Effects of plasma total ammonia content and pH on urea excretion in Nile tilapia

Nile tilapia (Oreochromis niloticus) were infused with ammonium salts, acid, and base to investigate the effects of changes in arterial plasma total ammonia content (Tamm) and pH (pHa) on plasma urea-nitrogen (urea-N) levels and urea-N excretory fluxes (Jurea-N). The tilapia did not possess a functional hepatic ornithine urea-cycle (no significant carbamyl phosphate synthetase III activity). Infused substances were dissolved in a saline vehicle and injected twice (5 mL kg-1), the first infusion to "prime" the animal and promote a more marked response to the second infusion, given 2.5 h later. The results reported are those of the second infusion. Infusion of 200 mM NH4Cl increased Tamm, reduced pHa, and increased plasma urea-N and Jurea-N. Two hundred mM NH4HCO3 increased Tamm and arterial plasma total CO2 content (TaCO2), reduced pHa, and increased Jurea-N. Fifty mM HCl reduced pHa but had no effects on urea dynamics. Fifty mM NaOH increased pHa, plasma urea-N levels, and Jurea-N. Two hundred mM NaHCO3 increased pHa, TaCO2, plasma urea-N levels, and Jurea-N. Infusion of the saline vehicle was without effect. The results indicate that ammonia loading and plasma alkalosis both stimulate urea excretion in uricolytic fish. The responses to hyperammonemia or alkalosis were not modified when combined with elevated plasma bicarbonate levels.

Local expression of cytokines in human colorectal carcinoma: evidence of specific interleukin-6 gene expression

The expression of cytokine mRNAs in tumor tissue, normal mucosa, and peripheral blood mononuclear cells (PBMCs) was studied in 12 patients with colorectal cancer undergoing surgical resection, to characterize local immune conditions. mRNA transcripts for interleukin (IL)-1 beta, IL-2, IL-2-R(p55), IL-4, IL-5, IL-6, and IL-10 were detected using the reverse transcriptase-polymerase chain reaction (RT-PCR) technique. IL-6 mRNA was expressed in tumor tissue in 83% of the cases but only in one case in normal mucosa (p < 0.001); serum levels of IL-6 did not show any correlation with IL-6 mRNA; IL-1 beta transcripts were present in all tumor tissue samples; no IL-4 expression was detected; IL-2 mRNA was only present in two tumors; IL-2R(p55) mRNA was found in 58% of tumors but not in normal mucosae (p = 0.005). The expression of IL-10 suggests that it does not play a central role in colorectal cancer immunosuppression, and cytokine expression in PBMCs indicates a different and independent activation. This study suggests a pattern of expression of inflammatory cytokines in the tumor microenvironment, probably produced by infiltrating immune cells. The absence of the specific immune-activating cytokines, IL-2 and IL-4, could indicate an impairment of the anticancer immune response; IL-2R results confirm the dysregulation of the IL-2/IL-2R activation pathway. These findings may lead to a better understanding of the role of cytokines and especially IL-6 at the tumor site and hence their importance in developing an effective immunotherapy.

Double-blind, placebo-controlled trial to assess the efficacy and tolerability of mepartricin in the treatment of BPH

BACKGROUND

Mepartricin, a semisynthetic polyene derivative with a favorable effect on urethro-prostatic function, was clinically evaluated, adopting the diagnostic and research criteria recommended by the First International Consultation on BPH.

METHODS

A multicenter, randomized, double-blind, parallel-group study compared mepartricin 40 mg/daily to placebo in the treatment of 196 patients with newly diagnosed BPH and mild-to-moderate symptomatology. International Prostate Symptom Score (I-PSS), quality of life (QoL) index and maximum urinary flow-rate (Qmax) were determined every 4 weeks for 6 months; postvoiding volume, prostate volume, and prostate-specific antigen (PSA) were assessed after 3 and 6 months of therapy.

RESULTS

Mepartricin was shown to determine a statistically significant improvement over placebo in I-PSS and QoL index from month 2 onwards, and a significant linear increase in Qmax over the study period. At month 6, the improvement in the mepartricin and placebo groups in I-PSS, QoL index, and Qmax was 6.3 (standard error (SE) 0.51) and 4.2 (SE 0.60) points (P = 0.003), 0.99 (SE 0.14) and 0.62 (SE 0.12) points (P = 0.036), and 2.7 (SE 0.46) and 1.2 (SE 0.46) ml/sec (P = 0.051), respectively. No significant differences were noted in postvoiding residual volume, prostate volume, or PSA. Mepartricin tolerability was good, showing no adverse events on sexual function.

CONCLUSIONS

Mepartricin proved to be an effective treatment of benign prostatic hyperplasia, determining an improvement in symptoms, quality of life, and peak urinary flow.

Metabolic characterization of Kloeckera apiculata strains from star fruit fermentation

A total of 37 strains of Kloeckera apiculata was isolated during the spontaneous fermentation of star fruit must. Each strain was differentiated from the others on the basis of its capacity to produce acetaldehyde, ethyl acetate, higher alcohols, acetoin and acetic acid. All the strains were characterized by the low production of higher alcohols and the high production of ethyl acetate, whereas consistent differences in the production of acetaldehyde, acetoin and acetic acid served to differentiate star fruit apiculate strains into six different phenotypes, present at different stages of the fermentation process. The metabolic strain diversity found can be interpreted as a natural consequence of environmental conditions, which influenced the frequency and selection of specific apiculate strains. From the biotechnological point of view the different metabolic biotypes represent an important source of strains for potential use as starter cultures for star fruit fermentation.

Natural beta interferon in acute type-C hepatitis patients: a randomized controlled trial

AIM OF THE STUDY

A multicentre randomized controlled trial to assess whether a short course of beta-interferon could reduce the rate of chronic evolution of acute hepatitis C, in line with recent observations, was started in Northern Italy in 1991.

METHODS

Forty acute hepatitis C patients were randomized to receive natural beta interferon 3,000,000 international units intramuscularly three times a week for 4 weeks or symptomatic drugs, and were followed up for a median period of 22.5 months.

RESULTS

The chronicity rate was 75% (15/20 patients) in the interferon-treated group, and 80% (16/20) in the untreated group. No difference in the duration of the acute phase of hepatitis was observed. Hepatitis C virus ribonucleic acid was determined in 21 cases and was positive in 19 cases at baseline and in 15/17 chronic and 1/4 non chronic cases at the end of follow-up. Side effects of therapy (flu-like syndrome in 40% of cases) were mild and short-lasting. No aminotransferase flare-ups were observed during treatment.

CONCLUSIONS

Beta interferon at the suggested regimen is well tolerated but does not seem to significantly influence the natural course of acute hepatitis C.

Stability in by-product formation as a strain selection tool of Saccharomyces cerevisiae wine yeasts

A strain of Saccharomyces cerevisiae homozygous for different physiological and metabolic characters was inoculated into two grape musts and the stability of the characters was tested by isolating clones at different fermentation stages. A total of 60 cell-clones were collected and asci dissected from each, yielding a total of 1200 single spore cultures, which were then tested for the segregation of several genetically controlled traits. From the parental strain, 10 asci were dissected and the 40 single spore cultures obtained were used as controls. Micro-fermentations were performed with the 200 single spore cultures obtained from clones isolated at the end of Trebbiano and Aglianico must fermentations. The majority of these spore cultures produced amounts of the secondary compounds at the same level as the parental strain. The progeny of three clones from the Trebbiano fermentation exhibited a significant increase in the production of isoamyl alcohol, whereas the progeny of one clone from the Aglianico fermentation differed in the production of acetoin and amyl alcohols. The variability found in the levels of by-products can also affect the organoleptic properties of the final product. The introduction of the 'metabolic characteristics stability' as a selective index for industrial strains is advised.

Chloride-sulphate exchange chemically measured in human erythrocyte ghosts

The purpose of this paper is to provide a clear description of a new chemical method to measure and analyze the net anion exchange (Cl-/SO4--) in resealed human erythrocyte ghosts. With this technique, we measured the influx of an inorganic divalent anion (SO4--) against a monovalent anion (Cl-) as a function of temperature. We found an apparent activation enthalpy Ea of 21-24 Kcal/mol. Besides the Cl-/SO4-- influx pH - dependence, measured under condition of electric anion equilibrium, shows a bell shape with a maximum around pH 6.3. In addition we accounted for the extracellular pH changes during the exchange of chloride for sulphate across the erythrocyte ghosts when bicarbonate is present in the medium. The pH drops sharply, then increases for the remaining experimental time course.

Molecular Probe Data Base (MPDB)

In this paper, the current status of the Molecular Probe Data Base (http://www.biotech.ist.unige.it/interlab/ mpdb.html ) is briefly presented together with a short analysis of its activity during 1997. This has been performed by statistically evaluating the 'logs' of the Internet servers that are used for its distribution with reference to the geographical origin of the requests, the words that were utilized to carry out of the searches and the oligonucleotides that were retrieved. Planned enhancements of this database are also described. They include a revision of its data structure and, even more relevant, of its data management procedures.

[Which graft for which patient? and when? II. Organ supply and allocation]

Despite progress realised in transplantation and organ procurement, there is an increasing gap between the number of patients on the national waiting list and the number of harvested organs. As a result, the appropriate organs must be matched with the appropriate patient, with two constraints: equity and efficacy. In a context of lack of organs, another public health problematic is to conciliate both the interests of a given patient and the interests of those on the waiting lists. In 1996, the French secretary of state for health instituted a public consultation committee chaired by the vice-president of the Comité consultatif national d'éthique, Counsellor Jean Michaud, to study organ allocation rules and to plan recommendations for the future. Using, as a starting point, the allocation rules initiated in the past by France Transplant and transiently applied by l'Etablissement français des Greffes, the committee conducted a large audition of health care professionals concerned with transplantation, individuals qualified in ethics, laws, sociology or ethnology, politicians and a sample representation of the population. A new corpus of allocation rules and procedures was then defined according to the committee recommendations and the advice of all medico-surgical transplantation teams, and published as a ministerial order in the Journal officiel de la République française in november 1996. It specifies shared principles and organ by organ specific allocation rules.

Glycerol and other fermentation products of apiculate wine yeasts

Ninety-six strains of apiculate wine yeasts were studied for their ability to produce glycerol, acetaldehyde, ethyl acetate, sulphur dioxide and hydrogen sulphide in synthetic medium. Hanseniaspora guilliermondii produced smaller quantities of glycerol, acetaldehyde and hydrogen sulphide than Kloeckera apiculata, whereas the production of ethyl acetate and sulphur dioxide was found to be similar. Strains characterized by different capacities and properties were found for both species. The existence of apiculate strains differing in secondary compound production is of technological interest, as these yeasts constitute potential flavour producers. Selected strains of apiculate yeasts might favour an enhanced flavour formation and yield desirable characteristics to the final product.

Secondary products formation as a tool for discriminating non-Saccharomyces wine strains. Strain diversity in non-Saccharomyces wine yeasts

A total of 78 strains of non-Saccharomyces yeasts were isolated: 30 strains of Kloeckera apiculata, 20 of Candida stellata, 8 of Candida valida and 20 of Zygosaccharomyces fermentati. The diversity of yeast species and strains was monitored by determining the formation of secondary products of fermentation, such as acetaldehyde, ethyl acetate and higher alcohols. Within each species, the strains were distinguishable in phenotypes through the production of different amounts of by-products. In particular, a great variability was found in C. stellata, where six different phenotypes were identified by means of the production of acetaldehyde, ethyl acetate, isobutanol and isoamyl alcohol. At different stages of the spontaneous fermentation different phenotypes of the non-Saccharomyces yeasts were represented, characterized by consistent differences in some by-products involved in the wine bouquet, such as acetaldehyde.

Molecular Probe Data Base (MPDB)

Molecular Probe Data Base contains detailed information on synthetic oligonucleotides with a sequence of up to 100 nucleotides. This database prevalently contains information related to human oligonucleotides used in diagnostics. Molecular Probe Data Base has been made available on-line through the Internet by means of Network Information Retrieval (NIR) tools since 1993. Two years ago, a collaboration with EMBL Data Library was also set up, so that the Molecular Probe Data Base has been integrated with other molecular biology data banks in the sphere of the SRS WWW network browser. In this paper, the most recent enhancements and the current status of the Molecular Probe Data Base are briefly presented.

[Three-dimensional transesophageal echocardiography: a new cardiologic diagnostic tool. Initial experience with 150 patients]

BACKGROUND

Three-dimensional transesophageal echocardiography is a new diagnostic tool and its potential has been investigated mainly in international centers dealing with research in the field of cardiac pathologies. The clinical usefulness and the potential additional information over multiplane transesophageal echocardiography in daily clinical practice have not been exstensively studied.

OBJECTIVES

This study sought to assess the feasibility and to define the potential role of three-dimensional technique in a clinical cardiology department.

POPULATION AND METHODS

One hundred-fifty patients (73 males, 77 females) aged 17-82 underwent a three-dimensional transesophageal echocardiographic study. Indications for the study were the following: 39 mitral (26%), 13 aortic (8%) and 4 tricuspidal (2%) valvulopathies, 23 valvular prostheses (15%), 6 aortic diseases (4%), 16 sources of embolism (10%), 16 congenital heart diseases (10%), 14 ischemic heart diseases (9.3%), 14 cardiomyopathies (9%), 5 other pathologies (3%). The 3 D examination quality was graded as insufficient, sufficient and good. The information obtained by "volume rendered" and "anyplane" three-dimensional echocardiography were compared with the traditional two-dimensional images to determine whether they provided additional information.

RESULTS

A total of 288 acquisitions were obtained in the 150 patients (1.9 acquisitions per patient). Examinations were graded of good quality in 99 patients (61%), sufficient in 36 (24%) and insufficient in 15 patients (10%). Additional informations were obtained in 33 patients (22%) by "volume rendered" echocardiography and by "anyplane echocardiography", including mitral regurgitation or repair for valvular prolapse (11 patients), aortic valve malformations and endocarditis (4 patients), congenital heart diseases (9 patients), right ventricular dysplasia (6 patients) or hypertrophic cardiomyopathy (1 patient), tricuspid regurgitation (2 patients). The additional information were obtained in patients in the group of good 3 D reconstructions quality in all but two cases.

CONCLUSIONS

The diagnostic use of the transesophageal technique with 3 D facilities permitted to obtain an overall 22% of additional information. These results will stimulate further study to evaluate the advantages of the three-dimensional technique in specific clinical fields of application.