Dengue Vaccination: Towards a New Dawn of Curbing Dengue Infection

Dengue is an infectious disease caused by dengue virus (DENV) and is a serious global burden. Antibody-dependent enhancement and the ability of DENV to infect immune cells, along with other factors, lead to fatal Dengue Haemorrhagic Fever and Dengue Shock Syndrome. This necessitates the development of a robust and efficient vaccine but vaccine development faces a number of hurdles. In this review, we look at the epidemiology, genome structure and cellular targets of DENV and elaborate upon the immune responses generated by human immune system against DENV infection. The review further sheds light on various challenges in development of a potent vaccine against DENV which is followed by presenting a current account of different vaccines which are being developed or have been licensed.

Receptivity and Remating Propensity in Female Spodoptera litura (Fabricius) after Mating with an Irradiated Male or Its F1 Male Progeny

The 'Inherited or F₁ sterility technique' (IS), using sub-sterilized male moths, is a widely proposed pest management tool for Lepidoptera pests in general, and the tobacco cutworm Spodoptera litura (Fabr.) in particular. However, the multiple mating tendency of female moths and the ejaculate quality of male moths might influence the efficiency of this technique. Reduced ejaculate quality was observed in irradiated males, as evidenced by radiation's impact on certain bio-parameters, such as the weight of the spermatophores and their protein content, sperm count, the molecular expression of the sex peptide receptor (SPR) and egg fertility, with a greater impact in F₁ male progeny. During the remating of females with untreated males, irrespective of the irradiation status of the first male, there was an increase in calling behavior, remating propensity and fertility in females, with a larger time gap between consecutive matings. The ability of F₁ male progeny to check remating propensity in females 24 h after the initial mating was lower than that of unirradiated males. Partially sterile (130 Gy) males were as successful as unirradiated males in inducing the level of mating refractoriness in females. Decreased ejaculate quality in F₁ male progeny could be associated with increased female receptivity during remating. Understanding the influence of male moth irradiation, insemination quality and post (initial)-mating intervals on the remating behavior of normal female moths and induced sterility might help in simulation modeling and optimizing IS insect programs.

Radiation Hormesis to Improve the Quality of Adult Spodoptera litura (Fabr.)

Mass rearing of insects of high biological quality is a crucial attribute for the successful implementation of sterile insect release programs. Various ontogenetic stages of Spodoptera litura (Fabr.) were treated with a range of low doses of ionizing radiation (0.25-1.25 Gy) to assess whether these gamma doses could elicit a stimulating effect on the growth and viability of developing moths. Doses in the range of 0.75 Gy to 1.0 Gy administered to eggs positively influenced pupal weight, adult emergence, and growth index, with a faster developmental period. The enhanced longevity of adults derived from eggs treated with 0.75 Gy and 1.0 Gy, and for larvae and pupae treated with 1.0 Gy, indicated a hormetic effect on these life stages. Furthermore, the use of these hormetic doses upregulated the relative mRNA expression of genes associated with longevity (foxo, sirtuin 2 like/sirt1, atg8) and viability/antioxidative function (cat and sod), suggesting a positive hormetic effect at the transcriptional level. These results indicated the potential use of low dose irradiation (0.75-1 Gy) on preimaginal stages as hormetic doses to improve the quality of the reared moths. This might increase the efficiency of the inherited sterility technique for the management of these lepidopteran pests.

Effect of Irradiation on Reproduction of Female Spodoptera litura (Fabr.) (Lepidoptera: Noctuidae) in Relation to the Inherited Sterility Technique

Radiobiological investigations on the reproductive behavior of female Spodoptera litura (Fabr.) were conducted with the aim of determining the suitable radio-sterilizing dose for females in order to release them along with sub-sterile males for effective implementation of the Inherited Sterility technique against this pest. Calling and copulation duration significantly increased, while mating success, oviposition, fertility and longevity significantly decreased with increasing radiation dose (100-200 Gy) compared to control. In view of the effect of irradiation on mating behavior and reproductive viability of female S. litura, 130 Gy was identified as a suitable radio-sterilization dose. Further molecular studies were conducted to corroborate this dose for female sterilization, along with a higher dose of 200 Gy in order to validate the gradational response of ionizing radiation. GC-MS analysis indicated decreased sex pheromone titer at 130 Gy, which was more pronounced at 200 Gy. Pheromone-associated genes, PBAN and PBAN-R showed decreased expression at 130 Gy, and were drastically reduced at 200 Gy. The fertility-related Vg gene also showed a negative correlation with radiation exposure. Based on these radiation responses of female S. litura, 130 Gy might be considered a suitable dose for complete female sterility and its inclusion in sterile insect programs against S. litura.

Virtual-source imaging and repeatability for complex near surface

Based on seismic interferometry, the virtual source (VS) method is able to produce virtual gathers at buried receiver locations by crosscorrelating the direct-downgoing waves with corresponding reflected-upgoing waves from surface-source gathers. Theoretically, the VS records can improve seismic quality with less negative impact from overburdened complexities. However, shallow complex structures and weathering layers at near surface not only severely distort the wavepaths, but also introduce multiples, surface waves, scattering noise, and interference among different wave modes. These additional seismic responsescontaminate both direct-downgoing and reflected-upgoing wavefields. As a result, the VS gathers experience spurious events and unbalanced illuminations associated with distorted radiation patterns. Conventional stacking operator can produce significant artifacts for sources associated with ineffective-wavepath cancellation. We review three publications and summarize a comprehensive workflow to address these issues using data-driven offset stacking, wavelet-crosscorrelation filtering, and radiation-pattern correction. A data-driven offset stacking theme, with each individual source contribution is weighted by certain quality measures, is applied for available offsets. The wavelet crosscorrelation transforms time-offset data into local time-frequency and local time-frequency-wavenumber domains. Filters are designed for the power-spectrum in each domain. The radiation-pattern correction spatially alters the contaminated direct-wavefields using a zero-phase matched filter, such that the filtered wavefield is consistent with the model-based direct P-wavefields observed at buried receiver locations. Our proposed workflow produces significant improvement as demonstrated in the 13 time-lapse field surveys that included substantial repeatability problems across a 17-month survey gap.

Fatigue in systemic lupus: the role of disease activity and its correlates

OBJECTIVES

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that leads to a variety of negative health outcomes resulting from inflammation in various organ systems. Although treatment continues to advance, fatigue remains one of the most salient, poorly understood and addressed patient complaints. Understanding the mechanisms of fatigue can help guide the development of interventions to improve health outcomes. The aim of this research was to evaluate the contribution of six variables (disease activity, insomnia, depression, stress, pain and physical health) to fatigue in SLE without concomitant fibromyalgia (FM).

METHODS

A total of 116 ethnically diverse, primarily female participants (91%) with SLE, receiving care at university medical centers, completed assessments of disease activity and quality of life outcomes (FACIT-FT, Insomnia Severity Index, Perceived Stress Scale (PSS-4), Pain Inventory, Depression-PHQ-9, and LupusPRO-physical function). All patients met the American College of Rheumatology classification criteria for SLE and did not have a known diagnosis of FM. Multivariate linear and stepwise regression analyses were conducted with fatigue (FACIT-FT) as the dependent variable, and the above six variables as independent variables.

RESULTS

Mean (SD) age was 39.80 (13.87) years; 50% were African American, 21% Caucasian, 13% Hispanic, 9% Asian and 8% other. Mean (SD) FACIT-FT was 20.09 (12.76). Collectively, these six variables explained 57% of the variance in fatigue. In the multivariate model, depression, stress and pain were significantly and independently associated with fatigue, but not disease activity, sleep or physical health. Stress had the largest effect on fatigue (β 0.77, 95% CI 0.17-1.38, p = 0.01), followed by depression (β 0.66, 95% CI 0.21-1.10, p = 0.005). On stepwise regression analysis, only stress, depression and pain were retained in the model, and collectively explained 56% of the variance in fatigue. All three remained independent correlates of fatigue, with the largest contribution being stress (β 0.84, 95% CI 0.27-1.42, p = 0.005), followed by depression (β 0.79, 95% CI 0.44-1.14, p < 0.001) with fatigue.

CONCLUSION

Stress, depression and pain are the largest independent contributors to fatigue among patients with SLE, without concurrent FM. Disease activity, sleep and physical health were not associated with fatigue. The evaluation of stress, depression and pain needs to be incorporated during assessments and clinical trials of individuals with SLE, especially within fatigue. This stress-depression-fatigue model requires further validation in longitudinal studies and clinical trials. Significance and innovation: • Disease activity, sleep, pain, stress, depression, and physical health have been reported individually to be associated with fatigue in lupus. This analysis evaluated the role of each and all of these six variables collectively in fatigue among patients with SLE without a known diagnosis of FM. • Disease activity, sleep and physical health were not significantly related to fatigue, but depression, stress and pain were. • The results emphasize the need to evaluate and treat fatigue in individuals with SLE utilizing a biopsychosocial approach, particularly in the realm of clinical trials. Behavioral medicine interventions are shown to be most effective for the treatment of depression, stress and pain.

Functional assessment of tyrosinase variants identified in individuals with albinism is essential for unequivocal determination of genotype-to-phenotype correlation

BACKGROUND

Oculocutaneous albinism type 1 (OCA1), caused by pathogenic variations in the tyrosinase gene (TYR), is the most frequent and severe form of hypopigmentary disorder worldwide. While OCA1A manifests as a complete loss of melanin pigment, patients with OCA1B show residual pigmentation of the skin, hair and eyes. Limited experimental evidence suggests retention of TYR in the endoplasmic reticulum (ER) causes OCA1 pathogenesis. However, a comprehensive functional analysis of TYR missense variations and correlation with genotype is lacking.

OBJECTIVES

Functional characterization of nonsynonymous tyrosinase variants in patients with OCA1 reported in the Albinism Database, dbSNP and the published literature, and an attempt to correlate them with reported and predicted phenotypes.

METHODS

Thirty-four reported missense variants of TYR were subcloned by site-directed mutagenesis, and the dual-enzyme activities of the variant proteins were compared with the wild-type. The degree of ER retention was also checked for each of the variants through endoglycosidase H (Endo H) digestion followed by immunoprecipitation and densitometric analysis.

RESULTS

Functional studies revealed one reported OCA1A variation with nearly 100% enzyme activity, 10 OCA1B variants lacking any enzyme activity, eight nonsynonymous single-nucleotide polymorphisms (SNPs) with ~30-70% of enzyme activity, and three SNPs that completely lacked activity altogether. The Endo H assay corroborated these results.

CONCLUSIONS

Loss of enzyme activity of TYR variants was completely in agreement with ER retention across all variants examined. The results of the assay clearly established that determination of the biological activity of identified variants in patients with OCA is essential to correlate the identified suspect genotype with the obvious phenotype of the disease.

Localized Castleman’s Disease in Retroperitoneum Mimicking Broad Ligament Leiomyoma – a Diagnostic Challenge

Primary retroperitoneal tumours pose a diagnostic dilemma and therapeutic challenges because of their location and late detection. Localized Castleman Disease (CD) in retroperitoneal location is a rare occurrence, with incidence of only 4% cases occurring in diverse locations like retroperitoneum. A rare case of unicentric localized Castleman Disease localized in broad ligament is hereby reported which was clinically & radiologically suspected as broad ligament leiomyoma but finally diagnosed as Castleman’s Disease, hyaline vascular type in a young female posing a diagnostic challenge both for the pathologist and clinician. Definite diagnosis is essential as complete surgical excision in case of unicentric Castleman’s Disease has good prognosis after resection.   

In silico analyses of missense mutations in coagulation factor VIII: identification of severity determinants of haemophilia A

Factor VIII (FVIII) mutations cause haemophilia A (HA), an X-linked recessive coagulation disorder. Over 1000 missense mutations in FVIII are known and they lead to variable clinical phenotypes (severe, moderate and mild). The exact molecular basis of this phenotypic heterogeneity by FVIII missense mutations is elusive to date. In this study, we aimed to identify the severity determinants that cause phenotypic heterogeneity of HA. We compiled and curated a data set of 766 missense mutations from the repertoire of missense mutations in FVIII. We analysed these mutations by computational programs (e.g. Swiss-PdbViewer) and different mutation analysis servers (e.g. SIFT, PROVEAN, CUPSAT, PolyPhen2, MutPred); and various sequence- and structure-based parameters were assessed for any significant distribution bias among different HA phenotypes. Our analyses suggest that 'mutations in evolutionary conserved residues', 'mutations in buried residues', mutation-induced 'steric clash' and 'surface electrostatic potential alteration' act as risk factors towards severe HA. We have developed a grading system for FVIII mutations combining the severity determinants, and the grading pattern correlates with HA phenotype. This study will help to correctly associate the HA phenotype with a mutation and aid early characterization of novel variants.

Regulation of Streptococcus mutans PTS Bio by the transcriptional repressor NigR

Streptococcus mutans is implicated in human dental caries, and the carbohydrate metabolism of this organism plays an important role in the formation of this disease. Carbohydrate transport and metabolism are essential for the survival of S. mutans in the oral cavity. It is known that a unique phosphoenolpyruvate-sugar phosphotransferase system PTS(B) (io) of S. mutans UA159 is expressed in sucrose-grown biofilms (Mol Oral Microbiol 28: 2013; 114). In this study we analyzed the transcriptional regulation of the operon (O(B) (io) ) encoding the PTS(B) (io) and showed that it was repressed by NigR, a LacI-like transcriptional regulator. Using electro-mobility shift assay, we described two operators to which NigR bound with different affinities. We also identified the transcriptional start site and showed that one of the operators overlaps with the promoter and presumably represses initiation of transcription. Mutational analyses revealed the key nucleotides in the operators required for high-affinity binding of NigR. PTS(B) (io) is expressed in S. mutans biofilms so understanding its regulation may provide improved strategies for caries treatment and prevention.

Spectrum of histopathological lesions in the fallopian tubes

Background: Fallopian tubes are common surgical specimen in the pathology laboratory; still there is a lack of data to describe the frequency of various histological fi ndings. The aim and objectives of this study was to describe the various histopathological fi ndings of fallopian tubes. Materials and Methods: Two thousand fi ve hundred and seventy fi ve cases where fallopian tubes were removed either separately or along with other female genital tract organs were studied retrospectively and their histopathological fi ndings documented. Results: Ectopic pregnancy comprised maximum number of cases closely followed by salpingitis. Primary neoplastic lesions were rare as compared to secondary malignancies. Serial sections of fallopian tube and sections from representative areas are essential for a pathologist so that the diagnosis of these pathological entities is not missed. Conclusion: Though the fallopian tubes remain unremarkable in majority of the surgical pathological specimens, it must be subjected for histopathological examination to demonstrate the pathological lesions. Journal of Pathology of Nepal (2013) Vol. 3, No.1, Issue 5, 356-360 DOI: http://dx.doi.org/10.3126/jpn.v3i5.7858

The SLE-associated Pbx1-d isoform acts as a dominant-negative transcriptional regulator

Pbx1 is a transcription factor involved in multiple cellular processes, including the maintenance of self-renewal of hematopoietic progenitors. We have shown that the CD4(+) T-cell expression of a novel splice isoform of Pbx1, Pbx1-d, is associated with lupus susceptibility in the NZM2410 mouse and in lupus patients. The function of Pbx1 in T cells is unknown, but the splicing out of the DNA-binding domain in Pbx1-d predicts a dominant-negative function. In support of this hypothesis, we have shown that Pbx1-d transduction accelerates differentiation of MC3T3-E1 osteoblast pregenitors and mimics the effect of short hairpin RNA silencing of Pbx1. Conversely, Pbx1-d transduction reduced the expression of Sox3, a gene strongly transactivated by Pbx1, and Pbx1-d did not bind the Sox3 promoter. These results constitute a first step towards the understanding on how Pbx1-d contributes to systemic autoimmunity in the NZM2410 mouse model as well as in lupus patients.

Quantitative dermatoglyphic asymmetry: a comparative study between schizophrenic patients and control groups of West Bengal, India

Quantitative Fluctuating (FA) and Directional asymmetry (DA) of dermatoglyphics on digito-palmar complex were analyzed in a group of 111 patients (males: 61, females: 50) with schizophrenia (SZ), and compared to an ethnically matched phenotypically healthy control (males: 60, females: 60) through MANOVA, ANOVA and canonical Discriminant analyses. With few exceptions, asymmetries are higher among patients, and this is more prominent in FA than DA. Statistically significant differences were observed between patient and control groups, especially in males. In both sexes, FA of combined dermatoglyphic traits (e.g. total finger ridge count, total palmar pattern ridge count) are found to be a strong discriminator between the two groups with a correct classification of over 83% probability.

Comprehensive analysis of the molecular basis of oculocutaneous albinism in Indian patients lacking a mutation in the tyrosinase gene

BACKGROUND

Oculocutaneous albinism (OCA) refers to a group of inherited disorders where the patients have little or no pigment in the eyes, skin and hair. Mutations in genes regulating multi-step melanin biosynthesis are the basis of four 'classical' OCA types with overlapping clinical features. There are a few reports on defects in TYR and a single report on SLC45A2 in Indians affected with OCA but no report on OCA2 (a major locus related to the disease) and TYRP1.

OBJECTIVES

To assess and describe a comprehensive picture of the molecular genetic basis of OCA among Indians with no apparent mutations in TYR.

METHODS

Twenty-four affected pedigrees from 14 different ethnicities were analysed for mutations in OCA2, TYRP1, SLC45A2 and SLC24A5 using the polymerase chain reaction-sequencing approach.

RESULTS

Two splice-site and four missense mutations were detected in OCA2 in seven unrelated pedigrees, including four novel mutations. Haplotype analysis revealed a founder mutation (Ala787Thr) in two unrelated families of the same ethnicity. A patient homozygous for a novel SLC45A2 mutation also harboured a novel OCA2 defect. No mutation was detected in TYRP1 or SLC24A5.

CONCLUSIONS

Our results suggest that an OCA2 gene defect is the second most prevalent type of OCA in India after TYR. The presence of homozygous mutations in the affected pedigrees underscores the lack of intermixing between the affected ethnicities. Direct detection of the genetic lesions prevalent in specific ethnic groups could be used for carrier detection and genetic counselling to contain the disease.

Prevalence and significance of antiphospholipid antibodies in selected at-risk obstetrics cases: a comparative prospective study

In a prospective comparative study we screened 112 women with a past history either of pre-eclampsia, eclampsia, recurrent abortion, IUGR, IUFD or abruptio placentae, with no apparent aetiology and a demographically matched cohort of 106 women having a past history of uncomplicated pregnancy outcome for the presence of antiphospholipid antibodies (aPL) and their significance. In the former group, the prevalence of aPL ranged from 10-46.87% compared with 8.49% in the later group. In women with the presence of aPL, the incidence of pre-eclampsia, early onset pre-eclampsia and abruptio placentae were 25%, 14.58% and 18.75%, respectively. In the same group, the abortion rate was 25% and live-birth rate was 64.58% with IUFD rate of 10.42%. Fetal morbidity rates were also higher in the mothers with aPL positivity, the incidence of IUGR was 27.08% and oligohydramnios was 33.33% in them. All these complications were statistically significant when compared with those of aPL negative mothers.

Mode of inheritance of finger dermatoglyphic traits among Vaidyas of West Bengal, India

BACKGROUND

It is well established that dermatoglyphics are genetically determined. But, to date, few studies have given attention to the inheritance pattern of dermatoglyphics. Furthermore, despite the existence of different advanced statistical packages, none of these previous studies implemented a model-fitting technique to reveal the mode of inheritance. Thus, the genetic nature of dermatoglyphics is still not clear.

AIM

In the present communication, an attempt has been made to provide some information regarding the genetics of finger dermatoglyphics by estimating the magnitude and mode of inheritance of these traits.

SUBJECTS AND METHODS

The fingerprints of 824 individuals from 200 families including two generations were collected from Barasat in North 24-Parganas, West Bengal. The study includes familial correlations between first-degree relatives and corresponding heritabilities. In the final stage, segregation analyses by the Pedigree Analysis Package (PAP) were conducted on these data to understand the mode of inheritance.

RESULTS

The major findings indicated the following: (a) Familial correlations in all possible relationships (except spouse correlation) were statistically significant and of comparable magnitude. (b) The corresponding heritabilities were in the range between 59% for Pattern Intensity Index (PII) and 77% for Total Finger Ridge Count (TFRC). These estimates were in agreement with previously published data on this subject. (c) By segregation analysis, the 'Sporadic', 'Environmental', 'No major gene effect' as well as 'No polygenic component' models were strongly rejected (p < 0.05) and the hypothesis of a major gene's (MG) influence on all studied traits was accepted, though the proportion of MG variance was low. (d) The Most Parsimonious Mendelian model clearly indicated the contribution of a major gene with dominant (for PII) and additive (for two ridge counts) effects.

CONCLUSION

The present report supports the evidence of the existence of a major gene on these dermatoglyphic traits and the transmission of this effect is consistent with Mendelian expectation.

OCA1 in Different Ethnic Groups of India is Primarily Due to Founder Mutations in the Tyrosinase Gene

Oculocutaneous albinism (OCA) is a heterogeneous group of autosomal recessive disorders characterized by an abnormally low amount of melanin in the eyes, skin and hair, and associated with common developmental abnormalities of the eye. Defects in the tyrosinase gene (TYR) cause a common type of OCA, known as oculocutaneous albinism type 1 (OCA1). The molecular basis of OCA has been studied extensively in different population groups, but very little information is available on Indian patients. Our investigation covering thirteen ethnic groups of India, some representing >20 million people, revealed that among 25 OCA families 12 were affected with OCA1, and that these cases were primarily due to founder mutations in TYR. We detected nine mutations and eight SNPs in TYR, of which six mutations (five point mutations & one gross deletion) were novel. In contrast to most reports describing compound heterozygotes, the presence of homozygotes in 10 out of the 12 pedigrees underscores the lack of intermixing between these ethnic groups in India. Haplotype analysis suggested a few founder chromosomes causing the disease in the majority of the patients. Direct detection of the mutations prevalent in specific ethnic groups could be used for carrier detection and genetic counselling.

High signal in knee osteophytes is not associated with knee pain

OBJECTIVE

Our understanding of the local source of pain in osteoarthritis (OA) remains unclear. We undertook this study to determine if the presence of high-signal osteophytes on magnetic resonance imaging (MRI) was associated with pain presence, location or severity.

METHODS

Subjects were chosen from the Boston Osteoarthritis of the Knee Study, a natural history study of symptomatic knee OA. Assessments included knee MRI, pain assessments and information on weight and height. Osteophyte signal was defined as areas of increased signal intensity in the osteophyte on fat-suppressed T2 weighted images, and graded in the joint margins where osteophyte size is graded. All patients were evaluated with the frequent knee symptoms question for pain presence, the Western Ontario McMasters Osteoarthritis Index (WOMAC) for pain severity, and location of self-reported pain was recorded as present or absent based on locations identified on a standardized diagram. The osteophyte signal measures anywhere within one given knee were summed, creating an osteophyte signal aggregate. Logistic regression was conducted with quartile of osteophyte signal aggregate as the independent predictor and frequent knee symptom question as the dependent outcome. Association between quartile of osteophyte signal aggregate and pain severity on WOMAC was assessed using a linear regression. Logistic regression was used to evaluate the association between compartment-specific high-signal osteophytes aggregates (independent variable) and compartment-specific knee pain (dependent variable). Analyses were adjusted for gender, body mass index (BMI), and age.

RESULTS

Two hundred and seventeen subjects were included in this analysis. They were predominantly male and 75% of subjects had radiographic tibio-femoral (TF) OA, and the remainder had patello-femoral (PF) radiographic OA. We did not find any association of high-signal osteophytes with presence of pain, pain severity or self-reported pain location.

CONCLUSION

High-signal osteophytes detected on MRI are not associated with the presence of pain, pain severity or the self-reported location of pain.

Synergism in immunotoxicological effects due to repeated combined administration of arsenic and lead in mice

Arsenic and lead are considered potent human hazards because of their neoplastic outcomes; increasing epidemiologic evidence indicates a link between heavy metal exposure and health risk. Since health risks of singly administered metals are well-established, in the present study we determined whether simultaneous repeated multimetal (arsenic + lead) exposure influences the development of immunotoxicity in mice exposed (in vivo) to lead acetate (10 mg/kg b.w.) and sodium arsenite (0.5 mg/kg b.w.) simultaneously. We report that in vivo multimetal exposure alters cell morphology, inhibits cell adhesion, nitric oxide release, intracellular killing ability, chemotactic migration, myeloperoxidase release, bacterial clearance from blood and spleen and increases DNA fragmentation. On measuring bacterial density in blood and spleen after 0, 24, 48 and 72 h post infection (with Staphylococcus aureus MC524) in control and multimetal treated groups, bacterial load showed delayed clearance from blood and spleen in the multimetal exposed group. We also found that in vivo exposure to the multimetal caused a decrease in cell adhesion, indicated by a fall in absorbance at 570 nm with respect to control. Exposure to multimetal led to morphological changes in macrophages, since more deformed cells were obtained in repeated combined exposure to arsenic and lead compared to control. Nitric oxide, which has a potent microbicidal activity in macrophages, was found to be released in fewer amounts in the multimetal exposed group from that of control group. It was observed that the viability of bacteria gradually decreased in control macrophage with time, whereas, in macrophages of multimetal exposed mice, the viability of S. aureus gradually increased. Chemotactic migration of splenic macrophages significantly decreased in the multimetal exposed group from that of control. Lysosomal enzyme release from splenic macrophages decreased upon simultaneous exposure to arsenic and lead, as is evident from the decrease in myeloperoxidase release in multimetal group from that in control. That the structural integrity of splenic macrophages is decreased in the multimetal exposed group is also evident from the enhanced percentage of DNA fragmentation after multimetal exposure, suggesting apoptotic death of splenic macrophage. Intracellular viable bacteria in the splenic macrophage from multimetal exposed group was 89.16 +/- 3.54% while that from control group was 49.19 +/- 1.16%, whereas single metal exposed groups showed a bacterial viability of 69.6 +/- 2.45% and 71.71 +/- 1.89% in arsenic and lead treated groups respectively. What is essentially noteworthy from the observed results is that lead and arsenic causes a greater immunotoxic effect when administered together as multimetal than when singly administered. Simultaneous exposure to lead and arsenic appears to be additive as is further established from the isobologram constructed by plotting the concentration of arsenic against the concentration of lead at which effect (in this case myeloperoxidase release) remained constant, a convex line showing synergism was demonstrated. The present study reports a definite synergistic trend of immunotoxicity during simultaneous exposure to arsenic and lead, that is, a multimetal challenge, as compared to the effects of independent exposure to them.

Genetics of Dermatoglyphic Asymmetry in Vaidyas of West Bengal, India

In this study of the genetics of dermatoglyphic asymmetry, we collected bilateral finger and palm prints of 824 individuals from 200 families including 2 generations from an endogamous caste (Vaidya) in Barasat, North 24-Parganas District, West Bengal. Two main types of asymmetry (fluctuating asymmetry and directional asymmetry) were calculated between the two hands. The study includes familial correlation between first-degree relatives, principal-components analysis, and maximum-likelihood-based heritabilities (by pedigree analysis). We found, first, that familial correlations in all possible pairs of relationships (except spouse correlation) were weak but positive; some were even statistically significant. No indication of assortative mating was observed, but the influence of maternal environment could not be discarded. The results also showed that X-chromosome linkage does not seem to be involved. A second major finding is that five principal factors could be extracted from all these asymmetric traits, explaining 74.207% of the overall cumulative variance. Asymmetry of finger and palmar areas were clearly separated by factor. In addition, the heritabilities of the extracted five factors were in the range of 8-24%. These estimates are in agreement with some previously published data. The heritabilities of the factors describing palmar asymmetry are slightly lower than those describing finger asymmetry. The present results support the hypothesis that both types of asymmetry have a genetic basis and are influenced by the intrauterine environment.

Lead induced modulation of splenic macrophage responses on humoral and cell mediated immunity

The heavy metal lead is an environmental toxic material that can induce pathophysiological changes in many organ systems. Previous studies have shown the effects of lead exposure on immune cells in different experimental animals, however, the mechanism of their influence on the immune system is unclear. We reported that in vivo lead exposure inhibits phagocytosis, nitric oxide release, induces DNA fragmentation suggesting the apoptotic death of the target cell. We have also presented evidence that inhibition of macrophage functional responses implicated alteration of humoral and cell mediated immunity. In vivo exposure to lead acetate alters the phagocytic capacity of splenic macrophages as evident from the reduction of phagocytic index of control from 19,792+/-1385.69 to 8893+/-893 in the treated group. The amount of nitric oxide released by the control cell 2.25+/-0.125 microM is also reduced to 1.9375+/-0.0625 microM upon in vivo lead treatment. Functional integrity of the target cell is also decreased after lead exposure as obtained from the percentage of DNA fragmentation. Control group shows 33.29+/-0.11% of fragmented DNA, which is enhanced to 42.43+/-0.725% following the lead treatment. A greater percentage of DNA fragmentation upon lead treatment probably indicating that the heavy metal induces apoptosis. The humoral immune response is also altered after lead exposure as indicated by the decrease of the antibody titre in control group from 1:2048 to 1:128 in the treated group. From the DTH reaction, it was observed that the mean diameter of swollen foot pad of control mice is 0.329+/-0.15 cm and that of lead treated mice is 0.274+/-0.056 cm. It can, therefore, be suggested that lead inhibits normal functional activities of splenic leukocytes, particularly phagocytosis and also affects the functional integrity of cells by inducing DNA fragmentation. The study may demonstrate the usefulness of investigation of humoral immune system and leukocyte functions as sensitive parameters in detecting the effects of lead toxicity.

Correction to Microscopically Determined Particle Size According to Diffraction Correction Theory

The theory of diffraction correction for transparent (phase) spherical particles under partially coherent illumination has been applied to the optical photomicrographic determination of particle size distribution for four different nearly monodisperse polystyrene latex samples. The thus corrected particle size distribution for each sample has been compared with the corresponding electron microscopic determination. Copyright 1999 Academic Press.

The Primary Electroviscous Effect in Polystyrene Latices of Small Particle Size Range Prepared with the Addition of Anionic Surfactant as Emulsifier. Effect of Increasing Concentrations of Quaternary Ammonium Counterions of Different Ionic Sizes and Stability Characteristic of the Latices and the Latex-Electrolyte Mixtures

Polystyrene latices were prepared by the emulsion polymerization method using hydrogen peroxide as an initiator and sodium dodecyl sulfate as the emulsifying agent. Latices of different particle sizes were prepared by the seeded growth technique. The particle size and its frequency distribution were determined by electron microscope. The viscosities and electrophoretic mobilities of the latex and latex:added electrolyte mixtures were measured in the presence of gradually increasing concentrations of quaternary ammonium counterions of different ionic sizes. The zeta-potentials were calculated by the computational method of Wiersema-Loeb- Overbeek (WLO); the surface charge densities sigma were calculated by the method of Loeb-Wiersema-Overbeek (LWO). The primary electroviscous effects were calculated by using the Booth equation. The free energies of adsorption Delta&Gmacr;ads of the counterions on the particle surface were calculated. The stability characteristic of the latices and latex-added electrolyte mixtures has been studied on the basis of the DLVO theory. Copyright 1998 Academic Press.

Multi-drug resistant typhoid fever with diarrhea

OBJECTIVE

To provide information about the characteristics of diarrheal stool in multi-drug resistant typhoid fever and observe the clinical course after treatment with furazolidone or ciprofloxacin.

SETTING

Hospital based.

SUBJECTS AND METHODS

Twenty one male children who were positive for multi-drug resistant S. typhi by blood and stool cultures, having diarrhea at the time of hospitalization comprised the subjects. Serum and stool electrolytes were estimated. Stool samples were also processed to detect established enteropathogens, leukocytes and red blood cells. Children were treated either with furazolidone or ciprofloxacin and evaluated till recovery.

RESULTS

Mean (+/- SD) pre-admission duration of fever and diarrhea of these cases were 19.1 (+/- 5.6) and 15.8 (+/- 4.6) days, respectively. Stool character in 81% of the patients was watery with mean (+/- SD) volume of stool 51.4 (+/- 25.1) ml per kg body weight in the first 24 hours of observation. Leukocyte count varied between 20-49 per high power field in 66.7% stool samples. Occult blood was present in only 19% cases. Fecal red blood cells in high power field were detected in 52.4% cases. Mean fecal electrolytes (mmol/liter) were as follows: sodium-53.8, potassium-51.4, chloride-41.6 and total CO2-24.3. Most of the children (71.4%) had no dehydration and had normal serum electrolytes. The isolated strains of S. typhi were multi-drug resistant. These children were treated successfully either with furazolidone or ciprofloxacin.

CONCLUSION

The stools of multi-drug resistant typhoid fever patients were watery with little blood. Their electrolyte contents were more similar to the diarrheal stool seen in shigellosis rather than cholera. Uncontrolled observations revealed that children recovered with furazolidone or ciprofloxacin therapy.

Correlation of biological activity (therapeutic and toxic) with solvochromic properties of metronidazole, emetine hydrochloride and diloxanide furoate

Goat blood, when incubated for different periods with diloxanide furoate, metronidazole and emetine hydrochloride, underwent changes in fatty acid constituents and their peroxidation products measured as malonaldehyde. These findings, together with the changes noted in the drug-lipid partition coefficient, are discussed in an attempt to correlate the lipid constitution and biological activity of the drugs.

Effect of propranolol hydrochloride on blood cell lipids in relation to partition coefficient and biological activity

Considering the high lipophilicity of propranolol (log P = 3.56), its interactions with the cell membrane lipids of goat blood have been investigated. It is observed that lipid loss after incubation of blood cells with propranolol hydrochloride in salt glucose medium for varying periods of time was accompanied with significant increases in PUFAs. Amongst the PUFAs studied the omega 3 and omega 6 fatty acids, the two important precursors of eicosenoids, have shown increase in varying amounts. This phenomenon is presumably responsible for the significant cardiovascular activity of this drug.

Dengue haemorrhagic fever (DHF) outbreak in Calcutta--1990

An outbreak of Dengue Haemorrhagic Fever (DHF) occurred in Calcutta between September and December, 1990. Children and young adults were the major victims. Haemorrhagic manifestations and shocks were the main features in most of the hospitalised cases. Five mouse pathogenic agents were isolated from 105 acute cases and all were identified as DEN-3. HI and CF test with 55 paired sera revealed evidence of dengue infection in 33 (60 per cent) and flavivirus group reaction including dengue in 17 (30.9 per cent). It was for the first time, that DEN-3 was considered to be the etiologic agent for DHF in Calcutta.

Correlation of phospholipid loss in goat whole blood with solvochromic properties of antiamebics like emetine, metronidazole and diloxanide furoate

Phospholipid content of whole blood lipid decreases significantly when goat blood is incubated for different length of time with different amebicidal agents (e.g., emetine, metronidazole and diloxanide furoate). The plots of relative per cent phosphate loss against incubation period show biphasic nature and suggest that the rates of phospholipid loss bears some relation with the drug's lipophilicity (log P in 1 octanol/water system). The absolute phospholipid loss seems to be governed by the drug's aquasolubility. Implication of these finding were discussed in terms of their clinical profiles assuming that the loss of phospholipid is due to drug's binding with the phospholipid layer in amebic cyst-coat, being the first step which may trigger a chain of events leading to the onset of drug action.

Effect of lignocaine on blood lipid in relation to partition coefficient and biological activity

To correlate lipophilicity of lignocaine with changes in lipid composition of blood as a result of in vitro incubation with the drug, phosphorus content and fatty acid compositions of blood lipids before and after lignocaine treatment have been compared with those of a standard phospholipid, lecithin, under similar conditions of drug treatment. The change in fatty acid constituents has been correlated with the biological activity (both therapeutic and toxic) of lignocaine.

Effect of isosorbide dinitrate on enzymatically estimated infarction size and on clinical condition of the patients of acute myocardial infarction

With the aim of reducing myocardial infarction size, isosorbide dinitrate (ISDN) was tried in 27 patients of acute myocardial infarction (AMI). There was 11% reduction of infarction size, in the ISDN treated group, in comparison to that of non treated group, though the result was not statistically significant. But, many of the in-hospital complications were significantly less in the treated group. After a critical analysis of the result it was concluded that a statistically insignificant result, as regard reduction of infarction size in AMI, cannot always exclude the utility of a drug therapy in AMI.