High referral accuracy for oral cancers and oral potentially malignant disorders using telemedicine

OBJECTIVE

To evaluate the accuracy of MeMoSA®, a mobile phone application to review images of oral lesions in identifying oral cancers and oral potentially malignant disorders requiring referral.

SUBJECTS AND METHODS

A prospective study of 355 participants, including 280 with oral lesions/variants was conducted. Adults aged ≥18 treated at tertiary referral centres were included. Images of the oral cavity were taken using MeMoSA®. The identification of the presence of lesion/variant and referral decision made using MeMoSA® were compared to clinical oral examination, using kappa statistics for intra-rater agreement. Sensitivity, specificity, concordance and F1 score were computed. Images were reviewed by an off-site specialist and inter-rater agreement was evaluated. Images from sequential clinical visits were compared to evaluate observable changes in the lesions.

RESULTS

Kappa values comparing MeMoSA® with clinical oral examination in detecting a lesion and referral decision was 0.604 and 0.892, respectively. Sensitivity and specificity for referral decision were 94.0% and 95.5%. Concordance and F1 score were 94.9% and 93.3%, respectively. Inter-rater agreement for a referral decision was 0.825. Progression or regression of lesions were systematically documented using MeMoSA®.

CONCLUSION

Referral decisions made through MeMoSA® is highly comparable to clinical examination demonstrating it is a reliable telemedicine tool to facilitate the identification of high-risk lesions for early management.

[Clinicopathological features of low-grade oncocytic renal tumor (CD117-negative, cytokeratin 7-positive): report of seven cases]

Objective: To explore clinicopathological features of low-grade oncocytic tumor (LOT) of the kidney and to analyze its relationship to hybrid oncocytic/chromophobe tumor (HOCT) of the kidney, renal oncocytoma (RO), and chromophobe renal cell carcinoma (chRCC). Methods: Seven LOTs were identified from the pathologic archives of two hospitals, including Xiangya Hospital (5 cases) and the Second Xiangya Hospital (2 cases) of Central South University between 2012 and 2019. Clinical data of the LOTs were collected. The tumor morphology was analyzed and immunohistochemistry was performed. Results: All LOTs occurred in adults, aged from 49 to 72 years (median 56.0 years, mean 60.7 years). The tumor size ranged from 2.5 to 6.0 cm (median 4.3 cm, mean 4.3 cm). There were three male and four female patients. Three cases occurred in the left kidney and four in the right. All the tumors were solitary lesions without the clinicopathologic background of Birt-Hogg-Dubé (BHD) syndrome or oncocytosis. Five patients had available follow-up data (follow-up period 23-95 months, median 69.0 months, mean 64.6 months) and all were alive without disease. Microscopically, all LOTs were well-circumscribed (7/7). Three LOTs were partly encapsulated. The tumors demonstrated a predominant growth pattern comprising prominently compact small nests surrounded by delicately branching thin-walled blood vessels, imparting an organoid architecture (7/7), but variable numbers of glandular or gland-like structures were often seen among the small nests (7/7). There were frequently areas with loose, edematous stroma, and the tumor cells exhibited reticular, trabecular, or single cell arrangements (6/7). Focal hemorrhage was also commonly present in both compact and loose areas (5/7). In addition, focally cystic formation and ossification occurred in the compact area of one case and in the loose area of another case. The tumor cells in LOT showed intermediate cytologic characteristics between RO and chRCC, including abundantly eosinophilic granular cytoplasm, ovoid to round nuclei with mostly smooth contours, discernable small nucleoli (RO features), frequently delicate perinuclear halos, and occasional binucleation (chRCC features). The tumors were typically CK7-positive and CD117-negative (7/7), and variable staining for PAX8 (5/7), P504s (2/7), and vimentin (1/7). They were negative for CK20, CD10 and FOXI1. All tumors retained SDHB immunostaining. Conclusions: LOT is a rare and indolent oncocytic renal tumor with homogeneously intermediate cytologic features between RO and chRCC. There are some clinicopathologic overlaps between LOT and sporadic HOCT. The distinctive morphology and immunophenotype of LOT suggest that it is potentially a distinct tumor entity.

Barriers to early detection and management of oral cancer in the Asia Pacific region

Objective

Oral cancer is amenable to early detection but remains a prominent cause of mortality in the Asia Pacific region. This study aimed to identify barriers to early detection and management of oral cancer in the Asia Pacific region.

Methods

A mixed-methods approach was employed triangulating findings from a survey and focus groups. The survey was conducted among seven representative members of the Asia Pacific Oral Cancer Network (APOCNET) across six countries. Focus groups were conducted to gain deeper insights into the findings of the survey.

Results

The identified barriers were a lack of national cancer control strategies and cancer registries and the limited availability of trained health care professionals. Overcoming these challenges in the Asia Pacific region where resources are scarce will require collaborative partnerships in data collection and novel approaches for continuous professional training including eLearning. Further, to overcome the lack of trained health care professionals, innovative approaches to the management of oral potentially malignant lesions and oral cancer including telemedicine were suggested.

Conclusion

The findings of this study should be taken into account when charting national cancer control plans for oral cancer and will form the basis for future collaborative studies in evaluating effective measures to improve oral cancer detection and management in low- and middle-income countries.

m-Health for Early Detection of Oral Cancer in Low- and Middle-Income Countries

Background: Up to 86% of oral cancer (OC) patients present at the late stage where survival is dismal. Limited access to specialist diagnosis is a significant factor for late presentation. The increasing use of smartphones presents an opportunity to use digital technology to facilitate early detection of OC. Aim: To evaluate the feasibility of using Mobile Mouth Screening Anywhere (MeMoSA^®) to facilitate early detection of OC. Methods: A mobile phone app named MeMoSA was developed and the feasibility of integrating this for documentation of oral lesions, and communication between dentists and specialists for management decisions were evaluated. The experience of dentists and specialists in using MeMoSA was determined using qualitative questionnaires. Results: Communication between specialist and dentists using MeMoSA stratified cases and streamlined referral of patients. Twelve of 48 patients were found to have oral lesions or signs suspicious of cancer and 3 required referrals. The patient's compliance for referral was tracked with MeMoSA. All dentists agreed that MeMoSA could facilitate early detection of OC and believed that MeMoSA could assist in the identification of oral mucosal lesions through direct communication with specialists and continuous learning in the recognition of high-risk lesions. Conclusions: MeMoSA has the potential to be used to promote equitable health care and streamline patient management that could result in early detection of OC.

Metal-Organic Framework MIL-101-NH2-Supported Acetate-Based Butylimidazolium Ionic Liquid as a Highly Efficient Heterogeneous Catalyst for the Synthesis of 3-Aryl-2-oxazolidinones

A novel heterogeneous catalyst, the ionic liquid (IL) of 1-butyl-3-methylimidazolium acetate (BmimOAc) immobilized on MIL-101-NH₂, denoted as IL(OAc^-)-MIL-101-NH₂, was prepared by the "ship-in-a-bottle" strategy. The IL of BmimOAc was prepared in the MIL-101-NH₂ nanocages primordially, in which the condensation product of MIL-101-NH₂'s amine group with 1,1'-carbonyldiimidazole (CDI) reacted with 1-bromo butane, and then the intermediate exchanged with potassium acetate. The structure and physicochemical properties of IL(OAc^-)-MIL-101-NH₂ were characterized by powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, DRS UV-vis, nitrogen adsorption-desorption, and elemental analysis. The results indicated that BmimOAc was anchored in the MIL-101-NH₂ skeleton via the acylamino group and confined in the nanocages in the form of a single molecule. The composite material of IL(OAc^-)-MIL-101-NH₂ exhibited excellent catalytic activity and catalytically synthesized 3-aryl-2-oxazolone in an excellent yield of 92%. It can be reused up to six times without noteworthy loss of its activity and demonstrated distinct size-selective property for substrates. It was conjectured that the diffusion kinetics of reactants could be controlled by the aperture size of the metal-organic framework support.

Uses and abuses of paediatric electroencephalography

OBJECTIVE

To investigate whether requests for standard paediatric electroencephalograms accord with guideline recommendations, subsequent changes in clinical management according to reported results, and extent to which the service meets waiting time targets.

DESIGN

Case series.

SETTING

Regional hospital, Hong Kong.

PATIENTS

All patients aged less than 18 years who underwent electroencephalography between December 2009 and February 2010.

MAIN OUTCOME MEASURES

Appropriateness of the electroencephalogram request and the impact of its findings on clinical management.

RESULTS

A total of 109 patients were recruited, but requests for standard electroencephalograms were considered 'inappropriate' with respect to guidelines in 44% of the patients, of which 50% were made to diagnose 'funny turns'. The standard electroencephalogram contributed to the diagnosis or management in only 28% of patients. In all of the latter, the request for an electroencephalogram had been appropriate. Nonspecialists made referrals for 86% of the patients. Inadequate information was provided in 66% of the requests. Standard electroencephalograms were performed within guideline targets, the wait being less than 4 weeks in 95% of requests.

CONCLUSION

An effective electroencephalogram service was being provided, though abuses were common. These were mainly because of misconceptions regarding the role and limitations of standard electroencephalograms. Through an educative, non-confrontational approach, and with time to explain guideline recommendations to clinicians, sustainable change in practice could be achieved so as to benefit patients, clinicians, and service provision.

Hemangioma of the diaphragm presenting with cardiac tamponade

We report a rare form of presentation of diaphragmatic hemangioma in a neonate. The patient presented with pericardial effusion and cardiac tamponade, requiring tapping of the pericardial effusion and subsequent en-bloc resection of the hemangioma with diaphragmatic reconstruction.

Giant myxoma causing right ventricular outflow tract obstruction

Atrial cardiac myxoma is the most common benign cardiac tumour. Atrial myxoma most commonly arises from the left atrium and, less frequently, from the right atrium or both ventricles. Cardiac myxoma arising from the tricuspid valve is rare. These tumours can present with right heart failure as a result of right ventricular outflow tract obstruction. A high index of suspicion and appropriate investigations are necessary for making the correct diagnosis. Fatal complications such as embolisation and obstruction of the outflow tract and other intracardiac structures make prompt surgical intervention necessary. We report on a patient with a rare type of giant myxoma arising from the tricuspid valve. He underwent successful operation with en-bloc removal of the tumour, while preserving the integrity of the tricuspid valve.

Pulmonary valve replacement after surgical repair of tetralogy of Fallot

OBJECTIVE

To evaluate the results of pulmonary valve replacement in patients with severe pulmonary regurgitation after tetralogy of Fallot repair in Hong Kong.

DESIGN

Retrospective review.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

Consecutive patients undergoing pulmonary valve replacement after repair of tetralogy of Fallot between August 2002 and December 2008.

MAIN OUTCOME MEASURES

Magnetic resonance imaging of right ventricular volume and cardiopulmonary exercise test data before and after the operation were documented and compared.

RESULTS

Over a 6-year period, 16 patients underwent pulmonary valve replacement for severe pulmonary regurgitation after prior complete repair for tetralogy of Fallot. There was no in-hospital mortality. The mean time interval between the initial repair and pulmonary valve replacement was 19 (standard deviation, 9) years. In three patients, the indication for pulmonary valve replacement was symptomatic severe pulmonary regurgitation, and asymptomatic progressive right ventricular dilatation in the remaining 13 patients. After pulmonary valve replacement, there was a significant decrease in the mean indexed right ventricular end-diastolic volume from 173 (standard deviation, 44) mL/m(2) to 103 (19) mL/m(2) (P=0.043). After the operation, there was also a tendency for improvement of the right ventricular ejection fraction and the maximum oxygen consumption: from 42% (standard deviation, 9%) to 47% (6%) [P=0.173], and 27 (4) mL/kg/min to 29 (4) mL/kg/min (P=0.208), respectively.

CONCLUSION

Pulmonary valve replacement for severe pulmonary regurgitation after tetralogy of Fallot repair is a safe procedure. However, the indications for such an operation in asymptomatic patients remain controversial. Further studies are required to better delineate the timing of pulmonary valve replacement in this patient group.

Isolated left ventricular non-compaction: an unusual indication for heart transplantation

We report a patient with isolated left ventricular non-compaction diagnosed by echocardiography and cardiac magnetic resonance imaging. She developed refractory congestive heart failure and subsequently underwent successful heart transplantation. This type of cardiomyopathy is thought to be caused by the arrest of normal embryogenesis of the endocardium and myocardium. The spectrum of clinical, radiological, and pathological abnormalities is discussed.

Primary cardiac angiosarcoma of left atrium

Cardiac angiosarcoma usually arises from the right atrium. We report an extremely rare case of primary angiosarcoma originating from the left atrium in a 70-year-old woman. This represents the ninth reported case of left-sided cardiac angiosarcoma in the English literature. Analysis of all nine cases shows that this malignant neoplasm occurs more in female patients with a mean age of 60 years, unlike the right-sided one which typically affects male patients in their early 40s. The prognosis of this tumor is extremely poor with life expectancy lying between 3 to 34 months despite early diagnosis by imaging and multimodality treatment.

Impact of diabetes on early and mid-term survival after coronary artery bypass graft surgery in the Hong Kong Chinese population

OBJECTIVE

To determine the impact of diabetes on early and mid-term survival in the Hong Kong Chinese population undergoing coronary artery bypass graft surgery.

DESIGN

Prospective study.

SETTING

Regional hospital, Hong Kong.

PATIENTS

A total of 904 consecutive patients following coronary artery bypass graft surgery from November 1999 to December 2003 were prospectively analysed. Among them, 377 (42%) diabetic and 527 (58%) non-diabetic patients were evaluated.

MAIN OUTCOME MEASURES

Hospital mortality, mid-term mortality, and percutaneous coronary intervention-free survival.

RESULTS

The diabetic group had a higher risk score than the non-diabetic group (mean+/-standard deviation: EuroSCORE 4.7+/-3.4 and 3.6+/-3.4, respectively; P<0.001). Hospital mortality was 3.4% in the diabetic group compared to 2.8% in the non-diabetic group (P=0.698). Multiple logistic regression analysis identified left ventricular ejection fraction of less than 30% and preoperative intubation as independent risk factors for early hospital death. There were 81 late deaths and the actuarial survival at 48 months for the diabetic and non-diabetic patients were 86% and 90%, respectively (P=0.298). The angina-free survival and percutaneous coronary intervention-free survival at 48 months for the diabetic and non-diabetic patients yielded no statistically significant difference.

CONCLUSIONS

Diabetes mellitus was not a predictor of early and mid-term mortality after coronary artery bypass graft surgery in our Chinese population. Furthermore, diabetes did not affect angina recurrence or intervention free-survival up to 4 years.

Mortality prediction in adult cardiac surgery patients: comparison of two risk stratification models

OBJECTIVE

To assess and compare the two commonly applied models--EuroSCORE and Parsonnet--in our local adult cardiac surgery patients, according to risk factor quantification related to mortality using a risk stratification protocol to assess the quality of cardiac surgical care.

DESIGN

Prospective study.

SETTING

Cardiac surgery centre in a regional hospital in Hong Kong.

PATIENTS

All adult patients undergoing coronary artery bypass graft and heart valve surgery at the Grantham Hospital were evaluated prospectively from November 1999 to July 2005.

MAIN OUTCOME MEASURES

In-hospital mortality was the defined end-point. Statistical analyses consisted of observed against expected mortality, Hosmer-Lemeshow goodness-of-fit test for calibration accuracy, and receiver operating characteristic curve for discrimination performance.

RESULTS

During the study period, 1247 patients underwent coronary artery bypass graft surgery and 1406 underwent heart valve surgery. Observed mortality rates in these two patient groups were 2.9% and 4.8% respectively. The expected mortality rates as predicted by the EuroSCORE were (mean+/-standard deviation) 4.0+/-3.3% and 5.2+/-3.0% respectively, and by the Parsonnet model were 5.9+/-4.2% and 7.3+/-4.4% respectively. EuroSCORE performed better than the Parsonnet model at predicting in-hospital mortality assessed by the Hosmer-Lemeshow goodness-of-fit test. The areas under the receiver operating characteristic curves in coronary artery bypass graft surgery were 0.76 for EuroSCORE and 0.74 for Parsonnet. The receiver operating characteristic curve areas in valve surgery were 0.77 for EuroSCORE and 0.79 for Parsonnet.

CONCLUSION

Despite significant geographic and demographic differences between European and Asian patients, in our local adult cardiac surgery patients, the EuroSCORE performed well with good calibration and discrimination in predicting mortality. There was a tendency for both models to over predict. However, the EuroSCORE can serve as a baseline for the development of a local risk model.

Foreign body-induced aorto-oesophageal fistula: a review of five cases and their management

Foreign body-induced aorto-oesophageal fistula is a rare cause of massive upper gastro-intestinal bleeding and, in the absence of a timely diagnosis and surgical intervention, can be fatal. During a period of 25 years, five patients with foreign body-induced aorto-oesophageal fistula underwent surgery in our department. Three patients survived. All survivors required more than one surgical intervention. The clinical course of these five patients and the management of this potentially fatal condition are reviewed.

Long-term anticoagulation therapy and thromboembolic complications after the Fontan procedure

BACKGROUND

The necessity for chronic anticoagulation of Fontan patients remains controversial. We determined the prevalence of thromboembolic complications after the Fontan procedure in relation to different long-term anticoagulation strategies.

METHODS

The clinical outcomes, postoperative anticoagulation strategies and occurrence of thromboembolic complications in 102 ethnic Chinese patients who had undergone Fontan procedure between 1980 and 2002 were reviewed.

RESULTS

The early and late surgical mortalities, all unrelated to thromboembolism, were 10.8% (11/102) and 5.8% (6/104), respectively. Of the 85 survivors, 46 (54%) were maintained on long-term warfarin therapy, 8 (9%) on aspirin prophylaxis while 31 (37%) were not on chronic anticoagulation. Four (4.5%) patients, two with and two without warfarin prophylaxis, developed thromboembolic complications at 0.14 to 7.7 years after the Fontan procedure (0.74%/patient-year). Three had a grossly dilated right atrium after atriopulmonary connection, two of whom had atrial fenestrations. The other had atrial tachycardia. Freedom from development of thromboembolic complications (mean+/-S.E.) at 1, 5 and 10 years after surgery was 97+/-19%, 96+/-2.5% and 92+/-4.2%, respectively. When compared with those on long-term warfarin therapy, patients without chronic anticoagulation were followed-up longer (p=0.001), more likely to have undergone atriopulmonary connection (p<0.001), less likely to have fenestrations (p=0.02) and cardiac arrhythmias (p=0.02) but not predisposed to increased risk of thromboembolism (p=1.00).

CONCLUSION

The study supports the contention that chronic anticoagulation may not be required for majority of ethnic Chinese Fontan patients. Nonetheless, it may perhaps be considered in those with grossly dilated right atrium, cardiac arrhythmias and residual right-to-left shunts.

Gender difference in self-esteem of Hong Kong Chinese with cardiac diseases

Self-esteem is an indicator of a person's subjective quality of life due to its close relationship to a person's behavioural competence, positive self-experience, and sense of self-actualization. The present study aimed to investigate the basis of self-esteem in people with cardiac diseases, according to gender, after their cardiac surgery. The findings showed that there were prominent gender differences in the subjects' self-esteem. Women (aged<60) showed statistically significant higher ratings in the importance of 11 life events importance and the satisfaction of three life events than men. The study also found cultural uniqueness: Hong Kong Chinese (both men and women) with cardiac diseases generally indicated that social (interpersonal) self-concept dimensions were more important than achievement (personal) self-concept dimensions in their life perception. These findings are noteworthy for setting optimum goals of rehabilitation apart from return to work.

Differential influences of various arsenic compounds on glutathione redox status and antioxidative enzymes in porcine endothelial cells

The cellular response and detoxification mechanisms in porcine endothelial cells (PAECs) to arsenic trioxide (As2O3), sodium arsenite (NaAsO2) and sodium arsenate (Na2HAsO4) were investigated. NaAsO2 at 20 microM for 72 h increased Cu/Zn superoxide dismutase activity resulting in elevated intracellular hydrogen peroxide levels, but As2O3 and Na2HAsO4 did not. Trivalent arsenic compounds increased intracellular oxidized glutathione (GSSG) and total glutathione (GSH) and cellular glutathione peroxidase (cGPX) and glutathione S-transferase (GST) activity, but not glutathione reductase activity. The increased cGPX activity resulted in an elevated cellular GSSG content. Na2HAsO4 increased the cellular GSSG level at 72 h compared to controls. These results imply that the increased GSH content responding to the oxidative stress by trivalent arsenic compounds may be mainly related to the regulation of GSH turnover. The increased GST activity implies that the elevated intracellular GSH level responding to the oxidative stress may be used to conjugate arsenic in PAECs and facilitate arsenic efflux.

C. elegans CED-12 acts in the conserved crkII/DOCK180/Rac pathway to control cell migration and cell corpse engulfment

We have identified and characterized a novel C. elegans gene, ced-12, that functions in the conserved GTPase signaling pathway mediated by CED-2/Crkll, CED-5/DOCK180, and CED-10/Rac to control cell migration and phagocytosis of apoptotic cells. We provide evidence that ced-12 likely acts upstream of ced-10 during cell migration and phagocytosis and that CED-12 physically interacts with CED-5 and forms a ternary complex with CED-2 in vitro. We propose that the formation and localization of a CED-2-CED-5-CED-12 ternary complex to the plasma membrane activates CED-10, leading to the cytoskeletal reorganization that occurs in the polarized extension of cell surfaces in engulfing cells and migrating cells. We suggest that CED-12 counterparts in higher organisms regulate cytoskeleton dynamics, as CED-12 does in C. elegans.

Severe mitral regurgitation due to mitral valve prolapse associated with Bland-White-Garland syndrome

Bland-White-Garland syndrome refers to the rare congenital cardiac abnormality whereby the left coronary artery arises from the pulmonary artery. The natural history of this condition is highly variable, ranging from death in early infancy to asymptomatic adult survival. It is sometimes diagnosed in adults with mitral regurgitation thought to be of ischaemic origin. We report a case of a 29-year-old man with Bland-White-Garland syndrome and concomitant mitral valve prolapse, and review the literature on the appropriate investigations and management of this abnormality. Recognition and diagnosis of this condition is important because of the potentially life-threatening complications, which may be prevented by surgical intervention.

Triploid pregnancy after ICSI of frozen testicular spermatozoa into cryopreserved human oocytes: case report

Although freezing oocytes is ethically more acceptable than cryopreservation of embryos, variable oocyte survival, fertilization rate and possible risk of increased ploidy after cryopreservation have precluded the widespread clinical application of oocyte cryopreservation in assisted reproduction techniques. We report a triploid pregnancy from intracytoplasmic sperm injection of recombinant FSH-stimulated frozen/thawed testicular spermatozoa into cryopreserved oocytes in a hormone replacement cycle. To our knowledge, this is the first report of a pregnancy where both gametes have been frozen. It illustrates the need for further research when applying new techniques in assisted reproduction.

A rare complication of PTCS: ruptured balloon with retained broken catheter

This report describes a rare situation in which a retained ruptured balloon with broken catheter was caught in an incompletely opened stent during a percutaneous transluminal coronary stenting (PTCS) procedure in a 84 year old gentleman. A short, warm heart bypass and single cross clamping coronary artery bypass grafting procedure was performed.

The ultrasound diagnosis of retained fetal bones in West African patients complaining of infertility

Prolonged retention of intrauterine bone is a recognised cause of secondary infertility. Between 1989 and 1995, eleven West African women had retained intrauterine bone as the cause of their infertility. All the women had had termination of pregnancies in their countries of origin. Transvaginal ultrasound scan detected bright intrauterine echoes suggestive of bone which was confirmed and removed at hysteroscopy. Subsequently eight women conceived spontaneously 12 pregnancies. Doctors treating West African women with infertility should be aware of this condition and include transvaginal ultrasound scan in their investigations.

Left ventricular rupture after mitral valve replacement

BACKGROUND

What are the immediate and long term outcomes of patients who had rupture of the left ventricle after mitral valve replacement?

METHODS

EXPERIMENTAL DESIGN

A retrospective study with a 20-year follow-up.

SETTING

Experience in a single tertiary referral cardiothoracic surgery hospital.

PARTICIPANTS

20 out of 3105 patients that received mitral valve replacement.

INTERVENTION

All these 20 patients received re-exploration for a trial of repair of left ventricular rupture either by an internal or an external or a combined repair.

MEASURES

Operative mortality and long term outcome of the survivals.

RESULTS

Most patients (16.80%) were female and had rheumatic mitral valve disease. The mean age of the patients was 58.1 years. All patients underwent attempted repair, usually by removal of the prosthesis and reconstitution of the ventricle from within the left atrium (75%). Thirteen (65%) patients died. Two late deaths were of unrelated cause. One surviving patient developed a late ventricular false aneurysm but did not undergo repeat surgery. One patient developed severe mitral regurgitation due to tissue failure of the bioprosthesis 12 years after surgery and she underwent a successful reoperation.

CONCLUSIONS

We believe that all patients should be placed back on cardiopulmonary bypass for an internal repair. The long term outcome of the survivals is satisfactory.

Identification and Expression Pattern of DNA Polymerase alpha Gene in a Marine Diatom, Skeletonema costatum

: To investigate the potential of DNA polymerase alpha as a marker for DNA replication in phytoplankton, two gene fragments that showed a high degree of similarity with eukaryotic DNA polymerase alpha were cloned from two strains of a diatom, Skeletonema costatum (Greville) Cleve. The gene fragments amplified with the polymerase chain reaction were 397 and 396 bp in length, respectively. The deduced amino acid sequences showed 44% to 61% similarity to the corresponding regions of DNA polymerase alpha sequences of eukaryotic organisms ranging from yeast to humans. The similarity was especially high in three evolutionarily conserved regions within the amplified fragments. Further, hybridization patterns from Southern blotting confirmed that the amplified fragments were an integral part on the genome of S. costatum. In batch cultures abundant messenger of DNA polymerase alpha appeared in the late exponential phase and the early stationary phase. This pattern suggests that DNA polymerase alpha expression is associated with actively dividing cells.

Surgical resection of pulmonary metastases

BACKGROUND

To review the results of complete surgical resection of pulmonary metastasis -- a ten-year experience.

SETTING

Retrospective analysis of all patients with lung secondaries who received complete surgical resection of pulmonary metastases (from 1984 to 1995) in Grantham Hospital, Hong Kong. Sixty patients over a 10-year period were studied.

METHODS

Eighty thoracotomies were performed with 88 tumour nodules excised. The follow-up period ranged from 5 months to 111 months.

RESULTS

Thirteen (14.8%) specimens were found to have tumour size greater than 5.0 cm. This may reflect late detection of metastatic tumour and probably accounts for the higher percentage of our patients receiving more major lung resections (63.3%) than just wedge resections (36.6%). The mean survival period for the subgroup with hepatocellular carcinoma was 28.2 months and for the nasopharyngeal carcinoma group was 25 months. The mean survival of the whole group was 26.4 months.

CONCLUSIONS

The favourable outcome for hepatocellular carcinoma and nasopharyngeal carcinoma could be due to the result of selection of patients with more favourable prognosis for surgery. The latent period, using 12 months as a break-off point, did not affect patient survival in our study.

Preclinical evaluation of drug-drug interaction potential: present status of the application of primary human hepatocytes in the evaluation of cytochrome P450 induction

Cytochrome P450 (CYP) inhibition and induction are the key mechanisms in drug-drug interactions. Aside from clinical studies, primary human hepatocytes may represent the most appropriate experimental system for the evaluation of CYP induction in humans. A consensus of an international panel on the present status and future research directions in the application of primary human hepatocytes in the evaluation of CYP-induction is presented here. The following observations are concluded to be generally true: (1) Human hepatocytes isolated from both biopsy samples and transplantable livers are suitable for induction studies. (2) Hormonally-defined media can be used for the evaluation of CYP induction. (3) Isozyme-selective induction of CYP1A and 3A by known inducers are observed. (4) Reproducibility of induction could be improved by using hepatocytes plated as confluent cultures. (5) Induction could be observed for hepatocytes treated at 1-3 days after culturing. (6) Treatment duration of 2 days in general leads to near maximal induction. (7) In general, there is a good qualitative correlation between human hepatocyte results in vitro and clinical observations in vivo. (8) When the same inducers were evaluated in independent laboratories, similar data were generally observed. We conclude that primary human hepatocytes represent an appropriate model for mechanistic evaluation of CYP induction and as a screening tool for CYP induction potential of xenobiotics. A set of data acceptance criteria are proposed: (1) Positive response should be observed with concurrent positive control chemicals; (2) reproducible observation should be observed with multiple human donors; (3) for negative response, the doses used should not be cytotoxic; and (4) replicate treatment and/or multiple dose treatment should be performed to allow statistical analysis. Future studies should include the further development of on: (1) The inducibility of CYP isozymes other than CYP1A and 3A, and phase II enzymes; (2) further development of culturing condition to allow optimal gene expression; (3) evaluation of the involvement of nonparenchymal cells on CYP induction of parenchymal cells; (4) the and validation of quantitative approaches to extrapolate in vitro data to in vivo data; (5) evaluation of possible individual variations and potential genetic polymorphism in inducibility; (6) further definition of species differences in CYP induction; (7) development of a 'normal' human hepatocyte cell line for CYP induction studies; (8) improvement of cryopreservation procedure of human hepatocytes; (9) definition of the molecular mechanisms of CYP induction; and (10) evaluation of the induction of phase II metabolic pathways.

Adolescents' and providers' perspectives on the need for and use of mental health services

PURPOSE

This study examines need for and use of services from both the adolescent's and the service provider's viewpoints.

METHODS

The Youth Services Project interviewed 792 youths from the juvenile justice, education, primary health care, and child welfare sectors (200 each); gathered anonymous tallies of the mental health of youthful clients at each sector; and conducted focus groups with providers.

RESULTS

A high percentage of youths (12-15%) met DSM-IV criteria for a mental health disorder, yet the sector clients were not identified as having mental health problems. Juvenile justice and child welfare sectors identified the highest percentage of adolescent clients as having mental health problems, and provided the most services (50-80%). The primary health care sector recorded no mental health disorders among the tallied clients, and provided the fewest mental health services (< 20%). Providers' complaints that they lacked knowledge concerning mental health assessment and lacked referral or treatment resources closely paralleled the degree to which their sector underserviced youths.

CONCLUSION

Lack of knowledge about the extent of need in adolescents, methods for assessing or treating, and referral resources handicap service providers and explain the gap between need and service.

Gene sequence and expression of an analog of proliferating cell nuclear antigen (PCNA) in the alga Tetraselmis chui and detection of the encoded protein with anti-rat PCNA monoclonal antibody

To identify a phytoplankton cell cycle marker detected by a monoclonal antibody against mammalian proliferating cell nuclear antigen (PCNA) (S. Lin, J. Chang, and E. J. Carpenter, J. Phycol. 30:449-456, 1994), a PCNA gene fragment was isolated by reverse transcription-PCR from the marine unicellular alga Tetraselmis chui Butcher (Prasinophyceae). The gene fragment was 616 bp in length and contained an open reading frame of 205 amino acids. The deduced amino acid sequence showed 80 and 88% similarity to human and rice PCNA, respectively. Southern hybridization indicated that the isolated gene fragment was part of the T. chui genome, with up to three copies in each haploid nucleus. Northern hybridization was used to detect a PCNA mRNA with a size of 1.2 kb from an exponentially growing algal culture. The T. chui gene fragment has been cloned into an expression vector, and a fusion protein was subsequently generated. Anti-rat PCNA simultaneously recognized the PCNA fusion protein and a single 33-kDa band in T.chui total protein extract. Our results indicate that T. chui PCNA is highly similar to its mammalian counterpart and that anti-rat PCNA is a good tool for detecting phytoplankton PCNA in general.

Minimally invasive surgery: video endoscopic thoracic sympathectomy for palmar hyperhidrosis

Palmar hyperhidrosis (PH) is a common disorder in Taiwan. It often causes social embarrassment and occupational handicaps. So far, there has been no satisfactory treatment for PH. In 1990, we first developed a minimally invasive technique: video endoscopic sympathectomy to treat PH. The procedure has subsequently proven to be a standard treatment for PH. In this study, a survey of 9988 cases of PH patients from 17 hospitals in Taiwan treated by this method during the past 5 years is presented. Although there were some variations in the model of anaesthesia, technique and extent of sympathectomy, the postoperative results were generally satisfactory. Both sides of sympathectomy were mostly accomplished within half an hour in one stage. The operative scars were tiny and concealed in the axillary region. The patients were discharged from the hospital after an overnight stay. Complications such as pneumothorax, haemothorax (0.3%) or Horner's syndrome (0.1%) were rare. There was no surgical mortality in this series. The most common complication was compensatory hyperhidrosis which was usually mild to moderate and tolerable after reassurance. The recurrence rate of PH was approximately 1% in the first year and less than 3% during the 3 years of follow up. Intraoperative monitoring of palmar skin temperature (PST) was advocated to confirm an adequate sympathectomy warranting a definite result. En bloc ablation of T2 segment invariably resulted in a rise of PST to about 2 degrees C and was considered as an adequate extent of sympathectomy for PH. The refined technique was extended to treat young children with PH and patients with craniofacial hyperhidrosis. The therapeutic results were generally excellent with minimal morbidity and rare recurrence. It is concluded that video endoscopic en bloc T2 sympathectomy is a simple, minimally invasive and effective treatment for both adults and children with PH and also for patients with craniofacial hyperhidrosis.

Surgical resection of pulmonary metastases from nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC), unlike other head and neck cancers,is known for its propensity for distant metastases. Chemotherapy remains the mainstay of treatment because of this and the chemosensitivity of the tumour, but long-term control is rare. The surgical management of pulmonary metastases of other extrathoracic malignancies prompted this review of surgical management of patients with NPC.

METHODS

Thirteen thoracotomies were performed in 12 patients with pulmonary metastases as the first and only site of relapse of nasopharyngeal carcinoma. Postoperative chemotherapy was given in four patients, radiotherapy to the mediastinum in one patient and both chemotherapy and radiotherapy in two patients. The survival pattern of this group of 12 patients was compared with a historical control group consisting of 65 patients without surgical resection.

RESULTS

Lymph node involvement was documented in four patients during operation. Four patients relapsed after surgical resection, two of them were from the group of three patients with lymph node involvement. The site of subsequent relapse was the lung for three patients and the skeletal system for the fourth. The 2 year actuarial survival of the surgically resected group compared favourably with the historical control group (80% and 24.1%, respectively; P=0.0002 by Mantel-Cox text).

CONCLUSIONS

Surgical resection of pulmonary metastases from NPC seems to be a promising approach thought the effect of case selection cannot be excluded and further studies are indicated. The importance of exploration and dissection of mediastinal nodes in the surgical management of pulmonary metastases from NPC was demonstrated.

Role of oral sodium phosphate and its effectiveness in large bowel preparation for out-patient colonoscopy

The aim of our study was to determine the tolerance and efficacy of oral sodium phosphate compared with polyethylene glycol electrolyte (PEG) solution on out-patient colonoscopy. Seventy-nine patients (35 male, 44 female) for elective out-patient colonoscopy were randomized to receive either PEG (GoLYTELY) solution or oral sodium phosphate (Fleet PhosphoSoda) before the procedure. Patients subsequently completed a questionnaire to assess tolerance to either regimen. The endoscopists, who were blinded to the type of bowel preparation, assessed the results in terms of residual faecal content and percentage of bowel wall visualized. Sixty-seven per cent (26) of 39 patients found Phospho-Soda easy to complete, compared with 53% (21) of 40 patients with PEG (P = 0.06). There was no statistical significance between the two groups in terms of symptomatology. Colonoscopic assessment of the Phospho-Soda group showed better cleansing compared to the PEG group at all levels of the colon (P = 0.02-0.002). Phospho-Soda is just as well tolerated as a standard PEG regimen and provides better cleansing of the bowel for colonoscopy.

Video thoracoscopic laser sympathectomy for palmar hyperhidrosis

Palmar hyperhidrosis (PH) is common in Orientals from subtropical areas. Many therapeutic modalities are used in practice, but none has proved to be entirely satisfactory. We have developed a new therapeutic technique by combining a video thoracoscopic system with a surgical laser unit (both waveguide CO2 laser and fibre-optic Nd:YAG laser). The operation was performed under general anaesthesia with alternative one-lung ventilation. With this technique, we are able to identify the sympathetic trunk on the TV screen and confirm its proper level with accurate ablation by intraoperative vasomotor monitoring. Consequently, an adequate sympathectomy can be definitely achieved through laser extirpation. We have successfully treated 300 PH patients with this technique from 1990 to 1992. The ages ranged from six to 63 years with a mean of 26.6. There were 125 males and 175 females. Most patients underwent en bloc ablation of the T2 segment which includes a major part of the T2 ganglion with its adjacent trunk which overlays the T2 rib head. All of them obtained a satisfactory relief of PH except 13 patients. The procedure did not result in a change of vital signs. There was neither obvious injury to lung nor bleeding. No Horner's syndrome was produced. The commonest complication was compensatory hyperhidrosis in various degrees encountered in about half of the cases. Two-thirds of the patients were followed up for more than 12 months and only three had recurrence. Based on our experience, the technique is considered to be a minor and safe procedure and able to achieve a definite and long-lasting therapeutic effect. It causes minimal discomfort and scarring. Particularly, the operation time and hospital stay were markedly shortened in comparison with other conventional open sympathectomy procedures.

Sjögren's syndrome with amyloid A presenting as multiple pulmonary nodules

A 29-year-old woman presented with diffuse pulmonary nodular amyloidosis and was subsequently diagnosed as having Sjögren's syndrome. We believe that this is the first case of Sjögren's syndrome presenting with secondary amyloidosis of the lung.

Are the WHO (1980) criteria for the 75 g oral glucose tolerance test appropriate for pregnant women?

OBJECTIVE

To determine the normal response to a 75 g glucose challenge in the context of an oral glucose tolerance test in the third trimester of pregnancy.

DESIGN

Prospective observational study.

SETTING

Antenatal clinic, Kandang Kerbau Hospital, Singapore.

SUBJECTS

Sixty-four normal pregnant women with a low risk for diabetes.

INTERVENTIONS

Glucose (75 g) challenge following an overnight fast after 28 weeks of gestation.

MAIN OUTCOME MEASURE

Venous plasma glucose levels taken before and 2 h after the glucose challenge.

RESULTS

Upper limits of normality were found to be fasting glucose 4.9 mmol/l and 2 h glucose 9.2 mmol/l.

CONCLUSION

The WHO (1980) criteria should not be used in pregnancy.

A double-blind, randomised, cross-over study comparing the 50g OGTT and the 75g OGTT for pregnant women in the third trimester

There is little consensus in the conduct and interpretation of the oral glucose tolerance test (OGTT) in pregnancy. In Singapore much data has been accumulated about the 50g OGTT while the converse is true of the 75g OGTT. A double-blind, randomised, crossover study of 56 subjects in the third trimester was conducted to compare both glucose challenges to determine if there was a difference in glucose handling in the context of a two hour OGTT. A significant difference (p < 0.001, t = 5.76) was found at two hours where the mean glucose concentrations were 5.2 +/- 0.8 mmol/L and 6.2 +/- 1.4 mmol/L for the 50g and 75g OGTT respectively. These findings suggest that the 75g OGTT is potentially more effective in unmasking pregnant subjects with impaired glucose tolerance.

A comparison between computerised (mean range) and clinical visual cardiotocographic assessment

OBJECTIVE

To compare computer cardiotocographic (CTG) analysis with clinical visual analysis.

DESIGN

A retrospective blind comparison of the two techniques of CTG assessment.

SETTING

Fetal Assessment Unit, King's College Hospital, London.

SUBJECTS

One hundred CTG traces of women referred to the unit were studied; the traces were taken after 32 weeks' gestation, within 10 days of delivery and where outcome was known.

INTERVENTIONS

The CTG traces were assessed both by the computer (System 8000 computerised CTG analyser, Oxford Sonicaid Ltd) and visually, by one of us.

MAIN OUTCOME

Computer mean range from 0 to 80 in ms clinical visual CTG score from 0 to 80 (arbitrary units). A score < 20 is ominous; suspicious when between 20 and 30; and normal when > 30.

RESULTS

There was close correlation between the computer mean range and clinical visual assessment (r = 0.78, n = 100, P = 0.001). However, there were 13 occasions where the computer classified the trace as abnormal when clinical visual assessment was normal, indicating computer false positives. All these pregnancies had normal outcomes. There were no traces where computer analysis was normal and clinical visual assessment abnormal.

CONCLUSIONS

Computerised CTG analysis gives an objective assessment which agrees closely with experienced visual assessment. It also provides a number which can be used to assess the value of fetal heart rate analysis.

Synthesis and anti-HIV-1 activity of 2'-"up"-fluoro analogues of active anti-AIDS nucleosides 3'-azido-3'-deoxythymidine (AZT) and 2',3'-dideoxycytidine (DDC)

1-(3-Azido-2,3-dideoxy-2-fluoro-beta-D-arabinofuranosyl)thymine (6, F-AZT) and 1-(2,3-dideoxy-2-fluoro-beta-D-threopentofuranosyl)cytosine (12, F-DDC) were synthesized from the potent antiherpes virus nucleosides 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)thymine (1, FMAU) and 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodocytosine (FIAC) in the hope that introduction of a 2-"up"-fluoro substituent might potentiate the anti-HIV activity of AZT and DDC. FMAU (1) was converted in three steps into 2,3'-anhydro-1-(2-fluoro-2-deoxy-5-O-trityl-beta-D-lyxofuranosyl)thymine (4), which when treated with NaN3 followed by detritylation afforded 6. F-DDC was prepared by two methods. Tritylation of FIAC followed by treatment of the product with thiocarbonyldimidazole afforded the 5'-O-trityl-3'-O-(imidazolyl)thiocarbonyl nucleoside 9. Upon radical reduction of 9 with Bu3SnH and AIBN, 5'-O-trityl-DDC 10 was obtained. Compound 10 was detritylated to give 12, which (when obtained by this procedure) resisted crystallization, but the diacetate 12' was obtained in crystalline form. Alternatively, FAC (14) was converted into N4,O5'-dibenzoyl derivative 15, which was treated with thiocarbonyldiimidazole. Reduction of 16 with Bu3SnH/AIBN followed by debenzoylation afforded 12, which was obtained in crystalline form. F-AZT did not exhibit any significant activity against the human immunodeficiency virus (HIV) in vitro. F-DDC, however, showed activity against HIV-1, but the therapeutic index is much inferior to that of AZT.

Unusual origins of the buccal and mylohyoid nerves

Dissection of the mandibular nerve in a cadaver of southern Chinese origin showed the mylohyoid nerve arising from the lingual nerve and the buccal nerve arising from the inferior alveolar nerve within the mandibular ramus. It is estimated that this variation in the origin of the buccal nerve occurs in 6.1% of the southern Chinese population.

Stenosis severity effects for unbalanced simple-pulsatile bifurcation flow

A numerical finite-difference analysis is made of a plane simple-pulsatile flow past a symmetrical bifurcation which contains an asymmetrical smooth-contoured stenosis in the trunk. In essence, such a situation could represent a stenosed common carotid artery immediately upstream from the carotid junction. The flow is unbalanced; two-thirds of it exits or enters through the lower branch. The effect on various flow parameters of the stenosis itself and on changes in its severity is investigated by comparing the results for a severe stenosis, a mild stenosis, and no stenosis. The simple-pulsatile forcing function is specified in terms of an oscillatory and a steady Karman number. To obtain a significant amount of backflow, the oscillatory trunk Karman number is taken as 1000 compared to the steady value of 250. The frequency of oscillation is stipulated by a trunk Stokes number of 10 pi. The numerical procedures utilize the vorticity-transport version of the Navier-Stokes governing equations. A non-orthogonal coordinate transform allows the calculations to be made in a rectangular grid where the central difference expressions are easily applied. The results are presented in terms of both kinematic and kinetic parameters. The variation in the basic kinematic variables of stream function and vorticity is shown by temporal sequences of contour plots at times of peak flow and during the flow reversal stages as well as by several velocity vector plots. Kinetic results are given in terms of the temporal variation in shear stresses along boundaries. The peak shears are found to occur at the zenith of the stenosis at times of peak flow: the value for the severe stenosis is twice as large as that for the mild stenosis. The midline pressure distribution in the trunk and the centerline pressure distributions in the branches are also included.

A study of the effects of a transversely moving boundary on plane Poiseuille flow

Numerical (finite-difference) solutions in vorticity-stream function variables using a nonorthogonal geometric transform are found for viscous flow through a plane channel in which a portion of the boundary oscillates to change the flow. Calculations were made for three rates of inflow and for three frequencies of oscillation. The boundary pumpage relative to inflow decreased with inflow Karman number and with the oscillatory period of the boundary. The maximum shear stress, as indicated by the maximum vorticity, increased with Karman number and occurred when the boundary was in the maximum stenotic position. It did not change with boundary period except for the case when the period was the smallest. The channel pressure drop was significantly affected by the pumpage as well as the boundary nonuniformity.

Specific D-glucose transport in sarcolemma vesicles

The sarcolemmal fraction prepared from rat skeletal muscle consists of osmotically active vesicles that accumulate D-glucose in preference to L-glucose, apparently by facilitated diffusion into intravesicular space. Stereospecific D-glucose uptake by these vesicles is a saturable rpocess, inhibited by phloridzin, by cytochalasin B, and by certain sugars, and enhanced by counterflow. An additional leak pathway permits entry of both D- and L-glucose into the vesicles. Stereospecific D-glucose transport by sarcolemmal vesicles is enhanced to a small extent by insulin, provided the hormone is administered prior to cell disruption. In membranes prepared from insulin-pretreated muscle, Ca2+ produces a small further enhancement. Local anesthetics preferentially inhibit stereospecific D-glucose transport. Apparent uptake of both D- and L-glucose is greater when vesicles are suspended in salt solutions rather than sucrose, an effect attributed to increased functional vesicular volume.