Preoperative and Postoperative Response to Inhaled Nitric Oxide

The preoperative dose response to inhaled nitric oxide (NO) was compared with the need for and response to NO after cardiac surgery in patients with congenital heart defect and secondary pulmonary hypertension. In a preoperative vasodilator test with inhaled NO 20, 40 and 80 ppm and oxygen, mean pulmonary artery pressure (PAP) was at least 40 mmHg and/or the pulmonary vascular resistance index (PVRI) 4 Wood units. Preoperatively, NO 40 ppm and Fi0₂ 0.9 reduced systolic pulmonary/systemic arterial pressure (PAPs/SAPs) from 0.89 (SD 0.10) to 0.80 (0.18) and pulmonary/systemic vascular resistance (PVR/SVR) from 0.26 (0.13) to 0.13 (0.08). Haemodynamic assessment was repeated in 11 patients postoperatively. NO treatment was started if PAPs/SAPs rose to 0.8 or the pulmonary oximetry fell below 40%. Postoperatively, eight of 11 patients, including 6 patients with Down's syndrome, needed NO. PAPs/SAPs decreased more than preoperatively: 48.5% vs 11.2, p = 0.0045. Pulmonary oximetry increased by 15.7%, p = 0.02. The degree of preoperative response to NO did not differ between the patients with postoperative pulmonary hypertension and the other children. Patients with early pulmonary hypertensive crisis (first 24 h; n = 6) had a higher PVRI (7.6 vs 4.4 Um²; p = 0.003) and PVR/SVR (0.34 VS 0.17; p = 0.02) preoperatively. Two patients died in pulmonary hypertensive crisis.     

Sizes of Dental Arches in Children with the Pierre Robin Syndrome and Isolated Cleft Palate Aged from 0.2 to Six Years

Abstract

Development of the dental arches and length and weight at birth were studied from 0.2 to 6 years of age in 78 children with Pierre Robin syndrome and 58 with isolated cleft palate. The growth of the maxillary dental arches was similar in both groups before palatal closure. The anterior width of the maxillary arch did not differ between the groups during the six year follow up period, but the depths of the maxillary and mandibular arches were significantly less (< 0.001) in the group with Pierre Robin syndrome compared with those with isolated cleft palates at the age of 3 and 6 years. The mandibular width at the first and second deciduous molars in the group with Pierre Robin syndrome was also significantly smaller (<0.01) than in the other group at the age of 6 years. The weight and length at birth were similar in both groups, and they were slightly lower than among the normal Finnish population.     

Localization and variable expression of G alpha(i2) in human endometrium and Fallopian tubes

BACKGROUND: Heterotrimeric G proteins take part in membrane-mediated cell signalling and have a role in hormonal regulation. This study clarifies the expression and localization of the G protein subunit G alpha(i2) in the human endometrium and Fallopian tube and changes in G alpha(i2) expression in human endometrium during the menstrual cycle. METHODS: The expression of G alpha(i2) was identified by Polymerase chain reaction (PCR), and localization confirmed by immunostaining. Cyclic changes in G alpha(i2) expression during the menstrual cycle were evaluated by quantitative real-time PCR. RESULTS: We found G alpha(i2) to be expressed in human endometrium, Fallopian tube tissue and in primary cultures of Fallopian tube epithelial cells. Our studies revealed enriched localization of G alpha(i2) in Fallopian tube cilia and in endometrial glands. We showed that G alpha(i2) expression in human endometrium changes significantly during the menstrual cycle, with a higher level in the secretory versus proliferative and menstrual phases (P < 0.05). CONCLUSIONS: G alpha(i2) is specifically localized in human Fallopian tube epithelial cells, particularly in the cilia, and is likely to have a cilia-specific role in reproduction. Significantly variable expression of G alpha(i2) during the menstrual cycle suggests G alpha(i2) might be under hormonal regulation in the female reproductive tract in vivo.     

Psychosocial work environment and cross‐cultural competence among native and foreign‐born registered nurses

Cross‐cultural competence is an essential component of the nursing profession, but little is known about the specific psychosocial work characteristics that potentially promote or hinder such competence. In the present study, psychosocial work characteristics were based on Karasek's Job Demand—Control Model. The researchers examined whether Karasek's psychosocial work characteristics, such as high‐strain jobs, high‐strain isolated jobs, active jobs, and active collective jobs, are associated with cross‐cultural competence (empathy, skills, positive attitudes, and motivation), and whether there are differences between native and foreign‐born registered nurses (RN) in these potential associations. A random sample of 744 native RNs (91.0% women) and a total sample (n = 212) of foreign‐born RNs (94.3% women) working in Finland were used. Data were collected using a questionnaire and analyzed with a series of multiple linear regression analyses. High‐strain and high‐strain isolated jobs were negatively associated with all four dimensions of cross‐cultural competence. Active collective jobs, but not active jobs, were positively associated with cross‐cultural skills. There were no differences between native and migrant nurses in these associations. The psychosocial work environment is associated with cross‐cultural competence in both native and migrant nurses. Improvements in psychosocial working conditions, especially minimizing negative factors in the work environment, such as high‐strain and high‐strain isolated jobs, may need to be considered as a part of the efforts aimed to enhance cross‐cultural competence among nursing personnel.     

Homozygosity for a HERG potassium channel mutation causes a severe form of long QT syndrome: identification of an apparent founder mutation in the Finns

OBJECTIVES

We studied the clinical characteristics and molecular background underlying a severe phenotype of long QT syndrome (LQTS).

BACKGROUND

Mutations of cardiac ion channel genes cause LQTS, manifesting as increased risk of ventricular tachycardia and sudden death.

METHODS

We studied two siblings showing prolonged QT intervals corrected for heart rate (QTc), their asymptomatic parents with only marginally prolonged QTc intervals and their family members. The potassium channel gene HERG was screened for mutations by deoxyribonucleic acid sequencing, and the electrophysiologic consequences of the mutation were studied in vitro using the whole-cell patch-clamp technique.

RESULTS

A novel missense mutation (L552S) in the HERG channel, present in the homozygous state in the affected siblings and in the heterozygous state in their parents, as well as in 38 additional subjects from six LQTS families, was identified. One of the homozygous siblings had 2:1 atrioventricular block immediately after birth, and died at the age of four years after experiencing unexplained hypoglycemia. The other sibling had an episode of torsade de pointes at the age of two years. The mean QTc interval differed significantly (p < 0.001) between heterozygous symptomatic mutation carriers (500 ± 59 ms), asymptomatic mutation carriers (452 ± 34 ms) and noncarriers (412 ± 23 ms). When expressed in vitro, the HERG-L552S formed functional channels with increased activation and deactivation rates.

CONCLUSIONS

Our data demonstrate that homozygosity for a HERG mutation can cause a severe cardiac repolarization disorder without other phenotypic abnormalities. Absence of functional HERG channels appears to be one cause for intrauterine and neonatal bradycardia and 2:1 atrioventricular block.     

Periodic properties of the histaminergic system of the mouse brain

Brain histamine is involved in the regulation of the sleep–wake cycle and alertness. Despite the widespread use of the mouse as an experimental model, the periodic properties of major markers of the mouse histaminergic system have not been comprehensively characterized. We analysed the daily levels of histamine and its first metabolite, 1‐methylhistamine, in different brain structures of C57BL/6J and CBA/J mouse strains, and the mRNA level and activity of histidine decarboxylase and histamine‐N‐methyltransferase in C57BL/6J mice. In the C57BL/6J strain, histamine release, assessed by in vivo microdialysis, underwent prominent periodic changes. The main period was 24 h peaking during the activity period. Additional 8 h periods were also observed. The release was highly positively correlated with active wakefulness, as shown by electroencephalography. In both mouse strains, tissue histamine levels remained steady for 24 h in all structures except for the hypothalamus of CBA/J mice, where 24‐h periodicity was observed. Brain tissue 1‐methylhistamine levels in both strains reached their maxima in the periods of activity. The mRNA level of histidine decarboxylase in the tuberomamillary nucleus and the activities of histidine decarboxylase and histamine‐N‐methyltransferase in the striatum and cortex did not show a 24‐h rhythm, whereas in the hypothalamus the activities of both enzymes had a 12‐h periodicity. These results show that the activities of histamine‐metabolizing enzymes are not under simple direct circadian regulation. The complex and non‐uniform temporal patterns of the histaminergic system of the mouse brain suggest that histamine is strongly involved in the maintenance of active wakefulness.