Stochastic simulation algorithms for query networks

One of the barriers to using belief networks for medical information retrieval is the computational cost of reasoning as the networks become large. Stochastic simulation algorithms allow one to compute approximations of probability values in a reasonable amount of time. We previously examined the performance of five stochastic simulation algorithms applied to four simple belief networks networks and found that the Self-Importance algorithm performed well. In this paper, we examine how the same five algorithms perform when applied to a belief network derived from the cardiovascular subtree of the Medical Subject Headings (MeSH). Both the Likelihood Weighting and Self-Importance algorithms perform well when applied to the MeSH-derived network, suggesting that stochastic simulation algorithms may provide reasonable performance in medical information retrieval settings.

Airway inflammation in sheep with acute airway hypersensitivity to inhaled Ascaris suum

In order to investigate the relationship between airway inflammation and the development of naturally occurring allergic airway hypersensitivity, the lower respiratory tract was studied in eighteen sheep 14 days after challenge with inhaled Ascaris suum antigen. Sheep could be classed into three groups on the basis of their response: group A (n = 6) had significant changes in both airway resistance and dynamic lung compliance; group B (n = 6) had changes in only dynamic lung compliance, and group C (n = 6) were nonresponders. The results showed that the volume density of secretory granules in lung mast cells was greater in hypersensitive sheep than in nonreacting sheep (p less than 0.01). This high volume density was due to a high numerical density of granules in the mast cells. There was, however, no significant difference between groups in the numerical density of mast cells and eosinophils, or the observed degree of degranulation of mast cells. Although lymphocytes were commonly seen within the airway epithelium and subepithelial regions, infiltration of neutrophils or aggregation of dense and nodular lymphoid tissues were not common in the airways of any sheep. There was no significant difference in the infiltration of neutrophils or the aggregation of lymphocytes and lymphoid tissue in airways between the three groups. These findings indicate that there is an inherent difference in the volume density of lung mast cell granules between hypersensitive and nonreacting sheep but that other inflammatory cells are probably not directly involved in the initial development of allergic airway hypersensitivity in this species.

The potential role of the ovine pharyngeal tonsil in respiratory tract immunity: a scanning and transmission electron microscopy study of its epithelium

The mucosal epithelium of the pharyngeal tonsil was studied in 10 conventionally raised sheep by scanning and transmission electron microscopy. The surface of the tonsil was covered by two types of topographically and ultrastructurally distinct epithelium. The epithelium overlying the lymphoid follicle region (follicle-associated epithelium) was compressed by adjacent ciliated epithelium and consisted of predominantly non-ciliated cells of varying height. The majority of these cells possessed microvilli or microfolds of varying number, height and density on their surface. Small numbers of squamous cells and, occasionally, intermediate cells were also present in these areas. Ultrastructurally, the microvillous cells showed features similar to M cells which occur in other mucosal sites. They contained cytoplasmic vesicles and vacuoles and formed intercellular digital junctions. Between these cells was a heavy infiltration of lymphoid cells. Focal disintegration of the mucosal epithelium was occasionally seen. The epithelium covering non-follicle areas consisted of mainly ciliated cells interspersed with some goblet cells and squamous cells, morphologically resembling those elsewhere in the respiratory tract. These findings have provided evidence which confirms that the ovine pharyngeal tonsil is part of the respiratory tract-associated lymphoid tissue.

Protective effect of zinc-induced metallothionein synthesis on gentamicin nephrotoxicity in rats

Wistar rats were used to study the protective effect of zinc-induced metallothionein (MT) synthesis on gentamicin nephrotoxicity. We found that s.c. pre-injection of ZnSO4 (Zn 10 mg/kg/day) for 5 days could ameliorate proximal tubular necrosis and acute renal failure caused by an 8-day s.c. injection of gentamicin (100 mg/kg/day), while preinjection of saline instead of zinc or zinc and gentamicin together could not. In the zinc-pretreated rats (n = 6), renal cortical metallothionein level was significantly higher than that of normal (n = 8, p less than 0.001) and the saline controls (n = 6, p less than 0.001). Since MT is a scavenger of hydroxyl radical, it is proposed that hydroxyl radical plays a role in the pathogenesis of gentamicin nephrotoxicity and that preinjection of zinc could ameliorate gentamicin nephrotoxicity via the induction of renal cortical MT synthesis.

[Nebulizing terbutaline therapy in children with acute asthma]

To evaluate the therapeutic effect of nebulized terbutaline in children with acute asthma, 21 children, aged 1 year and 7 months to 10 years, with acute asthma, were enrolled into this study, during the period from July to December 1989. Each patient received nebulized terbutaline (Bricanyl) 5 mg/dose over 10 minutes. The respiratory rate, pulse rate, blood pressure, peak expiratory flow rate and clinical severity score were recorded before, and at 10 minutes after treatment. Comparing with the data before treatment, respiratory rate, peak expiratory flow rate and clinical severity score at 10 minutes after treatment showed significant improvement (p value less than 0.05; less than 0.0005; less than 0.0001, respectively), but pulse rate and blood pressure did not differ significantly. It was concluded that administration of nebulized terbutaline, at a dose of 5 mg, was both safe and effective in treating acute asthma, and may be used as the first line measure in treating acute asthma in children.

Inhibition in fat-storing cell multiplication by a factor produced by normal cultured murine hepatocytes

In this study we demonstrate that hepatocytes isolated from normal mice may efficiently inhibit the multiplication of fat-storing cells (FSC) in culture, either in a coculture system where both cell types are separated by a filter of 0.45 microns pore size or via their conditioned medium. The inhibition may be completely reversed when the hepatocytes are removed and the culture medium is renewed. The inhibitory factor appears as early as 8 h in the medium with an almost maximum effect being reached after 24 h, as long as protein synthesis is allowed. It rapidly loses its efficiency through dilution. The inhibitory capacity of the conditioned medium is maintained after heating at 56 degrees C, dialysis of 100,000 x g centrifugation, but reduced after trypsin treatment. The infection of the hepatocytes by ectromelia virus causes an almost total suppression of the synthesis of the inhibitory factor. This latter result suggests that the multiplication of FSC, which may be inhibited by normal hepatocytes, would no longer be hindered in case of disregulation.

Mast cells in the bovine lower respiratory tract: morphology, density and distribution

The lower respiratory tract of six 8-day-old calves and six adult cows was fixed in either isotonic formal-acetic-acid or neutral buffered formalin in order to study the morphology, density and distribution of mast cells. They were found at all levels of the tract with the highest density in the major bronchi. Tissues from cows had significantly more mast cells than those from calves. There were significantly more mast cells detected in calf airways fixed with isotonic formal-acetic-acid compared with those seen in the same tissues fixed with neutral buffered formalin. Regardless of the age and fixation, mast cells were located predominantly in the alveolar septa and in the lamina propria of airways. They were also commonly encountered within the mucosal epithelium of the trachea. Ultrastructurally, mast cells in bovine airways and lung contained two types of intracytoplasmic granules as described in other species.

Chronic renal failure in young Old English Sheepdogs

Chronic renal failure was diagnosed in three young Old English Sheepdogs. Clinical signs were characterised by ill-thrift, polydipsia, polyuria, nervous signs and behavioural changes. Laboratory findings showed azotaemia, non-regenerative anaemia, hyperphosphataemia and isosthenuria. The kidneys were characterised histologically by interstitial fibrosis, and thickening and calcification of the tubular and glomerular basement membrane. A familial incidence could not be confirmed in these cases.

[Hemolytic disease of the newborn caused by maternal irregular antibody anti-E: report of one case]

A 3390 gm male baby was born smoothly at 41 weeks' gestation to a 35-year-old, gravida 3, para 3, mother by spontaneous vaginal delivery at this hospital. The mother denied ever having received a blood transfusion. Her first two uneventful pregnancies had resulted in two healthy fullterm infants. Physical examination of the baby showed normal, until 15 hours of age, when apparent jaundice with serum total bilirubin concentration up to 21 mg/dl was noted. The blood types of both baby and mother were group A, Rh(D) positive. Compatibility testing for exchange blood transfusion with group A whole blood showed positive reaction due to the presence of an irregular antibody. Two exchange blood transfusions were performed in the same day with compatible blood. Thereafter, the patient's condition was much improved, he was discharged one week later. The irregular antibody--anti-E was identified in both baby and mother. The maternal RBC phenotyping was CCDee (R1R1), and the baby, CcDEe (R1R2).

[Diagnostic value of transbronchial lung biopsy in diffuse or peripheral lung lesions]

The results of 102 cases of diffuse or peripheral lung lesions examined by transbronchial lung biopsy (TBLB), bronchial brushing (BB), and bronchial alveolar lavage (BAL) via fiberoptic bronchoscope, were reported. The positive diagnostic rate was 74.5% (76 cases). In lung cancer, the positive rate by means of BB was 77.1%, which was higher than that by TBLB (58.1%). In pulmonary tuberculosis, the positive rate by TBLB was 76.9%, higher than that by BAL fluid for identification of tubercle bacillus by culture (44.4%). If TBLB was combined with BB and BAL, the positive diagnostic rate would be further elevated. The data showed that if the size of the masses greater than or equal to 3cm in peripheral lung field on chest film, the possibility of lung cancer was greater than that of those less than 3cm. Most cases of localized infiltration in the lungs were caused by tuberculosis. But the diffuse lesions of the lungs were often caused by bronchiolo-alveolar carcinoma, adenocarcinoma, diffuse interstitial fibrosis of the lungs, silicosis, sarcoidosis, etc. By the careful study of the chest film and ascertainment of the exact locations of the pulmonary lesions there, we can carry out the TBLB and obtain a satisfactory specimen without any X-ray monitoring. In the present group of patients who underwent TBLB, one was complicated by haemorrhage (greater than 50ml) and two by pneumothorax, but all of them recovered promptly after proper management. By strick adherence to indication, adequate preoperative preparations and very careful performance of the procedure, the complications of TBLB could be reduced to minimum.(ABSTRACT TRUNCATED AT 250 WORDS)

Perinatal development of lymphoid tissue and its associated epithelium in the ovine pharyngeal tonsil: A morphological study

The perinatal development of lymphoid tissue and its associated epithelium in the pharyngeal tonsil of sheep was investigated by light and electron microscopy. The lymphoid cells first appeared in the subepithelium in a scattered form at about 92 days gestation. These cells proliferated rapidly during the last trimester of gestation, and had formed many dense aggregates at the time of parturition. At birth, the epithelium overlying the aggregates was extensively infiltrated with lymphocytes and showed early transformation of follicle-associated epithelium. The lymphoid tissue and its associated epithelium did not, however, fully develop until after birth, when well-differentiated follicle-associated epithelium and lymphoid follicles with vigorous lymphopoiesis were present. In 1-2 week old lambs, these structures were ultrastructurally similar to those seen in adult sheep although their size was smaller. The results of this study suggest that the lymphoid tissue of the ovine pharyngeal tonsil and its associated epithelium are morphologically ready to cope with antigens in the extra-uterine environment at birth, but that their full development and maturation are dependent postnatal antigen stimulation.

Selenium contents in human gallbladder bile

The selenium contents in human gallbladder bile were analyzed. Thirty-seven subjects were studied; 22 patients with cholelithiasis in Niigata Prefecture and 15 patients (13 with cholelithiasis and 2 with gallbladder polypus) in Kochi Prefecture. Five ml of bile was withdrawn with a syringe from the gallbladder during the operation and stored at -20 degrees C until analysis. For the analysis by gas chromatograph with an electron-capture detector, 0.2 ml of sample was used. The mean selenium contents in bile were 269 +/- 39.0 (mean +/- S.D.) ng/ml for the subjects in Niigata and 285 +/- 84.4 ng/ml in Kochi; without significant difference. Of 37 samples analyzed, the mean content was 276 +/- 61.0 ng/ml.

Adoptively transferred antigen-specific T cells can be grown and maintained in large numbers in vivo for extended periods of time by intermittent restimulation with specific antigen plus IL-2

The aim of the current study was to determine whether cultured tumor Ag-specific T cells could be induced to grow and maintained functional in large numbers in vivo by intermittent restimulation in vivo with specific Ag plus IL-2. T cells derived from spleens of B6 mice (Thy-1.2) immune to FBL-3, a Friend virus-induced leukemia, were activated by in vitro stimulation with irradiated FBL-3 and expanded by culture for 14 days with low concentrations of IL-2. The resultant FBL-3-specific T cell lines were adoptively transferred into cyclophosphamide pretreated congenic hosts (B6/Thy-1.1), and restimulated every 14 days by an injection of irradiated FBL-3 plus a 7-day course of IL-2. Donor T cells residing in the host were identified and quantified by use of antibody to the Thy-1.2 allele. The results confirmed that stimulation with FBL-3 on the day of transfer (day 0) plus IL-2 on days 0 to 6 induced rapid growth of donor T cells to approximately an 11-fold increase in total donor T cell number recoverable from host ascites and spleen by day 7. However, prolonging the course of IL-2 administration to 35 days did not maintain the number or the specific cytolytic function of donor T cells. By contrast, intermittent restimulation with specific Ag plus IL-2 induced intermittent regrowth of donor T cells in vivo, maintained the number of donor T cells in vivo at greater than the number input for longer than 1 mo, and allowed detection of substantially augmented donor T cell-mediated specific antitumor function over that period of time.

Adoptively transferred antigen-specific T cells can be grown and maintained in large numbers in vivo for extended periods of time by intermittent restimulation with specific antigen plus IL-2

The aim of the current study was to determine whether cultured tumor Ag-specific T cells could be induced to grow and maintained functional in large numbers in vivo by intermittent restimulation in vivo with specific Ag plus IL-2. T cells derived from spleens of B6 mice (Thy-1.2) immune to FBL-3, a Friend virus-induced leukemia, were activated by in vitro stimulation with irradiated FBL-3 and expanded by culture for 14 days with low concentrations of IL-2. The resultant FBL-3-specific T cell lines were adoptively transferred into cyclophosphamide pretreated congenic hosts (B6/Thy-1.1), and restimulated every 14 days by an injection of irradiated FBL-3 plus a 7-day course of IL-2. Donor T cells residing in the host were identified and quantified by use of antibody to the Thy-1.2 allele. The results confirmed that stimulation with FBL-3 on the day of transfer (day 0) plus IL-2 on days 0 to 6 induced rapid growth of donor T cells to approximately an 11-fold increase in total donor T cell number recoverable from host ascites and spleen by day 7. However, prolonging the course of IL-2 administration to 35 days did not maintain the number or the specific cytolytic function of donor T cells. By contrast, intermittent restimulation with specific Ag plus IL-2 induced intermittent regrowth of donor T cells in vivo, maintained the number of donor T cells in vivo at greater than the number input for longer than 1 mo, and allowed detection of substantially augmented donor T cell-mediated specific antitumor function over that period of time.

A case of zinc deficiency during long-term total parenteral nutrition

A 54-year-old housewife received total parenteral nutrition (TPN) because of an intestinal fistula and total wound breakdown after an emergency operation for perforation of the ileum and diffuse peritonitis. The TPN regimen reversed the catabolism and resolved the abdominal wound and enterocutaneous fistula. Zinc and copper were not supplemented because there was no licensed parenteral trace element solution available. At week 17 of TPN, eczematoid dermatitis appeared on the face, nasolabial folds and chin, and the perineal area. These changes, coinciding with a serum zinc level of 20 micrograms/dl, were consistent with zinc deficiency. Zinc supplementation was commenced giving 6 mg of elemental zinc intravenously daily. The response to zinc therapy was very dramatic. Not only did the serum zinc level increase, but the skin changes returned to normal within 7 days. The patient gradually resumed her usual diet and TPN was discontinued after an approximate duration of 21 weeks. She was later discharged in good health.

[Pest control and yield increase of areca by root-zone application of carbofuran in admixture with fertilizers]

The result of our experiment has shown that by root-zone application of carbofuran in admixture with fertilizers to Areca in spring the serious pest Tirathaba rufivena can be controlled for 4 months during flowering and young fruiting stage and the yield can increase by 50%. The final residual amount of carbofuran in fruits is below 0.1-0.01 ppm or too low to be examined, and there is no decrease in total alkaloid content in fruits.