The health of elderly residents in long term care institutions in New Zealand.

AIMS: To estimate the morbidity of residents in long term care institutions in Hamilton, New Zealand and examine the prescribing practice within these institutions. METHODS: One hundred residents were selected at random from the total population of residents in long-term institutions in Hamilton. Residents were examined by a physician to arrive at ICD-9 diagnoses and details were recorded about prescribing practice. RESULTS: Eighty residents were examined. Of these, 73% had dementia. Forty-five per cent were diagnosed as having heart failure and 44% cerebrovascular disease. The most common previously undiagnosed disorder was postural hypotension (24%). Residents were prescribed an average of 4.5 non-psychotropic medications. Seventy-seven per cent of residents were prescribed three or more medications. CONCLUSION: Elderly residents in long term care institutions in Hamilton have complex health care needs which offer particular challenges for doctors and other health care workers. Regular health care reviews could lead to more accurate diagnosis and better prescribing practice.

Neospora caninum: role for immune cytokines in host immunity.

Neospora caninum is a coccidial protozoan parasite that infects a large range of mammals including dogs, cats, mice, and cattle. Morphologically, N. caninum appears indistinguishable from Toxoplasma gondii, although they are genetically distinct. To date there have been no reported cases of this infection in humans, although nonhuman primates may be susceptible to infection. Inbred A/J mice develop no clinical and little histologic evidence of infection in spite of a high-dose inoculum of N. caninum. Splenocytes obtained from infected mice proliferate in vitro in response to both N. caninum and T. gondii-soluble antigen. A transient state of T cell hyporesponsiveness to parasite antigen and mitogen was observed at Day 7 p.i. This downregulatory response could be partially reversed by the addition of the nitric oxide antagonist LNMMA, but not antibody to IL-10. Mice infected with N. caninum produce significant quantities of IL-12 and IFN gamma, most evident shortly after infection. In vivo, antibody to IL-12 is able to neutralize immune resistance to the parasite. Moreover, in vivo depletion of IFN gamma with antibody renders the mice susceptible to infection. These observations suggest that N. caninum induces a T cell immune response in the infected host that is at least partially mediated by IL-12 and IFN gamma.

Induction of gammadelta T cells during acute murine infection with Toxoplasma gondii.

The importance of the host gammadelta T cell response to microbial pathogens is not yet fully understood. We report that inbred mice infected with T. gondii developed a gammadelta T cell proliferative response to parasite Ag. Mice depleted of either the alphabeta or gammadelta TCR were found to be significantly more susceptible to infection than the parent mouse strain. Proliferation of gammadelta T cells was observed in mice deficient in the TCR-alphabeta in response to UV-irradiated parasites. These T cells lyse parasite-infected syngenic macrophages. Adoptive transfer of these gammadelta T cells into beta2 microglobulin-deficient mice that have been depleted of both CD4+ and NK cells prolongs survival against acute parasite challenge when compared with nontransferred controls. The gammadelta T cells isolated from infected alpha -/- mice express a 10-fold increase in mRNA and produce high titers of IFN-gamma. These data suggest that gammadelta T cells may play an important role in the early host response to infection with T. gondii.

Production of nitric oxide (NO) is not essential for protection against acute Toxoplasma gondii infection in IRF-1-/- mice.

Production of nitric oxide (NO) by macrophages is important for the killing of intracellular pathogens. IFN-gamma and LPS stimulate NO production by transcriptional up-regulation of inducible nitric oxide synthetase (iNOS). In the present study we used mice with a targeted disruption of the IFN regulatory factor-1 gene (IRF-1-/-) to investigate the importance of NO in the host immune response against Toxoplasma gondii, a major cause of infection in newborns and those with AIDS. IRF-1-/- mice were more susceptible to acute Toxoplasma infection, and treatment with either exogenous IFN-gamma or in vivo neutralization of endogenous IFN-gamma had little effect on their susceptibility to infection. However, administration of exogenous IL-12 was able to prolong survival even when IFN-gamma was depleted. An in vivo depletion study suggested that the mechanism of this protective response is mediated in part by CD4+ T cells. The administration of IL-12 could not overcome the inhibition of lymphoproliferative response in T. gondii-infected mice and treatment with N-monomethyl-L-arginine (L-NMMA), a nitric oxide synthase (iNOS) antagonist in vitro was unable to reverse the immunosuppression. In response to Toxoplasma infection, splenocytes from IRF-1-/- mice exhibited increased production of IL-10 as well as a 30-fold increase in its message expression. These studies indicate that NO may not be essential for host immunity to the parasite, and moreover that IL-12 appears to induce an IFN-gamma-independent mechanism of protection against this opportunistic pathogen.

Operative balloon dilatation for pulmonary atresia with intact ventricular septum.

In six infants with pulmonary atresia and intact ventricular septum operative balloon dilatation was used to achieve continuity between the right ventricle and the main pulmonary artery as the initial procedure. Two of the six subsequently needed an aortico pulmonary shunt. All six are alive and well.

Severe pulmonary stenosis and duct dependent coarctation in a neonate. An embryological impossibility?

A baby presented in cardiac failure with cyanosis on the first day of life. Investigations demonstrated severe pulmonary valve stenosis and duct-dependent coarctation of the aorta. This combination is impossible to explain using recognised embryological theories.