Jewish Hospital

About: Jewish Hospital is a healthcare organization based out in Cincinnati, Ohio, United States. It is known for research contribution in the topics: Antigen & Population. The organization has 3881 authors who have published 3414 publications receiving 123044 citations.

Lactic Acid Translocation: Terminal Step in Glycolysis by Streptococcus faecalis

Abstract: Streptococcus faecalis obtains metabolic energy chiefly from the conversion of glucose to lactic acid; the present experiments deal with the mechanism of lactic acid translocation across the cytoplasmic membrane. Efflux of [14C]lactate from preloaded cells was accelerated by raising the external pH, and also by the ionophores nigericin and valinomycin. These results suggest that lactate leaves the cell by an electroneutral process, presumably as lactic acid. Further evidence was obtained by studying the entry of [14C]lactate into nonmetabolizing cells. It appears that the membrane is essentially impermeable to the lactate anion, but allows passage of lactic acid. The most persuasive evidence is that, upon establishment of a pH gradient such that the cytoplasm was alkaline, l-[14C]lactate accumulated in the cells against the concentration gradient. Accumulation was transient, and dissipated in parallel with the collapse of the pH gradient. The concentration gradient attained at the peak was a function of the pH difference. Ionophores which are known to collapse a pH gradient, such as nigericin and valinomycin, abolished accumulation of l-lactate. We infer that lactic acid translocation, whether into the cells or outward, is an electroneutral process and for that reason the distribution of lactic acid across the membrane is a function of the pH of cytoplasm and medium. The specificity of translocation and its kinetic parameters suggest that it is mediated by a carrier of low specificity.

Acinar cell carcinoma of the pancreas.

Abstract: Acinar cell carcinoma of the pancreas is a rare tumor for which the best chemotherapy regimen has not been clearly established. Here, we report on a female patient with an unusually long survival and a remarkable response to weekly paclitaxel. To our knowledge, this is the first time that paclitaxel has been associated with an objective response in this disease. The patient recurred after initial resection and failed multiple prior chemotherapeutic regimens. She received weekly paclitaxel at 80 mg/m2 and responded after eight doses, maintaining controlled disease for a total of 4 mo. We present her case in detail and review the available literature regarding this rare type of tumor.