Modulation of Cl- secretion by benzimidazolones. II. Coordinate regulation of apical GCl and basolateral GK

We previously demonstrated that the novel benzimidazolone, 1-ethyl-2-benzimidazolinone (1-EBIO), stimulates a sustained Cl- secretory response across T84 monolayers by opening a Ca(2+)-dependent basolateral K+ channel. In the present work, we evaluated the effects on Cl-secretion of other benzimidazolones, NS-004 and NS-1619, which have been shown to open cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channels. In contrast to 1-EBIO, neither NS-004 nor NS-1619 stimulated a significant Cl- secretory current (Isc). Neither NS-004 nor NS-1619 increased Isc subsequent to forskolin stimulation. However, when added after 1-EBIO, NS-004 and NS-1619 stimulated large sustained increases in Isc. In addition, NS-004 and NS-1619 potentiated the effects of carbachol. We used nystatin to permeabilize the apical or basolateral membrane to determine the effects of NS-004 and 1-EBIO on the basolateral K+ (IK) and apical Cl- (ICl) currents. Both NS-004 and 1-EBIO increased ICl, and the stimulated currents were inhibited by glibenclamide. In contrast, NS-004 failed to significantly affect IK, but subsequent addition of 1-EBIO induced a large increase in IK. The effects of 1-EBIO, NS-004, and NS-1619 on the Ca(2+)-dependent K+ channel (KCa) in T84 cells was determined in excised inside-out patches. Neither NS-004 nor NS-1619 affected K+ channel activity, whereas the subsequent addition of 1-EBIO produced a marked channel activation. Results similar to those observed in T84 monolayers were obtained from murine airway cell primary cultures: NS-004 or NS-1619 had no effect on Isc, whereas 1-EBIO stimulated a sustained Cl- secretory response. The results demonstrate that activation of CFTR alone is insufficient to evoke transepithelial Cl- secretion. Activation of the basolateral membrane K+ channel is a necessary component of the secretory response. Thus the basolateral membrane KCa may be a novel pharmacological target in cystic fibrosis therapy.

Adverse reactions to protamine sulfate following cardiac surgery

We report four patients who developed severe adverse reactions to protamine sulfate following cardiac surgery. Two types of reactions were seen. First, an immediate anaphylaxis which is a complement-dependent IgG antibody-mediated reaction. In the literature, 80% of patients who had similar reactions have had previous exposure to protamine. All patients adequately tested had positive skin tests and there is 6% mortality. The second reaction to protamine during cardiac surgery is characterized by delayed onset and profound vascular damage presenting as noncardiogenic pulmonary edema or total vascular collapse with prolonged hypotension and anasarca. These patients have negative skin tests and in our studies, no evidence of antibody mediated reaction, suggesting some other mechanisms may play a part. The mortality is high (30% of patients reported) and survivors have significant morbidity.

Molecular genetics of essential hypertension

Hypertension is a major public health problem in the developing as well as in developed countries due to its high prevalence and its association with coronary heart disease, renal disease, stroke, peripheral vascular disease, and related disorders. Essential hypertension (EH) is the most common diagnosis in this disease, suggesting that a monocausal etiology has not been identified. However, a number of risk factors associated with EH have also been identified such as age, sex, demographic, environmental, genetic, and vascular factors. Recent advances in molecular biological research had achieved clarifying the molecular basis of Mendelian hypertensive disorders. Molecular genetic studies have now identified mutations in several genes that cause Mendelian forms of hypertension in humans. However, none of the single genetic variants has emerged from linkage or association analyses as consistently related to the blood pressure level in every sample and in all populations. Besides, a number of polymorphisms in candidate genes have been associated with differences in blood pressure. The most prominent candidate has been the polymorphisms in the renin-angiotensin-aldosterone system. In total, EH is likely to be a polygenic disorder that results from inheritance of a number of susceptibility genes and involves multiple environmental determinants. These determinants complicate the study of blood pressure variations in the general population. The complex nature of the hypertension phenotype makes large-scale studies indispensable, when screening of familial and genetic factors was intended. In this review, recent genetic studies exploring the molecular basis of EH, including different molecular pathways, are highlighted.

Genome-wide analysis of the heat stress response in Zebu (Sahiwal) cattle

Environmental-induced hyperthermia compromises animal production with drastic economic consequences to global animal agriculture and jeopardizes animal welfare. Heat stress is a major stressor that occurs as a result of an imbalance between heat production within the body and its dissipation and it affects animals at cellular, molecular and ecological levels. The molecular mechanism underlying the physiology of heat stress in the cattle remains undefined. The present study sought to evaluate mRNA expression profiles in the cattle blood in response to heat stress. In this study we report the genes that were differentially expressed in response to heat stress using global scale genome expression technology (Microarray). Four Sahiwal heifers were exposed to 42°C with 90% humidity for 4h followed by normothermia. Gene expression changes include activation of heat shock transcription factor 1 (HSF1), increased expression of heat shock proteins (HSP) and decreased expression and synthesis of other proteins, immune system activation via extracellular secretion of HSP. A cDNA microarray analysis found 140 transcripts to be up-regulated and 77 down-regulated in the cattle blood after heat treatment (P<0.05). But still a comprehensive explanation for the direction of fold change and the specific genes involved in response to acute heat stress still remains to be explored. These findings may provide insights into the underlying mechanism of physiology of heat stress in cattle. Understanding the biology and mechanisms of heat stress is critical to developing approaches to ameliorate current production issues for improving animal performance and agriculture economics.

Electrolyte versus blood cardioplegia: randomized clinical and myocardial ultrastructural study

In 40 consecutive patients undergoing coronary artery bypass, one of two solutions for cardioplegia, each containing 30 mEq/L of K+ was used randomly. The groups were comparable except for intramyocardial temperature. With electrolyte solution (Group A), it was 16.5 degrees +/- 0.34 degrees C, while with blood from the pump-oxygenator (Group B) it was 20.3 degrees +/- 0.41 degrees C (p less than 0.001). After bypass left atrial pressure (LAP) was 11.9 +/- 0.67 torr in Group A and 8.1 +/- 0.49 torr in Group B (p less than 0.001). CPK-MB was elevated in 45% of Group A patients versus 15% in Group B (p less than 0.05). No patient died. Two myocardial infarctions occurred in Group A and one in Group B. Stereological morphometric electron microscopy was performed on biopsy specimens taken from the left ventricle (1) before perfusion, (2) after cardioplegia, and (3) 30 minutes after reperfusion. Group A showed marked intracellular edema, mitochondrial swelling, pronounced depletion of glycogen stores, and focal myofibrillary disorganization. Group B showed near normal myocardial ultrastructure with increased glycogen stores and minimal mitochondrial swelling. Morphometric analysis revealed a statistically significant increase in the degree of mitochondrial swelling (51%) in Group A compared with Group B after reperfusion (p less than 0.001). Thus, blood K+ cardioplegia resulted in better preservation of myocardial ultrastructure, lower ventricular filling pressure, and lesser CPK-MB release compared with this particular electrolyte cardioplegia.

Pursuing scale and quality in STI interventions with sex workers: initial results from Avahan India AIDS Initiative

BACKGROUND

Migration, population mobility, and sex work continue to drive sexually transmitted epidemics in India. Yet interventions targeting high incidence networks are rarely implemented at sufficient scale to have impact. India AIDS Initiative (Avahan), funded by the Bill and Melinda Gates Foundation, is scaling up interventions with sex workers (SWs) and other high risk populations in India's six highest HIV prevalence states.

METHODS

Avahan resources are channelled through state level partners (SLPs) to local level non-governmental organisations (NGOs) who organise outreach, community mobilisation, and dedicated clinics for SWs. These clinics provide services for sexually transmitted infections (STIs) including Condom Promotion, syndromic case management, regular check-ups, and treatment of asymptomatic infections. SWs take an active role in service delivery. STI capacity building support functions on three levels. A central capacity building team developed guidelines and standards, trains state level STI coordinators, monitors outcomes, and conducts operations research. Standards are documented in an Avahan-wide manual. State level STI coordinators train NGO clinic staff and conduct supervision of clinics based on these standards and related quality monitoring tools. Clinic and outreach staff report on indicators that guide additional capacity building inputs.

RESULTS

In 2 years, clinics with community outreach for SWs have been established in 274 settings covering 77 districts. Mapping and size estimation have identified 187,000 SWs. In a subset of four large states covered by six SLPs (183,000 estimated SWs, 65 districts), 128,326 (70%) of the SWs have been contacted through peer outreach and 74,265 (41%) have attended the clinic at least once. A total of 127,630 clinic visits have been reported, an increasing proportion for recommended routine check ups. Supervision and monitoring facilitate standardisation of services across sites.

CONCLUSION

Targeted HIV/STI interventions can be brought to scale and standardised given adequate capacity building support. Intervention coverage, service utilisation, and quality are key parameters that should be monitored and progressively improved with active involvement of SWs themselves.

Treatment of the alcohol intoxications: ethylene glycol, methanol and isopropanol

Intoxications with ethylene glycol, methanol, and isopropanol are among the most common ingestions, in the treatment of which a nephrologist plays an important role. These three substances have the ideal characteristics for intervention by hemodialysis, and the three parent compounds and their metabolites are readily dialyzable. Two of the three substances, ethylene glycol and methanol, are metabolized to more toxic substances, so that an early treatment strategy that removes the parent compound or blocks its metabolism can prevent the development of many of the adverse events that are often seen in these ingestions. Fomepizole, an inhibitor of alcohol dehydrogenase, slows the metabolism of these substances and is now approved by the US Food and Drug Administration for use in ethylene glycol intoxication. The present review addresses recent advances in the diagnosis and treatment of intoxication with ethylene glycol, methanol and isopropanol.

Stroke during coronary artery bypass grafting using hypothermic versus normothermic perfusion

Does the abandonment of hypothermic perfusion during cardiopulmonary bypass compromise cerebral protection and thus lead to a higher incidence of stroke? From 1987 to June 1993, 2,585 consecutive patients underwent myocardial revascularization using warm-body (perfusion at 37 degrees C), cold-heart (cold cardioplegic arrest) surgical technique and were followed for new overt neurologic deficits. Perfusion pressure was maintained between 50 and 70 mm Hg, and hematocrit was kept around 20%. There were 25 operative deaths (1%) in this normothermic group, and new neurologic deficits developed after operation in 25 patients (1%). These results were compared retrospectively with those in 1,605 patients who underwent myocardial revascularization between 1980 and 1986 with moderate hypothermic (25 degrees to 30 degrees C) perfusion, the same surgical team, and similar operative techniques. The normothermic group included more elderly patients, more patients with left ventricular dysfunction and unstable angina, and more frequent use of an internal mammary artery conduit. Neurologic complication rates were 1% and 1.3% for the normothermic and hypothermic perfusion groups, respectively. Risk factors for stroke that were identified included age greater than 70 years, severity of aortic arch atherosclerosis, and severe hypotension in the perioperative period. Thus, in a large clinical series, the incidence of overt neurologic injuries was found to be no higher with normothermic perfusion than with hypothermic perfusion.

Liposome encapsulated vitamin A compounds exhibit greater stability and diminished toxicity

Absorption and fluorescence studies of retinol (vitamin A alcohol) and retinol palmitate (vitamin A palmitate) intercalated in phosphatidylcholine (PC) liposomes show that these compounds are bound to the lipid bilayer. It is further found that retinol binds liposomes with greater affinity as compared to retinol palmitate. In addition, the delivery of liposome-incorporated retinoids to the blood has also been studied and it is found that these systems reduce blood viscosity and cause less lysis of red blood cells than retinoid compounds not complexed in liposomes.

Differences between men and women in reporting of symptoms during an asthma exacerbation

STUDY OBJECTIVE

Compared with men, women presenting to the emergency department with acute asthma are more likely to be admitted and to have a longer hospital stay. This study compares peak expiratory flow rate (PEFR) with reported symptom severity between men and women with acute asthma. The null hypothesis was that men and women report similar severity symptoms for similar levels of airway obstruction.

METHODS

This study combined data from 4 prospective cohort studies performed from 1996 to 1998 as part of the Multicenter Airway Research Collaboration. Using a standardized protocol, investigators at 64 EDs in 21 US states and 4 Canadian provinces provided 24-hour per day coverage for a median of 2 weeks.

RESULTS

Of the 1,291 patients with moderate to severe exacerbations (initial percentage of predicted PEFR <80%), 62% were women. Women were more likely than men to report "severe" complaints in terms of symptom frequency, symptom intensity, and resulting activity limitations (all P <.05). Women with moderate exacerbations were especially likely to describe their exacerbation as causing "severe" activity limitations (sex-PEFR interaction, P =.05).

CONCLUSION

Men are less likely than women to report severe asthma symptoms and activity limitations in the presence of airway obstruction. This finding supports use of objective measures of airway obstruction when managing patients with asthma so that those whose symptoms do not reflect the severity of their obstruction can be recognized and properly treated. It also reconfirms the need for increased research on differences between men and women in acute asthma.

CFTR and its key role in in vivo resting and luminal acid-induced duodenal HCO3- secretion

BACKGROUND AND AIMS

We investigated the role of the recently discovered, villous-expressed anion exchanger Slc26a6 (PAT1) and the predominantly crypt-expressed cystic fibrosis transmembrane regulator (CFTR) in basal and acid-stimulated murine duodenal HCO(3)(-) secretion in vivo, and the influence of blood HCO(3)(-) concentration on both.

METHODS

The proximal duodenum of anaesthetized mice was perfused in situ, and HCO(3)(-) secretion was determined by back-titration. Duodenal mucosal permeability was assessed by determining (51)Cr-EDTA leakage from blood to lumen.

RESULTS

Compared with wild type (WT) littermates basal duodenal HCO(3)(-) secretory rates were slightly reduced in Slc26-deficient mice at low ( approximately 21 mm), and markedly reduced at high blood HCO(3)(-) concentration ( approximately 29 mm). In contrast, basal HCO(3)(-) secretion was markedly reduced in CFTR-deficient mice compared with WT littermates both at high and low blood HCO(3)(-) concentration. A short-term application of luminal acid increased duodenal HCO(3)(-) secretory rate in Slc26a6-deficient and WT mice to the same degree, but had no stimulatory effect in the absence of CFTR. Luminal acidification to pH 2.5 did not alter duodenal permeability.

CONCLUSIONS

The involvement of Slc26a6 in basal HCO(3)(-) secretion in murine duodenum in vivo is critically dependent on the systemic acid/base status, and this transporter is not involved in acid-stimulated HCO(3)(-) secretion. The presence of CFTR is essential for basal and acid-induced HCO(3)(-) secretion irrespective of acid/base status. This suggests a coupled action of Slc26a6 with CFTR for murine basal duodenal HCO(3)(-) secretion, but not acid-stimulated secretion, in vivo.

A beta-blocker, not magnesium, is effective prophylaxis for atrial tachyarrhythmias after coronary artery bypass graft surgery

OBJECTIVE

To evaluate magnesium as a sole or adjuvant agent with currently used prophylactic drugs in suppressing postoperative atrial tachyarrhythmias (POAT) after coronary artery bypass graft (CABG) surgery.

DESIGN

Single-center prospective, randomized clinical trial.

SETTING

University hospital.

PARTICIPANTS

Patients (n = 400) undergoing CABG surgery.

INTERVENTIONS

Patients were randomized among 6 prophylaxis regimens: (1) control (no antiarrhythmics), (2) magnesium only, (3) digoxin only, (4) magnesium and digoxin, (5) propranolol only, and (6) magnesium and propranolol. Patients randomized to a regimen including magnesium received 12 g given during 96 hours postoperatively. Patients in a digoxin regimen received 1 mg after cardiopulmonary bypass and 0.25 mg daily. Patients in a propranolol regimen received 1 mg intravenously every 6 hours until able to take 10 mg orally 4 times a day. Prophylaxis regimens were discontinued after 4 days postoperatively.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was a sustained POAT or discharge from the hospital. Control patients had an incidence of POAT (38%) not significantly different from patients in magnesium-only (38%), digoxin-only (31%), and magnesium with digoxin (37%) regimens. Patients treated with propranolol had a significant reduction in POAT. Nearly identical POAT rates in the propranolol-only (18%) and propranolol with magnesium (19%) groups support the lack of efficacy of magnesium in this trial. Study design allowed analysis of and showed a beta-blocker withdrawal effect in addition to suppressive benefit of postoperative beta-blockers.

CONCLUSION

beta-Blocker prophylaxis is indicated to reduce the incidence of POAT in CABG surgery patients and to prevent a beta-blocker withdrawal effect in patients receiving these medications preoperatively. Digoxin and magnesium as sole or adjuvant agents do not offer suppressive or ventricular rate reduction benefits in POAT.

Predominant tubulointerstitial lupus nephritis

Predominant tubulointerstitial lupus nephritis is rare. Only eight cases have been described in the literature. We report the case of a 59-year-old man with systemic lupus erythematosus who presented with acute renal failure. On renal biopsy, he was found to have chronic tubulointerstitial nephritis with a mononuclear infiltrate. The immunofluorescence showed immune deposits in the tubular basement membranes, interstitium, and glomerular capsule. The glomeruli were minimally involved. He was initially treated with high-dose corticosteroids and supported with hemodialysis. Renal function improved and dialysis was discontinued after three treatments. The corticosteroid dosage was gradually tapered. Renal function after 72 months of follow-up has remained stable (serum creatinine, approximately 1.9 mg/dL) and except for one relapse, there has been no clinical or serologic evidence of lupus activity. Furthermore, 24-hour urinary protein excretion has remained within the normal range.

Quinalizarin anchored on Amberlite XAD-2. A new matrix for solid-phase extraction of metal ions for flame atomic absorption spectrometric determination

Amberlite XAD-2 has been functionalized by coupling it to quinalizarin [1,2,5,8-tetrahydroxyanthraquinone] by means of an -N = N- spacer. Elemental analysis, thermogravimetric analysis, and infrared spectra were used to characterize the resulting new polymer matrix. The matrix has been used to preconcentrate Cu(II), Cd(II), Co(II), Pb(II), Zn(II), and Mn(II) before their determination by flame atomic absorption spectrometry (FAAS). UO2(II) has been preconcentrated for fluorimetric determination. The optimum pH values for maximum adsorption of the metals are between 5.0 and 7.0. All these metal ions are desorbed (recovery 91-99%) with 4 mol L(-1) HNO3. The adsorptive capacity of the resin was found to be in the range 0.94-5.28 mg metal g(-1) resin and loading half-life (t1/2) between 5.3 and 15.0 min. The effects of NaF, NaCl, NaNO3, Na2SO4, Na3PO4, Ca(II), and Mg(II) on the adsorption of these metal ions (0.2 microg mL(-1)) are reported. The lower limits of detection for these metal ions are between 1 and 15.0 microg L(-1). After enrichment on this matrix flame AAS has been used to determine these metal ions (except the uranyl ion) in river water samples (RSD < or = 6.5%); fluorimetry was used to determine uranyl ion in well water samples (RSD < or = 6.3%). Cobalt from pharmaceutical vitamin tablets was preconcentrated by use of this chelating resin and estimated by FAAS (RSD approximately 4%).

Overexpression of osmotin gene confers tolerance to salt and drought stresses in transgenic tomato (Solanum lycopersicum L.)

Abiotic stresses, especially salinity and drought, are major limiting factors for plant growth and crop productivity. In an attempt to develop salt and drought tolerant tomato, a DNA cassette containing tobacco osmotin gene driven by a cauliflower mosaic virus 35S promoter was transferred to tomato (Solanum lycopersicum) via Agrobacterium-mediated transformation. Putative T0 transgenic plants were screened by PCR analysis. The selected transformants were evaluated for salt and drought stress tolerance by physiological analysis at T1 and T2 generations. Integration of the osmotin gene in transgenic T1 plants was verified by Southern blot hybridization. Transgenic expression of the osmotin gene was verified by RT-PCR and northern blotting in T1 plants. T1 progenies from both transformed and untransformed plants were tested for salt and drought tolerance by subjecting them to different levels of NaCl stress and by withholding water supply, respectively. Results from different physiological tests demonstrated enhanced tolerance to salt and drought stresses in transgenic plants harboring the osmotin gene as compared to the wild-type plants. The transgenic lines showed significantly higher relative water content, chlorophyll content, proline content, and leaf expansion than the wild-type plants under stress conditions. The present investigation clearly shows that overexpression of osmotin gene enhances salt and drought stress tolerance in transgenic tomato plants.

Scleral indentation following cryotherapy and repeat cryotherapy enhance release of viable retinal pigment epithelial cells

Retinal pigment epithelial (RPE) cells are an important component of intravitreal and epiretinal membranes in proliferative vitreoretinopathy (PVR) that contract and cause recurrent retinal detachment. Cryotherapy has been shown to enhance release of viable RPE cells into the vitreous cavity. This study demonstrates that repeat cryotherapy (refreezing) releases viable RPE cells in even larger numbers. Repeated indentation of the sclera after transscleral cryotherapy also releases more viable RPE cells than does cryotherapy alone or scleral indentation preceding cryotherapy. These findings suggest that refreezing should be avoided, and repeated indentation of the sclera should be minimized after cryotherapy.

Effect of an emergency department asthma program on acute asthma care

STUDY OBJECTIVE

To examine the effect of an emergency department program on acute asthma care.

METHODS

We conducted a before-after study of an acute asthma quality improvement initiative in an urban teaching hospital with 65,000 annual ED visits. In mid-1994, a multidisciplinary group identified deficiencies in acute asthma care, developed and implemented a local version of the National Asthma Education Program's practice guidelines (including a standard asthma order sheet), and provided new peak flow (PF) meters. The "before" group comprised all adults with acute asthma seen during January 1994 (n=51); "after" groups comprised all adults with acute asthma seen during October 1994, February 1995, and June 1995 (n=145). Data were compared across months using a nonparametric test for trend.

RESULTS

Although patient demographic characteristics and asthma severity were similar across months, ED process of care significantly changed. Initial PF measurements were obtained in 20% of patients before intervention, compared with 82%, 84%, and 83% during the postintervention months ( P for trend <.001). Follow-up PF readings were obtained in 22%, 70%, 78%, and 62% ( P <.001). Median delays to beta-agonist and steroid therapy decreased by approximately 16 minutes ( P <.001) and 34 minutes ( P =.04), respectively. Outcomes improved, with median ED length of stay decreasing by 58 minutes ( P =.01), and fewer inpatient admissions ( P =.05); there was no significant change in 4-week relapse to our hospital.

CONCLUSION

A guideline-based ED asthma program changed clinical practice and improved acute asthma care in a sustained fashion. The effect of this intervention on cost and other outcomes is uncertain.

Demonstration of glutathione peroxidase in rat liver peroxisomes and its intraorganellar distribution

Earlier, we reported that rat liver peroxisomes contain Cu-Zn superoxide dismutase (J. Biol. Chem. 267, 6870), thereby suggesting a new antioxidant role for this organelle in free radical metabolism. In this study, we report for the first time that mammalian peroxisomes also contain glutathione peroxidase. Using highly purified rat liver peroxisomes isolated by Nycodenz gradient, we found that peroxisomes contain glutathione peroxidase which shows enzymatic activity with different substrates such as hydrogen peroxide, cumene hydroperoxide, and t-butyl hydroperoxide. This activity could be inhibited in vitro by mercaptosuccinate. Western blot analysis revealed that peroxisomes from control and ciprofibrate-treated livers show immunoreactive bands with antibodies raised against glutathione peroxidase. The intraperoxisomal distribution of glutathione peroxidase was investigated by using peroxisomal membrane and matrix proteins. The results revealed that glutathione peroxidase is a matrix enzyme. The presence of glutathione peroxidase in peroxisomes provides an alternate enzyme system responsible for the degradation of organic peroxides and the degradation of H2O2 under conditions in which catalase is inactivated (e.g., ischemia-reperfusion and endotoxemia). These findings suggest that glutathione peroxidase in peroxisomes may play a novel role in the cellular antioxidant responses to various oxidative stress conditions.

Hypertonic saline fluid therapy following surgery: a prospective study

Successful resuscitation of the injured may be achieved more rapidly and with less fluid using hypertonic crystalloid solutions than with isotonic solutions. This randomized, double-blind study compared 0.9% normal saline (NS) to 1.8% hypertonic saline (HS) in 20 postoperative coronary artery bypass patients suffering uniform injury. Study solutions were administered to maintain physiologic endpoints: heart rate, blood pressure, and pulmonary capillary wedge pressure. The groups were similar with respect to age, body surface area, operative procedure, intraoperative fluid status, and intraoperative and postoperative red cell transfusion requirements. HS patients required 30% less fluid than NS patients and were in negative fluid balance during the study (-1,715 +/- 732 ml/24 hr, HS, vs. +266 +/- 825 ml/24 hr, NS; p less than 0.01). In contrast, NS patients were in positive fluid balance after 8 hours. Moreover, HS patients experienced less chest tube drainage than NS patients (981 +/- 88 ml, HS, vs. 1,700 +/- 285 ml, NS; p less than 0.01). Systemic and pulmonary hemodynamic measurements, oxygen delivery, oxygen consumption, and shunt fraction did not differ between the two groups. Serum sodium and osmolality increased in the HS group and peaked at 12 hours (145.4 +/- 1.4 mEq/L and 308.7 +/- 2.0 mOsm/kg, respectively) and correlated with the volume of HS infused (correlation coefficient = 0.81). No deaths occurred and no complication was attributed the hypertonicity of the solution. We conclude that 1.8% hypertonic saline is a safe alternative to isotonic crystalloid therapy in the fluid management of postoperative patients. Decreased third-space losses may occur with HS as suggested by the lower thoracic losses in the HS group; 1.8% NaCl may be the preferred solution in situations where excess free water administration is not desired, and where interstitial edema is detrimental to function and/or survival.

Spinal epidural cavernous haemangioma: a case report and review of literature

STUDY DESIGN

A case report of purely epidural cavernous haemangioma with MRI appearance and pathological features.

OBJECTIVE

To present a rare case of extradural mass with differential diagnosis.

SETTING

Delhi, India.

METHOD

A 55-year-old man presented with progressive weakness and diminished sensation in both lower limbs. MRI demonstrated a pure extradural mass with no bony invasion. Histopathology of the lesion revealed a typical cavernous haemangioma.

RESULT

The patient showed significant improvement after surgery.

CONCLUSION

Radiological presentation could be confusing in a purely epidural cavernous haemangioma. Awareness of the characteristics of the lesion will facilitate diagnosis and treatment of the lesion.

Colonic Cl channel blockade by three classes of compounds

We compared the potency and inhibitory actions of three different classes of organic acids on a Cl channel derived from colonic enterocyte plasma membrane vesicles. Chloride channels were incorporated into planar lipid bilayer membranes to examine the effects of the anthranilic acids, diphenylamine 2-carboxylic acid (DPC) and 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), the indanyl alkanoic acids, 2-[(2-cyclopentyl-6,7-dichloro-2,3-dihydro-2-methyl-1-oxo-1H-inden -5-yl)oxy] acetic acid (IAA-94) and its stereoenantiomer IAA-95, and the disulfonic stilbene, 4,4'-dinitro-stilbene-2,2'-disulfonic acid (DNDS). Except for DNDS, each of the blockers was equipotent from both the outer membrane and the cytoplasmic side of the channel protein. The potency order from the outmembrane side was DNDS greater than IAA-94 = IAA-95 greater than NPPB much greater than DPC. In contrast, the potency order from the cytoplasmic side was IAA-94 = IAA-95 greater than NPPB greater than DNDS much greater than DPC. DPC and NPPB caused a concentration-dependent decrease in the single-channel conductance (fast block). DNDS, IAA-94, and IAA-95 caused a flickery-type block and a concentration-dependent decrease in open-channel probability. Kinetic analysis revealed that blockade could be explained by a linear closed-opened-blocked kinetic scheme. Similarities in the electrostatic potential maps of these open-channel blockers suggest they may bind to a single shared binding site within the channel protein.