Sudden death and the forensic evaluation of neurocutaneous syndromes

On occasion the forensic evaluation of individuals who have died suddenly and unexpectedly may reveal intracranial vascular abnormalities such as capillary, venous- and arteriovenous malformations. Such vascular abnormalities may form part of a heterogeneous group of disorders called neurocutaneous syndromes and involve the skin, nervous system and other organ systems. These unusual conditions include Sturge–Weber, Osler–Weber–Rendu, Klippel–Trenaunay, Von Hippel-Lindau, Proteus and Wyburn-Mason syndromes in addition to ataxia telangiectasia. Causes and mechanisms of unexpected death include epileptic seizures, intracranial haemorrhage and thromboses. Differentiating these conditions at autopsy is important because of variable inheritance patterns and occasionally inaccurate clinical classifications. The autopsy evaluation requires review of the medical and family histories, and full external and internal examinations with photographic documentation and histologic sampling of lesions. Formal neuropathology, storage of blood and tissues for molecular studies if required, and liaison with a medical geneticist should be considered.     

Plasma CCN2/connective tissue growth factor is associated with right ventricular dysfunction in patients with neuroendocrine tumors

Background  

Carcinoid heart disease, a known complication of neuroendocrine tumors, is characterized by right heart fibrotic lesions. Carcinoid heart disease has traditionally been defined by the degree of valvular involvement. Right ventricular (RV) dysfunction due to mural involvement may also be a manifestation. Connective tissue growth factor (CCN2) is elevated in many fibrotic disorders. Its role in carcinoid heart disease is unknown. We sought to investigate the relationship between plasma CCN2 and valvular and mural involvement in carcinoid heart disease.     

Evaluation of the permeation characteristics of a model opioid peptide,H-Tyr-D-Ala-Gly-Phe-D-Leu-OH (DADLE), and its cyclic prodrugs across the blood-brain barrier using an in situ perfused rat brain model

The permeation characteristics of a model opioid peptide, H-Tyr-D-Ala-Gly-Phe-D-Leu-OH (DADLE), and its cyclic prodrugs [acyloxyalkoxy-based cyclic prodrug of DADLE (AOA-DADLE), coumarinic acid-based cyclic prodrug of DADLE (CA-DALE), and oxymethyl-modified coumarinic acid-based cyclic prodrug of DADLE (OMCA-DADLE)] across the blood-brain barrier (BBB) were determined using an in situ perfused rat brain model. The rat brains were perfused with Krebs-bicarbonate buffer containing test compounds in the absence or presence of a specific P-glycoprotein inhibitor (GF-120918). Brain samples were collected after perfusion and processed by a capillary depletion method. After liquid phase extraction with acetonitrile, samples were analyzed using high-performance liquid chromatography with tandem mass spectrometric detection. Linear uptake kinetics of DADLE and its cyclic prodrugs was observed within the range of 60 to 240 s of perfusion. The apparent permeability coefficient (P(app)) of DADLE across the BBB was very low (<10(-7) cm/s), probably due to its unfavorable physicochemical properties (e.g., charge, hydrophilicity, and high hydrogen-bonding potential). All three cyclic prodrugs, however, also exhibited low membrane permeation (P(app) <10(-7) cm/s) in spite of their more favorable physicochemical properties (e.g., no charge, high hydrophobicity, and low hydrogen-bonding potential). Inclusion of GF-120918 (10 microM) in the perfusates fully inhibited the P-gp activity in the BBB and dramatically increased the P(app) values of AOA-DADLE, CA-DADLE, and OMCA-DADLE by approximately 50-, 460-, and 170-fold, respectively. In contrast, GF-120918 had no effect on the P(app) value of DADLE. In addition, the observed bioconversions of the prodrugs to DADLE in the rat brains after 240-s perfusion were very low (5.1% from AOA-DADLE, 0.6% from CA-DADLE, and 0.2% from OMCA-DADLE), which was consistent with the in vitro bioconversion rates determined previously in rat brain homogenates.     

Twice-daily biphasic insulin aspart 30 versus biphasic human insulin 30: a double-blind crossover study in adults with type 2 diabetes mellitus

OBJECTIVE: The purpose of this study was to compare the pharmacokinetics and pharmacodynamics of the premixed insulin analogue biphasic insulin aspart (BIAsp 30) with the equivalent premixed biphasic human insulin (BHI 30), administered twice daily, in patients with type 2 diabetes mellitus. METHODS: In this randomized, double-blind, crossover trial, 13 patients (mean age, 64 years; baseline mean glycosylated hemoglobin, 7.7%; mean body mass index, 28.1 kg/m2) received 2 weeks of treatment with BIAsp 30 and 2 weeks of BHI 30 administered immediately before dinner and breakfast. At the end of each 2-week treatment period, 24-hour serum insulin and glucose profiles were determined using specific 2-sided enzyme-linked immunosorbent assays. All pharmacodynamic and pharmacokinetic end points were analyzed using analysis of variance. RESULTS: Total daily insulin exposure was similar between treatment periods. Mean area under the total insulin concentration-time profile during the 2 hours following administration of BIAsp 30 was 17% greater than that of BHI 30 after dinner and 44% greater after breakfast; both differences were statistically significant. The maximum serum insulin aspart concentrations following BIAsp 30 were significantly higher after dinner (18%) and breakfast (35%). Peak serum insulin concentration was reached 1 hour earlier after breakfast and 45 minutes earlier after dinner in the BIAsp 30 group; differences were significant only after breakfast. The mean daily prandial glucose excursion was significantly lower for BIAsp 30 (16.2 mmol x h x L(-1)) than BHI 30 (17.9 mmol x h x L(-1)). Postprandial 4-hour glucose excursions were significantly lower with BIAsp 30 than with BHI 30 after dinner and breakfast, but were significantly greater after lunch. Mean 24-hour and nocturnal serum glucose concentrations were similar, and both insulins were associated with < or = 7 minor and no major hypoglycemic events. CONCLUSIONS: Premeal injection of BIAsp 30 in a twice-daily regimen significantly reduced overall postprandial glucose excursions. This effect may be of importance when improvement in postprandial glucose control is desired.     

Identification and functional analysis of common human flavin-containing monooxygenase 3 genetic variants

Flavin-containing monooxygenases (FMOs) are important for the disposition of many therapeutics, environmental toxicants, and nutrients. FMO3, the major adult hepatic FMO enzyme, exhibits significant interindividual variation. Eighteen FMO3 single-nucleotide polymorphism (SNP) frequencies were determined in 202 Hispanics (Mexican descent), 201 African Americans, and 200 non-Latino whites. Using expressed recombinant enzyme with methimazole, trimethylamine, sulindac, and ethylenethiourea, the novel structural variants FMO3 E24D and K416N were shown to cause modest changes in catalytic efficiency, whereas a third novel variant, FMO3 N61K, was essentially devoid of activity. The latter variant was present at an allelic frequency of 5.2% in non-Latino whites and 3.5% in African Americans, but it was absent in Hispanics. Inferring haplotypes using PHASE, version 2.1, the greatest haplotype diversity was observed in African Americans followed by non-Latino whites and Hispanics. Haplotype 2A and 2B, consisting of a hypermorphic promoter SNP cluster (-2650C>G, -2543T>A, and -2177G>C) in linkage with synonymous structural variants was inferred at a frequency of 27% in the Hispanic population, but only 5% in non-Latino whites and African Americans. This same promoter SNP cluster in linkage with one or more hypomorphic structural variant also was inferred in multiple haplotypes at a total frequency of 5.6% in the African-American study group but less than 1% in the other two groups. The sum frequencies of the hypomorphic haplotypes H3 [15,167G>A (E158K)], H5B [-2650C>G, 15,167G>A (E158K), 21,375C>T (N285N), 21,443A>G (E308G)], and H6 [15,167G>A (E158K), 21,375C>T (N285N)] was 28% in Hispanics, 23% in non-Latino whites, and 24% in African Americans.     

What degree of work overload is likely to cause increased sickness absenteeism among nurses? Evidence from the RAFAELA patient classification system

AIM: This paper reports a study examining whether nurses' work overload is associated with increased sick leave and quantifying the loss of working days from work overload. BACKGROUND: The RAFAELA patient classification system indicates nursing care intensity in relation to an optimum and is one of the few validated monitoring instruments of patient-associated workload among nurses. However, it is not clear whether work overload is a risk factor for increased sickness absenteeism, an important occupational problem in health care. METHOD: An observational cohort study was carried out with 877 nurses, 31 wards and five Finnish hospitals. Patient-associated workload scores from the RAFAELA system were based on a 6-month monitoring period in 2004. Records of 12-month self certified (1-3 days) and medically certified (>3 days) periods of sick leave in the same year were obtained from employers' registers. FINDINGS: The mean workload was 9% (sd = 8%) above the optimum. There was a linear trend between increasing workload and increasing sick leave (P < or = 0.006). Among nurses with workload > or =30% above the optimum the rate of self certified periods of sick leave was 1.44 (95% CI 1.13-1.83) times higher than among those with an optimum workload. The corresponding rate ratio for medically certified sick leave was 1.49 (1.10-2.03). These excess rates of sickness absence resulted in 12 extra sick leave days per person-year. CONCLUSION: Measuring nurses' workload may be an important part of strategic human resource management of nurses to reduce sick leave among nurses.     

Absorption-promoting effects of chitosan in airway and intestinal cell lines: a comparative study

This work explored the interaction of chitosan with Calu-3 and Caco-2 cell lines, as models of the airway and intestinal epithelium, respectively. The toxicity, tight junction opening and mucoadhesive effects of chitosan were compared in the two cell lines. Additionally, the role of mucus in the absorption-promoting activity of chitosan was studied systematically. Notably, chitosan exhibited a different degree of toxicity on the Calu-3 and Caco-2 cells. Chitosan's tight junction-opening effect, observed in terms of reduction of transepithelial electrical resistance and permeability enhancement, was apparent in both cell lines, though somewhat lower in Caco-2 compared to Calu-3 cell layers (though overall permeability was higher in the former). Tight junction opening and association of chitosan with the epithelial cell layers were more prominent in mucus-containing than in mucus-depleted Calu-3 cells and non mucus-excreting Caco-2 monolayers. Overall, the work suggests that chitosan exhibits a different level of toxicity in airway, as compared to intestinal cells and although absorption enhancement is apparent in both cell lines, enabling its potential use as an absorption-promoting excipient in both pulmonary and oral macromolecular delivery, the magnitude and the duration of the effect are dependent on the level of mucus present on the epithelial surfaces.