Regulatory elements in the introns of the human HPRT gene are necessary for its expression in embryonic stem cells.

We have examined the expression of transfected human hypoxanthine phosphoribosyltransferase minigenes (HPRT) in mouse embryonic stem (ES) cells. cDNA constructs of this gene that have been successfully used in somatic cell lines failed to confer hypoxanthine/aminopterin/thymidine (HAT) resistance in ES cells. In contrast, constructs containing introns 1 and 2 from the HPRT gene produced a high frequency of HAT-resistant colonies. This observation allowed us to identify two sequences in these introns that influence expression of the HPRT gene in ES cells. One element, located in intron 2, is required for effective HPRT expression in these cells; the other element, located in intron 1, acts as an enhancer of HPRT expression. Using this information, we have constructed an HPRT minigene that can be used for either positive or negative selection in ES cell experiments. This dual capability allows the design of "in-out" procedures to create subtle changes in target genes by homologous recombination with the aid of this selectable minigene.     

The characterization of the specific binding of [3H]-N-acetylaspartylglutamate to rat brain membranes

[3H]-N-Acetylaspartylglutamate (NAAG) bound saturably and reversibly to crude synaptosomal rat brain membranes. Optimal binding occurred in Tris-HCl buffer, pH 7.2, at 37 degrees C using previously frozen, preincubated membranes. Saturation experiments revealed an apparent KD of 383 +/- 33 nM and a Bmax of 31 +/- 2 pmol/mg of protein. [3H]NAAG specific binding was displaceable by serine-o-sulfate, quisqualate, ibotenate, and glutamate with K1's in the nanomolar range, whereas the amino-phosphono analogues displaced [3H] NAAG in the micromolar range (APB greater than APV greater than APH). No specific binding was found in peripheral tissues. Within the central nervous system, the thalamus exhibited the greatest amount of binding, whereas binding was lowest in cortex. Calcium ions enhanced the specific binding, whereas sodium ions caused a concentration-dependent inhibition. These results suggest that [3H]NAAG labels an acidic amino acid receptor site designated "A-4," which recognizes the antagonist, 2-amino-4-phosphonobutyric acid, and that this receptor may mediate the neurophysiologic effects of endogenous NAAG.     

Acute pulmonary failure during remission induction chemotherapy in adults with acute myeloid leukemia or high‐risk myelodysplastic syndrome

BACKGROUND:

Acute pulmonary failure during remission induction therapy is a serious complication in patients with acute myeloid leukemia (AML). To the authors' knowledge, the course and prognosis of such patients is not well known.

METHODS:

A total of 1541 patients referred for remission induction chemotherapy of AML or high‐risk myelodysplastic syndrome were retrospectively reviewed.

RESULTS:

A total of 120 (8%) patients developed acute pulmonary failure within 2 weeks of the initiation of chemotherapy; 87 of these patients (73%) died during remission induction, whereas 17 (14%) achieved a complete response. The median survival among the 120 patients with early acute pulmonary failure was 3 weeks. Predictive factors for the development of early acute pulmonary failure by multivariate analysis were: male sex (P = .00038), acute promyelocytic leukemia (P = .00003), poor performance status (P = .001), lung infiltrates at diagnosis (P = .000001), and increased creatinine (P = .000005). Patients who had 0 to 1, 2, 3, or 4 to 5 adverse factors were found to have estimated predictive incidences of acute pulmonary failure of 3%, 13%, 23%, and 34%, respectively.

CONCLUSIONS:

Preventive approaches at the start of induction therapy in patients at high risk of pulmonary failure may improve the outcome of these patients. Cancer 2010. © 2010 American Cancer Society.     

The role of surgery and plastic reconstructive surgery in the treatment of chronic wounds

Summary BACKGROUND: The growing number of older people in our society and better treatment options for chronic diseases like diabetes are leading to higher numbers of patients with chronic wounds. METHODS: After a review of the literature and according to our own experiences the different therapeutic approaches-either conservative or surgical- to chronic wounds are elaborated. RESULTS: In spite of the high number of patients with chronic wounds only few studies concerning operative or conservative treatment are matching the criteria of evidence-based literature. Our own experience has shown that certain forms of decubital ulcers and exulcerated radiation injuries are preferably treated surgically. CONCLUSIONS: Knowledge about conservative and the ability for surgical treatment options of chronic wounds are important for a successful treatment of chronic wounds. Nevertheless more real scientific studies are needed in this field, which will certainly grow a lot in the future.      

Survival outcomes for clonal evolution in chronic myeloid leukemia patients on second generation tyrosine kinase inhibitor therapy

BACKGROUND:

Clonal evolution is frequently detected in patients developing resistance to imatinib. The outcome of patients with clonal evolution treated with second generation tyrosine kinase inhibitors is not known.

METHODS:

The authors analyzed the outcome of 177 CML patients after second tyrosine kinase inhibitor therapy.

RESULTS:

Ninety‐five patients were in chronic phase, 30 had clonal evolution, 28 were in accelerated phase (AP), and 24 were in AP plus clonal evolution. Major cytogenetic response rates were 58%, 54%, 28%, and 13%; 2‐year overall survival (OS) rates were 86%, 73%, 68%, and 33%; and 2‐year event‐free survival (EFS) rates were 69%, 67%, 31%, and 8%, respectively. The hematologic and cytogenetic response rates, OS, and EFS were no different between patients in chronic phase with clonal evolution and patients with chronic phase and no clonal evolution. However, clonal evolution had a significant adverse impact when associated with other features of AP. On multivariate analysis, clonal evolution had no independently significant effect on achieving major cytogenetic response on the second generation tyrosine kinase inhibitors. The factors predicting increasing major cytogenetic response to second generation tyrosine kinase inhibitors were prior achievement of major cytogenetic response with imatinib, higher hemoglobin levels, no splenomegaly, lower percentage of Philadelphia chromosome‐positive metaphases, and no prior chemotherapy.

CONCLUSIONS:

Clonal evolution constitutes a heterogeneous entity with variable outcome with second generation tyrosine kinase inhibitors, with trisomy 8, chromosome 17, and complex abnormalities having the worst outcome, regardless of the number of metaphases involved. The molecular events behind these abnormalities and potential therapeutic approaches directed at them need to be defined. Cancer 2010. © 2010 American Cancer Society.     

Zur pathologisch-anatomischen Begründung der Behandlung mit kolloidem Silber

Zusammenfassung Die schon lange bekannte Affinität der Zellen des reticulo-endothelialen Systems, speziell derKupferschen Sternzellen, für in Blutadern eingeführtes kolloides Silber ist im entzündlich veränderten Gewebe ungleich viel größer ist als im normalen. Die Niederschlagsbildung scheint dem Grad der örtlichen entzündlichen Veränderung annähernd zu entsprechen.Als Ursache für die Ausscheidung körniger Silberniederschläge wird die lokale Acidose des Entzündungsherdes angesehen, welche im weiteren zur Bildung entsprechender Silbersalze führt, deren Eigenschaften als Schwermetallsalze die therapeutische Wirkung bedingen. In gleicher Weise wird die Entstehung der Niederschläge in den durch den Allgemeinzustand stark beeinflußten großen Leibesdrüsen, wie besonders in Leber und Niere, aufgefaßt.Solche bis heute beim Menschen unbekannten Silberimprägnierungen konnten in allen sieben untersuchten Fällen dem Grade nach verschieden nachgewiesen werden. Es wurde damit eine natürliche Erklärung für die therapeutische Wirkungsweise gegeben.Mit 13 Abbildungen im Text.