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Biomedical subjects

A Lee

Publications and source records attributed to A Lee.

At least 415 records · Page 23Linked to original sources
PubMed1996

An apparent functional correlation between variations in amino acid residues in HLA-DR4.1 and 4.2 serological subtypes and oligonucleotide characterization.

HLA-DR4 can be subdivided serologically into two specificities, DR4.1 and DR4.2, using well-defined monospecific alloantisera used in the 11th International Histocompatibility Workshop. In this study, a total of 1095 random DR4-positive individuals from several ethnic groups were tested first for serotype DR4.1/4.2 and then for DRB1*04 alleles using polymerase chain reaction (PCR) followed by sequence-specific oligonucleotide probe hybridization (SSOPH). An almost 100% correlation between samples testing positive for DR4.1 and the presence of alanine at position 74 was observed, while samples testing positive for DR4.2 correlated with the presence of glutamic acid at position 74. DRB1*04 alleles 0401, 0402, 0404, 0405, 0408, 0409 and 0410 are aligned in functional groups which coincide with the serological subtype of DR4.1. DRB1*04 alleles 0403, 0406, 0407 and 0411 coincide with subtype DR4.2. Amino acid substitutions at positions 57, 71 and 86 indicate other significant variations between alleles within the serological subgroup of DR4.1 and define five minor subgroups. The serologic and oligonucleotide allelic subgroups are in turn correlated with recognized cellular Dw antigens. While sequence data provide evidence of structural differences, data on cellular antigens support a functional association between these designated groups and their significance in transplantation and GVHD. Testing results are categorized by ethnic group in order to establish frequency data for donor selection criteria.

Amino Acid Sequence↗
PubMed1996

The effect of retail store managers on aboriginal diet in remote communities.

Key nutrient densities of the diet of two remote northern coastal Aboriginal communities were measured using the store-turnover method during the periods that three store managers were responsible for each store respectively. Individual store managers were a greater determinant of nutrient density than the community itself. Furthermore, nutrient densities tended to be highest in both communities when their stores were administered by one particular store manager. The results support the notion that store managers wield considerable power over the food supply of remote Aboriginal communities, and raise questions concerning the ability of Aboriginal community members to influence their own food supplies in retail stores. However, the study also confirms that store managers can be important allies in efforts to improve Aboriginal dietary intake.

Analysis of Variance↗
PubMed1996

In vitro activities of azithromycin, clarithromycin, and other antibiotics against Chlamydia pneumoniae.

The in vitro susceptibilities of Chlamydia pneumoniae isolates to macrolide, tetracycline, and quinolone antibiotics were determined. Tetracycline, clarithromycin, and erythromycin had the lowest MICs in the first cell culture passage. Azithromycin required the lowest concentration for complete inhibition of inclusion formation on the second pass into antibiotic-free medium, likely reflecting its high intracellular concentrations.

4-Quinolones↗
PubMed1996

Atrophic gastric changes in both Helicobacter felis and Helicobacter pylori infected mice are host dependent and separate from antral gastritis.

BACKGROUND/AIMS: The role of host factors has been neglected in studies of the pathogenesis of Helicobacter associated disease. The aim of this study was to assess the response of different mouse strains to infection with a single strain of Helicobacter felis. METHOD: Six strains of inbred mice were infected with the identical H felis culture and were killed at one month, two months, and six months after infection to assess histopathological changes. In addition, two strains of mice were infected with a mouse adapted strain of H pylori and examined at six months after infection. RESULTS: In SJL, C3H/He, DBA/2, and C57BL/6 infected mice, severe to moderate chronic active gastritis was observed only in the body of the stomach, which increased in severity over time with specialised cells in the body glands being replaced. As the severity of this damage in the body increased and atrophic changes were seen, the level of bacterial colonisation of the antrum decreased. In contrast, in BALB/c and CBA mice, there was only mild gastritis in the antrum, no remarkable changes were detected in their body mucosa, and no atrophy was seen over time. In both these strains of mice, heavy bacterial colonisation was seen, which tended to increase over the period of the experiment. Of particular importance in this experiment was that bacterial colonisation was mainly restricted to the antrum yet the atrophy, when present, was only observed in the body of the stomach. H pylori infected C3H/He mice showed moderate colonisation of the antrum, which persisted up to six months with little development of atrophy. In contrast, H pylori in C57BL/6 mice showed excellent colonisation of the antrum at two months but six months after infection there was moderate to severe body atrophy, which was associated with a loss of bacteria from the antrum. CONCLUSIONS: These findings challenge current concepts of the development of Helicobacter induced atrophy in that active chronic gastritis of antrum or the body mucosa, or both, is not a prerequisite. They also suggest an autoimmune basis for the pathology although no autoantibody or antibody to the H+/K+ ATPase was detected. Loss of infecting helicobacters from the stomach together with development of an atrophic gastritis in the body of the stomach is similar to the pattern found in certain H pylori infected human subjects.

Animals↗
PubMed1996

Measuring anaesthetic outcomes.

We have identified some of the most frequently measured anaesthetic outcomes and their independent risk factors, and discussed the limitations and advantages in using various risk adjustment strategies. Many studies suggest that preoperative assessments may contribute to preventing the occurrence of anaesthetic-related morbidity and mortality, and to high levels of patient satisfaction. The use of health status measurements as a preoperative screening tool in assessing anaesthetic risk offers a potential area for future work. Research into measuring anaesthetic outcomes in a reliable and valid manner will be an important tool in improving standards of anaesthetic practice and in delivering quality anaesthesia to our patients.

Anesthesia↗
PubMed1996

A prospective randomized study of inpatient iv. antibiotics for community-acquired pneumonia. The optimal duration of therapy.

STUDY OBJECTIVE: To compare therapeutic outcome and perform a cost-benefit analysis of inpatients with community-acquired pneumonia (CAP) treated with a shortened course of i.v. antibiotic therapy. DESIGN: A prospective, randomized, parallel group study with a follow-up period of 28 days. SETTING: Bronx Veterans Affairs Medical Center (VAMC) and the Castle Point VAMC; university-affiliated VAMC general medical wards from September 1993 to March 1995. PATIENTS: Seventy-two male veterans and 1 female veteran with 75 episodes of CAP defined by a new infiltrate on chest radiograph and either history or physical findings consistent with pneumonia. Study population was 42%(31) black, 33%(24) white, and 25%(18) Hispanic. INTERVENTIONS: Patients were randomized (1:1:1) to 1 of 3 treatment groups: group 1 received 2 days of i.v. and 8 days of oral therapy; group 2 received 5 days of i.v. and 5 days of oral therapy; and group 3 received 10 days of i.v. therapy. Antibiotics consisted of cefuroxime, 750 mg every 8 h for the i.v. course, and cefuroxime axetil, 500 mg every 12 h for the oral therapy. MEASUREMENTS AND RESULTS: No differences were found in the clinical course, cure rates, or resolution of chest radiograph abnormalities among the three groups. A significant difference was found in the length of stay (LOS) among the three groups. The mean +/- SD LOS was 6 +/- 3 days in group 1, 8 +/- 2 days in group 2, and 11 +/- 1 days in group 3. The shortened LOS could potentially save $95.5 million for the Department of Veterans Affairs and $2.9 billion for the US private sector. CONCLUSIONS: Adult patients hospitalized for CAP who are not severely ill can be successfully treated with an abbreviated (2-day) course of i.v. antibiotics and then switched to oral therapy. A longer course of i.v. therapy prolongs hospital stay and cost, without improving the therapeutic cure rate.

Adult↗
PubMed1996

Dose-related gastrointestinal response to the ingestion of either isomalt, lactitol or maltitol in milk chocolate.

OBJECTIVES: To determine whether there were differences between different polyols (sugar alcohols) in terms of their ability to stimulate intolerance symptoms when consumed in milk chocolate. Also to discover whether symptomatology can be related to the dose of polyol ingested. DESIGN: The study was of a randomised double-blind cross-over design. SUBJECTS: 59 healthy volunteers aged 18-24 years were recruited from the student population of the University of Salford. All subjects successfully completed the trial. INTERVENTIONS: Subjects ingested 100 g milk chocolate containing 40 g bulk sweetner as either sucrose, isomalt, lactitol or maltitol or a mixture (10:30 w/w) of sucrose and isomalt, sucrose and lactitol or sucrose and maltitol. Each bar was taken as breakfast on one day with following products consumed at 1-week intervals. Subjects reported the incidence and severity of the symptoms of flatulence, borborygms, colic, motion frequency and loose stools. RESULTS: The ingestion of 30 g or 40 g lactitol resulted in a significant increase in the incidence and severity of all symptoms examined compared to reactions after the consumption of standard sucrose-containing chocolate (P <0.01). Similarly, 40 g isomalt led to an increased incidence of all symptoms, including mild laxation (P <0.01), but unlike lactitol none was rated as being severe. A reduction in isomalt to 30 g was marked by increased tolerance with evidence of only mild borborygms (P <0.01), mild flatulence, colic, and laxation (P <0.05), with no increase in motion frequency (P <0.35). Ingestion of 40 g maltitol caused less intolerance than 40 g isomalt, with evidence of only flatulence, borborygms and colic (P <0.01), symptoms being rated as only mild. A reduction to 30 g led to a decrease in all symptoms except mild flatulence. Maltitol did not have any laxative effect when ingested at either 30 g (P = 0.32) or 40 g (P = 0.13) per day. CONCLUSIONS: This work has shown that there are significant differences in the reporting of gastrointestinal symptomatology following the consumption of isomalt, lactitol and maltitol incorporated into milk chocolate. However, with all three polyols the incidence and severity of symptomatology was dose dependent.

Adolescent↗
PubMed1996

Disparities in access to family planning services in Jamaica.

In order to improve the effectiveness and subtainability of the family planning programme, the National Family Planning Board has devised a strategy to shift users to longer-acting methods and increase the role of the private sector. To design interventions, a better understanding of existing services was thought to be necessary. This study examines the distribution of family planning service delivery points in Jamaica and the services offered by the public and private sectors through an examination of records and questionnaire interviews. The study found that, because of the concentration of private sector providers-the main outlets for longer-acting methods-in urban areas, rural areas had poor access to these methods. Because rural areas are not attractive to private sector providers, the public sector should recognize the need to continue to serve these areas.

Delivery of Health Care↗
PubMed1996

Is there a place for radionuclide bone scintigraphy in the management of radiograph-negative scaphoid trauma?

OBJECTIVE: To evaluate the role of radionuclide bone scanning in patients with suspected scaphoid trauma, particularly in those with negative radiographs. DESIGN: Prospective. Radionuclide scans and carpal bone radiography were performed on all participants in the early post-injury period. SETTING: Cape Town tertiary centre trauma unit. PARTICIPANTS: Fifty patients who presented with clinical features suggestive of scaphoid trauma. MAIN OUTCOME MEASURE: Definitive radiographic diagnosis of fracture or persistent clinical features of scaphoid trauma. RESULTS: All patients who had fractures demonstrated on standard radiography either at the initial visit (13 patients) or at 2 weeks (8 patients) had positive scintiscans (sensitivity 100%). Four of 6 patients who had a positive scan but negative first and second radiographs had persistent tenderness on clinical examination which required extended immobilisation in a plaster cast. The overall positive predictive value of scintigraphy was 93%. All patients with a negative scan were clinically and radiologically negative at 2 weeks (negative predictive value 100%). Evidence of multifocal injury was present in 12 scans, but only 1 radiograph. Thirty-one patients (62%) were scanned within 48 hours of injury. CONCLUSION: Bone scintigraphy can be used in radiograph-negative scaphoid area injury to exclude the need for further follow-up reliably, but those with positive scans still require clinical examination and radiography at 2 weeks.

Carpal Bones↗
PubMed1996

Prevention of Helicobacter pylori infection.

The only successful strategy for large-scale eradication of an infectious disease from whole populations has been through immunization. In societies fortunate enough to have a healthcare infrastructure that allows mass vaccination, diseases such as poliomyelitis, whooping cough and diphtheria have been virtually eliminated. But what about infection with Helicobacter pylori, which has now been proved to be a major worldwide pathogen? Infection by H. pylori is lifelong, despite a vigorous immune response. How, then, could immunization be feasible? Recent investigations using a mouse model of H. pylori infection have shown that protective immunity can indeed be induced with an oral vaccine. Furthermore, protection was lifelong in the animal model. Also, more importantly, the vaccine actually cured existing infection, raising the exciting possibility of therapeutic immunization. Stimulated by the medical need, the race is now on to produce the first vaccine. However, many critical questions remain to be answered before the first patients are immunized with the complete vaccine. For example, what is the best antigen to target? Urease is currently the favourite antigen, but others will be tested. What about the adjuvant? LT, the heat labile enterotoxin of diarrhoeaogenic strains of Escherichia coli, is the most likely candidate, but we need to examine alternatives. Is there any risk of immunopotentiation? The answer is probably no, but this has to be proved. A vaccine against H. pylori will be developed, and infection with H. pylori will be prevented--the question remains 'how long will it take'?

Animals↗
PubMed1996

The nature of Helicobacter pylori.

Helicobacter pylori is an important pathogen in humans, causing chronic gastritis and playing a major role in the development of peptic ulcers and gastric cancer. The organism is highly adapted to the human stomach, largely due to its motility and ability to produce large amounts of urease. It binds specifically to the gastric mucosa via adhesion pedestals; colonization of the duodenum only occurs in the presence of gastric metaplasia. Infection with H. pylori leads to gastritis, but the majority of infected patients are asymptomatic, and it is thought that the ability of H. pylori to cause more severe disease may be related to the presence of the cagA gene. With improvements in public health and living conditions, the prevalence of H. pylori infection in developed countries is decreasing, and this is associated with a decline in the incidence of peptic ulcer and gastric cancer.

Gastritis↗
PubMed1996

Waiting for speech therapy: a group to help the under-3s.

It can take up to two years for a child with speech problems to be seen by a speech therapist. The waiting period can be stressful for parents and frustrating for the child, who may begin to show behaviour problems. Group sessions for up to 10 children with speech problems aged 2-3 years and their parents produced positive benefits during the waiting period. The groups were set up and managed by a health visitor with input from a speech and language therapist and outside speakers. The parents learnt how children's communication skills develop and were shown simple techniques for helping their child's speech. They were also helped to understand and manage behaviour problems such as tantrums which may be linked to the child's speech difficulties. The majority of parents confirmed that their children's speech had improved since joining the group. Parents gained mutual support from attending the groups and their children benefited from socialising with the other children. This was a low-cost, flexible scheme set up in response to local needs and demand, showing the benefits of teamwork and of involving parents in their children's treatment and care.

Child, Preschool↗
PubMed1996

Vaccination against Helicobacter pylori.

The initial steps have been taken towards the development of a vaccine against the human gastroduodenal pathogen, Helicobacter pylori. Proof of principle was achieved when mice were protected against challenge with living Helicobacter felis, a close relative of the human pathogen, following oral immunization with H. felis sonicate and the mucosal adjuvant, cholera toxin. Similar results with H. pylori antigen have allowed development of possible human vaccines. Recombinant urease protein has been proposed as a major vaccine candidate, together with the heat-labile toxin of Escherichia coli as the adjuvant. Probably the most significant finding in the early vaccine studies was that immunization of already infected mice resulted in a cure of Helicobacter infection. The possibility of a therapeutic vaccine makes commercial development more attractive, as large populations could be immunized without the potential for development of drug-resistant strains that currently restricts widespread antibiotic use. For advanced societies with powerful economies yet a high prevalence of H. pylori, such as Japan, vaccine development should become a high national health priority.

Animals↗
PubMed1996

[Liver neoplasms in patients with glycogen storage disease. Diagnostic and therapeutic problems].

In a family composed by eight brothers, five had a type I glycogen storage disease and three presented with liver tumors complicated with hemorrhage or malignant transformation, during the follow up. The periodic ultrasonographic control allowed the early diagnosis of these neoplasms. We describe the clinical picture and treatment of two patients. Metabolic alterations were corrected during the preoperative period with parenteral nutrition. Resection was successful in both cases. It is concluded that a close follow up and early treatment of these lesions is effective and avoids complications. In patients with multiple lesions and severe metabolic alterations, liver transplantation is the treatment of choice.

Adult↗