Biomedical subjects

J N Lin

Publications and source records attributed to J N Lin.

At least 19 recordsLinked to original sources

PubMed2003

Use of parenteral testosterone prior to hypospadias surgery.

Surgical correction of genital defects was formerly proposed when the size of the penis was sufficient to permit easy surgical repair. To enlarge penile size, temporary stimulation with testosterone or dihydrotestosterone cream has been used; however, the results were not only inconsistent, but absorption was also variable. We report our experience with parenteral testosterone as an adjunct to reconstructive genital surgery in 25 patients aged 6-18 months from July 1999 to December 2000, including 8 with penile hypospadias, 15 with penoscrotal hypospadias, and 2 with perineal hypospadias. Each had a penis that was significantly smaller than usual. Testosterone enanthate 25 mg was given i.m. once per month for a total of three doses before surgical repair. Penile length and glans circumference were measured before therapy and at operation. Side effects such as the development of pubic hair and acne were monitored. Bone age was checked 1 year later. An increase in penile length (from 19.8 +/- 2.4 mm to 23.8 +/- 2.0 mm) and glans circumference (from 27.4 +/- 1.4 mm to 37.84 +/- 2.6 mm) was apparent in all except 2 patients (P < 0.001 for both, paired t-test). Four patients had a significant increase in either penile length or glans circumference after the initial dose so that no further injections were required. No definite secondary effects were found. Preoperative parenteral testosterone therapy thus causes a significant increase in penile length and glans circumference without apparent side effects. We suggest that this therapy prior to microphallic hypospadias repair is appropriate.

Humans↗

PubMed2001

99mTc-sulphur-colloid and heat-denatured 99mTc-labelled red cell scans demonstrating a giant intrapelvic spleen in a girl after splenectomy.

A 17 x 12 x 5-cm giant intrapelvic mass in a 14-year-old girl is reported. This mass developed 6 years after a splenectomy for splenic torsion. The heat-denatured 99mTc-labelled red cell scan and 99mTc-sulphur-colloid scan confirmed the specific red cell sequestration function and reticuloendothelial activity in the giant intrapelvic spleen. The size and development of the giant intrapelvic spleen are unusual. The usefulness of functional images to diagnosis the nature of the intrapelvic mass is well demonstrated.

Adolescent↗

PubMed2001

Overview of migraine.

Migraine, one of the most common incapacitating headaches, afflicts 23 million adults in the United States. There is a controversy in the literature on the theoretical perspective of migraine, the efficacy of treatment strategies, measurement, and correlates. Thus, more research is needed on these issues. A wide range of treatments is available for migraine. In addition to terminating migraine headache, appropriate migraine care includes preventing its attacks and improving patients' quality of life by administrating pharmacologic preparations in conjunction with a variety of alternative methods.

Adult↗

PubMed2001

Effect of N(G)-nitro-L-arginine methyl ester on intestinal permeability following intestinal ischemia-reperfusion injury in a rat model.

Subclinical intestinal ischemia-reperfusion injury (IRI) causes an increase in mucosal permeability and may represent an early event in the pathogenesis of necrotizing enterocolitis in premature infants. Previous studies suggested that continuous, endogenous formation of nitric oxide (NO) maintains the mucosal integrity of the intestine, thus protecting the gut from injuries from blood-borne toxins and tissue-destructive mediators. This study was undertaken to assess whether the inhibition of NO production causes an increase in intestinal permeability in rats following IRI. Sprague-Dawley rats weighing 200-300 g were divided into 4 groups: (1) untreated group (normal control); (2) ischemia-reperfusion group; (3) early N(G)-nitro-L-arginine methyl ester (L-NAME), a specific inhibitor of NO production, treatment group, and (4) late L-NAME treatment group. Transient IRI was induced by 30-min occlusion, followed by reperfusion of the isolated ileal loop. The L-NAME was administered 15 min before and after mesenteric ischemia as a 25-mg/kg bolus. Fluorescein isothiocyanate-dextran (FITC-D) was used to quantitatively assess the alteration in mucosal permeability of the intestine. There was no significant increase in the portal vein FITC-D level among normal controls, ischemia-reperfusion group and late L-NAME-treated group, but there was an approximately 6-fold increase in the early L-NAME treatment group. The pathological features of the intestine following IRI include denudation of the villus epithelium and reduction of villus height, associated with marked inflammatory cell infiltration over the lamina propria. These results suggest that endogenous NO may play a role in the protecting intestinal integrity after IRI.

Animals↗

PubMed2001

Biliary atresia at the dawn of a new century.

Biliary atresia is a unique disorder in pediatric surgery. The incidence is 1 in 3,500 to 20,000 live births, but the disorder accounts for more than half of the patients requiring liver transplantation. After Kasai operation, the 5- and 10-year survival rate without the need of transplantation are 37-48% and 18-28%, respectively. An infectious pathogen, particularly the virus, has long been implicated as the causative agent of biliary atresia, but none has ever been identified. Ductal plate malformation is likely to be important in the pathogenesis of biliary atresia. Earlier diagnosis is associated with a better prognosis and biliary atresia should be considered in the differential diagnosis of prolonged jaundice in any infants older than 2 weeks of age. The experience of the surgeon and surgical decade are determinant in achieving success of the Kasai operation. Postoperative cholangitis affects more than 45% of the patients receiving Kasai operation and the afflicted patients are at risk of cessation of bile flow and exacerbation of preexisting liver cirrhosis. Hepatic fibrosis starts at the moment when biliary atresia develops and the ongoing inflammation will end up with liver cirrhosis and hepatic failure in most patients, including some with adequate bile drainage. The inhibition of liver cirrhosis in mice or rats by gene therapy, such as telomere gene delivery, transduction with the hepatocyte growth factor gene or blockade of TGF-beta signaling, may provide a new strategy to rejuvenate the ailing liver associated with biliary atresia in the future.

Biliary Atresia↗

PubMed2001

Hepatic Schistosomiasis japonica in a patient with gallstones and bile duct stones--a case report.

Schistosomiasis, a common parasitic disease in many countries, is found as imported cases in Taiwan. Responsible for human infections are five species, one of which, Schistosoma japonicum, is currently endemic in China and South-east Asia. Chronic infection with S. japonicum may lead to the development of liver fibrosis, calcification and portal hypertension. Under investigation by sonography and computed tomography (CT) scan, a peculiar "turtle-back" appearance of liver fibrosis and calcification may be found. Herein, we report a case referred to our department due to jaundice. The sonography of liver showed typical "turtle-back" appearance. Gallstones and bile duct stones were also found in this case. Surgical interventions with percutaneous transhepatic biliary drainage (PTBD), cholecystectomy and choledocholithotomy were performed to relieve the obstructive jaundice and remove the stones. There were no parasitic eggs in the extracted stones or in drained bile juice. However, deposits of calcified S. japonicum eggs in liver parenchyma and portal tracts were identified in liver biopsy. No special treatment was given for the schistosomiasis japonica because the calcified parasitic eggs were the sequelae of past infection.

Aged↗

PubMed2000

Sonographic features related to volvulus in neonatal intestinal malrotation.

This 3 year prospective study evaluated the sensitivity and specificity of abdominal ultrasonography and color Doppler ultrasonography in 31 neonates with suspected malrotation or malrotation with volvulus. Water instillation was used to detect duodenal dilatation, edema, and malrotated bowels. Twenty patients with ultrasonographic characteristics of inversion of the superior mesenteric artery and superior mesenteric vein were later surgically proved to have malrotation. Nine of these 20 patients also had volvulus. Sonographic features suggestive of volvulus included duodenal dilation with tapering configuration (8 of 9 cases, 89%), fixed midline bowel (8 of 9 cases, 89%), whirlpool sign (8 of 9 cases, 89%), and dilation of the distal superior mesenteric vein (5 of 5 cases, 100%). The sensitivity and specificity of duodenal dilation with tapering configuration for detecting volvulus were 89% and 92%, respectively; of fixed midline bowel, 89% and 92%; of whirlpool sign, 89% and 92%; and of dilation of distal superior mesenteric vein, 56% and 73%. The results of this study indicate that ultrasonographic features of inversion of the superior mesenteric artery and superior mesenteric vein could aid in the diagnosis of malrotation, and certain sonographic features can also be used to evaluate volvulus, a condition requiring emergent operation.

Blood Flow Velocity↗

PubMed2000

Treatment and outcome of congenital diaphragmatic hernia.

BACKGROUND AND PURPOSE: Congenital diaphragmatic hernia (CDH) is a challenging condition and is associated with a high mortality rate; optimal therapy remains unclear. This retrospective study describes the clinical characteristics of treatment and outcome in 48 infants with CDH. METHODS: Twenty-eight male (58%) and 20 female (42%) infants with CDH were treated from 1987 through 1998. The goals of the ventilator strategy were permissive hypercapnea (PaCO2 < or = 55 mm Hg) and avoidance of hyperventilation. Infants were initially ventilated with an intermittent mandatory rate of 40 to 60 per minute, peak inspiratory pressure of 20 to 25 cm H2O, and positive end-expiratory pressure of 5 cm H2O. High-frequency positive pressure ventilation was used if hypoxemia or severe hypercapnea (PaCO2 > 60 mm Hg) occurred. Most infants underwent repair after 3 days of age and only four infants underwent early repair within 24 hours of birth. A prophylactic chest tube was placed in the ipsilateral hemithorax postoperatively in all patients treated before 1996. The severity of respiratory distress was estimated by alveolar-arterial oxygen difference, oxygenation index, and alveolar-arterial ratio. RESULTS: Forty-six patients presented with Bochdalek CDH, and two with Morgangni CDH. Antenatal diagnosis was made in 10 cases. Respiratory distress was the major manifestation and usually occurred immediately after birth. Six cases were diagnosed several months after birth and presented mainly with gastrointestinal symptoms. Eleven patients died before surgery and 37 patients underwent surgical repair. Two infants died postoperatively because of congestive heart failure and tension pneumothorax, respectively. The overall mortality rate was 27%. The major causes of mortality were severe respiratory failure, persistent pulmonary hypertension, pneumothorax, and associated anomalies. CONCLUSION: Nearly 75% of patients in this series survived. This suggests that noninvasive respiratory care combined with delayed surgery may be an acceptable strategy for the treatment of CDH, and can be used in most medical institutions without equipment for extracorporeal membrane oxygenation therapy.

Female↗

PubMed1999

Prenatally detected tumor mass in the adrenal gland.

BACKGROUND/PURPOSE: Screening programs using urinary vanillylmandelic acid have detected neuroblastomas in early infancy with some success. With the widespread use of ultrasonography in modern obstetric practice, use of ultrasonography to screen for fetal neuroblastoma seems to be reasonable and practical. METHODS: Seven fetuses had suprarenal masses detected by maternal ultrasound scan at 32 to 37 weeks' gestation between 1993 and 1998. They were delivered normally if the pregnancy was uncomplicated, especially if it was without maternal preeclampsia or fetal hydrops. Each mass was further confirmed by ultrasound scan, computed tomography, or magnetic resonance imaging in the neonatal period. Tumor excision was performed at the age of 6 to 38 days of life. RESULTS: The size of the masses measured ranged from 2.0x2.0 cm to 4.5x4.5 cm. The diagnosis was adrenal hemorrhage in 1 neonate, Evan's stage I neuroblastoma in 3, and stage IV-S neuroblastoma in 3. All of the specimens with a diagnosis of neuroblastoma showed a favorable histology by the Shimada classification system. Infants with stage I disease were treated with tumor excision only, and they had survived without disease by 14, 18, and 25 months of follow-up. One infant with stage IV-S neuroblastoma was treated further with minimal chemotherapy and has survived without disease at the 66-month follow-up examination. Another child with stage IV-S neuroblastoma has survived with local recurrence and increasing liver metastasis and was still on chemotherapy at the 2-month follow-up examination. The third child with stage IV-S disease presented with massive hepatomegaly and bone marrow involvement, and disseminated intravascular coagulopathy had developed. The patient died on the 5th day of life without surgical intervention. CONCLUSIONS: The increasing use of obstetric ultrasonography has made the prenatal screening of neuroblastomas possible. The prognosis of infants with a suprarenal mass may be improved with this early detection and early surgical intervention.

Adrenal Gland Neoplasms↗

PubMed1999

Repair of hypospadias complications using the tubularized, incised plate urethroplasty.

BACKGROUND/PURPOSE: Secondary procedures to correct complications after hypospadias repair remain challenging especially for "hypospadias cripples." The tubularized, incised plate urethroplasty was first introduced by Snodgrass for the repair of primary hypospadias in 1993. The authors used this procedure to correct the complications after hypospadias repair in patients who had no abundant local skin flaps to be used for a neourethra. METHODS: Six patients underwent tubularized, incised plate urethroplasty for the correction of complications of hypospadias repair performed the previous year, including a large urethrocutaneous fistula (n = 1) and disruption of the neourethra (n = 5). Prior surgical procedures included transverse island tube urethroplasty in 4 cases and 2-stage urethroplasty in 2 cases. The average patient age at the time of secondary procedure was 4.6 years (range, 1 to 12 years). RESULTS: The mean follow-up period was 6 months (range, 2 months to 1 year). All the patients obtained a functional neourethra with a vertical, slitlike meatus. A small fistula developed in one child and mild meatal retraction in another. CONCLUSIONS: The tubularized, incised plate urethroplasty offers few complications and good cosmetic results. The authors recommend its use for patients who have had repeated surgeries for hypospadias repair, especially those in whom only limited local skin flaps can be utilized for a neourethra.

Child↗

PubMed1999

Aminoguanidine attenuates hemodynamic and microcirculatory derangement in rat intestinal ischemia and reperfusion.

BACKGROUND: Nitric oxide (NO) participates in the regulation of hemodynamic and microcirculatory changes in intestinal ischemia and reperfusion (I/R). However, the nature of the involvement of an inducible NO release has been controversial. This study evaluates the impact of an inducible NO synthase inhibitor, aminoguanidine, used as a treatment in a rat intestinal I/R model. METHODS: We investigated the hemodynamics by measuring the mean arterial pressure (MAP), and the microcirculatory responses of the intestine and liver to systemically administered aminoguanidine by use of laser-Doppler flowmetry (LDF), in vivo microscopy, and flow cytometry. RESULTS: During the 30-min ischemia of the selected 20-cm ileal segment, no MAP change was noted. At reperfusion, a marked decrease of MAP was noted and the lowest levels were noted 3 hours after reperfusion (67 +/- 4% vs. 99 +/- 5% in sham-operated control animals). A marked decrease in liver perfusion as measured by LDF was noted 1 hour after reperfusion and remained low at 5 hours (72 +/- 4% vs. 97 +/- 3% in sham-operated control animals). A marked decrease in intestine perfusion was noted by using LDF 1 hour after reperfusion and remained low at 5 hours (43 +/- 3% vs. 92 +/- 4% in sham-operated control animals). The flow velocity of the postcapillary venules of the intestine was markedly decreased (1.01 +/- 0.62 vs. 2.67 +/- 0.34 mm/s in sham-operated control animals) at 5 hours after reperfusion. The flow velocity of the postsinusoidal venules of the liver was also markedly decreased (1.01 +/- 0.62% vs. 2.67 +/- 0.34% in sham-operated control animals). Leukocyte-endothelial interaction (adhesion) was increased in the postcapillary venules of the intestine (54 +/- 12 vs. 6 +/- 4/microm2 in sham-operated control animals) and in the postsinusoidal venules of the liver (32 +/- 8 vs. 2 +/- 2/microm2 in sham-operated control animals). Concomitantly, the granulocyte count was increased (9.1 +/- 0.6 vs. 2.1 +/- 0.3% of total circulating leukocytes in sham-operated control animals), with an increase of CD 11b expression. Aminoguanidine administration (1 mg/kg) 0.5 hour before ischemia and 1 hour after reperfusion significantly increased MAP, increased intestine and liver perfusion, decreased adhesion, and decreased circulating granulocytes and CD 11b expression. CONCLUSION: Inhibition of an inducible NO release by aminoguanidine in intestinal I/R can attenuate hemodynamic and microcirculatory derangement.

Animals↗

PubMed1998

Anorectal malformations--update 1998.

Anorectal malformation is a common congenital anomaly. Its correction still challenges the wisdom and expertise of the pediatric surgeon. From 1977 through 1997, approximately 400 cases of this anomaly were treated at this institution. Prior to 1985, cut-back anoplasty and translocation anoplasty were the treatments of choice for the low anomalies, and abdominoperineal pull-through anoplasty or sacroperineal anoplasty (and their modifications) preferred for the intermediate or high defects. Since 1985, posterior sagittal anorectoplasty (PSARP) has been adopted exclusively as the operative procedure for the correction of the entire spectrum of anorectal malformations. Two hundred patients have undergone this procedure either primarily (N = 166) or secondarily (N = 34). PSARP is a procedure which enables the surgeon to repair the pelvic anatomy under direct vision, maximally utilizing all the existing continence muscles and hence resulting in better fecal continence. With minimal, limited or maximal division of the continence muscles under one same skin incision, the entire spectrum of this defect can be repaired. The result of cosmesis is generally regarded as better, and the immediate postoperative complications are fewer. In spite of all efforts, 10 to 30% of patients still suffer from total fecal incontinence which is intractable to all kinds of medications and enemas. A bowel management program with large volume enemas, either through the anus or a Malone appendicostomy, retrogradely or antegradely, to wash out stool in the colon and rectum may be necessary to keep the patient clean and more socially acceptable. Biofeedback therapy offers another alternative to improve continence with the development of better computer systems and manometry equipment. This review provides a new concept of the fecal continence mechanism and an operative procedure for constructing a new anorectum based on this concept for the treatment of patients with anorectal malformations.

Anus, Imperforate↗

PubMed1997

Ultrasonographic study of the sternocleidomastoid muscle in the management of congenital muscular torticollis.

BACKGROUND: Congenital muscular torticollis (CMT) in infancy is caused by the fibrotic change of the sternocleidomastoid muscle (SCMM). The etiology and management strategies remain controversial. METHODS: One hundred ninety-seven infants and children aged 1 month to 16 years who had CMT were examined by real-time ultrasonography of the SCMM between June 1995 and September 1996 in a prospective and longitudinal study. A total of 362 examinations were performed. There were 122 boys and 75 girls. RESULTS: The right side was involved in 117 patients (59.3%), the left side in 79 patients (40.1%), and both sides in one patient. The sonographic findings were homogeneous or heterogeneous (patchy) hyperechoic lesion within the SCMM, and all were diagnostic. The ultrasonographic appearance of the SCMM in this study has a close resemblance to the clinical course of CMT. The extent of fibrosis as represented by the cross section of lesion to muscle ratio (L/M ratio) decreased from 83.6% at 2 months to 59.9% at 9 months of age and further decreased to 40% beyond 1 year of age. This consistent decrease in fibrosis was caused by the increased normal muscle volume at the periphery and by the regenerated muscle fibers within the lesion. In this series of 197 patients, 32 (16.2%) eventually underwent surgery to release the SCMM because of persistent head tilt, chin deviation and limited range of neck motion beyond 1 year of age. The L/M ratio of the operative group was 62.7 +/- 16.0% compared with an L/M ratio of 54.5 +/- 14.2% (P = .035) for the nonoperative group at 1 year of age. The extent of fibrotic change in the cross section of the muscle was a significant factor in determining prognosis. In the longitudinal section, the fibrotic change was limited to only the lower third of the SCMM in 27 patients, and all of them recovered without operation. In 95 patients, the fibrotic lesion was limited to the middle and lower third or middle third only, and only six (6.3%) underwent operation. However, in 75 cases the entire length of muscle was involved, and 26 (34.7%) required surgical release of the contracted muscle. Whole-length muscle involvement was also important for predicting recovery without operative intervention. CONCLUSIONS: Ultrasonographic study of the SCMM is not only a valuable diagnostic tool but can also serve as a useful guideline for the treatment of infants who have congenital muscular torticollis.

Adolescent↗

PubMed1997

Factors related to detection of blood flow by color Doppler ultrasonography in intussusception.

Color Doppler ultrasonography was performed in 125 patients with 134 intussusceptions. Color flow was present in 121 cases of intussusception (group A) and was absent in 13 cases (group B). Young age and duration of symptoms greater than 48 hr were significantly related to the nonvisualization of blood flow detected by color Doppler sonography (P < 0.05). The successful rate of air reduction was significantly higher in group A than in group B (109 of 121 versus 4 of 13). Color Doppler ultrasonography is useful to predict the reducibility of an intussuscepted intestine. The nonvisualization of blood flow by this method is not a contraindication for air reduction.

Adolescent↗

PubMed1996

Diagnostic value of C-reactive protein in children with perforated appendicitis.

UNLABELLED: The diagnostic value of serum C-reactive protein (CRP) levels in children with perforated appendicitis was prospectively studied in 78 consecutive patients with histologically confirmed appendicitis. The patients were divided into two groups: group A included 56 patients with perforated appendicitis and group B consisted of 22 patients with simple appendicitis. Serum CRP level and leucocyte count were assayed in all and abdominal ultrasonography was performed in 75. The mean age group A patient was significantly lower than that of group B patients (7.5 vs. 10.4 years, P < 0.001). Group A patients had a significantly higher mean serum CRP levels than group B patients (92 vs. 31 mg/l, P < 0.001), while the mean leucocyte count was comparable in the two groups. Of 75 examined patients, 73 (97%) had a pre-operative sonographic diagnosis of appendicitis. CONCLUSION: Perforation is a common complication in children with appendicitis, especially in those of young age and with prolonged pain duration. Greatly increased serum CRP levels (> or = 50 mg/l) and abdominal ultrasonography are important diagnostic aids in such patients.

Adolescent↗

PubMed1995

Photoaffinity labeling of antibodies for applications in homogeneous fluoroimmunoassays.

A homogeneous noncompetitive immunoassay based on photoaffinity labeling techniques is described. Using this method, a fluorophore (reporter) can be specifically attached to an antibody in the vicinity of its antigen-combining sites. Upon antigen binding, changes in the fluorescence spectrum of the reporter molecule are often observed. Two fluorophores, pyrene and dansyl, were evaluated for this purpose. Also, this technology is ideal for fluorescence energy-transfer immunoassays that require labeling of the antibody with either a donor or acceptor fluorophore. In such cases, a fluorescent dye can be specifically attached near the antigen-combining site, where it can participate in high-efficiency energy transfer with its complementary fluorophore attached to the antigen.

Affinity Labels↗

PubMed1995

Intestinal malrotation and midgut volvulus: a 15-year review.

The records of 54 pediatric patients with symptomatic malrotation of the intestine seen over a 15-year period from 1978 to 1992 were reviewed. Bilious vomiting and bloody stools were the two most common clinical presentations in neonates, while bilious vomiting, recurrent abdominal pain and failure to thrive were the most common symptoms after the newborn period. Obscure symptoms, usually of appreciable duration, were common in many patients beyond infancy. Upper gastrointestinal radiologic examination is the preferred and more accurate method of diagnosing malrotation as it has greater sensitivity than barium enema study. Laparotomy showed 24 cases with midgut volvulus. The incidence of midgut volvulus in symptomatic malrotation was 42.1% in the neonatal period, and 50% beyond the neonatal period. The majority of patients were treated by Ladd's operation. Massive gangrene of the small bowel due to volvulus was noted in five neonatal cases. Three patients subsequently died of this complication. Four patients developed a bowel obstruction secondary to adhesions, which was relieved by enterolysis. This study reiterates that newborns with symptomatic malrotation require emergency laparotomy in order to prevent catastrophic massive bowel resection.

Adolescent↗

PubMed1995

Pneumatic reduction of intussusception in children.

Over the past decade, pneumatic reduction has been increasingly accepted as the treatment of choice for pediatric intussusception. However the effectiveness of air compared with the more traditional barium reduction of intussusception continues to be a source of concern and debate. From August 1993 to November 1994, pneumatic reduction was used to treat 75 episodes in 73 patients with proven intussusception at Chang Gung Memorial Hospital, Taoyuan. Two patients underwent air reduction twice because of recurrence following an initial successful reduction. The recurrence rate was 3%. Successful reduction was achieved in 65/75 (87%) episodes. None of the patients experienced any complications following the procedure. In two of the 10 patients in whom reduction failed, one was subsequently found to have a Meckel's diverticulum and the other a duplication cyst as a leading point. This prospective study indicates that air enema is a safe and effective form of treatment for intussusception in infants and children. Pneumatic reduction should be the treatment of choice in the initial management of intussusception.

Child↗