Case Series of Endoscopic Papillary Balloon Dilation for Children with Common Bile Duct Stones and a Review of the Literature

Background: Endoscopic sphincterotomy (EST) has been employed for the endoscopic treatment of common bile duct stones (CBDSs) and has been reported to have a high success rate for stone removal. However, EST is associated with a risk of bleeding, perforation, and sphincter of Oddi function disruption. To avoid these risks, endoscopic papillary balloon dilation (EPBD) is an option for CBDS. Sphincter of Oddi function preservation decreases long-term biliary infection and gallstone recurrence. EPBD may have advantages in children who require a long follow up. However, there have been few reports on pediatric cases, particularly in infants. Methods: From September 2017 to December 2023, we performed EPBD for four pediatric CBDSs. The patients were aged from 5 months to 8 years, including two infants aged 5 and 6 months. Furthermore, we reviewed the stone removal rate and complications of 545 ESTs performed at high-volume centers and 13 EPBD-reported cases in children with CBDSs. Results: CBDSs of all patients who underwent EPBD in our institution were successfully removed. No bleeding or perforation was noted; pancreatitis was observed in three patients. In an analysis of 545 ESTs in children, the stone removal rate was high, ranging from 83% to 100% (mean 96%). The incidence of pancreatitis was 0-9.6% (mean 4.4%), and the grade of pancreatitis was almost mild. The bleeding frequency was 1.3-5.4% (mean 2.7%). With regards to the grade of bleeding, seven cases were mild (64%) and four were moderate (36%). Compared with adults who underwent EST, the frequencies of pancreatitis and bleeding were almost equal in children; however, in children, once bleeding occurs, it has a higher risk of leading to blood transfusion. Stone removal via EPBD in children has a 100% success rate. Pancreatitis was responsible for all complications were related; its frequency was 46% (6/13 patients, including five mild cases and one moderate case), which is higher than that of EST and adult cases who underwent EPBD. In most children with pancreatitis, pancreatic enzyme levels returned to normal within 2-3 days following EPBD, and no severe cases caused by EPBD were reported. Conclusions: CBDS removal via EPBD in children has a high success rate with very low risk of bleeding and perforation. Although pancreatitis frequently occurs, most cases are mild. Sphincter of Oddi function preservation via EPBD is expected to prevent long-term stone recurrence and biliary tract infection, and EPBD is considered to be an effective method for CBDS removal in children.

Minimal endoscopic sphincterotomy followed by papillary balloon dilation to relieve choledocholithiasis in a 6-year-old girl with hereditary spherocytosis

A 6-year-old girl previously diagnosed with hereditary spherocytosis was admitted to our hospital with gallstones and cholangitis. Endoscopic retrograde cholangiopancreatography (ERCP) was performed, and fluoroscopy revealed a dilated common bile duct (CBD) without evident stones, possibly due to spontaneous excretion through the papilla of Vater. A 7-French plastic stent was inserted into the CBD. After the procedure, a marked increase in pancreatic enzyme levels was observed, and she was diagnosed with post-ERCP pancreatitis (PEP). Stent placement could have been a cause of pancreatitis; therefore, we removed the stent. Subsequently, recovery from pancreatitis was confirmed, although she suddenly complained of abdominal pain and was diagnosed with choledocholithiasis recurrence. ERCP was repeated, and fluoroscopy revealed a dilated CBD with a stone. A minimal endoscopic sphincterotomy (EST) was performed to reduce the risk of PEP, and a biliary dilation balloon placed across the papilla was gradually inflated until the waist of the balloon disappeared. Stones were extracted using a retrieval balloon catheter. The abdominal pain resolved immediately, and the patient recovered without developing PEP. To our knowledge, this is the first case report of a pediatric patient treated with minimal EST followed by papillary balloon dilation for choledocholithiasis.

Cap-assisted colonoscopy can increase the rate of sessile serrated lesion detection at the left lateral decubitus position: A retrospective case-control study

We investigated the effectiveness of cap-assisted colonoscopy conducted with the patient in the left lateral decubitus position at both the colonoscope's insertion and withdrawal timepoints compared to the effectiveness of colonoscopy without a cap conducted in the supine position at withdrawal. This was a case-control study, based on historical comparisons of patients over 2 time periods. The first group of patients underwent colonoscopies with a transparent cap and the patient was in the left lateral decubitus position at both the insertion and withdrawal timepoints from April to June 2019. The subsequent group underwent colonoscopies without a cap and with the patient in the supine position at withdrawal from July to September 2019. The rates of successful intubation, cecal intubation time, and number, size, shape, and location of the detected adenomas and sessile serrated lesions were compared between the 2 groups. Data from 644 colonoscopies (cap-assisted colonoscopy + left lateral decubitus position, n=320; other colonoscopies, n=324) were analyzed. The demographic characteristics and technical performances were similar. The SSL detection rate was significantly higher with cap-assisted colonoscopy and the left lateral decubitus position than with other colonoscopies (3.4% vs 0.93%, P=.029). The adenoma detection rates in the 2 groups were similar (31% and 28%, respectively, P=.43).Cap-assisted colonoscopy in the left lateral decubitus position may increase the detection rate of sessile serrated lesions compared to colonoscopy without a cap and supine position at withdrawal.

Mini-probe endoscopic ultrasound for the diagnosis of congenital esophageal or duodenal stenosis

PURPOSE

The usefulness of endoscopic ultrasound (EUS) in pediatric populations has been recently appreciated; however, published studies on mini-probe EUS in the diagnosis of congenital esophageal stenosis (CES) or congenital duodenal stenosis (CDS) in pre-school patients remain scarce. This study aimed to report the utility of mini-probe EUS for the diagnosis of CES or CDS in pre-school patients based on the etiology.

METHODS

We retrospectively reviewed the medical records of pediatric patients with CES or CDS who underwent mini-probe EUS through the stenotic segments at our hospital between December 2006 and December 2021.

RESULTS

Five patients with CES and one with CDS were enrolled. The median age and body weight when EUS was performed were 12.5 months and 8.5 kg, respectively. Hypoechoic lesions were observed on EUS in three patients, which were assessed as cartilage; one patient had no hypoechoic lesion but had a focal thickness of the muscular layer. They were diagnosed with tracheobronchial remnants based on EUS. The full circumferential wall thickness of the esophagus was visualized in one patient with fibromuscular hypertrophy. The histopathological findings confirmed the diagnoses. In the patient with CDS, EUS findings revealed pancreatic parenchyma encircling the stenotic part of the duodenum. The preoperative diagnosis was annular pancreas. The patient underwent duodenoduodenostomy, and intraoperative findings confirmed the diagnosis.

CONCLUSION

Mini-probe EUS can be recommended as a feasible and safe technique for infants and toddlers. It can effectively diagnose CES or CDS based on etiology and can inform treatment strategies for pre-school patients.

A 2-week intensive gastrointestinal endoscopy training program for pediatricians

BACKGROUND

In Japan there are limited opportunities for pediatricians to learn gastrointestinal (GI) endoscopy. This study investigated whether a short-term intensive training for 2 weeks in an adult GI setting enabled pediatricians to acquire basic technical competence for pediatric GI endoscopic procedures.

METHODS

This was a retrospective case series of pediatricians who underwent 2 weeks of intensive endoscopy training at an adult endoscopy unit in a community hospital. The numbers of esophagogastroduodenoscopy (EGD) and ileocolonoscopy procedures each pediatrician performed were evaluated. All enrolled pediatricians were asked to answer questionnaires regarding the 2 week intensive GI endoscopy training program.

RESULTS

There were 17 enrolled pediatricians, of whom 13 were men; average age 32 years (range 27-54). The median (range) numbers of EGDs and ileocolonoscopies performed by each pediatrician during the 2-week training period were 102 (66-144) and 14 (1-48), respectively. Fifteen out of 17 pediatricians experienced more than 100 GI endoscopies during the 2 weeks. All pediatricians performed biopsies as part of some EGD procedures. All 17 pediatricians found this program satisfactory. All pediatricians became cable of performing pediatric EGD (i.e., for children ≤15 years) after this training program. Sixteen pediatricians have continued to perform pediatric GI endoscopy since this training program.

CONCLUSIONS

A short-term intensive training program for 2 weeks in an adult GI setting enabled pediatricians to acquire basic technical competence for pediatric endoscopic procedures.

Characteristics and treatment of congenital esophageal stenosis: A retrospective collaborative study from three Japanese children's hospitals

BACKGROUND/PURPOSE

There is no consensus on treatment strategy of congenital esophageal stenosis (CES). This study aimed to assess appropriateness of the treatment we have provided to patients with CES over the past four decades.

METHODS

We carried out a retrospective chart review of 83 CES patients treated at three children's hospitals between 1973 and 2015. Each patient underwent an initial treatment with either surgery or a series of dilation that was followed by surgery if dilation failed to improve esophageal transit. Demographic data, course of treatment, outcomes, and complications were analyzed.

RESULTS

During this initial treatment, 19 and 64 patients underwent surgery and dilation, respectively. Out of the 64 patients who underwent dilations as an initial treatment, 26 patients eventually required surgery. Out of all patients who required surgery (19 initial treatments + 26 failed dilations), 29 had tracheobronchial remnants and 16 had fibromuscular hypertrophy. Six patients experienced esophageal perforation during dilation and ten experienced anastomotic leakage after surgery. No patients had swallowing difficulties at the latest follow up, 141(9-324) months.

CONCLUSIONS

Dilation is recommended as an initial therapy, especially if histological diagnosis of CES is uncertain. Persistent swallowing difficulties after 2 series of dilation may be an indication for surgery.

LEVELS OF EVIDENCE

level IV.

Recurrent massive bleeding from a small intestinal arteriovenous malformation after surgery for biliary atresia in an infant: a case report and literature review

BACKGROUND

Small intestinal arteriovenous malformation (AVM) can cause bleeding. Most small intestinal AVMs occur during adulthood, rarely in infancy. We report a case of an infant with hemorrhage due to small intestinal AVM early and recurrently after Kasai portoenterostomy (PE) for biliary atresia (BA).

CASE PRESENTATION

A 51-day-old male infant was admitted to our institution for obstructive jaundice. Laparotomic cholangiography revealed BA (IIIb1μ), and Kasai PE was performed at 60 days of age. On postoperative day 17, he developed massive melena and severe anemia. Contrast-enhanced computed tomography (CT) revealed that the jejunum around the PE site was strongly enhanced with enhancing nodules in the arterial phase, and a wide area of the Roux limb wall was slightly enhanced in the venous phase. As melena continued, emergency laparotomy was performed. There were no abnormal macroscopic findings at the PE site except for a clot in the Roux limb 5 cm away from the PE site, and the Roux limb was resected 5 cm. On further investigation, a red spot was detected on the jejunal serosa 30 cm away from the Roux-en-Y anastomosis site. PE and wedge resection for the red spot were performed. Histopathologically, both specimens indicated AVM. He was jaundice-free 65 days after the first surgery. However, at 7 months of age, he developed massive melena again. Contrast-enhanced CT and upper gastrointestinal endoscopy revealed no bleeding lesions. Hemorrhagic scintigraphy showed a slight accumulation at the hepatic hilum prompting an emergency surgery. Intraoperative endoscopy detected a bleeding lesion at the PE site, and the Roux limb was resected (approximately 6 cm). Intraoperative frozen section analysis of the stump of the resected jejunum revealed no abnormal vessels. PE was performed, and permanent section analysis revealed an AVM in the resected jejunum. The postoperative course was uneventful without re-bleeding.

CONCLUSIONS

We experienced a case of recurrent massive bleeding from small intestinal AVM in an infant after surgery for BA. Intraoperative endoscopy and frozen section analysis helped identify the bleeding lesion and perform a complete resection of the small intestinal AVM, even after surgery, in the infant.

Current status and future challenges in the endoscopic management of non-variceal upper gastrointestinal bleeding in children

PURPOSE

This study aimed to elucidate the characteristics of non-variceal upper gastrointestinal bleeding (NVUGIB) in children and the outcomes of endoscopic hemostasis (EH) performed by pediatric surgeons.

METHODS

We retrospectively reviewed the medical records of pediatric patients with NVUGIB who had undergone esophagogastroduodenoscopy (EGD) at our hospital, between December 2006 and March 2020.

RESULTS

Thirty-six patients were included. The most common endoscopic diagnosis was gastritis (28%), followed by gastric ulcer (25%) and duodenal ulcer (25%). Thirty patients (83%) had underlying diseases, including a recent viral infection (39%), followed by Helicobacter pylori infection (14%). Fourteen patients (39%) underwent EH, exhibiting a high initial rate of hemostasis (100%). This was achieved in 12/14 patients by clipping. One patient was treated using a combination of a hypersaline and epinephrine (HSE) injection and coagulation therapy, as the ulcer exceeded the width of the hemoclips. Rebleeding occurred in one patient (7.1%) initially treated with pure ethanol injections. The partial view of the pediatric duodenum prevented the placement of hemoclips; hence, the patient was treated using a combination of HSE and coagulation therapy.

CONCLUSION

Clipping, injection, and/or coagulation therapy can lead to high success rates for hemostasis, considering the anatomical characteristics in a pediatric population.

Recurrent intestinal ischemia following surgery for gastric and duodenal perforations: a case report

Background

Extremely low birth weight (ELBW) is a risk factor for various gastrointestinal complications. In the recent decades, advances in medicine have increased the survival of ELBW infants with necrotizing enterocolitis (NEC). To our knowledge, there have been no reports of neonates or infants developing simultaneous gastric and duodenal perforations and later developing NEC. We report a case of an extremely low birth weight infant (ELBWI) who developed both gastric and duodenal perforations at the same time and developed NEC after operation for gastric and duodenal perforations.

Case presentation

The patient was a female infant with ELBW who developed both gastric and duodenal perforations at the same time and developed NEC after operation for gastric and duodenal perforations. After birth, endotracheal intubation was performed. However, barotrauma occurred during positive pressure ventilation, resulting in a large area of emphysema in the left lower lung field, leading to collapse of the left lung. This giant bulla may have compressed the pulmonary vein, possibly resulting in pulmonary venous thrombosis (PVT). This episode could have triggered simultaneous gastric and duodenal perforations. In addition, we hypothesized that PVT caused acute arterial ischemia, leading to the development of NEC. The infant was started on heparin for anticoagulation. Later, the infant developed non-immunoglobulin E (IgE)-mediated gastrointestinal food allergies (non-IgE-GI-FAs). The giant bulla associated with barotrauma might have caused PVT, resulting in arterial emboli and multiple simultaneous gastrointestinal perforations.

Conclusions

Anticoagulation therapy with heparin for acute arterial thrombosis is effective for preventing the development of short bowel syndrome. Duodenal and intestinal surgery probably acted as risk factors for the subsequent development of non-IgE-GI-FAs. The infant had been stabilized at the time of writing this report.

Predictive factor for intraoperative tumor rupture of Wilms tumor

PURPOSE

For Wilms tumor, intraoperative tumor rupture with wide tumor spillage during surgical manipulation raises the classification to stage 3. Then, postoperative chemotherapy must be more intensive, and abdominal radiotherapy is added. Therefore, intraoperative tumor rupture should be avoided if possible. However, predictive factors for intraoperative tumor rupture have not been sufficiently described. Here we examined the risk factors for intraoperative tumor rupture.

METHODS

Patients with Wilms tumor who underwent treatment according to the National Wilms Tumor Study or the Japanese Wilms Tumor Study protocol at our institution were reviewed retrospectively. Collected cases were categorized into two groups: the ruptured group and the non-ruptured group. Risk factors for intraoperative tumor rupture, including the ratio of the tumor area to the abdominal area in a preoperative single horizontal computed tomography slice (T/A ratio), were investigated in both groups.

RESULTS

The two groups were not different in age, body weight, tumor laterality, sex, or histological distribution. The T/A ratio in the ruptured group was significantly higher than that in the non-ruptured group. Receiver operating characteristic curve analysis identified a discriminative value for a T/A ratio >0.5.

CONCLUSION

The T/A ratio can be a predictive factor for intraoperative tumor rupture of Wilms tumor.

Early Pathophysiologic Feature of Arthropathy in Juvenile Dogs Induced by Ofloxacin, a Quinolone Antimicrobial Agent

Arthropathy in dogs induced by ofloxacin, a quinolone antimicrobial agent, was pathophysiologically investigated. In the in vivo studies, ofloxacin was administered orally once or twice at 20 mg/kg/day to male juvenile (3-month-old, n = 3) or adult (36-month-old, n = 2) dogs, and the humeral and femoral heads were examined pathologically. Unlike adult dogs, fluid-filled vesicles were macroscopically observed on the articular surfaces of one juvenile dog 24 hours after a single treatment with ofloxacin. These lesions were seen in all juvenile dogs by twice dosing. Microscopically, fissures or cavity formations in the middle zone of the articular cartilage were noted only in juvenile dogs. Furthermore, the cartilage matrix from the abnormal area to the articular surface showed a decreased safranin-O staining intensity, suggesting proteoglycan depletion. Ultrastructurally, chondrocytes in the middle zone of juvenile dogs displayed dilatation of the cisternae in the rough endoplasmic reticulum as an initial hallmark. In the in vitro studies, chondrocytes isolated from the articular cartilage of naive juvenile dogs were exposed to ofloxacin at 6.3–100 μg/ml for 24 hours. Although no changes were noted in the deoxyribonucleic acid synthesis, protein synthesis, or proteoglycan release at concentrations of up to 100 μg/ml, the proteoglycan synthesis was evidently decreased in a dose-dependent manner from 12.5 μg/ml. The results obtained suggest that the inhibitory action of ofloxacin on proteoglycan syntheses in the chondrocytes may largely contribute to the early morphologic features in the articular cartilage of the juvenile dog.

Purification and Characterization of O-Methyltransferase I Involved in Conversion of Demethylsterigmatocystin to Sterigmatocystin and of Dihydrodemethylsterigmatocystin to Dihydrosterigmatocystin during Aflatoxin Biosynthesis

O-Methyltransferase I, which catalyzes conversions both of demethylsterigmatocystin (DMST) to sterigmatocystin (ST) and of dihydrodemethylsterigmatocystin (DHDMST) to dihydrosterigmatocystin (DHST) during aflatoxin biosynthesis, was purified to apparent homogeneity from the cytosol fraction of the mycelia of Aspergillus parasiticus NIAH-26 through the following chromatography series: phenyl-Sepharose, DEAE-Sepharose, phenyl-Sepharose, Sephacryl S-300, and Matrex gel Green A. The apparent molecular mass was estimated at 150 kDa based on Sephacryl S-300 gel filtration chromatography, and the denaturing molecular mass was 43 kDa based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The pI of the enzyme was 4.4, and the optimal pH for activity was broad, from 6.5 to 9.0. In competition experiments using the purified enzyme, the formation of ST from DMST was suppressed when DHDMST was added to the reaction mixture and DHST was newly formed. These results indicate that DMST and DHDMST commonly serve as substrates for the enzyme. The K(m) of the enzyme for DMST was 0.94 muM, and that for DHDMST was 2.5 muM. Interestingly, MT-I kinetics deviated substantially from standard Michaelis-Menten kinetics, demonstrating substrate inhibition at a higher substrate concentration.

Purification and characterization of two versiconal hemiacetal acetate reductases involved in aflatoxin biosynthesis

Two versiconal hemiacetal acetate (VHA) reductase activities (designated I and II), which catalyzed the reaction from VHA to versiconol acetate (VOAc) during aflatoxin biosynthesis, were purified to apparent homogeneity from the cytosol fraction of the mycelia of Aspergillus parasiticus mutant NIAH-26 through the following chromatography steps: first, fractionation with ammonium sulfate and then fractionation in succession with phenyl-Sepharose, DEAE-Sepharose, Sephacryl S-300, hydroxylapatite, and Matrex gel Green A chromatography. VHA reductase I and VHA reductase II were completely separated at the end of the DEAE-Sepharose step. The apparent molecular masses of reductase I and reductase II were estimated (by gel filtration) to be approximately 390 kDa; their denaturing molecular masses were 39- and 40-kDa, respectively (by sodium dodecyl sulfate-polyacrylamide gel electrophoresis). Their pI values were 6.6 and 6.0, respectively (as determined by isoelectric focusing), and the optimal pH values were 8.0 and 9.0, respectively, although both enzymes exhibited a broad optimal pH range of between 7.5 and 9.0. The K(m) values of reductase I and reductase II for VHA were 35.4 and 25.4 muM, respectively. On the other hand, in the cell-free experiments involving either VHA reductase fraction and high-performance liquid chromatography, both (2'S)- and (2'R)-VOAc enantiomers were formed from racemic VHA and more of the 2'R isomer than the 2'S isomer was produced, indicating that the VHA reductase fractions have very similar stereospecificities to the substrate.

Isolation of microorganisms and substances inhibitory to aflatoxin production

Aflatoxins are toxic and carcinogenic secondary metabolites produced by Aspergillus flavus and A. parasiticus. The contamination of crops, feeds, and foods with aflatoxins can have serious effects on the health of humans and animals. Although many studies have been done to develop aflatoxin-control strategies, most are limited in their effectiveness. As part of an effort to develop control procedures, we have devised simple and safe methods that are useful for identifying microorganisms that effectively inhibit aflatoxin production by fungi. These include the microtitre agar plate assay using norsolorinic acid-accumulating mutant fungi, the ultraviolet light photography method using an instant film, the tip culture method, a convenient RNA extraction method for reverse transcription-polymerase chain reaction (RT-PCR) analysis, and other methods. Results of a recent trial have shown that Achromobacter xylosoxidans significantly inhibited aflatoxin production by A. parsiticus, and that the main inhibitory substance produced by the bacterium was cyclo(L-leucyl-L-prolyl). This result confirms that the methods described herein are useful for identifying microorganisms that inhibit aflatoxin production by fungi and could contribute to the development of methods to reduce aflatoxin contamination in commodities.

Silent period and H reflex from soleus muscle as an index in a neuro-muscular function after reconstruction of anterior cruciate ligament

To clarify that the mixed nerve silent period (SP) and H reflex from soleus muscle may become an index expressed neuro-muscular function after reconstruction of anterior cruciate ligament (ACL), we studied the alteration of SP and H reflex from the soleus muscle in the patient with ACL reconstruction. Subjects were three patients with after ACL reconstruction, who were two male athletes (case A and B) and a female aerobics instructor (case C). Recording of SP and H reflex was performed longitudinally from one month post operation to six months post operation. As a result of this study, in case A, following findings were appeared; shortening of duration of SEP increasing the coefficient of variation of SP and increasing the amplitude ratio of H/M in non-operative side at the same time when his overusing activity of non-operative side. With case B, an appearance of long latency reflex (LLR) and an increase of coefficient of variation of SP in the operative side were verified in the period when many assists were required in order to correct motion image in rehabilitation. Concretely, from after the reconstruction over 5 months, LLR was appeared in SP of operative side, and increases of coefficient of variation was most remarkably in 4 months after the reconstruction, amplitude H/M ratio of operative side showed high value in 4 months after the reconstruction. With case C, remarkable problematical point was not found at the time of activity of daily life (ADL) acquisition and occupation return. So, with case C, feature findings of both SP and H reflex were not appeared. The results suggested that SP and H reflex from soleus muscle have become an index expressed neuro-muscular function of lower extremity and supra-spinal function in the patient after reconstruction of ACL.

Neuromuscular function after reconstruction of anterior cruciate ligament--a case study using evoked electromyography

To clarify the neuro-muscular function of a lower extremity after reconstruction of anterior cruciate ligament (ACL), we studied the alteration of H reflex and Silent period (SP) from the soleus muscle in a patient with ACL reconstruction. Subject was an eighteen year-old male and high school basketball player after a reconstruction of right ACL. Recording of H reflex and SP was started at one month after operation, and ended at six months post operation with a test at every month. As a result of this study, the amplitude ratio of H/M(max) was increased at post four months after ACL reconstruction on operative side. Little variation of SP was acquired in non-operative side. However, that in operative side was increased compared with non-operative side and gradually decreased until post six months. Post six months, the variation of SP in operative side was recovered as that of non-operative side. And, on the operation side, long-latency reflex (LLR) was appeared during SP from one month to five months after, especially its appearance pattern was most markedly post four months. However, post six months, LLR disappeared during SP. The result of H reflex, SP and LLR appearance suggested a following hypothesis; until post six months after ACL reconstruction, even the small and simple task (i.e. an ankle planter flexion with a slight effort) needs to an intervention of a various supra-spinal function. In this case, autonomy of central nervous system related to an out-put mechanism in lower-extremity was acquired post six months.

Implications for using H-max/M-max ratio in H-reflex parameters for elderly subjects compared with young subjects

The H-max/M-max ratio has long been used to understand motoneuron excitability induced by the Ia fibers. However, we contend that when comparing young and elderly subjects, this measurement can be controversial. We compared the modulation of the soleus H-max and M-max at five different muscle lengths between elderly and young subjects. The young subjects demonstrated a significant modulation of both H-max and M-max between dorsiflexion (DF) and plantarflexion (PF) positions. In contrast, the elderly subjects demonstrated no difference in H-max and M-max between DF and PF positions. However, it was more interesting to note that those elderly subjects who had similar H-max/M-max ratios to the young subjects at 0 deg showed identical modulation of H-max and M-max to that of the young In this paper, we discuss that H-reflex comparisons between young and elderly subjects may be confounded by the initial H-max/M-max ratio. This finding has implications for both the statistical analysis of this data as well as the theoretical interpretation of H-reflex measurements.

Physical aging by soft ultrasonic wave enhances ethanol metabolism: metabolic process of wine as followed by 400 mhz 1H-NMR spectroscopy

In natural aging of spirits or wine, the dynamic structure of ethanol-water clusters changes to a smaller and more uniform state. Through experience we know that naturally aged ones have higher metabolism than the non-aged ones. Also, the same effect as natural aging can be obtained in various types of spirits or wines by the treatment for a period of time with soft ultrasonic wave (US). In this study, we compared ethanol metabolism in human subjects dosed with non-treated white wine (control = CON) and with US treated wine. Ethanol levels in human sera were followed by 400 MHz 1H-NMR spectroscopy after administration of wine doses. Experimental results indicated that ethanol metabolism was enhanced 18% in subjects when US treated wine was used rather than when non-treated (CON) was used. Other experiments using rabbits showed that a 20% ethanol-aqueous solution was absorbed 18% more rapidly by the group dosed with US wine than by the CON group. From these experimental facts, it was theorized that ethanol metabolism depends on the rapidity of ethanol absorption in the human body. And it can be concluded that US treatment brings about the same effect on spirits or wines as natural aging.

Enzyme reactions and genes in aflatoxin biosynthesis

Aflatoxins are highly toxic and carcinogenic substances mainly produced by Aspergillus flavus and Aspergillus parasiticus. Sterigmatocystin is a penultimate precursor of aflatoxins and also a toxic and carcinogenic substance produced by many species, including Aspergillus nidulans. Recently, the majority of the enzyme reactions involved in aflatoxin/sterigmatocystin biosynthesis have been clarified, and the genes encoding the enzymes have been isolated. Most of the genes constitute a large gene cluster in the fungal genome, and their expression is mostly regulated by a product of the regulatory gene aflR. This review will summarize the enzymatic steps and the genes in aflatoxin/sterigmatocystin biosynthesis.

Gastric Myoelectrical Activity Increases after Moderate-Intensity Exercise with no Meals under Suppressed Vagal Nerve Activity

Postprandial gastric myoelectrical activity recorded by electrogastrogram (EGG) with the subject in a supine position has shown to be enhanced after moderate-intensity pedaling exercise in an upright seated position, despite the suppression of vagal nerve activity. However, it is still unknown whether the effect is due to the exercise itself and/or a meal or how the position change has influenced the effects. To address this, we used a position-controllable cycle ergometer to examine the effects of the moderate-intensity exercise on EGG activity and the high-frequency (HF) component of heart rate variability (HRV), an index of vagal nerve activity. To eliminate the effect of position change, we carried out the exercise and the EGG recording in the supine position. The peak amplitude of the EGG was enhanced by prior moderate-intensity exercise with a reduced HF component of HRV, which did not differ for postexercise conditions with or without a meal. The small amount of meal itself, however, enhanced both the peak amplitude of the EGG and the HF component of HRV. The peak frequency of EGG was reduced and the instability coefficient of EGG was increased only after the exercise itself. Taken together, these results suggest that the enhanced amplitude of gastric myoelectrical activity can be induced by moderate-intensity exercise itself, even with suppressed vagal nerve activity, and that the mechanism underlying the exercise effects would differ from that underlying the effect of a meal alone.

A non-arthropathic dose and its disposition following repeated oral administration of ofloxacin, a new quinolone antimicrobial agent, to juvenile dogs

A non-arthropathic dose and disposition of ofloxacin, a potent new quinolone antimicrobial agent, were assessed in male juvenile (3-month-old) dogs, when administered orally at 5, 10 and 20 mg/kg/day once daily for 8 consecutive days. Ofloxacin concentrations in sera and articular cartilages were analyzed by high-performance liquid chromatography (HPLC). Macroscopically, arthropathy characterized by fluid-filled vesicles in articular surface of the humerus and femur was observed in animals receiving 10 and 20 mg/kg/day of ofloxacin, but not in those given 5 mg/kg/day. At 20 mg/kg/day, arthropathy of comparable severity also occurred on day 2. Microscopically, the cavity formation in the middle zone of the articular cartilage was first identified and then necrotic chondrocytes were found numerous around the cavity, followed by appearance of chondrocyte clusters. In pharmacokinetics, peak serum concentration (Cmax) and area under the concentrations (AUC0-24) were increased in a dose-dependent manner. However, no remarkable differences in these two parameters were noted between a single and repeated treatments, suggesting no accumulation of the drug. The articular ofloxacin concentration 2 hr after treatment was approximately 1.8 (day 2) to 2.0 times (day 8) higher than the serum concentration. Based on these results, a non-arthropathic dose of ofloxacin in male juvenile dogs following an 8-day treatment is considered to be 5 mg/kg/ day, and its Cmax, AUC0-24 and articular cartilage concentrations 2 hr after treatment were 3.4 microg/ml, 35.1 microg-hr/m/ and 7.0 microg/g, respectively, under these experimental conditions. Thus, arthropathy due to ofloxacin may be predicted by monitoring serum drug concentration.

Automatic postural response systems in individuals with congenital total blindness

This study examined the effects of the absence of vision from birth on automatic postural responses to platform displacements during stance. Postural responses were induced by producing randomly four types of perturbations which consisted of forward and backward translations, and toe up and down rotations. Nine congenitally totally blind and nine sighted adults served as subjects. EMG signals were recorded from four muscles in the right leg, and reaction time to somatosensory stimuli generated by platform displacements was measured by pushing a hand-held button. To assess the ability to control postural balance, the root mean square (RMS) values for lateral and antero-posterior sway before, during, and after perturbations were calculated. The EMG amplitude in the gastrocnemius muscle of a blind subject was smaller than that of a sighted subject with eyes closed. No significant differences were found between blind and sighted subjects in EMG latencies of the lower extremity muscles in response to perturbations. The blind subjects had significantly faster reaction times to somatosensory stimuli triggered by platform displacements, but in toe down rotations no significant difference was found between blind and sighted subjects. The difference in the EMG latencies and reaction times between the two groups suggests that blindness from birth may not affect the spinal stretch reflex, but may affect a volitional act mediated through the motor cortex. There were also no significant differences in the RMS values for postural sway between blind and sighted subjects with eyes open or closed, although blind subjects swayed more after backward translations than did sighted subjects with eyes open. Results suggest that the ability to control postural balance during perturbations was not affected by vision loss from birth. Our findings suggest that the automatic postural response systems of humans are unaffected by the absence of vision from birth and are rather hard wired.

Absence of aflatoxin biosynthesis in koji mold (Aspergillus sojae)

Ten strains isolated from industrial soy sauce producing koji mold were identified as Aspergillus sojae and distinguished from Aspergillus parasiticus morphologically and physiologically. There was no detectable aflatoxin in any culture extracts of A. sojae strains. Strain 477 was chosen as a representative strain of industrial A. sojae for further molecular analysis. All enzymatic activities associated with the aflatoxin biosynthesis were not detected or negligible in strain 477 compared with that of the A. parasiticus strain. Southern analysis suggested that the genomic DNA of strain 477 contained aflatoxin biosynthetic pathway genes. In contrast, all industrial strains lacked detectable transcripts of aflR, the main regulatory gene for aflatoxin biosynthesis, under the aflatoxin-inducing condition. Our data suggest that defects in aflR expression cause the lack of expression of aflatoxin-related genes which results in the absence of aflatoxin biosynthesis in A. sojae strains.

Effects of high versus low-intensity resistance training on bone mineral density in young males

The purpose of this study was to investigate the effect of high-intensity and low-intensity resistance training upon bone mineral density (BMD) by comparing the BMD of young male powerlifters (n = 5), recreational trainees (n = 5), and controls (n = 5). Lumbar spine (L2-L4), proximal femur, and whole body BMDs were measured using dual-energy X-ray absorptiometry (DXA). The high-intensity group showed a significantly greater BMD when the whole body and trochanter regions were measured than the low-intensity and control group. The BMD of the lumbar spine, femoral neck, and Ward's triangle was greater in the high-intensity group compared with the control group. There was no significant BMD difference between the low-intensity and control group except at the trochanter region. These results suggest that high-intensity resistance training is effective for increasing BMD, but low-intensity resistance training is not.

Quantitative imaging of tyrosine hydroxylase and calmodulin in the human brain

The distributions of tyrosine hydroxylase and calmodulin in adult normal postmortem human brain were analyzed quantitatively. Consecutive coronal sections were obtained from the anterior area of the right hemisphere and were stained immunohistochemically for tyrosine hydroxylase and calmodulin. Stained sections were divided into approximately 3 million microareas at 50 microm intervals, and the immunohistochemical fluorescence intensity in each area was measured by a human brain mapping analyzer, which is a microphotometry system for analysis of the distribution of neurochemicals in a large tissue slice. Immunoreactive staining of tyrosine hydroxylase and calmodulin was observed in almost all brain regions, but its intensity varied. Relatively high levels of calmodulin were observed in brain regions with high levels of tyrosine hydroxylase, though high levels of tyrosine hydroxylase were not always observed in brain regions where high levels of calmodulin were distributed. In particular, high levels of both of tyrosine hydroxylase and calmodulin were distributed in the caudate nucleus and putamen. Previously it was shown that tyrosine hydroxylase was activated and dopamine synthesis was enhanced in the neostriatum region in mice and rats by the intracerebroventricular administration of calcium through a calmodulin-dependent system. The present results combined with these previous findings suggest that the activity of tyrosine hydroxylase in the caudate nucleus and putamen of humans may also be regulated by a calcium/calmodulin-dependent system.

A new inhibitor of 5'-hydroxyaverantin dehydrogenase, an enzyme involved in aflatoxin biosynthesis, from Trichoderma hamatum

Screening for inhibitors of 5'-hydroxyaverantin dehydrogenase, an enzyme involved in aflatoxin biosynthesis, resulted in the isolation of a new metabolite (1) from Trichoderma hamatum. On the basis of spectroscopic data, 1 was determined to be 4, 6-dihydroxy-5-methoxy-6a-methylcyclohexa[de]indano[7, 6-e]cyclopenta[c]2H-pyran-1,9-dione.

Role of cardiac renin-angiotensin system in sarcoplasmic reticulum function and gene expression in the ischemic-reperfused heart

The aim of this study was to explore the possible participation of cardiac renin-angiotensin system (RAS) in the ischemia-reperfusion induced changes in heart function as well as Ca2+-handling activities and gene expression of cardiac sarcoplasmic reticulum (SR) proteins. The isolated rat hearts, treated for 10 min without and with 30 microM captopril or 100 microM losartan, were subjected to 30 min ischemia followed by reperfusion for 60 min and processed for the measurement of SR function and gene expression. Attenuated recovery of the left ventricular developed pressure (LVDP) upon reperfusion of the ischemic heart was accompanied by a marked reduction in SR Ca2+-pump ATPase, Ca2+-uptake and Ca2+-release activities. Northern blot analysis revealed that mRNA levels for SR Ca2+-handling proteins such as Ca2+-pump ATPase (SERCA2a), ryanodine receptor, calsequestrin and phospholamban were decreased in the ischemia-reperfused heart as compared with the non-ischemic control. Treatment with captopril improved the recovery of LVDP as well as SR Ca2+-pump ATPase and Ca2+-uptake activities in the postischemic hearts but had no effect on changes in Ca2+-release activity due to ischemic-reperfusion. Losartan neither affected the changes in contractile function nor modified alterations in SR Ca2+-handling activities. The ischemia-reperfusion induced decrease in mRNA levels for SR Ca2+-handling proteins were not affected by treatment with captopril or losartan. The results suggest that the improvement of cardiac function in the ischemic-reperfused heart by captopril is associated with the preservation of SR Ca2+-pump activities; however, it is unlikely that this action of captopril is mediated through the modification of cardiac RAS. Furthermore, cardiac RAS does not appear to contribute towards the ischemia-reperfusion induced changes in gene expression for SR Ca2+-handling proteins.

Quantitative maps of GAbAergic and glutamatergic neuronal systems in the human brain

GABAergic and glutamatergic neuronal systems in adult normal human brains were shown quantitatively and in detail through the distributions of glutamate decarboxylase (GAD) and glutamate dehydrogenase (GDH), respectively. Consecutive coronal sections containing part of the striatum and the substantia nigra were obtained from the right hemisphere of three deceased persons with no history of neurological or psychiatric diseases and were stained immunohistochemically for GAD and GDH. Each stained section was divided into approximately 3 million microareas and the immunohistochemical fluorescence intensity in each area was measured by a human brain mapping analyzer, which is a microphotometry system for analysis of the distribution of neurochemicals in a large tissue slice. In the analyzed brain regions, conspicuously intense GAD-like immunoreactivity was observed in the substantia nigra, globus pallidus, and hypothalamus. GDH was widely and rather evenly distributed in the gray matter compared to GAD, although intense GDH-like immunoreactivity was observed in the lateral geniculate nucleus and substantia nigra. Within the substantia nigra, the globus pallidus, and other regions, characteristic distributions of GAD- and GDH-like immunoreactivity were found. We believe that the analysis of the human brain by this novel technique can help to understand the functional distribution of neuronal systems in the normal human brain and may be able to identify abnormal changes in the diseased human brain. It can also provide basic data to help in the interpretation of functional magnetic resonance imaging or positron emission tomography.

Effect of Zena F-III, a liquid nutritive and tonic drug, on the neurochemical changes elicited by physical fatigue in mice

The effects of a liquid nutritive and tonic drug (NTD) on the neurochemical changes elicited by physical fatigue in mice were investigated in terms of the calcium-dependent dopamine synthesizing function of the brain. In this study, Zena F-III (Taisho Pharmaceutical Co., Ltd., Japan), one of the most popular NTDs in Japan, containing 15 crude drug extracts together with taurine, caffeine, and vitamins, and formulated based on the precepts of traditional Chinese medicine, was used. Male mice were forced to walk for 0-6 h at a speed of 3 m/min using a programmed motor-driven wheel cage. The serum and brain calcium levels in the mice were significantly increased following forced walking. The increase in brain calcium level began later and was more gradual than that in the serum calcium level, and reached its maximum value following forced walking for 3 h. The neostriatal dopamine level was also significantly increased, and locomotor activity significantly decreased following forced walking for 3 h. Prior oral administration of F-III (10 ml/kg) attenuated the increases in the serum and brain calcium levels, the increase in the brain dopamine levels, and the decrease in locomotor activity induced by forced walking. Taking into consideration these findings with our previous reports, it is suggested that physical fatigue leads to an increase in dopamine synthesis in the brain through a calcium/calmodulin-dependent system, thereby inducing behavioral changes, and that F-III inhibits this pathway and may alleviate overwork-induced physical fatigue.

Mechanomyographic investigation of muscle contractile properties in preadolescent boys

The aim of the present study was to elucidate the muscle contractile properties of preadolescent boys using the mechanomyogram (MMG) and electromyogram (EMG). In 8 preadolescent boys and 10 male young adults, the EMG and MMG were recorded from quadriceps muscles during isometric knee extension contractions at levels of 10 to 80% MVC. The relationship of EMG and MMG to absolute force was approximated by a regression line (r > 0.8). The regression line of the EMG in preadolescent was located above that of the adults, whereas the MMG in both subject groups was fitted by virtually the same regression line. Thus, the MMG seems to be indicative of absolute force in preadolescents as well as young adults. Both groups showed a non-linear increase in the EMG and MMG with relative force (%MVC). The EMG and %MVC relationship was not significantly different between the two groups, whereas the MMG in preadolescents was smaller than that of adults over the range of force studied. The MMG increment with %MVC was more remarkable above 30 or 40% MVC in both groups; however, the rate of the increment in preadolescents was smaller than that in adults. The MMG and %MVC relationship suggests that the muscle contractile properties in preadolescent boys are characterized by immaturity of the fast twitch fibers.

A role of PKC in the improvement of energy metabolism in preconditioned heart

OBJECTIVE

A possible link between activation of PKC and improvement of energy metabolism during reperfusion in ischemic preconditioning hearts was examined.

METHODS

Isolated perfused rat hearts were preconditioned by 5-min ischemia and 5-min reperfusion in the presence and absence of a PKC inhibitor polymyxin B (50 microM) and then subjected to 40-min sustained ischemia and subsequent 30-min reperfusion. In another set of experiments, the hearts pretreated with and without a PKC activator PMA (15 pmol/5 min) were subjected to the sustained ischemia and reperfusion. Myocardial high-energy phosphates, glycolytic intermediates and mitochondrial oxygen consumption capacity were determined at appropriate experimental sequences.

RESULTS

Preconditioning enhanced the recovery of cardiac function such as left ventricular developed pressure, heart rate and rate-pressure product of the reperfused heart, suppressed the release of creatine kinase, enhanced the reperfusion-induced restoration of myocardial high-energy phosphates, attenuated the reperfusion-induced accumulation in glucose 6-phosphate and fructose 6-phosphate contents, abolished the ischemia-induced increase in tissue lactate content and prevented the ischemia-induced decrease in mitochondrial oxygen consumption capacity. Treatment of the perfused heart with PMA mimicked the effects of preconditioning on post-ischemic contractile function, enzyme release, levels of myocardial energy store, glycolytic intermediates and lactate, and mitochondrial function. Polymyxin B-treatment abolished the preconditioning-induced recovery of post-ischemic contractile function, the suppression of the release of CK, the restoration of myocardial energy store, and the preservation of mitochondrial function, whereas it did not cancel the improvement of glycolytic intermediate levels and the reduction in tissue lactate accumulation. Post-ischemic contractile function was closely related to restoration of high-energy phosphates and mitochondrial oxygen consumption capacity in all hearts subjected to ischemia/reperfusion.

CONCLUSION

The results suggest that activation of PKC and preservation of mitochondrial function are closely linked with each other in the preconditioned heart, which may lead to the improvement of post-ischemic contractile function.

Age-related changes in gait velocity and leg extension power in middle-aged and elderly people

To prevent a decline in gait with age, it is necessary to investigate age-related changes in gait performance and detect related factors. The purpose of this study was to assess the association between gait ability and leg extension power among middle-aged and elderly people. Height, weight, maximum gait velocity (MGV) and leg extension power (LEP) were measured in 752 males and females who participated in the National Institute for Longevity Sciences, Longitudinal Study of Aging (NILS-LSA). Age-related changes in MGV and LEP and the association between MGV and LEP were assessed. There were significant decline trends in height, weight, MGV and LEP with advancing age (p < 0.001). MGV showed a significantly positive correlation with LEP (in males: r = 0.48 p < 0.001, in females: r = 0.47; p < 0.001). Subjects aged 60 yrs and over showed a significantly higher correlation than those under 60 yrs in males, but not in females, after adjustment for height and weight. Although the relationships between MGV and LEP were different by age and gender, LEP may be one of the important factors in maintaining gait ability.

Quantitative imaging of substance P in the human brain using a brain mapping analyzer

The distribution of substance P (SP)-like immunoreactive neurons in the brains of aged normal human was analyzed quantitatively. Consecutive coronal sections in which the striatum and the substantia nigra were exposed widely, were obtained from the right hemisphere and stained immunohistochemically for SP. Each stained section was divided into approximately three million microareas and the immunohistochemical fluorescence intensity in each area was measured using a human brain mapping analyzer, which is a microphotometry system for analysis of the distribution of neurochemicals in a large tissue slice. These distributions are displayed in color and monochromatic graphics. In the analyzed brain regions, conspicuously intense SP-like immunoreactivity was observed in the substantia nigra and the internal segment of the globus pallidus. Within the substantia nigra, the SP-like immunoreactive intensity in the pars compacta was 25%, higher than that in the pars reticulata, and the distribution of melanin-containing neurons corresponded well to the distribution of the SP-containing structures. SP-like immunoreactive intensity in the internal segment of the globus pallidus, which was lower than that in the substantia nigra, was approximately twice as high as that in the external segment of the globus pallidus. Very intense immunoreactivity was localized at the most medial area of the internal segment of the globus pallidus. The SP-like immunoreactive intensity in the caudate nucleus and putamen was moderate, and the distribution was heterogeneous and observed in patches.

Cloning and characterization of the O-methyltransferase I gene (dmtA) from Aspergillus parasiticus associated with the conversions of demethylsterigmatocystin to sterigmatocystin and dihydrodemethylsterigmatocystin to dihydrosterigmatocystin in aflatoxin biosynthesis

O-Methyltransferase I catalyzes both the conversion of demethylsterigmatocystin to sterigmatocystin and the conversion of dihydrodemethylsterigmatocystin to dihydrosterigmatocystin during aflatoxin biosynthesis. In this study, both genomic cloning and cDNA cloning of the gene encoding O-methyltransferase I were accomplished by using PCR strategies, such as conventional PCR based on the N-terminal amino acid sequence of the purified enzyme, 5' and 3' rapid amplification of cDNA ends PCR, and thermal asymmetric interlaced PCR (TAIL-PCR), and genes were sequenced by using Aspergillus parasiticus NIAH-26. A comparison of the genomic sequences with the cDNA of the dmtA region revealed that the coding region is interrupted by three short introns. The cDNA of the dmtA gene is 1,373 bp long and encodes a 386-amino-acid protein with a deduced molecular weight of 43,023, which is consistent with the molecular weight of the protein determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The C-terminal half of the deduced protein exhibits 76.3% identity with the coding region of the Aspergillus nidulans StcP protein, whereas the N-terminal half of dmtA exhibits 73.0% identity with the 5' flanking region of the stcP gene, suggesting that translation of the stcP gene may start at a site upstream from methionine that is different from the site that has been suggested previously. Also, an examination of the 5' and 3' flanking regions of the dmtA gene in which TAIL-PCR was used demonstrated that the dmtA gene is located in the aflatoxin biosynthesis cluster between (and in the same orientation as) the omtA and ord-2 genes. Northern blotting revealed that expression of the dmtA gene is influenced by both medium composition and culture temperature and that the pattern correlates with the patterns observed for other genes in the aflatoxin gene cluster. Furthermore, Southern blotting and PCR analyses of the dmtA gene showed that a dmtA homolog is present in Aspergillus oryzae SYS-2.

[Is portal infusion chemotherapy uneffective for hepatic recurrence after resection for colorectal cancer?]

Sixty-six patients with colorectal cancer were studied regarding effects of prevention of hepatic recurrence in completely performed portal infusion chemotherapy. The regimen was continuous administration of 500-875 mg/body of 5-FU for 7 days and intraportal administration of 10 mg of MMC before and after 5-FU administration. Hepatic recurrence rate was 7.6% and the five year survival rate was 83.3% in portal infusion group, and 16% and 71.3% in the control group; the difference was not significant. However, the hepatic recurrence rate in patients administered more than 4 g of 5-FU was 2.5%; there was a significant difference between the portal group and control group. The five-year survival rate for patients administered more than 4 g of 5-FU was 92.3%, which was significantly higher than at less than 4 g. Excellent effects for prevention of hepatic recurrence and prognosis were obtained in patients administered more than 4 g of 5-FU. Thus, the compliance of 5-FU in portal infusion chemotherapy is important. Also, administration of MMC is suspected to enhance the effect of portal infusion chemotherapy.

Enzymatic formation of G-group aflatoxins and biosynthetic relationship between G- and B-group aflatoxins

We detected biosynthetic activity for aflatoxins G(1) and G(2) in cell extracts of Aspergillus parasiticus NIAH-26. We found that in the presence of NADPH, aflatoxins G(1) and G(2) were produced from O-methylsterigmatocystin and dihydro-O-methylsterigmatocystin, respectively. No G-group aflatoxins were produced from aflatoxin B(1), aflatoxin B(2), 5-methoxysterigmatocystin, dimethoxysterigmatocystin, or sterigmatin, confirming that B-group aflatoxins are not the precursors of G-group aflatoxins and that G- and B-group aflatoxins are independently produced from the same substrates (O-methylsterigmatocystin and dihydro-O-methylsterigmatocystin). In competition experiments in which the cell-free system was used, formation of aflatoxin G(2) from dihydro-O-methylsterigmatocystin was suppressed when O-methylsterigmatocystin was added to the reaction mixture, whereas aflatoxin G(1) was newly formed. This result indicates that the same enzymes can catalyze the formation of aflatoxins G(1) and G(2). Inhibition of G-group aflatoxin formation by methyrapone, SKF-525A, or imidazole indicated that a cytochrome P-450 monooxygenase may be involved in the formation of G-group aflatoxins. Both the microsome fraction and a cytosol protein with a native mass of 220 kDa were necessary for the formation of G-group aflatoxins. Due to instability of the microsome fraction, G-group aflatoxin formation was less stable than B-group aflatoxin formation. The ordA gene product, which may catalyze the formation of B-group aflatoxins, also may be required for G-group aflatoxin biosynthesis. We concluded that at least three reactions, catalyzed by the ordA gene product, an unstable microsome enzyme, and a 220-kDa cytosol protein, are involved in the enzymatic formation of G-group aflatoxins from either O-methylsterigmatocystin or dihydro-O-methylsterigmatocystin.

Involvement of adenosine receptor, potassium channel and protein kinase C in hypoxic preconditioning of isolated cardiomyocytes of adult rat

A possible mechanism for hypoxic preconditioning of adult rat cardiomyocytes was pharmacologically investigated. Isolated cardiomyocytes in all experimental groups were incubated for 120 min under hypoxic conditions followed by 15-min reoxygenation (sustained H/R). Sustained H/R decreased rod-shaped cells. Exposure of the cardiomyocytes to 20-min of hypoxia/30-min reoxygenation (hypoxic preconditioning) attenuated the sustained H/R-induced decrease in rod-shaped cells. The effects of hypoxic preconditioning were abolished by treatment with the protein kinase C (PKC) inhibitor polymyxin B, but abolished by neither the adenosine A1/A2-antagonist sulfophenyl theophylline (SPT) nor the ATP-sensitive potassium channel (K(ATP) channel) blocker glibenclamide. In another series of experiments, cardiomyocytes were incubated without hypoxic preconditioning in the presence of either the PKC activator PMA, adenosine or K(ATP)-channel opener nicorandil and then subjected to sustained H/R. Treatment of the cells with PMA, adenosine or nicorandil mimicked the effects of hypoxic preconditioning. The effects of treatment with adenosine and nicorandil were abolished by polymyxin B treatment. Combined treatment with both SPT and glibenclamide abolished the effects of hypoxic preconditioning, whereas it failed to abolish PMA-induced cytoprotection. These results suggest that the activation of PKC in hypoxic preconditioned cardiomyocytes coupled independently with stimulation of adenosine receptor or opening of K(ATP) channel, either of which is fully enough to exert the cytoprotective effects.

Bone mineral density differences between paraplegic and quadriplegic patients: a cross-sectional study

STUDY DESIGN

This cross-sectional study was conducted by comparing bone mineral density (BMD) of paraplegic and quadriplegic patients.

OBJECTIVES

The purpose of this study was to investigate the relationship between the bone mineral loss and injury level in spinal cord injury patients.

SETTINGS

Experiments were conducted at Yoneda Hospital and Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan.

METHODS

Lumbar spine (L2-4), proximal femur (femoral neck, trochanter region and Ward's triangle) and whole body BMD were measured in ten paraplegic and ten quadriplegic patients using dual-energy X-ray absorptiometry (DXA, HITACHI BMD-IX).

RESULTS

Significant differences were observed in the lumbar spine, trochanter region and upper extremities BMD between paraplegic and quadriplegic patients (P<0.05, P<0.05 and P<0.01, respectively), but not in the femoral neck, Ward's triangle, head, pelvis, lower extremities or whole body BMD.

CONCLUSION

These results suggest that the injury level influences on the lumbar spine, upper extremities and trochanter region BMD. From a biomechanical standpoint, it is possible to explain that the differences in mechanical loading exerted on bones also affected the difference of lumbar spine BMD in the two groups.

Transcript of a homolog of aflR, a regulatory gene for aflatoxin synthesis in Aspergillus parasiticus, was not detected in Aspergillus oryzae strains

Some strains of Aspergillus oryzae were shown to have homologs of aflR, a regulatory gene for aflatoxin synthesis in Aspergillus parasiticus. Transcription of an aflR homolog was examined in six strains of A. oryzae having the homologs, using polymerase chain reaction (PCR) coupled with reverse transcription. No PCR product was obtained when the RNA prepared from the A. oryzae strains cultivated under aflatoxin-producing condition was used as template for amplification of the aflR cDNA. By contrast, a PCR product of the expected size was obtained with RNA from A. parasiticus NIAH-26 processed by the same procedure. From genomic DNA of these strains, PCR products of the same size as above were obtained. Possible degradation of the aflR mRNA in the RNA preparation of the A. oryzae strains was negligible, because the calmodulin transcript was detected by PCR from the same RNA samples. Thus, the aflR homologs in the non-aflatoxigenic A. oryzae strains examined are not expressed even under aflatoxin-producing condition.

Quantitative mapping analyzer for determining the distribution of neurochemicals in the human brain

We developed a human brain mapping analyzer to determine the quantitative distribution of specific molecules, such as neurotransmitters or neuromodulators, based on a fluorescence microphotometry system that we had previously developed. The immunohistochemical fluorescence emitted from each microarea of a brain slice is collected into a photomultiplier tube through the pinhole and objective lens of a microscope. The brain slice is moved in the x- or y-direction by a motorized scanning stage under the objective lens, and the fluorescence intensities are measured quantitatively. The scanning speed is approximately 100 microareas/s, the maximum stage motion is 150 x 150 mm, and an unlimited amount of data can be gathered continuously by transfer to external memory devices. In this paper, this analyzer is characterized in detail, and the methods used for the preparation and analysis of human brain slices are described. As an example, the cholinergic distribution in hemispheric coronal slices of the adult human brain is analyzed. Each slice, immunohistochemically stained for choline acetyltransferase, was divided into approximately 3 million microareas (one area is 50 microm in diameter), and the distribution of the cholinergic neurons is shown.

Pharmacologic preconditioning induced by beta-adrenergic stimulation is mediated by activation of protein kinase C

Ischemic preconditioning (I-PC) occurs via activation of protein kinase C (PKC). This study was undertaken to determine whether pharmacologic preconditioning by beta-adrenergic stimulation (beta-PC) is mediated by PKC activation. Isolated rat hearts were subjected to 40-min ischemia and 30-min reperfusion. Beta-PC was induced by 0.25 microM isoproterenol pretreatment for 2 min followed by 10-min normoxic perfusion. Beta-PC enhanced the recovery of rate-pressure product of the ischemic/reperfused heart (79.1 +/- 8.4% vs. 12.4 +/- 1.6% of initial for Non-PC group, n = 6) and attenuated the release of creatine kinase during 30-min reperfusion (30.2 +/- 2.2 vs. 59.8 +/- 6.1 nmol/min/g wet wt for Non-PC group, n = 6), similar to an I-PC stimulus of 5-min ischemia and 5-min reperfusion. Treatment with 50 microM polymyxin B, a PKC inhibitor, abolished the cardioprotection of both beta-PC and I-PC. Furthermore, similar changes in subcellular distribution of PKC were induced by both beta-PC and I-PC. The changes in subcellular distribution of PKC-delta suggested its translocation from cytosol to membrane fraction, a marker of PKC activation. These results suggest that the cardioprotection induced by beta-PC, like I-PC, is mediated by PKC activation.

Effects of long-term treatment with eicosapentaenoic acid on the heart subjected to ischemia/reperfusion and hypoxia/reoxygenation in rats

The effects of eicosapentaenoic acid (EPA) and long-term treatment with EPA-ethylester (EPA-E) were examined in perfused rat hearts subjected to ischemia/reperfusion and adult rat cardiomyocytes subjected to hypoxia/reoxygenation. EPA (0.1 microM) improved postischemic contractile dysfunction of the ischemic/reperfused heart. EPA (10 microM) attenuated hypoxia/reoxygenation-induced morphological deterioration of cardiomyocytes. The results suggest the presence of direct cardioprotective effects of EPA. Rats were orally treated for 4 weeks with 1 g/kg/day of EPA-E to elucidate ex vivo effects of EPA, and the fatty acid composition of cardiac phospholipids was determined. The percent ratio of EPA in total fatty acids of cardiac phospholipids increased whereas that of arachidonic acid decreased. The percent ratio of n-3/n-6 fatty acid did not increase. Treatment with EPA-E did not improve the post-ischemic contractile function, but attenuated the ischemia/reperfusion-induced release of prostaglandins during reperfusion. Treatment with EPA-E preserved a better morphological appearance of the cardiomyocytes subjected to hypoxia/reoxygenation. The results suggest that the mechanisms responsible for cytoprotective effects of hypoxic/reoxygenated cardiomyocytes or inhibition of metabolic alterations of the ischemic/reperfused heart by long-term EPA-E treatment did not contribute substantially to recovery of post-ischemic contractile dysfunction. The direct in vitro effects of EPA may play a role in the protection of the heart from ischemia/reperfusion or hypoxia/reoxygenation injury.

Effects of high-intensity resistance training on bone mineral density in young male powerlifters

The effects of high-intensity resistance training on bone mineral density (BMD) and its relationship to strength were investigated. Lumbar spine (L2-L4), proximal femur, and whole body BMD were measured in 10 male powerlifters and 11 controls using dual-energy X-ray absorptiometry (DXA). There were significant differences in lumbar spine and whole body BMD between powerlifters and controls, but not in proximal femur BMD. A significant correlation was found between lumbar spine BMD and powerlifting performance. These results suggest that high-intensity resistance training is effective in increasing the lumbar spine and whole body BMD.

Beta-casomorphin-5 stimulates neurite outgrowth in a mouse neuroblastoma cell line (Neuro-2a)

We studied the effect of beta-casomorphin-5 (mu-acting opioid peptides derived from milk protein beta-casein) on neurite outgrowth of mouse neuroblastoma cell line, Neuro-2a. Beta-casomorphin-5 stimulated neurite outgrowth of Neuro-2a cells in a naloxone-reversible manner. The stimulating effect of beta-casomorphin-5 was observed even at picomolar concentrations. The selective mu-agonist, (D-Ala2, N-Me-Phe4, Gly5-ol)-enkephalin (DAMGO) exhibited the similar stimulating effect only at micromolar concentrations. On the other hand, (D-Pen(2,5))-enkephalin (DPDPE) (a delta-agonist), U-50,488 (a kappa-agonist), and endogenous opioid peptides, such as enkephalins and dynorphin A (1-13), showed no such stimulating effect. These results suggest that the neurite outgrowth-stimulating action of beta-casomorphin-5 may be mediated via a receptor which has mu-like characteristics and high sensitivity to beta-casomorphin-5, and that beta-casomorphins may play a role as a neurite elongation factor during the suckling period.

Aspergillus oryzae with and without a homolog of aflatoxin biosynthetic gene ver-1

Part of the nucleotide sequence of the ver-1 homolog in each of two strains of Aspergillus oryzae, Aspergillus sojae, and Aspergillus flavus were compared with two homologs in Aspergillus parasiticus. The homologs in A. oryzae and A. sojae (non-aflatoxin-producers) exhibited an extremely high degree (93.8-99.8% for A. oryzae, and 96.0-99.5% for A. sojae) of sequence identify with that of A. flavus and A. parasiticus. No two strains within the same species, except A. sojae, were identical. No sequence fingerprint was found to distinguish between A. oryzae and A. flavus, or between A. sojae and A. parasiticus. The predicted partial amino acid sequences (181 amino acids) of the ver-1 homologs had at most two amino acid changes relative to A. parasiticus SYS-4 ver-1. Transcripts of ver-1 homologs in the strains of A. oryzae and A. sojae examined were not detected by the polymerase chain reaction coupled with reverse transcription. By Southern analysis, a total of 46 strains of A. oryzae were examined for the presence of the ver-1 homolog. The homolog was detected in 38 strains, but not in 8 strains. Morphologically, strains with and without the ver-1 homolog were indistinguishable. Thus, A. oryzae contains strains with and without a homolog of the aflatoxin biosynthetic gene ver-1.