Hybridization of Schistosoma mansoni and Schistosoma japonicum in mice

Crossing experiments in mice with two human species of Schistosoma japonicum (Taiwan strain) and Schistosoma mansoni (Puerto Rican strain) were performed. The hybrid miracidia from the cross between female S. japonicum and male S. mansoni infected both Biophalaria glabrata and Oncomalania h. chiui. However, those from the reciprocal crossing could infect only B. glabrata. B. glabrata infected with hybrid miracidia of female S. mansoni x male S. japonicum survived up to 30 days while those infected with miracidia of S. mansoni remained alive for more than 100 days after the first shedding of cercariae. Relatively few hybrid eggs reached maturity either in tissues or in the feces of infected mice. A low percentage of F1 eggs hatched and the infectivity of F1 miracida was also low. Morphology and behavior of hybrid eggs, miracidia, cercariae, and adults were similar to the maternal species. The daily egg production of the hybrid worm pair was less than that of the normal one. The observations in the present study may be attributed to the maternal effects. However, the phenomenon of parthenogenesis in schistosomes cannot be confirmed.

Localization of vesicular glutamate transporters and neuronal nitric oxide synthase in rat nucleus tractus solitarii

Previously we reported that glutamate and neuronal nitric oxide synthase (nNOS) colocalize in neurons of the nucleus tractus solitarii (NTS). That finding provided anatomical support for the suggestion that nitric oxide and glutamate interact in cardiovascular regulation by the NTS. Here we test the hypothesis that nNOS colocalizes with vesicular glutamate transporters (VGluT1 and VGluT2) in the NTS. Immunoreactivity (IR) for VGluT better identifies glutamatergic terminals than does glutamate-IR, which may label metabolic as well as transmitter stores of the amino acid. We used fluorescent immunohistochemistry combined with confocal laser scanning microscopy to study IR for VGluT1, VGluT2 and nNOS in rat NTS. A high density of VGluT1-IR positive fibers was present in the gracilis and cuneatus nuclei while in the NTS we found a moderate density in the lateral and interstitial subnuclei and a low density in the dorsolateral, ventral and intermediate subnuclei. The medial, central, commissural and gelatinosus subnuclei contained few VGluT1-IR containing fibers. Thus, VGluT1 containing fibers are not prominent in portions of the NTS where cardiovascular afferent fibers terminate. In contrast, we found a high density of VGluT2-IR containing fibers in the gelatinosus subnucleus and subpostremal area and a moderate density in cardiovascular regions such as the dorsolateral and medial subnuclei as well as in the central and lateral subnuclei. We found a low density in the ventral, intermediate, interstitial and commissural subnuclei. VGluT1-IR and VGluT2-IR rarely colocalized in fibers within the NTS. VGluT1-IR did not colocalize with nNOS, but VGluT2-IR and nNOS-IR colocalized in fibers in all NTS subnuclei. When compared with the other NTS subnuclei, the dorsolateral, gelatinosus and subpostremal subnuclei had higher frequencies of colocalization of VGluT2-IR and nNOS-IR. VGluT2-IR positive fibers were also apposed to nNOS-IR positive fibers throughout the NTS. These data support our hypothesis and confirm that glutamatergic fibers in the NTS contain nNOS.

Colocalization of GluR1 and neuronal nitric oxide synthase in rat nucleus tractus solitarii neurons

Previously we demonstrated that glutamate and neuronal nitric oxide synthase (nNOS) containing neuronal elements are frequently apposed in subnuclei of the rat nucleus tractus solitarii. It is known that glutamate receptors (GluRs) of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) subtype participate in cardiovascular regulation by the nucleus tractus solitarii and that responses to AMPA receptor activation may be linked to NO. Therefore, in the present study, we further tested the hypothesis that the calcium-permeable subunit GluR1 of AMPA type GluRs and nNOS are colocalized in neurons of the nucleus tractus solitarii. Distribution of GluR1 and nNOS in rat nucleus tractus solitarii was investigated by double fluorescent immunohistochemistry combined with confocal laser scanning microscopy. Numerous GluR1 immunoreactive cells and fibers were present in subnuclei of the nucleus tractus solitarii. The staining intensity of GluR1 immunoreactive cells varied among subnuclei. Cells in the interstitial subnucleus contained the highest GluR1 staining intensity. A moderate intensity of staining was present in the intermediate, dorsolateral, ventral, and commissural subnuclei. A slightly lower level of GluR1 immunoreactivity was present in cells of the medial subnucleus. Cells in the central subnucleus contained a low level of GluR1 immunoreactivity. The staining intensity of GluR1 immunoreactive fibers also varied among subnuclei. Distribution of nNOS immunoreactivity in the nucleus tractus solitarii and other brain stem areas was the same as in our earlier reports. Superimposition of confocal images of nNOS immunoreactivity and GluR1 immunoreactivity allowed us to identify double-labeled structures. Nearly all neurons that were immunoreactive for nNOS contained GluR1 immunoreactivity, but only a proportion of GluR1 immunoreactive cells contained nNOS immunoreactivity. Double-labeled neurons were present in all subnuclei of the nucleus tractus solitarii. The percentages of GluR1 immunoreactive cells that also contained nNOS immunoreactivity differed among subnuclei of the nucleus tractus solitarii. Fibers that labeled for nNOS alone, GluR1 alone or both were present among labeled cells in these subnuclei. These data support the hypothesis that GluR1 and nNOS are colocalized in neurons of nucleus tractus solitarii. The demonstration of this anatomical relationship provides further anatomical support for the hypothesis that activation of AMPA receptors on neurons that synthesize NO in the nucleus tractus solitarii contributes to autonomic regulation.

An initial assessment of the feasibility and effectiveness of implementing diabetes shared care system in Taiwan--some experiences from I-Lan County

Diabetes is the fifth leading cause of death in Taiwan and the burden of suffering is still increasing. Building a comprehensive and efficient health care system is crucial to improve the outcome of the diabetics. We implemented the first diabetes shared care system of Taiwan in I-Lan County since August 1996 under the support of Department of Health, the Executive Yuan. This county-wide system was named 'Lan-Yang Diabetes Shared Care System' by the regional steering committee. Regional guidelines for diabetes management were developed after extensive discussion. A multidisciplinary diabetes care team was organized through a training and certification process. Registered patients held diabetes passports to keep clinical record. Physicians of the system use shared referral protocols and sheets. By the end of June 1999, 99 medical professionals had completed their training for diabetes shared care and been certified. The shared care system awarded 26 clinics to hang the lamp signs with the system logo to make them distinguishable. Such clinics have now been available throughout 12 townships in I-Lan County. The number of registered patients carrying diabetes passport increased to 3484 and there was a community-based patient group in every township of I-Lan County. The amount of continuing diabetes clinical training delivered by the specialists to the primary care physicians and non-physician professionals increased to 1681 person-hours per year. The proportion of registered patients undertaking fundus examination within 1 year increased to 30.9%, checking urine micro-albumin to 28.0% and checking HbA(1c) 72.8%, respectively. Mean HbA(1c) value decreased from 8.7% in the first year to 7.9% in the third year. Our study showed that under the co-ordination by regional health bureau with integration of different levels of medical facilities, governmental sectors and non-governmental community resources, the diabetes shared care model is feasible in Taiwan. Through its implementation, quality of regional diabetes care has achieved preliminary improvement.

Oral bacterial therapy promotes recovery from acute diarrhea in children

Lactobacilli in the intestines play an important role in developing natural defenses against both intestinal bacterial and viral infections. So a prospective clinical study was carried out at Cathay General Hospital to determine the effect of Lactobacillus acidophilus and Bifidobacterium infantis on the course of acute diarrhea in hospitalized children. Altogether 100 children between 6 and 60 months of age were collected and randomly allocated into 2 groups. Study group (n = 50) was given Infloran Berna, which contains 10(9) viable Lactobacillus acidophilus and 10(9) Bifidobacterium infantis, one capsule tid for 4 days and control group (n = 50) received parenteral rehydration only without any medication. Only 20 stool cultures in study group had positive culture results for Lactobacillus or Bifidobacterium. All children were evaluated for the degree of dehydration before rehydration. The clinical course of diarrhea was followed during the treatment period. Features on admission were similar between the study group and control group in age, duration of diarrhea at home, serum sodium & potassium and dehydration degree. The duration of diarrhea was defined as the time until the last appearance of watery stool. There was no difference between the study group and control group in the frequency of diarrhea stools on the day before admission (p > 0.05). However, the frequency of diarrhea for study group improved on the first and second day of hospitalization with statistical difference (p < 0.01). The duration of diarrhea during hospitalization in study group also decreased (3.1 vs. 3.6 days, p < 0.01). Oral bacterial therapy is an effective adjuvant therapy in rotavirus positive and negative children with diarrhea and can safely be administered during an episode of acute diarrhea.

Noise and related events in a neonatal intensive care unit

The purposes of this study were to explore noise distribution, its timing, and sources of peak noise in the neonatal intensive care unit (NICU) of a University Hospital in Southern Taiwan. Two surveys on noise distribution and peak noise of the warmer bed were conducted. Noise at radiate heated beds located in the central sites of two areas, one near (Area A) and the other away from (Area B) the nursing station, were measured continuously for one week using an electronic sound-meter. Peak noise with a sound level of > 65 on the A-weighted decibel scale (dBA) and associated sources were recorded for 48 hours. Monitoring periods of peak noise consisted of a weekday and a day on the weekend randomly selected for Area A. Results showed that mean noise levels at the warmer bed in Areas A and B were 62 and 61.4 dBA on average. In over 70% of the total observation time for both areas the sound levels were > 59 dBA. The noise intensity was particularly high between 8 a.m. and 4 p.m. The noise level on the weekend was lower than that on weekdays. During the 48-hour observation period, 4994 peak noises were recorded. Eighty-six percent of these peak noises were within ranges of 65-74 dBA and 90% were human-related factors. The primary non-human related source was monitor alarms. Additionally, peak noises occurred primarily during the 8-11 a.m. and 2-4 p.m. hours on the weekdays and weekends. These results indicate that modifications of staff behavior, care procedures, and apparatus may reduce the noise levels in the NICU.

Nitroxidergic influences on cardiovascular control by NTS: a link with glutamate

Glutamate (GLU) receptor activation, which is important in cardiovascular reflex transmission through the nucleus tractus solitarii (NTS), leads to release of nitric oxide (NO.) from central nitroxidergic neurons. Therefore, we hypothesized that GLU and NO. are linked in cardiovascular control by NTS. We first sought to determine if NO. released into NTS led to cardiovascular changes like those produced by GLU and found that the nitrosothiol S-nitrosocysteine, but not NO. itself or other NO. donors, elicited such responses in anesthetized rats. The responses were dependent on activation of soluble guanylate cyclase but, not being affected by a scavenger of NO., likely did not depend on release of NO. into the extracellular space. Responses to ionotropic GLU agonists in NTS, like those to S-nitrosocysteine, were inhibited by inhibition of soluble guanylate cyclase. Inhibition of neuronal NO. synthase (nNOS) also inhibited responses to ionotropic GLU agonists. The apparent physiologic link between GLU and NO. mechanisms in NTS was further supported by anatomical studies that demonstrated frequent association between GLU-containing nerve terminals and neurons containing nNOS. Furthermore, GLU receptors were often found on NTS neurons that were immunoreactive for nNOS. The anatomical relationships between GLU and nNOS and GLU receptors and nNOS were more pronounced in some subnuclei of NTS than in others. While seen in subnuclei that are known to receive cardiovascular afferents, the association was even more prominent in subnuclei that receive gastrointestinal afferents. These studies support a role for nitroxidergic neurons in mediating cardiovascular and other visceral reflex responses that result from release of GLU into the NTS.

Internal hernia caused by Meckel diverticulum in an infant: report of one case

Intestinal obstruction caused by internal hernia due to Meckel diverticulum is a rare disease. The condition is seldom diagnosed preoperatively. In this paper, we present a 10-month-old boy who suffered from abdominal pain, persistent vomiting, and mild fever for 2 days. Abdominal sonography, plain abdomen X-ray, and computed tomography merely showed mechanical ileus and partial malrotation. However, exploratory laparotomy revealed a Meckel diverticulum through which the small bowel had herniated. We introduce the Meckel diverticulum and internal hernia and discuss intestinal obstructions.

N-methyl-D-aspartate receptors on neurons that synthesize nitric oxide in rat nucleus tractus solitarii

The aim of this study was to determine whether neuronal nitric oxide synthase and N-methyl-D-aspartate receptors are co-localized in the rat nucleus tractus solitarii. Such co-localization would support the hypothesis that nitric oxide participates in nucleus tractus solitarii-mediated functions, such as cardiovascular regulation, by a link to N-methyl-D-aspartate receptors. We used double fluorescent immunohistochemistry using antibodies against neuronal nitric oxide synthase and N-methyl-D-aspartate receptor subunit 1, the fundamental subunit for functional N-methyl-D-aspartate receptors. Labeled brainstem sections were examined with confocal laser scanning microscopy. Most of the N-methyl-D-aspartate receptor subunit 1 immunoreactivity was in cell bodies and proximal dendrites of the numerous labeled cells in the brainstem. High levels of N-methyl-D-aspartate receptor subunit 1 immunoreactivity were present in the dorsal motor nucleus of vagus, hypoglossal nucleus and nucleus ambiguus. All subnuclei of the nucleus tractus solitarii contained moderate levels of N-methyl-D-aspartate receptor subunit 1 immunoreactivity. The distribution of neuronal nitric oxide synthase immunoreactivity in the nucleus tractus solitarii was similar to that described in earlier reports. Superimposition of images revealed that almost all neuronal nitric oxide synthase immunoreactive neurons in the nucleus tractus solitarii contained N-methyl-D-aspartate receptor subunit 1 immunoreactivity, but a lesser portion of N-methyl-D-aspartate receptor subunit 1-immunoreactive cells contained neuronal nitric oxide synthase immunoreactivity. Although all nucleus tractus solitarii subnuclei contained double-labeled neurons, the central subnucleus exhibited the highest density of double-labeled neurons.Co-localization of neuronal nitric oxide synthase and N-methyl-D-aspartate receptor subunit 1 in the nucleus tractus solitarii provides anatomical support for the hypothesis that N-methyl-D-aspartate receptor activation can affect nucleus tractus solitarii-controlled functions via actions on neurons that synthesize nitric oxide.

Food protein-induced enterocolitis syndrome: report of one case

We report a 76-day old infant who got diarrhea within the first week of life. He was treated as acute gastroenterocolitis and kept on feeding with regular infant formula. Because the symptoms persisted, the feeding formula was shifted to soy-based formula then to the highly-hydrolyzed formula and got improvement. But severe bloody diarrhea, vomiting, dehydration and fever developed after feeding with regular infant formula again. Based on the history and clinical presentations, cow's milk allergy was suspected. He received total parenteral nutrition for 5 days then fed with highly-hydrolyzed formula with slowly increasing amount. Thereafter tests for total eosinophil counts, total serum IgE, milk specific IgE antibodies and milk extract skin prick test were all unremarkable. Under the impression of food protein-induced enterocolitis syndrome (FPIES), a double-blind placebo-controlled food challenge (DBPCFC) with infant formula was performed. Regular infant formula induced severe vomiting, diarrhea, fever, acidosis and elevation of absolute neutrophil counts (ANC) of peripheral blood by 27,640/mm3. Based on the laboratory findings and challenge results, the patient fit the diagnostic criteria of food protein-induced enterocolitis syndrome.

Ultrasound screening of neonatal adrenal hemorrhage

Neonatal adrenal hemorrhage (NAH) is frequently overlooked because the majority of cases are asymptomatic. In this study, we investigated the clinical symptoms, echographic characteristics and incidence of NAH from January 1998 to December 1999 at Cathay General Hospital, Taipei, Taiwan. Among 3273 newborns who had ultrasound screening, 18 cases were diagnosed as having NAH. The incidence was 0.55% which was compatible with other reports. But there was a female predominance (10:8) which was different from previous reports. Only one premature baby was diagnosed with NAH. No patients had perinatal asphyxia, and this was different from other reports. The mean birth body weight was 3530 grams which was more than the 75th percentile of normal term baby birth weight. Sixteen cases had right-sided NAH and two cases had left-sided NAH. Eleven cases (61%) within this study were asymptomatic. The incidence of pathologic jaundice was 11%. Four babies (22%) had poor oral feeding combined with vomiting. Only one had severe anemia for which blood transfusion was required. There were no cases of adrenocortical insufficiency in our study. Only one patient received adrenalectomy. In conclusion, NAH can be detected early by sonography and most cases require only supportive treatment. Thus, unnecessary surgery and severe complications due to delayed diagnosis can be avoided.

Recurrent pancreatitis secondary to type V hyperlipidemia: report of one case

With the exception of cystic fibrosis and hereditary pancreatitis, case reports about pancreatitis in children have rarely been mentioned. We report here an 11-year-old boy with type V hyperlipidemia, who suffered from two episodes of acute pancreatitis. Sudden onset of severe upper abdominal pain, fever, and hypertriglyceridemia were the common presentations. Initial treatments including analgesics, fasting, parenteral nutrition support and following diet control with medium-chain triglycerides seem to be successful in our case.

Apposition of neuronal elements containing nitric oxide synthase and glutamate in the nucleus tractus solitarii of rat: a confocal microscopic analysis

The distribution of glutamate and neuronal nitric oxide synthase in the rat nucleus tractus solitarii was investigated by double fluorescent immunohistochemistry combined with confocal laser scanning microscopy. Cells and fibers that exhibited neuronal nitric oxide synthase immunoreactivity alone, glutamate immunoreactivity alone or both immunolabels were present in all subnuclei of the nucleus tractus solitarii, but staining intensities differed between the subnuclei. The percentages of double-labeled glutamate-immunoreactive cells also differed between the subnuclei. The central subnucleus contained the highest percentage of double-labeled glutamate-immunoreactive cells and the medial subnucleus contained the lowest. The percentages of double-labeled neuronal nitric oxide synthase-immunoreactive neurons likewise differed between the subnuclei. The central subnucleus contained the highest percentage of double-labeled neuronal nitric oxide synthase-immunoreactive neurons and the commissural subnucleus contained the lowest. Because of our interest in cardiovascular regulation, the anatomical relationship between glutamate-immunoreactive and neuronal nitric oxide synthase-immunoreactive fibers in the dorsolateral and commissural subnuclei was further examined at higher magnification. Close appositions were observed between neuronal nitric oxide synthase-immunoreactive and glutamate-immunoreactive fibers, between double-labeled and glutamate-immunoreactive fibers, and between neuronal nitric oxide synthase-immunoreactive and double-labeled fibers. We recognized that a single visual perspective might cause labeled fibers that pass in close proximity to appear to make contact. Therefore, we constructed three-dimensional images from serial optical sections obtained from the dorsolateral and commissural subnuclei by means of a confocal scanning microscope. Rotation of the three-dimensional images caused some fibers that had seemed to be in close apposition to other structures to separate from those structures. In contrast, some glutamate-immunoreactive and some neuronal nitric oxide synthase-immunoreactive fibers remained in close apposition regardless of the angle at which they were viewed. This study supports there being an anatomical link between glutamatergic and nitroxidergic systems in the nucleus tractus solitarii. Recognized physiological interactions between the two systems could occur through such a link.

The treatment of acidosis in acute lung injury with tris-hydroxymethyl aminomethane (THAM)

Mechanical hyperventilation of acidemic patients with acute lung injury (ALI) requires the use of high volumes and pressures that may worsen lung injury. However, permissive hypercapnia in the presence of shock, metabolic acidosis, and multi-organ system dysfunction may compromise normal cellular function. Tris-hydroxymethyl aminomethane (THAM) may be an effective method to control acidosis in this circumstance. Protonated THAM is excreted by the kidneys, so that carbon dioxide production is not raised. In an uncontrolled study, we administered THAM to 10 patients with acidosis (mean pH = 7.14) and ALI (mean lung injury score = 3.28) in whom adequate control of arterial pH could not be maintained during either eucapnic ventilation or permissive hypercapnia ventilation. THAM was given at a mean dose of 0.55 mmol/kg/h. Administration of THAM was associated with significant improvements in arterial pH and base deficit, and a decrease in arterial carbon dioxide tension that could not be fully accounted for by ventilation. Although further studies are needed to confirm these observations, THAM appears to be an effective alternative to sodium bicarbonate for treating acidosis during ALI.

Up-regulation of base excision repair activity for 8-hydroxy-2'-deoxyguanosine in the mouse brain after forebrain ischemia-reperfusion

The repair enzyme 8-oxoguanine glycosylase/ apyrimidinic/apurinic lyase (OGG) removes 8-hydroxy-2'deoxyguanosine (oh8dG) in human cells. Our goal was to examine oh8dG-removing activity in the cell nuclei of male C57BL/6 mouse brains treated with either forebrain ischemia-reperfusion (FblR) or sham operations. We found that the OGG activity in nuclear extracts, under the condition in which other nucleases did not destroy the oligodeoxynucleotide duplex, excised oh8dG with the greatest efficiency on the oligodeoxynucleotide duplex containing oh8dG/dC and with less efficiency on the heteroduplex containing oh8dG/dT, oh8dG/dG, or oh8dG/dA. This specificity was the same as for the recombinant type 1 OGG (OGG1) of humans. We observed that the OGG1 peptide and its activity in the mouse brain were significantly increased after 90 min of ischemia and 20-30 min of reperfusion. The increase in the protein level and in the activity of brain OGG1 correlated positively with the elevation of FblR-induced DNA lesions in an indicator gene (the c-fos gene) of the brain. The data suggest a possibility that the OGG1 protein may excise oh8dG in the mouse brain and that the activity of OGG1 may have a functional role in reducing oxidative gene damage in the brain after FblR.

The distribution of neuronal nitric oxide synthase in the nucleus tractus solitarii of the squirrel monkey

The distribution of neuronal nitric oxide synthase (nNOS) containing neurons and fibers in subnuclei of the nucleus tractus solitarii (NTS) in the squirrel monkey, Saimuri sciureus, was investigated by nNOS immunohistochemistry and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry. Generally, the staining pattern of nNOS and NADPH-diaphorase in the NTS was similar. A high density of neurons and fibers exhibiting both nNOS immunoreactivity and NADPH-diaphorase reactivity was present in the central, medial, intermediate, and dorsolateral subnuclei of the NTS. A moderate density of neurons and fibers that stained for both nNOS and NADPH-diaphorase was noted in the interstitial and ventromedial subnuclei. The gelatinosus and commissural subnuclei contained a low density of neurons and fibers exhibiting nNOS immunoreactivity and NADPH-diaphorase staining. The dorsal motor nucleus of vagus contained a high density of nNOS immunopositive and NADPH-diaphorase containing neurons and fibers at the rostral level, but contained a moderate density of positive fibers and very few positive neurons at the intermediate, subpostremal and commissural NTS levels. Incongruence was noted, however, between nNOS immunostaining and NADPH-diaphorase staining in blood vessels in the brainstem. Capillaries and small vessels exhibited strong staining for NADPH-diaphorase but no nNOS immunoreactivity. In summary, this work substantiates the presence of nNOS in subnuclei of the monkey NTS and is consistent with a role for NO(.) in neurotransmission in primate NTS.

The percutaneous penetration of prostaglandin E1 and its alkyl esters

The percutaneous delivery of PGE1 and its alkyl esters in alcoholic saline solution through hairless mouse skin was compared. The quantification of alkyl esters was based on the same principle as that for PGE1, which was converted to PGB1 to enhance the sensitivity and minimize the interference. Results showed that it was PGE1 that appeared in the receiver compartment for all alkyl esters examined. The flux of all alkyl esters of PGE1 in the same concentration was higher than PGE1 itself at most of saline vehicle with various fractions of alcohol. The maximal flux for a fixed concentration of each alkyl ester appeared at different fractions of alcohol. When the fractions of alcohol was kept constant, the alkyl ester that showed the maximal flux at this concentration appeared to have a longer chain length with increasing the fraction of alcohol. But isopropyl ester deviated from this order. It was concluded that the alkyl ester derivatives promoted the penetration of PGE1 mainly as a result of enhancing the drug partitioning into the stratum corneum. The alcohol fraction that needed to achieve the maximal flux at the same concentration increased with the increase of alkyl chain length, which resulted in the decrease of solubility parameter. It is necessary to optimize the fraction of alcohol in the saline solution in order to achieve the maximal flux at a fixed concentration for these alkyl esters with different alkyl chain length.

Egg production capacity of Paragonimus pulmonalis in cats

In the present study, each of 43 cats was fed with a single metacercaria of Paragonimus pulmonalis and 2 cats (controls) with 2 metacercariae. They were killed 22-372 days postinfection. In the test group, 18 (41.9%) cats were infected, as well as the 2 cats in the control group. Among the 18 worms recovered from the test group, 9 found in the lungs were mature, whereas 5 mature and 4 immature worms were in the pleural cavity. Most eggs from worms encased in a cyst were passed in the feces. However, eggs from worms in the pleural cavity were only found on the lung surface and pleural cavity. Mature worms in cysts seemed to exhibit higher egg production capacity than those in the pleural cavity. Paired mature worms from a cyst laid more eggs than a single encysted mature worm in vitro at room temperature.

Investigation of the percutaneous penetration of prostaglandin E1 and its ethyl ester

The optimization of percutaneous delivery of PGE1 and its ethyl ester in alcoholic buffer solution through hairless mouse skin was investigated. A reversed-phase HPLC system with a photodiode array detector was used to differentiate the UV spectra of the penetration products. By comparison of the UV spectrum for each chromatographic peak, the conversion of PGE1 ethyl ester to PGE1 by enzymatic hydrolysis was found to be the predominant degradation pathway during the in vitro penetration. The quantification of ethyl ester was developed based on the same principle as that for PGE1. It was then applied to monitor the penetration of prostaglandins through hairless mouse skin from the vehicles containing various fractions of alcohol. Results demonstrated that the alkyl group promoted the penetration mainly as a result of enhancing the drug partitioning into the stratum corneum at its maximal thermodynamic activity. The alcohol fraction around 20% seemed to be optimal for the percutaneous delivery of the ethyl ester. The use of collagen gel to carry PGE1 ethyl ester for percutaneous application was included for comparison. The effect of adding alcohol in the collagen gel on the penetration of PGE1 ethyl ester was found to be slightly lower than that from the same vehicle without collagen.

Function of GABA rho1 receptors is up-regulated by chronic GABA treatment in Xenopus oocytes

This study was aimed to investigate the effect of chronic gamma-aminobutyric acid (GABA) treatment on homomeric GABA rho1 receptors expressed in Xenopus oocytes. The rho1 mRNA-injected oocytes were incubated with 10 mM GABA for 2, 6, 24, 48 or 72 h, prior to the assessment of GABA-gated ion currents. The results showed that GABA exposure for more than 6 h dramatically enhanced the peak GABA-activated currents. In addition to current amplitude, the apparent GABA potency and cooperativity were significantly increased. The enhancement reached its plateau after a 24-h exposure. The up-regulation of GABA current amplitude was completely inhibited by cycloheximide, a translation inhibitor. This suggests that chronic GABA treatment may increase the translational activity of GABA rho1 subunit in Xenopus oocytes.

Direct evidence for nitric oxide synthase in vagal afferents to the nucleus tractus solitarii

The anatomical relationship between vagal afferents and brain nitric oxide synthase containing terminals in the nucleus tractus solitarii was studied by means of anterograde tracing combined with immunocytochemistry and immuno-electron microscopy. Biotinylated dextran amine was injected into the nodose ganglion with a glass micropipette. Four to eight days following the injection, regions of the nucleus tractus solitarii containing biotinylated dextran amine-labelled vagal afferents and those containing nitric oxide synthase-immunopositive terminals were congruent. Many neurons exhibiting nitric oxide synthase immunoreactivity were found within the biotinylated dextran amine-containing terminal field. However dense labeling of terminals with biotinylated dextran amine precluded determination if the terminals were nitric oxide synthase-immunoreactive. Therefore, we combined degeneration of vagal afferents after removal of one nodose ganglion with nitric oxide synthase immuno-electron microscopy. Axon terminals that possessed characteristic vesicle clusters and were partially or completely engulfed by glial processes were identified as degenerating vagal afferents. Degenerating axon terminals comprised 38% of the total axon terminals in the nucleus tractus solitarii in a sample of sections; and of the degenerating axon terminals, 67% were nitric oxide synthase-immunoreactive. Nitric oxide synthase immunoreactivity was present in 41% of the non-degenerating axon terminals. Prominent staining of dendrites for nitric oxide synthase immunoreactivity indicated that much of the nitric oxide synthase in the nucleus tractus solitarii is not derived from peripheral afferents. Of the total number of dendritic profiles sampled, half were nitric oxide synthase-immunoreactive. Our data support the hypothesis that nitric oxide or nitric oxide donors may be present in primary vagal afferents that terminate in the nucleus tractus solitarii. While this study confirms that vagal afferents contain brain nitric oxide synthase, it demonstrates for the first time that the majority of nitric oxide synthase immunoreactivity in the nucleus tractus solitarii is found in intrinsic structures in the nucleus. In addition, our data show that second or higher order neurons in the nucleus tractus solitarii may be nitroxidergic and receive both nitroxidergic and non-nitroxidergic vagal input.

Choledochal cyst in infancy: report of two cases

Choledochal cysts are malformations of the biliary ductal system, which rarely occur in infancy. In neonates and infants, choledochal cysts are congenital, may be associated with distal biliary atresia and typically presents with cholestatic jaundice and acholic stools characteristic of biliary obstruction. In older children and adults, it may be acquired in association with an anomalous pancreaticobiliary union and presents with any combination of intermittent jaundice, abdominal pain, and a palpable abdominal mass. Early detection of choledochal cysts is important in the prevention of the fatal complications of biliary obstruction. Here, we present two cases of congenital choledochal cyst in which the patients were 9 weeks old and 7 weeks old respectively. Both of them presented with jaundice, acholic stools, and hepatomegaly. Combined use of sonography, computed tomography and hepatobiliary scintigraphy demonstrated the presence of choledochal cysts. Thereafter, they underwent surgical excision of the cysts with Roux-en-Y reconstruction of the biliary tree; the results were successful.

Up-regulation of nitric oxide synthase and its mRNA in vagal motor nuclei following axotomy in rat

Effects of vagotomy on nitric oxide synthase (NOS) protein and mRNA levels in the dorsal motor nucleus of vagus (DMV) and nucleus ambiguus (NA) of rats were examined by nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) staining, brain NOS (bNOS) immunostaining and in situ hybridization. NADPH-d staining and bNOS immunoreactivity increased in neurons of the ipsilateral DMV and NA 5, 10, and 20 days after vagotomy. These changes were not observed in unoperated or sham-operated rats. In situ hybridization showed that bNOS mRNA levels were also elevated in neurons of DMV and NA on the operated side. Our results suggest that transection of vagal efferents up-regulates bNOS and its mRNA expression in the DMV and NA.

Sex-dependent expression of placental (P)-cadherin during mouse gonadogenesis

BACKGROUND

Placental (P)-cadherin is one of a family of cell adhesion molecules that participate in embryonic sorting and organogenesis. In previous work, P-cadherin was localized to Sertoli cells in the mouse testis as early as postnatal day 1. This early postnatal localization raised questions about when P-cadherin first appeared in the embryonic testis and whether P-cadherin was expressed differentially in the embryonic testis and ovary.

METHODS

The localization of P-cadherin, epithelial (E)-cadherin, and Müllerian inhibiting substance was determined in frozen sections of mouse gonads between embryonic days 10.5 and 18 using indirect immunohistochemistry. Alkaline phosphatase reactivity was used to identify germ cells.

RESULTS

The expression of P-cadherin was traced back to the indifferent stage of gonadogenesis where uniform distribution was observed in the indifferent gonad of both sexes. However, after sexual differentiation, the expression of P-cadherin in the testis was localized to Sertoli cells in the testicular cords, while its expression in the ovary fell below detectable levels.

CONCLUSIONS

The localization of P-cadherin in the male and female indifferent gonad is similar and cannot be used to distinguish the future testis and ovary. The localization of P-cadherin in the testis after sexual differentiation suggests a role for P-cadherin in testicular cord formation. The common temporal pattern of P-cadherin and Müllerian inhibiting substance expression in Sertoli cells is consistent with a shared regulatory mechanism.