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Biomedical subjects

A Lee

Publications and source records attributed to A Lee.

At least 505 records · Page 28Linked to original sources
PubMed1994

A comparison of Plasmalyte 148 and 0.9% saline for intra-operative fluid replacement.

Thirty patients undergoing major hepatobiliary or pancreatic surgery were randomly allocated to receive either 0.9% saline or Plasmalyte 148 (a balanced salt solution), at 15 ml.kg-1.h-1. Arterial blood gas analysis was performed before and after surgery. Plasma biochemistry (Na+, K+, Cl-, lactate) measurements were made before and after surgery and at 24 h after surgery. The patients receiving 0.9% saline had significantly increased chloride concentrations (p < 0.01), decreased standard bicarbonate concentrations (p < 0.01) and increased base deficit (p < 0.01) compared to those receiving Plasmalyte 148. There were no significant changes in plasma sodium or potassium or blood lactate concentrations in either group. The exclusive use of 0.9% saline intra-operatively can produce a temporary hyperchloraemic acidosis which could be given false pathological significance. In addition it may exacerbate an acidosis resulting from an actual pathological state. The use of a balanced salt solution such as Plasmalyte 148 may avoid these complications.

Acetates↗
PubMed1994

The iodide perchlorate discharge test in women with previous post-partum thyroiditis: relationship to sonographic appearance and thyroid function.

BACKGROUND: Post-partum thyroid disease occurs in 50% of anti-thyroid peroxidase (TPO) antibody positive women (detected at 16 weeks' gestation) and is characterized by a transient episode of hyper, hypo or hyper-hypothyroidism. In approximately 20% of these women the hypothyroidism is permanent. However, the extent of long-term thyroid dysfunction, possibly mediated by immune attack, in those anti-TPO Ab + ve women who have had only transient or no thyroid dysfunction during the postpartum period is not clear. OBJECTIVE: We have therefore studied the frequency of iodide organification defects by iodide perchlorate discharge testing, and of thyroid morphological abnormalities by ultrasound scanning in euthyroid women following their episode of post-partum thyroiditis (PPT). DESIGN: The study group comprised 17 women with previous PPT (PPT + ve) and 12 women who had positive anti-TPO antibodies during pregnancy but who did not develop PPT (PPT - ve). Women were studied 15-47 months following their episode of PPT. RESULTS: Iodide perchlorate discharge tests were positive (more than 10% discharge) in 7 (41%) PPT + ve and 5 (42%) PPT-ve subjects (P = NS). Morphological abnormalities on thyroid ultrasound were detected in 7 of 14 (50%) PPT + ve and 7 of 9 (77%) PPT - ve subjects (P = NS). There was a strong association between abnormalities of iodide organification and morphology: of 11 subjects with positive iodide perchlorate discharge tests, 10 had abnormal (positive) ultrasound scans; of 12 subjects with negative iodide perchlorate discharge tests 8 had negative ultrasound scans (P = 0.013, Fisher's exact test). CONCLUSIONS: Long-term subtle defects of thyroid function and morphology are common in women with anti-TPO antibodies in pregnancy, whether or not they develop post-partum thyroiditis. The clinical significance of these findings is unclear but a continuing thyroid pathological process is suggested.

Adult↗
PubMed1994

Persistent elevation of serum oestradiol levels by functional ovarian cysts despite effective pituitary desensitization with GnRH agonists.

OBJECTIVE: This study assessed whether functional ovarian cysts may prevent suppression of serum oestradiol levels even after pituitary desensitization had been achieved with buserelin. PATIENTS: Of 288 in-vitro fertilization (IVF) cycles studied 10 patients were found to have cysts with serum oestradiol levels > 200 pmol/l despite 3 weeks of buserelin. DESIGN AND MEASUREMENTS: The 10 patients with cysts were given 0.1 mg GnRH and serum gonadotrophins were measured at time 0, 30 and 60 minutes subsequently. Immediately following the GnRH stimulation test the cysts were aspirated transvaginally under ultrasound guidance. Serum oestradiol levels were again measured 3 days after cyst aspiration. RESULTS: Basal LH and FSH levels were < 3 U/l and there was no significant rise in response to GnRH. On the day of cyst aspiration serum oestradiol levels varied between 244 and 1127 pmol/l, and in all cases serum oestradiol levels fell to < 200 pmol/l within 3 days of cyst aspiration. CONCLUSION: In the presence of a functional ovarian cyst, failure to suppress the serum oestradiol level does not necessarily imply a failure of pituitary desensitization with a GnRH agonist.

Adult↗
PubMed1994

Molecular analysis of urease genes from a newly identified uncultured species of Helicobacter.

"Gastrospirillum hominis" is an uncultured gastric spiral bacterium that has recently been shown by 16S rDNA sequence analysis to be a newly recognized species of Helicobacter that infects humans, and it has been provisionally designated "Helicobacter heilmannii." We used PCR to directly amplify the urease structural genes of "H. heilmannii" from infected gastric tissue. DNA sequence analysis identified two open reading frames, ureA and ureB, which code for polypeptides with predicted molecular weights of 25,729 and 61,831, respectively. The urease subunit genes from "H. heilmannii" were cloned and expressed in Escherichia coli. Western blot (immunoblot) analysis showed that antiserum directed against the ureA and ureB gene products from H. pylori was cross-reactive with the corresponding polypeptides from "H. heilmannii." Analysis of the derived amino acid sequences of "H. heilmannii" UreA and UreB demonstrated that "H. heilmannii" urease is more highly related to the urease from H. felis (found in the stomachs of cats and dogs) than to the urease from H. pylori. These data are consistent with 16S rDNA sequence analysis and suggest that "H. heilmannii" is phylogenetically most closely related to H. felis.

Amino Acid Sequence↗
PubMed1994

Successful immunization against gastric infection with Helicobacter species: use of a cholera toxin B-subunit-whole-cell vaccine.

In previous studies we found that immunizing mice with a sonicate of Helicobacter felis and adjuvant cholera toxin (CT; 10 micrograms) protected the animals against challenge with viable H. felis. The aim of this study was to determine whether a low dose of CT or its nontoxic B subunit (CTB) was effective as an adjuvant in Helicobacter oral vaccines. Significant protection against viable H. felis challenge was achieved in the animals immunized with H. felis antigen plus the combination of 0.5 microgram of CT and 10 micrograms of CTB (96%), with H. felis antigen plus 0.5 microgram of CT (95%), and with H. felis antigen plus 10 micrograms of CTB (83%). No protective effect was found in the mice immunized with either H. felis antigen alone or adjuvant CTB and CT alone. Twenty-six percent of mice immunized with Helicobacter pylori antigen plus CT (10 micrograms) were protected against H. felis challenge, confirming the value of the model in predicting effects of immunization in humans. The observation that immunity can be induced with a nontoxic adjuvant CTB opens the way for human studies with H. pylori vaccines and is a further step along the road to effective strategies of prevention of gastroduodenal diseases of major world significance.

Animals↗
PubMed1994

Animal and public health implications of gastric colonization of cats by Helicobacter-like organisms.

The bacterial genus Helicobacter contains a number of species which colonize the gastric mucosa of mammals. Natural and/or experimental gastric pathology has been correlated with colonization in humans and a wide variety of animal species. Historical reports in the literature suggest that a high percentage of cats are colonized by large, spiral, gastric helicobacter-like organisms (GHLOs). One of these bacteria (Helicobacter felis) has been isolated on artificial media and has experimentally caused gastritis in gnotobiotic dogs. This study surveyed the prevalence of helicobacter colonization in random-source cats by using the urease assay. Histologic examination was performed to determine the degree of associated pathology present. GHLOs associated with chronic gastritis were present in 70% of the juvenile and 97% of the adult cats studied. Although further study is needed to determine specifically what role GHLOs play in feline gastrointestinal disease, these results indicate that helicobacter colonization should be considered in the pathogenesis of feline gastroenteropathy. Furthermore, the high prevalence of feline infection is interesting because cats have recently been implicated as a potential reservoir for human infection by helicobacter-like organisms.

Animals↗
PubMed1994

In situ hybridisation for the identification of Helicobacter pylori in paraffin wax embedded tissue.

A method for identifying Helicobacter pylori using a non-isotopic in situ hybridisation technique is described. A probe generated by polymerase chain reaction (PCR) with primers directed against parts of the Helicobacter pylori 16SrRNA sequence was used. Paraffin wax embedded gastric biopsy specimens from patients with and without gastritis were hybridised with the probe, and the method was shown to be sensitive and specific for H pylori.

Base Sequence↗
PubMed1994

Management of severe spasticity with intrathecal baclofen delivered by a manually operated pump.

Intrathecal baclofen abolishes spasticity in many patients with neurological diseases but there are few studies on its long-term effectiveness. Since 1986 a manually operated subcutaneous pump has been used to deliver baclofen intrathecally in 21 patients with a follow up of at least one year. Most patients had multiple sclerosis and all were wheelchair-bound. Sixteen patients had a complete and sustained benefit. In four other patients the treatment was effective in the short term but not in the long term. In the remaining patient the pump never worked. Complications included meningitis, pump failure, erosion through the skin, and baclofen overdose. Nevertheless, only three patients have asked to discontinue the treatment. We conclude that intrathecal baclofen, delivered by a manually operated implanted pump, is an effective treatment for severe spasticity in most patients.

Adult↗
PubMed1994

Red cells, HLA and platelet antibody formation in patients with multiple transfusions.

Totally 436 Chinese patients having received multiple transfusions of red cells and platelets on more than three occasions were screened for red cell antibodies. Twenty-six (6%) of them were positive. Anti-E, -Mia, and -c were the common alloantibodies. Nine patients were immunized during the period of regular transfusions, with a newly immunized rate of 2% (9/436). Among 436 patients, 387 were screened for HLA antibodies by lymphocytotoxicity test (LCT). The overall positive rate was 35%. Most of the antibodies identified were against the high-frequency HLA antigens in the Chinese population. About 10% of the LCT-positive cases reverted to negative state during the follow-up period. After chloroquine stripping of the target platelets, mixed passive hemagglutination assay was used to detect platelet antibodies other than HLA antibody. Fifty-eight of 161 cases (36%) were positive for platelet antibodies, but half of them disappeared within 1 month. Nineteen of the 58 patients had sepsis and 2 had jaundice. These findings suggested that HLA and platelet antibodies are common among Chinese, though their clinical significance and the role in platelet damage are doubtful.

Antibody Specificity↗
PubMed1994

Cognitive functioning in a mildly to moderately depressed geriatric sample: relationship to chronological age.

The neuropsychological performance of three age cohorts of depressed patients (46-59, 60-69, and 70-85) was compared with the performance of age-matched control subjects to determine whether advancing age potentiates the effect of depression on cognition. Depression and increasing age did not interact to produce more pronounced cognitive deterioration in our unmedicated, medically healthy, well-educated outpatients diagnosed with mild to moderate major depression. Test findings suggest that presence of mild to moderate depression may result in premature "aging" of specific cognitive abilities (such as nonverbal memory, word generation, and categorization), but once the seventh decade is reached, cognition in depressed and nondepressed individuals appears to be comparable.

Age Factors↗
PubMed1994

Referral of surgical patients to an anaesthetic clinic: a decision-making analysis.

Effective utilization of an anaesthetic clinic depends on appropriate referral of high-risk surgical patients. The decision-making behaviour of anaesthetists and nurses was examined to identify factors that influence the referral of patients to an outpatient anaesthetic clinic. Eleven consultant anaesthetists, seven anaesthetic trainees and sixteen nurses working in anaesthetic areas estimated the likelihood that they would refer patients for each of the 30 scenarios presented. The relative importance of each factor influencing the decision to refer as determined by the 34 participants were: type of procedure (22%), co-morbidities (18%), fitness (13%), history of anaesthetic problems (12%), medications (11%), age (10%), obesity (8%) and anxiety (6%). Indicative risk factors identified were aged 65 years or over, unable to climb more than two flights of stairs, presence of significant medical problems, gross obesity, history of anaesthetic problems, taking regular medications, scheduled for major surgery and expressed anxiety about the anaesthetic. There were large variations in the decision-making behaviour among health professional groups.

Adult↗
PubMed1994

Future research in peptic ulcer disease.

For the past 10 years, research into peptic ulcer disease has focused on the surprising suggestion that gastritis and peptic ulcers may be caused by the bacterium Helicobacter pylori. However, the time has now come to reappraise research directions, as a causal link has been established, and even the most ardent sceptics now accept that H. pylori infection is the major factor in most cases of peptic ulcer disease. As with any established microbial disease, we need to understand the epidemiology and mechanisms of pathogenesis, but the major focus should be towards improving therapies and defining the long-term outcome of H. pylori eradication. To devise novel therapeutic agents effectively, we must increase our knowledge of the basic physiology of H. pylori and its ecology in the stomach. This has been a surprisingly neglected area of research and major questions remain. Why does the organism flourish in different areas of the gastric mucosa when gastric pH is increased? Is a change in pH the reason for the potentiating effects of acid-inhibitory agents on anti-H. pylori activity? Will knowledge of the host and bacterial factors that initiate ulcerogenesis allow us to better predict H. pylori-associated ulcers by using non-invasive methods? As H. pylori is a major gastroduodenal pathogen, can we eliminate the infection from selected populations? What are the criteria that will allow therapeutic intervention? The first steps have been taken in the development of an effective vaccine, but who should be immunized?(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Are there ulcerogenic strains of Helicobacter pylori?

AIM: To outline the evidence for and against ulcerogenic strains of Helicobacter pylori. CONTROVERSY: Although H. pylori is now well established as a predisposing factor in peptic ulcer disease the question of why only a minority of people infected with H. pylori develop peptic ulceration remains unanswered and is the subject of much controversy. COMMON VIEW: Perhaps the most accepted view to date is the belief that there are ulcerogenic strains of H. pylori which produce a specific cytotoxin responsible for the ulceration. CONCLUSION: At the present time the case for ulcerogenic strains is not proven and the differences between H. pylori infected peptic ulcer patients and H. pylori infected non-ulcer subjects may relate simply to host factors.

Bacterial Toxins↗
PubMed1994

The use of a mouse model in the study of Helicobacter sp.-associated gastric cancer.

HYPOTHESIS: Long-term infection with Helicobacter pylori and the associated gastritis is now thought to cause a predisposition to gastric cancer through cellular changes resulting from inflammatory damage or because of direct effects of the bacterium. MICE AS MODELS FOR H. PYLORI-ASSOCIATED GASTRIC CANCER: Long-term infection of conventional Swiss mice with either H. felis or H. heilmannii results in atrophic gastritis. Infection of specific pathogen-free Balb/c mice results in the development of lesions similar to H. pylori-associated low-grade B-cell gastric lymphomas. CONCLUSION: H. pylori-infected mice appear to be excellent models for the study of tumours induced by this bacterium.

Animals↗
PubMed1994

Detection of BCR-ABL fusion genes in adult acute lymphoblastic leukemia by the polymerase chain reaction.

The sensitivity and clinical utility of the polymerase chain reaction (PCR) assay for the detection of BCR-ABL gene rearrangement was compared to conventional cytogenetics for the Philadelphia chromosome (Ph1) in adult acute lymphoblastic leukemia (ALL) patients entered onto a single clinical trial. Ninety-three patients had evaluable PCR assays for both the p190bcr-abl and p210bcr-abl type of BCR-ABL gene rearrangements. Twenty-one of 93 patients (23%) were positive for the BCR-ABL rearrangement by the PCR assay. Fourteen of these patients had the p210brc-abl BCR-ABL rearrangement characteristically seen in CML patients, while seven had the p190bcr-abl rearrangement seen in ALL alone. Of 61 patients analyzed, both with conventional cytogenetics and PCR, eight (13%) were positive for the Ph1, while 14 (23%) were positive for the BCR-ABL rearrangement by the PCR assay. Discordance between the PCR assay and cytogenetics occurred in eight cases where the PCR assay was positive and the cytogenetics negative, and two cases where the PCR assay was negative and cytogenetics positive. PCR positivity did not correlate with treatment response, survival, or relapse-free survival, but there was a higher percentage of L2 FAB morphology in the PCR+ cases compared to the PCR-cases (67 vs. 28%, p = 0.003). In addition, the data suggested that patients with a p190bcr-abl rearrangement have a better response to induction therapy, but a worse relapse-free survival compared to patients with a p210bcr-abl breakpoint, but these differences were not statistically significant. These data suggest that PCR and conventional cytogenetics may provide complementary information, since there appear to be a subset of patients who are Ph1-negative yet BCR-ABL positive by PCR. Further studies will be required to determine the prognostic significance of the detailed information about BCR-ABL breakpoints that is available from the PCR assay.

Adolescent↗
PubMed1994

The effect of user fees on the utilization of family planning services. A clinical study.

A new fee structure was introduced to the Advanced Training and Research in Fertility Management Unit in 1992. The study looked at the effect of the new fees on attendance and the choice of contraceptive methods through an examination of clinical records and a questionnaire survey. There was a decline in attendance of roughly 28 per cent between 1992 and 1993. The decline affected mainly new clients and those who accepted injectables. A reduction in the price of injectables is suggested since the fee for this short-term method is more in line with those charged for long-term and permanent methods.

Family Planning Services↗