Genomic analyses elucidate S-locus evolution in response to intra-specific losses of distyly in Primula vulgaris.

Distyly, a floral dimorphism that promotes outcrossing, is controlled by a hemizygous genomic region known as the S-locus. Disruptions of genes within the S-locus are responsible for the loss of distyly and the emergence of homostyly, a floral monomorphism that favors selfing. Using whole-genome resequencing data of distylous and homostylous individuals from populations of Primula vulgaris and leveraging high-quality reference genomes of Primula we tested, for the first time, predictions about the evolutionary consequences of transitions to selfing on S-genes. Our results reveal a previously undetected structural rearrangement in CYPᵀ associated with the shift to homostyly and confirm previously reported, homostyle-specific, loss-of-function mutations in the exons of the S-gene CYPᵀ. We also discovered that the promoter and intronic regions of CYPᵀ in distylous and homostylous individuals are conserved, suggesting that down-regulation of CYPᵀ via mutations in its promoter and intronic regions is not a cause of the shift to homostyly. Furthermore, we found that hemizygosity is associated with reduced genetic diversity in S-genes compared with their paralogs outside the S-locus. Additionally, the shift to homostyly lowers genetic diversity in both the S-genes and their paralogs, as expected in primarily selfing plants. Finally, we tested, for the first time, long-standing theoretical models of changes in S-locus genotypes during early stages of the transition to homostyly, supporting the assumption that two copies of the S-locus might reduce homostyle fitness.

[Computed tomography evaluation of metastasis of cutaneous melanoma]. / Valutazione con Tomografia Computerizzata delle metastasi da melanoma cutaneo.

PURPOSE: To assess the value of Computed Tomography (CT) in the diagnosis and in morphologic characterization of metastatic melanoma. MATERIALS AND METHODS: The data of total body CT of 124 consecutive patients with melanoma having a Breslow index 1 mm or a positive sentinel lymph node have been retrospectively reviewed. RESULTS: The CT scan showed loco-regional and/or distant metastases in 36 patients (39%). Ten of these (28%) had metastases only to lymph nodes, whereas 26 patients (72%) had multiple metastases. Nodal, pulmonary, brain, subcutaneous, hepatic, adrenal, bone, gastrointestinal, breast and abdominal wall metastases were detected in 80.6%, 47.2%, 25%, 25%, 16.7%, 13.9%, 11.1%, 5.6%, 5.6% and 2.8% of the patients respectively. All the patients with metastases also had a positive sentinel lymph nodes and/or symptoms of metastatic disease. CONCLUSIONS: CT fails to reveal any characteristic feature of metastatic melanoma, but it is of value in the diagnosis of loco-regional and distant metastases in III stage disease.

Small solitary pulmonary nodules: assessment of enhancement and enhancement patterns in benign and malignant tumours by high resolution computed tomography.

Our aim was to determine the accuracy of quantitative and qualitative findings of contrast-enhanced computed tomography (CT) by means of differential analysis of small uncalcified solitary pulmonary nodules and to compare the CT diagnosis with the results of transthoracic needle biopsies (TTNB). We assessed a consecutive series of 109 patients with 66 malignant or 45 benign pulmonary nodules before TTNB and surgery with contrast and high resolution computed tomography (HRCT). Pulmonary nodules were classified as small when equal to or smaller than 15 mm and large when larger than 15 mm. Diagnostic accuracy of CT qualitative evaluation was 95% for large nodules and 92% for small nodules. Specificity was 92% for small nodules, 80% for large nodules. Enhancing regular septa were observed in 28 hamartomas (80%) while except for two cases (3%), inner septa were absent or irregular in malignant tumours. TTNB accuracy was 70% for small nodules and 94% for large ones. Low-enhancing hamartomas are more frequent in Italy than in the US where the prevalence of high-enhancing granulomas in benign nodules reduces the specificity of quantitative CT analysis. We propose that certain geographic areas would benefit from enhanced-CT in place of TTNB in managing lung nodules equal to or less than 1.5 cm.

Noncalcified pulmonary hamartomas: computed tomography enhancement patterns with histologic correlation.

The objective of this study was to correlate contrast-enhanced computed tomography images of noncalcified hamartomas with histologic specimens to find specific computed tomography enhancement patterns. Over 4 years, 30 noncalcified hamartomas were surgically resected. Enhanced computed tomography images of these hamartomas were reviewed and correlated with histologic findings. Contrast-enhancing septa were present in 24 of 30 hamartomas (80%). Five hamartomas (15%) showed a nonspecific enhancement pattern. The presence of an air bronchogram was a rare finding (5%). Comparison between computed tomography images and pathologic specimens showed that areas with less enhancement corresponded to cartilagineus tissue, and enhancing septa corresponded to loose connective tissue within the cartilagineus core. The rare finding of an air bronchogram corresponded to bronchial epithelium within cartilagineus tissue.

[Assessment of complications in patients with lung transplantation with high resolution computerized tomography]. / Valutazione delle complicanze nei pazienti con trapianto polmonare mediante Tomografia Computerizzata con alta risoluzione.

INTRODUCTION: High Resolution Computed Tomography (HRCT) has been used by many authors to study the early complications of lung transplantation. Bronchoscopy, transbronchial biopsy and the clinical parameters are the tools of choice to diagnose such complications; HRCT showed excellent sensitivity (100%) and good specificity (93%) especially in detecting bronchial stenoses. We report the preliminary results of HRCT in detecting early/late complications in lung transplant recipients. MATERIAL AND METHODS: Sixteen lung transplant recipients (5 single and 11 double transplants) were examined with HRCT at the Servizio Speciale Diagnostica V of "La Sapienza" University (Rome, Italy). The CT findings were compared with the results of bronchoscopy and respiratory function tests. The patients (8 men and 8 women; age range: 18-57 years, mean: 37.5) had cystic fibrosis (9), emphysema (3), alpha-1-antitrypsin deficiency (1), idiopathic pulmonary fibrosis (2), and bronchiectasis (1). RESULTS AND DISCUSSION: During the follow-up, one patient died of pulmonary edema. CT findings were normal in 3 patients and mild pleural effusion was seen in 2. The other HRCT findings were: bronchial stenosis in 5 cases (which was bilateral in 1) and bronchial dehiscence in 1 patient; four cases of infection (1 CMV, 1 aspecific bacterial pneumonia, 1 Chlamydia psittacea and 1 Aspergillosis) and one of brochiolitis obliterans. A patient was treated for acute and one for chronic rejection. A CMV infection involved only the native lung in a patient. CT is easy to perform and a repeatable and well-tolerated tool with high sensitivity (100%) and good specificity (93%) in the early diagnosis of complications, particularly bronchial stenoses, which complications are often missed at bronchoscopy or clinically silent. CT should be always performed before bronchoscopy because it can provide valuable information for bronchoscopy targeting. CONCLUSIONS: In agreement with other authors we consider HRCT a very useful tool in the early diagnosis of the complications following lung transplantation.

The challenge of solitary pulmonary nodules: HRCT evaluation.

Both enhancement and morphologic analysis have been shown important in the HRCT study of solitary pulmonary nodules (SPNs). In our prospective study, 25 adult patients with benign (N = 8) or malignant (N = 17) SPNs were examined before and after contrast agent. We obtained three serial thin section CT scans every 60 s after the onset of the injection of contrast material. All 17 malignant nodules did enhance very significantly (P < 0.001). Benign nodules did not enhance significantly (P > 0.05). Using 20 HU as a threshold for positivity of the contrast test, our sensitivity was 100%, specificity was 74%, positive predictive value was 89.5%, negative predictive value was 100%, and accuracy was 92%; test bias was 1.118. In our opinion, HRCT evaluation of SPNs is the most widely available tool to save cost and decline in morbidity in management.

[The solitary pulmonary nodule: the preliminary results in differential diagnosis by high-resolution computed tomography with a contrast medium]. / Il nodulo polmonare solitario: risultati preliminari sulla diagnosi differenziale mediante Tomografia Computerizzata con alta risoluzione con mdc.

INTRODUCTION: High-resolution computed tomography (HRCT) with iodinated contrast material has been used by many authors to study solitary pulmonary nodules (SPNs). The degree of enhancement was correlated with the nodule malignancy. MATERIAL AND METHODS: Forty adult patients were examined, before and after contrast agent administration, with incremental dynamic CT. We selected 22 patients with SPNs (3-30 mm phi, except one with 40 mm phi). The CT numbers of the inner nodule were calculated before and 1, 2 and 3 minutes after the i.v. administration of a weight-related dose (1.5 mL/kg/min) of nonionic iodinated contrast agent. A dose of 100 mL contrast agent was used in the first 6 patients. The difference in CT numbers between unenhanced images and the images with maximum enhancement (max. attenuation) was also calculated. RESULTS: Histologic diagnoses included 4 tuberculomas, 3 hamartomas and 15 malignant tumors (9 adenocarcinomas, 5 squamous cell carcinomas and 1 non-Hodgkin lymphoma). The CT numbers (in Hounsfield units, HU) of malignant nodules ranged 12-31 HU (mean: 21.5 HU) before contrast agent administration; the "long-standing" tuberculomas ranged 11-22 HU (mean: 16.5 HU) and the hamartomas had a mean density of 10.5 HU. We excluded for the study two "fresh" tuberculomas, one of which was surrounded by a low-attenuation infiltrate (the halo sign). We selected a threshold value of 20 HU on enhanced CT images to distinguish malignant (> or = 20 HU) from benign (< or = 20 HU) nodules. All lung cancers had complete enhancement (mean density: 35.5 HU). With 20 HU as the threshold value for a positive test, sensitivity was 100%, specificity 85.7%, positive predictive value 93.8% and negative predictive value 100%; test bias was 1.067. CONCLUSION: Positron emission tomography (PET) with 2-[fluorine-18] fluoro-2-deoxy-D glucose is reported to be as accurate as enhanced HRCT, but it does not provide accurate morphological information, is not widely available and it is quite expensive: therefore, in our opinion, CT should be preferred. After examining over 100 patients, we may use our results in the decision analysis comparing surgical risk with cancer risk.

[Computed tomography in the preoperative staging of gastric cancer]. / La tomografia computerizzata nella stadiazione preoperatoria del cancro gastrico.

In gastric cancer patients, CT can demonstrate wall lesions, tumor spread to adjacent organs and metastases. Since the disease is often diagnosed in an advanced stage, some authors used CT to stage the tumor and to avoid surgery in the patients with unresectable lesions. We compared CT staging results with surgical findings in 22 gastric cancer patients. After fluid-filling and hypotonization of the stomach, CT detected gastric wall thickening in all cases. In 4 patients neoplastic nodes < 1 cm were considered as normal on CT images, while in 2 patients some nodes > 1.5 cm which had been considered as metastatic were negative at histology. Overall CT accuracy in diagnosing nodal involvement was 73%. The lack of fat plane used as the evidence of direct invasion of adjacent organs exhibited 45% overall accuracy for hepatic involvement and 82% accuracy for pancreatic involvement. Seven cases (32%) were mis-staged by CT: 4 patients (18%) were under-staged and 3 (14%) were over-staged. Since it does not always show the real extent of the disease, in the staging of gastric cancer CT is to be considered a complementary tool to surgical staging, even though it is often necessary to choose between radical or palliation surgery.

[Role of computed tomography in the follow-up of patients treated with radical surgery and reconstruction with myocutaneous flap for head and neck tumors in advanced stage]. / Ruolo della tomografia computerizzata nel follow-up di pazienti sottoposti a chirurgia radicale e ricostruzione con lembo miocutaneo per tumori della testa e del collo nello stadio avanzato.

January 1988 to April 1992, 26 patients with advanced head and neck carcinoma underwent head and neck reconstructive surgery with pectoralis major myocutaneous flap (PM-MCF). Over the same period, all cases were submitted to CT to assess the value of this technique in the follow-up. Fourteen patients relapsed (54%). Of them, 5 (36%) were positive on both clinical examination and CT; 8 cases (57%) exhibited evidence of disease on CT only and in 1 patient (7%) CT was negative and the recurrence appeared as a fistula on follow-up exams. CT was of great value in the management of the patients with advanced head and neck carcinoma treated with reconstructive surgery with PM-MCF. However, CT findings must be carefully interpreted because postoperative and postirradiation complications or anatomic alterations may mimic tumor recurrences.

[Computed tomography in the follow-up of interstitial lung disease in progressive systemic sclerosis]. / La Tomografia Computerizzata nel follow-up dell'interstiziopatia polmonare nella sclerosi sistemica progressiva.

Progressive systemic sclerosis (PSS) is a chronic multisystemic disease characterized by vascular changes, lung fibrosis and skin conditions. The lung is one of the most commonly involved organs in the patients suffering from this disease. Lung changes, along with heart involvement, represent one of the major causes of death in PSS patients. CT and high-resolution computed tomography (HRCT) scans and chest radiographs were obtained in 26 patients with PSS. The evaluation of chest films included the assessment of an average profusion score. The HRCT evaluation included pattern, extent and distribution of the disease. HRCT scans showed thickened septal lines in all patients and parallel subpleural lines in 6 patients (23%), while ground-glass opacification was seen in 2 cases (7.6%). Honeycomb pattern was observed in 8 patients (31%). Chest films showed definite interstitial opacification patterns in 8 cases only; 6 radiographs were equivocal and 12 (46%) normal. Five patients were followed 6 months to 3 years: 2 of them exhibited parallel worsening of skin conditions and of CT patterns, while X-ray findings in the chest were unchanged. In 2 cases skin and lung involvement were different (skin worsening and unchanged lung patterns, or viceversa). Finally, in 1 patient, the presence of patchy areas of air-space consolidation without air cysts on second-look was more consistent with bronchiolitis obliterans organizing pneumonia.

Specific diagnosis by CT and HRCT in six chronic lung diseases.

CT and high-resolution CT (HRCT) are both important modalities for imaging lung chronic disease, and certain features (distribution of disease in the axial plane, unilateral or bilateral disease, bronchovascular bundle thickening, septal thickening, central dot thickening, polygons, distortion of parenchyma, air-space disease, nodules) are well known to suggest specific diagnoses. In a series of 54 consecutive patients with six specific diseases (scleroderma or UIP, sarcoidosis, lymphangitic carcinomatosis, drug toxicity, lymphomas, eosinophilic granuloma), these diagnostic CT features were always present. In 50/54 cases, a histologic proof was obtained. In 36 patients with histologic confirmation of four different diseases and in six normal controls, we compared sensibility, specificity, and accuracy of chest radiography, chest CT, and HRCT and found the highest diagnostic accuracy by HRCT together with standard CT.

Computed tomography in invasive pulmonary aspergillosis.

Early recognition of invasive pulmonary aspergillosis and of other similar angiotrophic fungal pneumonias has been claimed in previous reports to be possible with computed tomography (CT) and may improve survival of immunocompromised hosts. Chest CT was performed, in the course of fungal pneumonia, in 11 leukemia patients with chemotherapy-induced neutropenia either with (n = 8) or without (n = 5) contrast enhancement. Early (n = 5), before the 7th day from the beginning of the clinical setting) chest CT always demonstrated one or more nodules or mass-like infiltrates surrounded by a halo of low attenuation. This halo was absent in middle (n = 4, after 7 days) and later (n = 4, after 15 days) CT examinations. The contrast-enhanced nodules or mass-like infiltrates showed a peripheral enhancement in 4/8 cases with a target feature (hyperdense peripheral ring and isodense central area). CT showed a non-specific enlargement of liver and spleen in 2 patients. Early chest CT should be used in the management of opportunistic pneumonias.

CT findings in fungal opportunistic pneumonias: body and brain involvement.

A population of 28 immunocompromised hosts with proved pulmonary infections by Candida species (n = 18) or angioinvasive fungal pneumonias (Aspergillus species, n = 7, Mucor species n = 2, Trichosporon capitatum n = 1) were retrospectively examined for any characteristic computed tomographic (CT) pattern. Chest CT examination in angioinvasive fungal pneumonias (AFP) showed in all cases nodules or mass-like infiltrates. The mass/nodules were surrounded by a halo of low attenuation in early scans (n = 3/10) and showed often a peripheral enhancement in 6/8 contrast-enhanced scans. CT abnormalities in AFP were confined to the chest. Of the 18 patients with Candida pneumonias, 6 showed a mixed air space-interstitial pattern, 4 a granular pattern, 6 some type of mass-like consolidation, without neither perifocal halo nor postcontrast enhancement. In two autoptically proved cases, both chest plain film and CT scans were normal (false negatives). In CT body examinations, were found in 6 cases, other sites of organ involvement by Candida species (of brain in 1/6).

[Gastric lymphomas. The role of echotomography]. / Linfomi gastrici. Ruolo dell'ecotomografia.

Even after the advent of endoscopic ultrasonography, conventional US can still be useful in the follow-up of advanced gastric lymphomas. Typical US pattern is (diffuse) hypoechoic thickening of the gastric wall. The conventional US findings, together with the barium examination, the endoscopic, histological and CT results were retrospectively (5 patients) and prospectively (5 patients) evaluated and compared of 10 patients with primary (n = 4) or secondary gastric lymphomas. Normal US gastric thickness was assessed as less than or equal to 7 mm. Four unresectable patients with secondary non-Hodgkin lymphomas underwent chemotherapy; their conventional US follow-up has been shown to correspond to CT findings and endoscopically-guided biopsies. Preliminary results show that increased echogenicity and reduced thickness in conventional US scans correspond to regression of the disease. The maximum gastric wall thickness found after chemotherapy was 10 mm, due to residual scarring.

[Nuclear magnetic resonance in pathology of the central nervous system in children]. / La risonanza magnetica nucleare nella patologia del sistema nervoso centrale in età pediatrica.

The following study aims to establish the role of MRI in investigation of the CNS in children. 300 patients are examined, 220 affected by CNS disease. The examinations were performed using SE sequence (T1-weighted images TR = 350-700 ms TE = 30-60 ms; T2-weighted images TR = 1500-2000 ms TE = 50-200 ms). In most of the patients general anesthesia or sedation was necessary. Patients are divided into groups based on pathology and the advantages and shortcomings of MRI are discussed. In conclusion, MRI should be the technique of choice in the evaluation of malformative affections, white matter and inflammatory disease; it should be complementary to CT and angiography in tumors and vascular pathology.

[Articular complications in sickle cell-thalassemia after childhood. Diagnostic problems]. / Complicanze articolari nella drepanocitosi-talassemia dopo l'età infantile. Problemi diagnostici.

The osteoarticular complications of drepanocytosis-thalassemia (DT) include: 1) bone infarction, or avascular necrosis (AVN), common at all ages; 2) acute septic arthritis and hematogenous osteomyelitis, that usually affect infants and children. Early diagnosis and treatment of the osteoarticular infectious complications is imperative, to maximize the chances of a favorable outcome, and to prevent the sequelae, ie pathological fractures, chronic osteomyelitis. Early roentgenographic features of involved areas are similar in acute osteomyelitis and in AVN--both of which cause painful bone crises, so as to make osteomyelitis (OM) a diagnostic challenge. Four cases of DT are reported. The patients, 17 to 37 years old, presented with bone infarcts. One of them (the youngest) had also multiple osteomyelitis of long bones. The 99m-Tc-MDP bone scans, performed only on the youngest patient, affected by OM, revealed increased uptake in both AVN and in OM locations, without differential diagnostic features. After a review of the literature, a diagnostic protocol is suggested, based on 99m-Tc colloid marrow scintigraphy for the early differential diagnosis between acute OM (normal or slightly-increased uptake), chronic OM (markedly increased uptake), and AVN (decreased uptake). Furthermore, MR imaging is stressed as the most promising tool, in the next future, for this kind of differential diagnosis.