Sites of antisperm antibody action.

Antisperm antibodies can affect sperm function in the cervical mucus, as they undergo capacitation, or during sperm-egg interaction. During capacitation, the sperm membrane destabilizes and antigens previously not available to antibodies may become exposed. Antibody attachment can reduce fertilization as measured by hamster egg preparation or the hemizona assay. A panel of monoclonal and polyclonal patient sera were tested for their ability to inhibit sperm-zona pellucida tight binding. We tested 25 monoclonals from a panel from the World Health Organization, but only nine were positive by indirect bead binding, indicating that the majority of the antibodies were not sperm surface antigens. The sera of 13 patients were used; three were negative and served as controls, nine had antibodies of the IgG isotype bound to 100% of the sperm heads examined, and seven also exhibited sperm specific IgA antibodies. Of the monoclonals tested, six inhibited zona binding by 60%. Sera of seven patients caused inhibition of greater than or equal to 50% zona binding; those from male patients caused the greatest inhibition. When further specific testing was conducted, one monoclonal caused the greatest inhibition of zona binding; sera of three patients inhibited zona binding by 70%. The antibodies, whether monoclonal or patient sera, were tested for their effect on capacitation. The ability to undergo hyperactivated motility after antibody exposure was assessed and no changes appeared due to antibody exposure. Serum from one of the patients appeared to affect sperm calcium influx to some extent. Sera from two patients appeared to reduce the number of spermatozoa capable of undergoing the acrosome reaction.(ABSTRACT TRUNCATED AT 250 WORDS)     

A specular reflection arising from the ventricular wall: a potential pitfall in the diagnosis of germinal matrix hemorrhage

Reflection artifacts may complicate the diagnosis of intracranial hemorrhage in preterm neonates. A linear focus of bright echoes in the region of the germinal matrix at or anterior to the caudothalamic grooves, often seen on parasagittal scans, may be mistaken for a germinal matrix hemorrhage but is actually a reflection of the ultrasound beam at the wall of the lateral ventricle. Cranial sonograms of 100 preterm infants were retrospectively analyzed and categorized with regard to presence and size of specular reflection. Eight cases demonstrated a bright echogenic focus; seven of these potentially could have been mistaken for hemorrhages.     

Comparison of three immunosuppressive regimens in cadaver renal transplantation: long-term cyclosporine, short-term cyclosporine followed by azathioprine and prednisolone, and azathioprine and prednisolone without cyclosporine

We conducted a randomized trial in seven Australian hospitals of the efficacy and safety of three immunosuppressive regimens after first transplantation of a cadaver kidney: long-term cyclosporine, short-term (three months) cyclosporine followed by azathioprine and prednisolone, and azathioprine and prednisolone without cyclosporine. Patients assigned to long-term cyclosporine (n = 138) or short-term cyclosporine followed by azathioprine and prednisolone (n = 141) had similar actuarial 12-month survival (98.4 vs. 96.4 percent) and graft survival (83.9 vs. 82.1 percent). Patients assigned to receive only azathioprine and prednisolone (n = 138), with optional use of antithymocyte globulin, had a significantly poorer survival rate (91.3 percent, P = 0.015) because of deaths from cardiac causes and infection, but their graft survival of 76.0 percent (P = 0.31) did not differ significantly from that of either group receiving cyclosporine. After the switch from cyclosporine to azathioprine and prednisolone, 15 percent of patients had reversible rejection episodes, but the frequency of rejection and graft loss did not differ from that in the long-term cyclosporine group. After the change to azathioprine and prednisolone, serum creatinine levels declined in nearly all patients, so that after three months they were comparable to those in the group receiving azathioprine and prednisolone only, and significantly lower than those in the group receiving long-term cyclosporine therapy (P less than 0.003). We conclude that the two cyclosporine regimens result in comparable patient and graft survival, but that changing to azathioprine and prednisolone at three months improves graft function.     

Sonography of the low transverse incision, cesarean section: a prospective study

Using sonography, the uterine incision site was prospectively studied in 36 asymptomatic patients, two days after cesarean section. The findings were compared with those seen in 21 symptomatic, postcesarean patients. In the asymptomatic patients, the incision site was visualized as an oval symmetric region of distinct echogenicity interposed between the lower uterine segment and the posterior wall of the urinary bladder. In eight of the 36 asymptomatic patients, a small (less than 1.5 cm) round hypoechoic mass was present in or adjacent to the uterine incision and distinct from the normal incision. These probably represented insignificant hematomas. Of the 21 symptomatic patients, 17 had either a subfascial hematoma, a bladder-flap hematoma, or endometritis. Two were sonographically normal, and one showed a hematoma in the paracolic gutter. In the remaining patient, there was a 5-mm asymmetrically placed hypoechoic mass representing an insignificant hematoma. Significant bladder-flap hematomas were characteristically round, greater than 2 cm masses asymmetrically placed in or adjacent to the uterine incision. Using sonography, the normal appearance of the lower uterine incision can be distinguished from significant hematomas.     

Incontinence of urine due to instability of micturition reflexes part II. Pudendal nucleus instability

Overinhibition or underfacilitation of the pudendal nucleus may cause profound involuntary relaxation of the striated muscles of the pelvic floor and perineum, including the “external” striated urethral sphincter. Pudendal nucleus instability may adversely affect urethral closure pressure and preclude a successful voluntary “recovery” effort to limit stress incontinence. It may also result in the involuntary loss of an important source of inhibition to the sacral micturition reflex center, which can lead to detrusor instability. The bilateral reciprocal relationship which exists between the detrusor reflex and the pelvic floor muscle tonus is fundamental to micturition instability syndromes. In this article, the pathophysiology of interaction of pudendal nucleus instability, detrusor reflex instability, and stress is described, and the importance of careful diagnostic evaluation of each case of incontinence is emphasized.     

Two bacteriophages of Clostridium difficile.

Two temperate bacteriophages of differing morphology and host range were isolated by screening 94 isolates of Clostridium difficile. Phage 41 had a 300-nm flexible tail, whereas phage 56 had a shorter tail with a contractile sheath. Electron microscopy of phage 56 lysates exposed to elevated magnesium concentrations showed small virus-like particles which were 21 nm in diameter. The addition of MgCl2 to semisolid agar overlays enhanced both the titer and plaque size of phage 56. Phage 56 was more temperature labile than phage 41 and demonstrated unusual lability in buffer at pH 7.0. One-step growth and adsorption experiments revealed that both phages had latent periods of about 60 min, but phage 56 adsorbed to its indicator strain more efficiently. Phage 56, which was obtained from a toxigenic strain of C. difficile, was used to lysogenize its nontoxigenic indicator strain, but no conversion to toxigenicity was observed in this strain.     

Nasopharyngeal swabs and nasopharyngeal aspirates equally effective for the diagnosis of viral respiratory disease in hospitalized children.

Paired nasopharyngeal swab and nasopharyngeal aspirate specimens from 125 patients were compared for viral diagnosis. The viral isolation rates were comparable for the two types of specimens. There was a high level of agreement between the two specimens in overall positivity rate by immunofluorescence and positivity in culture-confirmed patients.