Congenital diaphragmatic hernia diagnosed by magnetic resonance imagine in late infancy: Report of one case

We report the magnetic resonance imagine (MRI) findings of an 11-month-old baby with delay onset of congenital diaphragmatic hernia (CDH). The capability of visualizing diaphragmatic discontinuity, connecting bowel segments between abdomen and chest are clearly demonstrated. The various techniques of diagnosing diaphragmatic hernia are described and we emphasize the potential usefulness of MRI in CDH.

Role of laparoscopic cholecystectomy in the management of polypoid lesions of the gallbladder

This retrospective clinicohistopathologic study was performed to delineate the role of laparoscopic cholecystectomy in the management of polypoid lesions of the gallbladder. One hundred forty-three consecutive patients who had a preoperative sonographic diagnosis of polypoid lesions of the gallbladder with a diameter less than 1.5 cm and who underwent laparoscopic cholecystectomy at Cathay General Hospital were included in the analysis. Histopathologic study showed that 22 (15.4%) patients had true tumors, including adenoma (16), adenoma with focal adenocarcinoma (2), adenocarcinoma (3), and carcinoid tumor (1). Tumorlike lesions were found in 121 (84.6%) patients and included cholesterol polyp (106), adenomyomatous hyperplasia (10), inflammatory polyp (3), and papillary hyperplasia (2). The mean diameter of malignant polypoid lesions of the gallbladder was 1.35 +/- 0.42 cm, which was significantly larger than that of cholesterol polyps (0.66 +/- 0.40 cm, P = 0.0001) but not significantly larger than that of adenomyomatous hyperplasias (1.12 +/- 0.42 cm) and adenomas (1.08 +/- 0.47 cm). The mean age of patients with malignant polypoid lesions of the gallbladder (61.2 +/- 13.3 years old) was significantly older than that of patients with adenomyomatous hyperplasia (46.6 +/- 13.4 years, P = 0.03), cholesterol polyps (44.5 +/- 10.5 years, P = 0.0003), and adenomas (41.4 +/- 9.4 years, P = 0.0008). Clinical follow-up showed that most (98.6%) patients benefited from the minimal invasiveness of laparoscopic cholecystectomy with satisfactory surgical results. We conclude that laparoscopic cholecystectomy is a reliable, safe, and minimally invasive biopsy procedure and definite management of polypoid lesions of the gallbladder with a diameter less than 1.5 cm.

Congenital varicella syndrome as an unusual cause of congenital malformation: report of one case

Intrauterine infections with varicella-zoster virus following maternal varicella in early pregnancy and resulting in congenital malformations are rare. Herein we report a child with congenital varicella syndrome characterized by low birth weight, cicatricial scarring, hypoplasia of both lower extremities with joint contracture, congenital hip dislocation, corneal opacity, atresia of the sigmoid colon and a rarely associated cloaca anomaly. The varicella IgG remained positive after she was seven months old. Her mother developed chickenpox at the 14th week of gestation. The purpose of this article is to raise pediatricians' index of suspicion for congenital varicella syndrome when an infant is born with multiple congenital malformations with an apparent history of maternal varicella infection.

Mechanisms of inactivation of E-cadherin in breast carcinoma: modification of the two-hit hypothesis of tumor suppressor gene

Loss of heterozygosity (LOH) allows the expression of recessive mutation in tumor suppressor genes (TSG). Therefore, on the basis of Knudson's 'two-hit' hypothesis for TSG inactivation, the detection of a high LOH frequency in a chromosomal region is considered critical for TSG localization. One of these LOH regions in breast cancer is 16q22.1, which has been suggested to reflect the involvement of E-cadherin (E-cad), a cell-cell adhesion molecule. To confirm the tumorigenic role of E-cad, 81 sporadic invasive ductal carcinomas (IDCs) of the breast were tested for the 'two hits' required to inactivate this gene. A high frequency (37.3%) of LOH was detected in 67 informative tumors, but no mutation was found. To examine the possibility that transcriptional mechanisms serve as the second hit in tumors with LOH, specific pathways, including genetic variant and hypermethylation at the promoter region and abnormal expression of positive (WT1) and negative (Snail) transcription factors, were identified. Of these, promoter hypermethylation and increased expression of Snail were found to be common (>35%), and to be strongly associated with reduced/negative E-cad expression (P<0.05). However, unexpectedly, a significantly negative association was found between the existence of LOH and promoter hypermethylation (P<0.05), which contradicts the 'two-hit' model. Instead, since they coexisted in a high frequency of tumors, hypermethylation may work in concert with increased Snail to inactivate E-cad expression. Given that E-cad is involved in diverse mechanisms, loss of which is beneficial for tumors to invade but may also trigger apoptosis, this study suggests that maintaining a reversible mechanism, either by controlling the gene at the transcriptional level or by retaining an intact allele subsequent to LOH, might be important for E-cad in IDC and may also be common in TSGs possessing diverse functions. These findings provide clues to explain why certain TSGs identified by LOH cannot fulfil the two-hit hypothesis.

Surgical implications of pseudomonas aeruginosa necrotizing fasciitis in a child with acute lymphoblastic leukemia

Necrotizing fasciitis caused by Pseudomonas aeruginosa is extremely rare. Only 4 cases were reported in the literature. The authors report the occurrence of P aeruginosa necrotizing fasciitis starting out as a vulval abscess in a girl before induction chemotherapy for acute lymphoblastic leukemia. To our knowledge, this is the second case described in association with leukemia. In this case, the outcome was favorable because of early surgical intervention, confirming the diagnosis. J Pediatr Surg 36:948-950.

Distinguishing two types of gray mullet, Mugil cephalus L. (Mugiliformes: Mugilidae), by using glucose-6-phosphate isomerase (GPI) allozymes with special reference to enzyme activities

The resident and migratory types of gray mullet, Mugil cephalus, on the coast of Taiwan can not be separated morphologically. Allozyme analysis was applied to estimate genetic variation between the two types of gray mullet and to test whether they belong to different populations. After starch gel electrophoresis, different allelic frequency spectra of glucose-6-phosphate isomerase-A (GPI-A) between stocks was observed. The resident stock contained Gpi-A(135) and Gpi-A(100), whereas the migratory type contained Gpi-A(100) only. In addition, GPI activities of locus A showed two distinct profiles between the two alleles. The results broadly revealed that Gpi-A allelic frequency was not regulated by temperature changes even after 6 months of thermal acclimation. This suggests that natural selection may play a role in shaping the allelic frequency change during the migratory journey. These findings suggest that the Gpi-A allelic difference can be used for population discrimination.

Use of pulsed-field gel electrophoresis to investigate an outbreak of Serratia marcescens infection in a neonatal intensive care unit

Serratia marcescens is a well-recognized hospital-acquired pathogen, which has been associated with a number of specific outbreaks, particularly in critically ill neonates. We used pulsed-field gel electrophoresis (PEGE) typing to analyse an outbreak in a neonatal intensive care unit (NICU). We included samples from nine patients, three handwashes and ten environmental isolates from an outbreak (February to August 1999) in addition to four patient isolates from different wards of our hospital during the same time period. The clinical presentations of the outbreak included bacteraemia (four cases), pneumonia (three cases), umbilical wound infection (one case) and conjunctivitis (one case). Nine outbreak isolates exhibited an identical PFGE fingerprint, while the epidemiologically unrelated strains demonstrated distinct patterns. Epidemiological investigation failed to reveal a common source of the outbreak, although the epidemic S. marcescens strain was isolated from hand-washes and doors of incubators. We concluded that cross-transmission via transient contamination of hands was the major route for this outbreak. Strict handwashing practices, the cohorting and isolation of colonized and infected patients, and the regular dis-infection of incubators are crucial steps for preventing the transmission of S. marcescens in an NICU. This PFGE method is highly discriminatory for the thorough epidemiological investigation of an outbreak of S. marcescens.

Nickel-titanium mandibular bonded lingual 3-3 retainer: for permanent retention and solving relapse of mandibular anterior crowding

An innovative technique that involves a nickel-titanium mandibular bonded lingual 3-3 retainer was used to treat relapse of mandibular anterior crowding. The purpose of this study was to demonstrate clinical procedures and to study the effects of a new mandibular bonded lingual 3-3 retainer on the mandibular dental arch. In 18 patients, changes in the irregularity index and in arch dimensions (intercanine width, arch length, and arch depth) were measured against the patients' mandibular dental casts, which were obtained at completion of the previous orthodontic treatment (T(0)). These measurements were taken at the beginning of retreatment (T(1)), and 2 (T(2)), 4 (T(3)), and 6 (T(4)) months after initiation of retreatment. During the period of relapse (T(0)-T(1)), the irregularity index increased from 1.3 to 3.5 mm and the mandibular arch dimensions decreased. Four months after a segment of.018-in nickel-titanium archwire was bonded lingually from canine to canine, the irregularity index decreased from 3.5 to 1.0 mm and the arch dimensions increased and recovered their original posttreatment dimensions. The nickel-titanium archwire was left in place for permanent retention after the period of retreatment. This simple technique effectively solved relapse of mandibular anterior crowding in 4 months. This mandibular bonded lingual 3-3 retainer could be used both actively, to re-treat mandibular anterior crowding without the use of lingual brackets, and passively, for maintenance as a bonded lingual retainer.

Breast cancer screening in Taiwan and China

In contrast to incidence rates prevailing in women in Western countries, Chinese women in Taiwan and China are considered to have the lowest incidence of breast cancer in the world. However, in the past 20 years, breast cancer incidence in Chinese women has seen a dramatic increase of 50-100%, which strongly supports the need for breast cancer prevention and screening programs. It is also important to indicate that breast cancer in Chinese women is characterized by younger age at tumor onset. More than 50% of the total breast cancer diagnosed annually is found in premenopausal patients, creating the need to initiate breast cancer screening programs in this population. Initially, the breast cancer screening program depended on breast self-examination. Since Chinese women have relatively small breasts, it was assumed that breast cancer was easier to detect by self-examination. However, this strategy has failed. The dilemma of breast cancer screening can be summarized by the fact that Chinese have a rapidly increasing incidence of premenopausal breast cancer, while the overall incidence is still low. Therefore, since premenopausal women have denser breasts than postmenopausal women, and Chinese women have smaller breasts and a higher percentage of dense breasts, increased mammography screening frequency may be not the sole solution to increase detection in this age group. In our experience in Taiwan, the addition of breast ultrasound may be helpful. Nearly all the nonpalpable cancers detected by mammography in our women are due to microcalcifications, and ultrasound is more sensitive in detecting nonpalpable cancers; Therefore, we suggest that a screening program, based on ultrasound to detect nonpalpable cancers not associated with microcalcifications, along with mammography within a long period, may provide more effective protection for Taiwanese and Chinese women against breast cancer.

A second deciduous molar impacted in right maxillary sinus: a long-term follow-up

Primary tooth impaction is quite rare during the development of primary dentition. Various factors contribute to the impaction of a deciduous tooth, including malposition and malformation of the tooth bud, dentomaxillofacial disharmony, tumors, and cysts. This case was a 6-year-old female with complete left cleft lip/palate. A maxillary right second deciduous molar impacting at a high level approximate to the maxillary sinus was noted on the initial visit. To prevent surgical trauma to the surrounding tissue and succedaneous teeth, regular follow-up with radiographic examination was taken every 2 years. After a 7-year long-term follow-up, the impacted second primary molar in the right maxillary sinus had almost completely been resorbed with only about 10% of the original structure left. To the present, the resorption of the impacted deciduous molar seemed to have continued with no major pathological changes. Periodic radiographic examination is strongly advised until the total resorption process is completed.

Hirschsprung's disease presenting with diffuse intestinal pneumatosis in a neonate

In the neonate, pneumatosis intestinalis is almost always associated with necrotizing enterocolitis. The manifestation of diffuse intestinal pneumatosis in Hirschsprung's disease has been reported rarely. It may occur as a result of Hirschsprung's disease complicated with enterocolitis. We report a two-day-old female baby born at term with the problems of failure to pass meconium, progressive abdominal distension and bile stained vomiting. There was an early roentgenographic presentation of pneumatosis intestinalis which might have led to a diagnosis of necrotizing enterocolitis. However, the intestinal pneumatosis resolved within 48 hours. After anorectal manometry and contrast enema examination, an ileostomy was performed at the age of 23 days, and multiple biopsies of intestine showed aganglionosis up to the ileum at the level of 85 cm above the ileocecal valve. Unfortunately, the patient developed short bowel syndrome after operation and died suddenly after an accidental choking at the age of three months. This case suggests that Hirschsprung's disease may have an unusual early roentgenographic presentation with diffuse intestinal pneumatosis in the first few days of life. Anorectal manometries and suction biopsies are crucial for further diagnosis.

Utility assessment for different clinical phases of breast cancer in Taiwan

BACKGROUND AND PURPOSE

Utility is an important index of health-related quality of life (HRQoL). The purpose of this study was to assess utility in different clinical phases of breast cancer in patients in Taiwan.

METHODS

Based on a review of HRQoL literature pertaining to breast cancer and medical records of 979 breast cancer patients admitted to National Taiwan University Hospital from 1991 to 1995, a semi-open checklist describing the diagnosis and treatment activities and impacts of different clinical phases of breast cancer was constructed. The checklist was then reviewed and revised in consultation with surgeons, medical oncologists, radiation oncologists, nurses, and breast cancer patients. Thirty-one clinical and public health experts were invited to assess the utility of each phase with the visual analog scale (VAS), standard gamble (SG), and time trade-off (TTO) methods, according to the description of the average patient's life in the checklist. The Delphi technique was used to reach expert consensus.

RESULTS

The VAS utility scores were highest during screening phases (100 or 90), lower in phases of incidental finding of a tumor (75) and diagnosis (70), and lower still in the initial treatment phases, especially during adjuvant chemotherapy (50). The scores improved during the follow-up phases. There was a higher score for breast-conserving surgery (65) than modified radical mastectomy (60) only in the early follow-up phase. The scores for recurrence or metastasis (30) and terminal stage were considerably lower and reached the lowest level (10 in a general ward and 12.5 at home or in a hospice) among all phases. The utility scores assessed by SG and TTO were higher than those assessed by VAS.

CONCLUSIONS

In this study, we established a consensus among clinical and public health experts on the impact of different clinical phases of breast cancer on utility. The results of this study may be useful in cross-cultural comparisons and cost-utility analyses for breast cancer.

Novel kinetics of mammalian glutathione synthetase: characterization of gamma-glutamyl substrate cooperative binding

Glutathione (GSH) synthetase [L-gamma-glutamyl-L-cysteinyl:glycine ligase (ADP-forming), EC 6.3.2.3] catalyzes the final step in GSH biosynthesis. Mammalian glutathione synthetase is a homodimer with each subunit containing an active site. We report the detailed kinetic data for purified recombinant rat glutathione synthetase. It has the highest specific activity (11 micromol/min/mg) reported for any mammalian glutathione synthetase. The apparent K(m) values for ATP and glycine are 37 and 913 microM, respectively. The Lineweaver-Burk double reciprocal plot for gamma-glutamyl substrate binding revealed a departure from linearity indicating cooperative binding. Quantitative analysis of the kinetic results for gamma-glutamyl substrate binding gives a Hill coefficient (h) of 0. 576, which shows the negative cooperativity. Neither ATP, the other substrate involved in forming the enzyme-bound gamma-glutamyl phosphate intermediate, nor glycine, which attacks this intermediate to form GSH, exhibit any cooperativity. The cooperative binding of gamma-glutamyl substrate is not affected by ATP concentration. Thus, mammalian glutathione synthetase is an allosteric enzyme.

Variations of the bilirubin uridine-diphosphoglucuronosyl transferase 1A1 gene in healthy Taiwanese

The activity of uridine-diphosphoglucuronosyl transferase 1 (UGT1) may influence the concentration of serum bilirubin. Because UGT1 is too labile to be measured with classical biochemical methods, we analysed the whole UGT1A1 gene in 290 healthy Taiwanese adults by using the polymerase chain reaction method, and investigated the relationship between UGT1A1 genotypes and serum bilirubin levels. The results showed that slightly more than 50% of the subjects had one or more variant sites in UGT1A1 gene. The most common variant was A(TA)6TAA/A(TA)7TAA (6/7) in the promoter area, followed by heterozygous variation within the coding region, compound heterozygous and homozygous variations. Among the four variant sites within the coding region, 211 G to A was the predominate one, 1091 C to T was a novel variation, and 686 C to A was associated with 6/7. Subjects with 6/7 or heterozygous variation within the coding region or compound heterozygous (plus one homozygous) variation had significantly higher bilirubin levels than those with wild UGT1A1 gene. When the 290 subjects were stratified into six groups according to their serum bilirubin concentrations, the bilirubin levels were correlated well to the frequencies of variant UGT1A1 gene. Our results show that there is a strong association between UGT1A1 gene and bilirubin levels in healthy Taiwanese adults. The occurrence of A(TA)7TAA allele was relatively rare and the variation rate within the coding region was much higher in Taiwanese compared to that in Caucasians.

Prolonged neuromuscular block with mivacurium in a patient with cholinesterase deficiency

Mivacurium is a short-acting, nondepolarizing neuromuscular blocking agent hydrolyzed by plasma cholinesterase. Because it allows fast recovery, it is a commonly used muscle relaxant for patients undergoing short surgical procedures. We report the case of a 5-year-old boy who underwent outpatient inguinal herniorraphy and developed unexpected prolonged neuromuscular block after the use of mivacurium. He required mechanical ventilation support in the intensive care unit because he could not attain adequate muscle power 1 hour after termination of anesthesia; the muscular paralysis persisted for 5 hours after the bolus dose of 0.3 mg/kg mivacurium. Subsequent investigation revealed an extremely low plasma cholinesterase concentration (115 U/L), and this was later determined to be a congenital condition. This is the first reported case of cholinesterase deficiency diagnosed as a result of general anesthesia in Taiwan.

Genome-wide search for loss of heterozygosity using laser capture microdissected tissue of breast carcinoma: an implication for mutator phenotype and breast cancer pathogenesis

Breast cancer is considered to display a high degree of intratumor heterogeneity, without any obvious morphological and pathological steps to define sequential evolution, and its progression may vary among individual tumors. In an attempt to elucidate these etiological and phenotypic complexities, the present study, based on the fundamental concept that genomic instability is the engine of both tumor progression and tumor heterogeneity, was conducted to test the hypothesis that breast cancer pathogenesis is driven by double-strand break (DSB)-initiated chromosome instability (CIN). The rationale underlying this hypothesis is derived from the clues provided by family breast cancer syndromes, in which susceptibility genes, including p53, ATM, BRCA1 and BRCA2, are involved within the common functional pathway of DSB-related checkpoint/ repair. Because genomic deletion caused by DSB is reflected in the genetic mechanism of loss of heterozygosity (LOH), this genome-wide LOH study was conducted, using 100 tumors and 400 microsatellite markers. To minimize the effect of heterogeneity within tumors, the experimental technique of laser capture microdissection was used to ensure that genetic and phenotypic examinations were based on the same tumor cells. Support for our hypothesis comes from the observations that: (a) the extent of DSB-initiated CIN in tumors significantly increased as tumors progressed to poorer grades or later stages; (b) in the sequential steps toward CIN, the loci of p53 and ATM, the key checkpoint genes against DSB, were lost at the earliest stage; and (c) many loci identified to be important in breast tumorigenesis were the genomic sites possibly harboring the genes involved in DSB-related checkpoint/repair (including RAD51, RAD52, and BRCA1) or CIN (including FA-A, FA-D, and WRN), and a higher number of these loci showing LOH was significantly associated with increased level of DSB-initiated CIN (P < 0.0001). Breast cancers are thus considered to be sequentially progressive with CIN. However, CIN might also cause genetic heterogeneity, which was revealed by the findings that LOH at some markers was observed only in the component of ductal carcinoma in situ but not in the invasive component of the same tumors. In addition, some markers were found to preferentially lose at specific tumor grades, implying their contribution to genetic heterogeneity during tumor development. Therefore, this study suggests that breast cancer progression is clonal with regard to CIN, but different breast cancers would present distinct molecular profiles resulting from genetic heterogeneity caused by CIN.

Metaplastic carcinoma of the breast: analysis of eight Asian patients with special emphasis on two unusual cases presenting with inflammatory-type breast cancer

Metaplastic carcinoma of the breast is a rare form of breast cancer and has an uncertain prognostic significance. Cases from Asian countries have never been reported in the English literature. Between 1983 and 1998, we encountered 8 cases in our institution. There were 7 women and one man with a median age of 52.5 (37-73) years. Pathologic diagnosis included three poorly-differentiated adenosquamous carcinomas, two adenocarcinomas with spindle cell metaplasia, two matrix-producing carcinomas and one carcinosarcoma. Estrogen receptor was positive in 2 (25%) patients. Local recurrence or distant metastasis developed in 3 patients within one year of initial treatment. With a mean follow-up of 81 months (range, 19-183 months), 5 patients were disease-free at the time of this report. Interestingly, two of our patients had presented with huge-sized inflammatory breast cancer and were refractory to neo-adjuvant chemotherapy, but enjoyed an unexpected long disease-free survival after mastectomy. Although the clinical course of our patients appeared in general similar to that of the Western series, the two patients with inflammatory breast carcinoma ran a very unusual course, which may deserve further characterization.

Activity of p44/42 MAP kinase in the caudal subnucleus of trigeminal spinal nucleus is increased following perioral noxious stimulation in the mouse

The extracellular signal-regulated protein kinase-1 and -2 (ERK1 and ERK2), also referred to as the p44/42 mitogen-activated protein kinase (p44/42 MAP kinase), plays an essential role in neuronal signal transduction, but its function involved in nociceptive response has not been deeply studied yet. Here we report immunohistochemical evidence that p44/42 MAPK might be critical in nociceptive response. We found that after formalin was injected into the perioral skin of the upper lip of mice, the number of activated p44/42 MAPK-like immunoreactive neurons was significantly increased in the laminae I and II of the caudal subnucleus of the trigeminal spinal nucleus (Sp5C). The positive neurons and fibers were mostly concentrated in the middle portion of Sp5C dorsoventrally, where the afferent fibers innervating the skin of the upper lip are terminated. The reactive products were localized in perikarya, dendrites, nuclei, and diffusely in the neuropil. The present result suggests that p44/42 MAPK may be important in the transmission and modulation of noxious information in Sp5C.

Interdental distraction osteogenesis and rapid orthodontic tooth movement: a novel approach to approximate a wide alveolar cleft or bony defect

The closure of a wide alveolar cleft and fistula in cleft patients and the reconstruction of a maxillary dentoalveolar defect in traumatic patients are challenging for both orthodontists and surgeons. This is due to the difficulty in achieving complete closure by using local attached gingiva and the great volume of bone required for the graft. In this article, the authors propose using interdental distraction osteogenesis to create a segment of new alveolar bone and attached gingiva for the complete approximation of a wide alveolar cleft/fistula and the reconstruction of a maxillary dentoalveolar defect. They performed this procedure on one patient with a traumatic maxillary dentoalveolar defect and 10 patients with unilateral or bilateral cleft lips and palates who had varied dentoalveolar clefts/fistulas. Interdental and maxillary osteotomies were performed on one side of the dental arch by the cleft or defect. After a latency period of 3 days, the osteotomized distal segment of the dental arch was then distracted and transported toward the cleft or defect by using a toothborne intraoral distraction device. The alveoli and gingivae on both ends of the cleft or defect were approximated after distraction osteogenesis. The need for extensive alveolar bone grafting was eliminated. A segment of new edentulous alveolus and attached gingiva was created interdentally at a site distant to the cleft or defect. In the cleft patients, teeth were moved orthodontically into the regenerate (newly formed alveolar bone) dental crowding 1 week after distraction. The orthodontic tooth movement was rapidly completed in 3 months, and the edentulous space was eliminated. Interdental distraction osteogenesis minimizes an alveolar cleft/fistula and helps reconstruct a maxillary dentoalveolar defect by approximating the native alveoli and gingivae; it also creates new alveolar bone and gingiva for rapid orthodontic tooth movement.

Ion channel modulation as the basis for neuroprotective action of MS-153

MS-153, (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline, is a new neuroprotective drug. Recent data in the literature suggest that it inhibits glutamate accumulation occurring during ischemia and the translocation of protein kinase C gamma (PKC gamma). The present study was undertaken to prove the hypothesis that MS-153 blocks neuroreceptors and ion channels involved in glutamate accumulation. Neurons isolated from rat dorsal root ganglia and frontal cortex were used for recording channel currents by the whole-cell patch clamp technique. The effects of bath-applied MS-153 were examined on tetrodotoxin-sensitive and tetrodotoxin-resistant sodium channels and high voltage-gated calcium channels of dorsal root ganglion neurons, and channels activated by glutamate, N-methyl-D-aspartate (NMDA), kainate, alpha-amino-3-hydroxy-5-methyl-4-isoxarole propionic acid (AMPA), gamma-aminobutyric acid (GABA) and acetylcholine (ACh) in cortical neurons. MS-153 at a concentration of 300 microM had no effect on either tetrodotoxin-sensitive or tetrodotoxin-resistant sodium channels. High voltage-gated calcium channels were either suppressed or not affected by 1-300 microM MS-153. The variable blocking effect of MS-153 was due to the variable activity of intracellular components in individual neurons, especially that of PKC, whose translocation is known to be inhibited by MS-153. When 100 nM phorbol 12-myristate-13-acetate (PMA) was applied to neurons, MS-153 suppressed the calcium channel current more frequently. Calphostin C (0.5 microM), a specific PKC inhibitor, applied intracellularly via recording patch pipette, completely abolished MS-153 suppression of the calcium channel current. Currents induced by glutamate, NMDA, kainate, AMPA, GABA or ACh were not affected by MS-153 at 300 microM. It was concluded that MS-153 inhibited high voltage-gated calcium channels through interactions with PKC, thereby preventing massive release of glutamate from nerve terminals in ischemic conditions.

Characterization of an allelic variant in the nifedipine-specific element of CYP3A4: ethnic distribution and implications for prostate cancer risk. Mutations in brief no. 191. Online

CYP3A4 is involved in the metabolism of numerous biologically active compounds, including testosterone. A genetic variant located in the P450NF (nifedipine) specific element (NFSE) has been identified that disrupts a transciptional regulatory element located in the 5' regulatory region of CYP3A4. The CYP3A4 variant (CYP3A4-V) is associated with the clinical presentation of prostate cancer. There are significant differences in CYP3A4 metabolism and rates of prostate cancer across ethnic groups that may be associated with CYP3A4 genotypes. Therefore, we estimated the frequency of the CYP3A4 variant in three ethnic groups with different prostate cancer incidence rates. The frequency (q) of CYP3A4-V was significantly different (p<0.0001) in African Americans (q=0.53), U.S. Caucasians (q=0.09), and Taiwanese (q=0.0). CYP3A4-V segregated in a Mendelian manner in one large African American family, and 7 of 16 (44%) biologically unrelated "marry-ins" carried a CYP3A4 variant allele. Reflecting population-specific prostate cancer incidence rates, our results suggest a high frequency of this variant in African Americans compared with U.S. Caucasians and Taiwanese.

Changes in portal venous hemodynamics in patients with severe acute hepatitis over one year

PURPOSE

A wide range of portal vein blood flow velocity (PVV) values can be found in acute hepatitis. We studied course and medical significance of PVV changes in patients with severe acute hepatitis over a 1-year period.

METHODS

Portal venous hemodynamics were studied by Doppler sonography in 90 patients at study enrollment and 3, 6, and 12 months following an episode of severe acute hepatitis.

RESULTS

Forty-one survivors who had a maximum PVV at enrollment greater than or equal to the value measured at the third month were classified as the "declining PVV" group. Thirty-six survivors who had a maximum PVV at enrollment less than the value measured at the third month were classified as the "rising PVV" group. Thirteen patients died of acute hepatic failure and were classified as the fatality group. The fatality group had significantly lower maximum PVV, worse liver biochemical test results, and a higher prevalence of ascites at enrollment. In contrast, the declining PVV group showed significantly better liver biochemical test results and a lower prevalence of ascites. There was no significant difference in portal vein blood flow between the rising and declining PVV groups since portal vein diameter increased while PVV decreased.

CONCLUSIONS

An initially decreased PVV can be found in some patients with severe acute hepatitis and is inversely correlated with the severity of liver damage.

Nerve growth factor signaling in caveolae-like domains at the plasma membrane

Nerve growth factor (NGF) binding to its receptors TrkA and p75(NTR) enhances the survival, differentiation, and maintenance of neurons. Recent studies have suggested that NGF receptor activation may occur in caveolae or caveolae-like membranes (CLM). This is an intriguing possibility because caveolae have been shown to contain many of the signaling intermediates in the TrkA signaling cascade. To examine the membrane localization of TrkA and p75(NTR), we isolated caveolae from 3T3-TrkA-p75 cells and CLM from PC12 cells. Immunoblot analysis showed that TrkA and p75(NTR) were enriched about 13- and 25-fold, respectively, in caveolae and CLM. Binding and cross-linking studies demonstrated that the NGF binding to both TrkA and p75(NTR) was considerably enriched in CLM and that about 90% of high affinity binding to TrkA was present in CLM. When PC12 cells were treated with NGF, virtually all activated (i.e. tyrosine phosphorylated) TrkA was found in the CLM. Remarkably, in NGF-treated cells, it was only in CLM that activated TrkA was coimmunoprecipitated with phosphorylated Shc and PLCgamma. These results document a signaling role for TrkA in CLM and suggest that both TrkA and p75(NTR) signaling are initiated from these membranes.

Breast cancer risk associated with genotype polymorphism of the estrogen-metabolizing genes CYP17, CYP1A1, and COMT: a multigenic study on cancer susceptibility

Estrogen has been proposed to trigger breast cancer development via an initiating mechanism involving its metabolite, catechol estrogen (CE). To examine this hypothesis, we conducted a multigenic case-control study to determine whether polymorphisms of the genes responsible for CE formation via estrogen biosynthesis (CYP17) and hydroxylation (CYP1A1) and CE inactivation (COMT) are associated with an elevated risk for breast cancer in Taiwanese women, and whether the association between genotype and risk may be modified by estrogen exposure. One hundred and fifty breast cancer patients and 150 healthy controls were recruited. PCR-based RFLP assays were used to determine the genotypes of estrogen-metabolizing genes. The breast cancer risk associated with individual susceptibility genotypes varied among the three genes and was highest for COMT, followed by CYP1A1 and CYP17. After simultaneous consideration of all three genes and other well-established risk factors of breast cancer, the COMT genotype remained the most significant determinant for breast cancer development and was associated with a 4-fold increase in risk (95% confidence interval, 1.12-19.08). Furthermore, a trend of increasing risk for developing breast cancer was found in women harboring higher numbers of high-risk genotypes (P = 0.006), including the high activity CYP17 (CYP17 A2/A2), high inducibility CYP1A1 (CYP1A1 MspI vt/vt), and low activity COMT (COMT L/L) genotypes. The association of risk with the number of susceptibility genotypes was stronger in women with prolonged estrogen exposure (indicated by a higher number of estrogen exposure years or a higher number of estrogen exposure years between menarche and first full-term pregnancy), women with higher estrogen levels (implied by early menarche), and women with a higher body mass index (> or = 22.5). On the basis of comprehensive profiles of estrogen metabolism, this study supports the possibility that breast cancer can be initiated by estrogen exposure.