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Caroline Jones

Publications and source records attributed to Caroline Jones.

14 recordsLinked to original sources
PubMed2006

Analysis of local tissue-specific gene expression in cellular micropatterns.

While cellular micropatterning approaches are employed extensively in cell biology and tissue engineering, only a limited number of methods for analysis of local function in the context of a complex, microfabricated environment are currently available. The present study develops a novel strategy for analysis of local tissue-specific function in cellular micropatterns. Model hepatocytes (HepG2 cells) were seeded onto silane-modified glass slides containing robotically printed arrays of collagen type I. These model hepatocytes formed cell arrays with individual cell cluster dimensions (150 or 500 microm) corresponding in size to the printed collagen spots. Non-parenchymal cells (3T3 fibroblasts) were added to hepatocellular micropatterns to create heterotypic cocultures. Expression of hepatic phenotype in HepG2 cells was first verified by traditional techniques including intracellular staining and ELISA for albumin. In order to evaluate local liver function in the cellular microarray, individual array members composed of approximately 400 hepatocytes were retrieved using laser capture microdissection and analyzed with real-time reverse transcriptase (RT)-polymerase chain reaction (PCR). Hepatic function was assessed based on expression of four genes associated with differentiated liver phenotype: albumin, transferrin, alpha-fetoprotein, and alpha1-antitrypsin. "Titration" experiments, carried out to identify the smallest population of HepG2 cells yielding detectable mRNA levels and RT-PCR signals, showed that extraction area of 12,500 microm2 (corresponding to approximately 70 cells) provided detectable gene expression signals. All four liver-specific genes were routinely evaluated after extraction of approximately 400 HepG2 from the micropatterned surfaces. Significantly, selective retrieval and subsequent analysis of tissue-specific function was demonstrated for hepatic cells micropatterned alone and in coculture with non-parenchymal cells. In the future, methods described in this study will offer the possibility to investigate dynamic and reciprocal interactions between two or more cell types positioned on a microfabricated cell culture surface. We also envision the proposed approaches to be ideally suited for cell analysis in the context of combinatorial microenvironment.

3T3 Cells↗
PubMed2006

Deficits following nonoperative treatment of displaced midshaft clavicular fractures.

BACKGROUND: Displaced fractures of the midpart of the clavicular shaft are generally treated nonoperatively, and few functional deficits have been reported. Whereas prior investigators have presented radiographic and surgeon-based outcomes, we used a patient-based outcome questionnaire and objective muscle-strength testing to evaluate a series of patients who had received nonoperative care for a displaced midshaft fracture of the clavicle. METHODS: We identified thirty patients (twenty-two men and eight women with a mean age of thirty-seven years) who had sustained a displaced midshaft fracture of the clavicle. All patients were treated nonoperatively. At a mean of fifty-five months, and a minimum of twelve months, outcomes were measured with the Constant shoulder score and the DASH (Disabilities of the Arm, Shoulder and Hand) patient questionnaire. In addition, objective shoulder muscle-strength testing was performed with the Baltimore Therapeutic Equipment Work Simulator, with the uninjured arm serving as a control. RESULTS: The range of motion was well maintained, with flexion averaging 170 degrees +/- 20 degrees and abduction averaging 165 degrees +/- 25 degrees . Compared with the strength of the uninjured shoulder, the strength of the injured shoulder was reduced to 81% for maximum flexion, 75% for endurance of flexion, 82% for maximum abduction, 67% for endurance of abduction, 81% for maximum external rotation, 82% for endurance of external rotation, 85% for maximum internal rotation, and 78% for endurance of internal rotation (p < 0.05 for all values). The mean Constant score was 71 points, and the mean DASH score was 24.6 points, indicating substantial residual disability. CONCLUSIONS: Traditionally, good results with minimal functional deficits have been reported following nonoperative treatment of clavicular fractures. However, surgeon-based methods of evaluation may be insensitive to loss of muscle strength. We detected residual deficits in shoulder strength and endurance in this patient population, which may be related to the significant level of dysfunction detected by the patient-based outcome measures.

Adult↗
PubMed2005

Iatrogenic iodine as a cause of hypothyroidism in infants with end-stage renal failure.

Between 1996 and 2005, two of seven infants in our unit on overnight continuous-cycle peritoneal dialysis (CCPD) acquired hypothyroidism following normal thyroid function on neonatal screening. Case 1 had posterior urethral valves, commenced CCPD at day 29, and developed hypothyroidism requiring treatment at 3 months: TSH 258 micro/l (ref.: 0.3-3.8), total thyroxine 74 nmol/l (ref.: 77-159). Plasma iodine concentration was 7.44 micromol/l (ref.: 0.23-0.68). Iodine concentrations in peritoneal dialysis (PD) fluid were found to be higher at the end of the first cycle (11.4 micromol/l) than at the end of the twelfth cycle (1.55 micromol/l). Case 2 had posterior urethral valves, commenced CCPD on day 4 and was diagnosed with hypothyroidism following a prolonged jaundice screen. Thyroxine replacement was stopped 2 months after a renal transplant. A third child commenced CCPD on day 2 and had high plasma iodine concentrations at 8 weeks (5.79 micromol/l). He had borderline thyroid function, not requiring replacement. Our hypothesis is that these infants developed hypothyroidism as a consequence of iodine exposure via the Wolff-Chaikoff effect. Iodine levels were higher in the PD fluid than in plasma. This suggests that povidine-iodine 10% in the PD cap may be the source of the high plasma iodine levels.

Contrast Media↗
PubMed2005

Comparing action gestures and classifier verbs of motion: evidence from Australian Sign Language, Taiwan Sign Language, and nonsigners' gestures without speech.

Recent research into signed languages indicates that signs may share some properties with gesture, especially in the use of space in classifier constructions. A prediction of this proposal is that there will be similarities in the representation of motion events by sign-naive gesturers and by native signers of unrelated signed languages. This prediction is tested for deaf native signers of Australian Sign Language (Auslan), deaf signers of Taiwan Sign Language (TSL), and hearing nonsigners using the Verbs of Motion Production task from the Test Battery for American Sign Language (ASL) Morphology and Syntax. Results indicate that differences between the responses of nonsigners, Auslan signers, and TSL signers and the expected ASL responses are greatest with handshape units; movement and location units appear to be very similar. Although not definitive, these data are consistent with the claim that classifier constructions are blends of linguistic and gestural elements.

Adolescent↗
PubMed2004

Participation of African social scientists in malaria control: identifying enabling and constraining factors.

OBJECTIVE: To examine the enabling and constraining factors that influence African social scientists involvement in malaria control. METHODS: Convenience and snowball sampling was used to identify participants. Data collection was conducted in two phases: a mailed survey was followed by in-depth phone interviews with selected individuals chosen from the survey. FINDINGS: Most participants did not necessarily seek malaria as a career path. Having a mentor who provided research and training opportunities, and developing strong technical skills in malaria control and grant or proposal writing facilitated career opportunities in malaria. A paucity of jobs and funding and inadequate technical skills in malaria limited the type and number of opportunities available to social scientists in malaria control. CONCLUSION: Understanding the factors that influence job satisfaction, recruitment and retention in malaria control is necessary for better integration of social scientists into malaria control. However, given the wide array of skills that social scientists have and the variety of deadly diseases competing for attention in Sub Saharan Africa, it might be more cost effective to employ social scientists to work broadly on issues common to communicable diseases in general rather than solely on malaria.

Adult↗
PubMed2004

Malaria morbidity and immunity among residents of villages with different Plasmodium falciparum transmission intensity in North-Eastern Tanzania.

BACKGROUND: The relationship between the burden of uncomplicated malaria and transmission intensity is unclear and a better understanding of this relationship is important for the implementation of intervention programmes. METHODS: A 6-month longitudinal study monitoring risk factors for anaemia and febrile malaria episodes was conducted among individuals aged below 20 years, residing in three villages of different altitude in areas of high, moderate and low malaria transmission intensity in North-Eastern Tanzania. RESULTS: The burden of anaemia and malarial fever fell mainly on the youngest children and was highest in the village with high transmission intensity. Although a considerable percentage of individuals in all villages carried intestinal worms, logistic regression models indicated that Plasmodium falciparum was the only significant parasitic determinant of anaemia. Interestingly, children who carried low-density parasitaemia at the start of the study had a lower risk of contracting a febrile malaria episode but a higher risk of anaemia during the study period, than children who were slide negative at this point in time. CONCLUSION: Young children living in the high transmission village carried a very high anaemia burden, which could be attributed to malaria. The overall incidence of febrile malaria was also highest in the high transmission village particularly among those under five years of age. These data suggest that in rolling back malaria, available resources in prevention programmes should primarily be focussed on young children, particularly those residing in areas of high malaria transmission.

Adolescent↗
PubMed2004

Acute renal failure associated with Gemella haemolysans pneumonia.

We describe a 13-year-old boy who developed acute renal failure associated with Gemella haemolysans pneumonia. At presentation he was found to have macroscopic hematuria associated with lobar pneumonia. Gemella haemolysans was isolated from blood cultures. Renal failure was detected on admission, progressed and dialysis was required until day 18. Renal impairment had resolved by 3 months after the initial presentation. Histopathology of a renal biopsy showed focal proliferative glomerulonephritis, but the predominant abnormality was tubular damage associated with erythrocyte casts in tubular lumina. We believe that tubular damage due to hematuria rather than the glomerular changes was the most likely cause of renal failure.

Acute Kidney Injury↗
PubMed2004

A generic sandwich-type biosensor with nanomolar detection limits.

A quantitative and highly sensitive, yet simple and rapid, biosensor system was developed for the detection of nucleic acid sequences that can also be adapted to the detection of antigens. A dipstick-type biosensor with liposome amplification, based on a sandwich assay format with optical detection, was combined with a simple coupling reaction that allows the transformation of the generic biosensor components to target specific ones by a mere incubation step. This biosensor platform system was developed and optimized, and its principle was proven using DNA oligonucleotides that provided a nucleic acid biosensor for the specific detection of RNA and DNA sequences. However, the coupling reaction principle chosen can also be used for the immobilization of antibodies or receptor molecules, and therefore for the development of immunosensors and receptor-based biosensors. The generic biosensor consists of liposomes entrapping sulforhodamine B that are coated with streptavidin on the outside, and polyethersulfone membranes with anti-fluorescein antibodies immobilized in the detection zone. In order to transform the generic biosensor into a specific DNA/RNA biosensor, two oligonucleotides that are able to hybridize to the target sequence were labeled with a biotin and a fluorescein molecule, respectively. By simultaneously incubating the liposomes, both oligonucleotides, and the target sequence in a hybridization buffer for 20-30 min at 42 degrees C, a sandwich complex was formed. The mixture was applied to the polyethersulfone membrane. The complex was captured in the detection zone and quantified using a hand-held reflectometer. The system was tested using RNA sequences from B. anthracis, C. parvum and E. coli. Quantitation of concentrations between 10 fmol and 1000 fmol (10-1000 nM) was possible without altering any biosensor assay conditions. In addition, no changes to hybridization conditions were required when using authentic nucleic acid sequence-based amplified RNA sequences, and the generic biosensor compared favorably with those previously developed specifically for the RNA sequences. Therefore, the universal biosensor described is an excellent tool, for use in laboratories or at test sites, for rapidly investigating and quantifying any nucleic acid sequence of interest, as well as potentially any antigen of interest that can be bound by two antibodies simultaneously.

Animals↗
PubMed2003

Interaction of the repressor element 1-silencing transcription factor (REST) with target genes.

The repressor element 1-silencing transcription factor (REST) has been proposed to restrict expression of repressor element 1 (RE1) bearing genes to differentiated neurons by silencing their expression in non-neural tissue. Here, we have examined the interaction of REST with the M(4) muscarinic acetylcholine receptor gene. We show that REST binds to the RE1 of the M(4) gene in those cell lines and brain regions where the M(4) gene is expressed but not in those where the M(4) is not expressed. Furthermore, in cells that express M(4), the presence of REST represses but is insufficient to silence transcription of M(4). In non-neural cells REST is absent from the RE1 of the silent M(4) gene and perturbation of REST function fails to induce M(4) expression. We propose that REST acts to regulate expression levels of some RE1-bearing genes in neural cells, thereby playing an important role in defining neuronal activity.

Base Sequence↗
PubMed2003

Effect of humeral condylar resection on strength and functional outcome after semiconstrained total elbow arthroplasty.

BACKGROUND: Under certain conditions it is standard practice to excise ununited humeral condyles during insertion of a semiconstrained total elbow prosthesis. Since the osseous origins of the common extensors and flexor-pronator muscles are lost, it has been postulated that this excision has a negative effect on strength. We are not aware of any previous study in which this issue has been investigated with use of standardized, objective testing of muscle strength. METHODS: We used objective testing to determine the effect of condylar resection on the muscle strength of the elbow, forearm, wrist, and hand in thirty-two patients who had undergone total elbow arthroplasty. To eliminate bias, the normal, contralateral limb served as the control, and all strength values are given as a percentage of the normal side. The humeral condyles were intact in sixteen patients and had been resected in the other sixteen. Patient demographics were similar in the two groups. RESULTS: There were no significant differences between the two groups with regard to strength of pronation (103% of the normal side in the group with intact condyles compared with 89% in the group with resection of the condyles; p = 0.40), supination (68% compared with 89%; p = 0.49), wrist flexion (66% compared with 56%; p = 0.46), wrist extension (75% compared with 65%; p = 0.40), or grip strength (83% compared with 72%; p = 0.40). There was also no difference between the two groups with regard to the Mayo Elbow Performance Score (79 points in the group with intact condyles compared with 77 points in the group with resection of the condyles; p = 0.67). CONCLUSIONS: Condylar resection has a minimal, clinically irrelevant effect on forearm, wrist, and hand strength and no effect on the Mayo Elbow Performance Score following total elbow arthroplasty. Thus, the findings of our study support the practice of condylar resection, which simplifies total elbow arthroplasty for many conditions.

Activities of Daily Living↗
PubMed2002

Social sciences in malaria control.

The second annual meeting of the Partnership for Social Sciences in Malaria Control was held at the London School of Hygiene and Tropical Medicine, UK, from 8 to 10 January 2002.

Animals↗