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Biomedical subjects

A Natali

Publications and source records attributed to A Natali.

At least 109 records · Page 6Linked to original sources
PubMed1987

Immunoassayable somatomedin C in seminal plasma of azoospermic men.

Somatomedin C is a Sertoli cell peptide and since measurements of other Sertoli cell products in semen have provided a useful indices of testicular function, it was considered pertinent to measure the semen levels of Somatomedin C. Somatomedin C was measured by RIA in seminal plasma of vasectomized subjects (n = 18), subjects with agenesis of the seminal vesicles and vasa deferentia (n = 6) and subjects with azoospermia resulting from seminiferous tubule damage without obstruction (n = 23). Normal fertile subjects (24 men with a sperm concentration greater than 20 X 10(6)/ml) were used as controls. In all subjects, seminal levels of transferrin were also measured as an index of Sertoli cell function. The majority of seminal Somatomedin C appears to derive from the testis and/or epididymis. However, in several normal controls seminal levels of Somatomedin C (median = 3.52; range = 1.10-15.67 U/ejaculate) were found to be within the range for vasectomized subjects (median = 0.78; range = 0.46-4.20 U/ejaculate). In subjects with azoospermia the seminal levels of Somatomedin C (median = 2.06; range = 0.60-10.12 U/ejaculate) were significantly lower (P less than 0.02) than in fertile controls. However, values for these two groups overlapped. It is concluded that Somatomedin C in semen is not a reliable index of seminiferous tubule function and does not appear to be of diagnostic value in male infertility.

Humans↗
PubMed1986

Measurement of testosterone and its 5-alfa-reduced metabolites in human prostatic tissue using isotope dilution mass spectrometry.

5 alpha-Dihydrotestosterone (DHT) has been widely measured in human prostatic tissue using RIA since it is found to be involved in pathogenesis of human prostatic hyperplasia (BHP) and to be the best index for the follow-up of patients affected by prostatic cancer under endocrine treatment. A GC/MS method for the simultaneous determination of testosterone (T), dihydrotestosterone (DHT), 5 alpha-androstan-3 alpha,17 beta-diol (3 alpha-diol) and 5 alpha-androstan-3 beta-17 beta-diol (3 beta-diol) in prostatic tissue was developed based on the isotopic dilution technique. Trideuterated internal standards of each compound were previously synthesized in our laboratory. After previous extraction and purification on Sep-Pak C-18 cartridges and Lipidex DEAP columns, T and its metabolites were measured as heptafluorobutyric esters (HFB). Quantitative analysis was performed on a VG 7070 EQ mass spectrometer equipped with a fused silica capillary column using the Selected Ion Monitoring technique. Steroid values (means +/- SD; ng/g tissue) found in 9 human hypertrophic prostates were: T, 0.71 +/- 0.43; DHT, 4.46 +/- 1.41; 3 alpha-diol, 0.34 +/- 0.23; 3 beta-diol, 0.14 +/- 0.32.

Androstane-3,17-diol↗
PubMed1986

Immunostaining of transferrin and transferrin receptor in human seminiferous tubules.

Transferrin (TF) and transferrin receptor (TFr) were studied in human testicular biopsy specimens with the use of immunostaining techniques. A polyclonal antibody to human TF (obtained in goat), a murine monoclonal antibody (B3/25) to human TFr, and antisera antigoat IgG and antimouse IgG, both labeled with peroxidase, were used. In seminiferous tubules of subjects with normal spermatogenesis, TF was found mainly in Sertoli cells and, in lesser amounts (probably related to the presence of receptor-TF complexes), in spermatocytes and early spermatids. TFrs were found only in spermatocytes and early spermatids. In patients with spermatogenetic disorders, TF was always found in Sertoli cells, whereas TFrs were found in spermatocytes only when they were present. These results seem to demonstrate that in human seminiferous tubules, Sertoli cells are devoted to the production and/or storage of TF, whereas spermatocytes and early spermatids use TF.

Cytoplasm↗
PubMed1986

In vitro effects of an aromatase inhibitor on 5 alpha-reductase activity in human hypertrophic prostatic tissue.

To determine the effects of 4-hydroxy-4-androstene-3,17-dione (4-OH-A) on the in vitro conversion of testosterone (T) to 5 alpha-androstan-17 beta-ol-3-one (dihydrotestosterone, DHT), 5 alpha-androstan-3 alpha, 17 beta-diol and 5 alpha-androstan-3 beta, 17 beta-diol (diols), human benign hypertrophic prostatic (BPH) tissue was incubated with 4-14C-T as substrate, in the presence of 4-OH-A (10(-8) to 10(-6) M); the amounts of the 5 alpha-reduced metabolites formed were quantitated. The effects of 4-OH-A were compared with those of 17 beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one (4-MA), a known inhibitor of the 5 alpha-reductase. In the absence of 4-OH-A and 4-MA, human BPH tissue converted T to DHT and the diols readily. Both 4-OH-A and 4-MA induced significant and dose-related decreases in the formation of both DHT and the diols. The degree of inhibition induced by the different concentrations of 4-OH-A and 4-MA were 31, 41, 72% and 57, 87, 97%, respectively. The decreased formation of the diols was a consequence of the decreased availability of DHT (the immediate precursor of the diols) and was not due to direct effects of the inhibitors on the 3-hydroxysteroid dehydrogenases; both 4-OH-A and 4-MA were totally unable to modify the conversion of DHT to the diols, when 4-14C-DHT was used as substrate. Thus, 4-OH-A inhibits the process of 5 alpha-reduction of T in BPH tissue. This molecule might represent a potential new agent for the prevention and/or treatment of human BPH.

5-alpha Reductase Inhibitors↗
PubMed1986

Human mitochondrial DNA types in two Israeli populations--a comparative study at the DNA level.

Variations in human mtDNA restriction endonuclease fragment patterns were investigated in a sample number of 81 Israelis--Jews and Arabs--using total blood cell DNA. Eight new morphs were observed using five enzymes: HpaI, BamHI, HaeII, MspI, and AvaII. Of the 18 different combinations of fragment patterns (mtDNA types), only three were shared by both groups, but with striking frequency differences. The Arab sample disclosed "African" characteristics and was found to be slightly more polymorphic than the Israeli sample. One of the new types filled a "missing link" originally postulated in a phylogeny of mtDNA human types.

DNA Restriction Enzymes↗
PubMed1986

[Our experience in the surgical treatment of oncocytoma of the kidney].

Five patients, two men and three women age range 38 to 84 years, were treated for oxyphil cell adenoma of the kidney. Clinical signs were present in three cases and tumor size varied between 7 and 15 cm. Treatment was by nephrectomy in 4 cases and ablation of adenoma in the fifth patient, the tumor being located in the only functioning kidney in the latter. Close follow up surveillance for 32 months failed to detect any recurrence. Clinical and pathologic features of this neoplasm and therapeutic choice in these cases are discussed below. Although radical surgery has been employed in the past as principal therapy, more precise pre- and perioperative diagnosis should allow more frequent use of conservative surgery: partial nephrectomy or tumor excision.

Adenoma↗
PubMed1985

Ceruloplasmin and transferrin in human seminal plasma: are they an index of seminiferous tubular function?

Transferrin and ceruloplasmin have been measured by a solid-phase chemiluminescent method in seminal fluid and circulating blood of normal and vasectomized subjects (1 year after operation). This study has confirmed that approximately 80% of seminal transferrin comes from the testis, while seminal ceruloplasmin was not found different in the two groups. In patients affected by azoospermia due to seminiferous tubular damage (n = 15) in whom an obstruction was previously excluded, seminal transferrin was always below the normal range. On the contrary, seminal ceruloplasmin was always in the normal range, and circulating follicle-stimulating hormone was found above the normal range only in nine cases. No correlation was found between seminal transferrin and circulating follicle-stimulating hormone in such groups. In an unselected group of infertile patients with decreased sperm concentration and/or sperm motility, seminal transferrin was found correlated with the sperm count. These studies seem to suggest that seminal transferrin is a reliable index of seminiferous tubular function.

Ceruloplasmin↗
PubMed1985

Leiomyosarcoma of the prostate.

3 cases of prostatic leiomyosarcoma, observed over a 15-year period, are reported. 2 patients underwent radical surgical treatment only and succumbed to metastatic diffusion after 13 and 29 months, respectively. After palliative surgery, a 3rd man received subsequent radiation therapy for pelvic and pulmonary recurrences, and is alive with tumor after 6 years and 8 months. The diagnostic and therapeutic aspects of this uncommon and aggressive prostatic neoplasm are discussed.

Adult↗
PubMed1984

Human sera possess a limited antibody repertoire to influenza neuraminidase antigenic variants selected in vitro.

Four antigenic variants of the neuraminidase (NA) of A/Texas/77 (H3N2) virus were selected using monoclonal antibody at a frequency of one variant in 10(5) parental virions. The antigenic variants failed to react serologically with the monoclonal antibody used for their selection in vitro. The antigenic variants failed also to react serologically with a proportion of sera from children and adults although all of the sera reacted with the parental A/Texas/77 virus. Thus, certain human sera have a restricted antibody repertoire to influenza NA antigen which might enable virus antigenic variants to avoid anti-NA antibody-mediated neutralization in nature.

Adolescent↗
PubMed1983

Surgical repair of ureteral defects.

A nineteen year surgical experience with 35 patients requiring repair of ureteral defects is reported. Causes of ureteral damage are described, and the result of 18 patients treated with ileal ureter are compared with those of 17 cases where surgical procedures preserving urothelial continuity were used, such as bladder psoas hitch and renal autotransplantation. Significantly better results were observed with the latter techniques.

Adult↗
PubMed1981

Frequency of naturally occurring antibody to influenza virus antigenic variants selected in vitro with monoclonal antibody.

Antigenic variants of A/Texas/77 (H3N2) virus were selected in vitro using monoclonal antibody to virus haemagglutinin (HA). The antigenic variants and parental A/Texas/77 viruses were used to to evaluate the frequency of anti-HA antibodies in the sera of children and adults using single-radial-haemolysis (SRH) tests. Twenty to 41% of selected sera from adults, which contained antibody to the parental A/Texas/77 virus, failed to react with the different antigenic mutant viruses. A higher proportion of sera from children (37-58%) failed to react with the antigenic variants. Certain human sera and particularly those of children would appear to possess a more limited antibody repertoire to influenza HA, potentially allowing new antigenic variants to escape neutralization and spread in the community.

Adolescent↗
PubMed1980

Different patterns of replication in influenza virus-infected KB cells.

When KB cells were infected either with the fowl plague (FPV) Rostock strain (Hav1N1) or the WSN (H0N1) strain of influenza A virus the yield of cell-associated haemagglutinin and neuraminidase polypeptides was essentially comparable, but virus particles were not produced in the FPV-KB system. WSN virus-infected KB cells synthesized normal amounts of mature virus particles and had all the characteristics of a permissive replication cycle. Biosynthesis and transport of RNP antigen from nucleus to cytoplasm of infected cells were traced by immunofluorescent staining at 4 and 8 hours after the beginning of infection. While the fluorescent-stained material was totally confined to the nuclei in FPV-infected KB cells, RNP antigen migrated out of the nucleus during the replicative cycle of WSN virus in the same host cell. Patterns of virus-specific protein synthesis were studied by pulse-labelling with 35S-methionine. The most significant feature concerned the amplification of synthesis of virus-induced matrix (M) protein which did not occur in FPV-infected cells but occurred normally during WSN infection. The different patterns of replication in the same host cell when infected by different influenza A viruses is discussed.

Cell Line↗
PubMed1980

[Phosphorylation of viral polypeptides in cells infected with influenza virus].

Experiments carried out in vivo with WSN (H0N1) and FPV (Hav1N1) strains of influenza virus have shown the presence of phosphorylated virus-induced polypeptides. Notably it was interesting the behaviour of the non-structural NS1, NP nucleoprotein and membrane M viral components whose phosphorylation was different among the cellular hosts tested. In in vitro experiments we were able to demonstrate a protein-kinase-activity in purified virions. The similarities and differences found in vivo and in vitro systems are discussed taking into consideration the fact that viral replicative cycle is closely dependent from the cellular host and the pattern of influenza virus infection is unique between different hosts.

Orthomyxoviridae↗
PubMedDate not supplied

Simultaneous determination of testosterone, dihydrotestosterone and 5 alpha-androstan-3 alpha,-17 beta-diol by isotopic dilution mass spectrometry in plasma and prostatic tissue of patients affected by benign prostatic hyperplasia. Effects of 3-month treatment with a GnRH analog.

This article reports an isotope dilution mass spectrometric method for the simultaneous measurement of testosterone (T), dihydrotestosterone (DHT), and 5 alpha-androstan-3 alpha, 17 beta-diol (3 alpha-diol) in human plasma and prostatic tissue. After addition of tri-deuterated steroids as internal standards to prostatic tissue homogenates or plasma samples, extraction was performed with diethylether. The extracts were purified by two chromatographic steps (Sep-Pak C 18 cartridge and Sephadex LH-20) and injected into a gas chromatograph coupled with a mass spectrometer after derivatization with heptafluorobutyric acid. This method was highly specific and showed good precision, accuracy, reproducibility and sensitivity. T, DHT, and 3 alpha-diol were measured in human plasma and in prostatic tissue of seven patients with benign prostatic hyperplasia (BPH) treated for 3 months with a long acting GnRH analog before surgery. Plasma levels of T, DHT, and 3 alpha-diol were reduced by GnRH analog treatment to castrate levels. The tissue concentrations of the same steroids, compared with those obtained from 19 untreated patients, showed a mean reduction of about 90% for DHT and 3 alpha-diol, and about 75% for T. These results suggest that about 90% of prostatic DHT and 3 alpha-diol depend on testicular activity because they are dramatically reduced after pharmacologic castration.

Androstane-3,17-diol↗
PubMedDate not supplied

Vasopressin receptors in human seminal vesicles: identification, pharmacologic characterization, and comparison with the vasopressin receptors present in the human kidney.

Because of the presence of a high density of vasopressin receptors in the epithelial cells of porcine seminal vesicles similar to the V2 vasopressin receptors of renal tubules, human seminal vesicles and kidney were investigated using quantitative binding and adenylate cyclase studies. Tissues were obtained at surgery from 17 patients with urologic diseases. A homogeneous class of vasopressin binding sites have been found in both seminal vesicles and renal medulla. However, the vasopressin receptors present in these tissues are different in terms of ligand specificity and adenylate cyclase activation. In seminal vesicles, the V1 vasopressin antagonist d(CH2)5 TyrMeAVP is 36-fold, more potent than the V2 agonist dVDAVP in displacing [3H]AVP binding, while in the medullopapillary portion of kidney dVDAVP is 24-fold, more selective than d(CH2)5 TyrMeAVP for the arginine vasopressin binding site. Furthermore, arginine vasopressin induces a dose-dependent increase in adenylate cyclase activity in renal membranes, while it was ineffective in seminal vesicle membranes. These results indicate that a very high affinity (0.2 nM), low capacity (14 fmoles/mg protein) class of vasopressin receptors is present in human seminal vesicles, having pharmacologic characteristics similar to the V1 subtype of vasopressin receptors. The presence of a high affinity (1.6 nM), high capacity (350 fmoles/mg protein) V2 subtype of vasopressin receptors in human renal membranes is also confirmed. The density of the vasopressin receptors present in human seminal vesicles is inversely correlated with patient age, consistent with a physiologic role for vasopressin in the regulation of accessory sex gland activity.

Adenylyl Cyclases↗
PubMedDate not supplied

Heavy smoking is an important risk factor for erectile dysfunction in young men.

Clinical and basic science studies provide strong indirect evidence that smoking may affect penile erection. The objective of this retrospective research was to investigate the role of smoking for erectile dysfunction (ED) in order to obtain some insight into the prevention of ED. We reviewed the data from 860 male patients aged between 18 and 44 visited during the period January 1999 to December 2002. The patients were divided into three groups: smokers, never smokers and former smokers. All patients were submitted of medical history, such as, IIEF 5 Questionnaire, physical examination, serum levels of glucose, cholesterol, prolactin and free testosterone. Our data were compared with ISTAT (Italian Institute of Statistics) and data on the Italian population of smokers. We have stratified the data by age and area of residence. The 860 patients, mean age 32.4 y old (range 18-44), are distributed into three groups: smokers 460 (53.5%), never smokers 320 (37.2%) and former smokers 80 (9.3%). Current smokers in our series are 460 (53.5%) in comparison to 34.7% of male current smokers in Italy, in the same range (18-44). Out of 860, 337 are patients who smoked more than 20 cigarettes per/day (39.2%) and these data are extremely interesting; while comparing the same aged men through ISTAT, it is found that only 4% are heavy smokers. On analysing the incidence of heavy smoking in middle-aged patients affected by ED with the whole Italian population by means of ISTAT, taking into account males with the same age range and area of residence, it was shown that the data of our population (sample) compared all Italian middle-aged patients are 39.2 vs 4%; this explains the need for education within a comprehensive smoking cessation programme, and should be reserved especially for young smokers, in order to be aware and informed of the effect of tobacco on erectile function.

Adolescent↗