Xenopus laevis sperm receptor gp69/64 glycoprotein is a homolog of the mammalian sperm receptor ZP2

Little is known about sperm-binding proteins in the egg envelope of nonmammalian vertebrate species. We report here the molecular cloning and characterization of a recently identified sperm receptor (gp69/64) in the Xenopus laevis egg vitelline envelope. Our data indicate that the gp69 and gp64 glycoproteins are two glycoforms of the receptor and have the same number of N-linked oligosaccharide chains but differ in the extent of O-glycosylation. The amino acid sequence of the receptor is closely related to that of the mouse zona pellucida protein ZP2. Most of the sequence conservation, including a ZP domain, a potential furin cleavage site, and a putative transmembrane domain are located in the C-terminal half of the receptor. Proteolytic cleavage of the gp69/64 protein by a cortical granule protease during fertilization removes 27 amino acid residues from the N terminus of gp69/64 and results in loss of sperm binding to the activated eggs. Similarly, we find that treatment of eggs with type I collagenase removes 31 residues from the N terminus of gp69/64 and has the same effect on sperm binding. The isolated and purified N terminus-truncated receptor protein is inactive as an inhibitor of sperm-egg binding. Earlier studies on the effect of Pronase digestion on receptor activity suggest that this N-terminal peptide may contain an O-linked glycan that is involved in the binding process. Based on these results and the findings on the primary structure of the receptor, a pathway for the maturation and secretion of gp69/64, as well as its inactivation following fertilization, is proposed.     

Trichinosis in sows slaughtered at a Kentucky abattoir

From July 26 to 30, 1976, diaphragmatic pillar samples were collected from 513 sows slaughtered at a federally inspected abattoir in Kentucky. The sows represented 5 marketing areas: Rushville, In (186); Cincinnati, Oh )158); Indianapolis, In (70); Georgetown, Ky (54); and Columbus, Oh (45). Using the pooled-sample digestion technique, 3 dead trichina larvae were identified in 1 sample pooled from 15 diaphragms (10 g each). An attempt to identify the individually infected sow(s) was unsuccessful, but the pooled sample originated from animals marketed at Rushville, In. The prevalence (1 of 513) was 0.194%.     

Translactational induction of CYP4A expression in 10.5-day neonatal rats by the hypolipidemic drug clofibrate

Lactating mothers of 7.5-day neonatal rats were injected intraperitoneally with 500 mg kg-1 clofibrate for 3 consecutive days at 24-hour intervals; 24 hours after the final injection, the maternal cytochrome P450 4A (CYP4A) mRNA levels had risen 14- and 2.5-fold above the constitutive levels of expression seen in the liver and kidney, respectively. Lactational transfer of clofibrate to the suckling 10.5-day litter was demonstrated by the 15- and 5-fold elevation observed in the neonatal hepatic and renal CYP4A mRNAs, respectively, following suckling from drug-induced mothers. A significant decrease in the relative liver weights of these neonatal pups was seen following clofibrate exposure via maternal milk, in total contrast to the normally observed increase in liver/body weight ratios of rats treated with clofibrate. Western blot analysis using a polyclonal goat anti-rat CYP4A1 antibody also demonstrated a rise in the CYP4A protein levels in both the mothers and their litters following maternal clofibrate treatment.     

Serial coronary angiographic evidence that antioxidant vitamin intake reduces progression of coronary artery atherosclerosis

OBJECTIVE: To explore the association of supplementary and dietary vitamin E and C intake with the progression of coronary artery disease. DESIGN: A subgroup analysis of the on-trial antioxidant vitamin intake database acquired in the Cholesterol Lowering Atherosclerosis Study, a randomized, placebo-controlled, serial angiographic clinical trial evaluating the risk and benefit of colestipol-niacin on coronary artery disease progression. SETTING: Community- and university-based cardiac catheterization laboratories. SUBJECTS: A total of 156 men aged 40 to 59 years with previous coronary artery bypass graft surgery. INTERVENTION: Supplementary and dietary vitamin E and C intake (nonrandomized) in association with cholesterol-lowering diet and either colestipol-niacin or placebo (randomized). OUTCOME: Change per subject in the percentage of vessel diameter obstructed because of stenosis (%S) determined by quantitative coronary angiography after 2 years of randomized therapy on all lesions, mild/moderate lesions (< 50%S), and severe lesions (> or = 50%S). RESULTS: Overall, subjects with supplementary vitamin E intake of 100 IU per day or greater demonstrated less coronary artery lesion progression than did subjects with supplementary vitamin E intake less than 100 IU per day for all lesions (P = .04) and for mild/moderate lesions (P = .01). Within the drug group, benefit of supplementary vitamin E intake was found for all lesions (P = .02) and mild/moderate lesions (P = .01). Within the placebo group, benefit of supplementary vitamin E intake was not found. No benefit was found for use of supplementary vitamin C exclusively or in conjunction with supplementary vitamin E, use of multivitamins, or increased dietary intake of vitamin E or vitamin C. CONCLUSIONS: These results indicate an association between supplementary vitamin E intake and angiographically demonstrated reduction in coronary artery lesion progression. Verification from carefully designed, randomized, serial arterial imaging end point trials is needed.     

Morphologic changes in arterial grafts in rabbit ears

The morphology of auto- and allografted segments of rabbit central ear arteries was studied at various times after grafting. Autografts showed thrombosis only in the immediate postoperative period. Autografts developed intimal thickenings whose cellular elements at all stages were almost exclusively myointimal in type. Their medial smooth muscle cells were viable at all stages. Allografts frequently thrombosed within 8 weeks of grafting. Intimal thickenings that developed in the first 6 weeks in allografts mainly contained infiltrating hematogenous cells with few myointimal cells. Immune cells infiltrated all of the layers of allograft walls, and the smooth muscle cells of their medias showed increasingly severe degeneration and by 8 weeks had completely disappeared. In long established allografts, the intima was extremely thick and contained myointimal cells and fibrous tissue. Their medias were fibrosed. In long standing allografts, immune cell infiltration was no longer present. The thrombosis of allografted arteries that occurred within 8 weeks of grafting was related to immunologic events observed within the vessel grafts. Differences between myointimal cells and smooth muscle cells with regard to their morphology and orientation were identified. A possible origin of myointimal cells from endothelial cells is suggested.     

A reappraisal of sonolucent renal masses

The authors present a differential diagnosis of echo-free renal masses and emphasize that such lesions are not always simple cysts. Of 312 renal sonograms, 15 showed sonolucent masses which proved to be something other than a simple cyst. Pathological diagnoses included abscess, hematoma, renal artery aneurysm, hydronephrosis, and homogeneous or cystic tumor. To achieve optimal diagnostic accuracy, it is insufficient to rely solely on sonolucency as demonstrated on the sonogram. Any disparities in the radiological, clinical, or ultrasonic findings demand further evaluation. Nephrotomography, angiography, aspiration biopsy, or exploration should be selected in a sequence which is appropriate to ensure correct diagnosis while minimizing the risk to the patient.     

Extramedullary myeloid cell tumors in myelodysplastic-syndromes: not a true indication of impending acute myeloid leukemia

The purpose of this report is to record a patient with myelodysplastic syndrome (MDS) associated acute myelogenous leukemia (AML) and leukemia cutis who had blast expression of the neural cell adhesion molecule (NCAM) and to review the world literature on prognostic implications of extramedullary myeloid cell tumors (granulocytic sarcoma, myeloblastoma, chloroma and leukemia cutis) in MDS and MDS associated AML. Case report and world literature from January 1965-January 1994 for all cases of MDS-associated extramedullary myeloid cell tumors (EMT) is reviewed, and the first patient with EMT, MDS associated AML and blast expression of NCAM is described. There have been 46 cases of MDS associated EMT previously reported. 32 cases occurred in the absence of AML. AML developed in 47% of these patients at a mean of 38 weeks from initial EMT. Of the patients not developing AML, median survival from initial EMT was 11 weeks. Nine patients received chemotherapy at the time of EMT and had a median survival of 36 weeks. The median survival for patients receiving conservative therapy for EMT was 48 weeks. Patients (n = 15) with EMT and MDS associated AML had a poor outcome regardless of therapy with a median survival of 11 weeks. Unlike other forms of isolated EMT, MDS associated EMT is not always a forerunner of AML. Premature induction therapy for MDS associated EMT does not appear to prolong survival. EMT in the setting of MDS associated AML is associated with a poor prognosis despite aggressive chemotherapy. Blast expression of NCAM may prove to be a risk factor for EMT in MDS associated AML.