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Biomedical subjects

D M Campbell

Publications and source records attributed to D M Campbell.

At least 37 records · Page 2Linked to original sources

Preeclampsia in twin pregnancies: incidence and outcome.

OBJECTIVES: To confirm the increased incidence of preeclampsia in twin pregnancy and to determine the relationship to zygosity and placentation; to consider the perinatal outcome of twin pregnancies in this condition. METHODS: Retrospective study of all twin pregnancies (n = 2473) identified from the Aberdeen Maternity and Neonatal Databank to women resident in the Grampian Region of Scotland for the period 1950-1995. RESULTS: The increased relative risk for gestational hypertension, preeclampsia, and eclampsia in twin pregnancies compared to singleton pregnancies has been confirmed as significant both in primiparas and multiparas with little variation in rates over the time period under review. Neither the sex of the offspring nor zygosity influences the incidence of hypertensive disease, whereas preeclampsia is more common in association with monochorionic placentation. As the birth weight was lower and placental weight greater in MzMc twins compared to either MzDc or DzDc, there was a higher placental index in such cases. No difference in the birth weights of individual twins, the difference in birth weights between the twins, placental weight, or placental index were found in relation to hypertensive disease. Gestation at delivery was earlier in normotensive twin pregnancies than in those women who developed a hypertensive problem. This leads to a higher perinatal death rate and lower survival rate for the babies in normotensive women with a twin pregnancy. CONCLUSION: Although gestational hypertension, preeclampsia, and eclampsia all occur more commonly in twin pregnancy, this does not lead to significant growth retardation nor discordant fetal growth and a poor outcome for the twins. Although the incidence of preeclampsia is higher in twin pregnancies with monochorionic placentation, this does not seem to be mediated by deficiencies in placental development as assessed in this study.

Birth Weight↗

Postpartum fecal incontinence is more common in women with irritable bowel syndrome.

PURPOSE: Anal sphincter damage can occur during vaginal delivery and may lead to impairment of fecal continence. The aim of this study was to determine the influence of irritable bowel syndrome on symptoms of fecal incontinence following first vaginal delivery. METHODS: A prospective, observational study was performed before delivery, six weeks, and six months following delivery in primiparous women. A bowel function questionnaire was completed, and anal vector manometry, mucosal electrosensitivity, pudendal nerve terminal motor latency, and anal endosonography were performed. A total of 208 women were assessed before and after delivery, and 104 primigravid women were studied after delivery only. A total of 34 of 312 (11 percent) had an existing diagnosis of irritable bowel syndrome. RESULTS: The prevalence of abnormal manometry or endosonography was similar in women with and without irritable bowel syndrome. However, six weeks after delivery, women with irritable bowel syndrome had a higher incidence of defecatory urgency (64 percent) and loss of control of flatus (35 percent) compared with those without (urgency, 10 percent, P < 0.001; flatus, 13 percent, P = 0.007). The incidence of frank fecal incontinence was similar in the two groups. Women with IBS had increased mucosal sensitivity to electrical stimulation of the upper anal canal both before and after delivery. CONCLUSION: Women with IBS are more likely to experience subjective alteration of fecal continence postpartum compared with the healthy primigravid population, but they are not at increased risk of anal sphincter injury.

Colonic Diseases, Functional↗

Environmental risk factors for sporadic Escherichia coli O157 infection in Scotland: results of a descriptive epidemiology study.

The objective of the study was to obtain detailed descriptive epidemiological information on sporadic verocytotoxin-producing Escherichia coli O157 infection in Scotland in relation to transmission routes and host-related risk factors. Using a standardized questionnaire, the study was carried out throughout Scotland over an 18-month period from July 1992 and co-ordinated at the Communicable Diseases and Environmental Health (Scotland) Unit, Glasgow (CDEH(S)U). The subjects were laboratory-confirmed cases of Escherichia coli O157 infection, of whom 138 met the criteria for inclusion in the study. The most important findings were the high proportion of cases who had been exposed to environmental factors such as farm animals and/or their by-products; or who had participated in gardening or garden-play; or who had suspected or confirmed household water supply problems, prior to the onset of illness. The frequency and relative importance of environmental risk factors requires further quantification and study in order to assess where control measures can be directed most effectively. The implications for the NHS in preventing this crippling, life-threatening infection are considerable, not least in relation to hospitalization, dialysis and renal transplantation costs.

Adult↗

Comparison of various in vitro susceptibility methods for testing Stenotrophomonas maltophilia.

A total of 57 clinical isolates were screened by disk diffusion for a related pharmacodynamic study. Testing was performed using National Committee for Clinical Laboratory Standards guidelines, except that results were interpreted at 16 to 18 h and 48 h. Of the 57 isolates, 19 were randomly chosen for additional comparative susceptibility testing of five methods (disk diffusion, Etest, Alamar colorimetric broth microdilution, Vitek, and MicroScan) and an in-house broth microdilution method. The two diffusion methods (disk and Etest) had the closest correlation. The commercial broth microdilution methods and the in-house microdilution method generated inconsistent results for all agents except trimethoprim-sulfamethoxazole. Vitek compared poorly with both diffusion and microbroth dilution methods. The most significant discrepancies were evident with all methods when the incubation period was extended to 48 h. When results were interpreted at 48 h, the incidence of resistance for all bactericidal agents was approximately double the resistance observed at 16 to 18 h. The bacteriostatic agents, trimethoprim-sulfamethoxazole and doxycycline, demonstrated the greatest in vitro activity and were least influenced by extended incubation with diffusion methods. Because correlative in vivo and in vitro studies have not revealed an effective therapeutic regimen for serious S. maltophilia infections, susceptibility results with all testing methods should be interpreted with caution when choosing therapy for patients with life-threatening infections. Susceptibility testing for this heterogeneous group remains controversial and routine testing, with the possible exception of doxycycline (or minocycline) and trimethoprim-sulfamethoxazole, should be avoided. Our data support that if testing is done with bactericidal agents, consideration should be given to interpretation after 48-h incubation.

Anti-Bacterial Agents↗

Blood cultures positive for coagulase-negative staphylococci: antisepsis, pseudobacteremia, and therapy of patients.

A blood culture cohort study investigating issues related to isolation of coagulase-negative staphylococci (CoNS) and other skin microflora is reported. Data were collected over 12 weeks to determine the incidence of significant CoNS bacteremia versus that of pseudobacteremia (contaminants) and to evaluate drug therapy in patients with cultures positive for CoNS. In addition, the effectiveness of 0.2% chlorine peroxide as a bactericidal disinfectant was compared to that of 10% providone iodine. A total of 3,276 cultures of blood from 1,433 patients were evaluated in the study. Eighty-nine cultures were positive for skin flora, with 81 of 89 (91%) involving CoNS. The incidence of significant CoNS bacteremia was 20 of 81 (24.7%), that of indeterminate bacteremia was 10 of 81 (12.3%), and that of contamination was 59 of 81 (72.8%). The incidence of significant bacteremia involving CoNS was double the 10 to 12% rate based on previous estimations at our institutions. In tests with the two bactericidal disinfectants, 22 of 1,639 cultures (1.3%) in the chlorine peroxide group versus 37 of 1,637 (2.3%) in the providone iodine group were considered contaminated (P = 0.065). Rates of contamination for venipuncture versus catheter collection were not significantly different (P = 0.46). The overall contamination rate was 59 of 3,276 (1.8%), which is consistent with the lower end of published quality assurance benchmark standards. The low rate was believed to be due to the professional phlebotomy staff in our institutions. There was excellent agreement between retrospective analysis by reviewers, when formal criteria were used, and the attending physicians' intuitive clinical impressions in the classification of significant bloodstream infections (100% agreement) or contamination (95% agreement). However, physicians still used antimicrobial agents to treat nearly one-half of the patients with contaminated blood cultures, with vancomycin being misused in 34% of patients. In addition, 10% of patients with significant bacteremia were treated with inappropriate agents. There were no significant adverse events or prolonged hospital stays due to the unnecessary use of vancomycin; however, the additional costs of treating patients whose cultures contained CoNS contaminants was estimated to be $1,000 per patient. Measures to limit the unnecessary use of vancomycin (and other agents) are important.

Adult↗

Developing a successful call center: one hospital's story.

As our call centers continue to respond to changes in the healthcare industry and to customer demand, we understand that it is constantly necessary to reinvent8 ourselves. The call center industry, is, after all, only about 20 years old. It is constantly responding to technological advances. Medical call center managers must also respond to changes in healthcare delivery. We must keep a vigilant eye on industry trends. While we welcome information on other call centers to help us reformulate our targets, we must always customize information to our local market.

Computer Communication Networks↗

Significant antenatal factors in the development of lumbar spinal stenosis.

STUDY DESIGN: Adverse factors during pregnancy may permanently stunt the growth of the spinal canal. Subsequently, even in an optimal environment the canal cannot catch up in growth with the trunk and long bones because of its early maturation. The degree of retardation in canal size depends on the severity and timing of the adverse effect. The catch-up growth of the long bones mask the narrow canal, because the latter does not have growth potential, resulting in an adult of sufficient height and good proportions, but with a canal at risk for stenosis. OBJECTIVES: To investigate the influence of the antenatal environment on the growth of the lumber spinal canal. SUMMARY OF BACKGROUND DATA: To date, little is known about the effects of an adverse environment on the growth of the spinal canal, and no data have been reported on antenatal influencing factors. METHODS: Lumbar magnetic resonance imaging scans from 58 patients were examined. Dimensions of the central spinal canals were measured by computerized image analysis and compared with the subjects' obstetric data from their mothers' pregnancies. RESULTS: The L3 canal was found to be the most sensitive to the influence of the examined factors. Gestational age was the most significant factor; if short, it resulted in small adult canal. Small placental weight, greater maternal age, primiparity, low socioeconomic class, and low birth weight were also found to be significant in affecting the growth of the canal. CONCLUSIONS: An adverse antenatal environment does have a permanent, retarding effect on the growth of the lumbar spinal canal.

Adolescent↗

Contribution of voltage-dependent potassium channels to the somatic shunt in neck motoneurons of the cat.

The specific membrane resistivity of motoneurons at or near the soma (Rms) is much lower than the specific membrane resistivity of the dendritic tree (Rmd). The goal of the present experiments was to investigate the contribution of tonically active voltage-dependent potassium channels at or near the soma to the low Rms. These channels were blocked with the use of intracellular injections of cesium. Input resistance (RN), Rms/Rmd, a conductance representing voltage-dependent potassium channels on the soma, GK, and a conductance attributed to damage caused by electrode impalement, GDa, were estimated from voltage responses to a step of current. The effect of intracellular injections of cesium on electrotonic structure was determined with the use of two strategies: 1) a population analysis that compared data from two groups of motoneurons, those recorded with potassium acetate electrodes (control group) and those recorded with cesium acetate electrodes after the motoneurons were loaded with cesium; and 2) an analysis of changes in electrotonic structure that occurred over the course of multiple injections of cesium or during similar periods of time in control cells. RN of control and cesium-loaded motoneurons was similar. Over the course of the recordings, RN of control cells usually increased and this increase was associated with a hyperpolarization. In contrast, increases in RN after successive injections of cesium were closely linked to a depolarization. At corresponding membrane potentials, Rms/Rmd of cesium-loaded motoneurons was greater than Rms/Rmd of control motoneurons. Over the course of cesium injections, Rms/Rmd increased and the membrane potential depolarized. In contrast, increases in Rms/Rmd observed during the course of recordings from control cells were associated with a hyperpolarization. Compared with control cells at corresponding membrane potentials, GK was less in cesium-loaded cells. Increases in GK that occurred over the course of recordings in control cells were closely coupled to a depolarization. In cesium-loaded cells, GK usually decreased as the cell depolarized during the injections. In control cells, increases in GDa that occurred during the recording period were closely coupled to a depolarization. In contrast, changes in GDa that occurred during cesium injections were not related to the change in membrane potential and did not explain the corresponding changes in Rms/Rmd and membrane potential. The results of this study indicate that voltage-dependent potassium channels contribute to the somatic shunt (low Rms) in neck motoneurons and provide a voltage-dependent mechanism for the dynamic regulation of motoneuron electrotonic properties.

Action Potentials↗

Simplifying implant prosthetics.

This article presents a method of restoring an anterior single-tooth implant using the less complicated, less costly and less time-consuming method of a cement-retained restoration. With this method, the restorative dentist needs only the normal crown and bridge supplies.

Crowns↗

Endosonographic assessment of postpartum anal sphincter injury using a 120 degree sector scanner.

Obstetric injury is the principal cause of faecal incontinence in women. We describe use of a 120 degrees sector ultrasound probe to assess integrity of the anal sphincters in primigravid women. Eighty-eight women were successfully studied 6 weeks following vaginal delivery. Anal vector manometry and pudendal nerve studies were abnormal in 54 (61%), of whom 41 (71%) were symptomatic (urgency of defaecation, incontinence to flatus or faeces). The sonographic pattern of the anal sphincters described with a 360 degrees probe was reproduced. Forty-eight abnormal scans were reported by two radiologists with a kappa statistic of 0.65. Sphincter defects were found in 11 asymptomatic women. We conclude that anal endosonography has an important role screening for and diagnosis of postpartum anal sphincter defects. Use of a 120 degrees sector ultrasound probe may prove a cost-effective means of increasing the availability of this technique.

Adult↗

Diet in pregnancy and the offspring's blood pressure 40 years later.

OBJECTIVE: To determine how diet of the mother in pregnancy influences the blood pressure of the offspring in adult life. DESIGN: A follow up study of men and women born during 1948-1954 whose mothers had taken part in a survey of diet in late pregnancy. SETTING: Aberdeen, Scotland. POPULATION: Two hundred and fifty-three men and women born in Aberdeen Maternity Hospital. MAIN OUTCOME MEASURE: Systolic and diastolic blood pressure. RESULTS: The relations between the diet of mothers and their offsprings' blood pressure were complex. When the mothers' intake of animal protein was less than 50 g daily, a higher carbohydrate intake was associated with a higher blood pressure in the offspring (a 100 g increase in carbohydrate being associated with a 3 mmHg increase in systolic pressure (P = 0.02)). At daily animal protein intakes above 50 g, lower carbohydrate intake was associated with higher blood pressure (a 100 g decrease in carbohydrate being associated with an 11 mmHg rise in systolic blood pressure (P = 0.004)). These increases in blood pressure were associated with decreased placental size. CONCLUSION: Mothers' intakes of animal protein and carbohydrate in late pregnancy may influence their offsprings' adult blood pressure. This may be mediated through effects on placental growth.

Adult↗

Stenotrophomonas maltophilia: emergence of multidrug-resistant strains during therapy and in an in vitro pharmacodynamic chamber model.

Emergence of Stenotrophomonas maltophilia as a nosocomial pathogen is becoming increasingly apparent. Pleiotropic resistance characterizes S. maltophilia. Furthermore, a slow growth rate and an increased mutation rate generate discordance between in vitro susceptibility testing and clinical outcome. Despite original susceptibility, drug-resistant strains of S. maltophilia are often recovered from patients receiving beta-lactams, quinolones, or aminoglycosides. Given the disparity among various in vitro susceptibility methods, this study incorporated a unique pharmacodynamic model to more accurately characterize the bacterial time-kill curves and mutation rates of four clinical isolates of S. maltophilia following exposure to simulated multidose regimens of ceftazidime, ciprofloxacin, gentamicin, and ticarcillin-clavulanate. Time-kill data demonstrated regrowth of S. maltophilia with all four agents. With the exception of ticarcillin-clavulanate, viable bacterial counts at the end of 24 h exceeded the starting inoculum. Ciprofloxacin only reduced bacterial counts by less than 1.0 log prior to rapid bacterial regrowth. Resistant mutant strains, identical to their parent strain by pulsed-field gel electrophoresis, were observed following exposure to each class of antibiotic. Mutant strains also had distinct susceptibility patterns. These data are consistent with previous reports which suggest that S. maltophilia, despite susceptibility data that imply that the organism is sensitive, develops multiple forms of resistance quickly and against several classes of antimicrobial agents. Standard in vitro susceptibility methods are not completely reliable for detecting resistant S. maltophilia strains; and therefore, interpretation of these results should be done with caution. In vivo studies are needed to determine optimal therapy against S. maltophilia infections.

Anti-Bacterial Agents↗

The influence of dietary advice on nutrient intake during pregnancy.

To assess the effect of an antenatal nutrition programme designed specifically for the local population, questionnaires on nutrition knowledge, attitudes to healthier eating and 4 d diet diaries were completed by women attending routine antenatal clinics. Women who received the nutrition education programme were allocated into an Intervention Education Group whilst those women who did not were allocated into a Routine Education Group. The results showed that knowledge about nutrition was significantly higher in the intervention group. However, no significant differences were detected between the two groups for attitude variables or nutrient intake. It is concluded, therefore, that the most-widely-read form of nutrition advice for pregnant women may have some impact on nutrition knowledge but has little effect on nutrient intake during pregnancy.

Adolescent↗

The changing pattern of cerebral palsy in Avon.

The overall rate of cerebral palsy excluding post-neonatal cases, has remained relatively constant, varying between 1.93 and 2.27 per 1000 births over the 20-year period between 1969 and 1988 in Avon. The rate of the subgroup of spastic cerebral palsy varied from 1.40 to 1.78 per 1000 births over the same time period. In singletons the corresponding figures were 1.80-2.17 per 1000 births and 1.28-1.67 per 1000 births, and in multiple births the figures were 7.12-8.80 per 1000 births and 7.12-8.44 per 1000 births. Although the overall rates have remained fairly constant there was an increase in incidence in the later years among children with low birthweight and short gestation.

Birth Weight↗