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Biomedical subjects

N Johnson

Publications and source records attributed to N Johnson.

At least 163 records · Page 9Linked to original sources
PubMed1995

Using a vaginal tube to separate the uterus from the vagina during laparoscopic hysterectomy.

Hysterectomy performed totally by laparoscopy has few advocates because separating the cervix from the vagina is difficult. This technical difficulty can be overcome by placing a wide-bore plastic tube in the vagina to expose the cervico-vaginal junction and stretch the vaginal fornices. The stretched vagina falls away from the cervix as diathermy cuts over the tube rim. The tube guides the incision, and the plastic protects any adjacent structures. The most convenient external diameter is between 4-5 cm. Made from smooth, electrically-inert plastic, the tube's opposite distal end has a valve that maintains the pneumoperitoneum. We have used it in 73 cases, and the only associated complication has been one vault pelvic hematoma.

Female↗
PubMed1995

[Segmental myocarditis in Churg-Strauss syndrome. Review of the literature apropos of a case].

We describe a 25-year old man in whom segmental myocarditis and pericarditis was diagnosed using two-dimensional echocardiography. Churg-Strauss syndrome was suspected in the presence of asthma and evidence of hypereosinophilia. Early therapy with oral prednisone led to resolution of pericarditis but septal hypokinesia was still present after 4 years. The pathophysiology of segmental myocarditis in the Churg Strauss syndrome is discussed.

Adult↗
PubMed1995

Immunogenicity of the recombinant serine rich Entamoeba histolytica protein (SREHP) amebiasis vaccine in the African green monkey.

We report the first study in non-human primates of the safety and immunogenicity of a recombinant vaccine designed to prevent amebic liver abscess. In a pilot study, a recombinant vaccine containing the serine rich Entamoeba histolytica protein (SREHP) attached to a maltose binding protein (SREHP/MBP), which has been shown to be effective in preventing amebic liver abscess in rodent models of infection, was used to immunize two African Green Monkeys. Vaccination with SREHP/MBP resulted in no systemic side-effects. The monkeys receiving the SREHP/MBP protein developed antibodies that recognized the recombinant SREHP/MBP molecule, the native SREHP protein, and the surface of amebic trophozoites. Antiserum from SREHP/MBP-vaccinated monkeys could block the adhesion of E. histolytica trophozoites to mammalian cells, a feature that may correlate with vaccine efficacy. Attempts to produce amebic liver abscess in naive African Green Monkeys by direct hepatic inoculation with virulent E. histolytica trophozoites was not successful, suggesting this species is probably not suitable for vaccine efficacy studies.

Animals↗
PubMed1995

The prevalence of a family history of cancer in general practice.

The presence of a family history of cancer of the colorectum, breast, uterus and ovary is associated with an increased risk for that type of cancer. The aim of this study was to assess the prevalence of a family history of these cancers in the community. Nurses asked all attenders at health checks aged 35-64 about the presence of a history in close relatives of cancer diagnosed under the age of 70. Information was obtained from 8109 patients. Of the sample, 3.1% had a family history of colorectal cancer; 4.8% of women had a family history of breast cancer, whilst 1.9% had a family history of uterine or ovarian cancer. Projecting the results to a population of 2000 demonstrated that a general practitioner with a list size of 2000 could expect to have 30-40 patients in whom an appropriate management strategy would need to be considered.

Adult↗
PubMed1995

Cost effectiveness of 5-hydroxytryptamine3 receptor antagonists: a retrospective comparison of ondansetron and granisetron.

As clinical and economic analyses to date have shown clear benefits of using the new 5-hydroxytryptamine3 receptor antagonists (5-HT3RAs) over traditional antiemetics, the choice between them may necessitate the assessment of comparative cost-effectiveness. This paper presents the results of an assessment of the relative cost-effectiveness of two current 5-HT3RAs: ondansetron and granisetron. The analysis was based on a retrospective assessment of the cost and effectiveness (defined as no vomiting and no worse than mild nausea) of these new antiemetics. Efficacy data were based on the results of two recently published directly comparative clinical studies of ondansetron versus granisetron in the treatment of chemotherapy-induced emesis following both single-dose and fractionated chemotherapy. The cost of treatment was derived by combining clinical data from these studies with manufacturers' drug prices, and published costs of drug administration and emetic episodes. Costs for inpatient stay and side-effects were assumed to be equal across both treatment alternatives. The results were expressed in terms of the total cost per patient of emetic treatment and the cost per well-controlled patient. On this basis, granisetron was found to be more than 50% more cost-effective than ondansetron. This result was robust to variation in key assumptions concerning efficacy and cost, although ondansetron would become the more cost-effective if the dose was reduced to one 8 mg i.v., with no concomitant loss of efficacy.

Antineoplastic Agents↗
PubMed1995

Gemcitabine: clinical and economic impact in inoperable non-small cell lung cancer.

This study assesses retrospectively the clinical and economic impact of gemcitabine monotherapy on the management of inoperable stage III/IV non-small cell lung cancer in Germany. Based on current methods of clinical practice and using the best outcome data available, the costs and benefits of gemcitabine were compared to a dual therapy (ifosfamide/etoposide). While the two treatments showed broadly equivalent efficacy in terms of tumour response rate and survival, a cost analysis showed the potential for savings with gemcitabine. These largely related to hospital hotelling costs, due to the fact that gemcitabine may be given as an out-patient therapy. Further savings were found in investigative procedures and the management of treatment toxicity. Excluding the cost of the chemotherapy, gemcitabine was associated with potential savings of DM3,026 over two cycles of therapy, which included a 40% decrease in hospitalization costs and a 54% decrease in the cost of managing adverse events. We conclude that gemcitabine monotherapy could offer considerable cost savings while offering the potential for improved quality of palliative treatment compared to existing in-patient treatments, and it may have a place in shifting care from an in-patient to an out-patient setting in line with recent health care reforms.

Antimetabolites, Antineoplastic↗
PubMed1995

IL-8/IL-8 receptor expression in psoriasis and the response to systemic tacrolimus (FK506) therapy.

Recently, the keratinocyte IL-8/IL-8 receptor (IL-8R) pathway has been implicated in the pathogenesis of psoriasis, and there is evidence that the potent macrolide immune suppressant tacrolimus (formerly FK506) can inhibit this pathway in vitro. In this study, determination of the expression of cytokine mRNAs in lesional skin of patients with active disease by reverse transcriptase polymerase chain reaction revealed transcripts for IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-6, IL-8, IL-8R, IL-10, interferon-gamma (IFN-gamma), IL-2R and transforming growth factor-beta (TGF-beta), but not IL-2 or IL-4. IL-8 was the only cytokine expressed in affected skin of all patients but not in clinically normal skin of healthy subjects. In seven CD4+ T cell clones propagated from the lesional skin of an untreated psoriasis patient, IL-8 was expressed by the skin-derived T lymphocytes and not by feeder cells (irradiated autologous blood lymphocytes); IL-1 beta, IL-2, IL-6 and IL-10 were also expressed by some or all of the T cell clones. IL-8 mRNA was not detected in the skin of any patient after the start of systemic tacrolimus therapy; IL-1 beta, IL-6 and IFN-gamma transcripts were also reduced. By 12 weeks, the mean psoriasis area and severity index (PASI) had decreased from 18.8 to 3.8, a reduction of 80%. In the same post-treatment biopsies, however, message for IL-8R persisted. Estimation of circulating IL-8 levels by enzyme immunoassay showed that all patients with detectable IL-8 before treatment had decreased levels in response to treatment with tacrolimus; reductions in PASI scores were accompanied by decreases in IL-8 levels, that varied both in rate and extent. Partial relapse, which in a minority of patients followed the initial period of remission, and was precipitated by drug dose reduction, was accompanied by an increase in circulating IL-8. These findings add credence to the view that the IL-8/IL-8R autocrine/paracrine pathway may be important in the pathogenesis of psoriasis. They further suggest that interference with IL-8 production and/or that of other key chemokines may be an important mechanism underlying the therapeutic efficacy of tacrolimus, and other agents such as cyclosporin A, with similar molecular actions.

Adolescent↗
PubMed1995

The effect of uterine contractions on fetal oxygen saturation.

OBJECTIVE: To find out what happens to fetal arteriolar oxygen saturation during a uterine contraction. DESIGN: Prospective observational study. SETTING: Labour ward, St James's University Hospital, Leeds. SUBJECTS: Eighteen women in normal labour monitored with a fetal scalp surface pulse oximetry sensor, an intrauterine pressure catheter, and a head to cervix force transducer. METHODS: The effect of intrauterine pressure and head to cervix force on fetal arteriolar oxygen saturation was examined using time series analysis and a regression model of 159 contractions. OUTCOME MEASURE: Fetal oxygen saturation during a contraction. RESULTS: The average oxygen saturation drops after a contraction. The greatest drop in oxygen saturation is reached 92 s after the peak of a contraction and takes approximately 1 min 30 s to recover (P = 0.036). CONCLUSION: Uterine contractions during normal labour affect fetal oxygen saturation.

Female↗
PubMed1995

Variation in caesarean and instrumental delivery rates in New Zealand hospitals.

A study of Caesarean section and instrumental delivery rates in the maternity hospitals in New Zealand delivering over 1,000 women per year was undertaken. The results at Middlemore Hospital were compared with those seen elsewhere. The Caesarean section rate at Middlemore Hospital in 1993 was significantly lower than the other large maternity hospitals in New Zealand. The Caesarean section rate at Middlemore from 1988 to 1993 has shown a significant downward trend which is different from the trends at other hospitals. The spontaneous vaginal delivery rates at Middlemore Hospital were higher than at other New Zealand hospitals between 1988 and 1993. We conclude that Middlemore Hospital has been successful in maintaining low interventional delivery rates by New Zealand and international standards--the Caesarean section rate remains below 10% and the spontaneous vaginal delivery rate approaches 85%. This is likely to be a consequence of a number of factors operating together but there is evidence to suggest that obstetric management policies at Middlemore do play a role in this.

Cesarean Section↗
PubMed1995

Team management of atrophic edentulism with autogenous inlay, veneer, and split grafts and endosseous implants: case reports.

Predictable success of autogenous graft and implant reconstructions is critically dependent on preoperative alignment and prosthetic considerations planned by the surgeon and the restorative dentist in a team approach. In such cases the surgeon has an opportunity to place accurate bone grafts that allow implants to be secured in both the correct position and correct axis for good prosthetic restoration. With careful thought, the restorative dentist and surgeon can plan the location, shape, and volume of an implant-graft reconstruction. Nine requirements for successful onlay grating with implants and five case reports illustrating the team approach are presented.

Accidents, Traffic↗
PubMed1995

Comparing fetal pulse oximetry with scalp pH.

OBJECTIVE: To determine whether pulse oximetry has the potential to replace scalp blood pH sampling in infants with abnormal cardiotocographs. STUDY DESIGN: The average scalp oximetry reading in labor recorded with an experimental N400 system was compared with fetal scalp blood pH. RESULTS: The average oximetry readings were unrelated to the pH of aerobically sampled fetal scalp blood. There was no subgroup of acidemic infants with a low oximetry reading. CONCLUSION: Pulse oximetry readings with present technology do not reflect scalp pH. The equipment is improving, but at this time pulse oximetry is not a simple alternative for scalp capillary blood sampling.

Blood Gas Analysis↗
PubMed1994

N-acetylgalactosamine glycosylation of MUC1 tandem repeat peptides by pancreatic tumor cell extracts.

Synthetic peptides corresponding to the human mucin MUC1 tandem repeat domain (20 residues) were glycosylated in vitro by using UDP-N-[3H]acetyl-D-galactosamine (GalNAc) and lysates of pancreatic tumor cell lines. Results obtained with peptides of different lengths (from one to five repeats) suggest that increasing the number of tandem repeats has neither a positive nor a negative effect on the density of glycosylation along the MUC1 tandem repeat protein backbone. Purified glycopeptides were sequenced on a gas-phase sequencer, and glycosylated positions were determined by measuring the incorporated radioactivity in fractions collected following each round of Edman degradation. The results showed that two of three threonine residues on the MUC1 tandem repeat peptides were glycosylated by pancreatic tumor cell lysates at the following positons: GVTSAPDTRPAPGSTAPPAH (underlined T indicates position of GalNAc attachment). None of the serine residues were glycosylated. Determination of the mass of the glycopeptides by mass spectrometry confirmed that a maximum of two molecules of GalNAc were covalently linked to each 20-residue repeat unit in the peptides. The data presented here show that acceptor substrate specificity of the UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase detected in lysates of pancreatic and breast tumor cell lines is identical and is limited to some but not all threonines in the MUC1 tandem repeat peptide sequence. The influence of primary amino acid sequence on acceptor substrate activity was evaluated by using several peptides that contain single or double amino acid substitutions (relative to the native human MUC1 sequence). These included substitutions in the residues that were glycosylated and substitutions of the surrounding primary amino acid sequence. The results of these studies suggest that primary amino acid sequence, length, and relative position of the residue to be glycosylated dramatically affect the ability of peptides to serve as acceptor substrates for the UDP-GalNAc:polypeptide N-acetylgalatosaminyltransferase.

Acetylgalactosamine↗
PubMed1994

Who finds cervical laser therapy painful?

To identify women who find outpatient laser cervical surgery painful we designed a prospective observational study correlating surgical pain with multiple variables. The pain scoring systems were validated by comparing the subjective linear analogue score with an objective scoring method. The pain of surgery was compared with age, parity, acute anxiety scores, psychological state, premenstrual syndrome scores, phase of the menstrual cycle, contraceptive use, menstrual history, nature of the lesion, and intraoperative bleeding. Anxious women with no children suffered most. Nulliparity, acute preoperative anxiety, and a history of dysmenorrhea independently predict high pain scores. Young women and those using the combined oral contraceptive pill also find laser surgery more painful but this is because they are less likely to have delivered children and more likely to suffer from dysmenorrhea. Psychological state, premenstrual syndrome score, phase of the menstrual cycle, type of surgery, and perioperative bleeding have no predictive value. We suggest that nulliparous women and dysmenorrhea sufferers who are anxious about outpatient surgery but ambivalent about hospital admission should be offered cervical surgery under general anesthesia. Parous women who do not suffer from dysmenorrhea can be reassured that outpatient laser treatment should be tolerable.

Adult↗