Biomedical publications in the selected CARICOM countries

Objective: To compare biomedical research productivity among selected CARICOM countries. Design and Methodology: Biomedical publications of the selected CARICOM countries (Bahamas, Barbados, Dominica, Guyana, Grenada, Haiti, Jamaica, Suriname, and Trinidad & Tobago) were retrieved using 'PubMed' and 'ScImago Journal & country Rank' (SJR) databases. The publications for each country were then normalized by factors such as total population, gross domestic product (GDP) and Internet usage rate. Results: Total number of papers published by all 9 countries was 7,281 and 8,378 in PubMed (1990- 2015) and SJR databases (1996-2017) respectively. Jamaica produced highest number of biomedical publications [PubMed: 3,928 (54%) and SJR: 2,850 (34%)]. However, when adjusted, Grenada had the highest research publications per million populations, per billion GDP and per 1,000 Internet users in both databases. For trend analysis, PubMed showed that Jamaica produced highest number of additional publications each year ­ on an average 4.8 followed by Trinidad & Tobago (4.4). According to SJR, Jamaica had also highest number of citations (42,311) and H-index (76) followed by Trinidad & Tobago (29,152 and 71). Barbados had the highest number of citations per document (24.9) followed by Haiti (18.4). Conclusion: There was a marked imbalance noted among the CARICOM countries in terms of biomedical research and publications. A CARICOM-wide research may be embarked to explore disparities in biomedical research productivity and thus formulate informed health policies to alleviate diseases and eradicate poverty.

Expressed microRNA associated with high rate of egg production in chicken ovarian follicles.

MicroRNA (miRNA) is a highly conserved class of small noncoding RNA about 19-24 nucleotides in length that function in a specific manner to post-transcriptionally regulate gene expression in organisms. Tissue miRNA expression studies have discovered a myriad of functions for miRNAs in various aspects, but a role for miRNAs in chicken ovarian tissue at 300 days of age has not hitherto been reported. In this study, we performed the first miRNA analysis of ovarian tissues in chickens with low and high rates of egg production using high-throughput sequencing. By comparing low rate of egg production chickens with high rate of egg production chickens, 17 significantly differentially expressed miRNAs were found (P < 0.05), including 11 known and six novel miRNAs. We found that all 11 known miRNAs were involved mainly in pathways of reproduction regulation, such as steroid hormone biosynthesis and dopaminergic synapse. Additionally, expression profiling of six randomly selected differentially regulated miRNAs were validated by quantitative real-time polymerase chain reaction (RT-qPCR). Some miRNAs, such as gga-miR-34b, gga-miR-34c and gga-miR-216b, were reported to regulate processes such as proliferation, cell cycle, apoptosis and metastasis and were expressed differentially in ovaries of chickens with high rates of egg production, suggesting that these miRNAs have an important role in ovary development and reproductive management of chicken. Furthermore, we uncovered that a significantly up-regulated miRNA-gga-miR-200a-3p-is ubiquitous in reproduction-regulation-related pathways. This miRNA may play a special central role in the reproductive management of chicken, and needs to be further studied for confirmation.

Breed-specific transcriptome response of spleen from six to eight week old piglet after infection with Streptococcus suis type 2.

Different pig breeds have shown differential susceptibility to the pathogen infection; however, molecular mechanisms of the infection susceptibility are not fully understood. Streptococcus suis type 2 (SS2) is an important zoonotic pathogen. To identify the genes responsible for infection susceptibility, pigs from two different breeds (Enshi black and Landrace) were inoculated with SS2 and their spleen transcriptome profiles were investigated in the present study. The differentially expressed genes (DEGs) were analyzed from infected versus control pigs in each breed, and then compared between both pig breeds. Enshi black pig showed more DEGs than Landrace (830 vs. 611) and most of these were due to down-regulated genes (543 vs. 387). However some DEGs were uniquely expressed in one breed, some were expressed in opposite direction in both breeds. A number of candidate genes and pathways are identified which might be involved in susceptibility to SS2, for example, MMP9 and Resistin were only significantly expressed in Landrace. NPG3 and PMAP23 were up-regulated in Landrace whereas down-regulated in Enshi black. LENG8 in control Landrace have inherently higher expression than control Enshi black. IGKV6 is down-regulated in Landrace but up-regulated in Enshi black. Overall, the transcriptome profiles are consistent with the clinical signs, i.e. the Enshi black is more susceptible to SS2 infection than Landrace. This is the first study to identify differential gene expression between indigenous and modern commercial pigs after in vivo SS2 infection using RNA-seq. The significant DEGs in splenic profiles between two pig breeds suggested considerable involvement of genetic background in susceptibility to the SS2 infection in pigs.

Tumour targeted delivery of encapsulated dextran-doxorubicin conjugate using chitosan nanoparticles as carrier.

Doxorubicin (DXR) commonly used in cancer therapy produces undesirable side effects such as cardiotoxicity. To minimize these, attempts have been made to couple the drug with dextran (DEX) and then to encapsulate this drug conjugate in hydrogel nanoparticles. By encapsulation of the drug conjugate in biodegradable, biocompatible long circulating hydrogel nanoparticles, we further improved the therapeutic efficacy of the conjugate. The size of these nanoparticles as determined by quasi-elastic light scattering, was found to be 100+/-10 nm diameter, which favors the enhanced permeability and retention effect (EPR) as observed in most solid tumors. The antitumor effect of these DEX-DXR nanoparticles, was evaluated in J774A.1 macrophage tumor cells implanted in Balb/c mice. The in vivo efficacy of these nanoparticles as antitumor drug carriers, was determined by tumor regression and increased survival time as compared to drug conjugate and free drug. These results suggest that encapsulation of the conjugate in nanoparticles not only reduces the side effects, but also improves its therapeutic efficacy in the treatment of solid tumors.

Biodistribution of fluoresceinated dextran using novel nanoparticles evading reticuloendothelial system.

The rapid clearance of circulating nanoparticles from the blood stream coupled with their high uptake by liver and spleen has thus far been overcome by reducing the particle size, and by making the particle surface hydrophilic with poloxamers and poloxamines. We have prepared hydrogel nanoparticles of polyvinylpyrrolidone of a size less than 100 nm diameter with precise size distribution. Since the inner cores of these particles are also hydrophilic, these particles are capable of encapsulating water-soluble compounds. Biodistribution of these particles shows practically negligible (<1%) uptake by the macrophages in liver and spleen, and approximately 5-10% of these particles remain in circulation even 8 h after i.v. injection. Increasing the surface hydrophobicity as well as particle size can increase the RES uptake of these particles. Because of longer residence in blood, the hydrogel nanoparticles have potential therapeutic applications particularly in cancer: the water-soluble cytotoxic agents encapsulated in these particles can be targeted to tumors while minimizing the likelihood of toxicity to reticuloendothelial system (RES).

Academic performance of various categories of students admitted to Lady Hardinge Medical College, New Delhi.

A retrospective study of 4 consecutive academic batches of students was conducted to analyse the performance level of students in 3 university examinations of MBBS. The students were divided into 3 categories based on the criteria of entrance into the medical college. The category I included students who entered through a tough pre-medical test, category II comprised those nominated by government and defence personnel and category III included the Schedule Caste and Schedule Tribe students. The results of the category I was remarkably better than that of II while that of category III was dismal. The last two categories had a large number of students leaving the college without completing their course resulting in 5.4% wastage of precious medical seats and psychological distress. Necessary remedial measures must be planned at the earliest.

Mastoid canals in adult human skulls.

Mastoid canals (tunnels) were observed in 41 (7.7%) of 265 dry human skulls. The canals were 2-27 mm long. This feature has not been reported before. dissection of 30 mastoid regions in cadavers showed that the canals contained a branch of the occipital artery and a vein. It is possible that during development of the mastoid process the squamous temporal bone ossifies over the vessels, giving rise to the canals.

Submandibular gland with multiple ducts.

A morphological peculiarity was observed in the form of a submandibular gland having three ducts. These ducts opened separately into the oral cavity. Only the upper and the largest of these three ducts was in the usual position and had the expected relation to the lingual nerve. Such a condition is to be kept in mind by a surgeon or a radiologist performing sialography. Unless each of the duct in instilled he may miss pathological findings.

Sequential renal functions in leprosy.

Sequential renal functions have been studied in eight patients of lepromatous leprosy during and after subsidence of erythema nodosum leprosum. The renal functions which were impaired during reaction were observed to improve during quiescent phase unless there were associated complications like amyloidosis. The possible mechanisms for altered renal functions during reactive phase of the disease have been discussed.

Sequential renal functions in leprosy

Sequential renal functions have been studied in eight patients of lepromatous leprosy during and after subsidence of erythema nodosum leprosum. The renal functions which were impaired during reaction were observed to improve during quiescent phase unless there were associated complications like amyloidosis. The possible mechanisms for altered renal functions during reactive phase of the disease have been discussed.

Renal functional status in lepromatous leprosy.

Renal functional status was evaluated in 122 patients with lepromatous leprosy. Renal functions were found to be markedly impaired in patients with erythema nodosum leprosum (ENL) in the active or quiescent phases. Although uncomplicated lepromatous leprosy patients did show significant renal impairment as compared to healthy controls, the degree of impairment was less than that of the reactive cases. Diminished endogenous creatinine clearance and proteinuria were the common abnormalities detected. Serum creatinine was significantly increased only in reactive cases. Blood urea was found to be marginally increased in a few patients although not to a statistically significant degree. Renal involvement did not bear any relation to the duration of illness or to the Bacteriological Index.