Decreased HDL cholesterol in subclinical hypothyroidism: the effect of L-thyroxine therapy

Thyroid function and lipid tests were measured in 29 premenopausal women with subclinical hypothyroidism. This group was compared with 41 euthyroid women matched for age and metabolic parameters. In basal condition there was no difference in thyroid hormone levels between the two groups except for TSH concentration (P less than 0.01). Total cholesterol, triglycerides and apolipoprotein (apo A1, A2, B) of women with subclinical hypothyroidism were not different from controls. HDL cholesterol was significantly decreased in subclinical hypothyroidism compared to the controls (P less than 0.01). With thyroxine therapy, normalization of serum TSH was associated with (1) no significant change in total cholesterol and triglycerides, (2) an increase of HDL cholesterol (P less than 0.01) and apoprotein A1 (P less than 0.05) levels. Total cholesterol/HDL cholesterol ratio was increased in subclinical hypothyroidism (P less than 0.01). During L-thyroxine therapy this ratio returned to normal value. Decreased HDL cholesterol concentration might cause coronary heart disease reported in women with subclinical hypothyroidism.     

Regulation of the enzymatic function of the lymphocyte-specific tyrosine protein kinase p56lck by the non-catalytic SH2 and SH3 domains.

The enzymatic activity of the lymphocyte-specific tyrosine protein kinase p56lck appears to be tightly regulated by phosphorylation of the conserved carboxy-terminal tyrosine residue 505. Indeed, substitution of this tyrosine residue by a non-phosphorylatable phenylalanine results in a constitutively activated version of p56lck that can transform rodent fibroblasts. In this report, we evaluate the functions of the conserved non-catalytic Src homology (SH) domains 2 and 3 of p56lck in the regulation of its enzymatic activity in NIH3T3 fibroblasts. We found that deletion of the SH2 or, to a lesser extent, the SH3 domain of p56lck resulted in an increase in the tyrosine protein kinase activity of wild-type Lck polypeptides. The SH2 domain (but not the SH3 domain) was also required for full oncogenic transformation by Lck molecules activated through removal of tyrosine 505. This effect did not appear to be the result of a diminution of the enhanced catalytic activity of F505 Lck polypeptides. However, it may relate to the findings that the SH2 domain can bind and possibly enhance phosphorylation of specific phosphotyrosine-containing proteins. Taken together, these observations imply roles for the non-catalytic SH2 and SH3 domains in the regulation of the catalytic activity of p56lck. They suggest that the enzymatic function of this Src-related polypeptide is physiologically repressed by processes dependent on the presence of the SH2 and SH3 sequences. Moreover, they indicate that the SH2 domain also plays a positive role in the function of activated p56lck molecules in NIH3T3 cells.     

Vertebral hemangiomas presenting with neurologic symptoms

Six cases of spinal hemangiomas with neurologic symptoms are reported. In three of them the diagnosis was obtained before surgery using plain x-rays and spinal computed tomography scan or biopsy. In the other cases the diagnosis was not done before surgery. In two cases preoperative embolization had minimized blood loss during surgery. Laminectomy was performed in three cases. Large removal and/or vertebrectomy was carried out in the other cases. Our results and a review of the literature about the investigations and treatment of vertebral hemangiomas led us to propose a stereotypical management of spinal hemangiomas with neurologic symptoms.     

Immunohistochemical localization of a beta-galactoside-binding lectin in rat central nervous system. I. Light- and electron-microscopical studies on developing cerebral cortex and corpus callosum

From a lectin isolated from human brain (HBL-14), that specifically binds beta-galactosides, a polyclonal antiserum was raised that also recognizes a similar rat brain lectin (RBL-16). These antibodies allowed the immunocytochemical localization of the lectin during rat brain development by optical and electron microscopy. The presence of RBL-16, first detected at embryonic day 15, was specially increased from postnatal day 1 to 10. Its level decreased thereafter but it could still be detected in adult rat brain. The lectin, predominantly neuronal until postnatal day 13, was also present in astrocytes and perivascular cells where no developmental regulation was observed in contrast to neurons. Electron microscopy showed that the lectin was transiently expressed in the axoplasm of almost all neurons in layer I around the birth date, after which it remained inside neurons, including cell bodies and dendrites, in all examined regions. The lectin was clearly localized in postsynaptic structures. This beta-galactoside-specific lectin may be involved in synaptogenesis and neurite fasciculation as well as in intracellular traffic as discussed.     

Prevalence of Hearing Impairment and Hearing Complaints in Older Adults: A Study in General Practice

In one general practice, 660 people aged 60 years or over werescreened by means of pure tone audiometry and a specific questionnaireto assess the prevalence of hearing impairment and hearing complaints.Hearing impairment was defined as an average loss of 35 dB ormore in the 1, 2 and 4 kHz frequencies in one or both ears.In total, 37.4% (95% Cl, 33.3–41.1%) of the participantswas hearing impaired. The prevalence was higher in men (55.1%)than in women (44.9%) and clearly increased with age in bothsexes. The prevalence of hearing complaints in terms of hearingdifficulties and/or tinnitus, was 37.3% (95% Cl, 33.6–41.0%),and increased with age, especially in women. Of the subjectswith hearing impairment, 64.4% reported hearing complaints.Of the subjects without hearing impairment, 21.1% experiencedhearing complaints. This study suggests that screening olderadults with relatively simple methods, may identify a largeproportion of men and women in general practice with hearingproblems. Providing information to both patients and generalpractitioners about the possibilities of hearing improvementis a crucial step in making people become more aware of hearingproblems. This could ultimately lead to improvement of the qualityof life of older men and women with hearing problems.