Discovery and characterization of a selective, nonpeptidyl thrombopoietin receptor agonist

OBJECTIVE: Peptide and other small molecule agonists have been described for several cytokines and growth factors. Hydrazone compounds described here as thrombopoietin receptor agonists were identified as activating STAT proteins in a Tpo responsive cell line. METHODS: STAT activation and analysis of signal transduction pathways in cell lines and normal human platelets was elucidated by Western blot and electrophoretic mobility shift assays. Proliferation assays in cell types responsive to other cytokines determined specificity for Tpo receptor. Flow cytometry quantified differentiation of CD34(+) cells into CD41(+) megakaryocytes and platelet production in vitro. RESULTS: Activation of STAT5, mitogen-activated protein kinase, p38, and early response genes by SB 394725 was similar to that induced by Tpo. SB 394725 induced a reporter gene response under a STAT activation promoter as well as the megakaryocyte-specific gpIIb promoter. The compound induced proliferation of Tpo responsive lines but demonstrated no activity in cell lines responding to other cytokines, i.e., erythropoietin, granulocyte-colony stimulating factor, interleukin-3, interferon-gamma. The response of normal human Tpo receptors was elucidated by measuring growth and differentiation of human bone marrow in vitro. Activation of endogenous Tpo receptors by SB 394725 was demonstrated in human and chimp platelets, but not in platelets of other species including mouse, dog, rabbit, or cynomolgus monkey. CONCLUSIONS: SB 394725, a small molecule with a molecular weight of 452 Da, is capable of activating Tpo-specific signal transduction, proliferation, and differentiation responses similar to the responses and functions of the protein growth factor, Tpo.     

Gonorrhoea in the asymptomatic patient: Presentation and the role of contact tracing for heterosexual men and women and for homosexual men

Summary Clinically silent gonorrhoea is the major problem in the control of the disease. Only 12 per cent of infected women reported in 1974 because of symptoms, compared with 97 per cent of infected heterosexual men and only 35 per cent of homosexual men with gonococcal proctitis alone. Homosexual men, compared with heterosexual men, had twice as many subsequent sexual contacts after infection and had a higher incidence of early syphilis. Eighty-four per cent had experienced passive anorectal intercourse. Ninety-seven per cent of men with gonococcal urethritis reported because of symptoms, but occasionally (particularly after unsuccessful treatment) urethral gonorrhoea in men may be clinically silent and even require tests of the overnight urethral secretion for diagnosis. For women, and for homosexual men who have had passive anorectal (or oral) intercourse, the indication for attendance for tests for gonorrhoea should be having run the risk, and not the presence of symptoms. Routine tests of the anorectum for gonorrhoea are essential in cases of women at risk, and for most homosexual men since over 80 per cent of these men will have had passive anorectal intercourse. Because gonococcal infections following treatment-failure are often clinically silent in both women and men, symptoms cannot be relied upon to indicate such failure. Follow-up smears and cultures are always essential.

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Kasuistik von Patienten mit asymptomatischer Gonorrhöe und die Bedeutung der durch Personen durchgeführten Kontaktermittlung bei heterosexuellen Männern und Frauen sowie bei homosexuellen Männern

Zusammenfassung Die asymptomatische Gonorrhöe ist das Hauptproblem bei der Kontrolle dieser Krankheit. Nur 12 Prozent der erfaßten infizierten Frauen im Jahre 1974 kamen wegen Beschwerden zur Untersuchung im Gegensatz zu 97 Prozent der infizierten heterosexuellen Männer und nur 35 Prozent der homosexuellen Männer mit isolierter gonorrhoischer Proktitis. Im Vergleich mit heterosexuellen Männern hatten homosexuelle Männer zweimal so viel sexuelle Kontakte nach der Infektion und eine höhere Inzidenz einer Syphilis im Frühstadium. 84 Prozent hatten passiven anorektalen Verkehr gehabt. 97 Prozent der Männer mit gonorrhoischer Urethritis meldeten sich wegen Beschwerden, aber gelegentlich (insbesondere nach unzureichender Behandlung) kann die gonorrhoische Urethritis bei Männern klinisch stumm sein und sie kann sogar Untersuchungen der nächtlichen urethralen Sekretion zur Diagnose erfordern. Für Frauen und für homosexuelle Männer, die passiven anorektalen (oder oralen) Verkehr gehabt haben, sollte der Grund ihres Kommens nicht das Vorhandensein von Symptomen sein, sondern ein mögliches eingegangenes Infektionsrisiko. Routine-Untersuchungen der Analgegend auf Gonorrhöe sind bei Frauen nach entsprechendem Geschlechtsverkehr unbedingt erforderlich, gleichfalls bei den meisten homosexuellen Männern, weil über 80 Prozent dieser Männer wohl einen passiven anorektalen Verkehr gehabt haben werden. Da Gonokokken-Infektionen nach Behandlungsversagen bei Männern und Frauen oft asymptomatisch sind, ist das Verschwinden der Symptome keine verläßliche Indikation für eine erfolgreiche Behandlung. Ständige Überwachung in Form von Abstrichen und kulturellen Untersuchungen ist auf alle Fälle erforderlich.

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This paper was presented in part on 27 September 1974 at a meeting of the British Society for Antimicrobial Chemotherapy.     

Identification of altered dipeptidyl-peptidase activities as potential biomarkers for unipolar depression

Background

Changes in circulatory aminopeptidases [dipeptidyl-peptidase-IV (DPP-IV), Prolyl-oligopeptidase (POP) and Leucine aminopeptidase (LAP)] activities have been found to be associated with psychiatric illnesses and inflammatory diseases.

Methods

The discriminatory indices of aminopeptidases activities were assessed by enzymatic assays in plasma samples from 240 unipolar depression (UD) patients and 264 matched controls. In addition the relationship between soluble and cellular DPP-IV activity was determined in plasma and blood cells from healthy subjects.

Results

Greater than 95% of the plasma DPP-IV activity could be blocked by inhibitors, demonstrating the specificity of the assay. Also, DPP-IV protein and activity levels were strongly correlated. In contrast, only 50% of the membrane-bound activity in blood cells was inhibited, which suggested that other similar peptidases may be present in these cells. UD patients had decreased plasma levels of DPP-IV and POP activities compared to healthy controls with a concomitant increase in LAP activity. Finally, testing of the LAP/DPP-IV ratio resulted in good discrimination of UD patients from controls with an area under the curve—receiver operating characteristic of 0.70.

Limitations

Further biological validation studies using different cohorts are warranted.

Conclusions

The finding that plasma DPP-IV activity was decreased and LAP activity was increased in UD patients suggests the potential value for testing the levels of these enzymes for improved classification of patients. In addition, the changes in these enzymes, suggests that the proteolytic maturation of their proneuropeptide and prohormone subtrates may also be affected in UD, resulting in altered production of the associated bioactive peptides.     

Coal fly ash is a major carbon flux in the Chang Jiang (Yangtze River) basin

Fly ash—the residuum of coal burning—contains a considerable amount of fossilized particulate organic carbon (FOC_ash) that remains after high-temperature combustion. Fly ash leaks into natural environments and participates in the contemporary carbon cycle, but its reactivity and flux remained poorly understood. We characterized FOC_ash in the Chang Jiang (Yangtze River) basin, China, and quantified the riverine FOC_ash fluxes. Using Raman spectral analysis, ramped pyrolysis oxidation, and chemical oxidation, we found that FOC_ash is highly recalcitrant and unreactive, whereas shale-derived FOC (FOC_rock) was much more labile and easily oxidized. By combining mass balance calculations and other estimates of fly ash input to rivers, we estimated that the flux of FOC_ash carried by the Chang Jiang was 0.21 to 0.42 Mt C⋅y⁻¹ in 2007 to 2008—an amount equivalent to 37 to 72% of the total riverine FOC export. We attributed such high flux to the combination of increasing coal combustion that enhances FOC_ash production and the massive construction of dams in the basin that reduces the flux of FOC_rock eroded from upstream mountainous areas. Using global ash data, a first-order estimate suggests that FOC_ash makes up to 16% of the present-day global riverine FOC flux to the oceans. This reflects a substantial impact of anthropogenic activities on the fluxes and burial of fossil organic carbon that has been made less reactive than the rocks from which it was derived.

Fossil particulate organic carbon (FOC) is a geologically stable form of carbon that was produced by the ancient biosphere and then buried and stored in the lithosphere; it is a key player in the geological carbon cycle (1–7). Uplift and erosion liberate FOC from bedrock, delivering it to the surficial carbon cycle. Some is oxidized in sediment routing systems, but a portion escapes and can be transported by rivers to the oceans (5, 8–10). Oxidation of FOC represents a long-term atmospheric carbon source and O₂ sink, whereas the reburial of FOC in sedimentary basins has no long-term net effect on atmospheric CO₂ and O₂ (1, 9, 11). Exhumation and erosion of bedrock provide a natural source of FOC (2, 8), which we refer to as FOC_rock. Human activities have introduced another form of FOC from the mining and combustion of coal. Burning coal emits CO₂ to the atmosphere but also leaves behind solid waste that contains substantial amounts of organic carbon (OC) that survives high-temperature combustion (12–14). This fossil-fuel-sourced carbon represents a poorly understood anthropogenic flux in the global carbon cycle; it also provides a major source of black carbon, which is a severe pollutant and climate-forcing agent (12–15).Previous studies sought to quantify black carbon in different terrestrial and marine environments and to distinguish fossil fuel versus forest fire sources (14–18). In this study, we focused on fly ash—the material left from incomplete coal combustion. As a major fossil fuel, coal supplies around 30% of global primary energy consumption (19, 20). Despite efforts to capture and utilize fly ash, a fraction enters soils and rivers; the resulting fossil OC from fly ash (FOC_ash) has become a measurable part of the contemporary carbon cycle (14). FOC_ash is also referred to as “unburned carbon” in fly ash (21–25); it provides a useful measure of combustion efficiency and the quality of fly ash as a building material (e.g., in concrete) (23–26). Industrial standards of FOC_ash content in fly ash have been established for material quality assurance (23, 24, 26, 27). However, the characteristics and fluxes of FOC_ash released to the environment, and how these compare to FOC_rock from bedrock erosion, remain less well understood.To fill this knowledge gap, we examined the Chang Jiang (Yangtze River) basin in China—a system that allowed us to evaluate the influence of FOC_ash on the carbon cycle at continental scales. In the 2000s, China became the largest coal-consuming country in the world, with an annual coal consumption of over 2,500 Mt, equating to ∼50% of worldwide consumption (19, 20, 28). Coal contributed over 60% of China’s national primary energy consumption through the 2000s. A significant portion of this coal (approximately one-third) was consumed in the Chang Jiang (CJ) basin, where China’s most populated and economically developed areas are located (29). Significant amounts of fly ash and FOC_ash continue to be produced and consumed in the CJ basin. To determine the human-induced FOC_ash flux, we investigated the FOC_ash cycle in the CJ basin. We characterized OC in a series of samples including fly ash, bedrock sedimentary shale, and river sediment through multiple geochemical analyses. We then estimated the CJ-exported FOC_ash flux and evaluated how human activities modulated FOC transfer at basin scales. We found that in the CJ basin, coal combustion and dam construction have conspired to boost the FOC_ash flux and reduce the FOC_rock flux carried by the CJ; as a result, these two fluxes converged over an interval of 60 y.     

Focal nodular hyperplasia: a review of current indications for and outcomes of hepatic resection

Background

Focal nodular hyperplasia (FNH) is a common benign disease of the liver with no recognized potential for malignant transformation. The term describes an entity of lobular proliferation of normally differentiated hepatocytes, frequently around a central fibrous scar. Two key issues influence surgical decision making in FNH: diagnostic certainty, and symptomatic assessment.

Methods

A systematic review of studies reporting hepatic resections of FNH was performed. Indications and outcomes in adult populations were examined with a focus on diagnostic workup, patient selection and operative mortality and morbidity.

Results

Diagnostic modalities in the majority of studies involved ultrasound and computed tomography. Fewer than half employed magnetic resonance imaging (MRI). In instances in which MRI was not available, diagnostic accuracy was inferior.

Conclusions

Percutaneous biopsy should be avoided to prevent the risk for tumour seeding. Patients presenting with asymptomatic definitive FNH can be safely managed conservatively. In symptomatic patients surgical resection is a safe and effective treatment for which acceptable rates of morbidity (14%) and zero mortality are reported. However, evidence of symptom resolution is reported with conservative strategies. Diagnostic uncertainty remains the principal valid indication for FNH resection, but only in patients in whom contrast-enhanced MRI forms part of preoperative assessment.     

The risks of red cell transfusion for hip fracture surgery in the elderly

Background and Objectives The benefits and indications for blood transfusion among surgical patients are controversial. There is evidence which suggests that blood transfusion is associated with poor clinical outcomes and risks of infection, but there are few data in the elderly population. Materials and Methods Data were collected on haemoglobin concentrations and transfusions in 919 patients undergoing hip fracture repair at a university hospital over a 2‐year period. 28‐day and 180‐day mortality were specified as primary outcomes. A composite infection outcome (chest infections, urinary tract infections and wound infections) was the main secondary outcome. Preoperative, operative and/or postoperative transfusions were the main exposure variable. Regression analyses were used to explore the associations between transfusion and outcomes, adjusting for pre‐defined preoperative variables. Results 300 patients (32·6%) were transfused at least once during their admission. There was no evidence of a significant difference in either 28‐day survival or 180‐day survival between transfused and non‐transfused hip fracture patients. The transfused group had higher adjusted composite infection rate (HR, 1·91; 95% CI, 1·41–2·59, P < 0·001) and prolonged length of stay in hospital than the non‐transfused group (HR, 1·15; 95% CI, 1·07, 1·23, P < 0·001). Anaemia at the time of admission, extra capsular fracture and using walking aids in an indoor setting were preoperative variables, which predicted the need for transfusion. Conclusion Among an elderly population with hip fracture, blood transfusion was not associated with changes in mortality, but was associated with an increased rate of postoperative infection. These data add to the wider literature about adverse clinical outcomes in patients receiving blood transfusions and emphasises the need for prospective trials to evaluate the role of transfusion in the elderly.