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Biomedical subjects

B Bruno

Publications and source records attributed to B Bruno.

70 records · Page 4Linked to original sources
PubMed1988

The Ins(1,4,5)P3-sensitive Ca2+ store of non-muscle cells: endoplasmic reticulum or calciosomes?

The binding of a number of extracellular ligands (hormones, growth factors, neurotransmitters etc.) to their plasma membrane receptors causes hydrolysis of phosphatidylinositol bisphosphate to initiate the formation of two second messengers, inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] and diacylglycerol, DAG. DAG has been shown to activate protein kinase C, whereas Ins(1,4,5)P3 induces the release of Ca2+ from an intracellular pool. This rapidly mobilizable, Ins(1,4,5)P3-sensitive Ca2+ store has until now been identified as the endoplasmic reticulum, ER. We demonstrate that this is untenable and provide evidence for the existence of an unrecognized organelle, the 'calciosome'. This conclusion is based on the following experimental evidence. (1) There is no correlation between the abundance of ER and the amount Ins(1,4,5)P3-sensitive Ca2+ release. (2) There is no correlation between ER markers and those for the Ca2+ store [Ins(1,4,5)P3 binding and sensitivity, Ca2+ uptake]. (3) A protein similar to striated muscle calsequestrin, CS, has been identified in microsomal fractions from a number of tissues; it copurifies with markers of the Ca2+ store, but not with those of ER. (4) Subcellular localization of the CS-like protein by electron microscopy reveals that in all cells so far analysed this protein is localized in small, membrane-enclosed structures, calciosomes, which are also stained by an anti-Ca2+-ATPase antibody. Calciosomes appear to be morphologically distinct from any other known cell organelle. (5) Although they stain different portions of the calciosomes (membrane and lumen, respectively), anti-Ca2+-ATPase and anti-CS antibodies do not recognize any antigen in ER cysternae; antibodies directed against known components of ER do not bind to calciosomes.

Animals↗
PubMed1988

Immunocytological identification of the microsomal calcium store of nonmuscle cells.

The biochemical and functional similarities between skeletal muscle sarcoplasmic reticulum and the microsomal Ca2+ store of nonmuscle cells are discussed. It is shown that antibodies raised against two characteristic proteins of sarcoplasmic reticulum, Ca2+ ATPase and calsequestrin, recognize similar proteins in nonmuscle cells. The subcellular distribution of these two antigens was studied at the subcellular levels in ultrathin cryosections. In a variety of cell types these two proteins were found to be localized in small membrane enclosed vesicles, apparently distinct from other known organelles. We propose that these newly recognized structures (calciosomes) represent the functional equivalent of sarcoplasmic reticulum in nonmuscle cells.

Animals↗
PubMed1986

Quantitative evaluation of Leydig cells in testicular biopsies of men with varicocele.

A quantitative analysis of Leydig cells was performed in 23 testicular biopsies of men with left varicocele and sperm count ranging from zero to 95,000 sperm/mm3. The oligozoospermic patients had more Leydig cells and higher FSH and LH serum levels than the patient group with more than 10,000 sperm/mm3. The Leydig cell density appeared tightly correlated (p less than 0.01) with the serum level of LH. In oligozoospermic subjects, an altered Leydig cell function could trigger an increased LH secretion; this seems likely to be responsible for the stimulation of interstitial cells resulting in an exaggerated recruitment of mature Leydig cells from their precursors. The comparative analysis of left and right testes failed to show differences in Leydig cell density and spermatogenesis in normozoospermic and oligozoospermic patients. This suggests that the two testes are equally involved by a possible, although unknown, detrimental effect of left side varicocele.

Adult↗
PubMed1986

The postnatal maturation of efferent tubules in the rat: a light and electron microscopy study.

The postnatal maturation of the epithelium and tubule wall of efferent tubules in the rat was investigated by light and transmission electron microscopy, from birth to 50 days of age, when sperms were released from the seminiferous tubules and appeared in the genital duct. At the end of the first week of life, an endocytotic apparatus is differentiated in the epithelial cells. During the third week of life, efferent tubules developed specializations for the transport of sperms and fluids, namely the appearance of ciliated elements interspersed among the principal cells of the epithelium, and differentiation of myoid elements in the tubule wall. The appearance of specializations related to endocytosis and fluid transport across the epithelium preceded the canalization of the seminiferous cords which, in fact, is reported to appear at the end of the second week of life in the rat, along with the initial secretion of testicular fluid. This suggested that the maturation of efferent tubules is not triggered by the passage of testicular fluid, as surmised for the postnatal differentiation of caput epididymis. The postnatal maturation of efferent tubules was almost complete 35 days after birth. The appearance of sperms in the genital duct of 50-day-old animals was not associated with any remarkable structural change.

Animals↗
PubMed1985

[Salivary levels of immunoglobulin and dental caries in children].

IgG, IgA, IgM and lysozyme levels were determined in whole unstimulated saliva from ten children aged seven-nine years. IgA levels were significantly higher (p less than 0.05) in caries-susceptible subjects when compared with the caries-free ones. High levels of IgG seemed to correlate with a high DMF score. No correlation was found between lysozyme levels and DMF score.

Child↗
PubMed1985

Insulin resistance and secretion in polycystic ovarian disease.

In order to verify the relationship between insulin resistance and hyperandrogenism in Polycystic ovary disease (PCOD), circulating levels of insulin in response to oral glucose tolerance test (OGTT) were assessed in 23 PCOD patients and 10 matched control subjects without obesity, acanthosis nigricans and impaired glucose tolerance. In PCOD patients serum total testosterone (T), dehydroepiandrosterone sulfate (DHEA-S), LH and LH/FSH ratio were significantly higher than in control subjects; whereas urinary 17-ketosteroids (17-KS) and glycemic response to OGTT were not different. PCOD patients were clearly hyperinsulinemic before and during OGTT compared to the control group: mean +/- SD basal insulin (Io) (23.4 +/- 10.3 vs 11.3 +/- 4.6 microU/ml, p less than 0.001) and the sums of insulin levels (sigma I) during OGTT (341.4 +/- 148.9 vs 162.2 +/- 56 microU/ml, p less than 0.001). In the two groups serum T, but not DHEA-S, LH, urinary 17-KS and the degree of obesity, was strongly associated with Io (r = 0.458, p less than 0.01) and sigma I (r = 0.419, p less than 0.02), as well as with insulin resistance as assessed by basal (r = 0.425, p less than 0.02) and postglucose challenge (r = 0.384, p less than 0.05) insulin to glucose ratio. These results confirm that the hyperinsulinism and insulin resistance in PCOD is not related to obesity and suggest that the hyperandrogenism may be partially responsible of the observed imbalance in glucose-insulin homeostasis.

Adolescent↗
PubMed1982

[Arrest of maturation in spermatogenesis].

The ultrastructural aspects of the germinal epithelium of 10 infertile men affected by maturative arrest of spermatogenesis were studied. We noted an increased number of malformed germinal cells. Marginal nuclear vescicles were present in spermatogonia of patients affected by spermatogonial arrest. The few spermatid present in the germinal epithelium of the patients affected by a spermatidic arrest presented changes of the nuclear condensation, the acrosome, and the tail. The Sertoli cells presented an immature aspect of the nucleus and changes of the "mantle". A possible correlation between the Sertoli cells changes and the altered spermatogenesis was proposed.

Humans↗
PubMedDate not supplied

The poster presentation as an educational tool.

The authors describe their experiences in using the poster presentation to develop undergraduate nursing students in the scholarly role of professional nursing practice. The posters were used as a means for students to communicate their accomplishments in implementation and evaluation of an innovative clinical project. Methods for development, exhibition, and evaluation of the poster project are described.

Audiovisual Aids↗
PubMedDate not supplied

Hormonal and seminal parameters in infertile men.

500 infertile patients (250 with and 250 without left side varicocele) and 33 fertile men were evaluated as far as seminal parameters and the hormonal status were concerned. Sperm motility was constantly lower in infertile patients also when infertile group was compared to fertile one with the same sperm density. Serum testosterone levels were lower in infertile groups when compared to fertile men, and this confirms the existence of an androgenic deficit as a common finding in infertility associated or not to varicocele. FSH and LH increased (p less than 0.001) when sperm density dropped to less than 5 X 10(6) spermatozoa/ml. A negative correlation was found between both gonadotropins and sperm count (p less than 0.001), also after exclusion of azoo- and oligozoospermic (less than 5 X 10(6) spermatozoa/ml) patients (p less than 0.01). Gonadotropins were moreover tightly correlated between each other (p less than 0.001). Our data suggest that both gonadotropins are tightly tuned with sperm output and thus with the spermatogenic potential.

Follicle Stimulating Hormone↗
PubMedDate not supplied

Fluorescence microscopic detection of acrosin in different morphologic types of human spermatozoa.

The immunoreaction for acrosin in different morphological types of human spermatozoa was evaluated by light microscopy in the semen of 68 male partners of infertile couples. The antigen had a cup-shaped distribution in the anterior region of the head in normal spermatozoa, and in those with an isolated abnormal mid-piece or tail. On the contrary acrosin was absent, or it did not show a cup-shaped immunostaining, in most spermatozoa with malformed heads with the exception of those with a large oval form. The assessment of immunoreaction for acrosin and of vitality of different morphological types of spermatozoa in the same ejaculates, suggested that the antigen was intrinsically absent in abnormal-headed but vital spermatozoa. It is concluded that an inherent lack, or an abnormal synthesis of acrosin during spermatogenesis is associated to the abnormal development of the spermatozoa head.

Acrosin↗
PubMedDate not supplied

Cyclophosphamide (3.6 g/m2) therapy with G-CSF support for resistant myeloma.

BACKGROUND: In myeloma patients resistance to both melphalan- and doxorubicin-containing regimens has been related to very short survival (approximately 6 months). The development of effective regimens combined with a low toxicity rate is mandatory in this patient subgroup. METHODS: Fourteen resistant myeloma patients were treated with cyclophosphamide (a total of 3.6 g/m2 was delivered in 2 doses on days 1 and 3) and prednisone (2 mg/kg, days 1-4) every month for 4 cycles. G-CSF support was administered to reduce myelosuppression. RESULTS: This combination was well tolerated. Granulocyte levels fell below 0.1 x 10(9)/L in all patients after a median of 9 days (range 8-11), followed by recovery to 0.5 x 10(9)/L after a median of 12 days from the start of treatment (range 10-13 days). Platelets never fell below 50 x 10(9)/L. All patients were treated on an outpatient basis and only 2 required hospitalization for major complications (pneumonia and heart failure). Response to cyclophosphamide was observed in 6/14 patients: 2 achieved complete remission, 4 showed a 50% or greater reduction of the M-component. Five patients are still in remission after 2, 6, 7, 9 and 10 months; 1 relapsed after 10 months. All patients except one are alive 4-16 months from the start of treatment. CONCLUSIONS: This schedule may represent a new approach for resistant myeloma, and its very low toxicity allows it to be delivered on an outpatient basis.

Aged↗