Compressive Strength of Iliac Bone ECM Is Not Reduced in Osteogenesis Imperfecta and Increases With Mineralization

Osteogenesis imperfecta (OI) is an inheritable, genetic, and collagen-related disorder leading to an increase in bone fragility, but the origin of its “brittle behavior” is unclear. Because of its complex hierarchical structure, bone behaves differently at various length scales. This study aims to compare mechanical properties of human OI bone with healthy control bone at the extracellular matrix (ECM) level and to quantify the influence of the degree of mineralization. Degree of mineralization and mechanical properties were analyzed under dry conditions in 12 fixed and embedded transiliac crest biopsies (control n = 6, OI type I n = 3, OI type IV n = 2, and OI type III n = 1). Mean degree of mineralization was measured by microcomputed tomography at the biopsy level and the mineral-to-matrix ratio was assessed by Raman spectroscopy at the ECM level. Both methods revealed that the degree of mineralization is higher for OI bone compared with healthy control. Micropillar compression is a novel technique for quantifying post-yield properties of bone at the ECM level. Micropillars (d = 5 μm, h = 10 μm) were fabricated using focused ion beam milling and quasi-statically compressed to capture key post-yield properties such as ultimate strength. The qualitative inspection of the stress–strain curves showed that both OI and healthy control bone have a ductile response at the ECM level. The quantitative results showed that compressive strength is not reduced in OI bone and is increasing with OI severity. Nanoindentation measurements revealed that OI bone tends to have a higher Young's modulus, hardness, and dissipated energy compared with healthy bone. Micropillar strength and indentation modulus increased linearly and significantly (p < .0001) with mineral-to-matrix ratio. In conclusion, this study indicates that compressive mechanical properties of dry OI bone at the iliac crest are not inferior to healthy control at the ECM level and increase with mineralization. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).     

Enhancement of peroxisomal enzymes, cytochrome P-452 and DNA synthesis in putative preneoplastic foci of rat liver treated with the peroxisome proliferator nafenopin

The peroxisome proliferator (PP) nafenopin (NAF) enhanced tumordevelopment in rat liver through promotion of a subtype of putativepreneoplastic cell foci, characterized by weak cytoplasmic basophilia(1,2). In order to elucidate the selective growth advantageof these weakly basophilic foci (WBF) we investigated the effectsof NAF on their metabolic phenotype and DNA synthesis. In WBF,as well as in other foci subpopulations and in hepatocellularcarcinomas the occurrence of five NAF-inducible enzymes, i.e.of peroxisomal ß-oxidation (acyl-CoA oxidase, bifunctionalprotein and thiolase), catalase and cytochrome P-452 was studiedby immunohistochemical methods. In untreated livers almost allfoci were stained with the same intensity as the surroundingtissue. When NAF was applied, most of the liver foci showedconsiderably less staining than the non-focal parenchyma inwhich pronounced enzyme induction had occurred. However, thesubpopulation of WBF showed a more heterogeneous pattern ofenzyme expression varying from less to even more than in theadjacent tissue. A similarly broad range of expression of peroxisomalenzymes was found in hepatocellular carcinomas. On average,however, the tumors exhibited less staining and lower activityof peroxisomal ß-oxidation than the surrounding parenchyma.WBF always showed higher rates of DNA synthesis than other focisubtypes and unaltered liver. In     

Correlation between antifungal susceptibility testing ofCandida isolates from patients with HIV infection and clinical results after treatment with fluconazole

Summary In an open-label controlled study 23 HIV-infected patients (CDC IV A–E) with documented oropharyngeal candidosis were treated with 100 mg fluconazole orally over 5 days (53 episodes; 1–6 treatments/patient). Efficacy data were compared with a control group of 21 patients who received treatment for 10–21 days with 100 mg fluconazole for candidosis. Candida isolates were repeatedly recovered from patients before and after treatment with fluconazole and antifungal susceptibility testing (microbroth-dilution) was done. Inoculum size, medium pH, incubation time and temperature were standardized. Up to 85% of patients responded to therapy clinically and mycologically.Candida albicans was the most important yeast (86%) isolated from cultures of oral washings. In 90% ofC. albicans isolates MIC to fluconazole were low (1.56 mg/l). Primary resistance to fluconazole was not seen, but secondary resistance occurred in two cases clinically andin vitro (MIC25 mg/l). Short treatment for 5 days was as successful as for 10 to 21 days without leading to significantly more recurrences of oral candidosis in these patients. Selection ofCandida spp. other thanC. albicans (e. g.Candida krusei, Torulopsis glabrata) under repeated fluconazole treatment occurred rarely. One patient developed clinical signs of chronic recurrent candidiasis, where onlyC. krusei could be cultured repeatedly.

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Korrelation zwischen MHK-Bestimmung bei Candida-Isolaten von Patienten mit HIV-Infektion und Therapieverlauf nach Behandlung mit Fluconazol

Zusammenfassung In einer offenen kontrollierten Studie wurde bei 23 HIV-infizierten Patienten (CDC IV A–E) eine dokumentierte oropharyngeale Candidose mit 100 mg Fluconazol oral über 5 Tage behandelt (53 Episoden; 1–6 Episoden/Patient). Die Ergebnisse wurden mit einer Kontrollgruppe verglichen, in der 21 HIV-infizierte Patienten über 10–21 Tage mit 100 mg Fluconazol behandelt wurden. Von den Patienten wurden vor und nach jeder Therapie mit Fluconazol Candida-Isolate gewonnen, differenziert und einer Resistenztestung unterzogen (Mikro-Dilutionstechnik). Für die Resistenztestung wurden Inokulumgröße, pH des Mediums, Inkubationszeit und -temperatur standardisiert. Bis zu 85% der Patienten zeigten klinisch und mykologisch eine Heilung/Besserung.Candida albicans war der am häufigsten isolierte Hefepilz (86%) aus sämtlichen Proben, die mit Mundspülungen gewonnen wurden. 90% allerC. albicans-Isolate warenin vitro Fluconazol-empfindlich (MHK 1,56 mg/l). Eine Primärresistenz gegenüber Fluconazol wurde nicht beobachtet, aber in zwei Fällen trat sowohl klinisch als auchin vitro eine Fluconazol-Resistenz gegenüberC. albicans auf (MHK 25 mg/l). Eine Behandlung der Candidose mit 100 mg Fluconazol über 5 Tage führte zu einer vergleichbaren Heilungs-/Besserungsrate wie über 10–21 Tage, ohne daß die Rezidivrate wesentlich erhöht war. Eine therapiebedingte Selektion von Nicht-albicans-Arten(Candida krusei, Torulopsis glabrata) nach Fluconazol-Behandlung wurde selten beobachtet. Allerdings bestand bei einem Patienten der (klinische) Verdacht auf eine durchC. krusei unterhaltende orale Candidose, da nurC. krusei wiederholt nachgewiesen werden konnte.

     

Intestinal non-Hodgkin's lymphoma: a multicenter prospective clinical study from the German Study Group on Intestinal non-Hodgkin's Lymphoma.

PURPOSE: Intestinal non-Hodgkin's lymphomas are not well characterized. We therefore studied prospectively their clinical features and response to standardized therapy. PATIENTS AND METHODS: Fifty-six patients with primary intestinal lymphoma were included in a prospective, nonrandomized multicenter study. Lymphoma resection was recommended and staging was performed according to the Ann Arbor classification. Patients were scheduled to receive six cycles of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) chemotherapy, and at stages EIII to EIV, they received additional involved-field radiotherapy. Corticosteroids were used in patients who could not receive chemotherapy. RESULTS: Thirty-five patients had intestinal T-cell lymphoma (ITCL), 21 patients had intestinal B-cell lymphoma (IBCL; 18 diffuse large-cell lymphomas, two marginal-cell lymphomas, and one follicle-center lymphoma). Thirty-four patients at stages EI to EII (14 ITCL and 20 IBCL) and nine patients at stages EIII to EIV (all ITCL) received chemotherapy. No patient in stages EIII to EIV received radiotherapy, because death occurred in 12 of 14 patients. Two-year cumulative survival in patients with IBCL was 94% (95% CI, 82% to 100%) and higher than in patients with ITCL (28% [95% CI, 13% to 43%]; P <.0001), even when only stages EI to EII were considered (ITCL, 37.5% [95% CI, 16.5% to 58.5%]; P <.0001). IBCL patients compared with ITCL patients were at lower lymphoma stages (P <.01), had higher Karnofsky status (P <.005), had intestinal perforation less often (P <.05), required emergency operation less often (P <.05), received CHOP (P <.05) more often, and reached complete remission (P <.0005) more frequently. CONCLUSION: IBCL patients at stages EI and EII respond well to chemotherapy, but the prognosis and treatment of ITCL patients is unsatisfactory.     

Specialized DNA arrays for the differentiation of pancreatic tumors.

PURPOSE: Malignant tumors of the pancreas are frequently indistinguishable from inflammatory tumors arising in the context of a chronic pancreatitis with the use of conventional imaging techniques. Thus, cytologic analysis of cells obtained by abdominal ultrasound, computed tomography, or endoscopic ultrasound-guided fine needle aspiration biopsy is required for diagnosis. However, the reliability of cytologic analyses of pancreatic fine needle aspirates remains unsatisfactory, with a diagnostic accuracy of < or =80%. The purpose of the current study was therefore to develop a novel diagnostic approach based on expression profiling of biopsy material using a specialized diagnostic cDNA array. EXPERIMENTAL DESIGN: Previous gene expression profiling studies were reevaluated to design a 558-feature diagnostic array. Minimal amounts of residual material from pancreatic cytology samples as well as surgically resected tumor and control tissue specimens were analyzed using the diagnostic array and a newly developed statistical classification system. RESULTS AND CONCLUSIONS: Our diagnostic approach resulted in 95% accurate differentiation between ductal adenocarcinomas and nonmalignant tumors of the pancreas. The diagnostic array, in conjunction with conventional diagnostic procedures, is thus suitable to significantly improve the reliability of pancreatic cancer diagnostics and can be expected to become a valuable new tool in the routine workup of suspect masses in the pancreas.     

Risk-Adjusted Cancer Screening and Prevention (RiskAP): Complementing Screening for Early Disease Detection by a Learning Screening Based on Risk Factors

BackgroundRisk-adjusted cancer screening and prevention is a promising and continuously emerging option for improving cancer prevention. It is driven by increasing knowledge of risk factors and the ability to determine them for individual risk prediction. However, there is a knowledge gap between evidence of increased risk and evidence of the effectiveness and efficiency of clinical preventive interventions based on increased risk. This gap is, in particular, aggravated by the extensive availability of genetic risk factor diagnostics, since the question of appropriate preventive measures immediately arises when an increased risk is identified. However, collecting proof of effective preventive measures, ideally by prospective randomized preventive studies, typically requires very long periods of time, while the knowledge about an increased risk immediately creates a high demand for action.SummaryTherefore, we propose a risk-adjusted prevention concept that is based on the best current evidence making needed and appropriate preventive measures available, and which is constantly evaluated through outcome evaluation, and continuously improved based on these results. We further discuss the structural and procedural requirements as well as legal and socioeconomical aspects relevant for the implementation of this concept.     

Suramin induces and enhances apoptosis in a model of hyperoxia-induced oligodendrocyte injury

Recent evidence suggests oxygen as a powerful trigger for cell death in the immature white matter, leading to periventricular leukomalacia (PVL) as a cause of adverse neurological outcome in survivors of preterm birth. This oligodendrocyte (OL) death is associated with oxidative stress, upregulation of apoptotic signaling factors (i.e., Fas, caspase-3) and decreased amounts of neurotrophins. In search of neuroprotective strategies we investigated whether the polysulfonated urea derivative suramin, recently identified as a potent inhibitor of Fas signaling, affords neuroprotection in an in vitro model of hyperoxia-induced injury to immature oligodendrocytes. Immature OLs (OLN-93) were subjected to 80% hyperoxia (48 h) in the presence or absence of suramin (0, 30, 60, 120 microM). Cell death was assessed by flow cytometry (Annexin V, caspase-3 activity assay) and immunohistochemistry for activated caspase-3. Immunoblotting for the death receptor Fas, cleaved caspase-8 and the phosphorylated isoform of the serine-threonin kinase Akt (pAkt) was performed. Suramin lead to OL apoptosis and potentiated hyperoxia-induced injury in a dose-dependent manner. Immunoblotting revealed increased Fas and caspase-8 expression by suramin treatment. This effect was significantly enhanced when suramin was combined with hyperoxia. Furthermore, pAkt levels decreased following suramin exposure, indicating interference with neurotrophin-dependent growth factor signaling. These data indicate that suramin causes apoptotic cell death and aggravates hyperoxia-induced cell death in immature OLs. Its mechanism of action includes an increase of previously described hyperoxia-induced expression of pro-apoptotic factors and deprivation of growth factor dependent signaling components.     

Outpatient Care: Planning a Satellite Laboratory for Ambulatory Patient Care

Peripheral neuropathy is a common consequence of diabetes that often results in loss of protective sensation. Early identification of this loss is critical to minimize secondary complications. The authors’ purpose was to assess the behavior patterns of physical therapists as to their opinions and behaviors related to sensory testing for individuals with diabetes. A questionnaire was sent to physical therapists across the United States with the following results: a high level of agreement concerning the benefits of sensory testing, but with a far less agreement as to the actual performance of sensory testing by those same physical therapists.