MTHFR gene polymorphisms and outcome of methotrexate treatment in patients with rheumatoid arthritis: analysis of key polymorphisms and meta-analysis of C677T and A1298C polymorphisms

Association of two key variants mapping to the MTHFR gene (C677T (rs1801133) and A1298C (rs1801131)) with response to methotrexate (MTX) remains controversial. We investigated these and other markers spanning the gene as predictors of MTX efficacy and adverse events in a UK rheumatoid arthritis (RA) patient cohort and performed a meta-analysis of the two key variants using all published data. The tagging single nucleotide polymorphisms (SNPs) were genotyped in 309 patients with well-defined outcomes to MTX treatment and 17 studies were included in the meta-analysis. No association of the SNPs tested was detected with MTX efficacy or toxicity in our UK cohort. After combining our data with previous studies by meta-analysis, the random effects pooled odds ratios (OR) for both C677T and A1298C showed no association with efficacy or toxicity for either of the SNPs (efficacy: OR=1.05 (95% confidence interval (CI) 0.83-1.32) and OR=0.81 (95% CI 0.53-1.24), respectively; toxicity: OR=1.38 (95% CI 0.90-2.12) and OR=1.19 (95% CI 0.80-1.78), respectively). The available evidence suggests that the MTHFR C677T and A1298C gene polymorphisms are not reliable predictors of response to MTX treatment in RA patients.

Identification of higher risk thin melanomas should be based on Breslow depth not Clark level IV

BACKGROUND

There is good prognostic correlation for the two microstaging systems, Breslow depth and Clark level, commonly used to stage melanomas. Many investigators have reported that Breslow depth is the superior microstaging method. Although Clark level has been dropped from most of the proposed American Joint Committee on Cancer (AJCC) melanoma staging system, the AJCC system still includes Clark Level IV as a criterion for upstaging thin melanomas. The authors sought to determine whether this is appropriate, based on melanoma patient data in the Duke Comprehensive Cancer Center database.

METHODS

Of the 8833 patients registered between January 1, 1970 and December 31, 1995, complete data on Breslow depth and Clark level was available for 4560 patients who were without nodal or metastatic disease at presentation. Ten-year survival was measured from the date of excision of the primary tumor until death from melanoma and analyzed using Kaplan-Meier and Cox proportional hazard methodologies.

RESULTS

When analyzed separately, both increased Breslow thickness and Clark level correlated with shorter survival times. During subgroup analysis, Breslow thickness remained a significant prognostic indicator of survival at Clark Levels III and IV. Conversely, at narrow levels of Breslow thickness (i.e., 0-0.75 mm, > 0.75 -1.0 mm, > 1.0-1.5 mm) survival times were indistinguishable between Clark Levels III and IV. For the broader Breslow thickness interval of 0-1.0 mm, a barely significant difference between Clark Levels III and IV could be obtained. However, for this thickness range, even greater differences in survival could be obtained by merely comparing Breslow subgroups (i.e., < or = 0.8 mm vs. > 0.8-1.0 mm, < or = 0.9 mm vs. > 0.9-1.0 mm).

CONCLUSION

The authors' data suggested that, after controlling for Breslow depth, Clark level was not a good prognostic indicator for survival. If the AJCC's objective is to design a classification system that will reliably predict the higher risk melanomas, then the system should be based on tumor thickness, which is clearly a better prognostic indicator, and should not be modified because of Clark level.

Biodegradation of diethyl phthalate in soil by a novel pathway

Biodegradation of diethyl phthalate (DEP) has been shown to occur as a series of sequential steps common to the degradation of all phthalates. Primary degradation of DEP to phthalic acid (PA) has been reported to involve the hydrolysis of each of the two diethyl chains of the phthalate to produce the monoester monoethyl phthalate (MEP) and then PA. However, in soil co-contaminated with DEP and MeOH, biodegradation of the phthalate to PA resulted in the formation of three compounds, in addition to MEP. These were characterised by gas chromatography-electron ionisation mass spectrometry and nuclear magnetic resonance as ethyl methyl phthalate, dimethyl phthalate and monomethyl phthalate, and indicated the existence of an alternative pathway for the degradation of DEP in soil co-contaminated with MeOH. Transesterification or demethylation were proposed as the mechanisms for the formation of the three compounds, although the 7:1 ratio of H(2)O to MeOH means that transesterification is unlikely.

Patients' opinions regarding direct access to dermatologic specialty care

Many factors such as cost have been used by managed care systems to limit patient access to specialty care, including dermatology. To date, however, patients' opinions regarding these decisions have not been analyzed. The purpose of the study was to survey patient opinions regarding the efficacy, costs, and desirability of gatekeeper-mediated versus direct access to dermatologic specialty care. One hundred fifteen of 150 consecutive patients who were seen in an outpatient dermatology clinic completed an anonymous survey concerning their current visit. They were asked about referral to the dermatologist by other physicians, number of prior physician visits, and efficacy of therapies received. Patients rated their level of satisfaction with generalist versus specialist care for their condition and evaluated the importance of direct access to dermatologic specialty care. Thirty-nine percent of respondents (42 of 108) were on their first visit to the dermatologist for their current condition. One half of respondents (57 of 115) had previously seen another physician for this condition. Thirty percent (34 of 115) had been referred to the dermatologist by another physician, most often a family practitioner or internist. Two thirds (38 of 57) of those seen by a previous physician had received therapy from that physician, but only one third (12 of 35) believed it to have been of any benefit. Twenty-three percent (11 of 47) claimed to have incurred more than five visits to the other physician before seeing the dermatologist. Twenty-four percent of patients (12 of 50) were "very satisfied" with the previous physician's care compared with 89% (100 of 112) with the dermatologist's care. Only 6% of respondents (7 of 122) believed a generalist could adequately treat their skin disease. Eighty-seven percent (100 of 115) described direct access to dermatology as being "very important" to their health care. The results of this study suggest that many patients may prefer dermatologic specialists over generalists as primary caregivers for diseases of the skin. They may favor direct access to dermatologic specialty care for its efficacy and for cost and time savings.

SDS-degrading bacteria attach to riverine sediment in response to the surfactant or its primary biodegradation product dodecan-1-ol

A laboratory-scale river microcosm was used to investigate the effect of the anionic surfactant sodium dodecyl sulphate (SDS) on the attachment of five Pseudomonas strains to natural river-sediment surfaces. Three of the Pseudomonas strains were chosen for their known ability to express alkylsulphatase enzymes capable of hydrolysing SDS, and the other two for their lack of such enzymes. One strain from each category was isolated from the indigenous bacterial population present in the river sediment used; other isolates were from soil or sewage. The alkylsulphatase phenotypes were confirmed by gel zymography of cell extracts. Addition of SDS to mixed suspensions of river sediment with any one of the biodegradation-competent strains stimulated the attachment of bacteria to the sediment particles. In contrast, the attachment of biodegradation-incompetent strains was weak and, moreover, was unaffected by SDS. The SDS-stimulated attachment for competent organisms coincided with rapid biodegradation of the surfactant. The primary intermediate of SDS biodegradation, dodecan-1-ol, accumulated transiently, and the numbers of attached bacteria correlated closely with the amount of dodecan-1-ol present. Direct addition of dodecan-1-ol also stimulated attachment but the effect was more immediate compared with SDS, when there was a lag period of approximately 2 h. To account for these observations, a model is proposed in which SDS stimulates the attachment of biodegradation-competent bacteria through its conversion to dodecan-1-ol, and it is hypothesized that the observed reversibility of the attachment is due to the subsequent removal of dodecan-1-ol by further bacterial metabolism.

On the control of immediate early (alpha) mRNA survival in cells infected with herpes simplex virus

The alpha or immediate early mRNA of herpes simplex virus strain HSV-2(G) had a half-life of about 15 min if made in the absence of viral protein synthesis but was relatively stable if viral protein synthesis occurred, either freely or restricted by the presence of the proline analogue azetidine. In contrast, the alpha mRNA of other strains of the virus is stable, even in the absence of protein synthesis. Studies with recombinant viruses showed that the region of the viral DNA between 0.58 and 0.65 map units [which includes the gene (vhs, UL41) that controls virion-mediated shutoff of host protein synthesis] is important in determining the survival of alpha mRNA. In mixed infection experiments HSV-2(G) inhibited alpha as well as host protein synthesis but the shutoff activity appeared to be short-lived. Within 3 h after infection, as a result of protein synthesis, cells became completely resistant to shutoff by superinfecting virus.

Copyright law: how it affects your hospital and you

Nurse administrators, inservice educators, and other nursing supervisors need to be aware of how copyright law affects the use of educational materials in hospitals, medical centers, and nursing homes. The United States' Copyright Act of 1976, along with Congressional guidelines and federal rulings, have a great deal to say regarding photocopying, off-air videotaping, and use of materials borrowed from lending libraries. Examples of copyright infringement are given, with suggestions for avoiding them.