Intracortical tunnels: an early sign of hyperparathyroidism in chronic uremia under periodic hemodialysis

The authors studied the hand bones in 83 uremic patients undergoing periodic hemodialytic treatment, with microfocus and magnification, valuing particularly the debated findings of cortical striation (tunnelling). In 33 cases the radiological signs have been compared with the values of plasma parathyroid hormone and a significant relationship was found between the hyperparathyroidism and the development of cortical striation. The intracortical tunnels are proposed as an important sign for the early diagnosis of renal osteodystrophy.     

Effects of hormones on development and function of lymphoid tissues: II. Delayed development of immunological capacity in pituitary dwarf mice

The present report describes the morphology of lymphoid tissues and the humoral antibody response during primary and secondary immune responses to sheep erythrocytes (SRBC) in Snell-Bagg hereditary pituitary dwarf mice. It has been found that while 19S primary response was depressed to a great extent, 7S secondary response reached practically normal levels. Histological studies of the peripheral lymphoid tissues have shown patterns of cellular depletion in nonthymus-dependent areas in dwarfs killed during primary response, while these areas appeared markedly cellular after a second antigenic stimulation.

It is suggested that the cell systems involved in antibody production during primary and secondary responses to SRBC may be separate and different. As a result, the endocrine imbalance of the dwarf mice affects only the primary response to SRBC.

     

The metabolism and imaging in live cells of the bovine prion protein in its native form or carrying single amino acid substitutions

Prion diseases are probably caused by an abnormal form of a cellular glycoprotein, the prion protein. Recent evidence suggests that the prion strain causing BSE has been transmitted to humans, thereby provoking a variant form of Creutzfeldt-Jacob disease. In this work, we analyzed the behavior of normal and malformed isoforms of the bovine PrP in transfected mammalian cell lines. Biochemical and immunocytochemical assays were complimented with imaging of live cells expressing fusion constructs between PrP and GFP. Bovine homologues of human E200K and D178N (129M) mutations were used as models of pathogenic isoforms. We show that the GFP does not impair the metabolism of native and mutant bPrPs and is thus a valid marker of PrP cellular distribution. We also show that each amino acid replacement provokes alterations in the cell sorting and processing of bPrP. These are different from those ascribed to both murine mutant homologues. However, human and bovine PrPs carrying the D178N genotype had similar cellular behavior.     

Laurdan fluorescence: a simple method to evaluate sperm plasma membrane alterations

OBJECTIVE: To determine, by a simple fluorescence method, sperm plasma membrane alterations related with changes of lipid bilayer that, together with routine semen analysis, could help to elucidate the causes of the unexplained male infertility problems. DESIGN: Pilot study. SETTING: Andrology laboratory and biochemistry institute, medical school. PATIENT(S): Men whose semen was studied for infertility problems. INTERVENTIONS(s): No therapeutic intervention was performed on patients. MAIN OUTCOME MEASURE(S): Presence of spermatozoa plasma membrane alterations evidenced by evaluation of Laurdan fluorescence Generalized Polarization (GP) and reported as a function of increasing cell concentration, spermatozoa total motility, linear speed, and vitality. RESULT(S): Reporting GP values as a function of increasing sperm cell concentration, it is evident that the samples are distributed in two distinct areas: at >32 x 10(6) cells per milliliter, mean GP value was 0.303 +/- 0.015, whereas for lower sperm cell concentrations, the mean GP was 0.365 +/- 0.026 (P<.001). These data indicate that the spermatozoa plasma membranes are characterized by liquid-crystalline phases with different ordering degree and polarity and that about 50% of samples with normal semen characteristics (> or =20 x 10(6) cells per milliliter) show high GP values. CONCLUSION(S): Laurdan fluorescence can be used as a simple method to evaluate spermatozoa plasma membrane alterations, particularly in a group of infertile men presenting normal semen parameters. In these samples, Laurdan could be used as a simple tool for infertility assessment. In fact, it is known that compositional and physicochemical alterations of bilayer features can be important for the fertilizing ability of spermatozoa because they are necessary for a proper physiological membrane activity.     

Relationship between tumour shrinkage and reduction in Ki67 expression after primary chemotherapy in human breast cancer.

The association between tumour shrinkage and reduction in kinetic cell activity after primary chemotherapy in human breast cancer is still a matter of investigation. 157 patients with T2-4, N0-1, M0 breast cancer received primary chemotherapy consisting of either the CMF regimen + tamoxifen (the first consecutive 76 cases) or the single agent epirubicin (the subsequent 81). Ki67, p53, bcl2, c-erbB2 and steroid hormone receptors were evaluated immunohistochemically in tumour specimens obtained before chemotherapy and at surgery. Tumour shrinkage of >50% occurred in 72.4% of patients. Ki67 expression significantly decreased after chemotherapy; the reduction correlated with tumour response in both univariate (P < 0.005) and multivariate analysis (P = 0.02). p53, bcl-2, steroid hormone receptor and c-erbB2 immunostaining were scarcely affected. Baseline bcl2 (P = 0.04) and c-erbB2 (P = 0.02) were directly and inversely associated with the reduction in Ki67 immunostaining, respectively. Baseline p53 expression (P < 0.01) was directly related with Ki67 expression at residual tumour, whereas oestrogen receptor expression (P < 0.001) was inversely related. Ki67 at residual tumour was a better predictor for relapse-free survival (RFS) than baseline Ki67. Clinical response (P < 0.03), but not reduction in Ki67, was a significant independent predictor for disease recurrence. Chemotherapy was found to induce tumour shrinkage and to reduce the number of cells in the cell cycle, but its effect on tumour biology/aggressiveness was minimal. Reduction in Ki67 immunostaining correlated with clinical response but failed to be related to RFS. Ki67 expression at surgery rather than at baseline appears to be a better predictor for disease relapse.