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Biomedical subjects

C N Lee

Publications and source records attributed to C N Lee.

161 records · Page 9Linked to original sources
PubMed1986

Sclerosing haemangioma in Singapore.

The Singapore experience with 11 cases of sclerosing haemangioma of lung seen from 1970-1984 is analysed. There is female preponderance (9/11) and the majority (8/11) were asymptomatic. Seven patients were treated by wedge resection and 4 had lobectomies. Microscopically, the lesion had variegated growth pattern with characteristic polygonal cells present in the stroma. All patients were well after surgery. The longest follow-up period is 7 years with no recurrence seen. This is an unusual, distinctive and benign entity which should be distinguished from other inflammatory conditions in the lung.

Adolescent↗
PubMed1985

Changes of luteinizing hormone and progesterone for dairy cows after gonadotropin-releasing hormone at first postpartum breeding.

Gonadotropin-releasing hormone administered at breeding enhances fertility of dairy cows, so a study was designed to evaluate the mechanism for enhanced fertility following administration of gonadotropin-releasing hormone at first postpartum breeding. Twenty-four cows were assigned randomly to one of two treatments, 100 micrograms of gonadotropin-releasing hormone intramuscular or saline vehicle intramuscular at insemination. Blood samples for luteinizing hormone assay were taken at 2-h intervals prior to breeding and .5-h intervals for 3 h after insemination. Composite morning milk samples for progesterone assay were collected for 30 days after insemination or until next estrus. Cows given gonadotropin-releasing hormone had higher luteinizing hormone concentrations in blood serum following treatment than cows given saline, 13.2 versus 3.0 ng/ml. There was no relationship between luteinizing hormone and subsequent conception. Progesterone for cows that became pregnant was higher throughout sampling days. Mean progesterone concentrations were 4.6 versus 2.2 ng/ml in pregnant and nonpregnant cows during the first 4 days after insemination. Cows treated with gonadotropin-releasing hormone that conceived had higher progesterone than other cows, and that was evident at the first 4 days postbreeding.

Animals↗
PubMed1985

Surgical treatment of double-orifice mitral valve in atrioventricular canal defects. Experience in 25 patients.

Double-orifice mitral valve is an uncommon but surgically important condition. The experience in 25 cases of double-orifice mitral valve associated with atrioventricular canal defects was reviewed. This constituted 4.3% of the 581 cases of atrioventricular canal defects operated upon between 1961 and July, 1984. The combined mitral orifice area ranged from 85% to 91% of normal in those patients whose valves were sized intraoperatively. Ten associated cardiac defects were repaired in six patients. Of 23 patients having cleft mitral valve, 21 had partial closure of the cleft. There was one operative death (4.0%), which occurred early in the series in a patient in whom the tissue bridge was severed and massive mitral regurgitation resulted. In the remaining 24 patients the tissue bridge was left intact, and all survived operation. No patient had clinically significant mitral stenosis during a follow-up of 1 to 14 years (mean 4.9 years). Two patients (8%) developed progressive mitral regurgitation and required mitral valve replacement 3 and 11 years postoperatively. One of these patients died and a second death occurred suddenly 2 years following operation. All survivors are in Functional Class I or II. The noncleft orifice of a double-orifice mitral valve usually is competent and rarely requires closure. The cleft, because it constitutes a type of parachute (single papillary muscle) valve, should be closed partially so as to relieve valve incompetence without causing undue stenosis. The incidence of late development of mitral regurgitation is similar to that of atrioventricular canal without double-orifice mitral valve. Repair of atrioventricular canal associated with double-orifice mitral valve can be achieved with a low operative mortality and excellent late results.

Adolescent↗
PubMed1985

The role of fibreoptic bronchoscopy in the management of respiratory burns.

We found that fibreoptic bronchoscopy was a useful, simple, safe and accurate method in the diagnosis of inhalation injury, determining the type, the site and the extent of damage sustained. The most common mucosal damage was erythema and oedema of the supraglottic and glottic tissues, though in a few cases more severe and extensive injury was seen. Death seemed to be determined largely by the extent of skin burn but since there did not appear to be a close relationship between the severity of skin burn and the presence of inhalation burn, we suggest that the two types of injuries be evaluated separately. The main therapeutic role lies in the assessment and anticipation of imminent upper airway obstruction caused by oedema of the supraglottic tissues and the glottis. Endotracheal intubation could then be carried out promptly. Changes in clinical features and laboratory results were too slow to be of use in the prediction of upper airway obstruction, but could be indirect indicators of lower and peripheral airway injury.

Adolescent↗
PubMed1984

Concentrations and composition of glycosaminoglycans in the female bovine reproductive tract.

Our objective was to isolate glycosaminoglycans from various regions of the female bovine reproductive tract to ascertain their concentrations and composition. Oviducts, uterine horns, and cervices from 104 female bovine reproductive tracts obtained at slaughter were flushed with 5 ml phosphate buffered saline. Following proteolysis, glycosaminoglycans were isolated by alcoholic precipitation, and concentrations were quantitated by high performance liquid chromatography. Concentrations of glycosaminoglycans decreased significantly anterior to the cervix. There was an increase of chondroitin sulfates and heparin-like material in estrual cervical mucus compared with cervical mucus collected during the luteal phase of the estrous cycle.

Animals↗
PubMed1983

Efficacy of gonadotropin-releasing hormone administered at the time of artificial insemination of heifers and postpartum and repeat breeder dairy cows.

The efficacy of gonadotropin releasing hormone (GnRH) on the fertility of dairy heifers and postpartum cows was studied. In one study, 300 cows were assigned randomly to 1 treatment from a 2 X 2 design, and 2 ml of 0.15M saline solution or 100 micrograms of GnRH was given IM on postpartum day (PPD) 14 and at the time of 1st postpartum breeding. In a 2nd study, repeat breeder cows (n = 346) were given saline solution or GnRH at the time of the 3rd breeding. In a 3rd study, heifers (n = 185) were given saline solution or GnRH at 1st breeding. Animals were observed for repeat estrus, and pregnancy diagnoses were made by rectal palpation 45 to 60 days after breeding. Conception rates were 15% to 18% higher for cows given GnRH, whether at PPD 14 or at the first postpartum breeding. When GnRH was given at the first breeding, conception rates were significantly higher (P less than 0.05). Conception rates for repeat breeder cows given GnRH were 25% higher than those in controls (P less than 0.005). Conception rates for heifers did not differ between treatments.

Animals↗
PubMed1980

An improved ultrafiltration method for free thyroxine and triiodothyronine in serum.

We describe an ultrafiltration technique for rapidly and directly determining free triiodothyronine or free thyroxine, or both. After equilibrating serum at 37 degrees C with purified tracer of high specific activity, we placed 0.15 mL of serum in 2.8 mL of phosphate buffer (0.1 mol/L, pH 7.4) in the ultrafiltration cell and obtained successive 0.2- and 0.6-mL fractions of protein-free ultrafiltrate. Under our conditions free ligand concentration was independent of flow rate. After purifying the second fraction with protein-coated charcoal, we could determine the proportion of free triiodothyronine or free thyroxine. Samples from normal adult men and women, including women who were taking oral contraceptives or were pregnant, and from hypo- and hyperthyroid patients gave results that agreed with those obtained by equilibrium dialysis. Speed is the main advantage of the method: one technologist can complete the procedure in 2 h and, using a multi-micro-ultrafiltration system, can process many samples in one day. For laboratories where index-type reactions are performed routinely and direct free triiodothyronine or free thyroxine is determined only on selected specimens, this method is superior to dialysis. It is also very convenient for rapidly purifying tracers, to at least 97% radiochemical purity, with 94% recovery and no dilution.

Dialysis↗
PubMedDate not supplied

Coronary artery bypass grafting in patients with left main coronary artery stenosis. Improved survival in a predominantly Oriental population.

Over the last 10 years, there has been a reduction of surgical mortality in coronary bypass grafting for left main coronary artery disease. Most of the available literature reports are of Caucasian populations. We report our experience of the surgical treatment of this disease in a predominantly Oriental population. From 1 January 1987 to 30 June 1991, 86 consecutive patients had coronary artery bypass surgery for left main stenosis. There were 65 men and 21 women with an age range of 34 to 80 years (mean age: 58 years SD +/- 8.63). There were no operative deaths and 1 hospital death (1.2%) from a non-cardiac cause. The perioperative myocardial infarction rate was 3.5% (3/86). These results are better than some earlier series in which hospital mortality was reported as high as 12.6% and the preoperative myocardial infarction rate 11.8%. In this series where the patients are predominantly Oriental, the results are comparable if not better than in series reported in centres where the population is predominantly Caucasian.

Age Factors↗
PubMedDate not supplied

Fibronectin levels in normal pregnancy and preeclampsia.

Vascular endothelial damage is reported to be the prime cause of preeclampsia, and elevated levels of fibronectin have been found before clinical signs of preeclampsia were manifested. The total plasma fibronectin concentrations in 212 blood samples from 173 normotensive healthy pregnant women at various gestational ages were measured. Fibronectin levels were also determined for 20 blood samples from 20 preeclamptic patients obtained at the time of clinical manifestation of preeclampsia. Blood samples from 46 non pregnant women of reproductive age were used as controls. The results showed that the total plasma fibronectin concentration during reproductive age was independent of age and the average level during pregnancy decreased with gestational age. Preeclamptic patients had a significantly elevated level of total fibronectin compared with healthy pregnant women. The total fibronectin concentration is a promising biochemical marker for preeclampsia, but a more specific endothelial method of measurement is needed before it is put to clinical use.

Adult↗
PubMedDate not supplied

Rotavirus gastroenteritis associated with afebrile seizure in childhood.

From September 1994 to April 1995, we encountered eight children, two boys and six girls, (aged 1 year 6 months to 9 years), presented with acute diarrhea followed by afebrile, generalized tonic-clonic seizures, or transient loss of consciousness with urine incontinence. Their biochemical data, including serum electrolyte levels, were within normal limits. The infective agent causing diarrhea was later proved by stool examination to be rotavirus, judged to be serotype G1 by reverse transcription - polymerase chain reaction (RT-PCR) typing. Cerebrospinal fluid (CSF) examinations performed in seven of the eight patients were within normal limits, and cultures for bacteria and virus were negative. The electroencephalograms (EEGs) performed from 1 to 13 days after seizure showed abnormal in six, and normal in two, patients. Follow-up EEGs, performed from 4 to 11 months after onset of seizure, were all normal. None had seizure recurrence despite the fact that no long-term anticonvulsant had been given. From observation here, the authors emphasize that there is a close relationship between rotavirus and afebrile seizure, and the course of afebrile seizure following rotavirus gastroenteritis is usually benign. Further studies are needed to elucidate the underlying pathogenesis.

Child↗
PubMedDate not supplied

Betel nut and smoking. Are they both protective in ulcerative colitis? A pilot study.

Two-hundred and twenty-three Asian patients with inflammatory bowel disease were sent a questionnaire about smoking and betel nut chewing habits. The 116 responses from patients with ulcerative colitis were compared with answers from 79 healthy members of the community. Twelve per cent of male patients were currently smokers compared with 31% of healthy controls (chi 2 = 20.9 P < 0.05). No such differences existed between female patients and controls. Thirteen per cent of male patients regularly used betel nut compared with 20% (chi 2 = 3.9 P < 0.05). Both smoking and betel nut chewing appear to reduce the risk of developing ulcerative colitis, although these effects may be linked.

Adult↗
PubMedDate not supplied

Identification of VP7 serotypes of human rotaviruses by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction.

Serotype specificity of human rotaviruses in Taiwan remained unclear. This study has established three methods for identification of G serotypes, fluorescent focus neutralization test (FFN), enzyme-linked immunosorbent assay by incorporating VP7 (G) serotype-specific monoclonal antibodies (ELISA-MAb) and reverse transcription-polymerase chain reaction (RT-PCR). FFN is a reference standard test for determination of G serotype. RT-PCR and ELISA-MAb were used for serotyping of rotavirus isolates and appeared to be accurate and more sensitive than FFN. Nevertheless, for serotyping the rotaviruses present in clinical stool samples, ELISA-MAb was not satisfactory, only 65.5% of the 264 specimens could be serotyped. The sensitivity of serotype prediction by RT-PCR was 89.4%. When both ELISA-MAb and RT-PCR were taken into account, G serotype could be predicted for 93.2% of the specimens. Serotyping results were comparable with the RNA profiles. Rotaviruses with similar RNA electrophoretic pattern had the same serotype specificity. RNA patterns could be used as a reference for prediction of serotypes. Because ELISA is easy to perform and less expensive, it would be suggested as a screening test. RT-PCR could be used for samples which could not be serotyped by ELISA-MAb. Furthermore, RT-PCR is especially valuable when serotype-specific monoclonal antibodies are not available.

Antigens, Viral↗