Gap junctional control of glial glutamate transporter expression

The uptake of glutamate into astroglia is the predominant mechanism to terminate glutamatergic neurotransmission and to prevent neurotoxic extracellular glutamate concentrations. Here, we show that uncoupling cultured cortical astrocytes with the gap junction blocker, propofol, or the Cx43 mimetic peptide, Gap27, inhibits the expression of GLT-1, the major glutamate transporter subtype in the cortex. The dependence of GLT-1 expression on gap junctions was further confirmed by the use of astrocytes in which either the expression of Cx43, the major astrocytic gap junction protein, was inhibited by RNA interference or which were derived from animals carrying an astrocyte-specific deletion of the Cx43 gene. In both cases, reduced astrocytic coupling was associated with a pronounced decline in GLT-1 expression. Finally, a luciferase reporter gene assay demonstrated that blockade of gap junctions/connexins suppressed transcriptional activity of GLT-1 promoter. These observations unravel a previously unrecognized role of gap junctions in the control of glial glutamate transport.

Die Erfassung psychosozialer Belastungen und Ressourcen in der Onkologie - Ein Literaturüberblick zu Screeningmethoden und Entwicklungstrends

A substantial percentage of cancer patients suffers from psychosocial distress to severe mental disorders and psychosocial crisis during the course of the illness and cancer treatment. However, only a small percentage of patients with severe psychosocial distress and mental disorders in the present oncological practice is accurately identified, diagnosed, and appropriately treated. Therefore, sufficient knowledge about psychosocial distress and mental disorders as well as screening procedures are urgent concerns to improve psychosocial care for cancer patients. First, the article provides an overview of psychosocial distress and the epidemiology of mental disorders in cancer patients. Then a few of the most important objectives and problems of psychosocial assessment in cancer patients will be explained. The following part will offer an overview of questionnaires and screening procedures that are frequently used to assess psychosocial distress, mental disorders, personal and social resources, and health related quality of life in cancer patients.

Serum osmolality and outcome in intensive care unit patients

BACKGROUND

The aim of the present study was to compare 16 routine clinical and laboratory parameters, acute physiologic and chronic health evaluation (APACHE) and sequential organ failure assessment (SOFA) score for their value in predicting mortality during hospital stay in patients admitted to a general intensive care unit (ICU).

METHODS

A retrospective observational clinical study was carried out in a 15-bed ICU in a university hospital. Nine hundred and thirty-three consecutive patients with ICU stay > 24 h (36.2% surgical, 29.1% medical and 34.7% trauma) were observed. Blood sampling, patient surveillance and data collection were performed. The primary outcome was mortality in the hospital. We used receiver operating characteristic (ROC) analyses and logistic regression to compare the 16 relevant parameters, APACHE II and SOFA scores.

RESULTS

Two hundred and thirty-three out of the 933 patients died (mortality 25.0%). One laboratory parameter, serum osmolality [area under the curve (AUC) 0.732] had a predictive value for mortality which lay between that of APACHE II (AUC 0.784) and SOFA (AUC 0.720) scores. When outcome prediction was restricted to long-term patients (ICU stay > 5 days), serum osmolality (AUC 0.711) performed better than either of the standard scores (APACHE AUC 0.655, SOFA AUC 0.636). Using logistic regression analysis, the association of clinical parameters, age and diagnosis group with mortality was determined.

CONCLUSION

Elevated serum osmolality at ICU admission is associated with an increased mortality risk in critically ill patients. Serum osmolality is cheaper and more rapid to determine than the scoring systems. However, further studies are needed to evaluate the predictive value of serum osmolality in different patient populations.

Rapid Improvement of Liver Function in a Patient with HIV and Hepatitis B Coinfection Treated with Lamivudine and Tenofovir

Since the introduction of HAART, the clinical importance of hepatitis virus infection and its complications in human immunodeficiency virus (HIV)-infected persons have continuously grown. Coinfection with hepatitis B virus (HBV) and HIV is one of the leading causes of morbidity and mortality. To date, neither the optimal time point for initiation of anti-HBV therapy nor the best therapeutic approach has been clearly defined. We report the case of a 22-year-old African woman infected with HBV- and HIV-1 coinfection and severe impairment of liver function. HAART including lamivudine and tenofovir was started. Three weeks later, the patient achieved not only a restoration of her clinical situation and liver function, but she also demonstrated a complete suppression of both viruses. This impressive clinical course might be explained by the application of antiviral combination therapy including lamivudine and tenofovir. Tenofovir has shown a higher activity against HBV than other drugs. In addition, combination therapy for chronic hepatitis B might be more effective than monotherapy. Future studies need to clarify the value of combination treatment for patients with chronic hepatitis B.

[Solitary fibrous tumor of the liver]

Solitary fibrous tumor (SFT) is commonly found on serosal surfaces, and is rarely localized in the liver. There are benign and malignant variants of hepatic SFT. We report a new case of benign SFT. Our patient, a 63-year old woman, who has been followed for 5 years for an asymptomatic liver mass, was admitted for abdominal pain. Ultrasonography (US), CT, MR Imaging and angiography showed the liver mass with typical imaging features, situated in the right hepatic lobe with blood supply from the hepatic artery. Histopathological examination demonstrated a highly vascularized tumor, composed of short spindle cells alternating with hypocellular collagenous regions, with a hemangiopericytoma-like vascular pattern. The immunohistochemical staining was positive for CD 34. Tumor resection was performed. Follow-up 8 years after the resection showed no tumor recurrence or metastasis, thus confirming the initial diagnosis of benign SFT.

Die deutsche Version des NCCN Distress-Thermometers

Zusammenfassung: Das NCCN Distress-Thermometer ist ein vom National Comprehensive Cancer Network (NCCN) entwickeltes Screeninginstrument zur Erfassung psychosozialer Belastungen bei onkologischen Patienten. Es besteht aus einer Skala von 0 bis 10 und einer Problemliste als Überweisungsschema zu entsprechenden professionellen Diensten. International wird ein Cut-off-Wert von 5 als Signal empfohlen, dass ein Patient auffällig belastet ist und Unterstützung benötigt. Die deutsche Adaptation erfolgte an einer Stichprobe von n = 475 Krebspatienten in der onkologischen Rehabilitation. Zur Validierung wurde die Hospital Anxiety and Depression Scale (HADS-D) und die Kurzform des Fragebogens zur Progredienzangst (PA-F 12) eingesetzt. Die Diskriminationsfähigkeit des Distress-Thermometers ist besonders zur Identifikation einer hohen Belastung (HADS Cut-off > 11) mit AUC-Werten von 0.71 bis 0.76 gut. Bei einem Cut-off-Wert von 5 im Distress-Thermometer zeigen sich bei moderater Belastung in den Merkmalen Angst und/oder Depressivität (HADS Cut-off > 8) eine Sensitivität bis 84 % und eine deutlich niedrigere Spezifität von bis zu 47 %. Bei einem HADS Cut-off > 11 und einem Cut-off-Wert von 5 im Distress-Thermometer liegen die Sensitivitätswerte bei bis zu 97 % und die Spezifitätswerte bei 41 %. Die Spezifität des Instruments ist in der deutschen Stichprobe niedriger als die in internationalen Studien gefundenen Werte, die Sensitivität ist entsprechend höher. Das NCCN Distress-Thermometer stellt aufgrund seiner hohen Akzeptanz, seiner Kürze und guten Praktikabilität im klinischen Alltag ein Screeninginstrument dar, das für den weiteren Einsatz in der onkologischen Versorgung empfohlen werden kann.

AIDS-related progressive multifocal leukoencephalopathy in the era of HAART: report of two cases and review of the literature

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system. It is caused by the JC virus (JCV), a human polyomavirus replicating in human glial cells. PML is the result of the reactivation of latent JCV infection that usually occurs in the setting of cellular immunodeficiencies such as HIV-1 infection. Epidemiologic data suggest that the impact of highly active antiretroviral therapy (HAART) on the incidence of PML is less profound than seen with other opportunistic infections. Given the lack of an effective and specific therapy for PML, HAART remains the only therapeutic option in patients with PML. However, a significant number of cases appear unresponsive to antiretroviral therapy. Moreover, there is growing data on unexpected inflammatory cases of PML after initiation of HAART. Thus, PML will remain a relevant cause of morbidity and mortality in HIV- 1-infected patients. Here we report two cases of PML, along with a concise review of the literature on this important disease.

Successful administration of aggressive chemotherapy concomitant to tuberculostatic and highly active antiretroviral therapy in a patient with AIDS-related Burkitt's lymphoma

Treatment of AIDS-related malignant lymphoma (ARL) remains a therapeutic challenge. There are concerns not only about infectious and haematological complications in HIV-infected patients during intensive chemotherapy, but also about potential interactions between chemotherapy and highly active antiretroviral therapy (HAART). Current data on patients treated concomitantly with intensive chemotherapy and HAART are limited, and no data exist on patients with ARL suffering from active opportunistic infections. We report the case of a 38-year-old man with advanced HIV-1 infection, pulmonary tuberculosis and Burkitt's lymphoma. Intensive chemotherapy was administered in parallel with tuberculostatic therapy and HAART. Six months later, the patient achieved not only a complete remission of Burkitt's lymphoma and sustained viral suppression, but also a full recovery from tuberculosis. This case report provides some useful observations on the successful application of intensive chemotherapy in addition to tuberculostatic therapy and HAART in HIV-infected patients.

Axon pathfinding and the floor plate factor Reissner's substance in wildtype, cyclops and one-eyed pinhead mutants of Danio rerio

The ventral median floor plate (FP) is a well-examined embryonic structure, which is involved in neuron differentiation and axon outgrowth. The FP of different vertebrates expresses the glycoprotein Reissner's substance (RS). This glycoprotein is also produced by the dorsal median subcommissural organ (SCO). We examined if the dorsal SCO and the ventral FP are interdependent for the expression of RS and looked for indications for a role of RS in axon outgrowth. Therefore, we examined zebrafish embryos of wildtype (wt) and the mutants cyclops(tf219) (cyc) and one-eyed pinhead(tz257) (oep), which both lack the FP. Our studies demonstrate that the FP is not necessary in order to induce the expression of RS in the SCO. The pattern of the anti-RS immunolabelling in the mutants is, however, changed compared to wt zebrafish embryos. As a consequence of the lacking FP and the degenerated ventricle system in cyc and oep mutants, a Reissner's fibre (RF) is not formed. Our studies confirm earlier results about the axon growth in cyc mutants, and provide the first detailed data about the aberrant axon growth in oep mutants. The modified outgrowth of the medial longitudinal fascicle in both mutants could be associated with the lack of RS/RF in the rhombencephalon and spinal cord. The neurites of the posterior commissure follow the aberrant position of the SCO in oep mutants. Our results suggest that both the RS of the ventral FP/flexural organ (FO) and the RS of the dorsal SCO have an influence on the outgrowth of axons and formation of commissures.