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Biomedical subjects

R J Shaw

Publications and source records attributed to R J Shaw.

At least 91 records · Page 5Linked to original sources
PubMed1996

Brief cognitive screening of the elderly: a comparison of the Mini-Mental State Examination (MMSE), Abbreviated Mental Test (AMT) and Mental Status Questionnaire (MSQ).

One hundred and fifty unselected elderly community subjects were assessed by Mini-Mental State Examination (MMSE), Abbreviated Mental Test (AMT) and Mental Status Questionnaire (MSQ). The effects on cognitive test scores of potential confounding (non-cognitive) variables were evaluated. Sensitivities and specificities were: MMSE 80% and 98%; AMT 77% and 90%; and MSQ 70% and 89%. The MMSE identified significantly fewer false positives than the AMT and MSQ. The major effect of intelligence on cognitive test scores has previously been underestimated. Age, social class, sensitivity of hearing and history of stroke were also significantly correlated with cognitive test scores. Years of full time education and depression only affected the longer MMSE and CAMCOG. The MMSE (cut-off 20/21) can be recommended for routine screening. However, as scores are affected by variables other than cognitive function, particularly intelligence, further assessment of identified cases may fail to reveal significant functional impairment.

Aged↗
PubMed1996

Effect of angiotension II on the expression of the early growth response gene c-fos and DNA synthesis in human vascular smooth muscle cells.

OBJECTIVES: The aims of this study were to characterize the angiotensin II receptor subtype present on vascular smooth muscle cells from human saphenous vein and to assess the effect of angiotensin II on the expression of the early growth response gene c-fos and on DNA synthesis. METHODS AND RESULTS: Using radioligand binding studies, we have defined the angiotensin II receptors present on these cells as being predominantly of the AT1 subtype. Angiotensin II increased peak intracellular calcium levels by 126 +/- 16 nmol/l (mean +/- SEM) in 17/49 cultures. Angiotensin II induced c-fos expression in a concentration-dependent manner only in cultures that exhibited an intracellular calcium transient in response to stimulation with angiotensin II. The induction of c-fos was inhibited by the selective AT1 antagonist losartan in accordance with the binding studies. Angiotensin II stimulated DNA synthesis with a maximal increase of 66.4% +/- 20.5% over serum-free levels at 1 nmol/l (mean +/- SEM, n = 6, P < 0.05). DNA synthesis declined with increasing angiotensin II concentration, falling to control values at 1 mumol/l, suggesting that a growth-inhibitory influence may counter-balance the stimulatory effect that is observed at lower concentrations. CONCLUSION: Vascular smooth muscle cells from human saphenous vein possess predominantly AT1 receptors and in response to angiotensin II show an induction of c-fos and a modest increase in DNA synthesis.

Angiotensin II↗
PubMed1996

Increased inflammatory cytokines and new collagen formation in cutaneous tuberculosis and sarcoidosis.

BACKGROUND: Interactions between mononuclear cells, vascular endothelium, fibroblasts, and cytokines during the inflammatory reaction within a granuloma have the potential to contribute to the progression to fibrosis. METHODS: Biopsy specimens of six tuberculous and eight sarcoidosis skin lesions were examined by immunohistochemistry to seek evidence for the presence of inflammatory and fibrotic reactions in human granulomatous disease. Additionally, to understand how a T cell mediated delayed type hypersensitivity reaction--a component of chronic granulomatous inflammation--could progress to fibrosis, the human in vivo model of the cutaneous tuberculin Heaf reaction to purified protein derivative (PPD) was studied in a group of 48 subjects. RESULTS: Granulomas from tuberculous and sarcoidosis skin biopsy specimens were seen to contain cells with marked staining by antibodies to fibronectin, transforming growth factor beta (pan TGF-beta), and type 1 procollagen (PCP-1). Accentuated staining of extracellular matrix was seen both in the granulomas and in the peri-granulomatous regions. Less prominent staining was observed using antibodies against interleukin 1 beta (IL-1 beta) and alpha-smooth muscle actin (alpha-SMA). Biopsies of Heaf reactions revealed cells staining for IL-1 beta, tumour necrosis factor alpha (TNF-alpha), platelet derived growth factor B (PDGF-B), and fibronectin which were detected as early as day 1 and persisted throughout the 14 day study period. Cells staining for PCP-1 increased to greatest abundance at day 14. All these cytokines were present in low abundance in biopsy specimens from sites inoculated with saline only. CONCLUSIONS: Evidence is provided that granulomas in tuberculosis and sarcoidosis behave as active centres of fibrogenesis. Using the Heaf model, the temporal relationship between the early appearance of cytokines and the later increase in the collagen precursor PCP-1 linked the immune mediated chronic inflammatory response with subsequent fibrosis and suggested that the tuberculin Heaf reaction will serve as a model for studying the early events of granuloma formation in patients with tuberculosis and sarcoidosis.

Actins↗
PubMed1996

Comparison of polymerase chain reaction for IS6110 and Amplicor in the diagnosis of tuberculosis.

BACKGROUND: Polymerase chain reaction (PCR) amplification of Mycobacterium tuberculosis DNA offers the potential of a sensitive and specific diagnostic test for tuberculosis. To evaluate this technique from the clinician's perspective, samples were collected from patients with chronic respiratory disease and the sensitivity and specificity of a newly introduced commercially available PCR kit (Amplicor) was compared with that of an established method to detect the target sequence IS6110. METHODS: Sputum or bronchial washings from patients with active tuberculosis, previously treated tuberculosis or other selected respiratory illnesses were analysed by both techniques and their sensitivity and specificity determined. RESULTS: Amplicor was more specific than IS6110 in the diagnosis of active infection (98% versus 79%). Both techniques were equally sensitive (92%). CONCLUSION: These results suggest that analysis of respiratory samples by Amplicor PCR in inner city populations of patients has greater specificity for a diagnosis of active tuberculosis than PCR for IS6110, and thus Amplicor PCR may aid the clinician in making a diagnosis of active tuberculosis.

Base Sequence↗
PubMed1996

Increase in interleukin (IL)-1 beta and IL-6 in bronchoalveolar lavage fluid obtained from infants with chronic lung disease of prematurity.

Chronic lung disease (CLD) of prematurity is associated with an initial increase in pulmonary neutrophils followed by pulmonary fibrosis. We determined whether the proinflammatory cytokines, IL-1 beta and IL-6, were increased in the bronchoalveolar lavage fluid obtained from nine infants (median gestation 25 wk, birthweight 820 g) who developed CLD, seven (28 wk, 1110 g) who recovered from the respiratory distress syndrome (RDS), and four (38 wk, 2690 g) control infants. IL-1 beta and IL-6 protein were both increased in the bronchoalveolar lavage fluid from the CLD groups when compared with the RDS and control groups. This difference for both the cytokines was most marked on d 10 of age, when results from infants with and without CLD were compared (IL-1 beta, 4.6 versus 1.1 ng/mL, p < 0.05; and IL-6, 9.5 versus 1.5 ng/mL, p < 0.05). Immunocytochemistry of lavage cells for IL-1 beta, IL-6, and IL-8 protein showed alveolar macrophages to contain all three cytokines, with lesser staining evident in neutrophils, and in epithelial cells occasionally obtained by lavage. The contribution of alveolar macrophages and luminal cells to the increase in IL-6 and IL-1 was determined by performing semiquantitative reverse transcription-polymerase chain reactions on RNA extracted from lavage cells. IL-6 mRNA expression was increased in lavage cells from the CLD infants when compared with the RDS group. However, the expression for IL-1 beta and IL-8 mRNA was similar in both groups. These results suggest that IL-1 beta, IL-6, and IL-8 may contribute to the pathogenesis of CLD, and that, in CLD, IL-6 may be produced by cells within the air spaces.

Bronchoalveolar Lavage Fluid↗
PubMed1995

A single residue can modify target-binding affinity and activity of the functional domain of the Rho-subfamily GDP dissociation inhibitors.

The GDP dissociation inhibitors (GDIs) represent an important class of regulatory proteins for the Rho- and Rab-subtype GTP-binding proteins. As a first step toward identifying the key functional domain(s) on the Rho-subtype GDI, truncations of the amino and carboxyl termini were performed. Deletion of the final four amino acids from the carboxyl terminus of Rho GDI or the removal of 25 amino acids from the amino terminus had no significant effect on the ability of the GDI to inhibit GDP dissociation from the Rho-like protein Cdc42Hs or on its ability to release Cdc42Hs from membrane bilayers. However, the deletion of 8 amino acids from the carboxyl terminus of Rho GDI eliminated both activities. To further test the importance of the carboxyl-terminal domain of the Rho GDI molecule, chimeras were constructed between this GDI and a related protein designated LD4, which is 67% identical to Rho GDI but is less potent by a factor of 10-20 than Rho GDI in functional assays with the Cdc42Hs protein. Two sets of chimeras were constructed that together indicated that as few as 6 amino acids near the carboxyl terminus of Rho GDI could impart full GDP dissociation inhibition and membrane dissociation activities on the LD4 molecule. Further analysis of this region by site-directed mutagenesis showed that a single change at residue 174 of LD4 to the corresponding residue of Rho GDI (i.e., Asp-174-->Ile) could impart nearly full (70%) Rho GDI activity on the LD4 molecule.

Amino Acid Sequence↗
PubMed1995

Development and characterization of a novel xenograft model permissive for human papillomavirus DNA amplification and late gene expression.

Human papillomaviruses (HPVs) are important human pathogens associated with a range of epithelial neoplasia. The rising incidence of HPV infection and association of HPV with malignancy has led to increased interest in appropriate management of these infections. Development of new therapies for viral warts has been frustrated by the lack of availability of models permissive for viral replication. Here we describe the development of HPV-severe combined immunodeficient mouse model which reproduces mature HPV-infected epithelia. Grafting of anogenital and laryngeal papillomas harbouring either HPV-6 or HPV-11 resulted in the formation of a differentiated neo-epithelium exhibiting the hallmark features of HPV infection including basal hyperplasia, acanthosis and koilocytosis. The reformed warty epithelium contained amplified HPV DNA and expressed capsid protein in the differentiated layers. A striking feature is the production of macroscopic papillomata in an anatomically relevant and accessible site, providing a system of particular relevance for the temporal evaluation of developing lesions and selection of antiviral agents.

Animals↗
PubMed1995

Increase in interleukin-8 and soluble intercellular adhesion molecule-1 in bronchoalveolar lavage fluid from premature infants who develop chronic lung disease.

Interleukin-8 (IL-8), soluble intercellular adhesion molecule-1 (sICAM), elastase and neutrophils were assessed in bronchoalveolar lavage fluid from nine infants who developed chronic lung disease (CLD) after respiratory distress syndrome (RDS), seven who had recovered from RDS, and in four control infants. IL-8, sICAM, elastase and neutrophils in bronchoalveolar lavage fluid were increased in the CLD group, the differences being most pronounced at 10 days of age. When babies with and without CLD were compared at 10 days of age, bronchoalveolar lavage fluid from the babies with CLD had significantly increased IL-8 (114.0 vs 12.7 ng/ml), sICAM (19.0 vs 1.1 micrograms/ml), elastase (6.9 vs 0.9 micrograms/ml) and neutrophils (1.9 vs 0.4 x 10(9)/l). In serum the increased concentration of IL-8 observed at birth in the CLD (247 pg/ml) and RDS (192 pg/ml) groups decreased over three weeks to the concentrations observed in the controls (< 70 pg/ml). Persistent inflammation could be a major contributory factor in the development of CLD.

Bronchoalveolar Lavage Fluid↗
PubMed1995

Enhanced expression of type 1 procollagen and transforming growth factor-beta in tuberculin induced delayed type hypersensitivity.

AIMS: Tissue fibrosis is a common and serious consequence of chronic inflammation. The mechanism linking these two processes is poorly understood. The present study has utilised a human in vivo model of a delayed type hypersensitivity (DTH) reaction, the tuberculin Heaf reaction, induced by intradermal tuberculin in BCG immunised subjects, to dissect the relation between these two processes. METHODS: Punch skin biopsy specimens were obtained on day 5, day 13 and six to 16 weeks following the tuberculin Heaf test in 18 subjects with grade 3 or 4 responses. Skin biopsy specimens from six subjects served as controls. The specimens were examined using immunohistochemical staining for type 1 procollagen and transforming growth factor-beta (TGF-beta), as well as in situ hybridisation for type 1 procollagen messenger RNA (mRNA). RESULTS: Immunohistochemical analysis revealed increased deposition of TGF-beta in tissue matrix in the biopsy specimens obtained on day 5 following the tuberculin Heaf test. There was also extensive type 1 procollagen staining in the biopsy specimens obtained as early as day 5. Procollagen-1 staining was maximal on day 13, and was present in biopsy specimens from tuberculin Heaf test sites up to eight weeks after the tuberculin inoculation. The type 1 procollagen was localised within cells surrounding areas of inflammatory infiltrate and in perivascular tissues. The presence of new collagen formation was confirmed by in situ hybridisation using oligonucleotide probes for type 1 procollagen mRNA in cells in sections from biopsy specimens obtained on day 13. CONCLUSIONS: These data from a human in vivo model of a DTH response indicate that the immune response is intimately associated with an increase in the production of growth factors and the initiation of a fibrotic response.

Base Sequence↗
PubMed1995

Mycobacterial infection in HIV seropositive and seronegative populations, 1987-93.

BACKGROUND: Although the causes of the worldwide resurgence of tuberculosis are multifactorial, the HIV epidemic is believed to have had a central role. Control is further threatened by the emergence of multidrug-resistant tuberculosis. METHODS: A retrospective evaluation was undertaken of trends in pulmonary and extrapulmonary culture positive mycobacterial pathology, and the prevalence of drug-resistant tuberculosis in both HIV seropositive and, presumptively, HIV seronegative patients receiving their clinical care at St Mary's Hospital, London. Five hundred and thirty eight patients (188 of whom were known to be HIV seropositive) with positive mycobacterial isolates between January 1987 and March 1993 were identified from laboratory records. These were cross referenced with drug surveillance records. RESULTS: Overall, between 1987 and 1992 there was a progressive 3.5 fold increase in positive mycobacterial isolates and a 2.5 fold increase in patients with proven mycobacterial infection. This increase was greater within the HIV seropositive population. A total of 663 positive mycobacterial isolates was evaluated; the major pathogen identified was Mycobacterium tuberculosis (379 isolates, 57%). Three hundred and fourteen patients were diagnosed as having M tuberculosis, 49 of whom were HIV seropositive. M tuberculosis was predominantly isolated from the lung. Of 358 positive cultures for M tuberculosis (68 HIV seropositive, 290 presumptively HIV seronegative), only 27 isolates (7.6%), almost exclusively derived from presumed HIV seronegative patients, were resistant to either isoniazid, rifampicin, or both drugs together. No increases in drug-resistant isolates were observed over this period. CONCLUSIONS: There has been a considerable increase in the incidence of tuberculosis in both HIV seronegative and seropositive populations during the study period. The emergence of drug-resistant tuberculosis was not observed.

Adolescent↗
PubMed1995

Pulmonary complications of HIV disease: 10 year retrospective evaluation of yields from bronchoalveolar lavage, 1983-93.

BACKGROUND: Pulmonary disease is a major contributor to morbidity and mortality in patients with HIV infection and AIDS. The aim of this study was to describe bronchoscopic findings and the spectrum of pulmonary pathogens in HIV seropositive patients undergoing investigation of respiratory disease over a 10 year period in a major UK referral centre. METHODS: Recruitment was procedure based with data being captured when bronchoscopy was clinically indicated. Data were evaluated from 580 HIV seropositive patients (559 men, age 13-65 years) over a 10 year period from June 1983 to March 1993. RESULTS: A total of 947 bronchoscopies was performed. The most frequent pulmonary pathogen isolated from bronchoalveolar lavage (BAL) fluid in 44% of all bronchoscopies was Pneumocystis carinii. Of all patients studied, 324 (55%) had at least one cytologically confirmed episode of P carinii pneumonia; this was AIDS defining in 219 (38%) of patients who underwent bronchoscopy. Between 1987 and 1993 the overall diagnostic yield from BAL fluid was 76%; 25% of all bronchoscopies yielded positive microbiological results, the most frequent isolates being Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas spp, and Haemophilus influenzae. Mycobacteria were identified in 8% of patients; M tuberculosis was the most common being identified in 3% of lavage samples and in 4% of patients. No drug-resistant M tuberculosis was found. Viral isolates (mainly cytomegalovirus) were identified in up to 31% of BAL fluid samples. Endobronchial Kaposi's sarcoma was seen in 15% of patients at bronchoscopy. CONCLUSIONS: Of the 1956 newly diagnosed HIV seropositive patients receiving clinical care at St Mary's Hospital over this period, approximately 30% underwent bronchoscopy. Diagnostic rates for P carinii pneumonia, endobronchial Kaposi's sarcoma, and bacterial and mycobacterial infection have remained largely constant since 1989. Bronchoalveolar lavage produces high diagnostic yields generally, and P carinii pneumonia remains a common cause of pulmonary disease in these patients.

Adolescent↗
PubMed1994

Pharmacological modulation of platelet-derived growth factor (B) mRNA expression in alveolar macrophages and adherent monocytes.

The macrophage profibrotic cytokine, Platelet Derived Growth Factor B [PDGF(B)], is thought to play a central role in orchestrating the fibrotic response in the pathogenesis of cryptogenic fibrosing alveolitis. In this study, we have asked if drugs that increase intracellular cAMP and are commonly administered to patients with lung disease have the ability to downregulate PDGF(B) mRNA. Incubation of human alveolar macrophages from healthy smokers in the presence of dibutyryl cAMP prevented the previously reported dexamethasone-induced increase in PDGF(B) mRNA (P < 0.05). Similarly, the combination of aminophylline (2.5 mM) and salbutamol (1 microM) prevented the adherence-dependent increase in PDGF(B) mRNA in adherent human peripheral blood monocytes (P < 0.05), whilst causing an increase in the mRNA expression of the cAMP-dependent gene c-fos (P = 0.059), and an increase in the intracellular concentration of cAMP (P = 0.05). Finally, the presence of a lower concentration of aminophylline (0.25 m) in conjunction with salbutamol (1 microM) also prevented the dexamethasone-induced increase in PDGF(B) mRNA in alveolar macrophages from healthy smokers (P < 0.05). Stimulation by these drugs was not associated with a change in the abundance of the mRNA of the house-keeping gene, glyceraldehyde-3-phosphate dehydrogenase. We speculate that drugs, which increase intracellular cAMP, may provide a novel therapeutic avenue whereby PDGF(B) expression in patients with cryptogenic fibrosing alveolitis may be reduced.

Base Sequence↗
PubMed1994

A technique for the isolation and purification of viable mucosal mast cells/globule leukocytes from the small intestine of parasitised sheep.

Romney sheep, 1-2 years old, immunized by at least three anthelmintic abbreviated infections of 80-100,000 Trichostrongylus colubriformis larvae usually produced high numbers of intestinal mucosal mast cells/globule leukocytes (MMC/GLs). In isolating these cells, the importance of maintaining the intestine at 37 degrees C, removal of mucus with dithiothreitol, enzymatic dispersion and careful in vitro handling procedures for maximising cell viability are emphasised. The MMC/GLs were separated from most contaminant cells by using a Percoll discontinuous gradient. MMC/GLs collected at the 60/100% Percoll interface were passed through a complement coated nylon wood column to remove the contaminating eosinophils. Viable MMC/GLs were able to grow in vitro in the presence of Concanavalin A and survive in culture for up to 30 days. The MMC/GLs were readily identified by ultraviolet light microscopy after staining with auramine O.

Animals↗
PubMed1994

Ultrastructure of oncosphere and early stages of metacestode development of Echinococcus granulosus.

The ultrastructure of the oncospheres and developing metacestodes in vitro of Echinococcus granulosus was studied with emphasis on the origin of the laminated layer. The activated oncospheres measured 28 microns (S.D. = 1.83), and by day 5 of in vitro culture the metacestodes attained diameters up to 52 microns (S.D. = 2.66). The oncospheral plasma membrane of the tegument appeared to be formed by a microtubular cytoskeleton arranged in a predetermined pattern. By day 2 there were three main types of vesicles in the perikaryon: Vd, Vg1 and Vg2. Vesicles appeared to be synthesized in the perikaryon and continuously transported to the periphery, where the Vd vesicles could contribute to the ground substance of the syncytial tegument. We suggest that the Vg1 and Vg2 vesicles contribute to the laminated layer where, by day 5, they were seen in increased density and forming aggregations on the outer border.

Animals↗
PubMed1994

Echinococcus granulosus: the mechanism of oncosphere lysis by sheep complement and antibody.

A heat-labile component of normal sheep serum (56 degrees C for 30 min but not 50 degrees C for 30 min) was able to lyse oncospheres in vitro. The degree of effect, and the proportion of oncospheres lysed, was related to the concentration of normal unheated sheep serum complement, or other sources of complement (rabbit, mouse) in the culture. Lower concentrations were required for lysis if the culture serum was obtained from sheep immune to E. granulosus infection. Heat inactivation of normal or immune sheep serum removed any lytic ability. No lysis occurred in any concentration of unheated foetal lamb serum. However, unheated foetal lamb serum was able to restore the lytic effect to heated normal or immune serum. This suggests that lysis in both immune and normal serum is antibody-dependent and complement-mediated. The lysis in normal serum would appear to be due to natural cross-reacting antibodies that can fix complement at the oncosphere surface. The complement lesion resulted in damage to the plasma membrane. This then peeled back, predisposing the oncosphere to osmotic destruction. The use of bleach to dissolve the embryophore caused damage to the plasma membrane similar to that caused by complement. Developing metacestodes at 3 days of age in vitro in immune serum were susceptible to the addition of complement at that time.

Animals↗
PubMed1994

Identification of M. tuberculosis ribosomal RNA in mouthwash samples from patients with tuberculosis.

It is often not possible to obtain satisfactory sputum samples from patients suspected of having pulmonary tuberculosis. In this study, we asked whether it was possible to identify M. tuberculosis ribosomal RNA (rRNA) in mouthwash samples, and in a prospective clinical study, whether the presence of this rRNA correlated with clinical M. tuberculosis infection. Using a combination of reverse transcriptase and polymerase chain reaction amplification, it was possible to identify M. tuberculosis rRNA in mouthwash samples. M. tuberculosis rRNA was identified in mouthwash samples from patients with active tuberculosis more commonly than in samples from control subjects (P < 0.05). The test was positive in four of ten patients with active pulmonary tuberculosis, one of eight contacts, none of eight past cases of tuberculosis, two of eight patients with other diagnosis and one of five healthy volunteers. M. tuberculosis rRNA was identified in sputum from four of eight patients and in bronchoscopy trap samples from four of five patients with active tuberculosis. However, one of ten sputum samples and two of five bronchoscopy samples from subjects with a clinical diagnosis other than active tuberculosis were positive. These results indicate that although it is technically possible to identify M. tuberculosis on the basis of the presence of rRNA in mouthwash samples, the poor sensitivity and specificity of the technique suggest that it is unlikely to be useful clinically.

Base Sequence↗