Clinical Predictors of Pseudohypoxia-Type Pheochromocytomas

INTRODUCTION

Pheochromocytomas (PCCs) are rare tumors of neural crest origin with divergent transcriptional and metabolic profiles associated with mutational cluster types. Pseudohypoxia-type (PHT) PCCs have a poor prognosis; however diagnostic genetic testing is not always available. We aimed to investigate clinical parameters predictive of PHT PCCs.

METHODS

Patients who underwent resection and genetic testing for PCC at two academic centers from 2006-2020 were retrospectively studied. Patients with PHT mutations (SDH-AF2/B/C/D, VHL) were compared to non-pseudohypoxia-type (nonPHT) PCCs to identify widely available clinical parameters predictive of PHT PCCs. Demographic, clinical, and pathologic characteristics were compared using student's T and ANOVA tests. Operative hemodynamic instability was defined as systolic blood pressure (SBP) >  200 mmHg, SBP increase of >  30% relative to baseline, and/or heart rate (HR) > 110 bpm. Mann-Whitney U test was used to assess area under the curve (AUC), sensitivity, and specificity. Recursive partitioning was used to model predictive thresholds for PHT PCC and develop a predictive score.

RESULTS

Of the 79 patients included in the cohort, 17 (22%) had PHT and 62 (78%) had nonPHT PCCs. PCC patients with >  2 of the examined predictive clinical parameters (preoperative weight loss [> 10% body weight], elevated preoperative hematocrit [>  50%], normal baseline heart rate [< 100 bpm], and normal plasma metanephrines [< 0.60 nmol/L]) were more likely to have PHT PCCs (AUC = 0.831, sensitivity = 0.882, specificity = 0.694, all p < 0.001).

CONCLUSIONS

Widely available preoperative clinical parameters including indicators of erythropoiesis (hemoglobin, hematocrit, and red blood cell count), baseline heart rate, plasma metanephrines, and weight loss may be useful predictors of PHT PCCs and may help guide management of PCCs when genetic testing is unavailable/delayed.

Study on the mechanism of Wuzi-Yanzong-Wan-medicated serum interfering with the mitochondrial permeability transition pore in the GC-2 cell induced by atractyloside

Wuzi-Yanzong-Wan (WZYZW) is a classic prescription for male infertility. Our previous investigation has demonstrated that it can inhibit sperm apoptosis via affecting mitochondria, but the underlying mechanisms are unclear. The purpose of the present study was to explore the actions of WZYZW on mitochondrial permeability transition pore (mPTP) in mouse spermatocyte cell line (GC-2 cells) opened by atractyloside (ATR). At first, WZYZW-medicated serum was prepared from rats following oral administration of WZYZW for 7 days. GC-2 cells were divided into control group, model group, positive group, as well as 5%, 10%, 15% WZYZW-medicated serum group. Cyclosporine A (CsA) was used as a positive control. 50 μmol·L-1 ATR was added after drugs incubation. Cell viability was assessed using CCK-8. Apoptosis was detected using flow cytometry and TUNEL method. The opening of mPTP and mitochondrial membrane potential (MMP) were detected by Calcein AM and JC-1 fluorescent probe respectively. The mRNA and protein levels of voltage-dependent anion channel 1 (VDAC1), cyclophilin D (CypD), adenine nucleotide translocator (ANT), cytochrome C (Cyt C), caspase 3, 9 were detected by RT-PCR (real time quantity PCR) and Western blotting respectively. The results demonstrated that mPTP of GC-2 cells was opened after 24 hours of ATR treatment, resulting in decreased MMP and increased apoptosis. Pre-protection with WZYZ-medicated serum and CsA inhibited the opening of mPTP of GC-2 cells induced by ATR associated with increased MMP and decreased apoptosis. Moreover, the results of RT-qPCR and WB suggested that WZYZW-medicated serum could significantly reduce the mRNA and protein levels of VDAC1 and CypD, Caspase-3, 9 and CytC, as well as a increased ratio of Bcl/Bax. However, ANT was not significantly affected. Therefore, these findings indicated that WZYZW inhibited mitochondrial mediated apoptosis by attenuating the opening of mPTP in GC-2 cells. WZYZW-medicated serum inhibited the expressions of VDAC1 and CypD and increased the expression of Bcl-2, which affected the opening of mPTP and exerted protective and anti-apoptotic effects on GC-2 cell induced by ATR.

[Advances in researches on enamel biomimetic mineralization]

Dental enamel biomimetic mineralization is a process to form the enamel-like mineral structures, which possess unique microstructure and exceptional physic-chemical properties, by mimicking the mechanism of natural enamel formation and biomineralization. Varieties of techniques such as molecular mimetic synthesis and molecular self-assembling were used to accomplish the microenvironment and molecular conditions similar to that of natural tooth enamel within human body. Early remineralization and biomineralization is the future of restoration for enamel defect, research on such products have huge potential in clinical applications, with speedy advancement in recent two decades. This review summarizes the major advances in researches on enamel biomimetic mineralization in recent years.

[Mechanism of action of Jieduhuayu granules for remission of oxidative stress in hepatocytes]

Objective: To study and explore the effect and mechanism of action of Jieduhuayu granules on oxidative injury of human liver L02 cells. Methods: Human liver L02 oxidative injury model was established with 0.1 mmol/ L H(2)O(2) intervention for 1 h, and treated with different concentrations of Jieduhuayu (JDHY) solution. Hepatocytes were divided into five groups: normal, H(2)O(2), H(2)O(2) + JDHY (0.5 mg/ml), H(2)O(2) + JDHY (1 mg/ml), and H(2)O(2) + JDHY (1.5 mg/ml). MTT assay was used to detect hepatocytes activity. Transmission electron microscope was used to observe mitochondrial morphology in hepatocytes. Biochemical test was used to detect the levels of superoxide dismutase, lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, malondialdehyde, and reduced glutathione and albumin in hepatocytes. Western blot was used to detect the expression levels of rabbit anti-phosphatidylinositol 3-kinase (PI3K), AKT and mTOR in hepatocytes. One-way analysis of variance was used for comparison between multiple groups, and the LSD method was used for pairwise comparison. Results: Compared with the normal group, the cell proliferation activity (P < 0.05), mitochondrial vacuolization, superoxide dismutase activity, reduced albumin and glutathione content, and PI3K, AKT, and mTOR protein expression levels in the H(2)O(2) group were all significantly reduced (P < 0.05), while the content of malondialdehyde and the activities of alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase were significantly increased (P < 0.05). Compared with H(2)O(2) group, the cell proliferation activity (P < 0.05), alterations in morphological remission of mitochondria, superoxide dismutase activity, reduced albumin and glutathione content, and PI3K, AKT and mTOR protein expression levels in the H(2)O(2) + JDHY (1 mg/ml) and H(2)O(2) + JDHY (1.5 mg/ml) group (P < 0.05) were all significantly increased (P < 0.05), while malondialdehyde content and alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase activities were significantly decreased (P < 0.05). Conclusion: Jieduhuayu granule can effectively improve oxidative stress and mitochondrial injury in hepatocytes, and its effect may be related to the promoting expression of PI3K/AKT/mTOR signaling pathways.

[Follow-up study of patients with chronic obstructive pulmonary disease complicated with pulmonary hypertension]

Objective: To investigate the relationship between clinical characteristics of patients with chronic obstructive pulmonary disease (COPD) with pulmonary hypertension (PH) and COPD exacerbation over a three-year observation period. Methods: A total of 366 cases of stable COPD patients were enrolled from the Department of Respiratory Medicine of the First Affiliated Hospital of Henan University of Science and Technology. The patients underwent pulmonary function tests(PFT), COPD assessment test (CAT), Saint George's respiratory questionnaire (SGRQ), transthoracic echocardiogrophy(TTE), chest CT and biochemical detection. The likelihood of PH was evaluated based on the peak tricuspid regurgitation velocity (TRV) measured by echocardiography at rest and other indicators, which were represented by low, medium, and high probability, respectively. Highly probability was defined as PH. The mean values of the groups were compared using a two-tailed unpaired t test for normally distributed variables. Qualitative data were assessed using a χ² test. Pearson correlation analysis was performed, and risk factors were analyzed using logistic regression analysis and stepwise regression analysis. P<0.05 was considered to indicate statistical significance. Results: The prevalence of patients with high likelihood of PH was 18.3% (n=67) in a series of 366 patients with COPD. The median estimated systolic pulmonary artery pressure in patients with PH was (51.7±6.7) mmHg(1mmHg=0.133 kPa). There were differences between patients with high likelihood of PH and those with low to moderate likelihood of PH for the following factors: age (76.0 vs. 64.0), body mass index (BMI) [(21.4±6.0) kg/m² vs. (22.6±7.2)kg/m²], brain natriureticpeptide (BNP) [(50.8±9.1) pg/ml vs. (36.4±8.1) pg/ml], toral number of acute exacerbation in three-year [(6.1±0.1) times vs. (2.8±0.4) times], CAT (17.0 vs. 10.0), SGRQ (48.9 vs. 32.1), carbon monoxide diffusion percentage of predicted value (D_LCO%) [(51.9±21.9)% vs. (67.0±22.1)%]; all the differences being statistically significant(mean P<0.05).There was a negative correlation between D_LCO% and SPAP (r=-0.28, P<0.01).In patients with high likelihood of PH, the percentage of low attenuation area (LAA%) and interstitial abnormalities in chest CT were higher than those in patients with low to moderate likelihood of PH (56.1% vs. 34.3% and 30.8% vs. 15.6%, mean P<0.05).LAA% ≥ 30% and pulmonary interstitial abnormalities were independent risk factors for pH [beta value were 1.479, 1.065, OR value was (3.640-5.720), 95%CI (1.462-8.571), mean P<0.01]. The ratio of main pulmonary diameter to aortic artery diameter was significantly correlated with estimated systolic pulmonary artery pressure(r=-0.35, P<0.01).Age ≥75 years, FEV₁%predicted value<50% and the presence of PH increased the likelihood of exacerbations of COPD over three years[beta value (0.459-1.211), OR value (3.643-5.722), 95%CI (1.463-8.904), mean P<0.01]. Conclusions: COPD patients with high likelihood of PH assessed by echocardiography were older, had a lower BMI, and presented with a worse health status compared to those with low to moderate likelihood of PH. The presence of PH assessed by echocardiography was related to future COPD exacerbations in COPD patients, and emphysema was closely related to PH assessed by echocardiography.

NMR-based metabolomics approach to study the effects of Wu-Zi-Yan-Zong-Wan on triptolide-induced oligospermia in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Wu-Zi-Yan-Zong-Wan (WZYZW) is a commonly used Chinese medicinal recipe for oligozoospermia. Oligozoospermia is a common disease that harms human fertility, there is no effective therapeutic medicine at present. However, the underlying pharmacological mechanism remains unclear.

METHODS

Oligozoospermia rats model induced by Tripterygium glycosides (TG) was established to inspect the efficiency of WZYZW in the treatment of oligozoospermia by traditional pharmacodynamics combined with NMR-based metabolomics. Multivariate statistics were used to extracted the underlying biomarkers and metabolic pathways of WZYZW in the treatment of oligozoospermia.

RESULTS

The results showed that TG disturbed many metabolites and metabolic pathways such as oxidative stress (choline, O-phosphocholine, betaine and ascorbate), energy metabolism in mitochondria (glucose, lactate, succinate, fumarate, 3-hydroxybutyrate and alanine), mitochondrial apoptosis markers (Bax and Bcl-2) and amino acids metabolisms (arginine, branched-chain amino acids, taurine and myo-inositol).

CONCLUSIONS

WZYZW could significantly reverse the disturbed metabolites to their normal status by their abilities of anti-oxidation, anti-apoptosis, balancing the osmotic pressure regulatory molecules and regulating the amino acids metabolism. This study provides pharmacological basis and guidance for the clinical usage of WZYZW.

[Effect of endoscopic vidian neurectomy in patients with coexisting allergic rhinitis and bronchial asthma]

Objective: To evaluate the clinical significance of endoscopic vidian neurectomy (EVN) on outcomes in patients with coexisting refractory allergic rhinitis (AR) and bronchial asthma, and to analyze its influence factor. Methods: Clinical data of 109 patients with moderate to severe persistent intractable AR and bronchial asthma who were allocated to the bilateral EVN group (surgery group, 70 cases) or conservative medication group (drug group, 39 cases) from 1 May 2008 to 30 April 2013 in Department of Otorhinolaryngology Head and Neck Surgery, Third Xiangya Hospital, Central South University were retrospectively analyzed, including 47 cases of male and 62 cases of female aged (32.7±6.8) years.Ninety-five patients were followed up for at least 3 years. The Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), Visual Analog Scale (VAS), Asthma Quality of Life Questionnaire (AQLQ), Total Asthma Symptom Score (TASS), forced expiratory volume in 1 second of predicted (FEV1) and medication scores were evaluated at 6 months, 1 year and 3 years after undergoing the initial treatments in the two groups. Multiple factor analysis was used to determine the factors influencing the improvement after EVN. Results: Postoperative scores of RQLQ were significantly lower than preoperative scores during follow-up in surgery group (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 2.39±0.61 (x±s), 0.81±0.43, 0.89±0.32, 1.06±0.24, respectively, all P<0.001). Postoperative scores of VAS were significantly lower than preoperative scores during follow-up in surgery group (the preoperative score and postoperative score at 6 months, 1 year,3 years after operation was 7.13±1.04, 2.52±1.47, 2.70±1.42, 2.85±1.64, respectively, all P<0.05). Scores of RQLQ and VAS in surgery group were significantly lower than those of drug group. Postoperative scores of AQLQ were significantly higher than preoperative scores during follow-up in surgery group (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 3.78±0.81, 4.99±0.45, 4.75±0.71, 4.62±0.64, respectively, all P<0.05), and were significantly higher than those of drug group. The TASS and FEV1 were not significantly changed in surgery group. The postoperative medication scores for AR were gradually reduced after surgery (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 0.99±0.21, 0.37±0.12, 0.39±0.26, 0.45±0.11, respectively, all P<0.05), and the postoperative medication scores for Asthma were gradually reduced after surgery too (the preoperative score and postoperative score at 6 months, 1 year, 3 years after operation was 1.27±0.31, 0.82±0.29, 0.85±0.23, 0.96±0.19, respectively, all P<0.05), and all the postoperative medication scores were significantly lower than those of drug group. At the end of the follow-up, the improvement rates for AR and asthma were 90.6% (58/64) and 45.3% (29/64), respectively. Asthma outcomes were significantly improved by controlling rhinitis symptoms in patients whose asthma attacks were induced by "rhinitis onset" or "climate change" . Conclusion: For patients with AR and bronchial asthma, EVN can significantly control AR symptoms, and improve asthma outcomes in patients whose asthma attacks are induced by rhinitis onset and/or climate change.

International multicentre review of perioperative management and outcome for catecholamine-producing tumours

BACKGROUND

Surgery for catecholamine-producing tumours can be complicated by intraoperative and postoperative haemodynamic instability. Several perioperative management strategies have emerged but none has been evaluated in randomized trials. To assess this issue, contemporary perioperative management and outcome data from 21 centres were collected.

METHODS

Twenty-one centres contributed outcome data from patients who had surgery for phaeochromocytoma and paraganglioma between 2000 and 2017. The data included the number of patients with and without α-receptor blockade, surgical and anaesthetic techniques, complications and perioperative mortality.

RESULTS

Across all centres, data were reported on 1860 patients with phaeochromocytoma or paraganglioma, of whom 343 underwent surgery without α-receptor blockade. The majority of operations (78·9 per cent) were performed using minimally invasive techniques, including 16·1 per cent adrenal cortex-sparing procedures. The cardiovascular complication rate was 5·0 per cent overall: 5·9 per cent (90 of 1517) in patients with preoperative α-receptor blockade and 0·9 per cent (3 of 343) among patients without α-receptor blockade. The mortality rate was 0·5 per cent overall (9 of 1860): 0·5 per cent (8 of 517) in pretreated and 0·3 per cent (1 of 343) in non-pretreated patients.

CONCLUSION

There is substantial variability in the perioperative management of catecholamine-producing tumours, yet the overall complication rate is low. Further studies are needed to better define the optimal management approach, and reappraisal of international perioperative guidelines appears desirable.

Mimengosides J and K: two new neuroprotective triterpenoids from the fruits of Buddleja lindleyana

Two new 11-methoxyl substituted triterpenoids, named as mimengosides J (1) and K (2), along with seven known compounds, were isolated from the fruits of Buddleja lindleyana. Their structures were elucidated on the basis of spectroscopic analysis. In addition, the new ones were evaluated for protective effects against damage of SH-SY5Y cells induced by 1-methyl-4-phenylpyridinium ion (MPP⁺) and the results indicated that those may be one of the candidate compositions of Buddleja lindleyana for the treatment of neurodegenerative disease.

Effect of pH on uranium(VI) biosorption and biomineralization by Saccharomyces cerevisiae

Biosorption of radionuclides by microorganisms is a promising and effective method for the remediation of contaminated areas. pH is the most important factor during uranium biosorption by Saccharomyces cerevisiae because the pH value not only affects the biosorption rate but also affects the precipitation structure. This study investigated the effect of pH on uranium (VI) biosorption and biomineralization by S. cerevisiae. Cells have the ability to buffer the solution to neutral, allowing the biosorption system to reach an optimal level regardless of the initial pH value. This occurs because there is a release of phosphate and ammonium ions during the interaction between cells and uranium. The uranyl and phosphate ions formed nano-particles, which is chernikovite H₂(UO₂)₂(PO₄)₂·8H₂O (PDF #08-0296), on cell surface under the initial acidic conditions. However, under the initial alkaline conditions, the uranyl, phosphate and ammonium ions formed a large amount of scale-like precipitation, which is uramphite (NH₄)(UO₂)PO₄·3H₂O (PDF #42-0384), evenly over on cell surface.

Absence of single critical dose for the amorphization of quartz under ion irradiation

In this work, we first simulated the amorphization of crystalline quartz under 50 keV [Formula: see text]Na ion irradiation with classical molecular dynamics (MD). We then used binary collision approximation algorithms to simulate the Rutherford backscattering spectrometry in channeling conditions (RBS-C) from these irradiated MD cells, and compared the RBS-C spectra with experiments. The simulated RBS-C results show an agreement with experiments in the evolution of amorphization as a function of dose, showing what appears to be (by this measure) full amorphization at about 2.2 eV⋅[Formula: see text]. We also applied other analysis methods, such as angular structure factor, Wigner-Seitz, coordination analysis and topological analysis, to analyze the structural evolution of the irradiated MD cells. The results show that the atomic-level structure of the sample keeps evolving after the RBS signal has saturated, until the dose of about 5 eV⋅[Formula: see text]. The continued evolution of the [Formula: see text] structure makes the definition of what is, on the atomic level, an amorphized quartz ambiguous.

Lack of evidence for a harmful effect of sodium-glucose co-transporter 2 (SGLT2) inhibitors on fracture risk among type 2 diabetes patients: a network and cumulative meta-analysis of randomized controlled trials

AIM

To evaluate the comparative effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors on risk of bone fracture in patients with type 2 diabetes mellitus (T2DM).

METHODS

PubMed, EMBASE, CENTRAL and ClinicalTrials.gov were systematically searched from inception to 27 January 2016 to identify randomized controlled trials (RCTs) reporting the outcome of fracture in patients with T2DM treated with SGLT2 inhibitors. Pairwise and network meta-analyses, as well as a cumulative meta-analysis, were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A total of 38 eligible RCTs (10 canagliflozin, 15 dapagliflozin and 13 empagliflozin) involving 30 384 patients, with follow-ups ranging from 24 to 160 weeks, were included. The fracture event rates were 1.59% in the SGLT2 inhibitor groups and 1.56% in the control groups. The incidence of fracture events was similar among these three SGLT2 inhibitor groups. Compared with placebo, canagliflozin (OR 1.15; 95% CI 0.71-1.88), dapagliflozin (OR 0.68; 95% CI 0.37-1.25) and empagliflozin (OR 0.93; 95% CI 0.74-1.18) were not significantly associated with an increased risk of fracture. Our cumulative meta-analysis indicated the robustness of the null findings with regard to SGLT2 inhibitors.

CONCLUSIONS

Our meta-analysis based on available RCT data does not support the harmful effect of SGLT2 inhibitors on fractures, although future safety monitoring from RCTs and real-world data with detailed information on bone health is warranted.

Simulation of Rutherford backscattering spectrometry from arbitrary atom structures

Rutherford backscattering spectrometry in a channeling direction (RBS/C) is a powerful tool for analysis of the fraction of atoms displaced from their lattice positions. However, it is in many cases not straightforward to analyze what is the actual defect structure underlying the RBS/C signal. To reveal insights of RBS/C signals from arbitrarily complex defective atomic structures, we develop here a method for simulating the RBS/C spectrum from a set of arbitrary read-in atom coordinates (obtained, e.g., from molecular dynamics simulations). We apply the developed method to simulate the RBS/C signals from Ni crystal structures containing randomly displaced atoms, Frenkel point defects, and extended defects, respectively. The RBS/C simulations show that, even for the same number of atoms in defects, the RBS/C signal is much stronger for the extended defects. Comparison with experimental results shows that the disorder profile obtained from RBS/C signals in ion-irradiated Ni is due to a small fraction of extended defects rather than a large number of individual random atoms.

[Protective effect of Wuziyanzong Pills on rats with experimental oligoasthenospermia and its action mechanism]

OBJECTIVE

To investigate the protective effect of Wuziyanzong Pills (WYP) in the rat model of oligoasthenospermia (OAS) and its action mechanism.

METHODS

Sixty male SD rats were equally randomized into six groups: normal control, OAS model, Shengjing Capsules (1.6 g per kg of the body weight), low-dose WYP (1 g per kg of the body weight), medium-dose WYP (2 g per kg of the body weight), and high-dose WYP (4 g per kg of the body weight). The OAS model was established by intragastric administration of Tripterygium glucoside at 30 mg per g per d for 6 weeks. From the 3rd week of modeling, the rats of the medication groups were treated intragastrically with corresponding drugs for 4 weeks. Then all the rats were sacrificed for measurement of the testicular and epididymal organ coefficients, examination of epididymal sperm quality and apoptosis, and detection of the openness of the sperm mitochondrial permeability transition pore (MPTP). Histopathological changes in the testis were observed by HE staining and the apoptosis of spermatogenic cells determined by Hochest staining.

RESULTS

WYP obviously improved the organ coefficients of the testis and epididymis, increased sperm concentration, motility and viability, decreased the apoptosis of spermatogenic cells, and inhibited the abnormal openness of MPTP in the OAS model rats. HE staining showed that the number and levels of spermatogenic cells were significantly increased while Hochest staining manifested that the apoptosis of spermatogenic cells was remarkably inhibited in the seminiferous tubules of the testis in the WYP-treated rats.

CONCLUSIONS

WYP can improve sperm quality and reduce the apoptosis of spermatogenic cells (including sperm) in OAS model rats, which may be related with its inhibitory effect on the abnormal openness of MPTP.

A meta-analysis of bevacizumab combined with chemotherapy in the treatment of ovarian cancer

INTRODUCTION

Angiogenesis plays an important role in the biology of ovarian cancer. The clinical efficacy and side effects of bevacizumab, the vascular endothelial growth factor inhibitor, on survival and toxicity in women with this ovarian cancer, was not conclusive. We performed this systematic review and meta-analysis in order to clarify the efficacy of bevacizumab combined with chemotherapy in the treatment of ovarian cancer.

MATERIALS AND METHODS

We searched the electronic database of MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and CNKI for clinical controlled trials of comparing bevacizumab combined with chemotherapy and chemotherapy alone in the treatment of ovarian cancer. The primary outcomes of eligible studies included median progression-free survival (PFS), overall survival (OS), and toxicities such as enterobrosis, hypertension, albuminuria, congestive heart failure (CHF), neutrophils, thrombosis, and bleeding. The Hazard ratio (HR) and relative risk were used for the meta-analysis and were expressed with 95% confidence intervals (CIs). All the statistical analyses were carried out by  Stata 11.0 software (http://www.stata.com; Stata Corporation, College Station, TX, USA).

RESULTS

We included 5 studies with 1798 cases in the bevacizumab combined with the chemotherapy group and 1810 subjects in the chemotherapy alone group. The pooled results showed that bevacizumab + chemotherapy compared with chemotherapy alone can significant prolong the median PFS (HR, 0.64; 95% CI, 0.46-0.82; P < 0.05) but not the OS (HR, 0.84; 95% CI, 0.59-10.9; P > 0.05); the toxicity analysis showed that the enterobrosis, hypertension, albuminuria, neutrophils, thrombosis, and bleeding were significantly increased in the bevacizumab + chemotherapy group compared with chemotherapy alone (Pall < 0.05). But the CHF risk between the two groups was not statistical different (P > 0.05).

CONCLUSION

Bevacizumab combined with chemotherapy prolonged the median PFS in patients with ovarian cancer but also increase the risk of developing enterobrosis, hypertension, albuminuria, neutrophils, thrombosis, and bleeding.

[Wuzi yanzong pills increases sperm mitochondrial membrane potential and protects its ultrastructure in oligo-asthenozoospermia model rats]

OBJECTIVE

To study the effects of Wuzi Yanzong Pills (WYP) on sperm mitochondrial membrane potential (MMP) and its ultrastructure in oligo-asthenozoospermia model rats.

METHODS

Oligo-asthenozoospermia models were made in 50 male rats weighing 200 - 220 g by intragastric administration of Tripterygium Glucosides at 30 mg per kg per d for 8 weeks, and then equally allocated to a model control, a Huangjing Zanyu Capsule (HZC) control, a low-dose WYP, a medium-dose WYP, and a high-dose WYP group. Another 10 age-matched normal male rats were included as normal controls. The rats in the model and normal control groups were given intragastrically distilled water at 10 ml/kg, those in the HZC group administered HZC at 3.01 g/kg, and those in the low-, medium- and high-dose WYP groups medicated with WYP at 2.30, 4.60 and 9.20 g/kg, respectively, once daily for 30 days. At 30 minutes after the last administration, we detected the sperm MMP by JC-1 fluorescent staining and flow cytometry, and examined the sperm ultrastructure under the JEM-1230 transmission electron microscope.

RESULTS

JC-1 + % and its fluorescence intensity were (33.77 +/- 6.19)% and 1 468 +/- 496 in the model control, (56.34 +/- 10.35)% and 3 277 +/- 895 in the HZC control, (40.80 +/- 10.40)% and 2 016 +/- 767 in the low-dose WYP, (59.40 +/- 6.51)% and 3 897 +/- 643 in the medium-dose WYP, and (60.71 +/- 7.81)% and 3 371 +/- 647 in the high-dose WYP group, significantly reduced in comparison with (70.80 +/- 4.92)% and 4 360 +/- 945 in the normal control group (P < 0.05), but remarkably higher in the medium- and high-dose WYP groups than in the model controls (P < 0. 05). After modeling, the sperm membrane was loose and degenerated, the mitochondria swelling, variously sized and with incomplete membrane, and the axonemal structure unclear or ruptured. After 30 days of WYP administration, compared with the model control group, the rats exhibited integrated sperm membrane and mitochondrial membrane, reduced mitochondrial swelling and basically normal axonemal and microtubular structures.

CONCLUSION

Tripterygium Glucosides could decrease the sperm mitochondrial membrane potential and damage the mitochondrial structure, while WYP could significantly increase the sperm mitochondrial membrane potential and reduce the sperm mitochondrial structure damage. The protection of the integrity of sperm mitochondrial structure and function is one of the mechanisms of WYP acting on oligo-asthenozoospermia.

In Vivo and In Vitro Silica Induces Nuclear Factor Egr-1 Activation Mediated by ERK 1/2 in RAW264.7 Cell Line

The transcription factor early growth response gene (Egr-1) is a stress response gene activated by various forms of stress. The effect of silica on transcription and expression of Egr-1 was investigated in rat lung and in RAW264.7 cells. Silica induced the expression of Egr-1 in vivo and was mainly located in alveolar macrophage cells and lung epithelial cells. Furthermore, silica induced Egr-1 mRNA and protein expression in cultured RAW264.7 cells. Immunofluorescence microscopy revealed translocation of Egr-1 to the nucleus in response to silica. The contribution of the extracellular signal-regulated kinase (ERK) pathway to the activation of Egr-1 in response to silica was examined. Exposure to silica resulted in a rapid phosphorylation of ERK 1/2 kinases in RAW264.7 cells. MAP Kinase Kinase (MEK) inhibitor U0126 prevented Egr-1 induction by silica. The results suggest that silica could induce Egr-1 activation in macrophages in vivo and in vitro and that phosphorylated ERK 1/2 may be involved in this action.

Management of follicular tumors of the thyroid

The incidence of well-differentiated thyroid cancers is rising. Follicular cancer represents 10-20% of these lesions. While the vast majority of thyroid nodules of follicular origin are benign, fine needle aspiration cannot provide cytologic evidence of capsular and/or vascular invasion; therefore, patients should undergo surgical excision. Frozen section is not recommended for intraoperative evaluation of follicular neoplasia. Patients deemed to have follicular cancer require near-total or total thyroidectomy and postoperative (131)I ablation. The optimal management of minimally invasive follicular cancer remains an area of controversy, but long-term prognosis for these patients is excellent. Areas of research should focus on identification of molecular markers of malignancy and aggressiveness of follicular neoplasia.

Surgical treatment for upper or middle esophageal carcinoma occurring after gastrectomy: a study of 52 cases

Fifty-two patients presenting with upper or middle esophageal carcinoma after gastrectomy between 1980 and 2003 were analyzed retrospectively. Among them, there were five cases of total gastrectomy, six cases of proximal partial gastrectomy and 41 cases of distal subtotal gastrectomy. The interval between gastrectomy and the diagnosis of esophageal carcinoma ranged from 2 to 22 years. Surgical procedures included resection of the esophageal lesion with esophageal replacement using non-reversed or reversed gastric tubes (2 and 3 cases respectively), and short or long segment colon (5 and 40 cases respectively); two cases underwent a palliative procedure (jejunostomy). Complications included cervical anastomotic leaks (3 cases), pulmonary infection (3 cases), atelectasis (2 cases) and cordis arrhythmia (5 cases), all of which responded to treatment. In our group, resection of the esophageal lesions and reconstruction of the esophagus was performed in 45 cases (86.5%), exclusion and bypass procedure of esophageal carcinoma and following radiotherapy and chemotherapy in four (7.7%), eternal jejunostomy for intestinal nutrition in two (3.9%) and death occurred in one case (1.9%) due to multiple organ dysfunction syndrome (MODS). Esophageal resection combined with lymph node dissection is indicated for the treatment of upper or middle esophageal carcinoma following gastrectomy. While esophageal substitutes can include non-reversed or reversed gastric tubes as well as short or long segment colon interpositions, we usually recommend the use of colon interposition. The 1-, 3- and 5-year survival rate of cases with resection of the esophageal lesions and reconstruction of the esophagus was 84.6%, 57.7% and 26.7% respectively.

Arsenite induces oxidative DNA adducts and DNA-protein cross-links in mammalian cells

Arsenic is generally recognized as a nonmutagenic carcinogen because sodium arsenite induces DNA damage only at very high concentrations. In this study we demonstrate that arsenite concentrations above 0.25 microM induce DNA strand breaks in both human leukemia cells and Chinese hamster ovary cells. Therefore, DNA damage may be involved in arsenic-induced carcinogenesis. Formamidopyrimidine-DNA glycosylase and proteinase K greatly increased DNA strand breaks in arsenite-treated cells, providing evidence that a large portion of arsenite-induced DNA strand breaks come from excision of oxidative DNA adducts and DNA-protein cross-links. Because DNA strand breaks appear only temporarily during excision repair, the level of detectable DNA strand breaks will be low at any given time point. For this reason many previous studies have only detected low levels of DNA strand breaks. We also show that catalase, and inhibitors of calcium, nitric oxide synthase, superoxide dismutase, and myeloperoxidase, could modulate arsenite-induced DNA damage. We conclude that arsenite induces DNA adducts through calcium-mediated production of peroxynitrite, hypochlorous acid, and hydroxyl radicals.

Fission yeast Rad17 associates with chromatin in response to aberrant genomic structures

Fission yeast checkpoint protein Rad17 is required for the DNA integrity checkpoint responses. A fraction of Rad17 is chromatin bound independent of the other checkpoint proteins throughout the cell cycle. Here we show that in response to DNA damage induced by either methyl methanesulfonate treatment or ionizing radiation, increased levels of Rad17 bind to chromatin. Following S-phase stall induced by hydroxyurea or a cdc22 mutation, the chromatin-bound Rad17 progressively dissociates from the chromatin. After S-phase arrest by hydroxyurea in cds1Delta or rad3Delta cells or by replication mutants, Rad17 remains chromatin bound. Rad17 is able to complex in vivo with an Rfc small subunit, Rfc2, but not with Rfc1. Furthermore, cells with rfc1Delta are checkpoint proficient, suggesting that Rfc1 does not have a role in checkpoint function. A checkpoint-defective mutant protein, Rad17(K118E), which has similar nuclear localization to that of the wild type, is unable to bind ATP and has reduced ability in chromatin binding. Mutant Rad17(K118E) protein also has reduced ability to complex with Rfc2, suggesting that Lys(118) of Rad17 plays a role in Rad17-Rfc small-subunit complex formation and chromatin association. However, in the rad17.K118E mutant cells, Cds1 can be activated by hydroxyurea. Together, these results suggest that Rad17 binds to chromatin in response to an aberrant genomic structure generated from DNA damage, replication mutant arrest, or hydroxyurea arrest in the absence of Cds1. Rad17 is not required to bind chromatin when genomic structures are protected by hydroxyurea-activated Cds1. The possible checkpoint events induced by chromatin-bound Rad17 are discussed.

Low triglyceride levels affect calculation of low-density lipoprotein cholesterol values

The Friedewald formula for the calculation of low-density lipoprotein cholesterol (LDL-C) values is fairly accurate provided the triglyceride value is less than 400 mg/dL. It is not clear whether the estimation is also valid in the presence of low triglyceride and high cholesterol levels. We describe herein a patient with a low triglyceride value of approximately 50 mg/dL, a high cholesterol level, and a discrepant LDL-C level. The LDL-C level using the Friedewald calculation turned out to be much higher than the LDL-C level using direct measurement. We, therefore, suggest that in the presence of low triglyceride and high cholesterol levels, the LDL-C level should be measured directly instead of using the Friedewald calculation.

Role of fission yeast primase catalytic subunit in the replication checkpoint

To investigate the cell cycle checkpoint response to aberrant S phase-initiation, we analyzed mutations of the two DNA primase subunit genes of Schizosaccharomyces pombe, spp1(+) and spp2(+) (S. pombe primase 1 and 2). spp1(+) encodes the catalytic subunit that synthesizes the RNA primer, which is then utilized by Polalpha to synthesize the initiation DNA. Here, we reported the isolation of the fission yeast spp1(+) gene and cDNA and the characterization of Spp1 protein and its cellular localization during the cell cycle. Spp1 is essential for cell viability, and thermosensitive mutants of spp1(+) exhibit an allele-specific abnormal mitotic phenotype. Mutations of spp1(+) reduce the steady-state cellular levels of Spp1 protein and compromised the formation of Polalpha-primase complex. The spp1 mutant displaying an aberrant mitotic phenotype also fails to properly activate the Chk1 checkpoint kinase, but not the Cds1 checkpoint kinase. Mutational analysis of Polalpha has previously shown that activation of the replication checkpoint requires the initiation of DNA synthesis by Polalpha. Together, these have led us to propose that suboptimal cellular levels of polalpha-primase complex due to the allele-specific mutations of Spp1 might not allow Polalpha to synthesize initiation DNA efficiently, resulting in failure to activate a checkpoint response. Thus, a functional Spp1 is required for the Chk1-mediated, but not the Cds1-mediated, checkpoint response after an aberrant initiation of DNA synthesis.

The forehead flap for nasal reconstruction

CONTEXT

Reconstruction of extensive nasal defects often represents a significant challenge owing to several unique qualities of the nose, such as complex topography, mobile free margins, and multiple nasal subunits. Furthermore, loss of internal nasal lining and/or structural skeletal support may be present following removal of extensive skin cancers.

OBJECTIVE

To describe our experience with the use of forehead flap reconstruction for extensive nasal defects.

DESIGN

Retrospective case series.

SETTING

Academic health care hospital system.

PATIENTS/INTERVENTION

One hundred forty-seven patients with extensive nasal defects repaired with a forehead flap.

MAIN OUTCOME MEASURES

The functional and aesthetic results were assessed. The characteristics of defects repaired with the forehead flap and the need for lining and/or cartilage were examined.

RESULTS

The forehead flap was used to repair 147 nasal defects after Mohs excision of nonmelanoma skin cancer. Full-thickness skin was lost in all cases, structural skeletal support in 68 cases (46%), and internal mucosal lining in 45 cases (31%). Our experience and surgical technique using the forehead flap are described.

CONCLUSIONS

The forehead flap represents one of the best methods for repair of extensive nasal defects. Near-normal functional and cosmetic results can be achieved.

Nasal reconstruction utilizing a muscle hinge flap with overlying full-thickness skin graft

BACKGROUND

Deep nasal defects of the dorsum, sidewall, and ala can be challenging to repair.

OBJECTIVE

The article describes our experience with a muscle hinge transposition flap with overlying local full-thickness skin grafting for repair of deep nasal defects in a single-stage procedure.

METHODS

A muscle hinge transposition flap with overlying local full-thickness skin grafting was used immediately after Mohs micrographic surgery to repair 12 deep nasal defects of the dorsum, sidewall, alar lobule, and supratip.

RESULTS

No cases of infection, flap, or graft necrosis occurred in our series. Cosmetic and functional outcomes were judged from good to excellent by patient and surgeon. To enhance the cosmetic outcome, 5 patients underwent spot dermabrasion within 2 months of repair.

CONCLUSION

For properly selected small to medium-sized deep nasal defects (1-2 cm) that lack a sufficiently loose adjacent tissue reservoir for a single-stage local flap, a muscle hinge transposition flap with local full-thickness skin grafting can provide consistently satisfying aesthetic and functional results.

Analysis of fission yeast primase defines the checkpoint responses to aberrant S phase initiation

To investigate the checkpoint response to aberrant initiation, we analyzed the cell cycle checkpoint response induced by mutations of Schizosaccharomyces pombe DNA primase. DNA primase has two subunits, Spp1 and Spp2 (S. pombe primases 1 and 2). Spp1 is the catalytic subunit that synthesizes the RNA primer, which is then extended by DNA polymerase alpha (Polalpha) to synthesize an initiation DNA structure, and this catalytic function of Polalpha is a prerequisite for generating the S-M phase checkpoint. Here we show that Spp2 is required for coupling the function of Spp1 to Polalpha. Thermosensitive mutations of spp2(+) destabilize the Polalpha-primase complex, resulting in an allele-specific S phase checkpoint defect. The mutant exhibiting a more severe checkpoint defect also has a higher extent of Polalpha-primase complex instability and deficiency in the hydroxyurea-induced Cds1-mediated intra-S phase checkpoint response. However, this mutant is able to activate the Cds1 response to S phase arrest induced by temperature. These findings suggest that the Cds1 response to the S-phase arrest signal(s) induced by a initiation mutant is different from that induced by hydroxyurea. Interestingly, a polalphats mutant with a defective S-M phase checkpoint and an spp2 mutant with an intact checkpoint have a similar Polalpha-primase complex stability, and the Cds1 response induced by hydroxyurea or by the mutant arrests at the restrictive temperature. Thus, the Cds1-mediated intra-S phase checkpoint response induced by hydroxyurea can also be distinguished from the S-M phase checkpoint response that requires the initiation DNA synthesis by Polalpha.

Analysis of relative binding affinity of E7-pRB of human papillomavirus 16 clinical variants using the yeast two-hybrid system

A number of genotypes of the human papillomaviruses (HPV) are associated with malignancies of the uterine cervix. Sequencing work has revealed the existence of intratype HPV variants with minor differences in the nucleotide sequence. More recent data suggest the possibility that some of the variants may have different modes of clinical manifestation. In this study, sequences of the E6 and E7 oncogenes of 17 HPV16 isolates derived from PAP smear samples of Taiwanese patients were analyzed. A number of E6 and E7 novel variants were found. Particularly, a prevalent (64.7%) E6 polymorphic site A442C with an E113D amino acid substitution seems specific to Taiwanese patients. In E7, two novel but silent polymorphic sites G663A (41.2%) and T846C (88.2%) were also prevalent in the samples analyzed. The yeast two-hybrid system was adopted for rapid assessment of relative E7-pRb binding affinity in the variants. The relative binding affinities of the E7 proteins of different HPV types to pRB were in close agreement with previous biochemical data. A T663G/C24W polymorphic change in E7 correlated with a decrease in E7-pRb relative binding affinity the significance of which remains to be clarified. This semi-quantitative biochemical and genetic approach may be useful as a first step in the development of clinical protocols for the screening and identification of important HPV variants for clinical interpretation and for further functional analysis by transfection or other bioassays.

A novel mutant allele of the chromatin-bound fission yeast checkpoint protein Rad17 separates the DNA structure checkpoints

To further dissect the genetic differences between the checkpoint pathway following S-phase cdc arrest versus DNA damage, a genetic screen was performed for checkpoint mutants that were unable to arrest mitosis following cell-cycle arrest with a temperature-sensitive DNA polymerase delta mutant, cdc20-M10. One such checkpoint mutant, rad17-d14, was found to display the cut phenotype following S-phase arrest by cdc20-M10, but not by the DNA synthesis inhibitor hydroxyurea, reminiscent of the chk1 mutant. Unlike chk1, rad17-d14 was not sensitive to UV irradiation. Interestingly, the ionising radiation sensitivity of rad17-d14 was only at higher doses, and cells were found to be defective in properly arresting cell division following irradiation in S phase, but not G(2) phase. Biochemical analysis attributes the checkpoint defects of rad17-d14 to the failure to phosphorylate the checkpoint effector Chk1p. To investigate if Rad17p monitors the genome for abnormal DNA structures specifically during DNA synthesis, chromatin association of Rad17p was analysed. Rad17p was found to be chromatin associated throughout the cell cycle, not just during S phase. This interaction occurred irrespective of the arrest with cdc20-M10 and, surprisingly, was also independent of the other checkpoint Rad proteins, and the cell-cycle effectors Chk1p and Cds1p.

Inhibition of nitric oxide release by an aqueous extract of Tinospora tuberculata

An aqueous extract of Tinospora tuberculata stems was found to scavenge nitric oxide (NO) in vitro in both cell and cell-free systems. When the aqueous extract was added to lipopolysaccharide-stimulated murine macrophages, it inhibited NO release dose-dependently, and similar activity was found in a cell-free system using sodium nitroprusside as a NO donor. These findings may help to explain, in part, certain pharmacological activities of Tinospora tuberculata.

Particle-core study of halo dynamics in periodic-focusing channels

This paper reports on an approach to investigate the dynamics of halo particles in mismatched charged-particle beams propagating through periodic-focusing channels using the particle-core model. The proposed method employs canonical transformations to minimize, in new phase-space variables, the flutter due to the periodic focusing to allow making stroboscopic plots. Applying this method, we find that in periodic-focusing systems, certain particles initially not in the halo region can be brought into resonance with the core oscillation to become halo particles.

The preclinical pharmacologic study of dopamine transporter imaging agent [99mTc]TRODAT-1

The purpose of this study was to investigate the pharmacologic characteristics of TRODAT-1 (2beta-((N,N'-bis(2-mercaptoethyl)ethylene diamino)methyl), 3beta-(4-chlorophenyl)tropane) labeled with [99mTc] as an imaging agent for dopamine transporter (DAT). Radiochemical purity of [99mTc]TRODAT-1 was over 90%. The partition coefficients in octanol and buffer were 2.12 and 2.19 at pH 7.0 and 7.4, respectively. Animal studies have been performed in rats, rabbits, and normal and hemi-Parkinsonian model monkeys. Biodistribution displayed moderate uptake in rat brain (0.28 %ID/organ at 2 min) and the striatal uptake was 0.193, 0.142, and 0.136 %ID/g at 2, 60, and 120 min, respectively. The ratios of striatal/cerebellar (ST/CB) uptake were 2.4, 4.45, and 2.45 %ID/g at 60, 120, and 240 min, respectively. The major radioactivity was excreted by the hepatobiliary system. Blood clearance kinetics was performed in rabbits, and the initial half-life of 1.18 min and late half-life of 367.8 min were obtained. Brain single photon emission computed tomography imaging studies in normal monkeys showed the ratios of ST/CB uptake were 1.56-2.0 %ID/g and indicated that both uptake and retention in the striatal area were associated with the DAT. The imaging of hemi-Parkinsonian model monkeys also displayed the expected selectivity, the highest uptake being observed in the basal ganglia area of the normal side. Thereby, it is suggested that [99mTc]TRODAT-1 is a safe and useful imaging agent for localization of the presynaptic DAT in the brain.

Tinospora tuberculata suppresses nitric oxide synthesis in mouse macrophages

We have obtained evidence that co-incubation of thioglycollate-elicited peritoneal macrophages with an aqueous extract of Tinospora tuberculata inhibits lipopolysaccharide-stimulated excessive production of nitric oxide (NO) in vitro. This effect is concentration-dependent and appears to involve suppression of both inducible nitric oxide synthase (iNOS) activity and NADPH-diaphorase activity, thus altering NO production. As NO is one of the critical mediators in various disorders and iNOS inhibitors may have therapeutic potential, these results may explain some aspects of the multifunctional properties of Tinospora tuberculata, which has been used in various folk remedies in southeast Asia and China.

Semiautomated typing of human papillomaviruses by restriction fragment length polymorphism analysis of fluorescence-labeled PCR fragments

A simplified version of a PCR-based reductional restriction fragment length polymorphism (rRFLP) approach for typing of human papillomaviruses (HPVs) is described previously [Wang et al., 1997]. It is achieved by the use of a biotin-labeled primer in PCR which, on restriction digestion and staining, is associated with only a single restriction fragment. In this report, we describe a further development of the rRFLP approach with the use of a fluorescence-labeled primer in PCR and fragment detection by laser scanning in an automatic sequencer. HPV typing is achieved by computer-assisted matching of the fluorescence-labeled rRFLP patterns with a database of rRFLP patterns of all known anogenital HPV types. On analysis of the typing of 133 HPV-positive cases using this procedure, 20 different HPV types were detected in exfoliated cervical cells in PAP smear samples derived from Taiwanese women. The results indicate the existence of a heterogeneous population of HPV types in Taiwan. Although most cases were associated with the more common HPV types, a significant fraction (about 20%) of the HPV types detected was related to the less common genotypes, which are often not included in commercial kits available for HPV typing. The results indicate the importance of covering as many HPV types as possible in clinical HPV genotyping protocols.

Isolated extragenital bowenoid papulosis of the neck

We report a case of extragenital bowenoid papulosis (BP) in a healthy immunocompetent 42-year-old man. The lesions occurred on the anterolateral aspects of the neck and were not associated with genital, oral, or periungual lesions. Lesional skin tested positive with the Digene hybrid capture system cocktail assay that identifies infection with a mixture of high to intermediate oncogenic human papillomavirus (HPV) types, including types 16, 18, 31, 33, 35, 45, 51, 52, and 56. This cocktail assay identifies infection with HPV types typically associated with high-grade squamous intraepithelial lesions and invasive carcinoma. This case represents the sixth case of isolated cutaneous BP occurring a significant distance from the genital region.

[Purity analysis of cephalosporins with capillary zone electrophoresis]

A capillary zone electrophoresis method is proposed for the purity determination of nine cephalosporin drugs. A background electrolyte comprising of either 20 mmol/L pH 9.20 borate buffer or 20 mmol/L pH 6.86 phosphate buffer was used for most drugs studied except for cefaloridine which formed neutral molecules at these pH values. For it 50 mmol/L pH 2.05 phosphate buffer was used instead. Internal normalization method was employed for quantitation. The method is simple, rapid and versatile. Analysis was completed within 8 min. The merits and limitations of the method were also discussed.

The C-terminal region of Schizosaccaromyces pombe proliferating cell nuclear antigen is essential for DNA polymerase activity

Proliferating cell nuclear antigen (PCNA), the processivity factor (sliding clamp) of DNA polymerases (Pols), plays essential roles in DNA metabolism. In this report, we examined the functional role of the C-terminal region of Schizosaccaromyces pombe PCNA both in vitro and in vivo. The deletion or Ala substitution of the last 9 aa (252-260A), as well as Ala replacement of only 4 aa (252-255A) at the C terminus, failed to substitute for the wild-type PCNA protein for cell growth in S. pombe. Two other PCNA mutant proteins, A251V and K253E, exhibited cold-sensitive phenotypes. Several yeast strains harboring mutations, including those at the acidic C-terminal region, showed elevated sensitivity to DNA damage. The ability of the mutant PCNA proteins to stimulate DNA synthesis by Poldelta and Polepsilon also was studied in vitro. The mutant proteins that did not support cell growth and a mutant protein containing a single amino acid substitution at position 252, where Pro is replaced by Ala, stimulated Poldelta and Polepsilon activities poorly. All mutant PCNA proteins, however, were assembled around DNA by the clamp loader, replication factor C, efficiently. Thus, the C-terminal region of PCNA is important for interactions with both Poldelta and Polepsilon and for cell survival after DNA damage. The C terminus of sliding clamps from other organisms has been shown to be important for clamp loading as well as polymerase interactions. The relationship between the conserved sequence in this region in different organisms is discussed.

The birhombic transposition flap for soft tissue reconstruction

BACKGROUND

Soft tissue reconstruction requires a thorough understanding of both anatomy and tissue movement. Flaps and grafts should be considered when simpler closure methods result in excessive tension or distortion of surrounding structures.

OBJECTIVE

We describe our experience with the birhombic transposition flap.

METHODS

The birhombic flap was used to repair 19 surgical defects after excision of skin cancer.

RESULTS

The average defect size was 3.0 x 2.4 cm with the 19 wounds located on the nose (6), forearm (5), hand (4), forehead/temple (3), and preauricular cheek (1). No cases of excessive tension, infection, or flap necrosis occurred.

CONCLUSION

Conceptualization of a larger defect into multiple smaller defects may be useful to facilitate closure of each smaller defect in an easier fashion. Our series demonstrates the usefulness of this concept with the birhombic transposition flap repair.

Schizosaccharomyces pombe replication and repair proteins: proliferating cell nuclear antigen (PCNA)

Schizosaccharomyces pombe has a cell cycle progression with distinctive phases that serves as a perfect model system for investigating DNA replication and repair of eukaryotic cells. Here, we use proliferating cell nuclear antigen (PCNA) of S. pombe to demonstrate how the function of this protein in both DNA replication and repair can be assessed by genetic and biochemical approaches. We describe a method of introducing site-specific mutations into the fission yeast PCNA gene pcn1(+). The in vivo effects of these pcn1 mutants in a strain with a null pcn1 background are described and their in vitro biochemical properties are characterized. Mutants described here are those that are defective in enhancing processivity of DNA polymerase delta, show temperature-sensitive growth, and have increased sensitivity to hydroxyurea (HU), UV and gamma irradiation, and methyl methanesulfonate (MMS). Three mutants that show reduced growth rate in vivo and decreased capacity to enhance polymerase delta DNA synthetic activity and processivity in vitro-pcn1-1, pcn1-5, and pcn1-26-are described as examples of using a genetic approach to identify the biochemical function of replication proteins. One cold-sensitive growth allele, pcn1-3, that has a recessive cold-sensitive cdc phenotype and shows sensitivity to HU and UV and gamma irradiation is used as an example of using the genetic approach to reveal the function of replication proteins in repair. The power of combining both biochemical and genetic disciplines is emphasized. Methods for site-directed mutagenesis, in vitro analysis of mutant proteins, and in vivo characterization of mutants in response to UV or gamma irradiation, MMS, HU, and temperature, as well as genetic epistasis are described. Locations of functionally significant residues on the PCNA tertiary structure are summarized.

Intrathymic immunomodulation and the "infectious" tolerance pathway in allograft recipients

BACKGROUND

We have previously shown that >75% of LEW cardiac allografts survive indefinitely in BUF rats pretreated at Day -21 intrathymically (IT) with donor alloantigen in conjunction with a single intravenous dose of ALS. Spleen cells can adoptively transfer the tolerant state to new cohorts of test recipients. This study was designed to analyze cellular and humoral events contributing to the "infectious" tolerance pathway in this model.

METHODS

Spleen cells (25 x 10(6)) harvested from BUF recipients bearing long-term cardiac allografts were injected intravenously into lightly irradiated (450 R) secondary BUF rats, followed 24 h later by transplantation of LEW of ACl hearts. Cardiac allografts were then analyzed serially by reverse transcription polymerase chain reaction for Th1 and Th2 cytokine gene expression. Donor-specific IgM and IgG alloantibody responses in host serum were screened by flow cytometry.

RESULTS

Transfer of regulatory spleen cells harvested between Days 80 and 140 from tolerant hosts induced tolerance to heart grafts in a donor-specific manner. In the early posttransplant period, selective sparing of Th2 cytokines was noted. Adoptively transferred hosts showed overall depression of IgM, but a vigorous IgG1 and IgG2a alloantibody response.

CONCLUSION

IT + ALS-induced tolerance can be transferred in a donor-specific "infectious" manner to new cohorts of engrafted recipients. The development of tolerance is nontemporally bound, and associates with an early Th2-type immune deviation at the graft site. The elevated levels of T cell-dependent IgG1 and IgG2 may interfere with the antigen reactivity and alloresponsive effector functions, contributing to graft acceptance in the "infectious" tolerance pathway.

Mutator phenotype induced by aberrant replication

We have identified thermosensitive mutants of five Schizosaccharomyces pombe replication proteins that have a mutator phenotype at their semipermissive temperatures. Allele-specific mutants of DNA polymerase delta (poldelta) and mutants of Polalpha, two Poldelta subunits, and ligase exhibited increased rates of deletion of sequences flanked by short direct repeats. Deletion of rad2(+), which encodes a nuclease involved in processing Okazaki fragments, caused an increased rate of duplication of sequences flanked by short direct repeats. The deletion mutation rates of all the thermosensitive replication mutators decreased in a rad2Delta background, suggesting that deletion formation requires Rad2 function. The duplication mutation rate of rad2Delta was also reduced in a thermosensitive polymerase background, but not in a ligase mutator background, which suggests that formation of duplication mutations requires normal DNA polymerization. Thus, although the deletion and duplication mutator phenotypes are distinct, their mutational mechanisms are interdependent. The deletion and duplication replication mutators all exhibited decreased viability in combination with deletion of a checkpoint Rad protein, Rad26. Interestingly, deletion of Cds1, a protein kinase functioning in a checkpoint Rad-mediated reversible S-phase arrest pathway, decreased the viability and exacerbated the mutation rate only in the thermosensitive deletion replication mutators but had no effect on rad2Delta. These findings suggest that aberrant replication caused by allele-specific mutations of these replication proteins can accumulate potentially mutagenic DNA structures. The checkpoint Rad-mediated pathways monitor and signal the aberrant replication in both the deletion and duplication mutators, while Cds1 mediates recovery from aberrant replication and prevents formation of deletion mutations specifically in the thermosensitive deletion replication mutators.

Fanconi anemia C protein acts at a switch between apoptosis and necrosis in mitomycin C-induced cell death

Deregulation of apoptosis seems to be a hallmark of the Fanconi anemia (FA) syndrome. In order to further define the role of the FA protein from complementation group C (FAC) in apoptosis, we characterized parameters modified during the mitomycin-C (MMC)-induced apoptotic program. It is shown that despite a higher level of cell death for FA compared to normal lymphoblasts after MMC treatment, FA cells do not display a marked DNA fragmentation. Furthermore, while playing a central role in MMC apoptosis of normal lymphoblasts, the activity of caspase-3-like proteases is altered in FA cells. Interestingly, the disruption of the mitochondrial transmembrane potential (Deltapsi), an early event that can lead to apoptotic or to necrotic death, is accomplished similarly in FA and in normal cells. Finally, it is shown that the overexpressed FAC protein inhibited the apoptotic steps, with the exception of the decrease of the Deltapsi. Altogether, our results indicate that the FAC protein acts at a step preceding the activation of the caspases and after the modification of the Deltapsi, a decision point at which cells can be pushed toward either apoptosis or necrosis and which, consequently, regulates the balance between the two modes of cell death.

Human papillomavirus DNA replication. Interactions between the viral E1 protein and two subunits of human dna polymerase alpha/primase

Papovaviruses are valuable models for the study of DNA replication in higher eukaryotic organisms, as they depend on host factors for replication of their DNA. In this study we investigate the interactions between the human papillomavirus type 11 (HPV-11) origin recognition and initiator protein E1 and human polymerase alpha/primase (pol alpha/primase) subunits. By using a variety of physical assays, we show that both 180- (p180) and 70-kDa (p70) subunits of pol alpha/primase interact with HPV-11 E1. The interactions of E1 with p180 and p70 are functionally different in cell-free replication of an HPV-11 origin-containing plasmid. Exogenously added p180 inhibits both E2-dependent and E2-independent cell-free replication of HPV-11, whereas p70 inhibits E2-dependent but stimulates E2-independent replication. Our experiments indicate that p70 does not physically interact with E2 and suggest that it may compete with E2 for binding to E1. A model of how E2 and p70 sequentially interact with E1 during initiation of viral DNA replication is proposed.

In vivo biodistribution of a radiotracer for imaging serotonin-1A receptor sites with PET:[11C]LY274601

LY274601 [R-(+)8-thiomethyl-2-(di-n-propyl-amino)tetralin], a full agonist of the 5-HT1A receptor with high affinity and selectivity, was labeled with 11C and 3H, and its in vivo behavior was studied to evaluate [11C]LY274601 as a PET radiotracer for imaging 5-HT1A receptor sites in living brain. Following intravenous tail injection into mice, [11C]LY274601 showed high blood-brain barrier permeability and accumulated in regions known to have high densities of 5-HT1A receptor sites such as the brain stem including the raphe nuclei. The binding of the radiotracer in target tissues is blocked by pre-injection of the 5-HT1A receptor selective ligand 8-OH-DPAT (1 mg/kg, s.c.), suggesting that the binding is specific to 5-HT1A receptor sites. Using ex vivo autoradiography, the target tissues such as hippocampus CA1-4 fields, piriform cortex, dorsal raphe nucleus and lateral septum were visualized as hot spots. These tissues were observed to have binding 2-2.7 times greater than the cerebellum. The distribution of the radiotracer agrees well with the distribution of 5-HT1A receptors revealed by in vitro autoradiography with [3H]8-OH-DPAT. However, the radiotracer was metabolized quickly and cleared from target tissues with a half life of approximately 15 min. [11C]LY274601 showed high non-specific binding in regions with low number of 5-HT1A receptor sites such as cerebellum.

Cytotoxicities of alkaloids from processed and unprocessed seeds of Strychnos nux-vomica

AIM

To examine the cytotoxicities of 6 crude Strychnos alkaloid fractions from the seeds of Strychnos nux-vomica unprocessed or processed with various traditional processing methods and 13 pure Strychnos alkaloids from the fractions.

METHODS

Using cell culture, their inhibitory effects on Vero cell growth-inhibition assay, and host cell DNA synthesis by [3H]thymidine ([3H]TdR) uptake assay.

RESULTS

The IC50 of processed seeds were 155% and 212% of unprocessed ones in cell growth-inhibition assay and in [3H]TdR uptake assay, respectively. The IC50 of 13 compounds were 0.45-0.80 mmol.L-1 and 0.50-12 mmol.L-1, respectively. The processing method with sand bath exhibited a wide safety margin compared with other traditional processing methods or no processing. The isomers of Strychnos alkaloids and their N-oxides showed much lower cytotoxicities among these alkaloids. Isobrucine N-oxide showed the lowest cytotoxicity. The contents of isomers and N-oxides of Strychnos alkaloids were the highest in the sand processing.

CONCLUSION

Processing of nux vomica plays a critical role in its toxicity.

Complete spontaneous regression of pulmonary metastatic melanoma

BACKGROUND

Complete spontaneous regression of melanoma metastatic to the lungs is a rare event.

OBJECTIVE

To report a case of biopsy-proven melanoma metastatic to the lung with complete spontaneous regression.

METHODS

Multidisciplinary case report.

RESULTS

A 35-year-old white female was diagnosed with metastatic melanoma to the lung. A pleural biopsy confirmed the diagnosis. Partial spontaneous regression was noted by a staging computed tomography scan prior to enrollment in an investigational protocol. Complete spontaneous regression occurred over 5 months without any form of conventional or alternative therapy, and the patient remains disease-free 3 years after diagnosis.

CONCLUSIONS

Our case represents the seventh case of complete spontaneous regression of melanoma metastatic to the lung, and the only case with histologic confirmation of both the primary and pulmonary metastatic lesions. The patient was pregnant twice between the time of her initial diagnosis of primary melanoma and pulmonary metastatic disease.