Persistence of Escherichia coli, Salmonella choleraesuis, Aujeszky's Disease virus and Blue Eye Disease virus in ensilages based on the solid fraction of pig faeces

AIMS

This study was carried out to determine the survival time of Escherichia coli, Salmonella choleraesuis, Aujeszky's Disease virus and Blue Eye Disease virus in ensilages based on the solid fraction of pig faeces.

METHODS AND RESULTS

The four micro-organisms were inoculated into microsilos based on the solid fraction of pig faeces, sorghum and molasses. They were left for 0, 7, 14, 28 and 56 days, after which the state of each microsilo was evaluated, and isolation of the inoculated agents was attempted. The four inoculated agents were isolated only on day 0 of ensilage. The viral agents were identified through the cytopathic effect and fluorescence.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

It is concluded that ensilages based on the solid fraction of pig faeces appear to reduce the risk of the transmission of the agents inoculated in this study and help to reduce the environmental impact by using the solid in animal feed.

Exocrine pancreatic insufficiency in tropical sprue

BACKGROUND

Pancreatic insufficiency may appear secondary to several intestinal disorders. It may contribute to malabsorption in tropical sprue (TS).

METHODS

The exocrine pancreatic function was evaluated with the indirect pancreolauryl test (PT) in 56 patients with TS. The PT results were analyzed and correlated with serum albumin levels, degree of intestinal atrophy, and steatorrhea.

RESULTS

Abnormally low values were found in 36 (64.2%) cases. A significant relationship was not observed between PT and hypoalbuminemia. Patients with more severe damage by intestinal biopsy tended to have lower PT values. No relationship was found between pancreatic insufficiency and steatorrhea (expressed as g/24 h), but patients with pancreatic insufficiency had increased stool fat concentrations (expressed as percentage of wet stool weight). All patients responded favorably to treatment with folic acid and tetracycline. Fifteen patients with abnormal initial PT values underwent a repeat PT after a 6-week therapy; all of them showed normalization of PT values.

CONCLUSIONS

The abnormal exocrine pancreatic function found with an indirect test in patients with TS is probably secondary to a low pancreatic hormonal stimulation due to intestinal damage, as occurs in celiac sprue. These abnormalities are reversible after specific treatment for TS.

Ca2+ channels that activate Ca2+-dependent K+ currents in neostriatal neurons

It is demonstrated that not all voltage-gated calcium channel types expressed in neostriatal projection neurons (L, N, P, Q and R) contribute equally to the activation of calcium-dependent potassium currents. Previous work made clear that different calcium channel types contribute with a similar amount of current to whole-cell calcium current in neostriatal neurons. It has also been shown that spiny neurons possess both "big" and "small" types of calcium-dependent potassium currents and that activation of such currents relies on calcium entry through voltage-gated calcium channels. In the present work it was investigated whether all calcium channel types equally activate calcium-dependent potassium currents. Thus, the action of organic calcium channel antagonists was investigated on the calcium-activated outward current. Transient potassium currents were reduced by 4-aminopyridine and sodium currents were blocked by tetrodotoxin. It was found that neither 30 nM omega-Agatoxin-TK, a blocker of P-type channels, nor 200 nM calciseptine or 5 microM nitrendipine, blockers of L-type channels, were able to significantly reduce the outward current. In contrast, 400 nM omega-Agatoxin-TK, which at this concentration is able to block Q-type channels, and 1 microM omega-Conotoxin GVIA, a blocker of N-type channels, both reduced outward current by about 50%. These antagonists given together, or 500 nM omega-Conotoxin MVIIC, a blocker of N- and P/Q-type channels, reduced outward current by 70%. In addition, the N- and P/Q-type channel blockers preferentially reduce the afterhyperpolarization recorded intracellularly. The results show that calcium-dependent potassium channels in neostriatal neurons are preferentially activated by calcium entry through N- and Q-type channels in these conditions.

[Detection of immunoglobulin A in serum and saliva of patients with hepatitis A]

Specific secretory serum IgA antibodies to the hepatitis A virus from samples from patients with clinical symptoms compatible to hepatitis A, their contacts, and healthy subjects were analyzed using an ELISA technique; results were compared with those of specific serum IgM antibodies to the hepatitis A virus. The following results were attained in 175 blood samples: coincidence by 98.8%; sensitivity by 96.8%; and specificity by 100%. Two cases were negative to IGA and positive to IGM. On comparing the presence of IGA in saliva with the presence of IGM in blood, coincidence was of 88.1%; sensitivity, of 40.9% and specificity, of 100%. Of the 22 cases with positive IGM in blood, only 9 showed specific IGA antibodies in the saliva. The 111 cases who had negative IGM in blood were also negative to IGA. The obtained data suggest that specific serum IGA antibodies to the hepatitis A virus are an indicator of a recent or occurrent infection due to this virus and thus it may be considered and alternative for the diagnosis of this disease.

[The laboratory diagnosis of the intestinal malabsorption syndrome of intestinal origin]

Normal absorption and digestion occurs in sequential stages. In the lumen of the proximal intestine pancreatic enzymes and bile salts transform complex substances in simple products which can be absorbed by the enterocyte and transported by lymphatics or portal veins. Malabsorption syndromes can be secondary to alterations in both digestion and/or absorption process. We herein review the tests used to establish the diagnosis of intestinal malabsorption syndromes with special reference to those available in our country. Finally we propose an algorithm taking into account the frequency of diseases causing malabsorption in Mexico.

[The in-vitro digestive availability of lipase and trypsin in pancreatic supplements under different degrees of acidity]

We evaluated the in vitro disintegration time and the remanent digestive activity of eight pancreatic supplements under pH conditions similar to the gastrointestinal tract. They were incubated for 45 min at various pH levels (1, 3 or 6) and continued thereafter at pH 6, for another 135 min. The activities of lipase and trypsin were evaluated titrimetrically every 15 min. At pH 6, the products without an enteric coat and Creon, showed the shortest disintegration times; under acidic conditions, those times were longer in all the enteric coated products. At constant pH 6, lipase activity was greater in Creon, Pankreon and Cotazym-B; trypsin activity was greater in Nutrizym-C, Onoton and Cotazym-B. After acidic pH exposure enzyme bioavailability was decreased in all the products. Disintegration times and acid inactivation of enzymes, should be considered when prescribing PS.

Serum testosterone:dihydrotestosterone ratio and CA 19-9 in the diagnosis of pancreatic cancer

The testosterone:dihydrotestosterone ratio (T:DHT) and the antigenic marker CA 19-9 were studied in the serum of 21 male patients with pancreatic cancer and 62 controls with other gastrointestinal malignancies or benign pancreatobiliary disease. Specificity of the T:DHT ratio was 98%, significantly better than the specificity of CA 19-9 at both a 37 U/ml cutoff level (61%) and at 100 U/ml (79%). Sensitivity of the T:DHT ratio was 67%, and that of CA 19-9, 71% and 90% at the upper and lower cutoff levels, respectively. False-negative results of the T:DHT ratio were found predominantly in cases of advanced pancreatic cancer, whereas all four stage I patients had an abnormal (less than 5) T:DHT ratio. These results suggest that the T:DHT ratio is a useful marker for pancreatic cancer in males. It can be used alone or in combination with CA 19-9, and should be further evaluated in the differential diagnosis of patients with the early stages of this disease.

[Serum macroamylase in a subject with non-Hodgkin's lymphoma]

Macroamylasemia (MA) is a rare condition characterized by an active macromolecular complex formed by normal amylase with abnormal proteins; to our knowledge, it has not been previously described in Mexico. The size of the macromolecular complex precludes its renal excretion; thus MA is characterized by high levels of amylase in serum with normal amylasuria. We report a 53-year-old male with abdominal pain and hyperamylasemia who was erroneously diagnosed as pancreatitis. Amylase in urine was normal and a protein electrophoresis demonstrated hyperglobulinemia. Several months after the initial work-up, the diagnosis of non-Hodgkin's lymphoma was established. Serum pancreatic amylase was again found elevated with normal urinary amylase. Precipitation of amylase with polyethylene-glycol was of 81% (normal: less than 70%). This established the diagnosis of MA associated to non-Hodgkin's lymphoma. After chemotherapy, the abnormal macroamylasemia and hyperglobulinemia disappeared.

[Diagnostic usefulness of Ca 19-9 antigen in cancer of the pancreas and neoplasms of the pancreato-biliary intersection]

Antigen CA 19-9 was measured in the serum of a group of 16 patients with pancreatic cancer, in 19 patients with non-pancreatic gastrointestinal malignancies, and in 19 others with benign pancreatobiliary disease. The test showed a high sensitivity with a low specificity and a positive predictive value for diagnosis of pancreatic cancer when confronted with a group of controls that included both benign and malignant gastrointestinal disease. The low specificity was due to high CA 19-9 values in other gastrointestinal cancers, especially in carcinoma of the ampulla and the biliary tract. When the latter were added to the group of patients with pancreatic cancer, and the diagnostic accuracy of the test was re-evaluated, sensitivity, specificity and both positive and negative predictive values increased. Values of CA 19-9 over 100 U/ml are highly predictive of malignancy in patients with pancreato-biliary disease.

Effects of synthetic steroid contraceptives on biliary lipid composition of normal Mexican women

The effects of two hormonal contraceptives upon the biliary lipid composition of Mexican women were evaluated in a prospective study. Twenty-one healthy volunteers of reproductive age were allocated into three groups (7 subjects each). Group I served as the experimental control (all subjects were bearing a non-medicated IUD), group II received i.m. norethisterone enanthate (NET-e) 200 mg every two months, and group III received an oral combination of 1-norgestrel 150 micrograms and ethinyl estradiol 30 micrograms. The bile lithogenic index as assessed by the relative proportion of cholesterol to bile acids and lecithin was determined in duodenal bile samples obtained before (baseline), during (4 months), and after (12 months) contraceptive administration. The results indicated that NET-e administration resulted in a slight although significant increase of the lithogenic index while the oral formulation did not. The overall data were interpreted as demonstrating that administration of these steroid contraceptives does not constitute a risk factor in terms of gallstone formation in the population studied. The estrogen-like behavior exhibited by NET-e is discussed.