Non-contraceptive hormones and the risk of rheumatoid arthritis in menopausal women

BACKGROUND

Several reproductive factors appear to affect a women's risk of developing rheumatoid arthritis. This study's purpose was to determine whether use of non-contraceptive hormones is among them.

METHODS

A population-based case-control study was conducted in King County, Washington and Group Health Cooperative of Puget Sound, a prepaid health plan. New cases of rheumatoid arthritis in peri- or postmenopausal women (n = 135) were verified through clinical examination and compared with 592 controls. Both groups were interviewed in person about hormone use and demographic and reproductive factors.

RESULTS

The age-adjusted relative risk (RR) among women who had ever used non-contraceptive oestrogens was 1.04 (95% confidence interval [CI]: 0.70-1.55), and among women who had ever used progestins it was 0.66 (95% CI: 0.40-1.08). For current users of oestrogen only, the RR was 0.97 (95% CI: 0.62-1.53), and among current users of oestrogen plus progestin it was 0.81 (95% CI: 0.45-1.45). Multivariate analyses yielded similar results. There was little evidence of a dose-response relationship with duration of use or with frequency of progestin use.

CONCLUSIONS

Use of non-contraceptive oestrogens appears to have little effect on the risk of developing rheumatoid arthritis in menopausal women. There may be a modest reduction in risk among progestin users.

Smoking, obesity, alcohol consumption, and the risk of rheumatoid arthritis

There is some evidence that sex hormones may influence the incidence of rheumatoid arthritis. Obesity has been found to increase endogenous estrogens, particularly among postmenopausal women. Although the association of endogenous hormones with smoking and alcohol use is less clear, we examined the relation of these three factors with rheumatoid arthritis in women. We conducted a population-based case-control study of rheumatoid arthritis in King County, WA, and Group Health Cooperative of Puget Sound. We compared 349 incident cases of rheumatoid arthritis with 1,457 controls selected by random digit dialing or by random selection from the enrollment files of Group Health Cooperative. We conducted personal interviews to collect data on weight, smoking, alcohol history, reproductive variables, and other demographic variables. Women with 20 or more pack-years of smoking had a relative risk of 1.5 [95% confidence interval (CI) = 1.0-2.0] compared with never-smokers. Post-menopausal women who averaged more than 14 alcoholic drinks per week had a reduced risk of rheumatoid arthritis (relative risk = 0.5; 95% CI = 0.2-1.7). Women in the highest quartile of body mass index had a risk of 1.4 (95% CI = 1.0-2.0) relative to women with lowest body mass index.

Publicity and pricelessness: grassroots decisionmaking and justice in rationing

The "grassroots turn" in bioethical discussions about justice in allocation of health care resources has attracted a great deal of support; in the absence of a convincing theory of justice in rationing, democratic decisionmaking concerning priority setting emerges with a kind of inevitability. Yet there remain suspicions about this approach--most importantly, worries about the socially corrosive impact of explicit, public decisionmaking that in effect sets a price on the lives of persons. These worries have been quieted, particularly by the work of Leonard Fleck, but not altogether stilled. I explore more sympathetically the ideals to which concerns about public rationing somewhat dimly respond, and suggest constraints on priority setting discussions which might accommodate those ideals rather better.

Core values in health care reform: a communitarian approach

Controlling health care costs should allow the nation to provide more health services and higher quality care to more people. The authors are concerned, however, that many of the reform efforts will unwittingly undermine the culture of care in their pursuit of savings and access. This article is a plea to maintain the core moral values and the social and institutional commitments that are essential in the delivery of care, so that the health care community is not turned into a health industry. The authors' communitarian approach aims to preserve the balance between individual rights and social responsibilities, the moral integrity of a caring society, and the unique character of mutual trust between patients and health care personnel. They advocate an orientation toward preventing disease and promoting health, an imperative of reforming the violent, reckless, and costly aspects of American society, and a moral justification for cutting administrative waste, defensive medicine, and excessive profits rather than rationing beneficial and humane health services.

Rheumatoid arthritis in Tlingit Indians: clinical characterization and HLA associations

OBJECTIVE

To characterize the features of rheumatoid arthritis (RA) in Tlingit Indians, to identify the HLA-DR alleles associated with RA in the Tlingit, and to determine whether disease severity or specific clinical manifestations correlate with the presence of specific HLA antigens.

METHOD

Thirty-seven Tlingit patients with RA and 75 controls were evaluated clinically; comparative HLA studies were carried out in 33 patients and 62 controls.

RESULTS

The results of this clinical study of RA in the Tlingit confirms that the disease found in them is classical RA, characterized by an early age of onset, a high frequency of nodules, serum rheumatoid factor (RF) and antinuclear antibodies (ANA); an often severe clinical course, with a high frequency of erosive disease and frequent need for surgical joint repair, and an often positive family history. In Tlingit volunteers who did not have RA we also found an increased prevalence of RF and ANA. Neither HLA-DR1 nor DR4 was found to be associated with RA in the Tlingit. The commonest DR antigen in patients with RA was DR14. The most frequent DRB1 allele was DRB1*1402 (Dw16).

CONCLUSION

The Tlingit population had a very high frequency of the DRB1*1402 allele, which shares key sequence homology with DRB1*0401 (Dw4) and DRB1*0101 (Dw1), associated with RA in other racial groups. No correlations were found between specific HLA-DRB1 alleles or combinations of alleles and specific disease features or severity.

Post injury hypermetabolic response and magnitude of translocation: prevention by early enteral nutrition

The relationship between hypermetabolism and bacterial translocation was investigated in guinea pigs receiving a 40% burn. Animals were infused intragastrically with a complete enteral diet or Ringer's solution for 48 h, given 10(10) 14C-labeled Escherichia coli intragastrically, and killed 4 h later. Resting metabolic expenditure (RME), translocation (dpm of the 14C-labeled E. coli) to the portal blood and ileal mucosa, plasma cortisol, and urinary vanillylmandelic acid (VMA) were determined. Enterally fed animals had significantly lower RME, cortisol, VMA, and dpm, but higher mucosal and body weight than the Ringer's group. Disintegrations per minute (dpm) in the blood were positively correlated with RME (r = 0.856), cortisol (r = 0.872), VMA (r = 0.759), and dpm mucosa (r = 0.836) and inversely correlated with mucosal weight (r = -0.883). We conclude that bacterial translocation is reduced by early feeding and is an important cause of hypermetabolism and stress hormone production after burn injury.

Rheumatoid factor, HLA-DR4, and allelic variants of DRB1 in women with recent-onset rheumatoid arthritis

OBJECTIVE

To examine the relationship of rheumatoid factor (RF) to HLA-DR4 and alleles of DRB1 in women with recent-onset rheumatoid arthritis (RA).

METHODS

Incident cases of RA were identified as part of a prospective, population-based case-control study. HLA typing was completed for 246 cases meeting criteria for definite or classic RA.

RESULTS

One hundred thirty-six patients (55%) were positive for DR4, and 130 (53%) were RF positive. DR4 was found to be strongly associated with seropositivity (odds ratio 4.1, P < 0.0001). Patients with a shorter interval from RA onset to RF testing had a higher frequency of seropositivity than those with a longer interval (< or = 18 months 60%, > 18 months 33%). Further analysis of patients who had RF testing within 18 months of RA onset showed that the frequency of seropositivity was significantly greater among DR4-positive patients who had the shared sequence stretch of DR beta 1 associated with RA susceptibility (76% RF positive) than among DR1-positive patients who had this sequence (45% RF positive) (odds ratio 3.8, P = 0.01). Moreover, the frequency of seropositivity among DR1-positive patients with the sequence did not differ from that among all patients without the shared sequence (47%) (odds ratio 0.9, P = 0.8).

CONCLUSION

HLA-DR4 is strongly associated with seropositivity in women with recent-onset RA. The amino acid sequence of DR beta 1 that is associated with susceptibility to RA and is shared between DR4 and DR1 appears not to be the primary determinant of seropositivity in these women.

Role of early enteral feeding and acute starvation on postburn bacterial translocation and host defense: prospective, randomized trials

OBJECTIVES

To investigate the effect of: a) starvation during the preburn period and b) immediate postburn enteral nutrition on the permeability of the gut to microorganisms and the ability of the host to kill translocated bacteria.

DESIGN

Prospective, randomized, experimental trials.

SETTING

Laboratory.

SUBJECTS

Balb/c mice and Hartley guinea pigs.

INTERVENTIONS

In the first experiment, mice were starved for 0, 6, 12, 18, or 24 hrs before receiving gavage with 10(10) 14C-labeled Escherichia coli and a 20% burn injury. In the second experiment, guinea pigs received a 40% burn injury and were randomized to receive a complete enteral diet (175 kcal/kg/day) or infusion of an equal volume of lactated Ringer's solution via a previously placed gastrostomy for 6, 24, or 48 hrs. After each feeding period, 10(10) 14C Escherichia coli were infused intragastrically. In both experiments, the animals were killed 4 hrs after gavage, and mesenteric lymph nodes, spleen, liver, lungs, peritoneal fluid, and blood were harvested aseptically.

MEASUREMENTS

For each tissue or fluid, the number of viable E. coli and radionuclide counts of the 14C E. coli were measured and the percentage of translocated bacteria that remained alive was calculated.

MAIN RESULTS

In mice, 18 and 24 hrs of preburn starvation increased translocation only to the mesenteric lymph nodes, but it also enhanced bacterial killing in all tested tissues. Guinea pigs that were fed enterally for 6, 24, and 48 hrs postburn had significantly lower bacterial translocation in all tissues compared with animals infused with lactated Ringer's solution. Additionally, enhanced killing of translocating organisms was observed after 24 and 48 hrs of feeding.

CONCLUSIONS

Starvation preburn has different consequences than starvation postburn on translocation and bacterial killing. Postburn enteral nutrition decreases the load of viable bacteria in the tissues via a double mechanism: an initial decreased translocation and a subsequent improved ability to kill bacteria that do translocate.

Nesting Requirements of the Yellow-Tailed Black-Cockatoo, Calyptorhynchus Funereus, in Eucalyptus Regnans Forest, and Implications for Forest Management

The nesting requirements of the yellow-tailed black-cockatoo (Calyptorhynchus funereus) were studied at 68 sites in Eucalyptus regnans forest in the Strzelecki Ranges, South Gippsland, Victoria. Nest trees were located and their characteristics related to forest stand variables. Eighteen nest hollows were found. Nest trees had a mean diameter at breast height of 2.5 m, a mean estimated age of 221 years, a mean height of 58 m and for live nest trees a mean crown diameter of 22 m. The currently proposed rotation time for silvicultural systems of 80-150 years will reduce the number of hollow-bearing trees suitable for nesting yellow-tailed black-cockatoos. Adequate numbers of trees must be retained in logged areas and wildlife corridors and reserves, and protected to ensure a continual supply for yellow-tailed black-cockatoos and other hollow-dependent species. If agonistic behaviour is operating between female yellow-tailed black-cockatoos, nesting potential may be enhanced if trees retained on coupes are evenly distributed rather than clumped. Silvicultural systems that facilitate the protection of trees retained on coupes would benefit the conservation of the yellow-tailed black-cockatoo.

Influence of dietary fiber on microbial growth in vitro and bacterial translocation after burn injury in mice

Translocation of enteric bacteria from the gut to the mesenteric lymph nodes and beyond can cause life-threatening infection and multiple-organ failure in immunocompromised and traumatized patients. One of the conditions that promotes bacterial translocation is disruption of the normal gut flora, which results in bacterial overgrowth. In vitro methods were used to determine whether the fibers pectin, cellulose, chitosan, kaolin, lignin, or soy had bactericidal properties. Our results indicated that only chitosan and lignin significantly reduce microbial growth in vitro. A burned mouse model (20% total-body surface area) was used to study the effects of dietary lignin, cellulose, pectin, and chitosan on burn-induced bacterial translocation. Animals were fed a standard mouse diet containing no fiber, pectin, cellulose, lignin, or chitosan (10% of diet) for 14 days ad libitum. On day 14, all animals were burned. Four hours later the animals were killed and the mesenteric lymph nodes, spleen, liver, and cecum were aseptically harvested for determination of quantitative aerobic microbial growth. The animals which received chitosan, and lignin to a lesser extent, added to their diet had significantly lower levels of bacteria in the cecum, mesenteric lymph nodes, and liver. We suggest that addition of chitosan and possibly lignin to the diet may reduce the amount of bacterial translocation after burn injury, presumably by reducing the bacterial population of the cecum.

T-cell receptor polymorphisms in Tlingit Indians with rheumatoid arthritis

Rheumatoid arthritis (RA) develops as a result of the interaction of both genetic and environmental factors. Among the genes in humans that have been suggested as candidate susceptibility genes in RA are those encoding the T cell receptor for antigen (TCR). A high prevalence and early age of onset of RA has previously been reported in Alaskan Tlingit Indians. In this study, the frequency of seven different restriction fragment length polymorphisms (RFLPs) in the TCR alpha and beta gene complexes were measured in a population of Alaskan Tlingit Indians. No statistically significant differences were noted when the frequencies of these RFLPs were compared between Tlingits with RA and healthy controls (p > 0.05). These results do not support the hypothesis of an RA-susceptibility allele in the vicinity of these TCR alpha or beta genes. Since TCR RFLPs have not been extensively studied in native American populations, TCR polymorphism frequencies in the Tlingits were also compared to the frequencies observed in a second control group of healthy Caucasians. Statistically significant differences were observed in these comparisons implying a different distribution of individuals in these populations with different TCR repertoires.

Maternal-fetal disparity in HLA class II alloantigens and the pregnancy-induced amelioration of rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis frequently remits during pregnancy, for unknown reasons. Since an immune response to paternally inherited fetal HLA can occur during normal pregnancy and since rheumatoid arthritis is an autoimmune disorder with a known HLA class II antigen association, we tested the hypothesis that maternal-fetal disparity in HLA alloantigens might be associated with the pregnancy-induced remission of rheumatoid arthritis.

METHODS

We studied 57 pregnancies of 41 women with rheumatoid arthritis, 18 prospectively and 39 retrospectively. Serologic and DNA techniques were used to study HLA class I and II antigens. For newborns, typing was performed from cord-blood samples obtained at delivery. For four young children, typing was performed from DNA extracted from hair samples.

RESULTS

We found significantly more maternal-fetal disparity in HLA-DR and DQ antigens in pregnancies characterized by the remission or improvement of rheumatoid arthritis than in pregnancies characterized by active disease. Further studies using DNA-typing techniques to define allelic variants of HLA-DR and DQ antigens confirmed this observation. Maternal-fetal disparity in alleles of HLA- DRB1, DQA, and DQB occurred in 26 of 34 pregnancies characterized by remission or improvement (76 percent), as compared with 3 of 12 pregnancies characterized by active arthritis (25 percent) (odds ratio, 9.7; P = 0.003). The difference between the two groups was most marked for alleles of HLA-DQA.

CONCLUSIONS

Amelioration of rheumatoid arthritis during pregnancy is associated with a disparity in HLA class II antigens between mother and fetus. These findings suggest that the maternal immune response to paternal HLA antigens may have a role in the pregnancy-induced remission of rheumatoid arthritis.

Maternal-fetal disparity in HLA class II alloantigens and the pregnancy-induced amelioration of rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis frequently remits during pregnancy, for unknown reasons. Since an immune response to paternally inherited fetal HLA can occur during normal pregnancy and since rheumatoid arthritis is an autoimmune disorder with a known HLA class II antigen association, we tested the hypothesis that maternal-fetal disparity in HLA alloantigens might be associated with the pregnancy-induced remission of rheumatoid arthritis.

METHODS

We studied 57 pregnancies of 41 women with rheumatoid arthritis, 18 prospectively and 39 retrospectively. Serologic and DNA techniques were used to study HLA class I and II antigens. For newborns, typing was performed from cord-blood samples obtained at delivery. For four young children, typing was performed from DNA extracted from hair samples.

RESULTS

We found significantly more maternal-fetal disparity in HLA-DR and DQ antigens in pregnancies characterized by the remission or improvement of rheumatoid arthritis than in pregnancies characterized by active disease. Further studies using DNA-typing techniques to define allelic variants of HLA-DR and DQ antigens confirmed this observation. Maternal-fetal disparity in alleles of HLA- DRB1, DQA, and DQB occurred in 26 of 34 pregnancies characterized by remission or improvement (76 percent), as compared with 3 of 12 pregnancies characterized by active arthritis (25 percent) (odds ratio, 9.7; P = 0.003). The difference between the two groups was most marked for alleles of HLA-DQA.

CONCLUSIONS

Amelioration of rheumatoid arthritis during pregnancy is associated with a disparity in HLA class II antigens between mother and fetus. These findings suggest that the maternal immune response to paternal HLA antigens may have a role in the pregnancy-induced remission of rheumatoid arthritis.

Role of the physician in encouraging use of advance directives

Advance directives provide patients with the chance to tailor health care decisions to their own values even after they have lost the capacity to make decisions. Federal legislation enacted in 1990 and now effective will ensure widespread awareness of this opportunity. However, the extent to which advance directives actually contribute to improving patient care will depend much more on how physicians educate and counsel their patients than on what the law mandates.

Bioethics education. Expanding the circle of participants

Bioethics education now takes place outside universities as well as within them. How should clinicians, ethics committee members, and policymakers be taught the ethics they need, and how may their progress best be evaluated?

Fecundity before disease onset in women with rheumatoid arthritis

OBJECTIVE

To examine fecundity prior to disease onset in women with rheumatoid arthritis (RA).

METHODS

Two hundred fifty-nine RA patients with an opportunity for pregnancy were compared with 1,258 control women as part of a prospective case-control study of recent-onset RA in women.

RESULTS

A 12-month or longer interval to pregnancy was found in 42% of RA cases compared with 34% of controls (odds ratio = 1.44, 95% confidence interval 1.10, 1.91). This difference was not accounted for by an older age when attempting to become pregnant among the RA cases compared with the controls. The result was unrelated to rheumatoid factor or HLA-DR4 status.

CONCLUSION

Women with RA were found to have decreased fecundity prior to disease onset, compared with control women.

An analysis of transaction logs to evaluate the educational needs of end users

End users at the University of Southern California (USC) have free access to the last ten years of MEDLINE through a local online system known as USCInfo. Librarians at USC Norris Medical Library provide documentation and offer formal and informal training on the use of the system to search MEDLINE. To assess the educational needs of the end users, 643 searches were analyzed. Although a high proportion (84%) of the searches were judged to be successful, the use of medical subject headings (MeSH) to obtain optimal results was low; only 20% of all successful subject searches employed MeSH. Also, the advanced features of the system were underutilized. While it is promising to learn that many end users are obtaining positive results, methods which will encourage end users improve their retrievals need to be developed.

Making peace in gestational conflicts

Mary Anne Warren's claim that "there is room for only one person with full and equal rights inside a single human skin" ([1], p. 63) calls attention to the vast range of moral conflict engendered by assigning full basic moral rights to fetuses. Thereby, it serves as a goad to thinking about conflicts between pregnant women and their fetuses in a way that emphasizes relationships rather than rights. I sketch out what a 'care orientation' might suggest about resolving gestational conflicts. I also argue that the care orientation, with its commitment to the significance of the partial and the particular, cannot be absorbed within standard, impartialist moral theory.

Peroxidase: a novel pathway for chemical oxidation in human term placenta

Hydrogen peroxide-dependent oxidation of xenobiotics in a crude fraction of human term placental membranes (nuclei, mitochondria and microsomes) was investigated. Guaiacol was employed as a model substrate. The rate of its oxidation was found to be dependent on the concentration of protein, H2O2 and the substrate as well as the pH of the buffer. Several other classical substrates for peroxidases from different sources viz. pyrogallol, benzidine, p-PDA, DMBD, ABTS, TMPD and TMBD and endogenous chemicals such as bilirubin and epinephrine were also found to undergo oxidation. The xenobiotic oxidizing capacity of the membranes was retained by CaCl2 (0.5 M) extract as well as by the partially purified enzyme obtained by affinity (Con A) chromatography. The H2O2-dependent chemical oxidation by the partially purified peroxidase was inhibited by NaN3 and KCN (IC50 values 41 and 23 microM respectively). These results suggest that peroxidase may be a major enzyme in human term placenta capable of oxidation of endogenous chemicals and xenobiotics.

Remission of rheumatoid arthritis during pregnancy and maternal-fetal class II alloantigen disparity

Rheumatoid arthritis (RA) is an autoimmune disorder known to be associated with specific class II genes. Although it has been known since 1938 that the majority of women with RA experience disease improvement or remission during pregnancy, the reasons remain unknown. Pregnancy represents an immunologic challenge and maternal immune recognition of the semi-allogeneic fetus occurs as part of normal pregnancy. We hypothesized that maternal immune response to fetal HLA antigens might be associated with the effect of pregnancy on arthritis activity. To test this hypothesis, we studied HLA antigens in mother-child pairs comparing maternal-fetal HLA antigen sharing for pregnancies where arthritis improved with those where disease was active. No significant difference was observed in the two groups for class I HLA antigens. Fetal-maternal disparity for HLA-DR and HLA-DQ antigens was observed significantly more frequently in pregnancies with remission or improvement compared with those in which disease was active. These observations suggest that maternal immune response to fetal paternally-inherited class II HLA antigens may be important in RA remission observed during pregnancy.

HLA antigens in Tlingit Indians with rheumatoid arthritis

HLA-DR4 has been described in association with rheumatoid arthritis (RA) in multiple populations. We have studied HLA antigens in Alaskan Tlingit Indians. HLA-DR4 was decreased in the RA group (n = 32) compared with controls (n = 62) (6% vs 21% p = 0.07). The predominant DR4 allele observed was DRB1*0403 (Dw13.1). The most striking observation in these studies was a marked predominance of the DRB1*1402 allele encoding Dw16 (DRw14). This allele was present in 91% of RA cases, but was also highly prevalent in controls (80%, OR = 2.4 p = 0.20). DRB1*1402 only was observed in 47% of cases and 31% of controls. The DRB3*0101 (DRw52), and the DQA*0501 and DQB*0301 alleles encoding a subset of DQw3 were associated with DRB1*1402 in cases and in controls. HLA-Bw62 was increased in RA cases (28%) compared with controls (8%) (OR = 4.5, p = 0.01, corrected p = ns).

Metabolic and immune effects of enteral ascorbic acid after burn trauma

A burned guinea-pig model (30 per cent BSA) was used to study the effect of vitamin C on immune and metabolic responses following burn trauma. Thirty-six guinea-pigs received identical enteral diets (175 kcal/kg) except for the amount of vitamin C. Groups I, II, III and IV were given formulae delivering no vitamin C, (1 RDA) 15 mg/kg/day, 75 mg/kg/day or 375 mg/kg/day, respectively. Resistance to infection was evaluated by injecting each animal with 0.1 ml of 1 x 10(9) Staph. aureus 502A subcutaneously on day 10. On day 14, Staph. aureus abscesses were excised and the numbers of viable colonies were determined. Results showed no statistical differences between groups in the clearance of Staph. aureus. From days 2 to 12, animals in groups I, II and III had body weights of approximately 97 per cent of preburn body weight. Animals in group IV, however, had a body weight gain, 102 per cent of preburn body weight on day 12. Animals in group IV also had significantly lower metabolic rates on day 12 as compared to the animals in the other groups. These results suggest that large amounts of vitamin C have beneficial effects on the maintenance of body weight and metabolic rate following burn trauma.

Pregnancy outcome in women with rheumatoid arthritis before disease onset

Pregnancy outcome before disease onset was evaluated for women with rheumatoid arthritis (RA) and control women as part of a prospective case-control study of newly diagnosed RA. An analysis of women who were ever gravid revealed no statistically significant difference in any adverse pregnancy outcome between RA cases (n = 144) and controls (n = 605) including spontaneous abortions and stillbirths. Thus, in contrast to reports both of an increase of adverse pregnancy outcomes and a decrease in women who subsequently develop RA, we found no evidence for any difference in pregnancy outcome in the RA group.

Rheumatoid arthritis in women. Incidence rates in group health cooperative, Seattle, Washington, 1987-1989

As part of a prospective case-control study of newly diagnosed rheumatoid arthritis (RA) in women, we identified all cases of probable, definite, or classic RA diagnosed in 1987-1989 in 18-64-year-old women who were members of a health maintenance organization based in the Seattle, Washington area. Using both the 1958 and the 1987 American Rheumatism Association criteria for the diagnosis of RA and enrollment data from the health maintenance organization, we calculated the incidence by age and diagnostic class. Rates of RA incidence in women increased steadily with age. The incidence of probable, definite, or classic RA ranged from 13.1 per 100,000 person-years at risk for 18-29-year-old women to 82.1 per 100,000 person-years for 60-64-year-old women. The overall incidence rate, age-adjusted to the 1980 US female population, was 27.9/100,000 person-years. The overall incidence rate for definite/classic RA, age-adjusted to the 1980 US female population, was 23.9 per 100,000 person-years. When compared with adjusted rates of incidence of definite RA in Rochester, Minnesota, in 1950-1974, the incidence rates we found were 44.7% lower. Methodologic differences, changes in diagnostic criteria, and a declining incidence of RA among women over time may all be partial explanations for these results. The possible effects of reproductive factors, including oral contraceptives use, are discussed.

The sequence specificity domain of cytosine-C5 methylases

Prokaryotic DNA[cytosine-C5]methyltransferases (m5C-methylases) share a common architectural arrangement of ten conserved sequence motifs. A series of eleven hybrids have been constructed between the HpaII (recognition sequence: Cm5CGG) and HhaI (recognition sequence: Gm5CGC) DNA-methylases. The hybrids were over-expressed in E.coli and their in vivo methylation phenotypes investigated. Six were inactive by our assay while five of them retained partial methylation activity and full specificity. In all five cases the specificity matched that of the parent methylase which contributed the so-called variable region, located between conserved motifs VIII and IX. This was the only sequence held in common between the active hybrids and for the first time provides unequivocal evidence that the specificity determinants of the mono-specific m5C-methylases are located within the variable region. Correlation of the hybrid methylase structure with the efficiency of methylation suggests that conserved motif IX may interact with the variable region whereas motif X most probably interacts with the N-terminal half of the molecule.

Changes in IgG glycoform levels are associated with remission of arthritis during pregnancy

It was found that the percentage of IgG-associated agalactosyl N-linked oligosaccharides (G0) falls during normal human pregnancy and rises to values higher than before conception following delivery (n = 10, 39-55 days after delivery). Serial bleeds from a normal pregnant woman showed a fall in the percentage G0 during gestation and a rapid rise post-partum. A similar study on a pregnant arthritic woman with a pathologically elevated percentage G0 also showed a fall in percentage G0 during pregnancy and a rapid rise post-partum. The changes in IgG glycosylation in the pregnant arthritic woman occurred simultaneously with the pregnancy-induced remission and post-partum recurrence of disease. A further seven pregnant women with rheumatoid arthritis were studied and analysis of their G0 values pre- and post-partum confirmed the result. In a further series of experiments using an animal model of rheumatoid arthritis, DBA/1 mice with collagen-induced arthritis were found to have elevated G0 levels compared with control mice. The percentage G0 was found to fall simultaneously with pregnancy-induced remission to the same value as non-arthritic pregnant mice. Post-partum recurrence of arthritis in these mice was also accompanied by a simultaneous and rapid rise in percentage G0. Pseudopregnancy did not result in a change in the percentage G0, confirming the effect of true pregnancy. Since the proportion of agalactosyl IgG is abnormally high in the serum of patients with rheumatoid arthritis these changes in IgG glycoform levels, or the factors which control them, may be related to the mechanisms underlying remission of arthritis in humans during pregnancy.

Dw14(DRB1*0404) is a Dw4-dependent risk factor for rheumatoid arthritis. Rethinking the "shared epitope" hypothesis

HLA-DR4 has been shown to be associated with risk for developing rheumatoid arthritis (RA) in multiple populations and racial groups. The allelic variants of DR4 share the DR4 serologic specificity but differ by 1 to 3 amino acids in the third hypervariable region (positions 67 to 74) and at positions 57 and 86 of the DR beta 1 chain. We have examined DR4 variants in 61 DR4+ RA cases and 55 DR4+ healthy controls. Dw14 was not associated with RA risk in DR4 heterozygous (DR4,X) cases. Only 15% of DR4,X cases had the Dw14 allele compared with 28% of DR4,X controls. In homozygous (DR4,4) individuals who also expressed Dw4, however, Dw14 was associated with increased RA risk. Moreover, the relative risk for Dw4,Dw14 (16.1, p = 0.001) actually exceeded that of Dw4,Dw4 (2.2, p = ns). Thus Dw14 is not an independent risk factor for RA but is a synergistic risk factor for individuals who also have the Dw4 allele.

Multi-trace-element supplementation in enteral formulas for burned guinea pigs

A burned guinea pig model (30% total-body surface area) was used to study the effects of supplemental trace elements. The animals were fed via gastrostomy with identical formulas (175 kcal.kg-1.day-1, 20% of calories as protein) supplemented with varying amounts of the multi-trace-element preparation MTE-5. Animals in group 1 received no MTE-5, group 2 received 5 ml/L diet, group 3 received 20 ml/L diet, and group 4 received 50 ml/L diet. After 14 days of tube feeding, the animals were killed. Results indicated no significant differences in resting metabolic rate or body weight. However, animals in group 4 were found to have heavier carcass, jejunum gut, and mucosal weights compared with animals in group 1. In a second experiment, all animals received 5 ml of MTE-5/L diet. In each group, however, one of the trace elements (manganese, chromium, selenium, and copper) was elevated to the concentration found in 50 ml of MTE-5. The results shows no significant group differences when only one of the trace elements was elevated in the diet. Together, these results demonstrated that the addition of trace elements to an enteral diet increased carcass and gut mucosal weight in a standard dose-response fashion. All four of the trace elements evaluated were necessary for this response. It is suggested that the addition of larger requirements of trace elements than previously reported may be beneficial after thermal injury.

Metabolic and immune effect of vitamin E supplementation after burn

The effect of dietary vitamin E supplementation was studied in burned guinea pigs. Forty-four guinea pigs bearing a catheter gastrostomy received a 30% total body surface area full thickness flame burn and were given identical enteral diets (175 kcal/kg/day) except for the amount of vitamin E. Groups 1, 2, 3, and 4 received 0, 4 mg/kg/day (approximately equivalent to guinea pig's RDA) 20 or 100 mg/kg/day of vitamin E respectively. After 14 days of enteral feeding, there were no significant differences between groups in the body weights and the weights of carcass, gastrocnemius muscle, liver, and spleen. Resting metabolic expenditure on PBD 3, 6, 9, and 12 was similar in all groups. No statistical differences were seen in ear-thickness response to 2,4-dinitrofluorobenzene and lymphocytic proliferative responses to phytohemagglutinin. However, mucosal weight and protein content in group 1 were significantly less compared to groups 2 and 4 (p less than 0.05). Anemia was also significantly greater in group 1. Histologic examination of the intestinal wall, however, did not yield any physical differences associated with the addition of vitamin E to the diet. This study suggests that vitamin E supplementation in diets of burned animals may have a beneficial effect on maintenance of intestinal mucosa and erythrocyte counts over a wide-dose range.

Effect of vitamin A in enteral formulae for burned guinea-pigs

A burned guinea-pig model (30 per cent body surface area) was used to study the effects of dietary vitamin A. Sixty-five female guinea-pigs were infused enterally via gastrostomy feeding tubes with identical formulate (175 kcal/kg/day, 20 per cent of calories as protein) containing varying amounts of vitamin A. Groups I, II, III and IV received formulae containing 0, 10,000 iu (approximately equivalent to the guinea-pigs' RDA), 50,000 iu (5 x RDA) and 250,000 iu (25 x RDA) of vitamin A per litre, respectively. After 14 days of tube feeding, the animals were killed. Group I animals had evidence of vitamin A deficiency including low haemoglobin levels, lower red blood cell counts and lower caecal mucosal weight. Findings of hypervitaminosis A were observed only in animals given the highest dose of vitamin A (25 x RDA). These were elevated serum alkaline phosphatase and complement C3 levels and enlarged adrenal glands. Group IV also showed defective cell-mediated immunity as reflected by reduced delayed cutaneous response to dinitrofluorobenzene. In a second experiment groups I, II, III and IV were given formulas containing 0, 1 x RDA, 5 x RDA, and 10 x RDA of vitamin A respectively for 14 days. Through postburn days 12 to 14 they were injected subcutaneously with 3 x 10(8) of Staphylococcus aureus once daily. On postburn day 15 the animals were killed and the numbers of viable bacteria at each injection site were counted. No significant differences were observed in viable bacterial numbers between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the 1987 revised criteria for rheumatoid arthritis in a cohort of newly diagnosed female patients

The revised criteria for the diagnosis of rheumatoid arthritis (RA) were presented in 1987. We tested these criteria on 135 women from a population-based study of patients with newly diagnosed RA. None of the 19 women with probable RA and 100 of the 116 women with definite RA met the 1987 criteria. The 1987 criteria appear to be less sensitive or more specific than the criteria formulated in 1956.

Partial purification and characterization of a peroxidase activity from human placenta

Peroxidases can metabolize a variety of xenobiotics to reactive intermediates capable of binding to protein or DNA. The potential role of these enzymes in fetotoxicity has not been explored. In this study, the presence of peroxidase activity was observed in human term and pre-term placenta. Human term placental peroxidase activity (HTPP) was partially purified by concanavalin A affinity chromatography from CaCl2 extracts of the particulate fraction. HTPP appears to be a membrane-bound glycoprotein. Arachidonic acid-dependent oxidation of guaiacol was not observed, suggesting that the peroxidase activity was not due to prostaglandin synthase. Moreover, HTPP preparations were devoid of catalase and spectrally dissimilar from human haemoglobin, cytochrome P-450, eosinophil peroxidase and myloperoxidase, suggesting an endogenous origin. An Mr of approx. 119,000 was determined for HTPP by gel filtration. Cathodic slab-PAGE of cetyltrialkylammonium bromide-solubilized HTPP yielded two peroxidase-staining bands.

Tyrosine loading increases dopamine metabolite concentrations in the brain

Administration of haloperidol (1.5 mg/kg) to rats increased concentrations of dopamine metabolites in the corpus striatum, nucleus accumbens, hypothalamus and amygdala. Treatment of similar rats with various doses (25, 100 or 400 mg/kg) of tyrosine methyl ester in combination with the haloperidol led to additional elevations of 3,4-dihydroxyphenylacetic acid (DOPAC) in the corpus striatum and hypothalamus at the lowest dose tested. Therefore, it is concluded that during periods of increased neuronal activity, as induced by haloperidol, tyrosine availability may become a rate-limiting factor in dopamine metabolism.

Transcriptional proofreading in Escherichia coli

A novel transcriptional proofreading mechanism associated with the beta-subunit of wild-type RNA polymerase from Escherichia coli is suggested from the following data. The purified holoenzyme contains an NTPase activity which specifically converts noncognate NTPs to their corresponding NDP in a template-dependent manner during in vitro transcription of synthetic single- and double-stranded templates. In contrast, purified enzyme from an rpoB mutant which shows increased transcriptional error lacked template-dependent NTP hydrolytic activity. The NTP hydrolytic activity of wild-type enzyme was critically dependent on the integrity of the initiation complex, and required continued transcriptional elongation. Transcription and translation of the lacZ gene proceeded 17% faster in the mutant than in its wild-type parent. These results are discussed in terms of a proofreading model in which the rate of transcription is limited by proofreading events that involve recognition and hydrolysis of noncognate NTPs before they can be misincorporated into RNA.

The effect of PGE in multiple experimental models. II. Effect on steady-state levels of plasma and brain amino acids and transmitters

Elevations in prostaglandin E (PGE) have been documented in tumor and trauma patients. The physiologic significance of this elevation is not fully established. Utilizing a long-acting derivative of PGE, 16,16-dimethyl-prostaglandin E (dPGE), in a rat model, we evaluated its effects on metabolic rates, amino acid, and neurotransmitter metabolism. dPGE was not found to significantly alter resting metabolic rate. It did decrease the plasma level of three amino acids, including tyrosine. Although dPGE also decreased brain tissue levels of tyrosine, no significant alterations were observed on amine neurotransmitters or metabolites.

Possible role of ammonia in experimental cancer anorexia

Plasma concentrations of ammonia were elevated significantly in tumor-bearing rats prior to the onset of anorexia and continued to increase as the tumor grew and anorexia developed. Associated with this hyperammonemia were elevated levels of brain glutamine and large neutral amino acids (phenylalanine, tyrosine, tryptophan, methionine, histidine). Concentrations of the dopamine metabolites, DOPAC or HVA were elevated in the corpus striatum, nucleus accumbens, hypothalamus and amygdala of anorectic tumor-bearing rats only, while levels of the serotonin metabolite, 5-HIAA, were increased in these brain regions in both anorectic and non-anorectic tumor-bearing rats. Infusing ammonium salts into non-tumor-bearing rats elicited anorexia and alterations in brain amino acid profile and neurotransmitter metabolism that were similar to those observed in anorectic tumor-bearing rats. Therefore, we conclude that ammonia released by tumor tissue may have a direct role in the etiology of experimental cancer anorexia.

The relationship of burn-induced hypermetabolism to central and peripheral catecholamines

The role of brain and circulating catecholamines as mediators of burn-induced hypermetabolism was investigated in two experiments. Following a 30% body surface area full-thickness open-flame burn, rats exhibited a short period (3 to 4 days) of anorexia followed by a more prolonged (several weeks) hyperphagic-hypermetabolic response. During this hypermetabolic period, norepinephrine concentrations were increased in the brain and circulating epinephrine levels were elevated. Depletion of brain norepinephrine using 6-hydroxydopamine led to increased body weight gain, but did not increase resting energy expenditure in burned rats. Similarly, the reduction of circulating catecholamines through removal of the adrenal medulla resulted in a decreased loss of body weight and only slight reductions in resting energy expenditure. Therefore, these results suggest that although brain norepinephrine and circulating epinephrine have a role in the full expression of hypermetabolism, these compounds do not appear to be major mediators of this response to burn trauma.

Reduction of tumor growth following treatment with a glutamine antimetabolite

Assessment of arterial-venous differences across transplanted methylcholanthrene-induced sarcomas in rats revealed significant decreases in plasma concentrations of glutamine, serine and glucose. Treatment with the glutamine antimetabolite, acivicin, significantly reduced tumor weights by 65% at the conclusion of the experiment 34 days after tumor induction. These results suggest that glutamine is an essential metabolic substrate for tumor growth and that blockade of glutamine utilization can inhibit the growth of these transplantable sarcomas.

Reversal of neurochemical aberrations after tumor resection in rats

Assessment of biochemical parameters in methylcholanthrene sarcoma-bearing rats 2 days after the onset of anorexia revealed several biochemical aberrations in blood and brain. Plasma levels of glucose were decreased and lactate concentrations were increased. The plasma and brain amino acid profiles were also greatly altered in these rats, characterized by increased brain concentrations of glutamine and large neutral amino acids. Analysis of regional neurotransmitter and metabolite levels by high-performance liquid chromatography suggested increases in the neuronal activity of dopamine and serotonin in each brain region examined. Surgical removal of the tumors in another group of anorectic tumor-bearing rats was followed by the return of normal feeding within 6 days. Associated with the normalization of food intake was the reversal of these biochemical aberrations in blood and brain. It is hypothesized that the utilization of glutamine and excretion of ammonia by tumor tissue is the precursor of these alterations in brain amino acids and neurotransmitters, which may be causing anorexia.