The Golgi complex of the early spermatid in guinea pig

After aldehyde-tannic fixation, Zinc-iodine-osmium fixation, Phospho Tungstic acid-chromium stain and two cytochemical reactions, the ultrastructure of the Golgi complex of early spermatids in the guinea pig reveals two different regions. One, close to the cell surface, involves endoplasmic reticulum (ER), intermediate vesicles, and Golgi outer cisternae and has membranes of uniform thickness and symmetrical trilaminar pattern, a strong ZIO precipitate, and an almost negligible cytochemical reaction to polysaccharides and cholesterol. The other region, close to the nucleus, exhibits thicker, sometimes asymmetric membranes, a polygonal network coating the thick cisterna, condensing vacuoles and areas of the acrosomal membrane, an intense reaction to polysaccharides and cholesterol, and packages of different densities in the condensing vacuoles and acrosome. This work also shows the coincidence of the cytochemical marker of cholesterol with the polygonal coating of clathrin in the condensing face of the Golgi.     

Achilles tendon: MR imaging at 1.5 T

Thirty magnetic resonance (MR) examinations of the Achilles tendon were performed: 20 from patients without suspected tendon abnormalities; ten from patients with suspected tendon abnormalities. The appearance of the normal Achilles tendon is hypointense and flattened. Partial tears appeared as high-signal intratendinous collections, complete acute ruptures appeared as tendinous discontinuity, and uncomplicated surgical repairs appeared as areas of tendinous continuity with inhomogeneous signal in the operative site. Chronic tendinitis appeared as a diffuse thickening of the tendon. MR imaging of the Achilles tendon at 1.5 T enabled the determination of the degree of tendinous continuity, which may help with diagnosis, treatment, and the pacing of rehabilitation.     

Twin embolization syndrome: prenatal sonographic detection and significance

Twin embolization syndrome (TES) is a complication of monozygotic twinning following in utero demise of the co-twin. Passage of thromboplastic material into the circulation of the surviving twin results in ischemic structural defects of the central nervous system, gastrointestinal tract, and genitourinary system. In six cases of this rare abnormality, sonographically normal fetuses subsequently demonstrated ventriculomegaly, porencephaly, cerebral atrophy, or microcephaly following demise of the co-twin. Extracranial abnormalities included small bowel atresia (two cases) and renal cortical necrosis (one case). Surviving twins all had neurodevelopmental delay at follow-up. Two fetuses were aborted because of sonographically apparent, progressively severe brain abnormality. The lone survivor of a dizygotic triplet gestation was normal, despite sonographic findings of TES in the co-triplets. Because of poor outcome, prenatal sonographic diagnosis of TES may influence antenatal or neonatal management of the surviving monozygous twin. Recognition of TES may permit accurate postnatal counseling of prognosis and recurrence risks.     

The B cell IgM Fc receptor: further evidence for the B cell origin of "null" chronic lymphocytic leukemia

Fifty-three cases of chronic lymphocytic leukemia (CLL) were studied for the presence of the B cell IgM Fc receptor (Fc microR) using an aggregated IgM reagent. Restricted surface immunoglobulin, using conventional immunofluorescent techniques and FACS analysis, was detected in 43 cases (81%). The cells in the remaining ten cases (19%) expressed negligible surface immunoglobulin (slg-) and did not form E rosettes (E-), but this "null" subset clearly expressed the B cell Fc microR. The coincident membrane expression of the B1 antigen and the la- like antigen, as well as serial studies showing surface membrane light chain acquisition (in one patient), provided additional evidence for the B cell origin of this slg-E- subset. This subgroup of CLL appears to correspond phenotypically to a normal counterpart at a stage of B cell differentiation between the pre-B cell and the slgM+ early B cell. The B cell Fc microR appears to be a consistent and potentially useful marker for sl gE ("null") CLL.     

Amniotic sheets

Seventeen cases of an aberrant sheet of tissue in the amniotic cavity are described to expand and clarify previous observations of this entity. The sheet of tissue demonstrates a thickened base and a free edge that undulates. The fetus moves freely about the sheet of tissue. There are no associated fetal deformities, and infants have no manifestations of the amniotic-band syndrome. Evidence suggests that these sheets may originate from "wrapping" of the amniochorionic membrane over a uterine synechia. These benign sheets of tissue should not be confused with the amniotic-band syndrome.