Pyridine Nucleotide-Linked Lactate Dehydrogenase of Tetrahymena: Evidence for D- and L-Enzymes in the Mitochondria.

An NAD-linked lactate dehydrogenase (LDH) in a crude mitochondrial fraction obtained from Tetrahymena homogenates was previously reported by this laboratory. This fraction contains the NADH and succinate oxidase system as well as the mitochondrial cytochromes and carries out oxidative phosphorylation. The preparation catalyzes the oxidation of D- and L-lactate linked only to certain analogs of NAD; it has not been possible to demonstrate NAD-dependent D- or L-lactate oxidation nor is there any evidence that either of these enzymes is a flavoprotein as indicated by their inability to reduce directly certain artificial electron acceptors.

Dynamic cardiomyoplasty: expectations and results.

Background: Cardiac transplantation is an option for only a small minority of patients with severe, chronic congestive heart failure. Transformed skeletal muscle has the potential to provide a durable form of fatigue-resistant muscle power to assist the cardiovascular system.

Methods: Since the first dynamic cardiomyoplasty performed by Carpentier and colleagues in 1985, the techniques to make this operative procedure an effective assist to the failed myocardium have been refined.

Vestibular dysfunction in a child with embryonic exposure to accutane.

Children with a history of embryonic exposure to Accutane (isotretinoin) are at great risk for major physical malformations, brain malformations, and decreased intelligence. A case is presented of a 4-year 7-month-old black male with a history of embryonic exposure to Accutane who was born with embryopathy that includes bilateral major ear deformities. The child has a significant bilateral conductive hearing loss, and, in addition, a left sided sensorineural loss.

Major long-term complications in 1,422 permanent venous access devices.

A retrospective review was undertaken of 1,422 permanent venous access devices (PVADs) implanted from 1989 to 1991 at Hahnemann University Hospital. This included 730 single-lumen Hickman catheters, 368 double-lumen Hickman catheters, 307 single-lumen Portacath infusion ports, and 17 double-lumen Portacath infusion ports. Indications for placement were as follows: antibiotics in 28%; chemotherapy in 51%; hyperalimentation in 4%; intravenous fluids in 4%; hemodialysis in 3%; and undocumented indications in 10%.

Intrinsic resistance to the lethal effects of x-irradiation in insect and arachnid cells.

Twelve cell lines representing 10 genera of three orders (Diptera, Lepidoptera, and Orthoptera) of the class Insecta and one cell line (Acarina) from the class Arachnida were examined to discern their sensitivity to the lethal effects of x-irradiation. Radiosensitivity was measured by a combination of colony formation and population growth curve techniques. Each of these arthropod cell lines is significantly more radioresistant than mammalian cells, though the degree of resistance varies greatly with order.

Immunohistochemical localization of murine stage-specific embryonic antigens in human testicular germ cell tumors.

Monoclonal antibodies raised against and/or recognizing stage-specific antigens on preimplantation mouse embryos and stem cells of murine teratocarcinoma were used to localize these antigens immunohistochemically on human testicular germ cell tumors. SSEA-1, the antigen found on mouse embryonal carcinoma (EC) cells and embryonic cells from the 8-cell stage embryo onward, including the fetal primordial germ cells, was detected on yolk sac carcinoma components of human tumors, but not on EC cells. SSEA-3, the antigen found on follicular ova, fertilized eggs, early cleavage stage embryonic cells, and visceral endodermal cells of the mouse embryo, but not on mouse EC cells, was detected on human EC cells.

The vestibular complex in a prosimian primate (Galago senegalensis): morphology and spinovestibular connections.

The morphology of, and distribution of spinal afferents to, the vestibular complex of a prosimian primate (lesser bushbaby, Galago senegalensis) were studied using cytoarchitectural, myeloarchitectural and selective silver impregnation methods. The vestibular complex of Galago consists of superior (SVN), lateral (LVN), medial (MVN) and spinal (SpVN) nuclei, each nucleus having cell populations of characteristic size, shape and distribution within its borders. There is morphological and experimental evidence for the existence of subgroups f, 1, x, y and z and a hitherto undescribed subgroup located in dorsomedial portions of the rostral two-thirds of the MVN.

Effect of exogenous fatty acids on growth, membrane fluidity, and phospholipid fatty acid composition in yeast.

The growth response of a double-mutant fatty acid auxotroph of yeast Saccharomyces cerevisiae to exogenous saturated fatty acids of a homologous series from 12:0 to 16:0, each supplied with oleate, linoleate, linolenate, or cis-delta 11-eicosenoate, cannot be explained in terms of the efficiency of incorporation of the fatty acids into phospholipids or alteration of membrane fluidity. There is, however, a negative correlation between growth and levels of 12:0 plus 13:0 in phospholipids, as well as a positive correlation between growth and levels of 14:0, 15:0, and 16:0. We, therefore, conclude that the predominant factor in these phospholipid fatty acyl chain modifications is maintenance of an optimal concentration of C14:0 through C16:0 in phospholipids of this organism.

Serial pH changes in the duodenal bulb during smoking.

The effect of smoking on the pH of the duodenal bulb was studied in 10 normosecretors and 10 hypersecretors using a Beckman pH electrode. The pH was monitored during three study periods, basal, smoking, and postsmoking, of 1 hr each. The pH remained below 3.

Acculturation and psychopathology among Puerto Rican women in mainland United States.

This study explores relationships between the stress of acculturation and the existence of psychopathology among 72 Puerto Rican women in mainland United States. Significant correlations were found between level of acculturation and education and both personality adjustment and psychopathology. Implications for Puerto Rican family structure are discussed, and suggestions for further research are offered.

Anatomical comparison between acupuncture and nerve block.

Although there are numerous acupuncture points, it is our purpose to point out the similarity in the location of some of these and the location of anatomic sites commonly used for local and regional anesthesia. We believe that acupuncture can be used in conjunction with local anesthesia, nerve-block, or alone, in the control of pain arising from pathologic states.

Triglyceride sub-classes of various dog adipose tissue sites.

Lipids were extracted from four dog adipose tissue sites, perirenal, pericardial, inguinal subcutaneous, and mesenteric. The triglycerides were purified by thin-layer chromatography and the sub-classes separated by silver nitrate-silica gel plates. Gas chromatography was used to delineate the fatty acid composition of each subclass.

Factors Affecting the Survival of Auxotrophs and Prototrophs of Saccharomyces cerevisiae in Mixed Populations.

Moat, Albert G. (Hahnemann Medical College, Philadelphia, Pa.), Isabel J.