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M Bergomi

Publications and source records attributed to M Bergomi.

At least 37 records · Page 2Linked to original sources
PubMed1990

Eradication of a disseminated mouse lymphoma by 1,3-bis(2-chloroethyl)-1-nitrosourea is immunologically mediated and accompanied by de novo generation of anti-tumor cytotoxicity.

The anti-tumor effect of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) was examined in BALB/c mice bearing increasing burdens of a syngeneic lymphoma (YC8). A single i.p. injection of the drug resulted in over 75% of cures when given at day 3, 5, 7 or 10 after an i.v. inoculum of 10(4) YC8 cells. The efficacy of BCNU on mice bearing large tumor burdens (from day 5 on) was not only due to its tumoricidal activity, but was immunologically mediated. Residual tumorigenic cells could be recovered in the livers of 5-day tumor bearers (TB) up to 2 weeks after BCNU treatment and only a low percentage of cures could be achieved when BCNU was administered to nude mice. In addition, BCNU-cured mice specifically rejected a lethal YC8 challenge and their splenocytes developed anti-tumor cytotoxicity in response to in vitro stimulation with YC8 cells. During kinetic experiments a 2-week period elapsed after BCNU injection before an anti-tumor cytotoxic T-lymphocyte (CTL) response could be generated by spleen cells of BCNU-treated 5-day TB. This period was characterized by immunosuppression as evaluated from impairment in the generation of lymphokine-activated killer (LAK) cells or of allospecific primary CTL responses by spleen cells from BCNU-treated 5-day TB and BCNU-treated normal mice. LAK cells first recovered and could be generated 7 days later, whereas primary allospecific CTL responses could only be detected by day 14, concomitantly with the generation of anti-tumor cytotoxicity by 5-day TB. The development of secondary in vitro CTL responses, however, was permanently abrogated. Spleen cells from BALB/c mice immunized either with YC8 or with DBA/2 minor histocompatibility antigens and treated with BCNU 1 week after the last immunization failed to mount an in vitro CTL response to their immunizing antigen, even when the cultures were supplemented with recombinant interleukin-2.

Animals↗
PubMed1990

Relationship between zinc in serum and hair and some hormones during sexual maturation in humans.

We have measured the levels of zinc in serum (Zn-S) and in hair (Zn-H) in 391 adolescents, in good health, aged between 11 and 14 years. To evaluate the relationship between zinc status and sexual maturation we have analyzed, in the same subjects, the serum concentrations of the following hormones: luteinizing hormone (LH), follicle stimulating hormone (FSH), dehydroepiandrosterone-sulphate (DHA-S), testosterone (T) and estradiol (E2). No significant relationship between zinc in the biological samples and the hormones measured in all subjects was observed; only in prepuberal females was a positive correlation found between Zn-S and E2. A significant relationship between Zn-S and LH was observed only for males with short stature or low weight (less than 25th percentile) (r = 0.359, p = 0.010; r = 0.47, p = 0.008, respectively). When prepuberal males with short stature were considered, a significant association between Zn-S and T appeared (r = 0.399, p = 0.006). In females with short stature (less than 25th percentile), partial correlation coefficients showed a significant association between FSH and zinc in hair (r = 0.435, p = 0.004), while in girls with low weight, FSH appeared positively related to zinc in hair (r = 0.470, p = 0.003) and negatively related to zinc in serum (r = -0.320, p = 0.050). Our results suggest that zinc plays an important role in the metabolism of hormones linked to sexual maturation.

Adolescent↗
PubMed1989

Expression of retrovirus-related, cytotoxic T lymphocyte- and transplantation-defined antigens in NIH/3T3 transfectants after a single passage in nude mice.

Transfection of T24c-Ha-ras oncogene into NIH/3T3 fibroblasts resulted in the establishment of a transformed cell line (pT) that was tumorigenic when injected s.c. both into Swiss outbred nude mice and normal NIH inbred mice. The passage into nude mice, however, led to the development of a tumor variant (pT-nude) able to subsequently grow into sublethally x-irradiated but not into immunocompetent NIH mice. NIH mice immunized with this tumor variant developed a strong specific CTL response against the immunizing cell line, whereas the parental transformed pT cell line was not lysed. Clones were derived by limiting dilution from anti-pT-nude bulk population and were tested on a panel of transformed NIH/3T3 lines before and after their growth as tumor into nude mice. All of these lines were lysed by the Lyt-2+ CTL clones as a sole consequence of one in vivo passage into nude mice. The cross-reactive Ag were shown to be related to endogenous retroviral products as assessed by 1) immunoprecipitations of gp70, p15E, and p30 viral proteins in the nude variants but not in parental lines, and 2) by the ability of retroviruses from irradiated pT-nude cells to infect NIH/3T3 or pT lines making them susceptible to lysis by anti-pT-nude CTL clones. These results show that a single passage in nude mice can induce retrovirus-related, cell-surface Ag in transplanted neoplastic cells.

Animals↗
PubMed1989

Determinants of bile secretion: effect of bile salt structure on bile flow and biliary cation secretion.

The effect of five bile salts, deoxycholate, chenodeoxycholate, cholate, ursodeoxycholate, and ursocholate, possessing (in decreasing order) different hydrophobicity, on bile flow and biliary secretion of total calcium, magnesium, sodium, and potassium was studied in 10 patients with T-tubes. Each subject was infused intraduodenally with one or two bile salts, given separately, to produce a selective enrichment of biliary bile salts with the infused bile salt. The choleresis induced per 1-mumol increase of bile salt output was greater during the secretion of 7 beta-hydroxylated bile salts, ursodeoxycholate (0.029 ml), and ursocholate (0.027 ml), followed in decreasing order by deoxycholate (0.023 ml), chenodeoxycholate (0.019 ml), and cholate (0.009 ml). Deoxycholate stimulated the greatest increase in cation secretion per unit increase in bile salt output, followed by chenodeoxycholate and cholate. The two 7 beta-hydroxylated bile salts induced greater cation secretion than did their 7 alpha-epimers. Whereas biliary concentration of divalent cations differed depending on the structure and concentration of the infused bile salt, the concentration of monovalent cations was constant for any species and concentration of infused bile salt. Relationships between bile salt and divalent cation concentration indicate that 1 mumol of secreted biliary deoxycholate, the most hydrophobic bile salt, associates with the greatest amount of calcium (0.046 mumol) and magnesium (0.022 mumol), followed by chenodeoxycholate (0.020 and 0.010 mumol, respectively) and cholate (0.012 and 0.008 mumol, respectively). The capacity of ursodeoxycholate and ursocholate to associate with calcium and magnesium seems to be less than that of their 7 alpha-epimers. These data suggest that of the common bile salts, the more hydrophobic bile salts stimulate bile flow and cation secretion better than the more hydrophilic bile salts, whereas ursodeoxycholate and ursocholate are more effective than their more hydrophobic 7 alpha-epimers. Whereas different bile salts seem to influence the secretion of sodium and potassium mainly by virtue of their choleretic properties, the effect of bile salt structure on biliary secretion of calcium and magnesium suggests the presence of a secretory link that might be consistent with cation-bile salt binding.

Bile↗
PubMed1989

Relationship between lead exposure indicators and neuropsychological performance in children.

This study surveyed 237 schoolchildren in a lead-polluted industrial area in northern Italy to assess the relationship between various biological indicators (lead in blood, hair and teeth, and delta-aminolevulinic dehydratase [ALA-D] activity) and some neuropsychological functions, assessed by a battery of five psychometric tests. The geometric means of lead measured in blood, hair and teeth were 10.99 micrograms/dl, 6.79 micrograms/g and 6.05 micrograms/g, respectively. Mean ALA-D activity was 51 mU/ml RBC. By analysis of covariance, after regressing out the variance accountable to confounding variables (age, sex, occupation/education of parents), Total and Verbal WISC-R IQ and Toulouse Pieron test results were significantly affected by the levels of lead in teeth. ALA-D values also appeared to be related to WISC-R IQ results (Total, Verbal and Performance).

Child↗
PubMed1989

Cadmium in blood, urine and hair related to human hypertension.

A case-control study was performed to assess whether cadmium is related to hypertension in a non-occupationally exposed population. 63 male subjects affected by mild stable hypertension, pharmacologically untreated, were investigated together with 63 male normotensive controls individually matched for sex, age, body mass index, smoking habits and work activities. Cadmium in blood, zinc and copper in serum, the three elements in urine and hair, together with some biological parameters involved in pathogenesis of hypertension, were investigated. The mean Cd blood value in hypertensives (H) was 0.58 micrograms/L vs 0.44 micrograms/L in normotensives (N) (t = 2.03; p less than 0.05) with a greater difference in non-smokers (0.41 micrograms/L vs 0.25 micrograms/L) (t = 2.69, p less than 0.01). Furthermore, both systolic and diastolic blood pressure were significantly related to cadmium blood levels (r = 0.20 and 0.19 respectively, p less than 0.05). Smoking habit affected cadmium levels only in the blood, not in the other biological matrices examined. No significant difference of cadmium content in urine and hair was found between normotensives and hypertensives but Cd/Cu ratio in urine was significantly lowered in the second group.

Adult↗
PubMed1987

Zinc and copper levels in serum, urine, and hair of humans in relation to blood pressure.

Zinc and copper status was evaluated in 63 early hypertensives and compared with that of 63 normotensives matched for sex, age, smoking habits and body mass index. Zinc and copper in serum, urine and hair were measured, and the serum activity of two zinc-dependent enzymes (AP and LDH) were analysed. Mean urinary copper concentration in patients was 14.11 micrograms g-1 creatinine compared with 9.16 micrograms g-1 creatinine in normotensive subjects (paired "t" = 3.94, p less than 0.001). Serum AP and LDH were significantly decreased (16 and 36%, respectively) in the patients compared with controls, although almost all values fell within the normal range of activities. Systolic and diastolic pressures were significantly and positively correlated to urinary copper excretion. These correlations were still apparent after correcting blood pressure values for other urinary measurements. Blood pressure levels (both systolic and diastolic) were also negatively correlated with the two zinc-dependent enzymes.

Adult↗
PubMed1983

[Not Available].

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History, Modern 1601-↗
PubMed1982

[Not Available].

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History, Ancient↗
PubMed1982

[Behavior during the work week of biological indicators of exposure to lead].

The AA. have studied the weekly changes of haematic and urinary parameters of lead occupational exposure. For this aim, they have collected in 14 ceramic workers 3 blood samples for day and all urine samples for day and all urine samples from monday to friday. The PbB and FEP levels did not show significant variations during working week. The measurement of ALA in single urines shows that this parameter is characterized by remarkable fluctuations within the same day in all subjects examined. The correction of values by density gave negative results while the correction by creatinine decreases the daily fluctuations but only in some cases. The execution of test in urine of 24 hours seems to give the most reliable correlation with lead exposure levels because of its relative constancy during week.

Adult↗
PubMedDate not supplied

Zinc, copper, and zinc- or copper-dependent enzymes in human hypertension.

Imbalance of zinc and copper status has been hypothesized in human hypertension. A case-control study was carried out to elucidate the possible relationship between zinc and copper status and essential hypertension. Thirty-one subjects affected by mild stable hypertension, pharmacologically untreated, were investigated together with 31 normotensive controls individually matched for sex, age, and smoking habits. Zinc and copper in serum and urine wee measured, and serum activities of alkaline phosphatase (AP), lactic dehydrogenase (LDH), copper-zinc superoxide dismutase (Cu-Zn SOD), lysyl oxidase (LOX), and monoamine oxidase (MAO) were evaluated. No significant difference in serum and urine zinc and copper content as far as in serum activity of zinc (AP and LDH) or copper (Cu-Zn SOD, LOX, and MAO)-dependent enzymes was found between hypertensives and normotensives. Positive relationships were found in normotensives between serum and urine levels of zinc (r = 0.577; p = 0.001) and copper (r = 0.394; p = 0.028), and between serum copper and Cu-Zn SOD (r = 0.534; p = 0.002). In normotensives, diastolic blood pressure and serum zinc were positively related (r = 0.370; p = 0.041). In hypertensives, inverse correlations were observed between diastolic blood pressure and AP (r = -0.498; p = 0.004) and Cu-Zn SOD (r = 0.452; p = 0.011), and between systolic blood pressure and LOX (r = -0.385; p = 0.033). Diastolic blood pressure was related to LDH inversely in hypertensives (r = -0.357; p = 0.049) and positively in normotensives (r = 0.457; p = 0.010). In normotensives, diastolic blood pressure was inversely related with MAO (r = -0.360; p = 0.046). These findings support the hypothesis that an imbalance of zinc and copper status might be involved in human hypertension.

Alkaline Phosphatase↗
PubMedDate not supplied

The epidemiology of selenium and human cancer.

The relation between the trace element selenium and the etiology of cancer in humans remains elusive and intriguing, despite the number of epidemiologic studies published on the topic. We address some methodologic issues, such as misclassification of exposure, particularly to single selenium compounds, effect modification, confounding, and other sources of bias, which may explain the inconsistencies in the literature. We also review the results of cohort studies, which have yielded either inverse or null or direct associations between selenium exposure and subsequent cancer risk. To date, no beneficial effect on cancer incidence at major sites, including prostate cancer, has emerged from the Finnish program begun in 1984 to increase the average selenium intake in its population. Populations exposed to unusually high or low levels of environmental selenium might offer unique opportunities to investigate if selenium exposure is related to the etiology of human cancer.

Anticarcinogenic Agents↗
PubMedDate not supplied

Adverse health effects of selenium in humans.

Epidemiologic studies and case reports have shown that chronic exposure to selenium compounds is associated with several adverse health effects in humans. An early toxic effect of selenium is on endocrine function, particularly on the synthesis of thyroid hormones following dietary exposure of around 300 micrograms Se/d, and on the metabolism of growth hormone and insulin-like growth factor-1. Other adverse effects of selenium exposure can be the impairment of natural killer cells activity and at higher levels, hepatotoxicity and gastrointestinal disturbances. Dermatologic effects, such as nail and hair loss and dermatitis, occur after exposure to high levels of environmental selenium. Assessing the toxicity and morbidity after long-term exposure to environmental selenium is difficult: neurotoxicity, particularly the degeneration of motor neurons leading to increased risk of amyotrophic lateral sclerosis, might occur after chronic exposure to both organic and inorganic selenium compounds. The results of laboratory investigations and cohort studies suggest that selenium species exhibit a bivalent effect in cancer, either increasing or decreasing risk. Current environmental selenium exposure limits appear to be inadequate for averting adverse health effects.

Biomarkers↗