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.