Enhanced resistance to Nocardia brasiliensis infection in mice depleted of antigen-specific B cells

This study deals with the roles of T and B cells in Nocardia brasiliensis infection in mice. Nocardia injected into the animals' footpads caused inflammatory responses and mycetomas in situ, resulting in granulomatous lesions of subcutaneous tissues and eventual bone destruction. These clinical features resemble those of humans infected with Nocardia. The effect, if any, of antibody was studied by passively transferring anti-Nocardia serum into either immunologically normal or T-deficient infected mice. Such transfers had no protective function in either group. To the contrary, the antibody seemed to favor infection and worsen bone disease compared to that in mice not given antibody. Furthermore, passive transfer of the antibody along with injection of Nocardia coated with the antibody magnified the severity of subsequent symptoms. Although these experiments ruled out any role for antibody in protection from Nocardia, they did not directly prove T cell participation in such resistance. Therefore, the role of T cells during Nocardia infection was examined further by transferring spleen cells depleted of B lymphocytes bearing receptors for a Nocardia extract (NE). Lethally irradiated mice reconstituted with a population depleted of NE-specific B cells totally lacked the ability to form antibodies to NE; however, they mounted effective delayed-type hypersensitivity reactions and completely controlled their Nocardia infection, establishing the importance of cell-mediated immunity in halting this disease process.

Enhanced resistance to Nocardia brasiliensis infection in mice depleted of antigen-specific B cells

This study deals with the roles of T and B cells in Nocardia brasiliensis infection in mice. Nocardia injected into the animals' footpads caused inflammatory responses and mycetomas in situ, resulting in granulomatous lesions of subcutaneous tissues and eventual bone destruction. These clinical features resemble those of humans infected with Nocardia. The effect, if any, of antibody was studied by passively transferring anti-Nocardia serum into either immunologically normal or T-deficient infected mice. Such transfers had no protective function in either group. To the contrary, the antibody seemed to favor infection and worsen bone disease compared to that in mice not given antibody. Furthermore, passive transfer of the antibody along with injection of Nocardia coated with the antibody magnified the severity of subsequent symptoms. Although these experiments ruled out any role for antibody in protection from Nocardia, they did not directly prove T cell participation in such resistance. Therefore, the role of T cells during Nocardia infection was examined further by transferring spleen cells depleted of B lymphocytes bearing receptors for a Nocardia extract (NE). Lethally irradiated mice reconstituted with a population depleted of NE-specific B cells totally lacked the ability to form antibodies to NE; however, they mounted effective delayed-type hypersensitivity reactions and completely controlled their Nocardia infection, establishing the importance of cell-mediated immunity in halting this disease process.

Determination of ovarian function using first morning urine steroid assays

A new direct radioimmunoassay measuring ovarian steroid metabolites in small aliquots of urine has been evaluated. For this purpose urinary levels of estrone-3-glucuronide (E1G) and pregnanediol-3-glucuronide (PG) were correlated with plasma values of estradiol (E2) and progesterone (P), respectively, from days 5 to 24 of the cycle in 24 women with normal cycles. Urine samples were representative of 1) first morning voiding; 2) 24-hour collection; and 3) all voidings except for the first morning one. The correlation between urinary E1G and PG with plasma values of E2 and P was statistically significant for the 3 collections of urine. The first morning voiding is selected as the sample of choice to determine E1G and PG due to its ease of collection and its high correlation with plasma E2 and P levels (r = .60, P less than .001; r = .73, P less than .001, respectively).

[Possible regulatory role of 5'-methylthioadenosine on enzymatic methyl esterification of membrane protein]

In the present study the effect of 5'methylthioadenosine (MTA), a natural metabolite of S-adenosylmethionine (AdoMet), on the enzymatic methyl esterification of intact erythrocyte membrane proteins has been investigated. The thioether significantly affects the methylation process :50% inhibition being observable at 100 microM MTA. This inhibition is due to the action of MTA on the enzyme protein methylase II. Since MTA is present in micromolar amounts in the cells, the reported effect could be of physiological interest and suggests a new regulatory role of this AdoMet metabolite.

[Prolactinomas and "idiopathic" hyperprolactinemia. Case series]

Endocrine features in 22 women affected by idhyopatic hyperprolactinemia and in ten women affected by prolactin secreting adenoma have been assessed basic levels of FSH, LH, E2, T3, T4, and PRL were evaluated and dynamic tests by GnRH, TRH and bromocryptine were performed prolactin basal value and TRH dynamic test show some value in differentiating hydiopatic hyperprolactinaemia from prolactynomas, but no hormon by itself nor dynamic test show a reliable effectiveness for this diagnosis.

Mechanism of propylamine-transfer reactions. Kinetic and inhibition studies on spermidine synthase from Escherichia coli

Spermidine synthase (EC 2.5.1.16) purified from Escherichia coli has been subjected to a kinetic analysis including initial velocity and substrate analogs inhibition studies. Evidence is reported for a ping-pong mechanism, indicating that a propylaminated form of the enzyme is an obligatory intermediate in the reaction mechanism. S-Adenosyl(5')-3-methylthiopropylamine exerts a competitive substrate inhibition by combining with the improper stable enzyme form, while putrescine does not show any inhibitory effect. In order to investigate the substrate binding sites, new sulfonium-deaminated analogs of S-adenosyl(5')-3-methylthiopropylamine have been synthesized and assayed as substrates and as inhibitors of the reaction. The replacement of the amino group of adenine, or propylamine moiety of the sulfonium compound by the hydroxyl group, or both, resulted in a complete loss of activity as substrate. On the other hand, the deaminated analogs exert a competitive inhibition with respect to putrescine. On the basis of these results and in analogy with methyltransfer reactions, three recognition sites for S-adenosyl(5')-3-methylthiopropylamine on propylamine transfer enzymes are proposed.

5'-Methylthioadenosine phosphorylase from Caldariella acidophila. Purification and properties

The occurrence of 5'-methylthioadenosine phosphorylase in Caldariella acidophila, a thermophilic bacterium growing optimally at 87 degrees C, is reported. It represents the first example in prokaryotes of a phosphoryolytic cleavage of the thioether. The reaction products, purified by ion-exchange chromatography, have been identified as 5-methylthioribose-1-phosphate and adenine by several analytical procedures. The enzyme has been purified to homogeneity in 32% yield by using DEAE-cellulose and hydroxyapatite chromatography, gel filtration and isoelectric focusing. The enzyme shows a high degree of thermophilicity, its temperature optimum being at 93 degrees C; furthermore no loss of activity is observable after exposure for 1 h at 100 degrees C. The kinetic data indicate a sequential mechanism of the reaction. The apparent Km values are 0.095 mM for 5'-methylthioadenosine and 6.1 mM for phosphate. The specificity of the reaction is rather strict. Experiments performed with analogues of the substrate, i.e. 5'-methylthioinosine, 5'-dimethylthioadenosine sulfonium salt, 5'-n-butylthioadenosine, 5'-isobutylthioadenosine, 5'-isobutylthioinosine, adenosylhomocysteine, 5'-thioethanoladenosine, adenosine, indicate the relevance of the adenine amino group and the sulfur in thioether form in the binding to the enzyme protein.

Preparation and analysis of new sulfonium derivatives from S-adenosyl(5')-3-methylthiopropylamine

The paper reports the preparation and the chromatographic separation of new deaminated analogs of S-adenosyl(5')-3-methylthiopropylamine, i.e. S-adenosyl(5')-3-methylthiopropanol and S-inosyl(5')(-3-methylthiopropanol. These compounds can be used as specific inhibitors of polyamine biosynthesis. It is also reported the characterization of new sulfonium compounds by U.V. spectrophotometry, thin layer chromatography, high voltage electrophoresis, hydrolysis to known fragments.

Bromocriptine in the treatment of hyperolactinemic amenorrhea

Thirty women with secondary amenorrhea and hyperprolactinemia were studied; galactorrhea was present in 25 of them, and 18 were infertile. Serum prolactin (PRL) levels were high in all cases, between 26 and 120 ng/ml. All women were treated with bromocriptine in increasing doses from 2.5 to 5.0 or 7.5 mg daily, according to the response obtained, for 4 months. In 27 patients a PRL determination was performed during treatment; values returned to normal (up to 20 ng/ml) in 23 women and remained high in 4. Galactorrhea disappeared in 21 of 25 women. Ovulatory menses were re-established in 17 patients (56.6%). Seven women became pregnant (38.8%), one of them after bromocriptine and clomiphene were given simultaneously in the same cycle. According to our results and a literature review the following conclusions may be drawn: (1) bromocriptine is a useful therapeutic tool for re-establishing menstruation and inducing ovulation in patients with the hyperprolactinemic-amenorrhea syndrome; (2) the association of bromocriptine and clomiphene could be the next step in the treatment of patients who fail to ovulate with bromocriptine alone.

[5-methylthioadenosine phosphorylase from C.acidophila. 2. Identification and characterization of reaction products]

Evidences for a phosphorolitic cleavage of 5'-MTA by a specific enzyme from C. acidophila are reported. Methylthioribose-1-phosphate and adenine have been identified as reaction products, by several analytical procedures.

Substrate specificity of 5'-methylthioadenosine phosphorylase from human prostate

5'-Methylthioadenosine phosphorylase was purified approx. 340-fold from human prostate by using affinity chromatography by Hg-coupled Sepharose. The enzyme, responsible for the breakdown of 5'-methylthioadenosine into adenine and methylthioribose 1-phosphate, was partially characterized. The apparent Km for 5'-methylthioadenosine is 25 microM. It is activated by thiols and shows an absolute requirement for phosphate ions. New analogues of 5'-methylthioadenosine were prepared and their activity as substrates or inhibitors of the reaction was investigated. The replacement of the 6-amino group of the adenine moiety by a hydroxy group, as well as the replacement of N-7 by a methinic radical, resulted in an almost complete loss of activity. Otherwise the replacement of sulphur by selenium, as well as that of the methyl group by an ethyl one, is compatible with the activity as substrate. The positively charged sulphonium group also prevents catalytic interaction with the enzyme. The inhibitory effect of 5'-methylthiotubercidin (competitive) and 5'-dimethylthioadenosine sulphonium salt (non-competitive) was also demonstrated. The reported results suggest three binding sites between the substrate and the enzyme.

[5'-methylthioadenosine phosphorylase from the human prostate. 1. Purification and partial characterization]

5'-Methylthioadenosine phosphorylase has been purified approximately 340-fold in 20% yield from human prostate: the use of affinity chromatography by Sepharose-Hg has been found particularly advantageous. The enzyme has been partially characterized and an apparent Km of 2.5 x 10(-5) M has been calculated for 5'-methylthioadenosine. The reaction is activated by thiols and shows an absolute requirement for phosphate ions.

[Electrogustometric threshold in diabete and chronic ethylism. Survey on 230 patients (author's transl)]

This study completes a previous one in which the authors tested the electrogustometric threshold in 300 normal subjects used as controls. The collected datas has been computerized on a programable calculator according to a lognormal model. Comparison between the electrogustometric threshold in diabetic patients, ethylic ones and controls demonstrate that they are statistically different. More than a half of the diabetics and ethylics have abnormaly high electrogustometric thresholds. The responses have been studied as a function of the evolution of the disease, of the clinical form and of gravity. Diabete and chronic ethylism do not disturb the gustatic function at the same speed and with the same intensity: one year evolution is at least necessary for diabetics, and ten years for ethylics in order to detect abnormal electrogustometric thresholds. But if the action of ethylic intoxication is slower, it determines the most important gustometric deteriorations.