Measurement of right ventricular dP/dt. A simultaneous/comparative hemodynamic and Doppler echocardiographic study]

Right ventricular systolic function is difficult to assess by Doppler echocardiography. We studied 14 patients with tricuspid regurgitation on Doppler echocardiographic examination with the object of determining an index of right ventricular contractility based on the continuous Doppler signal of the regurgitant jet. The rate of increase in right ventricular pressure was calculated between 2 points, V1 and V2, situated on the ascending limb of the velocity profile of the tricuspid regurgitation and compared with the dP/dt max measured simultaneously at right heart catheterisation. The different values of V1 and V2 were: 0 and 1 m/s, 0 and 2 m/s, 0.5 and 1.5 m/s, 1 and 2 m/s and 0.5 and 2 m/s. An excellent correlation was observed between the catheter dP/dt max and the rate of increase in pressure measured by Doppler between 0 and 2 m/s (r = 0.93; p = 0.0001) and between 0.5 and 2 m/s (r = 0.93; p = 0.0001). The correlation was not as close between 0 and 1 m/s (r = 0.69; p = 0.048) and there was no correlation with the measurements between 0.5 and 1.5 m/s and between 1 and 2 m/s. Doppler echocardiography could therefore be used for non-invasive assessment of right ventricular systolic function in clinical practice.     

Comparison of individual follow-up and computerized record linkage using the Canadian Mortality Data Base

We compared two methods of ascertaining mortality in a historical prospective mortality study. Computerized Record Linkage (CRL) with the centralized historical Canadian Mortality Data Base (CMDB) was carried out on 2469 men and an attempt was also made to trace the subjects by individual follow-up (IFU). All but 88 were traced and 60 were reported to be dead. CRL was able to locate the deaths of three men who had been untraced by IFU. Contradictory information on vital status was obtained on 5 subjects--in 4 of them, the discrepancy was resolved in favour of CRL. Overall, CRL using the CMDB performed very well. We also consider factors that affect the relative costs of the two methods, which should be balanced against the accuracy of information obtained.     

Nosocomial infections on a rehabilitation unit in an acute care hospital

In a one-year retrospective review, 138 symptomatic infections were identified in 145 admissions to a rehabilitation unit. One hundred twenty-six (91%) infections were either urinary or skin and soft tissue infections. The daily incidence of infection increased with increasing numbers of infections for infected patients. Patient factors associated with infection included male sex, young age, spinal cord injury, admission for management of decubitus ulcers or urinary infection, history of urinary infection, urologic interventions or skin breakdown, and bladder and bowel incontinence. All patients with a history of chronic urinary infection or skin breakdown developed infection. In a logistic regression model, factors that were independently associated with risk of infection in the remaining patients included sex, incontinence, chronic neurologic disease, and prior urologic interventions. This review suggests rehabilitation patients are at high risk of acquiring nosocomial infection. The subgroup of patients with the highest risk of infection are identifiable by specific characteristics.     

Increased Production of Interferon‐γ by Leishmania Homologue of the Mammalian Receptor for Activated C Kinase‐Reactive CD4+ T cells among Human Blood Mononuclear Cells: An Early Marker of Exposure to Leishmania?

A prospective study was undertaken to define early predictive immunological marker(s) of exposure to Leishmania in naïve subjects who have never been exposed to any Leishmania and who were also free of any cutaneous leishmaniasis lesions. These naïve subjects could have been exposed to Leishmania in a rain forest where Leishmania guyanensis and their natural vectors and mammalian host are cocirculating. The production of interferon (IFN)‐γ in response to the Leishmania homologue of the mammalian receptor for activated c kinase (LACK), a candidate for vaccine against leishmaniasis was analysed. At the end of their stay in the rain forest, LACK‐specific CD8⁺ T cells were detected in subjects whose peripheral blood mononuclear cell (PBMC) produced IFN‐γ in response to soluble Leishmania antigens (SLA) and in those whose PBMC remained unresponsive to SLA. However, LACK‐specific CD4⁺ T cells were detected only in PBMCs from individuals who became IFN‐γ responders to SLA. In subjects whose PBMC became positive to SLA, LACK‐reactive CD4⁺ T cells producing high level of IFN‐γ were detectable before the SLA‐reactive IFN‐γ producing CD4⁺ T cells, suggesting that the former readout assay could be used as an early predictive immunological marker of exposure to Leishmania in subjects who remained disease free.     

Virological markers in the cerebrospinal fluid from HIV-1-infected individuals.

We analysed 127 specimens of cerebrospinal fluid (CSF) from 118 HIV-1-infected individuals at different stages of infection. Intrathecal antibody synthesis was evident in 23 samples tested and was more frequently directed against HIV than against rubella virus, herpes simplex virus, varicella zoster virus or cytomegalovirus. HIV was isolated from only 14% of the 127 CSF specimens, but from 82% of CSF-paired blood samples. HIV antigen was detected in 12% of CSF specimens and 44% of paired plasma samples. Twenty specimens analysed using the polymerase chain reaction (PCR) detected proviral DNA in 75% of CSF specimens. The low rate of virus recovery from CSF was caused by neither the freezing of specimens prior to culture nor therapy. In contrast, virus isolation from CSF was significantly associated with CSF cell count. Virus isolation and antigen detection in CSF were not correlated with either the Centers for Disease Control disease stage or the peripheral CD4+ lymphocyte count, whereas viraemia was significantly associated with a low CD4+ lymphocyte count. Moreover, virus isolation and antigen detection in CSF were not associated with symptoms of subacute HIV encephalitis, suggesting that these markers are not of potential value in the diagnosis of HIV-specific neurologic complications. The value of PCR in this field merits further investigation.