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Biomedical subjects

D Jones

Publications and source records attributed to D Jones.

At least 343 records · Page 19Linked to original sources
PubMed1996

A comparative analysis of embryo implantation potential in patients with severe teratozoospermia undergoing in-vitro fertilization with a high insemination concentration or intracytoplasmic sperm injection.

The objective of this study was to assess fertilization, implantation and pregnancy rates in infertile patients with severe teratozoospermia [P (poor prognosis) pattern sperm morphology assessed by strict criteria] treated by in-vitro fertilization (IVF) using a high insemination concentration (HIC), or by intracytoplasmic sperm injection (ICSI). This was a retrospective cohort study performed in an academic tertiary institution. The outcome of 115 consecutive ICSI cycles was compared to that of a similar number of cycles of IVF with HIC performed during a similar time frame and matched by woman's age and basal serum (cycle day 3) follicle stimulating hormone concentrations. The inclusion criteria were sperm morphology </=4% normal forms (P pattern) and >/=1x10(6) total motile spermatozoa per ejaculate. The diploid fertilization rate in the HIC-IVF group was 86% and in the ICSI group 68% (P < 0.05). Importantly, an equal number of embryos was transferred to both groups of patients. The morphological quality of the embryos (proportion of transfers having superior morphology embryo scores) was significantly better in the ICSI group than in the patients receiving HIC-IVF. Although there was a clear trend for better implantation and pregnancy rates in the ICSI group, these differences were not statistically significant. We conclude that, although HIC-IVF resulted in a higher fertilization rate than ICSI in patients with severe teratozoospermia, ICSI produced a significantly higher proportion of morphologically superior embryos with a tendency towards a higher implantation potential. Therefore, teratozoospermic patients having adequate numbers of motile spermatozoa should be offered ICSI as an alternative to modified (HIC) IVF treatment.

Cohort Studies↗
PubMed1996

Complications and effectiveness of gastrostomy feedings in pediatric cancer patients.

PURPOSE: The objective of this study was to assess the complications and efficacy of gastrostomy (GT) feedings in pediatric cancer patients. PATIENTS AND METHODS: We reviewed the medical records of 33 pediatric cancer patients who received enteral nutrition via a GT. RESULTS: Median age was 9.4 years (range, 1-19.8 years), and 28 of the 33 patients had solid tumors. Seventeen patients had a significant weight loss (median, 8.5%) and therapy-related weight loss was anticipated in 16 patients. The GT device was placed an average of 5.5 months after diagnosis. Twenty-five patients were fed via a tube and eight via a button device. The tube was placed surgically in 21 cases (including all eight button types) and endoscopically in 12. Nutritional support lasted a median of 9.5 months. One or more complications occurred in 30 patients and were categorized as (a) insertion site reactions (inflammation, 23; infection/colonization, 14; exuberant granulation tissue, 6); (b) mechanical problems (leaking, 3; obstruction, 2; breakage, 1; accidental dislodgement, 2); (c) insertion site bleeding, 8; and (d) feeding intolerance, 12. Only one insertion site cellulitis progressed to a systemic infection. All eight patients with a button GT experienced insertion site complications, with local infection occurring significantly more often in patients with the button than in those with the tube GT. There were no significant associations between insertion technique and type of complication. Twenty-seven patients (82%) achieved or maintained ideal body weight with this intervention. CONCLUSIONS: GT feeding was associated with minor complications, but permitted effective nutritional support for pediatric cancer patients.

Adolescent↗
PubMed1996

The cost effectiveness of renal provision in the UK.

Discusses the need for reliable research-based evidence detailing the costs and benefits provided by different operational and strategic structures of renal replacement therapy. Suggests that in choosing the most appropriate form of dialysis the treatment options may be limited for clinical, practical or financial reasons. Proposes that the renal services must support patients in empowering them to make informed choices concerning the dialysis modality which offers them the highest quality of life. Brings into perspective the need for a balance between patients' quality of life and the financial constraints on the NHS.

Adaptation, Psychological↗
PubMed1996

Retroviral insertional activation in a herpesvirus: transcriptional activation of US genes by an integrated long terminal repeat in a Marek's disease virus clone.

Insertional activation of host proto-oncogenes has been recognized as a basic mechanism by which nonacute retroviruses induce cancer. Our previous work has demonstrated that retroviruses can efficiently integrate into DNA virus genomes. Specifically, coinfection of cultured fibroblasts with a chicken herpesvirus, Marek's disease virus (MDV), and a chicken retrovirus results in frequent stable retroviral insertions into the herpesvirus genome. Such insertions could alter the expression of herpesvirus genes, possibly resulting in novel phenotypic properties. In this article, we report the characterization of a replication-competent clone of MDV with integrated retroviral sequences. This virus was isolated from a chicken following injection of fibroblasts coinfected with MDV and the retrovirus, reticuloendotheliosis virus. Transcripts originating from the reticuloendotheliosis virus long terminal repeat promoters were found to encode the adjoining MDV genes, SORF2, US1, and US10. This virus replicates well in culture but has an unusual phenotype in chickens, characterized by an attenuated virulence which produces no nerve lesions but, rather, severe thymic atrophy. While the causal relationship between the insertion and the observed phenotypes remains to be established, our data provide the first evidence of retroviral insertional activation of herpesvirus genes.

Amino Acid Sequence↗
PubMed1996

Effects of hypoxia and hypercapnia on patterns of sleep-associated apnea in elephant seal pups.

This project examined the effects of alterations in respiratory drive on the occurrence of sleep apnea in Northern elephant seal pups (Mirounga angustirostris). Sleep pattern was unaffected by levels of hypoxia (approximately 13%) or hypercapnia (approximately 6%) that doubled respiratory frequency during slow-wave sleep (SWS). During sleep in air, short periods of continuous breathing (mean length = approximately 2.6 min) alternated with periods of apnea (mean length = approximately 6.1 min). Under hypoxic or hypercapnic conditions, the frequency of occurrence of apneas was reduced primarily due to the occurrence of some sleep episodes without periods of apnea. In episodes in which apneas did occur, they began later in the sleep episodes, but their length and the length of the periods of eupnea were not significantly altered. During each period of eupnea, however, the instantaneous respiratory rate and the total number of breaths increased. Breathing during sleep was restricted to SWS, never occurring during rapid eye movement (REM) sleep, regardless of the respired gas mixture. If the levels of hypoxia and hypercapnia were raised further, all episodes of apnea during sleep could be eliminated together with all episodes of REM sleep. One interpretation of the data is that the threshold for altering breathing during eupnea (instantaneous breathing frequency and number of breaths per episode of eupnea) is lower than that for altering the lengths of the periods of apnea and eupnea and that the muscle atonia associated with REM sleep extends to all respiratory muscles.

Animals↗
PubMed1996

311C90, a new central and peripherally acting 5-HT1D receptor agonist in the acute oral treatment of migraine: a double-blind, placebo-controlled, dose-range finding study.

311C90 is a novel, centrally and peripherally, acting 5-hydroxytryptamine1D receptor agonist. We investigated the efficacy and safety of 1, 5, and 25 mg of oral 311C90 in the acute treatment of migraine in a randomized, double-blind, placebo-controlled, parallel-group clinical trial involving 84 patients. The proportion of patients in whom the headache improved within 2 hours from moderate or severe to mild or no pain (primary efficacy measure) was 15% for placebo-treated patients and 27% (1 mg), 62% (5 mg), and 81% (25 mg) for patients treated with 311C90. Treatment differences compared with placebo were 12% (95% CI - 12, 37; p = 0.460) for 1 mg 311C90, 47% (CI 21, 73; p < 0.005) for 5 mg 311C90, and 66% (CI 43,89; p < 0.001) for 25 mg 311C90. Photophobia and nausea also showed improvement after 311C90. Adverse events were generally mild and transient in all treatment groups. There were no clinically significant changes in ECG recordings, blood pressure, or laboratory tests. Oral 311C90 (5 and 25 mg) is highly effective and well tolerated in the acute treatment of migraine. The response rates and treatment differences compared with placebo in this study suggest possible superiority over existing antimigraine therapies. This needs to be confirmed in formal comparative trials.

Administration, Oral↗
PubMed1996

Recurrent crystal-storing histiocytosis of the lung in a patient without a clonal lymphoproliferative disorder.

A 54-year-old woman developed an asymptomatic solitary lung mass, which recurred 10 years after resection. Both lesions consisted of a localized collection of intra-alveolar and interstitial macrophages filled with numerous eosinophilic cytoplasmic crystals. The crystals were non-birefringent, periodic acid-Schiff-negative, and showed polytypic reaction with both kappa and lambda light chains, and alpha, mu, and gamma heavy chains. No immunoglobulin gene rearrangements were detected. This lesion is consistent with crystal-storing histiocytosis, which has been reported in association with plasmacytoma. However, in this case, the absence of monotypic immunoglobulin staining within the crystals or the surrounding plasma cells, the absence of DNA rearrangements, and the long asymptomatic course raise the possibility that this lesion may be reactive. Similar lesions are seen in the lungs of mice with immune defects. Crystal-storing histiocytosis may represent a general reaction pattern to excess immunoglobulin.

Crystallization↗
PubMed1996

Haemophilus influenzae central corneal ulcer associated with cosmetic lens wear.

PURPOSE: We report a case of keratitis caused by Haemophilus influenzae involving daily wear contact lens use. METHODS: After positive cultures from corneal scrapings and contact lenses, the patient was diagnosed with Haemophilus influenzae keratitis. RESULTS: After 16 days of treatment with topical ciprofloxacin and trimethoprim sulfate-polymyxin B sulfate, the keratitis resolved. CONCLUSIONS: Cultures will help identify rare corneal pathogens such as Haemophilus influenzae and help in directing appropriate treatment.

Adult↗
PubMed1996

Golf-related injuries seen at hospital emergency departments.

Golf-related injuries are reported for 300 patients attending emergency departments of south-east Queensland hospitals over a six and a half year period. The main mechanisms of golf-related injury were being hit by a club (37%), hit by a ball (28%), sprains/strains (9.67%) and slips/falls (7%). For adult players, the main source of injury was being hit by a ball, while for children and adolescents being struck by a golf club accounted for 77 percent of hospital presentations. In the total study group, 46 people (15%) were admitted to hospital following their presentation at the emergency departments. Injury prevention and player education strategies are suggested as a means of reducing injuries in this popular sport.

Adolescent↗
PubMed1996

Speech-language evaluation of closed head injured subjects in South Africa: cultural applicability and ecological validity of a test battery.

This paper addresses the communicative outcome of a group of closed head injured (CHI) subjects in South Africa. Communicative outcome is evaluated on one test battery currently used for medico-legal assessments in South Africa. It was found that a number of the tests were sensitive to breakdown in this sample, but that the demographic factors of first language and pre-injury education significantly affected performance on some tests. Many test performances were significantly related to return to work, thus confirming the importance of communicative skills in the workplace, and the speech-language pathologist's role in vocational assessment and rehabilitation.

Adult↗
PubMed1995

Identification and cloning in yeast artificial chromosomes of a region of elevated loss of heterozygosity on chromosome 1p31.1 in human breast cancer.

We have mapped a region of high loss of heterozygosity in breast cancer to a 2-cM interval between the loci D1S430 and D1S465 on chromosome 1p31.1. This region shows allelic imbalance in around 60% of breast tumors. As part of a strategy to clone the target gene(s) within this interval, we have generated a yeast artificial chromosome contig spanning over 7 Mb. YACs from the CEPH and Zeneca (formerly ICI) libraries have been obtained by screening with PCR-based STSs from the region for both previously identified loci and newly isolated STSs. The YACs have been assembled into a contig by a combination of approaches, including analysis of their STS content, generation of new STSs from the ends of key YACs, and long-range restriction mapping. These YAC clones provide the basis for complete characterization of the region of high loss in breast cancer and for the ultimate identification of the target gene(s).

Base Sequence↗
PubMed1995

Suppression of rhythmic discharges of medullary neurones in organotypic cultures of new-born rats by calcium antagonists.

The contribution of transmembrane calcium flux to the generation of periodic bioelectric activity in cultured organotypic medullary tissue of 6 day old rats was determined by adding calcium antagonists (CA) to the recording saline and by lowering the calcium concentration of this saline. Organic CA flunarizine and verapamil (50-100 mumol/l) reversibly suppressed rhythmic discharge and diminished the CO2 response of medullary neurones within 30-60 min. Inorganic CA cobalt and magnesium exerted the same effects within a few minutes. After lowering the calcium concentration rhythmic activity became unstable, but recovered on exposure to increased CO2 concentration, the excitatory effect of which was strongly reduced. These findings point to a significant role for transmembrane calcium flux and intracellular calcium concentration in sustaining both periodic activity and the CO2 response of medullary neurones.

Animals↗
PubMed1995

A pharmacological profile of the selective silent 5-HT1A receptor antagonist, WAY-100635.

WAY-100635 (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2- pyridinyl)cyclohexanecarboxamide trihydrochloride) is an achiral phenylpiperazine derivative that binds with high affinity and selectivity to the 5-HT1A receptor. WAY-100635 displaced specific binding of the 5-HT1A radioligand, [3H]8-OH-DPAT (8-hydroxy-2-(di-n-propylamino)tetralin), to rat hippocampal membranes with a pIC50 of 8.87. This represented a greater than 100-fold selectivity relative to binding at other 5-HT receptor subtypes and major neurotransmitter receptor, reuptake and ion channel sites. In functional assays, WAY-100635 was a potent 5-HT1A receptor antagonist, with no evidence of any 5-HT1A receptor agonist or partial agonist activity. In the isolated guinea-pig ileum WAY-100635 was a potent and, at high concentrations, an insurmountable antagonist of the 5-HT1A receptor agonist action of 5-carboxamidotryptamine, with an apparent pA2 value (at 0.3 nM) of 9.71. WAY-100635 blocked the inhibitory action of 8-OH-DPAT on dorsal raphe neuronal firing in the anaesthetised rat at doses which had no inhibitory action per se. In behavioural models, WAY-100635 itself induced no overt behavioural changes but potently antagonised the behavioural syndrome induced by 8-OH-DPAT in the rat and guinea-pig (minimum effective dose = 0.003 mg/kg s.c. and ID50 = 0.01 mg/kg s.c., respectively). WAY-100635 also blocked the hypothermia induced by 8-OH-DPAT in the mouse and rat with ID50 values of 0.01 mg/kg s.c. These data indicate that WAY-100635 will be used as a standard antagonist in further studies of 5-HT1A receptor function.

8-Hydroxy-2-(di-n-propylamino)tetralin↗