Trichinella infection and clinical disease

Trichinellosis is caused by ingestion of insufficiently cooked meat contaminated with infective larvae of <it>Trichinella</it> species. The clinical course is highly variable, ranging from no apparent infection to severe and even fatal disease. We report two illustrative cases of trichinellosis. Returning to Denmark a few days after having eaten roasted pork in the Republic of Serbia, a female patient suffered from severe vomiting, epigastric pain, diarrhoea, and later myalgia, generalized oedema, and prostration. A biopsy showed heavy infestation with <it>Trichinella spiralis</it>, 2000 larvae/g of muscle. Life-threatening cardiopulmonary, renal and central nervous system complications developed. The patient recovered after several months. Her husband, who also ate the pork, did not have clinical symptoms, but an increased eosinophil count and a single larva in a muscle biopsy confirmed infection. The epidemiology, clinical manifestations, diagnosis, treatment and prevention of trichinellosis are reviewed.      

Characterization of basal and re-inflammation-associated long-term alteration in pain responsivity following short-lasting neonatal local inflammatory insult

Recently, several studies have suggested that neonatal noxious insult could alter future responses to painful stimuli. However, the manifestations, mechanisms, and even developmental nature of these alterations remain a matter of controversy. In part, this is due to the lack of detailed information on the neonatal sensitive period(s) during which noxious stimulation influences future nociception, and the time-course and distribution of the resultant abnormalities. The present paper describes these parameters in a rat model of short-lasting (24 h) neonatal local inflammation of a hindpaw produced by injection of 0.25% carrageenan (1 μl/g). Examinations of paw withdrawal responses to thermal and mechanical stimulations in adult animals, which as neonates were subjected to this insult, showed that the previously-reported long-term hypoalgesia and hyperalgesia are not mutually exclusive outcomes of early noxious experience. Long-term hypoalgesia was apparent at the basal conditions and was equally strong in the previously injured and uninjured paws, which suggests a globally-driven deficit. In contrast, long-term excessive hyperalgesia had the strongest manifestation in the neonatally-injured paw after re-inflammation, indicating significant segmental involvement in its generation. The differences between mechanisms underlying the observed hypoalgesia and hyperalgesia are further underscored by the finding that, while the former is detectable only after animals reach the second month of life, the latter is elicitable immediately upon cessation of the initial neonatal inflammation. Nevertheless, we detected a significant overlap in the neonatal sensitive periods for generation of these effects (both occurring within the first postnatal week). Also, neither the basal hypoalgesia nor excessive re-inflammation-associated hyperalgesia subsided with age and were detectable in 120–125-day-old rats. These finding provide a framework within which the entire complex of long-term effects of early noxious experience can be understood and examined.     

Precut papillotomy versus persistence in difficult biliary cannulation: a prospective randomized trial

BACKGROUND AND STUDY AIMS: Failed biliary cannulation occurs in up to 10% of patients undergoing ERCP. There is some controversy as to the safety and efficacy of using precut techniques to achieve biliary cannulation in difficult cases. To date, no randomized trial has compared the success and complication rates of precut with the rates for persistence when biliary cannulation is difficult. The aim of this study was to compare the success rates and complication rates of precut with the success rates and complication rates of persistence in cases of difficult biliary cannulation. PATIENTS AND METHODS: Patients without prior sphincterotomy who required biliary cannulation were screened. A "difficult biliary cannulation" was arbitrarily defined as failed cannulation after 12 minutes. These patients were then randomized to continue treatment by needle-knife cut over the roof of the papilla or by persistence with a non-wire-guided, single-lumen papillotome. "Primary" success was defined as deep cannulation within 15 minutes of randomization. Primary and final success rates and complication rates within 30 days after ERCP were compared. RESULTS: Over a 38-month period a total of 642 patients were screened. Patients in whom biliary cannulation was successful within a time period of 12 minutes or less formed the reference group (n = 580). The remainder of the patients were randomly assigned to the "precut" arm (n = 32) or to the "persistence" arm (n = 30). Primary success rates and complication rates were similar in the precut and persistence arms (75% and 4% respectively for the precut arm vs. 73% and 9% for the persistence arm). The final successful cannulation rate in the entire group of 642 patients was 99.5%. CONCLUSIONS: In experienced hands, precut papillotomy and persistence in cannulation are equally effective in cases of difficult cannulation, with a similar complication rate.     

Mast cells modulate the pathogenesis of elastase-induced abdominal aortic aneurysms in mice

Abdominal aortic aneurysm (AAA), an inflammatory disease, involves leukocyte recruitment, immune responses, inflammatory cytokine production, vascular remodeling, neovascularization, and vascular cell apoptosis, all of which contribute to aortic dilatation. This study demonstrates that mast cells, key participants in human allergic immunity, participate in AAA pathogenesis in mice. Mast cells were found to accumulate in murine AAA lesions. Mast cell-deficient KitW-sh/KitW-sh mice failed to develop AAA elicited by elastase perfusion or periaortic chemical injury. KitW-sh/KitW-sh mice had reduced aortic expansion and internal elastic lamina degradation; decreased numbers of macrophages, CD3+ T lymphocytes, SMCs, apoptotic cells, and CD31+ microvessels; and decreased levels of aortic tissue IL-6 and IFN-gamma. Activation of mast cells in WT mice via C48/80 injection resulted in enhanced AAA growth while mast cell stabilization with disodium cromoglycate diminished AAA formation. Mechanistic studies demonstrated that mast cells participated in angiogenesis, aortic SMC apoptosis, and matrix-degrading protease expression. Reconstitution of KitW-sh/KitW-sh mice with bone marrow-derived mast cells from WT or TNF-alpha-/- mice, but not from IL-6-/- or IFN-gamma-/- mice, caused susceptibility to AAA formation to be regained. These results demonstrate that mast cells participate in AAA pathogenesis in mice by releasing proinflammatory cytokines IL-6 and IFN-gamma, which may induce aortic SMC apoptosis, matrix-degrading protease expression, and vascular wall remodeling, important hallmarks of arterial aneurysms.     

Influenza virus hemagglutinin-specific cytotoxic T cell response induced by polypeptide produced in Escherichia coli

We have tested the abilities of various polypeptides of A/PR/8/34 (H1N1) virus, constructed by recombinant DNA techniques, to induce influenza virus-specific secondary cytotoxic T lymphocyte (CTL) responses. A hybrid protein (c13 protein), consisting of the first 81 amino acids of viral nonstructural protein (NS1) and the HA2 subunit of viral hemagglutinin (HA), induced H-2-restricted, influenza virus subtype-specific secondary CTL in vitro, although other peptides did not. Using a recombinant virus, the viral determinant responsible for recognition was mapped to the HA2 portion of c13 protein. Immunization of mice with c13 protein induced the generation of memory CTL in vivo. The CTL precursor frequencies of A/PR/8/34 virus- and c13 protein-immune mice were estimated as one in 8,047 and 50,312, respectively. These results indicate that c13 protein primed recipient mice, even though the level of precursor frequency was below that observed in virus-immune mice.     

Hemagglutinin-specific cytotoxic T-cell response during influenza infection

Specific cytotoxic thymus-derived (T) lymphocytes were detected in the cervical lymph nodes and spleen during influenza infection of mice. The cytotoxic T cells can distinguish target cells infected with different influenza A subtypes. Infection with parent viruses and their recombinant progeny possessing the hemagglutinin of one parent and the neuraminidase of the other demonstrated that significant cytotoxicity occurred only when the hemagglutinin of the immunizing viruses was the same as that of the virus used to infect the target cell. In addition to this specific cytotoxic response to the major surface antigen, a cross-reactive response could be detected when the relatively nonpermissive L cell was used as the target cell. These results indicate there is a specific cytotoxic T-cell response to the surface hemagglutinin, and a cross-reactive cytotoxic response, not directed to the hemagglutinin, during influenza infection. The cytotoxic T-cell response specific for the hemagglutinin antigen may play an important role in in vivo immunity to influenza.     

Hepatitis B Immunisation in Health Care Workers

Background

Hepatitis B virus (HBV) infection is an important occupational risk in health care workers (HCW). In spite of HBV vaccine availability in Armed Forces, the high prevalence of HBV infection in HCW continues to be a problem. The study was undertaken to study the HBV vaccine-compliance among HCW.

Methods

A cross-sectional study was conducted at a tertiary care hospital. HCW were requested to fill up the pre set questionnaire to assess the HBV vaccination coverage.

Result

Amongst 254 HCW, only 57.7% were vaccinated against HBV. The vaccine compliance was lowest among housekeeping professionals. The mean age at vaccination was high (30.5 years). Amongst the vaccine non-compliant subjects, 34.3% were above 30 years of age. 32.2% HCW completed primary vaccination after spending more than 10 years in the profession. Accessibility of HBV vaccine, knowledge and perception of HBV risk were important factors in vaccine non-compliance.

Conclusion

Due to low and delayed HBV vaccine-compliance, HCW continue to be at the risk of occupational HBV. Health education highlighting occupational risk of HBV, accessibility of vaccine and mandatory vaccination of HCW is recommended to increase HBV vaccine compliance among HCW.Key Words: Health care workers, Hepatitis B virus, Occupational risk, Hepatitis B vaccine