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Biomedical subjects

R B Jones

Publications and source records attributed to R B Jones.

At least 109 records · Page 6Linked to original sources
PubMed1998

Eye malformations associated with treatment with carbamazepine during pregnancy.

Four children are presented and their eye malformations described. One girl had bilateral anophthalmos, a boy and a girl had bilateral severe microphthalmos, and a boy had a unilateral optic disc coloboma. The mothers of all for children were treated with carbamazepine during pregnancy. The teratogenic effect of carbamazepine and its likely role in the genesis of the eye malformations is discussed.

Abnormalities, Drug-Induced↗
PubMed1998

Identification of T cells that respond to serovar-specific regions of the Chlamydia trachomatis major outer membrane protein in persons with serovar E infection.

Protection from Chlamydia trachomatis infection is serovar-specific and T cell-dependent; however, the T cell epitopes identified to date have not been serovar-specific. The chlamydial major outer membrane protein (MOMP) contains serovar-specific B cell epitopes in four regions of the molecule whose amino acid sequence varies among serovars, the variable segments (VS). Serovar-specific T cell epitopes were sought by examining proliferation of blood mononuclear cells (PBMC) from Chlamydia-infected patients in response to VS peptides of serovar E MOMP. Serovar E-specific peptides from VS1, VS2, and VS4 stimulated PBMC to a greater extent in serovar E-infected than in non-E-infected subjects. Peptides containing constant regions of MOMP were recognized equally by all infected persons. The observed responses were attributable to T cells. T cell recognition of serovar-specific regions of MOMP is common and may contribute to the serovar-specific protection previously observed.

Amino Acid Sequence↗
PubMed1998

Phylogenetic analysis of the Chlamydia trachomatis major outer membrane protein and examination of potential pathogenic determinants.

Phylogenetic analysis was utilized to investigate biological relationships (tissue tropism, disease presentation, and epidemiologic success), as evidenced by coevolution, among human strains of Chlamydia trachomatis. Nucleotide sequences of omp1, the gene encoding the major outer membrane protein (MOMP) of C. trachomatis, were determined for 40 strains representing 11 serovars. These data were combined with available omp1 sequences from GenBank for an analysis encompassing a total of 69 strains representing 17 serovars infecting humans. Phylogenetic analysis of the nucleotide and inferred amino acid sequences showed no evolutionary relationships among serovars that corresponded to biological or pathological phenotypes (tissue tropism, disease presentation, and epidemiologic success). In addition, no specific residues that may have evolved to play a role in determining biologically relevant characteristics of chlamydia, such as tissue specificity, disease presentation, and epidemiologic success, were apparent in the MOMP. These results suggest that variation in MOMP may have arisen from a need to be diverse in the presence of immune pressure rather than as a function of pathogenicity. Therefore, the role of MOMP in disease pathogenesis and infection may be passive, and it may not be the major ligand responsible for directing infection of various human cell types.

Bacterial Outer Membrane Proteins↗
PubMed1998

Compiling a national register of babies born with anophthalmia/microphthalmia in England 1988-94.

AIM: To describe the prevalence of anophthalmia/microphthalmia in babies born in England 1988-94, as well as their overall survival, and the incidence of associated eye and non-eye malformations; to determine the usefulness of different sources of medical and health service information for establishing a retrospective register of anophthalmia/microphthalmia. METHODS: Multiple sources for initial (retrospective) case ascertainment were surveyed, followed by questionnaires to clinicians to establish severity, associated malformations, and aetiology for England, 1988-94. The population surveyed was all births in England for this time period (4,570,350 births). Cases included live births, stillbirths, or terminations after prenatal diagnosis of congenital anomaly, with anophthalmia/microphthalmia, with or without other malformations and syndromes. Trisomy 13 was subsequently excluded. RESULTS: The proportion of cases notified by any one information source was not more than 26% (Office for National Statistics Register 22%, paediatricians 26%, district sources 25%). Sixty nine per cent of cases (51% of severe cases) were notified by only one source. A total of 449 cases were reported, prevalence 1.0 per 10,000 births. The prevalence was stable over time, although the proportion notified by clinicians rose in more recent years. Thirty four per cent of affected babies had mild microphthalmia. Of those with severe anophthalmia/microphthalmia, 51% were bilateral, other eye malformations were present in 72%, non-eye malformations in 65%, and a "known aetiology" was attributed in 22%. Three quarters of those severely affected survived infancy. CONCLUSIONS: Despite high response rates from the sources of information contacted, the lack of duplication between sources indicates the difficulties of retrospective ascertainment and the need for multiple sources when establishing a register. Anophthalmos/microphthalmos is usually associated with other malformations. Most cases are of unknown aetiology.

Abnormalities, Multiple↗
PubMed1998

Erosive oesophagitis: outcome of repeated long term maintenance treatment with low dose omeprazole 10 mg or placebo.

AIMS: To investigate the efficacy of daily maintenance treatment with omeprazole 10 mg in reducing the relapse rate of healed erosive oesophagitis. METHODS: Three hundred patients with erosive oesophagitis (grade 2 or greater) received omeprazole 20 mg daily for 12 weeks, followed by 40 mg daily for a further 12 weeks if required. After healing, patients were randomised to double blind treatment with omeprazole 10 mg daily or placebo for up to 18 months. On relapse the treatment cycle was repeated. RESULTS: The cumulative healing rate at 12 weeks in the initial healing period was 95%, and 96% and 98% on rehealing courses after relapse in the first and second maintenance periods respectively. After 12 weeks of treatment, 98% of patients were free from heartburn and 97% were free of all reflux related symptoms. Relapse in the subgroup of patients who relapsed in both maintenance periods was infrequent on omeprazole 20 mg daily: only 9% at two years. Gastrin concentrations rose above normal in one third of patients. One patient had linear hyperplasia of endocrine cells and another had micronodular hyperplasia. There were no side effects definitely attributable to omeprazole. CONCLUSION: Maintenance treatment with omeprazole 10 mg daily keeps about 60% of patients with erosive oesophagitis in prolonged remission. Patients relapsing once are likely to do so again; they can subsequently be treated effectively with omeprazole 20 mg daily.

Anti-Ulcer Agents↗
PubMed1998

High-dose chemotherapy with autologous hematopoietic progenitor-cell support as part of combined modality therapy in patients with inflammatory breast cancer.

PURPOSE: To evaluate the feasibility of high-dose chemotherapy (HDC) with autologous hematopoietic progenitor-cell support (AHPCS) as part of combined modality therapy (CMT) in patients with inflammatory breast cancer (IBC). PATIENTS AND METHODS: From April 1993 to March 1997, 30 patients with IBC were treated at our program. Twenty-three patients received neoadjuvant chemotherapy (NAC) before HDC; 18 patients also received adjuvant chemotherapy following surgery, but before HDC. All patients received HDC with high-dose cyclophosphamide, cisplatin, and carmustine (BCNU) with AHPCS. Every patient underwent surgery either before (27 patients) or after (three patients) HDC. Patients received radiotherapy after HDC in addition to tamoxifen if their tumors were estrogen receptor-positive. RESULTS: Thirteen patients experienced grade 3 or 4 nonhematologic noninfectious toxicities. In 12 patients (40%), this represented drug-induced lung injury, which in all cases responded to a 10-week course of corticosteroids. The only treatment-related death was secondary to hemolytic-uremic syndrome (HUS). Another patient suffered grade 4 CNS toxicity, which was completely reversible. All patients engrafted promptly. Eight patients relapsed, five of whom had a poor pathologic response to NAC. Relapses were local (five patients), local plus systemic (one), or systemic only (two). Median follow-up time from diagnosis and HDC is 23.5 (range, 7 to 49) and 19 (range, 4 to 44) months, respectively. Twenty-one patients (70%; 95% confidence interval [CI], 51% to 86%) remain alive and free of disease 4 to 44 months after HDC. Median disease-free survival (DFS) and overall survival have not yet been reached. CONCLUSION: HDC as part of CMT is feasible in patients with IBC. The toxicity of this treatment program is significant, but tolerable. Despite the short follow-up duration, the promising DFS observed in this group of patients warrants randomized studies that include a HDC-containing arm in patients with IBC.

Adenocarcinoma↗
PubMed1998

White matter disease induced by high-dose chemotherapy: longitudinal study with MR imaging and proton spectroscopy.

PURPOSE: The purpose of this study was to determine the time course for development of white matter changes induced by high-dose chemotherapy. METHODS: Eight patients with advanced breast cancer were entered into a prospective, longitudinal trial that included examination by MR imaging and proton MR spectroscopy before chemotherapy and through 12 months after treatment with carmustine, cyclophosphamide, and cisplatin, combined with autologous hematopoietic progenitor cell support (AHPCS). RESULTS: Six patients completed induction chemotherapy, at which time all MR imaging studies appeared normal. At 3 months after the conclusion of high-dose chemotherapy and beyond, three of the four patients remaining in the study showed an increasing volume of white matter changes, which appeared to stabilize during the period from 6 months to 1 year. Maximal volumes of abnormal white matter ranged from 73 to 166 cm3. MR spectroscopy showed little or no change in metabolic ratios through the period of observation, although there was a suggestion of small transient treatment-related decreases in the ratio of N-acetyl aspartate (NAA) to creatine. CONCLUSION: White matter changes are common sequelae of treatment with high-dose chemotherapy combined with AHPCS, occurring early in the period following high-dose chemotherapy, with a rapid and progressive accumulation to about 6 months, but not accompanied by persistent neurologic symptoms. The MR spectroscopic analyses suggest a minimal disturbance of the neuronal marker NAA, a finding that may in part explain the good neurologic outcome.

Adult↗
PubMed1997

A prospective randomized trial of buffy coat versus CD34-selected autologous bone marrow support in high-risk breast cancer patients receiving high-dose chemotherapy.

High-dose chemotherapy with hematopoietic progenitor cell support is administered increasingly to selected categories of patients with high-risk malignancies. Bone marrow and/or peripheral blood progenitor cells (PBPCs) are commonly cryopreserved with the cryoprotectant dimethyl sulfoxide (DMSO), which can cause a variety of systemic side effects when the graft is thawed and infused. The progenitor cells thought to be responsible for hematopoietic recovery express the CD34 antigen and constitute 1% to 3% of the marrow cells and 0.5% of the PBPC fraction. Transplantation of a CD34(+) graft would markedly reduce the volume and thus the amount of DMSO required, thereby decreasing the infusion-related toxicities. In this study, 89 high-risk breast cancer patients received high-dose therapy and were randomized to receive an autologous CD34(+) marrow graft (Arm A) versus a standard buffy coat fraction (Arm B). After marrow infusion, significant increases in diastolic and systolic blood pressure, as well as significant decreases in heart rate, were documented in Arm B compared to Arm A patients (P < .001). None of the patients in Arm A experienced any clinically serious adverse events associated with the marrow infusion compared to 6% of the Arm B patients. The median time to neutrophil engraftment was 13 days for Arm A and 11 days for Arm B patients (P = .218). The median time to platelet engraftment was 27 days for Arm A and 20 days for Arm B patients (0.051). There were no other significant differences between the two arms of the study with respect to thrombocytopenia-related complications or immune function reconstitution. Additionally, patients on Arm A who received >/=1.2 x 10(6) CD34(+) cells/kg had no delay in platelet recovery (22 days), compared to patients on Arm B, who also received greater than 1.2 x 10(6) CD34(+) cells/kg (20 days) (P = .604). In conclusion, this prospective randomized study demonstrates that breast cancer patients who receive high-dose therapy with autologous CD34(+) marrow support have reduced marrow infusion-related toxicity, comparable time to neutrophil engraftment and immune function recovery posttransplant, and for those who receive <1.2 x 10(6) CD34(+) cells/kg, comparable time to platelet engraftment compared to women who receive buffy coat fractions of marrow.

Adult↗
PubMed1997

BTS 67 582 stimulates insulin secretion from perifused rat pancreatic islets.

The novel antidiabetic agent BTS 67 582 (1,1-dimethyl-2-[2-(4-morpholinophenyl)]guanidine monofumarate) demonstrated a concentration-dependent stimulation of insulin release in perifused rat pancreatic islets. EC50 values of 7.7 microM and 6.3 microM were obtained for BTS 67 582 in the presence of 8 mM glucose, after islets were pre-equilibrated with 4 and 8 mM glucose respectively. In contrast, there was little or no stimulation of insulin release at substimulatory (4 mM) or maximal stimulatory (15 mM) glucose concentrations. The plasma EC50 value for the glucose lowering effect of BTS 67 582 in fasted normal rats was 3.9 microM indicating a similar potency in vivo. In islets, BTS 67 582 completely antagonised (EC50 value of 13.2 microM) the actions of the selective ATP-dependent K+ channel opener diazoxide indicating K+ channel blocking activity. BTS 67 582 only weakly reversed the alpha2-adrenoceptor mediated inhibition of insulin release in islets (EC50 of 83 microM). BTS 67 582, like other imidazoline/guanidine insulin releasing agents, appears to promote insulin release via an effect on the islet ATP-dependent K+ channel which is not mediated by binding to the sulphonylurea receptor.

Animals↗
PubMed1997

Chlamydia trachomatis and febrile complications of postpartum tubal ligation.

OBJECTIVE: Our goal was to determine whether chlamydia-infected women have a higher rate of febrile complications after postpartum tubal ligation. STUDY DESIGN: Cross-sectional analysis of 1447 women tested for chlamydial infection within 2 weeks of delivery and who underwent postpartum tubal ligation was performed. Subjects were identified with the Regenstrief Institute for Health Care database. Infected subjects were compared with uninfected subjects for incidence of fever not explained by nongynecologic sources. RESULTS: Women infected with Chlamydia trachomatis at delivery were more likely to experience febrile postoperative complications after tubal ligation (p < 0.0001, relative risk 9.5, 95% confidence interval 4.5 to 20.1). CONCLUSION: Women undergoing postpartum tuba ligation may benefit from prompt diagnosis and preoperative treatment of chlamydial infection.

Adult↗
PubMed1997

Olfaction in the domestic fowl: a critical review.

It has been known for some time that many species of birds, including domestic fowl Gallus domesticus, have an olfactory sense. However, the functional significance of avian olfaction is less clear. We review neurobiological, embryological and behavioral evidence relevant to the question of how domestic fowl use the sense of smell. Evidence suggests a potential role for olfaction in the formation of attachments to familiar objects or environments; in the elicitation of fear responses by alarm and predator-related odors; in the control of feeding and drinking; and in avoidance of noxious substances. The fact that domestic fowl can detect and respond to a wide range of odors, in a variety of behavioral contexts, has important practical implications, especially in relation to welfare and husbandry.

Animal Husbandry↗