Thermal stabilities of lupin seed conglutin gamma protomers and tetramers

Various experimental approaches have been used in this work to assess the thermal stabilities of lupin seed conglutin gamma at two pH values, 4.5 and 7.5, at which the protein exists as a protomer and a tetramer, respectively. The patterns of thermal unfolding at the two pH values differed significantly; the tetramer aggregated and became insoluble, whereas the protomer was still soluble after thermal treatment. Also, the midpoint transition temperatures were dramatically different, being 60.3 and 75.1 degrees C for the protomer and tetramer, respectively. The behavior of conglutin gamma at neutral pH was also affected by disulfide formation/interchange, in that some unfolded protein molecules became covalently stabilized. More detailed analyses by differential scanning calorimetry and indirect fluorescence measurements, using 8-anilino-1-naphthalenesulfonic acid as a probe, confirmed the remarkable differences observed in the thermal stabilities of the two protein forms and allowed models for their unfolding patterns to be drawn.

A large 6q deletion is a common cytogenetic alteration in fibroadenomas, pre-malignant lesions, and carcinomas of the breast

To assess whether early breast lesions are the precursors of invasive carcinomas, three classes of breast lesions, namely benign tumors (including fibroadenomas), putative premalignant lesions (including cases of atypical hyperplasia), and invasive carcinomas, were compared at the cytogenetic and molecular cytogenetic levels. Genetic relatedness was clearly demonstrated by the sharing of several anomalies, among which 6q deletions outnumbered all of the other alterations detected. Indeed, deletions of the long arm of chromosome 6, most likely occurring in epithelial cells, were present in 83.9% of benign breast tumors, 64% of putative premalignant lesions, and 77.4% of analyzable carcinomas. Furthermore, the interval between 6q24 and qter appeared to be the common region of deletion in all three classes of breast lesions, whereas the minimal common region of deletion was 6q27-qter. Interestingly, the latter region was reported previously to be deleted in benign ovarian tumors and recently found to harbor a gene (SEN6) that is important for SV40-mediated immortalization of human cells.

Long-term safety of an early ACE-inhibitor treatment of patients with acute myocardial infarction: results of the 3 year follow-up period on 696 Swiss patients randomized to the ISIS-4 trial. ISIS-Switzerland Study Group

Several large scale clinical trials showed that early ACE inhibitor treatment in patients with acute myocardial infarction reduced 30-day mortality. While the short-term evidence of benefit and risks appears to be consistent among trials, scarce data are available with respect to the long-term effects of short-term treatments. This study shows that the early reduction in mortality rate observed among patients treated with captopril persists for up to 3 years. This suggests that the benefit achieved in the acute phase in not lost even after a long period of time.

[99mTc-MIBI characterization of breast microcalcifications. Correlations with scintigraphic and histopathologic findings]

INTRODUCTION

Microcalcifications which do not belong to focal lesions are a difficult diagnostic problem to solve with mammography. We investigated the yield of 99mTc-Sestamibi (MIBI) scintigraphy in the assessment of the benign or malignant nature of these lesions and compared nuclear medicine with histologic and immuno-histochemical findings.

MATERIAL AND METHODS

Twenty-seven areas of microcalcifications (0.3-5 cm in largest diameter) were considered; no solid masses or cysts were detected by mammography and sonography. The mammographic features of these microcalcifications were suggestive of malignancy in 3 cases and of benignity in 14; the diagnosis was questionable in the other 10 cases. MIBI scintigraphy was considered positive for malignancy when there was tracer uptake in the breast. Cytologic samples of all lesions were obtained with fine-needle aspiration under stereotactic guidance. Histology was performed in the 13 lesions considered malignant or dubious at mammography, independent of their cytology; histology was combined with immunohistochemical tests to assess intracellular mitochondria count and the number of vessels. The other 14 lesions, which were benign at mammography and cytology, were followed-up yearly for two years, and no change in clinical or radiological findings was demonstrated.

RESULTS

Histology diagnosed 8 ductal carcinomas (3 invasive carcinomas and 5 carcinomas in situ) and 5 benign lesions (1 sclerosing adenosis and 4 fibrocystic diseases, 3 of them associated with ductal hyperplasia). Scintigraphy was positive in 4/8 malignant lesions (3/3 invasive carcinomas, 1-3.5 cm in largest diameter; 1/5 carcinomas in situ, 5 cm in largest diameter) and negative in 4/5 benign lesions (we had one false positive in a fibrocystic disease associated with ductal hyperplasia). Tracer uptake was observed in all lesions with a high intracellular mitochondria count, except for 2 carcinomas in situ (0.3 and 0.8 cm in largest diameter, respectively); no benign or malignant lesion was well vascularized. Scintigraphy was negative also in the other 14 benign lesions with no histology.

CONCLUSIONS

99mTc-MIBI scintigraphy was able to characterize both invasive ductal carcinomas and benign lesions, which results hold even though our series was small because of the selection criteria we used. Thus, all invasive ductal carcinomas were identified and we had only one false positive (1/19) in benign lesions. In contrast, the technique was inadequate in carcinomas in situ, probably because their size and biological patterns vary greatly. Thus, scintigraphy was negative in 4/5 lesions (all < 1 cm O) and positive in only 1/5 (5 cm O). Therefore we conclude that 99mTc-MIBI scintigraphy cannot replace stereotactically-guided fine-needle aspiration in breast microcalcifications with questionable mammographic findings.

Mucinous cystic tumors of the pancreas: clinicopathological features, prognosis, and relationship to other mucinous cystic tumors

The clinicopathological features of 56 patients with mucinous cystic tumors (MCTs) of the pancreas were studied. Particular attention was paid to the prognosis of MCTs and the relationship to their ovarian, hepatic, and retroperitoneal counterparts. To distinguish MCTs from pancreatic intraductal papillary-mucinous tumors, MCTs were defined as tumors lacking communication with the duct system and containing mucin-producing epithelium, usually supported by ovarian-like stroma. All 56 tumors occurred in women (mean age 48.2 years) and were preferentially (93%) located in the body and tail of the pancreas. In accordance with the WHO classification, MCTs were divided into adenomas (n = 22), borderline tumors (n= 12), and noninvasive and invasive carcinomas (n = 22). Survival analysis revealed the extent of invasion to be the most significant prognostic factor (p<0.0001). Malignancy correlated with multilocularity and presence of papillary projections or mural nodules, loss of ovarian-like stroma, and p53 immunoreactivity. Stromal luteinization with expression of tyrosine hydroxylase, calretinin, or alpha inhibin was found in 66% of the cases. We conclude that the biologic behavior of MCTs is predictable on the basis of the extent of invasion. The similarities (i.e. gender, morphology, stromal luteinization) between pancreatic MCT and its ovarian, hepatobiliary, and retroperitoneal counterparts suggest a common pathway for their development.

Ki-ras and p53 gene mutations in pancreatic ductal carcinoma: a relationship with tumor phenotype and survival

We investigated a series of clinically well documented pancreatic ductal adenocarcinomas for the presence of molecular alterations of the p53 and Ki-ras genes and their correlations with p53 nuclear immunohistochemical expression. The results were evaluated in comparison with cellular expression, by ductal cancer cells, of gastric (PGII) and intestinal (CAR-5) antigens and with several clinicopathologic parameters such as grade, stage, size and lymph-node status. Ki-ras gene mutation at codon 12 was detected in 77.7% of cases with no relationship with tumor grade, stage, and survival of the patients. p53 gene mutations were found in 18/31 (58%) cases and p53 immunohistochemical overexpression was detected in 51/104 (49%) of cases. Both Ki-ras and p53 gene mutations were found in 13/31 (41.9%) of adenocarcinomas examined, while Ki-ras and p53 overexpression was detected in 19/45 (42.2%). A positive correlation between p53 overexpression and tumour grade was found (p0.0001) but no relationship was found between p53 overexpression, tumor stage, lymph-node status and size of the tumors. A trend toward an association of p53 overexpression with poorer survival was found in patients with pancreatic cancers of the same grade, stage or with the same immunophenotype, but the data did not reach statistical significance. The expression of gastric and intestinal antigenic markers in pancreatic adenocarcinomas and the presence of molecular abnormalities analogous to those found in gastric and colorectal cancers suggest common genetic pathways in gastrointestinal and pancreatic carcinogenesis.

Immunohistochemical localization of alpha- and betaA-subunits of inhibin/activin in human normal endocrine cells and related tumors of the digestive system

Activin A and inhibin A, first isolated from the ovary, are dimeric proteins able to modulate pituitary FSH secretion. Inhibin A is a heterodimer composed of one alpha-subunit and one betaA-subunit (alpha-betaA), while activin A is a homodimer of the betaA-subunit (betaA-betaA). Their identification in several tissues has suggested that they have numerous physiological functions, acting as either paracrine or autocrine factors. The aim of this study was to evaluate the expression of activin A and inhibin A in normal endocrine cells and in 70 endocrine tumours from different sites in the gastro-entero-pancreatic system, using specific monoclonal antibodies directed against the alpha- and betaA-subunits of inhibin/activin. Immunoreactivity for the betaA-subunit, but not for the alpha-subunit, was observed in normal G, EC, and GIP cells of the antrum and duodenum, and in pancreatic A cells. BetaA-subunit expression was observed in G cell and A cell tumours, and in a few insulinomas and ileal EC cell carcinoids. The alpha-subunit was found in rare cells in 7 of the 70 tumours and was colocalized with the betaA-subunit in only 1 tumor. Specific types of endocrine cells from the gut and pancreas appear to produce only activin A, a possible paracrine or autocrine modulator. Activin A is mainly produced by tumours derived from endocrine cells that normally express it.

Within-patient variability of hormone and cytokine concentrations in heart failure

Several studies on disease and treatment effects on neurohormones have been conducted with small numbers of patients, using one blood sample as representative of their states. The aim of this study was to assess the within-patient variability of plasma concentrations of several hormones and cytokines of recent interest, in patients with moderate heart failure and controlled stable background therapy over 3 weeks. Blood for neurohormone and cytokine assays was sampled in duplicate from 18 patients with moderate heart failure. After an initial visit, the patients were kept on stable therapy until the second blood sampling 21 +/- 3 days later. The plasma concentrations of several neurohormones (endothelin, renin, angiotensin II, aldosterone, norepinephrine) and cytokines (interleukin-6 (IL-6), interleukin-13 (IL-13), ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF) and soluble receptor type I of tumour necrosis factor-alpha, (sTNF-RI) were measured with immunochemical methods. Some cytokines (IL-13, CNTF and LIF) were not detected. Despite clinically satisfactory ACE inhibition, circulating angiotensin II and aldosterone levels were still elevated in some patients, suggesting aldosterone escape. The between-visit agreement of plasma concentrations measured in duplicate was less than 35% for all circulating factors, except renin which showed a higher variability throughout the 3-week study period.

Treatment of acute myocardial infarction today

The management of acute myocardial infarction (AMI) has undergone major changes in the last decade. Today clinical practice can be based on sound evidence derived from a large number of well-conducted, randomized, large-scale clinical trials. Because of this, Scientific Societies, such as the European Society of Cardiology, have recently produced evidence-based guidelines for the treatment of AMI. This article summarizes the up-to-date, evidence-based treatments for patients with AMI, and their limitations in terms of uncertainty and transferability to real populations.

Epidemiologic variables and outcome of 1972 young patients with acute myocardial infarction. Data from the GISSI-2 database. Investigators of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI-2)

BACKGROUND

Acute myocardial infarction in younger patients is uncommon, occurring mainly in men. The recent introduction of thrombolysis improved survival, left ventricular function, and infarct size.

OBJECTIVE

To evaluate characteristics and clinical outcome of the patients younger than 50 years randomized in the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico study. All patients received a thrombolytic treatment.

METHODS

The 11483 patients were divided into 3 age subgroups: younger than 50 years (17.2%), between 50 and 70 years (60.2%), and older than 70 years (22.6%). All relations between variables were first determined by an unadjusted analysis. An adjusted analysis was performed by multiple logistic regression models for in-hospital and 6-month mortality.

RESULTS

While older patients had a significantly higher rate of a history of hypercholesterolemia, diabetes, and hypertension, smoking and a positive family history were significantly more frequent in younger patients. Total in-hospital and 6-month mortality were significantly lower in patients younger than 50 years (2.7% and 1.2%, respectively) than in patients between 50 and 70 years old (6.9% and 2.7%) and those older than 70 years (21.1% and 8.4%). After multivariate analysis, the predictive value of age was confirmed.

CONCLUSIONS

Our findings, based on a large group of patients who received thrombolytic treatment, suggest that younger age is a significant independent indicator of a favorable prognosis after acute myocardial infarction.

Immunohistochemical localization of acidic fibroblast growth factor in normal human enterochromaffin cells and related gastrointestinal tumours

Acidic fibroblast growth factor (aFGF) is a member of the structurally related heparin-binding growth factor family. The best studied members of this family are aFGF and basic FGF (bFGF), which are potent mitogens and differentiation factors for mesoderm-derived cells, including fibroblasts. This study was designed to verify the immunohistochemical expression of aFGF in normal human endocrine cells of the gut and in related endocrine tumours. We examined normal gastrointestinal mucosa from seven different subjects and 41 gut endocrine tumours from different sites, including stomach, duodenum, and small and large intestine, using an aFGF polyclonal antibody with no cross-reactivity for bFGF. We localized aFGF in a fraction of serotonin-producing enterochromaffin (EC) cells of the normal gut, while it was absent in gastrin (G), CCK, secretion (S), somatostatin (D) and glicentin (L) cells. aFGF immunoreactivity was also expressed in serotonin producing EC cell tumours, but not in other functional types of gut endocrine neoplasms investigated, including gastric ECL cell, duodenal somatostatin and gastrin cell, and rectal L cell tumours. A positive correlation was found between expression of aFGF and the amount of tumour fibrous stroma, suggesting that aFGF may be involved in proliferation and activity of stromal fibroblasts.

Prognostic criteria in nonfunctioning pancreatic endocrine tumours

To identify prognostic subgroups among non-functioning (nonsyndromic) pancreatic endocrine tumours, a series of 61 tumours were analysed systematically for macroscopic, histopathological and immunohistochemical variables potentially predictive of malignancy. High-grade nuclear atypia, elevated mitotic rate and multifocal necrosis allowed us to separate 5 poorly differentiated carcinomas from 56 well differentiated tumours. Among the latter, 29 well-differentiated carcinomas showing gross local invasion or metastases were identified. Vascular or perineural microinvasion, Ki67 proliferative index > 2%, mitotic rate > or = 2, size > or = 4 cm, capsular penetration, nuclear atypia, lack of progesterone receptors and presence of calcitonin were among the variables correlated with malignancy. The first two were the most sensitive and specific. Their presence or absence was used in the 27 tumours lacking evidence of malignancy at the time of surgery to separate 11 cases with increased risk of malignancy (in 2 of which metastases developed during follow-up) from 16 cases with limited risk. The resulting four prognostic groups of non-functioning pancreatic endocrine tumours (limited- and increased-risk tumours, well-differentiated carcinomas and poorly differentiated carcinomas) showed distinct survival curves, which were significantly affected by vascular microinvasion, Ki67 proliferative index and metastases.

Nuclear DNA content and pathology in radically treated pancreatic carcinoma. The prognostic significance of DNA ploidy, histology and nuclear grade

BACKGROUND

Nuclear DNA content and pathology are considered to be prognostically relevant in several solid tumors, but controversial findings have emerged in pancreatic carcinoma (PC). Histopathology and DNA ploidy were each correlated with survival in radically treated PC to ascertain the hierarchy of their prognostic significance.

METHODS

DNA ploidy was assessed by flow cytometry (FC) in neoplastic tissue samples from 60 patients with PC who were followed until death. Representative neoplastic areas were obtained by microdissection from archival paraffin embedded material (excluding any carcinoma with a coefficient of variation of the G0/G1 peak higher than 8%). Histologic data and FC patterns were related to prognostic behavior using univariate multivariate statistical analysis.

RESULTS

Aneuploid cancers were detected in 39 of 60 patients. Univariate analysis showed that histologic grade, nuclear grade, and ploidy were significantly related to prognosis. On multivariate analysis, only histologic grade and DNA ploidy (diploid vs. aneuploid) were significant with significant interaction.

CONCLUSIONS

The prognostic value of pathology and ploidy was demonstrated in patients treated radically for PC. As in other tumors characterized by a short survival, the clinical usefulness of any prognostic parameters is somewhat limited. However, the significant relationship between prognosis and DNA ploidy might be of interest in a cost-benefit analysis for selecting patients in whom an attempt at radical surgical treatment or adjunctive chemotherapy may be justified.

[Time loss in the therapy of acute heart infarct]

As part of the ISIS study, the prehospitalization phase in 570 patients with acute myocardial infarction was evaluated and protocolled in 34 Swiss hospitals. The aim was to assess whether the time lapse between onset of pain symptoms and start of treatment could be shortened. It was felt that, particularly in the case of lethal cardiac arrhythmias, rapid intervention could secure reversal or controlled relief of symptoms and/or conduction disorders. The study protocol recorded the specific time lapses between onset of symptoms and notification of the physician, notification of the physician and hospital admission, and between hospital admission and therapeutic action. The longest time lapse observed was the patient's delay (57%). Delay by the patient was shortened when pain symptoms (a) occurred during daytime, (b) were preceded by symptoms in the week before the infarction, (c) occurred at work, and (d) occurred during exercise, particularly in the company of unknown persons. The longest time lapse observed in hospital was associated with the night shift. The time lost through delay in contacting a doctor, the main factor in delaying therapeutic action in acute myocardial infarction, is very difficult to influence since the target group for a public information campaign is hard to identify. On the other hand, the "door to needle" time lapse observed in hospital can be reduced by the introduction of clear-cut guidelines.

Nuclear DNA content and pathology in radically treated pancreatic carcinoma. The prognostic significance of DNA ploidy, histology and nuclear grade

BACKGROUND

Nuclear DNA content and pathology are considered to be prognostically relevant in several solid tumors, but controversial findings have emerged in pancreatic carcinoma (PC). Histopathology and DNA ploidy were each correlated with survival in radically treated PC to ascertain the hierarchy of their prognostic significance.

METHODS

DNA ploidy was assessed by flow cytometry (FC) in neoplastic tissue samples from 60 patients with PC who were followed until death. Representative neoplastic areas were obtained by microdissection from archival paraffin embedded material (excluding any carcinoma with a coefficient of variation of the G0/G1 peak higher than 8%). Histologic data and FC patterns were related to prognostic behavior using univariate multivariate statistical analysis.

RESULTS

Aneuploid cancers were detected in 39 of 60 patients. Univariate analysis showed that histologic grade, nuclear grade, and ploidy were significantly related to prognosis. On multivariate analysis, only histologic grade and DNA ploidy (diploid vs. aneuploid) were significant with significant interaction.

CONCLUSIONS

The prognostic value of pathology and ploidy was demonstrated in patients treated radically for PC. As in other tumors characterized by a short survival, the clinical usefulness of any prognostic parameters is somewhat limited. However, the significant relationship between prognosis and DNA ploidy might be of interest in a cost-benefit analysis for selecting patients in whom an attempt at radical surgical treatment or adjunctive chemotherapy may be justified.

The saccharide chain of lupin seed conglutin gamma is not responsible for the protection of the native protein from degradation by trypsin, but facilitates the refolding of the acid-treated protein to the resistant conformation

Native glycosylated and enzymically deglycosylated conglutin gamma (a lupin seed oligomeric protein) both showed an unusual resistance to tryptic degradation. The result of this treatment was that a single 40-residue peptide was cleaved from the N-terminus of conglutin gamma light subunit. Acid treatment of the two protein forms led to their substantial unfolding, as indicated by CD spectra. After this treatment, both polypeptides were completely degraded by trypsin after a few minutes of incubation. Conversely, trypsin pulse experiments run under renaturing conditions demonstrated a different refolding behaviour of the two proteins: the glycosylated form became resistant to trypsin after a 7-h renaturation, while the deglycosylated form required 42 h renaturation. These results were confirmed by CD spectra and reverse-phase HPLC analyses of the glycosylated and deglycosylated conglutin gamma forms. Therefore, it was concluded that the saccharide chain of conglutin gamma increased the rate of formation of a trypsin-resistant conformation upon refolding of the acid-treated protein, without playing any direct role in the protection of the native protein from proteolysis.

Ganglioneuroblastoma of the spinal cord

We report a case of ganglioneuroblastoma of the spinal cord in a 42-year-old man. MR examination was nonspecific, and the diagnosis was made from histologic findings. The MR picture was that of an intramedullary, mainly solid tumor with a central necrotic or cystic portion. The clinical picture and course were also nonspecific.

[Multiple heterogeneous cysts of the jaw. A clinical case]

A 23-year-old white man was referred to this Odontostomatologic Service for evaluation of palatal swelling lesion. Oral inspection showed a poor oral conditions and multiple caries. A panoramic radiograph revealed 3 mandibular and 4 maxillary radiolucent lesions. No major nor minor clinical and radiographic criteria of Gorlin's syndrome were present; furthermore clinical features and laboratory blood values, ruled out a possible association with Maroteaux-Lamy, Hunter, and Hurler' syndromes and hyperparathyroidism. The 7 radiolucent lesions were surgically enucleated and the histologic study revealed that these lesions consisted in: 1 keratocyst, 1 naso-palatine cyst, 4 radicular cysts and 1 fiber-connective tissue.

Intraductal papillary-mucinous tumours represent a distinct group of pancreatic neoplasms: an investigation of tumour cell differentiation and K-ras, p53 and c-erbB-2 abnormalities in 26 patients

Intraductal papillary growth of mucin producing hypersecreting, columnar cells characterizes a group of rare pancreatic exocrine neoplasms which we propose to call intraductal papillary-mucinous tumors (IPMT). We analysed the histopathology of 26 IPMT in relation to gastro-enteropancreatic marker expression, genetic changes and biology. Four IPMT showing only mild dysplasia were considered to be adenomas. Nine tumours displayed moderate dysplasia and were regarded as borderline. Severe dysplasia-carcinoma in situ changes were found in 13 IPMT which were therefore classified as intraductal carcinomas. Six of these carcinomas were frankly invasive and two of these had lymph node metastases. The invasive component resembled mucinous non-cystic carcinoma in all but one tumour which showed a ductal invasion pattern. Immunohistochemically, an intestinal marker type was found in most carcinomas, while gastric type differentiation prevailed among adenomas or borderline tumours. K-ras mutations (seven at codon 12 and one at codon 13) were found in 31% of IPMT (2 adenomas, 1 borderline, 5 carcinomas). Nuclear p53 overexpression was detected in 31% of IPMT (6 carcinomas and 2 borderline IPMT) and correlated with p53 mutations (one at exon 8 and the other at exon 5) in two carcinomas. p53 abnormalities were unrelated to K-ras mutation. c-erbB-2 overexpression was observed in 65% of IPMT, with various grades of dysplasia. Twenty-two of 24 patients are alive and well after a mean post-operative follow-up of 41 months. Only two patients, both with invasive cancer at the time of surgery, died of tumour disease. It is concluded that pancreatic IPMT encompass neoplasms which, in general, have a favorable prognosis, but are heterogeneous in regard to grade of dysplasia and marker expression. Adenoma, borderline tumour, intraductal carcinoma and invasive carcinoma can be differentiated. p53 changes but not K-ras mutation or c-erbB-2 overexpression are related to the grade of malignancy. Most IPMT differ in histological structure, marker expression and behaviour from ductal adenocarcinoma.

K-ras and p53 gene mutations in pancreatic cancer: ductal and nonductal tumors progress through different genetic lesions

We studied K-ras and p53 gene mutations in a panel of 57 primary pancreatic cancers including ductal and nonductal tumors. DNAs were obtained from formalin-fixed, paraffin-embedded material. Target sequences were amplified by polymerase chain reaction and analyzed by denaturing gradient gel electrophoresis and sequencing. Both K-ras and p53 genes were frequently mutated in ductal cancers (25 of 35, 71.4%; 18 of 35, 51.4%, respectively). K-ras mutations were confined to the second position of codon 12 where base transitions and transversions were equally observed. p53 changes were mainly missense mutations. Transitions and transversions were found equally with a prevalence of G:C-->A:T changes among transitions. No gene alterations were present in the 6 exocrine nonductal tumors and (with one exception) in the 12 endocrine tumors analyzed. Our results indicate that mutated K-ras and p53 genes can cooperate in the establishment of ductal pancreatic cancers, whereas other genetic events have to be present in nonductal tumors. Moreover, K-ras alterations may represent an early event in ductal tumorigenesis, as suggested both by the high gene mutation frequency and by the presence of mutations in low-grade tumors. On the contrary, p53 gene changes seem to represent an event required for the malignancy progression of ductal tumors from lower to higher grades.

Diffuse leptomeningeal melanomatosis of the spinal cord: a case report

A rare case of diffuse leptomeningeal melanosis presenting with symptoms of spinal cord compression due to the presence of anterolateral arachnoid cyst and treated with Spetzler's drainage system is reported. The diagnosis of diffuse melanosis of the leptomeninges is rarely possible during life. In the present case MRI was of great help in the definition of the limits of the pathological process and the presence of the anterior compressing cyst. After laminectomy and a biopsy of the pathological tissue which achieved the histological diagnosis, an external drainage was inserted to reduce the cyst extension and to exclude the presence of melanocytes in the cystic fluid before a peritoneal shunt was placed. At 8th month of follow-up the patient is doing well with a dramatic reduction of symptoms and a significant reduction of spinal cord compression. The diagnostic role of MRI and the relationship between leptomeningeal melanosis and arachnoid cyst are discussed.

Determinants of left ventricular function before and after regression of myocardial hypertrophy in hypertension

Using digitized M-mode echocardiograms, we evaluated the determinants of left ventricular (LV) systolic and diastolic function in 30 hypertensives with LV hypertrophy (LV mass > 230 g and normal LV diastolic diameter), before (LV mass 319 +/- 26 g) and after normalization of LV mass (196 +/- 21 g) by antihypertensive treatment with angiotensin converting enzyme inhibitors. As a control group we selected 50 normal subjects. Using multiple regression analysis we studied the relative role of preload (LV end-diastolic diameter), afterload (end-systolic wall stress), inotropic state (systolic pressure/end-systolic LV diameter ratio), and LV mass on LV systolic (peak shortening rate of LV diameter) and diastolic function (peak lengthening rate of LV diameter). The major determinant of systolic function was the end-systolic stress in hypertensives before treatment and the systolic pressure/end-systolic LV diameter ratio in normals and in hypertensives after treatment. The major determinant of diastolic function was LV mass in hypertensives before treatment and end-systolic stress in normals and in hypertensives after normalization of LV mass by treatment. Preload seems not to influence LV function in normals and in hypertensives with normal LV diameter. The inotropic state is the major determinant of systolic function in normals and in hypertensives after treatment, whereas this role is played by afterload in hypertensives before treatment. The diastolic function is primarily influenced by after-load in normals and in hypertensives after regression of myocardial hypertrophy, whereas in hypertensives with myocardial hypertrophy LV mass is the major determinant of diastolic function.

Low doses of scopolamine increase cardiac vagal tone in the acute phase of myocardial infarction

BACKGROUND

Reduced cardiac vagal tone in patients with myocardial infarction (MI) is associated with a high risk of sudden death. Muscarinic blocking agents in small doses induce a paradoxical increase in cardiac vagal activity in normal subjects. We tested whether low doses of scopolamine delivered transdermally enhance tonic and reflex cardiac vagal activity in patients in the acute phase of MI.

METHODS AND RESULTS

Patients were randomized to a scopolamine (n = 17) or a placebo patch (n = 19) in a double-blind fashion 4.20 +/- 0.18 days after acute MI. Cardiac vagal activity was assessed by testing the arterial baroreflex sensitivity (BRS) using the phenylephrine method and by power spectral analysis of the RR interval variability. Twenty-four hours after scopolamine, we found a significant increase in BRS (from 7.05 +/- 1.21 to 13.99 +/- 2.33 ms/mm Hg, P < .05) and in RR variability, expressed as the mean standard deviation of 512 normal consecutive RR intervals (from 18.09 +/- 2.64 to 31.16 +/- 4.16 milliseconds, P < .05). The amplitude of respiratory sinus arrhythmia, measured by the absolute power of the high-frequency spectral component, was also enhanced (from 62.55 +/- 21.49 to 305.33 +/- 95.68 milliseconds squared, P < .05), whereas the power in the low-frequency spectral component of the RR variability, which results from the interaction between cardiac sympathetic and vagal activity, did not change significantly (from 73.12 +/- 24.44 to 126.46 +/- 44.29 milliseconds squared, P = .93).

CONCLUSIONS

In patients in the acute phase of MI, low doses of scopolamine cause a sustained increase in cardiac vagal tone and improve the autonomic indices associated with mortality.