Effect of nanocatalysts on the transesterification reaction of first, second and third generation biodiesel sources- A mini-review

Biodiesel is a fuel that has numerous benefits over traditional petrodiesel. The transesterification process is the most popular method for biodiesel production from various sources, categorized as first, second and third generation biodiesel depending on the source. The transesterification process is subject to a variety of factors that can be taken into account to improve biodiesel yield. One of the factors is catalyst type and concentration, which plays a significant role in the transesterification of biodiesel sources. At present, chemical and biological catalysts are being investigated and each catalyst has its advantages and disadvantages. Recently, nanocatalysts have drawn researchers' attention to the efficient production of biodiesel. This article discusses recent work on the role of several nanocatalysts in the transesterification reaction of various sources in the development of biodiesel. A large number of literature from highly rated journals in scientific indexes is reviewed, including the most recent publications. Most of the authors reported that nanocatalysts show an important influence regarding activity and selectivity. This study highlights that in contrast to conventional catalysts, the highly variable surface area of nanostructure materials favours interaction between catalysts and substrates that efficiently boost the performance of products. Finally, this analysis provides useful information to researchers in developing and processing cost-effective biodiesel.

White papilloma involving both vocal cords: A Case Report

White papilloma are rare lesions that may occur at any site of mucosa- lined respiratory tract especially in vocal cords. Morphologically it appears villas looking, clinically & microscopically benign in most cases. We report a 70 years old male patient with white papilloma near anterior commissure involving both vocal cords found during indirect laryngoscopy. The lesion was completely resected with a unipolar coagulation device under direct laryngoscopy. Histopathological examination showed papilloma of vocal cords associated with Human papilloma virus(HPV) wart. To our knowledge this is the second reported case concomitant white papilloma with concomitant HPV in the vocal cords. Bangladesh J Otorhinolaryngol; April 2020; 26(1): 73-76

Use of Bioresorbable Vascular Scaffold technology in treating coronary bifurcation lesions: A report about long-term clinical results and review of available literature

INTRODUCTION

BVS proved safe in humans. ABSORB trials showed them performing similar to Drug Eluting Stents in simple coronary interventions. We assessed a registry of 63 patients with bifurcation lesions, treated by BVS and followed their outcomes up-to 5 years.

METHODS

Patients who satisfied the inclusion criteria were included. Data about contact information, baseline characteristics, findings of coronary angiogram, details of their interventional treatment; short and long-term outcomes up till 5 years was collected.

RESULTS

Acute feasibility of implantation in bifurcation was high (98 %). Rate of stent thrombosis, acute or sub-acute, was 3.1 %. Rate of re-intervention was 38 %. The average time for an event to occur was 1.6±0.8 years. Over 5 years, 56 % had developed MACE. Patients with MACE were more likely females, hypertensive, smokers, with acute presentations (p=NS), and diabetic (72 % vs 33 % non-diabetic; p=0.002). Patients treated with hybrid strategy of BVS and DES were more likely to develop MACE (64 % vs 49 % for others; P=ns). Patients treated by simple provisional stenting were less likely to develop MACE (45 % vs 60.5 %; p=ns). The average SYNTAX score of MACE patients was 27 vs 20; p=0.06). Diabetes was independently associated with MACE. Hypertension was of borderline statistical significance (2-sided Log rank for Hypertension p=0.06, for Diabetes p=0.01).

DISCUSSION

The use of multiple stenting strategies to treat true bifurcation lesions using BVS is feasible with low rate of serious adverse events, albeit on the long run, the rate of re-intervention is high and stringent follow up is required (Tab. 7, Fig. 3, Ref. 37).

Design and synthesis of fluorogenic substrate-based probes for detecting Cathepsin B activity

Cathepsin B plays key roles in tumor progression with its overexpression being associated with invasive and metastatic phenotypes and is a primary target of protease activated antibody-directed prodrug therapy. It therefore represents a potential therapeutic and diagnostic target and effort has been made to develop fluorescent probes to report on Cathepsin B activity in cells and animal models of cancer. We have designed, synthesized, and thoroughly evaluated four novel "turn on" probes that employ a lysosomotropic dansylcadaverine dye to report on Cathepsin B activity. Enzyme activity assays using a recombinant human enzyme and cancer cell lysates coupled with confocal microscopy experiments demonstrated that one of the probes, derivatized with the self-immolative prodrug linker p-aminobenzyl alcohol, can selectively report on Cathepsin B in biological samples including live cells.

Anti-phospholipid Antibody Syndrome Presenting as Huge Ascites: A Case Report

Antiphospholipid Syndrome (APS) is characterized by arterial, venous or small vessel thromboses and/or pregnancy morbidity in the presence of persistently elevated titers of antiphospholipid antibodies. Since virtually any organ can be involved, the clinical presentation of APS is very varied. Abdominal manifestations are rare but may be life-threatening, and include Budd-Chiari Syndrome. We report the case of a 26-year-old woman with primary APS, on aspirin treatment, who presented to us at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh in March 2017 with ascites for which she had been receiving treatment for abdominal tuberculosis. Following clinical and laboratory evaluation, she was diagnosed as a case of Budd-Chiari Syndrome with portal hypertension and initiated treatment with warfarin. There should be a high index of clinical suspicion for Budd-Chiari as a cause of ascites in patients with APS, since early recognition and treatment can significantly improve patients' survival.

Methanol Induced Toxic Amblyopia--A Case Report

A 28-year-old man, smoker having history of occasional alcohol intake--was admitted in the Department of Medicine, Bangabandhu Sheikh Mujib Medical University (BSMMU) with gradual diminution of vision in both eyes 10 days after consumption of homemade alcoholic beverage in a wedding ceremony. His initial acuity of vision was limited to no perception of light in right eye and hand movement in left eye. Fundus examination revealed pale optic discs in both eyes. The patient was treated with Injection Methylprednisolone 1000 mg intravenous slowly over 1 hour for 3 consecutive days. This was followed by oral prednisolone 60 mg daily for 14 days and then gradually tapered over 4 weeks. The patient also received Injection Hydroxycobalamine and Injection Folinic Acid for 2 weeks. On the 3rd day of treatment there was perception of light in the right eye and on the 10th day the visual acuity improved to hand movement. In the left eye, the visual acuity gradually improved to 6/60 on 3rd day and on 10th day improved to 6/24. Four weeks later, the visual acuity had recovered in both eyes to 6/18. Combination of intravenous and oral steroid along with vitamin B1 and folinic acid has been found effective in treating severe methanol induced optic neuropathy.

Acute Kidney Injury is More Common in Acute Haemorrhagic Stroke in Mymensingh Medical College Hospital

Acute kidney injury (AKI) is a common complication after acute stroke and is an independent predictor of both early and long-term mortality after acute stroke. Acute kidney injury is associated with increased mortality in haemorrhagic stroke patients. This cross sectional observational study was conducted in Nephrology, Neuromedicine and Medicine department of Mymensingh Medical College & Hospital, Mymensingh from July 2012 to June 2014. A total of 240 patients with newly detected acute stroke confirmed by CT scan of brain were included in this study. According to this study, 15.42% of acute stroke patients developed AKI. Among the patients with haemorrhagic stroke 21.87% developed AKI while only 13.07% patients with ischaemic stroke developed AKI. So, early diagnosis and management of AKI in patients with acute stroke especially in haemorrhagic stroke is very important to reduce the morbidity and mortality of these patients.

Association of infertile patients having polycystic ovarian syndrome with recurrent miscarriage

Polycystic ovarian syndrome (PCOS) has a pivotal role in the development of various complications during pregnancy. Polycystic ovarian syndrome women having elevated LH and hyper insulineuia may be at increased risk of miscarriage. The study was done to find out the recurrent pregnancy loss among the PCOS patient. This was a cross sectional case control study in total 100 infertile patients between age 20-40 years attending BSMMU out patient Department from July 2011 to June 2012, among them 50 infertile patients with PCOS regarding as a case and 50 infertile patients without PCOS selected as a control. Regarding case (infertile patients with PCOS) shows 20(40%) recurrent miscarriage and among control (infertile patients without PCOS) shows recurrent miscarriage 6(12%). And also among case group shows insulin resistance 8(16%) and control group insulin resistance 1(2%). Six (75%) abortion occur among PCOS with insulin resistance and 5(62.5%) abortion occur among PCOS with raised testosterone level. It is observed that recurrent miscarriage is higher in PCOS group. And also concluded that insulin resistance and raised testosterone level is responsible for this condition. So, further large scale study would be needed to reduce the chance of recurrent pregnancy loss by treatment with insulin sensitizer in case of obese PCOS with insulin resistance patient.

Creating and virtually screening databases of fluorescently-labelled compounds for the discovery of target-specific molecular probes

Our group has recently demonstrated that virtual screening is a useful technique for the identification of target-specific molecular probes. In this paper, we discuss some of our proof-of-concept results involving two biologically relevant target proteins, and report the development of a computational script to generate large databases of fluorescence-labelled compounds for computer-assisted molecular design. The virtual screening of a small library of 1,153 fluorescently-labelled compounds against two targets, and the experimental testing of selected hits reveal that this approach is efficient at identifying molecular probes, and that the screening of a labelled library is preferred over the screening of base compounds followed by conjugation of confirmed hits. The automated script for library generation explores the known reactivity of commercially available dyes, such as NHS-esters, to create large virtual databases of fluorescence-tagged small molecules that can be easily synthesized in a laboratory. A database of 14,862 compounds, each tagged with the ATTO680 fluorophore was generated with the automated script reported here. This library is available for downloading and it is suitable for virtual ligand screening aiming at the identification of target-specific fluorescent molecular probes.

Suppression of network activity in dorsal horn by gabapentin permeation of TRPV1 channels: implications for drug access to cytoplasmic targets

The effectiveness of gabapentin (GBP) in the treatment of neuropathic pain depends on access to the α2δ-1 accessory subunit of voltage-gated Ca(2+) channels. Access may be limited by its rate of entry via the neuronal system L-neutral amino acid transporter. The open pore of capsaicin-activated TRPV1 channel admits organic molecules such as local anesthetics and we calculated that GBP entry via this route would be 500× more rapid than via the transporter. Capsaicin should therefore increase GBP effectiveness. We used a quaternary GBP derivative (Q-GBP) as sole charge carrier in whole-cell recording experiments on rat dorsal root ganglion (DRG) neurons. Under these conditions, capsaicin produced a capsazepine-sensitive inward current thereby confirming Q-GBP permeation of TRPV1 channels. We have previously established that 5-6 days exposure to 100 μM GBP decreases excitability of dorsal horn neurons whereas 10 μM is ineffective. Excitability was monitored using confocal Ca(2+) imaging of rat spinal cord slices in organotypic culture. GBP effectiveness was augmented by transient exposures of cultures to capsaicin and robust suppression of excitability was seen with 10 μM GBP. Experiments with an inhibitor of the neutral amino acid transporter, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH 300 μM), showed the actions of GBP seen in the presence of capsaicin were independent of its entry by this route. Capsaicin potentiation of GBP depression of dorsal horn activity may therefore reflect drug permeation of TRPV1 channels. Agonist activation of TRP channels may provide a means for improving drug access to cytoplasmic targets in selective neuronal populations defined on the basis of type of TRP channel expressed.

Prodrug-inspired probes selective to cathepsin B over other cysteine cathepsins

Cathepsin B (CTB) is a cysteine protease believed to be an important therapeutic target or biomarker for several diseases including aggressive cancer, arthritis, and parasitic infections. The development of probes capable of assessing CTB activity in cell lysates, living cells, and animal models of disease are needed to understand its role in disease progression. However, discovering probes selective to cathepsin B over other cysteine cathepsins is a significant challenge due to overlap of preferred substrates and binding site homology in this family of proteases. Herein we report the synthesis and detailed evaluation of two prodrug-inspired fluorogenic peptides designed to be efficient and selective substrate-based probes for CTB. Through cell lysate and cell assays, a promising lead candidate was identified that is efficiently processed and has high specificity for CTB over other cysteine cathepsins. This work represents a key step toward the design of rapid release prodrugs or substrate-based molecular imaging probes specific to CTB.

Precocious puberty presenting with menarche at the age of 6 years - a case report

Precocious puberty or central precocious puberty can be very confusing and truly unexpected. After all who know children could go into puberty too early? There is treatment for this condition. Present report has stated that central precocious puberty is becoming more frequent. Many factors may contribute to children who exhibit signs of early precocious puberty. Here we are reporting a case of premature menarche of 6 years old girl who initially presented with continuous per vaginal bleeding for 3 months as a onset of menarche later on after clinical examination and investigations she was diagnosed a precocious puberty due to juvenile premature hypothyroidism. After the successful treatment with thyroxin, level of TSH gradually was decreased and subsequently normal. There after per vaginal bleeding stopped and clinically improved.

Correlation between grades of intraventricular hemorrhage and severity of hypoxic ischemic encephalopathy in perinatal asphyxia

This study was done to find out the correlation between various grades of Intraventricular Hemorrhage (IVH) and stages of HIE in perinatal asphyxia and to determine the short-term outcome of the affected baby. This observational study was conducted in Neonatal ward of Dhaka Shishu Hospital (DHS) and Dhaka Medical College Hospital for period of 37 months from January 2004 to January 2007. Total 189 perinatally asphyxiated babies were enrolled for HIE staging and cranial Ultrasonogram (USG) to find out grades of IVH. Finally 178 newborns were fulfilling all the necessary criteria for statistical analysis of the collected data on prescribed questionnaire. Among 178 perinatally asphyxiated newborns HIE stages - I, II, III were 50(28%), 10(56%) and 28(16%) respectively. Out of this 178 neonates total 50(28%) developed various grades IVH. Grades of IVH, I, II, III, IV were 15(30%), 18(36%), 10(20%) and 7(14%) respectively. There was significant correlation between the severity of HIE staging and grades of IVH. Short term outcome was poor in HIE-III, IVH grade III and IV. There is a direct relationship between different grades of IVH and stages of HIE. That is more the severe stages of HIE there is more chances to develop severe grades of IVH, Immediate morbidity and mortality is dependent on the grades of IVH and severity of stages of HIE.

A successful pregnancy outcome following abdominal metroplasty

A 35 years old lady presented to Out Patients Department of Bangabandhu Sheikh Mujib Medical University for secondary subfertility with history of recurrent abortion. She was diagnosed a case of bicornuate uterus following laparoscopy. After 3 months of her last abortion she was advised for metroplasty. Metroplasty was done, forming a single cavity. Dye test was positive on right side and negative on left side. After 3 months of metorplasty hysterosalphingography (HSG) was done and reports shows bilateral patent uterine tubes. One year after metroplasty. She was pregnant with letrozole and Gonadotrophin. Her pregnancy was diagnosed by ultrasonography and advised for admission. She was on regular antenatal follow up and all investigation was done. Anomaly scan was done at 20 weeks of pregnancy. She was properly immunized. Pregnancy period was uneventful until 37 weeks. At 37 weeks LUCS was done. A female healthy baby was born. APGAR score was 7/10 at 1, 10/10 at 5 minutes, baby weight 2.8kg postpartum period was uneventful. After abdominal metroplasty successful pregnancy outcome was occurred.

Pulmonary alveolar microlithiasis (PAM) in a child

A 4 year 7 month-old girl of consanguineous parents presented with only fever for 25 days but no cough or respiratory distress. Ches x-ray showed bilateral diffuse nodulo-striate opacities in both lungs. Investigations for any infection were negative including tuberculosis. Thoracoscopic biopsy showed alveolar microliths on histopathology suggesting the diagnosis of pulmonary alveolar microlithiasis (PAM).

Assessment of renal function by estimation of fractional excretion of sodium in asphyxiated newborns

This case control study was conducted in Neonatal unit of Dhaka Shishu (Children) Hospital to assess the validity of fractional excretion of sodium (FENa) as a reliable renal function test in asphyxiated newborns. Seventy five appropriate newborns aged between 0-120 hours were randomized in two groups, (Group I; n=50, cases or study group) and (Group II; n=25, controlled group). Blood urea, serum creatinine, serum electrolytes, urinary electrolytes, creatinine, osmolalities, specific gravity, FENa were estimated. Blood urea, Serum creatinine and FENa are increased in perinatal asphyxia. Controls were selected from newborns who had spontaneous breathing immediately after birth and with Apgar score >8 to 10 at 5 minutes. Mean blood urea and serum creatinine were raised in asphyxiated newborn. Blood urea mean±SD was 7.1±3.1mmol/L and serum creatinine mean±SD was 120.8±73.6μmmol/L. Thirty four percent (34%) patients had raised level of blood urea and serum creatinine both, 18% patients had raised (>2.5%) FENa and 48% patients had raised blood urea in asphyxiated newborns. Hyponatremia was also found in asphyxiated newborns. Urinary sodium and creatinine excretion were also higher in the asphyxiated newborns than non asphyxiated newborns. Urinary volume and osmolality were similar in cases and controls. In this study 24% patients died, of which 62.5% were in HIE stage 3, 4.16% were in HIE stage 2 and 1% was in HIE stage 1. Elevated level of serum creatinine (130.0±60.0) and FENa (2.9±1.4) were found in dead patients. Oliguria (0.99±0.6) was also found in dead asphyxiated newborns. Increase in fractional excretion of sodium (FENa) is shown to be directly related to the degree of renal impairment which is again directly related to the degree of asphyxia in the newborns. FENa can be used as an indicator of renal tubular dysfunction in the asphyxiated newborns.

Breastfeeding and cognitive development of children: assessment at one year of age

Breastfeeding is the fundamental component of child survival strategy. It significantly influences neurological development of children. The study was conducted to assess whether exclusive and prolonged breastfeeding improves children's cognitive development, including low birth weight (LBW) babies, in a developing country setting like Bangladesh. This observational study was done on a cohort of newborn infants who were discharged from the special care baby unit of Dhaka Shishu Hospital during January 2006 to December 2008 with proper counseling about exclusive and prolonged breastfeeding. Their neuro-developmental follow-up was started at 4 weeks postnatal age and continued at 3-monthly intervals up to 1 year of age. At each visit, cognitive development was assessed using the Bayley Scales of Infant Development (BSID II). Cognitive development was compared between the babies of exclusive vs. non exclusive breastfeeding, normal weight vs. low birth weight and male vs. female babies. A total of 105 cases were successfully followed-up during this period. Out of these 47(44.8%) babies were exclusively breastfed up to 6 month of age and 58(55.2%) were in nonexclusive group. Overall Psychomotor Development Index (PDI) was slightly more (108.40 ± 23.06 vs. 103.23 ± 19.87) in the exclusive breast fed babies in comparison to nonexclusive breast fed babies, but was significantly more in babies having birth weight >2.5 kg in comparison to those having birth weight of <2.5 kg. Other parameters of cognitive development were more or less same in both normal and LBW groups. Mental and motor development was same in both boys and girls. In behavior ratings, cooperation was significantly high (5.89 ± 2.54 vs. 4.71 ± 3.13, p=0.05) and vocalization (5.89 ± 1.07 vs. 4.58 ± 1.16) was also high, though not significant, in girls than boys.

Synthesis of phenylacetic acid regioisomers possessing an N-substituted 1,2-dihydropyrid-2-one pharmacophore — Evaluation as inhibitors of cyclooxygenases and 5-lipoxygenase

The Suzuki–Miyaura cross-coupling reaction provides a useful method for the synthesis of methyl 2-(2-chloropyridyl or 2-methoxypyridyl)phenylacetates. The 2-chloropyridyl or 2-methoxypyridyl ring system can be readily elaborated to N-substituted (OH, Me, CHF2, H) 1,2-dihydropyrid-2-one ring systems that are useful synthons for use in bioorganic and medicinal chemistry applications.

Ethanesulfohydroxamic acid ester prodrugs of nonsteroidal anti-inflammatory drugs (NSAIDs): synthesis, nitric oxide and nitroxyl release, cyclooxygenase inhibition, anti-inflammatory, and ulcerogenicity index studies

The carboxylic acid group of the anti-inflammatory (AI) drugs indo-methacin, (S)-naproxen and ibuprofen was covalently linked via a two-carbon ethyl spacer to a sulfohydroxamic acid moiety (CH(2)CH(2)SO(2)NHOH) to furnish a group of hybrid ester prodrugs that release nitric oxide (NO) and nitroxyl (HNO). Biological data acquired for this hitherto unknown class of ethanesulfohydroxamic acid ester prodrugs showed (i) all compounds exhibited superior NO, but similar HNO, release properties relative to arylsulfohydroxamic acids, (ii) the (S)-naproxen and ibuprofen prodrug esters are more potent AI agents than their parent NSAID, (iii) the indomethacin prodrug ester, in contrast to indomethacin which is highly ulcerogenic, showed no visible stomach lesions [ulcer index (UI) = 0 for a 80 μmol/kg oral dose] while retaining potent AI activity, and iv) that the indomethacin prodrug ester, unlike indomethacin which is an ulcerogenic selective COX-1 inhibitor, is a selective COX-2 inhibitor (COX-2 selectivity index = 184) devoid of ulcerogenicity that is attributed to its high COX-2 SI and/or ability to release cytoprotective NO.

Triaryl (Z)-olefins suitable for radiolabeling with iodine-124 or fluorine-18 radionuclides for positron emission tomography imaging of estrogen positive breast tumors

A group of (Z)-1,2-diphenyl-1-[4-[2-(4-methylpiperazin-1-yl)ethoxy]phenyl]but-1-enes were synthesized using methodologies that will allow incorporation of a [(124)I]iodine substituent at the para-position of either the C-1 phenyl ring or the C-2 phenyl ring, or a [(18)F]OCH(2)CH(2)F substituent at the para-position of the C-2 phenyl ring. These [(124)I] and [(18)F] radiotracers are designed as potential radiopharmaceuticals to image estrogen positive breast tumors using positron emission tomography (PET).

Triaryl (Z)-olefins suitable for radiolabeling with carbon-11 or fluorine-18 radionuclides for positron emission tomography imaging of cyclooxygenase-2 expression in pathological disease

A group of (Z)-1,1-diphenyl-2-(4-methylsulfonylphenyl)alk-1-enes were synthesized using methodologies that will allow incorporation of a [(11)C]OCH(3) substituent at the para-position of the C-1 phenyl ring, a [(11)C]SO(2)CH(3) substituent at the para-position of the C-2 phenyl ring, a [(18)F]OCH(2)CH(2)F substituent at the para-position of the C-1 phenyl ring, and a [(18)F]CH(2)CH(2)F substituent at the C-2 position of the olefinic bond. The [(11)C] and [(18)F] radiotracers are designed as potential radiopharmaceuticals to image cyclooxygenase-2 (COX-2) expression in any organ where COX-2 is upregulated. The COX-1/COX-2 inhibition data acquired suggest that compounds having a [(11)C]OMe or [(18)F]OCH(2)CH(2)F substituent at the para-position of the C-1 phenyl ring may be more suitable for imaging COX-2 expression in view of their ability to exclusively inhibit the COX-2 isozyme.

Celecoxib analogs possessing a N-(4-nitrooxybutyl)piperidin-4-yl or N-(4-nitrooxybutyl)-1,2,3,6-tetrahydropyridin-4-yl nitric oxide donor moiety: synthesis, biological evaluation and nitric oxide release studies

A new group of hybrid nitric oxide (NO) releasing anti-inflammatory (AI) coxib prodrugs (NO-coxibs) wherein the para-tolyl moiety present in celecoxib was replaced by a N-(4-nitrooxybutyl)piperidyl 15a-b, or N-(4-nitrooxybutyl)-1,2,3,6-tetrahydropyridyl 17a-b, NO-donor moiety was synthesized. All compounds released a low amount of NO upon incubation with phosphate buffered saline (PBS) at pH 7.4 (2.4-5.8% range). In comparison, the percentage NO released was higher (3.1-8.4% range) when these nitrate prodrugs were incubated in the presence of L-cysteine. In vitro COX-1/COX-2 isozyme inhibition studies showed this group of compounds are moderately more potent, and hence selective, inhibitors of the COX-2 relative to the COX-1 enzyme. AI structure-activity relationship data acquired showed that compounds having a MeSO2 COX-2 pharmacophore exhibited superior AI activity compared to analogs having a H2NSO2 substituent. Compounds having a MeSO2 COX-2 pharmacophore in conjunction with a N-(4-nitrooxybutyl)piperidyl (ED50=132.4 mg/kg po), or a N-(4-nitrooxybutyl)-1,2,3,6-tetrahydropyridyl (ED50=118.4 mg/kg po), moiety exhibited an AI potency profile that is similar to aspirin (ED50=128.7 mg/kg po) but lower than ibuprofen (ED50=67.4 mg/kg po).

Phenylacetic acid regioisomers possessing a N-difluoromethyl-1,2-dihydropyrid-2-one pharmacophore: evaluation as dual inhibitors of cyclooxygenases and 5-lipoxygenase with anti-inflammatory activity

A novel class of phenylacetic acid regioisomers possessing a N-difluoromethyl-1,2-dihydropyrid-2-one pharmacophore attached to its C-2, C-3 or C-4 position was designed for evaluation as anti-inflammatory (AI) agents. A number of compounds exhibited a combination of potent in vitro cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibitory activities. 2-(1-Difluoromethyl-2-oxo-1,2-dihydropyridin-4-yl)phenylacetic acid (9a) exerted the most potent AI activity among this group of compounds. Molecular modeling studies showed that the N-difluoromethyl-1,2-dihydropyridin-2-one moiety present in 9a inserts into the secondary pocket present in COX-2 to confer COX-2 selectivity, and that the N-difluoromethyl-1,2-dihydropyrid-2-one group (9a) binds close to the region of the 15-LOX enzyme containing catalytic iron (His361, His366). Accordingly, the N-difluoromethyl-1,2-dihyrdopyrid-2-one moiety possesses properties that make it an attractive pharmacophore suitable for the design of dual COX-2/5-LOX inhibitory AI drugs.

Synthesis of celecoxib analogues possessing a N-difluoromethyl-1,2-dihydropyrid-2-one 5-lipoxygenase pharmacophore: biological evaluation as dual inhibitors of cyclooxygenases and 5-lipoxygenase with anti-inflammatory activity

A novel class of 1-(4-methanesulfonylphenyl and 4-aminosulfonylphenyl)-5-[4-(1-difluoromethyl-1,2-dihydropyrid-2-one)]-3-trifluoromethyl-1H-pyrazole hybrid cyclooxygenase-2 (COX-2)/5-lipoxygenase (5-LOX) inhibitory anti-inflammatory agents was designed. Replacement of the tolyl ring present in celecoxib by the N-difluoromethyl-1,2-dihydropyrid-2-one moiety provided compounds showing dual selective COX-2/5-LOX inhibitory activities. 1-(4-Aminosulfonylphenyl)-5-[4-(1-difluoromethyl-1,2-dihydropyrid-2-one)]-3-trifluoromethyl-1H-pyrazole exhibited good anti-inflammatory (AI) activity (ED(50) = 27.7 mg/kg po) that compares favorably with the reference drugs celecoxib (ED(50) = 10.8 mg/kg po) and ibuprofen (ED(50) = 67.4 mg/kg po). The N-difluoromethyl-1,2-dihydropyridin-2-one moiety provides a novel 5-LOX pharmacophore for the design of cyclic hydroxamic mimetics for exploitation in the development of COX-2/5-LOX inhibitory AI drugs.

Comparative study between tubotympanic and atticoantral types of chronic suppurative otitis media

This prospective study was done to compare the different aspects of tubotympanic (group I) and atticoantral types (group II) of chronic suppurative otitis media. The study included 200 patients of chronic suppurative otitis media, of them 100 were of tubotympanic type and 100 were with atticoantral disease. The age (mean +/- SD) of group I and II were 17 +/- 2.7 years and 12 +/- 2.3 years respectively (P < 0.05). The majority of the patients having poor socio-economic condition 69% in group I and 87% in-group II. In both groups, slum dwellers with bathing habit in pond or river and illiterate were more sufferer (P < 0.05). There was central perforation in all patients in-group I, and in-group II, 67% were with attic and 33% were with marginal perforations. In group I, aural discharge was mucoid or mucopurulent in majority of cases 80% and in-group II foul smelling scanty ear discharge was from 88% of subjects. In atticoantral type, hearing impairment was more than tubotympanic disease. Complications were more in atticoantral type of disease. In-group II, post auricular sinus 25% was the commonest extracranial complication followed by subperiosteal abscess 18%, and meningitis 10% was the commonest intracranial complication followed by brain abscess 8%. In tubotympanic type conservative treatment with reconstructive surgery were the treatment of choice, whereas radical or some modifications of radical surgery (with or without reconstruction) were the treatment plan for atticoantral disease. Among the groups the mortality rate was only 4% in-group II and was due to intracranial complications. The study recommends early detection and effective surgical treatment of the disease to improve the situation.

Vegetarian diet in the treatment of fibromyalgia

Brain tryptophan is low in fibromyalgia. Intake of protein rich in large neutral amino acids is reported to lower brain tryptophan. This study was undertaken to assess whether any reduction of such proteins by exclusion of animal protein from the diet reduced pain and morbidity in fibromyalgia patients. It was an open, randomized controlled trial. 37 subjects with fibromyalgia were enrolled in the vegetarian diet and 41 in the amitriptyline groups. The outcome was assessed with the help of frequencies of fatigue, insomnia & non-restorative sleep, pain score on a 10-point VAS and tender point count. Fatigue, insomnia and non-restorative sleep were present in 41, 26 and 32 subjects before and in 3, 0 and 0 subjects respectively at six weeks of treatment in the amitriptyline group. The pain score and tender point count were 6.2 +/- 1.9 & 16.1 +/- 2.3 before and 2.3 +/- 1.3 & 6.4 +/- 3.0 after treatment. All these differences were significant (P < 0.001). In the vegetarian diet group, fatigue, insomnia and non-restorative sleep were present in 36, 24 and 27 subjects before and in 34, 29 and 29 subjects at six weeks of treatment. The pain score and tender point count were 5.7 +/- 1.8 and 15.7 +/- 2.4 before and 5.0 +/- 1.8 & 14.7 +/- 3.6 after treatment. All these differences were insignificant except that in the pain score. The decrease in the pain score, though significant, was much smaller than that in the amitriptyline group. So, it may be concluded that vegetarian diet is a poor option in the treatment of fibromyalgia.

Retention versatility of silica-supported comb-shaped crystalline and non-crystalline phases in high-performance liquid chromatography

Silica-supported comb-shaped polymer (Sil-ODA18) provided a specific selectivity towards aromatic and non-aromatic solutes. Selectivity of Sil-ODA18 and ODS (polymeric and monomeric) columns towards polycyclic aromatic hydrocarbons and geometric isomers have been discussed in respect of molecular shapes and sizes. The retention versatility of this phase arises from the orientation change on transition from the ordered crystalline to the less ordered non-crystalline state. Selectivity in the crystalline and non-crystalline regions of Sil-ODA18 is similar to that of polymeric and monomeric ODS phases, respectively. Sil-ODA18 column also exhibited the characteristic temperature dependency of liquid-crystalline phases, i.e., an increase in retention with increasing temperature on transition from crystalline to isotropic state.

Genetics of isozymes in grasspea

We studied the inheritance and linkage of ACO-1, ACO-2, AAT-1, AAT-2, EST-3, EST-6, FDH, LAP-1, PGD-2, SKDH, and TPI-1 in four F2 populations of grasspea (Lathyrus sativus L.) using horizontal starch-gel electrophoresis. Mendelian inheritance was observed for all of the isozymes studied. All isozymes showed codominant gene expression except for EST-3, which was expressed in a dominant fashion due to the presence of a null allele. Monomeric quaternary structure was observed for ACO-1, ACO-2, EST-6, LAP-1, and SKDH. Dimeric quaternary structure was observed for AAT-1, AAT-2, FDH, PGD-2, and TPI-1. The isozyme loci Aat-2 and Skdh were linked with a map distance of 28 cM.

Laboratory evaluation of selected larvicides and insect growth regulators against field-collected Culex quinquefasciatus larvae from urban Dhaka, Bangladesh

Five organophosphates (OPs) (chlorpyrifos, chlorpyrifos methyl, fenthion, malathion, and temephos), 3 pyrethroids (bifenthrin, cypermethrin, and permethrin), 1 phenyl pyrazole (fipronil), 2 microbial pesticides (Bacillus thuringiensis serovar. israelensis [B.t.i.] and Bacillus sphaericus), and 3 insect growth regulators (IGRs) (diflubenzuron, methoprene, and pyriproxyfen) were evaluated against field-collected Culex quinquefasciatus larvae from urban Dhaka, Bangladesh. The LC90 values of all OPs, except for temephos (LC90 = 0.0096 ppm), were high, ranging from 0.13 ppm (fenthion) to 2.882 ppm (chlorpyrifos methyl). Pyrethroid LC90 values were 0.021 ppm (bifenthrin), 0.00061 (cypermethrin), and 0.017 ppm (permethrin). Fipronil exhibited a superior activity with LC90 value of 0.000896 ppm. Technical powders of B.t.i. and B. sphaericus (VectoBac TP and VectoLex TP) were considered highly effective against the Cx. quinquefasciatus larvae. The IGRs also were effective with pyriproxyfen (LC90 = 0.0011 ppm), being 3 times and 47 times more active than diflubenzuron (LC90 = 0.0034 ppm) and methoprene (LC90 = 0.052 ppm), respectively. In general, toxicity ranking of chemicals and microbials tested was phenyl pyrazole > IGRs > pyrethroids > microbials > OPs.

Effect of alum on free-living and copepod-associated Vibrio cholerae O1 and O139

The effects of alum [KAl(SO4)2] on free-living and copepod-associated Vibrio cholerae O1 and O139 were investigated by using plate counts and immunofluorescence direct viable counting (DVC). Growth of alum-treated cells in 0.5/1000 Instant Ocean seawater was inhibited, i.e., no growth was obtained on Luria-Bertani (LB) agar or thiosulfate-citrate-bile salt-sucrose (TCBS) agar. However, a significant number of the inhibited cells maintained viability, as measured by DVC. In comparison, a significant number of V. cholerae organisms associated with zooplankton, most of which were crustacean copepods, were viable but nonculturable, with only a small number of cells retaining culturability on LB and TCBS agar. Both DVC and viable plate counts (CFU) were significantly greater for V. cholerae O1 and O139 associated with zooplankton than for V. cholerae in water alone, i.e., without copepods. It is concluded that alum is an effective coagulant but not an effective killing agent for V. cholerae and that association with copepods offers protection for V. cholerae O1 and O139 against alum and chlorine treatments.

IgA nephropathy in teaching hospitals of Dhaka

A light and immunofluorescence microscopic study on renal biopsies were performed on 42 patients. Nephrotic syndrome with accompanying microhematuria and recurrent hematuria (Macroscopic/microscopic) with or without renal failure were the commonest indications for renal biopsy. Primary IgA nephropathy was diagnosed in five cases. Among the IgA nephropathy patients, the commonest light microscopic finding was mesangial proliferative glomerulonephritis. Macroscopic hematuria with proteinuria was the commonest feature. Three of the patients had hypertension at the time of renal biopsy. The age of the patients ranged from 19-38 years with a mean of 26 years. The high frequency of hypertension, degree of proteinuria and associated renal failure in one patient that it is a progressive disease. This preliminary study revealed that IgA nephropathy exists in Bangladesh. Larger samples need to be studied with a view to find out its prevalence and its peculiarities in this part of the world.

Complications and outcome of percutaneous endoscopic gastrostomy in different patient groups

A retrospective study of percutaneous endoscopic gastrostomy (PEG) was performed to evaluate the complications of PEG and determine the role of prophylactic antibiotics in preventing early wound infection and to evaluate the outcome of patients in different groups (neurological disease, head injury, AIDS). Percutaneous endoscopic gastrostomy was performed on 50 patients between March 1991 and November 1993 and the survey was completed in July 1994. The average time to PEG placement post-cerebrovascular accident or head injury was 5 weeks. No deaths were attributable to the procedure. Four of 50 (8%) patients died in the first 30 days (early mortality). Wound infection (early eight, late five) was the most common complication: two of 13 patients receiving prophylactic antibiotics and six of 37 not receiving antibiotics had early wound infection. At completion of follow-up 19 of 26 patients with neurological disease had died (median survival = 370 days), three resumed oral feeding and four continued PEG feeding. All head injury patients (n = 6) were alive and had resumed oral feeding; five returned home. All AIDS patients (n = 7) died within 12 months (median survival = 138 days), although improved nutritional state was found after gastrostomy feeding. In conclusion, PEG placement is a useful procedure to assist feeding in multiple patient groups. Wound infection is a common but not life threatening complication. The need for prophylactic antibiotics to prevent early wound infection has not been proven. The 5 week delay in PEG insertion may contribute to lower early mortality. The 100% survival rate in head injury patients may reflect their young age and absence of underlying medical illness. In AIDS patients, improved nutritional state is not known to translate into better quality of life or prolonged survival.

A simple filtration method to remove plankton-associated Vibrio cholerae in raw water supplies in developing countries

Plankton to which cells of Vibrio cholerae O1 and/or O139 were attached was introduced into 0.5% Instant Ocean microcosms maintained at 25 degrees C. The bulk of the plankton and associated particulates was removed with a filter constructed from either nylon net and one of several different types of sari material, the latter being very inexpensive and readily available in villages in Bangladesh, where V. cholerae is endemic. V. cholerae was enumerated before and after filtration to evaluate the efficiency of the filtration procedure. The results obtained indicate that 99% of V. cholerae, i.e., those cells attached to plankton, were removed from the water samples. Epidemic strains of V. cholerae O1 and O139 from various geographical sources, including Bangladesh, Brazil, India, and Mexico, were included in the experiments. Removal of vibrios from water by this simple filtration method was found to yield consistent results with all strains examined in this study. Thus, it is concluded that a simple filtration procedure involving the use of domestic sari material can reduce the number of cholera vibrios attached to plankton in raw water from ponds and rivers commonly used for drinking. Since untreated water from such sources serves as drinking water for millions of people living in developing countries (e.g., Bangladesh), filtration should prove effective at reducing the incidence and severity of outbreaks, especially in places that lack fuel wood for boiling water and/or municipal water treatment plants. The results of this study provide the basis for determining such reductions, which are to be carried out in the near future.

Deaths in visceral leishmaniasis (Kala-azar) during treatment

Twenty-seven out of five hundred and fifty three patients hospitalized for visceral leishmaniasis (Kala-azar) died during treatment with sodium antimony gluconate. Data from these patients were evaluated to find out the cause of death. Eight patients had associated diseases such as pulmonary tuberculosis (3), severe malnutrition (1), acute gastroenteritis (1), spleenic infarction (1), acute renal failure (1) and atrial septal defect (1) which could be attributed to death. Twelve patients developed spontaneous haemorrhages from nose, gums and gastrointestinal tract and died, despite of adequate supportive measures. Seven other patients who were improving slowly with antimony therapy died unexpectedly. Though, cause of death could be explained in some patients with associated disease conditions, it could not be explained in others as significant clinical manifestations, haematological, biochemical and electrocardiographic alterations were not evident prior to death. Our impression is that mortality in Kala-azar patients during standard antimonial therapy is more related to the drug rather than the disease process.

Serogroup conversion of Vibrio cholerae non-O1 to Vibrio cholerae O1: effect of growth state of cells, temperature, and salinity

Recently, we reported the occurrence of seroconversion from Vibrio cholerae non-O1 to V. cholerae O1, but little is known about the environmental and physiological factors influencing seroconversion. We investigated effects of temperature (4, 25, and 35 degrees C) and salinity ( < 0.05 and 10%0.), as well as the stage of growth of cells, on serogroup conversion. Seroconversion of V. cholerae occurred under various environmental conditions. However, the rate of seroconversion in natural water ( < 0.5% salinity) and synthetic seawater microcosms (10%0 salinity), employing cells harvested from stationary phase culture, was approximately 2 logs higher than cells harvested from cultures in the logarithmic phase (i.e., 10(5) versus 10(3) per 10(10) cells. Thus, the physiological state of the cells, and to a lesser degree, temperature and salinity, is an important factor in the conversion of V. cholerae from non-O1 to O1 serogroup.

Potential virulence of viable but nonculturable Shigella dysenteriae type 1

We examined a virulent strain of Shigella dysenteriae type 1 after induction into the viable but nonculturable (VBNC) state for its ability to (i) maintain the Shiga toxin (stx) gene; (ii) maintain biologically active Shiga toxin (ShT); and (iii) adhere to intestinal epithelial cells (Henle 407 cell line). PCR was used to amplify the stx gene from VBNC cells of S. dysenteriae type 1, thereby establishing its presence even when cells are in the VBNC state. VBNC S. dysenteriae type 1 ShT was monitored by the enzyme-linked immunosorbent assay with mouse monoclonal antibodies against the B subunit of ShT and affinity-purified rabbit polyclonal antibodies against ShT. We used the Henle 407 cell line to study the adhesive property of VBNC S. dysenteriae type 1 cells in a series of tissue culture experiments. Results showed that VBNC S. dysenteriae type 1 not only maintained the stx gene and biologically active ShT but also remained capable of adhering to Henle 407 cells. However, S. dysenteriae type 1 cells lost the ability to invade Henle 407 cells after entering the VBNC state. From results of the study, we conclude that VBNC cells of S. dysenteriae type 1 retain several virulence factors and remain potentially virulent, posing a public health problem.

Serogroup conversion of Vibrio cholerae

Vibrio cholerae serogroup O1 can be detected in the environment in a viable but nonculturable form, whereas V. cholerae non-O1 cells can be readily cultured during interepidemic periods in geographical regions where cholera is endemic. In the present study, pure cultures of V. cholerae non-O1 cells contained O1 cells when examined by immune-fluorescence microscopy. Laboratory microcosms were used to examine the outgrowth of the O1 cells in cultures of non-O1 V. cholerae. One O1 cell per 10(6) non-O1 cells could be detected by direct fluorescent-monoclonal antibody staining but only after incubation of the non-O1 culture for 48 h. Individual O1 cells were not detected in cultures incubated less than 48 h. Hybridization study, using a polymerase chain reaction (PCR) amplified fragment of the O-antigen of V. cholerae O1 as a probe, revealed the existence of a homologous gene in a microcosm sample of V. cholerae non-O1 containing serogroup-converted cells. The mechanism by which O1 cells can occur in cultures of non-O1 V. cholerae most likely resulted from spontaneous mutation of gene(s) encoding the O-somatic properties and (or) chemical, physical, or biological changes in the environment inducing expression or repression of the controlling gene(s). These findings have important implications for the epidemiology of cholera and the environmental source(s) of toxin producing V. cholerae O1.

Enterobacterial repetitive intergenic consensus sequences and the PCR to generate fingerprints of genomic DNAs from Vibrio cholerae O1, O139, and non-O1 strains

Enterobacterial repetitive intergenic consensus (ERIC) sequence polymorphism was studied in Vibrio Cholerae strains isolated before and after the cholera epidemic in Brazil (in 1991), along with epidemic strains from Peru, Mexico, and India, by PCR. A total of 17 fingerprint patterns (FPs) were detected in the V. cholerae strains examined; 96.7% of the toxigenic V. cholerae O1 strains and 100% of the O139 serogroup strains were found to belong to the same FP group comprising four fragments (FP1). The nontoxigenic V. cholerae O1 also yielded four fragments but constituted a different FP group (FP2). A total of 15 different patterns were observed among the V. cholerae non-O1 strains. Two patterns were observed most frequently for V. cholerae non-01 strains, 25% of which have FP3, with five fragments, and 16.7% of which have FP4, with two fragments. Three fragments, 1.75, 0.79, and 0.5 kb, were found to be common to both toxigenic and nontoxigenic V. cholerae O1 strains as well as to group FP3, containing V. cholerae non-O1 strains. Two fragments of group FP3, 1.3 and 1.0 kb, were present in FP1 and FP2 respectively. The 0.5-kb fragment was common to all strains and serogroups of V. cholerae analyzed. It is concluded from the results of this study, based on DNA FPs of environmental isolates, that it is possible to detect an emerging virulent strain in a cholera-endemic region. ERIC-PCR constitutes a powerful tool for determination of the virulence potential of V. cholerae O1 strains isolated in surveillance programs and for molecular epidemiological investigations.