Diagnosis of the Prader-Willi syndrome by proving the absence of the unmethylated PW71 DNA fragment

The Prader-Willi syndrome (PWS) is a genetic disorder which is difficult to diagnose from clinical symptoms in newborns and young children. However, it is known that in PWS a fragment within the q11-13 region of the paternally derived chromosome 15 is deleted. Recently it has been observed that the D15S63 (PW71) locus in chromosome 15q11-13 is methylated on the maternally derived chromosome, but unmethylated on the paternally derived chromosome. Based on this observation a rapid diagnostic test (the PW71 methylation test) using methylation-sensitive restriction enzymes has been developed for patients presumed to have PWS. We have studied 56 patients; 30 patients with classical features of PWS and 26 patients with only psychomotor retardation and obesity, referred to us from different parts of Sweden. Twenty-nine of the 30 classical PWS patients were found to have an absence of the unmethylated paternally derived PW71(D15S63) locus in chromosome 15q11-13. None of the patients with only obesity and psychomotor retardation had this "absence" pattern on chromosome 15q11-13. Using the PW71 methylation test on patients with PWS, a concordance of 96% was found. The PW71 methylation test is presently the method of choice for rapid diagnostic testing of patients suspected of having PWS.     

Gastrointestinal perforation by chicken bones

Four cases of gastrointestinal perforation by chicken bones are presented. Variability in the clinical manifestations generally precludes a correct preoperative diagnosis of intraabdominal chicken bone abscess. However, in 2 patients, a diagnosis was possible with plain abdominal radiographs. Although the abnormalities seen were nonspecific, the identification of a chicken bone with an associated mass or extraluminal gas collection in a patient with signs of peritonitis, mechanical bowel obstruction, or pneumoperitoneum strongly suggests the diagnosis. A history of alcoholism or wearing dentures strengthens it.     

Human marrow cells capable of erythropoietic differentiation in vitro: definition of three erythroid colony responses

A systematic study has been undertaken to analyze the spectrum of erythropoietic colonies obtained in cultures of human marrow cells plated in methyl cellulose. Colonies were identified as erythropoietic on the basis of the appearance in them of hemoglobin-containing erythroblasts. As found previously in mouse marrow cultures, three sequentially appearing types of colonies which differed in their ultimate cluster content could be readily distinguished. Small erythroid colonies containing 1-2 clusters reached a peak after 7-8 days; small bursts containing 3-8 clusters reached a peak after 10-12 days; and large bursts containing greater than 16 clusters reached a peak after 17-20 days. The previously reported enhancing effect of human leukocyte conditioned medium on burst formation seen in cultures of human nonadherent cells was found to be due largely to an effect on the formation of the largest, late appearing type of burst. By analogy with the mouse, the progenitors of such bursts would represent a primitive cell type which has a close relationship with pluripotent stem cells, as well as a second and independent close relationship to the progenitors of granulopoietic colonies.     

Healing of osteoporotic vertebral compression fractures following cure of Cushing's syndrome

Reversibility of gross radiologically manifest steroid-induced osteoporosis is disputable. A young boy with endogenous Cushing's syndrome with severe osteoporosis, demonstrating satisfactory recovery of osteoporotic changes within 2 years after cure of Cushing's syndrome, is described.     

The presurgical management with erythrocytapheresis of a patient with a high-oxygen-affinity, unstable Hb variant (Hb Bryn Mawr)

BACKGROUND: Hemoglobin (Hb) Bryn Mawr is an unstable Hb variant resulting in congenital hemolytic anemia. This variant Hb also has an increased affinity for oxygen. The perioperative transfusion management of this disorder is described, and the first genomic analysis of this Hb variant is given. CASE REPORT: An 11-year-old boy, heterozygous for Hb Bryn Mawr, was referred for cholecystectomy. Sequence analysis of genomic DNA confirmed that the patients was heterozygous for a T–>C transition in the codon for amino acid 85, causing a substitution of serine for phenylalanine in the beta-globin chain. On the basis of whole-blood O2 dissociation studies, projected tissue O2 delivery would have been suboptimal during general anesthesia; therefore, a partial red cell exchange transfusion was performed to lower variant Hb and prevent tissue hypoxia during surgery. The red cell mass to be exchanged (50%) was determined from the calculated increase in O2 delivery capacity required to maintain an O2 extraction of 4 to 5 mL of O2 per dL of whole blood. The p50 of whole blood from the patients immediately after the exchange transfusion was 16.0 torr. At the time of surgery, the p50 was normal (25.9 torr). The patient's whole blood 2,3 DPG levels were 4.70 mmol per mL of red cells (before transfusion) (normal range=4.8 +/? 0.3 mmol/mL red cells), 4.07 mmol per mL of red cells (immediately after transfusion), and 4.55 mmol per mL of red cells (48 hours after transfusion). CONCLUSION: This patient with Hb Bryn Mawr was prepared for surgery with a partial exchange transfusion to prevent tissue hypoxia during anesthesia. Decreased 2,3 DPG levels immediately after transfusion resulted in increased O2 affinity of whole blood; however, 48 hours after exchange transfusion, a normal p50 (due to both removal of variant Hb and regeneration of 2,3, DPG) was observed. Partial exchange transfusion is useful in the preoperative management of patients with Hb variants characterized by increased O2 affinity.     

Percutaneous feeding gastrostomy with the Seldinger technique: review of 252 patients

Over a period of 60 months, percutaneous nonendoscopic gastrostomy for enteral feeding was successfully performed with the Seldinger technique in 250 of 252 consecutive patients. Local anesthetics alone (without intravenous sedatives) were used in 248 patients (98%). The 30-day mortality was 14.2% and included two procedure-related deaths (0.8%). Major complications necessitating surgery occurred in three patients (1.2%), and one patient had a major gastrointestinal hemorrhage (0.4%) treated medically. Minor complications occurred in 4.4% of patients. The results compare favorably with those found with alternative techniques (surgical or endoscopic) for gastrostomy. The authors conclude that this procedure is simple, is relatively safe, and represents a preferred method of gastrostomy for enteral feeding.