Reproductive history, occupational exposures, and thyroid cancer risk among women textile workers in Shanghai, China

OBJECTIVES

Thyroid cancer risk has been previously associated with increased age at first pregnancy and history of miscarriage. Occupational risk factors for thyroid cancer, with the exception of radioactive iodine, have not been well investigated. We conducted a case-cohort study nested in a cohort of 267,400 female textile workers in Shanghai, China, who had been followed for cancer incidence during 1989-1998.

METHODS

The analysis included 130 incident thyroid cases and 3,187 subcohort non-cases. Reproductive history was determined by questionnaire at baseline. Historical exposures were reconstructed from work history and information on factory processes and exposures. Cox proportional hazards analysis was performed to estimate hazard ratios (HR) for reproductive factors and occupational exposures.

RESULTS

Associations were observed between thyroid cancer and employment in jobs with 10 or more years of benzene exposure (HR 6.43, 95% CI: 1.08, 38) and formaldehyde exposure (HR 8.33, 95% CI: 1.16, 60). Administration workers also had an increased risk (HR 1.56, 95% CI: 1.08, 2.25). No associations between examined reproductive factors and thyroid cancer were observed in this study.

CONCLUSIONS

Despite statistically imprecise risk estimates, the findings suggest potential associations with some occupational chemical exposures in this cohort of textile workers.

Effect of preoperative short course famotidine on TILs and survival in breast cancer

BACKGROUND

Histamine receptor antagonists have been shown to induce tumor-infiltrating lymphocytes (TILs) in colonic cancers and improve survival. The role of histamine receptor anatagonists in breast cancer is unclarified.

AIM

To evaluate the role of histamine receptor antagonists in inducing (TILs) in breast cancer.

METHOD

Forty-five patients with operable breast cancers (25 cases who received preoperative famotidine and 20 controls) were studied for the effect of famotidine in inducing TILs and survival in breast cancer.

RESULTS

Significant TILs were seen in 75% (18/24) of cases as opposed to 35% (7/20) controls. In logistic regression analysis the only variable found to be predictive of TILs was famotidine, odds ratio 7.324 (1.693-31.686) P=0.008. In Cox's regression presence of TILs was favorably associated with improved disease free survival at a median follow up of 35.56 months. The hazard ratio for disease relapse was 3.327 (1.174-9.426) P=0.024 in TIL negative as compared to TIL positive patients. Famotidine use alone was not significant in the original model, however, on incorporation of quadrant of involvement in addition to other established prognostic factors in the above multivariate model, it assumed borderline significance with a hazard ratio for disease free survival 3.404 (1.005-11.531, P=0.049).

CONCLUSIONS

Preoperative short course famotidine induces TILs in breast cancer. Patients with TILs demonstrable in tumor specimens had an improved disease free survival. Famotidine may improve disease free survival in breast cancer and these findings need validation in larger population subsets.

Thrombotic thrombocytopenic purpura associated with Human Immunodeficiency Virus infection

Thrombotic thrombocytopenic purpura (TTP) belongs to the group of diseases called Thrombotic microangiopathies (TMA). While several triggering conditions are known, often none is apparent in the individual case. We report a patient presenting with TTP that was associated with a Human Immunodeficiency Virus (HIV) infection, with its consequent diagnostic, therapeutic and prognostic implications. Further, our case had individual clinical features that were of interest within the TTP-HIV subgroup.

Cardiac myxoma with glandular elements: a histologic, histochemical, and immunohistochemical evaluation

Epithelial differentiation in cardiac myxoma is a rare phenomenon. Out of 104 surgically excised specimens, we studied 3 cases of cardiac myxoma with glandular differentiation. All the cases had well formed glands in addition to the myxoma cells lying in a myxoid background. Detailed histochemical and immunohistochemical studies suggest that the epithelial islands in cardiac myxoma show an enteric phenotype.

Discovery of novel targets of quinoline drugs in the human purine binding proteome

The quinolines have been used in the treatment of malaria, arthritis, and lupus for many years, yet the precise mechanism of their action remains unclear. In this study, we used a functional proteomics approach that exploited the structural similarities between the quinoline compounds and the purine ring of ATP to identify quinoline-binding proteins. Several quinoline drugs were screened by displacement affinity chromatography against the purine binding proteome captured with gamma-phosphate-linked ATP-Sepharose. Screening of the human red blood cell purine binding proteome identified two human proteins, aldehyde dehydrogenase 1 (ALDH1) and quinone reductase 2 (QR2). In contrast, no proteins were detected upon screening of the Plasmodium falciparum purine binding proteome with the quinolines. In a complementary approach, we passed cell lysates from mice, red blood cells, or P. falciparum over hydroxychloroquine- or primaquine-Sepharose. Consistent with the displacement affinity chromatography screen, ALDH and QR2 were the only proteins recovered from mice and human red blood cell lysate and no proteins were recovered from P. falciparum. Furthermore, the activity of QR2 was potently inhibited by several of the quinolines in vitro. Our results show that ALDH1 and QR2 are selective targets of the quinolines and may provide new insights into the mechanism of action of these drugs.

Colour Doppler and grey scale ultrasound features of HIV-related vascular aneurysms

Atypical aneurysms of large elastic arteries owing to human immunodeficiency virus (HIV) vasculopathy are a well described complication of acquired immunodeficiency syndrome (AIDS). However, there are no reports describing the ultrasound features of these lesions. We performed a retrospective review of ultrasound images of 12 patients presenting with 39 HIV-related aneurysms over a 2 year period. Of these there were a total of 12 patients with symptomatic lesions comprising the superficial femoral artery (n=5), the origin of the internal carotid artery (n=3), the popliteal artery (n=2), the common femoral artery (n=1) and the common iliac artery (n=1). The remainder were asymptomatic and were demonstrated radiologically. The ultrasound features of large symptomatic HIV-related femoral and carotid aneurysms were typical of pseudoaneurysms with a defect or "blow-out" in the vessel wall and turbulent pulsatile flow. Of note was the presence of marked thickening of the vessel adjacent to the aneurysm and hyperechoic "spotting" of the arterial wall. These ultrasound features described may be unique to HIV vasculopathy.

Ketamine dependence

Ketamine hydrochloride is a safe and rapid-acting non-opioid, lipid soluble anaesthetic with a short elimination half-life that is used for medical and veterinary purposes. It produces a state of "dissociative anaesthesia", probably from action on N-methyl-D-aspartate (NMDA) receptors. The psychotropic effects of ketamine range from dissociation and depersonalization to psychotic experiences and include a sensation of feeling light, body distortion, absence of time sense, novel experiences of cosmic oneness and out-of-body experiences. Abuse of ketamine has been reported, the typical abuser being an individual who uses multiple drugs and has some contact with medical agencies. This case demonstrates the effects of large doses of ketamine in a person with polysubstance abuse. The case also highlights development of significant tolerance to ketamine without prominent withdrawal symptoms. Caution in use of ketamine is reiterated in light of its abuse liability.

Giant cell arteritis--a rare cause of fever of unknown origin in India

Giant cell arteritis (GCA) is a systemic large vessel vasculitis. Awareness of various manifestations of GCA is essential for early recognition and prompt treatment so as to prevent complications like blindness. GCA is one of the relatively common causes of fever of unknown origin (FUO) in the elderly in USA and Europe. However, no such cases have been reported from India. A case of GCA presenting as FUO is reported and the literature reviewed.

Combined role of Casoni test and indirect haemagglutination test in the diagnosis of hydatid disease

PURPOSE

To study the combined role of Casoni test and indirect haemagglutination (IHA) test in the diagnosis of hydatid disease.

METHODS

Twenty eight suspected cases of hydatid disease were subjected to Casoni intradermal test using commercially available antigen (Span Diagnostics, India) after collecting pre-test serum samples. The serum samples were tested by IHA using an indigenously developed IHA test.

RESULTS

Considering the clinical diagnosis of hydatid disease as the gold standard, the specificity of both Casoni test and IHA was 47%, however, the sensitivity of IHA was higher (81.8%) than Casoni test (63.8%). With the two tests considered together the sensitivity was 90.9%.

CONCLUSIONS

Combined use of Casoni test and IHA test could establish presumptive and cost effective diagnosis in upto 90.9% of clinically suspected cases of hydatid disease.

Sulfur mustard-stimulated protease: a target for antivesicant drugs

One of the mechanisms of the skin blistering effect (vesication) of sulfur mustard (bis-(2-chloroethyl)sulfide, HD) is believed to be via the stimulation of specific protease(s) at the dermal-epidermal junction. Cultured normal human epidermal keratinocytes (NHEK) were used as a model to study and characterize protease stimulated by the mustards 2-chloroethyl ethyl sulfide (CEES), 2-chloro-N-(2-chloroethyl)-N-methylethanamine hydrochloride (nitrogen mustard, HN(2)) and HD. The results obtained using a chromozym (TRY) peptide substrate protease assay revealed the optimum mustard concentrations and time for protease stimulation to be about 200 microM (CEES), 100 microM (HN(2)) and 100 microM (HD) and 16 h. The mustard-stimulated protease was membrane bound and was inhibited by adding a Ca(2+) chelator (either 2 mM EGTA (ethylene glycol-bis(amino ethyl ether) N,N,N',N' tetraacetic acid) or 50 microM BAPTA AM (1,2-bis(z-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, tetraacetoxy methyl ester) alone or in combination), a serine protease inhibitor diisopropyl fluoro-phosphate (DFP, 1 mM), or a protein synthesis inhibitor cycloheximide (35 microM) in the extracellular medium. These results suggest that mustard toxicity may involve the stimulation of trypsin/chymotrypsin-like serine protease, dependent on Ca(2+) and new protein synthesis. Protein purification by gel exclusion and hydrophobic chromatography produced a 70-80 kDa protease, which had an amino acid sequence homologous with a mammalian-type bacterial serine endopeptidase. Based on this information, research is in progress to identify the protease stimulated by HD in NHEK and to determine whether its inhibitors are useful as prospective antivesicant drugs.

Experimental studies on synergism between aminoglycosides and the antimicrobial antiinflammatory agent diclofenac sodium

The antiinflammatory agent diclofenac sodium (Dc) exhibited remarkable antibacterial effects both in vitro and in vivo. Fifteen different bacteria sensitive to Dc as well as to a number of common antibiotics were tested for synergistic effects in vitro. Disc diffusion test with Dc and aminoglycosides assessed by stringent computation showed clear-cut synergism. Synergism between Dc and streptomycin (Sm) was found to be statistically significant (p < or = 0.01) when compared with their individual effects. By the checkerboard assessment procedure, the fractional inhibitory concentration (FIC) index of this combination was found to be 0.49, confirming synergism. The mouse protective capacity of this combination was then evaluated in vivo against S. typhimurium as the virulent infecting bacterium, and the size of bacterial load determined from infected autopsied animals. Statistical analysis by Student's 't' test suggested this drug combination is highly synergistic; synergism was also noted between Dc and other aminoglycosides.

Potentiality of a new compound for in vitro differentiation between halophilic and non-halophilic vibrios

Sensitivity of 21 halophilic vibrios and 16 clinical isolates of non-halophilic vibrios was determined against a new possible antivibrio agent, a pyrimidine analogue, 4, 6-dimethylpyrimidine -2-thiol (4,6-DMPT). It appeared to be a vibriocidal agent, having a mean MIC and MBC of 32 microg/ml for halophilic strains and 64 microg/ml for non-halophilic strains and an LD50 of 300 mg/Kg body weight of mice. Thus, 4,6-DMPT may help an in vitro distinction between halophilic and non-halophilic vibrios. Sensitivity of these strains was also studied with respect to pteridine, crystal violet and Tween 80 hydrolysis as further markers distinguishing between these 2 groups which could also be differentiated by their growth on TCBS or/and CLED media.

PARP determines the mode of cell death in skin fibroblasts, but not keratinocytes, exposed to sulfur mustard

Sulfur mustard is cytotoxic to dermal fibroblasts as well as epidermal keratinocytes. We demonstrated that poly(ADP-ribose) polymerase (PARP) modulates Fas-mediated apoptosis, and other groups and we have shown that PARP plays a role in the modulation of other types of apoptotic and necrotic cell death. We have now utilized primary dermal fibroblasts, immortalized fibroblasts, and keratinocytes derived from PARP(-/-) mice and their wildtype littermates (PARP(+/+)) to determine the contribution of PARP to sulfur mustard toxicity. Following sulfur mustard exposure, primary skin fibroblasts from PARP-deficient mice demonstrated increased internucleosomal DNA cleavage, caspase-3 processing and activity, and annexin V positivity, compared to those derived from PARP(+/+) animals. Conversely, propidium iodide staining, PARP cleavage patterns, and random DNA fragmentation revealed a dose-dependent increase in necrosis in PARP(+/+) but not PARP(-/-) cells. Using immortalized PARP(-/-) fibroblasts stably transfected with the human PARP cDNA or with empty vector alone, we show that PARP inhibits markers of apoptosis in these cells as well. Finally, primary keratinocytes were derived from newborn PARP(+/+) and PARP(-/-) mice and immortalized with the E6 and E7 genes of human papilloma virus. In contrast to fibroblasts, keratinocytes from both PARP(-/-) and PARP(+/+) mice express markers of apoptosis in response to sulfur mustard exposure. The effects of PARP on the mode of cell death in different skin cell types may determine the severity of vesication in vivo, and thus have implications for the design of PARP inhibitors to reduce sulfur mustard pathology.

Cubilin dysfunction causes abnormal metabolism of the steroid hormone 25(OH) vitamin D(3)

Steroid hormones are central regulators of a variety of biological processes. According to the free hormone hypothesis, steroids enter target cells by passive diffusion. However, recently we demonstrated that 25(OH) vitamin D(3) complexed to its plasma carrier, the vitamin D-binding protein, enters renal proximal tubules by receptor-mediated endocytosis. Knockout mice lacking the endocytic receptor megalin lose 25(OH) vitamin D(3) in the urine and develop bone disease. Here, we report that cubilin, a membrane-associated protein colocalizing with megalin, facilitates the endocytic process by sequestering steroid-carrier complexes on the cellular surface before megalin-mediated internalization of the cubilin-bound ligand. Dogs with an inherited disorder affecting cubilin biosynthesis exhibit abnormal vitamin D metabolism. Similarly, human patients with mutations causing cubilin dysfunction exhibit urinary excretion of 25(OH) vitamin D(3). This observation identifies spontaneous mutations in an endocytic receptor pathway affecting cellular uptake and metabolism of a steroid hormone.

Elevated levels of high-mobility-group chromosomal proteins, HMGA1, in murine skin carcinoma

The high-mobility-group, HMGA1 (formerly HMGI(Y)) chromosomal proteins are known to be involved in gene regulation and their high expression is associated with neoplastic transformation of cells and metastatic tumor progression. Here, we present our results on the expression of HMGA1 in murine skin carcinoma as detected by acid-urea electrophoresis, reverse-phase high-performance liquid chromatography and Western blot. The enhanced expression of HMGA1 proteins directly correlates with the extent of cellular atypia and neoplastic changes noticed in the histopathology of tumor and suggest a potential use of these proteins as marker for determining the grade of skin tumor.

Patients in treatment centres: are they all dependents?

The congruence between self reported drug use and urinalysis data among 89 consecutive opioid dependents at their first contact in an outpatient clinic was examined. For this purpose self reports of drug use within preceding 72 hr, laboratory analysis of urine samples by thin layer chromatography (TLC) were carried out for various drugs. The same samples were also confirmed by gas liquid chromatography (GLC). Many subjects reported concomitant poly-drug use. The base rate was found to be low for other drugs besides heroin. The conclusion could be dra wn more con vincingly as regard heroin use. Inaccuracy in self-report of drug use has been observed using GLC as a gold standard. The subjects are likely to be more accurate when they report abstinence than when reporting drug use. These results also suggest that clinicians should be cautious while prescribing agonist/partial agonists especially based on only self-report for long term maintenance program, as many patients may not be really physiolologically dependent.

Hepatitis C virus core protein modulates the interferon-induced transacting factors of Jak/Stat signaling pathway but does not affect the activation of downstream IRF-1 or 561 gene

Hepatitis C virus (HCV) has a propensity to cause chronic infection, with a low proportion of patients exhibiting a sustained response to interferon-alpha (IFNalpha) therapy. An earlier report suggested that HCV inhibits IFNalpha-induced signal transduction through the Jak/Stat pathway by preventing the formation of the transacting factor ISGF3 complex, although the effect on downstream pathway and the specific viral protein responsible for inhibition of IFNalpha-mediated signal transduction were not elucidated. HCV core protein displays a number of intriguing functional properties and has been implicated in virus-mediated pathogenesis. In this study, we have analyzed the effect of core protein upon IFNalpha- or IFNgamma-induced regulation of the Jak/Stat signaling pathway. HCV core protein expression exhibited a reduced Stat1 expression in IFN-treated mammalian cells. A gel retardation assay suggested a reduced level of formation of the transacting factors, GAF and ISGF3, in IFN-treated cells. Further studies from protein expression and RNase protection assay revealed that the reduced level of GAF or ISGF3 formation could be attributed to modulation of Stat1 protein expression, an important player for innate immunity in host defense mechanism. However, these modulatory effects did not interfere with the activation of the downstream effector genes, IRF-1 and 561, in IFN-treated cells. Stable transfectants of cells after introduction of a plasmid DNA encoding both the structural and the nonstructural proteins of HCV also exhibited a similar effect. Taken together, these results suggest that although expression of the core protein alone or with other HCV proteins modulate transacting factors of Jak/Stat signaling pathway, expression of the downstream effector genes IRF-1 and 561 remains unaffected upon IFN treatment and may contribute to host defense mechanism.

Hepatitis C virus core protein: intriguing properties and functional relevance

Hepatitis C virus (HCV) often causes a prolonged and persistent infection, and an association between hepatocellular carcinoma (HCC) and HCV infection has been noted. The pathogenesis of liver damage is at least in part related to virus-mediated factors. Understanding the molecular basis of pathogenesis is a major challenge in gaining insight into HCV-associated disease progression. Recent experimental evidence using HCV cloned genomic regions suggests that the core protein has numerous functional activities. These include its likely role in encapsidation of viral RNA, a regulatory effect on cellular and unrelated viral promoters, interactions with a number of cellular proteins, an modulatory role in programmed cell death or apoptosis under certain conditions, involvement in cell growth promotion and immortalization, induction of HCC in transgenic mice, and a possible immunoregulatory role. These intriguing properties suggest that the core protein, in concert with cellular factors, may contribute to pathogenesis during persistent HCV infection.

Baculovirus-expressed vitamin D-binding protein-macrophage activating factor (DBP-maf) activates osteoclasts and binding of 25-hydroxyvitamin D(3) does not influence this activity

Vitamin D-binding protein (DBP) is a multi-functional serum protein that is converted to vitamin D-binding protein-macrophage activating factor (DBP-maf) by post-translational modification. DBP-maf is a new cytokine that mediates bone resorption by activating osteoclasts, which are responsible for resorption of bone. Defective osteoclast activation leads to disorders like osteopetrosis, characterized by excessive accumulation of bone mass. Previous studies demonstrated that two nonallelic mutations in the rat with osteopetrosis have independent defects in the cascade involved in the conversion of DBP to DBP-maf. The skeletal defects associated with osteopetrosis are corrected in these mutants with in vivo DBP-maf treatment. This study evaluates the effects of various forms of DBP-maf (native, recombinant, and 25-hydroxyvitamin D(3) bound) on osteoclast function in vitro in order to determine some of the structural requirements of this protein that relate to bone resorbing activities. Osteoclast activity was determined by evaluating pit formation using osteoclasts, isolated from the long bones of newborn rats, incubated on calcium phosphate coated, thin film, Ostologic MultiTest Slides. Incubation of osteoclasts with ex vivo generated native DBP-maf resulted in a dose dependent, statistically significant, activation of the osteoclasts. The activation was similar whether or not the vitamin D binding site of the DBP-maf was occupied. The level of activity in response to DBP-maf was greater than that elicited by optimal doses of other known stimulators (PTH and 1,25(OH(2)D(3)) of osteoclast function. Furthermore, another potent macrophage activating factor, interferon--gamma, had no effect on osteoclast activity. The activated form of a full length recombinant DBP, expressed in E. coli showed no activity in the in vitro assay. Contrary to this finding, baculovirus-expressed recombinant DBP-maf demonstrated significant osteoclast activating activity. The normal conversion of DBP to DBP-maf requires the selective removal of galactose and sialic acid from the third domain of the protein. Hence, the differential effects of the two recombinant forms of DBP-maf is most likely related to glycosylation; E. coli expressed recombinant DBP is non-glycosylated, whereas the baculovirus expressed form is glycosylated. These data support the essential role of glycosylation for the osteoclast activating property of DBP-maf.