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Biomedical subjects

L Jones

Publications and source records attributed to L Jones.

At least 145 records · Page 8Linked to original sources
PubMed1998

Peritoneal metastases in children with cancer.

BACKGROUND: This study attempted to evaluate the childhood malignancies associated with computed tomography (CT) detected peritoneal metastases as well as the diagnostic imaging characteristics of these metastases as shown on CT. METHODS: The authors reviewed all available pathology specimens and abdominopelvic CT scans of patients identified as having peritoneal metastases at three childhood cancer centers. Patient demographics, primary diagnosis, and CT characteristics of such metastases were evaluated. RESULTS: Peritoneal metastases were identified by CT in 32 children with cancer either at diagnosis (n = 20) or up to 6.2 years from diagnosis (n = 12). On CT, peritoneal disease appeared as a mass in 26 cases, as studding in 11 cases, as peritoneal enhancement in 15 cases, and as diffuse caking in 4 cases (15 patients had > 1 category of peritoneal metastasis). Thirteen patients had concurrent metastases in other sites. Fourteen patients died of progressive disease at a median of 10 months from the time peritoneal metastases were identified on CT. At last follow-up, the remaining 18 patients were alive, with follow-up ranging from 1 month to 9.7 years. As expected, peritoneal metastases were identified in patients with germ cell tumors and colon carcinoma. However, they also were observed in patients with epithelioid carcinoma, leiomyosarcoma, pineoblastoma, neuroblastoma, melanoma, and peripheral neuroectodermal tumor. CONCLUSIONS: Peritoneal metastases have variable appearance on CT, but most commonly appear mass-like. They are associated with a wider range of primary diagnoses than reported previously. The outcome varies with the type of the primary tumor and its responsiveness to existing therapies.

Adolescent↗
PubMed1998

Differences in uterine position of reproductively normal mares and those with delayed uterine clearance detected by scintigraphy.

The position of the uterus within the abdomen may affect a mare's ability to rapidly clear the uterine lumen of contamination. In this study, the position of the uterus was determined from left and right lateral flank scintigrams taken 1 and 2 h after intrauterine infusion of radiocolloid. Scintigraphy was performed during estrus in 44 mares, 24 were reproductively normal and 20 exhibited a delay in uterine clearance. Reproductively normal mares were nulliparous (n = 14) or pluriparous (n = 10), 3 to 21 yr of age, had no history of persistent uterine infections and cleared > 50% of a radiocolloid within 2 h of infusion into the uterus. Mares that exhibited a delay in uterine clearance were pluriparous (n = 18) or nulliparous (n = 2), 12 to 24 yr of age, had a history of endometritis and cleared < 30% of a radiocolloid within 2 h. The angle between the caudal-ventral aspect of the uterine image and cervix relative to horizontal as visualized on the scintigram was measured with a protractor. Results were analyzed by the General Linear Model System. The uterine-cervical angle relative to horizontal was more ventral in mares with delay in uterine clearance and was more horizontal in reproductively normal mares (mean +/- SEM-111.6 +/- 3.6 for delay in uterine clearance mares; 147.6 +/- 3.9 for reproductively normal mares; P < 0.0001). The mean angle for reproductively normal, pluriparous mares was steeper than that for nulliparous mares (141.1 +/- 2.9, 152.3 +/- 2.44 respectively; P = 0.004). There were no differences in angles between left and right lateral views within individuals. We conclude that a uterus that tilts ventrally in relation to the pelvic brim may contribute to the inability of delay in uterine clearance mares to rapidly clear their uterine lumen of contamination. Parity may contribute to the more ventral orientation of the uterus.

Animals↗
PubMed1998

A phase contrast (PC) rephase/dephase sequence of magnetic resonance angiography (MRA): a new technique for imaging distal run-off in the pre-operative evaluation of peripheral vascular disease.

OBJECTIVE: To prospectively compare a 3-D phase contrast (PC) magnetic resonance angiography (MRA) sequence (rephase/dephase) with digital subtraction angiography (DSA) in pre-operative evaluation for femoropopliteal grafting in peripheral vascular disease. Assessment of distal run-off vessels and suggested siting of distal graft anastomosis to the above or below knee segment of the popliteal artery was made. METHODS: Twenty-two lower extremities booked for infra-inguinal vascular reconstruction were imaged pre-operatively using MRA and DSA. A PC rephase/dephase sequence which includes gradient motion refocusing (Siemens 1.0 T Magnetom Impact TR 50 ms, TE 14/14 ms and 15 degree flip angle) and 3-D MIP algorithm reconstruction was used to obtain the MR images. Standard techniques were used to obtain the DSA images, and the mean and median time between imaging modalities was one month. Blinded review by a consultant vascular radiologist scored nine vessel segments for each limb and assessed which popliteal arterial segment would be most suitable for distal anastomosis. RESULTS: The score from DSA and MRA agreed for 155/198 vessel segments (kappa 0.57) and the suggested siting for distal anastomosis agreed for 19/22 limbs (kappa 0.72). Eighteen limbs had surgery as planned (distal anastomosis to the above knee popliteal eight limbs, below knee popliteal 10 limbs). For three limbs the siting of the distal anastomosis suggested by DSA and MRA disagreed. The more accurate modality was proved for one of three limbs and showed MRA to be superior to DSA. CONCLUSION: Three-dimensional PC rephase/dephase MRA is a promising technique which compared well with DSA in the pre-operative assessment of distal run-off for femoropopliteal grafting.

Aged↗
PubMed1998

Apoptosis after gamma irradiation. Is it an important cell death modality?

Apoptosis and necrosis are two different forms of cell death that can be induced by cytotoxic stress, such as ionizing radiation. We have studied the importance of apoptotic death induced after treatment with 6 Gy of gamma-irradiation in a panel of eight human tumour cell lines of different radiosensitivities. Three different techniques based on the detection of DNA fragmentation have been used, a qualitative one--DNA ladder formation --and two quantitative approaches--in situ tailing and comet assay. No statistically significant relationship between the two quantitative assays was found (r= 0.327, P = 0.159) so these methods seem to show different aspects of the process of cell death. The presence of the DNA ladder related well to the end-labelling method in that the least amount of end labelling was seen in samples in which necrotic degradation rather than apoptotic ladders were seen. However, as the results obtained by the comet assay are not in agreement with the DNA ladder experiments, we suggest that the distinction between the degraded DNA produced by apoptosis and necrosis may be difficult by this technique. Finally, although apoptosis has been proposed to be dependent on p53 functionality, and this may explain differences in cellular radiosensitivity, no statistically significant relationship was found between these parameters and apoptosis in the eight cell lines studied.

Apoptosis↗
PubMed1998

A family based association study of T102C polymorphism in 5HT2A and schizophrenia plus identification of new polymorphisms in the promoter.

Several studies have shown an association between schizophrenia and the C allele of a T-C polymorphism at nucleotide 102 and the 5HT2A receptor gene. In the present study we observed this association in a sample of 63 parent/offspring trios where the proband received a diagnosis of DSM-III-R schizophrenia using TDT analysis (chi2 = 6.26, P= 0.006, chi2 = 9.00, P=0.001 when one affected offspring was selected at random from each family, suggesting that the results are due to association rather than linkage). There was no significant difference between the transmission of C102 from heterozygous fathers and mothers, which fails to support a role for genomic imprinting in this effect. T102C does not result in an alteration of the amino acid sequence of the protein. We therefore screened the promoter of 5HT2A for polymorphisms using single-strand confirmation polymorphism analysis. An A-G polymorphism at -1438 that creates an HpaII restriction site was identified. This was found to be in complete linkage disequilibrium with T102C and is hence a candidate for the pathogenic variant in schizophrenia. Functional analysis of A-1438G using luciferase assay demonstrated significant basal promoter activity in 5HT2A expressing HeLa cells by both the A and G variants. However, comparison of the A and G variants showed no significant differences in basal activity nor when promoter activity was induced by cAMP and protein kinase C-dependent mechanisms.

Adult↗
PubMed1998

A meta-analysis and transmission disequilibrium study of association between the dopamine D3 receptor gene and schizophrenia.

We performed a meta-analysis of over 30 case-control studies of association between schizophrenia and a bi-allelic, Bali polymorphism in exon 1 of the dopamine D3 receptor gene. We observed a significant excess of both forms of homozygote in patients (P = 0.0009, odds ratio (OR) = 1.21, 95% Confidence Interval (CI) = 1.07-1.35) in the combined sample of 5351 individuals. No significant heterogeneity was detected between samples and the effects did not appear to be the product of publishing bias. In addition we undertook an independent, family-based association study of this polymorphism in 57 parent/proband trios, taken from unrelated European multiplex families segregating schizophrenia. A transmission disequilibrium test (TDT) showed a significant excess of homozygotes in schizophrenic patients (P = 0.004, odds ratio (OR) = 2.7, 95% CI = 1.35-5.86). Although no significant allelic association was observed, a significant association was detected with the 1-1 genotype alone (P = 0.02, OR = 2.32, 95% CI = 1.13-4.99). In addition when the results of the family-based association study were included in the meta-analysis, the homozygosity effect increased in significance (P = 0.0002, OR = 1.23, 95% CI = 1.09-1.38). The results of the meta-analysis and family-based association study provide independent support for a relationship between schizophrenia and homozygosity at the Bali polymorphism of the D3 receptor gene, or between a locus in linkage disequilibrium with it.

Alleles↗
PubMed1998

A study of chromosome 4p markers and dopamine D5 receptor gene in schizophrenia and bipolar disorder.

There are several lines of evidence which suggest that chromosome 4p may contain a major susceptibility locus for the functional psychoses. We previously reported a family (family 50) with cases of schizophrenia and schizoaffective disorder which gave maximum lod scores of 1.96 and 1.84 respectively with the markers D4S403 and a microsatellite near to DRD5 (DRD5-M). More recently Blackwood and co-workers described a family segregating bipolar and unipolar affective disorders which gives a maximum lod score of 4.1 with the marker D4S394, which lies 10 cM from D4S403. They obtained a combined maximum lod of 3.3 in their total sample of 12 bipolar families and found significant evidence of heterogeneity (chi 2 = 18.8, df = 2, P = 0.00008). Here we report the results of a linkage study of chromosome 4p markers in a sample of 24 multiply affected families with schizophrenia and related disorders. We obtained an overall maximum lod of 1.12 with D4S403 under both dominant and recessive modes of transmission, with no statistical support for heterogeneity within our sample. Examination of family by family data shows that only family 50 appears to show linkage at this locus. However, a discrepancy exists since our study examined families fulfilling criteria for a linkage study of schizophrenia while Blackwood et al examined families included in a genetic linkage study of bipolar disorder. This may be explained by the clinical features displayed by members of family 50, which show that all the affected members have some affective symptoms. It is therefore possible that a broad phenotype including unipolar depression, bipolar disorder, schizoaffective disorder and schizophrenia when accompanied by significant affective symptoms can result from mutations within a gene in this region. The dopamine D5 receptor gene lies within the region identified by the linkage studies and is therefore a major candidate for the putative disease gene. In family 50 we have looked for mutations of DRD5 by sequence analysis of the coding region and single stranded conformational polymorphism (SSCP) analysis of the promoter. SSCP analysis of the coding and promoter regions have also been carried out in unrelated cases of DSM-IIIR schizophrenia. Finally association studies of the (TC)n repeat in the promoter and schizophrenia, and DRD5-M and bipolar disorder were performed. These studies provided no further evidence supporting the possibility that mutations in DRD5 give rise to the linkage findings or are acting as susceptibility loci in schizophrenia or bipolar disorder.

Base Sequence↗
PubMed1998

Value of assessing parathyroid hormone-like activity in a case of extreme hypercalcaemia.

A previously well 70 year old woman was admitted to hospital following a three day history of vomiting and confusion. Her serum calcium was 6.58 mmol/l, phosphate 1.09 mmol/l, and alkaline phosphatase 91 iu/l. The mechanism of this hypercalcaemia was not obvious as there was no evidence of a primary malignancy, lymphadenopathy or hepatosplenomegaly. The calculation of indices of urinary excretion of calcium and phosphate suggested the presence of excessive parathyroid hormone (PTH) activity as the mechanism of hypercalcaemia. Plasma intact PTH, 25-hydroxycholecalciferol, and 1,25-dihydroxycholecalciferol were not raised suggesting the presence of PTH related peptide (rP). This led to a systematic search for a malignancy, which revealed the presence of a high grade B cell non-Hodgkin's lymphoma confined to the bone marrow. Plasma PTH-rP was subsequently shown to be raised confirming the interpretation of the initial urinary and calcium excretion indices. This case highlights the value of standard laboratory measurements such as urinary calcium and phosphate excretion in cases of hypercalcaemia of obscure aetiology, which can complement measurements of PTH and other calcitropic hormones.

Aged↗
PubMed1998

Pleural disease in patients undergoing lung transplantation for cystic fibrosis.

Cystic fibrosis (CF) is associated with varying degrees of pleural inflammatory reaction that occurs as a result of chronic pulmonary infections and intervention to pleural space. The amount of pleural reaction is associated with the difficulty involved when performing the pneumonectomy at the time of lung replacement. The aim of this study is to identify possible pre-transplantation parameters that may predict the extent of pleural adhesion density. The charts of the 32 CF patients who underwent lung transplantation were reviewed. The degree of pleural adhesions was graded as none, minimal, moderate or severe, by extensive retrospective chart review of the operative and pathology reports. Available Brasfield radiographic scores, chest computerized tomographic (CT) scan scores, and pulmonary function test results were correlated to the pleural density grades. CT scans were scored by one radiologist as none, mild focal, moderate focal, diffuse mild or severe pleural disease. The presence of severe adhesions was associated with lower diffusion capacity corrected for volume (DL(CO)/VA) (p=0.0022) and older age (p<0.05) at the time of transplant. The typical radiographic and pulmonary function findings of airway obstruction, parenchymal nodularity and air trapping did not correlate with pleural adhesion density. The eleven patients with severe pleural adhesions had a longer ICU course and remained intubated longer than the thirteen patients with none or minimal adhesions. The extent of severe adhesions associated with CF cannot be predicted by preoperative Brasfield radiographic scores of parenchymal disease or spirometry data. However, chest CT imaging and DL(CO)/VA measurements may be useful in predicting the extent of pleural adhesions and the degree of dissection difficulty associated with the pneumonectomies for lung transplantation in the CF recipients.

Adolescent↗
PubMed1998

Feasibility of pre-admission nurse clerking of patients with vascular disease.

A prospective study has been undertaken to determine the feasibility of nurse-led pre-admission clerking of patients with vascular disease. A total of 249 of 300 patients with planned admissions attended the clinic; 91% of patients with varicose veins, 83% of patients about to undergo endovascular procedures and 24% of patients awaiting arterial reconstruction were seen in the clinic. Patients with arterial disease were significantly more likely to rely on other people to bring them to the clinic than those with varicose veins. As a result of their age and frailty and their presenting symptoms, patients with arterial disease are less likely to benefit from a pre-admission clinic than patients with either varicose veins or general surgical disorders.

Adult↗