Different ploidy levels of megakaryocytes generated from peripheral or cord blood CD34+ cells are correlated with different levels of platelet release

Ploidy could be the key to understanding megakaryocyte (MK) biologyand platelet production. Human CD34⁺ cells purified fromumbilical cord blood (CB) and peripheral blood (PB) were investigatedon their capability to give rise, in a serum-free medium containingthrombopoietin, to MKs and platelets. CB-MKs showed reducedpolyploidization and platelet number compared with PB-MKs, but asimilar membrane phenotype. Most CB-MKs showed a 2N content of DNA(~80%) and only 2.6% had 8N, whereas 40% of the PB cells had 8N ormore. Platelets were substantially released in PB culture from day 12;at day 14 the CB-derived MKs were able to release platelets although ata reduced level (~35%), correlating with their reduced size. Adirect correlation was demonstrated by sorting polyploid cells fromPB-MKs and evaluating the platelets released in the supernatant.Furthermore, the study analyzed the expression and distribution ofcyclin D3 and cyclin B1. Cyclin D3 protein was increased in PB incomparison to CB-MKs; in PB culture most cells rapidly became positive,whereas in CB-derived cells cyclin D3 expression was evident only fromday 9 and in a reduced percentage. Cyclin B1 was essentially localizedat the nuclear level in the CB and was expressed during the wholeculture. In PB-MKs, at day 9, a reduction was observed, correlatingwith an advanced ploidy state. The data indicate the inability of the CB-MKs to progress in the endomitotic process and a direct correlation between DNA content and platelet production.     

Arenavirus antibody in rodents indigenous to coastal southern California

The purpose of this study was to extend our knowledge on the geographic and natural rodent host ranges of New World arenaviruses in California. Sera from 1,094 sigmodontine and 112 murine rodents were tested for antibody against Whitewater Arroyo and Amapari viruses. Antibody was found in 55 (4.6%) of the 1,206 rodents: 4 from northwestern San Diego County, 3 from Los Angeles County, and 48 from Orange County. The antibody-positive rodents included 8 (7.8%) of 103 Neotoma fuscipes, 1 (0.6%) of 180 Neotoma lepida, 1 (3.1%) of 32 Peromyscus boylii, 8 (11.0%) of 73 Peromyscus californicus, 1 (1.2%) of 85 Peromyscus eremicus, 30 (8.5%) of 353 Peromyscus maniculatus, and 6 (2.2%) of 268 Reithrodontomys megalotis. This study provides the first evidence that New World arenaviruses occur in Los Angeles and Orange counties and northwestern San Diego County, and the first evidence that Peromyscus and Reithrodontomys species are naturally infected with New World arenaviruses.     

Minimal inhibitory concentrations and time-kill determination of moxifloxacin against aerobic and anaerobic isolates

Moxifloxacin is a new oral 8-methoxy-quinolone with a wide spectrum of activity against Gram-negative and anaerobic bacteria, atypical micro-organisms and multi-resistant Gram-positive bacteria. This study was designed to assess the in vitro activity of moxifloxacin against Gram-positive bacteria with different resistance patterns, anaerobes and atypical micro-organisms such as Chlamydia and Mycoplasma. Moxifloxacin had good activity against Streptococcus pneumoniae with all strains inhibited by < or =0.12 mg/l. The minimal inhibitory concentrations (MICs) of moxifloxacin for Streptococcus pyogenes and Streptococcus agalactiae ranged from 0.03 to 0.5 mg/l while those of ciprofloxacin were about two- to four-fold higher (MICs=0.12-1 mg/l). Moxifloxacin was poorly active against enterococci but its activity against Clostridium and Bacteroides spp. was in the same range as that of metronidazole and superior to that of clindamycin. Moxifloxacin was substantially more active than both ciprofloxacin and sparfloxacin against Chlamydia.     

Antibacterial activity of moxifloxacin against periodontal anaerobic pathogens involved in systemic infections

A meta-analysis was performed on five studies conducted over the last decade to demonstrate a positive effect for the drug Uro-Vaxom® compared with Placebo in double-blind studies in patients with urinary tract infection (601 women), with special reference to the prevention of recurrences over an observation period of 6 months, the treatment being given for the first 3 months. The five studies were similar in design. The analysis by means of the Wilcoxon–Mann–Whitney test showed superiority of Uro-Vaxom in all five studies, (P<1%). The summarising Mann–Whitney (MW) statistics also indicated superiority with the Mann–Whitney value being 0.684. In all studies, the Uro-Vaxom group was statistically significant and clinically relevant superior to control with respect to the reduction of the frequency of UTIs and to dysuria, bacteriuria and leucocyturia. The confidence intervals (CI)s were small (0.64–0.72). The drug was well tolerated and compliance of patients was excellent in all studies. Oral immunotherapy with the Uro-Vaxom Escherichia coli (E. coli) extract is an effective prophylactic approach in the prevention of UTIs.     

Incidence and risk factors for the occurrence of non-AIDS-defining cancers among human immunodeficiency virus-infected individuals

BACKGROUND: The objective of this study was to determine the rates and predictors of non-AIDS-defining cancers (NADCs) among a cohort of human immunodeficiency virus (HIV)-infected individuals. METHODS: The authors conducted a retrospective study of 4144 HIV-infected individuals who had 26,916 person-years of follow-up and who had open access to medical care at 1 of the United States military HIV clinics during the years 1988-2003. Cancer incidence rates were race specific and were adjusted for age; these were compared with national rates using logistic regression to assess predictors of NADC development. RESULTS: One hundred thirty-three NADCs were diagnosed with a rate of 980 diagnoses per 100,000 person-years. The most frequent NADCs were skin carcinomas (basal cell and squamous cell), Hodgkin disease, and anal carcinoma. The results showed that there were higher rates of melanoma, basal and squamous cell skin carcinomas, anal carcinoma, prostate carcinoma, and Hodgkin disease among the HIV-infected cohort compared with age-adjusted rates for the general United States population. Predictors of NADCs included age older than 40 years (odds ratio [OR], 12.2; P < 0.001), Caucasian/non-Hispanic race (OR, 2.1; P < 0.001), longer duration of HIV infection (OR, 1.2; P < 0.001), and a history of opportunistic infection (OR, 2.5; P < 0.001). The use of highly active antiretroviral therapy (HAART) was associated with lower rates of NADCs (OR, 0.21; P < 0.001). A low CD4 nadir or CD4 count at diagnosis (< 200 cells/mL) was not predictive of NADCs. CONCLUSIONS: The most frequent NADCs were primary skin malignancies. Melanoma, basal and squamous cell skin carcinomas, anal carcinoma, prostate carcinoma, and Hodgkin disease occurred at higher rates among HIV-infected individuals. The implementation of screening programs for these malignancies should be considered. Most risk factors for the development of NADCs are nonmodifiable; however, the use of HAART appeared to be beneficial in protecting against the development of malignant disease.     

Q fever vaccine uptake in South Australian meat processors prior to the introduction of the National Q Fever Management Program

Despite the availability of a vaccine, the incidence of Q fever disease among populations at risk continues to be high. Q fever is an important cause of morbidity for workers, particularly in the meat and agricultural industries. Following an increase in 1998 in the number of Q fever notifications among meat processors to the Communicable Disease Control Branch, South Australia, a survey was conducted in the same year to assess the uptake of Q fever immunisation programs in meat processors and to identify barriers to offering these programs. This survey was conducted prior to the introduction of the National Q Fever Management Program in 2001 that provided a targeted vaccination program to specific at-risk occupations. The results of the survey highlighted that very few meat processors in South Australia offered a Q fever immunisation program to their workers. More importantly, this article highlights that there was a wide variety of attitudes and beliefs about Q fever disease and its prevention. These attitudes and beliefs have the potential to impact on whether workers at risk are offered or seek Q fever vaccination. Previous attitudes may return and levels of protection in at-risk occupations will decrease without a concerted effort at a state level. A replication of this study should benchmark the prevailing attitudes about Q fever programs. In response to the 1998 survey a number of strategies and initiatives were developed to address the barriers to Q fever vaccination in South Australian meat processors. The National Q Fever Management Program (2001-2005) further enhanced the ability to address barriers such as vaccine cost.     

Neonate with coxsackie B1 infection, cardiomyopathy and arrhythmias

A neonate with Coxsackie B1 infection who experienced significant congestive heart failure, cardiomyopathy and arrhythmia is reported. Viral myocarditis, an important cause of acquired heart disease in neonates, should be considered in the differential diagnosis of neonatal congestive heart failure and cardiomyopathy. A review of the literature is presented.