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Biomedical subjects

C Ricci

Publications and source records attributed to C Ricci.

At least 181 records · Page 10Linked to original sources
PubMed1990

Diagnostic imaging and surgical treatment of dumbbell tumors of the mediastinum.

We describe the diagnostic procedures and surgical approaches employed in 5 patients with dumbbell tumors of the mediastinum. Magnetic resonance imaging accurately described the existence and longitudinal extension of the intraspinal component of the tumor and assisted in choosing the appropriate surgical approach. Both the intrathoracic and intraspinal components of the tumor were resected at one time by a thoracic and neurosurgical team. We employed the Grillo technique three times and a separate laminectomy and thoracotomy approach. Magnetic resonance imaging proved the most useful diagnostic technique for suspected dumbbell mediastinal tumors. In our experience, the extended thoracotomy proposed by Grillo and co-workers worked well for small tumors involving only one foramen in which the intraspinal extension was limited to 2 to 3 cm, and when no more than two laminectomies were required. On the other hand, thoracotomy and a longitudinal paravertebral incision are preferable for larger tumors (more than 4 cm) involving more than one foramen in which the intraspinal extension exceeds 2 to 3 cm, for tumors requiring multiple laminectomy, and when bony infiltration is present.

Adult↗
PubMed1990

Perception of ambiguous figures after focal brain lesions.

Forty patients with unilateral frontal or posterior brain damage and 20 normal control subjects were tested on an ambiguous figures task (AFT). For each figure they were asked to recognize both ambiguous images. Subjects failing to recognize the second aspect of an ambiguous figure were prompted with the name of the image not yet perceived. The Wisconsin Card Sorting Test (WCST) was also administered to all subjects. Frontal patients exhibited greater difficulty in shifting from one aspect of an ambiguous figure to the other than did patients with more posterior lesions and control subjects. In addition, frontal-posterior and control differences were highly significant for number of prompts given. For the frontal patients, significant correlations were found between the number of prompts on the AFT and the number of perseverative errors on the WCST. Poor performance on the AFT can be considered as a "frontal lobe sign" of perceptual persevation.

Adult↗
PubMed1990

Low grade neuroendocrine tumors of the lung (bronchial carcinoids)--25 years experience.

From 1960 to 1986, 69 patients with low grade neuroendocrine tumours (LGNT) of the lung were admitted to our institution. Of these, 36 were male and 33 were female. The mean age was 43 years with a range of 9-76 years. Sixty-eight patients were operated upon of whom 11 had metastatic mediastinal lymphnodes. A complete follow-up ranging from 3 to 25 years was obtained in 61 patients. Actuarial survival was 95% at 5 years and 87% at 10 years. The most important factor influencing the prognosis was mediastinal lymph node involvement. In 9 patients with mediastinal lymph node metastases at operation, the survival at 5 and 10 years was 75% and 46%, respectively, with highly significant difference (P less than 0.0001) as compared with the nonmetastatic group. In conclusion, bronchial LGNT are generally benign, but encompass a potential for malignancy. The prognosis depends on the presence of regional lymph node metastases. The choice of adequate surgical treatment depends on the size, location and aggressiveness of the tumour and the status of the mediastinal lymph nodes. The condition of the lung parenchyma distal to the lesion must be taken into account.

Adolescent↗
PubMed1990

HBV-DNA, HBeAg/anti-HBe serological status in hepatitis B chronic individuals from central Italy.

A population of 488 HBsAg carrier individuals, from central Italy, classified on the basis of biochemical, clinical and histological parameters, was analysed for the presence of HBV-DNA in serum and its relationship with HBeAg/anti-HBe markers. The prevalence of HBV-DNA was 32.8% in chronic patients with biopsy-proven liver disease, and 20 and 4.3% respectively in asymptomatic carriers with and without altered ALT levels. The values in chronic patients were correlated with the histological activity. Concordance of HBV-DNA presence and HBeAg positivity was observed in only 61.4% of cases. However HBV-DNA prevalence in sera of anti-HBe positive individuals was very low in asymptomatic carriers with normal ALT levels (2.5%). Higher values were observed in anti-HBe positive chronic patients (15.8%) and in carriers occasionally found with changes in ALT without any other clinical sign of illness (16.7%). These data would indicate that HBV-DNA is the serological marker which is most closely related to liver disease.

Adult↗
PubMed1990

Regulation of nicotinamide-adenine dinucleotide synthesis in erythrocytes of patients with hypoxanthine-guanine phosphoribosyltransferase deficiency and a patient with phosphoribosylpyrophosphate synthetase superactivity.

1. The synthesis of nicotinamide-adenine dinucleotide from nicotinamide and nicotinic acid was compared over different time scales at both physiological (0.7 mumol/l) and high (0.2-3 mmol/l) substrate concentrations in erythrocytes from three patients with hypoxanthine-guanine phosphoribosyltransferase (hypoxanthine phosphoribosyltransferase, EC 2.4.2.8) deficiency (including one Lesch-Nyhan patient) and from one patient with phosphoribosylpyrophosphate synthetase superactivity. The above disorders are associated with grossly altered erythrocyte nicotinamide-adenine dinucleotide levels. 2. At the physiological substrate concentration and incubation times up to 2 h, nicotinamide proved the most efficient nicotinamide-adenine dinucleotide precursor for erythrocytes from both patients and control subjects. The conversion of nicotinamide to its mononucleotide, but not further metabolism, was impaired in phosphoribosylpyrophosphate synthetase-mutant cells. The Lesch-Nyhan and phosphoribosylpyrophosphate synthetase-mutant cells were unusual in that both showed no further stimulation of nucleotide synthesis at 18 mmol/l Pi compared with 1 mmol/l. 3. At the high substrate concentrations, using 18 mmol/l Pi, nicotinamide was a poor precursor in all instances. Using nicotinic acid, nucleotide formation was 30-fold that from nicotinamide, reaching its maximum at 0.2 mmol/l. Conversion of nicotinic acid to nicotinamide-adenine dinucleotide in the phosphoribosylpyrophosphate synthetase-mutant cells was again grossly impaired. 4. There was no evidence for increased nicotinamide-adenine dinucleotide breakdown in the phosphoribosylpyrophosphate synthetase-mutant cells under any of the above conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

The prognostic implication of thymoma histologic subtyping. A study of 80 consecutive cases.

In this study the authors have investigated the clinicopathologic correlations in 80 consecutive cases of thymoma in order to establish the clinical usefulness of histologic subtyping of these tumours. All cases were histologically examined and classified according to Salyer and Eggleston and to Marino and Müller-Hermelink classifications. Therefore, thymomas were subtyped as predominantly lymphocytic, mixed and predominantly epithelial and cortical, mixed and medullary, respectively. The frequency of the different histologic subtypes was determined, and histologic findings were related to patients' age, surgical stage, and survival. Through the application of Salyer and Eggleston classification, the three histologic subtypes did not correlate with patients' ages at time of diagnosis, surgical stage as determined by local infiltration, and prognosis as determined by survival curves. On the contrary, when Marino and Müller-Hermelink classification was applied, statistically significant relationships between histologic results and age, surgical stage, and prognosis were demonstrated. These results and their implications are discussed, with special reference to the important problem of histogenesis of thymomas and of their clinicopathologic staging.

Adult↗
PubMed1990

Normal age-related patterns of cellular and fatty bone marrow distribution in the axial skeleton: MR imaging study.

Knowledge of age-related distribution patterns of cellular and fatty marrow is critical to the interpretation of magnetic resonance (MR) imaging studies. To determine such patterns, the authors retrospectively evaluated 70 examinations each of the skull, cervical spine, thoracic spine, lumbar spine, pelvis, and proximal femur (420 examinations) in patients without known bone marrow abnormality who ranged in age from 6 months to older than 70 years. Two to four distinct patterns were identified in each anatomic area on spin-echo images obtained with a short repetition time and a short echo time. The relative frequency of the patterns for different age groups is consistent with the known physiologic conversion from cellular to fatty marrow with advancing age. Knowledge of these patterns should help in the interpretation of MR images of the axial skeleton.

Adult↗
PubMed1990

Lack of nocturnal serum thyrotropin surge after surgery.

The effects of surgery on TSH secretion, with particular regard to the nocturnal TSH surge, were evaluated in 10 consecutive patients followed for 6 days after surgery. Surgical trauma was associated in all patients with significant decreases in serum total and free T3 and a significant increase in serum rT3 levels, with no variations in serum total and free T4 concentrations. A marked increase in serum cortisol levels was observed, with higher values at night than in the morning. Serum cortisol levels and circadian rhythm normalized on the fifth day. Serum TSH values in the morning significantly decreased on the first day after surgery and returned to normal on the second day. Serum TSH values at night (2400-0200 h) were higher than in the morning preoperatively, but the nocturnal surge was abolished from days 1-5 after surgery and was restored only on the sixth day. Thus, surgery was associated with a prolonged loss of the nocturnal serum TSH surge. This effect on TSH secretion was more marked than predictable on the basis of serum TSH measurements in the morning alone. An inverse relationship was found between serum cortisol and serum TSH values at night, suggesting that the excessive endogenous cortisol secretion might play a role in the derangement of TSH secretion.

Adult↗
PubMed1990

Leiomyoma of the esophagus.

Leiomyoma of the esophagus was surgically treated in 15 patients in 1962-1987. Six patients were asymptomatic and nine presented with dysphagia alone or combined with retrosternal pain, vague thoracic discomfort, dyspnea and cough, or palpitations. Barium swallow and esophagoscopy provided the correct diagnosis preoperatively in most cases. Transthoracic enucleation of the tumor was performed via right thoracotomy in nine patients and left thoracotomy in six. The location of tumor was the upper third of the thoracic esophagus in three cases, middle third in six and lower third in six cases. There was no surgical mortality or morbidity. Surgical removal of esophageal leiomyoma thus gave relief of symptoms, with minimal risk and excellent functional outcome.

Adult↗
PubMed1990

Lymphocyte function response to gammaglobulin infusion in common variable and sex-linked agammaglobulinaemia.

Lymphocyte electrophoretic mobility and natural killer cytotoxic activity are marked deranged in agammaglobulinaemia. These alterations can be normalised by correction of the serum Ig pattern. This suggests that Ig activity goes beyond specific antibody activity. I.v. Ig, in fact, exert several activities that also involve T-cell regulatory functions. It would thus be more correct to speak of "immunotherapy" of humoral immunodeficiencies with i.v. Ig, rather than simple "immunosubstitution".

Adult↗
PubMed1990

[Mechanical staplers in exeresis surgery of pulmonary cancer].

Surgical stapling devices are widespread in many branches of surgery and are employed with success in thoracic surgery. Our experience is in line with that of other Authors: stapling of the bronchus is faster, does not contaminate the operative field and reduces the incidence of bronchopleural fistulas (4.76% to 1.59%). Parenchymal stapling is indicated for resection of bullae, metastases and peripheral lesions. The mechanical suture is air-tight and faster than manual suture. Pulmonary vessels may also be closed mechanically; however, we do not advocate the use of stapling devices especially in the closure of the pulmonary artery.

Aged↗
PubMed1990

[Magnetic resonance of the bone marrow].

Magnetic resonance imaging has opened new possibilities to current diagnostic radiology in the evaluation of bone marrow. In the past, bone marrow imaging was based on conventional radiology, nuclear medicine and computed tomography; they all exhibited some capabilities but also some limitations. Bone image on MR scans is due to bone marrow, with its different components of red and yellow marrow. Since red marrow is mostly liquid and yellow marrow contains large amounts of fat, the signal will vary, on T1-weighted images, according to their different proportions. There is a gradual change from red marrow to yellow marrow from birth to adulthood: this change determines the MR appearance of bone marrow, the different features of which should be known for a correct evaluation of pathologic findings. MRI is extremely effective in the evaluation of infiltrative disorders of bone marrow, such as leukemia, lymphoma, myeloma, primary and metastatic skeletal tumors, and infections. MRI allows depletive disorders of bone marrow and ischemic processes to be studied. Finally, MRI allows the non-invasive follow up of bone marrow pathologic conditions, thus representing a valid alternative to biopsy.

Bone Marrow↗
PubMed1990

Surgical approach to isolated mediastinal lymphoma.

With the aim of assessing the role of surgery in the management of isolated mediastinal lymphoma, we have reviewed the data of 123 operations performed on 102 patients (64 with Hodgkin's disease and 38 with non-Hodgkin's lymphoma). One death and four major complications occurred in these patients. Macroscopically radical resection was performed in 14 patients who are free of disease after 1 to 14 years. Debulking resection was performed in five patients: Three are alive after 5 to 11 years and two died after 36 and 40 months. Ten patients (seven with non-Hodgkin's lymphoma and three with Hodgkin's disease) had residual mediastinal masses of more than 2 cm after chemotherapy; to assess the nature of the lesion (fibrosis or residual disease), we subjected these patients to surgical restaging of the mediastinum: Results were negative in seven and positive in three. We conclude that open biopsy is indispensable to obtain good tissue specimens suitable for histologic and immunohistochemical assessment. Biopsy must be performed as a major surgical procedure to avoid reoperation: Mediastinoscopy and sternal splitting incisions proved the most reliable approaches. Locally radical or debulking resection might be considered in selected cases to enhance long-term results.

Adolescent↗
PubMed1990

Further insight into NAD synthesis in human erythrocytes: significance and relevance.

The cellular levels of NAD and its rate of synthesis from nicotinic acid (NA) were found to decrease from reticulocyte-rich fractions to mature erythrocytes separated on a density gradient. Decreased activity of NA-phosphoribosyltransferase in crude lysates was also observed from young to mature cells, while the uptake of extracellular NA did not show any difference. Impaired NAD synthesis, more likely than progressive breakdown, is suggested to cause NAD decrease during erythrocyte maturation.

Cell Survival↗
PubMed1989

Avoidance conditioning in amnesia: a single case experimental study.

We present a single case study of avoidance conditioning in a seriously amnesic patient with bilateral ischemic lesions of the brain. A four-path maze was used for conditioning. The procedure consisted in an aversive stimulus that the patient received every time he traced one of the four maze-paths connected to an electric shock generator with a stylus. Using a single case experimental design A-B-A, we found that the patient learned to avoid the path connected to the electric shock, although he never showed awareness of this. Our study confirms once again that conditioning is one of the residual learning capabilities in amnesic patients. Different neural systems are probably involved in conditioning processes.

Amnesia↗
PubMed1989

True thymic hyperplasia: a clinicopathological study.

In this report, we describe the clinicopathological features of 4 patients with true thymic hyperplasia. This controversial thymic lesion has only recently been defined as a variable, often massive enlargement of the thymus characterized by a nearly normal microscopic structure. Our study of 4 patients and review of the literature indicate that true thymic hyperplasia has a well-defined clinicopathological profile: prevalence in children or young male patients, absence of associated autoimmune diseases, and often presence of respiratory distress or peripheral blood lymphocytosis, or both. True thymic hyperplasia should be considered in the differential diagnosis of anterior mediastinal masses in children and young adolescents.

Adolescent↗