Verapamil reverses the ultrastructural alterations in the plasma membrane induced by drug resistance.

Two P388 cell sublines with different levels of resistance to daunomycin (DNM), P388/20 and P388/100 cells (approximately 20- and 100-fold resistance, respectively), undergo a significant (approximately 2-fold) increase in the number of intramembrane particles (IMPs) present at their plasma membrane, as compared to that exhibited by the parental, drug-sensitive P388 (P388/S) cell line. Regardless of the level of resistance, incubation of drug-resistant cells with verapamil, a well known reverting agent of anthracycline resistance, restores the morphology of the plasma membrane in these cells, yielding a pattern in which the number and size distribution of IMPs at both leaflets of the bilayer, become undistinguishable from those displayed by drug-sensitive cells. Furthermore, verapamil did not affect the ultrastructural organization of the plasma membrane of drug-sensitive cells.

Rapid kinetics of the interaction between daunomycin and drug-sensitive or drug-resistant P388 leukemia cells.

The initial stages of the interaction of daunomycin (DNM) with drug-sensitive (P388/S) and drug-resistant (P388/100) cells have been defined by a rapid kinetics stopped-flow procedure. The process can be described by two kinetic components. The faster component accounts for rapid occupation of cell surface sites by DNM, as supported by experiments with liposomes with different surface charge.

Aneuploidies, chromosome aberrations and dominant gene mutations detected in 113,913 consecutive newborn children in Mexico.

Data on 113,913 liveborn children from a hospital in Guadalajara, Jalisco (Mexico), were analysed for birth defects (BD); mutation rates were calculated for sporadic aneuploidy, chromosome aberrations and dominant gene mutations. The results showed a general incidence of 13.92 BD cases per 1000 liveborns, of which 1.

Achalasia microcephaly syndrome in a patient with consanguineous parents: support for a.m. being a distinct autosomal recessive condition.

A 4 9/12-year-old boy with achalasia microcephaly syndrome (AMS), born to a consanguineous couple, is reported. Comparative analysis of this case and the patients previously described in a Mexican family supports the notion that the syndrome is a distinct autosomal recessive condition. It is interesting that the area of origin and ethnicity of both the present and the previously reported cases is northwest Mexico.

The role of fine needle aspiration biopsy cytology in the evaluation of the clinically solitary thyroid nodule.

The imputation that a clinically solitary nodule is a suspicious sign of carcinoma has been the cause of too many surgical procedures as well as the subject of much controversy. This study evaluated the effectiveness of fine needle aspiration (FNA) biopsy cytology in diagnosing the uninodular goiters in 286 patients who presented with clinically solitary nodules. The final diagnoses in these cases included carcinoma (4.

Discrete systems, cell-cell interactions and color pattern of animals. II. Clonal theory and cellular automata.

The morphogenesis of the color pattern of animals is modeled with cellular automata. The cell-cell near neighbor interactions are taken into account and impose restrictions on the model. The allowed patterns are observed in reptiles, felines and fishes.

Autosomal dominant macroglossia in two unrelated families.

Two unrelated families, one with 15 and the other with 3 members affected with macroglossia as a sole trait, are described. It is concluded that this entity differs from previously reported syndromes presenting macroglossia and is inherited in an autosomal dominant fashion.

Ciliary and superciliary hypotrichosis. A distinct autosomal dominant trait.

A woman and her four children showed congenital sparse eyebrows, short, thin, misplaced and very scanty upper eyelashes and absent lower eyelashes. Erosion of the corneal epithelium was a common complication. This report confirms the condition as an autosomal dominant disorder.

Heart morphological changes in rats placed in a crowded environment.

A group of rats were stressed by placing them in a crowded environment. Examination of the hearts showed the following anatomic changes: (1) increased weight; (2) occlusion of capillaries by platelet thrombi; (3) endothelial swelling of capillaries; and (4) swelling and deformity of mitochondria.

Tracking procedures in follow-up studies of drug abusers.

One of the problems that researchers frequently confront is the tracking and locating of research subjects. "Deviant" populations may present special difficulties in this regard. The experiences of a trained field survey unit doing drug-related research are examined.