Establishment of a rat model of myocardial infarction with a high survival rate: A suitable model for evaluation of efficacy of stem cell therapy

The most common rat model of myocardial infarction (MI) is by ligation of left anterior descending (LAD) coronary artery but it is associated with high mortality and large variations in the infarct size. We evolved certain innovations/modifications in the existing technique including immobilization of the heart without exteriorization, identification of the LAD by pressing it proximal to the site of ligation by an ear-bud, and subsequently its ligation 8 mm from its origin, no touch technique of the lungs during surgery, removal of air from the chest cavity prior to its closure using an in-house tubing, and deflation of the lungs before extubation. We induced MI in 24 Sprague- Dawley (SD) rats using these modifications and carried out post-MI evaluation of hemodynamic parameters, serum cardiac enzymes and histological studies upto 90 days using 13 sham operated and 3 healthy SD rats as controls. Three of the 24 rats (13%) died <24 hours of MI, but thereafter no mortality was observed till the follow-up period of 90 days. The infarct size was consistent in all the rats (21±4% of left ventricular area). This model with low early and no long-term mortality may be suitable for studying efficacy of stem cell therapy in MI, where a follow-up of at least 13 weeks is required to assess myocardial regeneration.

Increased prevalence of extended spectrum beta lactamase producers in neonatal septicaemic cases at a tertiary referral hospital

Emergence of extended spectrum beta lactamases (ESBLs) producing strains of gram negative bacteria, as one of the leading cause of septicaemia often complicates the clinical and therapeutic outcome. The present study was undertaken to investigate the prevalence of ESBLs in bacteria isolated from neonatal septicaemic cases along with their antimicrobial sensitivity pattern. Blood samples were collected from 243 suspected cases of neonatal septicaemia. Apart from susceptibility testing, all the gram negative isolates were subjected to phenotypic tests for ESBL production. Amongst the positive test samples (n = 115), 84 were gram negative rods. ESBL was detected in 26 (32%) isolates. Results indicate that routine ESBL detection should be made imperative and empirical use of third generation cephalosporins must be discouraged.

Breastfeeding and obesity among Kuwaiti preschool children

OBJECTIVES

To determine if breastfeeding and its duration are associated with a reduced risk of obesity among Kuwaiti preschool children.

SUBJECTS AND METHODS

The sample consisted of 2,291 (1,092 males and 1,199 females) preschool children (3-6 years of age) and their mothers. The data were collected from September 2003 to June 2004. Height and weight measurements were used for defining weight status while other data were collected by questionnaire.

RESULTS

There was no significant association of breastfeeding or its duration with either overweight or obesity among preschool children after adjusting for effects of the confounders. The child's gender, age and birth weight were the significant factors influencing current weight. Girls were at 32% higher risk of becoming obese than boys. Children aged 4-5 years were at nearly 3 times higher risk of overweight and obesity than children of less than 4 years. Children with higher birth weight (>or=4 kg) had double the risk of obesity than those of normal birth weight (>or=2.5 to <4.0 kg). Maternal obesity was a strong predictor of obesity in the children. A child with an obese mother had nearly 2 times higher risk of being overweight (BMI between the 85th the 95th percentiles) and 3 times of being obese (BMI >or=95th percentile) compared to a child born to a mother with a normal body weight.

CONCLUSION

Breastfeeding and its duration are not associated with obesity status. However, there is a positive association between child and maternal obesity.

Observations on carbapenem resistance by minimum inhibitory concentration in nosocomial isolates of Acinetobacter species: an experience at a tertiary care hospital in North India

Acinetobacter species are emerging as an important nosocomial pathogen. Multidrug-resistant Acinetobacter spp. has limited the option for effective treatment. Although carbapenems are effective for the treatment of such infections, resistance to this drug has recently been reported. This study was undertaken to assess resistance to carbapenem in clinical isolates of Acinetobacter spp. from hospitalized patients by both disc-diffusion and minimum inhibitory concentration (MIC) methods. All clinical samples from suspected cases of nosocomial infections were processed, and 265 isolates were identified as Acinetobacter species. These isolates were tested for antibiotic resistance by the disc-diffusion method with 14 antimicrobials, including meropenem and imipenem. Thereafter, all Acinetobacter species were subjected to MIC for meropenem. More than 80% resistance to second- and third-generation cephalosporins, aminoglycosides, and quinolones was recorded. Thirty percent of the strains were resistant to cefoperazone/sulbactam. Resistance to meropenem was observed in 6.4% of Acinetobacter spp. while 8.3% of the isolates showed intermediate resistance detected by MIC. All carbapenem-resistant/intermediate strains were also resistant to other (>10) antibiotics tested by the disc-diffusion method. The rising trend of resistance to carbapenem poses an alarming threat to the treatment for such infections. Regular monitoring, judicious prescription, and early detection of resistance to carbapenem are necessary to check further dissemination of drug resistance in Acinetobacter spp.

Clinical and pathological response to taxanes (T) and anthracycline (AC) based neoadjuvant chemotherapy (NAC) in locally advanced breast cancer (LABC): A retrospective analysis from a single institution in North India

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Background: In India LABC remains a common presentation of breast cancer (BC). Pathological complete response (pCR) achievement is crucial for increasing survival in LABC. Taxanes and anthracyclines are amongst agents with highest activity in BC. We retrospectively evaluated clinical and pathological responses in LABC patients (pts) treated with T and AC based chemotherapy. Methods: 32 LABC pts with clinical stage IIB, IIIA, IIIB, IIIC who had received T & AC based NAC between October 2002 and October 2006 were evaluated. Patients received doxorubicin 60mg/m2 (21 pts) or epirubicin 75 mg/m2 (11 pts) and docetaxel 75 mg/m2 (all pts) 3 weekly for 3–4 cycles followed by surgery. Most pts received same chemotherapy as adjuvant and also radiation therapy and hormonal treatment depending upon ER, PgR status. Results: Baseline characteristics of 32 pts: median age 50 years (range 26–65); all female; performance status 0–1; clinical stage IIB (3 pts), IIIA (9 pts), IIIB (16 pts), IIIC (4 pts); node positive (25 pts), hormone receptor positive (17 pts), unknown (1 pt); 29 pts received 3 cycles of NAC, 3 pts received 4 cycles of NAC. Growth factor was used in all patients. 31 pts underwent MRM; 5 pts had clinically complete response (16%), 22 pts had partial response (69%), 4 pts had stable disease (12%), 1 pt had progressive disease (3%); pathological complete response was seen in 4 pts (12 %). There were 2 events of febrile neutropenia; grade 3 or 4 neutropenia was seen in 26 pts (81%). There was no significant thrombocytopenia, cardiovascular event and hypersensitivity reaction. Conclusions: Our analysis indicates that T and AC based chemotherapy is well tolerated and effective in Indian pts with LABC with response rates similar to international studies.

No significant financial relationships to disclose.

Microincision bimanual phacoemulsification and Thinoptx® implantation through a 1.70 mm incision

PURPOSE

To prospectively assess the efficacy of bimanual phacoemulsification and implantation of Thinoptx, an injectable intraocular lens (IOL), inserted through 1.70 mm clear corneal incision.

SETTING

Department of Ophthalmology, Southend Hospital NHS Trust, UK.

METHODS

A total of 50 eyes of 49 randomly selected patients with cataracts had microincision clear corneal bimanual phacoemulsification (MICS) with implantation of Thinoptx IOL in the capsular bag. All patients underwent full preoperative assessment. Postoperative assessment was carried out at 3 and 6 weeks and at 15 months.

RESULTS

In all 50 cases the IOL was inserted through 1.70 mm clear corneal incision. The mean best-corrected visual acuity was 0.02 (6/6-1) at 6 weeks and was 0.17 (6/10) at the final follow-up. The mean final surgically induced astigmatism at 6 weeks was 0.0106. Coloured haloes around artificial lights were perceived by 69.23% of patients at 6 weeks and by 61.29% at the final follow-up. One patient underwent IOL exchange for this. Posterior capsular opacification was noticed in 31.26% at 6 weeks and in 64.51% at 15 months. Anterior capsular opacification was noticed in 5.26% at 6 weeks and in 16.12% at 15 months. In one patient the IOL had to be exchanged because of tilt and displacement of the IOL due to anterior capsular phimosis.

CONCLUSIONS

We conclude Thinoptx can be safely inserted through 1.70 mm incision used for bimanual phacoemulsification. Distance and near visual acuity achieved with this IOL is satisfactory. There is no significant change in keratometric astigmatism following this procedure. However, posterior capsular opacification rate was significantly higher with this IOL. Haloes around light sources were significant.

Slow Ca2+ channels neither contribute to upstroke of action potential nor to pacemaker potential in spontaneously active freshly isolated three day embryonic chick ventricle

Contribution of slow Ca2+ channels to the upstroke of action potential (AP) and pacemaker potential was studied by observing the effects of Ca2+ channel activators- high [Ca2+]0, Bay-K-8644, isoproterenol, forskolin and dibutyryl-cAMP on spontaneous AP of freshly isolated 3 day embryonic chick ventricle (3 day ECV). The spontaneous APs showed maximal upstroke velocity (+Vmax), maximum diastolic potential (MDP), overshoot (Eov) and AP duration at -20 mv (APD20) of 42.60 +/- 2.40 V/sec, -59.05 +/- 0.95 my, 16.30 +/- 0.53 mv and 70.32 +/- 4.60 msec, respectively (an average value of 35 preparations). Bay-K-8644 (0.1-0.8 microM), isoproterenol (5-10 pM) and forskolin (0.1-2.0 microM) induced a concentration-dependent increase in APD20 and Eov without affecting +Vmax. Dibutyryl-cAMP (1 microM) also enhanced the APD20 and Eov and had no effect on +Vmax. Elevation of [Ca2+]0 from 0.6 mM to 9.6 mM caused a concentration-dependent increase in APD20 and Eov leaving +Vmax unaltered. Elevated [Ca2+] and the other Ca2+ channel activators had no significant effect on MDP in above concentration range. Increase in APD20 and Eov could be explained at least by activation of slow Ca2+ channels but the lack of any change in +Vmax clearly suggests that the slow Ca2+ channels do not contribute to the upstroke of AP. All these interventions reduced the rate of spontaneous firing without any noticeable effect on MDP. This finding shows that the slow Ca2+ channels also do not contribute directly to the generation of pacemaker potential in spontaneously active freshly isolated 3 day ECV.

Modulation of spontaneous electrical activity of freshly isolated 3-day embryonic chick ventricle by cAMP and cGMP

Effects of cyclic nucleotides 8-Bromo-cAMP and 8-Bromo-cGMP (membrane permeable analogs of cAMP and cGMP) were examined on action potential (AP) configuration and rate of spontaneous firing of the freshly isolated 3-day embryonic chick ventricle (ECV) to assess the role of L-type slow Ca2+ channels in upstroke of AP and spontaneous electrical activity (pacemaker potential). The 3-day ECV exhibited prominent automaticity and spontaneous APs characterized by maximum upstroke velocity (+V(max)), maximum diastolic potential (MDP), overshoot (E(ov)), AP duration at -20 mV (APD20) and cycle length (CL) of 33.09 +/- 3.18 V/sec, -63.77 +/- 1.17 mV, 17.40 +/- 0.91 mV, 51.20 +/- 3.05 m sec and 795 +/- 150 m sec, respectively (n = 10 preparations). 8-Br-cAMP (1 mM) caused significant increase in E(ov) and APD20 (37% and 56%, respectively, p < 0.01), but failed to produce any stimulatory effect on +V(max) and MDP. Surprisingly, 8-Br-cAMP produced negative chronotropic effect on spontaneous firing (automaticity) and enhanced the CL significantly by 43% (p < 0.05). 8-Br-cGMP, however, had no effect on AP configuration and the rate of spontaneous firing. The present findings with 8-Br-cAMP suggest that L-type slow Ca2+ channels do not contribute to upstroke of AP and pacemaker potential of spontaneously firing freshly isolated 3-day ECV. The negative chronotropic effect of 8-Br-cAMP suggests that the ionic mechanism underlying pacemaker potential is [Ca]i-dependent. However, the lack of any effect of 8-Br-cGMP on spontaneous electrical activity of freshly isolated 3-day ECV indicates that cGMP does not modulate the basal Ca2+ channel activity in young embryonic myocardium.

Therapeutic uses of Ocimum sanctum Linn (Tulsi) with a note on eugenol and its pharmacological actions: a short review

The medicinal plants are widely used by the traditional medical practitioners for curing various diseases in their day to day practice. In traditional systems of medicine, different parts (leaves, stem, flower, root, seeds and even whole plant) of Ocimum sanctum Linn (known as Tulsi in Hindi), a small herb seen throughout India, have been recommended for the treatment of bronchitis, bronchial asthma, malaria, diarrhea, dysentery, skin diseases, arthritis, painful eye diseases, chronic fever, insect bite etc. The Ocimum sanctum L. has also been suggested to possess antifertility, anticancer, antidiabetic, antifungal, antimicrobial, hepatoprotective, cardioprotective, antiemetic, antispasmodic, analgesic, adaptogenic and diaphoretic actions. Eugenol (1-hydroxy-2-methoxy-4-allylbenzene), the active constituent present in Ocimum sanctum L., has been found to be largely responsible for the therapeutic potentials of Tulsi. Although because of its great therapeutic potentials and wide occurrence in India the practitioners of traditional systems of medicine have been using Ocimum sanctum L. for curing various ailments, a rational approach to this traditional medical practice with modern system of medicine is, however, not much available. In order to establish the therapeutic uses of Ocimum sanctum L. in modern medicine, in last few decades several Indian scientists and researchers have studied the pharmacological effects of steam distilled, petroleum ether and benzene extracts of various parts of Tulsi plant and eugenol on immune system, reproductive system, central nervous system, cardiovascular system, gastric system, urinary system and blood biochemistry and have described the therapeutic significance of Tulsi in management of various ailments. These pharmacological studies have established a scientific basis for therapeutic uses of this plant.

MR venography in cerebral venous sinus thrombosis

A case of left transverse and sigmoid sinus thrombosis in a 60 years female is reported. The diagnosis was confirmed on MRI with MR venography.

Multiple coronary risk factors in healthy older Kuwaiti males

OBJECTIVE

The objective was to examine the percentage and severity of obesity and some common biochemical coronary heart disease (CHD) risk factors in a sample of healthy Kuwaiti adult males > or =45 y of age. We also sought to determine the percentage of males at increased risk due to the presence of multiple CHD risk factors.

DESIGN

The study was a cross-sectional study.

SETTING

The study was conducted in all men who underwent a mandatory job related physical examination or who sought to obtain retirement benefits.

SUBJECTS

A total of 740 healthy Kuwaiti males between the ages of 45 to 80 y.

RESULTS

In all, 37% of the men were obese, 26% had elevated glucose values and 52% had elevated or high cholesterol levels. Some had multiple risk factors for CHD, including age > or =45 y, obesity, male gender, hyperglycemia and hypercholesterolemia. Blood glucose values increased consistently from younger (45-54 y) to older age groups (55-64 and > or =65 y). Blood glucose values varied inversely with education level.

CONCLUSIONS

In societies with relatively uniform income levels, educational level may be a better indicator of chronic disease risk than income per se. These results, showing a high percentage of men with several risk factors and high mean values, suggesting more severe risk, suggest that immediate action should be taken to develop a public health intervention strategy to educate Kuwaiti men to become aware of the causes and correlates of CHD and how to decrease their risk for CHD and heart attack, the leading cause of death in Kuwait.

Prevalence of coronary risk factors in healthy adult Kuwaitis

Obesity has been shown to be a serious health risk and is associated with a wide range of comorbid conditions, including diabetes mellitus, coronary heart disease (CHD), gall bladder disease, hypertension, osteoarthritis, and certain cancers. Studies in Kuwait and other Gulf States indicate that obesity is prevalent and may be increasing. Previous studies in Kuwait have mostly focused on the epidemiology of overweight and obesity in children, adolescents, and young adults. Relatively less is known about the prevalence of overweight and obesity and its correlates in older adults for whom obesity may be more closely related to CHD risk. The purpose of this study was to examine the prevalence of overweight and obesity in 9755 adult men and women and to determine the relationship of weight to other risk factors for chronic disease. For the first time we examine a sample of older Kuwaitis to explore the relationship between high BMI, hypercholesterolemia and hyperglycemia. One-third of adult Kuwaitis are obese (BMI > 30 kg/m2), 4.7% of Kuwaiti females have severe obesity (BMI > 40 kg/m2). BMI, cholesterol, and glucose values increase with age across the life span. Older Kuwaitis have a greater constellation of risk factors for chronic diseases. The results of a multiple linear regression model in which cholesterol values were studied, controlling for age, BMI, blood glucose, and sex revealed that age, BMI and sex were significant predictors of cholesterol values. These results indicate that actions to reduce obesity, hypercholesterolemia, and hyperglycemia are needed.

In vitro inhibition of proliferation of estrogen-dependent and estrogen-independent human breast cancer cells treated with carotenoids or retinoids

Both estrogen-receptor (ER) positive MCF-7 and ER-negative Hs578T and MDA-MB-231 human breast cancer cells were treated with carotenoids (beta-carotene, canthaxanthin and lycopene) and retinoids (all-trans-, 9-cis- and 13-cis-retinoic acid and all-trans-retinol). Among carotenoids, beta-carotene significantly reduced the growth of MCF-7 and Hs578T cells, and lycopene inhibited the growth of MCF-7 and MDA-MB-231 cells. Canthaxanthin did not affect the proliferation of any of the three cell lines. All-trans- and 9-cis-retinoic acid significantly reduced the growth of both MCF-7 and Hs578T cells, whereas 13-cis-retinoic acid and all-trans-retinol had a significant effect only on MCF-7 cells. MCF-7 and Hs578T cells treated with all-trans-retinoic acid (all-t-RA) were further studied for the mechanism behind growth inhibition. Retinoic acid receptors alpha and gamma (RARalpha, gamma) in MCF-7 cells and RARalpha, beta and gamma in Hs578T cells were not induced by all-t-RA treatment at either the protein or mRNA level. Hs578T cells treated with all-t-RA had significantly more cells in the G0/G1 stage of the cell cycle, but the same was not observed for MCF-7 cells. All-t-RA induced a dose-dependent cell death in MCF-7 cells, which may be a necrotic phenomenon. These results demonstrate that ER status is an important, although not essential factor for breast cancer cell response to carotenoid and retinoid treatments, and the mode of action of all-t-RA in MCF-7 and Hs578T cells is not through the induction of RAR. Other mechanistic pathways that are either followed by or concomitant with growth inhibition are possible.

Frequency- and time-dependent effects of fendiline on action potentials of guinea pig papillary muscle

The action of fendiline on cardiac electrical activity was investigated in guinea pig papillary muscle by monitoring frequency- and time-dependent changes in membrane potential, action potential (AP) configuration and conduction velocity. Isolated guinea pig papillary muscles driven at 0.1 to 3 Hz showed a concentration-dependent reduction of +Vmax, overshoot, and AP duration at -20mV (APD20) in the presence of fendiline (1-320 microM), reflecting inhibition of Na+ and L-type Ca2+ channels, respectively. No significant change in resting potential and AP duration at 90% repolarization (APD90) were observed. Inhibition of +Vmax and APD20 was more prominent at higher frequency of stimulation (2 Hz) than at lower ones (0.2 Hz), demonstrating frequency-dependent block of Na+ and Ca2+ channels including an open channel block. A good relationship between changes in +Vmax and APD20 suggested some commonality in the mechanism of inhibition of Na+ and Ca2+ channels by fendiline. Time-dependence of effects of fendiline, observed in presence of bolus dose (200 microM), showed an earlier onset of inhibition of +Vmax and APD20, particularly at higher frequencies. Missed beats and conduction block also appeared earlier in preparations driven at higher frequency. These findings suggest a frequency-dependent (and open channel) block of Na+ and Ca2+ channels by fendiline, leading to inhibition of fast and slow conduction in addition to its reported inactivated Ca2+ channel block.

Retinoids, carotenoids, and human breast cancer cell cultures: a review of differential effects

Cancer of the breast is the most common incident cancer and cause of death from cancer in women. Several epidemiologic studies have reported a significant inverse relationship between the intake of vitamin A and/or provitamin A-rich foods and the incidence of certain cancers, including breast cancer. A large number of studies have been conducted to determine the effect of retinoids (all-trans-retinoic acid, in particular), and to a lesser extent of carotenoids, on breast cancer using cell culture models. In general, the results of these studies demonstrate beneficial effects of all-trans-retinoic acid on different breast cancer cells. This review compares studies conducted in different laboratories using retinoids and carotenoids as treatments for breast cancer cells and suggests what may be the underlying reasons for the differential effects of these compounds on the same cell lines.

Subcellular accumulation of beta-carotene and retinoids in growth-inhibited NCI-H69 small cell lung cancer cells

Delivery of beta-carotene in tetrahydrofuran slowed the growth of NCI-H69 small cell lung cancer cells. Analysis of cells and cellular fractions revealed that beta-carotene-treated cells accumulated beta-carotene as well as some polar metabolites, primarily in the crude nuclei. Cells were grown at 1 x 10(5) cells/ml and treated with 20 microM beta-carotene. Growth monitoring up to 15 days indicated an inverse relationship between the duration of beta-carotene treatment and the rate of cell growth. Reverse-phase high-performance liquid chromatography analysis of treated cells showed the presence of beta-carotene, retinoic acid, retinol, and retinal, with beta-carotene accounting for the major material recovered. When cellular fractions were analyzed for beta-carotene, it was found to be located primarily in the crude nuclei. These results demonstrate that treatment of small cell lung cancer cells with beta-carotene results in a reduced growth of the cells. Further investigation is required to show a direct effect of beta-carotene or its intracellular polar metabolites on these cells. Accumulation of beta-carotene in the nucleus suggests a need for evaluating the nuclear role for beta-carotene.