PubMed Health⌕ Search

Biomedical subjects

N L Wang

Publications and source records attributed to N L Wang.

At least 37 records · Page 2Linked to original sources
PubMed1998

Prenatal and neonatal intussusception.

Intussusception found in the 1st month of life is rare and usually discussed as one entity, neonatal intussusception, but in fact, includes the intussusceptions occurring both prenatally and neonatally, of which the clinical presentations and results are different. Four full-term babies with prenatal intussusception presenting as intestinal atresia (IA) and three premature babies with neonatal intussusception mimicking necrotizing enterocolitis (NEC) are presented. Prenatal intussusception, as one of the causes of IA produces prominent signs of intestinal obstruction immediately after birth. Preoperative evaluation usually fails to yield a definitive diagnosis, but surgery is usually performed in time and is successful. In neonatal intussusception, full-term infants usually have a pathological lead point and the colon is almost always involved. A barium enema is thus useful in diagnosis. Premature babies, on the other hand, rarely have a colonic component, and the clinical features are insidious and similar to NEC. This results in diagnostic confusion that may lead to a dangerous delay in appropriate surgical correction. A high level of suspicion about this condition in cases diagnosed presumptively with NEC is important. Serial abdominal sonograms may be helpful in the early diagnosis of neonatal intussusception.

Fatal Outcome↗
PubMed1998

Is surgery necessary for primary non-refluxing megaureter?

From January 1990 to December 1995, a total of 22 patients with primary non-refluxing megaureter were treated in our hospital. The age distribution was 7 days to 8 years. The follow-up period was from 1 to 6 years. Nineteen of these 22 children underwent surgical intervention: 3 were operated upon at the time of diagnosis; the other 16 were initially treated conservatively, but underwent subsequent surgery due to impairment of renal function (13) or breakthrough infections (3). The failure rate for conservative management was about 84% (16/19): only 3 patients treated conservatively showed spontaneous resolution. The surgical success rate was 89.5% (17/19). The pathological change in the ureterovesical junction (UVJ) was adynamic in 13 cases and fibrotic in 6 (including 1 ectopic ureter). The postoperative complications were vesicoureteric reflux in 3 cases, with spontaneous resolution 6 months later, and UVJ stenosis in 1, which was resolved by reoperation. It is concluded that surgery is not necessary in every case, but still plays an important role in most cases. Early surgery can achieve good results and reduce renal damage.

Child↗
PubMed1998

Mesenchymal hamartoma of the liver: a case report.

Mesenchymal hamartoma of the liver (MHL) is a rare lesion occurring mainly in infants and children. It is often misdiagnosed clinically as a malignant tumor because of its rapid increase in size within a short period of time, or as a hepatic cyst or abscess because of its cystic appearance. Although a benign lesion, MHL may cause heart failure, due to arteriovenous shunts, or death if untreated, as a result of respiratory complications. A typical case of MHL was recently encountered in a 15-month-old boy. The patient presented with progressive abdominal distension; surgery revealed a large mass arising from the right lobe of the liver. The mass was predominantly solid, but collections of fluid were also present. Loose mesenchymal tissue and branched, tortuous bile ducts were the key diagnostic features. When predominantly cystic, MHL may mimic a lymphangioma both grossly and microscopically. Prudent examination of the cystic structures can establish a correct diagnosis.

Diagnosis, Differential↗
PubMed1994

Polyclonal antibody against a complement-activating pectin from the roots of Angelica acutiloba.

Anti-sera against a complement-activating pectin (AR-2IIb), which was purified from the roots of Angelica acutiloba Kitagawa, were obtained by immunization of rabbits, and a polyclonal anti-AR-2IIb antibody of the IgG class was purified by affinity chromatography on AR-2IIb-immobilized Sepharose and Protein G-Sepharose. Periodate oxidation of AR-2IIb significantly reduced its inhibitory activity on the reactivity of AR-2IIb to anti-AR-2IIb-IgG, but pronase digestion of AR-2IIb did not affect its inhibitory activity. Other pharmacologically active pectins from A. autiloba, Bupleurum falcatum, and Glycyrrhiza uralensis and the complement-activating pectic arabinogalactan from A. autiloba also showed significant inhibitory activities on the reactivity of AR-2IIb to anti-AR-2IIb-IgG, but these inhibitory activities were lower than that of AR-2IIb. Other pectins, polygalacturonic acid, arabinogalactan, galactan, and araban tested had negligible inhibitory activity. Endo-a-(1-->4)-polygalacturonase digestion of AR-2IIb indicated that its "ramified" region (rhamnogalacturonan core possessing neutral oligosaccharide side-chains) contained epitopes for anti-AR-2IIb-IgG, but that 2-keto-3-deoxyoctulosonic acid (KDO)-containing regions and oligogalacturonides obtained from AR-2IIb were not recognized by anti-AR-2IIb-IgG. Although carboxyl-reduction of galacturonic acid in the "ramified" region decreased the inhibitory activity of the "ramified" on its reactivity to anti-AR-2IIb, an acidic tetrasaccharide unit in the rhamnogalacturonan core had negligible inhibitory activity.

Animals↗
PubMed1994

FL-120A-D', new products related to kinamycin from Streptomyces chattanoogensis subsp. taitungensis subsp. nov. I. Taxonomy, fermentation and biological properties.

Six new kinamycin antibiotics, designated as FL-120A-D' (1-6) were isolated from the culture filtrate of Streptomyces sp. strain IY2-13. Based on its cultural, physiological, morphological and chemical characteristics, this strain was identified as a new subspecies of Streptomyces chattanoogensis and named S. chattanoogensis subsp. taitungensis. These kinamycins have demonstrated a potent activity against Gram-positive aerobic and anaerobic bacteria.

Animals↗
PubMed1994

[A randomized controlled study of the anti-cicatricial effect of preoperative subconjunctival triamcinolone on the filtering bleb].

A randomized controlled study of the anticicatricial effect of preoperative subconjunctival triamcinolone acetonide (TA) on the filtering bleb in 89 eyes (61 cases) of refractory glaucoma showed that the rates of surgical success in the TA groups were 77.3-89.0% and that in the control group 48.0%. The varying dosages of TA produced insignificant differences; however, the proportional distribution of the types of filtering blebs differed significantly among the various dosage groups, and complications occurred mostly in the high dosage group of 12 mg. The study indicated that TA raised the surgical efficacy in treating refractory glaucoma and the dosages of choice were 4-8mg.

Adult↗
PubMed1992

Conservative treatment of neonatal hydronephrosis.

From February 1990 to January 1991, 19 cases of hydronephrosis in children of less than one year of age were managed at Mackay Memorial Hospital. In the majority of these patients, there were evident causes such as ureteropelvic junction stenosis, ureterovesical reflux or a posterior urethral valve for which definite therapeutic measures were performed. However, some cases had no obvious origins and the hydronephrosis was speculated to be from nonobstructive or physiologic dilatation of the kidneys. The conventional tools, such as intravenous pyelogram or renal ultrasound, which comprise the mainstay of diagnosis, provide limited information on renal functional status. Recent introduction of the Tc-99m diethylene triamine penta-acetic acid (DTPA) diuretic renal scan has enabled us to distinguish between obstructive and nonobstructive hydronephrosis and helps us to determine whether or not surgery is necessary. In the past year, eight patients with hydronephrosis of less than one year of age were diagnosed as nonobstructive after a series of evaluations using renal ultrasound, voiding cystourethrography (VCUG) and Tc-99m DTPA diuretic renal scan. Follow-up studies by echography or DTPA renal scan revealed spontaneous resolution of the dilated collecting systems in these cases and confirms our belief that some hydronephrosis in neonates and infants may resolve spontaneously and may just be a manifestation of physiologic change during development. The value of the Tc-99m DTPA diuretic renal scan in the diagnosis of obstructive uropathy is discussed.

Female↗
PubMed1979

[Studies on staphylococcal enterotoxin B. III. Purification with absorbents].

The biological and immunological activities of Staphylococcal enterotoxin B are stable in pH 2.0 approximately 11.0, and also resistant to proteolytic enzyme (trypsin, pepsin) digestion for 3 approximate 4 hours. Therefore, the toxin could be purified with trypsin digest and then absorbed on kaolin and Kieselgel, followed by eluting the different pH buffer solutions. Further purifications was chromatographied on CM-Sephadex column.

Absorption↗
PubMed1978

[Studies on staphylococcal enterotoxin B. 1. Quantitative assay by capillary tube single diffusion test (author's transl)].

A method for rapidly identifying and quantitating small amount of staphylococcal enterotoxin B was developed on capillary tube single diffusion test. The high sensitivity of method has the advantages to save antiserum and incubation period. Some factors such as concentration of antigen and antiserum, incubation temperature, buffer systems, and position of capillary tube all might affect the test accuracy. If all those affecting factors were concerned, the toxin would probably be standardized. The most accessible quantitative estimation was accomplished by means of (1) plotting a precipitation curve from the different concentrations of standardized staphylococcal enterotoxin B; (2) the sample to be test was diluted by serial two-fold method with the same buffer system; (3) select suitable 3--5 dilutions to perform capillary tube diffusion test, taking the values of precipitation bands as abcissa and sample dilutions as longitudinal axis, rendered the precipitation curve of sample exquisitely paralled to that of the standard; (4) calibrate the figure values of sample exactly on the precipitation curve, and reading the toxin content of specimen to be tested from standard curve.

Enterotoxins↗
PubMed1978

[Studies on staphylococcal enterotoxin B. II. Production and regulation (author's transl)].

Enterotoxigenic strain of Staphylococcus aureus (ATCC 14458) was grown under various conditions with constant shaking to determine the requirements for maximum toxin production. It was evident that 3% tryptic soy broth, 3% NZ-Amine NAK + 3% casein hydrolysate, 3% NZ-Amine NAK + 1% yeast extract, and 3% NZ-Amine NAK + 1% yeast extract + 0.2% glucose are most available toxin production media. But concentration of glucose could strictly triggered the enterotoxin producing efficiency. When glucose concentration was less than 0.5%, although with higher yield, the toxin production was delayed for certain period of time. However, if glucose concentration was up to more than 0.5%, the enterotoxin production was almost inhibited. Some metabolites of glucose to elucidate the inhibitory effect have also investigated. Our results indicated that glycerol and citric acid inhibited the toxin production directly, while the inhibitory effect of lactic acid and acetic acid were due to those acidic metabolites, decreased the pH value of media, and adversely suppressed the bacterial growth.

Culture Media↗
PubMedDate not supplied

Inhibition of the dopamine system in rat amygdala attenuates the picrotoxin-induced locomoter hyperactivity and hypertension.

The aim of the present study was to investigate whether picrotoxin-induced locomotor hyperactivity and hypertension can be inhibited by dopaminergic inhibition in rat amygdala. Locomotor activity was detected using a modularized infrared light matrix system in freely moving rats. In anaesthetized rats, blood pressure was measured while dopamine release was detected using in vivo voltammetry with carbon fibre electrodes. Systemic administration of picrotoxin (1-4 mg/kg) increased both locomotor activity (including horizontal motion, vertical motion and total distance travelled) and the number of turnings (both clockwise and anticlockwise), but inhibited postural freezing. The locomotor hyperactivity induced by systemic administration of picrotoxin was mimicked by direct injection of a small dose (1-3 micro g in 1.0 micro L) of picrotoxin into the amygdala. In vivo voltammetry data revealed that systemic administration of picrotoxin increased the release of dopamine in the amygdala of rat brain accompanied by hypertension. Local injection of kainic acid into the paramedian reticular nucleus (PRN) of the medulla oblongata decreased both the spontaneous release of dopamine in the amygdala and spontaneous levels of locomotor activity in rats. Furthermore, the picrotoxin-induced locomotor hyperactivity, hypertension and increased amygdaloid dopamine release were all suppressed following chemical stimulation of the PRN with kainic acid. Blockade of dopamine receptors with systemic or intra-amygdaloid injection of haloperidol (a dopamine receptor antagonist) significantly attenuated the picrotoxin-induced locomotor hyperactivity and hypertension. These results demonstrate that picrotoxin-induced hyperactivity and hypertension involve an increase in amygdaloid dopamine transmission that can be modulated by ascending projections from the PRN in the medulla oblongata.

Amygdala↗
PubMedDate not supplied

The stage I yolk sac tumor of testis in children younger than 2 years, chemotherapy or not?

Yolk sac tumor is the most frequent germ cell tumor of testis in children. For stage I yolk sac tumor of testis in children younger than 2 years, high inguinal orchiectomy alone has been the standard treatment, with a cure rate of at least 75%. Here, we compare the treatment results of receiving chemotherapy or no chemotherapy after orchiectomy, to analyze the role of chemotherapy. From February 1987 to January 1997, 22 children younger than 2 years, with stage I yolk sac tumor of testis, were included in the study. All patients had high inguinal orchiectomy without retroperitoneal lymphadenectomy. Initial diagnostic imaging studies included computed tomographic scan of abdomen, chest radiography, and long bone survey. Clinical stage I was defined as a tumor completely resected with no evidence of local regional lymph node involvement or distant metastases. Serum alpha-fetoprotein (AFP) was assessed at diagnosis. After orchiectomy, diagnosis, and staging, patients were stratified into two treatment groups, with or without chemotherapy, according to the decision of the parents. Ten children received chemotherapy consisting of cisplatin, vinblastine, and bleomycin (PVB, modified "Einhorn regimen") for 12 weeks. The remaining 12 patients were followed up according to a "wait and see" policy. Determination of AFP was performed monthly during the first postoperative year, every other month during the second year, every 3 months during the third year, every 6 months during the fourth year, and yearly until the fifth postoperative year at least. The duration of follow-up ranged from 3 months to 119 months (median, 53 months). The Kaplan-Meier plot estimated an overall survival rate of 91.6% at 7 years after diagnosis. Among the 12 patients without chemotherapy, 2 children had relapses at 4 and 6 months after diagnosis, respectively. One was cured with PVB chemotherapy. The other patient died with refractory lung metastasis, in spite of intensive multimodality salvage therapy. The Kaplan-Meier plot showed a survival rate of 80% at 7 years and a relapse-free survival rate of 81.8% at 5 years after diagnosis. All children receiving chemotherapy were alive and free from relapse. There was no significant treatment-related toxicity. Our results may suggest that PVB chemotherapy after orchiectomy is an affective and safe regimen for stage I yolk sac tumor of testis in children younger than 2 years. Instead of four courses of PVB as used here, two or three courses could be enough. To elucidate the necessity for chemotherapy and to determine the number of courses of PVB needed (if chemotherapy is given), a randomized study of more cases is warranted.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

The management of anorectal malformations.

From 1982 to 1990, 120 cases of anorectal malformation (84 males and 36 females) were admitted to Mackay Memorial Hospital; 101 cases were corrected surgically. Among these, 40 cases were high (H) or intermediate (I) type, and 61 cases were low (L) type. In the 40 cases of the H and I type, 13 (Group 1) received Stephens' procedure (SPR) and the remaining 27 (Group 2) received Peña's procedure (PSARP). For the L type, translocation anoplasty, cut-back anoplasty and limited PSARP were employed in 10, 45 and 6 cases, respectively. Anorectal continence results were evaluated by Kiesewetter's criteria. In Group 1, the results were good in 25%, fair in 17% and poor in 58%. In Group 2, the results were good in 70% and fair in 30%. In addition to better anorectal continence, the PSARP resulted in a lower rate of major complications. In the L type, the results were excellent without significant difference among the types of surgery employed.

Anal Canal↗
PubMedDate not supplied

Torticollis: a long-term follow-up study.

To achieve better guidelines for the future management of torticollis, this study analyzed surgical and nonsurgical management of 253 torticollis patients who were treated in this hospital from 1971 to 1993. Of those, 37 cases received operation only, 78 cases were operated after failed physical therapy, and 138 cases were treated only at the Rehabilitation Department. If free neck movement was considered to be the primary goal of treatment, most parents were satisfied with the results. However, if facial and skull deformities were the serious sequelae of torticollis, then only less than half of the surgical and nonsurgical groups of patients were graded as normal. Further, 10.9% of physical therapy group and 7% of the surgical patients need further operation to release the fibrotic bundle which limited their neck movement. Therefore, it is suggested that torticollis treatment should include early interventions such as adjusting sleep position, careful planning of physical therapy and/or operation and a long term follow-up period as essential for better management of torticollis.

Child↗