Penumbral mismatch is underestimated using standard volumetric methods and this is exacerbated with time

BACKGROUND AND AIMS

The mismatch between perfusion weighted images (PWI) and diffusion weighted images (DWI) using MR is increasingly being applied in patient selection for therapeutic trials. Two approaches to the calculation of the mismatch volume exist--the commonly used volumetric and the more precise co-registration method, the latter of which considers lesion topography. That there are differences in the mismatch volume analysed by each method and that these are time dependent was hypothesised.

METHODS

Patients within 48 h of ischaemic stroke onset had baseline MR PWI/DWI mismatch and T2 outcome volumes at 3 months. Volumetric mismatch volume was defined as PWI minus DWI lesion. Co-registration mismatch volume was defined as the PWI defect lesion not overlapped by the co-registered DWI lesion.

RESULTS

72 patients of median age 74.0 years were studied. Median baseline MR was at 5.9 h (IQR 3.0, 20.4 h) after stroke onset. Consistent underestimation of the mismatch volume occurred using the volumetric method (volumetric median 9.3 ml, IQR 0, 63 ml; co-registration median 20.1 ml, IQR 3.2, 69.8 ml; p<0.0001). This difference increased with time from stroke onset (p = 0.006).

CONCLUSIONS

Volumetric analysis consistently underestimates the PWI/DWI mismatch volume compared with the more precise co-registration method. This effect increases with time.

A dynamic micro-CT scanner based on a carbon nanotube field emission x-ray source

Current commercial micro-CT scanners have the capability of imaging objects ex vivo with high spatial resolution, but performing in vivo micro-CT on free-breathing small animals is still challenging because their physiological motions are non-periodic and much faster than those of humans. In this paper, we present a prototype physiologically gated micro-computed tomography (micro-CT) scanner based on a carbon nanotube field emission micro-focus x-ray source. The novel x-ray source allows x-ray pulses and imaging sequences to be readily synchronized and gated to non-periodic physiological signals from small animals. The system performance is evaluated using phantoms and sacrificed and anesthetized mice. Prospective respiratory-gated micro-CT images of anesthetized free-breathing mice were collected using this scanner at 50 ms temporal resolution and 6.2 lp mm(-1) at 10% system MTF. The high spatial and temporal resolutions of the micro-CT scanner make it well suited for high-resolution imaging of free-breathing small animals.

Mental disorders, disability and health service use amongst Vietnamese refugees and the host Australian population

OBJECTIVE

To compare the prevalence of common mental disorders, disability and health service utilization amongst Vietnamese refugees resettled in Australia for 11 years, with data obtained from a national survey of the host population.

METHOD

A stratified multistage probability household survey of 1611 Vietnamese undertaken in the state of New South Wales was compared with data from 7961 Australian-born respondents. Measures included the CIDI 2.1 and the MOS SF-12.

RESULTS

The 12-month prevalence of anxiety, depression and drug and alcohol dependence amongst Vietnamese was 6.1% compared with 16.7% amongst Australians. Vietnamese with a mental illness reported higher disability but exhibited similar levels of mental health consultation. The overall service burden of mental disorders was lower for the Vietnamese.

CONCLUSION

The findings suggest that refugee groups resettled for some time in Western countries may show sound mental health adaptation and do not necessarily impose a burden on general or mental health services.

Que faut-il attendre de la chirurgie coronaire sans circulation extracorporelle ?

Coronary artery bypass surgery with beating heart (off-pump) has become more common in the last ten years allowing seven randomized studies with at least 60 patients, comparing off-pump and on-pump coronary bypass. Anaesthesia, monitoring and haemodynamic complications are described. Randomized studies concluded to less elevation of biochemical markers of myocardial and renal injury, less hydric inflation, less cerebral microemboli, reduction of homologous blood transfusions, of hospital stay and global costs. However in low risk patients no reduction in myocardial infarction, atrial fibrillation, stroke, acute renal failure, early reoperation, surgical site infection and mortality were observed. Non-randomized studies suggest a benefit in stroke and mortality in elderly patients but the possibility of incomplete revascularization remains.

Efficacy of laparoscopic cholecystectomy in acalculous gallbladder disease: long-term follow-up

OBJECTIVE

Our aim was to determine the efficacy of laparoscopic cholecystectomy in symptomatic patients with ultrasound negative and abnormal gallbladder ejection fractions; Patients with gallbladder ejection fractions less than 35% on hepatobiliary scan were offered laparoscopic cholecystectomy.

METHODS

Between January 1995 and January 2001, 1564 patients underwent laparoscopic cholecystectomy at our institution: 256 were confirmed to have acalculous gallbladder disease by pathology report and reconfirmation of abnormal hepatobiliary scan data. A 30-day postoperative follow-up was obtained by retrospective medical record review. For this study, we contacted all 256 patients by mail questionnaire and followed up on nonresponders with telephone interviews; we also reviewed hospital records to verify preoperative symptom patterns. The survey was completed by 154 patients (60%): 48 (31%) by mail and 106 (69%) by telephone interviews. The study included 115 (75%) female and 39 (25%) male patients, and the average age was 42 years (range, 13 to 95). All hepatobiliary laboratory parameters were normal pre- and postoperatively. The survey was completed in December 2001, 1 to 5 years postoperatively (mean 3 years).

RESULTS

Preoperatively, 142 patients (92%) had right upper quadrant pain, 114 (74%) had nausea, 88 (57%) had vomiting, 120 (73%) had heartburn, and 118 (77%) had food intolerance. In a 30-day postoperative period, these numbers had reduced to 48 (37%), 14 (90%), 8 (5%), 22 (14%), and 34 (22%), respectively. had laparoscopic cholecystectomy, and 95% stated that they would recommend laparoscopic cholecystectomy to other patients.

CONCLUSION

This study shows that patients with acalculous gallbladder disease benefit from laparoscopic cholecystectomy.

Toxicity and Efficacy of Concurrent Gemcitabine and Radiotherapy for Locally Advanced Pancreatic Cancer

Gemcitabine has been demonstrated to be a potentradiosensitizer in the laboratory and in the clinic (1-7)and has proven clinical systemic activity to pancreaticcancer. Responses to systemic gemcitabine inpatients with metastatic pancreatic adenocarcinomahave been documented in phase I, phase II, and phaseIII clinical settings (8,9). Moreover, a recent randomizedtrial of gemcitabine vs 5-FU as first-linetherapy in patients with advanced pancreatic adenocarcinomademonstrated a modest median survivalbenefit (4.41 vs 5.65 mo,p= 0.0025) for those patientswho received gemcitabine compared to those whoreceived 5-FU (10). In addition, gemcitabine wasshown to improve cancer-related symptoms and performancestatus as assessed by a quantitative clinicalbenefit scale in both untreated and previouslytreated patients with metastatic adenocarcinoma ofthe pancreas (10,11). Based on these data, the FDAapproved gemcitabine as a first-line agent for patientswith advanced adenocarcinoma of the pancreas.

Antibody inhibition of cytomegalovirus: the role of natural killer and macrophage effector cells

To explore mechanisms by which antibody might inhibit cytomegalovirus (CMV), we measured the ability of intravenous CMV-IgG (CytoGam) to reduce viral yield in the presence of effector cells. Foreskin fibroblasts were infected with a clinical strain of CMV, and CytoGam was added along with effector cells consisting of either unfractionated peripheral blood mononuclear cells (PBMCs), natural killer (NK) cells, or macrophages. The combination of CytoGam and either of the effector cell types markedly inhibited established CMV infection in vitro. In addition, CytoGam combined with effector cells protected the monolayer from CMV-induced cytopathic effects. Antibody-dependent, effector cell-mediated functions may underlie the ability of CytoGam to prevent or modulate CMV infection in vivo.

Crystallographic point groups of five-dimensional space. 2. Their geometrical symbols

Our previous paper emphasized a method for obtaining the crystallographic point groups of five-dimensional space, i.e. the subgroups of the crystal family holohedries. Moreover, it recalled the names of the crystal families and the symbols of their holohedries. These results being obtained, this paper gives a geometrical symbol to each of these point groups described as Weigel-Phan-Veysseyre symbols (WPV symbols). In most cases, these symbols make it possible to reconstitute all the elements of the groups. The point symmetry operation symbols, which are the basis of the Hermann-Mauguin symbols (HM symbols) as well as of the WPV symbols, that have been defined from the cyclic groups generated by the five-dimensional point symmetry operations are recalled. The basic principles of the WPV system of crystallographic point-group symbols are explained and a list of 196 symbols of five-dimensional space out of 955 is given. All the information given by the WPV symbol of a point group is detailed and analysed through some examples and the study of the (hexagon oblique)-al crystal family. Finally, the polar point groups of five-dimensional space are specified.

Is the therapeutic index better with gemcitabine-based chemoradiation than with 5-fluorouracil-based chemoradiation in locally advanced pancreatic cancer?

PURPOSE

To retrospectively compare the toxicity and efficacy of concurrent gemcitabine-based chemoradiation with that of concurrent 5-fluorouracil (5-FU)-based chemoradiation in patients with unresectable pancreatic cancer.

PATIENTS AND METHODS

Between September 1996 and May 2000, 114 patients with localized unresectable adenocarcinoma of the pancreas were treated with concurrent chemoradiation. Locally advanced unresectable disease was defined as low-density tumor in contact with the superior mesenteric artery (SMA) or celiac artery, or occlusion of the superior mesenteric-portal venous confluence. Fifty-three patients were selected to receive gemcitabine in 7 weekly cycles (250-500 mg/m(2)) with concurrent radiotherapy (median dose 30 Gy, range 30-33 Gy in 10-11 fractions). The remaining 61 patients received continuous-infusion 5-FU (200-300 mg/m(2)) with concurrent radiotherapy (30 Gy in 10 fractions). Radiotherapy was delivered to the primary tumor and regional lymphatics. Patients receiving gemcitabine and those receiving 5-FU had a similar mean Karnofsky performance status (KPS, 89% vs. 86%), distribution of tumor grade (43% vs. 33% poorly differentiated), and percent weight loss (all p = NS). However, patients treated with gemcitabine had a significantly larger median maximum cross-sectional tumor area (TA, 8.8 cm(2) vs. 5.7 cm(2), p = 0.046) and were significantly younger (median age 60 vs. 68 years, p <0.001). Severe acute toxicity (ST) was defined as toxicity requiring a hospital stay of more than 5 days, mucosal ulceration with bleeding, more than 3 dose deletions of gemcitabine or discontinuation of 5-FU, or toxicity resulting in surgical intervention or death. Kaplan-Meier analysis was used to calculate the actuarial rate of local progression on imaging (LP), the rate of distant metastasis (DM), and the overall survival (OS) rate. The imaging was reviewed in resected patients.

RESULTS

Patients receiving gemcitabine developed significantly more ST during treatment (23% vs. 2%, p < 0.0001) than did those receiving 5-FU. Patients treated with gemcitabine had a similar 10-month LP rate (62% vs. 61%), 10-month DM rate (55% vs. 47%), 1-year OS rate (42% vs. 28%), and median OS duration (11 months vs. 9 months) to patients treated with 5 FU (all p = NS). Five patients who received gemcitabine and 1 patient who received 5-FU underwent margin-negative pancreaticoduodenectomy after chemoradiation. Three patients had a short segment (<or= 1 cm in length) of low-density tumor abutting the SMA, 1 had involvement of the common hepatic artery, and 1 had a short-segment occlusion of the superior mesenteric vein, amenable to venous resection and reconstruction. The other patient was thought to have inflammatory changes discontiguous with the tumor surrounding the SMA, which resolved after therapy. TA >10 cm(2) (p = 0.03) and poor differentiation (p = 0.07) were associated with a worse survival duration; however, other factors, such as KPS and weight loss >10% and age did not influence OS.

CONCLUSION

Despite the selection of healthier patients to receive gemcitabine, there was a significantly higher severe toxicity rate than with 5-FU. The median and 1-year survivals were not significantly different with the use of concurrent gemcitabine; however, the tumors treated were significantly larger. Additionally, a small number of patients with minimal arterial involvement whose disease met our radiographic definition of unresectable disease had margin-negative resections after treatment with gemcitabine-based chemoradiation. These possible benefits and the high rate of severe toxicity define a very narrow therapeutic index for concurrent gemcitabine-based chemoradiation given by this schedule of administration.

Toxicity and efficacy of concurrent gemcitabine and radiotherapy for locally advanced pancreatic cancer

BACKGROUND

Gemcitabine and radiotherapy are a potent combination. A clinical assessment of the therapeutic ratio for locally advanced pancreatic cancer patients has not yet been reported.

AIM OF STUDY

To assess the toxicity, survival, and pattern of failure of locally advanced pancreatic cancer patients treated with concurrent gemcitabine-based chemoradiation. Patients and Methods. Between the dates of December 1996 and August 2000 51 patients with locally advanced unresectable adenocarcinoma of the pancreas were treated with concurrent gemcitabine and radiotherapy at MDACC. Patients received 250-500 mg/m2 of gemcitabine weekly x7 over 30 min and 30-33 Gy in 10-11 fractions over two weeks to the primary tumor and regional lymphatics. Severe toxicity was defined as admission > 5 d, mucosal ulceration, > 3 dose deletions of gemcitabine or toxicity resulting in surgical intervention or that resulted in death.

RESULTS

The median survival was 11 mo. Overall, 37 of 51 patients had objective evidence of local progression. The actuarial rate of local progression rate at 9 mo was 70%. The 9-mo distant metastasis rate was 52%. Tumors > or = 10 cm2 had worse local control, distant control, and overall survival. Six patients underwent pancreaticoduodenectomy after therapy. After review of the imaging, only four of these patients had minimal arterial involvement, one was incorrectly staged, and one had initial inflammatory change on CT that resolved. Twelve of 51 (24%) patients suffered severe acute toxicity, and 17 of 51 (33%) patients were admitted for supportive care.

CONCLUSION

Concurrent gemcitabine and radiotherapy can be a very difficult combination to administer safely. Our results do not suggest a prolongation of median survival for patients with localized pancreatic cancer treated with this therapy. It is possible that gemcitabine-based chemoradiation contributes to the margin-negative resectability of a small number of patients with minimal arterial involvement, but this benefit is obscured by the frequent toxicity encountered in most patients. Locally advanced pancreatic cancer patients should continue to be enrolled on prospective studies investigating novel combinations of cytotoxic and/or biologic agents with concurrent radiotherapy.

Contrast-enhanced magnetic resonance angiography of the cervical vessels: experience with 422 patients

BACKGROUND AND PURPOSE

Contrast-enhanced magnetic resonance angiography (CEMRA) permits acquisition of high-spatial-resolution, venous-suppressed, 3D MR angiograms of the cervical carotid and vertebral arteries. In this study, an elliptic centric-view ordering with either MR fluoroscopic triggering or test bolus timing was used. The use of CEMRA of the cervical vessels has changed our clinical practice and is replacing conventional angiography for the evaluation of most carotid and vertebral artery diseases.

METHODS

We retrospectively reviewed our experience with the use of CEMRA performed in 422 patients from January through December 1999.

RESULTS

CEMRA was performed to evaluate transient ischemic attack and ischemic stroke in 239 patients, asymptomatic carotid bruit in 88 patients, and other neurological symptoms in 95 patients. Carotid endarterectomies were performed in 97 patients (103 procedures), and conventional angiography was performed in 12 of these patients. CEMRA was used to evaluate for the presence of an arterial dissection in 85 of the 239 patients with transient ischemic attack and ischemic stroke. Of this group, 32 patients had cervical arterial dissection, and pseudoaneurysm was detected in 11 of these patients. Compared with ultrasonography of the cervical vessels, CEMRA provided additional information in 43 of 422 patients and led to changes in the decision as to whether to perform carotid endarterectomy in 5 patients.

CONCLUSIONS

Use of CEMRA permits noninvasive evaluation of patients suspected of having carotid or vertebral disease and avoids the potential complications of conventional angiography.

T4 rectal cancer treated with preoperative chemoradiation to the posterior pelvis followed by multivisceral resection: patterns of failure and limitations of treatment

PURPOSE

To analyze the overall pattern of treatment failure and sites of pelvic disease recurrence relative to the radiation fields used in treating patients with clinically staged T4 rectal cancer with preoperative chemoradiation followed by multivisceral resection.

METHODS AND MATERIALS

Between 1990 and 1998, 45 patients with T4 rectal cancer were treated with preoperative chemoradiation. Clinical staging was according to the system of the American Joint Cancer Committee and was based on endoscopic ultrasonography, chemotherapy (CT), and physical examination. A diagnosis of T4 disease required evidence of invasion of a contiguous structure on CT (n = 31) or endorectal ultrasonography (n = 6), vaginal mucosal involvement on pelvic examination (n = 6), or a combination of these findings (n = 2). Chemoradiation was delivered with 18 MV photons using a 3-field belly-board technique. The median total dose was 45 Gy in all patients (range 45-63). Nine patients received a boost with external beam radiotherapy (EBRT) (n = 5, 1.8-18 Gy), intraoperative RT (n = 3, 10-20 Gy), or interstitial brachytherapy (n = 1, 20 Gy). All patients received concurrent chemotherapy consisting of protracted venous infusion 5-fluorouracil (300 mg/m(2), 5 d/wk). Resection was not performed in 13 (29%) of the 45 patients because of metastases detected before resection or patient refusal. Multivisceral resection and pelvic exenteration was required in 21 (66%) and 11 (34%) of 32 patients, respectively. We compared the location of pelvic disease recurrence with the RT simulation films. The Kaplan-Meier method was used to calculate the 4-year actuarial pelvic and distant recurrent rates and the overall survival rate.

RESULTS

The median length of follow-up was 31.0 months for all patients and 40.0 months for patients alive at last follow-up. When only the resected cases were considered, the local recurrence rate was 20%. Distant metastases occurred in 44% of cases; the overall survival rate was 69%. When all patients were considered, the local recurrence rate was similar (24%), but the rate of distant recurrence (51%) was higher and the overall survival rate lower (50%). Pelvic disease was controlled in all 8 patients whose disease responded well to chemoradiation (either a histologically complete response or microscopic residual disease). Three of 4 patients with close or positive margins had pelvic recurrences despite intraoperative RT and brachytherapy. Nine of the 10 pelvic recurrences occurred in the radiation field. Elective external iliac nodal irradiation was not used, and nodal metastases were not seen in that region. In 1 case, marginal recurrence occurred in a common iliac node at the superior edge of the treatment field.

CONCLUSIONS

Despite aggressive multimodality therapy including multivisceral resection, a high rate of pelvic and distant disease recurrence occurred in patients with clinically staged T4 disease. Regional disease recurred almost exclusively in the radiation field. The intraoperative RT and interstitial brachytherapy doses used did not prevent pelvic disease recurrence in patients with close or positive margins. Novel strategies such as higher preoperative doses of RT with or without altered fractionation or more effective radiosensitizers are needed to improve locoregional control in patients with T4 disease. Future strategies must also include more effective systemic therapy.

Demonstration of the extrinsic coagulation pathway in teleostei: identification of zebrafish coagulation factor VII

It is not known whether the mammalian mechanism of coagulation initiation is conserved in fish. Identification of factor VII is critical in providing evidence for such a mechanism. A cDNA was cloned from a zebrafish (teleost) library that predicted a protein with sequence similarity to human factor VII. Factor VII was shown to be present in zebrafish blood and liver by Western blot analysis and immunohistochemistry. Immunodepletion of factor VII from zebrafish plasma selectively inhibited thromboplastin-triggered thrombin generation. Heterologous expression of zebrafish factor VII demonstrated a secreted protein (50 kDa) that reconstituted thromboplastin-triggered thrombin generation in immunodepleted zebrafish plasma. These results suggest conservation of the extrinsic coagulation pathway between zebrafish and humans and add credence to the zebrafish as a model for mammalian hemostasis. The structure of zebrafish factor VIIa predicted by homology modeling was consistent with the overall three-dimensional structure of human factor VIIa. However, amino acid disparities were found in the epidermal growth factor-2/serine protease regions that are present in the human tissue factor-factor VIIa contact surface, suggesting a structural basis for the species specificity of this interaction. In addition, zebrafish factor VII demonstrates that the Gla-EGF-EGF-SP domain structure, which is common to coagulation factors VII, IX, X, and protein C, was present before the radiation of the teleosts from the tetrapods. Identification of zebrafish factor VII significantly narrows the evolutionary window for development of the vertebrate coagulation cascade and provides insight into the structural basis for species specificity in the tissue factor-factor VIIa interaction.

Identification of TFII-I as the endoplasmic reticulum stress response element binding factor ERSF: its autoregulation by stress and interaction with ATF6

When mammalian cells are subjected to stress targeted to the endoplasmic reticulum (ER), such as depletion of the ER Ca(2+) store, the transcription of a family of glucose-regulated protein (GRP) genes encoding ER chaperones is induced. The GRP promoters contain multiple copies of the ER stress response element (ERSE), consisting of a unique tripartite structure, CCAAT(N(9))CCACG. Within a subset of mammalian ERSEs, N(9) represents a GC-rich sequence of 9 bp that is conserved across species. A novel complex (termed ERSF) exhibits enhanced binding to the ERSE of the grp78 and ERp72 promoters using HeLa nuclear extracts prepared from ER-stressed cells. Optimal binding of ERSF to ERSE and maximal ERSE-mediated stress inducibility require the conserved GGC motif within the 9-bp region. Through chromatographic purification and subsequent microsequencing, we have identified ERSF as TFII-I. Whereas TFII-I remains predominantly nuclear in both nontreated NIH 3T3 cells and cells treated with thapsigargin (Tg), a potent inducer of the GRP stress response through depletion of the ER Ca(2+) store, the level of TFII-I transcript was elevated in Tg-stressed cells, correlating with an increase in TFII-I protein level in the nuclei of Tg-stressed cells. Purified recombinant TFII-I isoforms bind directly to the ERSEs of grp78 and ERp72 promoters. The stimulation of ERSE-mediated transcription by TFII-I requires the consensus tyrosine phosphorylation site of TFII-I and the GGC sequence motif of the ERSE. We further discovered that TFII-I is an interactive protein partner of ATF6 and that optimal stimulation of ERSE by ATF6 requires TFII-I.

BMP7 controls collecting tubule cell proliferation and apoptosis via Smad1-dependent and -independent pathways

Bone morphogenetic protein-7 (BMP7) controls ureteric bud and collecting duct morphogenesis in a dose-dependent manner (Piscione TD, Yager TD, Gupta IR, Grinfeld B, Pei Y, Attisono L, Wrana JL, and Rosenblum ND. Am J Physiol Renal Physiol 273: F961-F975, 1997). We defined cellular and molecular mechanisms underlying these effects in embryonic kidney explants and in the mIMCD-3 cell model of collecting tubule morphogenesis. Low-dose (0.25 nM) BMP7 significantly increased tubule number and cell proliferation. Similar to BMP2, high-dose (10 nM) BMP7 inhibited cell proliferation and stimulated apoptosis. To define molecular mechanisms, we identified signaling events downstream of BMP7. High-dose BMP7, but not low-dose BMP7, activated Smad1 in mIMCD-3 cells. Moreover, the inhibitory effects of high-dose BMP7 and BMP2, but not the stimulatory effects of low-dose BMP7, on tubulogenesis and cell proliferation were significantly reduced in mIMCD-3 cells stably expressing Smad1(Delta458), a dominant negative mutant form of Smad1, but not in cells stably expressing wild-type Smad1. We conclude that BMP7 exerts dose-dependent effects on ureteric bud or collecting duct cell proliferation and apoptosis by signaling via Smad1-dependent and Smad1-independent pathways.

Investigating the use of services for Vietnamese with mental illness

An ethnographic-based interview was conducted with 324 Vietnamese-speaking adult caregivers living in the New South Wales state of Australia, focusing on types of services used for identifying and/or intervening for binh tam than (mental ill-health), difficulties encountered, and recommendations for enhancing services. Almost one in two interviewees (n= 158) had used such services during the previous twelve months, including those provided by local Vietnamese-speaking doctors (100%), Asian naturalists, spiritual healers, witchcraft doctors, herbalists, and folk healers (>50%), as well as mainstream psychiatric hospital facilities (50%) and community services (>30%). Descriptive data on the difficulties and recommendations were related to four major domains: accessibility, acceptability, accommodation, and affordability, explaining patterns of caregivers' help-seeking behaviors and their choices of services.

ATF6 as a transcription activator of the endoplasmic reticulum stress element: thapsigargin stress-induced changes and synergistic interactions with NF-Y and YY1

ATF6, a member of the leucine zipper protein family, can constitutively induce the promoter of glucose-regulated protein (grp) genes through activation of the endoplasmic reticulum (ER) stress element (ERSE). To understand the mechanism of grp78 induction by ATF6 in cells subjected to ER calcium depletion stress mediated by thapsigargin (Tg) treatment, we discovered that ATF6 itself undergoes Tg stress-induced changes. In nonstressed cells, ATF6, which contains a putative short transmembrane domain, is primarily associated with the perinuclear region. Upon Tg stress, the ATF6 protein level dropped initially but quickly recovered with the additional appearance of a faster-migrating form. This new form of ATF6 was recovered as soluble nuclear protein by biochemical fractionation, correlating with enhanced nuclear localization of ATF6 as revealed by immunofluorescence. Optimal ATF6 stimulation requires at least two copies of the ERSE and the integrity of the tripartite structure of the ERSE. Of primary importance is a functional NF-Y complex and a high-affinity NF-Y binding site that confers selectivity among different ERSEs for ATF6 inducibility. In addition, we showed that YY1 interacts with ATF6 and in Tg-treated cells can enhance ATF6 activity. The ERSE stimulatory activity of ATF6 exhibits properties distinct from those of human Ire1p, an upstream regulator of the mammalian unfolded protein response. The requirement for a high-affinity NF-Y site for ATF6 but not human Ire1p activity suggests that they stimulate the ERSE through diverse pathways.

Ingested interferon-alpha prevents allograft islet transplant rejection

BACKGROUND

Ingested interferon (IFN)-alpha is a biological response modifier in experimental autoimmune encephalomyelitis and multiple sclerosis, and prevents type 1 diabetes in nonobese diabetic mice. Islet transplantation possesses significant potential advantages over whole-gland transplantation because it is simple, may achieve insulin independence, and has clear advantages over exogenous insulin therapy. Therefore, we examined whether ingested IFN-alpha, administered to islet allograft recipients, could prevent islet allograft rejection.

METHODS

Recipient C3H mice (H2k) were made diabetic and either untreated or treated with 10-1000 international units (IU) of ingested murine IFN-alpha daily from day -7 through day +14 after transplantation for a total of 21 days. Seven days after diabetes induction, recipients received allograft islets isolated from C57BL.10 donors (H2b) under the kidney capsule and were followed for overt diabetes via elevated blood glucose.

RESULTS

Control recipients and recipients fed 1000 IU all became diabetic by day 13, whereas mice ingesting IFN-alpha had delayed rejection for up to 27 (10 IU) to 29 days (100 IU) after islet transplantation. Treatment of recipients of islet allografts with ingested IFN-alpha doubles the time period before rejection compared with control mice. The feeding period with daily IFN-alpha was doubled from 21 days to 42 days in total, 7 days before transplantation and 35 days after transplantation.

CONCLUSION

Treatment of recipients of islet allografts with prolonged ingested IFN-alpha prevents rejection in a subset of recipients. Ingested IFN-alpha may prevent rejection if given continuously after transplantation.

Purification and analysis of in vivo-differentiated oligodendrocytes expressing the green fluorescent protein

A complete understanding of the molecular mechanisms involved in the formation and repair of the central nervous system myelin sheath requires an unambiguous identification and isolation of in vivo-differentiated myelin-forming cells. In order to develop a novel tool for the analysis of in vivo-differentiated oligodendrocytes, we generated transgenic mice expressing a red-shifted variant of the green fluorescent protein under the control of the proteolipid protein promoter. We demonstrate here that green fluorescent protein-derived fluorescence in the central nervous system of 9-day- to 7-week-old mice is restricted to mature oligodendrocytes, as determined by its spatiotemporal appearance and by both immunocytochemical and electrophysiological criteria. Green fluorescent protein-positive oligodendrocytes could easily be visualized in live and fixed tissue. Furthermore, we show that this convenient and reliable identification now allows detailed physiological analyses of differentiated oligodendrocytes in situ. In addition, we developed a novel tissue culture system for in vivo-differentiated oligodendrocytes. Initial data using this system indicate that, for oligodendrocytes isolated after differentiation in vivo, as yet unidentified factors secreted by astrocytes are necessary for survival and/or reappearance of a mature phenotype in culture.

TGF-(beta)1 maintains hematopoietic immaturity by a reversible negative control of cell cycle and induces CD34 antigen up-modulation

Somatic stem cells are largely quiescent in spite of their considerable proliferative potential. Transforming growth factor-(beta)1 (TGF-(beta)1) appears to be a good candidate for controlling this quiescence. Indeed, various mutations in the TGF-beta signalling pathway are responsible for neoplasic proliferation of primitive stem/progenitor cells in human tissues of various origins. In hemopoietic single cell culture assays, blocking autocrine and endogeneous TGF-(beta)1 triggers the cell cycling of high proliferative potential undifferenciated stem/progenitor cells. However, it has never been demonstrated whether TGF-(beta)1 has an apoptotic effect or a differentiating effect on these primitive cells, as already described for more mature cells. Using single cell experiments both in liquid or semi-solid culture assays and dye tracking experiments by flow cytometry, we demonstrate that low, physiological concentrations of TGF-(beta)1, which specifically maintain primitive human hemopoietic stem/progenitor cells in quiescence, have a reversible effect and do not induce apoptosis. We moreover demonstrate that these low concentrations prevent the rapid loss of the mucin-like protein CD34, a most common marker of immature hematopoietic stem/progenitor cells, which is progressively lost during differentiation. TGF-(beta)1 not only up-modulated the CD34 antigen before S phase entry but also maintained a high level of CD34 expression on cells which had escaped cell cycle inhibition, suggesting that proliferation inhibition and differentiation control by TGF-(beta)1 may be independent. These data provide additional evidence that TGF-(beta)1 acts as a key physiological factor ensuring the maintenance of a stem cell reserve.

Protein kinase A is a negative regulator of renal branching morphogenesis and modulates inhibitory and stimulatory bone morphogenetic proteins

Protein kinase A (PKA) regulates morphogenetic responses to bone morphogenetic proteins (BMPs) during embryogenesis. However, the mechanisms by which PKA regulates BMP function are unknown. During kidney development, BMP-2 and high doses of BMP-7 inhibit branching morphogenesis, whereas low doses of BMP-7 are stimulatory (Piscione, T. D., Yager, T. D., Gupta, I. R., Grinfeld, B., Pei, Y., Attisano, L., Wrana, J. L., and Rosenblum, N. D. (1997) Am. J. Physiol. 273, F961-F975). We examined the interactions between PKA and these BMPs in embryonic kidney explants and in the mouse inner medullary collecting duct-3 model of collecting duct morphogenesis. H-89, an inhibitor of PKA, stimulated branching morphogenesis and enhanced the stimulatory effect of low doses of BMP-7 on tubule formation. Furthermore, H-89 rescued the inhibition of tubulogenesis by BMP-2 (or high doses of BMP-7) by attenuating BMP-2-induced collecting duct apoptosis. In contrast, 8-bromo-cAMP, an activator of PKA, inhibited tubule formation and attenuated the stimulatory effects of low doses of BMP-7. To determine mechanisms underlying the interdependence of BMP signaling and PKA activity, we examined the effect of PKA on the known signaling events in the BMP-2-dependent Smad1 signaling pathway and the effect of BMP-2 on PKA activity. PKA did not induce endogenous Smad1 phosphorylation, Smad1-Smad4 complex formation, or Smad1 nuclear translocation. In contrast, BMP-2 increased endogenous PKA activity and induced phosphorylation of the PKA effector, cAMP-response element-binding protein, in a PKA-dependent manner. We conclude that BMP-2 induces activation of PKA and that PKA regulates the effects of BMPs on collecting duct morphogenesis without activating the known signaling events in the BMP-2-dependent Smad1 signaling pathway.

Anterior chest wall pain in postpartum costochondritis

Costochondritis is a common diagnosis in patients with anterior chest wall pain in whom serious disease has been excluded. The diagnosis is usually made on clinical grounds, because laboratory and imaging investigations usually provide little information. The authors describe a young woman with postpartum costochondritis and discuss the role of bone scintigraphy in confirming the clinical diagnosis.

Tandem subdiaphragmatic and pleural sequelae due to lost gallstones following cholecystectomy

We report two similar thoracoabdominal complications we encountered due to retained gallstones after cholecystectomy. These patients had had an open cholecystectomy after a failed laparoscopic attempt, with spillage of gallbladder debris intraoperatively. They were admitted more than 12 months later with subdiaphragmatic abscesses. Attempted computerized axial tomography (CT) guided drainage of these abscesses resulted in these patients developing pleural fluid collections, which required surgical drainage. The patients underwent exploratory laparotomies, and drainage of the subdiaphragmatic abscesses had revealed gallstones within the abscess cavity. A detailed presentation of these cases, with review of current literature and clinicopathologic issues for discussion are described.

Phosphodiesterase I, a novel adhesion molecule and/or cytokine involved in oligodendrocyte function

One of the more complex developmental processes occurring postnatally in the CNS is the formation of the myelin sheath by oligodendrocytes. To examine the molecular events that take place during myelination, we isolated oligodendrocyte-derived cDNA clones, one of which (p421.HB) represents a putative alternatively spliced isoform of rat brain-specific phosphodiesterase I (PD-Ialpha) and a species homolog of the human cytokine autotaxin. Analysis of the structural composition of the p421.HB/PD-Ialpha protein suggests a transmembrane-bound ectoenzyme, which, in addition to the phosphodiesterase-active site contains presumed cell recognition and Ca2+-binding domains. Consequently, it may be involved in extracellular signaling events. Expression of p421.HB/PD-Ialpha is enriched in brain and spinal cord, where its mRNA can be detected in oligodendrocytes and in cells of the choroid plexus. Expression in the brain increases during development with an intermediate peak of expression around the time of active myelination and maximal expression in the adult. We have identified four presumably alternatively spliced isoforms, two of which appear to be CNS-specific. Decreased levels of p421.HB/PD-Ialpha mRNA in the dysmyelinating mouse mutant jimpy, but not shiverer, suggest a role for p421.HB/PD-Ialpha during active myelination and/or late stages of oligodendrocyte differentiation. Furthermore, p421.HB/PD-Ialpha mRNA levels were reduced in the CNS at onset of clinical symptoms in experimental autoimmune encephalomyelitis. These data together implicate the importance of p421.HB/PD-Ialpha in oligodendrocyte function, possibly through cell-cell and/or cell-extracellular matrix recognition.

Satisfaction of Vietnamese patients and their families with refugee and mainstream mental health services

OBJECTIVE

The study examined levels of satisfaction with mainstream mental health services and specialized mental health services for refugees among Vietnamese psychiatric patients and their relatives. Demographic, diagnostic, symptomatic, and service-related issues that might influence satisfaction were investigated.

METHODS

Eighty-six Vietnamese patients were identified from case notes of mainstream inpatient services (N = 31), mainstream community services (N = 7), and a specialized refugee treatment unit (N = 48). During an interview, a scale measuring satisfaction with treatment as well as measures of anxiety, depression, and posttraumatic stress disorder was administered to them. A modified satisfaction scale was administered to 56 relatives.

RESULTS

Patients and relatives were, on average, moderately satisfied with treatment. Patients expressed greater satisfaction with the specialized treatment unit for refugees than with mainstream services, a finding that was not influenced by diagnostic differences or symptom levels at the time patients responded. Further analyses controlling for multiple comparisons revealed that the extent of the information provided and the ease of negotiating changes in treatment were the most salient variables in distinguishing satisfaction levels across the two types of treatment centers. Patients' fluency in English and their relatives' level of education were inversely associated with satisfaction scores, tentatively suggesting that the greater the ability of patients and their families to evaluate services, the less likely they were to express satisfaction with treatment.

CONCLUSIONS

Specialized mental health services for refugees may be more acceptable to refugee populations than their mainstream counterparts, perhaps because better communication with patients and their families is possible in the specialized services. Patients and families who are in a position to evaluate services fully are more likely to be critical of treatments offered.

Inositol phosphate metabolism during myocardial ischemia

Inositol phosphate release in intact heart in response to norepinephrine involves primarily release of inositol(1,4)bisphosphate (Ins(1,4)P2) rather than inositol(1,4,5)trisphosphate (Ins(1,4,5)P3) but Ins(1,4,5)P3 release predominates under conditions of post-ischemic reperfusion. In the current study, effects of myocardial ischemia on inositol phosphate responses were examined. Global myocardial ischemia in rat ventricle caused a reduction in the content of [3H]Ins(1,4)P3 (70-90%) and [3H]Ins(1,4,5)P3 (46%) and altered the pattern of norepinephrine stimulation such that increases in [3H]Ins(1,4,5)P3 were observed. Simulated ischemia in isolated right atria or isolated ventricular myocytes (P alpha 2 16-20 mmHg. pH 6.7. KCl 10 mM) produced similar changes. Reduction in O2 in the absence of other changes reduced the content of [3H]Ins (1,4)P2 (79%) in right atria whereas hypoxia and reduced pH were required to alter the [3H]Ins(1,4,5)P3 response. Progressive reduction in atrial ATP content using metabolic inhibitors caused a parallel decrease in [3H]Ins(1,4,5)P3 content (r = 0.96) without affecting [3H]Ins(1,4)P2 or the isomers of InsP1, showing that levels of Ins(1,4)P2 and Ins(1,4,5)P3 are regulated differently in the heart. These findings show that effects of ischemia on inositol phosphates in heart are complex and multifactorial, with Ins(1,4)P2 being affected under more moderately ischemic conditions than required for alterations in Ins(1,4,5)P3. These studies also demonstrate that ischemia produces similar effects on the release and metabolism of inositol phosphates in heart regardless of the ischemic model or the myocardial preparation used.

The influence of culture on psychiatric assessment: the Vietnamese refugee

The influence of culture on psychiatric diagnostic assessments remains controversial. The authors outline differences between the emic approach to assessment, which is informed by ethnographic concepts of the centrality of culture in shaping the psyche and its expressions, and the etic approach, which downplays cultural effects and focuses on the universal elements in manifestations of psychological distress. Based on the experience of assessing Vietnamese refugees in Australia, the authors explore semantic, contextual, and conceptual factors that may impede the psychiatric assessment of patients from other cultures. Areas of misinterpretation are illustrated using examples from the Vietnamese language. The authors discuss how variations in politicohistorical experiences within ethnic populations may result in differences in the modes of expressing and understanding mental illness. Recognition of the tension between etic and emic perspectives allows the clinician to draw on the most useful elements of each in assessing and treating individual patients.

Orphanin FQ inhibits synaptic transmission and long-term potentiation in rat hippocampus

It is known that opioid peptides acting on opioid receptors can modulate hippocampal synaptic functions. Although a novel member of the opioid receptor family, ORL1 receptors, that displays high-sequence homology with classical opioid receptors is abundant in the hippocampus, little is known regarding its role in synaptic function. The present study was designed to investigate whether activation of the ORL1 receptor by its natural ligand, orphanin FQ, could modulate synaptic transmission and synaptic plasticity in the hippocampus. The actions of orphanin FQ in the CA1 and dentate gyrus were examined by field potential recordings in response to stimulation of Schaffer collaterals and perforant path, respectively. Our results showed that orphanin FQ, but not the inactive analog des-Phe1-orphanin FQ, reduced both the slope of the excitatory postsynaptic potentials and population spike amplitude. The inhibitory effect of orphanin FQ is dose dependent and probably involves a presynaptic mechanism, as suggested by the significantly increased paired-pulse facilitation evoked in the presence of orphanin FQ. In addition, orphanin FQ was found to inhibit the induction of long-term potentiation at the Schaffer collateral-CA1 synapse. These results demonstrate that orphanin FQ can function as an inhibitory modulator regulating synaptic transmission and synaptic plasticity in the hippocampus, suggesting that activation of ORL1 receptors may play an important role in synaptic plasticity involved in learning and memory.

Mutations in the B2 bradykinin receptor reveal a different pattern of contacts for peptidic agonists and peptidic antagonists

The B2 bradykinin receptor, a seven-helix transmembrane receptor, binds the inflammatory mediator bradykinin (BK) and the structurally related peptide antagonist HOE-140. The binding of HOE-140 and the binding of bradykinin are mutually exclusive and competitive. Fifty-four site-specific receptor mutations were made. BK's affinity is reduced 2200-fold by F261A, 490-fold by T265A, 60-fold by D286A, and 3-10-fold by N200A, D268A, and Q290A. In contrast, HOE-140 affinity is reduced less than 7-fold by F254A, F261A, Y297A, and Q262A. The almost complete discordance of mutations that affect BK binding versus HOE-140 binding is surprising, but it was paralleled by the effect of single changes in BK and HOE-140. [Ala9]BK and [Ala6]BK are reduced in receptor binding affinity 27,000- and 150-fold, respectively, while [Ala9]HOE-140 affinity is reduced 7-fold and [Ala6]HOE-140 affinity is unchanged. NMR spectroscopy of all of the peptidic analogs of BK or HOE-140 revealed a beta-turn at the C terminus. Models of the receptor-ligand complex suggested that bradykinin is bound partially inside the helical bundle of the receptor with the amino terminus emerging from the extracellular side of helical bundle. In these models a salt bridge occurs between Arg9 and Asp286; the models also place Phe8 in a hydrophobic pocket midway through the transmembrane region. Models of HOE-140 binding to the receptor place its beta-turn one alpha-helical turn deeper and closer to helix 7 and helix 1 as compared with bradykinin-receptor complex models.

Efficacy of ICAM-1 antisense oligonucleotide in pancreatic islet transplantation

Significant islet allograft prolongation was achieved by ICAM-1/LFA-1 blockade. ICAM-1 antisense oligonucleotide IP-3082 was effective in improving islet function as well as prolonging graft survival.