Influence of transition rates and scan rate on kinetic simulations of differential scanning calorimetry profiles of reversible and irreversible protein denaturation.

The thermodynamic parameters characterizing protein folding can be obtained directly using differential scanning calorimetry (DSC). They are meaningful only for reversible unfolding at equilibrium, which holds for small globular proteins; however, the unfolding or denaturation of most large, multidomain or multisubunit proteins is either partially or totally irreversible. The simplest kinetic model describing partially irreversible denaturation requires three states: Formula [see text] We obtain numerical solutions for N, U, and D as a function of temperature for this model and derive profiles of excess specific heat (Cp) in terms of the reduced variables v/ki and k1/k3, where v is the scan rate. The three-state model reduces to the two-state reversible or irreversible models for very large or very small values of k1/k3, respectively. The apparent transition temperature (Tapp) is always reduced by the irreversible step (U-->D). For all values of k3, Tapp is independent of v/k1 at sufficiently slow scan rates, even when denaturation is highly irreversible, but increases identically for all models at fast scan rates in which case the excess specific heat profile is determined by the rate of unfolding. Accurate values of delta H and delta S can be obtained for the reversible step only when k1 is more than 2000-50,000 times greater than k3. In principle, approximate values for the ratio k1/k3 can be obtained from plots of fraction unfolded vs fraction irreversibly denatured as a function of temperature; however, the fraction irreversibly denatured is difficult to measure accurately by DSC alone.(ABSTRACT TRUNCATED AT 250 WORDS)


Report on the expanded role nurse project.

Based on increasing patient acuity, shortage of adequately prepared nurses, universal funding cutbacks as well as reduction in the numbers of medical residents in Ontario, University Hospital in London embarked on a project to develop and expand the role of the nurse in 1988. Utilizing the project objectives as a framework, this paper summarizes the status after three years by describing the extent to which the objectives have been or are being met. Factors which support and factors which impede success are identified and plans for action are presented.


A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 1. Principles and study design.

This article describes the design of an intercenter comparative study of treatment outcome in the treatment of children with a unilateral complete cleft of the lip and palate. The rationale and aims of this study are defined and treatment schemes of the participating centers are described. The findings are presented in a series of three papers (Parts 2, 3, and 4) dealing with the comparison of craniofacial form, dental arch relationships, and nasolabial appearance. In Part 5, conclusions and general recommendations regarding future research are discussed.


The advanced nurse practitioner: common attributes.

Nurses practice at different levels of expertise regardless of education, specialty area and primary, secondary, or tertiary care setting; therefore, education, specialization and location of practice must not be the sole determinants of advanced nurse practitioners. Rather, it is the appropriate knowledge base combined with specific characteristics and behaviors which clearly set them apart from other practitioners in nursing. Through a review of relevant literature this article defines advanced practice, describes different roles assumed by the advanced nurse practitioner and identifies and discusses some of the attributes and behaviors which are evident in all advanced practitioners.


The transition process: joint responsibility of nurse educators and employers.

The transition between school and work is a time of critical development for the beginning practitioner. Have nurse neophytes been set up for failure by academics? Are seasoned practitioners and administrators "eating our young" in service settings? What must be done to prepare confident and competent beginning practitioners? What must be done to ensure a working environment that encourages and nurtures the development of young nurses? Results of a brief survey conducted to determine if Canadian university schools of nursing invite feedback about competencies of new graduates, and a review of literature published about the subject, reveal that there is a limited interface in evaluating competencies of new graduates between university schools of nursing and clinical practice agencies. This paper discusses common issues in evaluation of new baccalaureate graduates' performance from the perspective of educators and employers. This paper also discusses issues related to the evaluation of new graduates as they are documented in the literature, findings of the aforementioned survey, and implications of the findings for nurse administrators and nurse educators.


A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 2. Craniofacial form and soft tissue profile.

The craniofacial morphology and the soft tissue profile were evaluated in this part of the intercenter study of the European Cleft Lip and Palate Research Group. The sample was comprised of cephalometric x-rays of the full cohort of 151 cases from the six European cleft palate centers. The facial morphology in complete unilateral cleft lip and palate patients was evaluated by means of roentgen cephalometry. Approximately 25 consecutive cases from each of six European cleft palate centers were compared. Only one center showed notable and consistent differences from the others. A contributing factor for these differences may be an inconsistent treatment regimen with many surgeons involved. Analysis of the soft tissue profile between the centers showed more pronounced differences than analysis of the skeletal profile. The treatment outcome in centers with more complex or expensive programs was no better than those centers using simpler management approaches.


A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 3. Dental arch relationships.

One hundred and forty-nine dental casts of subjects with complete unilateral clefts of the lip and palate from six European cleft palate centers were assessed by means of the Goslon Yardstick. The Yardstick proved capable of discriminating between the quality of the dental arch relationships between the six centers. Two centers showed especially poor results. Three centers obtained satisfactory results although differing surgical techniques were used in these centers. One of the centers showing satisfactory dental arch relationships employed a more complex and expensive treatment program than the other two centers, which both used simpler centralized treatment regimens.


A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 4. Assessment of nasolabial appearance.

One hundred and fifteen frontal and profile photographs of the nasolabial area of subjects with complete unilateral clefts of the lip and palate from six European centers were assessed. Four components of the nasolabial area were rated separately by a panel of judges using a five-point scale of attractiveness. The Tukey multiple comparison test showed significant differences between the centers. The relative position of the six centers in this study followed a similar pattern to their respective positions in the cephalometric and dental cast studies.


Dealing with practical problems in nursing management.

Nursing supervisors hear certain complaints from nurses with unusual frequency. In this article, seven common complaints are presented, and an example demonstrating each complaint is described. The obvious and not-so-obvious reasons behind each complaint are analysed, and suggestions made for supervisory behaviour which will reduce the likelihood of such complaints. When nursing supervisors actively pursue good managerial practices, the frequency of complaints will decline, interpersonal relations will improve, and increased supervisory effectiveness will result.


A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 5. General discussion and conclusions.

Part 5 is the final part of a series of five articles reporting on an international, multicenter clinical audit of treatment outcome for complete UCLP. A number of recommendations for the methodology of future studies is made especially with respect to entry criteria, sample size, assumptions of homogeneity, and the reproducibility and validity of outcome measures. The findings of the present study regarding clinical procedures are presented tentatively, and improvement and extension of the methodology are required. It appears, however, that acceptable results can be achieved by different programs and ultimately clinical choices may be based on factors such as complexity, costs, and demands of treatment. Standardization, centralization, and the participation of high volume operators were associated with good outcomes, and nonstandardization and the participation of low volume operators with poor outcomes. Therapeutic factors associated with good outcomes were the employment of a vomer flap to close the anterior palate, and poor outcomes with primary bone grafting and with active presurgical orthopedics.


The development of the expanded role nurse: background and questions surrounding the project.

In January, 1988 University Hospital in London, Ontario began a project to develop an expanded role for nurses who had Masters preparation and advanced knowledge and expertise in a clinical specialty. The rationale which support the decision to implement the project and a discussion of some of the issues relevant to that decision, are presented. An overview of the project goals is also included. The strengths, weaknesses and outcomes which have been identified during the first three years are dealt with in "Report on the Expanded Role Nurse Project" also published in this issue of the journal.


Cephalometric analysis of maxillofacial morphology in unoperated cleft palate patients.

This study was designed to investigate maxillofacial morphology in adolescents and adults with unrepaired cleft palate, with or without cleft lip. Twenty-two Chinese patients with unilateral cleft lip and palate (the UCLP group), and 21 Chinese with cleft palate (the CP group) were cephalometrically evaluated and classified into the five ranges established from the means and standard deviations for matched normal Chinese populations. Many subjects in both UCLP and CP groups showed an intrinsic maxillary retrusion and a steeper mandible. The others had nearly normal maxillofacial morphology. The tendency for maxillary retrusion and a steeper mandible became increasingly remarkable with age. In the long axis of upper incisors in subjects with permanent dentition, there were no UCLP subjects with labial inclination, whereas three CP subjects exhibited labial inclination.


Trends in prosthodontic treatment of cleft palate patients at one institution: a twenty-one year review.

This 21-year retrospective study evaluated the trends observed in the prosthodontic treatment of 269 patients. The patients were divided into three groups. The speech aid group consisted of 203 patients and showed a significant decrease in numbers over time. The maxillary obturator group consisted of 24 patients and did not show a significant change. The infant feeding prosthesis group consisted of 42 patients and showed a significant increase in numbers. Possible reasons for the trends observed are discussed.


Pulmonary function of individuals with congenital cleft palate.

Ventilatory pulmonary function was investigated in 160 children and adults with repaired or unrepaired congenital cleft palate in comparison with 130 normal children and adults. Pulmonary function tests included measurement of lung volumes, of maximal voluntary ventilation (MVV) and of forced spirometry parameters: forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio and mean forced expiratory flow during the middle half of FVC (FEF25-75). Patients with cleft palate demonstrated significant differences from normal individuals in some of the measurements made. Functional alterations were observed at higher frequency among adult patients with unrepaired clefts and mainly consisted of a reduction in expiratory flows and MVV. However, the deviations observed were usually discrete and probably of low physiopathologic significance. The results permit us to conclude that, in contrast to data reported by others, subjects with congenital cleft palate have little impairment of pulmonary ventilatory function.


Phonetic and phonologic skills of two-year-olds with cleft palate.

This article examines the phonetic and phonologic skills of 2-year-olds with cleft palate. Fifteen children, 10 children with cleft palate and five noncleft children, participated in the study. The children with cleft palate all received palatal surgery after 12 months of age and after the onset of meaningful speech. All subjects were video and audiotaped while interacting with their mothers during unstructured play. At least one hundred different spontaneous word productions were phonetically transcribed and analyzed for (1) percent consonants correct, (2) phonologic processes, and (3) "compensatory" articulation patterns. A comparison between the groups indicated that although the children with cleft palate exhibited more errors overall, they were similar to their noncleft peers in their phonologic process usage with two exceptions. Additionally, few "compensatory" articulation errors were noted in the speech of these children.


Operating safely in an underdeveloped country.

The visiting surgical team doing cleft lip and cleft palate repair in an underdeveloped country may find long hours and adverse conditions. Some of the trips are undertaken for resident education. It is the responsibility of the expedition leader to implement safety precautions for protection of both the patients and the volunteers in the operative party as suggested in this article. Equipment maintenance and modified sterilization techniques are also described.


First-year mortality among infants with facial clefts.

Children born with a facial cleft are not thought to be at a greater risk for infant mortality than are those without congenital anomalies. The purpose of this study was to investigate whether the presence of a facial cleft alone or its coexistence with other anomalies increases a child's risk for dying. Birth and death certificate data from Washington State for the years 1984 to 1988 were linked for infants who died before 1 year of age. Mortality rates for different types of facial clefts and for births without noted abnormalities were compared. Relative to infants with no diagnosed abnormalities noted in the birth certificate, infants with facial clefts without other abnormalities have a 3.7 fold increased odds for dying during their first year of life. This elevated risk for dying was fairly consistent during the first year of life. When facial clefts are associated with other abnormalities there is an 82.3 fold increase in odds for mortality during the first year of life. This elevated risk is highest during the neonatal period; 77% of all deaths occurred during the first 27 days. It is concluded that infants with facial clefts with or without associated anomalies have a significantly increased mortality risk when compared to infants without any diagnosed abnormalities at birth.


Craniofacial development in myotonic dystrophy.

Anthropometric, cephalometric, and dental data from 23 subjects (12 males and 11 females) afflicted with myotonic dystrophy were compared to similar data from normal subjects who participated in the Iowa Facial Growth Study. A two by two analysis of variance showed that myotonic subjects differed from normal subjects in headlength, head breadth, cephalic index, bizygomatic face width, nosebreadth, maxillary arch widths, palatal depth, anterior and posterior face heights, cranial base lengths, cranial base angles, and other cephalometric measures. Sex differences were observed for many of the variables. It is hoped that these findings will assist clinicians who treat patients having this disorder.


Microbiota associated with residual clefts and neighboring teeth in patients with cleft lip, alveolus, and palate.

Twenty patients with residual clefts or pronounced soft tissue grooves, treated for uni- or bilateral cleft lip, alveolus, and palate were included in this study. Ten patients were recalled for dental prophylaxis at regular intervals, 10 patients were not. One microbiologic sample was obtained from the cleft area and two samples from a tooth adjacent to the cleft (sites adjacent and distant to the cleft). Between the recall and the nonrecall group there were notable differences in the presence of anaerobic Gram-negative organisms. Fusobacterium spp., Prevotella melaninogenica, and P. intermedia were more often found in nonrecall patients. While rarely seen in recall patients, spirochetes and motile rods were a common feature of nonrecall patients. The putative periodontal pathogens Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were not detected in either group. The differences between the recall and the nonrecall groups were more pronounced when the respective samples from teeth were related to each other than when the samples obtained from the clefts were compared. The cleft flora was less complex irrespective of how good maintenance was and resembled the flora of teeth of well-maintained patients. Samples from clefts were never Wolinella positive, and harbored significantly less Capnocytophaga and Actinomyces viscosus than samples from dental sites.


Reproductive history of mothers of children with solitary, nonsyndromic cleft lip and/or palate.

The reproductive history was studied to evaluate if the three types of solitary, nonsyndromic clefts: cleft lip (CL), cleft lip and palate (CLP), and cleft palate (CP) are homogeneous entities. Occurrence of fetal loss, maternal health, and drug consumption of the mother during the pregnancy were compared in cases involving three types of clefts. Data was gathered from 87 children with clefts, 55 males and 32 females. Spontaneous abortions and vaginal bleeding were found to occur significantly more often in the (older) mother of a CLP child. This suggests that the factors involved in the etiology of CLP differ from the factors involved in CL and CP. Therefore, grouping of data of the three types of clefts in studies on the etiology should be avoided.


Growth comparison between children with cleft lip and/or palate and controls.

General growth from birth to 2.5 years of age of 45 children with a solitary, nonsyndromic cleft lip and/or palate (CL/P) was compared to that of 50 controls. Weight, height, and head circumference were studied in relation to possible influencing factors. Growth of children with CL/P was found to be similar, to a large extent, to that of the control sample, with the exception of growth measured by height. Whereas males in the control group are generally taller than females, the reverse is seen for the CL/P group. Feeding difficulties and intestinal disorders, airway infections, and cleft restoring operations do not account for differences among the groups with CL/P and the control group as was suggested in the literature. Feeding difficulties and intestinal disorders between 12 and 18 months of age and airway infections between 0 and 3 months of age were identified as having a negative influence on growth, measured by weight and height, though not on head circumference.


Cleft lip repair using intramuscular hydroxyzine sedation and local anesthesia.

Intramuscular hydroxyzine was used alone for sedation in 18 cleft lip repairs with patients under 6 weeks of age. After injection of local anesthesia, the infants were quiet throughout the procedure. Blood pressure, pulse, respiration, and temperatures were normal throughout and the oxygen saturation remained above 94% in all cases. There were no complications noted with this series of patients and no patient required conversion to general anesthesia. Intramuscular hydroxyzine combined with local anesthesia and nerve block has been found to be a safe and effective method for cleft lip repairs in selected neonates under 6 weeks of age.


Dental implants to rehabilitate a patient with an unrepaired complete cleft of the hard and soft palate: a clinical report.

Prosthetic rehabilitation of an edentulous adult with a complete residual cleft of his palates is presented. Lack of retention of his prosthesis made speech and eating difficult. Four osseointegrated dental implants were used to join the right and left maxillae and to provide mechanical retention for a complete overdenture obturator to improve function.


Isolation, partial amino acid sequence, and cellular distribution of heat-shock protein hsp98 from Neurospora crassa.

Hsp98 is one of the most prominent proteins synthesized during the heat-shock response of Neurospora crassa. We purified hsp98 and determined the amino acid sequence of two overlapping peptides obtained by cyanogen bromide cleavage. This 28 amino acid sequence from hsp98 has 75% homology with a region of the ClpB protein of Escherichia coli and 86% homology to a 96-kDa protein of Trypanosoma brucei. It also has 71% homology to hsp104 of Saccharomyces cerevisiae. Hsp98 was enriched in the microsomal fraction of heat-shocked cells. Sucrose gradient analysis of this cellular fraction showed that the three major high molecular weight heat-shock proteins (hsp98, 83 and 67) were more concentrated in polyribosomes than in monoribosomes. Another newly synthesized protein, p28, was strongly enriched in monoribosomes. After dissociation of the polyribosomes into ribosomal subunits, the three major heat-shock proteins were shown to be localized preferentially in the large subunit. Whereas p28 was also strongly associated with the large ribosomal subunit, a newly synthesized protein of about 22 kDa was exclusively associated with the small subunit.


Alteration of cytochrome P-450 2C11-dependent testosterone metabolism in Gunn rat liver.

Cytochrome P-450 2C11 (CYP2C11) is the main isozyme present in adult male rat liver and specifically hydroxylates testosterone in positions 2 alpha and 16 alpha. In Gunn rats, this isozyme is recognized by the anti-CYP2C11 antibody but its activity towards testosterone is dramatically decreased. Moreover, peptide mapping, after digestion of microsomal fractions by V8 protease and probing with anti-CYP2C11 antibody, exhibit a pattern which differs from that obtained with Wistar rats. Taken together, data suggest that the protein sequence of CYP2C11 from the Gunn rat differs from that of the Wistar rat.


Plasminogen binding by alpha 2-antiplasmin and histidine-rich glycoprotein does not inhibit plasminogen activation at the surface of fibrin.

alpha 2-antiplasmin (alpha 2-AP) exerts its inhibitory effect on fibrinolysis by rapidly inhibiting the plasmin evolved; in addition, it has been suggested that interference with the binding of plasminogen to fibrin, a function shared with histidine-rich glycoprotein (HRGP), may also be significant in inhibition of fibrinolysis. To elucidate if plasminogen binding by these two alpha 2-globulins may decrease the generation of plasmin by tissue-type plasminogen activator (t-PA) at the surface of fibrin, a system mimicking the fibrin/plasma interface was used. Attempts were made to differentiate the plasminogen binding from the plasmin inhibitory function of alpha 2-AP. The activation of human Glu-plasminogen (native plasminogen with NH2-terminal glutamic acid) by fibrin-bound t-PA was performed in a plasma environment using either normal plasma, alpha 2-AP- or HRGP-depleted plasmas supplemented with increasing amounts of the lacking protein, or in a reconstituted system with purified plasminogen and various concentrations of alpha 2-AP and HRGP. The activation of Glu-plasminogen in alpha 2-AP-depleted plasma containing a normal concentration of HRGP produced a time-dependent increase in the generation of plasmin. The addition of 1 microM-alpha 2-AP to this plasma prevented the formation of Lys-derivatives and produced a marked decrease (42%) in the number of plasminogen-binding sites. In contrast, the addition of 1.5 microM-HRGP to HRGP-depleted plasma containing a normal amount of alpha 2-AP produced only a modest (17%) decrease in the amount of plasmin(ogen) bound. Moreover, in a purified system the amount of plasminogen-binding sites and thereby of plasmin generated at the surface of fibrin in the presence of both alpha-2 globulins was similar to the amount generated in the presence of alpha 2-AP alone. These results indicate clearly that the formation of reversible complexes between plasminogen and alpha 2-AP does not interfere with the binding and activation of plasminogen at the fibrin surface. In contrast, the inhibition of plasmin by alpha 2-AP decreases importantly the number of plasminogen-binding sites (carboxyl-terminal lysines) and inhibits thereby the accelerated phase of fibrinolysis. It can be concluded that interference of the binding of plasminogen to fibrin by alpha 2-AP during plasminogen activation, does not play a significant role in inhibition of fibrinolysis, and that the plasminogen-binding effect of HRGP, if any, is obscured by the important inhibitory effect of alpha 2-AP.


Expression of a catalytically active human cytochrome P-4502E1 in Escherichia coli.

The cDNA coding for human cytochrome P-4502E1 has been expressed in Escherichia coli by placing it under the control of the isopropylthiogalactoside inducible trc promoter. Production of P4502E1 was demonstrated by immunoblots and by catalytic activity with dimethylnitrosamine as substrate. Modifications which favor expression in E. coli were made within the first seven codons. This resulted in approx. a 2- to 2.5-fold increase in P4502E1 isolated from the bacterial membranes as detected by immunoblots and catalytic activity. CO-reduced difference spectra of the modified P4502E1 revealed a peak at 452 nm, which is characteristic of hepatic P4502E1, and a molecular weight of 54 kDa. A partially purified preparation of recombinant P450 protein was active with dimethylnitrosamine, a substrate specific for this isozyme, when reconstituted with purified rat liver NADPH-cytochrome P-450 oxidoreductase. This activity was enhanced in the presence of cytochrome b5 and inhibited by the addition of antibody to the P4502E1 purified from pyrazole-treated rats. E. coli were capable of oxidizing p-nitrophenol when transformed with vector containing the human P4502E1 cDNA but not with vector alone. This in vivo metabolism of p-nitrophenol was increased 2-fold when the modified P4502E1 cDNA was used, which corresponds to the increase in P4502E1 content. Expression of human P4502E1 in E. coli appears to be an attractive system for producing large amounts of this isozyme, and for studies on the toxicological properties and structure-function relationship of the human P4502E1.


Renal excretion of pseudo-cross-linked human, porcine and bovine hemoglobins.

The present experiments were done to determine plasma retention, urinary excretion, and acute renal effects of bolus administration (20 mg/100 g), of hemoglobins (human, bovine and porcine) whose tetrameric structure was stabilized by a pseudo-cross-link between the beta-chains. Standard renal clearance studies showed that these preparations had no immediate adverse effects on GFR or ERPF, however, urine flow and electrolyte excretion commonly increased. Plasma disappearance curves best fit a double-exponential and showed components with half-times of 28 +/- 3 and 257 +/- 43 min. A variable fraction, 57 +/- 6%, appeared in the urine, in phase with the early-fast component of plasma disappearance. This in vivo finding of extensive urinary excretion conflicted with sedimentation velocity analysis of these preparations which indicated a homogenous preparation with mean molecular weight of a stable and therefore, unfilterable tetramer. It appears that the glomerular filter selects for permeant species not easily detected by sedimentation velocity analysis. The different species may reflect the presence, within the PXLs of conformational-slow-equilibria among isomeric forms with different degrees of filterability. It is important, useful and simple to determine urinary excretion as a means to ascertain molecular stability in vivo.


Turnover rates of different collagen types measured by isotope ratio mass spectrometry.

The rates of collagen turnover in different tissues have been estimated in growing rats previously exposed to gaseous 18O2. The abundance of the stable isotope was measured using isotope ratio mass spectrometry following combustion of isolated collagen-derived hydroxyproline. Using this method, problems of label reutilization associated with radiolabelling methods are avoided. In general the results confirm the slow turnover rates with half-lives of total collagen in skin, muscle and gut of 74, 45 and 244 d, respectively. The use of cyanogen bromide digests of whole tissues followed by isolation of collagen type-specific peptides has allowed the comparison of turnover rates of collagen types I and III, indicating that collagen type III is turned over more rapidly than type I.


Effect of thermodynamic water activity on amino-acid ester synthesis catalyzed by agarose-chymotrypsin in 3-pentanone.

Chymotrypsin linked to agarose beads by multi-point covalent attachment catalyzes synthesis of Ac-Trp-OEt in 3-pentanone even when the thermodynamic water activity (aw) of the system is reduced to as low as 0.4. If fully hydrated catalyst is added to the reaction mixture before removal of water, product is formed linearly once aw has stabilized. The initial rate is reduced from that if aw is kept close to 1 (0.47 mmol s-1 (kg enzyme)-1), to 50% (aw 0.9), 25% (aw 0.4) and < 1% (aw 0.25). The large drop between aw of 1 and 0.9 probably reflects the effects of water removal on the agarose gel structure. Catalyst partly dried (even only to aw 0.86) before adding to the organic phase is inactive. At reduced aw, the equilibrium (when reached) is shifted in favor of the ester, as expected.


Effects of 4-deoxy-L-threo-pentose, a novel carbohydrate, on neural cell proteoglycan synthesis and function.

A novel carbohydrate, 4-deoxy-L-threo-pentose (4-deoxyxylose), was synthesized by way of reductive dechlorination of a chlorodeoxy sugar. This carbohydrate, an analogue of xylose which is required for the initiation of glycosaminoglycan (GAG) synthesis, was used to explore the function of GAG side chains in neurite outgrowth on a laminin substrate. 4-Deoxyxylose inhibited the incorporation of 35SO4 into the GAGs of neuronal and astrocytic proteoglycans, with no effect being seen on the incorporation of [3H]glucosamine into proteoglycan. Direct analysis of the heparan sulphate fraction from such cells using nitrous acid digestion confirmed that the GAGs were undersulphated. No inhibition of either 35SO4 or [3H]glucosamine incorporation was observed in primary mouse hepatocytes exposed to 4-deoxyxylose. 4-Deoxyxylose produced a direct dose-dependent inhibition of neurite outgrowth by sensory neurons, and medium conditioned by neurons or astrocytes in the presence of 4-deoxyxylose displayed less laminin-complexed neurite-promoting activity than medium conditioned in its absence. These data suggest that 4-deoxyxylose inhibits neurite outgrowth by altering the sulphation of the GAGs of heparan sulphate proteoglycans.


Limited proteolysis of NADP-malate dehydrogenase from pea chloroplast by aminopeptidase K yields monomers. Evidence of proteolytic degradation of NADP-malate dehydrogenase during purification from pea.

NADP-malate dehydrogenase (L-malate: NADP oxidoreductase, EC 1.1.1.82) from leaves of Pisum sativum has been purified to homogeneity, as judged by polyacrylamide gel electrophoresis. In the crude leaf extract and in the absence of protease inhibitors in the isolation medium, the N-terminus of NADP-MDH was found to be highly susceptible to proteolysis. Evidence of proteolysis during purification includes observations of reduced subunit size on SDS-PAGE and reduced specific activity. Experiments were carried out to investigate the function of the N-terminal amino acid sequence extension of NADP-MDH. Limited proteolysis of highly active (600 units/mg protein) NADP-MDH using aminopeptidase K yielded catalytically active monomers of 34.7 kDa. The results support the conclusions that the N-terminal region is located at the surface of the protein, and that for maintenance of the native NADP-MDH dimer an N-terminal amino acid sequence is important.


Membrane-bound acetylcholinesterase: an early differentiation marker for skeletal myoblasts.

Cell-bound acetylcholinesterase (AChE) was found to be an early differentiation marker on embryonic chick skeletal myoblasts in mixed primary cell cultures. AChE biosynthesis was detected and characterized by (a) a sensitive microtiter assay, (b) use of selective inhibitors, and (c) with mono- and polyclonal antibodies. Both secreted and cell-bound AChE appeared on the first day in culture, at a time when no muscle cell fusion was observed. Characterization of this enzyme revealed that true AChE was bound and secreted by myoblasts. BW284c51, which permeates cell membranes poorly, inhibited all the cell-associated AChE activity on myoblasts, suggesting that the activity measured was on the outer cell surface. On the other hand, fibroblasts appeared to have no or very little bound enzyme and the low level of secreted enzyme activity had the characteristics of pseudo-, or butyrylcholinesterase. Polyclonal anti-Torpedo californica electroplax AChE antibody and several monoclonal antibodies were found to bind specifically to chick myoblasts. Since the cells had not been made permeable before antibody binding, a membrane-bound form of the enzyme was most likely being detected. The cell-bound true AChE was present in identifiable quantities from the first day of culture. Membrane-bound AChE can thus serve as an early differentiation marker for embryonic chick myoblasts in mixed primary cultures.


Factors affecting the manganese and iron activation of the phosphoenolpyruvate carboxykinase isozymes from rabbit.

Timed assays in which GTP and GDP were separated and quantitated by HPLC were developed and used to study the metal activation of the mitochondrial and cytosolic isozymes of phosphoenolpyruvate carboxykinase purified from rabbit liver. These assays allowed both directions of catalysis to be studied under similar conditions and in the absence of coupling enzymes. The mitochondrial enzyme is rapidly inactivated by preincubation with Fe2+, as had been shown previously for the cytosolic isozyme. The greatest activation by Fe2+ was obtained by adding micromolar Fe2+ immediately after enzyme to form the complete assay mixture that also contained millimolar Mg2+. In the direction of synthesis of OAA from Pep, the K0.5 values for Mn2+ and Fe2+ were in the 3-7 microM range when a nonchelating buffer, Hepes, was used. The buffer used strongly affected activation by Fe2+ at pH 7.4; activation was eliminated in the case of phosphate and K0.5 increased several-fold over that obtained with Hepes when imidazole was used. In non-chelating buffer, the pH optimum was near 7.4 for both isozymes and for both directions of catalysis. However, the near optimal pH range extended below 7.4 for the direction of oxaloacetate synthesis while the range was above 7.4 for Pep synthesis. In the direction of oxaloacetate synthesis: (1) Both isozymes required the presence of micromolar Mn2+ or Fe2+ in addition to millimolar Mg2+ in order to shown significant activity. (2) Fe2+ was as effective an activator as Mn2+ at pH 7 and below. In the direction of Pep synthesis: (1) Micromolar Mn2+ was a much better activator than Fe2+ at the higher pH values needed for optimal activity in this direction. (2) With increasing pH, decreasing activation was obtained with Fe2+ while the activity supported by Mg2+ alone increased. The results demonstrate the potential for regulation of either isozyme of Pep carboxykinase by the availability of iron or manganese.


Structural requirements for duodenal permeability of heparin-diamine complexes.

We have compared the physico-chemical behaviors alone and in the presence of a synthetic bilayer membrane, in aqueous solution and the bioavailability after intraduodenal administration to rabbits, of the two heparin diamine salts ITF-300 and ITF-331 with those of the heparin-amine salt ITF-1175. The three salts have similar structures but different characteristics of compounds tend to form aggregates in solution, but at different critical concentrations. The compounds induce fusion of single-walled vesicles of a synthetic peptide lipid into multi-walled lamellae. The minimal concentrations of the compounds required for the formation of such lamellae differ. This behavior in solution explains the differences in absorption in the animal model. This makes it possible to correlate enhanced heparin bioavailability with the structural nature of the diamine counter-ions used to prepare heparin salts.


Renal and hepatic output of glutathione in plasma and whole blood.

Measurement of glutathione (GSH) output by the rat kidney and liver demonstrated a substantial net release into red cells across both tissues. The results suggest important roles for kidney and liver in the maintenance of GSH concentrations in red cells and a significant role for the red cell in the interorgan transport of GSH.


Endobronchial brachytherapy.

Endobronchial brachytherapy is a palliative treatment primarily used for individuals with lung cancer. This article describes the brachytherapy and presents the nurse's role before, during, and after the procedure. Coordination between hospital staff--endoscopy department, pulmonologist, radiation oncologist, and radiology department--is important to assure the success of this procedure.


The control of erythropoiesis (Romanian contributions).

The main contributions of a Romanian team, headed by I. Baciu, in the field of the control of erythropoiesis are presented. The role of the central nervous system in the regulation of erythrocytes production and the identification of chemoreceptors sensitive to hypoxia in the central nervous system are disclosed. The studies concerning the secretion and the effects of erythropoietin are also emphasized. The paper provided references to the recent data concerning the structure of erythropoietin, the membrane receptors, the metabolism and the practical applications of the hormone.


Human responses to colonoscopy.

Registered nurses must not only anticipate the usual responses that a patient may experience during colonoscopy but also must be able to predict and prevent atypical responses. Normal healthy compensation (physiologic) and decompensation (pathophysiologic) responses as well as observable and measurable patient behaviors are included in a comprehensive assessment. In developing a plan of care, nurses must also consider the patient's past experiences, knowledge, and usual coping mechanisms. Professional nurses are responsible and accountable for diagnosing and treating human responses to actual or potential health problems. A human response framework emphasizes the multiple perspectives in which humans adapt to health and illness. This framework provides a model to clarify what constitutes a human response.


Anorectal manometry.

Anorectal manometry is used in the treatment of complex anorectal disorders, such as fecal incontinence and intractable constipation. In a 3-year period at one institution 308 anorectal manometries were performed. A total of 168 procedures were performed for complaints of fecal incontinence, 77 for constipation, and the remainder for a variety of anorectal disorders. Anorectal manometry in those under 20 years of age was performed most often to differentiate Hirschsprung disease from functional constipation, as well as to provide a differential diagnosis related to congenital anorectal anomalies. In patients between the ages of 21 and 40 years, evaluation of fecal incontinence (especially obstetrical injuries) was most significant. Fecal incontinence accounted for twice the number of anorectal manometries for those between the ages of 41 and 60. For those over 60 years of age, the majority of anorectal manometries were done for fecal incontinence rather than for constipation (nearly a 4:1 ratio). Anorectal manometry is a valuable physiologic adjunct in the evaluation, diagnosis, and treatment of organic and functional disorders of the anorectum.


The role of platelets and leukocytes in coagulation and fibrinolysis.

After briefly reviewing the literature concerning the role of leukocytes and platelets in coagulation and fibrinolysis, the authors present their own results on the effect of intact platelets and of platelet releasate on tissue plasminogen activator-induced lysis of plasma clots. At a final concentration of 7 IU/ml of tissue plasminogen activator in the clotted mixture, a suspension of intact platelets (110 x 10(6)/ml in final concentration) produced an acceleration of clot lysis, while the thrombin-induced platelet releasate obtained from the same platelet suspension caused an obvious inhibition of fibrinolysis. The respective mean lysis times obtained in 7 experiments were 91 min +/- 7.76 (mean +/- SEM) for the control clots, 65 min +/- 5.8 for the clots containing platelets and 114 min +/- 11.5 for the clots including platelet releasate. The statistical significance versus controls, calculated by paired difference analysis was p < 0.002 and p < 0.001, respectively. The results suggest that in the context of a potent activation of fibrinolysis the platelet surface would enhance the process by favouring the interaction between plasminogen and its activator, while the platelet releasate rich inhibitors would increase the resistance to lysis of the plasma clot.


Clinical pharmacology of commonly used drugs in GI practice. Part I.

Understanding the mechanism of action of pharmacologic agents allows the practitioner to rationally use them. This two-part review of clinical pharmacology attempts to address the chemical nature and action of drugs commonly used in gastrointestinal practice. Part I reviews agents used in the endoscopy laboratory for premedication and prophylaxis for infection. Part II will review the pharmacology of agents used in the daily practice of gastroenterology including antacids, H2 and proton pump blockers, cytoprotection agents, pancreatic enzymes, drugs for dissolution of gallstones, prokinetic agents, antiinflammatory agents for inflammatory bowel disease, and drugs for symptomatic treatment of functional bowel complaints.


Psychoneuroimmunology.

The recent findings on the close relation between the nervous and immune systems have led to the developing of a new interdisciplinary field: psychoneuroimmunology. This review outlines the topic of the research, the limits and the future trends of psychoneuroimmunology, emphasizing the reciprocal relationship between biological and psychological processes.


Sandostatin (octreotide acetate).

Sandostatin is an antineoplastic drug used to control diarrhea and improve hypokalema in patients with metastatic carcinoid tumors and vasoactive intestinal peptide-secreting tumors. Sandostatin has been used to treat life-threatening hypotension and acromegaly. Sandostatin has also been used after endoscopic retrograde cholangiopancreatography to reduce the motility of the pancreas. Generally side effects of Sandostatin are rare and medically manageable when recognized. Chronic therapy with Sandostatin warrants monitoring of serum electrolyte and blood glucose levels. Baseline thyroid studies should be investigated prior to therapy and monitored throughout therapy. Sandostatin may alter fat absorption and gallbladder function; therefore, monitoring of appropriate laboratory values and ultrasonography studies may also be indicated.


The role of nervous mechanisms in the immune response.

This review presents the results of experimental researches performed in the last decades by Cluj-Napoca physiologists, concerning the role of hypothalamic nervous centers in the triggering of the nonspecific (phagocytic reaction) and specific (primary and secondary) immune response. The following methods aiming to explore the involvement of the hypothalamic vegetative nervous centers have been applied: section of the spinal cord, somatoencephalic humoral isolation with preservation of spinal cord, stimulation or lesions under stereotaxic control of some hypothalamic areas, conditioned reflexes, electroconvulsant shocks. The results show that nervous centers from the tuberal area and from the posterior hypothalamus are involved in the regulation and integration of the immune response considered as a homeostatic function, in connexion with a preoptic, anterior and lateral hypothalamic area, with a receptive function to antigens and their endogenous products. The activation of phagocytosis (phagocytic response) can be elicited in dogs by electrical stimulation of the tuberal area and inhibited by section of the spinal cord, or by barbiturates. The specific immune response is moderately neuromodulated for antigens, as heterospecific red cells and more intensely for Salmonella and especially for the influenza virus. These results could allow an integration of other analytical data of cellular and molecular biology of immunity wider functional concept.


Pancreatitis in children.

The pathophysiology of pancreatic autodigestion is poorly understood. Pancreatitis affects all age groups, and the diagnosis is sometimes missed when serum amylase and lipase activities are not measured in the child with abdominal pain. Acute pancreatitis in children has become a more commonly seen condition and the causes have varied. Laboratory and radiological studies play an important role in determining the diagnosis and prognosis. Family history is important in the diagnosis of idiopathic hereditary pancreatitis. Most acute episodes resolve with supportive care, but the mortality in acute pancreatitis is currently about 15% (Hadorn et al., 1980). Endoscopic retrograde cholangiopancreatography or an endoscopic retrograde pancreatogram may be necessary to investigate relapses of pancreatitis. Chronic pancreatitis can be a life-threatening condition requiring lifetime medical management.


[A new method of global search for functional DNA segments using a fractal representation of nucleotide texts].

New global method for computer prediction of functional sites in nucleotide sequences, based on the fractal representation, is presented. Fractal representation of set of sequences (FRS) provides simple way for generating recognitions matrix of functionally similar sequences and simple estimations of its efficiency for searching homologous regions in new sequences. Other advantages of the method are absence of the necessity of sequences alignment during generating based set and searching new homologous regions and small CPU time. Usage of the method illustrated for searching globin and histone genes, for ALU repeats in human genome and long terminal repeats in virus genome.


[Heat capacity of DNA in native and denatured states].

Heat capacity of DNA in native and denatured states was estimated by the method of microcalorimetry. This value was shown to depend on the transition temperature and is determined by an increase of the number of oscillative freedom degrees of the polynucleotide chains in the state of statistical coils, and by hydrophobic effects and by "the melting of water ridge" located in native DNA in the B-form.


[Study of the conformational properties of C-terminal fragments of histones H1, H5, and beta-endorphin by circular dichroism].

Circular dichroism technique has been used for investigating the conformation of histone H1 and H5 C-terminal fragments and beta-endorphin. It has been shown that in aqueous solution these polypeptides adopt preferably the left-handed helical conformation of the poly-L-proline II type. The linear temperature dependence of the CD value during solution heating was found to be broken in the temperature interval between 50 and 55 degrees C. It was supposed to occur due to the conformation destruction.


[Symmetry of single-stranded DNA molecules].

A system of so-called coloured symmetry transformations is introduced, in the basis of which all possible symmetry groups of a single strand DNA molecule taken as a genetic text are derived. A strict description of functionally important symmetrical sites, such as palindromes, complementary palindromes, direct repeats is given in terms of the group theory. Possible role of symmetrical fragments in genome is discussed.


[Conservativeness of residues in nonpolar nuclei of microbial ribonucleases].

We present the application of a new method for analysis of nonpolar structure of proteins. A detailed analysis of the composition and properties of nonpolar nuclei and microclusters of microbial ribonucleases with known sequence have been carried out on the basis of 3D-structure of RNase Pbi and that of RNase Ti. It has been shown that all residues in nonpolar nuclei have high homology, about 95% for proteins with an identical scheme of S-S bridges and about 75% for nonidentical scheme of S-S bridges. The stability of nonpolar nuclei, conservation of their composition and their position in the protein globule allows one to assume that they play an important functional role in protein structure and possibly can be considered as independent structural elements of 3D-structure of a protein.


From basis functions to basis fields: vector field approximation from sparse data.

Recent investigations (Poggio and Girosi 1990b) have pointed out the equivalence between a wide class of learning problems and the reconstruction of a real-valued function from a sparse set of data. However, in order to process sensory information and to generate purposeful actions living organisms must deal not only with real-valued functions but also with vector-valued mappings. Examples of such vector-valued mappings range from the optical flow fields associated with visual motion to the fields of mechanical forces produced by neuromuscular activation. In this paper, I discuss the issue of vector-field processing from a broad computational perspective. A variety of vector patterns can be efficiently represented by a combination of linearly independent vector fields that I call "basis fields". Basis fields offer in some cases a better alternative to treating each component of a vector as an independent scalar entity. In spite of its apparent simplicity, such a component-based representation is bound to change with any change of coordinates. In contrast, vector-valued primitives such as basis fields generate vector field representations that are invariant under coordinate transformations.


[Kinetics of electron transfer in macromolecules].

With the help of retarded double-time Green function technique a method of estimation of electron transfer rate in protein macromolecules has been developed. Possible experimental test is suggested.


[Features of the effect of ammonium ion on the enzymatic activity of myosin and subfragment-1].

The kinetic isotope effect of hydrolysis of ATP by myosin subfragment-I in the presence of K+, NH4+, Rb+ was measured. VH/VD was found to be 1.8; 1.3; 2.0, respectively. According to the thermodynamic isotope effect induced by hydration, the kinetic isotope effect must increase with the increase of cation size from K+ to Rb+. The size of ammonium ions is the intermediate between K+ and Rb+, but the observed isotope effect in the presence of ammonium is much lower than in the presence of K+ and Rb+. The results suggest that monovalent cations occur near the active center of the enzyme and contribute to some extent to the hydrolysis reaction but the specificity of ammonium ions seems not to be due to its ideal steric accordance. The obtained results support the viewpoint that NH4+ ions as donor of protons participate in the chemical stage of ATP hydrolysis by subfragment-I.


Vector field approximation: a computational paradigm for motor control and learning.

Recent experiments in the spinalized frog (Bizzi et al. 1991) have shown that focal microstimulation of a site in the premotor layers in the lumbar grey matter of the spinal cord results in a field of forces acting on the frog's ankle and converging to a single equilibrium position. These experiments suggested that the neural circuits in the spinal cord are organized in a set of control modules that "store" a few limb postures in the form of convergent force fields acting on the limb's end-point. Here, we investigate how such postural modules can be combined by the central nervous system for generating and representing a wider repertoire of control patterns. Our work is related to some recent investigations by Poggio and Girosi (1990a, b) who have proposed to represent the task of learning scalar maps as a problem of surface approximation. Consistent both with this view and with our experimental findings in the spinal frog, we regard the issue of generating motor repertoires as a problem of vector-field approximation. To this end, we characterize the output of a control module as a "basis field" (Mussa-Ivaldi 1992), that is as the vectorial equivalent of a basis function. Our theoretical findings indicate that by combining basis fields, the central nervous system may achieve a number of goals such as (1) the generation of a wide repertoire of control patterns and (2) the representation of these control patterns with a set of coefficients that are invariant under coordinate transformations.


[Inhibition of mitochondrial ATP-synthetase by redox-agents].

Effects of phenol and phenothiazine on ATP synthesis and electron transport in submitochondrial particles were studied. Nitrophenols and phenothiazines inhibited ATP synthesis without notable effect on electron transport. On the contrary chlorphenols equally decreased the velocities of electron transport and ATP synthesis. The inhibitors studied showed the properties of electron acceptors in relation to the radicals, their acceptor properties corresponding to their ability to inhibit ATP synthesis.


Dynamic characteristics of the auditory cortex of guinea pigs observed with multichannel optical recording.

The spatiotemporal characteristics of neural activity in the guinea pig auditory cortex are investigated to determine their importance in neural processing and coding of the complex sounds. A multi-channel optical recording system has been developed for observing the cortical field of the mammalian brain in vivo. Using the voltage-sensitive dye: RH795, optical imaging was used to visualize neural activity in the guinea pig auditory cortex. Experimental results reveal a boomerang-shaped pattern of movement of activated neural cell regions for the evoked response to click as complex sounds. Parallel and sequential neural processing structure was observed. Although the exact frequency selectivities of single cells and tonotopical organization observed using microelectrode were not visible, the similar feature to the microelectrode evidences was imaged by extracting the strongly response field from the optical data.


Two-dimensional coding of linear acceleration and the angular velocity sensitivity of the otolith system.

There exist otolith-sensitive vestibular nuclei neurons with spatio-temporal properties that can be described by two response vectors that are in temporal and spatial quadrature. These neurons respond to the component of a stimulus vector on a plane rather than a single axis. It is demonstrated here that these "two-dimensional" linear accelerometer neurons can function as one-dimensional angular velocity detectors. The two-dimensional property in both space and time allows these neurons to encode the component of the stimulus angular velocity vector that is normal to the plane defined by the two response vectors. The angular velocity vector in space can then be reconstructed by three populations of such neurons having linearly independent response planes. Thus, we propose that these two-dimensional spatio-temporal linear accelerometer neurons, in addition to participating in functions of the otolith system that are based on detection of linear acceleration, are also involved in the generation of compensatory ocular responses during off-vertical axis rotations.


[Analysis of the reasons and mechanisms determining the occurrence of individual development in animals, beginning from the zygote (role of the cytoskeleton)].

Results of studies are presented revealing the role of motor activity (the energetic rule of skeletal muscles) as a factor determining the beginning of initiation of the organism individual development from the moment of zygote formation. The blockage of the cytoskeleton function (cytochalasin B, verapamil) was shown to result in the arrest of individual development and death of embryos. Mechanisms and causes of ambiguous action of these compounds are analysed. A biphasic pattern of the reaction of embryo cells is established. During the first short phase the function of microfilaments located near the membrane is blocked and further development of embryos is stopped. During the second, later and longer phase the function of cytoplasm microfilaments is blocked. The existing concepts as to the causes determining the individual development are discussed.


Detection of rotating gravity signals.

It is shown in the preceding paper that neurons with two-dimensional spatio-temporal properties to linear acceleration behave like one-dimensional rate sensors: they encode the component of angular velocity (associated with a rotating linear acceleration vector) that is normal to their response plane. During off-vertical axis rotation (OVAR) otolith-sensitive neurons are activated by the gravity vector as it rotates relative to the head. Unlike "one-dimensional" linear accelerometer neurons which exhibit equal response magnitudes for both directions of rotation, "two-dimensional" neurons can be shown to respond with unequal magnitudes to clockwise and counterclockwise off-vertical axis rotations. The magnitudes of the sinusoidal responses of these neurons is not only directionally selective but also proportional to rotational velocity. Thus, responses from such "two-dimensional" neurons may represent the first step in the computations necessary to generate the steady-state eye velocity during OVAR. An additional step involving a nonlinear operation is necessary to transform the sinusoidally modulated output of these neurons into a signal proportional to sustained eye velocity. Similarly to models of motion detection in the visual system, this transformation is proposed to be achieved through neuronal operations involving mathematical multiplication followed by a leaky integration by the velocity storage mechanism. The proposed model for the generation of maintained eye velocity during OVAR is based on anatomical and physiological properties of vestibular nuclei neurons and capable of predicting the experimentally observed steady-state characteristics of the eye velocity.


Modeling the dishabituation hierarchy: the role of the primordial hippocampus.

We present a neural model for the organization and neural dynamics of the medial pallium, the toad's homolog of mammalian hippocampus. A neural mechanism, called cumulative shrinking, is proposed for mapping temporal responses from the anterior thalamus into a form of population coding referenced by spatial positions. Synaptic plasticity is modeled as an interaction of two dynamic processes which simulates acquisition and both short-term and long-term forgetting. The structure of the medial pallium model plus the plasticity model allows us to provide an account of the neural mechanisms of habituation and dishabituation. Computer simulations demonstrate a remarkable match between the model performance and the original experimental data on which the dishabituation hierarchy was based. A set of model predictions is presented, concerning mechanisms of habituation and cellular organization of the medial pallium.


Human control of a simple two-hand grasp.

We investigated how people control fast, accurate movements of a load using a simple two-hand grasp. By providing a clear instruction to several subjects, we isolated a single control strategy. The kinematics produced by this control strategy are nearly indistinguishable from those produced during singlehand movements, but the torques are quite different: one hand accelerates not only itself, but also the load and the other hand, while the other hand brakes the hand-load-hand system. As a result, the hands squeeze the load with a large force during the movement. The dynamics of the hand-load-hand system are of the same form as the dynamics of a single-hand system. Apparently, by taking advantage of this dynamic similarity and of the spring-like properties of muscle, the human motor control system can control the two-hand grasp system simply by modifying the muscle activation patterns used to control single-hand movements. The task dynamics of two-hand grasp do not require that the load be squeezed during the movement, and squeezing the load wastes torque that could be used to move more quickly. However, the human motor control system may choose this squeezing strategy because it reliably brakes the hand-load-hand system despite inherent variability in the braking of individual hands.


Effect of vitamin K on neonatal erythrocytes.

This study investigated the possible oxidative effect of vitamin K3 (menadione) and Vitamin K1 (Konakion) on neonatal erythrocytes by controlled in vitro exposure. Menadione caused only mild morphological changes and did not decrease ATP levels. However, it oxidized intracellular hemoglobin to methemoglobin in neonatal cells more than in adult cells. Reduced glutathione contents were higher in neonatal cells, but less available for antioxidant protection. Konakion did not increase methemoglobin levels in newborn infants after a prophylactic injection. In vitro exposure to Konakion did not affect reduced glutathione and ATP levels, nor did it oxidize hemoglobin. However, extensive morphological changes were observed, attributed to the effect of its solvent. Therefore, it seems that menadione, which is no longer administered to newborns, causes oxidative stress in neonatal cells whereas Konakion, the current vitamin K1, does not, either in in vitro studies or by therapeutic administration.


Sialic acid level in maternal and neonatal lymphocytes and sera correlated to birth order and sex of the neonate.

Sialic acid (N-acetylneuraminic acid) was determined 1 h after normal term deliveries on peripheral blood lymphocytes from 42 mother-neonate pairs and in 29 maternal and neonatal sera. Results were evaluated according to maternal parity and sex of the neonate. The cases were divided into two groups: primiparae, and secundi- and multiparae. In primiparae the sialic acid level on lymphocytes from male neonates and from their mothers was by 23-30% decreased as compared to female neonatal and maternal cells. In the higher parity group, a significantly increased sialic acid level was found on lymphocytes from male as compared to female neonates, and maternal serum sialic acid concentration, unrelated to the newborns' sex, was by 17-20% increased as compared to primiparae. The results suggest that with increasing parity higher levels of sialic acid on male neonatal cells may possibly contribute to mask fetal male-specific histocompatibility antigens. Increased sialic acid levels in maternal sera from secundi- and multiparae suggest its possible contribution to an increased serum blocking effect.


In vivo activated cord blood lymphocytes express high affinity interleukin-2 receptor: evaluation of their responsiveness to in vitro stimulation with recombinant interleukin-2.

We report the phenotypical and functional characterization of a cord blood mononuclear lymphocyte subset (CBMC) which expresses the p55 chain of interleukin-2 receptor (IL-2R, CD25). The great majority of CD25-positive CBMC are activated CD3-positive T lymphocytes in that most of them are HLA-DR-positive, coexpress both CD4 and CD8 antigens and at least a part of them display high affinity IL-2R. In keeping with the expression of both chains of IL-2R (p55 and p75), enriched CD25-positive CBMC are able to display strong IL-2-induced proliferation and lymphokine-activated killing activity. The percentage of CD25-positive cells is higher in cord blood than in adult peripheral blood and their presence could be peculiarly important in the neonatal period, when specific T-cell-mediated immune responses are still on their way to full maturation.


Development changes of polyamine biosynthesis in rat liver.

To investigate the role of polyamine metabolism in fetal development, we determined the hepatic polyamine content and the activity of enzymes related to polyamine metabolism in fetal, newborn and adult rats. In the fetuses, spermidine was detected at the highest level, followed by spermine and then putrescine. Putrescine and spermidine levels were higher in the fetuses than in adult rats, while the spermine level was significantly lower in the fetuses. The activities of the enzymes investigated were also higher in the fetuses than in adult rats. These findings indicate that polyamine synthesis was enhanced in the fetal liver, and that degradation of spermidine via spermidine N1-acetyltransferase contributes to the increase in putrescine levels. Thus, our study suggests that an increase in putrescine is important for fetal growth and that putrescine per se has a significant role in fetal cellular proliferation.


Transfer of bilirubin covalently bound to 125I-albumin from blood to brain in the Gunn rat newborn.

Transfer of bilirubin covalently bound to albumin (Alb.B) from blood into brain was examined in Gunn rats at postnatal day 3, 7, 14, 28 or 70. The ratio of the 125I-Alb.B concentration in the brain to that in the plasma 2 h after the injection (RAB) was used as a criterion for Alb.B transfer. RAB in brain decreased with age until day 28. Significant correlations were indicated between 125I-Alb.B plasma levels and those in the brain at days 7 and 14, but not at day 28. These results suggested that 125I-Alb.B could transfer from the blood to the brain until day 14. Comparison of the relative amount of radioactivity accumulated in the brain by a 125I-Alb.B injection with that of 125I-albumin alone revealed higher radioactivity in the former than the latter only at day 14, suggesting a transient appearance of particular cellular elements with high affinity to bilirubin in the developmental stage of the brain.


Surface properties of mussel adhesive protein component films.

Mussel adhesive protein (MAP) is the adhesive agent used by the blue sea mussel (Mytilus edulis) to attach the animal to various underwater surfaces. It is composed of 75-->85 repeating decameric units with the reported primary sequence NH2-A(1)-K(2)-P(3)-S(4)-Y(5)-Hyp(6)-Hyp(7)-T(8)-DOPA(9)-K(10)-COOH. This study identifies and compares the surface properties of the decameric unit, selected fragments and individual amino acid constituents with the complete MAP preparation. These molecular systems were examined: (a) in the solid state as thin films formed on germanium substrata using multiple-attenuated-internal-reflectance infrared (MAIR-IR) spectroscopy, ellipsometry and contact angle analysis; and (b) in the solution state using circular dichroism (CD) spectroscopy. Extensive molecular modelling of the decamer was performed making integral use of the experimentally derived data. These cumulative semi-empirical and empirical results suggest a conformation for the decamer that closely associates the L-DOPA and tyrosine residues with the solid substratum. This model provides the first representation of MAP derived from a rational integration of theoretical and experimental data. On the basis of this model, a possible explanation for the bioadhesive properties of MAP is suggested.


Long-term histopathological study of new polypeptidic biomaterials.

The long-term histopathological evaluation of a new class of synthetic polypeptides, the poly(tert-butyloxycarbonylmethyl glutamates), as implantable drug delivery systems is addressed. This evaluation was performed in rat muscles over one year. The histological analysis included the measurement of many parameters, such as the type and thickness of the collagen capsule. The influence of the presence of progesterone, the selected active drug, could also be monitored over time.


Mechanical properties of biodegradable ligament augmentation device of poly(L-lactide) in vitro and in vivo.

To evaluate the mechanical properties of absorbable braided poly(L-lactide) (PLLA) fibre implants, 2.0 and 3.2 mm in diameter, maximum load defined as tensile load carrying capacity, elongation and axial rigidity were investigated after immersion in phosphate-buffered distilled water at 37 degrees C and pH 6.1 and after subcutaneous implantation in rabbit. The results confirm earlier indications that PLLA degrades faster in vivo than in vitro. The non-sterilized 2.0 mm implants lost 69% of initial tensile load carrying capacity in 46 wk in vitro. In vivo the loss of tensile load carrying capacity of the 2.0 and 3.2 mm implants was most marked between 6 to 12 wk. After 48 wk in vivo 2.0 and 3.2 mm implants retained 3 and 4% of initial tensile load carrying capacity respectively. Both in vitro and in vivo, elongation diminished in the same way as the maximum load. In vitro, mean axial rigidity of unsterilized 2.0 mm implants was 64 N during the first 34 wk but fell to 31 N at 46 wk. In vivo the initial mean axial rigidity of the 2.0 and 3.2 mm implants was 29 and 95 N respectively. At 24 wk the mean axial rigidity was 2 N in both implants.


Secondary cytotoxicity of cross-linked dermal sheep collagens during repeated exposure to human fibroblasts.

We investigated commercially available dermal sheep collagen either cross-linked with hexamethylenediisocyanate, or cross-linked with glutaraldehyde. In previous in vitro studies we could discriminate primary, i.e. extractable, and secondary cytotoxicity, due to cell-biomaterial interactions, i.e. enzymatic actions. To develop dermal sheep collagen for clinical applications, we focused in this study on the release, e.g. elimination, of secondary cytotoxicity over time. We used the universal 7 d methylcellulose cell culture with human skin fibroblasts as a test system. Hexamethylenediisocyanate-cross-linked dermal sheep collagen and glutaraldehyde-cross-linked dermal sheep collagen were tested, with intervals of 6 d, over a culture period of 42 d. With hexamethylenediisocyanate-cross-linked dermal sheep collagen, cytotoxicity, i.e. cell growth inhibition and deviant cell morphology, was eliminated after 18 d of exposure. When testing glutaraldehyde-cross-linked dermal sheep collagen, the bulk of cytotoxic products was released after 6 d, but a continuous low secondary cytotoxicity was measured up to 42 d. As a control, non-cross-linked dermal-sheep collagen was tested over a period of 36 d, but no secondary cytotoxic effects were observed. The differences in release of secondary cytotoxicity between hexamethylenediisocyanate-cross-linked dermal sheep collagen, glutaraldehyde-cross-linked dermal sheep collagen and non-cross-linked dermal sheep collagen are explained from differences in cross-linking agents and cross-links obtained. We hypothesize that secondary cytotoxicity results from enzymatic release of pendant molecules from hexamethylene-diisocyanate-cross-linked dermal sheep collagen, e.g. formed after reaction of hydrolysis products of hexamethylenediisocyanate with dermal sheep collagen.(ABSTRACT TRUNCATED AT 250 WORDS)


In vitro rheological evaluation of antithrombogenicity or anticoagulability of styrene derivative polymer.

In vitro evaluation of antithrombogenicity or anticoagulability of styrene derivative polymer with functional silyl groups, the polymer treated with acid, polystyrene and glass as a reference was attempted using a rheological method. The results were compared with those obtained from measurements of platelet adhesion. The coagulation process of blood in polymer-coated tubes was monitored using a damped oscillation-type rheometer recently developed. The change of fluidity during coagulation of blood was dependent on the polymers. Poly((4-vinylphenyl)dimethyl-2-propoxysilane) (poly(1)) was more antithrombogenic than polystyrene and acid-treated poly(1). The evaluation of antithrombogenicity or anticoagulability for the polymers and glass by the rheological method coincided well with that obtained from other methods. Furthermore, it was confirmed that the rheological method would be useful for elucidating mechanisms of coagulation of blood as well as thrombus formation in developing artificial blood-compatible materials.


Skin organ culture model to test the toxicity of polyoxyethylene networks.

Films of polyoxyethylene network were prepared from two types of triethoxysilane-terminated prepolymers. In this way, films of polyoxyethylene network with possible applications in the biomedical field could be made easier. To test their biocompatibility, these networks were added to organ cultures of adult human skin and embryonic chicken skin. A rapid toxic effect was observed, especially with the urethane-linked network. Enzymatical degradation of the network by enzymes in the culture medium might be responsible for the formation of toxic metabolites. Testing of related chemical compounds in our in vitro assay suggested that the formation of a silane group with an amino terminal is most likely to be responsible for the toxic effects observed.


Effect of loading on a substitute oral mucosa and underlying bone.

Some mechanical effects of stresses on a bone and oral mucosa model were investigated. A substitute oral mucosa on a substrate of plano-parallel sections of bovine cortical bone modified indenter load/penetration characteristics such that the effects of loads on bone were deferred. In the case of the silicone rubber used, approximately five times the load could be withstood by the bone before it was indented than if no overlay was used. The thicker the overlay the more of the energy applied was absorbed in deforming the intermediary layer. Experimental results confirm that oral mucosa is a modifier of direct loads falling on bone and give some indication of their magnitude.


Thermal expansion of glassy polymers.

The thermal expansion of a number of glassy polymers of interest in dentistry has been studied using a quartz dilatometer. In some cases, the expansion was linear and therefore the coefficient of thermal expansion readily determined. Other polymers exhibited non-linear behaviour and values appropriate to different temperature ranges are quoted. The linear coefficient of thermal expansion was, to a first approximation, a function of both the molar volume and van der Waal's volume of the repeating unit.


Polymer membranes in clinical sensor applications. I. An overview of membrane function.

Polymer membranes are used in a wide variety of molecular sensing devices many of which are of potential clinical interest. The role of the polymer and the physical properties required of it are, however, rarely clearly defined. An extensive review is presented of the range of polymers whose use as membranes is described in the sensor literature. This forms the basis of an overview of membrane function in potentiometric amperometric and fibre optic sensors. In particular, the interaction of permeability, permselectivity and transmembrane potential is highlighted, together with the role of polymer membranes as matrices for the immobilization of reactive chemical and biological agents.


Polymer membranes in clinical sensor applications. II. The design and fabrication of permselective hydrogels for electrochemical devices.

Hydrogels, particularly the tough, low water content materials, have potential advantages in the field of clinical biosensors because of their established use as medical polymers. The factors that control transport behaviour in these polymers are discussed with particular reference to ion selectivity. The nature of the transport behaviour in relation to coated wire electrode performance is presented and an extension of these permselectivity studies to the fabrication of miniaturized devices, such as ISFETs, is described. Linear soluble hydrogel polymers, coated on to sensor substrates, may be converted to insoluble membranes using solid photosensitive aromatic monomers, such as N-vinyl carbazole. Photolithographic patterning is achieved using a UV source together with appropriate masking, followed by an oxygen plasma etch process. Gas plasma etching, which selectively removes uncross-linked (masked) areas forms the basis of an all dry, low-temperature patterning process capable of giving micrometre-scale resolution. This novel photographic process, which does not damage or extract enzymes or ionophores, can advantageously be extended to the fabrication of poly(vinylchloride)-based membranes.


Polymer membranes in clinical sensor applications. III. Hydrogels as reactive matrix membranes in fibre optic sensors.

The potential of hydrogel copolymer membranes in clinical sensors, based on fibre optics, is addressed. The particular properties of the membranes of relevance in this application are the ease of refractive index modulation and the potential of the hydrogel to act as a permselective barrier in which a colorimetric agent may be immobilized. The results presented illustrate the complexity of colorimetric and refractive index effects together with their dependence on pH and tonicity for hydrogels of a given composition range. The incorporation of an acryloyl-functionalized reagent (bromopyrogallol red) is used to illustrate the way in which a working pH sensor based on these combined properties may be designed and fabricated.


[Program of care of disabled patients at a health center].

To systematise primary attention to the disabled by means of a programme of specific action. To create a Risk Map for the problem of "abandonment of the elderly disabled". Retrospective descriptive study. SITE. El Palo Health Centre (Málaga). First two years of the programme (1989-1991). Patients with physical and/or mental disability attending to Centre to obtain services. The basic Primary Attention Team. Key informants, the Voluntary Social service. Activities: Recruitment strategies: Programme of Planned Home Visits (Subscribers' Register, Individualised Care Plan), Risk Map of Basic Area. 142 patients were included in the first year, and 203 in the second year, carrying out 4.66 and 5.95 programmed visits per patient per year, respectively. The Risk Map defined 28 areas ranked according to risk.


[Descriptive study of patient compliance in pharmacologic antihypertensive treatment and validation of the Morisky and Green test].

To ascertain the degree of correct use of a course of medication in a sample of patients with high blood pressure attending Primary Attention consultation, and to validate the Morisk and Green completion test. This is a transversal observational study carried out in two stages, which aims to analyse the variable rate of correct following of instructions. The sample was selected at random. SITE. The study was carried out within the framework of Primary Care. The sample was drawn from patients with high blood pressure under treatment by medication, including 96 patients of whom only 86 completed the study. Measurement of the actual incidence of correct use was carried out by means of counting the pills in the patients' homes, and the theoretical incidence of correct use by means of the Morisky and Green Test. We class those who take between 80-110% of the prescribed pills as completing the course correctly. We found: 18.6% took less medication (Margin of reliability (MR) 95%: 10, 3-26.8%), 23% took more than they should (MR 95%: 14.4-32, 2%) and 58.1% took medication as instructed (MR 95%: 48-68%, without significant differences either by sex or age. The test's sensitivity in detecting those who complied with instructions was 52%, and specificity was 44.4%. 1. The number of over-consumers is particularly notable. 2. Responses to the test do not show any relationship with correct use of medication in this study. 3. In our view the test could only be used in a hypothetical population where there were no over-consumers.


[Health self-perception in the elderly: relationship with several socioeconomic and health variables].

To learn how the elderly people in our health area see their own state of health (AS) in relation with certain variables. Transverse. Survey of socio-economic and health characteristics. Community oriented primary care. 232 psychically capable people aged 65 or over, selected at random among those attended by three general medical groups of the Rekaldeberri Primary Care Unit (Bilbao). 41.4% considered their health to be good or very good. The association between AS and various variables is worked out by odds ratio calculation using logistic regression. Age and sex ar not significantly associated with AS. The variables most closely associated to negative AS were the number of illnesses affecting daily life, the number of symptoms, the number of pharmaceutical products consumed and functional incapacity of any degree. Patients' perception of their own health varies widely between the different studies. As is an easy parameter to obtain, summarizes both subjective and objective aspects, and is useful in assessing an elderly person's overall state of health.


[Epidemiologic study of 245 cases of children hospitalized with measles].

The object of the present study is an analysis of the characteristics common to children hospitalised because of measles. A retrospective descriptive study was made of all the children in hospital with measles over a six month period. SITE. The study was carried out in the Hospital Infantil La Fe, in Valencia. All of the children taken into hospital between January 1983 and December 1988, with diagnosed measles as a stated factor in their hospitalisation, aged between 4 months and ten years. Treatments were extremely varied, depending on the symptoms of the patient. In most cases an antithermic or analgesic was administered (70%). The data was compiled from clinical histories. We note two epidemics, in 1983 and 1987. 58% of the children were less than 3 years old, and the average age observed was 2.73 years (SD = 2.40). The standard rate of body mass, (PE-IMC) in 81% of the cases, averaged -1.129, and the SD was 1.431, significant with respect to the general population (p 0.001). Only 14% of the children had been previously vaccinated. 76% of the children presented complications. New risk factors were not identified. Most notable was the importance of nutritional state and correct vaccination.


[Revised Denver test: prospective study in primary care nursing consultations].

OBJECTIVE MAIN: To ascertain psychometric development and periodically monitor further development, using the Revised Denver Test (DDST-R) to structure attention given in the area in which the child is deficient. SITE. "Las Lagunas" Health Centre, Mijas Costa (Málaga) in the Nursing Consultations for Mother and Child, Primary Attention. All the children seen in the Nursing Consultations under the Healthy Child sub-programme. Carrying out of the DDST-R, detection of anomalies, structuring of treatment, referral to paediatrician where necessary. 215 Tests carried out, 194 )90.23%) normal, 21 (9.76%) deviant. There were 100 females (46.51%), of whom 93 (93%) were found to be normal (93%) with 7 (7%) deviant. 18 children were affected in one area, 3 in two areas. Frequency of deviance by area: Personal-Social 6 (2.79%), Language 12 (5.58%) Fine Motor control 1 (0.46%) Gross motor control 3 (1.39%) Others 2 (0.93%). The DDST-R provides a useful means of screening to detect deviance in the area under study. Because it is easy to use it is suitable for Primary Attention, and should be included as a matter of routine in the examinations carried out by Nursing in the Attention to the Healthy Child sub-programme, to assist in structuring the care given in the areas noted as deficient.


[Prevalence of dental caries, in children from a basic health area].

To ascertain the actual state of dental health among the school population, with a view to taking the requisite preventive and corrective measures. Additionally, to evaluate the effectiveness of the dental health programme. This was a crossover study, following the dental examinations of pupils in first year E.G.B. (6 and 7 years old), fifth year E.G.B. (10, 11 and 12 years old) and eighth year E.G.B. (13, 14 and 15 years old). SITE. Chipiona Primary Health Care Centre. Staff from the Chipiona (Cádiz) Health Centre, an odonto-stomatologist and a paediatrician. Altogether, 808 schoolchildren, belonging to the seven schools in the area, were surveyed: 217 from first year E.G.B., 260 from the fifth year and 330 from the eighth year. The percentage of pupils with a history of caries (prevalence). The CAOD rises progressively from 1.10 (at 6 years old) to 15.07 (at 15). The COD studied reaches a highpoint of 0.42 at 12 years old. The level of dental repair-work has its lowest value at 6 years old for permanent teeth (0.48); and its highest proportion is 8.39, which appears in the permanent teeth of 13 year-old children. Levels of caries greater than in other areas of Spain were found. Therefore, measures need to be adopted in the community, both in order to lower these figures and to increase the amount of dental repair-work.


[Influence of the HIV (+) cases on the epidemiology of infantile tuberculosis in Barcelona].

To understand better the characteristics of tuberculosis (TBC) in children and to identify sources of infection. Crossover study. SITE. At the community level in the city of Barcelona. Children under 15 with tuberculosis, who were diagnosed between Oct 1, 1989 and Sept 30, 1990 and were resident in Barcelona. Among the 78 cases found, we identified the source of infection for 26 children (33.3%). 6 of these (23.1%) had been infected by three cases of HIV+. A relationship was posited between the economic level of the population and the incidence of TBC. This was confirmed by the economic level of the families (80% of the sources of infection identified belonged to professions requiring few or no qualifications) and where they lived, given that the specific rate for children under 15 in the most depressed social-economic area (Ciutat Vella) was 206 per 100,000, whereas in the wealthiest area (Sarrià-Sant Gervasi) the rate was 4.3 per 100,000. This study makes clear the importance of investigating the contacts of children with tuberculosis. It should be fundamental for the TBC control programmes to focus closely on those with HIV. They are much more likely to contract and spread TBC to the least protected groups of the population, especially to the children of poor families.


[Occupational health in the province of Toledo: comparison with national data].

To gain some preliminary understanding of the health situation in the workplace and to strengthen this field at the Primary Care level. A retrospective and analytical study into the period 1985 to 1988, both inclusive. SITE. Pathologies at work (accidents and work-derived illnesses) declared in Toledo province and in the rest of Spain during the period stated above. A lower rate of accidents at work was observed in Toledo than in the rest of Spain (47.68 per 1,000 workers as against 66.44 per 1,000; chi 2 = 806.45). However Toledo showed higher mortality (0.35% as against 0.20%; chi 2 = 40.71) and a higher percentage of time off work (81.56% as against 68.77%; chi 2 = 483.93). Looking at work accidents in relation to sectors of activity, industry and construction, we found more in Industry and Construction than in Agriculture and Services. Work-derived illnesses made up a low percentage of work pathology (0.33% in Toledo and 0.39% in Spain). The main illnesses were: dermatosis, bursitis, illness caused by vibrations and disease arising from lead and its derivatives. It is essential to study much more thoroughly both health at work and the more general work context, emphasising the key importance of Primary Care and the need to improve the present system for notifying pathologies at work.


[Prevalence of alcoholism in the population attending a urban health center].

To find out the prevalence of alcoholism among those attending an urban Health Centre. To establish the level of concordance between the CAGE and MALT-O tests in the detection of alcoholism and to assess the effectiveness of the joint use of the above tests. Observational, crossover study. SITE. San Ignacio de Loyola Health Centre (Cuenca). A sample of 499 people of both sexes and over 18 years old was chosen from among the people attending the Centre. Systematic sampling from a random starting-point was used. Each person was interviewed with a questionnaire containing the CAGE and MALT-O items and sociodemographic data. The person who gave at least two positive answers in both tests was considered an alcoholic. A total of 402 filled-in questionnaires were returned. 27 people were found to have two or more positive items, which mean a 6.7% prevalence of alcoholism (CI 95% = 4.2-9.1). This broke down into a prevalence of 1.33% among women and 13.63% among men (p < 0.0001). The concordance level, determined by the Kappa coefficient, between the two tests was 0.29 (CI 95% = 0.11-0.47). The prevalence of alcoholism found is greater than in other national studies on the out-patient population, although it continues to be low in comparison with several foreign surveys. On the other hand, we seem to gain nothing in the detection of alcoholism by adding the MALT-O to the CAGE test, even when the concordance level between the two tests has come out low.


[Undergraduate teaching of primary health care. A Delphi study].

Given both the limited experience of Undergraduate Teaching in Primary Health Care (PHC) and the lack of contact between different teaching centres, we sought to identify the minimum contents of a potential Syllabus. We made a distinction between items of knowledge required and skills students would have to develop. We undertook a Delphi study, which was longitudinal, prospective and observational. We defined three groups of experts among groups with PHC teaching experience. 20 Associate Lecturers at Undergraduate level, attached to Health centres; 20 postgraduate PHC teachers, and 7 University staff members involved with Public Health and Preventive and Community Medicine teaching. The reply rate from the three questionnaires was about 60%. There was a high level of agreement. Of the items of knowledge which scored highest, we noted: the doctor-patients relationship, the Promotion of Health and Health education, Integrated Health Programmes, Prevention of Disease and Care of Risk-Groups. Of the skills, we pointed to the Clinical Interview, the construction of a Clinical History at the PHC level, Detection of Risk factors and Physical Examination. The most valued items of knowledge are those related to the overall Conception of Health, Promotion and Prevention. The most highly-scored skills are those concerning the Doctor-Patient relationship. Questions relating to the Individual are prioritised over those concerning Family and Community. There is a high level of agreement that the acquisition of the necessary theoretical knowledge must be accompanied by the ability to put them into practice.


[Opinion of family and community medicine resident physicians in Spanish hospitals].

To find out the opinions of Family and Community medicine interns concerning various aspects of their teaching during their period of hospital training. Crossover study. SITE. Within hospitals. Family and Community Medicine residential interns in Spanish hospitals. Out of the questionnaires returned by mail, 78.4% thought that their hospital training was adequate; 83.6% believed they were well enough trained to practise professionally; 76% considered that their hospital's technical equipment had been useful for their training; 66% felt they had sufficient back-up from the staff; 60% contributed to scientific statements or publications; 59% thought that their centre's library was inadequately equipped; and 45.4% stated that their pay as interns, or in the future as specialists, was too low. Family and Community Medicine interns' current training is in general satisfactory. Certain aspects, such as stocking libraries, salaries and contributions to scientific reports should be improved.


[Quality control of care provided for urinary infections].

To evaluate the quality of the care provided for low-level urinary infections in the Toledo Health Area. Retrospective study based on data on procedures supplied from clinical histories. SITE. Primary Care teams in the Toledo Health Area. Those patients over 14 with a provisional diagnosis of low-level urinary infection, who were attended between June and November, 1991, at the Health Centres participants (n = 243). The fulfillment level of six previously defined criteria was analysed. Looking at the clinical histories, we noted 75.3% non-fulfillment of Criterion 1 (anamnesis and examination), 51.8% of Criterion 5 (follow-up) and 59.3% of Criterion 6 (referral). Among the reasons we identified as causes of these findings were inadequate use of registration systems and the existence in different Centres of various procedures for treating urinary infections. The initial suspicion that the treatment and control of urinary infections in our Area contained a problem of attendance was confirmed. Corrective measures were established for the re-assessment. The positive role of quality controls, carried out under the aegis of Area managements, was clear.


Assessment of antibody dependent cell cytotoxicity in autoimmune thyroid disease using porcine thyroid cells.

Antibody Dependent Cell Cytotoxicity (ADCC) appears to be involved in Autoimmune Thyroid Disease (AITD). Homologous system may trigger non-specific reactions which might obscure specific ADCC. Heterologous target cells may be useful for studying ADCC, provided relevant antigen(s) are expressed. We therefore tested the capacity of porcine thyroid cells to elicit ADCC reaction in the presence of sera from various patients with AITD. Porcine thyroid cells were used in a 4-hr chromium release assay in the presence of 1/10 heat inactivated human sera and human peripheral blood lymphocytes at a 30:1 effector-target ratio. There was a significant correlation (r = 0.64; P < 0.01) between ADCC activities tested on human or porcine thyroid cells. Serum or IgG effects on porcine thyroid ADCC were dose-dependent between 1/10 to 1/10,000 dilutions. Non-thyroid cell systems were unaffected by thyroid cytotoxic sera. Porcine thyrocyte susceptibility to ADCC peaked at the fourth day of culture and was enhanced by addition of TSH or TSH and methimazole in the culture medium. Using this heterologous system, we demonstrated ADCC activity in a significant proportion of patients with thyroiditis (14/19), Graves' opthalmopathy (19/44) or of mothers of children with congenital hypothyroidism (14/39) and in the children themselves (15/39). Discrepancies observed in some sera between ADCC activity and antithyroperoxidase antibody suggest that thyroperoxidase is not the only antigen involved in ADCC. These results indicate that porcine thyroid cells appear suitable for ADCC assay in patients with AITD. Also this system should be helpful to characterize the antigen-antibody involved.


Quantitative analysis of islet glutamic acid decarboxylase p64 autoantibodies in insulin-dependent diabetes mellitus.

Autoantibodies against the beta-cell M(r) 64,000 protein (p64), recently identified as an isoform of glutamic acid decarboxylase (GAD), are prevalent in patients with insulin-dependent diabetes mellitus (IDDM). Dog islets were found to represent an abundant source of native p64 allowing the study of antigen-antibody interactions in IDDM. A quantitative, standardized assay for p64 antibodies based on dog islets was developed and evaluated. Utilizing dog and human islets the p64 antibodies were detected in 17/19 (89%) new onset 15-32-year-old patients, compared to 15/19 (79%) in a rat islet assay. ICA were detected in 15/19 (79%) patients and correlated with the presence of p64 antibodies (rs = 0.59, P < 0.004) but not with age at onset, sex, or C-peptide levels. Sensitivity therefore is improved with the dog islet p64 antibody assay which will allow future studies requiring native p64 antigen in larger quantities are possible based on our findings.


Divergent effects of thyroid HLA-antigens on T and natural killer (NK) cell cytotoxicity.

We have used non-autoimmune non-neoplastic human thyroid cells to explore the role of surface class I and DR antigens on these cells' sensitivity towards T and Natural Killer (NK) cell cytotoxicity. Non-treated thyrocytes expressed class I but no DR antigens. Following incubation with gamma-interferon (gamma-IFN) class I antigens were markedly elevated and DR expression was induced. Whereas non-treated thyrocytes were minimally lysed by sensitized T cells, they served as appropriate targets for NK cells. Following incubation with gamma-IFN, the thyroid cells became highly sensitive to T cell lysis, with no significant reduction in their vulnerability to NK cell killing. The addition of monoclonal anti class I or DR antigens, or brief acid treatment which specifically eliminates class I molecules, inhibited T cell cytotoxicity but enhanced the sensitivity to lysis by NK cells. Thus, the presence of HLA antigens on the same thyroid cells have an opposite effect on two major cytotoxi mechanisms. Our findings are relevant within the context of recent suggestions of intervening with target HLA antigens for the management of autoimmune and malignant diseases.