Tracking the Variations in Trace Elements, Some Nutrients, Phenolics, and Anthocyanins in Grewia asiatica L. (Phalsa) at Different Fruit Development Stages.

Grewia asiatica L. (phalsa) is a very prevalent berry in Pakistan and is consumed extensively as raw or in the form of juice. Here, for the first time, we assessed phalsa from Pakistan in terms of variations in macro and micro minerals, nutrients, and bio-active phyto-constituents including total phenolic and anthocyanin contents at different fruit developmental stages. It was found that the sugars in phalsa increased from D1 (small at the initial fruit setting stage) to D6 development stage (fully ripened fruit) where sugars at D5 (near to fully ripe) and D6 stages were many times greater than at D1, D2 (unripe close to full-size completion), D3 (close to semi ripe), and D4 stage (semi ripened and full-size attainment). Total acidity of was declined in all developmental stages, where the D1 stage displayed maximum and D6 with the lowest acidity. Ascorbic acid was decreased from D1 to D2 and then increased gradually from D3 to D5 stages. At the D6 stage, again a steep decline in ascorbic acid was observed. The total phenolics (mg gallic acid equivalents/100g) at stage D6 were higher (136.02 ± 1.17), whereas D1 being the lowermost in total phenolic content (79.89 ± 1.72). For anthocyanins (mg/100g), an increasing pattern of changes was observed in all stages of phalsa fruit where the D1 stage showed lower (13.97 ± 4.84) anthocyanin contents which then increased gradually at stage D2 (67.79 ± 6.73), but increased sharply at D3 (199.66 ± 4.90), D4 (211.02 ± 18.85), D5 (328.41 ±14.96) and D6 (532.30 ± 8.51) stages. A total of four anthocyanins such as cyanidin, delphidine-3-glucoside, pelargonidin, and malvidin in phalsa were identified using HPLC procedures, and a significant > 90 % DPPH inhibition in phalsa was observed at the D5 and D6 development stages. The macro and micro minerals including Ni, Zn, Fe, Ca, Cu, Mg, Na, P, and K contents were decreased from initial (D1) stage to the final (D6) development stage, while only Fe displayed an increasing trend from the initial to final fruit development stages (D1-D6). Conclusively, these findings could be of great interest for patients who are intended to consume phalsa as adjuvant therapy against diabetes and metabolic syndromes and other diseases involving reactive oxygen species with minimum metal toxicity.

Force generation of KIF1C is impaired by pathogenic mutations.

Intracellular transport is essential for neuronal function and survival. The most effective plus-end-directed neuronal transporter is the kinesin-3 KIF1C, which transports large secretory vesicles and endosomes.1-4 Mutations in KIF1C cause hereditary spastic paraplegia and cerebellar dysfunction in human patients.5-8 In contrast to other kinesin-3s, KIF1C is a stable dimer and a highly processive motor in its native state.9,10 Here, we establish a baseline for the single-molecule mechanics of Kif1C. We show that full-length KIF1C molecules can processively step against the load of an optical trap and reach average stall forces of 3.7 pN. Compared with kinesin-1, KIF1C has a higher propensity to slip backward under load, which results in a lower maximal single-molecule force. However, KIF1C remains attached to the microtubule while slipping backward and re-engages quickly, consistent with its super processivity. Two pathogenic mutations, P176L and R169W, that cause hereditary spastic paraplegia in humans7,8 maintain fast, processive single-molecule motility in vitro but with decreased run length and slightly increased unloaded velocity compared with the wild-type motor. Under load in an optical trap, force generation by these mutants is severely reduced. In cells, the same mutants are impaired in producing sufficient force to efficiently relocate organelles. Our results show how its mechanics supports KIF1C's role as an intracellular transporter and explain how pathogenic mutations at the microtubule-binding interface of KIF1C impair the cellular function of these long-distance transporters and result in neuronal disease.

A Severe Case of Molluscum Contagiosum Immune Reconstitution Inflammatory Syndrome in a Patient with Human Immunodeficiency Virus.

Paradoxical immune reconstitution inflammatory syndrome (IRIS) in human immunodeficiency virus (HIV)-positive patients initiating antiretroviral treatment (ART) is caused by restored immunity to specific antigens, resulting in worsening of a pre-existing infection. Molluscum contagiosum (MC) is commonly noted in HIV-positive individuals but ART alone is usually sufficient to bring about resolution. We present a rare case of severe MC-IRIS that worsened despite immune reconstitution. LEARNING POINTS: Molluscum contagiosum is a common opportunistic infection which can have severe manifestations in immunocompromised individuals.Antiretroviral treatment alone is usually sufficient to clear the infection, however refractory cases can persist despite immune reconstitution.Failure to improve or worsening immune reconstitution inflammatory syndrome should raise suspicion for additional immunological dysfunction.Surgery, cytodestructive therapies and chemotherapeutic agents can be considered in extensive, persistent disease.

Acute Suppurative Thyroiditis Secondary to Escherichia coli Infection.

Infections of the thyroid gland are rare. Its innate resistance to infections can be attributed to its unique anatomical features and rich blood supply. High clinical suspicion is required as a delay in diagnosis can lead to significant morbidity and mortality. Major pathogens include the Gram-positive Staphylococcus aureus and Streptococcus species; however, Gram-negative organisms have been found especially in immunocompromised hosts. We present a rare case of acute suppurative thyroiditis (AST) secondary to Escherichia coli (E. coli) infection in a woman known to be infected with human immunodeficiency virus (HIV). LEARNING POINTS: Thyroid abscesses are rare and can be confused with more common pathologies involving the neck such as a goitre, adenoma, intracystic haemorrhage, pharyngeal abscess and subacute thyroiditis.A high index of suspicion for a thyroid abscess is required for patients who present with an anterior neck swelling to avoid a late diagnosis, which is associated with significant morbidity and mortality.Acute suppurative thyroiditis is more commonly caused by Gram-positive organisms. Gram-negative organisms such as E. coli remain a rare cause. However, if a thyroid abscess is suspected clinically, broad-spectrum antibiotics can be lifesaving before definite culture and sensitivity results are available.

Secondary hypertension: An update on the diagnosis and localisation of a pheochromocytoma or paraganglioma.

Most cases of hypertension are because of essential hypertension, however 5% - 15% of cases can be a result of a secondary cause. In this article, we focus on the endocrine causes of secondary hypertension with a particular focus on pheochromocytomas (PCCs) and paragangliomas (PGLs). Around 15 endocrine disorders can initially present with hypertension. Amongst those PCCs and PGLs are rare but potentially life-threatening causes. An early diagnosis and timely referral can be life-saving. Herein, we present an approach for screening and diagnosis of these patients and focus on the importance of genetic testing.

SDHB-Associated Paraganglioma Syndrome in Africa-A Need for Greater Genetic Testing.

A germline mutation is identified in almost 40% of pheochromocytoma/paraganglioma (PPGL) syndromes. Genetic testing and counseling are essential for the management of index cases as well as presymptomatic identification and preemptive management of affected family members. Mutations in the genes encoding the mitochondrial enzyme succinate dehydrogenase (SDH) are well described in patients with hereditary PPGL. Among patients of African ancestry, the prevalence, phenotype, germline mutation spectrum, and penetrance of SDH mutations is poorly characterized. We describe a multifocal paraganglioma in a young African male with an underlying missense succinate dehydrogenase subunit B (SDHB) mutation and a history of 3 first-degree relatives who died at young ages from suspected cardiovascular causes. The same SDHB mutation, Class V variant c.724C>A p.(Arg242Ser), was detected in one of his asymptomatic siblings. As there are limited data describing hereditary PPGL syndromes in Africa, this report of an SDHB-associated PPGL is a notable contribution to the literature in this growing field. Due to the noteworthy clinical implications of PPGL mutations, this work highlights the existing need for broader genetic screening among African patients with PPGL despite the limited healthcare resources available in this region.

A universal stress protein in Mycobacterium smegmatis sequesters the cAMP-regulated lysine acyltransferase and is essential for biofilm formation.

Universal stress proteins (USPs) are present in many bacteria, and their expression is enhanced under various environmental stresses. We have previously identified a USP in Mycobacterium smegmatis that is a product of the msmeg_4207 gene and is a substrate for a cAMP-regulated protein lysine acyltransferase (KATms; MSMEG_5458). Here, we explored the role of this USP (USP4207) in M. smegmatis and found that its gene is present in an operon that also contains genes predicted to encode a putative tripartite tricarboxylate transporter (TTT). Transcription of the TTT-usp4207 operon was induced in the presence of citrate and tartrate, perhaps by the activity of a divergent histidine kinase-response regulator gene pair. A usp4207-deleted strain had rough colony morphology and reduced biofilm formation compared with the WT strain; however, both normal colony morphology and biofilm formation were restored in a Δusp4207Δkatms strain. We identified several proteins whose acetylation was lost in the Δkatms strain, and whose transcript levels increased in M. smegmatis biofilms along with that of USP4207, suggesting that USP4207 insulates KATms from its other substrates in the cell. We propose that USP4207 sequesters KATms from diverse substrates whose activities are down-regulated by acylation but are required for biofilm formation, thus providing a defined role for this USP in mycobacterial physiology and stress responses.

PTPN21 and Hook3 relieve KIF1C autoinhibition and activate intracellular transport.

The kinesin-3 KIF1C is a fast organelle transporter implicated in the transport of dense core vesicles in neurons and the delivery of integrins to cell adhesions. Here we report the mechanisms of autoinhibition and release that control the activity of KIF1C. We show that the microtubule binding surface of KIF1C motor domain interacts with its stalk and that these autoinhibitory interactions are released upon binding of protein tyrosine phosphatase PTPN21. The FERM domain of PTPN21 stimulates dense core vesicle transport in primary hippocampal neurons and rescues integrin trafficking in KIF1C-depleted cells. In vitro, human full-length KIF1C is a processive, plus-end directed motor. Its landing rate onto microtubules increases in the presence of either PTPN21 FERM domain or the cargo adapter Hook3 that binds the same region of KIF1C tail. This autoinhibition release mechanism allows cargo-activated transport and might enable motors to participate in bidirectional cargo transport without undertaking a tug-of-war.

Synthesis, spectroscopic characterization and antimicrobial activities of benzoxazolone derivatives.

: Background: Pathogenic microbial diseases are now the key virulence in our daily life. Significant research has been carried out in order to trigger the bacterial infections. Amongst the organic molecules, oxazolone and derivatives were found to have excellent bioactivities including antimicrobial activities. METHODS: By keeping in mind the considerable antimicrobial activities of class benzoxazolones, a series of benzoxazolone derivatives 3-16 have been synthesized. Out of which five compounds 10, 11, 14, 15, and 16 were new synthetic derivatives whereas compounds 9, 12, and 13 were already known compounds. These compounds have been synthesized by refluxing of amino phenol and 1,1-carbonyldiimidazole1 (C3H3N2)2CO) (CDI) in a dry THF and then treated with commercially available acid chloride. The structures of the compounds were elucidated on the basis of 1H-NMR, EIMS and elemental analysis. All the compounds were screened for their antibacterial activities and tested by agar well diffusion method. RESULTS: Compounds 14 and 16 showed good activity against S. aureus. Compound 5 showed good while 14 and 16 were found to be most active against E. coli using cefuroxime as a standard. Antifungal activities were carried out by using standard drug nystatin and compounds 4, 5, 9, 11 and compound 12 were found to be active against C. albicans. Compounds 4, 5, 9 and compound 10 showed good while 7, 11, and compound 13 showed excellent activities against Chrysosporium sp. Compounds 6, 7 and compound 12 were found to be most active against A niger and A. flavus, respectively. CONCLUSION: A number of derivatives were identified to have potent antimicrobial activities and may serve as lead compounds for future research.

Allostery and conformational dynamics in cAMP-binding acyltransferases.

Mycobacteria harbor unique proteins that regulate protein lysine acylation in a cAMP-regulated manner. These lysine acyltransferases from Mycobacterium smegmatis (KATms) and Mycobacterium tuberculosis (KATmt) show distinctive biochemical properties in terms of cAMP binding affinity to the N-terminal cyclic nucleotide binding domain and allosteric activation of the C-terminal acyltransferase domain. Here we provide evidence for structural features in KATms that account for high affinity cAMP binding and elevated acyltransferase activity in the absence of cAMP. Structure-guided mutational analysis converted KATms from a cAMP-regulated to a cAMP-dependent acyltransferase and identified a unique asparagine residue in the acyltransferase domain of KATms that assists in the enzymatic reaction in the absence of a highly conserved glutamate residue seen in Gcn5-related N-acetyltransferase-like acyltransferases. Thus, we have identified mechanisms by which properties of similar proteins have diverged in two species of mycobacteria by modifications in amino acid sequence, which can dramatically alter the abundance of conformational states adopted by a protein.

Ethnic disparities in routine immunization coverage: a reason for persistent poliovirus circulation in Karachi, Pakistan?

Karachi is the only mega city in the world with persistent poliovirus transmission. We determined routine childhood immunization rates in Karachi and identified predictors of vaccine completion. A population-based cross-sectional survey was conducted in Karachi between August and September 2008. Data on demographics, socioeconomic, and DTP3 vaccination status in children 12 to 23 months old were collected. Logistic regression was used to identify predictors of vaccination completion. Overall, 1401 participants were approached; 1391 consented to participate. Of these, 1038 (75%) were completely vaccinated. Punjabi families had the highest DTP3 coverage (82%), followed by Urdu-speaking families (79%). Pashtun (67%) and Bengali (48%) families had the lowest vaccine coverage. Children of mothers with ≥ 12 years of schooling (OR = 25.4; 95% CI = 5.7-113.1) were most likely to be vaccinated. A quarter of study participants were unvaccinated. Targeted strategies for boosting DTP3 rates in communities with low immunization coverage are essential for polio eradication in Karachi.

Cyclic AMP-dependent protein lysine acylation in mycobacteria regulates fatty acid and propionate metabolism.

Acetylation of lysine residues is a posttranslational modification that is used by both eukaryotes and prokaryotes to regulate a variety of biological processes. Here we identify multiple substrates for the cAMP-dependent protein lysine acetyltransferase from Mycobacterium tuberculosis (KATmt). We demonstrate that a catalytically important lysine residue in a number of FadD (fatty acyl CoA synthetase) enzymes is acetylated by KATmt in a cAMP-dependent manner and that acetylation inhibits the activity of FadD enzymes. A sirtuin-like enzyme can deacetylate multiple FadDs, thus completing the regulatory cycle. Using a strain deleted for the KATmt ortholog in Mycobacterium bovis Bacillus Calmette-Guérin (BCG), we show for the first time that acetylation is dependent on intracellular cAMP levels. KATmt can utilize propionyl CoA as a substrate and, therefore, plays a critical role in alleviating propionyl CoA toxicity in mycobacteria by inactivating acyl CoA synthetase (ACS). The precision by which mycobacteria can regulate the metabolism of fatty acids in a cAMP-dependent manner appears to be unparalleled in other biological organisms and is ideally suited to adapt to the complex environment that pathogenic mycobacteria experience in the host.

Disposition of pharmacologically active dietary isoflavones in biological systems.

Dietary isoflavones, popularly known as phytoestrogens, represent one of the most biologically active classes of flavonoids. Numerous in vitro and in vivo studies provide convincing evidence regarding their beneficial effects on human health. These isoflavones are increasingly being investigated as potential alternate therapies for a range of hormone-dependent conditions, including cancer, menopausal symptoms, osteoporosis and cardiovascular diseases. However, they exhibit poor oral bioavailability which limits their clinical utility in humans. The reason being, they are substrates of a plethora of enzymes and transporters and undergo extensive conjugative metabolism which facilitates their rapid elimination from biological systems. In addition, a number of experimental studies have also revealed that these isoflavones are potent inhibitors of various cytochrome P450 isoforms and transporters which play an important role in the disposition of many commonly prescribed drugs. Thus, there arise chances of observing clinically relevant herb-drug interactions which could sometimes be life-threatening. This review gives a comprehensive understanding of these dietary phytoestrogens with regard to their absorption, biodistribution and the role of enzyme-transporter interplay affecting their disposition in biological systems. Further, the effects of these phytoestrogens on the activity and kinetics of drug metabolizing enzymes and various clinically relevant influx/efflux transporters and the resulting diet-drug interactions have also been discussed.

Accidental poisoning in children.

OBJECTIVE: To assess the pattern of acute poisoning in children at Liaquat National Hospital, Karachi. METHODS: The one-year descriptive study was conducted in the Paediatric Emergency Unit of the Liaquat National Hospital, Karachi, from April 1, 2006 to March 31, 2007, involving all patients under 12 years of age who visited the unit with a history of accidental exposure to toxic substances. Demographic data and all other relevant information were obtained mainly by retrieving hospital records and the admission register. Immediate outcomes were analysed in terms of admission, discharge and 'left against medical advice' (LAMA). RESULTS: During the study period, 43 cases of accidental poisoning were registered, constituting 0.58% of the total emergency visits. Most (46.5%) were less than 3 years of age. Pharmaceutical products (34.9%) were the leading cause of ingestion followed by kerosene oil (25.6%), organophosphorous (16.3%), alkali (9.3%) and acid (7%). Regarding the outcome of these cases, 29 were admitted, 7 were discharged and 7 patients left against medical advice. CONCLUSION: In our study, a small percentage of children presented with acute poisoning. Pharmacologic agents were a common source of poisoning in children. There is a need to further study and identify risk factors of acute poisoning in children.