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Biomedical subjects

A Lee

Publications and source records attributed to A Lee.

At least 235 records · Page 13Linked to original sources
PubMed1999

Molecular characterization and interstrain variability of pHPS1, a plasmid isolated from the Sydney strain (SS1) of Helicobacter pylori.

The 5846-bp circular plasmid pHPS1 of Helicobacter pylori Sydney strain, SS1, was cloned, sequenced, and structurally characterized. The SS1 strain is widely used in animal studies of H. pylori infection. The sequence of pHPS1 revealed three open reading frames (ORFs), all of which are transcribed. Two ORFs encode putative plasmid replication proteins, RepA and RepB, similar to replicases resident on theta plasmids. In contrast, the function of ORF2 remains cryptic due to the absence of sequence similarity with any known protein in sequence databases. In addition, species specificity of these three coding regions was shown using DNA dot blot hybridization in 57 diverse clinical H. pylori isolates and 32 Helicobacter and Campylobacter strains. RepA appears to be the predominant plasmid replication protein of H. pylori and the deduced amino acid sequence was highly conserved (76-96%) in 8 H. pylori isolates, including SS1. RepB was detected in 3 H. pylori isolates examined in this study, 2 of which possess only the repB gene. Analysis of the protein sequences of these two replicases, together with previously characterized H. pylori plasmid replication proteins, supports the formation of a distinct class of H. pylori plasmid proteins. Moreover, comprehensive analysis of the whole genome sequence of H. pylori strain 26695, pHPS1, and other H. pylori plasmid sequences that are available revealed interesting insights as to the occurrence of plasmid-mediated recombination within H. pylori. Common regions between plasmids and chromosome sequences of H. pylori were identified in this study which could only have arisen by genetic recombination, thus providing the first line of evidence, albeit indirectly, of the contribution of H. pylori plasmids in generating an extensive genetic heterogeneity characteristic of this important gastroduodenal pathogen.

Chromosome Mapping↗
PubMed1999

Comparative gastrointestinal tolerance of sucrose, lactitol, or D-tagatose in chocolate.

D-tagatose is a potential new sugar substitute. Ingested D-tagatose is incompletely absorbed from the small intestine; unabsorbed D-tagatose reaches the colon where it is completely fermented. In a double-blind, controlled crossover study, the gastrointestinal effects were compared following acute consumption of 40 g plain chocolates containing 20 g of sucrose, lactitol, or D-tagatose by 50 healthy adults ages 18 to 24 years. Consumption of D-tagatose was not associated with a significant increase in the frequency of passing feces, or in the number of subjects passing watery feces. However, lactitol consumption was associated with an increase in both of these occurrences. Consumption of chocolate containing D-tagatose and lactitol resulted in significant increases in colic, flatulence, borborygmi, and bloating compared to consumption of the sucrose-containing chocolate, but the majority of symptoms were described as only "slightly more than usual." D-tagatose-containing chocolate did not provoke significantly more of these symptoms than lactitol-containing chocolate. A significant number of subjects reported nausea following consumption of D-tagatose chocolate compared to the sucrose chocolate control, and multiple symptoms occurred in some subjects. Overall, these results demonstrate that a 20-g dose of D-tagatose is tolerated well in comparison to lactitol.

Adolescent↗
PubMed1999

The gastric transitional zones: neglected links between gastroduodenal pathology and helicobacter ecology.

The gastric transitional zones are the junctional zones between the different types of mucosa: antral-body, body-cardia, and antrum-duodenum. In this article, the importance of the transitional zone in determining disease outcome, specifically duodenal ulcer, gastric ulcer, and possibly gastric cancer, is reviewed. Both gastric ulcers and duodenal ulcers are located immediately adjacent to the transitional zones. The transitional zones are dynamic rather than static areas. Local acid levels determine the behavior of Helicobacter pylori at the antral-body transitional zone and, as a consequence, the geographic distribution of gastritis in the stomach and the formation of duodenal ulcer and gastric ulcer. This review also explains that diffuse antral gastritis and multifocal atrophic gastritis are part of the same disease and not separate entities.

Atrophy↗
PubMed1999

No further development of renal scarring after antireflux surgery in children with primary vesicoureteral reflux: review of the results of 99mtechnetium dimercapto-succinic acid renal scan.

PURPOSE: Reports of previous studies using excretory urography indicate that significant numbers of new scars developed in 5 to 31% of cases and scarring progressed in 11 to 16% after antireflux surgery. We evaluated renal scarring after surgery using a more accurate method, that is dimercapto-succinic acid renal scintigraphy. MATERIALS AND METHODS: Between 1985 and 1997 antireflux surgery was performed for primary vesicoureteral reflux in 223 children at our hospital. Of these patients 45 boys and 29 girls with a median age of 74 months at surgery in whom preoperative and postoperative renal scans were available form the basis of our retrospective study. Renal scan was performed 0.3 to 58 months (median 2) preoperatively and 5.3 to 44 months (median 18.7) postoperatively. A total of 24 children (39 renal units) were followed further by additional scanning for as long as 25 to 120 months (median 43.2) postoperatively. Each scan was blindly reviewed for the size, number and zone location of cortical defects based on morphology. Interval changes were grouped into categories as improved, no change, progressed and new scar formation. RESULTS: Postoperatively there was no ureteral obstruction. Pyelonephritis developed in 2 patients (2.7%) and asymptomatic bacteriuria was noted in 35 (47.3%) postoperatively. Of the renal units 110 (86.6%) showed no change, while 15 (11.8%) were improved and 2 (1.6%) had progression. In no case was new renal scar formation observed. CONCLUSIONS: Contrary to most previous reports involving excretory urography, our results indicate no significant progression of renal scarring after antireflux surgery. In most cases postoperative followup renal scans demonstrated no significant morphological change. When there was change, it mostly involved the disappearance or decrease of renal scars.

Child↗
PubMed1999

Mother rats bar-press for pups: effects of lesions of the mpoa and limbic sites on maternal behavior and operant responding for pup-reinforcement.

This series of studies explored the operant response rates for pup-reinforcement of female Sprague Dawley rats that were either postpartum or cycling and sustained lesions of the medial preoptic area (mpoa), the lateral amygdala, the nucleus accumbens, or sham lesions. The last experiment tested the effects on operant responding of preventing direct access to pups in mpoa and sham-lesioned postpartum mothers. All animals were trained prior to mating on an FR-1 bar-press schedule to criterion (50 presses in 30 min) for a food (Froot Loops) reward in an operant chamber. At the end of pregnancy animals that were to be tested postpartum were provided in their home cages with six newborn foster pups; mother-litter interactions were observed on the last 3 days of pregnancy and throughout the postpartum period. On each of these same days after a period of separation from pups, females were tested in the operant box for delivery of rat pups. With each bar-press response, a rat pup rather than a Fruit Loop was delivered down a gentle shoot into the hopper. Non-postpartum, but maternal, multiparous animals who were showing estrous cycles were tested using the same procedures. The first and second studies showed that animals (both postpartum and as cycling multiparous animals) with mpoa lesions exhibited a significant reduction in bar-press rate for pup reinforcement in the operant box. In postpartum animals, amygdala lesions also produced a bar-press deficit, whereas nucleus accumbens lesions did not. All lesioned groups showed deficits in maternal responding in the home cage and deficits in retrieval in the operant box. These results indicate that systems associated with the mpoa mediate both the stereotypical maternal behaviors and pup-reinforcement. In contrast, the expression of home cage maternal behavior is dependent on the integrity of both the amygdala and nucleus accumbens, whereas operant responding need not be. These results indicate a dissociation of mechanisms mediating expression of the species-typical maternal behavior and pup-reinforcement.

Amygdala↗
PubMed1999

Indocyanine green clearance reflects reperfusion injury following liver transplantation and is an early predictor of graft function.

BACKGROUND/AIMS: Primary graft dysfunction is difficult to predict. We have previously shown that indocyanine green clearance measured at 24 h following orthotopic liver transplantation predicts graft survival and outcome. We prospectively evaluated the use of indocyanine green clearance (with a cut-off value of 200 ml/min) as a marker of graft function following orthotopic liver transplantation and investigated its relationship with the markers of reperfusion injury during orthotopic liver transplantation. METHODS: In all patients indocyanine green clearance was measured at 24 h. Repeated blood samples were taken before, during the anhepatic and reperfusion phase and up to 12 h following orthotopic liver transplantation to measure the levels of neutrophil elastase and reactive oxygen intermediates. All patients studied had normal hepatic arterial pulse on Doppler-ultrasound post orthotopic liver transplantation. RESULTS: All patients with indocyanine green clearance >200 ml/min recovered following orthotopic liver transplantation and remained well up to 3 months of follow up. Four patients had an indocyanine green clearance <200 ml/min; three were re-transplanted for graft failure within 3 days of the transplant, while one survived after prolonged intensive support and hospitalization. Indocyanine green clearance significantly correlated with reactive oxygen intermediates production and neutrophil elastase during orthotopic liver transplantation (r=-0.61, p<0.002 and r=-0.66, p<0.0009, respectively). Indocyanine green clearance was also significantly correlated with alanine aminotransferase and prothrombin time at 24 h post-transplantation (r=-0.35, p<0.02 and r=-0.4, p<0.0077, respectively). CONCLUSION: Indocyanine green reflects the degree of reperfusion injury and is a good early marker of primary graft function. Indocyanine green clearance over 200 ml/min is associated with favorable outcome.

Adult↗
PubMed1999

Social support, social selection and self-assessed health status: results from the veterans health study in the United States.

This study provided a comprehensive assessment of the association between social support and health using longitudinal data from the Veterans Health Study. Unlike previous studies which examined the relationship between one single domain of social support with either mental or physical health, the present study assessed the effects of three different domains of social support on multiple measures of health. The findings of the study indicated that social support tended to mediate the deleterious effects of non-military traumatic events; whereas the adverse consequences of traumatic events experienced in the military were not affected by social support, suggesting that stressors associated with combat had a long lasting effect on the health status of veterans. The study results revealed that compared with those with better health, respondents with poor health were more likely to have lower levels of social support, suggesting that poor health might be a barrier to a person's ability to participate and/or maintain social relationships. The study also showed that different types of social support had varying beneficial effects on different measures of health. While perceived support had a strong effect on all the measures of health (except alcoholism) included in the study, living arrangement had a significant effect on post-traumatic stress disorder or physical health and participation in group activities had a strong effect only on physical functioning. The results of the study highlight the need for future research to determine whether particular types of social support affect various aspects of health differently. This simultaneous focus on multiple support functions and health outcomes is important because it provides insight into the mechanisms linking social support to health.

Adult↗
PubMed1999

Three-dimensional ultrasonographic imaging of fetal tooth buds for characterization of facial clefts.

The purpose of this prospective study was to investigate whether the antenatal characterization of fetal facial clefts can be improved by three-dimensional ultrasonographic visualization of fetal tooth buds. Between January 1996 and June 1998, seventeen consecutive fetuses with facial clefts were examined for fetal maxillary tooth buds in the cleft area using three-dimensional multiplanar reconstruction. It was possible in all cases to classify the clefts either as cleft lip alone or unilateral cleft lip and palate or bilateral cleft lip and palate. Three-dimensional computed tomography and histological jaw sections of three stillborn infants were produced in order to examine the correlation between the sonographic, radiographical and histological findings. The prenatal characterization of the facial clefts by means of a visualization of the tooth buds showed to be accurate postnatally in all cases. The sonographic proof of tooth buds might gain increasing importance as this technique seems to facilitate and improve the prenatal classification of suspected facial clefts.

Adult↗
PubMed1999

Assessment of functional status, low back disability, and use of diagnostic imaging in patients with low back pain and radiating leg pain.

We analyzed data from outpatients with chronic low back pain (LBP) in the Veterans Health Study (n = 563) to examine the relationship between localized LBP intensity and radiating leg pain in assessing patient functional status, low back disability, and use of diagnostic imaging. Based on the localized LBP intensity, the study subjects were divided into tertiles (low, moderate, and high intensity). The study subjects were also stratified by the extent of radiating leg pain. Using analysis of variance and multiple regression analysis, we compared the relative importance of localized LBP intensity and radiating leg pain in explaining the variability in the means of the SF-36 scales and low back disability days, and in the proportion of patients who had used diagnostic imaging. The results of the study indicate that measures of localized LBP intensity and radiating leg pain contribute separately to the assessment of patient functional status, low back disability, and use of diagnostic imaging. These results suggest that localized LBP intensity and radiating leg pain may represent two different approaches in assessing back pain severity. Future epidemiological and health services research should consider both measures in assessing the impact of LBP on patient functional status, low back disability, and use of diagnostic imaging.

Adult↗
PubMed1999

Sustained antihypertensive actions of a dual angiotensin-converting enzyme neutral endopeptidase inhibitor, sampatrilat, in black hypertensive subjects.

Our objective was to evaluate the safety and antihypertensive efficacy of sampatrilat, a novel dual inhibitor of both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP), in subjects poorly responsive to ACE inhibitor monotherapy. The ability of sampatrilat (50 to 100 mg daily) (n = 28) to lower blood pressure was compared with that of the ACE inhibitor lisinopril (10 to 20 mg daily) (n = 30) using a double-blind, randomized, parallel group study design over a 56-day treatment period in black hypertensives. Changes in systolic (SBP) and diastolic (DBP) blood pressure were determined using repeated ambulatory blood pressure (ABP) monitoring. Both sampatrilat and lisinopril decreased plasma ACE concentrations after 28 and 56 days. The decrease in plasma ACE concentrations (U/L) was greater after lisinopril (-9.33 +/- 0.52) as compared with sampatrilat (-6.31 +/- 0.70) (P = .0001) therapy. Lisinopril, but not sampatrilat, increased plasma renin activity. Lisinopril produced a transient decrease in mean 24-h ABP (mm Hg) at 28 days (SBP = -9.0 +/- 2.3, DBP = -5.7 +/- 1.3; P < .01), which returned to pretreatment values by 56 days of therapy. Alternatively, sampatrilat produced a sustained decrease in mean ABP over the 56-day treatment period (day 28: SBP = -7.3 +/- 1.8, DBP = -5.2 +/- 1.2; P < .01: day 56: SBP = -7.8 +/- 1.5; DBP = -5.2 +/- 0.95; P < 0.01) with a greater treatment effect on DBP than that of lisinopril at day 56 (P = .05). Treatment-emergent adverse events were noted to be similar between both treatment groups. We conclude that the antihypertensive actions of ACE/NEP inhibitor monotherapy in black subjects offers a novel therapeutic approach to patients otherwise resistant to the sustained antihypertensive actions of ACE inhibitor monotherapy.

Adult↗
PubMed1999

Neuropsychological patterns in right versus left frontotemporal dementia.

Patients with frontotemporal dementia (FTD) often present with an asymmetric left or right-sided anterior cerebral perfusion abnormality that is associated with differential behavioral symptoms. However, whether patients with primarily right versus left FTD also have unique neuropsychological characteristics has not been previously investigated. Comparisons of 11 patients with right-sided FTD and 11 with left FTD indicated that the 2 patient groups showed relatively distinct cognitive profiles. Patients with right FTD exhibited relatively worse performance on PIQ than VIQ, and on select nonverbal executive tasks relative to their verbal analogs (e.g., design fluency < word generation; Picture Arrangement < word sequencing). In contrast, patients with left FTD showed the opposite pattern. In addition, the 2 patient groups differed on several absolute test scores; patients with right FTD demonstrated more errors and perseverative responses, and worse percent conceptual level responses, on the Wisconsin Card Sorting Test, while the left FTD patients obtained significantly worse scores on the Boston Naming Test, and Stroop word reading and color naming. Verbal and nonverbal memory, mental speed, visual perceptual-constructional skill, and IQ subtest scaled scores did not significantly differ between groups. These data indicate that FTD should not be viewed as a unitary disorder, and that neuropsychological testing holds promise for the differential diagnosis of right versus left FTD.

Dementia↗
PubMed1999

Radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia after orthotopic heart transplantation.

Patients with orthotopic heart transplantation may develop a variety of arrhythmias. Successful radiofrequency catheter ablation for tachyarrhythmias from manifest and concealed accessory bypass tracts in transplant patients has been previously reported. We present a patient with orthotopic heart transplantation who developed typical atrioventricular nodal tachycardia, which was successfully treated by radiofrequency catheter ablation.

Aged↗
PubMed1999

Autism and congenital blindness.

The nature of autism in congenitally blind children has long been a source of interest and perplexity. A group of nine congenitally blind children with an autism-like syndrome were closely matched on chronological age and verbal mental age with nine sighted autistic children, and were compared on the Childhood Autism Rating Scale (Schopler, Reichler, & Renner, 1986) and the Behavior Checklist for Disordered Preschoolers, together with the Play Items for Disordered Preschoolers (Sherman, Shapiro, & Glassman, 1983). A checklist of clinical features characteristic of autism (derived from DSM-III-R) was also completed through an interview with teachers. There was substantial similarity between the groups, but also suggestive evidence of possible group differences, specifically in the domain of social-emotional responsiveness. Research on the psychological development of congenitally blind children promises to yield insights into the nature of autism itself.

Affect↗
PubMed1999

Distribution of HLA gene and haplotype frequencies in Taiwan: a comparative study among Min-nan, Hakka, Aborigines and Mainland Chinese.

A total of 8,497 blood samples were typed for HLA-A, B, DR and DQ. Of these, 7,137 Min-nan, 714 Hakka, 535 Mainland Chinese (152 from North China, 211 from Middle China, and 172 from South China) and 111 Aborigines were randomly selected from Tzu Chi Taiwan Marrow Donor Registry (TCTMDR). Differences in HLA gene and antigen frequencies have been observed between various ethnic groups of the Chinese population in Taiwan. The phylogenic tree shows Taiwan Aborigines and Javanese cluster together; Min-nan shares a common cluster with Hakka, Southern Hans and Thai; and Northern Hans shares a cluster with Middle Hans. The separation between Northern/Middle and Southern Chinese Hans support the idea that Northern and Southern Chinese have different genetic background. Aborigines appeared to be quite distinct in the distribution of a majority of the class I and class II antigens. High frequency of HLA-A24 (60.4%) and relatively restricted HLA polymorphisms are noted in Aborigines. The HLA haplotypes with high frequency in Aborigines included A24-B60-DRB1*04, A24-B60-DRB1*14, A24-B48-DRB1*04, and A24-B48-DRB1*14, which are different from the other ethnic groups. Although the phylogenic tree separates Aborigines and Han Chinese populations, 4 out of 20 most common HLA-A, -B, and -DR haplotypes presented in both Aborigines and Han Chinese may reflect an ancient common origin or intermixture between early settlers of Han Chinese and Taiwan Aborigines. The results in this study are essentially a summary of the observed gene/haplotype frequencies and differences among various ethnic groups in Taiwan.

Asian People↗