Progressive Cenozoic cooling and the demise of Antarctica's last refugium.

The Antarctic Peninsula is considered to be the last region of Antarctica to have been fully glaciated as a result of Cenozoic climatic cooling. As such, it was likely the last refugium for plants and animals that had inhabited the continent since it separated from the Gondwana supercontinent. Drill cores and seismic data acquired during two cruises (SHALDRIL I and II) in the northernmost Peninsula region yield a record that, when combined with existing data, indicates progressive cooling and associated changes in terrestrial vegetation over the course of the past 37 million years. Mountain glaciation began in the latest Eocene (approximately 37-34 Ma), contemporaneous with glaciation elsewhere on the continent and a reduction in atmospheric CO(2) concentrations. This climate cooling was accompanied by a decrease in diversity of the angiosperm-dominated vegetation that inhabited the northern peninsula during the Eocene. A mosaic of southern beech and conifer-dominated woodlands and tundra continued to occupy the region during the Oligocene (approximately 34-23 Ma). By the middle Miocene (approximately 16-11.6 Ma), localized pockets of limited tundra still existed at least until 12.8 Ma. The transition from temperate, alpine glaciation to a dynamic, polythermal ice sheet took place during the middle Miocene. The northernmost Peninsula was overridden by an ice sheet in the early Pliocene (approximately 5.3-3.6 Ma). The long cooling history of the peninsula is consistent with the extended timescales of tectonic evolution of the Antarctic margin, involving the opening of ocean passageways and associated establishment of circumpolar circulation.

Postnatal outcome of antenatally diagnosed intra-abdominal cysts.

The aim of this study is to establish the postnatal diagnosis and outcome of all abdominal cystic lesions diagnosed antenatally over a 13-year period. All prenatally suspected and postnatally confirmed intra-abdominal cysts seen and delivered between 1991 and 2004 were identified. Antenatal diagnosis, gestational age at delivery, sex and postnatal diagnosis and outcome were recorded. Fifty-five patients were identified with an antenatal diagnosis of abdominal cystic lesion. There were 53 live births and 2 intrauterine deaths. In 13 cases (24%) the cyst had resolved on a postnatal scan. Sixteen (29%) required surgical intervention postnatally. Twenty-six (47%) were given a "non-specific" diagnosis of abdominal cyst antenatally. Three (11%) of these non-specific cysts had resolved on postnatal scan. A "specific" diagnosis of the abdominal cyst was made antenatally in 29 cases (53%) of which 12 (43%) had the diagnosis confirmed postnatally. In ten (35%) of these there was a normal postnatal scan. Antenatal ultrasound scans may not reliably predict the exact pathological diagnosis of abdominal cystic lesions. However this study provides valuable information on the proportion of correctly diagnosed lesions and those that will persist into the postnatal period allowing more informative counselling for prospective parents.

Multidisciplinary approach to expansion thoracoplasty for congenital spinal deformity: a preliminary report.

BACKGROUND: In children with congenital chest wall deformities, the vertical expandable prosthetic titanium Rib (VEPTR) has recently been developed to move the emphasis away from corrective spinal fusion, to expanding the deformed hemithorax. The aim of this paper is to demonstrate the need for paediatric surgeons in what is primarily an orthopaedic procedure. MATERIALS AND METHODS: All patients less than 5 years old who had primary congenital scoliosis with poor respiratory function and were treated by VEPTR at our institution in conjunction with the spinal orthopaedic surgeons were reviewed. RESULTS: All 6 cases required rib exposure and thoracostomy by a paediatric surgeon. One required exposure of the ribs only, 3 required an extrapleural thoracotomy and 2 required intrapleural thoracotomy with a patch repair of the rib space. None of the patients required blood transfusion and there were no early complications. All patients showed radiological improvement of their spinal and thoracic deformity as well as improvement in their respiratory function. CONCLUSION: Paediatric surgeons play an important role in the thoracic exposure required for this orthopaedic procedure. The benefit of a multidisciplinary approach is highlighted in this paper. The VEPTR implant may replace major spinal fusion surgery in this challenging group of patients.

Fibroepithelial polyps causing ureteropelvic junction obstruction in children--a case report and review article.

Fibroepithelial polyps are extremely rare benign mesodermal tumours in children that can cause ureteropelvic junction (UPJ) obstruction. We report on a 10-year-old boy presenting with UPJ obstruction due to a fibroepithelial polyp, and review 28 similar published paediatric cases.

Infantile hypertrophic pyloric stenosis: an infectious cause?

The aetiology of infantile hypertrophic pyloric stenosis (IHPS) remains unclear. The aim of this study was to test the hypothesis that a common bacterium, Helicobacter pylori (HP) may be implicated in the pathogenesis of IHPS. Thirty-nine consecutive infants with confirmed IHPS had their stool analysed with an enzyme immunoassay for the presence of HP. An age/sex-matched group of infants with unrelated surgical conditions were also tested. No positive results for the presence of HP stool antigen were obtained in the study nor the control group. The results of this study demonstrate no causative link between HP and IHPS. A genetic basis has been implicated for IHPS. However, evidence does exist that IHPS is a condition acquired after birth and that an infective agent may be involved in the pathogenesis. Further studies are required to elucidate perinatal factors that may induce the expression of this condition in a genetically sensitive individual.

Rectal adenocarcinoma following cranio-spinal radiotherapy for cerebellar medulloblastoma.

The authors present a case of a 16-year-old female diagnosed with rectal adenocarcinoma 10 years after receiving cranio-spinal radiotherapy for a cerebellar medulloblastoma. While the risk of a second malignancy is recognised to be increased in children previously treated with radiotherapy, rectal adenocarcinoma is a rare presentation. A child presenting with symptoms of weight loss and a change in bowel habit in a patient who has previously received radiotherapy should alert practitioners to the possibility of a colorectal malignancy.

Somatostatin for intractable postoperative chylothorax in a premature infant.

A premature infant of 31 weeks' gestation underwent repair of an oesophageal atresia, distal tracheo-oesophageal fistula and anal stenosis. A lymphatic leak was noted at the time of surgery. Chylous drainage persisted and an intravenous infusion of somatostatin was begun. The volume of chyle drained fell dramatically within the first 24 h and was negligible by the 5th day of treatment. No reaccumulation of the chylothorax was seen after the cessation of somatostatin. To our knowledge this is the youngest reported child in whom somatostatin has been used successfully in treating a postoperative chylothorax.

Long-chain L-3-hydroxyacyl-coenzyme A dehydrogenase deficiency neuropathy: response to cod liver oil.

Docosahexaenoic acid (DHA) deficiency has recently been documented in several children with long-chain L-3-hydroxyacyl-coenzyme A dehydrogenase deficiency (LCHADD). We studied a 13-year-old boy with LCHADD who had limb girdle myopathy, recurrent myoglobinuria, and progressive sensorimotor axonopathy with demyelination. At 11 years of age, he was started on cod liver oil extract, high in DHA content. Over 12 months, he demonstrated a marked clinical recovery. Nerve conduction studies (NCS) demonstrated reappearance of previously absent posterior tibial and peroneal nerve responses and the amplitudes on motor ulnar and median NCS markedly increased from 7- to 14-fold, respectively.

Provision of HPA-1a (PlA1)-negative platelets for neonatal alloimmune thrombocytopenia: screening, testing, and transfusion protocol.

HPA-1a-negative platelet products are not routinely available for newborns with alloimmune thrombocytopenia. In this article we describe a program established to identify normal pheresis donors who are HPA-1a-negative and to organize their future donations so that our regional blood center would always have an HPA-1a-negative platelet product available. The solid phase red cell adherence assay was used for initial screening of platelet pheresis products. HPA-1a-negative donors were confirmed with the platelet suspension immunofluorescence test using three anti-HPA-1a sera. Screening of 2600 plateletpheresis donor samples identified 40 HPA-1a-negative donors. Of these, 36 are active and are coded for recognition on the daily pheresis inventory sheet. Theoretically, assuming four donations per year and donors' cooperation with scheduling, these 36 donors would enable us to have at least one HPA-1a-negative product available every day. In addition, a decision tree for patient management using platelet serology and availability of HPA-1a-negative products was developed. The GTI-PAK trade mark 12 is the major technique used for serologic screening of mothers of patients thought to have neonatal alloimmune thrombocytopenia. By screening pheresis donors and developing a clinical decision tree, HPA-1a-negative products, a rare resource, can be fully utilized.

Fetal polycystic kidney disease associated with glutaric aciduria type II: an inborn error of energy metabolism.

The findings of hyperechoic and enlarged fetal kidneys on routine antenatal ultrasonography is a non-specific finding that alerts the physician to a differential diagnosis of various genetic and non-genetic disorders, including fetal polycystic disease and Beckwith-Wiedeman syndrome. Detection of fetal or neonatal polycystic kidneys should alert the physician to the possibility of an associated lethal autosomal recessive inborn error of fatty acid metabolism known as multiple acyl-CoA-dehydrogenase defect (MADD). We report a case of fetal nephromegaly associated with rare inborn error of MADD. This case highlights the need for appropriate laboratory investigation of hyperechoic, enlarged fetal kidneys, and neonatal polycystic disease. The association of MADD with postnatally diagnosed polycystic disease of the kidney has been reported. The antenatal detection of nephromegaly followed by the subsequent postnatal diagnosis of MADD has not been previously reported. MADD should be considered in the differential diagnosis of this antenatal finding. Appropriate diagnostic procedures should be conducted, either pre- or postnatally, in order that appropriate genetic counseling may be provided for this autosomal recessively inherited disorder.

Detection of metabolic disorders among selectively screened people with idiopathic mental retardation.

Fifth-eight people receiving residential or other services for idiopathic mental retardation were evaluated for evidence of metabolic disease. Five (8%) demonstrated persistent urinary organic acid abnormalities on at least three occasions, which pointed towards specific genetic metabolic defects. Instigation of specific treatment programs may have improved the quality of life for one of these participants. Appropriate genetic counseling was provided but could have been instigated much earlier had these investigations been performed as part of a routine workup for idiopathic mental retardation. This pilot study suggests a need for evaluation of other similar populations with idiopathic mental retardation.

Pancreatitis in patients with organic acidemias.

STUDY OBJECTIVE: The discovery of pancreatitis in two children with methylmalonic acidemia led us to review the experience with pancreatitis in a large number of patients with organic acidemias to determine whether pancreatitis is an important complication of these disorders. DESIGN: Case series. SETTING: Pediatric metabolism services at five tertiary care centers. PATIENTS: Records of all patients with organic acidemias followed at the five institutions during the past 10 years were reviewed. Pancreatitis was recognized by symptoms and laboratory findings and confirmed by imaging studies, surgery, or autopsy. At three institutions all cases of pancreatitis in children younger than 10 years were reviewed. MEASUREMENTS AND RESULTS: Nine children with pancreatitis (seven with acute and two with chronic cases) were identified among 108 children with branched-chain organic acidemias. They ranged in age from 13 months to 9 years. Five had methylmalonic acidemia, three had isovaleric acidemia, and one had maple syrup urine disease. There were three deaths; acute hemorrhagic pancreatitis occurred in two children, and chronic pancreatitis was found at autopsy in a third. All three patients with isovaleric acidemia and pancreatitis were identified after the occurrence of pancreatitis. The survey of pancreatitis at three institutions found 57 other patients (none with an inborn error) in addition to three patients with inborn errors included in this study. CONCLUSIONS: Acute or chronic pancreatitis may complicate branched-chain organic acidemias and must be considered in the assessment of patients with these disorders who have acute clinical deterioration and vomiting, abdominal pain, encephalopathy or shock, or milder symptoms. Conversely, an inborn error of organic acid metabolism should be considered in children with pancreatitis of unknown origin.

3-Hydroxydicarboxylic and 3-ketodicarboxylic aciduria in three patients: evidence for a new defect in fatty acid oxidation at the level of 3-ketoacyl-CoA thiolase.

Three patients presented with evidence of a fatty acid oxidation disorder. Analysis of urinary organic acids by gas chromatography/mass spectrometry demonstrated the presence of medium-chain (C6-C12) dicarboxylic, 3-hydroxydicarboxylic, and 3-ketodicarboxylic acids in all three urines. 3-Ketodicarboxylic aciduria is reported for the first time here, as are the mass spectra for 3-ketosuberic, 3-ketosebacic, and 3-ketododecanedioic acids and the oximated spectrum for 3-ketoadipic acid. The presence of 3-ketodicarboxylic acids suggests a defect at the level of a long-chain 3-ketoacyl-CoA thiolase, an enzyme for which a deficiency state has not previously been described. Our patients may represent the first cases of a long-chain thiolase defect.

Donor deferral registries.

In the last half of this century, donor deferral registries have grown in size, scope, and importance for blood collection organizations and regulatory agencies. This has occurred despite the lack of direct evidence that, when used with all other methods, they contribute meaningfully to the safety of the blood supply. Any decrease in the perceived benefit of deferral registries has been a result of the introduction of a panoply of serological testing of donor blood intended to detect transmissible disease. As the sensitivity of serological testing improves, the relative merit of the subjective methods used for blood supply safety diminish. Although computers have become a mainstay in the management of deferral registries, accurate and consistent donor identification, good manual systems, and quality control of data bases are key features to their successful management. As with the other subjective methods used in maintaining blood supply safety, techniques must be developed to determine the value of the many features of donor deferral registries. Efforts must be made to simplify these processes and focus on those elements that provide important contributions to blood supply safety. Today, donor deferral registries are major activities in most blood centers and are believed to play a significant role in blood supply safety. It is time for their role to be carefully reexamined.

The significance of the blood-borne viruses: blood banking and transfusion medicine.

Most of the blood-borne infections that have held our attention during the last half of this century have been well characterized. Although HIV and the hepatitis viruses have enormous world-wide public health implications, there has been considerable success in their prevention of transmission by transfusion. The technology is available to treat and eliminate from virtually all non-cellular blood products the transmission of disease caused by those viruses for which we have had the greatest concern. However, for the cellular blood products the basic methods of prevention continue to be imperfect: donor selection and viral serological testing. The significance of the transmission of blood-borne agents by these products depends upon the frequency of the agent in the donor population and the serological screening performed. There is a marked degree of variation in frequency of these infections, dependent upon geography, living conditions, and life style. Data on the frequency of transfusion-transmitted disease are meagre and usually based upon indirect estimates. In the United States the frequency of the transmission of HIV by cellular blood products is estimated to be 1:125,000 products transfused. A similar estimate for the transmission of hepatitis is 1:200 products transfused. For the developing countries, some of which experience the highest rates of hepatitis and HIV infection in their populations, data on the frequency of transfusion transmission are not generally available. In recent years, new evidence has stimulated interest in a few transfusion-transmissible diseases that, although uncommon from the public health perspective, have both real and potential transfusion impacts for the use of plasma and plasma derivatives as well as cellular products.(ABSTRACT TRUNCATED AT 250 WORDS)

Reliable prenatal diagnosis of Canavan disease (aspartoacylase deficiency): comparison of enzymatic and metabolite analysis.

Prenatal diagnosis has been undertaken in 17 pregnancies in 15 families at risk for aspartoacylase deficiency. Amniocentesis was at 14-18 weeks gestation followed by measurement of amniotic fluid N-acetyl-L-aspartate (NAA) levels in all pregnancies and amniocyte aspartoacylase activity in most pregnancies. In one case amniocentesis was performed at 11 weeks gestation in conjunction with chorionic villus sampling. At 14-18 weeks of gestation, control levels of NAA were 0.30-2.55 mumol/L. The fetus was predicted to be affected in 8 of the pregnancies, 4 of which were confirmed by enzyme analysis on fetal tissue and 2 by the clinical and metabolic expression of Canavan disease in a newborn. In two cases there was no fetal tissue available for enzyme confirmation. One of these had the highest amniotic fluid NAA level (8.68 mumol/L) and in the other pregnancy there were two amniocenteses, both with markedly elevated levels. Of 9 fetuses predicted to be normal, 8 newborns were clinically and biochemically normal. A single case with amniotic fluid NAA in the normal range (1.56 mumol/L, measured in one laboratory only) resulted in an aborted fetus in whom aspartoacylase was deficient in cultured skin fibroblasts. We propose that amniotic fluid NAA levels remain the best predictor of an affected fetus and recommend that the assay be performed in multiple laboratories.