Anti-human proacrosin antibody inhibits the zona pellucida (ZP)-induced acrosome reaction of ZP-bound spermatozoa.

The anti-acrosin monoclonal antibody AcrC5F10 inhibited proacrosin activation, proacrosin-human zona pellucida glycoprotein A (ZPA) binding, and the zona pellucida (ZP)-induced acrosome reaction of the ZP-bound spermatozoa but had no significant effect on sperm-ZP binding. These results suggest that proacrosin-acrosin may play an important role in the ZP-induced acrosome reaction of spermatozoa after primary binding to the ZP.

Biotin deficiency complicating parenteral alimentation: diagnosis, metabolic repercussions, and treatment.

Biotin deficiency associated with total parenteral nutrition is an emerging clinical problem; criteria for diagnosis and dosage for treatment are unclear. We have diagnosed and successfully treated biotin deficiency in three patients. Each patient had alopecia totalis, hypotonia, and developmental delay. Two developed the characteristic scaly periorificial dermatitis; one had only an intermittent scaly rash on the cheeks and occipital scalp. Zinc and essential fatty acid supplements were adequate; serum zinc levels and triene/tetraene ratios confirmed sufficiency of these nutrients. None of the patients received biotin prior to diagnosis, and each had decreased excretion of urinary biotin and increased urinary excretion of organic acids diagnostic of deficiency of two biotin-dependent enzymes (methylcrotonyl-coenzyme A carboxylase and priopionyl-coenzyme A carboxylase). Only one patient had a plasma biotin concentration below the normal range (Ochromonicas danica assay). The rash, alopecia, and neurologic findings responded dramatically to biotin therapy (100 micrograms/day in all patients; an initial larger dose of 1 mg/day for 1 week plus 10 mg/day for 7 weeks in one patient), and did not recur. However, abnormal organic acid excretion persisted in one patient who did not receive the larger dose. We conclude that plasma biotin concentration does not reflect biotin status in all cases and speculate that the biotin supplement currently recommended for pediatric patients (20 micrograms/day) may not be adequate therapy for biotin deficiency and might not even be adequate to maintain normal biotin status during TPN.

Biotin-responsive in vivo carboxylase deficiency in two siblings with secretory diarrhea receiving total parenteral nutrition.

Two siblings with a congenital syndrome of secretory diarrhea and seizures developed progressive skin rash, alopecia, and mucocutaneous candidiasis while receiving biotin-free total parenteral nutrition. Abnormally low urinary biotin excretion was associated with these clinical findings, but the serum concentration of biotin was within the normal range. There was also increased urinary excretion of lactic acid, 3-hydroxyisovaleric acid, 3-hydroxypropionic acid, and 3-methylcrotonylglycine. The younger of the two children subsequently died with severe metabolic acidosis. In the oder sibling, intravenous treatment with biotin (200 micrograms/day) resulted in resolution of the organic aciduria. A larger dose (10 mg/day) appeared to be required for rapid improvement in the skin lesions. These cases suggest that clinically significant biotin deficiency can occur in patients with chronic diarrhea receiving biotin-free total parenteral nutrition.

A preliminary study of circulating vitamins in a Puerto Rican migrant farm population in New Jersey.

A preliminary survey of circulating vitamin B12 biotin, folate, thiamin, riboflavin, vitamin B6, pantothenate, nicotinate, and vitamin A & B-carotene of 53 Puerto Rican migrant farm workers was undertaken. Results indicate that hypovitaminemia existed particularly for vitamin B12, vitamin B6 and vitamin A.