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Biomedical subjects

G Verde

Publications and source records attributed to G Verde.

At least 19 recordsLinked to original sources
PubMed2000

Isospin fractionation in nuclear multifragmentation

Isotopic distributions for light particles and intermediate mass fragments have been measured for 112Sn+112Sn, 112Sn+124Sn, 124Sn+112Sn, and 124Sn+124Sn collisions at E/A = 50 MeV. Isotope, isotone, and isobar yield ratios are utilized to estimate the isotopic composition of the gas phase at freeze-out. Analyses within the equilibrium limit imply that the gas phase is enriched in neutrons relative to the liquid phase represented by bound nuclei. These observations suggest that neutron diffusion is commensurate with or more rapid than fragment production.

Journal Article↗
PubMed1997

Using views for retrieving data from extremely heterogeneous databanks.

Information in molecular biology or biology in general is contained in a multitude of different databanks each specializing in a certain area. This specialization is useful since it improves the maintainability of the data and the flexibility of the overall structure which until now manages to exist without almost any standards. However, information gathering from these extremely heterogeneous sources is difficult since the desired data may be scattered over many databanks. This paper presents the concept of views implemented in the retrieval system SRS that uses links between databanks and a sophisticated parsing engine for information extraction to provide a flexible way of searching and obtaining data across databank boundaries. The implementation provides homogeneous access to all databanks using two types of views: the list-view which displays selected data-fields in their original format and the table-view available for HTML and plain ASCII text which tries to represent the data in a format independent from that of the source databank.

Amino Acid Sequence↗
PubMed1995

Percutaneous ethanol injection (PEI): what is its role in the treatment of benign thyroid nodules?

Ultrasound-guided percutaneous ethanol injection (PEI) was first proposed by Livraghi in 1990 as a possible therapy for autonomously functioning thyroid nodules (AFTN). The procedure is performed on out-patients; is rapid; there is no need of anesthesia, nor of bed rest or patient observation after treatment. Under direct sonographic control a limited amount of 95% sterile ethanol (1-5 ml) is slowly injected into the nodule. In predominantly cystic nodules complete fluid removal is preliminarily performed, and thereafter ethanol is injected on the basis of the aspirated fluid volume without removing the needle. PEI-induced thyroid damage is characterized by coagulative necrosis and haemorrhagic infarction due to vascular thrombosis, and is well defined from the surrounding thyroid parenchyma. Several papers have confirmed the effectiveness of PEI. Normalization of serum TSH and thyroid hormones, marked decrease of nodule volume, and effacement of the previously hyperfunctioning area at thyroid scintiscan are reported in 64-85% of toxic AFTN. Nontoxic AFTN are successfully treated in 80-100% of the cases. PEI significantly superior to aspiration alone in inducing volume reduction of benign cystic thyroid nodules, and the recurrence rate is only 2.5-5%. Complications requiring hospitalization were not reported, but the importance of experienced operators must be stressed to avoid transient dysphonia due to recurrent laryngeal nerve damage. Prior to PEI malignancy must be ruled out by fine needle aspiration in all patients. Radioiodine and surgery remain the treatments of choice of large toxic thyroid nodules, but PEI can be effectively used in selected cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Ethanol↗
PubMed1994

Ultrasound guided percutaneous ethanol injection in the treatment of cystic thyroid nodules.

OBJECTIVE: The management of cystic lesions in the thyroid remains controversial. We examined the efficacy and safety of ultrasound guided percutaneous ethanol injection for the treatment of benign cystic thyroid nodules in euthyroid patients. STUDY DESIGN: (A) Preliminary randomized trial: 20 patients with predominantly cystic thyroid nodules were randomized in two groups and followed up for 1 month. Group 1 underwent fine needle aspiration of the fluid component of the nodules; Group 2 underwent percutaneous ethanol injection at the end of fine needle aspiration of the cyst fluid. (B) Prospective study: 32 patients with the same clinical characteristics (Group 3) were treated by fine needle aspiration and percutaneous ethanol injection, and followed up for 12 months. METHODS: Groups 1 and 2: clinical evaluation, thyroid ultrasonography, thyroid scintiscan and serum thyroid hormone profile were performed before treatment and one month later. Group 3: clinical evaluation, thyroid ultrasonography and serum thyroid hormone profile were performed in basal conditions and 1, 3, 6, 9, 12 months after treatment. Thyroid scintiscan was performed before treatment and 3-6 months later. RESULTS: (A) Randomized study: one month after treatment, nodule volume decrease in Group 2 was significantly higher than in Group 1 (Group 2: median 14.75 range 6-29.9 ml; Group 1: median 3.65 range 0.2-18.5 ml; P < 0.01). Nodule volume reduction was greater than 50% versus baseline in 8 (80%) patients in Group 2 and in 3 (30%) patients in Group 1 (P < 0.01). (B) Prospective study (Group 3): a significant nodule volume reduction (P < 0.01 vs pretreatment) was observed 1 and 12 months after percutaneous ethanol injection (pretreatment: median 14.5, range 1.5-65.8 ml; 1 month: median 3.5, range 0.4-38.9 ml; 12 months: median 2.5, range 0.4-34.5 ml). Nodule volume reduction greater than 50% was recorded in 24 (80%) patients. Groups 1-3: recurrence of cyst fluid was demonstrated by ultrasonography in 8 patients of Group 1, in 3 patients of Group 2 and in 1 patient of Group 3. No relevant adverse effects or significant biochemical changes were observed. CONCLUSIONS: Ultrasound guided percutaneous ethanol injection of cystic thyroid nodules is a safe, low-cost and effective therapeutic procedure in patients with benign thyroid cystic nodules. Indeed, nodule volume reduction was significantly greater and more frequent in patients treated by percutaneous ethanol injection than in those patients who underwent fluid aspiration alone. These results were confirmed in a long-term prospective trial and only one fluid recurrence was observed during 12 months of follow-up.

Adolescent↗
PubMed1992

Distal nephron function in Bartter's syndrome: abnormal conductance to chloride in the cortical collecting tubule?

Five patients with the clinical patterns of Bartter's syndrome underwent a series of clearance studies in order to characterize the underlying tubule defect. Free water generation during maximal water diuresis (CH2O), expressed as percentage of the distal delivery (CH2O + CCl), was lower in the patients (72.5 +/- 3.2%) than in controls (84.4 +/- 5.5, p < 0.0001). During maximal water diuresis and furosemide administration (40 mg i.v. as bolus), NaCl reabsorption along the diluting nephron segments could be separated into 2 components, that occurring in the loop of Henle (DRNaHL) and that occurring in tubule segments beyond the macula densa (DRNaDT): DRNaHL was normal, while DRNaDT was reduced (3.1 +/- 0.8 vs. 6.2 +/- 2.5 ml/min in controls, p < 0.015). Thus, according to this furosemide protocol, our patients had normal solute reabsorption in the loop of Henle but reduced NaCl reabsorption in tubule segments beyond the macula densa. During 0.9% saline infusion (2 liters in 2 h, after stimulation of distal Na reabsorption with fludrocortisone) fractional excretion (FE) of K showed a linear rise with the increase of FECl-FEK, however, was much higher in the patients than in controls for every FECl level. In contrast, the infusion of Na2SO4, after fludrocortisone administration, induced similar FEK increases in patients and in controls. Thus, in these patients Na reabsorption in the distal nephron (possibly the cortical collecting tubule) was associated with the generation of a higher than normal electric potential gradient in the presence of Cl but not of another poorly reabsorbable anion, such as SO4(2-). These observations indicate that, in our patients, Henle's loop function is normal, while the collecting tubule function is abnormal. We suggest that NaCl wasting and enhanced tubular secretion of H+ and K in our patients might result from an abnormally low conductance to Cl in distal nephron site(s) where Na reabsorption is electrogenic, possibly the cortical collecting tubule. A larger than normal transtubular electric gradient would be generated by Na reabsorption, causing: (1) a direct stimulation of tubular secretion of K and H+ (leading to hypokalemia and alkalosis) and (2) inhibition of the reabsorption of Na ('trapped' into the tubular lumen by electric forces), with consequent extracellular volume contraction, hyperreninemia and hyperaldosteronism.

Adolescent↗
PubMed1991

Doxorubicin for acromegaly: a case report.

We report the case of an acromegalic woman, aged 35 years, with a huge GH-secreting tumor, repeatedly treated with neurosurgery and radiotherapy, not responsive to bromocriptine (Br) and octreotide (SMS), whose clinical picture evolved to coma due to endocranic hypertension. Since remnant size was too large to be further treated by surgery, chemotherapy with doxorubicin (DOX) (100 mg i.v. every three weeks up to 0.5 mg/m2 over 7 months) was started. Treatment was followed by a rapid improvement of clinical picture with resumption out of coma, progressive decline of GH levels (from 800 ng/ml to 15 ng/ml) and a slight shrinkage of tumor. No side effects were observed during DOX administration. We suggest that in those few acromegalic patients resistant both to SMS and Br, and with poor prognosis, DOX may be effectively used.

Acromegaly↗
PubMed1989

Body iron status in critically ill patients: significance of serum ferritin.

Serial measurements of blood haemoglobin, serum iron, serum transferrin, total iron-binding capacity, transferrin per cent saturation and serum ferritin were determined in 51 post-operative critically ill patients to investigate body iron status in severely stressed patients. The results showed decreased blood haemoglobin, serum iron, serum transferrin and transferrin saturation compared to an increase in serum ferritin levels. These results indicate that there is inadequate availability of iron to tissues (secondary to rearrangement of body iron to the advantage of the iron storage compartment), which is often present in severely critically ill patients. A positive correlation was found between the initial (ferritin) levels and SAPS (r = 0.41, p less than 0.01). In addition, the increase of ferritin concentration parallels a worsening of the clinical status in severely ill patients. This is due to enhanced release by the macrophage system. From this, we consider serum ferritin as an acute-phase protein and a useful marker of the severity of the clinical status. It appears to be useful in predicting the patient's outcome, but is not reliable in evaluating iron stores in stressed patients.

Adolescent↗
PubMed1987

Medical treatment of acromegaly with SMS 201-995, a somatostatin analog: a comparison with bromocriptine.

We studied the effects of acute and chronic sc administration of SMS 201-995 (SMS), a long-acting somatostatin analog, in acromegalic patients. The results were compared with those obtained in the same patients treated with oral bromocriptine (Brc). A single dose of 50 micrograms SMS administered to 28 patients induced a more rapid, greater, and more prolonged reduction in plasma GH levels than did 2.5 mg Brc. Chronic treatment [60-330 days; mean 208 +/- 23 (+/- SEM)] with SMS (100-300 micrograms/day) induced in 16 patients a significantly greater decrease in mean plasma GH and somatomedin-C levels than did 20 mg Brc. Combined treatment with the 2 agents had an additional effect. The clinical and metabolic parameters of acromegaly dramatically improved in all patients whose plasma GH and somatomedin-C levels decreased even if they were not normalized by SMS. Reduction in tumor size occurred in 3 of the 10 patients examined by computed tomography before and during SMS treatment. We conclude that SMS is more effective than Brc and that the 2 drugs may be complementary in the medical treatment of acromegaly.

Acromegaly↗