Expression of KB cell alkaline phosphatase isoenzymes during growth in immunosuppressed LEW rats.

Alkaline phosphatase isoenzyme expression of human tumor xenografts was studied by the growing of KB cells in immunosuppressed neonatal LEW rats. In culture these cells produced the oncoamniotic (FL) isoenzyme as the major form and the Regan isoenzyme as a minor fraction as well as a "hybrid" that shared properties of both of the other isoenzymes. Despite a reduction in specific activity, this isoenzyme pattern was essentially unchanged during in vivo growth. KB cells "pretreated" in culture with the glucocorticoid prednisolone in hyperosmolal medium exhibited a decrease in the levels of the oncoamniotic (FL) isoenzyme and an increase in the Regan isoenzyme. During growth of pretreated cells in vivo, a time-dependent resumption in the expression of the oncoamniotic (FL) isoenzyme was associated with the disappearance of the Regan isoenzyme. This shows that the expression of the oncoamniotic (FL) isoenzyme is not restricted to human tumor cells monophenotypic with respect to alkaline phosphatase.     

Octylcyanoacrylate versus polyurethane for treatment of burns in swine: a randomized trial

In order to determine whether the enhanced reepithelialization of second-degree burns treated with octylcyanoacrylate (OCA) was due to its occlusive nature we compared reepithelialization (REP) and infection rates of second degree burns treated with OCA and polyurethane film (Tegaderm) in swine. Forty-four standardized partial thickness burns were created by applying an aluminum bar preheated to 80 degrees C to the backs of pigs for 20 s and randomly treated with OCA or Tegaderm. Full thickness biopsies were taken at 7, 10 and 14 days for blinded histopathological evaluation of rates of infection and reepithelialization. T-tests and chi(2) tests were used for group comparisons. There were no between group difference in the rates of reepithelialization and infection. All wounds were reepithelialized by day 14 and there were no infections in either group. We conclude that treatment of partial thickness burns with OCA spray or Tegaderm results in similar rates of reepithelialization and infection, suggesting that the beneficial effects of OCA on reepithelialization are due to its occlusive nature.     

Soft tissue sarcomas of adults: state of the translational science.

Sarcomas--like leukemias, which are also mesodermal malignancies--carry biological significance disproportionate to their clinical frequency. Identification of mutations and translocations associated with these tumors has illuminated aberrant signaling pathways that cause these diseases, determine their behavior, and are therapeutic targets. Activated receptor-associated tyrosine kinase c-kit, mutated in most gastrointestinal stromal tumors, has proven a clinically effective target for enzyme inhibition. A translocation involving a single gene family, consisting of EWS and related genes, has been identified in five different sarcomas, and its chimeric protein products could prove similarly amenable to inhibitors. Resolution of the histopathological complexity is being aided by data from molecular and chromosomal characterization. Improvements in imaging, definition of prognostic factors, and surgical and radiotherapeutic treatment have resulted in improved local control. Continued progress will depend on further adapting the rapidly evolving technologies of genomics and proteomics. It will also depend upon accurate histopathological diagnosis based on validated reagents and consistent methodologies applied to adequate tissue samples derived from patients with complete clinical data. Finally, multicenter, coordinated trials, such as those that occurred with assessment of imatinib mesylate in metastatic gastrointestinal stromal tumors, will assure the most rapid reductions in morbidity and mortality.     

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.      

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.