Overexpression of sorcin enhances cardiac contractility in vivo and in vitro

Sorcin (SOR), an EF-hand Ca(2+)-binding protein, interacts with the sarcolemmal proteins Annexin VII and L-type Ca(2+)-channel and with the sarcoplasmic reticulum (SR) Ca(2+)-release channel (ryanodine-receptor, RYR), and has been implicated to influence the intracellular Ca(2+)-homeostasis. The present study aimed at investigating the effects of increased SOR expression on force development and relaxation in virus transfected rat hearts and isolated cardiomyocytes. We generated an adenovirus encoding the SOR coding DNA with a separate cassette for green fluorescent protein (GFP) both driven by the CMV-promoter to induce SOR-overexpression (Ad.SOR.GFP). As control served an adenovirus carrying an empty cassette with a separate cassette for GFP also driven by CMV-promoters (Ad.GFP). Cardiomyocytes of healthy male rats were isolated, transfected and cultured for 48 h with Ad.SOR.GFP as well as Ad.GFP as control. In addition, Ad.SOR.GFP was injected into coronary arteries via a catheter-based technique and rat hearts were transfected in vivo for 12 days. Echocardiography was performed to assess cardiac function at 7 and 12 days before the animals were sacrificed. A 1.7-fold increase of the SOR protein amount in cultured myocytes treated with Ad.SOR.GFP compared to Ad.GFP-transfected cells indicated a successful overexpression of SOR. Cell-contracting experiments using infected cardiomyocytes (transfection: 48 h; frequency: 0.5 Hz) exhibited a significantly higher peak force of contraction (FOC) in the SOR-overexpression group (n = 64) vs. control (n = 21) (6.8% +/- 0.2% vs. 4.3% +/- 0.1%). Beta-adrenergic stimulation with forskolin resulted in similar increases in FOC. Echocardiography of in vivo transfected rat hearts exhibited enhanced fractional shortening (65.9 +/- 5.5% vs. 79.3 +/- 2.5%) and decreased end-systolic diameters indicating enhanced cardiac contractility. Gross morphology was similar in both groups after 14 days of transfection. These results strengthen the notion that overexpression of SOR improves cardiac contractility independent of beta-adrenergic stimulation and may prove beneficial in the treatment of decreased cardiac output such as heart failure.

Preoperative intravenous fluid therapy decreases postoperative nausea and pain in high risk patients

The potential for preoperative IV rehydration to reduce postoperative nausea and vomiting (PONV) and pain in patients undergoing ambulatory surgery remains unclear, with conflicting results reported. We sought to determine whether preoperative IV rehydration with a balanced salt solution would decrease the incidence of PONV in patients at increased risk for these symptoms. Eighty ASA grade I-III patients presenting for gynecologic laparoscopy were randomized to receive large (2 mL/kg per hour fasting) or small (3 mL/kg) volume infusions of compound sodium lactate solution over 20 min preoperatively. A standardized balanced anesthetic was used. The incidence and severity of PONV and pain, and need for supplemental antiemetic and analgesic therapy, were assessed by a blinded investigator at 0.5, 1, and 4 h postoperatively, and on the first and third postoperative days. The incidence (control 87% versus large volume 59%) and severity of PONV were significantly reduced in the large volume infusion group at all time intervals. The large volume infusion group also had decreased postoperative pain scores and required less supplemental analgesia. Preoperative correction of intravascular volume deficits effectively reduces PONV and postoperative pain in high risk patients presenting for ambulatory surgery. We recommend the preoperative administration of 2 mL/kg of compound sodium lactate for every hour of fasting to patients with an increased PONV risk presenting for ambulatory surgery.

Prognostic value of placental ultrasound in pregnancies complicated by absent end-diastolic flow velocity in the umbilical arteries

Our objective was to evaluate the utility of gray-scale placental ultrasound for the detection of pathological lesions in the placentas of preterm pregnancies with abnormal fetoplacental blood flow (defined by absent or reversed end-diastolic flow velocities [ARED] in the umbilical arteries) before 32 weeks of gestation. Sixty consecutive structurally and chromosomally normal singleton pregnancies were evaluated. Pre-defined criteria were used to describe placental appearances using gray-scale real-time ultrasound. Proximal uterine artery Doppler waveforms were recorded using pulsed and color Doppler ultrasound. Each patient had a thrombophilia profile. Following delivery, a single perinatal pathologist reviewed each placenta at a gross and microscopic level blinded to the placental ultrasound findings. Placental shape or texture was abnormal on gray-scale ultrasound in 43/59 (73%) and echogenic cystic lesions (ECL) were found in 16 (27%). Uterine artery Doppler was abnormal in 47/60 (78%) cases. Thirty-eight pregnancies were subsequently delivered by planned Caesarean section in the fetal and/or maternal interest (birthweights 540-2300 g, mean gestational age 30.6 weeks) and 21 pregnancies resulted in the vaginal delivery of a stillborn fetus where fetal weight and/or gestational age did not justify Caesarean section (birthweights 85-600 g, mean gestational age 24.9 weeks). ECL had a low positive predictive value for both villous infarcts (63%) and for focal/massive perivillous fibrin deposition (40%). Nevertheless, the combination of abnormal uterine artery Doppler and abnormal gray-scale findings (abnormal placental morphology or ECL) was strongly predictive of stillbirth (17/21; sensitivity 81%, PPV 52%, p = 0.006 Fisher's exact test). Pregnancies with ARED in the umbilical arteries have a high perinatal mortality associated with pathology of the placental villi. Ultrasound examination of the placenta and its maternal blood supply may contribute to the perinatal management of these pregnancies.

The biflavonoid, amentoflavone degrades DNA in the presence of copper ions

Previous reports from this laboratory have shown that flavonoids including apigenin are capable of inducing oxidative DNA cleavage in the presence of copper ions. In the present report, we have examined the ability of amentoflavone, a biflavonoid which is a dimer of apigenin, to catalyze the degradation of DNA. Amentoflavone was found to degrade calf thymus DNA in the presence of Cu(II) at a rate almost twice that of apigenin. Amentoflavone was also shown to reduce Cu(II) to Cu(I) and to generate hydroxyl radicals in the presence of copper ions. In the presence of Cu(II), the absorption spectrum of amentoflavone undergoes a shift and a quenching effect indicating that the biflavonoid is capable of binding to copper ions. Amentoflavone and apigenin were isolated from Cycas rumphii and Trifolium alexandrinum, respectively. The results are discussed in relation to the putative chemopreventive mechanism of amentoflavone.

Congenital infiltrating lipomatosis of the face and neck

Congenital infiltrating lipomatosis is a rare clinicopathologic entity characterized by infiltrating lipomatous tumors which, although of benign nature, have a tendency to recur after surgery. This has a predilection for the extremities and the trunk and is seen as overgrowth of soft tissue and bone. It rarely affects the face and neck. We describe two cases of congenital infiltrating lipomatosis of face and neck depicting the bone and soft tissue changes seen on computed tomography, along with a review of the literature on the subject.

Plasmid mediated amikacin resistance in clinical isolates of Pseudomonas aeruginosa

Ten multidrug resistant (MDR) isolates of Pseudomonas aeruginosa, obtained from hospitalized burn patients, were selected for plasmid detection, curing and transformation experiments. These isolates were also studied for plasmid mediated resistance. All the isolates were found to harbour R plasmid. Curing and transformation experiments showed that resistance to amikacin was plasmid mediated. -lactamase production was also tested. It is suggested that plasmids should be characterised in all MDR P. aeruginosa strains and a nation wide antibiotic policy should be made to minimise the emergence of drug resistance.

Search for pi(0)-->nu(mu)nu(mu) decays in the LSND detector

We observe a net beam excess of 8.7+/-6.3(stat)+/-2.4(syst) events, above 160 MeV, resulting from the charged-current reaction of nu(micro) and/or nu;(mu) on C and H in the LSND detector. No beam-related muon background is expected in this energy regime. Within an analysis framework of pi(0)-->nu(mu)nu;(mu), we set a direct upper limit for this branching ratio of Gamma(pi(0)-->nu(mu)nu;(mu))/Gamma(pi(0)-->all)<1.6 x 10(-6) at 90% confidence level.

Tuberculosis diagnosis and treatment practices of private physicians in Karachi, Pakistan

In a densely populated urban area of Karachi, Pakistan, a questionnaire survey was made of the knowledge and practices of 120 private general practitioners about the diagnosis and treatment of tuberculosis [TB]. The majority knew that cough, fever and weight loss were the main symptoms of TB, but less than half knew that blood in sputum, poor appetite and chest pain were associated with the disease. Only 58.3% of physicians used sputum microscopy for diagnosing TB and 35.0% used it as a follow-up test. Only 41.7% treated TB patients themselves, the remaining referring their patients to specialists. Around 73.3% of the doctors were aware of the 4 first-line anti-TB drugs. Efforts to improve the knowledge of private practitioners, and strategies to enhance public-private collaboration for TB control in urban areas are urgently required

Experimental model for cartilage tissue engineering to regenerate the zonal organization of articular cartilage

OBJECTIVE

Regeneration of the zonal organization of articular cartilage may be an important advancement for cartilage tissue engineering. The first goal of this study was to validate our surgical technique as a method to selectively isolate chondrocytes from different zones of bovine articular cartilage. The second goal was to confirm that chondrocytes from different zones would have different proliferative and metabolic activities in two-dimensional (2-D) and 3-D cultures. Finally, to regenerate the zonal organization, we sought to make multi-layered constructs by encapsulating chondrocytes from different zones of articular cartilage.

DESIGN

Cartilage slices were removed from three (upper, middle, and lower) zones of articular cartilage of young bovine legs. Histology and biochemical composition of the cartilage slices were analyzed to confirm that they had been obtained from the proper zone. Growth kinetics and gene expression in monolayer culture and matrix formation in photopolymerizing hydrogels were evaluated. Multi-layered photopolymerizing hydrogels were constructed with chondrocytes from each zone of native cartilage encapsulated. Cell viability and maintenance of the cells in the respective layer were evaluated using the Live/Dead Viability kit and cell tracking protocols, respectively. After 3 weeks, the multi-layered constructs were harvested for histologic examination including immunohistochemistry for type II collagen.

RESULTS

Analysis of histology and biochemical composition confirmed that the cartilage slices had been obtained from the specific zone. Chondrocytes from different zones differed in growth kinetics and gene expression in monolayer and in matrix synthesis in 3-D culture. Cells encapsulated in each of the three layers of the hydrogel remained viable and remained in the respective layer in which they were encapsulated. After 3-week culture, each zone of multi-layered constructs had similar histologic findings to that of native articular cartilage.

CONCLUSION

We present this as an experimental model to regenerate zonal organization of articular cartilage by encapsulating chondrocytes from different layers in multi-layered photopolymerizing gels.

Tuberculosis diagnosis and treatment practices of private physicians in Karachi, Pakistan

In a densely populated urban area of Karachi, Pakistan, a questionnaire survey was made of the knowledge and practices of 120 private general practitioners about the diagnosis and treatment of tuberculosis (TB). The majority knew that cough, fever and weight loss were the main symptoms of TB, but less than half knew that blood in sputum, poor appetite and chest pain were associated with the disease. Only 58.3% of physicians used sputum microscopy for diagnosing TB and 35.0% used it as a follow-up test. Only 41.7% treated TB patients themselves, the remaining referring their patients to specialists. Around 73.3% of the doctors were aware of the 4 first-line anti-TB drugs. Efforts to improve the knowledge of private practitioners, and strategies to enhance public-private collaboration forTB control in urban areas are urgently required.

Ultrasound in abdominal tuberculosis

BACKGROUND

The present study was done to emphasize the importance of ultrasound (US) and US-guided fine-needle aspiration biopsy (FNAB) in the diagnosis of abdominal tuberculosis.

METHODS

Sixty-six proven cases of abdominal tuberculosis were selected for this study. The diagnosis was based on clinical features, US observations, FNAB, operative findings, and responses to appropriate antitubercular treatment. The US findings were interpreted with regard to the involvement of lymph nodes, intestine, peritoneum, solid viscera, and abdominal abscesses. Patients with disease limited to the musculoskeletal and genitourinary systems were not included in the study.

RESULTS

Peritoneal tuberculosis was the most common form, of the "wet" ascitic type. Ascites was clear in 19 patients and complex in 17. Tuberculous lymphadenopathy was seen in 37 patients. There was a predilection of periportal, peripancreatic, and mesenteric locations compared with the degree of retroperitoneal involvement. Calcification and heterogeneous echotexture were seen in seven cases. FNAB confirmed the diagnosis of tubercular lymphadenopathy in 19 patients. Intestinal disease was seen in 14 patients. Hepatic or splenic involvement was seen as diffuse organomegaly; less commonly, focal lesions were seen.

CONCLUSION

This combination of US findings in proper clinical settings are diagnostic of tuberculosis. FNAB confirms the diagnosis in lymphadenopathy, abscesses, and focal lesions of the viscera.

Synthesis and antimicrobial activities of some isocoumarin and dihydroisocoumarin derivatives

A new series of the isocoumarin derivatives of ibuprofen, fluribiprofen, naproxen, valproic acid and 1-naphthoic acid have been synthesized via condensation of homophthalic acid with their respective acid chlorides. The conversion of the latter two isocoumarins into (dl)-3,4-dihydroisocoumarins has also been achieved. Most of the synthesized compounds showed antifungal and antibacterial activities.

Nosocomial Klebsiella infection in neonates in a tertiary care hospital: protein profile by SDS-page and klebocin typing as epidemiological markers

PURPOSE

To find out the prevalence of Klebsiella in hospital acquired neonatal infections in a tertiary care set up and to evaluate the role of klebocin typing and protein profile by SDS-PAGE in epidemiological typing of the isolates.

METHODS

Hospital born neonates transferred to the neonatal unit after birth and available in the unit 48 hours later comprised the study group. Two hundred and three neonates were found eligible for inclusion in the study. Repeated blood cultures, other relevant clinical specimens and environmental samples were collected and identified according to the standard techniques. Isolated clinical and environmental Klebsiella pneumoniae strains were subjected to klebocin typing and protein profiling by SDS-PAGE at regular intervals.

RESULTS

Multi drug resistant K. pneumoniae were the commonest organism isolated in 30 neonates leading to the incidence of Klebsiella nosocomial infection to be 14.7%. Klebocin typing of the K. pneumoniae isolates showed four patterns with type 312 being the commonest (43.4%). Whole cell protein analysis by SDS-PAGE of K. pneumoniae isolates revealed four types of banding pattern. Analysis of the typing method showed that the typeability and reproducibility of klebocin was 83.3% and 73.3% respectively whereas typeability and reproducibility of SDS-PAGE was 100%.

CONCLUSIONS

Based on the present study it is concluded that SDS-PAGE typing method is better than klebocin typing in neonatal nosocomial infection. It is also suggested that protein profile by SDS-PAGE may be used as a tool for epidemiological typing of Klebsiella pneumoniae isolates in laboratories where genomic based molecular typing technique is not available.

Serotonin-Cu(II)-mediated DNA cleavage: mechanism of copper binding by serotonin

It has been proposed that considerable DNA damage may be caused by endogenous metabolites produced during the body's normal metabolic processes. 5-hydroxytryptamine (serotonin) is an important neurotransmitter in brain and spinal cord. We have previously shown that serotonin induces oxidative cleavage of DNA strands in the presence of copper ions. In the present paper we have examined the mechanism of copper binding by serotonin using absorption spectroscopy, Cu(II)-mediated lipid peroxidation and by determining the oxidation of the serotonin molecule. Addition of increasing concentrations of Cu(II) to serotonin leads to a progressive enhancement in the absorption band and is accompanied by a shift towards a lower wavelength indicative of the formation of an oxidised species of serotonin. Studies with the structurally related molecules tryptophan and melatonin showed that only serotonin is able to reduce Cu(II) to Cu(I). Similarly, only serotonin was found to be able to abolish the copper-mediated peroxidation of mitochondria. These results suggested the involvement of the phenolic group in copper binding. Further, it was also shown that the binding of copper to serotonin leads to the formation of a quinone in the absence of molecular oxygen. Based on these results, a model has been proposed in which serotonin reduces two molar equivalents of Cu(II) to Cu(I) through a reaction involving two electron oxidation of the phenolic ring to a quinone methide.

Predictors of inpatient mortality in 190 adult patients with tuberculous meningitis

INTRODUCTION

Tuberculous meningitis (TBM), a tuberculous infection of the leptomeninges, carries significant morbidity and mortality. To date, little literature is available regarding TBM in Pakistan.

METHODS

All adult patients with TBM admitted to a tertiary care teaching hospital in Karachi, were reviewed retrospectively.

AIMS

To describe the demographic profile, clinical features, laboratory and radiological picture of these patients and to identify predictors of mortality.

RESULTS

Among the 190 patients analyzed, majority (28%) were between 21-30 years of age. Fever (90%), impaired consciousness (63%) and nausea/vomiting (50%) were the most common presenting symptoms. Thirty four percent were categorized as clinical stage III. CSF cultures were positive in only 5%. Thirty seven percent had an associated lung pathology on a chest X-ray. Neuroimaging revealed meningeal enhancement in 27% and hydrocephalus in 23%. All patients were treated with antituberculous therapy; 79% received concomitant steroid therapy. Neurosurgical intervention was required in 13% and mechanical ventilation support in 12%. Overall mortality was 20% and neurological sequelae were seen in 42% of the survivors. Univariate analysis showed age greater than sixty years, clinical stage III and mechanical ventilation as predictors of mortality. The logistic regression model, however, revealed that stage III presentation was not an independent predictor.

CONCLUSION

We continue to see late presentations of TBM in our setting. The current study has shown that age greater than sixty years and the need for mechanical ventilation are significant independent predictors of mortality.

Daphwazirin, biscoumarin glycopyranoside from Daphne oleoides

Daphwazirin, a new biscoumarin glycoside (1), along with four known compounds (2), (3), (4) and (5) has been isolated from the roots of Daphne oleoides. Its chemical structure is established as 7-hydroxy-8-[2-oxo-2H-1-benzopyran-7'-(O-alpha-L-rhamnosyl)-6'-yl]-2H-1-benzopyran-2-one through spectroscopic techniques and chemical analysis.

Triterpenes from Mimusops elengi

Pentacyclic triterpenes (1) and (2) have been isolated from Mimusops elengi and assigned structures 3beta,6beta,19alpha,23-tetrahydroxy-urs-12-ene and 1beta-hydroxy-3beta-hexanoyllup-20 (29)-ene-23, 28-dioic acid, respectively, on the basis of spectroscopic studies including 2D-NMR. The compound 1 showed moderate inhibiting activity against beta-glucuronidase enzyme

Abnormalities of conduction after total correction of Fallot's tetralogy: a prospective study

OBJECTIVE

To determine the frequency of post-operative conduction abnormalities in Pakistani patients undergoing total correction for Fallot's Tetralogy.

PATIENTS AND METHODS

One hundred and fifteen patients of Fallot's Tetralogy underwent definitive repair between January, 1999 and April, 2000. Their mean age was 12.89 years (range 3-30 years). One hundred nine patients (94.78%) had severe cyanosis and 6 patients (5.21%) were moderately cyanotic due to mild right ventricular outflow tract (RVOT) obstruction. Thirty percent patients required frequent hospital admissions within 6 months before the time of operation due to -hyper-cyanotic spells. The mean haematocrit was 50.83 (range 28-71). The majority of patients were in NYHA class-III (57%) and 45% had previous palliative shunt procedures done. Surgical access was through the RVOT in 90% cases and trans-atrial in 10%. RVOT patch was used in 55.9%, Pulmonary artery patch in 13.5% and trans-annular patch in 17.1% of cases.

RESULTS

The mean bypass time was 79.15 min and the mean cross clamp time 51.23 min. Average stay in the intensive care unit was 4.48 days. Twenty-three patients required re-exploration for bleeding. Sixty-nine patients required inotropic support. Fifteen patients had transient heart blocks and two had complete heart block requiring permanent pace-maker. Nineteen patients had various transient arrhythmias which were managed medically. Univariate analysis showed that higher age at operation, low preoperative heart rate, prolonged bypass time, prolonged cross clamp time and presence of patch on pulmonary artery were more common in patients who developed various heart blocks. However, none of these factors had statistical significance or definitive cause-effect relationship with heart blocks.

CONCLUSION

With careful surgical technique, total correction of Fallot's tetralogy can be conducted in children and young adults, with a very low risk of conduction abnormalities.

Sociocultural aspects of areca nut use

This paper aims to describe the sociocultural context of areca nut use through exploring people's norms and values and the meaning underlying a wide range of different practices. A historical review is followed by an examination of more recent evidence, including quantitative and qualitative research conducted in the United Kingdom. It is concluded that some reports involving the various uses of areca nut and the conclusions drawn are confusing and that future studies need to be more explicit. While a sound scientific background is required, important sociocultural and religious issues around areca nut use must also be understood if health promotion initiatives are to be considered.

Prevalence of Aspergillosis in chronic lung diseases

Eighty eight patients of chronic lung diseases (CLD) attending TB and Chest department of J.N. Medical college Hospital were studied to find out the prevalence of Aspergillus in Broncho-alveolar Lavage (BAL) and anti- aspergillus antibodies in their sera. Direct microscopy and fungal culture of BAL was done. Antibodies were studied by immunodiffusion (ID) and Enzyme linked immunosorbent assay (ELISA). Dot blot assay for anti-aspergillus antibodies was also performed in sera of patients which were either positive by ID or by ELISA. Aspergillus was isolated in culture from 13(14.7%) cases of CLD, while, 30.6% cases showed anti-aspergillus antibodies by serological methods. Aspergillus fumigatus was the predominant species isolated. 17(19.3%) cases of CLD showed antibody against Aspergillus by ID, 22(25%) by ELISA, while 19 of 27 seropositive cases also showed positive results by Dot Blot assay. In cases of bronchogenic carcinoma and pulmonary tuberculosis, anti-aspergillus antibodies were detected equally by ID and ELISA in 21.42% and 21.05% cases respectively. In bronchial asthma, the antibodies could be detected in 60% cases by ELISA, while, in only 10% cases by ID. ELISA was found more sensitive than ID for detection of anti-aspergillus antibodies. The sensitivity of Dot Blot lies some what between ID and ELISA. It is concluded that prevalence of Aspergillosis is quite high in chronic lung diseases, culture and serological test should be performed in conjunction and more than one type of serological tests should be performed to establish the diagnosis.

CRB1 mutations may result in retinitis pigmentosa without para-arteriolar RPE preservation

PURPOSE

To report a new phenotype in retinitis pigmentosa (RP) patients with CRB1 mutations at the RP12 locus.

PATIENTS

Thirty-seven patients from two Pakistani families with severe retinitis pigmentosa.

METHODS

Samples were screened with single-strand conformation polymorphism analysis followed by DNA sequencing of the coding sequence of the CRB1 gene.

RESULTS

Two novel CRB1 mutations were discovered. No patients had evidence of preservation of the para-arteriolar retinal pigment epithelium (PPRPE) that has been previously reported in all cases of RP associated with CRB1 mutations.

CONCLUSIONS

Patients with severe autosomal recessive (or simplex) RP who lack the finding of PPRPE should not be excluded from molecular analysis of CRB1 purely because they lack the clinical feature of PPRPE. This report illustrates that RP at the RP12 locus is not clinically uniform. The absence of PPRPE cannot be used to exclude CRB1 as a potential molecular explanation for RP.

Impact of endovascular repair for abdominal aortic aneurysms in octogenarians

A total of 50 consecutive patients (86% male; median age, 82 years) underwent endovascular repair of abdominal aortic aneurysms (AAAs) ranging from 4.0 to 9.0 cm (median, 5.2 cm). Efficacy of aneurysm exclusion was assessed by angiography, duplex scan, and/or contrast-enhanced computed tomography (CT). Acute technical success was 82%. Access failed in one patient, and immediate conversion to open operation was required in two patients. Improper deployment of the endoluminal graft (ELG) across the renal arteries occurred in one patient. The median operation time, estimated blood loss, packed red blood cells received, contrast volume, and length of intensive care and hospital stay were 128 min, 200 mL, 0.1 unit, 297 mL, 0.9 days, and 3 days, respectively. ELG limb thrombosis was seen in one patient. There were 4 (8%) early endoleaks, and 2 endoleaks were discovered in other patients at 3 and 6 months. Local/vascular and remote/systemic postoperative complications were seen in 13 (26%) and 9 (18%) patients, respectively. At a median follow-up of 11 months (range 2 to 36 months), clinical success was 78%. The aneurysm sac diameter (n = 49) decreased from a preoperative median of 5.2 to 4.7 cm (p = 0.0001). Technical success was high, and results at 11 months were satisfactory. Long-term outcomes require further study.

Ursene type nortriterpene from Debregeasia salicifolia

A new triterpene, 3beta-19alpha-dihydroxy-30-norurs-12-ene (1), has been isolated from the methanolic extract of Debregeasia salicifolia stems. Its structure has been elucidated with the help of one- and two-dimensional NMR and NOE studies. Lupeol, beta-sitosterol, stigmasterol and oleanolic acid are also reported for the first time from this species.

Beta blocker eye drops related airway obstruction

OBJECTIVE

To assess the awareness among chest physicians, ophthalmologists and patients about use of eye drops with particular reference to beta blockers such as timolol as an agent of aggravating breathlessness in predisposed subjects.

DESIGN

Cross-sectional study.

METHOD

A survey of 20 chest physicians, 20 ophthalmologists and 200 patients suffering from obstructive airway disease was conducted in 2 hospitals and a welfare center of Karachi from August to September 1997.

RESULTS

The results indicate that ophthalmologists showed more awareness than chest physicians regarding use of beta blocker eye drops by patients with obstructive airways disease (p = 0.004). Patient awareness was low as well.

CONCLUSION

There is a need to update doctors and educate general public about the side effects of beta blocker eye drops in patients with obstructive airway disease.

Sol-gel open tubular ODS columns with reversed electroosmotic flow for capillary electrochromatography

Sol-gel chemistry was successfully used for the fabrication of open tubular columns with surface-bonded octadecylsilane (ODS) stationary-phase coating for capillary electrochromatography (OT-CEC). Following column preparations, a series of experiments were performed to investigate the performance of the sol-gel coated ODS columns in OT-CEC. The incorporation of N-octadecyldimethyl[3-(trimethoxysilyl)propyl]ammonium chloride as one of the sol-gel precursors played an important role in the electrochromatographic performance of the prepared columns. This chemical reagent possesses a chromatographically favorable, bonded ODS moiety, in conjunction with three methoxy groups allowing for sol-gel reactivity. In addition, a positively charged nitrogen atom is present in the molecular structure of this reagent and provides a positively charged capillary surface responsible for the reversed electroosmotic flow (EOF) in the columns during CEC operation. Comparative studies involving the EOF within such sol-gel ODS coated and uncoated capillaries were performed using acetonitrile and methanol as the organic modifiers in the mobile phase. The use of a deactivating reagent, phenyldimethylsilane, in the sol-gel solution was evaluated. Efficiency values of over 400,000 theoretical plates per meter were achieved in CEC on a 64 cm x 25 microm i.d. sol-gel ODS open tubular column. Test mixtures of polycyclic aromatic hydrocarbons, benzene derivatives, and aromatic aldehydes and ketones were used to evaluate the CEC performances of both nondeactivated and deactivated open tubular sol-gel columns. The effects of mobile-phase organic modifier contents and pH on EOF in such columns were evaluated. The prepared sol-gel ODS columns are characterized by switchable electroosmotic flow. A pH value of approximately 8.5 was found correspond to the isoelectric point for the prepared sol-gel ODS coatings.