[The evaluation of day hospital activities: an analysis of intervention protocols and a comparison between the indicators of the activities of the day hospital and of the regular admission]

Day hospital (DH) activity may avoid in-staying of patients resulting in an increase of efficiency and in a more satisfying diagnostical-therapeutical process for the patient. All the same, it is quite difficult to identify parametres and indicators to be used in the evaluation and quantification of DH, so that both scientific literature reporting experiences and law are lacking. One of the reasons is probably due to the lack of nosological characterization of patients and protocols of DH activity, so that the definition relies only on organizational and technical parameters. Characterization of protocols of intervention is the basic approach to the present DH investigation. Parameters such as: multiplicity of services, weekly planning of the activity and surveillance needed by the patient are considered the fundamental criteria to identify and quantify DH in the present research carried out at the University Regional Hospital of Pisa. The aim of this article is, on one side, to give a methodology of investigation based, as far as possible, on "explicit" indicators and parameters, so that the experience may be exported into other contexts and on the other, to give an example of resource analysis and efficiency evaluation which were internally used for "audit" review.

[Recovery evaluation in a pediatric heart surgery unit using the AP-DRG classification system (All Patient Diagnosis Related Groups)]

The evaluation of Health Care activities, particularly of those concerning hospitals, is one of the most important aims for the National Health Service for a "fair" resource allocation. In the recent past a great bulk of research has been directed to methods for patient classifications in relation to resource needs. Diagnosis Related Groups (DRG) is one of the most important patient classification systems related to resource allocation which has been developed in the U.S. Medicare Program (HCFA-DRGs) during the eighties and more recently adopted all over Europe, Italy included. Wide experimentation has been developed during the recent past concerning DRGs confirming its validity, but also has disclosed its limits, mostly concerning applicability outside U.S., identification of specific patient subgroups (like the pediatric patient population) and capability in distinguishing patients with apparently similar resource needs, but different clinical severity conditions. In order to overcome such limits, DRGs have been subjected to some important modification: All patient DRG (AP-DRG) is a system which should pay more attention to some patient subgroups, such as the pediatric one. Research is still looking for methods, easily extensible to the whole hospital informative system concerning the possibility of distinguishing patients with different level of severity condition. With the double aim of experiment the actual utility in the use of AP-DRG, more than HCFA-DRG in a pediatric population and find further indexes for complexity and/or severity characterization of the hospital case-mix, the 1992 in-patients hospital files of the pediatric cardiosurgery hospital CREAS-IFC-CNR was reviewed. Results confirm that some increase in the identification of the case-mix do occur by using the AP-DRG system, even if a better clinical characterization could be possible (i.e. AP-DRG 108). Of particular interest is the fact that descriptive statistical analysis of position and variability parameters do confirm the importance of the length of stay as a brief index for hospital efficiency evaluation and its organizative model characterization.

The "Tor Vergata" epidemiological blood pressure study. Hereditary and environmental factors

The aim of this study was to evaluate the influence of hereditary and/or environmental factors on blood pressure patterns. The study group consisted of 1002 individuals. Comparison of blood pressure values among groups was performed by the Bravais-Pearson r correlation coefficient. Results among the different groups were: p < 0.001 in the parents-offspring group (n = 413) for both systolic (SBP) and diastolic blood pressure (DBP); p < 0.001 in the father-offspring group (n = 382) for SBP only; p < 0.001 in the mother-offspring group (n = 389) for both SBP and DBP; NS in the father-son group (n = 199) for any blood pressure value; p < 0.01 in the father-daughter group (n = 183) for SBP only; p < 0.001 in the mother-son and daughter groups (n = 201 and n = 188 respectively) for both SBP and DBP. Family aggregation analysis disclosed p < 0.01 and p < 0.05 for SBP and DBP respectively in the mother-her sibling group. No significant values were found in the father-his sibling group or between offspring and either their paternal or maternal uncles/aunts. Conversely, a significant correlation (p < 0.001) was found between spouses (fathers and mothers) for both SBP and DBP. These results support the hypothesis that both hereditary and environmental factors exert their influence on blood pressure patterns. We performed both univariate and bivariate statistical analyses. The latter included a) variable separation, b) independent variables, and c) variable correlation. Bivariate analysis of variable correlation proved to be the most suitable.

Regulation of a carotenoid biosynthesis gene promoter during plant development

Carotenoids are terpenoid pigments which are accumulated in the chloroplasts of leaves and in the chromoplasts of many flowers and fruits. Phytoene desaturase (Pds), the second dedicated enzyme in carotenoid biosynthesis, is encoded in tomato by a single copy gene. A 2 kb fragment from the tomato Pds gene, comprising 1.5 kb from the promoter and 0.5 kb from the 5' non-translated region, is able to drive developmentally regulated expression of the GUS reporter gene in transgenic tomato and tobacco plants. In tomato, high levels of Pds/GUS expression are found in organs and at stages of development where chromoplasts are formed: petals, anthers and ripening fruits. Tobacco petals and fruits, which do not contain chromoplasts, show instead low levels of Pds/GUS expression. Transgenic tobacco seedlings were subjected to treatment with a range of inhibitors of carotenoid and chlorophyll biosynthesis. The results indicate that, in green tissues, carotenoid and chlorophyll levels are tightly co-regulated and that a chemically induced arrest in pigment biosynthesis results in activation of the Pds promoter. The promoter is also induced in etiolated seedlings, which contain much lower carotenoid levels than light-grown seedlings. These data suggest that in green tissues Pds gene transcription may respond to end-product regulation.

The Immunological Effects of Dust Containing Metals and Compounds in Workers of a Plant Producing Plastic Materials. Preliminary Study

Lymphocyte subpopulations were studied in 14 men working in a plant producing plastic materials in comparison with a control group of similar age and smoking habit. The workers were exposed to dust containing particles of calcium carbonate, polyvinylchloride, phtalates, unsaturated oils, paraffin wax, iron oxides, titanium bioxides, barium, zinc, lead and lead chromate. In the exposed workers, T helper/ inducer lymphocytes (mainly CD4+-CD45RO- “virgin” lymphocytes) and CD19+ B lymphocytes were significantly reduced without changes of serum IgM, IgG and IgA. A highly significant correlation was found between B lymphocytes (reduced in the workers about 40 %) and CD4+-CD45R0+ “memory” lymphocytes (reduced about 20 %). Moreover, blood lead (correlated with urinary chromium) demonstrated a highly significant negative correlation with B lymphocytes.

This study demonstrates that combined exposure to toxic agents produces specific modifications in the lymphocyte subsets without changes in immunoglobulins and confirms the results of previous studies showing that the exposure to lead or chromate induces reduction of lymphocytes in the peripheral blood.

Hepatitis B virus precore/core variation and interferon therapy

Precore/core genes from hepatitis B e antigen (HBeAg)-positive and antibody to HBeAg (anti-HBe) positive individuals with active hepatitis have been analyzed to search for correlations with response to interferon before and after treatment. Pretreatment, no precore stop codon mutants were detected, even at the 3% level, in HBeAg-positive responders or nonresponders. In anti-HBe-positive patients, precore mutants did not influence response. No significant core amino acid variability was observed in HBeAg-positive patients, irrespective of interferon response. However, anti-HBe-positive cases had multiple core protein substitutions, mostly in B- ant T-helper cell epitopes, but responders had fewer (P = .02 for responders versus nonresponders and reactivators). None of four responders, three of seven reactivators, and three of three nonresponders had mutations within the major T-helper epitope from aa50 to aa69 (P = .03). Precore mutants appeared in eight of nine natural seroconverters compared with 3 of 10 interferon-induced anti-HBe seroconverters (P = .01). Those in whom precore wild-type remained after treatment often tested negative in the last available sample using polymerase chain reaction (PCR), whereas emergence of mutants led to ongoing viremia in all cases. In anti-HBe-positive cases, precore sequences remained stable during therapy, except for 2 cases in whom a precore mutant appeared accompanied by reactivation. In the core protein, anti-HBe-positive cases selected a mean of 3.5, 1.6, and 1.7 amino acid substitutions in responders, nonresponders, and reactivators respectively (P = NS). In conclusion, core but not precore sequence before therapy may predict response. Appearance of precore mutants during therapy usually predicts failure to clear virus but substitution in core does not influence outcome.

Hepatitis B virus precore/core variation and interferon therapy

Precore/core genes from hepatitis B e antigen (HBeAg)-positive and antibody to HBeAg (anti-HBe) positive individuals with active hepatitis have been analyzed to search for correlations with response to interferon before and after treatment. Pretreatment, no precore stop codon mutants were detected, even at the 3% level, in HBeAg-positive responders or nonresponders. In anti-HBe-positive patients, precore mutants did not influence response. No significant core amino acid variability was observed in HBeAg-positive patients, irrespective of interferon response. However, anti-HBe-positive cases had multiple core protein substitutions, mostly in B- ant T-helper cell epitopes, but responders had fewer (P = .02 for responders versus nonresponders and reactivators). None of four responders, three of seven reactivators, and three of three nonresponders had mutations within the major T-helper epitope from aa50 to aa69 (P = .03). Precore mutants appeared in eight of nine natural seroconverters compared with 3 of 10 interferon-induced anti-HBe seroconverters (P = .01). Those in whom precore wild-type remained after treatment often tested negative in the last available sample using polymerase chain reaction (PCR), whereas emergence of mutants led to ongoing viremia in all cases. In anti-HBe-positive cases, precore sequences remained stable during therapy, except for 2 cases in whom a precore mutant appeared accompanied by reactivation. In the core protein, anti-HBe-positive cases selected a mean of 3.5, 1.6, and 1.7 amino acid substitutions in responders, nonresponders, and reactivators respectively (P = NS). In conclusion, core but not precore sequence before therapy may predict response. Appearance of precore mutants during therapy usually predicts failure to clear virus but substitution in core does not influence outcome.

Multiple isoforms of Arabidopsis casein kinase I combine conserved catalytic domains with variable carboxyl-terminal extensions

Three cDNA clones encoding isoforms of casein kinase I (CKI) were isolated from Arabidopsis thaliana. One full-length clone, designated CKI1, contained an open reading frame of 1371 bp encoding a protein of 51,949 D with an isoelectric point of 9.7. In addition to the highly conserved catalytic domain (of about 300 amino acids), the Arabidopsis CKI isoforms contain 150 to 180 amino acid carboxyl-terminal extensions, which show among themselves a lower level of sequence conservation. These extensions do not show any sequence similarity to nonplant CKI isoforms, such as rat testis CKI delta, which is their closest isolated homolog, or to yeast CKI isoforms. Three additional isoforms of Arabidopsis CKI were found in the data bases of expressed sequence tags and/or were isolated serendipitously in nonspecific screening procedures by others. One of them also shows a carboxyl-terminal extension, but of only 80 amino acids. Casein kinase activity was detected in the soluble fraction of Escherichia coli strains expressing the CKI1 protein. This activity showed the crucial properties of CKI, including the ability to phosphorylate the D4 peptide, a specific substrate of CKI, and inhibition by N-(2-aminoethyl)-5-chloroisoquinoline-8-sulfonamide, a specific CKI inhibitor. Like several recombinant CKI isoforms from yeast, CKI1 was able to phosphorylate tyrosine-containing acidic polymers.

Ultrasound diagnosis of suspected urinary tract obstruction using a stimulated diuresis test

The aim of this study was to evaluate whether a stimulated diuresis test associated with ultrasound is able to differentiate pelvic dilation due to atonicity from pelviureteric junction obstruction (PUO). 42 patients (25 f, 17 m) with minimal or moderate renal pelvis dilation revealed by sonography were selected for the test. Three different measurements of the anteroposterior diameter (APD) of the renal pelvis were done at the renal hilus level, by using a transversal ultrasound scan: the first under spontaneous diuresis conditions, the second after hydration with 1.5 liters of water, and the third with a full bladder 15 min after intravenous injection of 20 mg frusemide. All the patients underwent pyelography. Baseline APD (bAPD) linearly correlated with the PAD both after hydration and frusemide (r = 0.89 and r = 0.84, respectively). A descriptive evaluation of the frequency distribution of the bAPD suggested the possibility that the data samples could belong to three populations with different underlying pathophysiological conditions. Correspondence analysis between bAPD distribution and PUO suggested that the best grouping of data was: group 1 (11 patients) bAPD < 13 mm, group 2 (14 patients) 13 > or = bAPD < or = 20 mm, group 3 (17 patients) bAPD > 20 mm (likelihood ratio chi 2 46.36; d.f. = 2). Standard intravenous pyelography showed an increase in pelvis size compatible with PUO in 2 patients from group 2 and in all patients from group 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Lymphocyte subpopulations of workers in a plant producing plastic materials (preliminary study)

Lymphocyte subpopulations were studied in 31 men working in a plant producing plastic materials in relation with control groups of similar age and smoking habit. 8 workers (group A) were exposed to solvents (mainly methylethylketone and dimethylformamide), 8 men (group B) to dust containing particles of calcium carbonate, polyvinylchloride, phtalates, unsaturated oils, paraffin wax, iron oxides, titanium bioxides, barium, zinc and lead and 15 men (group C), working in the same department as group B, were studied after a period of 16 months during which lead chromate was employed in the preparation of colors. The lymphocyte subpopulations were normal in group A, while in B there was a significant increase of HLA-DR + cells (monocytes, B and activated T lymphocytes). In group C, T helper/inducer lymphocytes (mainly CD4(+)-CD45RO- "virgin" lymphocytes), CD19+ B lymphocytes, CD3-HLADR+ and CD3-CD25+ (activated B lymphocytes and monocytes) were significantly reduced without changes of serum IgM, IgG and IgA. Highly significant correlation was found between B lymphocytes (reduced in the workers about 40%) and CD4(+)-CD45R0+ "memory" lymphocytes (reduced about 20%). Moreover, blood lead (correlated with urinary chromium) showed a highly significant negative correlation with the B lymphocytes. This study demonstrates that combined exposure to toxic agents produces specific modifications in the lymphocyte subsets without changes in immunoglobulins and confirms the results of previous researches showing that the exposure to lead or chromate induces reduction of lymphocytes in the peripheral blood.

Vanadate and cardiovascular system

Rats were given 1, 10, 40, or 100 ppm of vanadium in drinking water for seven months, while rabbits received 1 ppm of vanadium (as sodium metavanadate, NaVO3) in drinking water for twelve months. Rats developed arterial hypertension through complex effects of vanadium on central neurogenic pathways, central and periferal catecholaminergic mechanisms, specific autacoidal systems (kallikrein-kinin, reninangiotensin-aldosterone, enkephalin ones), and effectors (vessels and heart). The above effects of vanadium were in part confirmed in the rabbits which, however, did not show arterial hypertension since the increase of vascular resistance was counteracted by a reduction of both cardiac inotropism and cardiac output. Vanadium was accumulated in tissues as vanadyl; higher levels were found in the bone and in the kidney, but relevant amounts were determined in aorta, heart and brain. There was evidence, in the rabbits, that vanadium reduces synthesis and/or release of nitric oxide, the endothelium-derived vasodilating factor, likely through a reduced formation from bradykinin. The functional, analytical and morphological results obtained in this study show that chronic exposure to vanadium induces arterial hypertension by mechanisms only in part related to the levels and times of exposure, and to the species.

Reconstitution of Arabidopsis casein kinase II from recombinant subunits and phosphorylation of transcription factor GBF1

In contrast to the well-defined tetrameric structure of animal and yeast casein kinase II (CKII), plant CKII is found in two forms: a monomeric form and an oligomeric form whose subunit composition is not well defined. The Arabidopsis homologs of the catalytic subunit alpha (CKA1) and the regulatory subunit beta (CKB1) of CKII were expressed in Escherichia coli to examine their ability to form complexes, the effect of CKB1 on the catalytic activity, and the relationship of the recombinant enzymes to those isolated from plant material. Both subunits were found mainly in the inclusion body fraction in the bacterial expression strains, and they were solubilized and renatured with the recovery of catalytic (CKA1) and stimulatory (CKB1) activities. The combination of purified CKA1 and CKB1 proteins resulted in up to 100-fold stimulation of casein kinase activity compared with the CKA1 activity alone, showing that CKB1 has biochemical properties similar to those of the beta subunit from animals. CKA1 and CKB1 spontaneously assembled into a tetrameric complex, CKA1(2)CKB12, which had properties very similar to those of the oligomeric CKII form isolated from broccoli. However, the properties of the catalytic subunit CKA1 alone differed from those of the broccoli monomeric form of CKII-like activity. Phosphorylation of transcription factor GBF1 with the reconstituted CKA1(2)CKB1(2) enzyme resulted in stimulation of its DNA binding activity and retardation of the protein-DNA complex; these results are identical to those obtained previously with isolated nuclear CKII from broccoli.

Renal toxicity and arterial hypertension in rats chronically exposed to vanadate

The effects of 1, 10, or 40 micrograms/ml of vanadium, given for six or seven months as sodium metavanadate in drinking water on cardiovascular and biochemical variables and the electrolyte metabolism of male Sprague-Dawley rats were investigated. At the end of the exposure period, all animals exposed to vanadate had increased systolic and diastolic blood pressure. This effect was not dose dependent and heart rate and cardiac inotropism were not affected. The role of defective renal function and electrolyte metabolism in such effects was supported, in the rats exposed to 10 and 40 ppm of vanadium, by the following changes: (a) decreased Na, + K(+)-ATPase activity in the distal tubules of nephrons; (b) increased urinary excretion of potassium; (c) increase in plasma renin activity and urinary kallikrein, kininase I, and kininase II activities; (d) increased plasma aldosterone (only in the rats treated with 10 ppm of vanadium). The alterations in the rats exposed to 1 ppm of vanadium were: (a) reduced urinary calcium excretion; (b) reduced urinary kallikrein activity; (c) reduced plasma aldosterone. These results suggest that blood hypertension in rats exposed to vanadate depends on specific mechanisms of renal toxicity related to the levels of exposure.

[Aging of the aorta: a morphological study]

Aim of this study was to evaluate the aging of aorta with respect to atherosclerotic modifications: abdominal aorta echotomography is the preferred approach for this study. In 354 elderly patients, 65 and over, we have evaluated the diameter and the course of the aorta, the presence of atherosclerotic plaques in the aorta and iliac vessels, and the presence of aneurysms. Two kinds of findings could be identified by echotomography: age-related physiologic modifications, represented essentially by an increase of the aortic diameter; pathologic changes, characteristic for atherosclerosis, of which aneurysms are the most dangerous complications.

[Falls and fractures in the elderly. Causes and consequences]

OBJECTIVE

To evaluate the causes of non-pathologic traumatic fractures in the elderly and their consequences on quality of life.

DESIGN

A prospective trial.

FOLLOW-UP

12 months for the inpatients and 3 months for the outpatients.

SETTING

Basal assessment in orthopaedic hospital; follow-up in geriatric unit.

PATIENTS

Both inpatients and outpatients, 65 years and over, both sexes, both living in a nursing home and in their own home, admitted to an orthopaedic hospital because of a fall, with diagnosis of a subsequent fracture. Criteria of exclusion: patients with pathologic fracture. 121 patients were enrolled, 108 had a complete follow-up.

SURVEYS

Health and functional status prior to the fracture, causes and concomitant causes of the fall, site of the fracture, complications and functional disabilities.

RESULTS

The most frequent cause of fracture is an accidental fall, especially in younger elderly, other causes being acute cardiovascular and neurological diseases. Fractures occur more frequently in females. The most serious injuries affect frailer subjects, with advanced age, neurologic and multiple chronic diseases. Fracture of femur is the most frequent fracture and it has the highest risk complications, functional disabilities and death.

CONCLUSIONS

Because of the high frequency of accidental falls, the authors emphasize the necessity of primary prevention, especially the removal of architectural barriers both at home and in public environment.

Constitutive, light-responsive and circadian clock-responsive factors compete for the different l box elements in plant light-regulated promoters

The l box is a conserved regulatory motif which is found upstream of plant genes (rbcS, cab and nia) whose transcription is regulated by light and the circadian clock. Gel retardation and UV cross-linking assays were used to resolve two different groups of I box binding factors (IBFs) in tomato nuclear extracts. Active components of the first group (IBF-1) recognize the l box of the light-responsive rbcS promoter; one factor within this group, IBF-1a, also recognizes the adjacent G box, which has been shown previously to bind a different class of plant transcription factors, the G box binding factors (GBFs). To the limit of experimental resolution, IBF-1a and GBF compete for the same nucleotides on the G box. Nevertheless, these two activities are biochemically and immunologically distinct. The relative abundance of IBF-1a shows a vast decrease in dark-adapted plants. Factors in the second group (IBF-2), recognize the l box of the nia promoter, which is regulated both by light and the circadian clock; one factor within this group, IBF-2a, also binds the l box of a second promoter showing similar regulation, the cab promoter. The IBF-2a binding sites on the cab and nia promoters show extensive homology to a circadian clock-responsive promoter element from wheat. The abundance of IBF-2a is diurnally regulated and shows a dramatic induction around the onset of the light period. Transfer of the plants in continuous darkness demonstrates that this induction is under the control of a circadian clock.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of a sunflower (Helianthus annuus L.) mutant, deficient in carotenoid synthesis and abscisic-acid content, induced by in-vitro tissue culture

Genetic variation induced by tissue culture has been characterized in many species. The present study was conducted to genetically and phenotypically characterize an albino mutant in sunflower induced by in-vitro culture. A single recessive gene defective in carotenoid biosynthesis eventually leads to a chlorophyll loss due to photobleaching, absence of seed dormancy, and a low level of endogenous abscisic acid (ABA) in cotyledons and leaves. Further characterization has shown that the endogenous level of the hormone does not increase after drought stress and that the mutation prevents anthocyanin synthesis.

[Back pain in health care workers]

Back pain is a major health and economic problem for preventive medicine. It has been found to be significantly associated with nursing. The present paper reviews a number of epidemiological studies on back pain in nurses and examines the main confounding factors. The different approaches to back pain prevention are briefly discussed.

The use of recombinant interferon alfa-2b in elderly patients with anti-HCV-positive chronic active hepatitis

OBJECTIVE

To compare efficacy and tolerance of recombinant interferon alfa-2b in the treatment of anti-HCV-positive chronic active hepatitis (CAH) in subjects aged 65 years and above with those less than 65.

DESIGN

A randomized controlled trial.

SETTING

Outpatients in two hospitals.

PATIENTS

65 consecutive outpatients with anti-HCV-positive CAH for 1 to 30 years, having basal aminotransferase levels at least twice the normal value. Those 65 and over were randomized to an interferon group (A, n = 22) or a no-treatment group (B, n = 22). All those under 65 received interferon (group C, n = 21).

INTERVENTION

Interferon at a dose of 3 mU 3 times a week for a 6-month period. A normalization of serum aminotransferase levels was considered a positive response to therapy.

RESULTS

Response to therapy was positive in 62% of the treated elderly compared to 57% of the adults (P = 0.85). The two groups of responders showed a common highly significant reduction of aminotransferase (P < 0.001). Side effects were similar in elderly and young. Two untreated elderly showed spontaneous normalization of aminotransferase.

CONCLUSION

Interferon in anti-HCV-positive CAH is useful in the elderly, allowing normalization of aminotransferase, improvement of the histology and remission of the disease in 62% of the cases. Side effects seem to be independent of age. Further studies are required to assess both duration of remission and usefulness of cyclic therapy in previous responders.

Regulation of carotenoid biosynthesis during tomato development

Phytoene synthase (Psy) and phytoene desaturase (Pds) are the first dedicated enzymes of the plant carotenoid biosynthesis pathway. We report here the organ-specific and temporal expression of PDS and PSY in tomato plants. Light increases the carotenoid content of seedlings but has little effect on PDS and PSY expression. Expression of both genes is induced in seedlings of the phytoene-accumulating mutant ghost and in wild-type seedlings treated with the Pds inhibitor norflurazon. Roots, which contain the lowest levels of carotenoids in the plant, have also the lowest levels of PDS and PSY expression. In flowers, expression of both genes and carotenoid content are higher in petals and anthers than in sepals and carpels. During flower development, expression of both PDS and PSY increases more than 10-fold immediately before anthesis. During fruit development, PSY expression increases more than 20-fold, but PDS expression increases less than threefold. We concluded that PSY and PDS are differentially regulated by stress and developmental mechanisms that control carotenoid biosynthesis in leaves, flowers, and fruits. We also report that PDS maps to chromosome 3, and thus it does not correspond to the GHOST locus, which maps to chromosome 11.

Zinc and copper in tissues of rats with blood hypertension induced by long-term lead exposure

Male Sprague-Dawley rats received for 14 months 0, 15, 30 and 60 micrograms/ml of lead in drinking water. Both blood pressure and tissue lead were augmented with a dose-response effect, while cardiac inotropism was increased only in the rats treated with 60 ppm of lead. In the exposed animals, zinc and copper were unchanged in kidneys and testicles and augmented in the brain, while copper, but not zinc, was reduced in the heart. These data suggest a possible relation between the modifications of copper and zinc metabolism and the effects of lead on cardiovascular homeostasis.

High-performance liquid chromatographic determination of N-methylformamide and N-methyl-N-(hydroxymethyl)-formamide in human urine

A reliable high-performance liquid chromatographic (HPLC) method which allows the determination in human urine of two important metabolites of N,N-dimethylformamide (DMF), namely N-methylformamide (MMF) and N-methyl-N-(hydroxymethyl)formamide (DMFOH), is reported. A single-step rapid purification of urine was performed on a C18 solid-phase extraction column and the eluate was injected directly on to the HPLC column. HPLC was carried out isocratically on Aminex Ion Exclusion HPX-87H column using 7.5.10(-4) M sulphuric acid as the mobile phase with ultraviolet detection at 196 nm. The method is specific, accurate, precise and sufficiently sensitive to be applied to the biological monitoring of MMF and DMFOH in workers exposed to DMF.