The role of radiographic phase-contrast imaging in the development of intracochlear electrode arrays

OBJECTIVE

This study describes the application of a new radiographic imaging modality, phase-contrast radiography, to in vitro human temporal bone imaging and investigates its use in the development of new electrode arrays for cochlear implants.

BACKGROUND

The development of perimodiolar electrode arrays for cochlear implants requires detailed information from postoperative radiologic assessment on the position of the array in relation to the cochlear structures. Current standard radiographic techniques provide only limited details.

MATERIALS AND METHODS

Nucleus standard electrode arrays and perimodiolar Contour electrode arrays were implanted into the scala tympani of 11 human temporal bones. Both conventional and phase-contrast radiographs were taken of each temporal bone for comparative purposes.

RESULTS

Phase-contrast imaging provides better visualization of anatomic details of the inner ear and of the structure of the intracochlear electrode array, and better definition of electrode location in relation to cochlear walls.

CONCLUSION

Phase-contrast radiography offers significant improvement over conventional radiography in images of in vitro human temporal bones. It seems to be a valuable tool in the development of intracochlear electrode arrays and cochlear implant research. However, this new radiographic technique still requires certain computational and physics challenges to be addressed before its clinical use can be established.

Photoproduction of the rho(0) meson on the proton at large momentum transfer

The differential cross section, d sigma/dt, for rho(0) meson photoproduction on the proton above the resonance region was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The rho(0) channel was extracted from the measured two charged-pion cross sections by fitting the pi(+)pi(-) and p pi(+) invariant masses. The low momentum transfer region shows the typical diffractive pattern expected from Reggeon exchange. The flatter behavior at large -t cannot be explained solely in terms of QCD-inspired two-gluon exchange models. The data indicate that other processes, like quark interchange, are important to fully describe rho photoproduction.

High-dose cytosine arabinoside and idarubicin treatment of chronic myeloid leukemia in myeloid blast crisis

Chronic myeloid leukemia in myeloid blast crisis (CML-MBC) is highly resistant to standard induction chemotherapy regimens. Anecdotal results from previous clinical trials support the concept of dose escalation in patients with CML-MBC. Eight patients with CML-MBC were treated with cytosine arabinoside (Ara-C) 1.5-3.0 g/m2 intravenously over 1 hr every 12 hr for 12 doses and idarubicin 12 mg/m2 intravenously daily for 3 days. Sixteen previous reports describing the use of Ara-C-based chemotherapy regimens in patients with CML-MBC were also reviewed. Our patients' median age was 62 years (range, 42-69 years). One patient achieved complete hematologic remission (95% confidence interval, 0.3%, 53%). The median survival for our patients was 7.3 months. These results were not different from previous published reports using Ara-C-based chemotherapy regimens to treat CML-MBC. In summary, the combination of high-dose Ara-C and idarubicin did not improve the overall prognosis of patients with CML-MBC. Innovative approaches need to be explored for this patient population.

Truncated STAT proteins are prevalent at relapse of acute myeloid leukemia

Signal transducer and activator of transcription (STAT) proteins are implicated in the control of cell survival, proliferation and differentiation in response to hematopoietic cytokines. C-terminally truncated STAT isoforms (STATbeta), as opposed to the full length form (STATalpha), have a competitive or even transdominant negative effect on gene induction mediated by the STAT pathway. We have previously demonstrated that while constitutively active STAT proteins were detected in ten of 36 (28%) for STAT3 and eight of 36 (22%) for STAT5 in pretreatment samples from newly diagnosed acute myeloid leukemia (AML) patients, a significantly larger fraction of samples [21 of 27 (78%)] expressed STATbeta proteins. To determine whether STATbeta expression was maintained or increased after relapse in AML, we compared STAT activity and isoform expression at diagnosis and at relapse in 17 patients. In this selected group, constitutively active STAT3 was detected in 13 of 17 (76%) AML samples at diagnosis but was detected in only four of these patients at relapse. Constitutively active STAT5 was detected in three of 17 (18%) AML samples at diagnosis; but only two at relapse. In contrast, STATbeta protein expression was observed in 12 of the 17 pretreatment samples (71%) and in 16 of 17 samples at relapse. Only one patient did not express STATbeta at relapse. Our results suggest that STATbeta isoform expression, rather than level of constitutive activity, may be involved in disease progression in AML.

Lamellipodia in invasion

In vivo imaging of GFP-labeled metastatic tumor cells reveals cell orientation towards blood vessels. Orientation of tumor cells during chemotactic responses to ligands such as EGF begins with lamellipod extension. Evaluation of some of the downstream events in lamellipod extension indicates: (1) plasma membrane distribution of the EGF receptor is uniform but internalized receptor accumulates on the side of the cell closest to the source of EGF; (2) the alpha p110 isoform of PI-3 kinase is required; and (3) protrusion of the lamellipod relies upon the combined actions of the Arp2/3 complex and cofilin for generation of filamentous actin.

Thiotepa-associated cardiomyopathy during blood or marrow transplantation: association with the female sex and cardiac risk factors

Thiotepa (TT) has not been reported to cause cardiomyopathy, whereas cyclophosphamide (Cy)-related cardiomyopathy is well characterized. To search for cases of acute onset cardiomyopathy associated with TT, we retrospectively reviewed 171 patients who received TT-containing conditioning regimens for blood or marrow transplantation (BMT). Nine of 171 patients (5.3%) developed clinical congestive heart failure in the post-BMT period. The median time to onset of heart failure was 15 days after BMT (range 5-30). The median pre-BMT left ventricular ejection fraction (LVEF) was 50% (range 42-65%) as determined by two-dimensional echocardiogram, or gated blood pool scan. At the time of cardiomyopathy onset, LVEF was 30%. Six patients died of causes unrelated to heart failure. All affected patients who developed congestive heart failure following administration of TT had some evidence of cardiac dysfunction prior to transplantation. Significant risk factors for the development of cardiomyopathy included low pre-BMT-LVEF and female sex--particularly in females receiving allogeneic transplantation. The incidence of congestive heart failure with TT-containing regimens was similar to the incidence using other regimens with and without Cy. The mean time to clinical evidence of TT-associated cardiomyopathy was longer than the mean time reported with Cy. We recommend caution in using high-dose TT-containing regimens for patients with histories of cardiac dysfunction.

Phase I/pharmacodynamic study of N-acetylcysteine/oltipraz in smokers: early termination due to excessive toxicity

An N-acetylcysteine (NAC)/oltipraz (OLZ) combination was studied in healthy volunteer smokers who received daily NAC (1200 mg/day) and were randomized to weekly placebo (Arm A), OLZ 200 mg (Arm B), or 400 mg (Arm C). Treatment was for 12 weeks with follow-up at 16 weeks. The objective was to study toxicity and the modulation of pharmacodynamic end points. After treatment of 19 of a planned 60 subjects, (Arm A, six; Arm B, four; and Arm C, nine), the study was closed because of toxicity. Eight subjects failed to complete 12 weeks of drug administration, (Arm A, two, and Arm C, six). The most frequent side effects were gastrointestinal, fatigue, conjunctival irritation, and skin rash. Pharmacodynamic end points were measured pretreatment and 48 h after the dose of OLZ at weeks 1, 5, and 12 and 4 weeks after the end of treatment. Glutathione (GSH) was measured in plasma and in peripheral blood lymphocytes (PBLs). Other end points measured in PBLs were the enzyme activities of total glutathione-S-transferase (GST), GSTpi, and NAD(P)H:quinone oxidoreductase; and the mRNA expression of gamma-glutamylcysteine synthetase gammaGCS), GSTpi, and NAD(P)H:quinone oxidoreductase. GSH in PBLs, GST (total), and the mRNA of gammaGCS showed increases at some time points in some subjects. Most consistent was the mRNA of gammaGCS, which showed a > or = 30% increase at one or more time points in 11 of 19 subjects. Other end points were unchanged. We concluded that NAC/OLZ modulates some end points related to GSH but is too toxic for chemoprevention at the doses used.

The ep -->e'p eta reaction at and above the S11(1535) baryon resonance

New cross sections for the reaction e p-->e p eta are reported for total center of mass energy W = 1.5--1.86 GeV and invariant momentum transfer Q2 = 0.25--1.5 (GeV/c)(2). This large kinematic range allows extraction of important new information about response functions, photocouplings, and eta N coupling strengths of baryon resonances. Newly observed structure at W approximately 1.65 GeV is shown to come from interference between S and P waves and can be interpreted with known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.

Intraoperative hemorrhage during patent ductus arteriosus ligation in dogs

OBJECTIVE

To determine the prevalence of intraoperative hemorrhage in a consecutive series of dogs undergoing patent ductus arteriosus (PDA) ligation at a veterinary teaching hospital, and to describe strategies to reduce the risk of ductus perforation and deal with hemorrhage when it occurs.

STUDY DESIGN

Retrospective clinical study.

ANIMALS

Sixty-four dogs.

METHODS

The records of all dogs undergoing PDA ligation at the University Veterinary Center, Sydney between May 1989 and February 1998 were reviewed and the prevalence and nature of complications identified.

RESULTS

Serious hemorrhage occurred in 4 of 64 dogs (6.25%) that underwent PDA ligation. In all cases, hemorrhage resulted from perforation of the craniomedial aspect of the ductus while attempting to expose the tips of the dissecting forceps. Hemorrhage was controlled in 3 dogs by clamping the main pulmonary artery, digital compression of the descending aorta, and completion of ductus ligation during an approximately 5-minute period of circulatory arrest. The remaining dog exsanguinated during an unsuccessful attempt to locate, clamp, and ligate the bleeding point. The mortality rate for PDA ligation was I of 64 dogs (1.6 %).

CONCLUSIONS

The technique described in this report permits simple ligation of a range of different ductus morphologies in dogs of varying breeds, weights, and ages. In the event of serious hemorrhage, prompt ventricular outflow occlusion and ductus ligation followed by rapid whole blood transfusion is life saving in most cases.

Addressing social and cultural disparities in tobacco use

Disparities in smoking as a function of ethnicity exist, but part of that disparity appears to be mediated by education level. Smoking prevalence differences by ethnicity disappear or decrease substantially when controlling for education level. Nonetheless, ethnicity remains an important consideration when striving to understand the mechanisms associated with smoking, as well as in the development of smoking prevention and treatment programs. In this paper, the complex interrelationships among ethnicity, social class, and smoking are discussed in brief, and a framework for developing a systematic means of addressing social disparities in tobacco use is described.

Do out-of-hours co-operatives improve general practitioners' health?

General practitioners (GPs) have been found to have a higher level of anxiety and depression then hospital managers and consultants. In 1995 and 1998, we surveyed GPs in Buckinghamshire. We found that the development of out-of-hours co-operatives was an important factor in the improvement in GPs' health status.

Sociodemographic predictors of adherence to annual cervical cancer screening in minority women

The Papanicolaou (Pap) test is an effective screening mechanism for reducing morbidity and mortality from cervical cancer. Nevertheless, Pennsylvania ranks fifth in national cervical cancer incidence and fourth in national cervical cancer mortality, with a significant number of cases contributed by Philadelphia. Substantial subgroups of American women, specifically ethnic minorities, the elderly, the uninsured, and the poor, have not been screened or are not screened at regular intervals. A secondary data analysis was conducted to test whether age, income, insurance coverage, marital status, level of education, and number of persons living at home could predict whether a woman among convenience sample of 204 black and Hispanic women adhered to annual Pap testing. A woman was considered adherent to annual Pap testing if she reported undergoing a Pap smear in the 14 months preceding her enrollment in the study. African American woman who were high school graduates and had insurance coverage were more likely to be adherent to annual Pap testing. Hispanic women older than 50 years and born outside the mainland United States were less likely to be adherent to annual Pap testing. Findings suggest that cancer nurses working to promote cervical cancer screening in Philadelphia should continue to target at-risk populations, specifically uninsured and less-educated black and Hispanic women older than 50 years who were born outside the mainland United States.

[Radiation-induced superficial fibrosis and TGF-alpha 1]

Radiation-induced fibrosis is a late sequela of both therapeutic and accidental irradiations, which has been described in various tissues, including the lung, liver, kidney and skin. This review presents different aspects of superficial radiation-induced fibrosis, such as clinical observations, histological changes, cellular and molecular regulations, and medical management. Recent evidence on the critical role played by TGF-beta 1 in the initiation, development and persistence of fibrosis are discussed, as well as the possibility that this cytokine may constitute a specific target for antifibrotic agents.

Unilateral hydronephrosis resulting from intraluminal obstruction of the ureter by adenosquamous endometrioid carcinoma arising from disseminated endometriosis

A case of adenosquamous carcinoma arising in the background of disseminated pelvic endometriosis presented as unilateral hydronephrosis and a polypoid intraluminal ureteral mass. This is the first case of a malignancy arising in endometriosis presenting as an obstructive ureteral mass. The patient had a history of total hysterectomy and bilateral salpingo-oophorectomy 5 years earlier because of an endometriotic cyst, and had since been under unopposed estrogen replacement therapy. An analysis of the case and related literature is presented. Possible pathogenic mechanisms are discussed.

Mortality in Western Australian psychiatric patients

BACKGROUND

The aim was to examine mortality in psychiatric patients in Western Australia (WA), over a time period of considerable change in the delivery of mental health services.

METHODS

A population-based record linkage analysis was undertaken to quantify mortality among people with mental illness in WA. Mortality rates were calculated in users of mental health services and compared with rates in the whole population of WA. Trends in mortality were also examined using relative survival analysis, and proportional hazards regression.

RESULTS

The overall mortality rate ratio was 2.57 in males (95% CI: 2.51-2.64), and 2.18 in females (2.12-2.24). The highest cause-specific mortality rate ratio was for deaths due to suicide [RR: 7.37 in males (95% CI: 6.74-8.05) and 8.38 in females (95% CI: 7.11-9.89)], with mortality rate ratios being significantly greater than 1 for all other major causes of death. A relative survival analysis found that the excess mortality risk was concentrated in the first few years after first contact with mental health services. Proportional hazards regression analysis found a slight elevation of mortality rates over time.

CONCLUSIONS

Mortality among psychiatric patients remains high and appears to be increasing. Highest excess mortality rate is associated with suicide, but mortality rates are significantly elevated for all major causes of death.

Suicide and attempted suicide among older adults in Western Australia

BACKGROUND

Suicide rates are high in later life. Risk factors include male sex and depressive illness. This study investigated the relationship between suicidal behaviour and contact with mental health services among the elderly in Western Australia.

METHODS

Record linkage was used to obtain records of hospital admissions and mental health service contacts for all suicide attempts and deaths in the period 1980-95. Standardized incidence ratios were calculated for the elderly, general population and people with mental health service contacts. Cox regression was used to evaluated potential risk factors for elderly people who were in contact with mental health services.

RESULTS

People over 60 years of age accounted for 15% of suicides and 4.6% of attempted suicides. Suicide rates were 3.3 times higher in males and 4.4 times higher in females when compared to the general population of elderly people. For attempted suicide, the rate was 5.8 times higher in males and 6.6 times higher in females with prior contact with mental health services. Highest risk of suicide was found in patients with diagnoses of affective psychoses (RR = 3.7), adjustment reaction (RR = 3.2) or depressive disorder (RR = 2.8). The diagnosis of cancer was associated with decreased risk of suicide (RR = 3.6) and attempted suicide (RR = 1.9).

CONCLUSIONS

Suicide rates are high among the elderly in Western Australia. Suicide is significantly associated with the diagnosis of mood disorder. Suicide attempts are less common, and are associated most strongly with mood and personality disorders. The decreased risk of self-harm behaviour among patients with cancer warrants further investigation.

Excess cancer mortality in Western Australian psychiatric patients due to higher case fatality rates

OBJECTIVE

To investigate the association between mental illness and cancer incidence, mortality and case fatality.

METHOD

A population-based record linkage study was undertaken based on 172,932 patients of mental health services in Western Australia. Records of mental health service contacts were linked with cancer registrations and death records.

RESULTS

While there was little difference in overall cancer incidence rates between psychiatric patients and the general community (RR in males 1.05, 95%, CI 1.02-1.09, RR in females 1.02, 0.98-1.05), cancer mortality was 39%, higher in males (95%) CI: 32-46%) and 24% higher in females (17-32%).

CONCLUSION

People with mental illness in Western Australia do not show an increased incidence rate of cancer, but do have higher cancer mortality. This was attributed to a higher cancer case fatality rate among people with mental illness.

Search for neutrino oscillations at the palo verde nuclear reactors

We report on the initial results from a measurement of the antineutrino flux and spectrum at a distance of about 800 m from the three reactors of the Palo Verde Nuclear Generating Station using a segmented gadolinium-loaded scintillation detector. We find that the antineutrino flux agrees with that predicted in the absence of oscillations excluding at 90% C.L. nu;(e)-nu;(x) oscillations with Deltam(2)>1.12x10(-3) eV(2) for maximal mixing and sin (2)2straight theta>0.21 for large Deltam(2). Our results support the conclusion that the atmospheric neutrino oscillations observed by Super-Kamiokande do not involve nu(e).