Expression of interferon-γ and tumor necrosis factor-α in bone marrow T cells and their levels in bone marrow plasma in patients with aplastic anemia

Immune-mediated stem cell damage has been postulated to be responsible for disease initiation and progression in aplastic anemia (AA). It is hypothesized that T lymphocytes play a major role in destroying the bone marrow (BM) stem cells of AA patients by infiltrating the BM and secreting excessive levels of anti-hematopoietic cytokines, interferon-gamma (IFN-), and tumor necrosis factor-alpha (TNF-). We undertook this study to assess the pathogenic significance of anti-hematopoietic cytokines such as IFN- and TNF- in BM T cells and plasma of AA patients. Significantly elevated levels of IFN- and TNF- were found in the BM plasma of AA patients compared to controls (p=0.05 and 0.006, respectively). Intracellular IFN- and not TNF- in BM CD3⁺ T cells of AA patients was significantly higher compared to controls (p=0.04 and p=0.2, respectively). A follow-up analysis of expression of these cytokines in BM T cells and their levels in BM plasma in five AA patients before and 180 days (6 months) after antithymocyte globulin (ATG) and cyclosporin A (CsA) therapy showed a decline 180 days after therapy compared to pre-therapy. We thus conclude that increased production of both IFN- and TNF- in the BM may contribute to disease pathogenesis in AA and ATG therapy may induce hematological remission by suppressing the elevated levels of IFN- and TNF- in AA BM.     

Endocytosis is required for exocytosis and priming of respiratory burst activity in human neutrophils

Objective and design

Neutrophil generation of reactive oxygen species (ROS) is enhanced by exposure to pro-inflammatory agents in a process termed priming. Priming is depending on exocytosis of neutrophil granules and p47^phox phosphorylation-dependent translocation of cytosolic NADPH oxidase components. Clathrin-mediated endocytosis was recently reported to be necessary for priming, but the mechanism linking endocytosis to priming was not identified. The present study examined the hypothesis that endocytosis regulates neutrophil priming by controlling granule exocytosis.

Materials and methods

Clathrin-mediated endocytosis by isolated human neutrophils was inhibited by chlorpromazine, monodansylcadaverine, and sucrose. Exocytosis of granule subsets was measured as release of granule components by ELISA or chemiluminescence. ROS generation was measured as extracellular release of superoxide as reduction of ferrocytochrome c. p38 MAPK activation and p47^phox phosphorylation were measured by immunoblot analysis. Statistical analysis was performed using a one-way ANOVA with the Tukey–Kramer multiple-comparison test.

Results

Inhibition of endocytosis prevented priming of superoxide release by TNFα and inhibited TNFα stimulation and priming of exocytosis of all four granule subsets. Inhibition of endocytosis did not reduce TNFα-stimulated p38 MAPK activation or p47^phox phosphorylation. Inhibition of NADPH oxidase activity blocked TNFα stimulation of secretory vesicle and gelatinase granule exocytosis.

Conclusions

Endocytosis is linked to priming of respiratory burst activity through ROS-mediated control of granule exocytosis.

     

Strategic planning and designing of a hospital disaster manual in a tertiary care,teaching, research and referral institute in India

BACKGROUND:

As per the “Disaster Management Act, 2005” of India, it is mandatory for government hospitals in India to prepare a disaster plan. This study aimed to prepare a disaster manual of a 1 900 bed tertiary care hospital, in consultation and involvement of all concerned stakeholders.

METHODS:

A committee of members from hospital administration, clinical, diagnostic and supportive departments worked on an initial document prepared according to the Act and gave their inputs to frame a final disaster manual.

RESULTS:

The prepared departmental standard operating procedures involved 116 people (doctors and paramedical staff), and were then synchronized, in 12 committee meetings, to produce the final hospital disaster manual.

CONCLUSIONS:

The present disaster manual is one of the few comprehensive plans prepared by the stakeholders of a government hospital in India, who themselves form a part of the disaster response team. It also helped in co-ordinated conduction of mock drills.KEYWORDS: Disaster Management Act, Disaster manual, Hospital administration, Stakeholders, Mock drills     

Paradoxical structural effects in the unilaterally denervated spontaneously hypertensive rat kidney

OBJECTIVE: To determine the effects of chronic denervation on renal vascular structure and function in young adult spontaneously hypertensive rats (SHRs). DESIGN: Unilateral renal denervation (SHRUDx) or sham-operation (SHRS) was performed in SHRs at 6 weeks of age. At 10 weeks, rats were allocated to one of three procedures designed to examine renal vascular structure and function. A further group underwent bilateral renal denervation. METHODS: In SHRUDx or SHRS groups, either the kidneys were perfusion-fixed for stereological estimates of artery wall and lumen dimensions or for vascular casting to determine arteriole lumen diameters, or the rats were anaesthetized for estimation of glomerular capillary pressure. RESULTS: Chronic unilateral renal denervation had no significant effect on the development of hypertension between 6 and 10 weeks of age, as previously reported, but resulted in luminal narrowing of the interlobular artery (denervated group 52 +/- 2 mum, sham-operated group 64 +/- 1 mum; P < 0.01 for interaction between strain and treatment), without alterations in interlobular or arcuate artery wall dimensions. There were no significant effects on either afferent or efferent arteriole lumen diameters. Estimated glomerular capillary pressure was significantly lower in the denervated kidneys of SHRUDx (47 +/- 1 mmHg) compared with kidneys of the SHRS (50 +/- 1 mmHg; P < 0.04). Mean arterial pressure was approximately 12 mmHg lower in the bilaterally denervated SHRs than in the sham-operated SHRs. CONCLUSIONS: Although bilateral denervation attenuated the development of hypertension in SHRs, unilateral denervation did not, indicating that one neurally intact kidney was sufficient to drive the normal development of SHR hypertension, but only with apparent prohypertensive compensatory changes in the denervated kidney.     

Incidence,Predictors, and Prognostic Value of Acute Kidney Injury Among Patients Undergoing Left Atrial Appendage Closure

Objectives

The aims of this registry were to determine the incidence, predictors, and prognostic value of periprocedural acute kidney injury (AKI) after left atrial appendage closure (LAAC).

Prophylactic antibiotics for simple hand lacerations: Time for a clinical trial?

BackgroundSimple hand lacerations (not involving bones, tendons, nerves, or vessels) are a common emergency department (ED) complaint. Whilst the practices of irrigation, debridement, foreign body removal, and suture repair are well accepted, the use of prophylactic antibiotics is not. Without evidenced-based guidelines, practice is left to physician preference.ObjectivesThe aim of this study was to assess the need for, and the feasibility to perform, a randomised controlled trial to evaluate the role of prophylactic antibiotics in simple hand lacerations.MethodsThe study was done in three phases: (1) estimation of the national ED burden of simple hand lacerations and the use of antibiotic prophylaxis; (2) assessment of indications for antibiotic prophylaxis and (3) investigation of patient willingness to enrol in a randomised controlled trial and their preferred outcomes from simple hand lacerations. For Phase 1, we analysed the 2007 National Hospital Ambulatory Medical Care Survey. For Phase 2, we surveyed ED physicians in three urban teaching institutions (two in Brooklyn, NY and one in Washington, DC). For Phase 3, we surveyed ED patients at the same three institutions.ResultsPhase 1: out of 116.8 million ED visits nationally in 2007, 1.8 million (1.6%) were due to simple hand lacerations, of which 1.3 million (71%) required repair. Of those repaired, 27% (95% CI, 19–35%) were prescribed prophylactic antibiotics, most commonly cephalexin (73%). Phase 2: out of 108 providers surveyed, 69 (64%) responded. 16% (95% CI, 9–27%) reported prescribing prophylactic antibiotics routinely, most commonly cephalexin (84%, 95% CI, 67–93%). The degree of contamination was the most important factor (91%, 95% CI, 82–96%) in the physicians’ decision to prescribe antibiotics. Phase 3: of the 490 patients surveyed, 64% (95% CI, 60–68%) expressed interest in participating in a study to evaluate the use of prophylactic antibiotics. Their primary concern was prevention of infection (77%, 95% CI, 73–81%).ConclusionSimple hand lacerations represent a substantial number of ED visits in the United States. Absence of clear guidelines, disparity in physician practice, and patient interest in infection prevention all support performing a prospective randomised controlled trial to establish the role of antibiotic prophylaxis in simple hand lacerations.