Virulent influenza A viruses induce apoptosis in chickens

Virulent avian influenza A viruses produce lethal disease in chickens. Since cell death can be caused by either necrosis or apoptosis, we investigated the types of cell death that occur in natural hosts, chickens, infected with virulent avian viruses. Using biochemical methods, we demonstrate that virulent avian influenza viruses induce apoptosis of vascular endothelial cells in liver, kidney, and brain. Viral antigens were also detected in these organs, suggesting that viral replication induces apoptosis in infected chickens. These results indicate that apoptosis does occur in virulent avian influenza virus infection in a natural host, and may contribute to the lethality of the virus.     

Long-term survival after radical resection of advanced pancreatic cancer

A 65-yr-old man who underwent pancreaticoduodenectomy with portal vein resection for pancreatic cancer is alive 8 yr after surgery. Originally, computed tomography (CT) revealed an 8-cm tumor in the pancreatic head. The tumor had infiltrated the portal vein, but grew expansively, so there was neither biliary obstruction nor jaundice. Pancreaticoduodenectomy with resection of the portal vein was performed for pancreatic cancer. Many tumor-infiltrating lymphocytes were seen within cancer cell nests on routine histopathology. We performed immunostaining for CD8, and found that a large number of the lymphocytes were CD8⁺ T cells. The patient’s prognosis was considered poor because the tumor was large and had infiltrated the portal vein. We suspect that long-term survival may be related to the response of CD8⁺ T cells to the cancer.     

Failure of inactivated influenza A vaccine to protect healthy children aged 6−24 months

BACKGROUND: The efficacy of inactivated influenza vaccine in healthy infants and children younger than 24 months has not been confirmed. The aim of the present study was to determine the prophylactic effect of inactivated influenza vaccine against influenza A in healthy children aged 6-24 months. METHODS: Healthy infants and young children (6-24 months old) were immunized by subcutaneous injection of inactivated influenza vaccine before influenza seasons. Age matched children were randomly assigned as the control. These children were followed up from January to April in each year (2000, 2001 and 2002). The attack rates of influenza A infection was compared and statistically assessed. RESULTS: The attack rate of influenza A virus infection in the vaccine group and the control group were 14.8% (n = 27) vs 12.5% (n = 32) in 2000 (P = 0.526); 2.8% (n = 72) vs 7.2% (n = 69) in 2001 (P = 0.203); and 3.4% (n = 52) vs 8.9% (n = 56) in 2002 (P = 0.205). The attack rates of influenza A between the two groups were not significantly different. CONCLUSIONS: Inactivated influenza vaccine did not reduce the attack rate of influenza A infection in 6-24 month old children.     

Larvicidal action of ethanolic extracts from fruit endocarps of Melia azedarach and Azadirachta indica against the dengue mosquito Aedes aegypti

Ethanolic extracts from the kernels of ripe fruits from the Indian Lilac Melia azedarach and from the well-known Neem tree, Azadirachta indica were assayed against larvae of Aedes aegypti, the mosquito vector of dengue fever. The lethality bioassays were carried out according to the recommendations of the World Health Organization. Extracts were tested at doses ranging from 0.0033 to 0.05 g% in an aqueous medium for 24 and 48 h, at 25 or 30 °C, with or without feeding of the larvae. LC₅₀, LC₉₅ and LC₉₉ were determined. Both seed extracts proved lethal for third to fourth instar larvae. Non-fed A. aegypti larvae were more susceptible to Azadirachta extracts at both temperatures. Under a more realistic environmental situation, namely with fed larvae at 25 °C, the death rates caused by the Melia extract were higher, although at 30 °C the extract of Azadirachta had an even higher lethality. Inter allia, the LC₅₀ values for the crude extracts of these two members of the Meliaceae ranged from 0.017 to 0.034 g% while the LC₉₉ values ranged from 0.133 to 0.189 g%. Since no downstream processing was undertaken to purify the active agents in the extracts, our findings seem very promising, suggesting that it may be possible to increase the larvicidal activity further by improving the extraction and the fractionation of the crude limonoids, for instance removing the co-extracted natural fats.     

HIV-1 Tat enhances Kaposi sarcoma-associated herpesvirus (KSHV) infectivity

The high frequency of Kaposi sarcoma (KS) in immunodeficiency states, particularly in patients with AIDS, has been attributed to increased replication of KS-associated herpesvirus (KSHV), a necessary cofactor for KS development. However, experimental KSHV infection of endothelial lineage cells that compose KS lesions has been difficult even in the absence of immune cells. Here we show that HIV-1 Tat protein can directly promote KSHV transmission. Full-length HIV-1 Tat and a 13-amino-acid peptide corresponding to the basic region of Tat specifically enhances the entry of KSHV into endothelial and other cells, presenting evidence for an active role of HIV-1 in the development of KSHV-associated diseases. These results can explain why AIDS-KS is more frequent and clinically more aggressive than KS in other immunodeficiency states.     

Antimicrobial susceptibility of common pathogens isolated from postoperative intra-abdominal infections in Japan

The principle of empirical therapy for patients with intra-abdominal infections (IAI) should include antibiotics with activity against Enterobacteriaceae and Bacteroides fragilis group species. Coverage of Pseudomonas aeruginosa, Enterobacter cloacae, and Enterococcus faecalis is also recommended for hospital-associated IAI. A nationwide survey was conducted to investigate the antimicrobial susceptibility of pathogens isolated from postoperative IAI. All 504 isolates were collected at 26 institutions and referred to a central laboratory for susceptibility testing. Lower susceptibility rates to ciprofloxacin and cefepime were demonstrated in Escherichia coli. Among E. coli, 24.1% of strains produced extended-spectrum β-lactamase (ESBL). Carbapenems, piperacillin/tazobactam, cephamycins/oxacephem, aminoglycosides, and tigecycline had high activity against E. coli, including ESBL-producing isolates. Among E. cloacae, low susceptibility rates to ceftazidime were demonstrated, whereas cefepime retained its activity. P. aeruginosa revealed high susceptibility rates to all antimicrobials tested except for imipenem. Among B. fragilis group species, low levels of susceptibility were observed for cefoxitin, moxifloxacin, and clindamycin, and high susceptibility rates were observed for piperacillin/tazobactam, meropenem, and metronidazole. Ampicillin, piperacillin, and glycopeptides had good activity against E. faecalis. Imipenem had the highest activity against E. faecalis among carbapenems. In conclusion, we suggested the empirical use of antimicrobials with the specific intent of covering the main organisms isolated from postoperative IAI. Piperacillin/tazobactam, meropenem, or doripenem, are appropriate in critically ill patients. Combination therapy of cefepime (aztreonam in patients with β-lactam allergy) plus metronidazole plus glycopeptides, imipenem/cilastatin or cephamycins/oxacephem plus ciprofloxacin plus metronidazole are potential therapeutic options.     

CT evaluation of paraaortic lymph node metastasis in patients with biliary cancer

Background The extent of paraaortic lymph node (PAN) metastasis parellels that of distant metastases in patients with biliary carcinoma. Accurate preoperative assessment of PAN metastasis has a crucial impact on surgical indications. In this retrospective study, we evaluated whether computed tomography (CT) scans were useful for diagnosing PAN metastases and excluding patients with PAN metastases from an indication for surgery.Methods Between March 1999 and November 2003, 57 patients with biliary carcinoma underwent radical lymphadenectomy or surgical biopsy of PANs. Nine of these patients were diagnosed as having PAN metastasis microscopically. All patients had undergone abdominal CT scans before surgery. To diagnose PAN metastases, we used the following diagnostic criteria. (1) Size; when lymph nodes were greater than 12 mm, 10 mm, 8 mm, or 6 mm in longo or short-axis diameter, the nodes were considered metastatic. (2) Shape and size; when the axial ratio of a lymph node was greater than 0.5, 0.7, 1.0, and the maximum diameter of the long or short axis was greater than 12 mm, 10 mm, 8 mm, or 6 mm, the node was considered metastatic. (3) Internal structure; if the internal structure of a PAN was heterogeneous, the node was considered metastatic. A positive predictive value was calculated for each included criterion when patients numbered ten or more.Results Positive predictive values using the above criteria ranged from 13% to 36%. Only one patient had PANs with heterogeneous internal structures.Conclusions We were unable to determine surgical indications based on the morphological criteria revealed by a CT scan.     

Transesophageal cross-sectional echocardiography

A transesophageal cardiac imaging system is described. This system employs hand-held mechanical sector and linear scanners each having a flexible tube and a small ultrasonic transducer contained within a small oil bag easily swallowed by adults. In the sector scanner, a small transducer in the esophagus rotates alternately and horizontal heart images are displayed. In the linear scanner, a small transducer in the esophagus moves up and down and vertical heart images are displayed. The system was evaluated in 31 adult subjects. In all subjects, stable high quality heart images were observed continuously from base to apex as the transducer was being withdrawn or advanced in the esophagus. In horizontal scans, entire heart images were observed at the level of the atrioventricular valves. In vertical scans, the bifurcation of the pulmonary artery could be observed clearly. There was little difference in the image quality among subjects.