Zinc deficiency in head and neck cancer patients.

Although a great deal of attention has been given to protein and calorie malnutrition in patients with head and neck cancer, zinc status has not been assessed properly in such patients in the past.

In this study we characterized zinc status by cellular zinc criteria and assessed several measures of protein and calorie malnutrition in patients with head and neck cancer. We determined prognostic nutritional index (PNI) based on serum albumin, serum transferrin, triceps skin fold measures, and delayed hypersensitivity, as proposed by Buzby et al. In this study, the baseline zinc status and PNI of 60 head and neck cancer patients were correlated with the tumor size and overall stage of the disease.

Our results showed that the tumor size and overall stage correlated significantly to zinc status whereas no correlation was seen with PNI, alcohol intake, or smoking in our study subjects.

We conclude that zinc status is a better indicator of tumor burden and stage of the disease in head and neck cancer patients than the patients' overall nutritional status.     

Non‐cardiac chest pain: time to extend the rapid access chest pain clinic?

Non‐cardiac chest pain is common. It has a low risk of coronary events, but causes considerable physical and social disability and inappropriate health‐care usage. It is a heterogeneous condition, which may be caused by or associated with gastro‐oesophageal, musculoskeletal or psychiatric abnormalities and sustained by psychological factors including catastrophisation, avoidance behaviour and abnormal help‐seeking. These may coexist and their relative contributions may vary in different patients or at different times in an individual patient. The absence of a unitary cause probably explains why treatment studies show only moderate success. An individualised biopsychosocial approach takes account of all causative and sustaining processes and has been shown to work in pain syndromes at other sites. We suggest that this approach should be tried for chest pain using a multidisciplinary clinic model including cardiologists, psychologists and nurses linked with a Rapid Access Chest Pain Clinic.     

Patterns of contrast enhancement of benign and malignant hepatic neoplasms during bolus dynamic and delayed CT

Bolus dynamic and delayed computed tomographic (CT) scans of the liver were evaluated in 43 patients with 54 hepatic hemangiomas and 111 patients with primary or secondary malignant hepatic neoplasms. Twelve patterns of contrast enhancement were recognized during the bolus dynamic phase and delayed scanning. A "typical" CT pattern for hemangiomas (present in 29 of 54 hemangiomas [53.7%]) was established: (a) diminished attenuation prior to intravenous contrast medium administration (excluding lesions arising in a liver with diffuse fatty infiltration), (b) peripheral contrast enhancement during the bolus dynamic phase, and (c) complete isodense fill-in on delayed scan images. Using these criteria, we distinguished hemangiomas from malignant neoplasms in most patients. Only one of 63 (1.6%) malignant neoplasms manifested these typical CT criteria of hemangioma. There is an 86% chance that a lesion with the typical CT appearance of hemangioma is actually a hemangioma, even when found in a patient with a known nonhepatic primary neoplasm.     

Histone deacetylase inhibitor induces DNA damage,which normal but not transformed cells can repair

Histone deacetylase inhibitors (HDACi) developed as anti-cancer agents have a high degree of selectivity for killing cancer cells. HDACi induce acetylation of histones and nonhistone proteins, which affect gene expression, cell cycle progression, cell migration, and cell death. The mechanism of the tumor selective action of HDACi is unclear. Here, we show that the HDACi, vorinostat (Suberoylanilide hydroxamic acid, SAHA), induces DNA double-strand breaks (DSBs) in normal (HFS) and cancer (LNCaP, A549) cells. Normal cells in contrast to cancer cells repair the DSBs despite continued culture with vorinostat. In transformed cells, phosphorylated H2AX (γH2AX), a marker of DNA DSBs, levels increased with continued culture with vorinostat, whereas in normal cells, this marker decreased with time. Vorinostat induced the accumulation of acetylated histones within 30 min, which could alter chromatin structure-exposing DNA to damage. After a 24-h culture of cells with vorinostat, and reculture without the HDACi, γH2AX was undetectable by 2 h in normal cells, while persisting in transformed cells for the duration of culture. Further, we found that vorinostat suppressed DNA DSB repair proteins, e.g., RAD50, MRE11, in cancer but not normal cells. Thus, the HDACi, vorinostat, induces DNA damage which normal but not cancer cells can repair. This DNA damage is associated with cancer cell death. These findings can explain, in part, the selectivity of vorinostat in causing cancer cell death at concentrations that cause little or no normal cell death.     

The impact of transfusion of leucodepleted platelet concentrates on cytomegalovirus disease after allogeneic stem cell transplantation

The impact of transfusion of leucodepleted platelet concentrates (PCs) on cytomegalovirus (CMV) disease was assessed in 215 allogeneic (145 unrelated and 70 related donor) transplants over 3 years. In 43%, both donor and patient were CMV seronegative (CMV-/-). All received CMV-seronegative red cells and random leucodepleted PCs. No CMV disease occurred in any CMV-/- (low risk) transplant. CMV infection occurred in 31 seropositive patients (26%); 13 died and five deaths were attributable to CMV disease. When compared with historical controls, who received CMV-seronegative PCs, we found no difference in transfusion-acquired CMV in the current cohort.     

Nocturia: a risk factor for falls in the elderly.

OBJECTIVE: To determine if nocturia is a risk factor for reported falls and bone fractures in older persons. DESIGN: Cross-sectional study comparing falls in men and women with and without nocturia. SETTING: Longitudinal health screening program of ambulatory elderly participants. PARTICIPANTS: Participants included 988 (65.5%) women and 520 (34.5%) men who had completed their tenth annual visit to the program. MAIN OUTCOME MEASURES: Reported falls in the past year and reported bone fractures in the past 5 years. RESULTS: Participants who reported nocturia at least twice during the night were at significantly greater risk to report falls (Odds Ratio = 1.84; 95% CI = 1.05-3.22), and the risk increased in subjects reporting more than three nocturia events (Odds Ratio = 2.15; 95% CI = 1.04-4.44). The significant increase in falls reported by nocturia participants did not result in an increase in reported bone fractures in the past 5 years (P < 0.4360). CONCLUSIONS: Nocturia is an important risk factor for falls in ambulatory elderly persons. Preventive measures should be taken to decrease nocturia events and to decrease the risk of falling during these nocturia events.     

Effect of glucagon antibodies on plasma glucose,insulin and somatostatin in the fasting and fed rat

Summary A potent high-titre glucagon antibody pool was used to induce a state of acute glucagon deficiency in order to investigate the importance of glucagon in maintaining euglycaemia in the fed and fasted anaesthetised rat. Binding characteristics of the antiserum and evidence of its neutralisation of the biological effects of exogenous glucagon are described. The amount of antibody administered was capable of neutralising up to 12 times the total content of glucagon (approximately 1nmol) in the rat pancreas. The hyperglycaemic response to 1.43 nmol exogenous glucagon was significantly inhibited in the rat by glucagon antibodies given intravenously or intraperitoneally (p < 0.001). However, no changes in plasma glucose occurred in rats fasted 16 h (4.35±0.1 mmol/l or 24 h (4.0±0.05 mmol/l) after antibody administration. The same dose of glucagon antibodies produced no change in plasma glucose (6.1±0.2 mmol/l), immunoreactive insulin (1.85±0.05 g/l) or immunoreactive somatostatin (110±30 ng/l) in rats after antibody administration. Antibody excess, equivalent to a binding capacity for glucagon of 40 nmol/l in the plasma of recipient animals, was demonstrable at all times after passive immunisation. The absence of any affect on glucose concentrations following immunoneutralisation of glucagon suggests that glucagon secretion may not be a major factor in the maintenance of euglycaemia in the rat.     

Essential role of a kinesin-like protein in Arabidopsis trichome morphogenesis

Little is known about how cell shape is controlled. We are using the morphogenesis of trichomes (plant hairs) on the plant Arabidopsis thaliana as a model to study how cell shape is controlled. Wild-type Arabidopsis trichomes are large, single epidermal cells with a stalk and three or four branches, whereas in zwichel (zwi) mutants the trichomes have a shortened stalk and only two branches. To further understand the role of the ZWI gene in trichome morphogenesis we have cloned the wild-type ZWICHEL (ZWI) gene by T-DNA tagging, and report here that it encodes a member of the kinesin superfamily of microtubule motor proteins. Kinesin proteins transport diverse cellular materials in a directional manner along microtubules. Kinesin-like proteins are characterized by a highly conserved “head” region that comprises the motor domain, and a nonconserved “tail” region that is thought to participate in recognition and binding of the appropriate cargo.