TPGS-modified Chitosan Nanoparticles of EGFR Inhibitor: Physicochemical and In vitro Evaluation against HepG2 Cell Lines

BACKGROUND

Gefitinib (GFN) is an Epithelial Growth Factor Receptor (EGFR) inhibitor, and Food and Drug Administration (FDA) has approved medication to treat lung cancer. However, this investigation aimed to produce and characterize Gefitinib (GFN)-loaded chitosan and soy lecithin nanoparticles (NPs) modified with D-α-tocopheryl polyethylene glycol 1000 succinate mono ester (TPGS) and assess their therapeutic potential against HepG2 liver cell lines.

METHODS

Chitosan, a cationic polymer with biocompatible and biodegradable properties, was combined with soy lecithin to develop the NPs loaded with GFN using a self-organizing ionic interaction methodology.

RESULTS

The entrapment efficiency and drug loading were found to be 59.04±4.63 to 87.37±3.82% and 33.46±3.76 to 49.50±4.35%, respectively, and results indicated the encapsulation of GEN in NPs. The pH of the formulations was observed between 4.48-4.62. Additionally, all the prepared NPs showed the size and PDI range of 89.2±15.9 nm to 799.2±35.8 nm and 0.179±0.065 to 0.455±0.097, respectively. The FTIR bands in optimized formulation (GFN-NP1) indicated that the drug might be contained within the NP's core. The SEM photograph revealed the spherical shape of NPs. The kinetic release model demonstrated the combination of diffusion and erosion mechanisms. The IC50 value of GFN and GFN-NP1 formulation against the HepG2 cell lines were determined and found to be 63.22±3.36 μg/ml and 45.80±2.53 μg/ml, respectively. DAPI and PI staining agents were used to detect nuclear morphology.

CONCLUSION

It was observed that the optimized GFN-NP1 formulation successfully internalized and inhibited the growth of HepG2 cells. Hence, it can be concluded that the prepared NPs can be a new therapeutic option for treating liver cancer.

HDGF stimulates liver tumorigenesis by enhancing reactive oxygen species generation in mitochondria

Hepatoma-derived growth factor (HDGF) overexpression and uncontrolled reactive oxygen species (ROS) accumulation are involved in malignant transformation and poor prognosis in various types of cancer. However, the interplay between HDGF and ROS generation has not been elucidated in hepatocellular carcinoma. Here, we first analyzed the profile of HDGF expression and ROS production in newly generated orthotopic hepatomas by ultrasound-guided implantation. In situ superoxide detection showed that HDGF-overexpressing hepatomas had significantly elevated ROS levels compared with adjacent nontumor tissues. Consistently, liver tissues from HDGF-deficient mice exhibited lower ROS fluorescence than those from age- and sex-matched WT mice. ROS-detecting fluorescent dyes and flow cytometry revealed that recombinant HDGF (rHDGF) stimulated the production of superoxide anion, hydrogen peroxide, and mitochondrial ROS generation in cultured hepatoma cells in a dose-dependent manner. In contrast, the inactive Ser103Ala rHDGF mutant failed to promote ROS generation or oncogenic behaviors. Seahorse metabolic flux assays revealed that rHDGF dose dependently upregulated bioenergetics through enhanced basal and total oxygen consumption rate, extracellular acidification rate, and oxidative phosphorylation in hepatoma cells. Moreover, antioxidants of N-acetyl cysteine and MitoQ treatment significantly inhibited HDGF-mediated cell proliferation and invasive capacity. Genetic silencing of superoxide dismutase 2 augmented the HDGF-induced ROS generation and oncogenic behaviors of hepatoma cells. Finally, genetic knockdown nucleolin (NCL) and antibody neutralization of surface NCL, the HDGF receptor, abolished the HDGF-induced increase in ROS and mitochondrial energetics. In conclusion, this study has demonstrated for the first time that the HDGF/NCL signaling axis induces ROS generation by elevating ROS generation in mitochondria, thereby stimulating liver carcinogenesis.

Long-term DEHP/MEHP exposure promotes colorectal cancer stemness associated with glycosylation alterations

Plasticizers are considered as environmental pollution released from medical devices and increased potential oncogenic risks in clinical therapy. Our previous studies have shown that long-term exposure to di-ethylhexyl phthalate (DEHP)/mono-ethylhexyl phthalate (MEHP) promotes chemotherapeutic drug resistance in colorectal cancer. In this study, we investigated the alteration of glycosylation in colorectal cancer following long-term plasticizers exposure. First, we determined the profiles of cell surface N-glycomes by using mass spectrometry and found out the alterations of α2,8-linkages glycans. Next, we analyzed the correlation between serum DEHP/MEHP levels and ST8SIA6 expression from matched tissues in total 110 colorectal cancer patients. Moreover, clinical specimens and TCGA database were used to analyze the expression of ST8SIA6 in advanced stage of cancer. Finally, we showed that ST8SIA6 regulated stemness in vitro and in vivo. Our results revealed long-term DEHP/MEHP exposure significantly caused cancer patients with poorer survival outcome and attenuated the expression of ST8SIA6 in cancer cells and tissue samples. As expected, silencing of ST8SIA6 promoted cancer stemness and tumorigenicity by upregulating stemness-associated proteins. In addition, the cell viability assay showed enhanced drug resistance in ST8SIA6 silencing cells treated with irinotecan. Besides, ST8SIA6 was downregulated in the advanced stage and positively correlated with tumor recurrence in colorectal cancer. Our results imply that ST8SIA6 potentially plays an important role in oncogenic effects with long-term phthalates exposure.

Treatment effectiveness and side effects of patients with hepatitis C in the prisons of Southern Taiwan: a real-life retrospective analysis

OBJECTIVE

Hepatitis C is an important risk factor for cirrhosis and liver cancer in the Taiwanese population. Domestic prisons reported a higher rate of hepatitis C infection than the national average. Efficient and effective treatment of patients with hepatitis C in prisons is required to decrease the number of infections. This study analysed the effectiveness of hepatitis C treatment and its side effects in prison patients.

DESIGN

This retrospective analysis included adult patients with hepatitis C who received direct-acting antiviral agents between 2018 and 2021.

SETTING

The special hepatitis C clinics in the two prisons were run by a medium-sized hepatitis C treatment hospital in Southern Taiwan. Three direct-acting antiviral agents, sofosbuvir/ledipasvir for 12 weeks, glecaprevir/pibrentasvir for 8 or 12 weeks and sofosbuvir/velpatasvir for 12 weeks, were adopted based on patient characteristics.

PARTICIPANTS

470 patients were included.

OUTCOME MEASURE

The sustained virological response at 12 weeks after the end of treatment was compared between the different groups.

RESULTS

Most of the patients were men (70.0%) with a median age of 44 years. The most prevalent hepatitis C virus genotype was genotype 1 (44.26%). A total of 240 patients (51.06%) had a history of injectable drug use; 44 (9.36%) and 71 (15.11%) patients were coinfected with hepatitis B virus and HIV, respectively. Only 51 patients (10.85%) had liver cirrhosis. Most patients (98.30%) had normal renal function or no history of kidney disease. The patients had a sustained virological response achievement rate of 99.2%. The average incidence of adverse reactions during treatment was approximately 10%. Many of the adverse reactions were mild and resolved spontaneously.

CONCLUSION

Direct-acting antiviral agents are effective for treating hepatitis C in Taiwanese prisoners. These therapeutics were well-tolerated by the patient population.

Slow skeletal muscle troponin T acts as a potential prognostic biomarker and therapeutic target for hepatocellular carcinoma

Slow skeletal muscle troponin T (TNNT1) as a poor prognostic indicator is upregulated in colon and breast cancers. However, the role of TNNT1 in the disease prognosis and biological functions of hepatocellular carcinoma (HCC) is still unclear. The Cancer Genome Atlas (TCGA), real-time quantitative RT-PCR (qRT-PCR), immunoblot, and immunohistochemical analyses were applied to evaluate the TNNT1 expression of human HCC. The impact of TNNT1 levels on disease progression and survival outcome was studied using TCGA analysis. Moreover, the bioinformatics analysis and HCC cell culture were used to investigate the biological functions of TNNT1. Besides, the immunoblot analysis and enzyme-linked immunosorbent assay (ELISA) were used to detect the extracellular TNNT1 of HCC cells and circulating TNNT1 of HCC patients, respectively. The effect of TNNT1 neutralization on oncogenic behaviors and signaling was further validated in the cultured hepatoma cells. In this study, tumoral and blood TNNT1 was upregulated in HCC patients based on the analyses using bioinformatics, fresh tissues, paraffin sections, and serum. From the multiple bioinformatics tools, the TNNT1 overexpression was associated with advanced stage, high grade, metastasis, vascular invasion, recurrence, and poor survival outcome in HCC patients. By the cell culture and TCGA analyses, TNNT1 expression and release were positively correlated with epithelial-mesenchymal transition (EMT) processes in HCC tissues and cells. Moreover, TNNT1 neutralization suppressed oncogenic behaviors and EMT in hepatoma cells. In conclusion, TNNT1 may serve as a non-invasive biomarker and drug target for HCC management. This research finding may provide a new insight for HCC diagnosis and treatment.

Accuracy of Self-Injection Locking Radar System for Vital Signs Detection During the COVID-19 Pandemic at a Hospital in Taiwan: Measuring Vital Signs Accurately with SIL Radar for Hospital Healthcare

BACKGROUND Self-injection locking (SIL) radar uses continuous-wave radar and an injection-locked oscillator-based frequency discriminator that receives and demodulates radar signals remotely to monitor vital signs. This study aimed to compare SIL radar with traditional electrocardiogram (ECG) measurements to monitor respiratory rate (RR) and heartbeat rate (HR) during the COVID-19 pandemic at a single hospital in Taiwan. MATERIAL AND METHODS We recruited 31 hospital staff members (16 males and 15 females) for respiratory rates (RR) and heartbeat rates (HR) detection. Data acquisition with the SIL radar and traditional ECG was performed simultaneously, and the accuracy of the measurements was evaluated using Bland-Altman analysis. RESULTS To analyze the results, participates were divided into 2 groups (individual subject and multiple subjects) by gender (male and female), or 4 groups (underweight, normal weight, overweight, and obesity) by body mass index (BMI). The results were analyzed using mean bias errors (MBE) and limits of agreement (LOA) with a 95% confidence interval. Bland-Altman plots were utilized to illustrate the difference between the SIL radar and ECG monitor. In all BMI groups, results of RR were more accurate than HR, with a smaller MBE. Furthermore, RR and HR measurements of the male groups were more accurate than those of the female groups. CONCLUSIONS We demonstrated that non-contact SIL radar could be used to accurately measure HR and RR for hospital healthcare during the COVID-19 pandemic.

Leukocyte cell-derived chemotaxin 2 regulates epithelial-mesenchymal transition and cancer stemness in hepatocellular carcinoma

Leukocyte cell-derived chemotaxin 2 (LECT2) acts as a tumor suppressor in hepatocellular carcinoma (HCC). However, the antineoplastic mechanism of LECT2, especially its influence on hepatic cancer stem cells (CSCs), remains largely unknown. In The Cancer Genome Atlas cohort, LECT2 mRNA expression was shown to be associated with stage, grade, recurrence, and overall survival in human HCC patients, and LECT2 expression was downregulated in hepatoma tissues compared with the adjacent nontumoral liver. Here, we show by immunofluorescence and immunoblot analyses that LECT2 was expressed at lower levels in tumors and in poorly differentiated HCC cell lines. Using functional assays, we also found LECT2 was capable of suppressing oncogenic behaviors such as cell proliferation, anchorage-independent growth, migration, invasiveness, and epithelial-mesenchymal transition in hepatoma cells. Moreover, we show exogenous LECT2 treatment inhibited CSC functions such as tumor sphere formation and drug efflux. Simultaneously, hepatic CSC marker expression was also downregulated, including expression of CD133 and CD44. This was supported by infection with adenovirus encoding LECT2 (Ad-LECT2) in HCC cells. Furthermore, in animal experiments, Ad-LECT2 gene therapy showed potent efficacy in treating HCC. We demonstrate LECT2 overexpression significantly promoted cell apoptosis and reduced neovascularization/CSC expansion in rat hepatoma tissues. Mechanistically, we showed using immunoblot and immunofluorescence analyses that LECT2 inhibited β-catenin signaling via the suppression of the hepatocyte growth factor/c-MET axis to diminish CSC properties in HCC cells. In summary, we reveal novel functions of LECT2 in the suppression of hepatic CSCs, suggesting a potential alternative strategy for HCC therapy.

DLK2 Acts as a Potential Prognostic Biomarker for Clear Cell Renal Cell Carcinoma Based on Bioinformatics Analysis

Clear cell renal cell carcinoma (ccRCC) is the most common RCC subtype with a high mortality. It has been reported that delta-like 1 homologue (DLK1) participates in the tumor microenvironmental remodeling of ccRCC, but the relationship between delta-like 2 homologue (DLK2, a DLK1 homologue) and ccRCC is still unclear. Thus, this study aims to investigate the role of DLK2 in the biological function and disease prognosis of ccRCC using bioinformatics analysis. The TNMplot database showed that DLK2 was upregulated in ccRCC tissues. From the UALCAN analysis, the overexpression of DLK2 was associated with advanced stage and high grade in ccRCC. Moreover, the Kaplan-Meier plotter (KM Plotter) database showed that DLK2 upregulation was associated with poor survival outcome in ccRCC. By the LinkedOmics analysis, DLK2 signaling may participated in the modulation of ccRCC extracellular matrix (ECM), cell metabolism, ribosome biogenesis, TGF-β signaling and Notch pathway. Besides, Tumor Immune Estimation Resource (TIMER) analysis showed that the macrophage and CD8⁺ T cell infiltrations were associated with good prognosis in ccRCC patients. Finally, DLK2 overexpression was associated with the reduced macrophage recruitments and the M1–M2 polarization of macrophage in ccRCC tissues. Together, DLK2 may acts as a novel biomarker, even therapeutic target in ccRCC. However, this study lacks experimental validation, and further studies are required to support this viewpoint.

Bioinformatics Analyses Identify the Therapeutic Potential of ST8SIA6 for Colon Cancer

Sialylation of glycoproteins is modified by distinct sialyltransferases such as ST3Gal, ST6Gal, ST6GalNAc, or ST8SIA with α2,3-, α2,6-, or α2,8-linkages. Alteration of these sialyltransferases causing aberrant sialylation is associated with the progression of colon cancer. However, among the ST8- sialyltransferases, the role of ST8SIA6 in colon cancer remains poorly understood. In this study, we explored the involvement of ST8SIA6 in colon cancer using multiple gene databases. The relationship between ST8SIA6 expression and tumor stages/grades was investigated by UALCAN analysis, and Kaplan–Meier Plotter analysis was used to analyze the expression of ST8SIA6 on the survival outcome of colon cancer patients. Moreover, the biological functions of ST8SIA6 in colon cancer were explored using LinkedOmics and cancer cell metabolism gene DB. Finally, TIMER and TISMO analyses were used to delineate ST8SIA6 levels in tumor immunity and immunotherapy responses, respectively. ST8SIA6 downregulation was associated with an advanced stage and poorly differentiated grade; however, ST8SIA6 expression did not affect the survival outcomes in patients with colon cancer. Gene ontology analysis suggested that ST8SIA6 participates in cell surface adhesion, angiogenesis, and membrane vesicle trafficking. In addition, ST8SIA6 levels affected immunocyte infiltration and immunotherapy responses in colon cancer. Collectively, these results suggest that ST8SIA6 may serve as a novel therapeutic target towards personalized medicine for colon cancer.

Sinularin, an Anti-Cancer Agent Causing Mitochondria-Modulated Apoptosis and Cytoskeleton Disruption in Human Hepatocellular Carcinoma

Liver cancer remains a leading cause of death, despite advances in anti-cancer therapies. To develop novel drugs, natural products are being considered as a good source for exploration. In this study, a natural product isolated from a soft coral was applied to evaluate its anti-cancer activities in hepatocellular carcinoma SK-HEP-1 cells. Sinularin was determined to have half-maximal inhibitory concentration (IC₅₀) values of ~10 μM after 24, 48, and 72 h. The TUNEL assay and annexin V/PI staining results showed that sinularin induced DNA fragmentation and apoptosis, respectively. An investigation at the molecular level demonstrated that the expression levels of cleaved caspases 3/9 were significantly elevated at 10 μM sinularin. Mitochondrial and intracellular reactive oxygen species (ROS) levels were significantly increased following sinularin treatment, which also affected the mitochondrial membrane potential. In addition, it significantly lowered the mitochondrial respiration parameters and extracellular acidification rates at 10 μM. Further investigation showed that sinularin significantly attenuated wound healing, cell migration, and potential colony formation at 10 μM. Fluorescence microscopic observations showed that the distribution of F-actin filaments was significantly altered at 10 μM sinularin. Supported by Western blot analyses, the expression levels of AKT, p-ERK (extracellular-signal-related kinase), vimentin and VEGF were significantly down-regulated, whereas p-p38, pJNK and E-cadherin were significantly increased. Overall, at the IC₅₀ concentration, sinularin was able to significantly affect SK-HEP-1 cells.

Microalgal extract from thermotolerant Coelastrella sp. F50 retards the liver tumor progression by targeting hepatic cancer stem cells

Microalgae extracts have shown antitumor activities. However, the antitumor mechanism of them is not yet completely clear, especially the effect on cancer stem cells (CSCs). This study aimed to elucidate the antitumor activity and mechanism of microalgal extract from thermotolerant Coelastrella sp. F50 (F50) in hepatocellular carcinoma (HCC). Oncogenic behaviors were analyzed using cell proliferation, colony formation, invasion, sphere formation, and side population cells (SPCs) assays in HCC cells after F50 treatment. The molecular mechanism was further studied by quantitative real-time PCR, immunoblot, and immunofluorescence analyses. The chemopreventive efficacy of F50 was evaluated in rat orthotopic hepatoma, and the hepatic pathologies were investigated by immunohistochemical, immunoblot, and immunofluorescence analyses. F50 specifically suppressed hepatic CSCs (tumor spheres, drug efflux, CD133/ABCG2 CSCs markers) with no cytotoxicity in vitro. In the animal experiments, prophylactic F50 administration significantly attenuated tumor progression and improved liver function in HCC-bearing rats. In the mechanistic analysis, F50 potentially inhibited cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE₂ ) axis in HCC cells and rat hepatoma, and exogenous PGE₂ restored CSCs properties in F50-treated HCC cells. In summary, F50 extract inhibits hepatic CSCs by COX-2/PGE₂ downregulation and may facilitate a novel phytotherapy for HCC prevention.

Briarenols W-Z: Chlorine-Containing Polyoxygenated Briaranes from Octocoral Briareum stechei (Kükenthal, 1908)

Briareum stechei is proven to be a rich source of 3,8-cyclized cembranoids (briarane) with a bicyclo[8.4.0] carbon core. In the present study, four previously unreported briaranes, briarenols W–Z (1–4), along with solenolide A (5), briarenolide M (6), briaexcavatolide F (7), and brianolide (8), were isolated and characterized through spectroscopic analysis, and the absolute configuration of 8 was corroborated by a single-crystal x-ray diffraction analysis. Briaranes 2 and 5 were found to induce significant inflammatory activity in lipopolysaccharide (LPS)-induced RAW 264.7 mouse macrophage cells by enhancing the expression of the inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins.

Hepatoma-derived growth factor participates in concanavalin A-induced hepatitis

Hepatitis is an important health problem worldwide. Novel molecular targets are in demand for detection and management of hepatitis. Hepatoma-derived growth factor (HDGF) has been delineated to participate in hepatic fibrosis and liver carcinogenesis. However, the relationship between hepatitis and HDGF remains unclear. This study aimed to elucidate the role of HDGF during hepatitis using concanavalin A (ConA)-induced hepatitis model. In cultured hepatocytes, ConA treatment-elicited HDGF upregulation at transcriptional level and promoted HDGF secretion while reducing intracellular HDGF protein level and cellular viability. Similarly, mice receiving ConA administration exhibited reduced hepatic HDGF expression and elevated circulating HDGF level, which was positively correlated with serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. By using HDGF knockout (KO) mice, it was found the ConA-evoked cell death was prominently alleviated in KO compared with control. Besides, it was delineated HDGF ablation conferred protection by suppressing the ConA-induced neutrophils recruitment in livers. Above all, the ConA-mediated activation of tumor necrosis factor-α (TNF-α)/interleukin-1β (IL-1β)/interleukin-6 (IL-6)/cyclooxygenase-2 (COX-2) inflammatory signaling was significantly abrogated in KO mice. Treatment with recombinant HDGF (rHDGF) dose-dependently stimulated the expression of TNF-α/IL-1β/IL-6/COX-2 in hepatocytes, further supporting the pro-inflammatory function of HDGF. Finally, application of HDGF antibody not only attenuated the ConA-mediated inflammatory cascade in hepatocytes, but also ameliorated the ConA-induced hepatic necrosis and AST elevation in mice. In summary, HDGF participates in ConA-induced hepatitis via neutrophils recruitment and may constitute a therapeutic target for acute hepatitis.

Alanyl-tRNA synthetase genes of Vanderwaltozyma polyspora arose from duplication of a dual-functional predecessor of mitochondrial origin

In eukaryotes, the cytoplasmic and mitochondrial forms of a given aminoacyl-tRNA synthetase (aaRS) are typically encoded by two orthologous nuclear genes, one of eukaryotic origin and the other of mitochondrial origin. We herein report a novel scenario of aaRS evolution in yeast. While all other yeast species studied possess a single nuclear gene encoding both forms of alanyl-tRNA synthetase (AlaRS), Vanderwaltozyma polyspora, a yeast species descended from the same whole-genome duplication event as Saccharomyces cerevisiae, contains two distinct nuclear AlaRS genes, one specifying the cytoplasmic form and the other its mitochondrial counterpart. The protein sequences of these two isoforms are very similar to each other. The isoforms are actively expressed in vivo and are exclusively localized in their respective cellular compartments. Despite the presence of a promising AUG initiator candidate, the gene encoding the mitochondrial form is actually initiated from upstream non-AUG codons. A phylogenetic analysis further revealed that all yeast AlaRS genes, including those in V. polyspora, are of mitochondrial origin. These findings underscore the possibility that contemporary AlaRS genes in V. polyspora arose relatively recently from duplication of a dual-functional predecessor of mitochondrial origin.

Development of quality of care indicators for patients undergoing total hip or total knee replacement

OBJECTIVE

The objective of this study was to develop evidence-based quality indicators to measure key aspects of care that can be targeted to decrease variations in complication rates between surgeons performing total joint replacement.

DESIGN

RAND/University of California, Los Angeles (UCLA) modified-Delphi expert panel method. To accomplish this objective, a proposed set of quality of care indicators was developed through a comprehensive literature search and structured interviews with expert clinicians. An expert panel of orthopaedic surgeons was then convened to rate the validity of these quality indicators using the RAND/UCLA Appropriateness Method. Indicators were classified as valid by the panel based on the median panel rating and the amount of dispersion of panel ratings.

RESULTS

There were 101 candidate indicators of quality identified in the six domains of preoperative processes of care, intraoperative processes, postoperative processes, implant selection and the use of new technology, privileging of hospitals and surgeons, and outcomes and comorbidity assessment. A total of 68 of the 101 indicators were rated as valid with statistical agreement.

CONCLUSIONS

This study identifies measures of structure, process and outcome rated as valid quality indicators for hip and knee replacement. This project provides tools to measure and improve quality of care for patients undergoing total joint replacement.

Is social support associated with greater weight loss after bariatric surgery?: a systematic review

Social support may be associated with increased weight loss after bariatric surgery. The objective of this article is to determine impact of post-operative support groups and other forms of social support on weight loss after bariatric surgery. MEDLINE search (1988-2009) was completed using MeSH terms including bariatric procedures and a spectrum of patient factors with potential relationship to weight loss outcomes. Of the 934 screened studies, 10 reported on social support and weight loss outcomes. Five studies reported on support groups and five studies reported on other forms of social support (such as perceived family support or number of confidants) and degree of post-operative weight loss (total n = 735 patients). All studies found a positive association between post-operative support groups and weight loss. One study found a positive association between marital status (being single) and weight loss, while three studies found a non-significant positive trend and one study was inconclusive. Support group attendance after bariatric surgery is associated with greater post-operative weight loss. Further research is necessary to determine the impact of other forms of social support. These factors should be addressed in prospective studies of weight loss following bariatric surgery, as they may represent ways to improve post-operative outcomes.

Translational efficiency of redundant ACG initiator codons is enhanced by a favorable sequence context and remedial initiation

Earlier studies showed that the redundancy of ACG initiation codons enhanced the efficiency of translation initiation by 3- to 6-fold. Evidence presented here shows that this "redundancy effect" can be attributed to a favorable sequence context and, to a lesser extent, remedial initiation. In the case of redundant ACG initiator codons, the second ACG not only acts as a remedial initiation site for scanning ribosomes that skip the first ACG but also enhances the activity of the preceding initiator by providing a preferable "A" at its relative +4 position. Hence, non-successive ACG codons can be as effective as successive ACG codons in initiation, if positioned within a similar context. In contrast, redundant GUG initiation codons (GUG/GUG) bear an unfavorable "G" nucleotide at both the +4 and -3 positions relative to the first and second GUGs, respectively, such that redundant GUG codons act more poorly as translation initiation sites than does a single GUG with a favorable "A" nucleotide in the +4 position ( approximately 2.5-fold). Thus, the sequence context plays a much more important role than remedial initiation in modulating the efficiency of translational initiation from redundant non-AUG codons.

Osteoporosis prevention education programme for women

AIM

This paper reports an evaluation of a nurse-initiated education programme on four specific osteoporosis prevention behaviours which led to their adoption or to positive attitude changes.

BACKGROUND

In the past, osteoporosis was a serious health concern that most commonly affected women in Northern Europe and the United States of America, but was less commonly seen in Asian women. However, in Hong Kong, osteoporosis is currently among the top five conditions causing disability and prolonged hospital stay for older people. From an economic perspective, the most cost-effective approach is to focus on primary prevention via education, and nurses often have the responsibility of providing such educational programmes.

METHOD

A randomized controlled study was conducted from July 2004 to March 2005 with 76 women (38 cases and 38 controls) recruited in two private beauty clinics in Hong Kong. Pre-, post- and follow-up education data were compared regarding attitudes and adoption frequency before and after the education programme.

RESULTS

The results showed statistically significant increases for each behaviour: consumption of soy foods (P < 0.001), milk (P < 0.001), more exercise (P = 0.01) and vitamin D/exposure to sunlight (P < 0.001) for the case group compared with the control group. Most participants either disagreed (n = 15, 39.0%) or strongly disagreed (n = 23, 61.0%) that there was not enough information provided in the education programme to motivate them to change. They rated the nurse's performance as either satisfactory or very satisfactory on presentation, ability to answer their questions and ability to describe each behaviour clearly.

CONCLUSION

Although positive results with a nurse-initiated education programme were demonstrated, future research examining the effects of education and occupation on these four adoption behaviours should focus on more diverse populations with respect to age, income or ethnicity. The findings suggest the value of creative approaches in future health education for the prevention of osteoporosis, and the need for a critical appraisal of current strategies and a re-evaluation of services and funding.

Biological monitoring of environment exposure to safrole and the Taiwanese betel quid chewing

A rapid and sensitive biological monitoring (BM) method for assessing exposure to the environmental carcinogen safrole has been developed. The method is an isocratic high-performance liquid chromatographic (HPLC) analysis of urinary dihydroxychavicol (DHAB) and eugenol, the urinary metabolites of safrole. Good linearity, precision, and accuracy were demonstrated. A recovery of 98.8 +/- 5.4% (SD, n = 3) was found for DHAB and 84.1 +/- 3.4% (n = 3) for eugenol. The quantitation limits of the method were 8 ng for DHAB and 10 ng for eugenol. The validity of the method was demonstrated by a linear dose-response relationship observed in rats given oral doses of safrole at 30, 75, and 150 mg/kg body weight. The method was also used to monitor the environmental exposure to the Taiwanese betel quid (TBQ) chewing, because TBQ used in Taiwan not only contains areca (betel) nut, slaked lime, and catechu but also Piper betle inflorescence or its leaves. Both of the latter have a high content of safrole. The feasibility of the method to monitor TBQ chewing was demonstrated by an analysis of 153 spot human urine samples. The results showed that the p value of the nonparametric group comparison was < 0.001 for DHAB and 0.832 for eugenol. The TBQ chewers also exhibited a significantly higher rate of urinary DHAB (but not eugenol) than the nonchewers with an odd ratio of 3.47 (95% CI, 1.61-7.51). However, when only the eugenol-positive subjects were taken into analysis, the ratio rose to 24.38 (95% CI, 3.00-197.90).

Radionuclide colon transit study in patients with idiopathic constipation

BACKGROUND/AIMS

Constipation is the most common digestive complaint. Radionuclide colon transit study is a useful tool for assessing the motility of the colon. In this study, we evaluate patients with idiopathic constipation using the radionuclide colon transit study.

METHODOLOGY

We studied radionuclide colon transit in 23 patients with idiopathic constipation. Thirty healthy volunteers were included as a control.

RESULTS

Overall, patients with idiopathic constipation usually had slow or normal colon transit.

CONCLUSIONS

Our study suggested that the radionuclide colon transit study may be clinically useful in evaluating and assessing the efficacy of therapy in patients with idiopathic constipation.

Internationalization of general surgical journals: origin and content of articles published in North America and Great Britain from 1983 to 1998

HYPOTHESIS

The origin and characteristics of articles published in the 6 highest rated (Institute for Scientific Information classification) English-language general surgical journals have changed significantly during the past 15 years.

DESIGN

All articles published in 1983, 1988, 1993, and 1998 in 5 US surgical journals and 1 British surgical journal were reviewed and characterized.

MAIN OUTCOME MEASURES

Absolute numbers and proportions of national and international articles published in each journal.

RESULTS

Articles reviewed included 4868 in US journals and 1380 in the British journal. The total number of US journal articles decreased by 15.1%. The total number of British journal articles increased by 58.9%. The percentage of national articles decreased from 87.5% to 68.8% in US journals (P<.001) and constituted the minority of freely submitted articles in 1998 in 3 of 5 US journals. The percentage of national articles also decreased from 74.8% to 47.1% in the British journal (P<.001). Articles by European and Asian authors showed the most striking increases in all journals. The percentage of basic research articles declined in US journals from 23.3% to 17.9% (P =.001) owing to a 14.9% decline in national basic research articles. The percentage of clinical randomized studies increased from 2.2% to 4.1% (P<.008), but the increase was attributable to international articles. Government funding alone decreased from 13.6% to 11.2%, and government plus another source of funding decreased from 19.2% to 16.7% for national articles in US journals.

CONCLUSIONS

Internationalization of the highly rated British and the 5 highest rated US general surgical journals has occurred. The decrease in the number of national articles in the US journals has been accompanied by significant decreases in government funding and basic research articles and a static output of clinical randomized studies from North America.

Methodology standards associated with quality reporting in clinical studies in pediatric surgery journals

BACKGROUND/PURPOSE

Reports of clinical trials often lack adequate descriptions of design and analysis; recent attention has focused on improving this omission so readers can properly assess the strength of the findings and draw their own conclusions. Similar analysis of study design and methodologic standards associated with quality reporting has not been carried out for pediatric surgery journals.

METHODS

All studies (n = 642) published in 1998 in Journal of Pediatric Surgery (JPS) and Pediatric Surgery International (PSI), were reviewed for demographic data and study design. The frequency of reporting of 11 basic elements of design and analysis was evaluated in randomized clinical trials (RCT), nonrandomized clinical trials (NRCT), and retrospective cohorts (RC) from JPS by consensus of 2 assessors.

RESULTS

Of the 642 studies, 17% of articles (111 of 642) were classified as clinical studies. Sixty-three were comparative studies and consisted of RC (n = 48), NRCT (n = 12), and RCT (n = 3). Two-thirds of articles published were either case reports or case series (431 of 642), and 16% were basic science articles. Demographic analysis showed a wide range of topics addressed, 4 authors per article, and multiple country of origin of authors. More than 66% of all RCT in JPS reported on eligibility criteria, admission before allocation, random allocation, method of randomization, patients' blindness to treatment, treatment complications, statistical analyses, statistical methods, loss to follow-up, and statistical methods; 2 elements of design and analysis, however, were poorly reported: blind assessment of outcome (33%) and power (17%).

CONCLUSIONS

There were few randomized, controlled trials in pediatric surgery journals, and further attention should be given to evaluate the causal factors. Nine elements of quality reporting were well reported; however, 2 others were poorly reported; this may improve if editors of pediatric surgical journals provide authors with guidelines on how to report clinical trial design and analysis.

Long-term outcomes of the ileal pouch anal anastomosis: the association of bowel function and quality of life 5 years after surgery

INTRODUCTION

Previous studies have reported that mean health related quality of life (HRQL) levels generally attain normalcy following construction of an ileal pouch anal anastomosis (IPAA). It appears inconsistent, however, that these normal HRQL levels are achieved while bowel function (BF) scores generally remain statistically worse than "normal" (e.g., 4-8 stools/day, possible anal leakage, diaper usage). To investigate this inconsistency, the current study attempts to determine if any statistical associations are present between HRQL and BF, specifically in the long term. Multivariate regression analyses are performed using each of 8 individual HRQL domains against the full model of BF characteristics.

METHODS

All patients more than 5 years status post an ileal pouch anal anastomosis (IPAA) procedure for familial adenomatous polyposis (FAP) at a single institution were studied. FAP was chosen because patients are routinely asymptomatic preoperatively. BF (e.g., stool frequency, anal leakage) and HRQL (using the 8 health domains of the SF-36) were assessed by patient interview. Student's t tests and full model multivariate regression analyses were used to analyze associations between BF and HRQL.

RESULTS

The sample included 25 patients (14 male). Mean age was 39 years, mean follow-up time was 11 years. Although mean scores for the 8 individual HRQL domains were not statistically different from the general United States population, regression analyses of the different domains did demonstrate significant associations with varying levels of BF. While controlling for age and gender, the analyses show that the physical function domain is improved with the ability to pass flatus independent of stool, and physical role and mental health domains are improved with decreased stool frequency. The social function domain is improved with increased stool retention time, while the perception of general health is improved with less diaper usage and less sexual dysfunction.

CONCLUSIONS

This study shows that a statistically significant association between HRQL levels and BF is present. Of the numerous BF characteristics tested, five appear to be of greater importance with regard to certain HRQL domains. This finding may have clinical implications concerning pouch construction and surgical technique. Methodologically, this study demonstrates that merely using mean levels to describe HRQL may not elucidate meaningful relationships between important clinical outcomes, such as function and HRQL.

Primary duodenal adenocarcinoma: a 40-year experience

HYPOTHESIS

In patients with duodenal adenocarcinoma, certain pathologic features of the tumor will have prognostic significance.

DESIGN

Retrospective case series.

PATIENTS

Forty-nine patients diagnosed with duodenal adenocarcinoma between 1957 and 1998.

RESULTS

The tumors of 31 (63%) of the 49 patients underwent resection, 18 (37%) had surgical palliation or underwent biopsy. Mean (+/- SEM) survival for all patients was 49 +/- 9 months. The patients whose tumors were resected had longer survival than those who underwent palliation (mean +/- SEM, 66 +/- 13 months vs 18 +/- 6 months, P =.02). Multivariate analysis revealed large tumor size (P =.01), transmural invasion (P =.004), and moderate to poor tumor grade (P =.03) were negatively correlated with survival. Lymph node status did not influence survival.

CONCLUSIONS

Our 40-year experience with duodenal adenocarcinoma demonstrates that large tumor size, advanced histological grade, and transmural invasion are associated with decreased survival. These results underscore the importance of early diagnosis, and suggest the presence of nodal spread is not a contraindication to resection.

Improving the Surgeon's participation in research: is It a problem of training or priority?

BACKGROUND

Although numerous important contributions have originated from basic science research performed by surgeons, it seems that such dedicated work is becoming increasingly difficult to accomplish. What are the reasons for this change and what improvements can be made? This study aims to characterize the basic research training and careers of senior academic surgeons to assess and devise strategies for sustaining productive and quality surgical research.

METHODS

A 25-item survey was sent to 850 senior-level members of academic societies, including the Association of Academic Surgeons, Society of University Surgeons, and American Surgical Association. It addressed each surgeon's clinical and research training and career, as well as opinions concerning surgical research.

RESULTS

Three hundred seventy-seven (44%) surveys were received. Mean age was 64 years, and 73% were full professors. Seventy-two percent of respondents performed basic science research during training, and for 71% of this group, research was a significant reason for choosing a clinical specialty. Ninety-one percent performed research in the same specialty area during and after training. Of those who performed research during training, a full 99% continued to perform research on completion of training. However, 38% stopped performing basic research by age 39. Seventeen and twenty-three percent stopped basic research between 40 and 49 and between 50 and 59 years of age, respectively. The most common factors causing them to stop were increased clinical load (40%) and increased administrative duties (38%). For respondents who had stopped research prior to age 40, 73% cited increased clinical load as the primary reason. Eighty-five percent felt a dedicated research period should be included in surgery training.

CONCLUSIONS

Most respondents had participated in basic research during training, and continued similar research after training. However, an overwhelming clinical practice at the junior faculty level seemed to hinder research. We conclude: (1) the majority consensus is that research training is integral to the development of academic surgeons; (2) such research training opportunities appear adequate; however, (3) faculty performing research, particularly at the junior level, need to be better protected from other academic duties, such as clinical practice and administration. The challenge to the leadership of academic surgery will be to enhance such research productivity in the context of increasing academic demands.

Does better functional result equate with better quality of life? Implications for surgical treatment in familial adenomatous polyposis

PURPOSE

The main impetus for a patient with familial adenomatous polyposis to choose colectomy with ileorectal anastomosis over ileal pouch-anal anastomosis is the better functional result. However, does better functional result necessarily translate into better overall quality of life? Previous studies of other diseases have demonstrated no such correlation. This study was performed to determine whether any relationship exists between functional result and quality of life in patients with familial adenomatous polyposis after ileorectal anastomosis and ileal pouch-anal anastomosis.

METHODS

All patients with familial adenomatous polyposis who underwent colectomy with ileorectal anastomosis or proctocolectomy with ileal pouch-anal anastomosis from 1980 to 1998 were studied. Functional data were obtained by questionnaire. Health-related quality of life was assessed by two validated instruments, the SF-36 Physical and Mental Health Summary Scales and the SF-36 Health Survey, which measure physical and mental functioning and eight separate health-quality dimensions, including health perception, physical and social functioning, physical and emotional role limitations, mental health, bodily pain, and energy or fatigue.

RESULTS

Data were obtained in 44 of 68 patients, 14 with ileorectal anastomosis and 30 with ileal pouch-anal anastomosis. No differences were demonstrated between the two groups for patient age, mean follow-up time, and mean patient age at operation. Functional results were worse for the ileal pouch-anal anastomosis group vs. the ileorectal anastomosis group in number of bowel movements per day (7.5 vs. 5.2; P < 0.05), leakage (43 vs. 0 percent; P < 0.01), pad usage (17 vs. 0 percent; P < 0.01), perianal skin problems (33 vs. 7 percent; P < 0.01), food avoidance (80 vs. 43 percent; P < 0.01), and inability to distinguish gas (37 vs. 7 percent; P < 0.01). Results of the health-related quality-of-life surveys, however, demonstrated no difference between the ileal pouch-anal anastomosis and ileorectal anastomosis groups. The Physical and Mental summary scales for the ileal pouch-anal anastomosis and ileorectal anastomosis groups were not significantly different (Physical Health Scale, 50.3 vs. 50.9; Mental Health Scale, 51.7 vs. 49.6), and none of the eight dimensions of the SF-36 health survey demonstrated statistical differences between the ileal pouch-anal anastomosis and ileorectal anastomosis groups.

CONCLUSION

Better functional results were not equated with better quality of life in this pilot study. Although patients with the ileorectal anastomosis have better functional results than those with ileal pouch-anal anastomosis, the measured health-related quality of life as determined by a validated generic health-related quality-of-life instrument is the same for both groups. These results suggest that all patients with familial adenomatous polyposis might be optimally treated with an ileal pouch-anal anastomosis. More importantly, this study suggests that health-related quality of life should play a greater role in the evaluation of care and treatment in colon rectal surgery.

Lung volume reduction surgery: a cost and outcomes comparison of sternotomy versus thoracoscopy

It remains unknown whether it is better to perform lung volume reduction surgery (LVRS) through video-assisted thoracoscopy (VATS) or sternotomy. This study compares both approaches in terms of surgical and patient outcomes as well as the associated costs. All patients undergoing LVRS from 1995 to 1997 at one institution by a single surgeon (PFW) were investigated. Preoperative, postoperative, and cost data were obtained from medical and financial records. A total of 42 patients with severe emphysema underwent LVRS (19 via sternotomy and 23 via thoracoscopy). Both groups were comparable preoperatively. Comparison of intraoperative times revealed VATS takes longer to perform (sternotomy, 118 +/- 29 minutes; thoracoscopy, 168 +/- 20 minutes). Postoperatively, the sternotomy patients had more days on the ventilator, more days in the intensive care unit, more days with an air leak, and longer hospital stays. In both groups, the majority of patients reported improvement in oxygen dependence as well as quality of life. Neither surgical approach conferred any long-term medical advantage; however, the average total hospital costs and charges were reduced in the VATS group (average cost: VATS, $27,178; sternotomy, $37,299). This study concludes that 1) LVRS seems to be beneficial for selected patients with end-stage emphysema; 2) postoperative morbidity and length of hospital stay are decreased in the VATS group; 3) long-term improvement in postoperative pulmonary function is not influenced by surgical approach; and 4) the overall charges and costs of the VATS approach is less than that of sternotomy.

What is the best method of surgical training?: A report of America's leading senior surgeons

OBJECTIVES

To characterize the career choices and developments made by leading senior surgeons in this country and to examine hypothetically whether application of a short tracking program would have hindered their career decisions.

DESIGN

A survey pertaining to each surgeon's career, decisions, and opinions concerning surgical training.

SETTING AND PARTICIPANTS

Senior surgeons of regional and national surgical societies.

MAIN OUTCOME MEASURE

Survey responses.

RESULTS

A total of 352 surveys (41.4%) were received. Respondents answered that the most common reasons for choosing a specialty were role models or mentors (56%), research (51%), and available patient population (23%). The 2 most common stages in a career at which the respondents became interested in a specialty, or an area of expertise, were at the junior residency level (when the specialty was chosen) and at the assistant professor level (when a more specific topic within the specialty was chosen). The most common stage at which the group believed they acquired their expertise was also at the assistant professor level. Seventy-one percent of respondents believed broad training was superior to a short tracking system, although none had participated in shortened surgical training.

CONCLUSIONS

Most leading senior surgeons in this country still believe that broad surgical training is superior and should be maintained. Because career specialties in this surveyed group were generally chosen in early residency, a hypothetical application of the short tracking system would have still allowed for these important decisions to be made. Also, it seems likely that specialty and career development would not have been hindered because "expertization" mostly occurred after training was completed. Regardless of training method, a role model or mentor seems most important in career choices and developments.

Ion chromatography method and validation for the determination of sulfate and sulfamate ions in topiramate drug substance and finished product

A stability-indicating assay method has been developed for monitoring topiramate degradation in drug substance and finished product by quantifying sulfamate and sulfate ions. Topiramate in the solid state is stable under ambient conditions but can degrade under stress conditions (elevated temperatures and humidities). This method detects and quantitates sulfamate and sulfate ions (the inorganic part of the decomposition) and in conjunction with an assay method for topiramate and its known organic degradation product provides total molar accountability. The chromatographic system consists of a sodium hydroxide gradient (2-25 mM) and an anion-exchange HPLC column and an anion suppressor. The analysis is complete in 30 min. The method utilizes the same sample preparation as the topiramate assay method which increases sample efficiency and throughput. The method has been validated for analysis of degraded and nondegraded topiramate drug substance and finished product.

Surgical treatment of pathologic fracture of the femur

A retrospective study of the surgical treatment of 32 metastatic lesions of the femur in 30 patients at the Kaohsiung Medical College Hospital was performed from 1987 to 1994. There were 16 women and 14 men with an average age of 61 years. A surgical technique combining internal fixation or prosthesis and methylmethacrylate cement was used in all cases. Adequate pain relief was achieved in thirty-one cases (97 %). Of the entire group, 20 cases (62%) remained ambulatory, 10 cases (31%) were confined to a wheelchair, only two cases had implant failure and one suffered from infection.

Preemptive analgesia in patients undergoing appendectomy

OBJECTIVE

To evaluate the use of preemptive analgesia in patients who were undergoing an operation for acute appendicitis.

DESIGN

Double-blind, randomized control trial.

SETTING

Public hospital.

PATIENTS

Patients who presented with presumed appendicitis.

INTERVENTION

Patients received 1 of the following treatments: group 1, preemptive analgesia with a combination of lidocaine hydrochloride and bupivacaine hydrochloride; group 2, preemptive analgesia with saline solution; or group 3, nothing.

MAIN OUTCOME MEASURES

The Wong-Baker FACES Pain Rating Scale, analgesic requirements, number of analgesic doses required, and length of hospital stay.

RESULTS

No differences were noted in postoperative pain, the total number of analgesic doses per day, the quantity of narcotic medication administered, and the length of hospital stay.

CONCLUSIONS

Compared with healthy control subjects, preemptive analgesia did not reduce postoperative pain, reduce analgesic requirements, or shorten the length of hospital stay in patients who underwent an appendectomy. Premptive analgesia may be applicable only for patients without preoperative pain.

Biofeedback is effective therapy for fecal incontinence and constipation

OBJECTIVE

To define the role of biofeedback in fecal incontinence and constipation.

DESIGN

A case series of patients with fecal incontinence or constipation with pelvic floor dysfunction.

SETTING

Tertiary care center with an anorectal physiology laboratory.

PATIENTS

Patients with 1 of the following: (1) chronic or acute fecal incontinence, (2) fecal incontinence and neurologic injury, or (3) constipation with pelvic floor dysfunction.

INTERVENTION

Electromyogram-guided biofeedback retraining of the pelvic floor.

MAIN OUTCOME MEASURES

Resolution of electromyographic abnormalities and subjective resolution of fecal incontinence or constipation.

RESULTS

Of the patients with fecal incontinence, 92% experienced significant improvement with biofeedback without significant improvement in electromyographic values. Of the patients with constipation and pelvic floor dysfunction 80% experienced improvement with biofeedback without significant change in electromyographic values.

CONCLUSION

Biofeedback is effective in selected patients with fecal incontinence and constipation with pelvic floor dysfunction.

The spontaneous return of sensibility in breasts reconstructed with autologous tissues

Some spontaneous return of sensibility following autologous tissue breast reconstruction is often suspected but not well documented. In the present study, objective touch-pressure, pain, temperature, and vibratory sensibilities were recorded in 33 autologous breast reconstructions at an average of 25.2 months postoperatively. Correlation of the sensory return with patients' satisfaction toward reconstruction was done by a detailed questionnaire. All except one patient regained a variety of sensibilities touch pressure in 97 percent of patients (averaging 81.05 gm/mm2 versus control of 7.98 gm/mm2), pain in 88 percent of patients, heat in 64 percent of patients (45 percent of quadrants), cold in 82 percent of patients (67 percent of quadrants), and high- and low-frequency vibration in 100 percent of patients (high in 90 percent of quadrants, low in 96 percent). Subjectively, 94 percent considered their chest comfortable to touch following reconstruction compared with 34 percent following mastectomy. On a scale from 1 to 10, patients rated their reconstructions an average of 9.3. Our findings confirm the spontaneous return of sensibility following a variety of autologous tissue breast reconstructions. The value of the sensory return is suggested by the high degree of satisfaction in nearly all patients. Further attempts to correlate the degree of sensory return with the degree of satisfaction were inconclusive because of the uniformly high satisfaction reported by the patients. The mechanism of reinnervation appears to come both from the skin margins and from the deep surface of the flap. Future developments in breast reconstruction should take into consideration the eventual quality of sensory return.

Durability of prefabricated versus normal random flaps against a bacterial challenge

Numerous reports of flap prefabrication have demonstrated good survival. The durability of these flaps compared with that of other flap types or normal tissue, however, remains unknown. The purpose of this study was to determine how prefabricated flaps respond to a bacterial challenge compared with identically sized normal random-pattern flaps. Rat abdominal cutaneous-panniculus carnosus flaps were prefabricated with a standard-sized groin fasciovascular tissue carrier and then inoculated with Staphylococcus aureus. The prefabricated flaps were divided into two groups. Group one (standard prefabricated flap, n = 24) received no growth factor. Group two (n = 24) received an angiogenic growth factor between the carrier and flap tissue. A random-pattern flap served as a nonprefabricated control (n = 12). Grading of the prefabricated flaps with growth factor versus the standard prefabricated flaps versus controls showed dehiscence (41 versus 37 versus 4 percent), ulceration (21 versus 29 versus 18 percent), erythema/cellulitis (40 versus 44 versus 8 percent), and necrosis (9 versus 29 versus 0 percent). The control flaps had significantly less dehiscence, erythema/ cellulitis, and necrosis than the standard prefabricated flaps. Similarly, the prefabricated flaps with angiogenic growth factor had significantly less necrosis than the standard prefabricated flaps.

CONCLUSIONS

(1) prefabricated flaps were demonstrated to be less durable than random-pattern flaps against a bacterial challenge, (2) angiogenic growth factor may help to improve the durability of prefabricated flaps against bacterial infection, and (3) the biologic behavior of prefabricated flaps is not the same as that of normal tissue and deserves further investigation.

Microbial evaluation: 139 implants removed from symptomatic patients

Possible adverse effects of microbial organisms have been implicated in symptomatic silicone implant patients. In the literature, numerous authors have investigated the possible role of infection with respect to implant problems. To date, various bacterial species have been reported, including Staphylococcus aureus, Staphylococcus epidermidis, peptostreptococci, and Clostridium perfringens. Infections in polyurethane-coated prostheses also have been shown to prolong morbidity. Antibiotic use has been relatively empirical in this regard. The purpose of this study was, first, to determine the frequency, type, and clinical relevance of microbial colonization on implant surfaces removed from symptomatic patients and, second, to determine possible effects of microbial colonization on implant integrity (gel bleed, rupture). A total of 139 implants from 72 symptomatic patients were entered into the prospective clinical study between February of 1993 and July of 1994 at the UCLA Medical Center. The implant shell types included smooth (79 percent), polyurethane (8 percent), textured (7 percent), and smooth and Dacron (6 percent). The implant locations were subglandular (71 percent), submuscular (28 percent), and subcutaneous (1 percent). Of the 139 implants removed, 69 percent were intact and 31 percent were ruptured. Forty-seven percent of 139 implants were culture-positive. Propionibacterium acnes was isolated most frequently (57.5 percent), followed by Staphylococcus epidermidis (41 percent), and then Escherichia coli (1.5 percent). No fungal infections were identified. Culture positivity was not significantly associated with systemic symptoms. Sixty-seven percent of the positive culture implants were intact; 33 percent were ruptured. The frequency (47 percent) and types (P. acnes and S. epidermidis) of microbial colonization are determined in symptomatic silicone implant patients.

Safe ischemia time in free-flap surgery: a clinical study of contact-surface cooling

Although the effectiveness of cooling in extending tolerable ischemia time is well-established experimentally, most free-flap surgeons are still concerned about this problem and try to limit the ischemic period to less than 1 hr. Clinically, contact-surface cooling has been used empirically to prolong the limits of ischemia time; however, its applications are unproven. It also remains unknown whether contact-surface cooling has detrimental effects on flap tissue, such as vessel spasm leading to thrombosis. The purpose of this study was to determine, in a clinical setting, if skin, muscle, and bone free flaps of considerable size could tolerate prolonged cold ischemia without adverse effects. Flap size, cold ischemia time, and surgical outcomes were studied in 189 consecutive free flaps. Microvascular thrombosis occurred in 5/378 (1.3 percent) of anastomoses. The overall flap complication/flap loss rate was 7/189 (3.7 percent). Mean ischemia time for all flaps was 2 hr and 6 min (range: 30 min to 5 hr, with one case at 6 hr and 8 min). The mean ischemia time for cases with flap complications was 2 hr 20 min, while ischemia time for cases with thrombosis averaged 2 hr 13 min. The one flap loss had an ischemia time of 1 hr 35 min. No statistically significant correlations existed between duration of ischemia time or duration of contact-surface cooling and the incidence of thrombosis, flap complication, or flap failure. Among the conclusions were that, within a 4-hr period of cold ischemia, the application of the surface-cooling technique is not detrimental to free flap surgery; thus, concern for ischemia, and especially the "no reflow" phenomenon, generally should not interfere with efficient and orderly free-flap surgery.

Salvage of a below-the-knee amputation with a fillet of foot free flap: a 15-year follow-up

In the setting of traumatic injury, obtaining suitable coverage to salvage a below-the-knee amputation has been performed by using a variety of tissue flaps, including the fillet of foot free flap. This flap is a free tissue transfer that utilizes the soft tissues of the foot for stump coverage. In this report, we present a 15-year follow-up of a patient with a fillet of foot free flap to demonstrate its applicability and long-term efficacy. We also discuss technical aspects for performing this procedure. In this follow-up, we have found the flap to be extremely durable, even when placed in the weight-bearing position of the stump, and also lacking many of the usual complications associated with the weight-bearing portion (e.g., blisters, ulcerations). We conclude that the fillet of foot free flap is an excellent salvage flap for providing long-term length, coverage, and durability in an amputated, weight-bearing extremity.

Abdominal tuberculosis: the surgical perspective

The increasing incidence of pulmonary tuberculosis (TB) has led many to predict a corresponding increase in abdominal TB. This study reports the incidence, presentation, and outcome of abdominal TB to elucidate factors that might assist the surgeon to treat this potentially curable disease. A retrospective review of patients diagnosed with tuberculosis between 1993 and 1995 was performed at two hospitals. Diagnosis of abdominal TB was based on acid fast bacilli on tissue stains and/or culture. Seven patients were diagnosed with abdominal TB. Two patients were HIV positive; six were recent immigrants. Abdominal pain, fever, and significant weight loss were the most common symptoms. All preoperative radiologic tests failed to demonstrate findings suggestive of TB. All patients were brought to operation. Indications included perforated viscus (2), acute abdomen (1), small bowel obstruction (1), colocutaneous fistula (1), pelvic neoplasm (1), and biliary colic (1). Abdominal TB was either diagnosed or suspected intraoperatively in six patients. Postoperative anti-TB chemotherapy was promptly instituted. Although abdominal TB can be cured medically if treated early enough, the nonspecific presentation delays diagnosis in the majority of cases. Diagnosis of abdominal TB can be made or at least highly suspected intraoperatively such that anti-TB medications can be initiated promptly. Appropriate surgical therapy and prompt initiation of anti-tuberculosis medications can successfully treat abdominal TB.

Capsular synovial metaplasia as a common response to both textured and smooth implants

Recent reports suggested that the presence of synovial metaplasia in the capsular tissues of breast implants is greater with textured-shelled implants compared with smooth. Textured implants, however, have become popular only in the last few years. Therefore, the studies do not address the possibility that synovial metaplasia may be a dynamic process related to time (e.g., implant age) rather than implant shell surface. In the current study, 159 implant capsules (85 patients) removed between February of 1992 and July of 1993 at UCLA Medical Center were evaluated histologically and correlated with clinical data, including the age of implants. Synovial metaplasia was identified in 40 percent (64 of 159) of the capsule specimens. A logistic regression analysis that removed the effect of implant age demonstrated no correlation of implant shell type (textured versus smooth) with the presence of synovial metaplasia. Gel bleed, implant location, pericapsular fluid, implant rupture, and capsular contracture also did not have any significant association with synovial metaplasia in the current study. The incidence of synovial metaplasia appears to decrease with age (77 percent at < 5 years; 22 percent at > 15 years). Our findings suggest that synovial metaplasia is not rare and in fact may be a fairly common transitional histologic finding. It may be part of the common progression that occurs at the implant-capsule interface. The clinical significance remains unknown.

Clinical significance of intracapsular fluid in patients' breast implants

Clinical reports on the incidence and clinical significance of intracapsular fluid are lacking in the literature. It remains unknown whether the presence of intracapsular fluid has any relation to implant infection or colonization. The purpose of this study was to determine the frequency and type of intracapsular fluid, specifically, whether intracapsular fluid causes implant infection, implant rupture, or bacterial colonization. A total of 139 implants from 72 symptomatic patients were entered into the prospective clinical study. Our study demonstrated the presence of intracapsular fluid in 21 of 139 (15%) implants. Positive microbial cultures were identified in 39% of the implants in the positive intracapsular fluid group, compared to 43% in the negative fluid group. There was no statistically significant difference between these groups. Also, no adverse clinical relationship was demonstrated between local symptoms and presence of intracapsular fluid. There was, however, a positive trend toward the presence of fluid when implant shell types were nonsmooth (polyurethane and textured silicone implants). Further studies are indicated to elucidate the fluid production mechanism and possible secretory activity of prosthetic capsules interfacing the textured breast implant surface.

Estrogen receptors in gallbladder cancer: detection by an improved immunohistochemical assay

Although gallbladder carcinoma is the most common malignancy of the extrahepatic biliary tract, patients with this disease have a very poor prognosis. Previous investigations have documented the presence of estrogen receptors (ER) in gallbladder cancers for possible therapeutic benefit; however, the methods used for detection were largely imprecise, which led to a wide range of results. In light of these unclear results obtained with inferior techniques, we have attempted to determine more accurately the prevalence of ER positivity in gallbladder cancer using an improved, more specific immunohistochemical assay (IHA) for estrogen receptors. The IHA, which used a pronase pretreatment and the H222 monoclonal antibody, was performed on archival tumor specimens of 25 patients. There were no strongly or moderately positive specimens. Three specimens stained weakly positive, and 22 specimens (88%) were negative. The three specimens that were weakly positive showed neither statistical significance nor any identifiable trends with respect to patient sex, tumor stage, or histologic type. We conclude that, contrary to previous reports, weak estrogen receptor staining occurs in a very small percentage of gallbladder carcinomas. Furthermore, although the minimum concentration of ER required for potential therapeutic benefit is unclear, the addition of hormonal therapy in patients with gallbladder cancer is not likely to alter the outcome of this malignancy.

Is surface cooling effective for tissue preservation in free-flap surgery?

Effective tissue cooling can extend the period of safe ischemia. To determine whether the technique of surface cooling could produce an effectively low core temperature (4 degrees to 10 degrees C) in the flap core in a reasonable amount of time, bovine muscle/subcutaneous fat flaps, weighing 400, 800, and 2000 g, were brought to 37 degrees C and then surface cooled. Temperatures were then recorded every 5 min. All flaps were able to attain 4 degrees C in the core; the average times for the 400, 800, and 2000 g flaps to reach 4 degrees C were 136, 153, and 194 min, respectively. Although a clear inverse relationship existed between flap weight and effectiveness of core cooling, even relatively large flaps (2000 g) could still achieve sufficiently low core temperatures from surface cooling well within tolerable warm ischemia time. Concern for ischemia time generally should not interfere with efficient, orderly, free-flap surgery.

Assay of residual organic solvents in topiramate drug substance by capillary gas chromatography

The analysis of residual organic solvents (methanol, ethanol and toluene) in topiramate drug substance was investigated. Topiramate is a potent anticonvulsant drug under clinical evaluation. The drug is recrystallized from ethanol denatured by either methanol or toluene, and each residual solvent is controlled at 0.1% (w/w) level. A capillary gas chromatography (GC) method described in this manuscript utilizes a DB-WAX, 1 micron thick, 30 m x 0.53 mm i.d., column. Since topiramate is a thermally labile compound, the selection of the proper injector temperature is critical to the success of the analysis. The injector temperature was set at 120 degrees C to prevent degradation. The initial oven temperature was set at 55 degrees C for 8 min and programmed at a rate of 30 degrees C min-1 to a final temperature of 160 degrees C for 11 min. Helium was used as a carrier gas. The sample solvent selected was dimethylformamide pretreated with molecular sieves to remove trace amounts of alcohols that may interfere with the assay. The method was validated to be specific, linear, precise, sensitive, rugged and showed excellent recovery.

Purification and characterization of a collagenous protein secreted by a murine teratocarcinoma-derived cell line

A collagenous protein could be precipitated by (NH4)2SO4 from the culture medium of a murine teratocarcinoma-derived cell line (Ko, C.Y., Johnson, L.D. and Priest, R.E. (1979) Biochim. Biophys. Acta 581, 252-259). Further purification of this protein was achieved by combining DEAE-cellulose chromatography with either CM-cellulose or molecular sieve chromatography. The collagenous polypeptides had subunit molecular weights of 160 000, if determined by molecular sieve chromatography, or 190 000, if determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and they are not linked by disulphide bridges. Amino acid composition of this collagen is similar to that of a murine type IV collagen isolated from EHS sarcoma (Timpl et al. (1978) Eur. J. Biochem. 84, 43-52). The most prominent peptides resulting from cleavage of the protein by CNBr had estimated molecular weights of 25 000, 23 000, 11 700 and 9400. Pepsin treatment of this collagen under non-denaturing conditions produced three major fragments having molecular weights of 70 000, 45 000 and 43 000. We conclude that the collagen secreted by the murine teratocarcinoma-derived cell culture is a type IV basement membrane collagen. Therefore, this culture system should provide a continuous source of type IV collagen, which may be used to study the interaction of this collagen with other basement membrane components.

High-performance liquid chromatographic assay of codeine in acetaminophen with codeine dosage forms

An accurate, rapid, and specific high-performance liquid chromatographic (HPLC) assay was developed for codeine in acetaminophen with codeine combination products. The internal standard (chlorpheniramine maleate), codeine, acetaminophen, and several other test compounds or impurities were well separated. A complete analysis took < 10 min. The relative standard deviations of the retention time, precision, and accuracy were 0.5, 0.4, and 0.5%, respectively. An excellent linear correlation was obtained between the HPLC and GLC methods.

Isolation and characterization of hydroxyproline-containing proteins secreted by a murine carcinoma cell culture

A collagenous protein was isolated from a murine carcinoma cell culture, which has been shown to synthesize basement membrane. The molecular weight of this protein was estimated to be 155 000. It eluted from carboxymethyl-cellulose in the region near the alpha 1 and beta 11 components of calf skin collagen. 63--69% of the peptide-bound prolines were hydroxylated, and the 4-/3-hydroxyproline ratios ranged from 12 : 1 to 14 : 1. About 95% of the hydroxylysines in the peptide were glycosylated, and almost all of them were in the glucosylgalactosyl dissacharide form. Judging from the posttranslational characteristics, this collagenous protein is probably of basement membrane type.

High-pressure liquid-chromatographic assay of nucleotide-pool concentrations during polysaccharide biosynthesis in four ascomycetes

High-resolution liquid-chromatographic methods developed for analyzing nucleotide pools at the nanogram level in four representative species of ascomycetes (Penicillium citrinum, Aspergillus niger, Fusarium moniliforme, and Cladosporium herbarum) were used to study polysaccharide biosynthesis. Nucleotides extracted from the mycelial mat were preseparated from interfering polysaccharides, glycoproteins, and nucleic acids on a column of Biogel P-2. Resolution of 18 nucleotides from each fungal species was accomplished on AS-Pellionex-SAX, pellicular anion-exchanger by using a high-pressure liquid chromatograph. Nucleotides were identified by comparing peak retention-times, by differential u.v. absorption with two detectors in series at selected wavelengths, and by acid or enzymic hydrolysis with product identification by liquid chromatography. Pyrimidine bases exceeded purines by at least three fold, and uridine nucleotides often constituted 60-80 mole percent of the total nucleotides; extractable cytidine nucleotides were negligible. Uridine 5'-(2-acetamido-2-deoxy-alpha-D-glucopyranosyl disphosphate) is the preponderant nucleotide throughout the growth cycles of all four species, amounting to 30-60% of all nucleotides present. For all four fungal species, a burst of nucleotide formation was observed after the first 48h (15-30 mumol/g tissue), with fluctuations that eventually fell to 0.1 mumol/g on the tenth day.