Indoor air pollution.

This article summarizes the health effects of indoor air pollutants and the modalities available to control them. The pollutants discussed include active and passive exposure to tobacco smoke; combustion products of carbon monoxide; nitrogen dioxide; products of biofuels, including wood and coal; biologic agents leading to immune responses, such as house dust mites, cockroaches, fungi, animal dander, and urine; biologic agents associated with infection such as Legionella and tuberculosis; formaldehyde; and volatile organic compounds. An approach to assessing building-related illness and "tight building" syndrome is presented. Finally, the article reviews recent data on hospital-related asthma and exposures to potential respiratory hazards such as antineoplastic agents, anesthetic gases, and ethylene oxide.     

Initial therapy of bacterial meningitis with cefuroxime: Experience in 167 children

The morbidity and mortality of patients with bacterial meningitis treated initially with cefuroxime were studied and compared with the results of a previous prospective study of patients treated initially with ampicillin plus chloramphenicol in the same institution from 1979 to 1983. A retrospective chart review was completed in all cases of microbiologically confirmed bacterial meningitis admitted to the Hospital for Sick Children in Toronto, Ontario between January 1, 1984 and August 1, 1988. During this period all patients were treated initially with intravenous cefuroxime. The 167 children reviewed ranged in age from six weeks to 17.1 years (median 11.6 months). The case fatality rate was 7.8% and the rate of hearing deficit 13%. There were no statistically significant differences in abnormal neurological outcome (20 versus 20%, respectively), hearing loss (12.9 versus 13%, respectively), and case fatality rate (6.4 versus 7.8%, respectively) between the cohort of 1979-83 and the present study. The rate of hearing loss following meningitis caused by Haemophilus influenzae type b increased from 7.3 to 11.7% (P=0.26).     

Hypothalamic knife-cut hyperphagia and obesity in weanling rats

In previous reports weanling female rats fed a high-fat diet had a delayed response to hypothalamic knife cuts. In the present report similar cuts in similar rats fed a standard low fat diet became overweight without delay, suggesting that dietary fat is a critical variable in juvenile onset obesity. Adult rats given knife-cuts comparable to those in the weanlings gained weight far more rapidly and achieved higher weights than did those cut as weanlings, suggesting that appetite modulating axons can develop after weaning. Finally, group vs single housing did not influence the age of onset or the magnitude of knife-cut obesity.     

HLA-A,B,C and DR antigen frequencies in acquired immunodeficiency syndrome (AIDS) patients with opportunistic infections

During the past three years, an epidemic of acquired immunodeficiency syndromes (AIDS) involving the presence of specific forms of cancer (notably Kaposi's sarcoma) and infection (e.g., pneumocystis carinii) ordinarily seen only in severely immunosuppressed hosts has occurred among active homosexuals, Haitian immigrants, drug users, and hemophiliacs in large cities in the United States and elsewhere. An as yet unidentified viral agent is presumably the cause of the initial immunodeficiency and host genetic factors may influence the subsequent development of different clinical symptoms in different patients. We have previously reported that the HLA antigens DR5 and DR2 are associated with susceptibility to Kaposi's sarcoma (KS) in different Caucasian subpopulations. We now have also noted that AIDS patients with opportunistic infections have a normal frequency of DR2 and DR5 and a significantly increased frequency of DR3 and that the ultimate clinical expression of AIDS in patients with unexplained lymphadenopathy may depend upon genetic factors associated with these particular DR types.     

Diversity of domain V of 23S rRNA gene sequence in different Enterococcus species

The highly conserved central loop of domain V of 23S RNA (nucleotides 2042 to 2628; Escherichia coli numbering) is implicated in peptidyltransferase activity and represents one of the target sites for macrolide, lincosamide, and streptogramin B antibiotics. DNA encoding domain V (590 bp) of several species of Enterococcus was amplified by PCR. Twenty enterococcal isolates were tested, including Enterococcus faecium (six isolates), Enterococcus faecalis, Enterococcus avium, Enterococcus durans, Enterococcus gallinarum, Enterococcus casseliflavus (two isolates of each), and Enterococcus raffinosus, Enterococcus mundtii, Enterococcus malodoratus, and Enterococcus hirae (one isolate of each). For all isolates, species identification by biochemical testing was corroborated by 16S rRNA gene sequencing. The sequence of domain V of the 23S rRNA gene from E. faecium and E. faecalis differed from those of all other enterococci. The domain V sequences of E. durans and E. hirae were identical. This was also true for E. gallinarum and E. casseliflavus. E. avium differed from E. casseliflavus by 23 bases, from E. durans by 16 bases, and from E. malodoratus by 2 bases. E. avium differed from E. raffinosus by one base. Despite the fact that domain V is considered to be highly conserved, substantial differences were identified between several enterococcal species.     

Molecular cloning and nucleotide sequence of the pestivirus bovine viral diarrhea virus

The RNA genome of the cytopathic NADL isolate of bovine viral diarrhea virus (BVDV) has been molecularly cloned and the nucleotide sequence determined. The cloned sequence was 12,573 nucleotides in length, corresponding to a molecular weight of 4.3 X 10(6), having a base composition of 32.2% A, 25.7% G, 22.1% U, and 20.0% C. However, the sequences at the 5' and 3' termini of the RNA have not been unequivocally established. A single major open reading frame extending the length of the molecule was found in the viral-sense (positive polarity) sequence. This open reading frame was capable of encoding 3988 amino acids, representing 449 kDa of protein.     

C1-esterase inhibitor blocks T lymphocyte proliferation and cytotoxic T lymphocyte generation in vitro

We have previously shown that activated C1s complement and activated T cells cleave beta2-microglobulin (beta2m) in vitro leading to the formation of desLys58 beta2m. This process can specifically be inhibited by C1-esterase inhibitor (C1-inh). Furthermore we showed that exogenously added desLys58 beta2m in nanomolar amounts to a one-way allogenic mixed lymphocyte culture (MLC) increased the endogenous production of IL-2 and the generation of allo-specific cytotoxic T lymphocytes. C1-inh was purified from fresh human plasma and added to human or murine MLC and mitogen-stimulated lymphocyte cultures grown in the presence of complement-inactivated serum. Read-outs were cell proliferation, lymphokine production and development of T cell-mediated cytotoxicity. We found that addition of C1-inh to MLC and mitogen- exposed murine and human lymphocyte cultures inhibited proliferation, the development of allospecific cytotoxic activity, and changed the endogenous production of IL-2, IL-4, IL-10, IL-12 and IFN-gamma. These data clearly demonstrate a regulatory function of C1-inh on T cell- mediated immune functions.