Transitional premonocytes emerge in the periphery for host defense against bacterial infections

Circulating Ly6C^hi monocytes often undergo cellular death upon exhaustion of their antibacterial effector functions, which limits their capacity for subsequent macrophage differentiation. This shrouds the understanding on how the host replaces the tissue-resident macrophage niche effectively during bacterial invasion to avert infection morbidity. Here, we show that proliferating transitional premonocytes (TpMos), an immediate precursor of mature Ly6C^hi monocytes (MatMos), were mobilized into the periphery in response to acute bacterial infection and sepsis. TpMos were less susceptible to apoptosis and served as the main source of macrophage replenishment when MatMos were vulnerable toward bacteria-induced cellular death. Furthermore, TpMo and its derived macrophages contributed to host defense by balancing the proinflammatory cytokine response of MatMos. Consequently, adoptive transfer of TpMos improved the survival outcome of lethal sepsis. Our findings hence highlight a protective role for TpMos during bacterial infections and their contribution toward monocyte-derived macrophage heterogeneity in distinct disease outcomes.

Combinatorial Single-Cell Analyses of Granulocyte-Monocyte Progenitor Heterogeneity Reveals an Early Uni-potent Neutrophil Progenitor

Granulocyte-monocyte progenitors (GMPs) have been previously defined for their potential to generate various myeloid progenies such as neutrophils and monocytes. Although studies have proposed lineage heterogeneity within GMPs, it is unclear if committed progenitors already exist among these progenitors and how they may behave differently during inflammation. By combining single-cell transcriptomic and proteomic analyses, we identified the early committed progenitor within the GMPs responsible for the strict production of neutrophils, which we designate as proNeu1. Our dissection of the GMP hierarchy led us to further identify a previously unknown intermediate proNeu2 population. Similar populations could be detected in human samples. proNeu1s, but not proNeu2s, selectively expanded during the early phase of sepsis at the expense of monocytes. Collectively, our findings help shape the neutrophil maturation trajectory roadmap and challenge the current definition of GMPs.

A preliminary study on efficacy of rupatadine for the treatment of acute dengue infection

Currently there are no specific treatments available for acute dengue infection. We considered that rupatadine, a platelet-activating factor receptor inhibitor, might modulate dengue-associated vascular leak. The effects of rupatadine were assessed in vitro, and in a dengue model, which showed that rupatadine significantly reduced endothelial permeability by dengue sera in vitro, and significantly inhibited the increased haematocrit in dengue-infected mice with dose-dependency. We conducted a randomised, placebo-controlled trial in 183 adult patients in Sri Lanka with acute dengue, which showed that rupatadine up to 40 mg daily appeared safe and well-tolerated with similar proportions of adverse events with rupatadine and placebo. Although the primary end-point of a significant reduction in fluid leakage (development of pleural effusions or ascites) was not met, post-hoc analyses revealed small but significant differences in several parameters on individual illness days - higher platelet counts and lower aspartate-aminotransferase levels on day 7 in the rupatadine group compared to the placebo group, and smaller effusions on day 8 in the subgroup of patients with pleural effusions. However, due to the small sample size and range of recruitment time, the potential beneficial effects of rupatadine require further evaluation in large studies focused on recruitment during the early febrile phase.

Nutritional status of leprosy patients in India

Across-sectional epidemiological study was carried out at a Leprosy Referral Hospital in Delhi to assess the nutritional status of multibacillary leprosy patients in comparison to the general population using BMI. 150 people affected with multibacillary leprosy were included in the study, of whom 108 (72%) had WHO Grade 2 disability. 100 non leprosy patients were also included as a control group. Socio-demographic and clinical details as well as their height and weight were measured and the BMI computed. The findings clearly showed that under-nutrition (BMI < 18.5) was more common in people affected by leprosy than in those without leprosy, regardless of age or sex. Presence of disability made the incidence of under-nutrition more likely. The duration of disease, number of lesions or bacterial index had no impact on the level of nutrition. There may be multiple factors working together to lead to this under-nutrition and these are discussed briefly. If, we aim to provide high quality services with a holistic approach, a mandatory BMI should be calculated for every patient and if under nourished, a qualitative diet summary should be done and suitable nutritional advice given. Further, studies are needed for a better understanding of the occurrence and progression of under-nutrition in leprosy to find efficient ways to combat this problem.

Effects of environment and education on knowledge and attitude of nursing students towards leprosy

The objective of this cross-sectional comparative study was to find the effects of environment and education on knowledge and attitude of nursing students towards leprosy. Data were collected, using a pretested questionnaire, from the first year and third year students of a School of Nursing attached to a leprosy specialty hospital and also from a comparable School of Nursing attached to a general hospital. The results showed that trainees acquired more knowledge on leprosy during training in both schools of nursing. However, those trained in leprosy hospital environment had higher knowledge and attitude scores than those trained in general hospital environment. The attitude of the trainees attached to leprosy hospital was favourable even before they had formal training in leprosy. Those trained in the general hospital showed more favourable attitude after training compared to before training. School of Nursing attached to leprosy hospital provided an atmosphere conducive to learning and understanding more about leprosy. The trainees retained what was learnt because of regular association with patients affected by leprosy. For employment in hospital or community based services or research related to leprosy, nurses trained in a leprosy hospital would have added value of knowledge and attitude.

Awareness and attitudes towards leprosy in urban slums of Kolkata, India

Urban slums have proliferated in India with poor health and socio-economic status with no organized health system. They are at high risk for contracting communicable diseases including leprosy. In order to obtain reliable data on knowledge, attitudes and treatment of leprosy; a random sample cluster survey was done in Kolkata slums. House to house screening for leprosy was done in 6 representative random samples of slums, each with a population of at least 5000, using accepted methods for detection. Suspects were confirmed by medical officers. Intensive interviews were done by qualified male and female investigators. A majority had some knowledge of leprosy but hardly any knew early signs or symptoms or where to get proper diagnosis and treatment. Half the respondents felt leprosy must be treated separately from general patients but stated they had no hesitation in working with or visiting a leprosy patient. There were 11 suspects of which 9 were confirmed for leprosy and sent to nearest centre for MDT. Glaring gaps are noticed between knowledge and practice of slum population regarding leprosy. An integrated health program is needed urgently in urban slums to control leprosy and other diseases using a variety of resources including medical colleges.

A study of steroid-induced diabetes mellitus in leprosy

Steroids, while still the most powerful drugs to manage leprosy reactions, predispose some patients to other morbidities such as diabetes, glaucoma, hypertension etc. A prospective cohort study was done in Kolkata, India among leprosy patients in reaction to determine the extent of steroid induced diabetes mellitus (SID). All leprosy patients with type 1 or type 2 reactions or neuritis admitted in 2006 to the Leprosy Mission Hospital in Kolkata, who had no past or current history and whose blood sugars on fasting were <126 mg/dl or postprandial <200 mg/dl were monitored fortnightly while on steroid therapy, estimating blood glucose by a glucometer using standard strips. Of 81 patients, 19 (23.5%) manifested steroid-induced diabetes mellitus. Compared to those who didn't, there were significantly more LL/BL patients with positive BI among SID whose cumulative prednisolone dosage was nearly 9000 mg as compared to half the amount among others. Steroid induced diabetes is a serious complication among leprosy patients treated with prednisolone for reactions requiring careful monitoring for detection and appropriate clinical management.

The antiapoptotic protein Mcl-1 is essential for the survival of neutrophils but not macrophages

The antiapoptotic protein Mcl-1, a member of the Bcl-2 family, plays critical roles in promoting the survival of lymphocytes and hematopoietic stem cells. Although previous studies have implicated Mcl-1 in regulating the survival of neutrophils and macrophages, the in vivo function of Mcl-1 in these 2 cell lineages remained unclear. To address this, we have generated mice conditionally lacking Mcl-1 expression in neutrophils and macrophages. We show that Mcl-1 conditional knockout mice had a severe defect in neutrophil survival, whereas macrophage survival was normal. The granulocyte compartment in the blood, spleen, and bone marrow of Mcl-1 conditional knockout mice exhibited an approximately 2- to 3-fold higher apoptotic rate than control cells. In contrast, resting and activated macrophages from Mcl-1-deficient mice exhibited normal survival and contained up-regulated expression of Bcl-2 and Bcl-xL. These data suggest that Mcl-1 plays a nonredundant role in promoting the survival of neutrophils but not macrophages.

Leprosy among adolescents in Kolkata, India

Leprosy, manifesting during adolescence when significant physical and emotional changes are taking place, poses further stress and strain both on the individual and on the family. Based on hospital records, focus group discussions and in-depth interviews, data on 258 adolescent leprosy patients seen at a leprosy referral hospital in Kolkata, India, are presented. The male-female sex ratio was 1.93:1, 56.6% were multibacillary patients and 13.2% had grade 2 disability. At the time of final follow up, 10% of PB and 33% of MB patients had already discontinued treatment. The commonest complication was reaction (14.5%). Adolescents were still dependent on their parents for health matters. Data obtained from questionnaires confirmed the role of social stigma in hiding, delay in starting of MDT and defaulting. Frequent hospital admissions resulted in loss of jobs and disruption of studies and caused psychological disturbances. It is critical to identify and treat adolescent leprosy on a priority basis. Health education and counselling programmes must be more focused and acceptable. Further research is necessary.

Incidence of neuritis among paucibacillary leprosy patients during treatment and surveillance

A cohort study was done on 180 patients receiving the standard WHO PB-MDT regimen at the TLM Hospital in Kolkata, during MDT and 2 years of surveillance to determine the incidence of neuritis. Neuritis occurred in only 2 out of the 180 patients, confirming that the current WHO treatment for PB-MDT is attendant with minimal risk of neuritis. No risk factors were found, except pregnancy in a female patient. While addition of clofazimine in the new U-MDT under trial might take care of the occasional neuritis, further clinical research might be useful to identify sub-groups of PB patients at risk of neuritis.

The localization of thrombospondin-1 (TSP-1), cysteine-serine-valine-threonine-cysteine-glycine (CSVTCG) TSP receptor, and matrix metalloproteinase-9 (MMP-9) in colorectal cancer

Thrombospondin-1 (TSP-1) is a 450 kDa matrix bound glycoprotein involved in tumor invasion, metastasis, and angiogenesis. One of the receptors involved in TSP-1 mediated tumor cell adhesion and metastasis is the cysteine-serine-valine-threonine-cysteine-glycine (CSVTCG) receptor. One mechanism of TSP-1 in promoting tumor cell metastasis involves the up-regulation of matrix metalloproteinase-9 (MMP-9) expression, specifically through the CSVTCG TSP-1 receptor. TSP-1 and its CSVTCG receptor has been implicated in tumor progression in a variety of cancers including breast adenocarcinomas, head and neck squamous cell carcinomas, and pancreatic carcinomas. In this study, we examined 99 cases of colorectal cancer by immunohistochemical analysis to investigate 1) the localization of TSP-1 and CSVTCG TSP-1 receptor, 2) the relationship with MMP-9, and 3) the correlation of expression with clinical staging. Strong expression of TSP-1 was observed in the submucosa or the serosa adjacent to the tumor. Positive staining for CSVTCG TSP-1 receptor was observed in tumor cells and microvessels. MMP-9 was also expressed in tumor cells. In addition, staining intensity of CSVTCG TSP-1 receptor was higher in poorly differentiated adenocarcinoma than well or moderately differentiated adenocarcinoma. Tumors in which inflammatory cells stained strongly for CSVTCG TSP-1 receptor correlated with decreased incidence of distant metastasis and angiogenesis. These data were consistent with our previous studies for breast, pancreatic, and head and neck carcinoma. They suggest an important role for TSP-1 and CSVTCG TSP-1 receptor in tumor progression in colorectal cancer.

Nonocclusive mesenteric infarction in hemodialysis patients

BACKGROUND

Dialysis patients develop nonocclusive mesenteric ischemia (NOMI) at an increased rate. Previous studies have associated atherosclerosis and hemodialysis-induced hypotension as inciting factors for NOMI development. A retrospective review of 29 of 1,370 longterm hemodialysis patients who developed NOMI from January 1992 to December 1997 was performed. The NOMI patients were compared with a similar profile of hemodialysis patients to identify risk factors for the development of NOMI and for outcomes assessment.

STUDY DESIGN

All NOMI patients had hypotensive episodes during hemodialysis the week before the development of abdominal symptoms, and additional risk factors of hypertension (83%), diabetes (55%), and atherosclerosis (38%). The majority of patients (83%) experienced abdominal pain more than 24 hours before admission. Sixty-six percent of patients had leukocytosis on admission laboratory data.

RESULTS

Sixteen patients (55%) had ischemia of the small bowel, all underwent laparotomy, and nine (56%) died. Thirteen patients (45%) had ischemia of the colon and were managed nonoperatively; four (31%) of them died. Overall mortality rate for NOMI was 45%.

CONCLUSIONS

NOMI occurs at an increased rate in hemodialysis patients. Identification of patients at high risk for NOMI and dose monitoring of filtration rates may impact on the high mortality of this disease.