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Biomedical subjects

L Petrini

Publications and source records attributed to L Petrini.

18 recordsLinked to original sources
PubMed2001

Production and regeneration of protoplasts from Gremmeniella abietina and Ascocalyx abietis.

This work was undertaken to develop a system of protoplast isolation and regeneration for G. abietina and A. abietis that could be of use for the genetic manipulation of both species. Nuclear staining was performed to assess the nuclear conditions of the protoplasts. Of the 19 enzyme complexes studied, only 10 were found to have some lytic effect on either Gremmeniella, A. abietis, or both. Only snail enzyme (from Szeged University), Novozym 234, lytic enzyme L1, or mixtures of snail enzyme and Novozym 234 produced satisfactory yields of protoplasts. Regeneration of protoplasts was observed on complete and on minimal medium, and occurred from protoplasts plated out directly onto the surface and from those embedded in the agarose. In most cases, embedding increased the frequency of regeneration. Protoplasts formed after incubation at 20 degrees C regenerated at a frequency of approximately 5%, as opposed to 2% for those produced at 30 degrees C. As roughly 40% of the protoplasts were anucleate, the percentage of regeneration can be estimated as about 12.5% at 20 degrees C and 5% at 30 degrees C. Protoplasting appears to be a satisfactory method of obtaining material for genetic experiments with G. abietina and A. abietis when other methods are not directly applicable.

Ascomycota↗
PubMed2000

Cardiac function, physical exercise capacity, and quality of life during long-term thyrotropin-suppressive therapy with levothyroxine: effect of individual dose tailoring.

As recently claimed, TSH-suppressive therapy with L-T4 may have adverse effects on the heart, but these results have not been consistently confirmed. We assessed cardiac function by clinical, echocardiographic, and ergometabolic criteria in 19 patients (16 women and 3 men) receiving long term L-T4 at a fixed daily dose ranging from 1.8-4.0 microg/kg. The results showed significant alterations in several cardiac parameters suggestive of subclinical hyperthyroidism. In particular, intraventricular septum thickness (10.0+/-1.4 vs. 8.1+/-1.1 mm), left ventricular posterior wall thickness (9.4 1.5 vs. 8.1+/-1.1 mm), end-diastolic dimension (47+/-4 vs. 44+/-3 mm), and left ventricular mass index (102+/-15 vs. 75+/-15 g/m2) were significantly increased compared to values in age- and sex-matched euthyroid controls. Exercise tolerance (expressed as maximal tolerated workload; 102+/-14 vs. 117+/-12 watts), maximal VO2 achieved at peak exercise (maximum VO2, 17.3+/-3.3 vs. 21.9+/-2.5 mL/min x kg), and anaerobic threshold (expressed as a percentage of VO2max, 46.5+/-8.4 vs. 56.2+/-6.6) were significantly reduced in L-T4-treated patients. The L-T4 dose was then reduced to the minimal amount able to keep the serum TSH concentration at 0.1 mU/L or less in 7 patients who were reevaluated 6 months after the initial study. This individual tailoring of the TSH-suppressive L-T4 dose was in all cases associated with normalization of all echocardiographic and ergometabolic parameters. In conclusion, our findings show that abnormalities of heart morphology associated with impaired exercise performance occur as a consequence of long term therapy with fixed TSH-suppressive doses of L-T4, but that these abnormalities improve or disappear after careful tailoring of TSH-suppressive therapy.

Adult↗
PubMed2000

Cardiac dysfunction in acromegaly: evidence by pulsed wave tissue Doppler imaging.

OBJECTIVE: To verify whether the accuracy of data on myocardial function provided by pulsed-wave tissue Doppler imaging (PWTDI), a new echocardiographic application that allows quantitative measurements of myocardial wall velocities, could help towards a better understanding of the natural history of acromegalic cardiomyopathy. DESIGN: Eighteen patients with active acromegaly (ten men and eight women; mean age 48.0+/-15.0 years) with no other detectable cause of heart disease underwent PWTDI. Thirteen healthy individuals matched for age and body mass index acted as a control group. METHODS: Ejection fraction (EF), transmitral early/late diastolic velocity (E/A) ratio and isovolumic relaxation time (IVRT) were measured by conventional echocardiography; systolic peak (Sv) and early (Ev) and late (Av) diastolic peak velocities, Ev/Av ratio and regional IVRT (IVRTs) were obtained by PWTDI. RESULTS: All patients showed appreciably abnormal left ventricular global diastolic function represented by prolongation of the IVRT (P<0.001). Using PWTDI we found a prolongation of IVRTs and inversion of the Ev/Av ratio. In addition, the Ev/Av ratio proved to be significantly negatively correlated with IVRT; this correlation was not present in the case of the E/A ratio. Furthermore, a decrease in Sv was detected in the basal segment of the lateral wall (P<0.01), which had the greatest degree of diastolic dysfunction. CONCLUSIONS: PWTDI confirmed the acknowledged diastolic dysfunction that accompanies acromegalic cardiomyopathy and highlighted the greater sensitivity of regional PWTDI with respect to global Doppler diastolic indexes. Furthermore, by revealing an impairment of regional systolic function in presence of a normal EF, the findings with PWTDI contradicted the largely accepted theory that systolic function remains normal for several years in patients affected by acromegalic cardiomyopathy.

Acromegaly↗
PubMed1997

Lactose intolerance following antithyroid drug medications.

We recently observed 2 lactase-deficient women with Graves' disease who consistently developed severe diarrhea after ingestion of thionamide (methimazole and propylthiouracil) tablets containing lactose as carrier. The strict temporal relationship between ingestion of lactose-containing tablets and appearance of intestinal symptoms, as well as the absence of side effects following ingestion of methimazole tablets without lactose as carrier, provided the clue for the diagnosis. To our knowledge, severe diarrhea resulting from carrier lactose has not been previously reported for antithyroid drugs, and should be considered in occasional cases of patients with gastrointestinal symptoms on thionamide therapy.

Adult↗
PubMed1994

Long-term treatment of Nelson's syndrome by octreotide: a case report.

Medical management of Nelson's syndrome by drugs such as bromocriptine, sodium and magnesium valproate has provided disappointing or, at least, controversial results. We report here on the results of long-term (2 yr) treatment with the somatostatin analogue octreotide (300 micrograms daily sc) in one patient affected by Nelson's syndrome occurring after bilateral adrenalectomy for Cushing's syndrome. During treatment, skin hyperpigmentation and serum ACTH levels decreased dramatically and a slight (about 10%) reduction in tumor size, as assessed by computerized tomography, was also observed. These results suggest that octreotide may be useful for the medical management of Nelson's syndrome.

Adrenocorticotropic Hormone↗
PubMed1993

[Acromegalic arthropathy].

Six acromegalic patients, three males (aged 28 to 48 years) and three females (aged 57 to 75 years), with GH-producing pituitary adenoma, were studied through clinical examination, laboratory and instrumental tests. In all the patients frequent involvement of large joints, with crepitus and provoked pain, was found; while articular mobility was normal especially in the dorso-lumbar spine, a frequent seat of pain. Radiology showed typical features of an osteoarthritic process with characteristic widening of articular spaces, especially in weight-bearing large joints in symptomatic patients. The evolution of this arthropathy lead to anatomo-clinical pictures almost indistinguishable from osteoarthritis; however, in the early stages, the marked cartilaginous hypertrophy is responsible for peculiar anatomo-radiological pictures, principally represented by widening of articular spaces and intervertebral discal spaces, especially in the dorso-lumbar spine. As far as bone metabolism is concerned, neoproduction and reabsorption, both increased, proceed simultaneously; bone mass reduction is described in some segments. In our study, the two patients with active acromegaly showed bone mass reduction in the lumbar spine.

Acromegaly↗
PubMed1992

Percutaneous intranodular ethanol injection for treatment of autonomously functioning thyroid nodules.

BACKGROUND: The aim of the study is the assessment of percutaneous intranodular ethanol injection (PNEI) as an alternative therapeutic procedure to classic surgery and radioiodine administration in autonomously functioning thyroid nodule treatment. METHODS: Thirty-seven patients with hot nodules (18 pretoxic and 19 toxic) have been treated by means of PNEI under ultrasonographic guide. Ninety-five percent ethanol in a mean dose of 25 ml has been used. RESULTS: Nearly 80% of the patients showed normalization of thyroid-stimulating hormone levels and a complete recovery of extranodular tissue at scintiscan. All nodules decreased strikingly in size, many becoming undetectable. Mild and transient side effects were seen in 9% of the patients. CONCLUSIONS: PNEI seems to be a feasible procedure on outpatients. It is safe when performed by a well-trained staff using ultrasonographic control. It may be carried out at any age and in patients at risk for surgery. PNEI can be considered a useful alternative to surgery and radioiodine administration in all autonomously functioning thyroid nodules and particularly in pretoxic nodules.

Administration, Cutaneous↗
PubMed1991

Therapy of Graves' disease with sodium ipodate is associated with a high recurrence rate of hyperthyroidism.

To evaluate the long-term efficacy of sodium ipodate (IPO) in the treatment of hyperthyroid Graves' disease, we studied 12 consecutive patients with Graves' hyperthyroidism treated only with 500 mg IPO po daily for several weeks to 22 months. Serum thyroid hormone concentrations markedly decreased and serum free T3 values normalized in all patients within 7 days of therapy. Five patients (42%, Group 1) were euthyroid after 6 weeks of IPO treatment and remained so until IPO was discontinued after 22 months. Recurrence of hyperthyroidism after drug withdrawal occurred in only one of these Group 1 patients, who was promptly responsive to a second course of IPO. In contrast, seven of 12 patients (58%, Group 2) relapsed with recurrent hyperthyroidism between 14 and 42 days of IPO therapy. After IPO was withdrawn, these Group 2 patients were treated with methimazole (20-30 mg/day, initial dose), but the therapeutic response was poor and delayed. Two patients were still hyperthyroid after 6 months of methimazole treatment. Elevated serum FT3 concentrations were observed in the Group 2 patients at 21 days following the early normalization of serum FT3 concentrations. No changes in serum thyroglobulin and thyroid microsomal and TSH-receptor autoantibody titers were observed in either groups during IPO therapy. In conclusion, the results of the present study demonstrate that IPO rapidly restores euthyroidism, but its prolonged administration is associated with a high rate of relapse of hyperthyroidism and a poor response to subsequent methimazole treatment and that long-term IPO administration does not affect humoral markers of thyroid autoimmunity.

Adolescent↗
PubMed1991

The nocturnal serum thyrotropin surge is abolished in patients with adrenocorticotropin (ACTH)-dependent or ACTH-independent Cushing's syndrome.

TSH secretion was evaluated in 10 patients with ACTH-dependent (pituitary microadenoma, n = 5) or ACTH-independent [adrenal adenoma (n = 4) or carcinoma (n = 1)] Cushing's syndrome, and in 12 normal controls matched for age and sex. Serum TSH concentration was assayed at night, from 2200-0200 h, and in the morning, both basally and 30 min after iv injection of 200 micrograms synthetic TRH. Patients with hypercortisolism showed significantly reduced serum total T4 and T3 and free T3 concentrations and increased serum reverse T3 levels. Their mean baseline serum TSH concentration in the morning, albeit slightly lower, did not significantly differ from those of controls. The mean peak TSH value after TRH was significantly reduced, and a blunted TSH response to TRH was found in 4 out of 10 patients. At variance with normal controls, who showed nighttime TSH values 63-228% higher than morning values, 9 out of 10 patients had nighttime levels not different from or even lower than those in the morning; the remaining patient had nighttime TSH values marginally (33%) higher than in the morning. An inverse relationship (r = 0.80, P less than 0.001) was found between serum cortisol and TSH values both at night and in the morning. No differences were found either in the pattern of TSH secretion or in the TSH response to TRH between patients with ACTH-dependent and those with ACTH-independent Cushing's syndrome. These results show a substantial impairment of TSH secretion, and in particular the loss of the nocturnal surge of the hormone, in patients with Cushing's syndrome. Although the origin of the nocturnal TSH rise is probably multifactorial, cortisol, at least when secreted in excess, appears to play an important role in its regulation.

Adrenocorticotropic Hormone↗
PubMed1991

The lack of nocturnal serum thyrotropin surge in patients with nontoxic nodular goiter may predict the subsequent occurrence of hyperthyroidism.

TSH secretion, with particular regard to the nocturnal TSH surge, was evaluated in 115 subjects with non-toxic nodular goiter. All patients were clinically and biochemically euthyroid. After 18-36 months of follow-up (mean, 24 months), hyperthyroidism occurred in 21 (18%; group 1), while the remaining 94 remained euthyroid (82%; group II). The analysis of hormonal data at the time of first observation showed that the 2 groups had similar total and free T4 and T3 serum concentrations. Morning serum TSH values in group I were lower than those in group II patients (0.6 +/- 0.1 vs. 1.1 +/- 0.1 mU/L; P less than 0.001); this difference was even more striking for the nocturnal values (0.6 +/- 0.1 vs. 2.2 +/- 0.2 mU/L; P less than 0.0001); nocturnal values were significantly lower than morning values in group II, but not in group I. The mean peak TSH value after TRH was also significantly reduced in group I (5.5 +/- 0.4 vs. 9.2 +/- 0.7 mU/L; P less than 0.001). Morning TSH values in group II did not differ from those in controls (1.3 +/- 0.1 mU/L), whereas nocturnal and TRH stimulated peak TSH values were slightly but significantly lower. The nocturnal serum TSH values in control subjects were 62-390% higher than morning values. The nocturnal TSH surge was abolished in 18 of 21 (86%) group I patients and in 7 of 94 (8%) group II patients. TRH testing resulted in an absent or blunted TSH responses in 5 subjects in group I and 6 in group II. Analysis by the Galen and Gambino predictive model; comparing the abolition of the nocturnal TSH surge and the abnormal TRH test as predictors of the subsequent occurrence of hyperthyroidism, showed that the former had higher sensitivity (86% vs. 24%) and predictivity (72% vs. 45%). In conclusion, the results of the present study demonstrate that the evaluation of the nocturnal TSH surge may be useful in identifying patients with nontoxic nodular goiter in whom hyperthyroidism may eventually occur. Patients who lack the nocturnal serum TSH surge are more prone to develop thyroid hyperfunction; their thyroid status should, therefore, be more carefully and frequently monitored.

Adult↗
PubMed1988

Absence of serum thyroid hormone autoantibodies in patients chronically treated with amiodarone.

The role of iodine in the pathogenesis of thyroid hormone autoantibodies (THAA) was evaluated in a large series (n = 223) of patients submitted to chronic treatment (3-36 months) with the iodine-rich drug, amiodarone. Positive anti-T3 autoantibody (AbT3) tests were found only in one patient, whereas tests for anti-T4 autoantibody (AbT4) were negative in all cases. Likewise, the incidence of THAA in the control groups of patients with spontaneous thyroid disorders was low. The overall prevalence of THAA in the present series of 803 patients was 1.2% for AbT3 and 0.1% for AbT4. The present data strongly suggest that iodine plays a minor role, if any, in the occurrence of THAA.

Amiodarone↗
PubMed1987

[Collateral effects of 9-alpha-fluor-prednisolone acetate and kanamycin, administered by nasal spray. Clinical experience and experimental data].

Iatrogenic pathology due to treatment with steroid drugs used by systemic route is well known. On the contrary iatrogenic pathology due to topical use of these drugs is rarely reported. Two cases of abuse of 9-alpha- fluor-prednisolone and kanamycin administered by endonasal route are reported. The same treatment has been carried out in patients and rabbits. Clinical and bio-humoral data in patients and anatomo-pathological findings in rabbits are reported. The risks, sometimes underestimated, of an overdose of corticosteroid and antibiotic drugs used by endonasal route are pointed out.

Administration, Inhalation↗
PubMed1982

Root resorption after orthodontic treatment of traumatized teeth.

This study concerns the frequency and degree of root resorption in traumatized incisors that have been treated orthodontically. The subjects were twenty-seven patients (fifteen boys and twelve girls) with fifty-five traumatized incisors; fifty-five consecutive patients without traumatized teeth served as controls. All the control patients were treated with extraction of four first premolars and a fixed appliance (thirty-three with an edgewise and twenty-two with a Begg appliance). Signs of root resorption were registered with index scores from 0 to 4 (Fig. 1). The degree of root resorption in traumatized teeth was compared to that in the uninjured control teeth in the same patient and in the patients without trauma. Neither the intraindividual nor the interindividual comparisons support the hypothesis that traumatized teeth have a greater tendency toward root resorption than uninjured teeth. Root resorption (scores 2 to 4) was found in 51 percent of the traumatized incisors, in 43 percent of the incisors treated with edgewise appliances, and in 48 percent of those treated with Begg appliances. Traumatized teeth with signs of root resorption prior to orthodontic treatment may be more prone to root resorption during treatment.

Adolescent↗
PubMedDate not supplied

Octreotide treatment does not affect the size of most non-functioning pituitary adenomas.

The somatostatin analogue, octreotide (OC) has commonly been used in the management of growth hormone- and thyrotropin-secreting pituitary tumors, and shown to be effective both on hormone production and tumor size. Because OC receptors may be expressed also in some nonfunctioning pituitary adenomas, it has been postulated that OC might play a role in the treatment of these tumors as well. In the present study, the morphological effects of OC administration, as assessed by computer tomography (CT) scan, were evaluated in 8 patients (5 men, 3 women, age range 25-79 yr) affected by non-functioning pituitary tumors. The drug was given sc at the dose of 100 micrograms tid for 3-6 months. No significant change in visual field or tumor size occurred after OC treatment in 7 patients, whereas one showed a significant improvement of visual field associated with a decreased tumoral mass. These data suggest that OC is not an effective drug in the management of nonfunctioning pituitary adenomas.

Adenoma↗
PubMedDate not supplied

[Myxedema coma].

Myxedema coma, an extreme expression of hypothyroidism, represents a medical emergency with high mortality. Hypothermia and cerebro-vascular accidents should be taken into account for correct differential diagnosis. The treatment of myxedema coma is based on prevention of the precipitating factors and on the administration of generous doses of L-thyroxine and/or triiodothyronine, associated with steroids and drugs for respiratory and cardio-vascular complications.

Coma↗