Lipid profiles of Helicobacter pylori and Helicobacter mustelae grown in serum-supplemented and serum-free media

Many of Helicobacter species have been found to have novel cholesteryl glucosides (CGs). To study the biosynthetic mechanism of CGs, the lipid profiles of H. pylori and H. mustelae grown in serum-supplemented and cholesterol-restricted serum-free media were investigated. In contrast to the serum-supplemented state, helicobacters had less CGs in the serum-free state; a trace amount of CGs and no CG was detected in H. pylori and H. mustelae, respectively. The proportion of total and individual phospholipid also showed significant alteration. Unknown lipids which did not contain phosphate and sugar were detected in the serum-free state, but not in the serum-supplemented state. The CGs were found to be distributed mainly in the membrane fractions, and one of the unknown lipids was found exclusively in the cytosol fraction. Based on these data, it is apparent that the CGs of helicobacters are synthesized by de novo uptake of cholesterol from the media. The unknown lipids detected in the serum-free state may be storage lipids, appearing in response to depletion of nutrients, especially cholesterol, or other factors in the media.

Structural and functional comparison of trematode haemoglobins

Haemoglobins from three different species of trematodes (Gastrothylax crumenifer, Paramphistomum epiclitum and Isoparorchis hypselobagri) and their respective hosts were digested with papain. Peptides so produced were separated on 10-15% SDS-PAGGE. The probability of coincidence of the peptides was analysed statistically. Oxygen affinity curves of trematode haemoglobins were found to be a rectangular hyperbolic. The Hill coefficient values of all the trematode haemoglobins were found to be 1. The P50 values, at 25 degrees C in 0.2M phosphate buffer pH 7.4, ranged from 0.8 to 1.6 mmHg.

Imidazolines stimulate release of insulin from RIN-5AH cells independently from imidazoline I1 and I2 receptors

The effect on insulin release of efaroxan, an alpha 2-adrenoceptor antagonist and a highly potent drug at imidazoline I1 receptors, and the effects of seven other imidazoline compounds selective for the imidazoline I1 or I2 receptors, were studied in the rat insulinoma cell line RIN-5AH. The cells released insulin in response to glucose (0.3-10 mM), and efaroxan (100 microM) potentiated glucose-induced insulin release. (-)-Adrenaline completely displaced the binding of [125I]p-iodoclonidine to membranes of RIN-5AH cells, indicating that these cells do not express imidazoline I1 receptors. Cirazoline and idazoxan (100 microM), both highly potent drugs at imidazoline I2 receptors, and the guanidines guanoxan and amiloride (200 microM), also promoted insulin release from RIN-5AH cells. Irreversible blockade of imidazoline I2 receptors with 10 microM clorgyline did not prevent the stimulatory effects of cirazoline or idazoxan; however, these compounds completely reversed the inhibition by diazoxide (250 microM), an opener of ATP-dependent K+ channels (K+ATP channels), of glucose-induced insulin release. These data indicate that the imidazoline/guanidine compounds promote insulin release from RIN-5AH cells, by interacting with a novel binding site related to K+ATP channels that does not represent any of the known imidazoline I1 or I2 receptors.

Heat shock protein produced by Helicobacter pylori

The cells of Helicobacter pylori were suspended in the medium containing 35S-methionine. After a heat shock of the cells at 42 C for 5, 10, and 30 min, the production of proteins was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Out of many proteins produced by the cells, only 66 kDa protein production was dramatically increased by heat treatment. The N-terminal amino acid sequence of 66 kDa protein was quite similar to that of 62 kDa and 54 kDa proteins previously suggested as heat shock protein (HSP) of H. pylori based on the reaction with polyclonal and monoclonal antibodies against HSP 60 family proteins produced by other bacteria. Therefore, it was concluded that H. pylori produces the 66 kDa protein as its major heat shock protein which belongs to HSP 60 family.

Purification and properties of the hemoglobins of the platyhelminth Isoparorchis hypselobagri (Trematoda: Isoparorchidae) and its host Wallagu attu (catfish)

1. The hemoglobins of the trematode Isoparorchis hypselobagri and of its host Wallagu attu (catfish) were isolated and purified. 2. SDS-polyacrylamide gel electrophoresis showed both to consist of single, 15-17 kDa chains, having different electrophoretic mobilities. 3. Isoelectric focusing showed the trematode hemoglobin to be homogeneous with a pI of 4.2 and the host hemoglobin to consist of several components. 4. Gel filtration of freshly prepared trematode hemoglobin revealed one peak corresponding to M(r) approximately 17 kDa; gel filtration of a preparation which had been stored for 2-3 months demonstrated the presence of two peaks, whose elution volumes corresponded to M(r) of ca 35 and 17 kDa, respectively. 5. Reversed-phase chromatography of carboxymethylated 35 and 17 kDa peaks on a C8 column, gave a single peak a and two peaks b and c, respectively. 6. Edman degradation of peaks a, b and c obtained provided identical sequences of 27 amino acid residues for peaks a and c and another sequence differing at 10 of the 27 positions, for peak b. Edman degradation of the freshly prepared Isoparorchis hemoglobin provided the first 15 amino acid residues found for peaks a and c. The host hemoglobin gave an N-terminal sequence completely different from the trematode sequences. 7. Since gel filtration of the 35 and 17 kDa peaks showed no sign of an interconversion equilibrium, it appears that the 35 kDa peak and peak a represent a disulfide-bonded dimer of a monomer globin chain which shares the 27 N-terminal residues with chain c, the major monomer globin component of the 17 kDa peak.(ABSTRACT TRUNCATED AT 250 WORDS)

[Lipid composition of Helicobacter pylori]

In H. pylori, we examined the composition of total lipids. In thin-layer chromatography, three kinds of glycolipids were detected, which were named as G-1, G-2 and G-3. G-3 contained phosphates in addition to sugars. Total lipids consisted of 6.0% neutral lipids (weight %), 20.6% glycolipids (G-1, G-2) and 73.4% phospholipids (including G-3). Total glycolipids were approximately 25% of total lipids. After methanolysis, cholesterol was detected in the hexane extractable fraction and glucose was detected by GLC in the methanol fraction after trimethylsilylation, in all glycolipids. Therefore, these glycolipids are cholesteryl glycosides. Cholesteryl glycosides are found very rarely in bacteria, and have been detected only in a few species of mycoplasmas and spirochetes.

Antigen profile of Helicobacter pylori strains isolated from peptic ulcer patients in Dhaka, Bangladesh

The whole-cell-extract and the acid-extract preparations of Helicobacter pylori strains isolated from peptic ulcer patients and the NCTC 11638 control strain were studied to compare their antigen profiles. Besides, the anti-H. pylori-antibody profile in serum from H. pylori-infected peptic ulcer patients were also studied to define the antigen stimulating specific anti-H. pylori-antibody response in the infected patients. The whole-cell extract (WCE) and the acid-extract (AE) preparations showed a general antigenic homogeneity among the H. pylori strains isolated from the patients and the NCTC 11638 control strain. A humoral immune response against the infecting organism was observed and three antigenic bands of approximate molecular masses of 61 kDa, 58 kDa and 24 kDa were recognized by all the tested sera. Those bands were found to be unique for H. pylori and did not show any cross reaction with the Campylobacter jejuni antigenic bands. This makes them a candidate for the specific antigens required to develop a specific serological diagnostic test. Further purification and characterization of the protein bands may be carried out to define their probable diagnostic or immuno-pathogenic role.

Comparative spectral, electrophoretic and isoelectric properties of trematode haemoglobins

A comparative study of the spectral, electrophoretic and isoelectric properties of the haemoglobins of three trematodes, Paramphistomum epiclitum, Gigantocotyle explanatum and Gastrothylax crumenifer was carried out. A high absorption in the beta band region indicates that trematode haemoglobins have high oxygen affinities. Electrophoretic mobilities of all trematode and their host haemoglobins were different. The isoelectric points of trematode haemoglobins were found to focus in the acidic range except that of G. crumenifer haemoglobin I, which focused at an alkaline pH.

Comparison of the hemoglobins of the platyhelminths Gastrothylax crumenifer and Paramphistomum epiclitum (Trematoda: Paramphistomatidae)

1. Gastrothylax crumenifer and Paramphistomum epiclitum parasitize the water buffalo Bubalus bubalis. 2. Gastrothylas hemoglobin consisted of two fractions of ca 30,000 and ca 18,000 by gel filtration. SDS-electrophoresis showed both to be single, ca 15,000 chains. 3. Paramphistomum hemoglobin was ca 16,000 by both gel filtration and SDS-electrophoresis. 4. Reversed-phase chromatography of carboxymethylated trematode and buffalo globins gave single peaks and two peaks, respectively. Although Paramphistomum hemoglobin provided and N-terminal sequence, Gastrothylax hemoglobin did not, suggesting blocked N-terminals. The buffalo sequences were found to be identical to the sequences of the alpha and beta chains of bovine hemoglobin. 5. Although Paramphistomum hemoglobin consists of only one chain, Gastrothylax hemoglobin consists either of one chain which aggregates to a dimer or of two different chains, only one of which aggregates to a dimer.

Maternal factors affecting birthweight of uncomplicated pregnancy

Two hundred full-term pregnant mothers with no complication of pregnancy and no associated disease selected from Jinnah Postgraduate Medical Centre were studied for their nutritional status and other characteristics. The effect of these factors on birthweight of their new-born was determined. Total calorie intake per capita per day was low being 1913. The mean birthweight was 2.9kg, 26% weighed 2.5kg or less. No significant sex difference was observed in the birthweight. Variables having a significant positive influence on birthweight were maternal age at first delivery, up to 25 years, beyond which correlation was not significant; maternal weight and maternal total calorie intake (irrespective of source) up to an intake of 2500 calorie per day, beyond which correlation was not significant. Combined effect of these three maternal factors on birthweight was highly significant. Coefficient of correlation, R being 0.81.

Lactate dehydrogenase in two digenetic trematodes and their host

Polyacrylamide gel electrophoresis of the two digenetic trematodes, Gigantocotyle explanatum from the liver and Gastrothylax crumenifer from the rumen of the water buffalo, Bubalus bubalis revealed the presence of at least six and seven isoenzymes of lactate dehydrogenase (LDH), respectively in a partially purified enzyme preparation. The respective host tissues showed five isoenzymes of LDH, which are characteristic to the vertebrates. Both parachloromercuribenzoate and iodoacetate affected the LDH activity of the parasites and host tissues differently. Spectrophotometric analysis also showed different specific activity and susceptibility to the action of thiol inhibitors. The host LDH was quite stable at 57 degrees C for 30 min, but that of the parasites was less stable.

Acute lower respiratory tract infection due to virus among hospitalized children in Dhaka, Bangladesh

The nature of acute lower respiratory tract infection (ALRI) in hospitalized children and of the associated viral agents was assessed in a study of 601 children less than 5 years old over a 24-month period. Of these children, 80% were less than 24 months of age and the ratio of boys to girls was 1.7:1. Pneumonia (86.5% of cases) was the most frequently observed clinical manifestation. Shedding of virus was detected in 21.1% of the children; the highest rate occurred in infants 0-5 months old (27%) as compared with a rate of only 12.5% in children 25-60 months old. Virus was detected in 33.3%, 32.8%, 21.2%, and 20% of the cases of tracheobronchitis, bronchiolitis, pneumonia, and croup, respectively. Among the viruses detected, 78% were respiratory syncytial virus (RSV) (91% of infections with this virus occurred in children less than 2 years old) and 14.4% were influenza virus types A and B. Of the RSV infections, 61% occurred in infants less than 1 year old. The case-fatality rate was 6.8% overall and was 4.8% in virus-associated cases. No consistent pattern of seasonal occurrence of viral infections was discerned. RSV was detected throughout the year, with increased prevalence from January to April.

Histochemical and electrophoretic studies on phosphatases of some Indian trematodes

The isoenzymes of acid and alkaline phosphatases and their histochemical localization were studied by polyacrylamide disc gel electrophoresis in four species of trematodes: Gigantocotyle explanatum from the liver and Gastrothylax crumenifer from the rumen of water buffalo (Bubalus bubalis) and Echinostoma malayanum and Fasciolopsis buski from the small intestine of the pig (Sus scrofa). Both acid and alkaline phosphatases were present in the tegument, gastrodermis, suckers, testes, ovary, eggs, vitellaria and uterus but alkaline phosphatase activity was demonstrated only in the parenchyma and excretory ducts. Polyacrylamide gel electrophoresis revealed two to four isoenzymes for both acid and alkaline phosphatase.

Parental perceptions of enuresis. A collaborative study

Of 1,379 children 4 years of age and older who were patients in nine medical centers across the country, 346 (25.1%) were found to be enuretic. Their parents considered heavy sleeping and emotional problems as the main causes of enuresis in children; physical causes rarely were believed to be important. "Waking up the child" from sleep to urinate and "talking about the problem" were the main methods that parents used to treat enuresis. Very few used medication. Parents with a grade school level of education punish bed-wetting children at twice the rate of high school- and college-educated parents. Physicians need to be more aware that enuresis is an important problem for parents and that there are many widely held beliefs about cause and management.

Enuresis: a contrast of attitudes of parents and physicians

Questionnaires were used to survey 1,435 parents and 446 physicians in order to determine and compare attitudes and beliefs about enuresis. Although both groups thought that bed-wetting is a maturational problem, the parent group thought emotional causes were important and were less likely to accept small bladder size as an etiology. Parents thought that children should be dry at a much younger age than did the physicians (2.75 vs 5.13 years, respectively). Only 63% of parents thought that medical intervention is a good way to deal with a child's bed-wetting, yet 87% of the physicians suggested medical evaluation. A comparison of the various methods used to stop bed-wetting indicated that parents use waking the child, reassurance and talking with the child, restricting fluids, and punishment significantly more often than physicians. Although many physicians prescribe medication, only 6.6% of the parents thought that medicines are a "very good way" to treat enuresis. When developing a treatment plan for a child with enuresis, the physician should recognize the wide differences between parental and physician attitudes toward this common problem of childhood.