Dynamics of lipid adsorption at the electrified water∣1,2-dichloroethane interface

A recently introduced setup to measure the dynamic interfacial tension of expanding drops was used to compare the adsorption behaviour of a series of lipids at the electrified water∣dichloroethane interface. Phospholipids with saturated carbon chains of different length (DMPC, DPPC, DSPC, DAPC, DBPC), an unsaturated phospholipid (DOPC) and an ethanolamine (DSPE) were compared. It was found that the adsorption decreases with increasing chain length. Also, the increase of the flow rate reduces the degree of adsorption effectively. On the timescale of the experiments, the DSPE, DAPC and DBPC adsorption showed no potential dependence, whereas the adsorption of DOPC was stronger than that of the saturated lipids. Adsorption was modelled using the Langmuir adsorption isotherm; the potential dependence of adsorption is discussed.     

Expression of Disrupted-In-Schizophrenia-1, a schizophrenia-associated gene, is prominent in the mouse hippocampus throughout brain development

DISC1 (Disrupted-In-Schizophrenia 1) has been associated with schizophrenia in multiple genetic studies. Studies from our laboratory have shown that Disc1, the mouse ortholog of DISC1, is highly expressed in the dentate gyrus of the hippocampus in the adult mouse brain. Because developmental dysfunction of the hippocampus is thought to play a major role in schizophrenia pathogenesis, and the dentate gyrus is a major locus for adult neurogenesis in the mouse, we investigated Disc1 expression during mouse brain development. Strikingly, Disc1 is strongly expressed in the hippocampus during all stages of hippocampal development, from embryonic day 14 through adulthood. Disc1 mRNA was detected in the dentate gyrus at all stages in which this structure was identifiable, as well as in the cornu ammonis (CA) fields of the hippocampus, the subiculum and adjacent entorhinal cortex, and the developing cerebral neocortex, hypothalamus, and olfactory bulbs, all of which also express Disc1 in the adult mouse brain. In addition, Disc1 mRNA was seen in regions of the developing mouse brain which do not express Disc1 during adulthood, regions including the bed nucleus of the stria terminalis, reticular thalamic nucleus and reuniens thalamic nucleus. These results demonstrate that Disc1 marks the hippocampus from its earliest stages, and suggest that developmental Disc1 dysfunction may lead to defects in hippocampal function that are associated with schizophrenia.     

Selective immunolesion of cholinergic neurons leads to long-term changes in 5-HT2A receptor levels in hippocampus and frontal cortex

Although loss of cholinergic neurons in the basal forebrain is considered a key initial feature in Alzheimer's disease (AD), changes in other transmitter systems, including serotonin and 5-HT_2A receptors, are also associated with early AD. The aim of this study was to investigate whether elimination of the cholinergic neurons in the basal forebrain directly affects 5-HT_2A receptor levels. For this purpose intraventricular injection of the selective immunotoxin 192 IgG-Saporin was given to rats in doses of either 2.5 or 5 μg. The rats were sacrificed after 1, 2, 4 and 20 weeks. 5-HT_2A protein levels were determined by western techniques in frontal cortex and hippocampus. A significant 70% downregulation in frontal cortex and a 100% upregulation in hippocampus of 5-HT_2A receptor levels were observed 20 weeks after the cholinergic lesion when using the highest dose of 192 IgG-Saporin. Our results show that cholinergic deafferentation leads to decreased frontal cortex and increased hippocampal 5-HT_2A receptor levels. This is probably a consequence of the interaction between the serotonergic and the cholinergic system that may vary depending on the brain region.     

Levodopa, bromocriptine and selegiline modify cardiovascular responses in Parkinson's disease

Autonomic nervous system (ANS) involvement is frequently found in Parkinson's disease (PD), but its causal relationship to the disease itself and its medication is unclear. We evaluated the effects of PD medications on cardiovascular ANS functions. Heart rate (HR) responses to normal and deep breathing, the Valsalva manoeuvre and tilting, and blood pressure (BP) responses to tilting and isometric work were measured prospectively in 60 untreated PD patients randomised to receive either levodopa (n=20), bromocriptine (n=20) or selegiline (n=20) as their initial treatment. The results were compared with those of 28 healthy controls. The responses were recorded at baseline, after 6 months on medication and following a 6-week washout period. At baseline HR responses to normal breathing, deep breathing and tilting were already lower and the fall in the systolic BP immediately and at 5 min after tilting was more pronounced in the PD patients than in the controls. Six months' levodopa treatment diminished the systolic BP fall after tilting when compared to baseline, whereas bromocriptine and selegiline increased the fall in systolic BP after tilting and selegiline diminished the BP responses to isometric work. The BP responses returned to the baseline values during the washout period. The drugs induced no change in the HR responses. Thus PD itself causes autonomic dysfunction leading to abnormalities in HR and BP regulation and the PD medications seem to modify ANS responses further. Bromocriptine and selegiline, in contrast to levodopa, increase the orthostatic BP fall and supress the BP response to isometric exercise reflecting mainly impairment of the sympathetic regulation. Received: 17 February 2000 / Received in revised form: 25 May 2000 / Accepted: 15 June 2000     

Efficacy of a Church-Based,Culturally Tailored Program to Promote Completion of Advance Directives Among Asian Americans

Having an Advance Directive (AD) can help to guide medical decision-making. Asian Americans (AA) are less likely than White Americans to complete an AD. This pilot study investigated the feasibility and efficacy of a church-based intervention to increase knowledge and behavior change related to AD among Chinese and Vietnamese Americans. This study utilized a single group pre- and post-intervention design with 174 participants from 4 churches. Domain assessed: demographics; AD-related knowledge, beliefs, attitudes, and intentions; AD completion; and conversations with a healthcare proxy. Data were analyzed using Chi square and multiple logistic regression techniques. We observed significant increases in participants’ AD-related knowledge, intentions, and a gain in supportive beliefs and attitudes about AD, resulting in 71.8 % AD completion, and 25.0 % having had a proxy conversation. Providing culturally-tailored intervention and step-by-step guidance can help to achieve significant changes in AD related knowledge and behavior in AA church goers.     

One-stage laparoscopic restorative proctocolectomy: an alternative to the conventional approach?

PURPOSE: There is significant concern in the current literature over the safety of laparoscopic techniques in removal of the entire colon and rectum. The purpose of this study was to examine the results of a one-stage laparoscopic-assisted restorative proctocolectomy in patients with mucosal ulcerative colitis and familial adenomatous polyposis in a single institution experience. METHODS: All patients who underwent laparoscopic-assisted one-stage restorative proctocolectomy (29 mucosal ulcerative colitis; 3 familial adenomatous polyposis) over a 24-month period were followed up prospectively for short-term and long-term complications and functional outcome. RESULTS: There were 32 patients (17 males), with a median age of 32 years (range, 16-29 years). There were no conversions to open surgery. There were two intraoperative complications, an inconsequential rectal perforation during mobilization and one staple line misfire. There were 11 postoperative complications: 3 obstruction/ileus, 2 pouchitis, 2 wound infections, 2 strictures, 1 pelvic abscess, and 1 pouch leak (at the top of the "J"). Three patients required reoperation (1 temporary ileostomy, 1 lysis of adhesions, and 1 transpouch drainage). The median number of bowel movements was seven per day (range, 2-15). CONCLUSION: A one-stage laparoscopic-assisted restorative proctocolectomy can be performed effectively and safely. Given that techniques in laparoscopic large-bowel surgery are still evolving rapidly, the role of this operation in the surgical treatment of patients with mucosal ulcerative colitis and familial adenomatous polyposis is likely to expand in the near future.     

A PKR-like eukaryotic initiation factor 2alpha kinase from zebrafish contains Z-DNA binding domains instead of dsRNA binding domains

The double-stranded RNA (dsRNA)-dependent protein kinase (PKR) is induced as part of the IFN response in mammals and acts to shut down protein synthesis by the phosphorylation of eukaryotic initiation factor 2alpha (eIF2alpha). In fish, a PKR-like kinase activity has been detected, but the enzyme responsible has eluded characterization. Here, we describe a PKR-like kinase from zebrafish. Phylogenetic analysis shows that the C-terminal kinase domain is more closely related to the kinase domain of PKR than to any of the other three known eIF2alpha kinases. Surprisingly, instead of the two dsRNA binding domains found at the N terminus of PKR, there are two Zalpha domains. Zalpha domains specifically bind dsDNA and RNA in the left-handed Z conformation, often with high affinity. They have been found previously in two other IFN-inducible proteins, the dsRNA editing enzyme, ADAR1, and Z-DNA binding protein 1 (ZBP1), as well as in the poxvirus virulence factor, E3L. This previously undescribed kinase, designated PKZ (protein kinase containing Z-DNA binding domains), is transcribed constitutively at low levels and is highly induced after injection of poly(inosinic)-poly(cytidylic) acid, which simulates viral infection. Binding of Z-DNA by the Zalpha domain of PKZ was demonstrated by circular dichroism. PKZ inhibits translation in transfected cells; site-directed mutagenesis indicates that this inhibition depends on its catalytic activity. Identification of a gene combining Zalpha domains with a PKR-like kinase domain strengthens the hypothesis that the ability to bind left-handed nucleic acid plays a role in the host response to viruses.     

Small bowel volvulus with a jejunal trichobezoar

Background

Small bowel volvulus caused by a jejunal trichobezoar is an extremely rare and life-threatening emergency in children.

Case characteristics

An 8-year-old girl with abdominal pain and persistent bilious vomiting.

Observation

The abdominal computed tomography scan showed a solitary intraluminal mass and a whirl sign, suggesting the small bowel volvulus. Emergency laparoscopic exploration revealed the rotated segment of small bowel loops by a jejunal trichobezoar.

Outcome

Satisfactory recovery after surgery.

Message

Trichobezoars should be considered in the differential diagnosis of abdominal pain and projectile vomiting in children.