Spontaneous human mononuclear cell cytotoxicity to cultured tumor cells: reproducibility of serial measurements with the use of a chromium-51-release microcytotoxicity assay.

Twenty-three healthy human adults with naturally occurring (spontaneous) mononuclear cell cytotoxicity (MCC) to cultured human tumor cells were evaluated in a serial study over 23 months to determine whether their initial MCC levels remained stable. A 3-hour 51Cr-release microcytotoxicity assay, in which the HBT-3 cancer-derived cell line with HeLa markers and the ALAB breast cancer-derived cell line were used, was standardized and its suitability for such serial studies was evaluated. The data showed that the 51Cr-release assay is reproducible and suitable for use in serial studies of MCC. The intrinsic technical error for a single assay averaged 12.5% (2-26%) coefficient of variation. The greatest sources of technical variation with time were the passage level of the target cells and the temperature at which the effector cells were stored and handled. When these technical factors were controlled, naturally occurring MCC was fairly reproducible with time. Of the healthy individuals with initial high or low MCC levels, 61% tended to retain these levels in a stable fashion, but the remaining 39% studied showed fluctuations of MCC greater than 33% coefficient of variation.

Preservation of occlusal vertical dimension in overdentures.

The preextraction record is used to reestablish the occlusal vertical dimension in immediate and in later overdentures. A colored dot on the denture can be used to verify the occlusal vertical dimension after the dentures have been inserted.

Tuberculosis. The primary care physician's role in eradication.

The resurgence of tuberculosis in the United States presents a challenge for primary care physicians. The disease remains concentrated in the growing population of socioeconomically disadvantaged persons, immigrants from areas where drug resistance is common, certain racial groups, persons in extended-care facilities, alcohol and drug abusers, and persons infected with the human immunodeficiency virus. Because people in these groups are much less likely than others to seek regular medical care, it is difficult to identify and treat active tuberculosis in these populations. Contacts of patients with tuberculosis are equally difficult to identify. Active intervention by primary care physicians--including tuberculin screening, prophylactic therapy, treatment of active disease, and follow-up--is needed to help achieve the goal of eradicating tuberculosis.

Use of nifedipine in the hypertensive diseases of pregnancy.

OBJECTIVE: To review the available data about the use of nifedipine to treat hypertension in pregnancy. DATA SOURCES: All English language cases and studies published after 1984 and indexed in MEDLINE, Excerpta Medica, and BIOSIS PREVIEWS under the headings nifedipine, hypertension in pregnancy, uteroplacental blood flow, maternal/fetal hemodynamics, preeclampsia, and pregnancy outcome. MAIN OUTCOME MEASURES: The primary outcome indicators included the safety and antihypertensive efficacy of nifedipine in pregnancy; the effects of nifedipine on maternal/fetal hemodynamics; and the effect, if any, of nifedipine on perinatal outcome. CONCLUSIONS: Tradiational drug therapy choices for hypertension in pregnancy continue to be hydralazine for acute reduction of blood pressure and methyldopa for the management of chronic hypertension. Current data indicate that nifedipine is an appropriate second-line antihypertensive medication in pregnancy, but more clinical trials are needed before it can be considered an appropriate choice for initial therapy. As do other antihypertensive agents, nifedipine provides maternal benefit by lowering blood pressure and reducing the risk of cerebral hemorrhage and end-organ damage. However, perinatal benefit of nifedipine remains to be established.

Bite force discrimination by individuals with complete dentures.

The purpose of this study was to determine whether differences existed in interincisor bite force discrimination between a group of subjects wearing complete dentures and a group of dentate individuals. It was hypothesized that biting force is monitored at least in part by the sensory mechanism within the PDL and that the absence of the PDL would result in reduced bite force discrimination. A specially designed strain gauge scale was constructed for the measurement of bite force. Bite force discrimination was assessed at three different standards including 500, 1000, and 3000 gm. Data analysis revealed that, overall, bite force discrimination was not significantly different for the two groups. However, at the lightest standard of 500 gm, the dentate group performed significantly better (p less than .05) than the denture wearers. It is concluded that the sensory system within the PDL plays a role in monitoring bite force discrimination.