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Biomedical subjects

J Hyland

Publications and source records attributed to J Hyland.

At least 19 recordsLinked to original sources
PubMed1998

Molecular pathological analysis of testicular diffuse large cell lymphomas.

The molecular pathology of 20 lymphomas, which presented as testicular masses in patients with no evidence of previous lymphoma, was analyzed. These lymphomas occurred in men with a median age of 69 years (range, 37 to 87 years). Nine of the 14 patients with follow-up died of lymphoma (median survival, 12 months). All cases were diffuse large B-cell lymphomas that were positive for CD20 and commonly showed plasmacytoid differentiation (10 of 20 cases). Three cases were Burkitt's-like large cell lymphomas. Infiltration by lymphoma in the seminiferous tubules was seen in most cases. All lymphomas were negative for human herpesvirus 8 and Epstein-Barr virus by 35 cycles of polymerase chain reaction (PCR), suggesting that these viruses are not involved in the pathogenesis of primary testicular diffuse large B-cell lymphomas (DLBCL). PCR-based studies for t(14;18) and t(11;14) translocations, commonly seen in follicular and mantle-cell lymphomas, were negative in all cases. Nucleotide sequences of the V-D- and J segments of the immunoglobulin heavy chain gene (IgH) rearrangements obtained in 12 cases after PCR amplification were analyzed and compared with known germlines. The frequency of VH-family use in testicular DLBCL was similar to that reported for normal peripheral blood lymphocytes and follicular lymphomas. This contrasts with the previously published findings of preferential use of the VH3- or VH4-family by nodal DLBCL. Comparison with the published germlines showed a low similarity index in most of the cases, suggesting the presence of extensive somatic mutations. Ongoing mutation, as indicated by intraclonal variation in IgH sequence, was observed in all sequenced cases, suggesting direct antigen stimulation, which represents another difference between primary testicular and nodal DLBCL. Our results suggest that testicular lymphomas represent a subset of DLBCL that differs from their nodal counterparts in several respects. Their histological and molecular features show some similarities to those seen in marginal zone (MALT) lymphomas.

Adult↗
PubMed1996

Genetic linkage of familial granulomatous inflammatory arthritis, skin rash, and uveitis to chromosome 16.

Blau syndrome (MIM 186580), first described in a large, three-generation kindred, is an autosomal, dominantly inherited disease characterized by multiorgan, tissue-specific inflammation. Its clinical phenotype includes granulomatous arthritis, skin rash, and uveitis and probably represents a subtype of a group of clinical entities referred to as "familial granulomatosis." It is the sole human model with recognizably Mendelian inheritance for a variety of multisystem inflammatory diseases affecting a significant percentage of the population. A genomewide search for the Blau susceptibility locus was undertaken after karyotypic analysis revealed no abnormalities. Sixty-two of the 74-member pedigree were genotyped with dinucleotide-repeat markers. Linkage analysis was performed under a dominant model of inheritance with reduced penetrance. The marker D16S298 gave a maximum LOD score of 3.75 at theta = .04, with two-point analysis. LOD scores for flanking markers were consistent and placed the Blau susceptibility locus within the 16p12-q21 interval.

Adolescent↗
PubMed1995

Identification of COL2A1 gene mutations in patients with chondrodysplasias and familial osteoarthritis.

OBJECTIVE: To use a recently developed procedure for analysis of blood leukocyte DNA to detect mutations in the gene for type II procollagen (COL2A1) in patients with cartilage diseases ranging from early-onset familial osteoarthritis (OA) to lethal chondrodysplasias. METHODS: The technique of denaturing gradient gel electrophoresis was used to scan polymerase chain reaction (PCR) products from 45 exons and exon-flanking sequences of the COL2A1 gene in more than 70 patients with cartilage diseases whose severity ranged from mild to lethal. PCR products with abnormal migrations were then sequenced. RESULTS: Among the 3 patients with lethal hypochondrogenesis who were analyzed, all 3 were found to have a mutation in the COL2A1 gene. Among 17 patients with spondyloepiphyseal or spondyloepimetaphyseal dysplasia, 2 well-defined and 2 probable mutations were found. Among 15 patients with the Wagner-Stickler syndrome, 2 well-defined and 2 probable mutations were found. Among 45 patients with early-onset familial OA, 1 probable mutation was found. CONCLUSION: Using the procedure developed for analysis of the COL2A1 gene, mutations were detected in > 20% of patients with chondrodysplasias and up to 2% of patients with early-onset familial OA. However, these percentages are only minimal estimates because all possible mutations in the gene cannot be detected with this procedure.

Cartilage, Articular↗
PubMed1994

Requirement for bowel preparation in colorectal surgery.

To determine whether mechanical bowel preparation influences the incidence of anastomotic dehiscence following colorectal surgery, 186 patients undergoing elective left colonic or rectal resection were randomized before surgery to bowel preparation (n = 89) or no bowel preparation (n = 97). Surgical technique was standardized and no patient had a defunctioning colostomy. Seventeen patients were excluded (seven with preparation, ten without). Indications for surgery in the remaining 169 patients were carcinoma (133 patients), diverticular disease (26), inflammatory bowel disease (six) and miscellaneous conditions (four). Operations performed were left colonic resection or reversal of Hartmann's procedure (26 with preparation, 28 without) and anterior resection (56 versus 59). The overall morbidity rate (18 per cent) was similar in the two groups. All seven clinical anastomotic leaks occurred after low anterior resection, in three of the 39 patients who had undergone bowel preparation and four of the 36 who had not (P > 0.9). Two deaths occurred, both of patients who had received bowel preparation, one being secondary to anastomotic leakage. Bowel preparation does not influence outcome after elective colorectal surgery.

Aged↗
PubMed1994

Magnetic resonance imaging of rectal carcinoma: a prospective study.

Accurate preoperative staging of rectal cancer is necessary to identify patients who might benefit from adjuvant therapy. Magnetic resonance imaging (MRI) was evaluated in 20 consecutive patients with rectal cancer undergoing 'curative' surgery. Detailed histopathological examination of the resected lesion was correlated with findings of MRI. MRI staging concurred with histological staging in 18 of 20 patients using the Dukes or tumour node metastasis classification but in only 14 using the modified Astler-Coller system. MRI diagnosed transmural invasion in all but one patient with microscopic mural invasion (positive predictive value, 100 per cent; negative predictive value, 80 per cent; overall accuracy, 95 per cent). MRI correctly diagnosed tumour deposits or involved lymph nodes in 12 patients. MRI overstaged one patient, in whom nodes that were enlarged on imaging studies were negative at histological examination (positive predictive value, 92 per cent; negative predictive value, 100 per cent; overall accuracy, 95 per cent). MRI has a role in selected cases for the preoperative assessment of rectal carcinoma.

Aged↗
PubMed1994

A heart health survey at the worksite: the first step to effective programming.

1. Cardiovascular disease is the number one killer in Canada, accounting for 42% of all deaths. 2. Workplace policy and health promotion programs can have a significant impact on modifiable risk factors associated with the development of heart disease. 3. This article describes the results of a worksite cardiovascular risk behavior screening of 652 mining employees in Sudbury, Ontario. 4. The theoretical framework for this study is based on the PRECEDE-PROCEED model: to reach the ultimate outcome, improved quality of life changes must be made at both the individual as well as the environmental (workplace) level (Green, 1991).

Adult↗
PubMed1993

A fourth example suggests that premature termination codons in the COL2A1 gene are a common cause of the Stickler syndrome: analysis of the COL2A1 gene by denaturing gradient gel electrophoresis.

A series of oligonucleotide primers was designed to generate polymerase chain reaction products that contained exons 6 to 49 of the human gene for type II procollagen (COL2A1) and that could be used to detect sequence variations by denaturing gradient gel electrophoresis. To improve the sensitivity of the analysis, GC clamps were introduced into one primer of each pair. The procedure successfully detected 10 neutral single-base variations in the gene. In addition, the procedure detected a single-base deletion in exon 43 that introduced a premature termination codon in exon 44 and caused the Stickler syndrome (arthro-ophthalmopathy) in one family. The mutation is the fourth mutation in the COL2A1 gene shown to cause the Stickler syndrome. The mutation is similar to the first three mutations causing the disease in that they also introduced premature termination signals. Since only one mutation introducing a premature termination codon was found in the course of defining 120 or more mutations in type I and III procollagens, the results suggest that such mutations may have a special relationship to the Stickler syndrome.

Adult↗
PubMed1992

Anterior resection without a defunctioning colostomy: questions of safety.

The need to defunction the anastomosis at anterior resection remains controversial. As the policy in this unit has been not to perform a defunctioning colostomy during anterior resection, the outcome of a consecutive series of 114 anterior resections, all carried out without a covering colostomy, was studied. During the period February 1985 to September 1991, 21 abdominoperineal resections, six Hartmann's procedures and two resections with coloanal anastomosis were also performed. Within the anterior resection group six clinical leaks (5.3 per cent) occurred, all in the low anastomosis group (8 per cent leak rate) and all of which required an end colostomy. The perioperative mortality rate within the anterior resection group was 3.5 per cent; of the four deaths one was attributable to anastomotic dehiscence and sepsis and the others were due to unassociated medical conditions. The results demonstrate similar leakage and mortality rates to published studies where anterior resection is frequently performed with a defunctioning colostomy. These results indicate that the routine use of a defunctioning colostomy at anterior resection should now be questioned.

Adult↗
PubMed1992

Physiological and metabolic responses to open and laparoscopic cholecystectomy.

This study examined respiratory function and metabolic and subjective responses in patients undergoing laparoscopic (n = 10) and open (n = 11) cholecystectomy for chronic cholecystitis and biliary colic. Patient groups were matched for age, sex, weight and height. The duration of operation was similar in both groups. Respiratory function tests (vital capacity, forced expiratory volume in 1 s, peak flow and arterial blood gases), urinary cortisol, vanillylmandelic acid, metanephrines and nitrogen loss, serum complement component C3 and C-reactive protein (CRP), full blood count, erythrocyte sedimentation rate (ESR) and subjective responses as assessed on a pain analogue scale and by analgesic usage were determined for up to 48 h after surgery. Deterioration in perioperative respiratory function was significantly less for laparoscopic surgery. Arterial blood gas determinations indicated a greater perioperative decrease in arterial pH, with carbon dioxide retention in patients undergoing open cholecystectomy (P < 0.02), reflecting poorer respiratory performance. Hormonal profile changes demonstrated an increase in urinary vanillylmandelic acid in the laparoscopic cholecystectomy group (P < 0.04); no differences were detected in urinary cortisol, metanephrine or nitrogen excretion. Acute-phase responses were greatest in patients undergoing open cholecystectomy as determined by ESR and CRP level (P < 0.02 and P < 0.003, respectively). Pain and analgesic usage were significantly decreased in the laparoscopic cholecystectomy group (P < 0.0009) and P < 0.0001), which led to a decreased hospital stay after operation in these patients (P < 0.0001). These data indicate improved respiratory and subjective responses and diminished acute-phase responses associated with laparoscopic surgery. Catabolic hormone release may, however, be increased.

Acute-Phase Reaction↗
PubMed1992

The role of the defunctioning ileostomy in restorative proctocolectomy.

Restorative proctocolectomy is now the treatment of choice for most patients with ulcerative colitis and familial polyposis coli. Temporary defunctioning ileostomy has been advocated during the period of anastomotic healing to prevent pelvic sepsis. However, the ileostomy itself may be a source of significant complications. To examine ileostomy function we reviewed thirty five patients (mean age 34.5 +/- 1.95 years) who underwent restorative proctocolectomy. Thirty four patients had a defunctioning ileostomy established at the time of pouch anal anastomosis. Closure of the ileostomy has been carried out in 33 patients (mean closure time 3.1 +/- 0.29 months). One patient underwent early pouch excision. Thirteen of the 35 patients developed post-operative complications (37%), two directly related to the defunctioning ileostomy. Both occurred following closure of the stoma and required laparotomy. Serious complications associated with defunctioning ileostomy as demonstrated in this study are uncommon (8.5%). Given the potentially disastrous consequences of a pouch-anal anastomotic leak we feel that the relatively low morbidity associated with a defunctioning ileostomy justifies its continued routine usage in the operation of restorative proctocolectomy.

Adenomatous Polyposis Coli↗
PubMed1992

Radiological investigation in laparoscopic compared with conventional cholecystectomy--an early assessment.

The implications of laparoscopic cholecystectomy (LC) for radiology were assessed by comparing imaging investigations in 48 LC and 48 conventional cholecystectomy (CC) patients. In addition, we attempted to identify findings on pre-operative ultrasound (US) which predicted operative difficulties at LC. There were no per-operative or T-tube cholangiograms in the LC patients, but otherwise the pattern of investigation was similar in both groups. Forty of the 48 CC patients underwent cholangiography (per-operative cholangiography in 36, endoscopic retrograde cholangiopancreatography (ERCP) in two, and both in two) demonstrating calculi in eight (16.7%) cases. Only four LC patients had cholangiography (ERCP in all cases) demonstrating common bile duct (CBD) calculi in one (2.1%) case. Ultrasound failed to identify the gall-bladder with certainty in three of the five failed LC cases. Neither gall-bladder wall thickness, contraction nor calculus size on pre-operative US served as predictors of other per-operative difficulties. Our results indicate that there may be some patients with retained CBD calculi in the LC group. The role of pre-operative US in predicting operative difficulties needs further assessment in a prospective study.

Adult↗
PubMed1992

A homozygous stop codon in the lysyl hydroxylase gene in two siblings with Ehlers-Danlos syndrome type VI.

Ehlers-Danlos syndrome (EDS) is characterized by joint hypermobility, alterations in the skin and additional signs of connective tissue involvement. EDS type VI was the first connective tissue disorder for which a specific defect in collagen metabolism was identified, namely a deficiency of lysyl hydroxylase activity. We now report a homozygous single basepair substitution converting the CGA codon (Arg319) to a TGA termination codon in two siblings with EDS type VI. The healthy parents, who are first cousins, and two of the three healthy siblings of the patients are heterozygous. The mutation leads to an almost complete absence of lysyl hydroxylase activity in extracts derived from fibroblasts of the patients.

Adolescent↗
PubMed1991

Expression of a human cartilage procollagen gene (COL2A1) in mouse 3T3 cells.

Expression in a recombinant system has been difficult to obtain for any of the major fibrillar collagens that require processing by eight or more post-translational enzymes. Here, two DNA constructs were designed so that the promoter region of the gene for the pro-alpha 1(I) chain of human type I procollagen drove expression of the human type II procollagen gene in mouse NIH 3T3 cells, a culture line that normally synthesizes type I procollagen but not any cartilage-specific protein such as type II procollagen. Both constructs were expressed as both mRNA and protein. In clones expressing the construct at high levels, the steady-state levels of mRNA and the production of type II procollagen were comparable to the mRNA levels and production of type I procollagen from the endogenous mouse genes. Comparison of clones containing the two constructs demonstrated that sequences extending 80 base pairs beyond the major polyadenylation signal of the gene are not in themselves sufficient for correct termination and 3' processing of RNA transcripts. The results strongly suggest that specific sequences present in a downstream 3.5-kilobase SphI/SphI fragment determine the termination of the transcription. Of special importance is that the system will make it possible to examine the consequences of mutations in the human type II procollagen gene on the processing of RNA transcripts and on the functional properties of the protein simply by using the genomic DNA from leukocytes or other non-cartilaginous sources.

Animals↗
PubMed1991

Changes in luteinizing hormone bioactivity associated with gonadotrophin pulses in the cycling mare.

Equine plasma luteinizing hormone (LH) possesses both biological (in vitro bioassay, B) and immunological (radioimmunoassay, I) activities and the ratio of B:I varies with stage of the oestrous cycle. To estimate the contribution made by pituitary secretion and peripheral metabolism to changes in the B:I ratio, pituitary venous effluent and circulating plasma from 5 dioestrous and 2 oestrous mares were analyzed using both an in vitro bioassay and a radioimmunoassay. During dioestrus, LH was released in a pulsatile fashion with a frequency of 1.4 pulses/24 h and a pulse duration of 20-40 min (centrally) or 2-4 h (peripherally). Between pulses, further secretion of LH from the pituitary was undetectable. During spontaneous pulses, the B:I ratio increased as much as 2- to 3-fold and remained elevated for at least 1 h. A low dose of 10 ng/kg bodyweight (bwt) of the GnRH agonist Buserelin provoked similar changes, unless the exogenous stimulus was close to an endogenous LH discharge. A high dose (50 micrograms) of Buserelin reduced the B:I ratio significantly, in spite of a massive LH release. Samples taken from mares during oestrus showed constantly elevated B:I ratios, a consequence of much greater LH pulse frequency.

Animals↗