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Biomedical subjects

F Stern

Publications and source records attributed to F Stern.

At least 19 recordsLinked to original sources
PubMed1997

Proportionate mortality among unionized construction operating engineers.

This report presents the results of proportionate mortality ratios (PMR) and proportionate cancer mortality ratios (PCMR) among 15,843 members of the International Union of Operating Engineers who had died between 1988-1993. Operating engineers represent one of the 15 unions in the Building and Construction Trades Department and are responsible for the operation and maintenance of heavy earthmoving equipment used in the construction of buildings, bridges, roads, and other facilities. Using U.S. proportionate cancer mortality as the referent, statistically significant elevated mortality was observed for cancers of the lung (PCMR = 1.14, 95% confidence interval (CI) = 1.09-1.19) and bone (PCMR = 2.14, CI = 1.19-3.52). Using U.S. proportionate mortality as the referent, statistically significant elevated mortality was observed for other benign and unspecified neoplasms (PMR = 1.54, CI = 1.09-2.13), emphysema (PMR = 1.37, CI = 1.20-1.55), other injuries (PMR = 1.43, CI = 1.20-1.70) (which included crushing under/in machinery, tractor rollover, run over by crane), and suicide (PMR = 1.22, CI = 1.06-1.40). The PMR for leukemia, and aleukemia (PMR = 1.19, CI = 1.02-1.37), but not the PCMR (1.07, CI = 0.92-1.24), was also significantly elevated. Some of the occupational exposures that may have contributed to these excesses include diesel exhaust, asphalt and welding fumes, silica dust, ionizing radiation, and coal tar pitch. The present study underscores the need to control airborne exposures to these substances and for injury prevention efforts aimed at operating engineers in the construction industry.

Accidents, Occupational↗
PubMed1997

Turnover of short-lived proteins in chick leukocytes following dietary treatments.

The effect of protein intake (10 vs. 20%) on synthesis and degradation of short-lived leukocyte proteins in vitro was shown in 21-day-old chicks. Protein synthesis was measured for 1 or 2 h and protein degradation for 1.5 or 4 h following an 8-day dietary treatment. Leukocyte proteins were fractionated on a slab gel into 11 or 100 fractions, and the imaging radioactivity was calculated for protein synthesis and degradation. The degradation rates in most of the protein fractions were higher in the leukocytes of chicks fed 20% dietary protein than in those fed 10% protein. Protein fractions of M(r) approximately 25-37 kD exhibited the most marked differences between the two dietary treatments. This technique of measuring turnover rates of short-lived proteins in leukocytes could potentially be used to examine the effect of nutritional treatments in animals and man as well as to check the effect of catabolic conditions in humans on protein turnover.

Animals↗
PubMed1996

Macronutrient consumption and nutritional status in a selected well-established group of elderly people in a home for the aged in Israel.

OBJECTIVE: To evaluate the distribution pattern of the main macronutrients (protein, fat, carbohydrates) and fiber in a selected well-established group of elderly people, average age above 80 years. METHOD: Dietary consumption was evaluated in a well-established group of 21 elderly people in a home for the aged by in-person interview using a food frequency questionnaire. RESULTS: Daily energy intake was 1.87 Mcal (7.8 MJ) or 29.3 kcal/kg body weight, a value which lies within the range of 1.6 to 2.0 Mcal or 25 to 30 kcal/kg, found in 12 other studies conducted on elderly people. The average percentage of energy derived from macronutrients (with an individual range) was: protein 17.5 (13-22); fat 32.9 (25-44); and carbohydrates 49.6 (35-61). Fiber intake was 8.6 g/Mcal, lower than that found in three other studies. Positive coefficients of correlation were found between protein intake and the following parameters: serum urea (r = 0.28), cholesterol (r = 0.48) and DBP (r = 0.43). CONCLUSIONS: In our small group of elderly, energy derived from protein was higher than that in most of other studies reviewed, and that from fat was higher than in half of those studies. These values were remarkably higher than the suggested values. Energy derived from carbohydrates was close to that found in other studies. Monitoring of dietary macronutrients might improve the nutritional and the physiological status of the elderly.

Aged↗
PubMed1996

Estimation of vitamin needs--riboflavin, vitamin B6 and ascorbic acid-according to blood parameters and functional-cognitive and emotional indices in a selected well-established group of elderly in a home for the aged in Israel.

OBJECTIVE: To evaluate the vitamin status and the effects of micronutrient supplementation as determined by biochemical assays and functional, cognitive and emotional tests in a selected well-established group of elderly people, average age above 80 years. METHODS: Dietary consumption was evaluated by in-person interview using a food frequency questionnaire. Medical, biochemical, nutritional, functional, cognitive and behavioral parameters were assessed in elderly subjects (n = 12) living in a home for the aged, at baseline and after 42 days of micronutrient supplementation. The same parameters were assessed in additional subjects (n = 9), at baseline only. RESULTS: In all subjects, most of the micronutrients were not supplied at an adequate level. Supplementation of micronutrients at a level of 100% RDA improved parameters related to vitamin status, the activation coefficients (AC) of GR (glutathione reductase) and AST, blood ascorbic acid concentrations, functional-cognitive evaluation values, blood pressure, pulse rate, and serum cholesterol and triglycerides levels. At baseline, the following parameters significantly correlated with vitamin intake and were used for the estimation of vitamin needs: AC of GR, Tinetti Balance Evaluation, FIM and recorded morbidity. CONCLUSIONS: On the basis of limited available data, calculation of vitamin needs based on regression lines resulted in estimates (mg/day) of: > 150 for ascorbic acid, > 3 for riboflavin, > 3 for vitamin B6. Expanding the current practice of supplementing micronutrients at a level of 100% RDA (in tablet form) that already exists in some elderly societies should be considered after a comprehensive study in a large group of elderly people.

Aged↗
PubMed1995

Proportionate mortality among construction laborers.

This report presents the results of proportionate mortality ratio (PMR) analyses and proportionate cancer mortality ratio (PCMR) analyses among the 11,685 members of the Laborers' International Union of North America (LIUNA), who died between 1985-1988, using U.S. proportionate mortality rates as the comparison population. Statistically significant elevated mortality risks were observed for all malignant neoplasms (N = 3285, PMR = 1.13, CI = 1.09-1.17), as well as for site-specific neoplasms of the lung (N = 1208, PCMR = 1.06, CI = 1.00-1.12), stomach (N = 170, PCMR = 1.44, CI = 1.23-1.68), and thyroid gland (N = 10, PCMR = 2.24, CI = 1.07-4.12). The PCMRs for these malignant neoplasms were elevated among both white and non-white males, regardless of length of union membership, in most 10-year categories of age at death above 40 and for the three largest LIUNA regions examined. The study also observed 20 mesothelioma deaths, which indicated that some LIUNA members had been previously exposed to asbestos. Statistically significant elevated risks were also observed for deaths from transportation injuries (N = 448, PMR = 1.37, CI = 1.25-1.51), falls (N = 85, PMR = 1.34, CI = 1.07-1.66), and other types of injuries (N = 245, PMR = 1.61, CI = 1.42-1.83). The deaths due to injuries were most often observed among those members who had the shortest amount of time within the union, were younger, and first entered the union after 1955. This is the first study that has examined the general mortality experience limited to construction laborers only (Bureau of Census code 869).

Accidents, Occupational↗
PubMed1995

Assessment of mortality in the construction industry in the United States, 1984-1986.

Construction, one of the larger industries in the United States, employs 7.6 million workers, many in skilled trades occupations. Previously published data about potential worksite exposures and mortality of construction site workers are limited. We analyzed occupation and industry codes on death certificates from 19 U.S. states to evaluate mortality risks among men and women usually employed in construction occupations. Proportionate mortality ratios (PMRs) for cancer and several other chronic diseases were significantly elevated among 61,682 white male construction workers who died between 1984 and 1986. Men younger than age 65, who were probably still employed immediately prior to death, had significantly elevated PMRs for cancer, asbestos-related diseases, mental disorders, alcohol-related disease, digestive diseases, falls, poisonings, traumatic fatalities that are usually work-related, and homicides. Elevated PMRs for many of the same causes were observed to a lesser degree for black men and white women whose usual industry was construction. In addition, women experienced excess cancer of the connective tissue and suicide mortality. Various skilled construction trades had elevated PMRs for specific sites, such as bone cancer and melanoma in brickmasons, stomach cancer in roofers and brickmasons, kidney and bone cancer in concrete/terrazzo finishers, nasal cancer in plumbers, pulmonary tuberculosis in laborers, scrotal cancer and aplastic anemia in electricians, acute myeloid leukemia in boilermakers, rectal cancer and multiple sclerosis in electrical power installers, and lung cancer in structural metal workers. Using a standard population of blue collar workers did not result in fewer elevated PMRs for construction workers. Despite lifestyle differences and other limitations of the study, the large numbers of excess deaths observed in this study indicate the need for preventive action for construction workers.

Accidents, Occupational↗
PubMed1995

Haematopoietic cancer mortality among vehicle mechanics.

OBJECTIVE AND METHODS: This historical cohort study investigated causes of death among car and mobile equipment mechanics in the District of Columbia's Department of Public Works. Men who were employed for at least one year between 1977 and 1989 were eligible for inclusion in the cohort; follow up was up to the end of 1991. Three cases of leukaemia (index cases) had been reported among these workers before the inception of this study. This research was undertaken to estimate the relative risk of haematological cancer among mechanics working for the District of Columbia. RESULTS: Among the 335 male fleet maintenance workers, the all cause standardised mortality ratio (SMR) was 0.50 (33 observed deaths, 95% confidence interval (95% CI) 0.35-0.70), and the all cancer SMR was 0.55 (nine deaths, 95% CI 0.25-1.05). Three deaths from lymphatic and haematopoietic cancer were observed; the SMR was 3.63 (95% CI 0.75-10.63). In the subgroup with highest potential for exposure to fuels and solvents, the SMR for leukaemia and aleukaemia was 9.26 (two deaths, 95% CI 1.12-33.43), and the SMR for other lymphatic and haematopoietic neoplasms was 2.57 (one death from malignant lymphoma, 95% CI 0.06-14.27). All three lymphatic and haematopoietic cancer deaths were among car and mobile equipment mechanics (one was an index case). The two additional index cases were a fourth mechanic who died of leukaemia in 1992, after mortality follow up ended, and a fifth mechanic who was diagnosed with leukaemia in 1988 and is still alive. CONCLUSION: Many garage mechanics in this cohort regularly used petrol to clean parts and to wash their hands; some workers would occasionally siphon petrol by mouth. Benzene, a recognised cause of haematological cancer, is a component of petrol. Previous research indicates that garage mechanics may be at risk of leukaemia and other haematological cancers, presumably due to exposure to petrol; this study supports those findings.

Adult↗
PubMed1994

Optimal and stable conditions for the determination of erythrocyte glutathione reductase activation coefficient to evaluate riboflavin status.

To measure the activation coefficient (AC) of erythrocyte glutathione reductase (GR), suspended whole blood was lysed in a preincubation solution, with or without 100 microM flavin adenine dinucleotide (FAD). Upon addition of the reaction mixture, FAD concentration decreased about 10-fold. No AC values < 1 were obtained in any of the subjects. The range of unstimulated activity per g hemoglobin (Hb) was 5 to 12 U. AC values of healthy subjects (1.3) decreased to about 1.15 after vitamin supplementation of 1 RDA for 3 wk. In healthy young subjects consumption of dietary riboflavin at levels as low as 0.5 mg/d resulted in an AC of 1.6.

Adult↗
PubMed1988

Diversity of rat brain cysteine proteinase inhibitors: isolation of low-molecular-weight cystatins and a higher-molecular weight T-kininogen-like glycoprotein.

Conditions for extraction of rat brain soluble and particulate cysteine proteinase inhibitors (CPIs) were compared and an optimal one was selected to isolate low- and high-molecular-weight forms active toward papain or brain cathepsins B/L. The different forms were purified by affinity chromatography on alkylated papain, and identified on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels by use of Schiff's reagent, or by immunoblots using antisera to monomer or polymeric forms of human urinary cystatin c, to a human plasma histidine-rich glycoprotein (HRG), or to rat plasma T-kininogen. In particulates containing nuclei (P1) or synaptosomes (P2) the predominant CPI was an 80-kDa glycoprotein cross-reacting to anti-HRG and shown to be a T-kininogen by treatment with TPCK-trypsin, and subsequent bioassay of the released kinins. The levels found in rat brain were approximately 0.5 nmol/g wet weight. The higher-molecular-weight CPI potently inhibited cathepsin L hydrolysis of Leu-enkephalin at the Gly2-Gly3 bond with a Ki 10(-10) M. In contrast the low-molecular-weight CPIs were present in postmicrosomal fractions (S3) and cross-reacted with anti-cystatin c, but not with anti-HRG, anti-lysozyme, anti-beta protein amyloid peptide, or anti-T-kininogen. The low-molecular-weight forms were present at approximately 1-1.5 nmol/g wet weight and resembled "cerebrocystatin" purified previously from rat brain cytosol by M. Kopitar, F. Stern, and N. Marks [1983) Biochem. Biophys. Res. Commun. 112, 1000-1006.).

Animals↗
PubMed1983

Cerebrocystatin suppresses degradation of myelin basic protein by purified brain cysteine proteinase.

Procedures are described for extraction or release, assay and purification of cerebrocystatin an inhibitor of brain cathepsin B or of papain. Neurosecretory regions of rat brain contained significantly higher amounts of cerebrocystatin compared to cortex, cerebellum, mid- and lower brain regions, and spinal cord. Inhibitor was purified to apparent homogeneity by alkaline treatment of rat brain cytosol, followed by gel-filtration and affinity chromatography on Reacti-gel coupled to alkylated papain. Purified cerebrocystatin was a single polypeptide of Mr 12,500 as shown by gel-electrophoresis on urea-SDS slab gels. Cerebrocystatin inhibited the hydrolysis of BANA by papain (Ki, 1 nM) or by purified rat brain cathepsin B (Ki, 10 nM) and suppressed the hydrolysis of myelin basic protein (MBP) by cathepsin B (I50, 0.8 microM) and prevented its cleavage to form polypeptides of Mr 15,000-17,000.

Animals↗
PubMed1983

Observations on N alpha-deacetylation of model amino acids and peptides: distribution and purification of a specific N-acyl amino acid releasing enzyme in rat brain.

N alpha-Acyl amino acid releasing enzyme (NAARE), an enzyme cleaving acetylMet-Ala at the Met-Ala bond was purified from rat brain cytosol to apparent homogeneity by salt precipitation, gel filtration, and several steps of ion exchange. Levels of NAARE exceeded acylase measured with acetylmethionine in all brain regions and subcellular fractions examined: 60% was associated with cytosol and the remainder with debris or the crude nuclear and mitochondrial-synaptosomal subfractions. Activity was highest in pituitary and was approximately 0.5-0.6 that of liver or kidney. The purified enzyme preferentially hydrolyzed acetylmethionyl peptides: Km for acetylMet-Ala was 0.93; Vmax, 3.5 nmol-1 (kcat, 1185) with pH optimum of 8.9 as compared with 8.2 for acylases measured in cytosol. The purified enzyme was devoid of acylase and common exo- and endopeptidase contamination. Structure-activity relationships examined with synthetic formylated or acetylated peptides indicated no significant effects for di- or tripeptides if the second substituent was Ala, Ser, Asn, or Thr, but the activity was reduced 0.5-fold for Leu, a branched-chain amino acid. No hydrolysis was observed for polypeptides with five or more residues having N-terminal acetylated Tyr (enkephalin) or Ser (alpha-melanocyte-stimulating hormone, thymosin alpha 1), supporting the notion that the enzyme plays a role only in turnover of smaller peptides formed perhaps as a result of endopeptidase cleavage of proteins or polypeptides containing acetylated Met at the N terminus.

Amidohydrolases↗