survivors of multiple traumata and torture can be aided by psychiatric care. They recommend investigations with larger samples and suitable control groups to further clarify the relative contributions of trauma, diagnosis, and acculturation stress to treatment outcome.

Genetic Dissection of the Relative Roles of Auxin and Gibberellin in the Regulation of Stem Elongation in Intact Light-Grown Peas

Exogenous gibberellin (GA) and auxin (indoleacetic acid [IAA]) strongly stimulated stem elongation in dwarf GA1-deficient le mutants of light-grown pea (Pisum sativum L.): IAA elicited a sharp increase in growth rate after 20 min followed by a slow decline; the GA response had a longer lag (3 h) and growth increased gradually with time. These responses were additive. The effect of GA was mainly in internodes less than 25% expanded, whereas that of IAA was in the older, elongating internodes. IAA stimulated growth by cell extension; GA stimulated growth by an increase in cell length and cell number. Dwarf lkb GA-response-mutant plants elongated poorly in response to GA (accounted for by an increase in cell number) but were very responsive to IAA. GA produced a substantial elongation in lkb plants only in the presence of IAA. Because lkb plants contain low levels of IAA, growth suppression in dwarf lkb mutants seems to be due to a deficiency in endogenous auxin. GA may enhance the auxin induction of cell elongation but cannot promote elongation in the absence of auxin. The effect of GA may, in part, be mediated by auxin. Auxin and GA control separate processes that together contribute to stem elongation. A deficiency in either leads to a dwarfed phenotype.

Wnt10b promotes growth of hair follicles via a canonical Wnt signalling pathway

BACKGROUND

Wnt10b (wingless-related mouse mammary tumour virus integration site 10b) plays various roles in a wide range of biological actions, including hair-follicle development.

AIM

To assess the roles that Wnt10b plays in postnatal hair-follicle growth.

METHODS

Adenovirus vectors AdWnt10b, AdGFP, AdGFP plus AdRFP, AdWnt10b plus AdFrzB, and AdWnt10b plus AdSimBC were co-cultured separately with vibrissae. In situ protein expression of Wnt10b, β-catenin and Lef1 was determined by immunohistochemistry, and the proliferation status of the hair follicle was detected by 5-bromo-2-deoxyuridine (BrdU) labelling. The presence of Wnt signalling molecules in the three stages of hair-follicle growth was detected by PCR-based microarray.

RESULTS

AdWnt10b-infected cells were able to secrete bioactive Wnt10b, and when this was added into the basal medium, the vibrissae grew faster than in control medium or in medium containing canonical Wnt signalling antagonists. The in situ protein expression of Wnt10b was consistent with that of β-catenin and Lef1. The expression locus of Wnt10b was almost the same as the proliferating cells labelled by BrdU in the anagen hair follicle.

CONCLUSIONS

Wnt10b may promote hair-follicle growth by inducing the switch from telogen to anagen via a canonical Wnt signalling pathway to promote the proliferation of matrix cells.

Blunted respiratory responses to hypoxia in mutant mice deficient in nitric oxide synthase-3

In the present study, the role of nitric oxide (NO) generated by endothelial nitric oxide synthase (NOS-3) in the control of respiration during hypoxia and hypercapnia was assessed using mutant mice deficient in NOS-3. Experiments were performed on awake and anesthetized mutant and wild-type (WT) control mice. Respiratory responses to 100, 21, and 12% O(2) and 3 and 5% CO(2)-balance O(2) were analyzed. In awake animals, respiration was monitored by body plethysmography along with O(2) consumption (VO(2)) and CO(2) production (VCO(2)). In anesthetized, spontaneously breathing mice, integrated efferent phrenic nerve activity was monitored as an index of neural respiration along with arterial blood pressure and blood gases. Under both experimental conditions, WT mice responded with greater increases in respiration during 12% O(2) than mutant mice. Respiratory responses to hyperoxic hypercapnia were comparable between both groups of mice. Arterial blood gases, changes in blood pressure, VO(2), and VCO(2) during hypoxia were comparable between both groups of mice. Respiratory responses to cyanide and brief hyperoxia were attenuated in mutant compared with WT mice, indicating reduced peripheral chemoreceptor sensitivity. cGMP levels in the brain stem during 12% O(2), taken as an index of NO production, were greater in mutant compared with WT mice. These observations demonstrate that NOS-3 mutant mice exhibit selective blunting of the respiratory responses to hypoxia but not to hypercapnia, which in part is due to reduced peripheral chemosensitivity. These results support the idea that NO generated by NOS-3 is an important physiological modulator of respiration during hypoxia.

p53 induced by ionizing radiation mediates DNA end-jointing activity, but not apoptosis of thyroid cells

To understand the effects of ionizing radiation on thyroid cells, we investigated the role of p53 in mediating apoptosis and in DNA repair following in vivo and in vitro irradiation of thyroid cells. In vitro exposure of human thyroid cells to ionizing radiation of up to 5-8 Gy failed to induce apoptosis in primary cells. The same results were obtained when the thyroid gland was irradiated in the intact rat. To explore the mechanism of failure of the wild-type p53 in inducing apoptosis in thyroid cells, we investigated the expression of apoptosis-related genes, bax, bcl-2 and fas/APO-1 following irradiation or induction of temperature-sensitive p53. The expression of Bax, Bcl-2 and Fas/APO-1 in human primary cultured thyroid cells did not change after irradiation. To further confirm the results, we established a clonal cell line (tsFRO) in which a temperature sensitive p53 (Val138) expression vector was stably transfected to a thyroid carcinoma cell line lacking endogenous p53. Incubation of tsFRO cells at the permissive temperature for three days, however, did not induce apoptosis although G1 arrest was noted. Although enhanced expression of the bax mRNA level was observed, the expression of Bax, Bcl-2 and Fas/APO-1 protein did not change by shifting tsFRO cells to permissive temperature as well as irradiated primary cells. Furthermore, DNA end-jointing ability was examined by transfection of linearized luciferase plasmid into tsFRO cells. Increased luciferase activity occurred when the cells were cultured at the permissive temperature, indicating that the wild-type p53 enhances DNA end-jointing activity. Our results indicate that the wild-type p53 does not lead to apoptosis but facilitates DNA end-jointing in thyroid cells. These results may reflect specific responses in thyroid cells following irradiation.

Regulation of cyclooxygenase-2 expression in renal medulla by tonicity in vivo and in vitro

Renal medullary prostaglandins are believed to exert an important functional role in antagonizing vasopressin effects in dehydration. Studies were undertaken to determine the effect of hyperosmolality on cyclooxygenase (COX) isoform expression in the renal medulla. COX-1 and COX-2 mRNA and protein levels were determined by RT-PCR or Western blotting in Sprague-Dawley rats on varying water intakes, in Brattleboro rats and in Long-Evans controls. Over a wide range of urinary tonicity, COX-2 expression correlated closely with urine osmolality levels (R = 0.872). COX-1 levels did not vary. Immunolocalization showed that the stimulation of COX-2 expression by dehydration occurred predominantly in the collecting duct. Hypertonicity caused by addition of NaCl produced a dose- and time-dependent stimulation of COX-2 expression in mIMCD-K2 cells as well as in MDCK cells. COX-1 was unaffected. In the same cell lines, mannitol, sucrose, and raffinose also had a stimulatory effect. The tonicity-stimulated COX-2 expression in mIMCD-K2 cells was almost completely blocked by a tyrosine kinase inhibitor, genistein at 100 microM. In MDCK cells transfected with a 2.7-kb COX-2 promoter and lacZ reporter construct, NaCl induced a twofold increase in beta-galactosidase activity. Using mIMCD-K2 cells, hypertonic NaCl (600 mosmol/kgH(2)O for 24 h) induced a 33-fold increase in PGE(2) release determined by enzyme immunoassay, an effect completely blocked by 3 microM indomethacin or the COX-2-specific blocker N-(2-cyclohexy-4-nitrophenyl)methanesulfonamide (NS-398). We conclude that in inner medulla, COX-2 but not COX-1 is upregulated by hyperosmolality.

Mutation analysis of TMC1 identifies four new mutations and suggests an additional deafness gene at loci DFNA36 and DFNB7/11

Hearing loss is the most frequent sensorineural disorder affecting 1 in 1000 newborns. In more than half of these babies, the hearing loss is inherited. Hereditary hearing loss is a very heterogeneous trait with about 100 gene localizations and 44 gene identifications for non-syndromic hearing loss. Transmembrane channel-like gene 1 (TMC1) has been identified as the disease-causing gene for autosomal dominant and autosomal recessive non-syndromic hearing loss at the DFNA36 and DFNB7/11 loci, respectively. To date, 2 dominant and 18 recessive TMC1 mutations have been reported as the cause of hearing loss in 34 families. In this report, we describe linkage to DFNA36 and DFNB7/11 in 1 family with dominant and 10 families with recessive non-syndromic sensorineural hearing loss. In addition, mutation analysis of TMC1 was performed in 51 familial Turkish patients with autosomal recessive hearing loss. TMC1 mutations were identified in seven of the families segregating recessive hearing loss. The pathogenic variants we found included two known mutations, c.100C>T and c.1165C>T, and four new mutations, c.2350C>T, c.776+1G>A, c.767delT and c.1166G>A. The absence of TMC1 mutations in the remaining six linked families implies the presence of mutations outside the coding region of this gene or alternatively at least one additional deafness-causing gene in this region. The analysis of copy number variations in TMC1 as well as DNA sequencing of 15 additional candidate genes did not reveal any proven pathogenic changes, leaving both hypotheses open.

Absence of tubuloglomerular feedback responses in AT1A receptor-deficient mice

Experiments were performed in a recently generated strain of mice with an angiotensin II AT1A-receptor null mutation (M. Ito, M. I. Oliverio, P. J. Mannon, C. F. Best, N. Maeda, O. Smithies, and T. M. coffman. Proc. Natl. Acad. Sci. USA 92: 3521-3525, 1995) to examine the effects of chronic AT1A receptor deficiency on tubuloglomerular feeback (TGF) responses. All animals were genotyped by polymerase chain reaction using primers designed to amplify sequences from the deleted AT1A gene and from the neomycin resistance gene. Normal mice (AT1A +/+) and mice heterozygous (AT1A +/-) and homozygous (AT1A -/-) for the gene disruption were anesthetized, and stop-flow pressures (PSF) were determined during changes in loop perfusion rate with previously established micropuncture methods. In five AT1A +/+ mice (26 tubules) mean PSF at zero loop flow was 37.2 +/- 1.5 mmHg, falling to 28.2 +/- 1.9 mmHg at a flow of 45 nl/min (P < 0.0001). Flow rate causing the half-maximum response (V1/2) was 8.7 +/- 0.4 nl/min. In four AT1A +/- animals (19 tubules) mean PSF at zero flow was 39.9 +/- 2.4 mmHg, falling to 34.8 +/- 2.7 mmHg at 45 nl/min (mean V1/2 8.6 +/- 1.04 nl/min). In five AT1A -/- mice (24 tubules) PSF was not significantly affected by loop flow with PSF averaging 33.9 +/- 1.7 mmHg at zero flow and 33.2 +/- 1.6 mmHg at 45 nl/min (not significant). Mean arterial blood pressures in the anesthetized and laparotomized mice were 91.8 +/- 2.2, 97.1 +/- 3, and 80.7 +/- 3.2 mmHg in the AT1A +/+, AT1A +/-, and AT1A -/- animals, respectively. Blood pressure responses to exogenous angiotensin II were greatly blunted in the AT1A -/- mice. We conclude that AT1A receptor-mediated effects of angiotensin II are in essential component of TGF responsiveness under chronic conditions. Our studies show the feasibility of using complex micropuncture methods in mice, an approach that widens the potential of genetically altered mouse strains as experimental models.

Baseline radiographic osteoarthritis and semi-quantitatively assessed meniscal damage and extrusion and cartilage damage on MRI is related to quantitatively defined cartilage thickness loss in knee osteoarthritis: the Multicenter Osteoarthritis Study

OBJECTIVES

To provide a comprehensive simultaneous relation of various semiquantitative knee OA MRI features as well as the presence of baseline radiographic osteoarthritis (OA) to quantitative longitudinal cartilage loss.

METHODS

We studied Multicenter OA Study (MOST) participants from a longitudinal observational study that included quantitative MRI measurement of cartilage thickness. These subjects also had Whole Organ MRI Score (WORMS) scoring of cartilage damage, bone marrow lesions (BMLs), meniscal pathology, and synovitis, as well as baseline radiographic evaluation for Kellgren and Lawrence (KL) grading. Knee compartments were classified as progressors when exceeding thresholds of measurement variability in normal knees. All potential risk factors of cartilage loss were dichotomized into "present" (score ≥2 for cartilage, ≥1 for others) or "absent". Differences in baseline scores of ipsi-compartmental risk factors were compared between progressor and non-progressor knees by multivariable logistic regression, adjusting for age, sex, body mass index, alignment axis (degrees) and baseline KL grade. Odds ratios (OR) and 95% CIs were calculated for medial femorotibial compartment (MFTC) and lateral femorotibial compartment (LFTC) cartilage loss. Cartilage loss across both compartments was studied using Generalized Estimating Equations.

RESULTS

196 knees of 196 participants were included (age 59.8 ± 6.3 years [mean ± SD], BMI 29.5 ± 4.6, 62% women). For combined analyses of MFTC and LFTC, baseline factors related to cartilage loss were radiographic OA (KL grade ≥2: aOR 4.8 [2.4-9.5], cartilage damage (aOR 2.3 [1.2-4.4])), meniscal damage (aOR 3.9 [2.1-7.4]) and extrusion (aOR 2.9 [1.6-5.3]), all in the ipsilateral compartment, but not BMLs or synovitis.

CONCLUSION

Baseline radiographic OA and semiquantitatively (SQ) assessed MRI-detected cartilage damage, meniscal damage and extrusion, but not BMLs or synovitis is related to quantitatively measured ipsi-compartmental cartilage thinning over 30 months.

A tyrosine hydroxylase-neurofilament chimeric promoter enhances long-term expression in rat forebrain neurons from helper virus-free HSV-1 vectors

Helper virus-free herpes simplex virus (HSV-1) plasmid vectors are attractive for neural gene transfer, but a promoter that supports neuronal-specific, long-term expression is required. Although expression from many promoters is unstable, a 6.8-kb, but not a 766-bp, fragment of the tyrosine hydroxylase (TH) promoter supports long-term expression. Thus, 5' upstream sequences in this promoter may enhance expression. In this study, we evaluated expression from vectors that contain 5' upstream sequences from this promoter (-0.5 to -6.8 kb) inserted at the 5' end of either a neurofilament heavy subunit (NF-H) promoter or the cytomegalovirus (CMV) immediate early promoter. The TH-NFH promoter supported expression for 6 months in the striatum, 2 months in the hippocampus, and for 1 month in both perirhinal and postrhinal cortex (the longest time points examined). Expression was targeted to neurons. The enhanced expression may require specific sequences in the TH promoter fragment because replacing this fragment with a similar sized fragment of bacteriophage lambda DNA did not enhance expression. The reverse orientation of the TH promoter fragment also enhanced expression. Insertion of insulators from the chicken beta-globin locus between the TH-NFHlac transcription unit and the vector backbone may support a modest additional enhancement in expression. Other eucaryotic sequences may also enhance expression; a S. cerevisiae (40-kb fragment)-NFH promoter enhanced expression. In contrast, the TH-CMV promoter did not enhance expression. Thus, the TH-NFH promoter may support some physiological studies that require long-term expression in forebrain neurons.

Biomarkers in the lung cancer diagnosis: a clinical perspective

The propensity for tumor biomarkers to be detected in serum at an early disease stage has become an area of interest for clinicians. This study aimed to evaluate the efficiency of 7 tumor biomarkers, namely, carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), cytokeratin 19 (CYFRA-21-1), alpha-fetoprotein, carbohydrate antigen-125 (CA-125), carbohydrate antigen-19.9 (CA-19.9), and ferritin, independently or in combination for the diagnosis of lung cancer. Electrochemiluminescence immunization was used to determine biomarker levels expressed in 530 patients with pulmonary disease and 229 healthy subjects. The observed levels of CEA, NSE, CYFRA-21-1, CA-125, and CA-19.9 in patients with pathologically confirmed lung cancer were significantly higher than those in patients with benign pulmonary disease or control subjects. Adenocarcinoma, squamous cell carcinoma, and small cell carcinoma of the lung were associated with the highest observed levels of CA-125, CYFRA-21-1, and NSE, respectively. Combining biomarkers successfully led to the diagnosis of lung cancer. CEA + NSE + CA-125 showed the highest sensitivity for small cell carcinoma, at 83.33%, whereas CEA + NSE + CYFRA-21-1 + CA-125 showed 94.11% sensitivity for squamous cell carcinoma. The combination of 6 biomarkers, namely, CEA + NSE + CYFRA-21-1 + CA-125 + ferritin + CA-19.9, showed 80.49% sensitivity for adenocarcinoma. Combining biomarkers significantly aided in the diagnosis of lung cancer. However, this increased sensitivity on combination was accompanied by a decreased specificity for lung cancer subtypes. Combining biomarkers appropriately increases their sensitivity and helps with the diagnosis of lung cancer.

Propofol inhibits lung cancer cell viability and induces cell apoptosis by upregulating microRNA-486 expression

Propofol is a frequently used intravenous anesthetic agent. Recent studies show that propofol exerts a number of non-anesthetic effects. The present study aimed to investigate the effects of propofol on lung cancer cell lines H1299 and H1792 and functional role of microRNA (miR)-486 in these effects. H1299 and/or H1792 cells were treated with or without propofol and transfected or not with miR-486 inhibitor, and then cell viability and apoptosis were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry. The expression of miR-486 was determined by quantitative real-time polymerase chain reaction (qRT-PCR) with or without propofol treatment. Western blot was performed to analyze the protein expression of Forkhead box, class O (FOXO) 1 and 3, Bcl-2 interacting mediator of cell death (Bim), and pro- and activated caspases-3. Results showed that propofol significantly increased the miR-486 levels in both H1299 and H1792 cells compared to untreated cells in a dose-dependent manner (P<0.05 or P<0.01). Propofol statistically decreased cell viability but increased the percentages of apoptotic cells and protein expressions of FOXO1, FOXO3, Bim, and pro- and activated caspases-3; however, miR-486 inhibitor reversed the effects of propofol on cell viability, apoptosis, and protein expression (P<0.05 or P<0.01). In conclusion, propofol might be an ideal anesthetic for lung cancer surgery by effectively inhibiting lung cancer cell viability and inducing cell apoptosis. Modulation of miR-486 might contribute to the anti-tumor activity of propofol.