Delayed puberty in males with beta-thalassemia major: pulsatile gonadotropin-releasing hormone administration induces changes in gonadotropin isoform profiles and an increase in sex steroids

Patients with beta-thalassemia major often have pubertal delay, the etiology of which has not been fully elucidated. We investigated the pituitary-gonadal response to short-term subcutaneous pulsatile gonadotropin-releasing hormone (GnRH) administration (150 ng/kg body weight every 120 min for 7 days) in five young males (aged 13.6-19.0 years) affected by beta-thalassemia major and presenting signs of delayed puberty. Immunoreactive and bioactive gonadotropin levels were determined and their isoform profiles were examined, before and after GnRH treatment, in a pool of samples collected every 15 min for 240 min. Testosterone, androstenedione, 17-hydroxyprogesterone, dehydroepiandrosterone and 17 beta-estradiol were measured as markers of gonadal function on days 0, 1, 3, 5 and 7 of treatment. Five patients (aged 16.9-26.8 years) with confirmed diagnosis of idiopathic hypogonadotropic hypogonadism who were starting pulsatile GnRH therapy were also studied in the same protocol. Increased sex steroid levels were observed in both groups as a result of treatment. On day 7, the thalassemic patients had increased bioactive luteinizing hormone (LH) and follide-stimulating hormone (FSH), although immunoreactive LH and FSH were comparable to day 0. Moreover, fewer acidic and more basic immunoreactive and bioactive isoforms were noted in LH profiles on day 7. Similar results were observed in hypogonadal patients, who also had increased immunoreactive LH and FSH values. We suggest that the early stage of delayed puberty in thalassemia might be characterized by a neuroendocrine dysfunction resulting in an impaired hypothalamic GnRH release, which is inadequate for a proper pituitary stimulation. Pulsatile GnRH treatment seems to re-establish partially the correct pituitary-gonadal function.

Effects of gallopamil on epinephrine and norepinephrine plasmatic levels and on TxB2 and beta-tg release in patients with coronary artery disease during adrenergic stimulus with cold pressor test

We investigated the effect of gallopamil administration during a cold pressor test (CPT) in 18 patients suffering from chronic angina (CA) and in 21 healthy subjects. CA patients showed increased basal levels of beta-thromboglobulin and thromboxane B2 compared to control patients and normal plasma levels of catecholamines. CPT caused plasma catecholamines, beta-thromboglobulin and TxB2 levels to rise. This rise was greater in CA patients than in control patients. Administration of gallopamil (50 mg kg-1 three times a day for 30 days) reduced plasma levels of catecholamines, beta-thromboglobulin and TxB2 blood concentrations either under basal conditions or after CPT. Our data suggest that gallopamil is able to modulate the response induced by adrenergic stress.

The effect of non-steroidal antiandrogen flutamide on luteinizing hormone pulsatile secretion in male-to-female transsexual subjects

We evaluated LH pulsatile patterns before and 4 weeks after the oral administration of flutamide (750 mg/day) in 9 male-to-female transsexuals (age range 17-28 yr) requesting gender reassignment. Flutamide was given to explore the feedback role of androgens on the LHRH-LH unit in LH pulsatility in transsexuals. Seven normal age-matched men served as a control group, without receiving flutamide, due to ethical considerations. LH pulsatility was evaluated on samples collected every 15 min for 360 min. FSH, PRL, cortisol, SHBG and sex steroids were evaluated on pooled samples. LH pulses were analyzed by the Santen and Bardin algorithm, slightly modified. No differences in FSH, PRL, total- or free-testosterone, estradiol and SHBG levels were noted between transsexuals and controls. Normal circadian cortisol decline was observed in all subjects. Mean LH levels (p < 0.05) and LH pulses (p < 0.01) were significantly lower in transsexuals. Flutamide induced an increase in mean LH and testosterone levels (p < 0.01). After flutamide administration there was an increase in LH pulse frequency (P < 0.01) and the frequency and amplitude of LH pulses in transsexuals were restored to levels observed in controls. No differences in FSH, PRL or estradiol levels were found after flutamide. These data suggest that a decrease in LH pulse frequency could be an endocrine marker in male-to-female transsexuals. An increase in endogenous androgen negative feed-back could be speculated in these subjects. However, normal testosterone levels indirectly suggest that a normal that a normal qualitative LH secretion is maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Sumatriptan does not stimulate PRL and GH secretion in acromegaly

OBJECTIVE

Serotoninergic receptors are involved in the regulation of PRL and GH secretion. We studied the effects of sumatriptan, a new 5-HT1D receptor agonist, on PRL and GH secretion in active acromegaly.

EXPERIMENTAL DESIGN

After their informed consent, all subjects were submitted to sumatriptan or placebo administration in single blind and in a random order. The time interval between the tests was of 7 days.

ENVIRONMENT

We examined all patients in the morning, after 12 hours of fasting. All subjects were in recumbent position during the tests. Pulse rate and blood pressure were monitored during the test.

SUBJECTS

Eight acromegalics (42-65 years) and 10 age-matched (33-63 years) normal subjects.

PROTOCOL

Blood samples were taken after needle insertion kept patent by slow saline solution infusion. PRL and GH secretion were evaluated after sumatriptan (6 mg sc) and placebo. Blood samples were taken before (45, 15 and 0 minutes) and every 15 minutes for 2 hours after sumatriptan or placebo administration.

RESULTS

No significant changes in PRL secretion were observed after sumatriptan in both groups of subjects. A significant increase in GH levels after sumatriptan was observed in controls but not in acromegalics. An age-related negative trend in GH response to sumatriptan was observed in controls.

CONCLUSIONS

Our study indicated that 5-HT1D receptors are not involved in PRL and GH secretion in middle-aged acromegalics.

[Referential value of auditory threshold depending on age]

The value of "normal hearing" intended as the "base value of reference" to be used also for preventive as well as medical-legal purposes, is still subject of study and discussion. The Authors present the results relative to the definition of the hearing threshold in a vast "scrupulously screened" group of subjects between the ages of 15 and 65 (divided into 10 year bands), resident in industrial city areas and made up a homogeneous group of industrial workers with the same socioenvironmental characteristics. Distribution is calculated in hundreds of values relative to the average bilateral threshold for frequencies between 500 and 4000 Hz considering the 90th percentile the reference value.

[Intrahepatic cholangiojejunostomy on the third segment in non-operable neoplasms of the hepatic hilum]

The authors report their experience in 19 cases of primitive or secondary tumor of the hilus of the liver which couldn't benefit from radical operation. Palliative treatments--to resolve the jaundice (which is often the only responsible for a short-term exitus)--include surgical (intrahepatic bilio-digestive derivations) and non surgical procedures (PTDB, percutaneous transtumoral intubation). Considering the ephemeral results of the latter, the Authors take peripheral derivative operations into account and particularly the Soupault and Couinaud technique (intrahepatic colangiojejunostomy) performed in 7 patients with satisfying results. It is an easy and quick technique--because of constant anatomical situation of the left intrahepatic biliary distribution and of the superficial location of the duct of the III segment--which allows a lasting biliary decompression with a good residual life.

[The rationale in surgery of hepatic echinococcosis: total pericystectomy and resections. Personal experience]

The Authors report their fifteen years experience in the surgical treatment of hepatic hydatid cysts. They emphasize the difference in the incidence of radical procedures (pericystectomy and hepatic resections) registered in the two periods examined (1980-83 and 1987-93), stressing the role of current diagnostic imaging techniques and improved surgical procedures which allow to perform standard operations for a radical treatment of hepatic hydatid cysts. Total pericystectomy is considered the procedure of choice; rarely it can't be performed (high vascular risk in central cysts located between portal and hepatic veins) and consequently subtotal pericystectomy or conservative treatment are the only possible procedures. Hepatic resection is preferred in case of multiple cysts involving the same lobe or when a giant hydatid cyst replaces the lobe. A further therapeutical resource--in radical procedures--is offered by the use of antihelminth drugs with marked antiparasitic action (albendazole).

Treatment of acromegaly with octreotide: effectiveness and tolerability of its pulsatile administration by portable pump

This study was undertaken to evaluate effectiveness and tolerability of octreotide administered in active acromegaly by pulsatile means and compare these data with intermittent three-times-a-day therapy. We studied 13 acromegalics with active disease. All patients received octreotide subcutaneously administered in a pulsatile way using a portable pump delivering 25 micrograms every 120 minutes and in an intermittent way (100 micrograms three times daily) (TID). From pretreatment values (56.5 +/- 13.4 micrograms/L) the 24-h integrated mean GH levels (IC-GH) were significantly reduced both during pulsatile and TID octreotide administration (P < 0.01). IC-GH was significantly lower during pulsatile therapy (17.0 +/- 5.2 micrograms/L) than during TID (22.0 +/- 11.5 micrograms/L; P < 0.05). Before octreotide, IGF-I levels were 669.8 +/- 85.7 micrograms/L; during octreotide therapy they were reduced in 12/13 patients (TID 340.2 +/- 41.5 micrograms/L, pulsatile 338.1 +/- 55.3 micrograms/L; P < 0.01). A correlation between IC-GH and IGF-I levels was observed only during TID administration of octreotide (R = 0.652; P < 0.05). The 24-hour GH pattern fluctuated widely before the start of octreotide therapy. During TID administration, GH levels tended to rise again before the following octreotide injection; this did not occur during pulsatile therapy. Side effects were fewer during pulsatile (15%) than TID (31%) octreotide administration (NS). Asymptomatic gallstones appeared in 1 patient. In conclusion subcutaneous pulsatile octreotide administration in acromegalic patients by means of a small portable pump seems able to produce, a steadier control of GH-IGF-I hypersecretion and fewer side effects than TID administration at same dosage.

Effect of the acid-labile subunit on the binding of insulin-like growth factor (IGF)-binding protein-3 to [125I]IGF-I

In normal subjects, the major form of circulating insulin-like growth factor (IGF) is the GH-dependent 150K complex. This complex is formed by the IGF peptide, the acid-stable binding protein IG-FBP-3, and the acid-labile subunit (ALS), which, although not binding IGF, appears to be necessary to reconstitute the complex in its natural form. The ALS was purified in our laboratory from human serum by ammonium sulfate precipitation, ion exchange chromatography using DEAE-Sephadex A-50, Concanavalin-A-Sepharose-4B chromatography, and two sequential gel filtrations by fast performance liquid chromatography. As demonstrated by gel permeation chromatography on fast performance liquid chromatography, incubation for 2 h at 20 C of this preparation with [125I]IGF-I and recombinant IGFBP-3 (rIGFBP-3) allows the reconstitution of a complex of about 150 kilodaltons. In these experimental conditions, the ALS is not only able to increase the mol wt of the complex, but also to greatly increase the amount of IGF-I bound; in the absence of ALS, radioactivity in the mol wt volume of the complexed forms was lower than that in the mol wt volume of the free form (percentage of total [125I]IGF-I: rIGFBP-3 alone, 15% and 44%; in the presence of ALS, 41% and 24%, respectively). In both charcoal and polyethylene glycol ligand binding assays, competitive binding curves for the displacement of [125I]IGF-I from rIGFBP-3 by increasing concentrations of unlabeled IGF-I showed an increased binding activity of rIGFBP-3 in the presence of ALS. The effect of ALS on rIGFBP-3-binding activity was dose dependent. These data show that the non-IGF-binding ALS subunit of the 150-kilodalton complex can play an important role in the regulation of IGF-I or IGF-II binding to rIGFBP-3 and, therefore, on the levels of free IGF peptide, possibly by inducing conformational changes in rIGFBP-3. In addition, ligand and immunoblot reveal that ALS and rIGFBP-3 are able to form a high mol wt complex in the absence of IGF peptide. On the basis of these data, ALS seems to have a more complex function than that of simply increasing the mol wt of the IGF-IGFBP-3 complex.

Effect of octreotide on circulating IGF-I chromatographic profile: evidence for an inhibitory action on the formation of the 150-kDa ternary complex

OBJECTIVE

The increasing use in clinical practice of octreotide (a somatostatin analogue which inhibits the secretion of GH and other peptide hormones) led us to study the effects of this treatment on GH, insulin-like growth factors (IGF)-I and II and IGF-binding protein (IGFBP)-3, as well as on circulating IGFBP complexes in acromegalic patients.

DESIGN

The circulating concentrations of GH, IGF-I, IGF-II and IGFBP-3 were measured in acromegalic patients before and after 3, 6, 9, and 12 months of treatment with octreotide (group I: n = 5), and compared with those found in a group of patients (group II) treated with bromocriptine (n = 3), cabergoline (n = 7) radiotherapy (n = 3) or surgical therapy (n = 2). In pools of serum obtained from patients treated with octreotide, dopaminergic drugs, surgery and radiation, before and after therapy, immunoreactive IGF-I and IGFBP-3 were also evaluated after Superdex 200 gel filtration in neutral conditions.

RESULTS

Before treatment, the concentration of IGF-I and IGFBP-3 were above the normal range in all patients, while IGF-II levels were slightly reduced. After treatment with octreotide, IGF-I (P = 0.004), IGF-II (P = 0.02) and IGFBP-3 (P < 0.001) were significantly reduced as compared to basal levels. In subjects of group II, only IGF-I concentration was significantly reduced by the treatment (P = 0.02), and a negative correlation between IGF-I and IGF-II concentrations was found (r = -0.58, P < 0.0001). After gel filtration immunoreactive IGF-I and IGFBP-3 were found in the 150-kDa mol.wt. region in serum obtained from untreated patients and from treated patients of group II, while in the serum of octreotide-treated patients the IGF-I and IGFBP-3 peaks were shifted to the 60-kDa mol.wt. region, thus suggesting that the acid-labile subunit of the 150-kDa complex was drastically reduced. Since the GH concentrations in groups I and II were similar (M +/- SEM; 13.8 +/- 7.4 and 21.2 +/- 10.6 mU/l respectively), the marked reduction in acid-labile subunit in the octreotide treated patients can be explained by a direct inhibitory effect of somatostatin on the subunit.

CONCLUSIONS

Octreotide exerts an inhibitory effect not only on IGF-I but also on IGF-II. The reduced formation of the 150-kDa complex probably causes an increased metabolic clearance rate of IGF peptides which can account for the reduced concentration of both IGFs after treatment with octreotide.

Mitral valve prolapse in a case of Marfan syndrome with congenital cardiac disease, chronic obstructive pulmonary disease and schizophrenia

Mitral valve prolapse (MVP) is a common pathological finding in several inherited connective-tissue diseases among which the Marfan syndrome. In the literature several cases of Marfan syndrome characterized by schizophrenia, chronic obstructive pulmonary disease and severe mitral regurgitation due to a MVP have been reported. Our case of MVP was observed in a patient with Marfan syndrome with its characteristic musculoskeletal disorders associated with congenital cardiac disease, severe chronic obstructive pulmonary disease and schizophrenia. According to the latest genetic studies, Marfan syndrome seems to result from genetic mutations in an extracellular matrix glycoprotein, fibrillin. Authors believe that MVP represents only one of several pathological alterations which may be seen in the Marfan syndrome, as expression of a more generalized genetic disorder.

[The large hiatal stomach hernia and its surgical correction: the authors' personal experience]

The authors report their experience with hiatus hernia surgery (9 cases of large hernia with severe gastroesophageal reflux). The fundamental role of instrumental diagnostics in establishing both a clear indication for surgical correction and the quality of the results obtained is emphasized. Technical details of the surgical treatment are report as well. On the basis of their experience and in accordance with other authors the Nissen fundoplication is considered a valid antireflux procedure. Furthermore, the abdominal approach used for this procedure allows to treat other abdominal pathologies often associated with hiatal hernia.

[Reduced endothelium-dependent peripheral vasodilation in the aged]

Endothelial dysfunction may be present years before the clinical manifestations of atherosclerosis, which is particularly frequent in the late decades of life. Therefore, we have evaluated the presence of endothelial dysfunction in the elderly by measuring, by echo-Doppler technique, the vasodilatation of brachial artery in response to the hyperemia following forearm occlusion and decompression, a response that is dependent on endothelial function. We studied 10 subjects > 65 years (mean 72 +/- 8) and 10 subjects < 65 years (mean 40 +/- 6) all without clinical signs and without risk factors for atherosclerosis. The increase in brachial arterial flow during reactive hyperemia was similar in the young and elderly subjects (152 +/- 74% vs 129 +/- 63%, NS). While in the young at peak hyperemia we found a significant increase in brachial artery diameter from 3.4 +/- 0.9 to 4.1 +/- 1.0 mm (p < 0.005), there was no significant change in the elderly (from 3.0 +/- 0.7 to 3.1 +/- 0.7 mm, NS). In both groups sublingual glyceryl trinitrate produced a significant increase in brachial artery diameter (from 3.0 +/- 0.7 to 3.5 +/- 0.8 mm in the elderly, p < 0.01, and from 3.4 +/- 0.9 to 3.9 +/- 0.9 mm in the young subjects, p < 0.01, NS among groups), showing the absence in the elderly of structural vascular changes potentially responsible for absence of dilatation. In conclusion, elderly subjects without clinical signs or risk factors for atherosclerosis have a vascular endothelial dysfunction that may play an important role in pathologic processes of the cardiovascular system in the late decades of life.

Carotid stenosis and coronary artery disease in the elderly: the vascular surgeon's point of view

Surgical prevention of stroke is justified only when the perioperative morbidity and mortality rates are very low. Therefore, an accurate cardiac evaluation is essential for patients with a vascular disease like carotid stenosis, to reduce the surgical risk and improve prognosis. The aim of our retrospective study was to characterize subgroups of patients with high cardiac risk. From 1986 to 1993 at the Vascular Surgery Unit of the Department of Surgery and Surgical Emergencies at the University of Perugia, 857 carotid endarterectomies were performed on 739 patients. The stroke/death rate, at 30 days after surgery, was 2.16% per patient and 1.86% per procedure; cardiac mortality was 0. However, during follow-up 58 patients died: 55% of these deaths could be attributed to cardiac disease. No statistically significant differences emerged in cardiac mortality of patients with a positive history of cerebral vascular accident with respect to asymptomatics, neither among patients with carotid stenosis associated with complete contralateral occlusion nor among those without. Our group of patients had a 76% survival rate at 7 years after surgery, which is different from that reported by other studies. This may be due to some bias associated with the preoperative selection of the patients and the retrospective nature of our study. Nevertheless, in patients with carotid stenosis, the most important cause of death is cardiac ischemia, therefore a rigorous preoperative selection is mandatory particularly in elderly asymptomatic patients.

Functions and regulation of the acid-labile subunit of the 150 K complex

In normal subjects, the major form of circulating IGF is the GH-dependent 150 K complex. As demonstrated by gel-permeation chromatography, the acid-labile subunit (ALS) purified from human serum, incubated for 2 h at 20 degrees C with [125I]IGF-I and rIGFBP-3, is able to increase not only the molecular weight (mol. wt.) of the IGF-IGFBP-3 complex, but also the amount of IGF-I bound. In both charcoal and polyethylene glycol ligand binding assays, competitive binding curves for the displacement of [125I]IGF-I from rIGFBP-3 by increasing concentrations of unlabeled IGF-I showed an increased binding activity of rIGFBP-3 in the presence of ALS. The effect of ALS on rIGFBP-3 binding activity was dose dependent. In addition, ligand and immunoblot revealed that ALS and rIGFBP-3 are able to form a high mol. wt. complex in the absence of IGF peptide. On the basis of these data, ALS seems to have a more complex function than that of simply increasing the mol. wt of the IGF-IGFBP-3 complex. The regulation of ALS synthesis by rat hepatocytes in primary culture has also been evaluated by immunoblot. In agreement with the in vivo finding of an inhibitory effect of octreotide (a somatostatin analog) on the formation of the 150 K complex in acromegalic subjects, we could observe in vitro that octreotide produces a dose-dependent inhibition of ALS secretion into the hepatocyte conditioned medium. TGF-beta 1 was also inhibitory at high doses. On the contrary, we could not evidence any effect of IGF-I or IGF-II, while a small increase has been noted after incubation with T3.

Long-Duration Soft X-Ray Pulses by XeCl Laser Driven Plasmas and Applications

We report the characterization of a soft x-ray plasma source generated by a long-pulse XeCl excimer laser system. The output energy is 4 J at a wavelength of 308 nm in a 100-ns pulse. The intensity of radiation on target is estimated to be 4 × 1012 W cm-2. X-ray emission spectra of the plasma have been recorded using a double focusing spatial resolution spectrometer with a spherical mica crystal. From these measurements, the plasma temperature and electron density have been estimated. Various applications of such a plasma source have been investigated. First images of whole intact living cells from our system, imaged using the technique of soft x-ray contact microscopy, utilizing x rays in the "water window" region (280-530 eV), are shown. The suitability of the source for other applications, for example, x-ray lithography and radiation damage studies, to living cells are discussed. Possible improvements to the x-ray source for the various applications are proposed.

Effects of hypertension on intimal-medial thickness, left ventricular mass and aortic distensibility

The aim of the study was to evaluate arterial distensibility, intimal-medial thickening of the common carotid artery, left ventricular mass and the eventual correlations among these parameters in the hypertensive state. Our study population consisted of 89 hypertensive patients aged 35 to 80 years (mean age 60.8 +/- 10.6 years), and 76 normotensive subjects aged 45 to 85 years (mean age 61.2 +/- 11.1 years). Those patients constantly presenting systolic blood pressure values > or = 160 mmHg or diastolic blood pressure > 90 mmHg were diagnosed as hypertensive. Each patient underwent a B-mode echotomographic examination of the extracranial carotid tract performed with a Vingmed CFM 750 echotomographer with a 7.5 MHz probe and M-mode echocardiography with a Vingmed CFM 750 device equipped with a 3.0 MHz transducer. The results show the intimal-media thickness value in hypertensive patients (0.90 +/- 0.22 mm on the right and 0.92 +/- 0.22 mm on the left), was significantly greater than that in normotensive subjects (0.64 +/- 0.13 mm on the right and 0.64 +/- 0.13 mm on the left, p < 0.001); in hypertensive subjects, interventricular septum thickness (12.1 +/- 1.25 mm) was significantly greater than that in normotensive patients (9.1 +/- 0.77 mm, p < 0.001). In conclusion, we can say that hypertensive subjects have higher values of common carotid artery intimal-medial thickness than normotensives and that this finding is associated with the presence of left ventricular hypertrophy and with a reduction in arterial compliance. Vascular ultrasonography, as well as echocardiography and arterial mechanography can show, in hypertensive subjects, cardiac and vascular abnormalities in a non invasive way.

Opioid tonus and luteinizing hormone secretion in anorexia nervosa: priming effect with serotonin precursor L-5-hydroxytryptophan during pulsatile gonadotropin-releasing hormone administration

In anorexia nervosa (AN) luteinizing hormone (LH) release is often impaired during opioid blockade. We investigated whether a restoration of the endogenous sex steroid milieu, together with a rise in central serotonergic tone, could increase LH responsiveness to Naloxone (NAL) in seven young women affected by AN. The spontaneous pulsatility of gonadotropins and their response to gonadotropin-releasing hormone (GnRH) and NAL challenges were tested before and after 13 days of pulsatile GnRH treatment and oral administration of L-5-hydroxytryptophan. Low and unpulsatile gonadotropin levels, responsive to GnRH, but not to NAL, were found before treatment. Pulsatile GnRH brought about a quasi-normal secretory pattern and 17 beta-estradiol increased to preovulatory levels in six of seven patients. On day 13 the lack of response to NAL administration was still present, however. A neuroendocrine disorder seems to be present in AN, which appears more complex than in other forms of hypothalamic amenorrhea.

Hodgkin's disease: diagnostic accuracy of fine needle aspiration; a report based on 62 consecutive cases

We report on our series of 62 cases occurring between January 1977 and December 1990, which were diagnosed as Hodgkin's disease by fine needle aspiration (FNA) samples. The overall accuracy of the cytological diagnosis was high, with only four incorrect diagnoses and a positive predictive value of 93.5%. The value of FNA as a first level diagnostic technique in the screening of lymphadenopathies is discussed, as well as the limitations and pitfalls of the cytological diagnosis.

Differing responses of cortisol to oCRF during endonasal and oral treatment with DDAVP

Arginine vasopressin (AVP) exerts a potentiating effect on the responses of cortisol and ACTH to ovine CRF (oCRF). A stimulation test using AVP plus oCRF to assess ACTH reserve has been proposed. In central diabetes insipidus, long-term substitution therapy is commonly undertaken with desmopressin (DDAVP), an analogue of the natural hormone which has a greater antidiuretic action but whose effects on the ACTH-cortisol axis are still controversial. The aim of our study was to evaluate the variations in the responses of ACTH and cortisol to oCRF in various phases of the treatment of central diabetes insipidus: no treatment, endonasal treatment with DDAVP solution and oral treatment with DDAVP in tablet form. Seven patients suffering from central diabetes insipidus underwent testing with oCRF during the various phases of treatment. In the absence of DDAVP treatment, normal responses were registered for cortisol (basal 164.1 +/- 29.4 ng ml-1, peak 396.1 +/- 37.9 ng ml-1; P < 0.05) and ACTH (basal 20.4 +/- 3.9 pg ml-1, peak 86.3 +/- 20.9 pg ml-1; P < 0.05) in all patients. During oral treatment with DDAVP, no variation in cortisol response to oCRF was seen. By contrast, when DDAVP was administered endonasally, a significant reduction in cortisol responsiveness to oCRF (secretory area: 2429 +/- 548 ng ml-1 120 min) was noted in comparison with that found during the other two tests (no treatment: 3070 +/- 704 ng ml-1 120 min; oral DDAVP: 3419 +/- 650 ng ml-1 120 min; P < 0.05) performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of growth hormone insulin like growth factor-I axis in Down's syndrome

As GH therapy has been reported to increase growth velocity in children with Down's syndrome (DS), we studied the GH-IGF-I axis in some DS patients affected by growth retardation without serious congenital malformation, malnutrition or pathological thyroid or adrenal function. IGF-I and IGF-II were evaluated in 39 patients in basal conditions. The patients were subsequently divided into two groups with respect to the IGF-I basal value: Group 1 (GR 1) consisting of patients with abnormally low basal IGF-I concentration as compared to age matched control subjects, group 2 (GR 2) consisting of patients with IGF-I in the normal range. In 6 GR 1 patients and 12 GR 2 patients we evaluated GH and IGF-I concentrations after stimulation with arginine (0.5 g/kg bw), and recombinant GH (4 IU im). In the same patients, GH radioreceptor assay and serum GH-binding protein were evaluated. In all patients IGF-II proved normal (534 +/- 23 ng/ml; mean +/- SE), while IGF-I was pathological in 36% of subjects. The cause of the defective IGF-I secretion in these patients does not seem to depend on an impaired GH axis, as no significant difference in arginine-stimulated GH peak values was seen between GR 1 (29.6 +/- 5.3 ng/ml) and GR 2 (15.1 +/- 2.24 ng/ml). IGF-I concentration evaluated 12, 24, and 48 h after arginine stimulation was significantly increased only in GR 2 patients (peak value: 0.95 +/- 0.1, p = 0.0003 vs baseline; GR 1: 0.34 +/- 0.05 U/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

[The technical aspects of liver resection surgery: the authors' experience]

Based on their personal experience in hepatic resective surgery the authors dwell upon details of surgical technique which, well combined and sustained by advanced technological supports (ultrasonic dissector, laser-argon clotter, intraoperative echography), allow to perform wide parenchymal resections sheltered from dangerous complications. The safety achieved in such a surgery--now routinely performed--derives not only from improved diagnostic techniques (US, CT, MNR, angiography) and advances in anaesthesia-reanimation but, above all, from precise knowledge of organon segmental anatomy and close vascular correlations between the two hepatic hemisystems.

[Portal thrombosis: the diagnostic and therapeutic aspects and clinical cases]

The authors report their experience, from 1983 to 1992, in the treatment of portal vein thrombosis and discuss various aetiological factor of obstruction also underlining the frequent and important association with portal hypertension. The authors emphasize the crucial role of the modern diagnostic techniques such as endoscopy and imaging radiology (U.S., C.T., angiography). Although these techniques not always allow a conclusive evidence in relation to aetiology, however, it is possible to have a rationale for the treatment, i.e. medical, sclerotherapeutic or surgical. As related to the surgical procedures, the authors--based on their personal experience--believe the best are the non-derivative ones.

Excimer laser photoablative filtration surgery: histology and ultrastructure in 4 human cadaver eyes

The purpose of this study was to verify the feasibility of ab externo layer-by-layer excimer laser photoablative removal of limbal tissue down to the trabecular meshwork and to assess the damage caused by this procedure to the neighbouring structures. Excimer laser photoablation (193 nm) can remove layers of corneal tissue effectively with little or no damage to the adjacent areas. Previous experimental studies have demonstrated a decrease in outflow resistance after ab-externo photoablative removal of juxtacanalicular tissue. We have performed ab-externo photoablative removal of limbal tissue overlying the trabecular meshwork in four freshly enucleated eyes from our Eye Bank. The beam of an excimer laser (wavelength 193 nm; fluence 180 mJ/Sq.cm) was shaped using a metal mask with a rectangular opening of 1.2 x 2.5 mm. After removing the conjunctiva, photoablation was carried out at maximum surgical microscope magnification (40 x) until trabecular meshwork appeared at the bottom of the crater. Light microscopy showed that craters had smooth walls and their base reached the Schlemm's canal area; all structures appeared of normal morphology. Transmission electron microscopy showed a thin layer of amorphous material or pseudomembrane on the side walls of the crater; corneoscleral collagen fibers were abruptly interrupted and undistorted. At the bottom of the crater the trabecular meshwork and Schlemm's canal tissues appeared normal.