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Biomedical subjects

N Mathur

Publications and source records attributed to N Mathur.

At least 37 records · Page 2Linked to original sources
PubMed1994

Influence of dietary iron deficiency on nickel, lead and cadmium intoxication.

The influence of dietary iron deficiency on acute nickel, lead or cadmium toxicity as reflected by the induction of hepatic, renal, and intestinal metallothionein (MT), disposition of the metals and alterations in hematological parameters, was investigated in young rats to ascertain whether the toxic effects of these metals modify under anemic conditions. The administration of Cd induced hepatic, renal and intestinal MT while that of Ni or Pb induced hepatic MT only. While dietary Fe deficiency did not affect MT induction by Cd, it enhanced the synthesis of renal and intestinal MT by Ni and Pb. The accumulation of Pb in liver and kidney and that of Cd in liver only, were enhanced by Fe deficiency; the tissue deposition of Ni remained unaffected by Fe deficiency. The induction of hepatic MT by Ni, Pb or Cd appears to be related to the concomitant rise in the hepatic Zn, Ca and Fe levels in normal rats. However, dietary Fe deficiency increased the hepatic Zn in response to Ni or Cd and the hepatic Ca in response to Pb administration.

Animals↗
PubMed1994

A study of extra-auditory effects of noise.

Paper mill workers (106) exposed to noise ranging from 80 to 96 dBA were assessed for alteration in clinical status. Neurobehavioral functions were examined with the help of a questionnaire. The study did not reveal any changes attributable to noise in subjects exposed to 86-90 dBA and > 90 DBA noise in course of their occupations.

Adult↗
PubMed1994

Pentoxifylline and meclofenamic acid treatment reduces clinical manifestations in a murine model of AIDS.

C57/BL/6 mice infected with LP-BM5 MuLV virus developed an AIDS-like disease (MAIDS) with splenomegaly, leukopenia, thrombocytopenia, anemia, decreased numbers of helper/inducer and suppressor/cytotoxic T-cells and decreased production of interferon alpha. We have shown previously that HIV-associated Kaposi's sarcoma tissue contains high levels of prostaglandin E2 (PgE2), and this inhibits interferon synthesis through a cAMP-dependent second-messenger process. In this study we treated groups of MAIDS-infected mice with combinations of pentoxifylline, an agent which increases cAMP and inhibits phosphodiesterases, and sodium meclofenamic acid, a PgE2 inhibitor. Treated mice showed: 1) significantly higher total leukocyte and platelet counts, 2) higher total L3T4+ (helper/inducer) and Lyt-2+ (suppressor-cytotoxic) T-cell population. Pathologic examination also showed significantly less hepatosplenomegaly and lymphadenopathy in animals treated with pentoxifylline and meclofenamic acid. Partly, PgE2-induced suppression of interferon alpha production may mediate expression of retrovirus infection in this murine model of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Socioeconomic and health status of electronics workers employed in organized industry.

To study their socioeconomic and health status, 1,770 workers in the organized electronics industry in India were surveyed. Mean age of the workers employed in this industry was 32.5 +/- 6.01 years. The average per capita income/month was Rupees 333, indicating a higher socioeconomic status, compared with the status of the national population, as well as compared with their counterparts in the unorganized sectors. Respiratory symptoms and impairment rates were significantly higher in workers exposed to soldering fumes. The high prevalence of congested or inflamed throat was also related to chemical exposure specially among solderers and workers exposed to metal oxides. The ocular symptoms and signs were also related to chemical exposure. Musculoskeletal disorders were related to erratic ergonomic postures.

Adult↗
PubMed1993

Influence of dietary iron deficiency on acute metal intoxication.

The influence of dietary iron deficiency on acute nickel, lead or cadmium toxicity as reflected by the induction of hepatic, renal and intestinal metallothionein (MT), disposition of the metals, and alterations in hematological parameters was investigated in rats. The administration of cadmium induced the hepatic, renal and intestinal MT while that of nickel or lead induced hepatic MT only. However, dietary iron deficiency did not influence the cadmium induced tissue MT but enhanced the ability of nickel or lead to restore the normal synthesis of renal and intestinal MT lowered under the influence of reduced body iron status. The accumulation of lead in liver and kidney and that of cadmium enhanced in liver only, while tissue deposition of nickel remained unaffected by iron deficiency. The induction of hepatic MT by three metals appears related to the concomitant rise in the hepatic zinc, calcium and iron levels in normal rats. However, dietary iron deficiency increased the hepatic zinc in response to nickel or cadmium and that of heptic calcium in response to lead.

Animals↗
PubMed1993

Effects of vitamin E on cadmium-induced locomotor dysfunctions in rats.

The effect of co-administration of vitamin E (VE) on cadmium (Cd)-induced locomotor deficits in growing rats was investigated. Intraperitoneal administration of 0.4 mg Cd/kg/d for 4 w resulted in significant decreases in time of ambulation and stereotype and numbers of stereotypic and vertical movements, but the resting time was enhanced. Administration of VE (5 mg alpha - tocopherol acetate/kg im on alternate days) to these rats effectively antagonised these locomotor deficits. The data support the hypothesis that Cd may induce oxidative stress in the CNS and that treatment with an antioxidant may be beneficial against such damage.

Animals↗
PubMed1992

Structure of (E)-5-(methoxymethylene)-2,4-imidazolidinedione.

C5H6N2O3, Mr = 142.11, monoclinic, P2(1)/n, a = 3.862 (1), b = 16.329 (2), c = 10.088 (1) A, beta = 98.77 (2) degrees, V = 628.7 (2) A3, Z = 4, Dx = 1.50 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 1.18 cm-1, F(000) = 296, T = 296 K, R = 0.035 for 1124 independent reflections with I greater than 3 sigma(I). The structure is a hydantoin derivative with a methoxymethylene group substituted at the 5-position. Excluding the H atoms, the molecule is planar to within 0.032 A. All of the N and O atoms are involved in an intermolecular hydrogen-bonding network via N--H...O and C--H...O interactions. The packing arrangement is a linear ribbon motif with the ribbons stacked to form the short a axis.

Chemical Phenomena↗
PubMed1992

Clinical studies in workers engaged in maintenance of watermark moulds in a paper mill.

Thirty subjects engaged in maintenance and repair of moulds used for producing watermarks on paper were studied, along with 27 control subjects from the same paper mill. The workers were simultaneously exposed to copper, chromium, zinc, xylol, and fumes of sulphuric acid in the course of their work. The study subjects were investigated for clinical, occupational, radiological haematological and psychological details. The aforementioned combined exposure was found to be responsible for a high prevalence of symptoms pertaining to the respiratory system and higher nervous functions. Breathlessness (26.7%), expectoration (10.0%) and emphysema (10.0%) were significantly higher among the exposed subjects. The exposed subjects also showed lowered visuomotor coordination and delayed reaction to light and sound stimuli.

Adult↗
PubMed1992

A survey of chronic bronchitis among brassware workers.

A stratified random sample of 580 workers aged between 18 and 50 years representing each sub-occupation in the brassware industry was studied for the prevalence of chronic bronchitis in relation to occupational and environmental factors. The findings were compared with those obtained in a reference group (N = 131) belonging to similar socio-economic status and unexposed to a dusty environment. Although the exposed group showed higher prevalence of chronic bronchitis in comparison to that observed in the controls (10.5 vs 5.3%), the difference was not significant at the 5% level. It was observed that the workers engaged in non-dusty occupations such as brass sheet cutting and engraving showed the lowest prevalence of the disease (5.0%) while those engaged in the dusty occupations viz., casting, soldering, electroplating and polishing showed the highest prevalence (12.0%). The smoking adjusted odds ratios calculated in various sub-occupations showed the highest risk of developing chronic bronchitis among the polishers (2.74). Though the risk in other occupational sub-groups was double, it did not attain a level of significance. The smoking adjusted odds ratios in relation to length of exposure showed that the risk was significantly higher among the workers exposed for over 10 years compared to those who worked for less than 10 years in the grinding, soldering and brass ingot making operations. The study thus showed a dose-response relationship between length of exposure and chronic bronchitis while effect of age on the disease was not discernible probably due to the small number of cases and the young age of the study group. The concentration of various metals in the air samples drawn from the work environment where main processes were in operation, was low compared to the prescribed level by ACGIH.

Adolescent↗
PubMed1992

Respiratory symptoms and ventilatory capacity in metal polishers.

To evaluate the long-term effects of metal dusts on the bronchopulmonary system and the synergistic effect of cigarette smoke, a comparative study of spirometric measurements in 104 polishers and 90 unexposed controls was carried out in 25 brass and steelware polishing industries at Moradabad in northern India. The two groups were comparable in terms of age, height, smoking habit and socio-economic status. A total of 58.6% of the polishers had one or more respiratory symptoms, compared to only 25.5% of the controls (P < 0.05). Chronic cough was present in 21 polishers (20.2%) as compared to 11.1% of the controls. However, this difference was insignificant. Chronic phlegm was nearly three times as frequent among the polishers as among the controls (17.5% vs 4.4%) (P < 0.005). The prevalence of dyspnoea of varying grades was also significantly higher (16.3% as opposed to 4.4%) among the exposed groups. Chronic bronchitis (6.7%) and occupational asthma (4.8%) were found to be confined to polishers. The polishers also experienced acute respiratory symptoms during the work shift. The prevalence of acute respiratory symptoms was recorded for cough in 19 workers (44.1%) followed by dyspnoea in 14 workers (32.5%) and throat irritation in 11 workers (25.5%). Comparison of the mean values of pulmonary function parameters in the polishers and the controls showed significant differences in the smoking and non-smoking groups (P < 0.001). The polishers exhibited significantly greater acute reductions in various lung functions over the work shift, particularly for forced expiratory flow over the 25-75% portion of the spirogram (FEF25-75%) FEF25% and FEF50%, than did the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Clinical studies of employees in a sheet-forming process at a paper mill.

Formaldehyde resins are used to improve the wet strength of paper. During the sheet-forming process of paper manufacture, formaldehyde fumes are liberated. Twenty-two male subjects having such exposures in a paper mill and 27 unexposed subjects were clinically evaluated to determine the effect of low level formaldehyde exposure in a tropical country. The workers were exposed to 0.03 mg formaldehyde/m3 air as an 8-h TWA. Formic acid excretion in urine was 37.2 +/- 18.9 and 20.3 +/- 4.2 ug/L among the exposed and the unexposed subjects, respectively. Significantly more respiratory problems (31.8%) were observed among the exposed subjects as compared to controls. Complaints pertaining to gastrointestinal, musculoskeletal and cardiovascular systems were also more frequent in exposed subjects. In spite of formaldehyde concentrations being well within the prescribed ACGIH limits of 1 ppm, the high rates of sickness emphasise the need for detailed studies on formaldehyde-exposed subjects in tropical countries.

Adult↗
PubMed1992

Occupational morbidity among children employed in brassware industry.

Fifty seven male children between ages of 10-16 years engaged in the brassware industry at Moradabad in Northern India were studied for occupational morbidity. The finding were compared with those obtained in the children (n = 29) engaged in other ancillary units which did not involve exposure to the metal fumes and dust in their work environment. The study showed a high prevalence of respiratory morbidity in the children engaged in the main units in comparison to those employed in the ancillary units (40.3 vs 27.6%; p less than 0.05). This was associated with significantly higher prevalence of pulmonary impairment in the former group (21.0%) particularly demonstrating restrictive ventilatory abnormality (10.5%) followed by bronchial obstruction (7.0%). The high respiratory morbidity may be attributed to chronic exposure to the fumes and dust of the metals such as nickel, chromium and cadmium. The children employed in the ancillary as well as in the main units showed high prevalences of musculo-skeletal disorders (27.6 and 22.8%) which may be caused by sustained faulty posture adopted during work and physical stress.

Adolescent↗
PubMed1992

Blood chromium and nickel in relation to respiratory symptoms among industrial workers.

Seventy-eight workers exposed to fumes and dust of nickel and chromium in their occupation in the glass industry were studied for respiratory symptoms in relation to nickel and chromium concentrations in their blood. A significant (p less than 0.01) association was observed between respiratory symptoms and elevated blood nickel and chromium. An interaction between nickel and chromium was found in relation to the prevalence of respiratory symptoms.

Adolescent↗
PubMed1991

A cross-sectional study of pulmonary function among workers exposed to multimetals in the glass bangle industry.

Spirometric lung functions were evaluated in 220 asymptomatic glass bangle workers exposed to the salts of various heavy metals, such as arsenic, lead, zinc, copper, manganese, cobalt, cadmium, and selenium, which are used as coloring agents in the manufacture of glass bangles. The mean values of various spirometric variables (viz. FVC, FEV1, IMBC, and PEFR) were within normal range (more than 80% of the predicted values) in both smoking and nonsmoking glass bangle workers and did not reveal any significant differences in comparison with those observed in the unexposed controls. However, variables such as FEV1/FVC% ratio, FEF25-75 and FEF75-85 were reduced significantly (p less than 0.001) in the exposed group. The reduction was more marked in the smoking glass bangle workers indicating additive effect of cigarette smoking on the small airways. The exposed group showed a significantly higher prevalence (16.3%) of respiratory impairment in comparison to that observed in the controls (7.9%) as a result of exposure to various metals in the work environment (p less than 0.01). The respiratory impairment observed in the exposed group indicated primarily restrictive pattern of pulmonary abnormality (10.4%), while the controls revealed only 1.1% prevalence of this disease (p less than 0.001). The effect of the duration of exposure on the prevalence of respiratory impairment in the glass bangle industry revealed significantly higher prevalence (p less than 0.05) in those who worked for more than 10 years (23.0%) than in those who worked for less than 10 years (10.8%) thereby indicating that the duration of exposure is directly related to the prevalence of respiratory impairment.

Adult↗
PubMed1991

A study of the prevalence of respiratory morbidity among agate workers.

A random sample of 342 workers engaged in chipping and grinding of agate stones were surveyed in a cross-sectional study to assess the prevalence of respiratory morbidity in the agate industry. The findings were compared with those obtained in controls. The study showed a significantly higher prevalence of lung diseases among agate workers than among controls (63.4% vs 35.5%, P less than 0.001). The respiratory morbidity in agate workers and controls was maximal in the group aged 31+ years (83.3% and 42.2%, respectively). The prevalence of pneumoconiosis in agate workers (18.4%) was highly significant as compared with controls, in whom not a single case was found (P less than 0.001). However, there was no significant difference between the prevalence of pneumoconiosis in men and women of the exposed group (17.9% vs 19.6%). Among the cases of pulmonary diseases in agate workers, pneumoconiosis formed the largest group (18.4%), whereas among controls it was tuberculosis (12.1%). The prevalence of pulmonary tuberculosis was very high in both agate workers and controls (15.5% and 12.1%, respectively), probably because of poor socio-economic and unhygienic living conditions. The prevalence of chronic bronchitis was found to be higher among the control population as compared with the exposed group (6.7% vs 2.6%). It therefore appeared that agate dust had no role in precipitating chronic bronchitis. However, bronchial asthma appeared to have been aggravated due to agate dust, as the risk among agate workers was 7-fold that found among the controls. The prevalence of pneumoconiosis showed a dose-response relationship in both male and female agate workers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Spirometric abnormalities among welders.

A group of manual welders (N = 57) engaged in gas welding joint faces of moulded brasswares, age group 13-60 years (mean: 29.2 +/- 1.37 years), having a mean exposure period of 12.4 +/- 1.12 years (range: 1-35 years) were subjected to spirometry to evaluate the prevalence of spirometric abnormalities. The findings were compared with those obtained from a reference group (N = 131) (mean age: 31.2 +/- 1.35 years) engaged in nonwelding jobs such as packing, labelling, and transportation of the finished brassware articles. The welders showed a significantly higher prevalence of respiratory impairment (28.0%) than that observed among the unexposed controls (6.1%) (P less than 0.001), as a result of exposure to welding gases which comprised fine particles of lead, zinc, chromium, and manganese. This occurred despite the lower concentration of the pollutants at the work place. In the exposed group, the smoking welders showed a prevalence of respiratory impairment significantly higher than that observed in the nonsmoking welders (40.0 vs 18.7%) (P less than 0.10). A similar trend was observed in the control group indicating that smoking had a deteriorating effect on spirometric tests. The results of the pulmonary function tests showed a predominantly restrictive type of pulmonary impairment (12.3%) followed by a mixed ventilatory defect (8.7%) among the welders. The effect of age on pulmonary impairment was not discernible either in the exposed or unexposed group. The analysis of data in relation to duration of exposure showed significant correlation between the prevalence of respiratory abnormalities and length of exposure. Welders exposed for over 10 years showed a prevalence of respiratory abnormalities significantly higher than those exposed for less than 10 years (44.4 vs 13.3%) (P less than 0.01) thereby showing that occupational exposure to welding fumes resulted in increased prevalence of pulmonary impairment in the welders. Smoking also had a contributory role thereby suggesting an interaction between smoking and welding exposure on the prevalence of pulmonary impairment in the welders engaged in brassware industries.

Adolescent↗
PubMed1991

A study of respiratory morbidity and pulmonary function among solderers in the electronics industry.

Pulmonary function assessment of 197 solderers engaged in soldering printed circuit boards and other electronic components using lead-tin alloy impregnated solder in five major electronics workplaces in India was compared with the findings observed in 143 unexposed controls. Spirometry showed a significant impairment in the values of vital capacity (VC) and forced expiratory volume/forced vital capacity (FEV1/FVC) percent ratio in 47.2% of the solderers in comparison to 1.3% in the reference group (p less than 0.001). In the exposed group, female solderers particularly showed significantly higher (55.0%) prevalence of overall respiratory impairment in comparison to the 32.3% observed in their male counterparts (p less than 0.001). Bronchial obstruction was recorded in 7.6% of the solderers compared with 1.3% of the unexposed controls (p less than 0.01). The prevalence of restrictive and mixed ventilatory impairment was found to be 28.9 and 10.6%, respectively, among the exposed workers, while there was none among the control group. The solderers showed a predominantly restrictive pattern of pulmonary impairment that was mild in nature. Smoking caused no significant effect on the pulmonary impairment among the exposed workers. The study also did not show any significant differences in the prevalence of respiratory impairment between solderers exposed either less or more than 10 yr, thereby suggesting that there was no link between the respiratory impairment and duration of exposure. The industrial hygiene study conducted in the assembly section where soldering was done showed the mean concentration of lead to be 0.40 micrograms/m3 (range 0.12-0.43 micrograms/m3).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗