Search PubMed⌕ Search

Biomedical subjects

G Martin

Publications and source records attributed to G Martin.

At least 289 records · Page 16Linked to original sources

Flexible pay arrangements. The need for a systematic approach.

Regrading large numbers of staff is a difficult and sometimes painful exercise. Mike Palmer and Graham Martin describe how job evaluation was used in a restructuring of pathology staff and argue that the technique will be increasingly valuable when pay is settled at the local level.

England↗

Neurophysiological effects of substance P in primate hypertension models. Preliminary report.

Peripheral administration of the neuropeptide Substance P (SP) in rhesus monkeys and baboons caused a long lasting decrease in blood pressure, accompanied by a gradual normalization function of stress-induced bioelectrical activity changes in brain structures, relevant for cardiovascular regulation (frontal cortex, ncl. raphe, locus coeruleus). In addition, SP was found to normalize the disturbed interaction of brain structures of both hemispheres. Use of SP as a putative agent to treat essential hypertension in humans needs further studies.

Animals↗

An analysis of the Community Periodontal Index of Treatment Needs. Studies on adults in France. III--Partial examinations versus full-mouth examinations.

1005 persons were examined using the Community Periodontal Index of Treatment Needs. Presence or absence of every clinical sign was registered for each tooth. A specially written program computed CPITN values corresponding to full mouth or partial examinations. Results compare the prevalence and treatment needs obtained through either full mouth or partial examinations. Cross tabulation analysis of the number of cases detected by full mouth and partial examinations shows differences in detection rates of 23.5 per cent for deep pockets, 17.6 per cent for moderate pockets, 13.4 per cent for calculus, 3.2 per cent for bleeding and 53.0 per cent for health. When determining treatment needs using the partial examination procedure approximations of the number of subjects needing hygiene education and scaling are acceptable but the evaluation of the number of individuals needing complex therapy is greatly underestimated. The CPITN is most accurate using full mouth examinations.

Adolescent↗

[Effect of a sanguinarine mouthwash on children with and without upper extremity motor handicap].

A survey was done at the Center of Child Readaptation at Flavigny (Meurthe-et-Moselle) to determine the effect of a mouth rinse containing 0.03% sanguinaria extract, on the plaque accumulation and gingivitis of 30 children 8 to 17 years old. 13 children had a motricity handicap of their superior members and 17 did not. All subjects rinsed their mouths twice with 15 ml of solution each time. The mouth rinses were performed in the morning and in the evening during three weeks. The children were photographed and examined using the P1I and GI indices on days 0, 7, 14, 21 and 35. No statistical significant difference was observed at any moment between children with or without handicapped upper limbs. After 3 weeks of treatment the Plaque Index had decreased 47.3% and Gingival Index 55.6%.

Adolescent↗

[Congenital convexity of the feet. Anatomical study and practical conclusions].

The authors have studied the pathological anatomy of two congenital pes convex, (C.P.C) coming from an 8 days boy suffering of arthrogryposis. One of the feet has been dissected by stage whilst the other one has been operated on according to a procedure of correction of the deformities. The two feet combined an irreducible dislocation of the os naviculare on the neck of the talus, a calcaneo cuboïdeum subluxation, a moderate equinus of the hind foot, an important contracture of the extensor tendons and an elongation of the structural soft tissues of the sole. The main abnormalities of the talus and of the calcaneus involved the upper direction of the anterior articular facet, in relation to the dorsal dislocation of the os naviculare and the dorsal subluxation of the cuboïdeum. The subtalaris joint was little altered. The study of dissections and the clinical reports published connected with the observations of the authors confirm the pre-eminence of the transversal dislocation of the tarsus and of its irreducibility. On the other hand the abnormalities of the subtalar joint have been, probably over estimated. The sometimes important increase of talo calcaneal angle on A.P. radiographies may be explained by the incidence itself. The verticality of the talus is not a reliable feature of C.P.C. and the deformities of the fore foot are variable (pronation, supination). This study leads to a new definition of the C.P.C.: Congenital deformity of the foot with tarsi-transversa dislocation or subluxation involving mainly the talo-navicular joint. The criterious of diagnosis are debated and a logical surgical procedure of correction is suggested.

Ankle Joint↗

Adenovirus E1A represses protease gene expression and inhibits metastasis of human tumor cells.

Stable transfection of human tumor cell lines with the adenovirus-5 E1A gene repressed the expression of the secreted proteases, type IV collagenase, interstitial collagenase and urokinase. In addition, E1A blocked the 12-O-tetradecanoyl phorbol acetate (TPA) induction of interstitial collagenase transcription in HT1080 fibrosarcoma cells. Plasmids bearing the interstitial collagenase or type IV collagenase 5' flanking regions linked to a chloramphenicol acetyl transferase coding sequence were constructed and analysed for expression by transient cotransfections into HT1080 cells. Cotransfection with a plasmid bearing a functional E1A gene repressed transcription of the type IV collagenase promoter and blocked the TPA induction of the interstitial collagenase promoter. Furthermore, E1A repressed transcription from a TK promoter driven by AP-1 complex binding sites (TRE), suggesting that E1A interferes with the AP-1 trans-activation pathway. This effect was not, however, due to the repression of c-jun gene transcription by E1A. In fact, the expression of E1A rendered the c-jun gene hypersensitive to TPA induction. Concomitant with reduction in expression levels of secreted proteases, stable E1A transfectants showed reduced metastatic activity in vivo and reduced ability to traverse a reconstituted basement membrane in vitro. Monospecific anti-type IV collagenase antibodies inhibited invasive activity of parental tumor cell lines in the in vitro assay, suggesting a possible causal relationship between the repression of secreted proteases and loss of metastatic properties of the transformants.

Adenovirus Early Proteins↗

Anchorin CII, a collagen-binding chondrocyte surface protein of the calpactin family.

In an attempt to identify collagen-binding proteins on the chondrocyte surface, a protein of Mr 34KD, called Anchorin CII was isolated from chondrocyte membranes by affinity chromatography on type II collagen sepharose (Mollenhauer & von der Mark, 1983). The protein was localized on the chondrocyte surface by immunofluorescence labeling using a specific rabbit antibody (Mollenhauer et al., 1984), by immunogold labeling and by cell surface iodination (Pfäffle et al., 1988). Fab'fragments of anti anchorin CII reduced the binding of chondrocytes to type II collagen substrates (Mollenhauer et al., 1984). Analysis of the complete primary structure of anchorin CII revealed 4 repetitive domains of each 70-80 amino acid residues, and the absence of hydrophobic transmembrane sequences or signal peptides (Fernández et al., 1988). Thus, anchorin CII is another member of the calpactin/lipocortin/annexin family, although most other members of this family are located strictly intracellularly. Similar to lipocortin I, however, anchorin CII can be identified extracellularly, e.g. in the culture medium of chondrocytes and fibroblasts (Pfäffle et al., 1988). Here we report on further studies on sequence homologies to other annexins, and on the Ca(++)- and phospholipide binding of this protein.

Amino Acid Sequence↗

[Evaluation of time needed to treat periodontal conditions classified according to the C.P.I.T.N. index].

A questionnaire was sent to 623 members of the "French Society of Periodontology" with a view to assessing the time necessary to provide instructions concerning hygiene, carry out root planing, surgery on 3.5 to 5.5 mm pockets, surgery on pockets of 6 mm or more, and to ensure maintenance. 282 responses were received from the practitioners and were computer analysed. The time required for instructions concerning hygiene was estimated to be approximately 15 mn. This information was usually repeated 4 times. It was determined that scaling and root planing require an average of 29.19 mn per sextant. The surgical interventions for 3.5 to 5.5 mm and 6 mm or more pockets are estimated to last an average of 77.03 and 107.36 mn respectively. Finally, the assessment of the time necessary for maintenance of the whole mouth was 30 to 60 mn, with an average of 45.11 mn. A quarterly check-up was recommended by 48.9% of the practitioners. The treatment of complex cases requires much more time, and maintenance is indispensable in order to avoid relapse. A plaque control programme undertaken sufficiently early might avoid long treatment stages.

Dental Scaling↗

[In vitro study of the cytocompatibility of 3 biological glues].

Human derived fibrin glues are being used with increasing frequency in periodontal surgery. Three different fibrin glues were tested in an in vitro system for gingival fibroblast proliferation. The results show a cytocompatibility of these products which justifies their employment in periodontal therapy.

Biocompatible Materials↗

[Potentiometric concentration determination of cyanide ions in waste water].

Electrodic systems, consist of gold or silver and metals of the IV, or V, subsidiary groups of the periodic system of elements are qualified for that, because they based strength of their electrodic steepness, selectivity, potentionel stability and sensibility by destination of cyanid ions in waste-water. We are going to introduce a fast-analysis-method for cyanid ions in waste-water of technical processes, which had been tested practically by the continuous control of limits, demanded by the legislator.

Calibration↗

Simultaneous synthesis and degradation of glutamine in isolated rat liver cells. Effect of vasopressin.

When hepatocytes suspensions obtained from whole livers of 48-h-fasted rats were incubated in Krebs-Henseleit buffer with a near-physiological concentration (1 mM) of L-[1-14C]glutamine as substrate, the apparent removal of glutamine was low, but the release of 14CO2 was much larger than the enzymatically measured removal of glutamine. This indicates that glutamine was metabolized at rates much higher than those accounted for by the apparent removal of glutamine. This also suggests that glutamine utilization was, at least in part, masked by concomitant synthesis of glutamine from endogenous substrates via glutamine synthetase. Evidence that such synthesis occurred was obtained by: (i) addition of methionine sulfoximine, an inhibitor of glutamine synthetase, which caused a large increase in the apparent removal of glutamine; and (ii) measurement of the specific radioactivity of L-[1-14C]glutamine which was shown to decrease during incubation. Addition of vasopressin (10(-7) M) led to a marked increase in glutamine removal by a dual mechanism: it accelerated flux through glutaminase, the enzyme which initiates the hepatic degradation of glutamine, and inhibited flux through glutamine synthetase.

Animals↗

Stimulation of glutamine metabolism by the antiepileptic drug, sodium valproate, in isolated dog kidney tubules.

The effects of sodium valproate, a widely used antiepileptic drug and an hyperammonemic agent, on glutamine and glutamate metabolism were studied in isolated dog kidney tubules. Valproate markedly stimulated glutamine removal as well as the formation of ammonia, aspartate, pyruvate, lactate, alanine and glucose; the increase in ammonia formation was explained by a stimulation by valproate of flux not only through glutaminase (EC 3.5.1.2) but also through glutamate dehydrogenase (EC 1.4.1.3). By contrast, valproate did not stimulate glutamate removal or ammonia, aspartate and glucose formation from glutamate; this suggests that the increase in flux through glutamate dehydrogenase with glutamine as substrate was secondary to the increase in flux through glutaminase. Accumulation of pyruvate, alanine and lactate in the presence of valproate was much less from glutamate than from glutamine. Inhibition by amino-oxyacetate of accumulation of aspartate and alanine from glutamine caused by valproate did not prevent the acceleration of glutamine utilization and the subsequent stimulation of ammonia formation. These data are consistent with a stimulatory effect of valproate primarily exerted at the level of glutaminase in dog kidney tubules. However, the fact that assayed activity of glutaminase remained unchanged in the presence of valproate suggests that this compound accelerates flux through the latter enzyme by an indirect mechanism probably related to the renal metabolism of this compound.

Alanine↗

Granulocyte-macrophage colony-stimulating factor is an endogenous regulator of cell proliferation in juvenile chronic myelogenous leukemia.

Juvenile chronic myelogenous leukemia (JCML) is a rare myeloproliferative disorder of early childhood that is clinically and cytogenically distinct from the well-recognized adult type of chronic myeloid leukemia. Unlike the adult disease, growth of hematopoietic progenitors from peripheral blood (PB) occurs in the absence of exogenous stimulus even at low cell densities. This so-called "spontaneous" growth can be abrogated by adherent cell depletion and appears to depend on production of endogenous growth factors. We studied seven children with JCML to determine the nature of endogenous stimulators. With isolated PB mononuclear cells (PBMNCs) and a 3H-thymidine (3H-TdR) incorporation assay, JCML cells were shown to incorporate high levels of 3H-TdR when cultured in the absence of stimulus even at low cell densities. When neutralizing antisera prepared against each of the four known colony-stimulating factors (CSFs), GM-CSF, G-CSF, M-CSF, and interleukin-3 (IL-3), as well as antisera against interleukin-1 (alpha and beta) and tumor necrosis factor (TNF) were added to these cultures, only the antisera against recombinant human GM-CSF (rhGM-CSF) consistently resulted in significant inhibition of cell proliferation, achieving up to 72% inhibition of 3H-TdR incorporation in one case. Monoclonal antibodies (MoAbs) against rhGM-CSF resulted in a similar and highly significant degree of inhibition. A marked inhibitory effect of rhGM-CSF antiserum on "spontaneous" growth of PB CFU-GM derived colonies in semisolid medium was also demonstrated in four of five patients studied (87% to 90% inhibition). Production of growth factors by highly enriched JCML monocytes was variable. When initially studied in five of the seven patients, the monocytes from three of the patients revealed increased release of IL-1-like activities; two patients had levels similar to those of controls. One patient with normal levels when initially studied was later shown to have markedly increased amounts of IL-1-like activities in a second preparation of monocyte-conditioned medium (MCM). High levels of GM-CSF were detected in the initial MCM from one patient, but this may have indirectly reflected elevated IL-1-like activities present in the MCM. IL-3 and M-CSF levels were either low or undetectable in the patients studied as compared with MCM prepared with normal adult monocytes. These results clearly implicate GM-CSF as the primary endogenous regulator of JCML cell proliferation in culture and suggest that this malignant myeloproliferative disease may in part result from paracrine stimulation of marrow progenitor cells by growth factors/cytokines secreted by the malignant monocytes.

Bone Marrow↗

Electrophysiological properties of ventromedial medulla neurons in response to noxious and non-noxious stimuli in the awake, freely moving rat: a single-unit study.

The spontaneous and evoked activities of ventromedial medulla (VMM) neurons have been recorded in the chronic, awake, freely moving rat. The vast majority of neurons located at the level of the nucleus raphé magnus exhibited an irregular and variable (2-16 Hz) spontaneous activity and were activated by either cutaneous or auditory stimuli. Within this convergent neuronal class the neurons were activated by either cutaneous noxious and non-noxious inputs. The threshold for cutaneous activation was likely very low since a majority of units responded to air puffs, but the application of controlled brushing and pin-prick revealed that the VMM convergent neurons responded more for the noxious mechanical stimulation. Similar findings were found with pinch application. For both innocuous and noxious stimuli, the cutaneous receptive field was extremely extensive (almost all of the body); however, the application of the controlled brushing showed that for this innocuous stimulation, the most sensitive regions were the tail, back, snout and vibrissae and, to a lesser extent, the flank and paws. Preliminary experiments indicated that both the spontaneous and evoked activities of VMM convergent neurons were inhibited during stressful manipulations such as scruff lifting or defense reactions. These data contrast with other studies on VMM single unit recordings in anesthetized rats since the majority of these studies did not emphasize the VMM convergent group; in addition, with one exception, we did not find neurons exclusively driven by noxious inputs. Without excluding a role of the VMM convergent group in pain descending control systems, we proposed that this neuronal class is perhaps also involved in pain transmission or in general processess such as alertness and stress. Experiments are proposed in order to precisely determine the involvement of the VMM convergent neurons in alertness versus sensory discriminative aspects of nociception in the awake, freely moving rat.

Action Potentials↗