Garnet, the archetypal cubic mineral, grows tetragonal.

Garnet is the archetypal cubic mineral, occurring in a wide variety of rock types in Earth's crust and upper mantle. Owing to its prevalence, durability and compositional diversity, garnet is used to investigate a broad range of geological processes. Although birefringence is a characteristic feature of rare Ca-Fe3+ garnet and Ca-rich hydrous garnet, the optical anisotropy that has occasionally been documented in common (that is, anhydrous Ca-Fe2+-Mg-Mn) garnet is generally attributed to internal strain of the cubic structure. Here we show that common garnet with a non-cubic (tetragonal) crystal structure is much more widespread than previously thought, occurring in low-temperature, high-pressure metamorphosed basalts (blueschists) from subduction zones and in low-grade metamorphosed mudstones (phyllites and schists) from orogenic belts. Indeed, a non-cubic symmetry appears to be typical of common garnet that forms at low temperatures (<450 °C), where it has a characteristic Fe-Ca-rich composition with very low Mg contents. We propose that, in most cases, garnet does not initially grow cubic. Our discovery indicates that the crystal chemistry and thermodynamic properties of garnet at low-temperature need to be re-assessed, with potential consequences for the application of garnet as an investigative tool in a broad range of geological environments.

Association between p53 gene mutations and tobacco and alcohol exposure in laryngeal squamous cell carcinoma.

OBJECTIVES: To analyze the relationship between p53 gene mutations, tobacco smoke, and alcohol consumption in patients with laryngeal squamous cell carcinoma. DESIGN: We analyzed p53 gene mutations in exons 5 through 8 by polymerase chain reaction-single-strand conformation polymorphism analysis in a cohort of 84 patients with laryngeal squamous cell carcinoma. SETTING: University hospital. RESULTS: p53 gene mutations were detected in 24 (28.6%) cases (95% confidence interval, 19.3%-39.5%), and the GC to TA transversion (33%) was the most common type of mutation (95% confidence interval, 15.6%-55.3%). Most mutations mapped to the p53 DNA-binding domain, which is necessary for the physiological activity of p53 as a tumor suppressor. A statistically significant association was found between p53 mutations and exposure to tobacco smoke (P=.001), which was the only variable significantly associated with p53 mutations in a multivariate model. The association with alcohol consumption was only at a borderline level of significance (P=.065). CONCLUSION: Our data document that a smoking habit is the only independent variable associated with an increased risk of p53 mutations in the laryngeal mucosa.

Absence of otoacoustic emissions in insulin-dependent diabetic patients: is there evidence for diabetic cochleopathy?

In order to evaluate cochlear function in Type 1 diabetes mellitus, this study analyses otoacoustic emissions (OAEs) on normal hearing subjects with diabetes and on controls. Patients with Type 1 diabetes (n=60), with a mean age of 31+/-6.23 years, mean disease duration of 17.5+/-8.9 years, and mean HbA1c of 8.1+/-1.8%, of whom 43% had signs of retinopathy and 28% had clinical signs of neuropathy, were studied. All patients underwent an OAE analysis and brainstem-evoked potentials. Fifty-eight normal volunteers were used as controls for the OAE analysis. Seventeen patients (28.3%) had no OAEs in at least one ear and 10% in both ears. The mean intensity of the response was lower in diabetic subjects [7.1+/-4.4 vs. 10.9+/-9.3 dB SPL (sound pressure level)] than in controls. The cochlear impairment was over 5 dB for the 1-kHz frequency, which is the critical level for speech understanding. These findings suggest that cochleopathy can be detected in a relatively high proportion of subjects with Type 1 diabetes in spite of a normal audiometric hearing threshold.

Melanocytic neoplasia of the sole: diagnosis and therapeutic approach.

We examined retrospectively a series of 184 cases of melanocytic neoplasia of the sole observed and treated as out-patients from January 1977 to December 1987, comparing clinical and histological diagnoses. The original clinical diagnoses were divided into nevi, pigmented lesions of suspected malignancy, cutaneous melanomas and others. Of the 170 cases diagnosed clinically as nevus none was of melanoma. The risk that a pigmented skin lesion diagnosed as clinically benign is melanoma is so low as not to constitute a clinical problem. It is concluded that systematic removal of sole nevi is unjustified. If, however, there is the smallest doubt concerning a sole lesion, it should be removed and examined histologically.

[Medical treatment of arrhythmias in myocardial infarct. Results of the use of bunaftine]. / Terapia medica delle aritmie nell'infarto miocardico. Risultati dell'impiego della bunaftine

After a short survey of the physiopathology of arrhythmia in myocardial infarction, especially at the initial stage, the results of using bunaphthine in 21 personal cases of myocardial infarction are reported and the fully satisfactory results described. This substance is held to be an effective, useful antiarrhythmia drug which can be usefully employed in the prophylaxis of arrhythmia in myocardial infarction.

[Social importance of cardiovascular diseases]. / Importanza sociale delle malattie cardiovascolari

The continual increase in such cardiovascular diseases as rheumatic and sclerotic cardiopathy and cardiovascular syphilis over the last 30 yr is noted. The social and economic effects of these diseases is stressed and the hope is expressed that more active and effective measures will be taken by the State, especially with respect to worthwhile and radical prophylaxis.

[Atrio-ventricular and intra-ventricular conduction disorders in a case of acute cerebrovascular disease]. / Turbe della conduzione atrio-ventricolare e intra-ventricolare in un caso di cerebropatia vascolare acuta

Transient atrioventricular (1st-degree and 2nd-degree (type II) block, coronary node rhythm, dissociation) and intraventricular (left anterior hemiblock) disturbance were noted in a 67-yr-old man with acute cerebral thrombosis. It is suggested that one of more of the following factors were responsible from time to time for these unusual ECG signs: disturbance of neurovegetative regulation with predominant vagal hypertonus, circulation deficiencies in the conduction tissue due to decreased cardiac output, and histological lesion of specific tissue.