Biomedical subjects

Akira Okada

Publications and source records attributed to Akira Okada.

At least 19 recordsLinked to original sources

PubMed2006

One-trocar laparoscopy-aided gastrostomy in handicapped children.

BACKGROUND/PURPOSE: Percutaneous endoscopic gastrostomy has become a common technique to provide nutritional support to handicapped children with swallowing disorders; however, this technique is sometimes associated with serious complications. We report a novel method of 1-trocar laparoscopy-aided gastrostomy with special reference to its influence on gastroesophageal reflux (GER). METHODS: The subjects consisted of 22 profoundly handicapped children, aged from 1 to 14 years (median, 7 years). Twenty-four-hour esophageal pH monitoring was conducted preoperatively in all subjects and performed postoperatively in 12. The criteria for gastrostomy alone included no significant symptoms related to GER and distal esophageal acid exposure of less than 15%. Esophageal acid exposure was evaluated at the distal esophagus (P1) and at 10 cm proximal to P1 (P2). Stamm gastrostomy was performed by grasping the anterior gastric wall with forceps inserted through an operating channel associated with a laparoscope. Data are expressed as medians and ranges. RESULTS: There were neither perioperative mortality nor life-threatening complications except the detachment of the gastrostomy in one. Esophageal acid exposure was significantly increased postoperatively compared to preoperatively at P1 (2.1% [0.0%-4.7%] vs 4.6% [0.2%-8.7%], P = .02), but did not change much at P2 (0.2% [0.0%-1.5%] vs 0.8% [0.0%-7.6%], P = .07). No patient developed postoperative symptoms related to GER. CONCLUSIONS: One-trocar laparoscopy-aided gastrostomy is a feasible technique for handicapped children without symptomatic GER.

Adolescent↗

PubMed2006

Cow's milk protein allergy presenting with Hirschsprung's disease-mimicking symptoms.

BACKGROUND: Pediatric surgeons often encounter neonates who present with Hirschsprung's disease (HD)-like symptoms and plain x-ray findings, but respond well to conservative treatment. During our investigation of the etiology of this condition, which we named "benign transient nonorganic ileus of neonates" (BTNIN), we noticed that BTNIN included cases of cow's milk allergy (CMA). Therefore, a prospective study of the identity of BTNIN and CMA was conducted. METHODS: Cow's milk allergy was diagnosed when a baby showed HD-like symptoms after oral feeding, and a drug-induced lymphocyte stimulation test was positive for cow's milk with a titer of more than 300%. MATERIALS: Of 38 neonates with suspected HD, a surgical disorder was excluded by plain x-ray in 9, intestinal atresia was diagnosed in 3, and the remaining 26 were enrolled in this study. RESULTS: Of 26 cases, 9 were diagnosed as HD by manometric studies and 17 as CMA. Thirteen of 17 CMA cases had been fed with breast milk and 4 with formula milk. CONCLUSION: The proportion of CMA in the cases presenting with HD-like symptoms in the neonatal period is much higher than what we expected, and most cases of BTNIN are caused by CMA. If HD is ruled out, CMA should be considered.

Diagnosis, Differential↗

PubMed2005

Cow's milk allergy presenting Hirschsprung's disease-mimicking symptoms.

The authors present a neonatal case of allergic colitis, which manifested the difficulty of spontaneous defecation and irregular narrowing of distal rectum in contrast enema. Rectal suction biopsy showed positive acetylcholinesterase activity. These clinical, radiological and histological findings were indistinguishable from Hirschsprung's disease. Gastrointestinal symptoms were improved by the cessation of cow's milk formula. The present findings may impact on the less recognizable gastrointestinal manifestation of allergic colitis.

Animals↗

PubMed2005

Recurrent acute pancreatitis caused by malrotation of the intestine and effective treatment with laparoscopic Ladd's procedure.

We herein report a rare case of recurrent pancreatitis caused by malrotation of the intestine. Since the age of 10 years, a female patient showed recurrent epigastralgia and was diagnosed at age 16 years as suffering from acute pancreatitis. Upper gastrointestinal series showed that the duodenal bulb was elongated and rotated caudally. Endoscopic retrograde cholangiopancreatography showed that the descending portion of the duodenum was rotated and occluded the papilla of Vater. Under laparoscopy, the duodenal bulb was tracted caudally by the Ladd's ligament. By incision of this ligament, the entire duodenum was mobilized, with subsequent reduction of the rotation and compression of the pancreatic head. The girl's postoperative course was uneventful, and she has been asymptomatic for the last 3 years. In conclusion, malrotation of the intestine may be a rare cause of recurrent pancreatitis, and laparoscopic Ladd's procedure may be a less invasive and useful treatment.

Acute Disease↗

PubMed2005

Intentional limited resection for small peripheral lung cancer based on intraoperative pathologic exploration.

OBJECTIVE: The aim of this study was to assess the adequacy of our intentional limited resection for small peripheral lung cancer based on intraoperative pathologic exploration. METHODS: Patients who had stage IA non-small cell lung cancer (NSCLC) with a maximum tumor diameter of 2 cm or less were candidates for limited resection. If bronchioloalveolar carcinoma (BAC) was suspected on computed tomography and intraoperative pathologic exploration revealed the lesion as BAC without foci of active fibroblastic proliferation (Noguchi type A and B), wedge resection was performed. If the tumor was not suspected of being Noguchi type A or B, extended segmentectomy with intraoperative lymph node exploration was performed. RESULTS: Limited resection was performed in 34 patients, wedge resection in 14, and extended segmentectomy in 20. The median follow-up period after wedge resection was 36 months, and all patients are alive with no signs of recurrence. The median follow-up period after extended segmentectomy was 54 months. No local recurrences were found, but distant metastasis was diagnosed in one patient. The 5-year survival rate after extended segmentectomy was 93%. In the same period, lobectomy was performed in 57 patients with stage IA NSCLC with a maximum tumor diameter of 2 cm or less, and the 5-year survival rate was 84%. There were no significant differences in 5-year survival between extended segmentectomy and lobectomy. CONCLUSIONS: Careful selection of patients based on high-resolution computed tomography findings and intraoperative pathologic exploration makes intentional limited resection an acceptable option for the treatment of small peripheral NSCLC.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed2005

Endoscopic membranectomy with a high-frequency-wave snare/cutter for membranous stenosis in the upper gastrointestinal tract.

BACKGROUND/PURPOSE: As endoscopic equipment and instruments have been improved, the indication for endoscopic surgery has been extended. The authors achieved endoscopic membranectomy for congenital membranous stenosis in the upper gastrointestinal tract. METHODS: Case 1 was a 3-year-old girl with membranous stenosis in the descending duodenum. Case 2 was a 1-year-old boy with esophageal membranous stenosis. In case 1, a flexible endoscope with a banding chamber, the inside of which had a tiny groove for a high-frequency-wave snare, was inserted into the duodenum. The diaphragm was drawn into the chamber by endoscopic suction and tied with the snare around its base, then dissected by electrifying the snare. In case 2, the diaphragm was resected with a high-frequency-wave cutter, assisted by a balloon catheter pulling up the diaphragm from the distal side. RESULTS: In both cases, the stenosis was released adequately without complications, and oral feeding was restarted in a day after the procedure. CONCLUSIONS: Endoscopic membranectomy using a high-frequency wave snare/cutter was achieved safely and effectively in 2 children with congenital membranous stenosis in the upper gastrointestinal tract.

Child, Preschool↗

PubMed2005

Laparoscopically assisted anorectoplasty using perineal ultrasonographic guide: a preliminary report.

BACKGROUND/PURPOSE: As minimal invasive surgery, laparoscopically assisted anorectal pull-through has been reported with new devices. However, it is not easy to create an accurate pull-through canal (PTC) because of the narrow space between the urethra and puborectal sling. The authors describe a new method using perineal ultrasonography. METHODS: The rectourethral prostatic fistula was dissected laparoscopically. Externally, electrostimulation identified the center of the muscle contraction, over which a 1.2-cm skin incision was made, and the lower part of PTC was created by hemostat forceps guided by electrostimulation. An ultrasonographic probe applied to the perineum demonstrated the urethra, and the forceps was advanced behind the urethra into the pelvic cavity using the ultrasonographic guide. Anorectal pull-through was performed after dilatation of the PTC with dilators. RESULTS: The authors applied this procedure in 5 cases of male high and intermediate anomalies. Surgical damages to the urethra and the levator and vertical muscles were not encountered. Postoperative fluoroscopic study demonstrated good anterior angulation and intact contraction and relaxation of those muscles. CONCLUSION: The combination of laparoscopic dissection, pinpointing the center of anal sphincter by electrostimulation, and identification of the urethra by ultrasonographic images from the perineum facilitated creation of appropriate PTC in the muscle complex.

Anal Canal↗

PubMed2005

Medical treatment of infantile hypertrophic pyloric stenosis: should we always slice the "olive"?

BACKGROUND/PURPOSE: Laparoscopic pyloromyotomy has recently gained wide acceptance as the optimum treatment of infantile hypertrophic pyloric stenosis (IHPS). However, medical treatment may be superior to laparoscopic surgery in invasiveness. The efficacy of our regimen of intravenous atropine therapy for IHPS was assessed in comparison with surgical treatment. METHODS: Medical treatment was initially chosen for 52 (61%) of 85 infants with IHPS at our institute between 1996 and 2004. Atropine was given intravenously at 0.01 mg/kg 6 times a day before feeding. When vomiting ceased and the infants were able to ingest 150 mL/kg per day of formula after stepwise increases in the feeding volume, they were given 0.02 mg/kg atropine 6 times a day orally, and the dose was decreased stepwise. RESULTS: Of the 52 patients, 45 (87%) ceased projectile vomiting with treatment using intravenous (median, 7 days) and subsequent oral (median, 44 days) atropine administration. The median hospital stay was 13 days (6-36), and no significant complications were encountered during atropine therapy. The remaining 7 patients required surgery. Of 40 who underwent surgery, 4 had wound infections and 1 with hemophilia had postoperative hemorrhagic shock. The patients who underwent successful atropine therapy had body weights comparable with those who underwent surgery at the age of 1 year. CONCLUSIONS: The high success rate of intravenous atropine therapy for IHPS suggests that this therapy is an effective alternative to pyloromyotomy if the length of the hospital stay and the necessity of continuing oral atropine medication are accepted.

Atropine↗

PubMed2005

A single-stage operation for abdominal aortic aneurysm with concomitant colorectal carcinoma.

The coexistence of abdominal aortic aneurysm (AAA) and colorectal carcinoma needs special operative consideration. A single-stage operation for concomitant AAA and colorectal carcinoma has been thought to increase the risk of vascular prosthetic graft infection. We report two patients who received a single-stage operation for AAA and colorectal carcinoma. The first patient had a fusiform aneurysm of the infrarenal aorta. The second patient had a saccular aneurysm of the infrarenal aorta and a fusiform aneurysm of the left internal iliac artery. Both patients had left-sided colorectal carcinoma classified as Dukes' stage B. The two patients underwent a single-stage operation with Hartmann's procedure to avoid graft infection caused by anastomotic leakage. They tolerated the operation and had no postoperative complications including graft infection. A single-stage operation for concomitant AAA and left-sided colorectal carcinoma could be safely performed with Hartmann's procedure in two cases.

Adenocarcinoma↗

PubMed2004

The improved dissolution and prevention of ampoule breakage attained by the introduction of pretreatment into the production process of the lyophilized formulation of recombinant human Interleukin-11 (rhIL-11).

Lyophilized protein formulations sometimes pose problems such as the formation of a cloudy solution upon reconstitution. Ampoule or vial breakage can also occur during the production processes of lyophilized pharmaceutical products. Various efforts have been made to overcome those difficult problems. In this study, we introduce a particular temperature program into the production process of a recombinant human Interleukin-11 (rhIL-11) lyophilized formulation containing sodium phosphates (Na2HPO4/NaH2PO4, pH 7.0) and glycine in an attempt to improve its dissolution properties and to prevent ampoule breakage from occurring. The formulation was pretreated by nucleating ice and maintaining the solution overnight at a temperature of -6 degrees C. The solution was then completely frozen at a lower temperature. This pretreatment proved successful in not only producing a lyophilized cake which readily disintegrated and dissolved in the reconstitution media, but also prevented ampoule breakage from occurring during the production processes. In contrast, a lyophilized cake produced without the pretreatment created a cloudy solution particularly when reconstituted using water for injection contaminated with aluminum (Al3+), although the solution became transparent within 20-30 min. The pretreatment induced the crystallization of sodium dibasic phosphate (Na2HPO4) in the freeze-concentrate whereas direct freezing without the pretreatment did not crystallize the salt. Thermal analyses (DSC and TMA) showed that amorphous sodium dibasic phosphate in the freeze-concentrate became crystallized upon heating, accompanied by an increase in volume, which probably caused the ampoule breakage that occurred without the pretreatment. Although power X-ray diffraction (PXRD) experiments suggested that, with or without the pretreatment, glycine assumed the beta-form and sodium phosphate stayed amorphous in the final products, an electrostatic interaction between dibasic phosphate anions and rhIL-11, a highly cationic protein, would only exist in the lyophilized cake produced without the pretreatment. This interaction is highly likely because aluminum facilitates the formation of a cloudy solution upon reconstitution possibly by using the divalent anions which effectively reduce electrostatic repulsions between aluminum and the protein to form an aggregate structure that is not readily soluble. The pretreatment would circumvent the interaction by crystallizing the sodium salt before freezing creating a relatively soluble lyophilized cake that is much less sensitive to aluminum.

Chemistry, Pharmaceutical↗

PubMed2004

Amino acid transport is down-regulated in ischemic human intestinal epithelial cells.

Amino acid transport across the plasma membrane is essential for supplying enterocytes with amino acids for cellular metabolism. We studied amino acid transport during ischemic conditions using human intestinal epithelial cell line Caco-2. Cells were incubated under nutrient-deprived (phosphate-buffered saline, PBS), hypoxic, and ischemic (PBS+hypoxia) conditions. Ischemia resulted in a significant decrease in glutamine transport by a mechanism that decreased V(max) without affecting K(m). The expression of system ATB degrees (glutamine transporter) mRNA decreased in the ischemic and nutrient-deprived groups, suggesting that the down-regulation of glutamine transport is due to modification of expression of the ATB degrees gene. The transport of glutamate and leucine, DNA synthesis, and intracellular glutathione also decreased in the ischemic group. These findings throw some light on the mechanism of intestinal epithelial damage during ischemia.

Amino Acid Transport System ASC↗

PubMed2004

Laparoscopic left-sided Nissen fundoplication in children.

It is sometimes difficult or inappropriate to adopt the standard surgical steps of adult laparoscopic procedures in pediatric patients because of the inevitably smaller anatomical structures and confined intra-abdominal working space. During laparoscopic Nissen fundoplication difficulties are usually encountered, especially when dissecting the diaphragmatic crura, creating the retroesophageal window, and repairing the crura. Thus, we devised a technique to accomplish these steps in pediatric patients. Both crural dissection and repair are approached from the left side of the esophagus and the port configuration for the laparoscope and other instruments is altered, providing better surgical exposure and easier handing of the instruments, even in very small patients. We describe this technique in detail and our results.

Adolescent↗

PubMed2004

Balloon-occluded retrograde transvenous obliteration performed in a pediatric patient with isolated gastric fundal varices.

BACKGROUND: For giant gastric varices in association with portal hypertension, endoscopic treatment often is difficult. Although balloon-occluded retrograde transvenous obliteration (B-RTO) has been performed successfully in adult cirrhotic patients, there has been no report in pediatric patients. METHODS: A 10-year-old girl with biliary atresia (BA) who had been free of jaundice after hepatic portoenterostomy was detected to have isolated gastric fundal varices by routine endoscopy. They gradually enlarged up to 4 cm in diameter, showing a tense appearance, so prophylactic treatment was conducted. Magnetic resonance angiography showed the blood flow of the varices mainly drained by a large gastrorenal shunt. A balloon catheter was introduced into the gastrorenal shunt via the femoral vein and was inflated to occlude the outflow of the varices. Five percent ethanolamine oleate was injected into the varices, and the outflow occlusion was kept for more than 30 minutes. Extensive thrombosis was achieved by an additional embolotherapy after 17 months. Throughout the course, the patient has been doing well without bleeding or worsening of the liver function tests. CONCLUSIONS: B-RTO for isolated gastric fundal varices has been performed safely in a pediatric patient and seems effective in reducing the variceal size and tension.

Balloon Occlusion↗

PubMed2004

Outcome predictors for infants with cystic lung disease.

BACKGROUND/PURPOSE: This study aimed at identifying characteristic features indicating congenital cystic adenomatoid malformation of the lung (CCAM) and evaluating the outcome predictors to identify prenatally subgroups of fetuses with significantly different probabilities of mortality or severe respiratory difficulty. METHODS: Twenty-eight neonates who had undergone antenatal evaluation for cystic lung disease (CLD) were reviewed retrospectively. The patients were divided into 3 groups according to the severity of their clinical course; mild (n = 7), moderate (n = 13), and severe (n = 8). Ultrasonographic findings in the fetus and their pulmonary lesion were evaluated. The normal lung to thorax transverse area ratio (L/T) was measured by ultrasonography. RESULTS: High echogenicity of the lesion throughout pregnancy and polyhydramnios were frequently seen in CCAM. All of the patients with other CLD showed isoechogenicity at the end of pregnancy. All patients in the severe group had both polyhydramnios and fetal hydrops. L/T was increased in mild and moderate groups, whereas no patient in the severe group had an increase in L/T at the final measurement. Each value of final L/T in the severe group was less than 0.25. CONCLUSIONS: The subgroup of fetuses with an increased probability of mortality or severe respiratory difficulty could be predicted from the combination of polyhydramnios, fetal hydrops, and a final L/T value of less than 0.25.

Bronchi↗

PubMed2004

The usefulness of videomanometry for studying pediatric esophageal motor disease.

PURPOSE: Abnormalities in esophageal motor function underlie various symptoms in the pediatric population. Manometry remains an important tool for studying esophageal motor function, whereas its analyses have been conducted with considerable subjective interpretation. The usefulness of videomanometry with topographic analysis was examined in the current study. METHODS: Videomanometry was conducted in 5 patients with primary gastroesophageal reflux disease (GERD), 4 with postoperative esophageal atresia (EA), 1 with congenital esophageal stenosis (CES), and 1 with diffuse esophageal spasms (DES). Digitized videofluoroscopic images were recorded synchronously with manometric digital data in a personal computer. Manometric analysis was conducted with a view of concurrent esophageal contour and bolus transit. RESULTS: Primary GERD patients showed esophageal flow proceeding into the stomach during peristaltic contractions recorded manometrically, whereas patients with EA/CES frequently showed impaired esophageal transit during defective esophageal peristaltic contractions. A characteristic corkscrew appearance and esophageal flow in a to-and-fro fashion were seen with high-amplitude synchronous esophageal contractions in a DES patient. The topographic analysis showed distinctive images characteristic of each pathological condition. CONCLUSIONS: Videomanometry is helpful in interpreting manometric data by analyzing concurrent fluoroscopic images. Topographic analyses provide characteristic images reflecting motor abnormalities in pediatric esophageal disease.

Adolescent↗

PubMed2004

Can laparoscopic antireflux surgery improve the quality of life in children with neurologic and neuromuscular handicaps?

PURPOSE: Children with neurologic and neuromuscular handicaps frequently have various symptoms related to gastroesophageal reflux (GER) disease. The long-term efficacy of antireflux surgery remains controversial in such children with GER. The clinical results of such patients who underwent laparoscopic fundoplication were examined in the current study. METHODS: Between 1997 and 2003, laparoscopic fundoplication was performed in 56 handicapped children (mean age, 6 years), and gastrostomy was performed concurrently in 52. The main symptoms were emesis/hematemesis in 40 and respiratory symptoms, including repeated respiratory infection and distress, in 31. RESULTS: There were no severe postoperative complications or operative mortality. Emesis/hematemesis was controlled adequately in those without recurrence. Respiratory symptoms were controlled unsuccessfully in 16 patients (52%), 8 of whom required further respiratory care including nasal airway tube, tracheostomy, and laryngotracheal separation. Recurrence of GER disease occurred in 10 patients, 7 of whom underwent a second Nissen fundoplication successfully. Thirteen died within the median follow-up period of 14 months. CONCLUSIONS: Laparoscopic fundoplication is effective in controlling emesis/hematemesis, but its efficacy is limited in terms of respiratory problems in handicapped children. Further refinements in diagnostic and treatment strategies are mandatory to improve the quality of life in such patients.

Adolescent↗

PubMed2004

Optimal timing for living-related liver transplantation in children.

BACKGROUND: The pediatric end stage liver disease (PELD) score has been used widely to prioritize children awaiting cadaveric liver transplantation (LTx). To establish the objective parameter for optimal timing of living-related LTx (LRLTx), we have assessed our cases using the PELD score. METHODS: From 1997 to 2002, 24 children were evaluated 28 times for the indication of LRLTx. Among them, 15 were for jaundice and nine for growth failure, hepatopulmonary syndrome, and variceal bleeding. Nine of 24 children underwent LRLTx. They were divided into several groups according to their clinical course. The PELD score consisted of age, albumin, total bilirubin, prothrombine time-international ratio (INR) and growth failure. A cut-off value was obtained by the highest positive and negative predictive value. RESULTS: The PELD score in cases whose indication for LRLTx was approved was significantly higher compared with the cases who were not, and a cut-off value of 4 was obtained. The PELD score in cases who were alive after LRLTx was significantly lower compared with the cases who died after LRLTx or evaluation of the indication, and a cut-off value of 22 was established. CONCLUSION: LRLTx may be considered when the PELD score exceeds 4, and LRLTx may be required immediately when the PELD score exceeds 22.

Adolescent↗

PubMed2004

Functional role of hCngb3 in regulation of human cone cng channel: effect of rod monochromacy-associated mutations in hCNGB3 on channel function.

PURPOSE: The human cone photoreceptor cyclic nucleotide-gated (CNG) channel comprises alpha- and beta-subunits, which are respectively encoded by hCNGA3 and hCNGB3. The purpose was to examine the functional role of hCNGB3 in modulation of human cone CNG channels and to characterize functional consequences of rod monochromacy-associated mutations in hCNGB3 (S435F and D633G). METHODS: Macroscopic patch currents were recorded from human embryonic kidney (HEK) 293 cells expressing homomeric (hCNGA3 and hCNGB3) and heteromeric (hCNGA3/hCNGB3, hCNGA3/hCNGB3-S435F, and hCNGA3/hCNGB3-D633G) channels using inside-out patch-clamp technique. RESULTS: Both hCNGA3 homomeric and hCNGA3/hCNGB3 heteromeric channels were activated by cGMP, with half-maximally activating concentration (K(1/2)) of 11.1 +/- 1.0 and 26.2 +/- 1.9 micro M, respectively. The hCNGA3 channels appeared to be more sensitive to inhibition by extracellular Ca(2+) compared with hCNGA3/hCNGB3 channels, when assessed by the degree of outward rectification. Coexpression of either of rod monochromacy-associated mutants of hCNGB3 with hCNGA3 significantly reduced K(1/2) value for cGMP but little affected the sensitivity to extracellular Ca(2+), compared with wild-type heteromeric channels. The selectivity of hCNGA3, hCNGA3/hCNGB3, hCNGA3/hCNGB3-S435F, and hCNGA3/hCNGB3-D633G channels for monovalent cations were largely similar. Immunoprecipitation experiments showed association of hCNGA3 subunit with both of wild-type and mutant hCNGB3 subunits. CONCLUSIONS: The hCNGB3 plays an important modulatory role in the function of human cone CNG channels with respect to cGMP and extracellular Ca(2+) sensitivities. The rod monochromacy-associated S435F and D633G mutations in hCNGB3 evokes a significant increase in the apparent affinity for cGMP, which should alter cone function and thereby contribute at least partly to pathogenesis of the disease.

Calcium↗