Renal mRNA response to reduced perfusion pressure conserved despite denervation in mature ovine fetuses

We hypothesized that renal denervation in mature ovine fetuses reduces renin mRNA response to 24 h of reduced renal perfusion pressure (RPP). Seven occluder (O) (132.4 ± 1.2 days gestation) and six control (C) (131.5 ± 1.2 days gestation) fetuses underwent left renal denervation. Postoperatively, O fetuses experienced 24 h of reduced RPP by suprarenal aortic occlusion. Femoral arterial blood pressure (FAB) and plasma active renin (pARC) and prorenin (pPRC) concentrations were obtained hourly for 6 h and at h 23 and 24. Renin mRNA was measured by RNase protection assay. We quantitated renin containing glomeruli by immunocytochemistry. Variables were compared by ANOVA. Mean O group FAB reduction from baseline was −6.60 ± 0.41 mmHg. pARC and pPRC increased with occlusion, renal ARC and renal PRC 1 did not increase with occlusion. No effect in renin mRNA or number of positive glomeruli was noted with denervation in the basal state; however, significant increases were noted in response to RPP irrespective of innervation status. In conclusion, 24 h or reduced RPP in mature ovine fetus increases renal renin mRNA and the immunocytochemical expression of renin. This response is conserved despite denervation.

Lower nasal distribution of cortical cataract: the Blue Mountains Eye Study

Previous reports have indicated that cortical cataract commences in the lower nasal lens, possibly due to sunlight exposure because of the shallow brow temporally. The present study aimed to assess the lens sector distribution of cortcal cataract in a population. The Blue Mountains Eye Study assessed 3654 residents aged 49-97 years; 3270 phakic subjects had retroillumination lens photographs graded using the Wisconsin method, which divides the lens into eight radial sectors with a grid overlay. Graders estimated percentage of cortical opacity in each sector. The lower nasal area consistently had the greatest opacity, a pattern present at each age and similar in both sexes, despite the 20% greater cortical cataract in women. The mean area of lens cortex involved by opacities in the lower nasal hemisphere was four fold greater than in the upper temporal hemisphere at each age. The lower nasal distributon was highly symmetrical when both eyes were affected. When > 20% of the lower nasal lens quadrant had cortical opacity, 88% of bilaterally affected subjects had cortical cataract n the same quadrant of the fellow eye. The lower nasal distribution may indicate a role for sunlight in the aetiology of cortcal cataract, which could be considered when examining other cortical cataract risk factors, such as diabetes, vascular disease and hormonal factors in women.

Prevalence and correlates of depressive symptoms in the elderly of rural communities in southern Taiwan

The purpose of this study was to determine the prevalence and level of depressive symptoms and the influence of demographic characteristics on depressive symptoms in elders residing in rural Taiwan. Also, the association was explored between depressive symptoms and life stressors in the Taiwanese Elderly Stress Inventory (TESI). A cross-sectional design utilizing face-to-face administered instruments was used. A total of 195 older community residents participated in the study. Levels of depressive symptoms wese measured by the Geriatric Depression Scale - Short Form (GDS-SF) while life stressors were assessed with the Taiwanese Elderly Stress Inventory (TESI). Overall, 57% of the subjects had a GDS-SF score of 7 or above (M = 7.58, SD = 3.89), indicating that the majority were depressed. Additionally, gender, educational level, marital status, living arrangements, and socioeconomic status (SES) were significant factors to depressive symptoms. Women were more likely to experience depression than men. Elders who had received no formal education, were separated from their spouse due to death or divorce, lived alone, or had lower SES were at higher risk of more severe depression. Also, significant correlations were found between depressive symptoms and 19 stressors identified in the TESI. These stressors mostly include events related to physical functioning and family issues. The findings of this study will provide community health professionals in Taiwan with a better recognition of depressive symptoms in rural elders and stressors that are associated with depressive symptoms. This information can be used to plan health-related services and interventions for rural elders.

Stress, loneliness, and depression in Taiwanese rural community-dwelling elders

This study examined the stressors and stress levels, loneliness, and depression experienced by Taiwanese rural elders and determine if differences in the level of stress were associated with specific person-environmental characteristics. The relationship between stress and depression was also explored. A total of 201 older rural community residents participated in the study. Findings showed that rural elders experienced a number of stressors related to health and family issues. Differences in the degree of stressfulness of individuals differed by gender, educational level, living arrangement, and socioeconomic status (SES). Findings in this study also showed that there was a high association among stress level, depressive symptoms, and mood status. The findings of this study will assist community health policy-makers in determining the need for health-related services for rural elders experiencing these problems.

[Bilateral lesion of locus coeruleus in rats induces haemorrhage in multiple visceral organs]

AIM AND METHODS

The haemorrhagic changes of the urinary bladder, as well as that of other visceral organs, were checked histologically in rats being received bilateral electrolytic lesion of the locus coeruleus (LC).

RESULTS

Complete lesion of bilateral LC constantly induced severe haemorrhage of the urinary bladder, accompanied with blood congestion or slight haemorrhage of other visceral organs. Partial lesion of bilateral LC also induced blood congestion or slight haemorrhage in multiple visceral organs, but the urinary bladder did not show haemorrhage change. Reduction of stress by adrenalectomy before lesion of the LC, or administration of antagonist of histamine H2 receptor, had no obvious effect on the haemorrhage of the urinary bladder and histological changes of other visceral organs.

CONCLUSION

These results indicate that the haemorrhagic change of multiple visceral organs induced by bilateral lesion of the LC in rats is not due to stress, or due to involvement of histamine H2 receptor. The mechanism needs to be studied further.

Technetium-99m-sestamethoxyisobutylisonitrile scan as a predictor of chemotherapy response in malignant lymphomas compared with P-glycoprotein expression, multidrug resistance-related protein expression and other prognosis factors

The purpose of the present study was to predict the response of malignant lymphomas (MLs) to chemotherapy using technetium-99m methoxyisobutylisonitrile (Tc-MIBI) scan and to compare it with the predictive ability of P-glycoprotein (P-gp) expression, multidrug resistance-related protein (MRP) expression and other prognosis factors. Twenty-five ML patients were enrolled in this study prior to initiation of chemotherapy. Images were obtained 10 min after intravenous injection of Tc-MIBI, interpreted visually and the tumour-to-background (T/B) ratios calculated. Immunohistochemical analyses were performed on sections of the biopsy specimens to determine P-gp and MRP expression. Chemotherapy response was evaluated in the first 1-2 years after completion of chemotherapy. The mean T/B ratio of the 15 patients with a good response (3.3 +/- 0.6) was significantly higher than that of the 10 patients with a poor response (1.2 +/- 0.1). All 15 patients with a good chemotherapy response had positive Tc-MIBI scan results and negative P-gp and MRP expression. All 10 patients with a poor response had negative Tc-MIBI scan results and either positive P-gp or MRP expression. Other prognosis factors showed no significant difference in the incidence of good and poor responses. Tc-MIBI scan results represent P-gp or MRP expression more accurately than other prognosis factors and predict the chemotherapy response in ML patients.

Evaluation of hepatobiliary function by hepatobiliary scintigraphy in hepatoma patients after transcatheter arterial embolization

BACKGROUND

Transcatheter arterial embolization (TAE) is the treatment of choice for inoperable hepatocellular carcinoma. However, altered and impaired gallbladder function due to gallbladder infarction and bile duct necrosis following TAE have been reported.

METHODS

Hepatobiliary function was evaluated using quantitative Tc-99m DISIDA hepatobiliary scintigraphy in 40 hepatoma patients before and after TAE. The patients were separated into two groups: group 1 (20 patients), who received pre-cystic artery TAE, and group 2 (also 20 patients), who received post-cystic artery TAE.

RESULTS

After TAE, there were no significant changes in liver or bile duct function in the patients of either group. However, for group I patients, significantly decreased gallbladder function was found after TAE.

CONCLUSIONS

Altered and impaired gallbladder function is common in hepatoma patients who receive pre-cystic artery TAE, and Tc-99m DISIDA cholescintigraphy may be useful for evaluating hepatobiliary function in hepatoma patients who receive TAE.

Cerebral perfusion in patients with syndrome X: a single photon emission computed tomography study

OBJECTIVE

To test the hypothesis that syndrome X is a systemic vascular disorder, the authors studied 40 patients with this diagnosis using technetium-99m hexamethylpropylene amine oxime and single photon emission computed tomography (SPECT) brain images. Twenty-three of 25 cases with definite myocardial perfusion defects diagnosed by thallium-201 myocardial perfusion SPECT also had multiple hypoperfusion areas in the brain versus 2 of 15 patients without thallium myocardial defects. The parietal lobes were the most common hypoperfusion areas, and cerebellum was the least common. Syndrome X is a systemic vascular disorder with a high incidence of hypoperfusion lesions of the brain and is usually coincident with myocardial defects.

Risk factors for age-related macular degeneration: Pooled findings from three continents

OBJECTIVE

To assess the prevalence and potential risk factors for late age-related macular degeneration (AMD) in three racially similar populations from North America, Europe, and AUSTRALIA:

DESIGN

Combined analysis of population-based eye disease prevalence data.

PARTICIPANTS

There were 14,752 participants with gradable photographs from the Beaver Dam Eye Study (n = 4756), Rotterdam Study (n = 6411), and Blue Mountains Eye Study (n = 3585).

MAIN OUTCOME MEASURES

AMD diagnosis was made from masked grading of stereo macular photographs. Final classification of AMD cases was agreed by consensus between study investigators.

RESULTS

AMD prevalence was strongly age related. Overall, AMD was present in 0.2% of the combined population aged 55 to 64 years, rising to 13% of the population older than 85 years. Prevalence of neovascular AMD (NV) increased from 0.17% among subjects aged 55 to 64 years to 5.8% for those older than 85 years. Prevalence of pure geographic atrophy (GA) increased from 0.04% to 4.2% for these age groups. There were no significant gender differences in the prevalence of NV or GA. Subjects in the Rotterdam population had a significantly lower age-adjusted and smoking-adjusted risk of NV than subjects in the Beaver Dam and Blue Mountains populations. Apart from age, tobacco smoking was the only risk factor consistently associated with any form of AMD in all sites separately and in pooled analyses over the three sites.

CONCLUSIONS

These combined data from racially similar communities across three continents provide strong and consistent evidence that tobacco smoking is the principal known preventable exposure associated with any form of AMD.

Pharmacogenetic interactions between beta-blocker therapy and the angiotensin-converting enzyme deletion polymorphism in patients with congestive heart failure

BACKGROUND

Activation of the renin-angiotensin and sympathetic nervous systems adversely affect heart failure progression. The ACE deletion allele (ACE D) is associated with increased renin-angiotensin activation; however, its influence on patient outcomes remains uncertain, and the pharmacogenetic interactions with beta-blocker therapy have not been previously evaluated.

METHODS AND RESULTS

We prospectively followed 328 patients (age, 56.1+/-11.9 years) with systolic dysfunction (left ventricular ejection fraction, 0.24+/-0.08) to assess the impact of the ACE D allele on transplant-free survival (median follow-up, 21 months). Transplant-free survival was compared by genotype for the whole cohort and separately in patients with (n=120) and those without beta-blocker therapy (n=208) at the time of entry. Transplant-free survival was significantly poorer for patients with the D: allele (1-year percent survival II/ID/DD=94/77/75; 2-year=78/65/60; ordered log-rank test, P:=0.044). In patients not treated with beta-blockers, the adverse impact of ACE D allele was dramatically increased (1-year percent survival II/ID/DD=95/75/67; 2-year=81/61/48; P:=0.005). In contrast, in patients receiving beta-blocker therapy, no influence of ACE genotype on transplant-free survival was evident (1-year percent survival II/ID/DD=91/80/86; 2-year=70/71/77; P:=0.73).

CONCLUSIONS

In a cohort of patients with systolic dysfunction, the ACE D allele was associated with a significantly poorer transplant-free survival. This effect was primarily evident in patients not treated with beta-blockers and was not seen in patients receiving therapy. These findings suggest a potential pharmacogenetic interaction between the ACE D/I polymorphism and therapy with beta-blockers in the determination of heart failure survival.

Incidence of nursing home placement in a defined community

OBJECTIVE

To assess cumulative incidence and non-cognitive factors predicting nursing home placement in a defined older population.

DESIGN AND SETTING

Six-year follow-up of a population-based cohort living west of Sydney.

PARTICIPANTS

3654 non-institutionalised residents aged 49 years or older (82.4% of those eligible) participated in baseline examinations during 1992 to 1994.

MAIN OUTCOME MEASURES

Permanent nursing home admission for long-term institutionalised aged care in New South Wales, confirmed by records of approvals by the regional Aged Care Assessment Team and subsidy payments by government.

RESULTS

After excluding 384 participants who moved from the area or were lost to follow-up, 162 participants (5.0%) had been admitted to nursing homes on a permanent basis by October 1999. Of participants who died since baseline, 20% had been admitted to a nursing home before death. Of those alive, 1.6% were current nursing home residents. Six-year cumulative incidence rates for nursing home placement were 0.7%, 1.1%, 2.4%, 3.9%, 9.0%, 18.3% and 34.9% for people aged 55-59, 60-64, 65-69, 70-74, 75-79, 80-84 and 85 years or older, respectively. Non-cognitive factors at baseline predicting subsequent nursing home admission included each additional year of age (risk ratio [RR], 1.14), fair or poor compared with excellent self-rated health (RR, 2.9, 3.6), walking difficulty (RR, 3.6) and current smoking (RR, 1.9). People owning their homes had a decreased likelihood of nursing home placement (RR, 0.6).

CONCLUSIONS

Incidence rates of institutional aged care doubled for each five-year interval from the age of 60 years. A range of non-cognitive factors predict nursing home placement.

Dexamethasone for preventing nausea and vomiting associated with epidural morphine: a dose-ranging study

We conducted a dose-ranging study of dexamethasone for preventing nausea and vomiting within the first 24 h after the administration of epidural morphine. Two hundred twenty-five women (n = 45 in each of the five groups) undergoing simple abdominal total hysterectomy under epidural anesthesia were enrolled in this randomized, double-blind, placebo-controlled study. When the incision closure was completed, patients received IV dexamethasone, 10 mg, 5 mg, or 2.5 mg; IV droperidol 1.25 mg; or saline 2 mL. All patients received epidural morphine 3 mg for postoperative analgesia. We found that patients who received dexamethasone 5 mg or 10 mg or droperidol 1.25 mg were significantly different from those who received saline alone in the following variables: the total incidence of nausea and vomiting, the incidence of more than four vomiting episodes, the number of patients requiring rescue antiemetics, the total number of patients with no vomiting and/or no antiemetic medication (P < 0.05 to P < 0.01). The differences among dexamethasone 10 mg and 5 mg and droperidol 1.25 mg were not significant. Dexamethasone 2.5 mg was ineffective. In conclusion, because dexamethasone 5 mg was as effective as 10 mg as an antiemetic, we recommend the smaller dose for preventing nausea and vomiting associated with epidural morphine.

IMPLICATIONS

We conducted a dose-ranging study of dexamethasone for preventing nausea and vomiting within the first 24 h after the administration of epidural morphine. We found that dexamethasone 5 mg was as effective as 10 mg. We recommend the smaller dose for this purpose.

P-Glycoprotein and multidrug resistance-related protein expressions in relation to technetium-99m methoxyisobutylisonitrile scintimammography findings

The purpose of this study was to retrospectively study 48 patients with infiltrating ductal breast cancer to evaluate the relationship between the degree of accumulation of technetium-99m methoxyisobutylisonitrile (Tc-MIBI) and P-glycoprotein (Pgp) or multidrug resistance-related protein (MRP) expression in breast cancer tissues. Before surgery or biopsy, all 48 patients underwent scintimammography started 10 min after the injection of Tc-MIBI. Tumor:background (T:B) ratios were calculated from the Tc-MIBI scintimammography. Immunohistochemical analysis was performed on the pathological specimens of the 48 breast tumors to determine Pgp and MRP expression. According to the results of immunohistochemical analysis, the 48 breast cancers were separated into four groups: (a) group 1, 12 cancers with both positive Pgp expression and positive MRP expression; (b) group 2, 12 cancers with positive Pgp expression and negative MRP expression; (c) group 3, 12 cancers with negative Pgp expression and positive MRP expression; and (d) group 4, 12 cancers with both negative Pgp expression and negative MRP expression. Among the four groups, the T:B ratio was lowest in group 1 (1.13+/-0.10) and highest in group 4 (2.17+/-0.14), respectively (P < 0.05). The T:B ratios of groups 2 (1.30+/-0.25) and 3 (1.32+/-0.26) were between those of groups 1 and 4. Our data confirmed that Tc-MIBI scintimammography is useful for determining Pgp and MRP expression in patients with breast cancers.

Synergistic cytotoxicity of Rana catesbeiana ribonuclease and IFN-gamma on hepatoma cells

RC-RNase purified from Rana catesbeiana (bullfrog) oocytes is a pyrimidine-guanine sequence-specific ribonuclease. RC-RNase is derived from the RNase superfamily genes exerting distinct ribonucleolytic activity and possesses cytotoxicity to tumor cells, but rarely to primary cells. In this study, we utilized RC-RNase to function with antiproliferative cytokines. The combination with TNF-alpha or TNF-beta would not aggravate cell death. However, the combination with IFN-gamma could induce synergistic cytotoxicity verified by XTT assays toward three hepatoma cell lines bearing different differentiation stages. The distinct cytotoxicity from RC-RNase or RC-RNase/IFN-gamma on different hepatoma cells was correlated with the differentiation extent but not the proliferation rate of the cells. Despite the synergistic cytotoxicity and severe mitochondrial disruptions in the RC-RNase/IFN-gamma-treated cells, we scarcely detected any significant feature of apoptosis or necrosis by FACS analysis on annexin-V/propidium iodide staining. The mechanisms of cell death triggered by RC-RNase or RC-RNase/IFN-gamma require further investigation.

Effect of ketamine on presympathetic neurons in rostral ventrolateral medulla of rats

AIM

To study the effects of ketamine on central sympathetic and cardiovascular regulation.

METHODS

The experiment was performed on 25 urethane anaesthetized, artificially ventilated adult rats. A total of 32 presympathetic neurons in the rostral ventrolateral medulla (RVLM) were electrophysiologically identified, which had properties of both barosensitivity and projection to the spinal cord. Responses of these neurons to intravenously administrated ketamine (a non competitive N-methyl-D aspartate receptor antagonist) were observed.

RESULTS

Intravenous injection of ketamine (3, 6, 12 mg/kg body weight) increased the firing rate and blocked the barosensitivity of presympathetic neurons in the RVLM in a dose dependent manner.

CONCLUSION

Ketamine could affect the sympathetic outflow by blocking tonic baroreceptor inhibition of the presympathetic neurons in the RVLM.

Probing the structural diversities of long alpha-neurotoxins by fluorescence quenching studies

Trp fluorescence of Ophiophagus hannah neurotoxins (Oh-4, Oh-6A, Oh-7, and Oh-8) and Bungarus multicinctus (alpha-bungarotoxin was quenched by acrylamide and iodide. Acrylamide quenching studies indicated that the degree of exposure of Trp residues in the neurotoxins followed the order Oh-8 > Oh-7 > Oh-6A > Oh-4 > alpha-bungarotoxin, as did the accessibility for iodide. These results reveal that the exposed degree of Trp residues and the microenvironment surrounding Trp residues in the neurotoxins differ, even though their Trp residues and positively charged residues are located at the same or homologous positions. In contrast to unfolded Oh-4, Oh-6A, Oh-7, and alpha-bungarotoxin, unfolding of Oh-8 by reduction and S-carboxymethylation caused a notable decrease in the susceptibility of their Trp residues for iodide. These observations support the view that the side chains of Trp residues and positively charged residues in their native structure do not point toward the same spatial positions. Computer models of the neurotoxins are in good agreement with this proposition. These results elucidate why the conserved Trp residues and cationic groups do not always play the same roles in the biological activities of the neurotoxins.

Infection of human dendritic cells by dengue virus causes cell maturation and cytokine production

Dengue virus (DV) infection is a major problem in public health. It can cause fatal diseases such as Dengue hemorrhagic fever and Dengue shock syndrome. Dendritic cells (DC) are professional APCs required for establishing a primary immune response. Here, we investigated the role of human PBMC-derived DC in DV infection. Using different techniques, including plaque assay, flow cytometry analysis, nested RT-PCR, and confocal microscope and electron microscope examinations, we show that DV can enter cultured human DC and produce virus particles. After entrance, DV could be visualized in cystic vesicles, vacuoles, and the endoplasmic reticulum. The DV-infected DC also showed proliferation and hypertrophy of the endoplasmic reticulum as well as the swollen mitochondria. In addition, the DV-stimulated DC could express maturation markers such as B7-1, B7-2, HLA-DR, CD11b, and CD83. Furthermore, the infection of DC by DV induced production of TNF-alpha and IFN-alpha, but not IL-6 and IL-12. Although DC underwent spontaneous apoptosis in the absence of feeding cytokines, this process appeared to be delayed after DV infection. Our observations provide important information in understanding the pathogenesis of DV infection.

Dexamethasone prophylaxis of nausea and vomiting after epidural morphine for post-Cesarean analgesia

PURPOSE

To determine the minimum effective dose of dexamethasone in preventing nausea and vomiting associated with epidural morphine for post-Cesarean analgesia.

METHOD

One hundred and eighty parturients (n=45 in each of four groups) requiring epidural morphine for post-Cesarean analgesia were enrolled in this randomized, double-blinded, placebo-controlled study. At the end of surgery, parturients received either dexamethasone, at doses of 10 mg, 5 mg, 2.5 mg, or saline i.v.. Three milligrams epidural morphine were given to all parturients for postoperative analgesia. The incidence of PONV and side effects were estimated for 24 hr after delivery by blinded, trained nurse anesthetists.

RESULTS

Parturients who received dexamethasone, either 10 mg or 5 mg were different from those who received saline alone in the following parameters: the total incidence of nausea and vomiting, incidence of > 4 vomiting episodes, number the of parturients requiring rescue antiemetics, and the total number of parturients with no vomiting and/or no antiemetic medication (P < 0.05 to P < 0.01). The differences between dexamethasone 10 mg and 5 mg were not significant. Dexamethasone 2.5 mg was partially effective.

CONCLUSION

Dexamethasone, 5 mg i.v., is suggested as the minimum effective dose in preventing nausea and vomiting associated with epidural morphine for post-Cesarean analgesia.

Characterization of ataxia telangiectasia fibroblasts with extended life-span through telomerase expression

Ataxia-telangiectasia (A-T) is an autosomal recessive disease characterized by progressive cerebellar degeneration, immunodeficiencies, genomic instability and gonadal atrophy. A-T patients are hypersensitive to ionizing radiation and have an elevated cancer risk. Cells derived from A-T patients require higher levels of serum factors, exhibit cytoskeletal defects and undergo premature senescence in culture. We show here that expression of the catalytic subunit of telomerase (hTERT) in primary A-T patient fibroblasts can rescue the premature senescence phenotype. Ectopic expression of hTERT does not rescue the radiosensitivity or the telomere fusions in A-T fibroblasts. The hTERT+AT cells also retain the characteristic defects in cell-cycle checkpoints, and show increased chromosome damage before and after ionizing radiation. Although A-T patients have an increased susceptibility to cancer, the expression of hTERT in A-T fibroblasts does not stimulate malignant transformation. These immortalized A-T cells provide a more stable cell system to investigate the molecular mechanisms underlying the cellular phenotypes of Ataxia-telangiectasia.

Technetium-99m-tetrofosmin scintigraphy in the prediction of chemotherapy response of untreated malignant lymphomas and comparison with other prognostic factors

The aim of this study was to retrospectively predict the chemotherapy response of untreated malignant lymphomas using technetium-99m tetrofosmin (Tc-TF) scintigraphy and to compare the technique with other prognostic factors. In this study, before any chemotherapy, 25 patients with malignant lymphomas (ML) underwent Tc-TF scintigraphy. Scintigraphy was performed 10 minutes after intravenous injection of 20 mCi Tc-TF to calculate the tumor-to-normal (T/N) uptake ratio. In the first 1-2 years after complete chemotherapy, the response was evaluated by clinical and radiological methods. Compared with the 10 ML patients with poor chemotherapy response, the 15 ML patients with good response had a significantly higher mean T/N uptake ratio (3.23 +/- 0.56) versus 1.18 +/- 0.11). All of the 15 patients with good response had positive scintigraphic results whilst the 10 patients with poor response had negative scintigraphic results. When compared with other prognostic factors, Tc-TF scintigraphy was the tool to predict the chemotherapy response of ML patients.

Detection of cervical lymph node metastases of nasopharyngeal carcinomas with technetium-99m tetrofosmin single photon emission computed tomography and comparison with computed tomography

The purpose of this study was to evaluate the usefulness of technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) in the detection of cervical lymph node (LN) metastasis in nasopharyngeal carcinomas (NPC), and to compare Tc-99m TF SPECT results with computed tomography (CT) findings. Fifty patients with biopsy-proven NPC and suspected cervical LN metastases underwent head and neck Tc-99m TF SPECT and CT to detect cervical LN metastases. Cervical LN metastases of 40 patients were confirmed by histopathological examination of biopsy samples. For 22 LN lesions with discordant results between Tc-99m TF SPECT and CT, Tc-99m TF SPECT could correctly detect 4 metastatic and 7 benign LN lesions while CT could correctly detect 5 metastatic and 6 benign LN lesions. Agreement positive results of Tc-99m TF SPECT and CT could correctly detect all of the 18 metastatic LN lesions. Tc-99m TF SPECT has a better specificity but a lower sensitivity for detecting cervical LN metastases in NPC when compared with CT. The combined use of Tc-99m TF SPECT and CT could significantly increase the accuracy of detect cervical LN metastases in NPC compared with the single use of either Tc-99m TF SPECT or CT.

Neurotrophin dependence domain: a domain required for the mediation of apoptosis by the p75 neurotrophin receptor

The mechanisms underlying neurotrophin dependence, and cellular dependent states in general, are unknown. We show that a 29 amino acid region in the intracellular domain of the common neurotrophin receptor, p75NTR, is required for the mediation of apoptosis by p75NTR. Furthermore, contrary to results obtained with Fas, monomeric p75NTR is required for apoptosis induction, whereas multimerization inhibits the pro-apoptotic effect. Within the 29-residue domain required for apoptosis induction by p75NTR, a 14-residue region is sufficient as a peptide inducer of apoptosis. This 14-residue peptide requires the positively charged carboxyterminal residues for its effect on cell death, and these same residues are required by the full-length p75NTR. These studies define a novel type of domain that mediates neurotrophin dependence, and suggest that other cellular dependent states may be mediated by proteins displaying similar domains.

Dexamethasone for prophylaxis of nausea and vomiting after epidural morphine for post-Caesarean section analgesia: comparison of droperidol and saline

We have evaluated the prophylactic effect of i.v. dexamethasone 8 mg in preventing nausea and vomiting during epidural morphine for post-Caesarean section analgesia. Droperidol 1.25 mg and saline served as the control. We studied 120 parturients (n=40 in each group) receiving epidural morphine for post-Caesarean section analgesia, in a randomized, double-blind, placebo-controlled study. All parturients received epidural morphine 3 mg. Both dexamethasone and droperidol significantly decreased the total incidence of nausea and vomiting compared with saline, with incidences of 18, 21 and 51% for the three treatments respectively (P<0.01 and P<0.05 respectively). Parturients who received droperidol reported a more frequent incidence of restlessness (16%) than those who received dexamethasone (P<0.05).