Search PubMed⌕ Search

Biomedical subjects

G Young

Publications and source records attributed to G Young.

At least 73 records · Page 4Linked to original sources
PubMed1999

Coagulation abnormalities in the carbohydrate-deficient glycoprotein syndrome: case report and review of the literature.

The carbohydrate-deficient glycoprotein syndromes are a group of recently described autosomal recessive, metabolic defects affecting multiple systems. The disorder is caused by inefficient posttranslational glycosylation of glycoproteins. Patients with the syndrome present early in life with psychomotor retardation, seizures, hypotonia, and stroke-like episodes. They also have dysmorphic features including almond-shaped eyes, constant squint, inverted nipples, and buttock fat pads. One of the features of the syndrome is coagulopathy, and we report here a patient who presented with a prolonged activated partial thromboplastin time, and was subsequently diagnosed with the carbohydrate-deficient glycoprotein syndrome. We also summarize the results of five previously published studies of the coagulation system in these patients. Most of the reported patients are deficient in factor XI, protein C, antithrombin III, and protein S. Other coagulation proteins are less frequently affected. Both bleeding and thrombosis have been observed, yet the cause of the stroke-like episodes remains speculative. The carbohydrate-deficient glycoprotein syndrome is an increasingly recognized multisystem disorder affecting hemostasis, and thus will involve clinical hematologists as part of a multidisciplinary team caring for patients with the syndrome.

Blood Coagulation Disorders↗
PubMed1999

Sebastian syndrome: case report and review of the literature.

Macrothrombocytopenias (MTCP) are a heterogeneous group of disorders associated with thrombocytopenia and giant platelets, and may include other clinical or laboratory findings such as hereditary nephritis, sensorineural deafness, leukocyte inclusions, and cataracts. Patients with MTCP may have mild to moderate bleeding symptoms or be completely asymptomatic. The most recently described MTCP is the Sebastian syndrome (SS), which consists of thrombocytopenia with giant platelets and leukocyte inclusions. Only three previous reports about this syndrome have been published. Herein, we report the first African-American family with SS. The propositus is a 4-week-old male born to a mother carrying the diagnosis of chronic idiopathic thrombocytopenia purpura (ITP). His 4-year-old brother also has thrombocytopenia. There is no history of bleeding symptoms in any of the family members. The diagnosis was established by demonstrating thrombocytopenia with giant platelets and leukocyte inclusions on both peripheral smear and by electron microscopy. This report illustrates the importance of obtaining a family history when evaluating thrombocytopenia with special emphasis on a history of thrombocytopenia, renal disease, deafness, and cataracts. It is important to differentiate between MTCP and chronic ITP to avoid the unnecessary diagnostic studies, and, more critically, unneeded and potentially harmful therapy.

Adult↗
PubMed1999

Long-term treatment of refractory thrombocytopenia in a patient with Wiskott-Aldrich syndrome with vincristine, immunoglobulin, and methylprednisolone.

We report a child with Wiskott-Aldrich syndrome with severe, refractory, symptomatic thrombocytopenia who achieved an excellent response to combination therapy with vincristine 1.5 mg/m(2) x 1 day, intravenous immunoglobulin 1 g/kg x 3 days, and methylprednisolone 25 mg/kg x 3 days (VIM) for 7 years after failing multiple treatments. He did not have a histocompatible donor for bone marrow transplantation. When the patient ceased to respond to this regimen, he was rescued with pulse dexamethasone. Vincristine, immunoglobulin, and methylprednisolone might serve as a novel treatment option for the patient with refractory thrombocytopenia. Our patient had a sustained remission of symptomatic thrombocytopenia without toxicity. Furthermore, pulse dexamethasone might be an alternative treatment option to which patients with Wiskott-Aldrich syndrome may respond.

Antineoplastic Agents, Phytogenic↗
PubMed1999

Sex steroid and corticosterone levels of Adélie penguins (Pygoscelis adeliae) during courtship and incubation.

Plasma levels of sex steroids (progesterone, 17alpha-hydroxyprogesterone, total androgens, and estradiol) were measured at six stages from courtship to late incubation in Adélie penguins. The pattern of change detected in the levels of plasma total androgens (males) and estradiol (females) was consistent with that found in many birds, with elevated levels during courtship (total androgens, 4 ng/ml; estradiol, 0.5 ng/ml) declining to low, stable levels during incubation. Progesterone levels declined moderately from 1.3 to 0.75-1.0 ng/ml in females following egg laying, but levels of 0.8-1.2 ng/ml persisted in males throughout the study period. 17alpha-Hydroxyprogesterone levels were consistently low (approximately 0.2 ng/ml) in females but progressively declined in males from 0.75 during courtship to <0.3 ng/ml at egg laying and during foraging. Plasma corticosterone levels were measured over the same period and were elevated in both males and females at courtship (16-18 ng/ml) and while fasting on the nest (11-15 ng/ml), but had declined in birds returning from foraging at sea, suggesting that elevated levels are related to the metabolic demands of fasting.

17-alpha-Hydroxyprogesterone↗
PubMed1999

End-stage renal disease in two pediatric patients with Fechtner syndrome.

Fechtner syndrome, a disease in the spectrum of the hereditary nephridites, is a macrothrombocytopenia associated with sensorineural hearing loss, cataracts, nephritis, and characteristic leukocyte inclusions. Renal biopsy findings are consistent with those of Alport syndrome, and the associated renal disease is said to be unusual before mid to late adulthood. Here, we review the available literature on this disease and report two African-American pediatric patients with Fechtner syndrome who rapidly progressed to end-stage renal disease during adolescence. We conclude that chronic renal failure can occur at a young age in patients with Fechtner syndrome, with a possible relation to race/ethnicity. Fechtner syndrome, or other variants of Alport syndrome, need to be considered in patients presenting with proteinuria and thrombocytopenia.

Adolescent↗
PubMed1999

Characteristics and occurrence of phenolic phytochemicals.

Phenolic phytochemicals are the largest category of phytochemicals and the most widely distributed in the plant kingdom. The 3 most important groups of dietary phenolics are flavonoids, phenolic acids, and polyphenols. Flavonoids are the largest group of plant phenols and the most studied. Phenolic acids form a diverse group that includes the widely distributed hydroxybenzoic and hydroxycinnamic acids. Phenolic polymers, commonly known as tannins, are compounds of high molecular weight that are divided into 2 classes: hydrolyzable and condensed tannins. Quantification of food phenolics is just beginning, and preliminary results indicate high variability, even within a given food. Phenolics are biologically active compounds that may possess some disease-preventive properties. Evidence for their ability to prevent cancer or heart disease is preliminary and conflicting. The health benefits of phytochemicals have been reported in the popular press, and the public will come to dietitians for answers to their questions about phytochemicals.

Coumaric Acids↗
PubMed1999

Prothrombin G20210A mutation in a child with spinal cord infarction.

Prothrombin G20210A is a newly described common mutation that is associated with an increased risk of arterial and venous thrombosis. We describe a healthy child heterozygous for this prothrombin mutation who had a spinal cord infarct with no other prothrombotic risk factors.

Family↗
PubMed1999

Process capability measurement of frequent replacement spherical soft contact lenses.

Frequent replacement soft contact lenses must have good reproducibility in order to avoid clinical problems arising from manufacturing variations in lens parameters. This study assessed the actual and potential process capability of eight frequent replacement lenses (monthly or 2-weekly replacement) in relation to back vertex power, back optic zone radius, total diameter and centre thickness. Twenty-four lenses in three powers (-1.00, -3.00, -6.00 D) were measured for eight frequent replacement lenses: Acuvue, Acuvue 2, Biomedics 55, Encore, Focus, Optima FW, Soflens 66, Surevue. In general, the lenses showed adequate reproducibility in respect of those parameters likely to affect lens fit, namely back optic zone radius, total diameter and centre thickness. The process capability results showed some variation in reproducibility of BVP between lens types and between lens powers. Process capability was found to be a useful measure of contact lens reproducibility.

Journal Article↗
PubMed1999

Developing a distance learning honours degree in health promotion for delivery using the Internet.

Designing this programme for distance learning delivery, especially for the Internet has been a major learning experience for all the staff involved. However, addressing and resolving these issues has now provided us with a template for developing other programmes in distance learning mode. This was an endeavour that all our market research indicated we had to undertake since institutions of higher education, especially schools of healthcare are no different to commercial companies. Like commercial organizations, higher education institutions, too, are consumer facing and are in direct competition with other educational 'suppliers', i.e. other universities and colleges. If a university is to compete and to 'sell' its products well, it too must consider the Internet as a way of advertising its wares, streamlining its business model and eventually conducting its business. In our case, this means delivery of educational programmes. However, as Internet technologies are primarily designed for research and business, there is currently a lag in the development of tools that enable effective social learning. Our next programme via the Internet will be even better for the experiences we've undergone and the lessons we've learnt during this initiative.

Computer-Assisted Instruction↗
PubMed1999

Omafilcon A (Proclear) soft contact lenses in a dry eye population.

PURPOSE: We conducted a 3-month, randomized, comparative cross-over study to evaluate the clinical performance of lenses manufactured from omafilcon A on subjects with signs and symptoms of dry eye. The subjects' own daily wear soft lenses were used as controls. METHODS: Seventy-six subjects with objective evidence of dry eye, as defined in the NEI/Industry Workshop Report 1995, were fit with either the omafilcon A lenses (Proclear) or new control lenses. Subjects wore the lenses for 6 weeks and then crossed over to bilateral wear of the other lenses for an additional 6 weeks. During each part of the study, we examined subjects at 1 week, 1 month, and 6 weeks. Signs and symptoms of dry eye were evaluated, and on-eye dehydration of the lens was assessed. RESULTS: When the subjects were wearing the omafilcon A lenses, there was a statistically significant improvement in a number of subjective parameters including comfort, dryness, frequency of eye irritation, and frequency of burning. We found significantly less on-eye dehydration of the lens and fluorescein corneal staining with the omafilcon A lenses. CONCLUSIONS: This study indicated that the daily wear of omafilcon A lenses provided better comfort, fewer symptoms, less on-eye dehydration, and less fluorescein corneal staining than other soft daily wear contact lenses in subjects with mild to moderate dry eye.

Adolescent↗
PubMed1999

Shoulder dystocia.

Explore the source record for details and available documents.

Delivery, Obstetric↗
PubMed1999

The on-eye dehydration of proclear compatibles lenses.

PURPOSE: The purpose of the study was to evaluate the on-eye dehydration over time, of molded omafilcon A lenses (Proclear Compatibles) compared to a range of frequent replacement lenses. METHODS: Ten subjects wore a Proclear Compatibles lens in one eye and a control lens in the other eye for 4-, 8- and 12-hours. The control lenses were Acuvue, Soflens 66 and Optima frequent replacement lenses. Each subject wore three different pairs of lenses for each time period in a masked, randomized fashion. A gravimetric technique was used to determine lens water content. RESULTS: The Proclear Compatibles lenses showed significantly less relative dehydration than the Acuvue and Soflens 66 lenses. The Acuvue and Soflens 66 lenses showed a significant increase in relative dehydration with increasing wearing time. Subjective comfort was graded higher with the Proclear Compatibles than with the Acuvue lenses. There was a significant negative correlation between Acuvue dehydration and subjective ratings of comfort. CONCLUSIONS: The study showed that Proclear Compatibles lenses dehydrate significantly less than the other frequent replacement high-water content lenses. The Acuvue and Soflens 66 lenses showed increasing dehydration during the 4-12 hour wearing period.

Contact Lenses, Hydrophilic↗
PubMed1998

Eel (Anguilla japonica) testis 11beta-hydroxylase gene is expressed in interrenal tissue and its product lacks aldosterone synthesizing activity.

A recombinant expression vector containing Japanese eel (Anguilla japonica) testis cytochrome P450(11 beta) (11beta-hydroxylase) cDNA was introduced into COS-1 cells. Enzymatic activity of the expressed P450(11 beta) for corticosteroid synthesis was analysed by incubating transfected cells with 14C-labelled 11-deoxycorticosterone or 3H-labelled deoxycortisol as substrates. Thin layer chromatography of incubation medium revealed that a high percentage of 11-deoxycorticosterone was converted into corticosterone and 11-dehydrocorticosterone but no aldosterone was detected. Similarly, deoxycortisol was converted into cortisol and cortisone. These results show that eel P450(11beta) does not possess significant aldosterone synthesizing activity. Northern blot analysis detected a 1.8 kb transcript of P450(11beta) using RNA extracted from interrenals of untreated Japanese eel but no hybridization signal was apparent using RNA extracted from brain, spleen, heart, muscle or testis. Immunohistochemistry using an antiserum against P450(11beta) also revealed strong immunostaining in interrenal cells.

Aldosterone↗
PubMed1998

Positive-outcome bias and other limitations in the outcome of research abstracts submitted to a scientific meeting.

CONTEXT: Studies with positive results are more likely to be published in biomedical journals than are studies with negative results. However, many studies submitted for consideration at scientific meetings are never published in full; bias in this setting is poorly studied. OBJECTIVE: To identify features associated with the fate of research abstracts submitted to a scientific meeting. DESIGN AND SETTING: Prospective observational cohort, with 5-year follow-up of all research submitted for consideration to the major annual 1991 US research meeting in the specialty of emergency medicine. PARTICIPANTS: All research abstracts submitted for consideration at the meeting for possible presentation. MAIN OUTCOME MEASURES: Characteristics associated with acceptance for presentation at the meeting and subsequent publication as a full manuscript. RESULTS: A total of 492 research abstracts were submitted from programs in emergency medicine and other specialties affiliated with 103 US medical schools. A total of 179 (36%) were accepted for presentation and 214 (43%) were published in 44 journals. Of the 179 abstracts accepted for presentation, 111 studies were published. Scientific quality of abstracts or prestige of the journal in which the study was eventually published did not predict either of these outcomes. The best predictors (by logistic regression) of meeting acceptance were a subjective "originality" factor (odds ratio [OR], 2.07; 95% confidence interval [CI], 1.13-3.89) and positive results (OR, 1.99; 95% CI, 1.07-3.84), and, for publication, meeting acceptance (OR, 2.49; 95% CI, 1.49-4.35) and large sample size (OR, 2.26; 95% CI, 1.23-4.31). Forty-nine percent (241) of abstracts did not report on blinding, and 24% (118) did not report on randomization. Acceptance and publication were both more likely for positive outcomes (P=.03). Funnel plots showed the classic distribution of positive-outcome ("publication") bias at each of the submission, acceptance, and publication phases. Meeting acceptance predicted publication with a sensitivity of only 51%, specificity of 71%, positive predictive value of 57%, and negative predictive value of 66%. CONCLUSIONS: Positive-outcome bias was evident when studies were submitted for consideration and was amplified in the selection of abstracts for both presentation and publication, neither of which was strongly related to study design or quality.

Abstracting and Indexing↗
PubMed1998

Unpublished research from a medical specialty meeting: why investigators fail to publish.

CONTEXT: It is not known whether peer review of research abstracts submitted to scientific meetings influences subsequent attempts at publication. OBJECTIVE: To determine why research submitted to a scientific meeting is not subsequently published. We hypothesized that authors of abstracts rejected by a meeting are less likely to pursue publication than those whose abstracts are accepted, regardless of research quality. DESIGN AND PARTICIPANTS: Blinded review of abstracts submitted to a medical specialty meeting in 1991 and not published as full manuscripts within 5 years. In 1996, authors of 266 unpublished studies were asked to complete questionnaires. MAIN OUTCOME MEASURES: Submission of a full manuscript to a journal between 1991 and 1996; failure to submit a manuscript to a journal because the investigator believed it would not be accepted for publication. RESULTS: A total of 223 (84%) of the unpublished investigators returned the questionnaire. Only 44 (20%) had submitted manuscripts to a journal. Manuscript submission was not associated with abstract quality (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.80-1.64), positive results (OR, 0.75; 95% CI, 0.31-1.57), or other study characteristics. Having an abstract accepted for presentation at the meeting weakly predicted submission of a manuscript to a journal (OR, 1.88; 95% CI, 0.84-4.10). Authors of accepted abstracts were significantly less likely to believe a journal would not publish their manuscript than were authors of rejected abstracts (OR, 0.23; 95% CI, 0.0001-0.61). CONCLUSIONS: Study characteristics do not predict attempts to publish research submitted to a scientific meeting. Investigators whose research is rejected by a meeting are pessimistic about chances for publication and may make less effort to publish.

Abstracting and Indexing↗
PubMed1998

Use of pamidronate in the management of acute cancer-related hypercalcemia in children.

PURPOSE: To determine whether pamidronate is a safe and effective agent for the treatment of severe hypercalcemia of malignancy in children. MATERIALS AND METHODS: A retrospective review of the charts of five children treated with pamidronate 1-2 mg/kg for severe, refractory hypercalcemia of malignancy. All children failed conventional therapy. Statistical analysis was done utilizing the two-tailed Student's t-test. RESULTS: All five children had complete resolution of their hypercalcemia in a predictable pattern within 24-48 hours. The average decrease in serum calcium was 1.63 mmol/L (6.54 mg/dl). (P < .01) The adverse effects were mild and transient, and consisted of hypocalcemia, hypophosphatemia, and hypomagnesemia. CONCLUSIONS: Pamidronate at a dose of 1 mg/kg is a safe and effective treatment for severe, refractory hypercalcemia of malignancy in children.

Acute Disease↗