A novel mechanism for skeletal resistance in uremia

BACKGROUND: In treating secondary hyperparathyroidism, the target level of serum intact parathyroid hormone (I-PTH) should be three to five times normal to prevent adynamic bone disease. In circulation, there is a non-(1-84) PTH-truncated fragment, likely 7-84, which, in addition to PTH 1-84, is measured by most I-PTH immunoradiometric (IRMA) assays, giving erroneously high I-PTH values. We have developed a new IRMA assay in which the labeled antibody recognizes only the first six amino acids of the PTH molecule. Thus, this new IRMA assay (Whole PTH) measures only the biologically active 1-84 PTH molecule. METHODS: Using this new IRMA assay (Whole PTH) and the Nichols "intact" PTH assay, we compared the ability of each assay to recognize human PTH (hPTH) 1-84 and hPTH 7-84 and examined the percentage of non-1-84 PTH in circulation and in parathyroid glands. Possible antagonistic effects of the 7-84 PTH fragment on the biological activity of 1-84 PTH in rats were also tested. RESULTS: In 28 uremic patients, PTH values measured with the Nichols assay, representing a combined measurement of both hPTH 1-84 and hPTH 7-84, were 34% higher than with the Whole assay (hPTH 1-84 only); the median PTH was 523 versus 318 pg/mL (P < 0.001). Similar results were found in 14 renal transplant patients. In osteoblast-like cells, ROS 17.2, 1-84 PTH (10-8 mol/L) increased cAMP from 18.1 +/- 1.25 to 738 +/- 4.13 mmol/well. Conversely, the same concentration of 7-84 PTH had no effect. In parathyroidectomized rats fed a calcium-deficient diet, 7-84 PTH was not only biologically inactive, but had antagonistic effects on 1-84 PTH in bone. Plasma calcium was increased (0.65 mg/dL) two hours after 1-84 PTH treatment, while 7-84 PTH had no effect. When 1-84 PTH and 7-84 PTH were given simultaneously in a 1:1 molar ratio, the calcemic response to 1-84 PTH was decreased by 94%. In normal rats, the administration of 1-84 PTH increased renal fractional excretion of phosphate (11.9 to 27.7%, P < 0.001). However, when 1-84 PTH and 7-84 PTH were given simultaneously, the 7-84 PTH decreased the phosphaturic response by 50.2% (P < 0.005). Finally, in surgically excised parathyroid glands from six uremic patients, we found that 44.1% of the total intracellular PTH was the non-PTH (1-84), most likely PTH 7-84. CONCLUSION: In patients with chronic renal failure, the presence of high circulating levels of non-1-84 PTH fragments (most likely 7-84 PTH) detected by the "intact" assay and the antagonistic effects of 7-84 PTH on the biological activity of 1-84 PTH explain the need of higher levels of "intact" PTH to prevent adynamic bone disease.     

Diagnostik des Williams-Beuren-Syndroms

Zusammenfassung Fragestellung: Die Diagnose des Williams-Beuren-Syndroms (WBS) wird durch die klinische Variabilit?t erschwert. Daher sollen der diagnostische Wert sowohl des von Preus aufgestellten klinischen Scores als auch der Elastingenhemizygotie geprüft und miteinander verglichen werden. Methodik: Bei 13 Kindern mit Verdacht auf WBS wurden der Preus-Score erhoben und eine Fluoreszenz-in situ-Hybridisierungs-Analyse des Elastingens sowie eine Chromosomenanalyse durchgeführt. Ergebnisse: Neun der 13 Patienten zeigten eine Deletion eines Elastingens bei normalem Karyotyp. Zwei Patienten wiesen bei normaler Elastingendosis eine Chromosomenaberration auf. Der Preus-Score lag bei allen Patienten mit Elastindeletion >6 und war damit hoch positiv. Bei den übrigen Kindern wurde ein Preus-Score von 0,18; 0,37, 1,00 und 6,4 ermittelt. Schlu?folgerung: Bei allen Patienten mit WBS lagen in dieser Studie eine Elastingendeletion und ein hoch positiver Preus-Score vor. Ein positiver Preus-Score wurde jedoch auch bei Patienten mit Chromosomenaberrationen ermittelt. Unter Berücksichtigung dieser Ergebnisse und der Daten aus der Literatur sollte daher die Diagnose Wiliams-Beuren-Syndrom nur unter Vorbehalt gestellt werden, wenn keine Elastingendeletion nachweisbar ist. Da aber bisher unbekannte Mutationen bei den wenigen Patienten ohne Elastingendeletion denkbar sind, kann ein WBS auf molekularer Ebene nicht mit letzter Sicherheit ausgeschlossen werden. Bei diesen Patienten k?nnte der Preus-Score zur klinischen Diagnose beitragen. Setzt man für die Diagnose eines WBS im Preus-Score einen Endsummenwert von >1 voraus, so wird eine Sensitivit?t von 100% bei einer Spezifit?t von 92% erreicht.      

Formal retrospective case review and sudden infant death

A review of 24 consecutive sudden infant deaths was undertaken to evaluate the importance of the various stages in the postmortem assessment of such cases. Death in three cases was caused by obvious trauma. Of the remainder, 16 were attributed to sudden infant death syndrome (SIDS), 4 to accidental asphyxia (identified by death scene examination and/or formal case review) and 1 to a lingual thyroglossal duct cyst. Three (14%) of 21 deaths thought to be SIDS after postmortem examination were attributed to asphyxia following subsequent formal case review.     

Chronic illness in adolescents: Transfer or transition to adult services?

It is widely believed that the improved survival of young people with chronic diseases will be associated with the development of appropriate services within the adult healthcare domain. There is, however, little evidence to suggest that this is happening at a rate commensurate with clinical requirements. This paper highlights the multiplicity of barriers that impede the development of transition services to facilitate the transfer of medical care from the paediatric to the adult domain. Different models of transition care are described, and the terms 'transfer' and 'transition' are differentiated. The clinical demand for service development is highlighted, as well as the need for specific research in this area of healthcare delivery.     

Randomised controlled trial of zinc supplementation in malnourished Bangladeshi children with acute diarrhoea

OBJECTIVE: To evaluate the impact of zinc supplementation on the clinical course, stool weight, duration of diarrhoea, changes in serum zinc, and body weight gain of children with acute diarrhoea. DESIGN: Randomised double blind controlled trial. Children were assigned to receive zinc (20 mg elemental zinc per day) containing multivitamins or control group (zinc-free multivitamins) daily in three divided doses for two weeks. SETTING: A diarrhoeal disease hospital in Dhaka, Bangladesh. PATIENTS: 111 children, 3 to 24 months old, below 76% median weight for age of the National Center for Health Statistics standard with acute diarrhoea. Children with severe infection and/or oedema were excluded. MAIN OUTCOME MEASURES: Total diarrhoeal stool output, duration of diarrhoea, rate of weight gain, and changes in serum zinc levels after supplementation. RESULTS: Stool output was 28% less and duration 14% shorter in the zinc supplemented group than placebo (p = 0.06). There were reductions in median total diarrhoeal stool output among zinc supplemented subjects who were shorter (less than 95% height for age), 239 v 326 g/kg (p < 0.04), and who had a lower initial serum zinc (< 14 mmol/l), 279 v 329 g/kg (p < 0.05); a shortening of mean time to recovery occurred (4.7 v 6.2 days, p < 0.04) in those with lower serum zinc. There was an increase in mean serum zinc in the zinc supplemented group (+2.4 v -0.3 mumol/l, p < 0.001) during two weeks of supplementation, and better mean weight gain (120 v 30 g, p < 0.03) at the time of discharge from hospital. CONCLUSIONS: Zinc supplementation is a simple, acceptable, and affordable strategy which should be considered in the management of acute diarrhoea and in prevention of growth faltering in children specially those who are malnourished.     

Longitudinal neurological follow-up of a group of HIV-seropositive and HIV-seronegative hemophiliacs: results from the hemophilia growth and development study

BACKGROUND: Boys and young men with hemophilia treated with factor infusions before 1985 had a substantial risk of acquiring the human immunodeficiency virus (HIV) and the acquired immunodeficiency syndrome. This study was designed to assess the effects of HIV and hemophilia per se on neurological function in a large cohort of subjects with hemophilia, and to investigate the relationships between neurological disease and death during follow-up. METHODS: Three hundred thirty-three boys and young men (207 HIV seropositive and 126 HIV seronegative) were evaluated longitudinally in a multicenter, multidisciplinary study. Neurological history and examination were conducted at baseline and annually for 4 years. The relationship between neurological variables, HIV serostatus, CD4+ cell counts, and vital status at the conclusion of the study was examined using logistic regression models. RESULTS: The risks of nonhemophilia-associated muscle atrophy, behavior change, and gait disturbance increased with time in immune compromised HIV-seropositive subjects compared with HIV seronegative or immunologically stable HIV-seropositive subjects. The risk of behavior change in immune compromised HIV-seropositive hemophiliacs, for example, rose to 60% by year 4 versus 10% to 17% for the other study groups. Forty-five subjects (13.5%), all of whom were HIV seropositive, died by year 4. Subjects who died had had increased risks of hyperreflexia, nonhemophilia-associated muscle atrophy, and behavior change. CONCLUSIONS: These results indicate that immune compromised, HIV-seropositive hemophiliacs have high rates of neurological abnormalities over time and that neurological abnormalities were common among subjects who later died. By contrast, immunologically stable HIV-seropositive subjects did not differ from the HIV-seronegative participants. Hemophilia per se was associated with progressive abnormalities of gait, coordination, and motor function.     

Mukormykose als Ursache einer nekrotisierenden Enterokolitis

Zusammenfassung Die gastrointestinale Mukormykose ist ein seltenes Krankheitsbild. Betroffene Frühgeborene fallen durch eine Perforation im Magen-Darm-Trakt oder eine nekrotisierende Enterokolitis auf. Wir stellen ein Frühgeborenes der 24. SSW mit einer Darmperforation vor, bei dem eine Mukormykose des Darms sowohl durch die Kultur als auch im histologischen Pr?parat nachgewiesen wurde. Im Gegensatz zur „klassischen” nekrotisierenden Enterokolitis lag keine Pneumatosis intestinalis vor, es kam sehr früh zu einer Darmperforation, und der Dünndarm zeigte eine ausgepr?gte Minderperfusion. Diese Punkte k?nnten die Differenzierung zwischen gastrointestinaler Mukormykose und typischer nekrotisierender Enterokolitis erleichtern, was von Bedeutung ist, da nur die frühzeitige Diagnosestellung einen raschen Therapiebeginn (chirurgische Sanierung, Amphotericin B) und damit eine Verbesserung der schlechten Prognose erm?glicht.