Observation of quasi-two-dimensional nonlinear interactions in a drift-wave streamer

A streamer, which is a bunching of drift-wave fluctuations, and its mediator, which generates the streamer by coupling with other fluctuations, have been observed in a cylindrical magnetized plasma. Their radial structures were investigated in detail by using the biphase analysis. Their quasi-two-dimensional structures were revealed to be equivalent with a pair of fast and slow modes predicted by a nonlinear Schrödinger equation based on the Hasegawa-Mima model.

PDK1 regulates chemotaxis in human neutrophils

Phosphoinositide-dependent kinase (PDK1) plays a central role in signal transduction mediated by phosphatidylinositol 3-kinases (PI3K) and regulates cellular functions in neutrophils. Neutrophils from individuals diagnosed with localized aggressive periodontitis (LAP) present an in vivo phenotype with depressed chemotaxis. The aim of this study was to test the hypothesis that PDK1 regulates chemotaxis in neutrophils and is responsible for the abnormal neutrophil chemotaxis LAP. Neutrophil chemotaxis was significantly suppressed by the PDK1 inhibitor staurosporine. When cells were transfected with PDK1 siRNA, there was a significant reduction in chemotaxis, while superoxide generation was not significantly affected. In primary neutrophils from persons with LAP, PDK1 expression and activation levels were significantly reduced, and this reduction was associated with the reduced phosphorylation of Akt (Thr308) and chemotaxis. Analysis of these data demonstrates that PDK1 is essential for the chemotactic migration of neutrophils, and in the absence of PDK1, neutrophil chemotaxis is impaired.

In vitro splicing analysis showed that availability of a cryptic splice site is not a determinant for alternative splicing patterns caused by +1G-->A mutations in introns of the dystrophin gene

BACKGROUND

Splicing patterns are critical for assessing clinical phenotype of mutations in the dystrophin gene. However, it is still unclear how to predict alternative splicing pathways in such cases of splice-site mutation in the dystrophin gene.

OBJECTIVE

To identify elements determining alternative splicing pathways in intron +1G-->A mutations of the dystrophin gene.

RESULTS

We found that exon 25 is spliced out in the +1G-->A mutation in intron 25, resulting in mild Becker muscular dystrophy, and that a cryptic splice site within exon 45 was activated in severe Duchenne muscular dystrophy with a mutation of +1G-->A mutation in 45. Furthermore, in vitro splicing analysis using a pre-constructed expression vector showed that the mutant intron 25 produced one transcript that lacked exon 25. In contrast, the same splice-site mutation in intron 45 produced three splicing products. One product used the same cryptic donor splice site within exon 45 as the in vivo donor site and another product used a cryptic splice site within the vector sequence. Notably, the available cryptic splice site was not activated by the same G-->A mutation of intron 25.

CONCLUSION

It was concluded that sequences inserted into the in vitro splicing assay minigene contain cis-elements that determine splicing pathways. By taking other +1G-->A mutations in the introns of the dystrophin gene reported in the literature into consideration, it seems that cryptic splice-site activation is seen only in strong exons. This finding will help to elucidate the molecular pathogenesis of dystrophinopathy and to predict efficiency of induction of exon skipping with antisense oligonucleotides for treatment of Duchenne muscular dystrophy.

Dystrophin nonsense mutations can generate alternative rescue transcripts in lymphocytes

Secondary alterations in splicing have been reported to produce semi-functional mRNA from several nonsense mutations in the dystrophin gene. Disruptions of exonic splicing enhancers by single nucleotide changes are thought to underlie such alterations. The precise frequencies of such nonsense mutation-dependent splicing alterations, however, remain unknown. Here we analyzed the splicing patterns of dystrophin mRNA in lymphocytes from 38 patients with dystrophinopathies due to nonsense mutations in the dystrophin gene. In seven of the cases (18%), we observed partial skipping of the nonsense-encoding exon. Two of the seven cases, however, exhibited complex activation of a nonsense mutation-created splice site, which resulted in the generation of novel transcripts. Examination of cis-regulatory splicing elements through calculation of splicing probability scores and identification of potential splicing enhancer or silencer sequences failed to disclose a single cause for exon skipping. Remarkably, individual differences in splicing patterns were observed for cells from patients with identical nonsense mutations (C.5899C>T). Although five cases produced semi-functional dystrophin mRNAs, only one of these exhibited a mild clinical course. These results provide important insights about targets for exon skipping induced by candidate antisense oligonucleotides and for ribosomal read-through of nonsense mutations.

An image representation algorithm compatible with neural-associative-processor-based hardware recognition systems

A robust image representation algorithm compatible with the VLSI-matching-engine-based image recognition system has been developed. The spatial distributions of four-principal-direction edges in a 64 /spl times/ 64-pels gray scale image are coded to form a 64-dimension feature vector. Since the 2D edge information is reduced to a feature vector by projecting edge flags to the principal directions, it is named the projected principal-edge distribution (PPED) representation. The PPED vectors very well preserve the human perception of similarity among images in the vector space, while achieving a substantial dimensionality reduction in the image data. The PPED algorithm has been applied to medical radiograph analysis, which was taken as a test vehicle for algorithm optimization. The robust nature of the PPED representation has been confirmed by the recognition results comparable to the diagnosis by experts having several years of experience in a university hospital. Dedicated digital VLSI circuits have been developed for PPED vector generation in order to expedite the processing. A test hardware recognition system was constructed using the vector generation circuits, where the analog neural associative processor chip developed in a separate project was employed as a vector-matching engine. As a result, a successful medical radiograph analysis has been experimentally demonstrated using the hardware system. Feasibility of a very low-power operation of the system has been also demonstrated.

Fine positioning of a poloidal probe array

Multipoint detection is an essential requirement for investigating plasma turbulence which is a highly nonlinear phenomenon in space and time. We have fabricated an array of 64-channel poloidal probes surrounding the linear cylindrical plasma named LMD-U in order to study turbulence properties, particularly the nonlinear mode couplings, in the domain of poloidal wave number and frequency. However, misalignments of probe tips produce spurious modes, which do not exist in the real plasma, to distort the precise wave number measurements. The paper presents the description of the 64-channel poloidal probe array with means to adjust the probe positions, with discussion on the effects of the misalignments on the wave number measurements.

Megakaryocyte polyploidization is associated with decreased expression of polo-like kinase (PLK)

BACKGROUND

During differentiation, megakaryocytes (MK), the bone marrow precursors of circulating blood platelets, undergo polyploidization, repeated rounds of DNA replication without cell division. Mature normal MK may contain a DNA content of up to 128N, in contrast to normal diploid (2N) cells. The extent of polyploidy may influence the number of platelets produced by the MK. Therefore, understanding the molecular mechanisms regulating polyploidization could identify events involved in controlling both cell division and thrombopoiesis.

OBJECTIVE

We investigated the expression of several proteins involved in mitosis in cultured mouse MK, and tested the effect of expression on polyploidization.

METHODS

Western blot and immunofluorescent analyses were used to assess expression of cell cycle proteins in cultured MK. Populations of polyploidizing MK were separated on the basis of DNA content by flow cytometry. The gene encoding mouse polo-like kinase 1 (PLK-1) was introduced into MK by retroviral transduction, and its effects measured by flow cytometry.

RESULTS

Polyploid mouse MK expressed lower levels of two proteins, p55CDC and PLK-1, whose activity is necessary for cell cycle progression and completion of mitosis. Comparison of sorted 2N/4N and polyploid MK indicated that PLK-1 expression was absent in polyploid MK, while expression of other cell cycle proteins was similar in both populations. Forced expression of PLK-1 during MK differentiation was associated with decreased polyploidization.

CONCLUSION

These experiments suggest that PLK-1 is an important regulator of polyploidization in differentiating MK.

Fluoride Intake from Food and Liquid in Japanese Children Living in Two Areas with Different Fluoride Concentrations in the Water Supply

The purpose of this study was to estimate the average daily amount of fluoride from the diet ingested by Japanese children of ages susceptible to dental fluorosis in two areas with different fluoride concentrations in the water supply. Thirty-eight children aged 2-8 years participated in a survey of fluoride intake. Twenty-one out of 38 children lived in an area in which the community water fluoride concentration was an average of 0.555 ppm (moderate fluoride area: MFA), and 17 lived in a low fluoride area (LFA), which ranged between 0.040 and 0.131 ppm. To measure the fluoride intake, diets were collected with a duplicate-diet technique. The fluoride concentrations in each sample were measured using the diffusion technique of Taves and the electrode technique. Meanwhile, after clinical examinations for dental caries and fluorosis, 228 subjects aged 13-15 years were selected for analysis from the same communities. The mean DMFT in the MFA was significantly lower than that in the LFA. The severest grade of dental fluorosis observed was 'very mild' according to Dean's fluorosis index in both areas. The total daily fluoride intakes were 0.0252-0.0254 mg F/kg/day in the MFA and 0.0126-0.0144 mg F/kg/day in the LFA. Differences in the fluoride concentration of drinking water in this study were reflected in the fluoride intake from the diet in a typical Japanese diet.

The herbal medicine Rikkunshi-to stimulates and coordinates the gastric myoelectric activity in post-operative dyspeptic children after gastrointestinal surgery

Rikkunshi-to (TJ-43), a gastroprotective herbal medicine, has been used for the symptomatic relief of adult patients with dyspepsia. However, its mechanism has yet to be fully elucidated. The aim of this study is to evaluate the effect of TJ-43 on the gastric myoelectric activity in post-operative dyspeptic patients, whose symptoms persisted for over 1 year after gastrointestinal surgery. Electrogastrography (EGG) recordings were performed to calculate the biomechanical parameters on the dominant peak frequency (DPF). Eight pediatric patients with dyspeptic symptoms after gastrointestinal surgery were examined and six age-matched children without any dyspeptic symptoms were used as controls, and they were compared with nine age-matched children without any dyspeptic symptoms after gastrointestinal surgery as subcontrols. All patients exhibited symptomatic relief after the administration of TJ-43, and the mean symptom score decreased significantly after the treatment of TJ-43 over a 1-month period ( P<0.0001). The variability index (VI) and the percentage of normal waves (PNW) were calculated as irregularity parameters of DPF. The power ratio (PR) was calculated as a parameter of the gastric contractile activity. There were no significant differences in the VI and PNW between the controls and patients during the postprandial state after therapy, even though significant differences existed regarding those parameters between the controls and patients before the therapy. There were no significant differences in the DPF, VI, and PNW between the controls and subcontrols. Furthermore, PR exhibited a significant increase after therapy ( P<0.05). However, there was a significant difference in the PR between the controls and subcontrols ( P<0.05). Postprandial dip was observed in all control subjects, eight patients in the subcontrols, and two patients after administration of TJ-43, respectively. An abnormal gastric electrical activity therefore seems to be an important factor in the pathophysiology of post-operative dyspeptic children. The coordinating and stimulating effect of TJ-43 on the gastric myoelectric activity therefore seems to play an important role in the reduction of dyspeptic symptoms.

Laparoscopic intervention for intrathoracic stomach in infants

BACKGROUND

Intrathoracic stomach is an uncommon condition in infants. We report our experience managing such a condition successfully by laparoscopy in four patients.

METHODS

Patients' ages at the time of operation ranged from 30 days to 14 months. In all cases, the intrathoracic stomach was easily pulled down into the abdominal cavity. The phrenoesophageal ligament was completely resected, and the enlarged hiatus was narrowed by intraabdominal suturing technique. The esophagus was wrapped with the mobilized fundus in a floppy fundoplication. Anchoring sutures were placed between the wrapping cuff and crura.

RESULT

One patient had paraesophageal hernia (type 2), whereas the other had combined hiatal hernia (type 3). No adverse complications were observed in any of the cases. Symptomatic gastroesophageal reflux and radiographic recurrence of hernia were not seen in any case. The cosmesis was excellent in all cases.

CONCLUSIONS

We conclude that laparoscopic repair for intrathoracic stomach is a safe and feasible method when preoperative evaluation is conducted adequately.

Analysis of dystrophin mRNA from skeletal muscle but not from lymphocytes led to identification of a novel nonsense mutation in a carrier of Duchenne muscular dystrophy

Dystrophin mRNA expressed in peripheral lymphocytes of individuals with X-linked Duchenne muscular dystrophy (DMD) has been used as a source material for mutation analysis. Here we present the first report of failure of isolation of nonsense dystrophin mRNA in lymphocytes but success in skeletal muscle in a female carrier of DMD. The mutation responsible for dystrophin-negative muscle fibers of the carrier was analysed by direct sequencing of the reverse transcription PCR product of dystrophin mRNA. In her peripheral lymphocytes, no nucleotide change was detected in the 14 kb long mRNA. Remarkably, a novel nucleotide change of C1682T in exon 12, changing glutamine codon to stop codon (Q492X) was found to be present in her skeletal muscle. This change was heterozygous. Analysis of her genomic DNA disclosed heterozygous C and T nucleotides at nt 1682, confirming the genomic origin of the nonsense mutation. Although dystrophin cDNA prepared from lymphocytes was sequenced again after subcloning, mutation-retaining clone could not be isolated. This lymphocyte-specific disappearance of nonsense mRNA strongly suggested tissue-specific skewing of X-inactivation. However, both paternal and maternal dystrophin alleles were shown to be equally expressed in lymphocytes as well as in muscle, indicating no skewing of X-inactivation in lymphocytes. We concluded that the dystrophin mRNA of the DMD carrier was destabilized in lymphocytes. Our results indicated that analysis of mRNA in lymphocytes is not enough for exact carrier diagnosis of Duchenne muscular dystrophy.

Short wavelength temperature gradient driven modes in tokamak plasmas

New unstable temperature gradient driven modes in an inhomogeneous tokamak plasma are identified. These modes represent temperature gradient (ion and electron) driven modes destabilized in the short wavelength regions with k( perpendicular )rho(i,e)>>1, respectively. The instability occurs due to a specific plasma response that significantly deviates from Boltzmann distribution in the regions k( perpendicular )rho(i,e)>>1.

Intravenous atropine treatment in infantile hypertrophic pyloric stenosis

AIMS

To assess the efficacy of a new regimen of intravenous atropine treatment for infantile hypertrophic pyloric stenosis (IHPS) with special reference to regression of pyloric hypertrophy.

METHODS

Atropine was given intravenously at a dose of 0.01 mg/kg six times a day before feeding in 19 patients with IHPS diagnosed from radiographic and ultrasonographic findings. When vomiting ceased and the infants were able to ingest 150 ml/kg/day formula after stepwise increases in feeding volume, they were given 0.02 mg/kg atropine six times a day orally and the dose was decreased stepwise.

RESULTS

Of the 19 infants, 17 (89%) ceased projectile vomiting after treatment with intravenous (median seven days) and subsequent oral (median 44 days) atropine administration. The remaining two infants required surgery. No significant complications were encountered. Ultrasonography showed a significant (p < 0.05) decrease in pyloric muscle thickness, but no significant shortening of the pyloric canal after completion of the atropine treatment. The patients exhibited failure to thrive at presentation, but were thriving at 6 months of age (p < 0.01).

CONCLUSIONS

This atropine therapy resulted in satisfactory clinical recovery. Pyloric muscle thickness was significantly reduced.

Mechanisms responsible for recurrent gastroesophageal reflux in neurologically impaired children who underwent laparoscopic Nissen fundoplication

BACKGROUND

In this study, we attempted to define the lower esophageal sphincter (LES) motor events associated with the occurrence of gastroesophageal reflux (GER) in neurologically impaired children in whom of GER disease recurred after laparoscopic Nissen fundoplication (LNF).

METHODS

Of 45 neurologically impaired children who had previously undergone LNF, six children in whom recurrence of GER disease was documented by 24-h esophageal pH monitoring were studied. Concurrent esophageal manometry and pH monitoring were conducted for 1 h both before and after the administration of apple juice (10 ml/kg).

RESULTS

A total of 89 reflux episodes were recorded in the course of the study. Of these, 51 episodes (57%) were associated with transient LES relaxation. In the remainder, reflux occurred across a contracted LES in 21 episodes (24%) and during absent basal LES tone in 15 episodes (17%). In four of six patients, transient LES relaxation was responsible for more than half of the reflux episodes.

CONCLUSION

Transient LES relaxation is the predominant mechanism of reflux in neurologically impaired children with recurrent GER after LNF.

Successful laparoscopic fundoplication in children with ventriculoperitoneal shunts

We reported successful laparoscopic fundoplication in 2 pediatric cases with VPS and discuss the safety and feasibility of the procedure. Case 1: A 13-year-old girl with VPS underwent laparoscopic fundoplication. Case 2: a 9-year-old boy with VPS underwent laparoscopic fundoplication. In both cases, laparoscopic Nissen fundoplication was performed with a standard five-port technique with a low pressure of a pneumoperitoneum. The VPS system had no effect on port layout and intraabdominal manipulation and no adverse complications were observed in either case. The effect of a pneumoperitoneum in the VPS system remains controversial, however, the author emphasized that advanced laparoscopic surgery can be performed safely with creating a low pressure of a pneumoperitoneum.

4-nitro-9,10-dihydrophenanthrene and a polymorphic form of 4-nitrophenanthrene

The crystal structures of 4-nitro-9,10-dihydrophenanthrene, C14H11NO2, (I), and 4-nitrophenanthrene, C14H9NO2, (II), the latter having two crystallographically independent molecules, show that the molecules are not planar. The dihedral angles between the phenyl rings of the biphenyl skeletons are 28.64 (8) degrees for (I), and 10.34 (15) and 11.75 (13) degrees for the two molecules of (II). The differences in the dihedral angles have an effect on the photochemical reactivity of the molecules.

Motor abnormality in the gastroduodenal junction in patients with infantile hypertrophic pyloric stenosis

BACKGROUND/PURPOSE

Periodic clusters of phasic pressure waves in the gastroduodenal junction (GDJ) have been seen in patients with infantile hypertrophic pyloric stenosis (IHPS). This study investigated the details of these pressure waves in relation to disturbed transpyloric flow in IHPS.

METHODS

Manometric study was performed in 11 IHPS patients before and after atropine therapy and 2 non-IHPS infants. Pressure changes in the GDJ were measured with an 8-channel sleeve or a 9-channel sidehole micromanometric assembly under fluoroscopic control for 2 hours.

RESULTS

Clusters of phasic pressure waves (365 +/- 42 mm Hg) associated with an increase in basal pressure (10 +/- 3 mm Hg) were intermittently observed in the GDJ in all IHPS patients. Similar observations were not made in the non-IHPS infants. Most antral pressure waves occurred simultaneously with those pressure waves in the GDJ in the IHPS patients. Atropine (0.01 mg/kg) transiently abolished the phasic and tonic pressure waves for 19 +/- 10 minutes. Significantly fewer phasic pressure waves were observed after atropine therapy.

CONCLUSIONS

Characteristic phasic and tonic contractile activity in the GDJ is uncoordinated with the antral contractions in IHPS patients. Such incoordination may be an important factor in the disturbed transpyloric flow in IHPS.

Treatment of ruptured undifferentiated sarcoma of the liver in children: a report of two cases and review of the literature

Undifferentiated (embryonal) sarcoma of the liver (USL) is a highly malignant tumor of early life. Treatment choices for USL, especially with intraperitoneal rupture, are uncertain. Outcomes have been almost uniformly poor until recently. We describe two 7-year-old girls treated for ruptured USL. In the more recent patient, operative biopsy was followed by three cycles of cisplatin (CDDP), adriamycin (ADR), and cyclophosphamide (CPM). A fluid-filled cavity in the tumor showed enlargement and was drained. Two cycles of CDDP, ADR, vincristine (VCR), and ifosfamide were accompanied by reduction in tumor size, and trisegmentectomy was performed. She has no evidence of disease 3.5 years after surgery. In the other patient, left lobectomy was followed by a less intensive regimen, including CPM, VCR, and fluorouracil. This patient died of dissemination within 5 months. In 170 reported pediatric patients with USL, the 2-year disease-free survival was 17%. For the 96 such patients reported since 1980, 2-year disease-free survival had improved to 27%. More aggressive chemotherapy has been associated with this change. Of 8 patients with tumor rupture whose details have been reported (including the 2 present patients) after resection of the tumor, 4 died, 1 was alive with disease, and 3 were free of disease at 8, 49, and 58 months, respectively, after diagnosis. Ruptured USL should be treated with combination chemotherapy including CDDP and ADR, as well as with curative resection.

Postoperative fecoflowmetric analysis in patients with anorectal malformation

Because conventional methods of evaluating anorectal function do not necessarily provide good correlations between investigative results and symptoms in patients who have undergone surgery for an anorectal malformation (ARM), we recently introduced feco-flowmetry (FFM) to simulate natural anorectal evacuation. The purpose of this study was to embody significant parameters to elucidate the dynamics of anorectal activity on FFM. The parameters of FFM were compared with those of manometry and Kelly's clinical score (KCS) in 24 patients who underwent surgery for an ARM. There were three fecoflow patterns, namely, block (B) type, segmental (S) type, and flat (F) type. The B-type or S-type patterns were seen in patients classified as "clinically good." There were close relationships between the fecoflow pattern and both the operative procedure and the KCS (P = 0.01 and 0.001, respectively). Maximum fecal stream flow rate (Fmax) precisely reflected the tolerance rate of intended normal saline solution in the colorectum (TR), the evacuative rate (ER), and KCS. Fmax > 45 ml/s or TR > 70% or ER > 50% was statistically regarded as the borderline of fecal continence. Thus, the fecoflow pattern might reflect the motor activity of the pelvic floor muscle. FFM provided quantiative and qualitative evaluations concerning anorectal motor activity in patients who had undergone surgery for an ARM.

Cloning of rodent megsin revealed its up-regulation in mesangioproliferative nephritis

BACKGROUND

We recently cloned a new human mesangium-predominant gene, megsin. Megsin is a novel member of the serine protease inhibitor (serpin) superfamily. To elucidate functional roles of this gene, we cloned megsin in rodents and investigated its role in a rat nephritis model.

METHODS

Megsin homologues were cloned from cultured rat and mouse mesangial cDNAs utilizing polymerase chain reaction (PCR) with degenerative primers. Expression of megsin in three different types of resident glomerular cells was investigated by PCR. Levels of megsin mRNA expression at various time points in the anti-Thy1 rat nephritis model were studied by semiquantitative PCR and Northern blotting analysis. In order to investigate megsin protein expression in anti-Thy1 nephritis rats, we raised antibody against rat megsin-specific synthetic peptide, with which immunohistochemical studies were performed.

RESULTS

Rat and mouse megsins were composed of 380 amino acids, which revealed 75.3 and 73.9% identity, respectively, with human megsin at the amino acid level. Characteristic features as an inhibitory serpin were conserved in both rat and megsin megsins. PCR analysis revealed expression of megsin in cultured mesangial cells but not in glomerular epithelial or endothelial cells. In anti-Thy1 nephritis rats, semiquantitative PCR and Northern blotting showed that expression of megsin mRNA was up-regulated in glomeruli at day 8. Immunohistochemical studies demonstrated the prominent accumulation of megsin in glomeruli at the same time point. Megsin was mainly localized in mesangial area. The megsin expression level returned to the basal level at day 28.

CONCLUSION

Sequences of megsin were well conserved among different species. Rat megsin was also predominantly expressed in mesangial cells. Expression of megsin was up-regulated at the peak of hypercellularity and matrix accumulation in the mesangioproliferative glomerulonephritis model, suggesting that megsin may participate in the process of glomerulosclerosis by modulating extracellular matrix deposition or cell survival.

Usefulness of cord-blood harvesting for autologous transfusion in surgical newborns with antenatal diagnosis of congenital anomalies

BACKGROUND/PURPOSE

The risks of homologous transfusion and the effectiveness of predeposit autologous transfusion have been described. The authors examined the clinical usefulness of cord-blood harvesting for autologous transfusion in newborns who had congenital anomalies antenatally diagnosed that would require surgical intervention at or near the time of delivery.

METHODS

Of 112 cases of antenatal diagnosis of congenital anomalies, 50 mothers gave informed consent and enrolled in this study. Cord-blood was withdrawn immediately after clamping of the umbilical cord and was used for autologous transfusion in newborns within the first 3 days postpartum.

RESULTS

A mean of 72 +/- 54 mL of cord-blood was harvested (27 +/- 18 mL/kg). While preserving cord-blood for 3 days at 4 degrees C, no signs of clot formation or hemolysis were observed. The harvested cord-blood included plasma-free Hb ranging from 1 to 68 (13 +/- 18) mg/dL and thrombin-antithrombin III complex ranging from 2 to 273 (18 +/- 50) ng/mL. Bacteriologic examination of the stored cord-blood showed negative cultures, except for samples from 3 newborns after vaginal delivery. A mean of 46 +/- 34 mL of cord-blood was used in 26 patients for autologous transfusion. No significant complications related to cord-blood transfusion were recognized clinically.

CONCLUSIONS

Autologous cord-blood transfusion has the potential to be a useful alternative to homologous transfusion in newborns requiring surgery. Adequate collection and storage techniques for cord-blood must be developed. J Pediatr Surg 36:851-854.

Fiberoptic colonoscopic polypectomy in childhood: report and review of cases

BACKGROUND

Fiberoptic colonoscopy has been a routine therapeutic modality for colorectal polyps in pediatric patients. Methods of bowel preparation, anesthesia, area of investigation and treatment depending on histopathology are still controversial. In order to clarify the rationale of pediatric colonoscopy the present study was performed.

METHODS AND RESULTS

We analyzed the results of colonoscopic examination in 21 patients with colorectal polyps. Mean patient age was 3.7 years, with a range of 1--7 years. Rectal polyps were seen in 10 cases: seven had a solitary polyp (juvenile in six and adenoma in one) and three had multiple polyps (juvenile, lymphoid and Peutz--Jeghers coexisting with hyperplastic polyps). Sigmoid colon polyps were seen in 10 cases: all were solitary juvenile polyps, but one had adenomatous change. Another had multiple Peutz-- Jeghers polyps located in the entire colon. Flexible colonoscopic polypectomy was performed in 16 patients and transanal polypectomy was performed in four patients. Autoamputation was seen in two cases of juvenile polyp (resection was ultimately performed in a case having repeated autoamputation). After removing the polyps, all patients have had no recurrence for a period ranging from 6 months to 15 years, except for one case with Peutz--Jeghers syndrome.

CONCLUSIONS

Most polyps are located in the rectum or the sigmoid colon. Although the majority are solitary or juvenile polyps, because histopathologic variety is seen in pediatric colon polyps, histopathologic examination of each polyp is important to detect any dysplastic or adenomatous element with malignant potential and to make a suitable follow-up schedule. Symptomatic polyps should be removed by fiberoptic colonoscopy or transanal resection with total colon endoscopic examination under general anesthesia. Polypectomy using the electrocautery snare and clip is effective and safe and bowel preparation using polyethylene glycol electrolyte solution is sufficient for the procedure.

Pertussis toxin-sensitive and -insensitive mechanisms of alpha1-adrenoceptor-mediated inotropic responses in rat heart

In rat left ventricular papillary muscle, phenylephrine, an alpha1-adrenoceptor agonist, induced a triphasic inotropic response; an initial transient, small, positive inotropic effect followed by a transient chloroethylclonidine-sensitive negative inotropic effect and a sustained 2-(2,6-dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane (WB4101)-sensitive positive inotropic effect. Treatment with pertussis toxin for 2 days significantly inhibited only the transient negative inotropic effect without changing the sustained positive inotropic effect. This treatment also prevented the acetylcholine (1 microM)-induced negative inotropic effect. Further, phenylephrine-induced transient negative inotropic effect was attenuated in the presence of ouabain. These results suggest that pertussis toxin-sensitive or -insensitive G-protein may be responsible for alpha1-adrenoceptor subtype-mediated negative inotropic effect or positive inotropic effect, respectively, in which the transient negative inotropic effect was produced via the stimulation of Na+, K+ pump, presumably through pertussis toxin-sensitive G-protein-dependent pathway.

Operative management for sacrococcygeal teratoma diagnosed in utero

BACKGROUND/PURPOSE

Sacrococcygeal teratomas (SCT) diagnosed in utero have been reported to be large and associated with high perinatal mortality rate. However, operative management including timing of operation after birth, combined abdominal approach for devascularization, and the position of the patients during resection is not well established.

METHODS

A retrospective review of 14 patients with SCT between 1978 and 1999 was performed. To prevent massive bleeding during surgery, the authors used an abdominoperineal resection in the supine position after devascularization. The patients' clinical and sonographic characteristics, prenatal outcome, operative management, and postnatal outcomes were examined.

RESULTS

One fetus died in utero. Two patients died within a week, but no late death and no malignant degeneration were noted. A staged operation with devascularization was performed in 2 patients, and 1 death occurred. Surgical management was analyzed between survivors without massive bleeding at surgery (n = 9) and others (n = 4). A significant difference was observed in the subgroup of tumor resection with devascularization or supine position and that of early resection with devascularization or supine position.

CONCLUSIONS

Early resection using the abdominoperineal approach supported by close antenatal sonography may be preferable for a favorable outcome. Resection in the supine position after devascularization may have advantages of respiratory management, cardiac resuscitation, and bleeding prevention. J Pediatr Surg 36:545-548.