Progress and prospects in the management of bacterial infections and developments in Phytotherapeutic modalities

The advent of antibiotics revolutionized medical care resulting in significantly reduced mortality and morbidity caused by infectious diseases. However, excessive use of antibiotics has led to the development of antibiotic resistance and indeed, the incidence of multidrug-resistant pathogens is considered as a major disadvantage in medication strategy, which has led the scholar's attention towards innovative antibiotic sources in recent years. Medicinal plants contain a variety of secondary metabolites with a wide range of therapeutic potential against the resistant microbes. Therefore, the aim of this review is to explore the antibacterial potential of traditional herbal medicine against bacterial infections. More than 200 published research articles reporting the therapeutic potential of medicinal plants against drug-resistant microbial infections were searched using different databases such as Google Scholar, Science Direct, PubMed and the Directory of Open Access Journals (DOAJ), etc., with various keywords like medicinal plants having antibacterial activities, antimicrobial potentials, phytotherapy of bacterial infection, etc. Articles were selected related to the efficacious herbs easily available to local populations addressing common pathogens. Various plants such as Artocarpus communis, Rheum emodi, Gentiana lutea L., Cassia fistula L., Rosemarinus officinalis, Argemone maxicana L, Hydrastis canadensis, Citrus aurantifolia, Cymbopogon citrates, Carica papaya, Euphorbia hirta, etc, were found to have significant antibacterial activities. Although herbal preparations have promising potential in the treatment of multidrug-resistant bacterial infection, still more research is required to isolate phytoconstituents, their mechanism of action as well as to find their impacts on the human body.     

Prevalence of nonalcoholic fatty liver disease (NAFLD) in patients of cardiovascular diseases and its association with hs-CRP and TNF-α

Background

There is increasing recognition of association of nonalcoholic fatty liver disease (NAFLD) with cardiovascular disease (CVD). Metabolic syndrome is common in both NAFLD and cardiovascular diseases. Our study is designed to investigate the association of NAFLD with cardiovascular disease.

Methods

It''s a cross-sectional study which included 104 patients of coronary artery disease and hypertensive heart disease. Those patients having secondary causes of steatosis were excluded. Complete cardiovascular evaluation which included assessment of metabolic syndrome, routine biochemistries, viral markers, Ultrasonography (USG) abdomen, hs-CRP and TNF-α levels were obtained for all patients.

Results

Of all patients with cardiovascular disease, 19.2% (20/104) had essential hypertension with hypertensive heart disease the remaining 80.8% (84/104) patients had ischemic heart disease (IHD). On USG 69.2% (72/104) had NAFLD, these 50% (36/72) had grade 1 NAFLD and the rest grade 2 NAFLD. The hs-CRP levels and TNF-α were significantly higher in patients with NAFLD (p-value <0.001) and within patients with NAFLD the levels were higher in patients with grade 2 NAFLD. Also, binary logistic regression showed that high body-mass index (BMI), raised serum triglyceride levels, increased waist circumference and hypertension were significantly associated with the presence of NAFLD.

Conclusion

Our data indicates that NALD is highly prevalent in patients of cardiovascular disease (69.2%) and is significantly associated with metabolic syndrome and its individual components. The levels of hs-CRP and TNF-α were significantly higher in patients with NAFLD and showed an increasing trend with the severity of fatty liver.     

Neurotransmitter release in an arterial preparation and the action of alpha-adrenoceptor antagonists

1 This study examined the potentiating effects of competitive antagonists of the adrenergic alpha2 receptors and of phenoxybenzamine (POB) an irreversible antagonist, on the stimulation-induced efflux of [3H]-noradrenaline in arterial tissue of rabbit. This was done to determine if the lack of concordance of efflux potentiation by antagonists with the expectations of presynaptic negative feedback theory can be attributed to increasingly successful competition from rising perineuronal transmitter concentrations, when stimulation parameters are increased, in the presence of a fixed concentration of competitive antagonist. 2 Tissues were stimulated with a fixed pulse number and frequency, to rule out confounding factors, and major alterations in the concentration of released transmitter were achieved through variations in the pulse duration. 3 Rauwolscine potentiated transmitter release less at the longest, rather than at the shortest pulse duration, and showed a potentiation of release that was indifferent to the quantities of released transmitter. This was also seen with POB although it binds covalently to the presynaptic receptor. 4 Noradrenaline inhibited stimulation-induced transmitter release confirming the presence of presynaptic alpha inhibitory sites. 5 Yohimbine potentiated transmitter release the same as did rauwolscine and POB, and protected the relevant sites against POB potentiation, confirming site identity. The combination of POB and rauwolscine had no greater effect than did either alone certifying that they acted similarly and that maximally effective concentrations of each were used. 6 Consequently, noradrenaline breakthrough of presynaptic receptor blockade does not explain the non-conforming observations made with competitive antagonists in tests of presynaptic theory.     

Cardiovascular disease in athletes

Cardiovascular disease (CVD) is the leading cause of death in the United States, resulting in increased awareness of the preventive importance of regular physical activity. Because athletes are considered physically fit, occurrence of sudden athlete death from CVD is perplexing. Regular intense physical activity can cause changes to the cardiovascular system that mimic known CVD processes. Therefore, screening of athletes for conditions that may increase risk for sudden cardiac death (SCD) is challenging. This article focuses on this problem, discussing the athlete's heart, SCD and associated CV conditions, and preparticipation screening. We also review recommendations of the 26th Bethesda Conference on determining eligibility for competition in athletes with known CV abnormalities, and how the recommendations relate to individual disease processes.     

Leiomyosarcoma of the maxilla with spinal metastasis: a case report

Maxillary leiomyosarcoma is an uncommon tumor, and the occurrence of its metastasis to the spine is exceedingly rare. We report the case of a patient with maxillary leiomyosarcoma who developed a spinal metastasis 18 months following a total maxillectomy. Our patient represents only the third case of metastasis to the spine that has been reported in the literature, and the only reported case of metastasis to the iliac bone.     

Regarding the unitary theory of agonist and antagonist action at presynaptic adrenoceptors

1. The linkage between potentiation of field stimulation-induced noradrenaline release and blockade of the presynaptic inhibitory effect of exogenous noradrenaline by a presynaptic antagonist was examined in superfused rabbit aorta preparations. 2. Rauwolscine clearly potentiated the release of noradrenaline in response to 100 pulses at 2 Hz but reduced the capacity of noradrenaline to inhibit transmitter release to a questionable extent, and then only when comparisons were made with untreated, rather then to rauwolscine-treated, controls. 3. Aortic preparations exposed for 60 min to rauwolscine followed by superfusion with antagonist-free Krebs for 60 min retained the potentiation of stimulation-induced transmitter release but no antagonism of the noradrenaline-induced inhibition could be detected at either of two noradrenaline concentrations when comparisons were made with rauwolscine treated controls. 4. Comparisons of the inhibitory effect of exogenous noradrenaline (1.8 x 10-6 M) on transmitter efflux in the presence and absence of rauwolscine pretreatment revealed that the antagonist enhanced rather than antagonized the presynaptic inhibition by noradrenaline. 5 It is concluded that the unitary hypothesis that asserts that antagonist enhancement of transmitter release and its blockade of noradrenaline induced inhibition are manifestations of a unitary event are not supportable.     

Rate-independent inhibition by norepinephrine of 5-HT release from the somadendritic region of serotonergic neurons

Endogenous adrenergic drive regulates the firing rate of serotonergic neurons. However, advocates of feedback theory assert that 5-hydroxytryptamine (5-HT) released in the somatodendritic region of raphe neurons regulates both rate and release of 5-HT. Experiments were done to determine if the somatodendritic region might have receptors for norepinephrine that inhibit release of 5-HT independently of rate, as this would allow for discrete effects of norepinephrine on rate and release, even in the presence of functional feedback by 5-HT. The release of 5-HT at fixed frequencies of stimulation was substantially reduced when norepinephrine (1 and 3 x 10(-7) M) was present. Norepinephrine also inhibited the release of 3H-5-HT with delivery of a single stimulation pulse ruling out a remote action of the catecholamine. The alpha(1) antagonist prazosin did not modify the profile of norepinephrine inhibition. Further, the alpha(1) agonist phenylephrine had no effect on 3H-5-HT efflux. The alpha(2) antagonist yohimbine antagonized almost entirely the inhibition by norepinephrine at 1 Hz, and reduced it substantially at 3 Hz. Blockade of 5-HT(1) receptor sites with methiothepin did not reduce the inhibitory effect of norepinephrine on 3H-5-HT efflux. It is proposed that release of endogenous norepinephrine at synapses with 5-HT neurons could activate 5-HT neuron firing rate through alpha(1) receptors located at the soma and simultaneously short-circuit ongoing 5-HT feedback inhibition by inhibiting release through adrenergic alpha two receptors likely located at the dendrites.     

Clinical trials update from the European Society of Cardiology Meeting 2010: SHIFT, PEARL-HF, STAR-heart, and HEBE-III

This article provides information and a commentary on key trials relevant to the pathophysiology, prevention, and treatment of heart failure (HF) presented at the annual meeting of the European Society of Cardiology held in Stockholm in 2010. Unpublished reports should be considered as preliminary, since analyses may change in the final publication. The SHIFT study supports the use of ivabradine in patients with HF due to left ventricular systolic dysfunction and resting sinus rhythm rate ≥70 b.p.m. despite treatment with beta-blockers or where beta-blockers are contra-indicated. Results from PEARL-HF suggest that the potassium binding polymer RLY5016 may be useful for both prevention and treatment of hyperkalaemia in HF patients with or without concomitant chronic kidney disease. The STAR-heart study provides encouraging observational data about the potential for intracoronary stem cell transplantation in patients with HF. Results from HEBE-III showed no effect of erythropoietin on ejection fraction measured 6 weeks post-MI; although there were fewer cardiovascular events in patients assigned to erythropoietin, the study was too small to provide conclusive evidence of effect.     

The role of health insurance in explaining immigrant versus non-immigrant disparities in access to health care: Comparing the United States to Canada

Using a cross-national comparative approach, we examined the influence of health insurance on U.S. immigrant versus non-immigrant disparities in access to primary health care. With data from the 2002/2003 Joint Canada/United States Survey of Health, we gathered evidence using three approaches: 1) we compared health care access among insured and uninsured immigrants and non-immigrants within the U.S.; 2) we contrasted these results with health care access disparities between immigrants and non-immigrants in Canada, a country with universal health care; and 3) we conducted a novel direct comparison of health care access among insured and uninsured U.S. immigrants with Canadian immigrants (all of whom are insured). Outcomes investigated were self-reported unmet medical needs and lack of a regular doctor. Logistic regression models controlled for age, sex, nonwhite status, marital status, education, employment, and self-rated health. In the U.S., odds of unmet medical needs of insured immigrants were similar to those of insured non-immigrants but far greater for uninsured immigrants. The effect of health insurance was even more striking for lack of regular doctor. Within Canada, disparities between immigrants and non-immigrants were similar in magnitude to disparities seen among insured Americans. For both outcomes, direct comparisons of U.S. and Canada revealed significant differences between uninsured American immigrants and Canadian immigrants, but not between insured Americans and Canadians, stratified by nativity. Findings suggest health care insurance is a critical cause of differences between immigrants and non-immigrants in access to primary care, lending robust support for the expansion of health insurance coverage in the U.S. This study also highlights the usefulness of cross-national comparisons for establishing alternative counterfactuals in studies of disparities in health and health care.