Search PubMed⌕ Search

Biomedical subjects

J A Shaw

Publications and source records attributed to J A Shaw.

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

Microsatellite alterations plasma DNA of primary breast cancer patients.

The aim of this study was to analyze plasma DNA from primary and metastatic breast cancer cases for tumor-specific alterations and to compare these findings with immunocytochemistry and estimation of cytokeratin 19 (CK19) mRNA for detection of micrometastases. DNA was extracted from plasma, lymphocytes, and microdissected tumor tissue sections obtained from 71 patients with breast cancer and 9 controls. DNA samples were analyzed for loss of heterozygosity (LOH) and/or microsatellite instability (MI) by PCR with two polymorphic markers (DM-1 and D16S400). Reverse transcription-quantitative PCR (QPCR) and immunocytochemistry were used for detection of CK19 mRNA and protein. Breast cancer plasma DNA displayed frequent LOH (31.3%) and MI (11.6%) supported by the same alteration in microdissected tumor DNA. Most notably, 10 of the 39 patients with primary breast cancer showed LOH (n = 6) or MI (n = 4). We compared plasma tumor DNA, plasma and bone marrow QPCR, and blood and bone marrow immunocytochemistry in 32 of the patients with primary cancer. Of these, only one patient had immunocytochemically detectable carcinoma cells in the blood, and three showed abnormally high levels of plasma CK19 mRNA. All four of these patients had plasma DNA alterations. We then compared bone marrow findings: of the 10 primary breast cancers that showed LOH or MI, 6 had elevated CK19 mRNA and 5 had immunocytochemically positive cells. Tumor DNA is readily detectable in plasma of primary and metastatic breast cancer patients, and plasma DNA alterations (LOH and MI) reflect those seen in the tumor. The application of microsatellite analyses to plasma DNA may be useful in assessing tumor burden in breast cancer patients, particularly when combined with QPCR, and is preferable for patients with breast cancer, for whom sequential bone marrow aspiration is undesirable.

Adult↗
PubMed1999

Practice parameters for the assessment and treatment of children and adolescents who are sexually abusive of others. American Academy of Child and Adolescent Psychiatry Working Group on Quality Issues.

The assessment and treatment of children and adolescents with sexually abusive behavior requires an understanding of normal sexual development. A multiplicity of biological and psychosocial factors determines the child's sexual development, gender role, sexual orientation, patterns of sexual arousal, sexual cognitions, sexual socialization, and the integration of sexual and aggressive patterns of behavior. The individual's sexuality evolves in concert and as a result of interaction with family, ethnic, social, and cultural influences. These parameters summarize what we know about the epidemiology and phenomenology of sexually abusive youths and provide guidelines for the assessment and the selection of treatment interventions for these youths. Essential considerations in the assessment and treatment of sexually abusive youths, as well as the different categories of sexually abusive youths which should be recognized and which influence treatment decisions, are presented. The spectrum of currently available psychosocial and biological treatments will be summarized.

Adolescent↗
PubMed1999

Comparison of monthly intramuscular injections of Sandostatin LAR with multiple subcutaneous injections of octreotide in the treatment of acromegaly; effects on growth hormone and other markers of growth hormone secretion.

OBJECTIVE: To compare the effects of monthly intra-muscular injections of a long acting preparation of octreotide, Sandostatin LAR, with multiple daily subcutaneous injections of octreotide and to study the interrelationships between mean 24 h growth hormone profile, serum total and free IGF-1 levels, 24 h urinary growth hormone levels and serum IGFBP-3. DESIGN: Patients were assessed by 24 h GH profile off octreotide or any other GH modifying drug therapy; on subcutaneous octreotide (200-600 micrograms daily in divided doses for six weeks); and 28 days after the second of two injections of Sandostatin LAR (20 mg by intra-muscular injection) administered 28 days apart. Serum total and free IGF-1, serum IGFBP-3 and 24 h urinary GH were also measured on each occasion. RESULTS: Sandostatin LAR was well tolerated. None of the patients reported any adverse effect and all completed the study uneventfully. Mean GH off treatment was 10.1 +/- 3.0 micrograms/l falling equally significantly (P < 0.05) during therapy with subcutaneous octreotide to 3.0 +/- 0.7 micrograms/l and Sandostatin LAR to 2.8 +/- 0.7 micrograms/l. Fasting 0900 h GH was significantly reduced (P < 0.05) on Sandostatin LAR (3.0 +/- 0.7 micrograms/l) compared with subcutaneous octreotide (5.1 +/- 1.2 micrograms/l). Mean total IGF-1 off treatment was 658.6 +/- 56.1 micrograms/l and was reduced to a comparable extent with subcutaneous octreotide and Sandostatin LAR (466.0 +/- 59.7 and 448.6 +/- 59.5 micrograms/l respectively; both P < 0.05). Free IGF-1 off treatment was 3.1 +/- 0.6 micrograms/l and was reduced equally by subcutaneous octreotide and Sandostatin LAR (1.2 +/- 0.2 and 1.2 +/- 0.2 micrograms/l; both P < 0.05). IGFBP-3 was reduced to a greater extent during Sandostatin LAR than during subcutaneous octreotide (4518.2 +/- 247.3 vs 5132.8 +/- 280.7 micrograms/l; P < 0.05). Twenty-four hour urinary GH excretion was reduced to a comparable extent with both therapies. Highly significant positive correlations were found between mean 24 h GH levels and free IGF-1 (r = 0.66, P < 0.0001) and 24 h urinary GH excretion (r = 0.94, P < 0.0001). The relationships between mean 24 h GH levels and total IGF-1 and IGFBP-3 although significant showed less powerful correlations. CONCLUSIONS: These results suggest that Sandostatin LAR is well tolerated and as effective as subcutaneous octreotide. In addition, urinary growth hormone and serum free IGF-1 may prove valuable for outpatient follow-up of acromegalic patients, as both correlate well with mean 24 h serum growth hormone levels.

Acromegaly↗
PubMed1999

Glomerular expression of nephrin is decreased in acquired human nephrotic syndrome.

BACKGROUND: Nephrin recently has been identified as a putative adhesion molecule, expressed in the glomerulus, in which mutations cause congenital nephrotic syndrome of Finnish type. We sought to determine whether expression of nephrin is altered in human glomeruli in patients with acquired nephrotic syndrome. METHODS: We performed PCR amplification of nephrin cDNA, using cDNA previously prepared from single human glomeruli plucked fresh from the surface of human renal biopsies. We had available four cases of nephrotic syndrome (one membranous, three minimal change) and six normal controls. PCR product quantitation was by gel densitometry, confirmed by enzyme-linked immunosorbent assay using a specific oligonucleotide probe. Results were corrected for reaction efficiency and glomerular cellularity by expression as a ratio to levels of the 'housekeeping gene' glyceraldehyde phosphate dehydrogenase. RESULTS: Glomerular levels ofnephrin mRNA are significantly decreased in cases of minimal change nephrotic syndrome. An apparent reduction was also seen in the single case of membranous nephropathy which was available for study. CONCLUSIONS: Abnormalities of nephrin expression appear to be associated with acquired as well as congenital causes of human nephrotic syndrome.

Adult↗
PubMed1999

Febrile response after knee and hip arthroplasty.

Documentation of the normal fever response after total knee and hip replacement is important to avoid an unnecessary workup for sepsis, and to provide justification for early discharge (dictated by the current medical reimbursement climate) despite persistent postoperative fever. One hundred patients who underwent total knee arthroplasty and 100 patients who underwent total hip arthroplasty were reviewed, several of whom had extensive sepsis workups for evaluation of postoperative fever. No patient in this series had a documented joint infection. All patients were treated with warfarin for deep vein thombrosis prophylaxis. All patients used incentive spirometry and were started on ambulation training on postoperative Day 1. All were given antibiotic prophylaxis for 48 hours. The maximum daily postoperative temperature occurred in most patients on postoperative Day 1 and gradually leveled off toward normal by postoperative Day 5. Only one patient had a maximum temperature on postoperative Day 4 that was greater than that on postoperative Day 3. Patients undergoing revision procedures tended to have a more pronounced febrile response, but the differences were not statistically significant. No significant differences were seen between patients who had epidural anesthesia and patients who had general anesthesia. Seventeen patients had postoperative chest radiographs for evaluation of fever. None had significant atelectasis. The presence of a positive urine culture had no effect on the fever response, with most positive results being identified after the fever had returned toward normal. Postoperative fever after total joint arthroplasty is a normal inflammatory response. A workup for sepsis is not indicated in the perioperative period unless corroborating signs or symptoms are present. Early discharge is appropriate if the febrile response is decreasing progressively.

Anesthesia, Epidural↗
PubMed1998

Microsatellite instability in ductal carcinoma in situ of the breast.

Microsatellite instability (MI+) is associated with defects in mismatch repair, resulting in a 'mutator' phenotype and the development and progression of cancer. MI+ has been documented in invasive breast carcinomas. This study was undertaken to determine whether MI+ is found in the early non-invasive form of breast cancer, ductal carcinoma in situ (DCIS). We examined microdissected ducts from 23 cases of DCIS with 11 markers comprising mono-, di-, and trinucleotide repeats from six chromosomal regions. Five tumours (22 per cent) displayed MI+ at two or more loci, in all ducts examined. A further seven (30 per cent) tumours showed alterations at a single locus (the DM-1 trinucleotide), and for two of these, heterogeneity between ducts was observed. Alterations at microsatellite repeat motifs in the coding regions of four cancer-associated genes (TGF beta RII, IGFIIR, BAX, and E2F-4) were not observed. Immunohistochemistry revealed that there was no loss of reactivity for the mismatch repair proteins, MLH1, MSH2, and PMS2, in the DCIS cases. In general, MI+ tumours and those with alterations at the DM-1 microsatellite were predominantly of higher nuclear grade and expressing c-erbB-2, suggesting that aberrations in DNA repair functions may lead to the acquisition of a more aggressive phenotype in breast cancer.

Breast Neoplasms↗
PubMed1998

Reproducibility in the quantification of mRNA levels by RT-PCR-ELISA and RT competitive-PCR-ELISA.

The use of reverse transcription (RT) PCR for relative quantitation of gene transcripts relies on the reproducibility of the individual RT, PCR and product measurement steps. Semi-competitive RT-PCR (RT-cPCR) uses an internal competitor template in the PCR step to improve quantitation. We have surveyed the reproducibility of RT, PCR, RT-cPCR and measurement, amplifying the glyceraldehyde-3-phosphate dehydrogenase "housekeeping" gene from isolated renal glomeruli. We used an enzyme-linked immunosorbent assay (ELISA) to quantify PCR products. We also report our PCR-based method for constructing a competitor DNA identifiable independently of the native product. Our results show that the entire RT-PCR and ELISA process had a standard deviation (SD) of less than 10% (n = 10). This compared to an SD of less than 13% (n = 10) in PCR and ELISA. The SD for ELISA alone was less than 11% (n = 10). RT-cPCR quantitation gave an SD of approximately 15% (n = 10). These results support the use of standard RT-PCR for the relative quantitation of mRNA. RT-cPCR is also suited to relative quantitation, but it is also independent of the amplification saturation curve and permits the identification of differences in cellularity between samples.

DNA Primers↗
PubMed1997

Molecular pathology of breast cancer and its application to clinical management.

Breast cancer is a major cause of morbidity and mortality in women in many parts of the world. Breast carcinomas are heterogenous in their biological and clinical behaviour and a greater understanding of how they develop and progress could lead to more directed forms of screening and therapy. It is important to determine the molecular mechanisms underlying the natural history of breast cancer. Developments in the techniques for molecular analysis have meant that they can now be applied to a large range of clinical material such as cytological preparations and fixed, embedded material, so increasing the potential for relating any molecular alterations to clinical behaviour and response to therapy. In this review we consider recent developments in three areas of importance to breast cancer; genetic analysis-oncogenes, tumour suppressor genes, loss of heterozygosity, microsatellite instability, familial breast cancer; steroid receptors, oestrogen regulated proteins, epidermal growth factor receptor, growth factors particularly transforming growth factor beta; and cell adhesion, invasion and metastasis-E-cadherin, integrins, proteases. These are discussed in relation to potential for screening, prognosis and treatment.

Breast Neoplasms↗
PubMed1997

Loss of heterozygosity at chromosome 6q in preinvasive and early invasive breast carcinomas.

We have used polymerase chain reaction (PCR) analysis to study the incidence of allelic imbalance at four polymorphic microsatellite markers on chromosome 6q25.1-27, three dinucleotide repeats and one trinucleotide repeat, for microdissected tumour foci from a group of 75 'early' breast carcinomas. The tumours comprised 16 preinvasive cases of ductal carcinoma in situ (DCIS) and 59 mammographically detected early invasive carcinomas. Loss of heterozygosity (LOH) was detected at all four loci and in all types and grade of disease. The frequency of LOH ranged from 23% to 50% depending on the marker studied. The highest frequency of LOH was observed at the D6S186 locus for the cases of DCIS and at the oestrogen receptor locus for the invasive carcinomas. These data suggest that the inactivation of tumour-suppressor genes within this region on chromosome 6q is important for the development of these early lesions.

Adenocarcinoma↗
PubMed1997

Loss of heterozygosity at the mannose 6-phosphate insulin-like growth factor 2 receptor gene correlates with poor differentiation in early breast carcinomas.

Chromosome 6q has been shown to be one of the most frequent sites for allelic loss in human breast cancer. The mannose 6-phosphate/insulin-like growth factor 2 receptor (IGF2R) gene, which maps to chromosome 6q26-27, functions in the activation of TGF-beta1, a potent growth inhibitor for most cell types, the degradation of the mitogen IGF2 and the intracellular trafficking of lysosomal enzymes. Loss of heterozygosity (LOH) at the IGF2R locus with mutations in the remaining allele have been reported in liver cancers and recently in two high-grade cases of ductal carcinoma in situ of the breast. We have sought to confirm that allelic loss of IGF2R is an early event in the aetiology of breast cancer by screening a group of 'early' lesions for LOH at a polymorphic microsatellite marker within the IGF2R gene using polymerase chain reaction (PCR). Several microdissected tumour foci were analysed for each of 40 mammographically detected invasive carcinomas and 22 cases of pure ductal carcinoma in situ (DCIS). None of 25 (62.5%) informative early invasive carcinomas showed any evidence of LOH. This group comprised predominantly of well- to moderately differentiated cases (95%). However, 4 out of 18 informative DCIS cases (22%) showed clear evidence of LOH. Three of these were poorly differentiated (high-grade) lesions. These data suggest that loss of heterozygosity at the IGF2R gene is associated with poor differentiation at this early stage of breast cancer development and progression.

Breast Neoplasms↗
PubMed1997

Numerical chromosomal aberrations in Hodgkin's disease detected by in situ hybridisation on routine paraffin sections.

AIMS: To visualise directly numerical chromosomal aberrations and polyploidy in both Hodgkin and Reed Sternberg (HRS) cells and background cells from cases of Hodgkin's disease using in situ hybridisation. METHODS: Non-isotopic DNA in situ hybridisation was applied to interphase cell nuclei of Hodgkin's disease within routine paraffin embedded tissue sections. Two a satellite DNA probes, specific for chromosomes 3 and 12, were used to evaluate the feasibility of this approach. Double labelling with immunocytochemical detection of the CD30 antigen was used to identify HRS cells. Cytogenetic normal diploid and triploid placental tissue served as controls. RESULTS: The eight cases of Hodgkin's disease investigated displayed frequent polysomy, while the majority of background cells showed disomy signals. CONCLUSIONS: Numerical chromosomal aberrations were detected in HRS cells from eight cases of Hodgkin's disease by in situ hybridisation. These data show that in Hodgkin's disease HRS cells frequently display polyploidy compared with background cells and are, therefore, probably the only neoplastic component in this disease. Correlations between polysomy and tumour type or grade could not be made from these data owing to the limited number of cases examined and to problems with interpreting data from truncated nuclei.

Adolescent↗
PubMed1996

Yeast chitin synthases 1 and 2 consist of a non-homologous and dispensable N-terminal region and of a homologous moiety essential for function.

Predicted protein sequences of fungal chitin synthases can be divided into a non-homologous N-terminal region and a C-terminal region that shows significant homology among the various synthases. We have explored the function of these domains by constructing a series of nested deletions, extending from either end, in the CHS1 and CHS2 genes of Saccharomyces cerevisiae. In both cases, most or all of the sequences encoding the non-homologous N-terminal region (one-third of the protein for Chs1p and about one-fourth for Chs2p) could be excised, with little effect on the enzymatic activity in vitro of the corresponding synthase or on its function in vivo. However, further small deletions (20-25 amino acids) into the homologous region were deleterious to enzymatic activity and function, and often led to changes in the zymogenic character of the enzymes. Similarly, relatively small (about 75 amino acids) deletions from the C-terminus resulted in loss of enzymatic activity and function of both synthases. Thus, it appears that all the information necessary for membrane localization, enzymatic activity and function resides in the homologous regions of Chs1p and Chs2p, a situation that may also apply to other chitin synthases.

Amino Acid Sequence↗
PubMed1996

Amplification of specific mRNA from a single human renal glomerulus, with an approach to the separation of epithelial cell mRNA.

A method has been developed by which single human glomeruli may be plucked from fresh renal biopsies under direct vision, followed by separation of mRNA using oligo-dT-linked paramagnetic beads. The mRNA was amplified by reverse transcription and polymerase chain reaction (RT-PCR). Primers for a variety of human and rat proteins have been developed. The quantity of the amplified cDNA was measured by an enzyme-linked immuno-sorbent assay (ELISA), where biotinylated forward strands of DNA were captured, probed with a fluorescein-conjugated DNA oligomer, and then assayed with an enzyme-linked anti-fluorescein antibody. The cDNA-linked beads are reported to be stable and can be reused with different primer sets, thus forming a "bank' of samples from cases with defined glomerular disorders, which can be used to address new questions as they arise. Using rat glomeruli, a method has been devised which permits at least partial separation of epithelial cell mRNA from mesangial and endothelial cell mRNA.

Actins↗
PubMed1996

Efficacy of the Steri-Shield filtered exhaust helmet in limiting bacterial counts in the operating room during total joint arthroplasty.

Filtered exhaust helmets (space suits) have been reported as efficacious in decreasing wound infections following joint arthroplasty procedures; however, strict experimental control of the many variables related to the incidence of clinical infection has been lacking in these studies, making support of such conclusions difficult. Any potential benefit of filtered exhaust helmets in the control of infection rates can be logically assigned to the reduction of airborne bacterial counts within the operating room. A study was done using the Steri-Shield helmet (Bio-Medical Devices, Irvine, CA) to define its efficacy in limiting airborne bacterial contaminates during total joint arthroplasty. Forty-eight paired prosthetic hip and knee cases were evaluated using a block experimentation design. One case of each pair was done with all surgical and scrub personnel cloaked in Steri-Shield filtered exhaust helmets and the other with the same personnel in conventional paper hoods and masks. Air samples were obtained with an Anderson two-stage viable particle sampler (Anderson Samplers, Atlanta, GA) placed immediately adjacent to the wound. Quantitative microbial cultures were obtained. The filtered exhaust helmet evaluated in this study provided no increased protection against bacterial contamination in the area of the surgical field than conventional paper hoods and masks.

Air Microbiology↗
PubMed1996

Microsatellite instability in early sporadic breast cancer.

We have studied the incidence of microsatellite instability at three trinucleotide repeats and seven dinucleotide repeats from five chromosomal regions, in a group of 30 mammographically detected 'early' invasive breast cancers and correlated its occurrence with clinicopathological parameters. The myotonic dystrophy (DM-1) trinucleotide repeat was analysed in 48 additional cases. In 4 out of 78 (5%) paired tumour-normal DNA samples we found evidence of somatic microsatellite instability at DM-1: a novel allele of a different size was seen in the tumour DNA which was not present in the normal DNA sample. All four tumours that showed evidence of instability were from the core group of 30 cases (13%) and were well or moderately differentiated, oestrogen receptor-positive, infiltrating ductal carcinomas. Two of these tumours were unstable at nine of ten loci studied, both trinucleotide and dinucleotide repeats. DNA prepared from different normal tissues showed no evidence of instability, for all four instability cases. These data indicate that microsatellite instability is specific to the tumour DNA and is an early event in the genesis of some sporadic breast cancers.

Breast Neoplasms↗
PubMed1996

Laparoscopic trans-peritoneal adrenalectomy: a preliminary report of 14 adrenalectomies.

OBJECTIVES: Laparoscopic adrenalectomy offers the potential benefits of a smaller operation with more rapid hospital discharge, compared to open surgery. Only a few small series have been reported so far. We describe our preliminary experience of 14 adrenalectomies using this new technique. DESIGN: Review of all adrenalectomies (with the preoperative intention of laparoscopic removal) performed in an endocrine unit whose surgeon already had abdominal laparoscopic experience, particularly with cholecystectomy. PATIENTS AND MEASUREMENTS: Twelve patients (3 with Conn's syndrome, 3 Cushing's syndrome, 1 Cushing's disease, 2 phaeochromocytomas and 3 adrenal incidentalomas) were operated between September 1993 and February 1996. Operating times, operative technique, time from surgery to discharge, outcome and all complications were recorded prospectively. Comparative data were obtained from 14 consecutive open adrenalectomies performed by the same surgeon between February 1989 and February 1995. RESULTS: Fourteen glands were removed, two with a cholecystectomy, in 12 operations. Operating time (mean (range) 120 (60-225) min) was reduced with experience. Positioning the patient in the right lateral position facilitated left adrenalectomy. Time to discharge (mean (range)) was 5.3 (1-12) days. There were relatively minor complications in three patients, including two with Cushing's syndrome: a hernia at a port site, intra-peritoneal/wound haemorrhage and a pressure sore. Time to discharge for open adrenalectomy (mean (range)) was 6.5 (2-11) days and one case was complicated by wound infection. CONCLUSIONS: Laparoscopic adrenalectomy is a practical technique for appropriately trained surgeons who regularly undertake adrenalectomy. The smaller incisions offer potential advantages, particularly for patients with poor tissue quality due to Cushing's syndrome, but tissue haemorrhage may still be a problem in these patients. Time to hospital discharge was similar to that for open surgery.

Adenoma↗
PubMed1996

Twenty-one-month follow-up study of school-age children exposed to Hurricane Andrew.

OBJECTIVE: To explore the 21-month course of posttraumatic stress symptomatology (PTSS) and psychological morbidity in 30 school-age children (7 to 13 years) after exposure to Hurricane Andrew. METHOD: Pynoos' Posttraumatic Stress Disorder Reaction Index and Achenbach's Teacher's Report Form were administered at 8 and 21 months after Hurricane Andrew. RESULTS: At 21 months 70% of the children endorsed moderate-severe PTSS. The reduction in PTSS was greater for boys than girls. Psychopathology as measured by the Teacher's Report Form increased over the 19-month period. Boys demonstrated significant increases in internalizing symptoms and in Withdrawn, Anxious/Depressed, Social Problems, and Attention Problems scales, and girls showed a significant increase in the Anxious/Depressed scale. CONCLUSIONS: Twenty-one months after exposure to Hurricane Andrew, there were continuing high levels of PTSS and evidence of increasing emotional and behavioral problems. While girls sustained higher levels of PTSS, boys demonstrated higher indices of other psychopathology. The enduring effects of disaster associated with secondary stressors and "traumatic reminders" continue to be etiologically important for continuing psychological morbidity.

Adolescent↗