Creutzfeldt-Jakob disease and blood transfusion safety.

Transmissible spongiform encephalopathies (TSEs) are untreatable, fatal neurologic diseases affecting mammals. Human disease forms include sporadic, familial and acquired Creutzfeldt-Jakob disease (CJD). While sporadic CJD (sCJD) has been recognized for near on 100 years, variant CJD (vCJD) was first reported in 1996 and is the result of food-borne transmission of the prion of bovine spongiform encephalopathy (BSE, 'mad cow disease'). Currently, 230 vCJD cases have been reported in 12 countries, the majority in the UK (178) and France (27). Animal studies demonstrated highly efficient transmission of natural scrapie and experimental BSE by blood transfusion and fuelled concern that sCJD was potentially transfusion transmissible. No such case has been recorded and case-control evaluations and lookback studies indicate that, if transfusion transmission occurs at all, it is very rare. In contrast, four cases of apparent transfusion transmission of vCJD infectivity have been identified in the UK. Risk minimization strategies in response to the threat of vCJD include leucodepletion, geographically based donor deferrals and deferral of transfusion recipients. A sensitive and specific, high-throughput screening test would provide a potential path to mitigation but despite substantial effort no such test has yet appeared. The initial outbreak of vCJD appears to be over, but concern remains about subsequent waves of disease among those already infected. There is considerable uncertainty about the size of the infected population, and there will be at least a perception of some continuing risk to blood safety. Accordingly, at least some precautionary measures will remain in place and continued surveillance is necessary.

PIFA-mediated ethoxyiodination of enamides with potassium iodide.

The regioselective ethoxyiodination of enamides was developed using PIFA in combination with potassium iodide in ethanol. The reaction proceeds regioselectively with excellent yields and diastereoselectivities, providing valuable synthons for further functionalisations. Control experiments were conducted, indicating that the transformation occurs through an ionic manifold involving an in situ generated hypoiodite species.

Current and future implications of basic and translational research on amyloid-ß peptide production and removal pathways.

Inherited variants in multiple different genes are associated with increased risk for Alzheimer's disease (AD). In many of these genes, the inherited variants alter some aspect of the production or clearance of the neurotoxic amyloid ß-peptide (Aß). Thus missense, splice site or duplication mutants in the presenilin 1 (PS1), presenilin 2 (PS2) or the amyloid precursor protein (APP) genes, which alter the levels or shift the balance of Aß produced, are associated with rare, highly penetrant autosomal dominant forms of Familial Alzheimer's Disease (FAD). Similarly, the more prevalent late-onset forms of AD are associated with both coding and non-coding variants in genes such as SORL1, PICALM and ABCA7 that affect the production and clearance of Aß. This review summarises some of the recent molecular and structural work on the role of these genes and the proteins coded by them in the biology of Aß. We also briefly outline how the emerging knowledge about the pathways involved in Aß generation and clearance can be potentially targeted therapeutically. This article is part of Special Issue entitled "Neuronal Protein".

Transfusion-associated AIDS: serologic evidence of human T-cell leukemia virus infection of donors.

An assay for antibodies to membrane antigens of cells infected by human T-cell leukemia virus was used to examine serum from persons who donated blood to 12 patients with acquired immunodeficiency syndrome (AIDS) associated with blood transfusions. The occurrence of positive results in the assay was significantly greater among donors to the AIDS patients (9 of 117; 7.7 percent) than among random donors (1 of 298; 0.3 percent). Of 12 sets of donors examined, 9 sets included a donor whose serum gave positive results for the presence of the antibodies. In six of these nine sets, the seropositive donor was an individual who was also identified as a possible source of AIDS transmission when epidemiologic and immunologic criteria were used.

The expression and function of Ca(2+)-sensing receptors in rat mesenteric artery; comparative studies using a model of type II diabetes.

BACKGROUND AND PURPOSE: The extracellular calcium-sensing receptor (CaR) in vascular endothelial cells activates endothelial intermediate-conductance, calcium-sensitive K(+) channels (IK(Ca)) indirectly leading to myocyte hyperpolarization. We determined whether CaR expression and function was modified in a rat model of type II diabetes. EXPERIMENTAL APPROACH: Pressure myography, western blotting, sharp microelectrode and K(+)-selective electrode recordings were used to investigate the functional expression of the CaR and IK(Ca) in rat mesenteric arteries. KEY RESULTS: Myocyte hyperpolarization to the CaR activator calindol was inhibited by Calhex 231. U46619-induced vessel contraction elevated the extracellular [K(+)] around the myocytes, and inhibition of this 'K(+) cloud' by iberiotoxin was needed to reveal calindol-induced vasodilatations. These were antagonized by Calhex 231 and significantly smaller in Zucker diabetic fatty rat (ZDF) vessels than in Zucker lean (ZL) controls. Myocyte hyperpolarizations to calindol were also smaller in ZDF than in ZL arteries. In ZDF vessels, endothelial cell CaR protein expression was reduced; IK(Ca) expression was also diminished, but IK(Ca)-generated hyperpolarizations mediated by 1-EBIO were unaffected. CONCLUSIONS AND IMPLICATIONS: The reduced CaR-mediated hyperpolarizing and vasodilator responses in ZDF arteries result from a decrease in CaR expression, rather than from a modification of IK(Ca) channels. Detection of CaR-mediated vasodilatation required the presence of iberiotoxin, suggesting a CaR contribution to vascular diameter, that is, inversely related to the degree of vasoconstriction. Compromise of the CaR pathway would favour the long-term development of a higher basal vascular tone and could contribute to the vascular complications associated with type II diabetes.

Patient Outcomes and Cerebral Infarction after Ruptured Anterior Communicating Artery Aneurysm Treatment.

BACKGROUND AND PURPOSE: Anterior communicating artery aneurysm rupture and treatment is associated with high rates of dependency, which are more severe after clipping compared with coiling. To determine whether ischemic injury might account for these differences, we characterized cerebral infarction burden, infarction patterns, and patient outcomes after surgical or endovascular treatment of ruptured anterior communicating artery aneurysms. MATERIALS AND METHODS: We performed a retrospective cohort study of consecutive patients with ruptured anterior communicating artery aneurysms. Patient data and neuroimaging studies were reviewed. A propensity score for outcome measures was calculated to account for the nonrandom assignment to treatment. Primary outcome was the frequency of frontal lobe and striatum ischemic injury. Secondary outcomes were patient mortality and clinical outcome at discharge and at 3 months. RESULTS: Coiled patients were older (median, 55 versus 50 years; P = .03), presented with a worse clinical status (60% with Hunt and Hess Score >2 versus 34% in clipped patients; P = .02), had a higher modified Fisher grade (P = .01), and were more likely to present with intraventricular hemorrhage (78% versus 56%; P = .03). Ischemic frontal lobe infarction (OR, 2.9; 95% CI, 1.1-8.4; P = .03) and recurrent artery of Heubner infarction (OR, 20.9; 95% CI, 3.5-403.7; P < .001) were more common in clipped patients. Clipped patients were more likely to be functionally dependent at discharge (OR, 3.2; P = .05) compared with coiled patients. Mortality and clinical outcome at 3 months were similar between coiled and clipped patients. CONCLUSIONS: Frontal lobe and recurrent artery of Heubner infarctions are more common after surgical clipping of ruptured anterior communicating artery aneurysms, and are associated with poorer clinical outcomes at discharge.

Salivary gland adenoid cystic carcinoma: a review of chemotherapy and molecular therapies.

Adenoid cystic carcinoma (ACC) accounts for about 1% of all head and neck malignancies. It has a tendency for a prolonged clinical course, with local recurrences and distant metastases sometimes occurring many years after presentation. Standard treatment for salivary gland ACC is surgery and post-operative radiotherapy. The aim of this review was to examine the reported efficacy of various chemotherapy regimens and molecular therapies on recurrent/metastatic salivary gland ACC. One hundred and fourteen publications were reviewed on chemotherapy as well as possible molecular targets of therapy, including KIT, epidermal growth factor receptor (EGFR), human epidermal growth receptor-2 (HER-2), oestrogen and progesterone receptors, proliferating cell nuclear antigen (PCNA), Ki-67 and the p53, bcl-2 and SOX-4 genes. Reported response rates to combination chemotherapy are low and response duration generally short lived. The response to molecular therapies is low also. More research into novel molecular targets is needed.

Dissimilar effects of phorbol ester and diacylglycerol derivative on protein kinase activity in the monoblastoid U937 cell.

Mechanism, in addition to protein kinase C activation may mediate 12-O-tetradecanoylphorbol-13-acetate (TPA) stimulated differentiation of leukemic cells. We compared the effect of pretreating intact monoblastoid U937 cells with TPA or the diacylglycerol derivative, 1-oleoyl-2-acetylglycerol (OAG), by studying the protein kinase C dependent and independent histone phosphotransferase activity, the phosphorylation of endogenous substrates, and the ability to stimulate differentiation. In cellular fractions derived from cells treated with TPA or OAG, cytosolic protein kinase C activity decreased. In the detergent extracted particulate fraction, TPA produced a time and dose dependent decrease in protein kinase C activity. In contrast, OAG increased particulate protein kinase C activity. In addition, the particulate fraction derived from cells treated with TPA exhibited increased phosphatidyl serine and diolein independent histone phosphotransferase activity as well as an increase in the phosphorylation of two endogenous substrates with molecular weights of 120,000 and 80,000. OAG did not mimic these effects. When exposed to 32P-labeled intact cells, OAG and TPA stimulated phosphorylation of three substrates. Thus, the inability of OAG to mimic the effects of TPA was not due to lack of protein kinase C activation. TPA, but not OAG, stimulated differentiation of the U937 cell to a monocyte-like cell. These data demonstrate that TPA and OAG have dissimilar effects on protein kinase activity and differentiation in the U937 monoblastoid cell.

Lipoprotein modulation of the intracellular localization of protein kinase C and alteration of phorbol ester-stimulated differentiation in the human monoblastic U937 cell line.

The subcellular localization of protein kinase C and the ability of phorbol esters to alter cell phenotype were examined in the U937 monoblastic cell line. Protein kinase C activity was evaluated using an in vitro assay measuring histone phosphorylation in the cytosolic and detergent extracted particulate fractions obtained after disrupting cells that had been cultured previously under varying conditions. Depriving cells of serum for 2-3 days resulted in a time-dependent decrease in protein kinase C activity of the particulate fraction. The addition of as little as 0.5-1% fetal bovine serum to serum-deprived cells increased protein kinase C in the particulate fraction by up to 2- to 3-fold. In contrast lipoprotein-deficient serum did not mimic the effect of whole serum. However addition of high or low density lipoproteins to cells grown in lipoprotein-deficient serum or serum-free medium produced a concentration-dependent 2- to 3-fold increase in particulate protein C kinase activity. The maximal lipoprotein effect was similar to that observed with 5% fetal bovine serum and the concentrations of lipoproteins needed to increase protein kinase C activity were in the physiological range. Adherence to plastic was used as a marker of the differentiated phenotype. Cells cultured in lipoprotein-deficient serum did not differentiate in response to phorbol ester stimulation as well as cells cultured in 5% fetal bovine serum. These results suggest that serum lipoproteins modulate protein kinase C localization and the response to phorbol ester stimulation in the U937 cell.

Effect of retinoic acid on phorbol ester-stimulated differentiation and protein kinase C-dependent phosphorylation in the U937 human monoblastoid cell.

Phorbol esters stimulate differentiation of certain human leukemic cell lines. Although activation of protein kinase C may mediate certain effects of phorbol esters, controversy exists as to the role of protein kinase C activation in phorbol ester-induced differentiation. Retinoic acid modulates responses to phorbol esters in several cell types. Retinoic acid has also been found to alter protein kinase C-dependent phosphorylation in leukemic cells. We correlated the effects of retinoic acid on protein kinase C-dependent phosphorylation and differentiation stimulated by 12-O-tetradecanoylphorbol-13-acetate (TPA), a phorbol ester, in the human monoblastoid U937 cell line. At concentrations less than 1 nM, which were 100-fold less than those directly stimulating differentiation, retinoic acid potentiated TPA-induced differentiation of the U937 cell as assessed by enhanced adherence to plastic and acquisition of nonspecific esterase activity. TPA-stimulated decreases in cellular proliferation were not affected by retinoic acid treatment. Without altering the sensitivity to TPA, retinoic acid increased the maximal response to this agent. Retinoic acid enhanced TPA-stimulated phosphorylation of a Mr 48,000 substrate in intact 32P-labeled U937 cells and also increased the protein kinase C-dependent phosphorylation of a similar Mr 48,000 substrate and a Mr 80,000 substrate in cellular extracts. In cellular extracts the retinoic acid-induced enhancement of protein kinase C-dependent phosphorylation was predominantly localized to the cytosolic fraction. Increases in protein kinase C-dependent phosphorylation were evident within a 12-h exposure to 1 nM retinoic acid and were observed at retinoic concentrations of 0.01 to 1 nM. A retinoic acid-induced increase in the protein kinase C-dependent phosphorylation of an exogenous substrate, histone, was observed following diethylaminoethyl extraction of cytosol, but not a solubilized particulate fraction. The conditions of retinoic acid treatment increasing protein kinase C activity and enhancing protein kinase C-dependent phosphorylation of endogenous substrates were similar to those conditions potentiating phorbol ester-induced differentiation. Thus, the retinoic acid-induced amplification of phorbol ester signal transduction at the level of protein kinase C activation could mediate the effects of this vitamin on phorbol ester-induced differentiation.

Lymphokine-induced monocytic differentiation as a possible mechanism for hypercalcemia associated with adult T-cell lymphoma.

Patients with adult T-cell lymphoma frequently have hypercalcemia. Bone biopsies from these patients show increased numbers of osteoclasts. We hypothesized that substances produced by the malignant T-cell caused these phenomena by increasing the formation and/or activity of osteoclasts. To test this hypothesis, we cultured U937 cells in conditioned media from a clonal T-cell line derived from a patient with adult T-cell lymphoma and hypercalcemia. This conditioned media produced maturational changes in the U937 cells as evidenced by decreased proliferation, increased adherence, increased expression of complement receptors, and formation of multinucleated giant cells. These changes were synergistically enhanced by the addition of 1 alpha, 25-dihydroxyvitamin D3 which is known to promote monocyte differentiation. We also tested interleukin 2 and gamma- and alpha-interferon to see if they were responsible for the maturational changes. Although some effects were seen, these lymphokines could not account for all the changes induced by the T-cell conditioned media. These findings support the above hypothesis and suggest that other unidentified factors may promote the differentiation of osteoclast precursors and be involved in the pathogenesis of the hypercalcemia.

Human Papillomavirus and Head and Neck Cancer: Psychosocial Impact in Patients and Knowledge of the Link - A Systematic Review.

Head and neck cancer (HNC) currently affects approximately 11 200 people in the UK, with an increasing proportion known to be caused by the human papillomavirus (HPV). We undertook a systematic review of studies measuring the psychosocial impact of HPV-related HNC and also studies measuring knowledge about the link between HPV and HNC among different populations. Searches were conducted on MEDLINE, Embase, PsycINFO, CINAHL Plus and Web of Science, with reference and forward citation searches also carried out on included studies. Studies were selected if they (i) were original peer-reviewed research (qualitative or quantitative), (ii) mentioned HPV and HNC, (iii) measured an aspect of the psychosocial impact of the diagnosis of HPV-related HNC as the dependent variable and/or (iv) measured knowledge of the association between HPV and HNC. In total, 51 papers met the inclusion criteria; 10 measuring psychosocial aspects and 41 measuring knowledge of the link between HPV and HNC. Quality of life in those with HPV-positive HNC was found to be higher, lower or equivalent to those with HPV-negative HNC. Longitudinal studies found quality of life in patients was at its lowest 2-3 months after diagnosis and some studies found quality of life almost returned to baseline levels after 12 months. Knowledge of the link between HPV and HNC was measured among different populations, with the lowest knowledge in the general population and highest in medical and dental professionals. Due to the limited studies carried out with patients measuring the psychosocial impact of a diagnosis of HPV-positive HNC, future work is needed with the partners of HPV-positive HNC patients and health professionals caring for these patients. The limited knowledge of the association between HPV and HNC among the general population also indicates the need for research to explore the information that these populations are receiving.

Myogenic transcription factors regulate pro-metastatic miR-182.

Approximately 30% of patients with soft-tissue sarcoma die from pulmonary metastases. The mechanisms that drive sarcoma metastasis are not well understood. Recently, we identified miR-182 as a driver of sarcoma metastasis in a primary mouse model of soft-tissue sarcoma. We also observed elevated miR-182 in a subset of primary human sarcomas that metastasized to the lungs. Here, we show that myogenic differentiation factors regulate miR-182 levels to contribute to metastasis in mouse models. We find that MyoD directly binds the miR-182 promoter to increase miR-182 expression. Furthermore, mechanistic studies revealed that Pax7 can promote sarcoma metastasis in vivo through MyoD-dependent regulation of pro-metastatic miR-182. Taken together, these results suggest that sarcoma metastasis can be partially controlled through Pax7/MyoD-dependent activation of miR-182 and provide insight into the role that myogenic transcription factors have in sarcoma progression.

Multiple visual pigments in a photoreceptor of the salamander retina.

Although a given retina typically contains several visual pigments, each formed from a retinal chromophore bound to a specific opsin protein, single photoreceptor cells have been thought to express only one type of opsin. This design maximizes a cell's sensitivity to a particular wavelength band and facilitates wavelength discrimination in retinas that process color. We report electrophysiological evidence that the ultraviolet-sensitive cone of salamander violates this rule. This cell contains three different functional opsins. The three opsins could combine with the two different chromophores present in salamander retina to form six visual pigments. Whereas rods and other cones of salamander use both chromophores, they appear to express only one type of opsin per cell. In visual pigment absorption spectra, the bandwidth at half-maximal sensitivity increases as the pigment's wavelength maximum decreases. However, the bandwidth of the UV-absorbing pigment deviates from this trend; it is narrow like that of a red-absorbing pigment. In addition, the UV-absorbing pigment has a high apparent photosensitivity when compared with that of red- and blue-absorbing pigments and rhodopsin. These properties suggest that the mechanisms responsible for spectrally tuning visual pigments separate two absorption bands as the wavelength of maximal sensitivity shifts from UV to long wavelengths.

Recoverin regulates light-dependent phosphodiesterase activity in retinal rods.

The Ca2+-binding protein recoverin may regulate visual transduction in retinal rods and cones, but its functional role and mechanism of action remain controversial. We compared the photoresponses of rods from control mice and from mice in which the recoverin gene was knocked out. Our analysis indicates that Ca2+-recoverin prolongs the dark-adapted flash response and increases the rod's sensitivity to dim steady light. Knockout rods had faster Ca2+ dynamics, indicating that recoverin is a significant Ca2+ buffer in the outer segment, but incorporation of exogenous buffer did not restore wild-type behavior. We infer that Ca2+-recoverin potentiates light-triggered phosphodiesterase activity, probably by effectively prolonging the catalytic activity of photoexcited rhodopsin.

Calcitriol levels in hypercalcemic patients with adult T-cell lymphoma.

Hypercalcemia is a frequent complication in patients with adult T-cell lymphoma. We measured serum calcitriol (1,25-dihydroxyvitamin D3) levels in five hypercalcemic patients with adult T-cell lymphoma and compared the values with those of five patients with mycosis fungoides, a T-cell neoplasm not associated with hypercalcemia. All five patients with adult T-cell lymphoma had calcitriol levels in or below the normal range. These data show that elevated calcitriol levels are not uniformly elevated in this disorder and may not be the usual cause of hypercalcemia in this subgroup of patients with lymphoma.

Human immunodeficiency virus infection and indeterminate western blot patterns. Prospective studies in a low prevalence population.

Interpretation of human immunodeficiency virus (HIV) antibody results that are "indeterminate" rather than clearly positive or negative is problematic for the person delivering the result as well as for the individual being tested. To improve counseling messages for these individuals, we evaluated data collected from a well-characterized cohort of 387 blood donors who had been monitored for up to 2 years. We sought to determine if persons with indeterminate Western blot patterns were infected with HIV, and whether information derived from follow-up monitoring would assist in the development of counseling messages for persons on whom no follow-up information was available. Donors were studied by laboratory assays, clinical evaluation, and assessment of risk for HIV. The absence of HIV infection in 97 of 98 donors with indeterminate Western blot patterns was confirmed by clinical follow-up, Western blot assays of sequential samples, and negative gene amplification results. We propose supplemental guidelines to be used as an adjunct to existing interpretive criteria for counseling individuals when they first present with an indeterminate Western blot finding.

Current estimates of transfusion safety worldwide.

Blood safety is a global public health priority. However, the degree to which blood is, or is not free of infection risk varies greatly around the world. The major determinants of this variation in risk are the availability of resources to support blood safety measures such as testing and the qualitative and quantitative epidemiological patterns of blood-borne infections. These factors are outlined and examples are presented.