A spectrum of segmental multicystic renal dysplasia

Background. Multicystic renal dysplasia (MCDK) is a common anomaly well described in the literature, but less well described when involving only a portion of a kidney. Objective. To present the imaging spectrum, natural history and associated anomalies of six kidneys with segmental MCDK. Materials and methods. Five children with segmental MCDK (one with bilateral segmental MCDK) referred to our hospital between 1989 and 1996 were reviewed. All had at least one ultrasound examination. Four had a voiding cystogram and three had renal scintigraphy. Results. Four children had antenatal diagnosis of cystic renal abnormality. In two, with obvious duplex kidneys and associated ureteroceles, the diagnosis of upper moiety MCDK was obvious either antenatally or immediately postnatally. In the other three there were diagnostic difficulties. One patient had bilateral widespread cysts obscuring the functioning renal portions. Another presented in utero with a large ureterocele and a cystic upper pole that had involuted by birth. The fifth had a nephrectomy at 3 years for a multiloculated cystic mass. Varying degrees of involution occurred in the five kidneys seen early. Reflux was demonstrated into the ipsilateral functioning lower moiety and midpole. Conclusion. In these children as in other studies, the commonest presentation of segmental MCDK is in the upper pole of a duplex kidney associated with a ureterocele at the end of the atretic ureter. Atypical segmental MCDK may present a diagnostic dilemma and should be included in the differential diagnosis of multiloculated cystic masses and cystic kidneys. Received: 16 June 1998 Accepted: 16 November 1998     

Agenesis of the corpus callosum and cerebral anomalies in inborn errors of metabolism

Dysgenesis of the corpus callosum has been recognized as a marker for aberrant development of the central nervous system. It has been suggested that developmental defects of the corpus callosum may be more frequently encountered in patients with inborn errors of metabolism. The objectives of the present study were to determine the prevalence of developmental defects of the corpus callosum in patients attending a genetics-metabolic disorders clinic, to describe the spectrum of abnormalities in brain development in patients with confirmed inborn errors of metabolism and abnormalities of the corpus callosum as ascertained by neuroimaging and/or postmortem studies. Nineteen patients (10 males, 9 females) with confirmed metabolic diagnoses were identified by systematic search of the genetics clinic database. All 19 (100%) expressed variable degrees of hypoplasia, complete or partial agenesis (ACC). Abnormalities of head size were noted in 17/19 (89.5%). The majority 12/17 (70.5%) were associated with microcephaly, while macrocrania was noted in 5/17 (29.5%). Associated central nervous system (CNS) anomalies included abnormalities in ventricular morphology in 18/19 (94.7%), ventriculomegaly in 11/19 (63.1%), increased extraxial cerebrospinal fluid space in 11/19 (57.9%), changes in the gray matter (neuronal migration defects, porencephaly) in 9/19 (47.3%), white matter changes in 12/19 (63.1%) and abnormalities of the posterior fossa and hindbrain in 12/19 (63.1%). In patients with inborn errors of metabolism, dysgenesis of the corpus callosum serves as a marker for other developmental defects within the nervous system. We discuss here potential mechanisms by which metabolic defects affect diverse biochemical pathways, altering key neurobiological processes (e.g. defective cell membrane formation, cellular bioenergetics and cell-to-cell signaling), that eventually lead to structural abnormalities in the developing nervous system.     

Comparison of Outcomes of Allogeneic Hematopoietic Cell Transplantation for Multiple Myeloma Using Three Different Conditioning Regimens

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative therapy for patients with multiple myeloma, as it provides a graft-versus-myeloma effect alongside a myeloma-free graft. Although reduced-intensity conditioning regimens decrease nonrelapse mortality (NRM), there is a paucity of data with regard to the ideal conditioning regimen in myeloma. We conducted a retrospective comparison of 3 different preparative regimens used for allo-HCT for multiple myeloma at our institution in recent clinical trials: busulfan/fludarabine (BuFlu), fludarabine/melphalan 100 mg/m² (FM100), and fludarabine/melphalan 140 mg/m² (FM140). NRM, progression-free survival (PFS) at 3 years, and overall survival (OS) at 3 years were the primary endpoints. Secondary endpoints included time to engraftment, and the incidence of grades II through IV acute graft-versus-host disease and chronic graft-versus-host disease. A total of 73 patients received allo-HCT with these regimens. NRM at 3 years was seen in 3 (21%), 5 (28%), and 6 (24%) patients in the BuFlu, FM100, and FM140 groups, respectively. Three-year PFS in the BuFlu, FM100, and FM140 groups was 16% (hazard ratio [HR], 1.2; 95% confidence interval [CI], 0.6 to 2.1), 26% (HR, 0.6; 95% CI, 0.3 to 1.2), and 11% (reference), respectively. Three-year OS in the BuFlu, FM100, and FM140 groups was 39% (HR, 1.1; 95% CI, 0.5 to 2.2), 43% (HR, 0.7; 95% CI, 0.3 to 1.4), and 32% (reference), respectively. High-risk cytogenetics and relapsed disease prior to allo-HCT were found to be independent predictors of inferior OS on multivariate analysis, with a HR of 2.1 (P = .02) and 2.6 (P = .004), respectively. In contrast, the preparative regimen did not emerge as a predictor of PFS or OS. Durable clinical remission can be achieved in 11% to 25% of patients with multiple myeloma with the use of allo-HCT without any significant difference in the safety or efficacy of the conditioning regimen. High-risk cytogenetics and relapsed disease prior to transplant were associated with inferior PFS and OS.     

Hemangioblastoma of the IV ventricle

A case of solid hemangioblastoma in the IV ventricle in a 16-year-old boy is reported because of the rarity of this type of lesion. Microsurgical removal of the lesion was accomplished without any side effects in this highly vascular tumor in a strategic location.     

Immunological comparison of phospholipases A2 present in rattlesnake (genus Crotalus) venoms

The immunological properties of phospholipase A₂ present in venoms from seven species of rattlesnakes (genus Crotalus) from different geographical distributions have been compared. Rabbit antiserum to purified PLA₂ of Crotalus scutulatus salvini venom was used, employing inhibition of enzymic activity and immunodiffusion techniques. The amount of antiserum required for 50% inhibition of the PLA₂ activity in the venoms varied from slightly more than that required for inhibition of the activity in the homologous venom to a large amount (effectively zero inhibition). A particularly close relationship in the antigenic makeup was observed between the phospholipases of C. s. salvini and C. atrox venoms as evidenced by inhibition of enzymic activity and immunodiffusion studies. No immunological cross reactivity was observed between the enzymes of the subspecies C. s. salvini and C. s. scutulatus. The results suggest extensive variations in the antigenic structure of the phospholipase molecules. The findings may also have some taxonomic significance.