Influence of sulfur and Mn/S ratio on the hot ductility of steels during continuous casting

The influence of S and (Mn/S) on the crack susceptibility of continuous casting steels was studied. It is theoretically demonstrated that there is a critical value of the (Mn/S) ratio, (Mn/S)_c, under which a high susceptibility to cracking, during casting or deformation of as-cast material, is expected. The value of (Mn/S)_c increases as the S content of the steel decreases. Based on literature data and results from rolling continuous casting billets the following experimental equation has been found: (Mn/S)_c = 1.345 · S^?0.7934. A high similarity between this experimental equation and the theoretical one is achieved. A comparison between the equation found and previous expressions from literature was carried out. The MSC index as the ratio between the (Mn/S) ratio of a steel and the corresponding critical one was defined. The MSC index is a useful tool for the analysis of experimental results from literature.     

A homozygous mutation in the luteinizing hormone receptor causes partial Leydig cell hypoplasia: correlation between receptor activity and phenotype

Leydig cell hypoplasia (LCH) is characterized by a decreased response of the Leydig cells to LH. As a result, patients with this syndrome display aberrant male development ranging from complete pseudohermaphroditism to males with micropenis but with otherwise normal sex characteristics. We have evaluated three brothers with a mild form of LCH. Analysis of their LH receptor (LHR) gene revealed a homozygous missense mutation resulting in a substitution of a lysine residue for a isoleucine residue at position 625 of the receptor. In vitro analysis of this mutant LHR, LHR(I625K), in HEK293 cells indicated that the signaling efficiency was significantly impaired, which explains the partial phenotype. We have compared this mutant LHR to two other mutant LHRs, LHR(A593P) and LHR(S616Y), identified in a complete and partial LCH patient, respectively. Although the ligand-binding affinity for all three mutant receptors was normal, the hormonal response of LHR(A593P) was completely absent and that of LHR(S616Y) and LHR(I625K) was severely impaired. Low cell surface expression explained the reduced response of LHR(S616Y), while for LHR(I625K) this diminished response was due to a combination of low cell surface expression and decreased coupling efficiency. For LHR(A593P), the absence of a reduced response resulted from both poor cell surface expression and a complete deficiency in coupling. Our experiments further show a clear correlation between the severity of the clinical phenotype of patients and overall receptor signal capacity, which is a combination of cell surface expression and coupling efficiency.     

Thromboembolic events in beta thalassemia major: an Italian multicenter study

Oxidation of cholesterol (1a) or pregnenolone (1b) with pyridinium dichromate (PDC) in dimethylformamide (DMF) or in dichloromethane (DCM) and pyridinium chlorochromate (PCC) in DCM provided cholest-4-en-3,6-dione (2a) or pregn-4-en-3,6,20-trione (2b). TLC monitoration of the reactions implied that cholest-5-en-3-one (3a) or pregn-5-en-3,20-dione (3b) and cholest-4-en-3-one (4a) or pregn-4-en-3,20-dione (4b) might be intermediates. Individual oxidation of 3a or 3b with PDC and PCC could give 2a or 2b, but 4a or 4b remained unchanged. Further investigation indicated that 4a or 4b was an isomerization product of 3a or 3b on silica gel TLC plate rather than really existence in the reaction mixture. These results shown steroidal 5-en-3-ones were intermediates of the transformation of steroidal 5-en-3 beta-ols to steroidal 4-en-3,6-diones oxidized by PDC and PCC.     

Research of non-specific hyperreactivity of upper airways in subjects with gastro-esophageal reflux (G.E.R.): preliminary reports

An association between asthma and gastro-esophageal reflux (GER) is well recognized but the underlying mechanism is still unclear. The authors suggest that could exist an association between GER and upper airways hyperreactivity and this association could represents the mechanism underlying the lower esophageal sphincter releasing, that determine the reflux. In fact they suppose that, the noxious injury of acid reflux follows a course that could be: pharynx-->larynx-->bronchi-->1/3 inferior of the esophagus-->reflux. From these presuppositions the authors carried out a study on the possible relationship between GER and non-specific hyperreactivity of upper airways on 14 subjects, divided in 2 groups: 10 subjects with functional GER, 4 subjects suffering from GER caused by hiatus hernia as control group. All patients had a thorough medical history, ENT examination with rigid and flexible endoscope, anterior Rhinomanometry (RRM), skin-test for inhalant and alimentary allergens, RAST, audiometric exam, non-specific nasal provocation test (NSNPT) with histamine, using as control the number of sneezes. From a through analysis of objective examination and from the results of the NSNPT with histamine resulted that all subjects with functional GER were rhinopathics. In all tests both in vivo (Skin-test) and in vitro(RAST) for the most common allergens (pollens-inhalant-mycophites-alimentary) the results were negative. The authors also found an involvement of paranasal sinuses that raised: 91% in the patients with recurrents phlogosis due to non specific nasal hyperreactivity; 40.9% in the allergic subjects (20% in the Graminacee +; 32% in the Parietaria O. +; 76% in the Dermatophagoides Pt. +; others 4%); 100% in the ASA-intolerance subjects. The NSNSPT with histamine showed in the group with functional GER a hyperreactivity with sneezes in 6/10 subjects, and 1/4 subjects of the group with GER with hiatus hernia. The RRM variations showed an unilateral nasal hyperreactivity in 6/10, bilateral in 3/10 subjects of the group with functional GER. In the group with GER with hiatus hernia only 1/4 subject showed reliable unilateral RRM variation. From the analysis of data resulted that subjects with functional GER showed a completely involvement of the upper airways and not only of the pharynx and larynx, caused by non specific hyperreactivity at the NSNPT with histamine, associated with a chronic pathology.     

Carcinosarcoma of the gallbladder]

The authors analyse and comment on a case of carcinosarcoma of the gallbladder which they have recently observed. Given the rarity of this form of cancer, it is interesting to note that this case presents some peculiar aspects which have not been recorded in the few cases previously published on the subject. The peculiarities are such that they require a revision of what have until now been considered as intrinsic characteristics in the clinical observation of this kind of cancer. The authors maintain that the peculiarities of this case concern: a) the clinic onset of the illness and the relative aspecific symptomatology: b) that fact that laboratory tests did not signal any biochemical alteration; c) that the instrumental investigation's results pointed toward a non neoplastic pathology; d) that even the intra-operatory examination did not reveal any suspicious element; and last but by no means least the good survival of the patient which is definitely superior to other cases already reported in literature. The neoplasia, which manifested itself through a hemorrhage in the gallbladder, represented in fact the very initial stage of the illness, a condition rarely observed.     

Somatic mutations of the ret protooncogene in sporadic medullary thyroid carcinoma are not restricted to exon 16 and are associated with tumor recurrence

Germline point mutations in exons 10, 11, and 16 of the ret protooncogene have been identified as causative in multiple endocrine neoplasia type 2 and in familial medullary thyroid carcinoma (MTC). Somatic point mutations of the same gene, exclusively associated with codon 918 of exon 16, have also been reported in few cases of sporadic medullary thyroid carcinoma. We analyzed the blood and tumor DNA of 19 patients with sporadic MTC and 6 patients with primary parathyroid adenoma for point mutations at exons 10, 11, and 16 of the ret protooncogene by restriction analysis of the PCR-amplified product and by sequence analysis of exons 10 and 11. A Cys634-->Tyr mutation was found in both the tumoral and blood DNA of one patient, indicating that he was affected by an hereditary form of MTC, erroneously considered sporadic. In the other 18 patients with MTC, somatic point mutations of ret were found in 8 cases (44.4%). In 5 cases the mutation affected exon 16 (Met918-->Thr), and in 3 cases it affected exon 11 (Cys634-->Arg in 1 and Cys634-->Trp in 2); these 3 mutations were confirmed by sequence analysis. The remaining 10 patients had no mutation in exon 10 by either restriction analysis or sequence analysis. Clinical data showed that 75% of the patients whose tumor carried ret mutation had tumor recurrence and/or increased serum calcitonin concentrations during the postsurgical follow-up period as opposed to 10% of the patients without mutations (P < 0.02, by chi2 analysis). No ret mutation was found in the tumoral DNA from parathyroid adenomas. Our findings indicate that the somatic ret point mutation frequently found in sporadic MTC may affect not only exon 16 but also exon 11 and is associated with less favorable clinical outcome.     

Understanding shoulder arthroplasty

This article discusses the vital role of the professional nurse when caring for patients who have shoulder replacement surgery. The indications for surgery, recent advances in the surgical procedure, postoperative management, and potential complications are reviewed.