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Biomedical subjects

C M Jones

Publications and source records attributed to C M Jones.

At least 37 records · Page 2Linked to original sources
PubMed2000

Prevalence and severity of dental caries among American Indians and Alaska Natives.

OBJECTIVES: This paper reports findings from the 1991 IHS Patient Oral Health Status and Treatment Needs Survey (1991 IHS patient survey) and presents trends in caries among American Indian and Alaska Native (Native American) populations since 1957. METHODS: The 1991 IHS patient survey obtained data from approximately 10 percent (25,000) of the dental patients seen annually at IHS, tribal, and urban Indian clinics. The results of this survey are compared descriptively with previous surveys conducted by the IHS beginning in 1957. RESULTS: Findings from the 1991 IHS patient survey indicate that Native Americans experience a much higher prevalence of dental caries in their primary and permanent dentitions than the general US population. However, caries rates in Native American children peaked in 1983-84 and have been going down since that time. CONCLUSIONS: While progress has been made in preventing dental caries among Native Americans, the high prevalence and severity at all ages in this rapidly growing population have resulted in a large backlog of untreated disease with an overwhelming demand on the resources available to provide care. Continued emphasis on dental caries prevention and health promotion is an important part of the solution. New strategies such as targeting preventive services toward individuals and groups with the highest risk of disease and the use of modern conservative treatment methods to control disease must be employed. Full implementation of these strategies and identification of the resources required will depend upon new and ongoing partnerships among tribes, federal and state governments, and the private sector.

Adolescent↗
PubMed2000

Herpes simplex virus type 1-specific cytotoxic T-lymphocyte arming occurs within lymph nodes draining the site of cutaneous infection.

Various studies have shown that major histocompatibility complex class I-restricted cytotoxic T lymphocytes (CTL) can be isolated from lymph nodes draining sites of cutaneous infection with herpes simplex virus type 1 (HSV-1). Invariably, detection of this cytolytic activity appeared to require some level of in vitro culture of the isolated lymph node cells, usually for 3 days, in the absence of exogenous viral antigen. This in vitro "resting" period was thought to represent the phase during which committed CD8(+) T cells become "armed" killers after leaving the lymph nodes and prior to their entry into infected tissue as effector CTL. In this study we reexamined the issue of CTL appearance in the HSV-1 immune response and found that cytolytic activity can be isolated directly from draining lymph nodes, although at levels considerably below those found after in vitro culture. By using T-cell receptor elements that represent effective markers for class I-restricted T cells specific for an immunodominant glycoprotein B (gB) determinant from HSV-1, we show that the increase in cytotoxicity apparent after in vitro culture closely mirrors the expansion of gB-specific CTL during the same period. Taken together, our results suggest that HSV-1-specific CTL priming does not appear to require any level of cytolytic machinery arming outside the lymph node compartment despite the absence of any detectable infection within that site.

Animals↗
PubMed2000

Hex is a transcriptional repressor that contributes to anterior identity and suppresses Spemann organiser function.

One of the earliest markers of anterior asymmetry in vertebrate embryos is the transcription factor Hex. We find that Hex is a transcriptional repressor that can be converted to an activator by fusing full length Hex to two copies of the minimal transcriptional activation domain of VP16 together with the flexible hinge region of the (lambda) repressor (Hex-(lambda)VP2). Retention of the entire Hex open reading frame allows one to examine Hex function without disrupting potential protein-protein interactions. Expression of Hex-(lambda)VP2 in Xenopus inhibits expression of the anterior marker Cerberus and results in anterior truncations. Such embryos have multiple notochords and disorganised muscle tissue. These effects can occur in a cell non-autonomous manner, suggesting that one role of wild-type Hex is to specify anterior structures by suppressing signals that promote dorsal mesoderm formation. In support of this idea, over-expression of wild-type Hex causes cell non-autonomous dorso-anteriorization, as well as cell autonomous suppression of dorsal mesoderm. Suppression of dorsal mesoderm by Hex is accompanied by the down-regulation of Goosecoid and Chordin, while induction of dorsal mesoderm by Hex-(lambda)VP2 results in activation of these genes. Transient transfection experiments in ES cells suggest that Goosecoid is a direct target of Hex. Together, our results support a model in which Hex suppresses organiser activity and defines anterior identity.

Animals↗
PubMed1999

Use of SHIRPA and discriminant analysis to characterise marked differences in the behavioural phenotype of six inbred mouse strains.

Detailed characterisation of six inbred strains of mice commonly used in transgenic and knockout research was carried out using a battery of behavioural tests (SHIRPA) followed by discriminant analysis of the data. In the primary observation screen, DBA/2 mice were relatively irritable and vocalised during handling. C57BL/6 were hyperactive as measured by transfer arousal, arena activity and touch-escape tests. By contrast, C3H were markedly hypoactive, had significantly enhanced grip strength and were also significantly impaired on the visual placing task. In the elevated plus-maze, BALB/c mice showed the highest level of open arm entries and time spent in the open arms, indicating the lowest level of anxiety. There was a clear dissociation of strains on exploratory activity, as measured in the holeboard test and spontaneous locomotor activity (LMA). DBA/2 mice were hyperactive in LMA but demonstrated relatively low levels of holeboard exploration. None of the six strains learnt the water maze spatial learning task particularly well. C57BL/6 and 129/Sv demonstrated most ability and C3H showed no evidence of having acquired the task. The SHIRPA screening battery and discriminant analysis of the data have enabled us to determine the relevant contribution of a number of behavioural measurements to the marked differences in phenotype of mouse strains. These data confirm the importance of carrying out a comprehensive profile in order to accurately characterise the phenotype of gene-targeted and transgenic mice.

Animals↗
PubMed1999

Photofrin photodynamic therapy for treatment of AIDS-related cutaneous Kaposi's sarcoma.

OBJECTIVE: Kaposi's sarcoma, the most common malignancy in AIDS patients, often presents with painful cutaneous lesions that are difficult to treat effectively despite a wide variety of therapeutic approaches. We used photodynamic therapy in an attempt to provide effective palliative treatment for this disease. METHODS: Photodynamic therapy utilizes the activation by light of a photosensitizing drug that preferentially accumulates in tumor tissue such as Kaposi's sarcoma. We enrolled 25 patients who received 1.0 mg/kg of Photofrin 48 h before exposure to 100-400 J/cm2 of 630 nm light. RESULTS: Of the 348 lesions treated, 289 were evaluable: 32.5% had complete clinical response, 63.3% had partial clinical response and 4.2% were clinical failures. There was a strong correlation between response and light dose: 54% of lesions achieved a complete clinical response at optimum light dose (> 250 J/cm2). There was no correlation of response with CD4 cell count nor was there a change in CD4 cell count post-treatment. At 400 J/cm2 full field scabbing and necrosis occurred in 90% of the treated fields. Thus, the maximum tolerated dose was determined to be 300 J/cm2. At light doses of 250 J/cm2 and below the toxicities were limited to erythema and edema in the treatment field. Forty-three biopsies were taken 0.5 h to 4 months post-treatment. These showed little change in the B and T cell infiltrates identified. Kaposi's sarcoma cells disappeared post-treatment in certain lesions. CONCLUSION: Photofrin is effective palliative treatment for HIV-associated Kaposi's sarcoma.

Acquired Immunodeficiency Syndrome↗
PubMed1999

An anterior signalling centre in Xenopus revealed by the homeobox gene XHex.

BACKGROUND: Signals from anterior endodermal cells that express the homeobox gene Hex initiate development of the most rostral tissues of the mouse embryo. The dorsal/anterior endoderm of the Xenopus gastrula, which expresses Hex and the putative head-inducing gene cerberus, is proposed to be equivalent to the mouse anterior endoderm. Here, we report the origin and signalling properties of this population of cells in the early Xenopus embryo. RESULTS: Xenopus anterior endoderm was found to derive in part from cells at the centre of the blastocoel floor that express XHex, the Xenopus cognate of Hex. Like their counterparts in the mouse embryo, these Hex-expressing blastomeres moved to the dorsal side of the Xenopus embryo as gastrulation commenced, and populated deep endodermal adjacent to Spemann's organiser. Experiments involving the induction of secondary axes confirmed that XHex expression was associated with anterior development. Ventral misexpression of XHex induced ectopic cerberus expression and conferred anterior signalling properties to the endoderm. Unlike the effect of misexpressing cerberus, these signals could not neuralise overlying ectoderm. CONCLUSIONS: XHex expression reveals the unexpected origin of an anterior signalling centre in Xenopus, which arises in part from the centre of the blastula and localises to the deep endoderm adjacent to Spemann's organiser. Signals originating from these endodermal cells impart an anterior identity to the overlying ectoderm, but are insufficient for neural induction. The anterior movement of Hex-expressing cells in both Xenopus and mouse embryos suggests that this process is a conserved feature of vertebrate development.

Animals↗
PubMed1999

The relationship between water fluoridation and socioeconomic deprivation on tooth decay in 5-year-old children.

AIM: To examine the relationship between water fluoridation, socioeconomic deprivation and tooth decay in 5-year-olds. SETTING: 10,004 children: 1,051 in naturally fluoridated Hartlepool in 1991/92, 3,816 in fluoridated Newcastle & North Tyneside and 5,137 in non-fluoridated Salford & Trafford in 1993/94. OUTCOME MEASURES: Correlations between mean electoral ward dmft and ward Townsend Scores from the 1991 census. RESULTS: Regardless of the level of water fluoridation significant correlations were found between deprivation and tooth decay. Multiple linear regression models for dmft showed a statistically significant interaction between ward Townsend score, and both types of water fluoridation, confirming the more deprived the area the greater the reduction in tooth decay. At a Townsend score of zero (the English average) there was a predicted 43% reduction in decay in 5-year-olds in fluoridated areas. CONCLUSIONS: Tooth decay is strongly associated with social deprivation. The findings confirm that the implementation of water fluoridation has halved tooth decay in 5-year-old children and that the dental caries divide between rich and poor is reduced.

Child, Preschool↗
PubMed1999

BMP signalling in early Xenopus development.

Bone morphogenetic proteins (BMPs) are typically members of the transforming growth factor beta (TGF-beta) family with diverse roles in embryonic development. At least five genes with homology to BMPs are expressed during Xenopus development, along with their receptors and intracellular signalling pathways. The evidence suggests that BMPs have roles to play in both mesoderm induction and dorsoventral patterning. Studies in Xenopus have also identified a number of inhibitory binding proteins for the classical BMPs, encoded by genes such as chordin and noggin. These proteins appear to be responsible for establishing a morphogen gradient of BMP4 activity, which specifies different dorsoventral fates in early gastrulae. An emerging theme is that inhibition of BMP signalling is an important mechanism regulating cell fate decisions in early development.

Animals↗
PubMed1999

Pseudo-proteinuria following gelofusine infusion.

Transient massive proteinuria following cardiopulmonary bypass surgery was observed. It was characterized and attributed to post-operative gelofusine infusion. Gelofusine was found to interfere with dye binding but not immunochemical assays of proteinuria. Proteinuria following gelofusine infusion may not reflect underlying glomerular pathology.

Cardiopulmonary Bypass↗
PubMed1998

Trends in the provision of primary care dental general anaesthesia in the north of England, 1991/92 to 1994/95.

AIM: To investigate trends in the provision of primary care dental general anaesthesia (PCDGA) and any association with dental caries. DESIGN: Cross-sectional analysis of data about the provision of PCDGA in the general dental service and community dental service from 1991/92 to 1994/95. SETTING: The former North Western, Mersey, Northern and Yorkshire regions. METHOD: The combined rates of PCDGAs in the general dental service and community dental service, from 1991/92 to 1994/95 were calculated and compared with the levels of caries from the NHS dental epidemiology programme. RESULTS: All regions except the North Western had a lower rate at the end of the 1991 study but only the Northern region had a lower rate in 1994/95 than in 1993/94. Only weak correlations were found between the PCDGA rate in a health authority and the level of dental caries. CONCLUSIONS: PCDGA rates did not continue to decline during the period of this study. One of the principal recommendations of the Poswillo report was that the use of general anaesthesia should be avoided wherever possible. Other initiatives, perhaps the development of criteria for selection of patients, may be necessary if further reductions in PCDGA rates are to be achieved.

Anesthesia, Dental↗
PubMed1998

Establishment of a BMP-4 morphogen gradient by long-range inhibition.

Recent work suggests that signaling molecules such as activin are capable of acting at long range to establish a morphogen gradient in the amphibian embryo and that responding cells activate different genes at distinct threshold levels of activin. Other signaling molecules like BMP-4 and Xnr-2 also exert concentration-dependent effects, but these factors appear to diffuse less freely. This raises the question of whether gradients of these inducing factors are indeed established, and if so, how they are generated. In this paper we demonstrate directly that BMP-4 elicits graded responses in gastrula-stage embryos. We then show that an effective BMP-4 gradient is established not by diffusion of BMP-4 protein but by the long-range effects of two BMP-4 inhibitors, noggin and chordin. This provides a novel mechanism for the establishment of a morphogen gradient in vertebrate embryos.

Animals↗
PubMed1998

Visual Ability Score -- a new method to analyze ability in visually impaired children.

PURPOSE: We analyzed the correlation between the Preferential Looking (PL) acuities and the Visual Ability Scores (VAS) of 600 patients (many with severe retinopathy of prematurity) to determine their ability to perform various activities within the daily environment. METHODS: Visual acuity was measured by PL. Sixteen visual activities within the environment were analyzed. The VAS (range, 1-16) were calculated from the results of each activity and correlated with PL acuity. RESULTS: The PL acuities of the 600 patients ranged from 20/20 (1.0) to <20/3200 (0.006) [mean, 20/337(006)]. The VAS ranged from 1 to 16 points (mean, 10.65; SD, +/-4.80) and showed a high correlation with the PL acuities (r=0.917, p=0.0001). CONCLUSIONS: In addition to PL vision testing, analyzing the environmental visual behavior of young, severely visually impaired patients is important to accurately evaluate visual abilities. We found the VAS to be an important aid for low-vision specialists, especially for those with no access to a vision evaluation system such as PL.

Activities of Daily Living↗
PubMed1997

Water fluoridation, tooth decay in 5 year olds, and social deprivation measured by the Jarman score: analysis of data from British dental surveys.

OBJECTIVE: To examine the effect of water fluoridation, both artificial and natural, on dental decay, after socioeconomic deprivation was controlled for. DESIGN: Ecological study based on results from the NHS dental surveys in 5 year olds in 1991-2 and 1993-4 and Jarman underprivileged area scores from the 1991 census. SETTING: Electoral wards in three areas: Hartlepool (naturally fluoridated), Newcastle and North Tyneside (fluoridated), and Salford and Trafford (non-fluoridated). SUBJECTS: 5 year old children (n = 10,004). INTERVENTION: Water fluoridation (artificial and occurring naturally). MAIN OUTCOME MEASURE: Ward tooth decay score (score on the "decayed, missing, and filled tooth index" for each electoral ward). RESULTS: Multiple linear regression showed a significant interaction between Jarman score for ward, mean number of teeth affected by decay, and both types of water fluoridation. This confirms that the more deprived an area, the greater benefit derived from fluoridation, whether natural or artificial (R2 = 0.84, P < 0.001). At a Jarman score of zero (national mean score) there was a predicted 44% reduction in decay in fluoridated areas, increasing to a 54% reduction in wards with a Jarman score of 40 (very deprived). The area with natural fluoridation (at a level of 1.2 parts per million-higher than levels in artificially fluoridated areas) had a 66% reduction in decay, with a 74% reduction in wards with a Jarman score of 40. CONCLUSION: Tooth decay is confirmed as a disease associated with social deprivation, and the more socially deprived areas benefit more from fluoridation. Widespread water fluoridation is urgently needed to reduce the "dental health divide" by improving the dental health of the poorer people in Britain.

Child, Preschool↗