TMAO anaerobic respiration in Escherichia coli: involvement of the tor operon

The trimethylamine N-oxide (TMAO) respiratory system is subject to a strict positive control by the substrate. This property was exploited in the performance of miniMu replicon-mediated in vivo cloning of the promoter region of gene(s) positively regulated by TMAO. This region, located at 22 min on the chromosome, was shown to control the expression of a transcription unit composed of three open reading frames, designated torC, torA and torD, respectively. The presence of five putative c-type haem-binding sites within the TorC sequence, as well as the specific biochemical characterization, indicated that torC encodes a 43,300 Da c-type cytochrome. The second open reading frame, torA, was identified as the structural gene for TMAO reductase. A comparison of the predicted amino-terminal sequence of the torA gene product to that of the purified TMAO reductase indicated cleavage of a 39 amino acid signal peptide, which is in agreement with the periplasmic location of the enzyme. The predicted TorA protein contains the five molybdenum cofactor-binding motifs found in other molybdoproteins and displays extensive sequence homology with BisC and DmsA proteins. As expected, insertions in torA led to the loss of TMAO reductase. The 22,500 Da polypeptides encoded by the third open reading frame does not share any similarity with proteins listed in data banks.

[Behavior of the pituitary-thyroid axis in acromegalic subjects during prolonged intermittent and pulsatile treatment with octreotide]

Octreotide, as well as endogenous somatostatin, inhibits GH and TSH secretion. The drug is employed in the medical therapy of acromegaly. We studied the effects of a long-term (1-120 months; median 12 months) therapy with octreotide (300 micrograms/day) given in 3-times intermittent s.c. administration or in pulsatile s.c. (25 micrograms/120 min) way, upon the pituitary-thyroid axis. Thirteen patients (11 with normal thyroid function, 1 with secondary hypothyroidism, 1 with toxic goiter) with active acromegaly were studied. In the euthyroid patients no significative variations in both TSH levels and thyroid hormones were found during octreotide therapy. In the non-euthyroid patients octreotide did not induce changes in the dosages of drugs acting to thyroid function. The 24-hour IC-TSH levels did not show any variation during octreotide. TSH response to TRH was reduced (P < 0.05) during octreotide therapy. No correlation among TSH, IGF-I and GH levels was observed. Long-term treatment of acromegaly with octreotide reduces TSH response to TRH but do not interfere with both 24-hour IC-TSH levels and thyroid function.

A cross-over study with the two novel dopaminergic drugs cabergoline and quinagolide in hyperprolactinemic patients

Cabergoline and quinagolide, two new dopamine agonist drugs with long-lasting activity, are currently under investigation for the treatment of hyperprolactinemia. At present, studies comparing these drugs for tolerability and efficacy in the same patients are lacking. It was our aim to make such a comparison in an open randomized cross-over trial. Cabergoline (0.5 mg twice weekly) and quinagolide (75 micrograms once daily) were given orally. Each drug was administered for 12 weeks. Treatment with the second drug was started after the recurrence of hyperprolactinemia. Twelve women with hyperprolactinemia due to idiopathic disease (n = 6), microprolactinoma (n = 5) or postsurgical empty sella (n = 1) were evaluated. Six women were amenorrheic and 6 were oligomenorrheic. Ten had spontaneous or provoked galactorrhea. Baseline characteristics (age, clinical signs and PRL levels) of patients initially allocated to the two treatment groups were similar. Nine patients completed both treatment cycles and PRL levels were lower under cabergoline (10.7 +/- 3.7 micrograms/L) than under quinagolide (25.0 +/- 7.7 micrograms/L; p < 0.05). One patient discontinued cabergoline because of dryness of the eyes after having completed the quinagolide cycle and 2 patients initially treated with cabergoline discontinued quinagolide because of gastrointestinal symptoms. After completion of the first treatment cycle, the time of recurrence of hyperprolactinemia was significantly longer after cabergoline (14 +/- 7 weeks) than after quinagolide (5 +/- 1 weeks; p < 0.05). At week 12, normal PRL levels (< 20 micrograms/L) were observed in 10 and 6 women during cabergoline and quinagolide, respectively. Only one case was resistant to both drugs. The clinical effects of the two treatments were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of nicardipine on intimal-medial thickness and arterial distensibility in hypertensive patients. Preliminary results after 6 months

BACKGROUND

The aim of this study was to evaluate the effects of nicardipine, at the dosage of 80 mg/day in two administrations, on blood pressure, intimal-media thickness of the common carotid artery and on arterial distensibility after 6 months of therapy. The study population consisted of 23 patients, 13 male and 10 female, mean age 61.7 +/- 10.1 years, with systolic blood pressure 170.4 +/- 14.5 mmHg and diastolic blood pressure 98.3 +/- 5.7 mmHg, affected by essential arterial hypertension of slight to moderate degree. Twenty-three subjects underwent high resolution B-mode echotomography of the common carotid artery, performed twice by the same operator within a one-week period. Treatment for 6 months with slow release Nicardipine at a dosage of 80 mg in two daily administrations was seen to be efficient in reducing systolic and diastolic blood pressure values. It also reduced the carotid-femoral pulse wave velocity. The results of our study show that 6 month's treatment with slow-release Nicardipine at 80 mg in two daily administrations, in effective reducing systolic and diastolic blood pressure values, and, to a slightly significant degree, in reducing the value of the intimal-medial thickness of the common carotid. Naturally the data which emerge from our study are preliminary and require a definitive analysis at the end the study, which is foreseen after a two year period from the enrolment of at least one hundred patients.

The efficacy and tolerability of long-term cabergoline therapy in hyperprolactinaemic disorders: an open, uncontrolled, multicentre study. European Multicentre Cabergoline Study Group

OBJECTIVE

We assessed the efficacy and safety of the new, long-acting dopamine agonist drug cabergoline during long-term therapy of hyperprolactinaemia.

DESIGN

Open, prospective, multicentre study.

PATIENTS

One hundred and sixty-two females with either a microprolactinoma (n = 100), idiopathic hyperprolactinaemia (n = 54), empty sella syndrome (n = 7) or residual hyperprolactinaemia after surgery for a macroprolactinoma (n = 1). All had previously been treated with cabergoline or placebo for 4 weeks as part of a dose-finding study.

MEASUREMENTS

Menstrual pattern, adverse symptoms, blood pressure and pulse, serum PRL, blood count, liver and renal function were assessed after one month and subsequently at two-monthly intervals.

RESULTS

Treatment was started at doses of 0.25 mg (n = 3), 0.5 mg (n = 8), 1 mg (n = 150) or 2 mg (n = 1) per week, given either as a single weekly dose (n = 8) or divided into twice-weekly doses (n = 154), and was continued for at least 49 weeks in 123 patients. Final treatment doses ranged from 0.25 mg fortnightly to 2 mg twice weekly: most patients finished the study taking 0.5 mg once (n = 31) or twice (n = 77) weekly. Stable normalization of PRL levels was achieved in 138 subjects (85%), in 129 of whom the effective dose was < 1 mg per week. In the subset of 114 patients completing 49 weeks of therapy and having dose adjustments according to the protocol, the biochemical success rate was 92%. Fifty-nine of the 65 previously amenorrhoeic women (91%) and 44 of the 49 (90%) who were previously oligomenorrhoeic resumed regular menses and/or became pregnant during the study. Adverse events were reported in 64 patients (39.5%). In 84% of cases with adverse events, the symptoms were of mild or moderate severity and most occurred during the first few weeks of therapy; five patients (3%) discontinued treatment because of poor tolerance. The most frequent symptoms were dizziness (13% of patients), headache (13%), nausea (10%) and weakness and/or fatigue (10%). Of 27 patients who had previously been poorly tolerant of other dopamine agonists, 17 (63%) did not experience any side-effects and only one was intolerant of cabergoline. No adverse haematological or biochemical effects were detected except for a slight downward trend in haemoglobin which may have been related to the resumption of regular menses in previously amenorrhoeic or oligomenorrhoeic women. A mild hypotensive effect was observed, mean systolic and diastolic blood pressures falling by 5 and 4 mmHg respectively during treatment.

CONCLUSIONS

The results provide evidence for the long-term effectiveness and safety of cabergoline in the treatment of hyperprolactinaemia. Its ability to normalize PRL and restore gonadal function compares favourably with reported data on reference compounds while its tolerability profile and simple administration schedule offer potential advantages in terms of patient acceptability.

The isolation and characterization of estradiol-fatty acid esters in human ovarian follicular fluid. Identification of an endogenous long-lived and potent family of estrogens

The estradiol-fatty acid esters are highly potent and long-lived estrogens that were first isolated and identified from in vitro biosynthetic experiments (Mellon-Nussbaum S., Ponticorvo, L., Schatz, F., and Hochberg, R. B. (1982) J. Biol. Chem. 257, 5678-5684). Other studies have indicated that these esters exist endogenously, but the evidence is indirect, resting solely on the presence of a nonpolar saponifiable metabolite. Although there are similar reports of other naturally occurring fatty acid esters of biologically active steroid hormones, likewise, none has been isolated and characterized. In this study we have found that follicular fluid from the ovaries of women stimulated with gonadotrophins contains relatively large amounts of a nonpolar saponifiable derivative of estradiol (approximately 10(-7)M), which we presumed to be fatty acid esters. Using a combination of chromatographic techniques we isolated these estradiol metabolites and identified them by mass spectral analysis. They are a mixture of five different estradiol-17 fatty acid esters. The amount of each present was determined by separating the esters by reversed phase high performance liquid chromatography and then quantifying each peak by radioimmunoassay and UV absorption. The esters of estradiol are predominantly unsaturated, with linoleate the most abundant comprising 43% of the total. The other esters are: palmitate (20%), arachidonate (19%), oleate (14%), and stearate (4%). Thus these studies conclusively demonstrate the existence of these unusually powerful estrogens.

In vivo and in vitro effect of growth hormone on estradiol secretion by human granulosa cells

GH therapy increases the ovarian response to gonadotropin stimulation in women presenting with ovaries that are relatively resistant to conventional gonadotropin therapy. As it is not completely certain whether GH modulates the actions of FSH on granulosa cells directly or via insulin-like growth factor-I (IGF-I) production, we studied its effect on steroid release by human granulosa cells obtained from subjects affected by unexplained or male factor infertility. In all subjects, superovulation for in vitro fertilization/embryo transfer was induced by treatment with gonadotropins or GH plus gonadotropins combined. The effects of the different in vivo treatments were evaluated in the conditioned medium obtained after the first 24 h of incubation; granulosa cells from patients treated with GH released higher amounts of estradiol and progesterone into the medium than did granulosa cells from patients treated with gonadotropins alone. When the release of steroid due to the in vivo treatment was exhausted, cells were subjected to increasing concentrations of GH in the presence or absence of 200 nmol anti-IGF Sm 1.2 monoclonal antibody (MoAb) or the antitype I receptor alpha IR3 MoAb. The results revealed that GH stimulates estradiol production in a dose-dependent fashion, and the presence of the MoAbs drastically reduces the GH effect. These data demonstrate that the established stimulatory effect of GH on ovarian function is dependent not only on the increased levels of circulating IGF-I, but also on a direct effect of GH on granulosa cells, which seems to be mediated at least in part by the autocrine action of IGF, particularly IGF-II. In fact, chromatographic analysis of medium conditioned by human granulosa cells revealed that these cells clearly produce IGF-II and IGF-binding proteins and only small amounts of IGF-I. Since GH appears to be able to increase the in vitro effect of both IGF-I and IGF-II, we can hypothesize a sensitization of the granulosa cells to the IGF-II produced by the cells themselves, which acts through the IGF-I receptor.

Somatotropic function in short stature: evaluation by integrated auxological and hormonal indices in 214 children. The Italian Collaborative Group of Neuroendocrinology

GH secretion was evaluated in 214 children and adolescents (age, 5-16 yr; 160 males and 54 females) with short stature (height, < or = 5th percentile) by assessing mean spontaneous overnight GH concentration (normal values, > or = 3 and 3.9 micrograms/L for prepubertal and pubertal subjects, respectively) and responsiveness to stimulation with GH-releasing hormone combined with pyridostigmine (normal peak values, > or = 20 micrograms/L). Plasma insulin-like growth factor-I (IGF-I) was also measured. According to their GH secretory status, children were grouped as follows: group I, 154 subjects with normal spontaneous and stimulated GH (43 slow-growing and 111 normally growing); group II, 39 subjects with low spontaneous, but normal stimulated, GH (27 slow-growing and 12 normally growing); group III, 18 slow-growing subjects with low spontaneous and stimulated GH; and group IV, 3 subjects with normal spontaneous, but low stimulated, GH. The following conclusions were drawn. 1) Forty-five slow-growing subjects (21% of the total sample) had GH deficiency; 27 (12.6%) belonged to group II (with a preserved GH pituitary reserve, denoting a hypothalamic dysfunction) and 18 (8.4%) to group III (with a reduced GH pituitary reserve). 2) Forty-three slow-growing children in group I had normal GH secretion but low mean IGF-I, which may indicate nutritional problems or a biologically hypoactive GH molecule. 3) The remaining 111 subjects in group I (52%), with normal growth rate, but low mean parental height, were considered as having familial and/or constitutional short stature. GH responses after pyridostigmine plus GH-releasing hormone were normal in all children with a normal growth rate. These findings show that besides clinical evaluation, the assessment of spontaneous GH secretion, GH pituitary reserve, and IGF-I concentration allows proper pathophysiological characterization of short stature. By this approach, the frequency of GH deficiency in our sample was higher than commonly thought.

Molecular genetic analysis of the moa operon of Escherichia coli K-12 required for molybdenum cofactor biosynthesis

A 3.2 kb chromosomal DNA fragment which complements the defects in a series of twelve moa::Mucts insertion mutants has been sequenced. Five open reading frames (ORFs) were identified and these are arranged in a manner consistent with their forming an operon. The encoded proteins (MoaA-MoaE) have predicted molecular weights of 37,346, 18,665, 17,234, 8843 and 16,981 respectively. Examination of subclones of the whole locus in an expression system demonstrated the predicted products. N-terminal amino acid sequences for the moaA, B, C and E products confirmed the translational starts. Genetic analysis distinguished four classes of moa mutants corresponding to genes moaA, C, D and E. Potential promoter sequences upstream of moaA and a possible transcription termination signal have been identified. Genetic analysis of the chlA1 and chlM mutants, which have been biochemically characterized as defective in molybdopterin biosynthesis, indicates that these carry lesions in moaA and moaD respectively. The moa locus is orientated clockwise at 17.7 minutes in the chromosome.

Removal of the high-potential [4Fe-4S] center of the beta-subunit from Escherichia coli nitrate reductase. Physiological, biochemical, and EPR characterization of site-directed mutated enzymes

The beta-subunit of the nitrate reductase of Escherichia coli contains four groups of Cys residues (I-IV) which are thought to bind the single [3Fe-4S] center and the three [4Fe-4S] centers. The first or second Cys residue of group I was substituted by site-directed mutagenesis with Ala or Ser. Physiological, biochemical, and EPR studies were performed on the mutated enzymes. With small variations, the properties of these mutant enzymes do not differ from one another. They were found to be as abundant and as stably bound to the membrane as the native enzyme, provided the gamma-subunit was present. Although physiological activity was reduced, it was sufficient to allow growth on nitrate. The study of variations in EPR intensity as a function of the redox potential indicated that these enzymes only contained three iron-sulfur centers instead of the usual four in the native enzyme. Spectral EPR analysis showed that the [4Fe-4S] center of high redox potential (center 1, +80 mV) was missing. The loss of this center did not affect the stable integration of the other three centers. The data presented here are in total contrast to those we have reported for each of the other three centers (centers 2-4), the loss of which was detrimental to the integration of all centers and to the integration of the molybdenum cofactor (Augier et al., in press). Taken together, our results demonstrated that the first and second Cys residues of group I are the ligands of the [4Fe-4S] center (center 1, +80 mV) and that this center participates in electron transfer, but is dispensable. On the basis of these results, it is proposed that the [3Fe-4S] center (center 2, +60 mV) also plays a biological role and that in the native enzyme both high-potential centers, centers 1 and 2, contribute independently and in parallel to the electron transfer to the molybdenum cofactor.

[Evaluation of the anti-arrhythmic action of propafenone treatment and its influence on left ventricular function]

Twelve patients (9 males, 3 females, mean age 59.2 +/- 7.0 years) with hyperkinetic ventricular arrhythmias were treated for 30 days with 150 mg propafenone three times daily; the daily dosage was raised to 900 mg in non responders (< 85% reduction of ectopic ventricular beats/h). A 24-hour ECGD and mono- and bidimensional echocardiography were carried out at baseline, after 30 days on 450 mg, 30 days on 900 mg propafenone, and one week after drug withdrawal. Propafenone treatment was found to reduce significantly ectopic ventricular beats, especially with the higher dosage (44.9% reduction under 450 mg; 88.8% reduction under 900 mg). At the lower dosage, 25% of patients responded, under the higher dosage 88.9%; the latter dosage also induced a significant reduction of Lown class. Propafenone treatment was also accompanied by a reduction of maximum and mean heart rate, and by a lengthened PR interval which was almost always within the normal range, without changes of QTc. The two months of propafenone treatment did not induce significant changes of cardiac volume or left ventricular function; on the contrary, at the end of the treatment period an increase, albeit not a significant one, of the ejection fraction and a shortening of the circumference inversely proportional to the reduction in ectopic ventricular beats could be noted. In conclusion, propafenone was found to have a valid antiarrhythmic effect, especially at the 900 mg/day dosage without interfering with left ventricular function which was even found to improve under chronic treatment, probably as a result of improved compliance thanks to the reduction of ventricular ectopic beats.

Cerebrospinal fluid proteins in patients with leucoaraiosis: possible abnormalities in blood-brain barrier function

Some CSF protein abnormalities have been proposed as a possible marker for vascular dementia. We studied the CSF protein levels and albumin ratio in 21 patients (mean age 64.04 +/- 7.5) with progressive bilateral motor impairment, and a CT picture of leucoaraiosis. Seven of these patients also presented with dementia. Twenty-seven Alzheimer's disease patients (mean age 59.59 +/- 5.30) without leucoaraiosis were taken as controls. We also evaluated the correlations of the albumin ratio values with the diagnosis of dementia, the severity of cognitive impairment, the degree of cerebral atrophy and presence of infarcts on CT, and the abnormalities in CSF circulation, found on isotopic cisternography, in the leucoaraiosis group. After controlling for age and sex, the patients with leucoaraiosis showed greater CSF albumin levels (0.27 g/l +/- 0.11 vs. 0.21 g/l +/- 0.06; covariance analysis P = 0.066), CSF IgG values (4.68 mg/100 ml +/- 1.45 vs. 2.85 mg/100 ml +/- 1.03; covariance analysis P < 0.001), and a higher albumin ratio (0.0078 +/- 0.0027 vs. 0.0058 +/- 0.0019; covariance analysis P = 0.013) than those with Alzheimer's disease. The variations of these parameters were not apparently related to the presence of dementia in the leucoaraiosis group. A significantly higher albumin ratio was observed in patients with a slowed CSF circulation compared to those with normal CSF circulation (0.0086 +/- 0.0028 vs. 0.0059 +/- 0.0019; covariance analysis P = 0.05). We conclude that, independently from the presence of dementia, patients with leucoaraiosis have CSF abnormalities consistent with functional blood-brain barrier alterations.

Primary cutaneous endometriosis of thoracic skin with ovarian granulosa cell tumor

A case of non-cicatricial endometriosis of the thoracic skin is described in a patient affected by an ovarian granulosa cell tumor, adult type. To the best of our knowledge, this is the first case of this type of association reported in the literature although some cases in which endometriosis was related to high estrogen levels are well documented. We suggest that in presence of an estrogen secreting neoplasm, foci of endometriosis might not be such a rare condition if clinicians and pathologists carefully looked for it.

Site-directed mutagenesis of conserved cysteine residues within the beta subunit of Escherichia coli nitrate reductase. Physiological, biochemical, and EPR characterization of the mutated enzymes

We have used site-directed mutagenesis to alter the ligands to the iron-sulfur centers of Escherichia coli nitrate reductase A. The beta subunit of this enzyme contains four Cys groups which are thought to accommodate the single [3Fe-4S] center and the three [4Fe-4S] centers involved in the electron-transfer process from quinol to nitrate. The third Cys group (group III) contains a Trp at a site occupied by a Cys residue in typical ferredoxin arrangements or in the DmsB subunit of dimethyl sulfoxide (DMSO) reductase. In an attempt to determine the coordination site of the different iron-sulfur centers in the amino acid sequence, we have changed the Trp of group III to Cys, Ala, Phe, and Tyr and the first Cys residue of groups II-IV to Ala and Ser. Physiological, biochemical, and EPR studies were performed on the mutated enzymes. Substitution of Ala for either Cys184, Cys217, or Cys244 results in the full loss of all four iron-sulfur centers present in the wild-type enzyme. These inactive enzymes still possess the alpha,beta, and gamma polypeptides associated in a membrane-bound complex. These Cys have important structural roles and are very likely involved in the coordination of the iron-sulfur centers. Substitution of Cys184 with a Ser residue produces an enzyme containing the four iron-sulfur centers, but displaying reduced activity. EPR studies suggest that Cys184 is a ligand of the [4Fe-4S] center whose midpoint potential is -200 mV in the native enzyme. All substitutions performed in this study on Trp220 lead to mutant enzymes harboring the four iron-sulfur centers and a nitrate reductase activity close to that of the wild-type. In spite of the high similarity between the NarH and DmsB subunits, the Trp220-->Cys substitution does not allow the conversion of the [3Fe-4S] center of the nitrate reductase into a [4Fe-4S] center. Therefore, Trp220 does not seem to play any major role in the beta subunit.

Delta sleep-inducing peptide administration does not influence growth hormone and prolactin secretion in normal women

The aim of this study was to analyze the effects of delta sleep-inducing peptide (DSIP) on growth hormone (GH) and prolactin (PRL) secretion in eight healthy women with normal cycles (aged 17-36 years). GH and PRL secretion was studied in five women after DSIP (25 micrograms/kg bw IV over 30 min), arginine chlorhydrate (0.5 g/kg bw IV over 30 min) and simultaneous DSIP plus arginine chlorhydrate administration. In three other women the circadian rhythm of GH and PRL was studied during DSIP (25 micrograms/kg bw from 2130h to 2230h) and placebo IV infusion. Serum GH and PRL levels were normal under basal conditions and no effects were noted after the infusion of DSIP. The GH and PRL circadian rhythm was not modified by DSIP administration. DSIP did not influence GH and PRL responsiveness to arginine chlorhydrate. We found that at dosages which are known to modify ECG patterns, DSIP is unable to modify spontaneous or arginine chlorhydrate-induced GH and PRL secretion.

[The diagnostic and therapeutic strategies in neoplasms of the adrenal cortex: the authors' own experience]

The Authors report their limited series of neoplasms of the adrenal cortex, and underline the decisive role of the modern diagnostics based on imaging techniques (US--TC--NMR). These, in fact, often allow a good definition also in the non-functioning adrenal masses incidentally discovered (incidentalomas). The authors emphasize the high quality of such diagnostic methods offering a good reliability in discriminating the nature of the adrenal mass. These undeniable diagnostic advantages have a positive impact on the surgical strategy, allowing together with a careful morphological study of the lesion, to program in detail possible demolitive operations. The authors finally underline the importance of the surgical access: they are persuaded the best is the bilateral under-rib incision. This surgical approach assures a complete exploration of the abdominal and pelvic cavity; moreover, it allows to face every complication.

Dose-dependent suppression of serum prolactin by cabergoline in hyperprolactinaemia: a placebo controlled, double blind, multicentre study. European Multicentre Cabergoline Dose-finding Study Group

OBJECTIVE

Dopamine agonists have a well established place in the treatment of hyperprolactinaemic disorders but their use is associated with a high incidence of adverse effects. We have investigated the biochemical efficacy and side-effect profile of a range of doses of the novel, long-acting dopamine agonist, cabergoline, in suppressing prolactin (PRL) in hyperprolactinaemic women.

DESIGN

Multicentre, prospective, randomized, placebo controlled and double blind.

PATIENTS

One hundred and eighty-eight women with hyperprolactinaemia secondary to microprolactinoma (n = 113), idiopathic disease (n = 67), empty sella syndrome (n = 7) or following failed surgery for a macroprolactinoma (n = 1).

MEASUREMENTS

Weekly assessment of adverse symptoms, blood pressure and pulse, serum PRL, blood count, liver and renal function.

RESULTS

Patients received either placebo (n = 20) or cabergoline 0.125 (n = 43), 0.5 (n = 42), 0.75 (n = 42) or 1.0 mg (n = 41) twice weekly for 4 weeks. The five treatment groups were comparable in age (mean 31.8, range 16-46 years), diagnosis, previous therapy, and pretreatment serum PRL. PRL was suppressed to below half the pretreatment level in 5, 60, 90, 95 and 98% and normalized in 0, 30, 74, 74 and 95% of patients taking placebo or cabergoline 0.125, 0.5, 0.75 or 1.0 mg twice weekly respectively (Armitage's test, chi 2 = 39.3, P < 0.01). Cabergoline therapy (all doses) restored menses in 82% of the amenorrhoeic women not previously treated with dopamine agonists. Adverse events were recorded in 45% of patients in the placebo group and in 44, 50, 50 and 58% of those taking 0.125, 0.5, 0.75 and 1.0 mg cabergoline twice weekly (Armitage's test, P > 0.05). Over 95% of reported symptoms were relatively trivial, most frequently transient nausea, headache, dizziness, fatigue and constipation. More severe adverse events, interfering significantly with the patients' lifestyle, occurred in 13 (7.7%) patients taking cabergoline; treatment withdrawal was necessary in only one case. No adverse effects were detected on blood pressure or haematological or biochemical parameters.

CONCLUSIONS

We have shown a linear dose-response relationship for cabergoline in the treatment of hyperprolactinaemia in the range 0.125-1.0 mg twice weekly, with normalization of PRL in up to 95% of cases and acceptable tolerability throughout the dose range.

Molybdoenzyme biosynthesis in Escherichia coli: in vitro activation of purified nitrate reductase from a chlB mutant

All molybdoenzyme activities are absent in chlB mutants because of their inability to synthesize molybdopterin guanine dinucleotide, which together with molybdate constitutes the molybdenum cofactor in Escherichia coli. The chlB mutants are able to synthesize molybdopterin. We have previously shown that the inactive nitrate reductase present in a chlB mutant can be activated in a process requiring protein FA and a heat-stable low-molecular-weight substance. We show here that purified nitrate reductase from the soluble fraction of a chlB mutant can be partially activated in a process that requires protein FA, GTP, and an additional protein termed factor X. It appears that the molybdopterin present in the nitrate reductase of a chlB mutant is converted to molybdopterin guanine dinucleotide during activation. The activation is absolutely dependent upon both protein FA and factor X. Factor X activity is present in chlA, chlB, chlE, and chlG mutants.

Delayed puberty in uremia: pituitary-gonadal function during short-term pulsatile luteinizing hormone-releasing hormone administration

Pubertal development is frequently delayed or disordered in children with chronic renal failure. Both neuroendocrine and peripheral alterations due to uremia have been hypothesized to explain the impairment in the pituitary gonadal axis. The aim of the present study was to evaluate quantitative (immunological) and qualitative (biological) LH secretion, as well as FSH and sex steroids, before and during 7 days of sc LHRH administration (136-150 ng/kg bw every 120 min) in 5 uremic children (13.1-14.8 yr) with delayed puberty. Six nonuremic children (13.2-17.8 yr) with delayed puberty underwent the same schedule and served as control group. On day 0 mean immunoreactive LH (I-LH) levels were higher in uremic (4.5 +/- 0.9 mIU/ml) than in nonuremic (1.9 +/- 03 mIU/ml; p < 0.05) subjects while no differences were observed in bioactive LH (B-LH) levels (2.9 +/- 0.7 mIU/ml vs 2.4 +/- 0.3 mIU/ml). In both groups of subjects testosterone was at prepubertal levels. Spontaneous I-LH and B-LH pulses were observed sporadically in both uremic and nonuremic subjects. Short-term pulsatile LHRH administration induced significant increases in B-LH, I-LH, FSH and testosterone. The B/I LH ratio increased from day 0 (0.7 +/- 0.2) to day 7 (1.3 +/- 0.4; p < 0.05) in uremics while it showed wide fluctuations in nonuremic subjects. On day 7, 4 uremic and 5 nonuremic subjects showed a pulsatile release of B-LH after exogenous LHRH pulses. Our data document that in uremia there are qualitative as well as quantitative abnormalities in pituitary gonadal secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Therapeutic strategies in a male with delayed puberty

Therapeutical strategies in male with delayed puberty. Delayed puberty (absence of pubertal modifications after 14-15 years of age) due to transitory deficit of LHRH secretion often constitutes a difficult differential diagnostic problem for conditions of permanent LHRH deficit which can be identified only after 18 years of age in the idiopathic hypogonadotropic hypogonadism. After a period of clinical observation short-term therapy with pulsatile LHRH administration may take place. Therapy can be necessary: to document the functional integrity of the pituitary-gonadal axis; to promote pubertal modification such as to improve and physiologically sustain the patient; to tray a neuroendocrine activation of endogenous LHRH-LH secretion. Also delayed puberty linked to uremia seems to respond to short-term pulsatile LHRH administration. Pulsatile LHRH administration is the most physiological therapeutical approach to subject with delayed puberty. It seems to constitute a valid alternative to the therapy with testosterone or gonadotropins.

[Long-term treatment of central diabetes insipidus with oral DDAVP]

Clinical use of the DDAVP (1-Deamino-8-D-Arginine Vasopressin) is now the first choice in treatment of Central Diabetes Insipidus. It is an analogue of Vasopressin with a higher antidiuretic potency, less vasopressor activity, and a longer duration of action. This drug still presents some problems of administration route. A lot of studies were published about different administration routes of DDAVP: sublingual tablets, parenteral solution, nose spray and suction de-epithelialized skin. Some authors have utilized the oral route (solution or tablets) with good results in short-term treatment. We think the formulation in tablets of DDAVP is an efficacious support of the therapy in this disease also for long-treatment. In our study 3 patients with Central Diabetes Insipidus (aged 22-56; 2 idiopathic and 1 post-surgery) previously treated with DDAVP nasal solution (10 micrograms/day; 36-156 months), have been submitted to a chronic treatment with DDAVP tablets for a period of 24-36 months. The DDAVP tables were administered at the dosage of 400-600 micrograms/day in 2-3 administrations. The patients were studied at intervals of 3-6 months, and on each occasion full blood count, glucose, azotaemia, creatinine, liver function tests, electrolytes, urine volume, density and osmolality were estimated. The long-treatment with oral DDAVP was able to keep a good control of the disease in all patients. In case 1 we had a significant reduction of urine volume (p < 0.01) and a significant increase (p < 0.01) of urine osmolality in comparison with previous treatment with nasal solution; in case 2 and 3 no significant changes were observed. No side effects were noted during this study. The drug has been well tolerated and the compliance of patients was better during oral DDAVP than nasal solution. In our opinion the oral DDAVP is an effective and safe solution for the treatment of Central Diabetes Insipidus, and give to the patients a better quality of life in comparison to the nasal solution.