Search PubMed⌕ Search

Biomedical subjects

P Price

Publications and source records attributed to P Price.

At least 217 records · Page 12Linked to original sources
PubMed1988

Patterns of breast relapse after local excision +/- radiotherapy for early stage breast cancer.

One hundred patients with breast recurrence have been identified from patients at the Royal Marsden Hospital, treated by local excision +/- radiotherapy for early stage primary invasive breast cancer between 1961 and 1985. The mean follow-up was 58 months (range 1 month - 19 years). In 74/100 patients, breast recurrence occurred within the breast parenchyma, was not associated with systemic relapse and carried a relatively good prognosis with a median survival of 77 months from the time of breast relapse. In 67 patients with parenchymal relapse in whom the site of relapse could be reliably compared with that of the original tumour, 60 (90%) patients developed recurrent tumours at or close to the primary site. In 24/100 patients, breast recurrence occurred in the overlying skin and in only two of these patients (2% of total) did recurrence actually occur within the scar tissue. Skin relapse was associated with systemic relapse and carried a relatively poor prognosis with a median survival of 36 months from the time of recurrence. The pattern of breast relapse was similar in irradiated and unirradiated patients. Skin relapse appears to be a manifestation of metastatic disease while parenchymal relapse may represent regrowth of primary tumour. This pattern of breast relapse questions the requirement for radiotherapy to the whole breast after local excision for early stage breast cancer.

Adult↗
PubMed1988

The combined use of sodium valproate and metyrapone in the treatment of Cushing's syndrome.

We have investigated the combined use of metyrapone and sodium valproate in the treatment of five cases of dexamethasone-suppressible Cushing's disease and one case with dexamethasone non-suppressible disease. Metyrapone alone reduced 24 h urinary free cortisol (UFC) and plasma cortisol concentrations. Addition of sodium valproate to metyrapone produced a further reduction in these values in five of six patients with a reduction in plasma ACTH in three of five patients who had dexamethasone-suppressible disease. Plasma 11-deoxycortisol increased markedly on metyrapone. However, addition of valproate produced a further rise in 11-deoxycortisol values in four of five patients including the patient with dexamethasone non-suppressible disease. The results suggest that valproate may be a useful addition to metyrapone in the medical treatment of some patients with Cushing's syndrome and that it may have an action both at the hypothalamus and peripherally.

Adrenocorticotropic Hormone↗
PubMed1988

Identification of protein-binding sites in the hepatitis B virus enhancer and core promoter domains.

We have investigated the role of liver-specific trans-acting factor(s) in the regulation of hepatitis B virus (HBV) gene expression. A recorder plasmid (pEcoAluCAT; HBV nucleotides 1 through 1878) was constructed containing the HBV enhancer and the promoter region of the pregenomic RNA, which was ligated to the bacterial chloramphenicol acetyltransferase (CAT) gene. Upon transfecting this plasmid into various cell lines, the CAT gene was expressed only in cells of liver origin. Moreover, competition cotransfections with pEcoAluCAT and plasmids containing HBV enhancer sequences in human hepatoblastoma-derived HepG2 cells indicated the presence of titratable trans-acting factor(s) in these cells. Gel mobility shift assays using HBV enhancer and core promoter domains confirmed the existence of sequence-specific DNA-binding proteins in liver cell nuclear extract which bound to these regions. These binding sites encompass 17- and 12-nucleotide palindromes in the HBV enhancer and core promoter domains, respectively, when mapped by the methylation interference assay.

Base Sequence↗
PubMed1987

Nematospiroides dubius and Nippostrongylus brasiliensis: delayed type hypersensitivity responses to ovalbumin in the infected mouse.

Mice (C57BL) infected with the intestinal nematode Nematospiroides dubius showed depressed delayed type hypersensitivity responses to ovalbumin administered subcutaneously in Freund's complete adjuvant. IgG and IgM responses to this inoculum were unaffected. It is unlikely that the depression arose from impairment of the ear test response because responses to an extract of the adult parasite were measurable and ear testing with lipopolysaccharide yielded normal responses in infected mice. Furthermore, mice immunized on the day of infection responded normally, whilst long term infected mice ear challenged with antigen pulsed macrophages gave depressed responses. The in vitro proliferative responses of cells from the spleens and from the lymph nodes draining the site of immunization were enhanced marginally by N. dubius infection. Furthermore, these cells induced normal or elevated adoptive delayed-type hypersensitivity and IgG responses in irradiated recipients. These findings suggest that N. dubius does not compromise the development of ovalbumin specific T cells involved in a delayed type hypersensitivity response. Evidence for the induction of suppressor cells by N. dubius is discussed, and the findings are compared with results obtained with Nippostrongylus brasiliensis, a parasite which is rejected rapidly from the mouse.

Animals↗
PubMed1987

Immunological cross-reactivity between preS2 sequences of the hepatitis B virus envelope proteins corresponding to serological subtypes adw2 and ayw.

An immune response to epitopes localized on the preS region of the hepatitis B virus (HBV) envelope (env) is elicited during recovery from HBV infection and appears to play a role in virus clearance. Anti-preS antibodies (Ab) are expected to be protective against HBV infection as indicated by the virus-neutralizing capacity of Ab to a preS2-specific synthetic peptide preS(120-145). However, there is considerable amino acid variability between preS regions corresponding to distinct serological subtypes of HBV, raising the question whether the preS sequences are sufficiently related immunologically to have the potential of inducing cross-protective immunity. To answer this question concerning the preS2 region, antisera to synthetic peptides preS(120-153) and preS(128-153) corresponding to subtypes adw2 and ayw, as well as to the native env [ayw] protein were raised. Using the resulting polyclonal Ab, an immunological relatedness between preS2 sequences of subtypes adw2 and ayw was demonstrated. On the other hand, Ab selected by affinity chromatography or by cloning hybridoma cells may recognize with strong preference subtype-specific determinants within the preS2 region when the compared antigens are in solution rather than on the solid phase. These findings have implication for the design of: (1) preS2-specific immunogens and (2) immunoassays for quantitation of preS2 sequences in HBV env proteins.

Amino Acid Sequence↗
PubMed1987

The role of bone cells in increasing metaphyseal hard tissue in rapidly growing rats treated with prostaglandin E2.

The skeletal effects of graded doses of prostaglandin E2 (PGE2) given to weanling Sprague-Dawley rats for 3 weeks were investigated to elucidate the role of bone cells in increasing hard tissue mass. Decalcified (3 micron) sections were quantified in the light microscope by point hit and intersect counting using a Merz grid. Hard tissue mass (bone and calcified cartilage) and osteoblast, osteoclast and osteoprogenitor cell numbers were counted in metaphyseal tissue bands 0.24, 0.48, 0.72, 1.20, 1.68, 2.16, 2.64, 3.12, 3.60 and 4.08 mm from the growth plate metaphyseal junction. Changes were different and more marked in the secondary spongiosa than the primary spongiosa of the proximal tibial metaphysis of treated rats. In the primary spongiosa of rats treated with 3 or 6 mg PGE2/kg/d (1) an increase in bone and hard tissue masses and (2) a decrease in osteoclasts, osteoprogenitor cell numbers and surface to volume ratio was observed. In the secondary spongiosa (lower metaphysis) of rats treated with 2 same dose levels (1) an increase in bone mass, calcified cartilage cores, and hard tissue mass and perimeter, an elevation of osteoprogenitor cell and osteoblast numbers, a depression of osteoclast, osteoclast nuclei numbers and surface to volume ratio and new sites of intramembranous ossification (woven bone formation) originating from the cortico-endosteal envelope was observed. In this growing rat skeletal model, we showed that PGE2 increases metaphyseal calcified tissue mass by depressing hard tissue resorption and stimulating the replication and differentiation of osteoblast precursors to form new foci of woven bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

The effect of enkephalin analogue on pituitary hormone release in human obesity.

To elucidate further the role of opioid systems in the neuroendocrine alterations associated with obesity, we investigated the effect of the synthetic enkephalin analogue DAMME in 11 obese subjects and 10 lean controls. Prolactin responses to DAMME were similar in lean and obese, even in those obese subjects who had absent prolactin responses to insulin-induced hypoglycaemia. The obese showed impaired growth hormone release after both DAMME and insulin-induced hypoglycaemia compared to the lean subjects. The discordance of prolactin responses to DAMME and insulin-induced hypoglycaemia in the obese suggests that altered opioid systems are unlikely to account for the hypothalamic dysfunction present in obesity.

Adult↗
PubMed1987

Hepatitis B virus produced by transfected Hep G2 cells causes hepatitis in chimpanzees.

We have reported that clonal cells derived from Hep G2 cells transfected with a plasmid containing hepatitis B virus (HBV) DNA secrete spherical and filamentous forms of hepatitis B surface antigen (HBsAg), core particles, and virions into the culture medium. Here we describe the development of typical hepatitis in two chimpanzees following intravenous inoculation with the medium in which the transfected cells had grown. The liver biopsies from these animals showed characteristic lesions in parenchyma and portal tracts, more conspicuous at an earlier time in the chimpanzee that had received a greater number of virions. The amount of HBsAg in the serum of one infected chimpanzee increased with time after the initial inoculation and then decreased concomitantly with the appearance of antibodies against HBsAg and core antigens. HBsAg remained detectable in the other animal throughout the course of the experiment. The levels of hepatitis B "e" antigen in both animals peaked at week 5, signifying the acute phase of the infection. The activities of serum enzymes that are markers for necroinflammation also increased. The hepatitis HBsAg subtype of the virions isolated from the patient whose DNA was cloned and then used for transfection of the Hep G2 cells was the same as that found in the chimpanzees. Furthermore, the restriction enzyme analysis of the viral DNA isolated from the chimpanzees was identical to the cloned DNA. Thus, HBV DNA-transfected Hep G2 cells can support the replication of virions that, in turn, produce hepatitis in chimpanzees.

Animals↗
PubMed1987

Genetically determined resistance to murine cytomegalovirus: a role for lymphocytostatic macrophages.

Sensitivity to lethal infection with murine cytomegalovirus depends on the H-2 and background phenotype. H-2d appears to confer sensitivity in isolated cells, but sensitive BALB/c (H-2d) mice also exhibit non-specific immunosuppression which may indicate an impaired protective immune response. To determine the significance and mechanism of this immunosuppression, genetic factors controlling the activation, lymphocytostatic potential and accessory cell function of peritoneal macrophages were analysed after sub-lethal infection. In BALB/c mice, the number of peritoneal cells declined by 20% on day 3 post-infection and increased threefold over normal levels by day 7 with a progressive increase in macrophage activation and differentiation. Cells collected on day 7 exhibited lymphocytostatic activity which was not influenced by indomethacin and depressed their ability to act as accessory cells in a proliferative assay. Similar changes in the numbers of activated mature macrophages occurred in moderately resistant BALB.K (H-2k) mice showing an association with the background phenotype. In contrast peritoneal cell counts from resistant CBA (H-2k) mice were depressed by 80% on day 4 and the remaining cells enhanced the proliferation of syngeneic lymphocytes. However, later in the infection the percentage of peritoneal cells releasing virus declined rapidly and fewer cells became lymphocytostatic in both H-2k strains.

Animals↗
PubMed1987

Functional changes in murine macrophages infected with cytomegalovirus relate to H-2-determined sensitivity to infection.

Peritoneal macrophages were infected with murine cytomegalovirus in vitro, and indices of infection and macrophage function were monitored over 4 days. When the cells were assessed for the expression of viral antigen or for cytopathic effects, infection was found to be solely determined by the H-2 phenotype. Less than 10% of the macrophages from resistant H-2k strains were affected, whereas 90% of H-2d cells and approximately 80% of H-2b and H-2a cells became infected. Similar trends were demonstrable by the measurement of viral DNA. In H-2a cells (B10.A), Dd conferred sensitivity despite the resistant K and class II phenotype. The findings suggest a critical association between the class I antigens and an early stage in the infectious process. Indices of infection were paralleled by a loss of Fc receptor expression and optimal colloidal gold uptake, whereas most cells remained trypan blue negative, retained dehydrogenase and acid phosphatase activities, and did not release infectious virus during the period of study. This is consistent with a role for macrophages in the persistence of cytomegalovirus in the host.

Animals↗
PubMed1986

Periodicity in orientation discrimination and the unconfounding of visual information.

Orientation discrimination is a periodic function of mean orientation. Discrimination sensitivity (i.e. threshold-1) was measured at 7.5 deg increments around the clock for an 8 c/deg grating subtending 1.0 deg dia located 1.25 deg from the foveal centre. Discrimination sensitivity was best for horizontal and vertical orientations, but did not fall monotonically to minima at 45 deg and 135 deg. Instead it fell precipitously to minima at angles of only 20 deg to the horizontal and vertical, and there was a weak submaximum near 45 deg. This finding is consistent with the proposal that orientation discrimination is determined by the relative activity of broadly-tuned, orientation-sensitive neural elements, and that only a small number of elements are effective in any small retinal region. This idea can also explain why subjects do not confound a change of orientation with a simultaneous change of contrast or spatial frequency.

Discrimination, Psychological↗
PubMed1986

Prospective randomised trial of single and multifraction radiotherapy schedules in the treatment of painful bony metastases.

A prospective randomised trial comparing a single fraction of 8 Gy with 30 Gy in 10 daily fractions for the relief of metastatic bone pain was performed. In 28 months, 288 patients were randomised. Pain was assessed using a questionnaire completed by the patient at home on a daily basis. No difference was found in the speed of onset or duration of pain relief between the two treatment regimes, and pain relief was independent of the histology of the primary tumour.

Bone Neoplasms↗
PubMed1986

Immunological consequences of intestinal helminth infections. Cellular and anamnestic responses to ovalbumin.

Depressed IgG responses to ovalbumin administered with the inflammatory adjuvant, Al(OH)3, have previously been demonstrated in mice immunized 5 to 13 days after infection with Nematospiroides dubius, when the parasite is encysted in the intestinal mucosa or becoming established in the lumen. This report extends these findings to show that primary IgE and delayed-type hypersensitivity (DTH) responses, the generation of antigen-primed cells detectable in syngeneic irradiated recipients or in vitro and the recall of immunological memory are correspondingly impaired. Co-transfer experiments using irradiated recipients demonstrated weak suppressor activity in spleen cells from infected mice which was not attributable to T cells. The results suggest that N. dubius administered before immunization can impair the development of many classes of antigen-primed lymphocytes. The implications of this finding with respect to parasite survival are discussed.

Aluminum Hydroxide↗
PubMed1986

Immunological consequences of intestinal helminth infections: antigen presentation and immunosuppression by peritoneal cells.

The functional characteristics of peritoneal cells (PC's) acquired in response to infection with Nematospiroides dubius were studied to identify changes which could be associated with the high level, long-term survival of this parasite or explain its transient immunosuppressive properties. The number of cells in the peritoneal cavity increased steadily during the infection, and the population displayed a transient hyperresponsiveness to inflammatory stimulation. N. dubius did not affect the ability of antigen-pulsed PC's to induce humoral responses or delayed-type hypersensitivity (DTH) in primed recipients, but lymphoproliferative responses induced in vitro were depressed by PC's from infected donors. In addition, unpulsed PC's from N. dubius-infected mice depressed proliferative responses to parasite antigens by autologous mesenteric lymph node cells. These effects are attributable to increased lymphocytostatic activity in the PC's, which peaked one week after infection and correlated with the expansion of a population of large plastic-adherent vacuolated cells with elevated acid phosphatase activity (activated macrophages). Comparable inhibitory cells did not develop in the same period of time during a short-lived infection with Nippostrongylus brasiliensis.

Aluminum Hydroxide↗