Clinical medical sciences for undergraduate dental students in the United Kingdom and Ireland - a curriculum.

The technical aspects of dentistry need to be practised with insight into the spectrum of human diseases and illnesses and how these impact upon individuals and society. Application of this insight is critical to decision-making related to the planning and delivery of safe and appropriate patient-centred healthcare tailored to the needs of the individual. Provision for the necessary training is included in undergraduate programmes, but in the United Kingdom and Ireland there is considerable variation between centres without common outcomes. In 2009 representatives from 17 undergraduate dental schools in the United Kingdom and Ireland agreed to move towards a common, shared approach to meet their own immediate needs and that might also be of value to others in keeping with the Bologna Process. To provide a clear identity the term 'Clinical Medical Sciences in Dentistry' was agreed in preference to other names such as 'Human Disease' or 'Medicine and Surgery'. The group was challenged to define consensus outcomes. Contemporary dental education documents informed, but did not drive the process. The consensus curriculum for undergraduate Clinical Medical Sciences in Dentistry teaching agreed by the participating centres is reported. Many of the issues are generic and it includes elements that are likely to be applicable to others. This document will act as a focus for a more unified approach to the outcomes required by graduates of the participating centres and act as a catalyst for future developments that ultimately aim to enhance the quality of patient care.

Temperature perturbation studies of sarcoplasmic reticulum from malignant hyperthermia pig muscle.

The effects of varying temperatures from 25 degrees to 37 degrees C on calcium binding characteristics of sarcoplasmic reticulum from malignant hyperthermia-susceptible (MHS) and control pig muscle were examined. Two groups of MHS pigs were included: those with high susceptibility to malignant hyperthermia (MHS group) and a cross-bred, less susceptible group (MHX). At 25 degrees C, calcium binding was lower for MHS than for controls and MHX. As temperature was increased by 2 degrees C jumps, calcium binding decreased in all sarcoplasmic reticulum fractions. At 35 degrees C a sharp decrease in calcium binding occurred in the MHS and MHX fractions. The sharp decrease in calcium binding at 35 degrees C differentiated the MHS and MHX fractions from controls. The initial velocity (Vi) for calcium binding was lower in MHS fractions between 25 degrees and 35 degrees C when compared with MHX and controls. All fractions had increased Vi values as temperature increased from 25 degrees to 35 degrees C. From 35 degrees to 39 degrees Vi for controls increased markedly. In contrast, Vi for the MHX fraction decreased as temperature exceeded 35 degrees C. These temperature effects on calcium binding characteristics of sarcoplasmic reticulum from MHS and MHX muscle may be indicative of a membrane transition that impairs calcium binding.

Effects of NOS inhibition on the cardiopulmonary system and brain microvascular markers after intermittent hypoxia in rats.

We previously demonstrated that rats subjected to intermittent hypoxia (IH) by exposure to 10% O(2) for 4 h daily for 56 days in a normobaric chamber, developed pulmonary hypertension, right ventricular hypertrophy and wall-thickening in pulmonary arterioles, compared with normoxic (N) controls. These changes were greater in rats subjected to continuous hypoxia (CH breathing 10% O(2) for 56 days). Cerebral angiogenesis was demonstrated by immunostaining with glucose transporter 1 (GLUT1) antibody, in viable vessels, in CH and to a lesser degree in IH. In this study, adult Wistar rats were subjected to the same hypoxic regimes and given the nitric oxide synthase (NOS) inhibitor N(6)-nitro-L-arginine methyl ester (L-NAME) in drinking water (NLN, IHLN and CHLN regimes) to induce hypertension. There was significant systemic hypertension in NLN and IHLN rats, compared with N and IH, but surprisingly not in CHLN compared with CH. Hematocrit rose in all hypoxic groups (up to 79% in CHLN). There was no significant pulmonary hypertension in IHLN versus NLN rats, although there was asymmetric wall thickening in pulmonary arterioles. Cerebral GLUT1 immunoreactivity increased with L-NAME, with or without hypoxia, especially in CHLN rats, but conspicuously there was no evidence of angiogenesis in brains of IHLN compared with NLN rats. NOS blockade may attenuate the cerebral and pulmonary vascular changes of IH while augmenting cerebral angiogenesis in continuous hypoxia. However, whether cerebral effects are due to systemic hypertension or changes in cerebral nitric oxide production needs to be evaluated.

Effect of alveolar pressure on pulmonary artery pressure in chronically hypoxic rats.

The effect on pulmonary artery pressure of a rise in alveolar pressure differed in chronically hypoxic rats (10% O2 for 3-5 weeks) compared with control rats. Chronically hypoxic rats have newly muscularised walls in arterioles in the alveolar region. Isolated lungs of chronically hypoxic and control rats were perfused with blood under conditions in which alveolar pressure was greater than left atrial pressure during both normoxia and hypoxia. Alveolar pressure was the effective downstream pressure. Pressure-flow lines were measured at low and high alveolar pressure (5 and 15 mmHg). During normoxia pressure-flow lines of chronically hypoxic rats had a steeper slope (higher resistance) and greater extrapolated intercept on the pressure axis (effective downstream pressure) than control rats. In both groups of rats the change from low to high alveolar pressure during normoxia caused an approximately parallel shift in the pressure-flow line similar to the change in alveolar pressure. During hypoxia, which led to an increase in slope and intercept in both groups of rats, the effect of a rise in alveolar pressure differed in chronically hypoxic from control rats. In control rats there was a small parallel shift in the pressure-flow line that was much less than the increase in alveolar pressure; in chronically hypoxic rats there was a large parallel shift in the pressure-flow line that was greater than the increase in alveolar pressure. Thus in chronically hypoxic rats hypoxic vasoconstriction probably occurred mainly in muscular alveolar vessels, whereas in control rats it probably occurred upstream in extra-alveolar vessels. At constant blood flow the relation between pulmonary artery pressure and alveolar pressure was measured while alveolar pressure was reduced from approximately 15 mmHg to zero during both normoxia and hypoxia. In control and chronically hypoxic rats the slope of this line was less than 1. At an alveolar pressure of 2-3 mmHg there was an inflection point below which the line was nearly horizontal in control but negative in chronically hypoxic rats. During hypoxia the inflection point increased in control but not in chronically hypoxic rats, whereas the preinflection slope became negative. Apart from a rise in pulmonary artery pressure at all values of alveolar pressure, which occurred in both groups of rats, there was no change in the form of the curve in chronically hypoxic rats during hypoxia. These results also suggest constriction of extra-alveolar vessels in control rats and alveolar vessels in chronically hypoxic rats during hypoxia.

Comparison of the nutritional status of pregnant adolescents with adult pregnant women. I. Biochemical findings.

Biochemical findings on blood samples from 102 pregnant women in four age groups, 12-17, 18-19, 20-24, and 25-32, are reported. Samples represent 8 antepartum periods of 4 weeks each and 3 postpartum periods over 6 weeks. Blood analyses were carried out for hemoglobin, plasma iron, plasma total protein, glucose, plasma alkaline phosphatase, plasma ascorbic acid, plasma vitamin A and carotene, erythrocyte transketolase as a measure of thiamine status, plasma cholesterol, plasma lipid phosphorus, plasma total fatty acids, and triglyceride fatty acids. For the most part, means of these nutrients were in acceptable ranges for all age groups. Although adolescents had better levels than anticipated, the two younger groups on several occasions had means significantly lower than those of the two older groups, indicating that they needed greater nutritional support during pregnancy than older women.

Factors influencing access to primary health care via school health services.

The school health and community primary health care contacts were studied for a group of elementary school children who have sociodemographic characteristics often associated with poor access to primary health services. The school system is engaged in a demonstration project that attempts to link the home with community and school services. Visits to the school health room accounted for 85% of all contacts. A visit rate of 1.13 visits/child/year occurred at primary care sites. Ethnicity is the single most important predictor of use of school health services, followed by family status and number of visits for primary health care in the community. In contrast, use of community primary care facilities is best predicted by socioeconomic status (SES), family status, and sex. The patterns of care received by the population were characterized. Children whose care was initiated, referred, or facilitated by the school were designated as receiving "interactive" care, which occurred mostly among minority and lower SES children. The data suggest that the school provides access to preventive health care for all children and facilitates care for segments of the population that usually have difficulty achieving access to the health care system.

Incidence of breast-feeding in a low socioeconomic group of mothers in the United States: ethnic patterns.

Breast-feeding has been shown to have increased in incidence during recent years in the United States. However, this increase is not particularly evident in lower socioeconomic groups. Factors associated with the decision to breast-feed or not were investigated in a population of 379 mothers. Self-completed questionnaires were obtained from 94.5% of these mothers. Data with respect to demographics, reproductive history, prenatal care, and education were collected. Only 27.2% of the study population indicated that they intended to breast-feed. Using the chi2 test for equality of proportions, marital status, head of household, maternal and paternal ethnicity, maternal education, income, and number of pregnancy were found to be the most important variables associated with breast-feeding. The effect of ethnicity predominated over that of the other demographic variables when they were examined jointly within ethnic groups. The effect of ethnicity was apparent when the number of each ethnic group in the study population was compared with the percent of that group that intended to breast-feed: 145 Anglo-Americans, 43.5% breast-feeding; 131 black Americans, 9.2%; 62 Mexican Americans, 22.6%; 19 others, 42.1%. The importance of ethnicity in the decision to breast-feed has probably been underestimated. Efforts to increase breast-feeding in the United States ought to be designed with full consideration of this factor.

The effects of vincristine on platelet aggregation studied by a filter loop technique in the rat.

1 A method for measuring aggregation of platelets of adenosine diphosphate (ADP) is described using a filter inserted into the flowing aortic blood in the rat. 2 Repeated infusions of ADP resulted in a fall in the calculated aggregation index without significant changes in the platelet count. 3 Vincristine (0.05 mg/kg) intravenously caused significant inhibition of ADP-induced platelet aggregation. 4 Infusion of ADP caused some peripheral vasodilatation though it is unlikely that this contributed to the effects seen to any great extent.

Acculturation and the initiation of breastfeeding.

Despite the fact that breastfeeding is the most appropriate form of nutrition for the healthy term infant, the rate of initiation in the U.S. is declining. One demographic factor associated with this low rate is ethnicity and so in this study we measured acculturation (one aspect of ethnicity) into the U.S. and its relationship to the successful initiation of breastfeeding in a sample of women recruited approximately 2 months prenatally in a U.S.-Mexico border city. Interviews were administered in English or Spanish by bilingual interviewers prenatally (n = 906), natally (n = 788), and postnatally (n = 715). Acculturation (measured with a 20 item instrument) was strongly related to the intent to (p < 0.001) or the successful initiation of breastfeeding (p < 0.001). Marital status (p = 0.014) and education (p = 0.002) were related to breastfeeding prenatally and natally. Initiation of breastfeeding was highest among those women least acculturated (52.9%) and lowest in those most acculturated (36.1%) indicating an inhibiting effect of acculturation. To improve the rate of initiation of breastfeeding in the U.S. (a national health goal) intervention programs must consider cultural factors.

The acute effects of dexfenfluramine on human and porcine pulmonary vascular tone and resistance.

STUDY OBJECTIVES: Treatment with anorectics has become an important aspect of care for the severely obese. One such anorectic, the phenylethylamine dexfenfluramine (dFen), has been associated with the development of pulmonary hypertension. It works by reducing the neuronal uptake of 5-hydroxytryptamine (5-HT; serotonin) through inhibition of the 5-HT transporter. In this study we investigated whether dFen has a direct vasoconstrictor action on human and porcine pulmonary vasculature. DESIGN: For the human study, tissue was obtained from patients who had undergone lung and heart-lung transplantation. The effect of dFen was studied in seven isolated colloid perfused human lungs and in rings of human pulmonary artery (PA) dissected from the lungs of a further 19 patients. For the porcine study, regional pulmonary vascular resistances (PVRs) were measured in isolated perfused porcine lungs. Vasoconstriction was assessed following dFen alone and in combination with hypoxia, cyclo-oxygenase blockade (indomethacin, 10(-5) mol/L), or nitric oxide synthase (NOS) blockade (N(G)-nitro-L-arginine, 10(-5) mol/L). RESULTS: In the human study, 5-HT and dFen caused only limited increases in tension of isolated rings of PA. The concentration of dFen, 10(-4) mol/L, that was needed to increase tension was higher than that found normally in treated patients where peak levels are 3. 3 x 10(-7) mol/L. Other vasoconstrictors such as prostaglandin F(2)alpha, 10(-5) mol/L, and the thromboxane analog U46619, 10(-6) mol/L, produced far greater increases in tension. Ketanserin, 10(-4) mol/L, attenuated the constrictor response to 5-HT but had no effect on the constrictor response to dFen. Removal of the endothelium did not influence the response to dFen. In the isolated ventilated and perfused lungs, dFen caused an increase in PVR again only at a comparatively high concentration, 10(-4) mol/L. In the porcine study, dFen, 10(-4) mol/L, did not increase any PVR during normoxia or following NOS blockade. Small insignificant increases in PVR occurred during hypoxia and after cyclo-oxygenase blockade. CONCLUSION: These results do not support the view that dFen would act as a direct vasoconstrictor when given in the usual doses. However, delayed elimination of dFen could raise tissue concentrations to high levels and give rise to vasoconstriction and pulmonary hypertension.

Accuracy and precision of urinary pH determinations using two commercially available dipsticks.

The accuracy and precision of urinary pH determinations using commercially available dipsticks were studied. Two products were evaluated by 17 MT(ASCP) technologists over the pH range 4.5 to 9.0. The study included accuracy, reproducibility, variation among technologists, and variation between products. The results demonstrated considerable variation among technologists, products, and true pH levels in dipstick urinary pH determinations, and that very good or very poor results could be obtained, depending on the true pH level being sampled and on the choice of technologist.

Acute hypoxic ventilation, carotid body cell division, and dopamine content during early hypoxia in rats.

In a previous study, we showed that the acute hypoxic ventilatory response was blunted in anesthetized chronically hypoxic rats and was restored by blockade of the dopamine D2 receptor with domperidone. We now report observations made during 1-8 days of exposure to 10% O2 on the acute hypoxic ventilatory response and the effect of domperidone and relate them to dopamine content and cellular proliferation in the carotid body. Hypoxic exposure caused a parallel shift in the hypoxic response curve to higher levels of ventilation and arterial oxygen saturation. The greatest response occurred on day 1 and was unaffected by domperidone: dopamine content diminished and mitotic activity increased. By 8 days, hypoxic ventilation approached normal and was significantly augmented by domperidone; in the carotid body, dopamine levels had risen above the control level and mitoses had diminished. Thus the increase in ventilation was inversely related to carotid body dopamine content, which was depressed. The possibility of a causal relationship is discussed.

Dopamine and ventilatory effects of hypoxia and almitrine in chronically hypoxic rats.

We hypothesized that the temporary blunted ventilatory response to hypoxia seen in chronically hypoxic rats could be related to the increased amount of dopamine found in their carotid bodies. Rats, kept 2-3 wk in 10% O2, showed reduced nonisocapnic ventilatory responses to 21-12% inspiratory O2 fraction compared with control rats. Stimulus-response curves to almitrine, which simulates the action of hypoxia on the carotid body, were also depressed in chronically hypoxic rats. Responses to hypoxia and almitrine were significantly correlated in the two groups of rats. Dopamine depressed ventilation during normoxia, hypoxia, and almitrine stimulation in both groups, an action abolished by the dopamine-2 antagonist domperidone. Domperidone slightly increased responses to hypoxia and almitrine in control rats but had a greater enhancing effect in chronically hypoxic rats, such that there was no longer a difference between the responses of the two groups.

Ionic currents in carotid body type I cells isolated from normoxic and chronically hypoxic adult rats.

Whole-cell recordings were used to investigate the effects of a 3-week period of hypoxia (10% O2) on the properties of K+ and Ca2+ currents in type I cells isolated from adult rat carotid bodies. Chronic hypoxia significantly increased whole-cell membrane capacitance. K+ current amplitudes were not affected by this period of hypoxia, but K+ current density was significantly reduced in cells from chronically hypoxic rats as compared with normoxically maintained, age-matched controls. K+ current density was separated into Ca2+-dependent and Ca2+-independent components by bath application of 200 microM Cd2+, which blocked Ca2+ currents and therefore, indirectly, Ca2+-dependent K+ currents. Ca2+-dependent K+ current density was not significantly different in control and chronically hypoxic type I cells. Cd2+-resistant (Ca2+-insensitive) K+ current densities were significantly reduced in type I cells from chronically hypoxic rats. Acute hypoxia (Po2 15-22 mmHg) caused reversible, selective inhibition of Ca2+-dependent K+ currents in both groups of cells and Ca2+-insensitive K+ currents were unaffected by acute hypoxia. Ca2+ channel current density was not significantly affected by chronic hypoxia, nor was the degree of Ca2+ channel current inhibition caused by nifedipine (5 microM). Acute hypoxia did not affect Ca2+ channel currents in either group. Our results indicate that adult rat type I cells undergo a selective suppression of Ca2+-insensitive, voltage-gated K+ currents in response to chronic hypoxia in vivo. These findings are discussed in relation to the known adaptations of the intact carotid body to chronic hypoxia.

Ca2+ channel currents in type I carotid body cells of normoxic and chronically hypoxic neonatal rats.

Whole-cell patch-clamp recordings were used to study voltage-gated Ca2+ channel currents in type I carotid body cells of young rats born and reared in normoxia or in a chronically hypoxic (CH) environment (10% O2). Currents activated at potentials of -40 mV and more positive, and typically peaked at 0 mV in both groups of cells. Steady-state inactivation curves were similar in the two populations. Ca2+ currents were significantly larger in CH type I cells, but this was accounted for by the increased size of CH cells: current density was similar in both cell types. Nifedipine (5 microM) always partially inhibited currents and Bay K 8644 (2-5 microM) always enhanced currents, indicating the presence of L-type channels. In a small number of cells from each group, the N-type channel blocker omega-conotoxin GVIA caused partial, irreversible inhibition, but in most cells was without discernible effect. These results indicate that type I cells possess L-type Ca2+ channels, that N-type are expressed in some cells and that non-L, non-N-type channels are also present. Furthermore, chronic hypoxia does not appear to cause specific adaptive changes in the properties of Ca2+ channels in type I cells.

Social support, social influence, ethnicity and the breastfeeding decision.

A survey was conducted of all mothers delivering infants at a university medical center hospital in the month of July, 1981. The survey was conducted within 48 hours of delivery and addressed factors related to the breastfeeding decision. The mother's response to the question concerning choice of infant feeding was verified against the feeding records. One set of questions concerned the perceived general supportiveness toward breastfeeding of six individuals significant to the mother. Another set of questions identified who was most influential in the mother's breast or bottle feeding decision. The pattern of significant bivariate relationships between a person's supportiveness and breastfeeding varied across ethnic and maritial status groups. Single and multiple logistic analyses were conducted within ethnic groups to identify from whom support was most important for initiating breastfeeding. Among Black-Americans, support from a close friend was most important. Among Mexican-Americans, support from the mother's mother was most important. Among Anglo-Americans, support from the male partner was important. A broad variety of ensuing research issues are raised. An implication is that social support may be an important interventive variable, but the potentially supportive individual to be reached by an interventive program varies by ethnic group.

The impact of severely damaged cells in cytogenetic research.

In a large multilaboratory cytogenetic study of interlaboratory variations using 4 dose levels of triethylenemelamine and a control, a severely damaged cell was operationally defined as a cell which contained at least 10 aberrations of any type. A review of this study suggested that the use of this definition introduced a bias in the measurement and interpretation of results for the other cytogenetic categories studied. As a result, the original severely damaged cells were carefully reanalyzed to investigate the characteristics of this bias and to seek procedures to minimize or eliminate it. Results characterize this bias and demonstrate that when a severely damaged cell is defined as one containing at least 20 aberrations and those aberrations in the remaining non-severely damaged cells are classified by specific type, the bias is significantly reduced and chromosome analysis can be improved as a test system.

Acculturation and breastfeeding on the United States-Mexico border.

Previous studies have demonstrated a strong association between breastfeeding incidence and ethnic background, indicating the presence of strong cultural influences on infant-feeding patterns within ethnic groups. This study analyzed the relationship of acculturation into the United States, one aspect of ethnicity, to the initiation of breastfeeding among a sample of 213 women recruited approximately 2 months prenatally in the United States-Mexico border city of Brownsville, Texas. An in-depth, structured interview was conducted at that time (n = 213), at the time of birth (n = 207), and 2 to 3 weeks postnatally (n = 206). In addition, male partners of the mothers were interviewed prenatally when available (n = 119). Acculturation scores and demographic characteristics were tested relative to breastfeeding initiation. The degree of acculturation, age, and marital status were associated significantly with breastfeeding initiation (with breastfeeding continued at 2 to 3 weeks postnatally), but occupational status, education, and income were not. Breastfeeding incidence was highest among older, married, or low-acculturated, Anglo mothers. These data suggest that women being assimilated into the United States are inhibited in the initiation of breastfeeding. These findings suggest that to be successful, intervention programs to increase breastfeeding incidence must consider the cultural adaptation of different groups as they meld with the larger population.

A study of aspirin induced changes in bleeding time, platelet aggregation, and Sonoclot coagulation analysis in humans.

The purpose of this study was to determine whether or not a newer test of platelet function, Sonoclot coagulation analysis, can identify the patients who develop significant prolongation of bleeding time after aspirin ingestion. Template bleeding time, platelet aggregation in response to arachidonic acid, collagen, epinephrine, adenosine diphosphate, and ristocetin, and Sonoclot coagulation analysis were performed before and after ingestion of aspirin in 22 adult volunteers. Mean bleeding time increased from 5.32 +/- 2.16 min to 7.34 +/- 2.1 min, but remained within normal range (2.5 to 9 min). There was marked intersubject variability in the effect of aspirin on bleeding time, and difference between men and women was not significant. There was significant decrease in platelet aggregation in response to arachidonic acid, collagen and epinephrine. Sonoclot coagulation analysis did not show significant effect of aspirin administration. There was no correlation among changes in bleeding time, platelet aggregation, and Sonoclot coagulation analysis. Five patients with known platelet function disorders and prolonged bleeding times (mean = 18.5 min, range 14 to 22) without any other coagulation abnormalities were also studied. In four of these patients who had normal platelet count, Sonoclot graphs were morphologically similar to those in the volunteers with normal bleeding times, but in one patient with thrombocytopenia, morphology was altered. It is our conclusion that Sonoclot coagulation analysis is unlikely to identify patients with prolonged bleeding time in whom platelet count and other coagulation factors are normal.

Attitudes toward breastfeeding.

To understand why some lower socioeconomic status mothers delivering at a state university hospital breastfeed, while others do not, 26 attitude items were administered in a survey of 358 mothers. A factor analysis of these items yielded four interpretable factors: benefits to infant, social inconvenience, personal inconvenience, and physical inconvenience-medical benefits to child. These factors were significantly related to breastfeeding within each level of ethnicity and marital status. The results imply that emphasizing the benefits for the infant, and providing strategies for minimizing personal inconveniences, should promote breastfeeding in these populations.