Dysfunction of Thyroid Hormones Following Acute Coronary Syndrome in a Tertiary Care Hospital in Dhaka City.

In cardiovascular homeostasis thyroid hormone plays an important role. We planned to study the changes in thyroid hormone profile in acute coronary syndrome patients admitted in the coronary care unit and compare them between two groups: unstable angina/non-ST elevated Myocardial infarction (UA/NSTEMI) and ST elevated Myocardial infarction (STEMI). This study was a hospital based descriptive cross sectional study which was conducted from 01 March 2018 to 01 February 2019 in Coronary Care Unit of Bangladesh Medical College Hospital and laboratory tests were done in Microbiology Department of Bangladesh Medical College, Dhaka, Bangladesh. Eighty three cases of acute coronary syndromes were taken for the study. Troponin-I was measured as cardiac marker, Electrocardiogram, Complete blood count, blood glucose level, Blood urea, serum creatinine, serum electrolytes, Fasting lipid profile, Thyroid profile, Echocardiography 2D were done. Most of the respondents were distributed in age group 46-60 years where 34(64.15%) male and 19(35.85%) female. Out of 83 Acute Coronary Syndrome (ACS) patients, 27(32.53%) hypertensive, 22(26.50%) diabetic and 16(19.27%) were Chronic kidney disease (CKD). Abnormal lipid profile was present in 30(43.47%) patients. Among total 52 male and 31 female 9(17.30%) male and 6(19.35%) female had abnormal thyroid function. We further elaborated abnormal thyroid function tests in STEMI group and UA/Non STEMI group of ACS patients. We found 10 patients in STEMI group and 5 patients in UA/Non STEMI group with abnormal thyroid function 29.41% and 10.20% respectively which was not statistically significant (p=0.025). This study depicts abnormality in thyroid hormone profile in 18.07% patients of ACS. Abnormal thyroid function increases risk of coronary artery disease. TSH level of ACS patients on hospital admission could be helpful to evaluate further prognosis of the disease.

Human bone and amniotic membrane banking in Bangladesh for grafting: the impact of the international atomic energy agency (IAEA) programme.

The idea of establishing a human tissue bank in Bangladesh was started in 1985. However, in 2003, with the active cooperation of international atomic energy agency (IAEA) and Bangladesh Atomic Energy Commission, a tissue bank laboratory was upgraded as a unit for tissue banking and research. Due to increasing demand of allograft, this unit was transformed as an independent institute "Institute of Tissue Banking and Biomaterial Research (ITBBR)" in 2016. This is the only human tissue bank in Bangladesh, which processes human bone and amniotic membrane to provide safe and cost-effective allografts for transplantation. Importantly, banking of human cranial bone as autograft has also started at ITBBR. These processed grafts are sterilized using gamma radiation according to the IAEA Code of Practice for the radiation sterilization of tissues allografts. The amount of grafts produced by the ITBBR from 2007 to 2018 were 120,800 cc of bone chips, 45,420 cm2 of amniotic membranes, 277 vials of de-mineralized bone granules (DMB), 95 pieces of massive bones, and 134 pieces of cranial bones. Overall, 112,748 cc of bone chips, 40,339 cm2 of amniotic membranes, 174 vials of DMB, 44 pieces of massive bones, and 64 pieces of cranial bones were transplanted successfully. Nevertheless, to cope up with the modern advanced concepts of cell and tissue banking for therapeutic purpose, ITBBR is working to set up facilities for skin banking, stem cells banking including amniotic and cord blood derived stem cells and scaffold designing. To ensure the quality, safety, ethical and regulatory issues are sustainable in cell and tissue banking practices, ITBBR always works with the Government of Bangladesh for enhancing the national tissue transplantation programme within the contemporary facilities.

Amnion and collagen-based blended hydrogel improves burn healing efficacy on a rat skin wound model in the presence of wound dressing biomembrane.

BACKGROUND: A burn wound is one of the most frequent and devastating injuries for patients which requires extensive care. Early treatment of burn wounds improves healing significantly. OBJECTIVE: This study was designed to investigate the efficacy of amnion and collagen-based hydrogels on cutaneous burn wound healing in rats with covering membrane. METHODS: We prepared a novel cell free hydrogel comprising human amnion, rabbit collagen, carboxymethyl cellulose sodium salt, citric acid, methyl paraben, propyl paraben, glycerin and triethanol amine. The wound covering membrane was developed from rabbit collagen and prawn shell chitosan. Beside swelling ratio, water absorption, equilibrium water content, gel fraction and spreadability analysis, in vitro cytotoxicity and biocompatibility tests were performed for the formulated hydrogels. Following the skin irritation study, second-degree burns were created on the dorsal region of the rats and the gels were applied with/without covering membrane to study the wound contraction and re-epithelialization period. RESULTS: The formulated hydrogels were observed non-cytotoxic and compatible with human blood cells. No erythema and edema were found in skin irritation assay confirming the safety and applicability. Hydrogel consisting in a combination of amnion and collagen demonstrated significantly rapid wound healing, driven by complete re-epithelialization (16.75 ± 0.96 days) and closure by wound contraction (72 ± 3.27%, P < 0.0000009) when wound dressing membrane was used, whereas this gel alone healed about 62.5 ± 4.43% (P < 0.00001) and required 18.75 ± 0.50 days to complete re-epithelialization. Additionally, the gel with covering membrane treated group had maximum average body weight, food and water intake. CONCLUSION: The amnion and collagen-based blended gel offers alternative possibilities to treat skin wounds when covered with film, which could overcome the limitations associated with modern therapeutic products such as high costs, long manufacturing times, complexities, storing, and presence of living biomaterials.

Characterization of burn wound healing gel prepared from human amniotic membrane and Aloe vera extract.

BACKGROUND: Skin burn wound is a notable medical burden worldwide. Rapid and effective treatment of burnt skin is vital to fasten wound closure and healing properly. Amniotic graft and Aloe vera are widely used as wound managing biomaterials. Sophisticated processing, high cost, availability, and the requirement of medics for transplantation limit the application of amnion grafts. We aim to prepare a novel gel from amnion combined with the Aloe vera extract for burn wound healing which overcome the limitations of graft. METHODS: Two percent human amniotic membrane (AM), Aloe vera (AV) and AM+AV gels were prepared. In vitro cytotoxicity, biocompatibility, cell attachment, proliferation, wound healing scratch assays were performed in presence of the distinct gels. After skin irritation study, second-degree burns were induced on dorsal region of Wistar rats; and gels were applied to observe the healing potential in vivo. Besides, macroscopical measurement of wound contraction and re-epithelialization; gel treated skin was histologically investigated by Hematoxylin and eosin (H&E) staining. Finally, quantitative assessment of angiogenesis, inflammation, and epithelialization was done. RESULTS: The gels were tested to be non-cytotoxic to nauplii and compatible with human blood and skin cells. Media containing 500 µg/mL AM+AV gel were observed to promote HaCaT and HFF1 cells attachment and proliferation. In vitro scratch assay demonstrated that AM+AV significantly accelerated wound closure through migration of HaCaT cells. No erythema and edema were observed in skin irritation experiments confirming the applicability of the gels. AV and AM+AV groups showed significantly accelerated wound closure through re-epithelialization and wound contraction with P < 0.01. Macroscopically, AM and AM+AV treated wound recovery rates were 87 and 90% respectively with P < 0.05. Histology analysis revealed significant epitheliazation and angiogenesis in AM+AV treated rats compared to control (P < 0.05). AM+AV treated wounds had thicker regenerated epidermis, increased number of blood vessels, and greater number of proliferating keratinocytes within the epidermis. CONCLUSION: We demonstrated that a gel consisting of a combination of amnion and Aloe vera extract has high efficacy as a burn wound healing product. Amniotic membrane combined with the carrier Aloe vera in gel format is easy to produce and to apply.

Human tissue banking in Bangladesh: hope for the patients of massive burns, surgical wound and bone associated complications.

Each year throughout Bangladesh, thousands of people suffering from massive burns and surgical wounds require amniotic grafts for transplantation. Additionally, the stricken persons of the country have to embrace bone associated disability for the whole life due to traumatic complications need bone graft to treat. As a result, these two problems are the largest financial burden as this situation not only affect the family of patients but also cripple down national economy. However, institute of tissue banking in Bangladesh has undertaken the service program on the processing, preservation and clinical applications of amnion membrane and bone graft for rehabilitative surgery. Importantly, in recent years, this institute has started cranial bone autograft processing and transplantation. In accidental cases such as head injury, it is difficult to provide suitable cranial bone allograft according to demand. In this situation, injured cranial bone of the patient is being transported to the lab of the institute, where the scientist, tissue banker and medic work together immediately to process the cranial bone and sterilize by gamma radiation; and after quality assurance, the processed cranial bone autograft is being supplied for replacement surgery. The use of irradiated amnion and bone allografts and cranial bone autograft in reconstructive surgery restore normalcy to lives of many patients from disabilities. This tissue bank is based on finding and obtaining qualified donors from the community and a demand for tissue grafts from the hospitals. Although growing needs for tissue transplantation but raw and processed tissue grafts preservation and banking braces enormous logistical limitations. The only human tissue bank in Bangladesh, however, ensures the availability of tissue allografts of high quality and acceptability to the recipients for rehabilitative surgery for a decade, regardless patients' socio-economic status.

Fabrication of biocompatible porous scaffolds based on hydroxyapatite/collagen/chitosan composite for restoration of defected maxillofacial mandible bone.

Fabrication of scaffolds from biomaterials for restoration of defected mandible bone has attained increased attention due to limited accessibility of natural bone for grafting. Hydroxyapatite (Ha), collagen type 1 (Col1) and chitosan (Cs) are widely used biomaterials which could be fabricated as a scaffold to overcome the paucity of bone substitutes. Here, rabbit Col1, shrimp Cs and bovine Ha were extracted and characterized with respect to physicochemical properties. Following the biocompatibility, degradability and cytotoxicity tests for Ha, Col1 and Cs a hydroxyapatite/collagen/chitosan (Ha·Col1·Cs) scaffold was fabricated using thermally induced phase separation technique. This scaffold was cross-linked with (1) either glutaraldehyde (GTA), (2) de-hydrothermal treatment (DTH), (3) irradiation (IR) and (4) 2-hydroxyethyl methacrylate (HEMA), resulting in four independent types (Ha·Col1·Cs-GTA, Ha·Col1·Cs-IR, Ha·Col1·Cs-DTH and Ha·Col1·Cs-HEMA). The developed composite scaffolds were porous with 3D interconnected fiber microstructure. However, Ha·Col1·Cs-IR and Ha·Col1·Cs-GTA showed better hydrophilicity and biodegradability. All four scaffolds showed desirable blood biocompatibility without cytotoxicity for brine shrimp. In vitro studies in the presence of human amniotic fluid-derived mesenchymal stem cells revealed that Ha·Col1·Cs-IR and Ha·Col1·Cs-DHT scaffolds were non-cytotoxic and compatible for cell attachment, growth and mineralization. Further, grafting of Ha·Col1·Cs-IR and Ha·Col1·Cs-DHT was performed in a surgically created non-load-bearing rabbit maxillofacial mandible defect model. Histological and radiological observations indicated the restoration of defected bone. Ha·Col1·Cs-IR and Ha·Col1·Cs-DHT could be used as an alternative treatment in bone defects and may contribute to further development of scaffolds for bone tissue engineering.

Regulation of phosphorus bioavailability by iron nanoparticles in a monomictic lake.

Dissolved reactive phosphorous (DRP) in lake systems is conventionally considered to predominate over other dissolved P species, however, this view neglects an important set of interactions that occurs between P and reactive iron hydroxide surfaces. This study addresses the coupling of P with dispersed iron nanoparticles in lakes, an interaction that may fundamentally alter the bioavailability of P to phytoplankton. We used diffusive gradients in thin films (DGT) and ultrafiltration to study Fe-P coupling in the water column of a monomictic lake over a hydrological year. Fe and P were predominantly colloidal (particle diameters > ~5 nm < ~20 nm) in both oxic epilimnetic and anaerobic hypolimnetic waters, but they were both DGT-labile under sub-oxic conditions, consistent with diffusion and dissolution of Fe-and-P-bearing colloids within the DGT diffusive gel. During peak stratification, increases in Fe and P bioavailability were spatially and temporally coincident with Fe nanoparticle dissolution and the formation of a deep chlorophyll maximum at 5-8 m depth. These results provide a window into the coupling and decoupling of P with mobile iron colloids, with implications for our understanding of the behaviour of nutrients and their influence on phytoplankton community dynamics.

Locality and Word Order in Active Dependency Formation in Bangla.

Research on filler-gap dependencies has revealed that there are constraints on possible gap sites, and that real-time sentence processing is sensitive to these constraints. This work has shown that comprehenders have preferences for potential gap sites, and immediately detect when these preferences are not met. However, neither the mechanisms that select preferred gap sites nor the mechanisms used to detect whether these preferences are met are well-understood. In this paper, we report on three experiments in Bangla, a language in which gaps may occur in either a pre-verbal embedded clause or a post-verbal embedded clause. This word order variation allows us to manipulate whether the first gap linearly available is contained in the same clause as the filler, which allows us to dissociate structural locality from linear locality. In Experiment 1, an untimed ambiguity resolution task, we found a global bias to resolve a filler-gap dependency with the first gap linearly available, regardless of structural hierarchy. In Experiments 2 and 3, which use the filled-gap paradigm, we found sensitivity to disruption only when the blocked gap site is both structurally and linearly local, i.e., the filler and the gap site are contained in the same clause. This suggests that comprehenders may not show sensitivity to the disruption of all preferred gap resolutions.

Interactions between the oomycete Pythium arrhenomanes and the rice root-knot nematode Meloidogyne graminicola in aerobic Asian rice varieties.

BACKGROUND: Aerobic rice fields are frequently infested by pathogenic oomycetes (Pythium spp.) and the rice root-knot nematode Meloidogyne graminicola. Here, the interaction between Pythium arrhenomanes and Meloidogyne graminicola was studied in rice roots of two aerobic rice varieties. In different experimental set-ups and infection regimes, plant growth, rice yield, Pythium colonization, as well as establishment, development and reproduction of M. graminicola were studied. RESULTS: In this study, it is shown that the presence of P. arrhenomanes delays the establishment, development and reproduction of M. graminicola compared to single nematode infected plants. The delay in establishment and development of M. graminicola becomes stronger with higher P. arrhenomanes infection pressure. CONCLUSIONS: Our data indicate that P. arrhenomanes antagonizes M. graminicola in the rice root and that the plant benefits from this antagonism as shown by the yield data, especially when either of the pathogens is present in high levels.

TGF-ß/BMP signaling and other molecular events: regulation of osteoblastogenesis and bone formation.

Transforming growth factor-beta (TGF-ß)/bone morphogenetic protein (BMP) plays a fundamental role in the regulation of bone organogenesis through the activation of receptor serine/threonine kinases. Perturbations of TGF-ß/BMP activity are almost invariably linked to a wide variety of clinical outcomes, i.e., skeletal, extra skeletal anomalies, autoimmune, cancer, and cardiovascular diseases. Phosphorylation of TGF-ß (I/II) or BMP receptors activates intracellular downstream Smads, the transducer of TGF-ß/BMP signals. This signaling is modulated by various factors and pathways, including transcription factor Runx2. The signaling network in skeletal development and bone formation is overwhelmingly complex and highly time and space specific. Additive, positive, negative, or synergistic effects are observed when TGF-ß/BMP interacts with the pathways of MAPK, Wnt, Hedgehog (Hh), Notch, Akt/mTOR, and miRNA to regulate the effects of BMP-induced signaling in bone dynamics. Accumulating evidence indicates that Runx2 is the key integrator, whereas Hh is a possible modulator, miRNAs are regulators, and ß-catenin is a mediator/regulator within the extensive intracellular network. This review focuses on the activation of BMP signaling and interaction with other regulatory components and pathways highlighting the molecular mechanisms regarding TGF-ß/BMP function and regulation that could allow understanding the complexity of bone tissue dynamics.

Human Mesiodistal Tooth Width Measurements and Comparison with Dental Cast in a Bangladeshi Population.

AIM: This analysis was aimed to determine the mesiodistal tooth width of human teeth and to compare with the measurements on plaster model in a Bangladeshi population. MATERIALS AND METHODS: The samples of 2,892 teeth of Bangladeshi subjects were collected for this purpose. This article presents mesiodistal tooth width measurements made on all types of teeth and compares with the mesiodistal tooth width measurements of dental cast collected from Bangladeshi subjects between the ages of 18 and 24 years. The mesiodistal dimension was recorded, involving the maximum mesiodistal dimension of each tooth when measurement was rendered parallel to the occlusal and labial surfaces. Descriptive and comparative statistics were applied. RESULTS: The mean, standard deviation and 95% confidence interval of mesiodistal tooth width measurements were determined and have been with the mesiodistal tooth width measurements of dent al cast. Significant differences have been observed between mesiodistal tooth size of direct measurement on tooth (DMT) and measurement on plaster model (MPM) for the maxillary first molar (p < 0.001) and mandibular incisors to first premolar (p < 0.001). CONCLUSION: These data should prove to be helpful to the practitioner for performing successful orthodontic treatment in Bangladeshi population. CLINICAL SIGNIFICANCE: Direct measurement of mesiodistal tooth width and individual variation of maxillary and mandibular permanent central incisor to first molar of the Bangladeshi individuals showed some distinguishable features, which will certainly help an orthodontist for diagnosis and treatment plan of an orthodontic case.

Removal of copper ions from water using epichlorohydrin cross-linked beta-cyclodextrin polymer: characterization, isotherms and kinetics.

Beta-cyclodextrin (beta-CD) cross-linked with epichlorohydrin to form water insoluble beta-cyclodextrin polymer (beta-CDP) has been shown to be an effective sorbent for sorption of organic particles, but the sorption of copper (Cu2+) in aqueous solutions by beta-CDP has not been conducted. The objective of this study was to explore the sorption mechanism of beta-CDP for copper. The effects of different experimental conditions such as pH, ionic strength, contact time, and temperature were inspected using a batch method. In addition, binding scheme was estimated by using Fourier transform infrared (FTIR) spectroscopy, Xray photoelectron spectroscopy (XPS), a scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET) analysis. The adsorption of Cu2+ was observed to be higher at pH 6.0. The kinetic study revealed that the adsorption is fitted well by the pseudo-second-order kinetic model. The maximum binding of Cu2+ was estimated to be 111.11 mg/g through the Langmuir isotherm model--much higher than the existing sorption technologies. Hence, the adsorption-desorption trends of epichlorohydrin cross-linked with beta-CD, along with its good recyclability, establish an alternative, effective, and novel remediation technology for the removal of Cu2+ from aqueous solutions.

Mapping and identification of the region and secondary structure required for the maturation of the nukacin ISK-1 prepeptide.

The prepeptide NukA of the lantibiotic nukacin ISK-1 consists of an N-terminal leader peptide followed by a propeptide moiety that undergoes post-translational modifications, that is, formation of unusual amino acids by NukM, cleavage of the leader peptide and transport by NukT to yield a mature peptide. To identify the region and conformation required for the maturation of prepeptide, we expressed a series of NukA mutants, mutants with the N-terminus-truncated leader peptide and site-directed mutants with conserved residues in the leader peptide of type A(II) lantibiotics, which were evaluated on the basis of the production of nukacin ISK-1. In addition, the secondary structure data of NukA mutants or fragments were obtained by circular dichroism spectra. The results indicated the importance of the alpha-helical leader peptide with hydrophobic and hydrophilic orientation consisting of the conserved residues in type A(II) lantibiotics. The expression data from various combinations of the chimeric prepeptides consisting of NukA and LctA (the prepeptide of lacticin 481, which shows high identity with NukA) further revealed that the amino acid difference at the C-terminus of the propeptide moiety between NukA and LctA, especially His at position 15 and Phe at position 19, was important for the maturation processes by the nukacin ISK-1 biosynthetic enzymes. Our findings suggest that the determinants in NukA were critically involved in the biosynthesis of nukacin ISK-1 and would thus be important for recognition by the nukacin ISK-1 biosynthetic enzymes.

Nukacin ISK-1, a bacteriostatic lantibiotic.

We determined the mode of action of nukacin ISK-1. It did not cause membrane potential dissipation or the efflux of ATP or K(+) ions from the cells of a sensitive bacterial strain; however, it blocked the membrane depolarization activity of nisin. Nukacin ISK-1-treated cells had single arrangements of cells without the formation of a complete septum. A remarkable reduction in cell wall width was also observed, but cytoplasmic content was unaffected. We concluded that nukacin ISK-1 is bacteriostatic.

Lantibiotics: diverse activities and unique modes of action.

Lantibiotics are one of the most promising alternative candidates for future antibiotics that maintain their antibacterial efficacy through many mechanisms. Of these mechanisms, some modes of activity have recently been reported, providing opportunities to show these peptides as potential candidates for forthcoming applications. Many findings providing new insight into the detailed molecular activities of numerous lantibiotics are constantly being uncovered. The combination of antibiotic mechanisms in one lantibiotic molecule shows its diverse antimicrobial usefulness as a future generation of antibiotic. Since lantibiotics do not have any known candidate resistance mechanisms, the discovered distinct modes of activity may revolutionize the design of anti-infective drugs through the knowledge provided by these super molecules. In this review, we discuss the rising assortment of lantibiotics, with special emphasis on their structure-function relationships, addressing the unique activities involved in their individual modes of action.

Lantibiotics: insight and foresight for new paradigm.

Lantibiotics are a unique type of antimicrobial peptide produced by a large number of gram-positive bacteria that contain unusual amino acids, such as lanthionine and dehydrated amino acids. Ribosomally synthesized lantibiotic prepeptide consists of an N-terminal leader peptide followed by a C-terminal propeptide moiety that undergoes several post-translational modification events to yield a biologically active lantibiotic. Research on lantibiotics has drawn much attention in recent years and has undergone extensive progress as a step forward to the next paradigm. Unusual amino acids in lantibiotics solely contribute to their biological activity and also enhance their structural stability. Thus, enzymes involved in lantibiotic biosynthesis would have a high potential for peptide engineering by introducing unusual amino acids into desired peptides, which may establish a universal approach to advance the structural design of novel peptides, termed lantibiotic engineering. In this review, we focus on recent development with contemporary innovations and perspective of lantibiotic research.

Lysine-oriented charges trigger the membrane binding and activity of nukacin ISK-1.

The antibacterial activities and membrane binding of nukacin ISK-1 and its fragments and mutants were evaluated to delineate the determinants governing structure-function relationships. The tail region (nukacin(1-7)) and ring region (nukacin(7-27)) were shown to have no antibacterial activity and also had no synergistic effect on each other or even on nukacin ISK-1. Both a fragment with three lysines in the N terminus deleted (nukacin(4-27)) and a mutant with three lysines in the N terminus replaced with alanine (K1-3A nukacin ISK-1) imparted very low activity (32-fold lower than nukacin ISK-1) and also exhibited a similar antagonistic effect on nukacin ISK-1. Addition of two lysine residues at the N terminus (+2K nukacin ISK-1) provided no further increased antibacterial activity. Surface plasmon resonance sensorgrams and kinetic rate constants determined by a BIAcore biosensor revealed that nukacin ISK-1 has remarkably higher binding affinity to anionic model membrane than to zwitterionic model membrane. Similar trends of strong binding responses and kinetics were indicated by the high affinities of nukacin ISK-1 and +2K nukacin ISK-1, but there was no binding of tail region, ring region, nukacin(4-27), and K1-3A nukacin ISK-1 to the anionic model membrane. Our findings therefore suggest that the complete structure of nukacin ISK-1 is necessary for its full activity, in which the N-terminus three lysine residues play a crucial role in electrostatic binding to the target membrane and therefore nukacin ISK-1's ability to exert its potent antibacterial activity.

Socio-economic status of chronic arsenicosis patients in Bangladesh.

The study showed that the maximum number of arsenicosis patients (71%) belonged to low income group and 29% belong to middle class income group but none was found in high income group and all these patients were from rural areas of the country. Majority of all these patients was related with the traditional occupation of the country like cultivation (53%) in addition to lower level of educational background (81.5%). Most of the patients of chronic arsenicosis were suffering from malnutrition (91%). The present study which reflects that the vast majority of patients of chronic arsenicosis in the country belonged to low income group, but also to low educational background and individuals, who had been suffering from malnutrition, needs a special consideration in the management of the problem. Emphasis has been given to have access to arsenic-free water and protein rich diet to people of arsenic affected areas.

Clinicopathologic manifestations and outcome of dengue fever and dengue haemorrhagic fever.

During the peak period of outbreak from July through October, during the year 2000 through 2002, a total of 390 cases of either dengue fever (DF) or dengue haemorrhagic fever (DHF) were collected from medicine outpatient department (MOPD) of Bangabandhu Sheikh Mujib Medical University (BSMMU), Shahbag, Dhaka to study their clinicopathologic manifestations and management outcome. Data were collected using a structured questionnaire. Almost all of the patients presented with fever (100%), headache (98.2%), bodyache (97.7%), anorexia (100%) and nausea (100%) and the vast majority had skin rash (78.5%), backache (78.2%) and retro-orbital pain (79.7%). Mean +/-SD of duration of total illness was 7.57 +/- 1.11 days and that of fever and skin rash were 5.40 +/- 0.86 and 3.02 +/- 0.78 days respectively. Mean +/-SD of platelet count was 69643.59 +/- 32043.97/mm3 of blood and that of haematocrit was 41.18 +/- 2.65%. Almost all of the patients (97.7%) developed thrombocytopenia but only 4.1% developed leucopenia at sometime during the course of the disease and anaemia was found in 49.4% of the patients. Both anti-dengue IgG and anti-dengue IgM were positive in 55.1% of patients and either anti-dengue IgG or anti-dengue IgM was positive in 23.6% and 21.3% of patients respectively. Management outcome of the patients was quite satisfactory without any case fatality.

Inhibitory effect of a novel bisphosphonate, TRK-530, on dental calculus formation in rats.

BACKGROUND: A newly developed bisphosphonate, TRK-530 (disodium dihydrogen[4-(methylthio)phenylthio]methanebisphosphonate), has recently been reported to show anti-inflammatory and anti-bone-resorbing activity. Since bisphosphonates have been shown to inhibit the formation of calcium-phosphate crystals in vitro, TRK-530 may inhibit the formation of dental calculus. Therefore, the present study was performed to examine whether this compound has such an effect. METHODS: Three groups of Wistar rats fed a calculogenic diet (RC16) were treated with TRK-530 in drinking water at concentrations of 0 (control group), 0.75, and 1.5 mM. Another group received a daily subcutaneous injection of TRK-530 at a dose of 2.25 micromoles/rat, which was assumed to correspond to the maximum amount of this compound absorbed from the intestine when rats received 1.5 mM TRK-530 in drinking water. Rat dental calculus formation was evaluated. The crystalline nature of dental calculus was studied by x-ray diffraction analysis. Finally, the effects of TRK-530 on the precipitation of calcium-phosphate from solution were tested in vitro. RESULTS: TRK-530 in drinking water inhibited dental calculus formation dose-dependently. However, subcutaneous injection of TRK-530 did not have any significant effect, suggesting that the anticalculus effect of TRK-530 in drinking water was topical, not systemic. The calculus that formed in both the control and experimental groups was primarily hydroxyapatite, a main constituent of human dental calculus. TRK-530 inhibited the precipitation of calcium-phosphate from solution in vitro. CONCLUSIONS: TRK-530 inhibited the formation of dental calculus in a dose-dependent fashion via a local effect. Inhibition of the precipitation of calcium-phosphate from solution might be involved in the anticalculogenic mechanism of this drug.