Human anti-phosphorylcholine antibodies share idiotopes and are self-binding.

We have previously shown that BALB/c antipneumococcal polysaccharide antibodies with phosphorylcholine (PC) specificity are self-binding, mediated by hypervariable sequence structure of the heavy chain. We extended the observation of self-binding anti-PC antibodies to naturally occurring human anti-PC antibodies. Anti-PC antibodies were purified from normal donor sera and shown to bind to monoclonal antiidiotypic anti-T15 antibodies originally raised against the murine T15 idiotype. These human antibodies are self-binding which is inhibitable by the PC hapten and the murine T15 (50-73)-derived Vh peptide. The anti-PC antibodies were further separated into id-positive and id-negative anti-PC antibodies. Only the T15 id-positive preparation was self-binding. These findings demonstrate an evolutionary, conserved biological property between mouse and man associated with a naturally occurring antibacterial antibody. This conserved biological and structural property may have been selected in evolution because it is part of an important immune defense mechanism against bacterial and other environmental pathogens.

Familial systemic lupus erythematosus. Presence of a cross-reactive idiotype in healthy family members.

Sera of 27 members of 3 human kindreds with familial systemic lupus erythematosus (SLE) were examined for expression of a cross-reactive idiotype present on anti-DNA antibodies of SLE patients. By radioimmunoassay, serum samples from 6 of 8 SLE patients and 15 of 19 family members had high-titered reactivity with the antiidiotype, 3I. Isoelectric focusing and Western blot analysis of 3I-reactive bands revealed two patterns of reactivity: either a pattern of bands present at pH 5-7, or bands present at pH 5-7 with additional bands present at pH 7-8.5. Cationic bands were found to correlate with the presence of anti-DNA antibodies, indicating that immunoglobulin charge may be a factor in determining specificity for DNA. Millipore filter analysis revealed anti-DNA antibodies in sera of 4 of 8 SLE patients and 2 of 19 family members without SLE. In 2 additional SLE patients and 2 additional family members, anti-DNA antibodies were revealed when sera were analyzed under conditions that dissociate immune complexes. This study indicates that expression of an idiotype associated with anti-DNA antibodies is significantly increased in relatives of SLE patients and usually occurs in the absence of anti-DNA activity.

Altered distribution and excretion of N-1-methylnicotinamide in rats with Walker 256 carcinosarcoma.

Levels of nicotinamide and N-1-methylnicotinamide in serum, liver, and kidney as well as renal clearances and 24-hr urine levels of N-1-methylnicotinamide were compared in normal rats and rats bearing Walker 256 tumors. There was no significant difference between normal and tumor-bearing rats with regard to nicotinamide levels. With regard to N-1-methylnicotinamide, tumor-bearing rats had significantly lower serum and liver levels and significantly higher 24-hr urine levels and renal clearances. Walker 256 tumor tissue and liver and kidney from a normal and a tumor-bearing rat were separately examined for S-adenosylmethionine:nicotinamide methyltransferase activity. The specific activity in tumor tissue extract was greater than that in each liver extract, which, in turn, was much greater than the specific activity in each tissue (liver and kidney) from the tumor-bearing rat was equal to the specific activity in the corresponding tissue of the normal rat. S-adenosylmethionine:nicotinamide methyltransferase was obtained with 18-fold purification from a tissue extract of Walker 256 tumor. The enzyme activity required activation by thiols, and maximal activity was observed at pH 8.6. The Km's for the substrates, S-adenosylmethionine and nicotinamide, were 7.0 x 10--3 mM and 0.50 mM respectively. The Ki's for the products, S-adenosylhomocysteine and N-1-methylnicotinamide, were respectively, 25 x 10--3 mM and greater than 5 mM.

Folate and pterin metabolism by cancer cells in culture.

Malignant cells grown in culture excrete into their growth medium a folate catabolite that can be seen as a blue-fluorescent region on paper chromatograms of such media. This folate catabolite has now been identified by paper chromatography, thin-layer chromatography, and combined gas chromatography-mass spectrometry as 6- hydroxymethylpterin and not as pterin-6-carboxaldehyde as previously reported. Moreover, when pterin-6-carboxaldehyde was added to the growth medium of logarithmically growing malignant cells, it was primarily reduced to 6-hydroxymethylpterin. In contrast pterin-6-carboxylate was the principal product formed from added pterin-6-carboxaldehyde by normal established cell lines in culture. These results have been interpreted as indicative of a possible mechanism of folate catabolism in malignant cells. Folic acid or another folate derivative is oxidatively cleaved at the C-9-N-10 bond to yield pterin-6-carboxaldehyde as one of the products. This derivative is subsequently reduced to 6-hydroxymethylpterin, which is excreted into the growth medium.

Fractionation of mucopolysaccharides by countercurrent distribution in aqueous polymer two-phase systems.

A new procedure for the fractionation of mucopolysaccharides based upon differences in their partition behavior in aqueous polymer two-phase systems has been devised. Systems containing dextran, poly(ethylene glycol), trimethylamino-poly(ethylene glycol), potassium bromide and sodium phosphate buffer were employed. Countercurrent distributions were performed with a miniature countercurrent distribution device designed especially for use with aqueous polymer two-phase systems. An advantage over the widely used procedures involving precipitation of mucopolysaccharides as their quaternary ammonium detergent complexes is that the countercurrent distribution pattern of a particular mucopolysaccharide is not affected by the simultaneous presence of other mucopolysaccharides. Preliminary distributions of labelled mucopolysaccharides isolated from the cells and culture medium of monolayer cultures of rat tumor cells demonstrate that the procedure is particularly well suited for the fractionation of very minute quantities of mucopolysaccharides.

Antibodies of different specificities are self-binding: implication for antibody diversity.

Antibodies of the S107/T15 germline family possess variable region structures which allow them to form specific complexes. We extended the investigation of the immunochemical properties of self-binding antibodies (autobodies) to mutant antibodies: U4, which binds DNA, and U10, which has no identified antigenic specificity. U4 differs from the germline S107/TEPC15 autobody by one substitution in the variable heavy chain, which results in a loss of phosphorylcholine binding. Like TEPC15, U4 and U10 are also self-binding. While self-binding of the wild-type TEPC15 antibody is inhibited by free hapten phosphorylcholine self-binding of the anti-DNA antibody U4 is inhibited by DNA and by free nucleotides. The self-binding locus of U4 and U10 was further investigated using peptides derived from the variable region. A 22 residue peptide from the CDR2/FR3 variable heavy chain sequence of the TEPC15 germline structure specifically inhibits self-binding in solid-phase assays. Peptides from unrelated antibodies have no effect on self-binding. The finding of antibodies with identical specificities which are self-binding or not self-binding demonstrates the existence of a novel kind of antibody repertoire diversity controlled by variable sequence structures.

Propylthiouracil (PTU) pharmacology in the rat. I. Serum and thyroid PTU measurements by radioimmunoassay.

We have developed a highly sensitive and specific RIA for propylthiouracil (PTU) which uses 125I-labeled PTU as the radioactive ligand. At a final antibody dilution of 1:10,000, the detection limit for PTU was 100 pg; cross-reactivity with circulating, urinary, and intrathyroid PTU metabolites was negligible. Using this assay, serum and thyroid PTU levels were determined after short term (1 week) and long term (1 month) PTU treatment at doses of 0.0001-0.05%. Serum PTU was a linear function of the PTU dose (r = 0.99; P less than 0.001), whereas thyroid PTU was a linear function of the logarithm of the PTU dose (r = 0.99; P less than 0.001). Serum PTU levels were higher after 1 month of treatment than after administration for 1 week, probably because steady state conditions were not achieved after 1 week. At several doses, thyroid PTU levels were also higher after 1 month of treatment, but the differences were not as striking as those seen in the serum levels. The pharmacokinetic data are consistent with a multicompartmental model for PTU distribution. The logarithmic relationship between thyroid PTU and PTU dose suggests a saturable uptake mechanism for PTU by the thyroid; inhibition of thyroid PTU uptake by PTU itself could also explain these observations.

Propylthiouracil (PTU) pharmacology in the rat. II. Effects of PTU on thyroid function.

Using a sensitive and specific RIA for propylthiouracil (PTU), we examined the effects of short term (1 week) and long term (1 month) PTU treatment on thyroid function in the rat, and correlated changes in thyroid function with serum and thyroid PTU levels. After 1 week, dose-dependent decreases in thyroid PBI, serum T4, and serum T3 were observed, with concomitant elevations in the serum rT3 to T4 ratio and serum TSH. Fifty percent suppression of thyroid PBI occurred at a PTU concentration in the drinking water of 0.0005% (ED50), with concomitant serum and thyroid PTU levels of 0.3 micrograms/ml and 300 ng/thyroid, respectively. After 1 month of PTU, serum T4 values were lower than after 1 week of treatment for all PTU concentrations, but values for the other thyroid functional variables were similar to those in the 1 week group at comparable PTU dosage. The PTU dose-response curve for thyroid PBI was similar to that seen after 1 week of treatment, with an ED50 of 0.0004%. After discontinuation of PTU treatment, PTU disappeared from serum in a biexponential fashion, with an early rapid distribution phase (t 1/2 = approximately 4 h) and a second slower elimination phase (t 1/2 = approximately 2.6 days). In the thyroid, an initial increase in PTU content was seen up to 18 h after PTU withdrawal; thereafter, thyroid PTU declined linearly, with a t 1/2 of 1.4 days in both groups. After PTU withdrawal, thyroid PBI recovered with a t 1/2 of 1.09 days after 1 week on PTU, but recovery was prolonged (t 1/2 = 2.8 days) after 1 month of treatment. Log thyroid PTU and log thyroid PBI were linearly related after PTU withdrawal (r = 0.97; P less than 0.001) after 1 week but not after 1 month. Serum T4 and serum T3 remained below control values for 2 days, but then rapidly normalized, with T3 values rising transiently above the control value. This rebound occurred at a time when PTU was still present within the thyroid, before thyroid PBI had returned to baseline. These data indicate a close inverse relationship between PTU dose and both thyroid hormone biosynthesis and peripheral T4 deiodination. In addition, short and long term PTU treatments have quantitatively similar effects on thyroid function, although recovery of thyroid function is prolonged after long term treatment. The biexponential disappearance of PTU from the serum is compatible with a two-compartment model of PTU distribution. The early increase in thyroid PTU after drug withdrawal is suggestive of an inhibitory effect of PTU upon its own uptake by the thyroid, whereas the faster disappearance of PTU from the thyroid than from serum is consistent with intrathyroid drug metabolism.

Length and ponderal index at birth: associations with mortality, hospitalizations, development and post-natal growth in Brazilian infants.

BACKGROUND: Low birthweight infants suffer greater mortality and neonatal morbidity, grow less well in infancy and show poorer psycho-motor development. However, this simple categorization may obscure important differences in aetiology and prognosis between infants born stunted, thin, or both. METHODS: In 1993, all births in Pelotas, Brazil, were enrolled into a prospective study of health and development in infancy. Of 5249 live births, 5160 had length and weight measures at birth, and were classified into tertiles of length and ponderal index. All deaths and hospitalizations were monitored, and suspected developmental delay and attained growth at 12 months were assessed on a subsample of 1364 infants. Logistic regression was used to control for gestational age and socioeconomic status. RESULTS: There was no association between birth length and ponderal index tertiles. After adjusting for gestational age, infants in the lower tertiles of both length and ponderal index presented a 3.8-times higher risk of mortality from day 8 to day 365, and a 2.5-times higher risk of hospitalization compared to infants with greater birth lengths and/or ponderal indices. Suspected developmental delay was associated with length and, less strongly, with ponderal index, but there was no synergism between the two. Infants in the middle and upper tertiles of ponderal index at birth became thinner. CONCLUSIONS: Birth length was strongly associated with development at 12 months, but only infants born both short and thin were at increased risk of mortality and hospitalizations. The combination of the two measures provides a useful classification of the anthropometric status of the newborn.

PIP: A prospective study of all 5249 live births in Pelotas, Brazil, in 1993 examined interactions between health and development in infancy. The 5160 infants who had length and weight measurements taken at birth were classified into tertiles of length-for-age Z score and ponderal index--a measure of soft tissue growth. There was no association between these two measures. After adjustments for gestational age, infants in the lower tertiles of both length and ponderal index had a 3.8 times greater risk of mortality from day 8 to 365 and a 2.5 times higher risk of hospitalization than infants in the high tertile. However, infants born short but not thin, or thin but not short, were not at increased risk of either mortality or hospitalization. Suspected developmental delay at 12 months was associated with shorter stature at birth and, less strongly, with a lower ponderal index, but there was no synergism between the two measures. Infants in the middle and upper tertiles of ponderal index at birth became markedly thinner in the first year of life, while length changes were less strongly associated with initial status. Overall, these findings suggest that the combination of length and ponderal index at birth may provide a functionally relevant means of classifying the newborn's anthropometric status since the two measures are relatively independent of each other at the level of the individual and appear to affect different aspects of the infant's subsequent health and development.

The ontogeny of [3H]5-hydroxytryptamine binding in the lamb: effects of in vivo thyroidectomy.

The effects of congenital hypothyroidism in the late gestation ovine fetus include changes in serotonin concentrations in specific brain areas. To investigate possible ontogenic patterns of changes in 5-HT receptor function, we studied the binding characteristics of [3H]5-HT in the midbrain, hypothalamus and cerebral cortex in the late gestation ovine fetus and young lamb. We compared the binding characteristics of control fetuses to those of thyroidectomized fetuses, with or without thyroxine replacement therapy. In each of the areas examined, age-dependent changes in the receptor density (Bmax) for [3H]5-HT was observed. In cerebral cortex, Bmax was constant from 120 days gestation through the early neonatal period and increased significantly only at 25-30 days after birth. In hypothalamus, [3H]5-HT binding density decreased late in gestation (140-145 days) with a return after birth to values comparable to those at 120-125 and 130-135 days gestation. The midbrain also exhibited a significant age-dependent pattern of altered receptor density with a decrease in the 130-135 and 140-145 day gestational age groups compared to both younger and older lambs. In contrast, the affinity constant (Kd) for [3H]5-HT did not change over the ages evaluated in cerebral cortex or hypothalamus. In the midbrain, however, there was a significant increase in Kd at 1-5 days after birth compared to all other age groups. The ability of fetal thyroidectomy, with or without thyroxine replacement therapy, to alter patterns of [3H]5-HT binding was also tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging but not estrogen alters regional [3H]5-HT binding in the CNS of female Fischer 344 rats.

Age-related changes in serotonergic regulation of neuroendocrine function were investigated in female Fischer 344 rats; serotonin ([3H]5-HT) binding sites were characterized in several brain regions. Neither the number (Bmax) nor the affinity (Kd) of [3H]5-HT sites were altered in the frontal cortex of reproductively young and senescent groups. However, a significant decline in receptor affinity was observed in the hypothalamus and midbrain dorsal raphe nucleus. An increase in the density of binding sites was also observed in the hypothalamus with advancing age. Acute 48 h exposure to estrogen failed to influence [3H]5-HT binding site characteristics in these brain regions. In summary, these results suggest that age-related changes in [3H]5-HT binding are regionally specific. Moreover, the observed changes in hypothalamic 5-HT function may underlie neuroendocrine aging events.

Urinary excretion levels of unconjugated pterins in cancer patients and normal individuals.

Urinary excretion levels of seven unconjugated pterins in healthy individuals and in cancer patients, most of whom were undergoing chemotherapy, were measured utilizing a newly developed high-pressure liquid chromatographic system. Excretion of pterins in the control group appears to be under strict metabolic control as the values obtained were confined within a small range. When the mean excretion levels in control subjects were compared with those in cancer patients, we found a significant increase in the excretion of xanthopterin, neopterin and pterin and a significant decrease in isoxanthopterin by cancer patients. Biopterin levels, on the other hand, were found only slightly but not significantly increased, whereas pterin-6-carboxylic acid and 6-hydroxymethylpterin were found to be excreted in approximately equal amounts in both groups. Urinary excretion levels of pterins were monitored for a period of nine months in a patient being treated with chemotherapy for metastatic ovarian carcinomatosis. We found that the excretion pattern of pterins appeared to correlate with the clinical status of the patient. These results indicate that a definite imbalance in pterin, and possibly folate metabolism, is associated with the presence of malignant diseases.

A synthesis of nine major reports on physicians' competencies for the emerging practice environment.

Medical education and training programs generally have been slow to introduce curriculum content that reflects important changes in practice organization and health services delivery. However, impetus for curricular reform is gaining momentum as national organizations endorse new content for both medical school and residency education. The authors and colleagues at Tufts Managed Care Institute reviewed nine reports by key national organizations to assess their positions on curricular reform in light of changes in practice and the system of care. The reports agree generally on the evolving nature of practice, the need to address these changes during medical school and residency training, and the description of the new curriculum content that they advocate. The authors grouped these reports' specific recommendations under ten curriculum domains: health care system overview; population-based care; quality measurement and improvement; medical management; preventive care; physician-patient communication; ethics; teamwork and collaboration; information management and technology; and practice management. They describe the reports' rationales and cite specific knowledge and skills that these national organizations identify within each domain. This domain-based framework synthesizes and complements the recommendations of these national organizations. The authors conclude that implementing curricular reform remains a challenge. The information and competencies need to be organized and sequenced for stage of training and specialty, and barriers to change require strategic and operational planning. Having a common nomenclature and framework will facilitate the introduction of new content within schools and programs, across departments, and among institutions nationwide.

Indicators of organizational readiness for clinical information technology/systems innovation: a Delphi study.

The study presented in this article represents the second phase in a multi-phased research program focused on health care organization readiness for clinical information technology/system (IT/S) innovation. The overall purposes of this exploratory study were to: (1) validate the seven IT/S innovation readiness sub-dimensions of a heuristic organizational information technology/systems innovation model (OITIM) developed in phase one of the research program, and (2) identify indicators to assess the validated sub-dimensions. The study was conducted with an expert panel using a two-round modified Delphi technique. In Round #1, panelists supported retention of the OITIMs' seven theoretical IT/S innovation readiness sub-dimensions with an interrater agreement level range of 82-100%. Their sub-dimension importance ratings ranged from 3.27 to 3.72 (1=not important to 4=critically important) with the resources sub-dimension receiving the highest rating of 3.72. Panelists recommended that two sub-dimensions, 'Staffing and Skills' and 'Operations', be renamed to 'End-Users' and 'Management Structures', respectively, and that one sub-dimension, 'Administrative Support' be added. In Round #2, panelists identified a total of 316 indicators to assess the eight sub-dimensions. A two-step thematic analysis process was done with these indicators to reduce duplication and overlap. In Step 1, the investigator created ten preliminary theme categories per sub-dimension. In Step 2, a coding team categorized 279 (88%) of the 316 indicators into preliminary sub-dimension themes to create an organizational IT/S innovation readiness assessment taxonomy. This preliminary taxonomy was used to develop an organizational information technology/systems innovation readiness scale that is currently being pilot tested in phase three of the research program.

Measuring organizational readiness for nursing research programs.

Nursing research programs are important innovations for health services organizations (HSOs). Evidence supports the positive impact that successful programs have on both clinical practice and patient outcomes. In the current era of scarce health care resources, decision makers must be able to accurately judge HSO readiness for nursing research programs to facilitate their success. Judging innovation readiness is an important and complex process for decision makers. An Innovation Readiness Scale (IRS) was developed from research-based HSO contextual cues identified by nurse researchers as supportive of successful hospital-based nursing research programs. The IRS provides decision makers with a measure by which to judge HSO readiness for nursing research programs. Psychometric results are reported from a pilot and actual test of the IRS in two urban acute care settings involved in nursing research program innovation.

An assessment taxonomy for designing nursing research programs.

Clinical nursing research programs are a common structural component within nursing service organizations. Descriptive literature identifies many design features that are important in the development and success of organizational innovations, among which is the need to design programs that are congruent with the overall organization. Two exploratory Delphi studies were conducted to identify and classify organizational attributes that clinical nurse researchers considered critically important to the success of nursing research programs. Nadler and Tushman's Congruence Model for Organization Analysis was used as a framework to develop an assessment taxonomy for classification of the 64 critically important attributes identified by clinical nurse researchers.

Poverty and early childhood parenting: toward a framework for intervention.

The relationship between poverty and child rearing has been a persistent source of social concern in the United States. Drawing on available literature, this paper seeks to establish a conceptual approach to the interaction of these two complex variables. Appropriate interventions and strategies for their implementation are considered.

Doctoral programs in nursing: an examination of curriculum similarities and differences.

In this exploratory study, eight doctoral programs in nursing (four PhD and four DNS/DSN/DNSc) were surveyed to examine curricular similarities and differences between research-oriented and professional-oriented programs. Content analysis was utilized to examine manifest content of 101 units of analysis derived from questionnaire items. These items reflected environmental input, curricular design, and outcome variables. Findings suggested that more curricular similarities than differences existed between the two program types. Curricular design variables reflected the most differences in the areas of program purposes and objectives. Several areas were identified for additional research in each variable category.

[Prenatal care in Pelotas, Rio Grande do Sul, Brazil, 1993]. / Atenção pré-natal em Pelotas, Rio Grande do Sul, Brasil, 1993.

All 5304 births in the hospitals of Pelotas, Rio Grande do Sul, Brazil in 1993 were studied. Neonates were examined and their mothers were interviewed regarding sociodemographic conditions, family income, reproductive health, and medical care during pregnancy. Ninety-five per cent of women received prenatal care. The mean number of physician visits during pregnancy was 7 and the majority of the women (84.7%) began visits before the fifth month of pregnancy. Women who did not receive prenatal care were from the lowest socioeconomic stratum and were mostly adolescents or over 40 years of age. Incidence of low birth weight in this group was 2.5 times that of the group with more than five visits (p>0.001). Perinatal mortality rate was 50.6/1000 in the group without prenatal care and 15.8/1000 in the group with more than five visits. With regard to utilization of health care, the study shows that twenty-five per cent of women with high gestational risk received inadequate prenatal care. The rate was less than 10% in the group of women with low gestational risk. These results suggest the need for improvement in the quality of prenatal care with special attention for mothers with high gestational risk.

[The Children's Pastoral in Criciúma, Southern Brazil: coverage and socio-demographic characteristics of participating families]. / A Pastoral da Criança em Criciúma, Santa Catarina, Brasil: cobertura e características sócio-demográficas das famílias participantes.

This study describes the main social, economic, biological, and demographic characteristics of children and families who participate or have participated in the Children's Pastoral as compared to the overall urban population of Criciúma (Southern Brazil). A population-based cross-sectional study with a probabilistic sample of 2208 children under three years of age was conducted; 16.7% of the mothers confirmed having participated in the Pastoral at any given time, of whom 4.8% were currently participating, while the rest had dropped out. Black children and those over 12 months old or with two or more older siblings participated more frequently in the Pastoral. The main family factors associated with participation were mother's age (over 25), mother not working outside the home, low per capita income, low parental schooling, living in the neighborhood for more than 4 years, and death of sibling before age five. Reasons most often given by mothers for dropping out were migration, lack of time, and interruption of the Pastoral's activities in the neighborhood. The conclusion was that the Pastoral should prioritize the poorest of the poor and adopt measures to reduce drop-out rates.