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Biomedical subjects

H Jones

Publications and source records attributed to H Jones.

At least 109 records · Page 6Linked to original sources
PubMed1995

Simultaneous bilateral cataract extraction in the UK.

AIMS/BACKGROUND: Simultaneous bilateral extracapsular cataract extraction (SBCE) is not routinely performed in the developed world. This study investigated the safety and efficacy of this procedure as performed in the UK. METHODS: A review of 319 consecutive patients (638 eyes) who underwent SBCE with posterior chamber intraocular lens implantation is presented. RESULTS: The incidence of intraoperative complications was 7.7%. These included posterior capsule rupture (0.8%) and vitreous loss (0.3%). Postoperative complications were seen in 8.7% of operated eyes and included iris prolapse (0.3%) and raised intraocular pressure (3.0%). Endophthalmitis occurred in one eye (0.15%). There were no major bilateral complications, and, in particular, no cases of bilateral endophthalmitis. Final visual acuities compared favourably with reports for unilateral surgery. Eighty two per cent achieved a final visual acuity of 6/12 or better, and 41% tested 6/6 or better. CONCLUSION: This study illustrates that SBCE is not associated with an increased incidence of complications and that the visual results are good. Where indicated, and under strict surgical protocol, this procedure is safe.

Aged↗
PubMed1995

Apolipoprotein AI levels are increased in part as a consequence of reduced catabolism in nephrotic rats.

Apolipoprotein AI (apo AI) synthesis, measured as the turnover of 125I-labeled apo AI-labeled high-density lipoprotein (HDL), was increased significantly in rats with Heymann nephritis (HN) vs. control Sprague-Dawley (SD) rats. However, fractional apo AI catabolic rate was also significantly less in HN vs. SD. We used 125I-apo AI tyramine cellobiose HDL, a marker retained at the catabolic site, to establish where apo AI catabolism decreased in six HN rats, seven rats with adriamycin (Adria)-induced nephrosis, and six control SD. Total renal apo AI catabolism, plus urinary losses, were the same in all three groups, despite significant urinary apo AI in HN and Adria rats. Apo AI catabolism was reduced in skin in both nephrotic groups, accounting for approximately 44% of reduced in apo AI catabolism. Thus a significant fraction of apo AI is catabolized in skin of normal male rats. Reduced apo AI catabolism in skin contributes to increased plasma levels in nephrotic rats.

Animals↗
PubMed1995

Mast cells modulate allergic pulmonary eosinophilia in mice.

Mast cells are important effector cells in IgE-mediated acute allergic reactions. Mast cells also produce cytokines such as interleukin (IL)-3, IL-4, IL-5, tumor necrosis factor (TNF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) that regulate the function of eosinophils and the development of a late-phase inflammatory response to antigen challenge. To evaluate the role of mast cells on the development of IgE-mediated allergic pulmonary eosinophilia in vivo, we compared the eosinophil infiltration into lungs of mast cell deficient mice (WBB6F1/J-W/Wv) with their congenic normal littermates (W/W+). Mice were sensitized with alum-precipitated ovalbumin and challenged with aerosolized ovalbumin on day 12 after sensitization. Bronchoalveolar lavage (BAL) fluid, lung tissue biopsies, and blood samples were collected after ovalbumin challenge. Eosinophil numbers in the BAL and lung tissue, lung eosinophil peroxidase (EPO) activity and serum levels of IgE and IgG1 were measured. In sensitized W/W+ mice, there were increased numbers of eosinophils in the BAL fluid and lung tissue, and EPO levels were increased after ovalbumin challenge. Ovalbumin challenge of sensitized mast-cell-deficient mice produced fewer numbers of eosinophils in the BAL fluid and lungs, and EPO levels were also reduced compared with their challenged congenic littermates. On the other hand, levels of serum IgE and IgG1 were not different between W/Wv mice and their congenic littermates.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Involvement of IL-5 in a murine model of allergic pulmonary inflammation: prophylactic and therapeutic effect of an anti-IL-5 antibody.

Interleukin-5 (IL-5) is important in the control of differentiation, migration, and activation of eosinophils. In order to study the role of IL-5 in the development of eosinophilic inflammation of the airways, we have used a monoclonal antibody to murine IL-5 (TRFK-5) in a murine model of allergic pulmonary inflammation. B6D2F1 mice were sensitized with alum-precipitated ovalbumin and were challenged with aerosolized ovalbumin on day 12 after sensitization. Samples of bronchoalveolar lavage (BAL) fluid, lung tissue, blood, and bone marrow aspirate were collected at different times after ovalbumin challenge. Twenty-four hours after challenge there were significant increases in the number of eosinophils in the BAL fluid, lung tissue, and blood while bone marrow eosinophils were decreased. Treatment of sensitized mice with TRFK-5 (0.01-1 mg/kg, i.p.) 2 h before ovalbumin challenge reduced the numbers of eosinophils in the BAL fluid and lung tissue and prevented the decrease in bone marrow eosinophils in a dose-dependent fashion. The number of eosinophils in the BAL fluid, peribronchial and alveolar regions of the lung was also reduced when TRFK-5 (2 mg/kg, i.p.) was given up to 5 d after ovalbumin challenge. Furthermore, there was no evidence of increased epithelial damage, edema, or the presence of mucus that could have resulted from eosinophil apoptosis and release of toxic proteins after neutralization of IL-5. These results demonstrate an important role for IL-5 in the development of eosinophilic inflammation of the airways and for the migration of eosinophils from the bone marrow into blood in response to antigen challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1994

Making the new deal for junior doctors happen.

How can the new deal for juniors be implemented in today's overstretched health service? How do you get clinicians and management to work together? On the Wirral falling house officer morale and recruitment stimulated a new approach, action learning, which proved to be highly successful. Action learning is not a new approach in management terms, but it is rarely used in the health service. Guided by an experienced facilitator, a group of people learn management skills by exploring and resolving practical problems relevant to them. A group of general practitioners and consultants used action learning to teach themselves more about management and at the same time to make changes which addressed many of the junior doctors' difficulties and solved the hospital recruiting problem.

Group Processes↗
PubMed1994

Sleep and alertness in a 12-hour rotating shift work environment.

Industrial workers on rotating shifts were evaluated for the effects of rotating shift work. Twenty-five (86%) of 29 workers in the study area who work 12-hour shifts in a scheduled 16-day rotation participated. The mean number of hours of sleep at home after working day shifts (5.6 hours) was less than after the first three night shifts (6.0, 6.4, and 6.6 hours, respectively). At work, the mean number of hours at reported peak alertness was greater during the night shift (6.1 hours) than the day shift (4.9 hours), but the perceived alertness levels were relatively lower on the night shift. Increased perceived difficulty working and decreased perceived productivity and safety were reported on the first night of the night shift. We demonstrate that workers on rotating shift work exhibit low alertness-related outcomes on both shifts. These workers have early shift work starting times that appear to disrupt sleep patterns on both day and night shifts. At this work site, a number of interventions to lessen the effects of rotating shift work are being evaluated.

Adult↗
PubMed1994

Immunohistochemical detection of the H-ras, K-ras, and N-ras oncogenes in squamous cell carcinoma of the head and neck.

The expression of H-ras, K-ras and N-ras oncogenes was analyzed on frozen sections of squamous cell carcinoma of the head and neck (SCCHN) by immunohistochemistry using anti-ras monoclonal antibodies. Of 22 primary SCCHN, 15 (68%) stained positive for H-ras, 10 (45%) for K-ras and seven (32%) for N-ras. Thirteen specimens (59%) stained positive for at least two anti-ras monoclonal antibodies. The presence of immunohistochemically detectable H-ras, K-ras and N-ras proteins was most frequently associated with an increase in tumor size and later stages of disease (T3 and T4), with no apparent correlation with lymph node involvement, site of occurrence, degree of differentiation, age, sex, or race. Thus, overexpression of members of the ras gene family occurs as a relatively common even in SCCHN and may be an important event in the later stages of tumorigenesis.

Adult↗
PubMed1994

Characterization of a murine model of allergic pulmonary inflammation.

Pulmonary inflammation with eosinophil (EOs) infiltration is a prominent feature of allergic respiratory diseases such as asthma. In order to study the cellular response during the disease development, an animal model of IgE-mediated pulmonary inflammation with characteristic eosinophilia is needed. We developed a method for inducing severe pulmonary eosinophilia in the mouse and also studied the numbers of EOs in blood and bone marrow and the response to corticosteroid treatment. Animals were sensitized with alum-precipitated ovalbumin (OVA) and challenged with aerosolized OVA 12 days later when serum IgE levels were significantly elevated. Four to eight hours after challenge there were moderate increases in the number of EOs in the bone marrow and peripheral blood, but only a few EOs were observed in the lung tissue and in bronchoalveolar lavage (BAL) fluid. Twenty-four hours after challenge, there was a marked reduction of EOs in bone marrow, while the number of EOs peaked in the perivascular and peribronchial regions of the lung. Forty-eight hours after challenge, the highest number of EOs was found in the BAL fluid, making up > 80% of all cells in that compartment. The high levels of EOs in the lung tissue and BAL fluid lasted for 2-3 days and was followed by a more moderate but persistent eosinophilia for another 10 days. Nonsensitized animals showed no significant changes in the number of EOs in BAL fluid, lungs, blood or bone marrow. Histopathological evaluation also revealed epithelial damage, excessive mucus in the lumen and edema in the submucosa of the airways.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗
PubMed1993

X-ray analyses of aspartic proteinases. V. Structure and refinement at 2.0 A resolution of the aspartic proteinase from Mucor pusillus.

The structure of mucor pusillus pepsin (EC 3.4.23.6), the aspartic proteinase from Mucor pusillus, has been refined to a crystallographic R-factor of 16.2% at 2.0 A resolution. The positions of 2638 protein atoms, 221 solvent atoms and a sulphate ion have been determined with an estimated root-mean-square (r.m.s.) error of 0.15 to 0.20 A. In the final model, the r.m.s. deviation from ideality for bond distances is 0.022 A, and for angle distances it is 0.050 A. Comparison of the overall three-dimensional structure with other aspartic proteinases shows that mucor pusillus pepsin is as distant from the other fungal enzymes as it is from those of mammalian origin. Analysis of a rigid body shift of residues 190 to 302 shows that mucor pusillus pepsin displays one of the largest shifts relative to other aspartic proteinases (14.4 degrees relative to endothiapepsin) and that changes have occurred at the interface between the two rigid bodies to accommodate this large shift. A new sequence alignment has been obtained on the basis of the three-dimensional structure, enabling the positions of large insertions to be identified. Analysis of secondary structure shows the beta-sheet to be well conserved whereas alpha-helical elements are more variable. A new alpha-helix hN4 is formed by a six-residue insertion between positions 131 and 132. Most insertions occur in loop regions: -5 to 1 (five residues relative to porcine pepsin): 115 to 116 (six residues); 186 to 187 (four residues); 263 to 264 (seven residues); 278 to 279 (four residues); and 326 to 332 (six residues). The active site residues are highly conserved in mucor pusillus pepsin; r.m.s. difference with rhizopuspepsin is 0.37 A for 25 C alpha atom pairs. However, residue 303, which is generally conserved as an aspartate, is changed to an asparagine in mucor pusillus pepsin, possibly influencing pH optimum. Substantial changes have occurred in the substrate binding cleft in the region of S1 and S3 due to the insertion between 115 and 116 and the rearrangement of loop 9-13. Residue Asn219 necessitates a shift in position of substrate main-chain atoms to maintain hydrogen bonding pattern. Invariant residues Asp11 and Tyr14 have undergone a major change in conformation apparently due to localized changes in molecular structure. Both these residues have been implicated in zymogen stability and activation.

Amino Acid Sequence↗
PubMed1993

Phase I/II study of murine monoclonal antibody-ricin A chain (XOMAZYME-Mel) immunoconjugate plus cyclosporine A in patients with metastatic melanoma.

XOMAZYME-Mel (XMMME-001-RTA) is an immunoconjugate comprised of ricin A chain conjugated to a murine monoclonal antibody directed against high molecular weight melanoma antigens. Although not necessarily related to increased toxicity or decreased efficacy, the development of anti-immunoconjugate antibodies may limit repetitive dosing with an immunoconjugate. We evaluated the role of cyclosporine A in blocking the antibody response in patients with melanoma treated with XMMME-001-RTA. Patients received cyclosporine in divided daily doses to achieve serum levels by HPLC of 150-200 ng/ml on days 1-22. On day 3, XMMME-001-RTA was begun at dosages 0.2-0.6 mg/kg daily for 5 days. Treatment was repeated every 35 days. Three patients were treated in each dosage tier (0.2, 0.4, 0.6 mg/kg). Nine patients were entered and all nine were evaluable. Patients had histologically confirmed melanoma. Metastatic sites included skin, soft tissue, and lymph nodes (seven), lung (two), liver (one), and spleen (one). There were four men and five women aged 46-75 years. Toxicities included myalgia, arthralgia, hypoalbuminemia, fatigue, elevations in liver function tests, and increased peripheral edema. Four patients received two to five repeated dosages of XMMME-001-RTA. One wheal-and-flare reaction from an immunotoxin test dose of XMMME-001-RTA was noted after five cycles. After a test dose subsequent to one cycle, two patients experienced chest tightness without ECG changes and were removed from the study. All toxicities resolved without sequelae. One patient experienced partial lymph node remission for 9 months. A second patient had stable mediastinal disease for 20 months. XMMME-001-RTA is safe when given repeatedly with cyclosporine.

Aged↗
PubMed1993

A histological and electronmicroscopic study of intracorneal melanin in benign and malignant melanocytic lesions.

Intracorneal melanin is a feature quite frequently encountered in a range of melanocytic lesions, yet has rarely been described in the literature. We examined a variety of melanocytic lesions with increasing degrees of melanocytic atypia for this feature. The distribution and amount of intracorneal melanin is described and it was shown to be entirely within keratinocytes. In general, the amount of intracorneal melanin was related to increasing melanocytic atypia and was typically distributed in a disorderly fashion in malignant lesions.

Corneal Diseases↗
PubMed1993

School health education in the European Community.

The School Health Education Commission of the European Community is making efforts to improve school health education in the European Community countries. While past efforts have involved single issue causes, current activities emphasize a holistic perception of school health education. Radical education reforms throughout the European Community advocate improved health education. The movement toward quality health education in the European Community countries uses a model called the Health Promoting School, a cooperative effort involving schools, families, and communities. The model is being promoted through three stages: 1) national conferences held in each European Community country, 2) summer schools to provide teacher training, and 3) national projects, supported by the World Health Organization, agreement conducted to determine the efficacy of the Health Promoting School Model.

Europe↗
PubMed1993

Extrahepatic lipogenesis contributes to hyperlipidemia in the analbuminemic rat.

Hepatic lipid and apolipoprotein synthesis is increased in the nephrotic syndrome. Catabolism of triglyceride-rich lipoproteins is impaired in nephrotic syndrome but not in rats with hereditary analbuminemia (NA), suggesting that lipid synthesis should be increased by analbuminemia in the absence of proteinuria. In this study the rate of cholesterol and fatty acid synthesis in liver and extrahepatic tissue was measured in female NA and control Sprague-Dawley (SD) rats to determine whether lipid synthesis was indeed increased in isolated analbuminemia and to identify the site(s) of increased lipogenesis. We also measured the concentrations of apolipoproteins (apo) AI, B, and E in plasma, as well as the levels of the respective mRNAs in liver. Plasma cholesterol, triglycerides, and apo AI, B, and E were all increased severalfold in the NA rat (P < 0.001). Although liver apolipoprotein mRNA content was significantly increased (P < 0.001) for apo AI (643%), B (273%), and E (299%), 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity in liver microsomes and hepatic cholesterol synthesis were not significantly increased in the NA rats. Hepatic fatty acid synthesis and intestinal cholesterol synthesis were not increased in the NA rats. Surprisingly, intestinal fatty acid synthesis was elevated by 60% (P < 0.01). The NA rats demonstrated approximately fourfold increases in the incorporation of 3H2O into circulating cholesterol and fatty acids (P < 0.001). A 56% increase in the synthesis of total nonsaponifiable lipid was found in the extravisceral carcass (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗