Collagen-binding heat shock protein HSP47 expression during healing of fetal skin wounds

Wounds in fetal animals are known to heal without scar formation, but the mechanism involved remains unclear. Scar tissue is characterized by disorganized collagen bundles. The 47-kDa heat shock protein (HSP47) is a molecular chaperone that specifically targets collagen processing. However, the role of HSP47 in scar formation is poorly understood. We studied the relation of HSP47 expression in skin to scar formation during fetal wound healing. Immunohistochemical analysis demonstrated HSP47-positive cells in the epidermal cell layer of fetal and neonatal rat skin and the absence of such cells in subcutaneous tissue. After induction of a wound on the back of fetal and neonatal rats, the message of collagen type I was increased only in neonatal skin but not in fetal skin. HSP47-positive cells consistently increased for 7 days after wound induction in neonatal rats. In contrast, HSP47-positive cells and HSP47 protein were unchanged in fetal rats. We conclude that the scarless healing of fetal skin wounds is related to lack of change in HSP47 expression. HSP47 may thus be an important determinant of scar formation during wound healing.

Essential contribution of germline-encoded lysine residues in Jgamma1.2 segment to the recognition of nonpeptide antigens by human gammadelta T cells

Human gammadelta T cells display unique repertoires of Ag specificities largely imposed by selective usages of distinct Vgamma and Vdelta genes. Among them, Vgamma2/Vdelta2(+) T cells predominate in the circulation of healthy adults and respond to various microbial small molecular mass nonpeptide Ags. The present results indicate that the primary Vgamma2/Vdelta2(+) T cells stimulated with the distinct groups of nonpeptide Ags, including monoethyl pyrophosphate, isobutyl amine, and aminobisphosphonate, invariably exhibit Jgamma1.2 in the Vgamma2(+) TCR-gamma chains. Gene transfer studies revealed that most of the randomly cloned Vgamma2/Jgamma1.2(+) TCR-gamma genes bearing diverse Vgamma/Jgamma junctional sequences could confer the responsiveness to all these nonpeptide Ags, while none of the Vgamma2/Jgamma1.1(+) or Vgamma2/Jgamma1.3(+) TCR-gamma genes could do so. Furthermore, mutation of the lysine residues encoded by the Jgamma1.2 gene, which are unique in human Jgamma1.2 and absent in other human or mouse Jgamma segments, completely abrogated the responsiveness to all the nonpeptide Ags without affecting the response to anti-CD3 mAb. These results strongly suggested that the positively charged lysine residues in the TCR-gamma chain CDR3 region encoded by the germline Jgamma1.2 gene play a key role in the recognition of diverse small molecular mass nonpeptide Ags.

[Activities of thymidylate synthase and dihydropyrimidine dehydrogenase in patients with colorectal cancer]

Between 1998 and 2001, 82 colorectal cancers were resected in our hospital. The activities of TS and DPD were evaluated. TS activities in tumor tissues were significantly higher than in normal tissue, but the DPD activities had no significant difference between them. TS and DPD showed a correlation between normal and tumor tissues in stage III or IV patients. The TS value of patients with recurrence tended to be higher than that of patients with no recurrence. Especially in stage I or II patients with recurrence, who were administered 5-FU before recurrence, the TS value was significantly higher than in non-treated patients. In stage III or IV patients, it was considered that DPD prevention was important for 5-FU to effectively prevent TS. The TS value might be a new prospective risk factor for recurrence. Moreover, TS and DPD would be the index of biological malignancy.

Effects of adrenergic agonists on glycogenolysis in primary cultures of glycogen body cells and telencephalon astrocytes of the chick

The glycogen body (GB) is at the dorsal area of the lumbosacral spinal cord in birds and is composed of uniform cells that are characterized by high-glycogen storage. Previous morphological and embryological examinations suggest that the GB is derived from the neuroepithelium and contains many blood vessels and a few nerve fibers. However, the function of the GB and role of the glycogen are unknown. Mammalian astrocytes are major sites for glycogen stores in the central nervous system. The metabolic features of astrocytes have been defined by using cultured cells. As a first step toward investigating the function of GB, we established primary culture of chicken GB cells and telencephalon astrocytes. The cultured GB cells maintained high glycogen content and glial fibrillary acidic protein (GFAP) in the cytoplasm. The glycogen content of GB cells significantly increased with the glucose concentration in the medium. The effects of adrenergic agonists on glycogenolysis were different between GB cells and telencephalon astrocytes. The telencephalon astrocytes shared similar characteristics of glycogenolysis with mouse astrocytes, which are mainly affected by beta adrenergic receptor. Although GB cells were affected by noradrenalin (both alpha and beta adrenergic agonist), they were not affected by beta adrenergic agonist. These results showed that cultured GB cells were considered as one lineage of astrocytes because of their reactivity to antibody against GFAP; however, the metabolic features of GB cells were different from those of telencephalon astrocytes.

An open study of a lotion formulation to improve tolerance of tacrolimus in facial atopic dermatitis

BACKGROUND

We identified 19 patients with facial atopic eczema who failed to respond to tacrolimus (FK506) ointment, although tacrolimus ointment has shown excellent benefit for the treatment of recalcitrant facial erythema in most patients with atopic dermatitis.

OBJECTIVES

We attempted to determine the efficacy of an original lotion formulation of tacrolimus for facial atopic dermatitis resistant to tacrolimus ointment.

PATIENTS/METHODS

Recalcitrant facial erythema of these 19 patients was treated with an original tacrolimus lotion preparation for 6 months. Patch testing with white petrolatum was performed in both the 19 patients and in 30 other atopic dermatitis patients who had experienced excellent results with tacrolimus ointment.

RESULTS

Of the 19 resistant patients, those whose symptoms were greatly or moderately improved by the lotion were 95%, 89% and 89% after 2 weeks, 3 months and 6 months of treatment, respectively. Further, patch testing to petrolatum showed positive reactions in several (six of 19) patients, compared with none of 30 controls with atopic eczema that had responded to topical tacrolimus ointment.

CONCLUSIONS

The tacrolimus lotion had a significant effect on the recalcitrant facial erythema in adult patients with atopic dermatitis who were resistant to tacrolimus ointment. We suggest that one reason for the unresponsiveness to tacrolimus ointment may be because of contact sensitivity to white petrolatum.

[A case of squamous cell carcinoma of the oral floor showing a complete response to oral administration of UFT]

A 73-year-old male with squamous cell carcinoma of the oral floor (T1N0M0), who had not consented to radical treatment was treated with UFT by oral administration alone. After commencement of the administration, tumor remission was observed at 2 weeks and disappeared clinically at 8 weeks. The total period of oral administration of UFT was twenty-three months, and the total dose was 186.5 g as tegafur. Major adverse effects were pigmentation of hands and liver dysfunction. He remains under observation, and there is no evidence of tumor recurrence.

Expression of vascular endothelial growth factor in mouse tumours subjected to photodynamic therapy

The aim of this study was to define the appropriate fractionation interval between photodynamic therapy (PDT) for the enhancement of its anti-tumour effects. Tumour reoxygenation and the kinetics of tumour vascular cells following PDT were evaluated in mice by means of immunohistochemical staining for the vascular endothelial growth factor (VEGF) and the proliferating cell nuclear antigen (PCNA), respectively. The VEGF labelling indices (LIs) of the tumour cells and the PCNA LIs of the tumour vascular cells were assessed at various time intervals after PDT. The tumour cell VEGF LIs of the experimental groups at time points from 0 to 6 h after PDT were significantly higher than those of the control groups, but subsequently returned to control levels at 24 h after PDT. The vascular cell PCNA LI of the experimental group at 24 h after PDT was significantly lower than that of the control group, but returned to the control level at 48 h. These results indicated that the tumour subjected to PDT might be reoxygenated, and that the maximum damage to the tumour vasculature emerged at 24 h after PDT. We propose here that the fractionation interval between PDTs should be 24 h.

Validity and reproducibility of a self-administered food-frequency questionnaire to assess isoflavone intake in a japanese population in comparison with dietary records and blood and urine isoflavones

Valid food-frequency questionnaires (FFQ) need to be developed to assess isoflavone intake in investigations of its possible association with the lower incidence of breast and prostate cancer in Asian countries. We investigated the validity and reproducibility of isoflavone (daidzein and genistein) intakes from self-administered semiquantitative FFQ used in the JPHC Study (Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Diseases). We also investigated the number of food items that would be sufficient to ensure validity and reproducibility. We collected FFQ, dietary records (DR), blood and urine samples from 215 subjects among JPHC Study participants, estimated isoflavone intakes from FFQ and DR, and measured serum isoflavone concentration and urine isoflavone excretion. For daidzein, mean intakes estimated from FFQ and DR, serum concentration and urine excretion were 18.3 mg/d, 14.5 mg/d, 119.9 nmol/L and 17.0 micromol/d and for genistein, 31.4 mg/d, 23.4 mg/d, 475.3 nmol/L and 14.2 micromol/d, respectively. Results were similar when analyzed by sex. Spearman correlation coefficients for daidzein of energy-adjusted intakes from FFQ with those from DR, serum concentration and creatinine-adjusted urinary excretion were 0.64, 0.31 and 0.43, respectively. Correlations between two FFQ estimates with a 1-y interval were 0.76. Results were similar for genistein. The shorter version of the FFQ with three items (natto, miso and tofu for miso soup) showed a similar correlation. The original FFQ and the shorter versions have sufficient validity and reproducibility to be used in epidemiologic studies.

Lack of association between atopic eczema and the genetic variants of interleukin-4 and the interleukin-4 receptor alpha chain gene: heterogeneity of genetic backgrounds on immunoglobulin E production in atopic eczema patients

BACKGROUND

The genetic background of atopic eczema might be heterogeneous and there is a possibility that immunoglobulin (Ig)E responsiveness in patients with atopic eczema is controlled separately from the development of atopic eczema. Although both interleukin (IL)-4 and the IL-4 receptor alpha chain have an important role for IgE production and are therefore possible candidate genes for atopy, it has not been clarified whether these genes play any roles in atopic eczema patients who have normal IgE productivity.

OBJECTIVE

We aimed to assess whether the polymorphisms of the IL-4 gene and the IL-4 receptor alpha chain gene play any roles in atopic eczema patients, particularly in patients who have normal IgE productivity.

METHOD

We determined the genotype with regard to polymorphisms in the genes for IL-4 and the IL-4 receptor alpha chain (- 589C/T of IL-4; Ile50Val, Ala375Glu and Arg551Gln of IL-4 receptor alpha chain) in patients with atopic eczema using the fluorogenic 5' nuclease assay.

RESULTS

IL-4 and the IL-4 receptor alpha chain genotypes were not significantly associated with either total patients with atopic eczema or atopic eczema patients who had normal IgE productivity. The distribution of genotypes of IL-4-589C/T differed by the serum IgE levels in patients with atopic eczema.

CONCLUSION

These results suggest that the polymorphisms in the IL-4 gene and the IL-4 receptor alpha chain gene play no role in the development of atopic eczema in patients who have normal IgE productivity.

Intracellular localization of serotonin in mast cells of the colon in normal and colitis rats

Intracellular localization of serotonin (5-HT) in the mast cells of two phenotypes in normal rat colon and dextran sodium sulphate-induced colitis was studied by immunoelectron microscopy with a quantitative analysis of the distribution of immunogold labelling. Mucosal mast cells in normal rats contained round shape secretory granules with varying electron density. Immunogold labelling for 5-HT was concentrated over the secretory granules. In mucosal mast cells from colitis rats, vacuolated granules without 5-HT labelling were frequently observed and immunogold labelling over the secretory granules was significantly increased compared to controls. On the other hand, connective tissue mast cells in normal rats contained oval shape secretory granules with homogeneous electron density. Their immunogold labelling was diffusely scattered over the secretory granules as well as over the cytoplasm. In connective tissue mast cells from colitis rats, secretory granules with high electron density were increased and the immunogold labelling over the secretory granules was much higher than that in controls. The present results suggest that intracellular localization of 5-HT is different in two phenotypes of mast cells and they may release 5-HT in a different manner. Mucosal mast cells may release 5-HT by a degranulation or exocytosis, while connective tissue mast cells may release 5-HT by a diacrine manner of secretion.

Blood supply to the platysma muscle flap: an anatomic study with clinical correlation

PURPOSE

This study evaluated the blood supply of the superiorly based and posteriorly based platysma muscle myocutaneous flap.

MATERIALS AND METHODS

Four fresh cadaver specimens were injected with Microfil (Flow Technologies, Inc, Carver, ME) red stain in the common carotid artery and blue stain in the brachiocephalic vein. To clarify the blood supply to the platysma muscle, the blood vessels were first identified on lateral and posteroanterior radiographs of the specimens. Subsequently, anatomic dissection of the arteries and veins associated with the platysma muscle and overlying skin was performed.

RESULTS

The submental artery was the primary vessel to the platysma muscle. The superior thyroid artery, occipital artery, and posterior auricular artery were identified as secondary vessels. The external jugular vein provided the primary venous drainage, followed by the submental vein.

CONCLUSIONS

The superiorly based design has a reliable arterial blood supply (facial and submental arteries) and poor venous drainage. The posteriorly based design has a reliable venous drainage (external jugular vein), but the arterial blood supply is almost random (occipital artery).

Changes in the seasonal dependence of atopic dermatitis in Japan

Although it has been generally accepted that seasonal aggravation of skin symptoms is a basic feature of atopic dermatitis, recent studies have suggested a decrease in the seasonal dependence of the dermatosis in European countries over the past several decades. We examined incidence of seasonal deterioration of atopic dermatitis in Japanese subjects. The study population consisted of 682 patients aged 3 to 30 years with atopic dermatitis, who visited our outpatient clinic from August 1998 through July 2000. Of these, 452 (66%) showed a seasonal aggravation of skin symptoms, and 230 (34%) had perennial deterioration. The overall incidences of exacerbation in spring, summer, autumn and winter were 25%, 19%, 11% and 36%, respectively. Further, 358 (52%) showed unpredictable and irregular exacerbations of skin symptoms every few days or weeks. These irregular worsenings were more frequent in patients who showed perennial deterioration than in those with seasonal aggravation. From a comparison of the present results with those reported in the 1960s, it became evident that a real decrease in the incidence of seasonal aggravation of atopic dermatitis has occurred over the past three decades in Japan and that the incidence of summer deterioration has greatly decreased during the same period of time.

Application of the membrane filter technique to bromodeoxyuridine immunochemistry for exfoliative cytology

The membrane filter technique for smear specimens of tumors in bromodeoxyuridine (BrdU) immunochemistry is described. The staining results of Raji cells processed using the filter technique was compared with that obtained by the conventional cytospin method. Although the BrdU mean labeling index (LI) for in cytospin specimens was almost the same as the LI in membrane filter specimens, filter specimens showed excellent staining and less cell destruction compared with those processed by cytospin. Small amounts of tumor specimens such as squamous cell carcinoma and polymorphous low-grade adenocarcinoma also were processed using the membrane filter appliance. For squamous cell carcinoma, the LI for the filter specimens was 5.36+/-0.38 and that of the paraffin sections was 5.56+/-0.38. The membrane filter technique provided relatively undamaged specimens for exfoliative cytology and will be useful for immunohistochemical evaluation of tumor cells and for routine, noninvasive cytological screening.

Differential localization of prohormone convertases PC1 and PC2 in two distinct types of secretory granules in rat pituitary gonadotrophs

Prohormone convertases PC1 and PC2 are endoproteases involved in prohormone cleavage at pairs of basic amino acids. There is a report that prohormone convertase exists in the rat anterior pituitary gonadotrophs, where it had previously been considered that proprotein processing does not take place. In addition to luteinizing hormone and follicle-stimulating hormone, rat pituitary gonadotrophs contain chromogranin A (CgA) and secretogranin II (SgII), two members of the family of granin proteins, which have proteolytic sites in their molecules. In the present study we examined whether there is a close correlation between subcellular localization of prohormone convertases and granin proteins. Ultrathin sections of rat anterior pituitary were immunolabeled with anti-PC1 or -PC2 antisera and then stained with immunogold. Immunogold particles for PC1 were exclusively found in large, lucent secretory granules, whereas those for PC2 were seen in both large, lucent and small, dense granules. The double-immunolabeling also demonstrated colocalization of PC2 and SgII in small, dense granules and of PC1, PC2, and CgA in large, lucent granules. These immunocytochemical results suggest that PC2 may be involved in the proteolytic processing of SgII and that both PC1 and PC2 may be necessary to process CgA.

Fine structure of the retino-optic nerve junction in the chicken

The aim of this study is to investigate a fine structure of the retino-optic nerve junction in the chicken. We especially focused on the myelin sheaths and astrocytes in the intraocular optic nerve (ION) and its adjoining parts. A part of the axons of retinal nerve fiber layer (NFL) were myelinated. Ganglion cell axons were ensheathed by loose myelin in the NFL and by a compact one in the ION and optic nerve (ON). Myelin structure changed from loose type to a compact one within the very narrow NFL-ION junction. Loose myelin forming cells are dark type of oligodendrocytes in the retina. From the most peripheral ON to the choroidal part of ION, astrocytes contained abundant microtubules. The optic nerve around the lamina cribrosa is exposed to mechanical force during eye movement. It is suggested that these microtubules may perform the cytoskeletal function. Astrocytes in the retinal part of ION had longer processes filled with abundant gliofilaments. They may provide the mechanical support for the ganglion cell axons, which are exposed directly to intraocular pressure. Although astrocytes in the retinal level of ION extended their processes into the retina, their soma was never found in the retina.

Greater effect of dietary potassium tripolyphosphate than of potassium dihydrogenphosphate on the nephrocalcinosis and proximal tubular function in female rats from the intake of a high-phosphorus diet

We examined whether a difference in potassium dihydrogenphosphate (KH2PO4) and potassium tripolyphosphate (K5P3O10) as dietary phosphorus sources could differentially effect the nephrocalcinosis and proximal tubular function in female rats. Rats were fed on a diet containing KH2PO4 or K5P3O10, at the normal phosphorus level (normal phosphorus diet) or at a high phosphorus level (high-phosphorus diet) for 21 d. Nephrocalcinosis, as confirmed by a histological examination, was apparent in all rats fed on the high-phosphorus diet, and this condition was more severe in those rats fed on K5P3O10 than in those fed on KH2PO4. As indicators of the proximal tubular function, the N-acetyl-beta-D-glucosaminidase activity in urine and the urinary beta2-microglobulin excretion were significantly increased in those rats fed on the high-phosphorus diet containing K5P3O10. These results indicate that the intake of a high-phosphorus diet, more strongly influenced the nephrocalcinosis and proximal tubular function when K5P3O10 rather than KH2PO4 was used as the dietary phosphorus source.

Distribution of reticulospinal neurons in the chicken by retrograde transport of WGA-HRP

To determine the distribution of reticulospinal (RS) neurons in the chicken, WGA-HRP was injected into the cervical or lumbosacral enlargement either unilaterally or bilaterally. The brainstem reticular nuclei sent largely descending fibers to both the spinal enlargements. The mesencephalon (medial and lateral mesencephalic reticular formation) and the rostral pons (nucleus reticularis [n.r.] pontis oralis) project mainly to the cervical enlargement. RS neurons were mainly distributed from the pontomedullary junction to the rostral medulla including n. r. pontis caudalis and pars gigantocellularis, n. r. gigantocellularis, n. r. parvocellularis, n. r. paragigantocellularis, and n. r. subtrigeminalis. It is suggested that the majority of these neurons send axons at least as far as the lumbosacral enlargement. In the lower medulla, RS neurons were distributed in the dorsal and ventral parts of the central nucleus of the medulla.

Dietary fructooligosaccharides modify intestinal bioavailability of a single dose of genistein and daidzein and affect their urinary excretion and kinetics in blood of rats

The influence of dietary fructooligosaccharides (FOS) on bioavailability of genistein and daidzein in rats was estimated by measuring their concentrations in plasma collected from three different veins and in urine after a single intragastric administration of isoflavone conjugates. Sprague-Dawley male rats (6 wk old, n = 22) were fed a purified control (AIN-93G) diet or a FOS diet (AIN-93G + 5% FOS) for 7 d. A single dose of soy isoflavone conjugates, i.e., 8.5 mg as genistein and 33 mg as daidzein/kg body, was administered via a stomach tube at d 5. Blood samples were collected after administration via catheters in the portal and central veins and by puncture of the tail vein. The isoflavones in plasma and urine were analyzed by time-resolved fluoroimmunoassay. The genistein concentration in the portal blood increased rapidly, reaching a peak of 3.5 micromol/L in both groups at 1 h after administration. The concentrations in the central and tail venous blood were approximately half of those in the portal blood. In the FOS-fed group, both genistein and daidzein remained detectable at 24 and 48 h in the tail venous plasma. The urinary excretion of both isoflavones in the 24- to 48-h period after administration was significantly higher in the FOS-fed group than in the control group. The difference between the portal and central veins indicated hepatic uptake, probably leading to conjugation of aglycones and excretion into bile. FOS modified the absorption and enterohepatic recirculation of isoflavones.

Laterality of the spinocerebellar axons and location of cells projecting to anterior or posterior cerebellum in the chicken spinal cord

In the cervical and lumbosacral enlargements of the chicken, there are seven spinocerebellar nuclei, the Clarke's column, the spinal border cells, the ventral margin of the ventral horn of both enlargements, and the ventral marginal nucleus in the lumbosacral enlargement. In the present study, we investigated the laterality of spinocerebellar tract axons and the distribution of the spinocerebellar tract neurons projecting into the anterior or posterior part of the cerebellum in these seven nuclei by retrograde transport of wheat germ agglutinin-horseradish peroxidase. The spinocerebellar tract neurons with uncrossed axons were found in the cervical Clarke's column and the cervical spinal border cells, and with crossed ones in the lumbar Clarke's column, lumbar spinal border cells, lumbar lamina IX included in the ventral margin of the ventral horn of the lumbosacral enlargement, and the ventral marginal nucleus. The ventral margin of the ventral horn of the cervical enlargement and lumbar lamina VIII included in the ventral margin of the ventral horn of the lumbosacral enlargement issued spinocerebellar tract axons bilaterally. The spinocerebellar tract neurons of the lumbar spinal border cells and lumbar lamina IX projected to the anterior part of the cerebellum only. And those of the other nuclei projected to both the anterior and posterior parts.

Distribution of reticulocerebellar neurons in chicken reticular formation

The distribution of reticulocerebellar (RC) neurons was examined by the retrograde transport of horseradish peroxidase (HRP) or wheat germ agglutinin bound to HRP (WGA-HRP) in 7 White Leghorn chickens. A large number of labeled cells were found in the nucleus reticularis pontis caudalis (RP) of the pontomedullary junction and in the nucleus reticularis gigantocellularis (Rgc), parvocellularis (Rpc), subtrigiminalis (Rst), paragigantocellularis (Rpg) and paramedianus (RpaM) in the medulla. Slightly ventral to the vestibulocochlear nerve were many large RC neurons arranged in a longitudinal manner along the lateral edge of the brainstem reticular formation (the Dorsolateral edge cells, DLe cells). RC neurons were most numerous in the Rgc and accounted for 31.9% of the total number of labeled cells, followed by RP (24.2%), Rpc (12.7%), Rpg (10.8%), RpaM (6.7%), DLe cells (6.3%) and Rst (4.9%). The great number of RC neurons was found around the levels of the vestibulocochlear nerve.

A trial of oolong tea in the management of recalcitrant atopic dermatitis

BACKGROUND

Mild cases of atopic dermatitis (AD) generally improve with standard treatment. However, standard treatment fails many patients with recalcitrant AD skin lesions. Study results in animal models have demonstrated that the administration of tea (ie, green, black, or oolong) has suppressed type I and type IV allergic reactions.

OBJECTIVE

To test the effectiveness of oolong tea in the treatment of recalcitrant AD.

PATIENTS

Although 121 patients with recalcitrant AD were enrolled in the study, 118 patients completed the open study.

METHODS

Patients were asked to maintain their dermatological treatment. However, they were also instructed to drink oolong tea made from a 10-g teabag placed in 1000 mL of boiling water and steeped for 5 minutes. This amount was then divided into 3 equal servings and 1 serving was drunk daily after 3 regular meals. Photographs of 2 or 3 representative lesion sites were taken at baseline and at 1 and 6 months and the severity of pruritus was assessed on a 6-point Lickert-like scale ranging from markedly improved (>50% improvement) to worsened.

RESULTS

After 1 month of treatment 74 (63%) of the 118 patients showed marked to moderate improvement of their condition. The beneficial effect was first noticed after 1 or 2 weeks of treatment. A good response to treatment was still observed in 64 patients (54%) at 6 months.

CONCLUSION

The therapeutic efficacy of oolong tea in recalcitrant AD may well be the result of the antiallergic properties of tea polyphenols.

Causal relationship between a case of severe hepatic dysfunction and low exposure concentrations of N,N-dimethylformamide in the synthetics industry

A 19-year-old man suffered hepatic dysfunction after 5 months of exposure to N,N-dimethylformamide (DMF) at his job in the synthetic resins industry. Laboratory data revealed elevated levels of AST (578 IU/l), ALT (1193 IU/l), and gamma-GTP (107 IU/l), no viral infection with HAV, HBV, or HCV, and no history or evidence of hepatic injury, although he did have a slight abdominal abnormality and swelling which was detected by palpation. His urinary N-methylformamide level, as a biological exposure index of DMF, was 42.8 mg/l, indicating 10-30 ppm of DMF exposure. After 2 months he was reinstated in two workplaces, the former where he worked in the morning and the other in the afternoon where environmental DMF concentrations were less than those in the former workplace. On the 18th day after his reinstatement, his liver function became exasperated again. After the second period of medication and one month of rest from work, he had fully recovered and was reinstated, but to a workshop without DMF exposure.