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Biomedical subjects

A Cavallo

Publications and source records attributed to A Cavallo.

At least 37 records · Page 2Linked to original sources
PubMed1997

Recurrence of thymoma: analysis of clinicopathologic features, treatment, and outcome.

OBJECTIVE AND METHODS: This study reports clinicopathologic features, treatment, and outcome of 30 recurrent thymomas out of 266 totally resected thymomas. RESULTS: The mean disease-free interval to recurrence was 86 months. Recurrence occurred less frequently and after a longer disease-free interval after resection of encapsulated versus invasive thymomas. The presence of associated myasthenia gravis did not affect recurrence proportion, disease-free interval, or survival after recurrence. A local recurrence occurred in 11 patients, 17 patients had a distant recurrence, and the extent of the recurrence could not be determined in 2 cases. Surgical treatment of the recurrent tumor was attempted in 16 cases, and a total resection was possible in 10 cases; exclusive radiotherapy was done in 11 cases. Overall 5- and 10-year survivals were 48% and 24%, respectively. In a univariate analysis, survival was significantly better in the presence of a local recurrence and in case of a total resection of the recurrent tumor. The use of adjuvant therapy after the resection of the initial thymoma had no effect on reducing the incidence of recurrence, in prolonging the disease-free interval, or in improving survival after the development of the recurrence. In a multivariate survival analysis, significant prognostic factors were the presence of a local recurrence and total resection of the recurrent tumor. CONCLUSIONS: Surgical resection is recommended in patients with recurrent thymoma. Local recurrence and total resection of the recurrent tumor are associated with excellent prognosis. A poor prognosis may be anticipated in the presence of distant recurrence and when radical surgical treatment is not done.

Adult↗
PubMed1997

Effects of menopause and nasal occlusion on breathing during sleep.

Prevalence of sleep-disordered breathing (SDB) is reported to increase in menopausal women. We examined response to a nocturnal respiratory challenge (nasal occlusion) during overnight polysomnography in 31 women (45 to 55 yr). Thirteen were premenopausal, four perimenopausal, and 14 postmenopausal by history and hormonal assay. Nasal occlusion increased the apnea hypopnea index (AHI) (occlusion mean = 6.6 +/- 8.0 versus baseline mean = 1.6 +/- 2.6, p < 0.01) and arousal index (occlusion mean = 35.1 +/- 20.1 versus baseline mean = 20.7 +/- 11.6, p < 0.001), but did not change the oxygen saturation nadir in those with respiratory events (occlusion mean = 91.8 +/- 4.2 versus baseline mean = 92.0 +/- 11.6). Menopausal groups did not differ on AHI, arousal index, or oxygen saturation nadir in either condition. Key variables were compared between occlusion responders (n = 11) and nonresponders (n = 20). Responders and nonresponders were not distinguished by age, menopausal status, nor several cephalometric or anthropometric variables. Body mass index (31.1 +/- 8.5 versus 24.3 +/- 3.4, p < 0.003), neck circumference (34.0 +/- 2.5 versus 32.5 +/- 1.7 cm, p < 0.05), and mandibular-hyoid distance (18.5 +/- 3.8 versus 14.5 +/- 5.7 mm, p < 0.05) were greater in responders. These findings suggest hormonal factors may be less important than weight and facial morphology in midlife development of SDB in women.

Anthropometry↗
PubMed1997

Atypical mycobacteriosis in a lung transplant recipient.

Although mycobacterial infections are more frequent in lung transplant recipients than in other solid organ recipients only occasional reports of infection from atypical Mycobacteria have been reported in patients receiving lung transplantation. We present a case of pleural and cutaneous infection due to Mycobacterium fortuitum in a double-lung transplant recipient. The infection was rapidly responsive to therapy with a two drug regimen and no reduction of immunosuppression was necessary.

Anti-Bacterial Agents↗
PubMed1996

Pleural epidermoid carcinoma from displaced skin following extrapleural pneumothorax in a patient exposed to asbestos.

This report illustrates a rare case of primary epidermoid carcinoma of the pleura in a patient previously treated by artificial extrapleural pneumothorax for active tuberculosis. The patient had also been occupationally exposed to asbestos. Light microscopic examination showed two different lesions: laminar pleural fragments were covered by normal squamous epithelium that was similar in all respects to epidermis, whereas nodular fragments were composed of well-differentiated infiltrating carcinoma. These findings support the hypothesis that the carcinoma arose from normal epidermis seeded in the pleural cavity during multiple air refills to maintain the pneumothorax. A possible interaction between asbestos fibres and chronic inflammation might have potentiated tumour development.

Aged↗
PubMed1996

Effects of isradipine sustained release on platelet function and fibrinolysis in essential hypertensives with or without other risk factors.

The aim of this study was to assess the chronic effects of a highly selective dihydropiridine calcium channel blocker, israpidine, in its sustained release form (I-SRO), on platelet functions and fibrinolytic parameters in subjects with essential hypertension (EH) combined or not with other well-known cardiovascular risk factors, such as cigarette smoking (EH+S) and type II diabetes mellitus (EH+DM). Thirty-six patients with essential hypertension with sitting diastolic blood pressures of 96-104 mmHg without (EH, n = 12) or with other risk factors (EH+S, n = 12, EH+DM, n = 12) were enrolled. After a 4-week, single-blind, placebo run-in period, the subjects received I-SRO 5 mg once daily for 18 weeks. After both placebo and 6 and 18 weeks of I-SRO treatment, the following parameters were measured: sitting blood pressure by mercury sphygmomanometer; platelet aggregation, plasma beta-thromboglobulin (BTG), platelet factor-4 (PF4), and plasminogen activator inhibitor 1 (PAI-1) by means of ELISA methods; and euglobulin lysis time before (ELT) and after standardized (10 min) venous occlusion (ELT-VO). In the group of patients as a whole compared with placebo, I-SRO significantly reduced SBP/DBP platelet aggregation, BTG, PF4, ELT, and ELT-VO. Significant reductions in these parameters were also observed in each group. In addition to the antihypertensive effect, I-SRO chronic treatment may favorably affect the platelet function and fibrinolytic system in essential hypertension with or without other cardiovascular risk factors.

Antihypertensive Agents↗
PubMed1996

Effects of benazepril and nicardipine on microalbuminuria in normotensive and hypertensive patients with diabetes.

Diabetic nephropathy is the most frequent cause of chronic renal failure. The onset of microalbuminuria in patients with diabetes mellitus, which seems to be related to blood pressure and the control of glycemia, is predictive of the development of true proteinuria. This multicenter, single-blind, randomized study examined the effects of benazepril and nicardipine on overnight microalbuminuria in 57 normotensive and 46 hypertensive diabetic patients. At the end of a 3-month placebo run-in period, the patients were stratified on the basis of the presence or absence of arterial hypertension and, within each stratum, randomized to receive one daily tablet of 10 mg benazepril or one tablet of 20 mg nicardipine twice daily for 6 months. Renal hemodynamics was investigated in 25 patients. Both drugs decreased overnight microalbuminuria throughout the study period, but benazepril was more effective than nicardipine (p = 0.025); in the patients with hypertension, both drugs led to a similar marked reduction in systolic and diastolic blood pressure. This study shows that benazepril was more effective than nicardipine in reducing overnight microalbuminuria in patients with diabetes mellitus, independently of their antihypertensive properties.

Adult↗
PubMed1996

6-Hydroxymelatonin sulfate excretion in human puberty.

We investigated the relationship of urinary excretion rate of 6-hydroxymelatonin sulfate (SM), the main metabolite of melatonin, with pubertal development and determined the day to day variability of SM excretion. Healthy subjects 4-31 years old completed one or multiple timed overnight urine collections. SM excretion rate per body size was significantly higher in 99 prepubertal subjects (35.5 +/- 2.3 ng/h/kg and 0.97 +/- 0.06 microgram/hr/m2) than in 86 pubertal subjects (18.1 +/- 1.1 ng/hr/kg and 0.61 +/- 0.03 microgram/hr/m2) or in 29 adults (15.0 +/- 1.5 ng/hr/kg and 0.59 +/- 0.06 microgram/hr/m2); no significant difference was present in pubertal stages 2 to 5. Among the prepubertal children, SM excretion rate in mid childhood was significantly higher than in late childhood. The variability of SM and creatinine excretion examined in 52 children, adolescents and adults with three or four collections was defined as the mean of the 52 coefficients of variation for the multiple measures in each subject. The variability of total nocturnal SM (25.9 +/- 2.6%) was similar to that of total creatinine (21.7 +/- 2.3%) and neither was significantly correlated with the variability in start time or duration of urine collection. The results suggest that, relative to body size, melatonin secretion rate is higher in mid childhood, decreases during late childhood, and remains stable from pubertal stage 2 to adulthood. The decline in melatonin secretion rate occurs during the developmental phase of disinhibition of the gonadotropin releasing hormone pulse generator. Hence, we infer that melatonin may be a suppressive factor of puberty during childhood. The substantial individual variability observed for SM excretion calls for caution in using single urine collections in longitudinal studies or in studies of drug responses.

Adolescent↗
PubMed1996

Pharmacokinetics of melatonin in human sexual maturation.

To determine whether melatonin pharmacokinetics change during puberty, we infused melatonin iv in 9 prepubertal, 8 pubertal, and 16 adult subjects and measured melatonin in serum and saliva, and 6-hydroxymelatonin sulfate in urine. A pilot study of 3 adult males showed dose linearity, absence of saturation kinetics, and unaltered metabolism and urinary excretion for doses of 0.1, 0.5, and 5.0 micrograms/kg. All other subjects received 0.5 microgram/kg melatonin. The results of pharmacokinetic parameters calculated from serum melatonin showed no significant gender differences in adults. However, developmental differences were significant between prepubertal children and adults for terminal elimination rate constant (1.08 +/- 0.25 vs. 0.89 +/- 0.11 h-1), elimination half-life (0.67 +/- 0.12 vs. 0.79 +/- 0.10 h), and area under the concentration-time curve (250.9 +/- 91.8 vs. 376.9 +/- 154.3 (pg/mL).h, respectively). At all time points melatonin levels were higher in serum than in saliva, and the ratio between serum and salivary melatonin varied up to 55-fold within and between individuals. Results based on salivary melatonin showed significant differences between prepubertal children and adults for the terminal elimination rate constant (1.90 +/- 0.95 vs. 1.06 +/- 0.28 h-1). The described group differences in pharmacokinetic parameters suggest that prepubertal children metabolize melatonin faster than adults. The inconsistent ratio between serum and salivary melatonin calls for caution in the use of salivary melatonin for pharmacokinetic studies or to infer pineal function. The present findings, suggestive of faster melatonin metabolism in prepubertal children, combined with the known decline of serum melatonin with age and higher excretion rate of the metabolite in prepubertal children lead us to conclude that the prepubertal pineal gland has a higher melatonin secretion rate than the adult gland.

Adolescent↗
PubMed1996

Sleep, breathing, and cephalometrics in older children and young adults. Part I -- Normative values.

STUDY OBJECTIVES: Aims were (1) to provide normative values for sleep and sleep-related breathing variables and physical features (cephalometrics, body mass index [BMI], and tonsillar size) in older children/adolescents and young adults, (2) to describe sex and age group differences, and (3) to evaluate relationships between physical features and sleep-related breathing variables. DESIGN: Standard polysomnographic variables describing sleep and breathing were measured during a single night. Cephalometric measures were obtained from a standing lateral skull radiograph. SUBJECTS: Normal, healthy boys (n=23; mean age=13.3+/-2.1 years), girls (n=22; mean age =13.8+/-1.8 years), men (n=23; mean age=22.2+/-1.5 years), and women (n=24; mean age=22.4+/-1.8 years) with BMI less than 27 were evaluated. RESULTS: Sleep variables showed age group and sex differences consistent with published norms. Slow-wave sleep and rapid eye movement (REM) latency declined with age; transient arousals increased with age. Sleep-related breathing variables showed few changes related to age group or sex; small but statistically significant sex differences were found for arterial oxygen saturation nadir (lower in male subjects) and respiration disturbance index in non-REM sleep (greater in male subjects). Differences in cephalometric measures largely reflected normal growth and expected sex differences. No significant relationships between sleep-related breathing variables and physical findings were observed. CONCLUSIONS: These data provide well-controlled normative values for sleep, breathing, and cephalometrics in a group of normal older children, adolescents, and young adults. The data provide useful reference points for patients of these ages in whom sleep apnea is suspected, particularly since such clinical studies are normally based on first-night polysomnography. Furthermore, these values represent developmentally appropriate grouping of the data.

Adolescent↗
PubMed1996

High resolution sonography of the flexor tendons in trigger fingers.

A sonographic study was conducted to analyze changes of the flexor tendons in patients with trigger fingers. We evaluated thickness and echotexture of the flexor tendons of the fingers in 54 patients with 66 symptomatic digits using 10 and 13 MHz "small parts" transducers; the results were compared with those observed in 20 normal controls. Images were obtained on the volar surface of the hand, at the head of metacarpals, and at the base of first phalanx, where the first annular pulley of the digital canal is located and where the changes occurring during passive assisted extension of the fingers were evaluated. Normal tendons were 2.9 to 4.4 mm thick (mean, 3.71 +/- 0.46) and had fibrillar echotexture. Patients had tendons ranging from 3.8 to 6.7 mm (mean, 5.41 +/- 0.94); the difference from controls was highly significant (P < 0.001). A cyst was attached on the volar surface of the involved tendons in 15 cases. Diffuse thickening of the synovial sheath was present in 20 tendons, whereas 17 tendons had irregular internal echotexture. Extension movements caused changes in shape of both cysts and peritendinous envelopes. In conclusion, sonography seems able to identify a variety of pathologic changes affecting tendons in these patients and may help both to explain the pathophysiology of their clinical situation and guide therapeutic decisions.

Adolescent↗
PubMed1995

A simplified gonadotrophin-releasing hormone test for precocious puberty.

BACKGROUND AND OBJECTIVE: The gonadotrophin-releasing hormone (GnRH) test is important for the evaluation of children with disorders of puberty. Traditionally, the test determines the peak LH and the peak FSH responses from 5 to 8 blood samples, which makes it cumbersome and costly. We suspected that the test could be simplified to require fewer hormonal measurements. DESIGN: A retrospective clinical study. PATIENTS: Subjects were 44 girls and 7 boys with signs of precocious puberty, of whom 39 were diagnosed as definite central precocious puberty. Fifty-five diagnostic tests and 39 tests for suppression during GnRH-analogue treatment were reviewed. MEASUREMENTS: LH and FSH were measured in serum samples obtained during a standard GnRH test. PARAMETERS: LH and FSH responses and the LH:FSH ratio at 30, 45 and 60 minutes, and the respective peak levels. For each parameter, the sensitivities and specificities were estimated and the receiver operating characteristic curve was constructed. RESULTS: The receiver operating characteristic curves for the LH responses at 30, 45 and 60 minutes and peak, were similar and showed high specificities and sensitivities for the diagnosis of central precocious puberty. A single LH cut-off (15 IU/I) had diagnostic sensitivity > 90% and specificity > 80% for LH concentrations at 30, 45 or 60 minutes and peak, and sensitivity > 90% to detect suppression. Calculations of the LH:FSH ratio did not improve the diagnostic accuracy of the GnRH test achieved by LH alone. CONCLUSIONS: A single LH determination 30 minutes after GnRH administration is as useful as the peak LH; FSH measurements are unnecessary for the differential diagnosis of central precocious puberty. We propose that for the diagnosis of central precocious puberty and for treatment monitoring, the GnRH test to be simplified to LH measurement in a single blood sample at 30 minutes.

Child↗
PubMed1995

Island flaps including the Bezier type in the treatment of malignant melanoma.

Despite the trend in current surgical practice in the treatment on melanoma to produce smaller excisional defects, any technique which can introduce a surgical closure that does not require split skin grafting must be of benefit. This paper introduces and illustrates a range of island flap techniques that employ no skin grafting for the treatment of malignant melanoma defects. The new cutaneous island flap described, termed the Bezier or the French Curve, employs a double V-Y appositional closure method, thus giving a more refined reconstructive result that fits into the line of the body curves aesthetically. The design of the Bezier flap is almost identical in size and shape to the excisional defect, with a facial or muscular base for vascular support. Appropriate guidelines that determine the design and application of this island flap technique are listed. They are illustrated both diagrammatically and clinically. Other flaps illustrated include fasciocutaneous island flaps and myocutaneous island flaps that use a single V-Y flap appositional closure technique. All these flaps were designed with special reference to the dermatomes, which act as an aid memoire upon which the flaps are marked.

Adolescent↗
PubMed1995

Stability of melatonin in aqueous solution.

Melatonin solutions are frequently used in human, animal, and in vitro research. Generally, fresh solutions are prepared, for fear of instability of melatonin in solution. We tested the high-performance liquid chromatography (HPLC) stability of melatonin in aqueous solutions stored room temperature, 4 degrees C, and -70 degrees C for up to 6 months. Solutions were prepared in a laminar flow hood using sterile technique, directly into sterile, pyrogen-free glass vacuum vials for storage. Different concentrations were tested (1.0-113.0 micrograms/ml). There was no loss of potency as assessed by HPLC, and the preparations remained sterile and pyrogen-free. We conclude that melatonin solutions may be prepared in batches maintained in sterile, pyrogen-free vials at 4 degrees C or at -70 degrees C until use within 6 months. This method will save on research time used for preparation of fresh solutions and will reduce the number of dose validation tests for each new experiment.

Chromatography, High Pressure Liquid↗
PubMed1995

[Magnetic resonance in the assessment of perianal fistula].

This study was aimed at investigating the effectiveness of Magnetic Resonance Imaging (MRI) in the diagnosis of perianal fistulas, by comparing imaging findings with those provided by rectal examination (RE) or surgery. The present data refer to 20 patients with anorectal fistulas in whom 24 main fistulous tracks were found. The fistulas were classified according to Parks and Kennedy's criteria, based on their relationship to the sphincters. In the 15 surgical patients, 15 of 17 fistulas were correctly identified by MRI (88.2%). In one case the submucous path of the fistula was missed, while another patient was misdiagnosed as having an intersphincter fistula which turned out to be a transphincter one at surgery. In the 5 non-surgical patients, only 4 of 7 MR-detected tracks were identified at RE. An intersphincter fistula was missed on rectal examination but demonstrated by both MRI and endoscopy. A suprasphincter track in a patient who was initially asymptomatic and thereafter developed a perianal abscess, was missed at clinics but became apparent on MR images. In one case anorectal examination underestimated the extent of the fistulous track, which was thought to be low while MRI demonstrated it to be high. Twelve abscesses were seen on MR images, all of them classified at surgery. One posterior pararectal suppurative collection in a non-surgical patient was apparent only at MRI. In our experience, in agreement with the latest literature reports, MRI has proved to be a very reliable method in the assessment of anorectal inflammatory diseases. We believe that MRI may play a valuable role in the preoperative assessment of the complex conditions causing a high risk of recurrence or anal incontinence as a result of inadequate treatment.

Adult↗
PubMed1995

[Mediastinal Castleman's disease].

Castleman's disease(CD) is an uncommon lymph node syndrome, generally located in mediastinum side, rarely systemic. Two histhologic types are described: the more common, termed the hyaline-vascular type, generally asymptomatic, and the second termed plasma cell type, with systemic manifestations of the disease, like fever, anemia and weight loss. The authors present a case of a young man with Castleman's disease, treated by prednisone without reduction of the adenopathy, and thus successfully operated, and discuss about aetiopathogenic theories and treatment of this disease.

Adult↗
PubMed1994

The use of computed radon entry rates to understand radon concentration in buildings.

The central role played by basement depressurization in drawing radon-contaminated soil gas into a structure has been demonstrated by calculating the radon entry rate from radon concentration and air infiltration measurements at different levels of basement depressurization in a single-family research house. The radon entry rate is found to be a linear function of basement depressurization in this house which indicates that the flow of soil gas into the structure is laminar. The radon entry rates calculated before and after using a mitigation procedure is shown to provide a better measure of the mitigation efficacy than the standard before and after mitigation radon measurements in a research house. In addition, an analysis of the possible flow characteristics of soil gas and uncontaminated air into a basement indicates that any attempt to predict long-term average radon exposure from short-term screening measurements will only be possible under severely restricted conditions.

Air Pollution, Indoor↗
PubMed1994

LHRH test in the assessment of puberty in normal children.

We compared the performance of a sensitive immunoradiometric assay for luteinizing hormone (LH) with a standard radioimmunoassay and assessed the utility of a single LH determination after a standard dose of LH-releasing hormone (LHRH) in distinguishing pubertal from prepubertal state. Nocturnal integrated LH concentration and LH response to a standard LHRH test were assessed in 56 normal children aged 6-17 years. For each assay we examined sensitivities at fixed specificities and areas under the receiver-operator characteristic curves. The results show that: (1) the immunoradiometric assay exhibits better test performance; (2) a single blood sample 30, 45, or 60 min after LHRH administration is as useful to distinguish pubertal from prepubertal state in normal children as the peak LH estimated by multiple blood sampling, and (3) a single cutoff level for IRMA LH can be applied to these time points.

Adolescent↗