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Biomedical subjects

J Parker

Publications and source records attributed to J Parker.

At least 19 recordsLinked to original sources
PubMed2001

Lower extremity strength deficits in peripheral arterial occlusive disease patients with intermittent claudication.

The purposes of this study were to quantify the degree and distribution of lower extremity weakness in patients with peripheral arterial occlusive disease (PAOD) compared to apparently healthy older patients and to determine if performance of a simple functional measure correlates with lower extremity strength. Older patients (n = 46), 31 with PAOD (mean age = 69.9 years; mean ankle-brachial index = 0.67) and 15 without PAOD (mean age = 62.6 years; mean ankle-brachial index = 1.20), underwent isometric strength testing of hip, knee, and ankle musculature. In patients with PAOD, dorsiflexion strength was 15% lower (p < 0.05) in the more affected limb (55 +/- 4 Newton-meters; mean +/- SE) versus the less affected limb (65 +/- 5 Newton-meters). Overall, the dorsiflexor muscles of the more affected extremity were 22% weaker (p < 0.05) in the PAOD group than in the non-PAOD group (73 +/- 6 Newton-meters). No other significant differences in strength were found between the PAOD and the healthy elderly groups or between the more affected and less affected limbs in the PAOD patients. The time to perform five sequential sit-to-stand transfers using an armless chair was 23% greater (p < 0.01) in the PAOD group (13.0 +/- 0.5 s) than in the healthy elderly (10.7 +/- 0.9 s). In the PAOD patients, dorsiflexor strength was correlated with chair stand time (r = -0.37, p < 0.05). The authors conclude that PAOD patients with intermittent claudication are functionally limited by dorsiflexion weakness, impairing their ability to perform tasks requiring distal lower extremity strength.

Aged↗
PubMed2000

Treatment of separation anxiety in dogs with clomipramine: results from a prospective, randomized, double-blind, placebo-controlled, parallel-group, multicenter clinical trial.

The efficacy and tolerability of clomipramine in the treatment of separation anxiety in dogs was tested in a prospective, randomized, double-blind, placebo-controlled, parallel-group, international multicenter clinical trial. For a diagnosis of separation anxiety, dogs had to exhibit at least one of the following signs in the absence of their owner: destruction, defecation, urination and/or vocalization, as well as the behaviour suggestive of "hyper-attachment" to their owner. A total of 95 dogs were randomized to receive one of the three treatments for 2-3 months: "standard-dose" clomipramine (1 to <2 mg/kg, PO, q. 12 h); "low-dose" clomipramine (0.5 to <1 mg/kg, PO, q. 12 h); and placebo (PO, q. 12 h). All dogs received behavioural therapy. Dogs were examined at four time points (days 0, 28, 56 and 84) after the initiation of therapy. Improvement in each dog's behaviour at days 28, 56 and 84 was evaluated in comparison to its behaviour at day 0.The results showed that, compared to placebo, dogs receiving standard-dose clomipramine were rated improved at least three times faster for the signs destruction, defecation and urination. At most time points, more dogs in the standard-dose clomipramine group were rated improved for the signs destruction, defecation and urination, and in an owner's global assessment of the dog's overall behaviour (p<0.05 at certain time points). However, there were no statistically significant differences at any time point between the standard dose and the placebo groups in the sign vocalization. The low-dose clomipramine group produced no statistically significant effect when compared with placebo. Mild and transient vomiting was noted as a side effect of clomipramine in a small number of dogs.It is concluded that addition of standard-dose (1 to <2 mg/kg, PO, q. 12 h) clomipramine to conventional behavioural therapy for 2-3 months ameliorated the signs of separation anxiety in dogs.

Journal Article↗
PubMed2000

Comparative studies of the effects of recombinant GM-CSF and GM-CSF administered via a poxvirus to enhance the concentration of antigen- presenting cells in regional lymph nodes.

Repeated subcutaneous (s.c.) injections of recombinant granulocyte-macrophage colony-stimulating factor (recGM-CSF) for 4-5 days can enrich an immunization site with antigen-presenting cells (APC), which has been correlated with improved immune responses in experimental and clinical studies. A recombinant vaccinia virus encoding the GM-CSF gene (rV-GM-CSF) has been developed and can generate specific antitumour immunity in a whole tumour cell vaccine. In the present study, we examined whether rV-GM-CSF could produce and release GM-CSF locally which, in turn, might enrich a site of immunization for APC as previously shown for recGM-CSF. S.c. injection of rV-GM-CSF significantly (P<0.05) enhanced the percentage and overall number of APC, measured by class II expression levels, in the regional lymph nodes that drain the injection site. Dose- and temporal-dependent studies showed class II expression levels in the draining lymph nodes were maximally enhanced 5-7 days after a single injection of 10(7)plaque-forming units (pfu) of rV-GM-CSF. Flow cytometry revealed that the increase in class II expression resulted from (i) a higher class II expression level on CD19(+)B cells and (ii) an increase in the number of CD11c(+)/class II(+)professional APC within the draining lymph nodes. Moreover, isolation of lymph nodes from rV-GM-CSF-treated mice revealed their capacity to support higher levels of antigen-specific T cell proliferation and allospecific cytotoxic responses. A comparison between a single injection of rV-GM-CSF and a 4-day course of recGM-CSF revealed comparable changes in class II expression and functional T cell assays. GM-CSF can be delivered in a recombinant poxvirus, and the local production of the cytokine results in cellular and phenotypic changes that are similar to those of recGM-CSF. The ability to utilize rV-GM-CSF as a single inoculum may be more compatible with traditional immunization strategies.

Animals↗
PubMed2000

Laparoscopic excision of endocervicosis of the urinary bladder.

Endocervicosis is a benign lesion in which endocervical mucosa develops in anatomic locations distant from the endocervical canal. Two cases of infiltrating endocervicosis of the urinary bladder were managed by laparoscopic partial cystectomy. This avoided the morbidity of laparotomy and provided improved visualization of the extent of bladder resection required to remove the lesion completely.

Adult↗
PubMed2000

Callosal atrophy correlates with temporal lobe volume and mental status in Alzheimer's disease.

BACKGROUND: Recent studies have reported significant atrophy of the corpus callosum (CC) in Alzheimer's Disease (AD). However, it is currently unknown whether CC atrophy is associated with specific cortical volume changes in AD. Moreover, possible atrophy in extra-callosal commissures has not been examined to date. The purpose of the present study was to quantify atrophy in two cerebral commissures [the CC and the anterior commissure (AC)], to correlate this measure with cognitive status, and to relate commissural size to independent measures of temporal lobe volume in AD patients. METHODS: A sample of AD patients and of age- and education-matched normal control subjects (NCs) underwent MRI and a cognitive test battery including the Dementia Rating Scale and Mini Mental State examination. Mid-sagittal regional areas within CC and AC were measured along with superior, middle and inferior temporal lobes volumes. RESULTS: Alzheimer's Disease patients had significantly smaller callosa than did NCs. The callosal regions most affected in AD included the midbody, isthmus and genu. The isthmus and midbody areas of the CC were positively correlated with cognitive performance and with superior temporal lobe volume in AD patients. The mid-sagittal area of the AC and the superior temporal volumes did not differ between AD patients and NCs. CONCLUSIONS: The study demonstrated that the regional morphology of the CC correlates with current cognitive status and temporal lobe atrophy in AD. As well, the lack of difference for the AC suggests that commissural atrophy in AD is regionally specific.

Aged↗
PubMed2000

All-trans-retinoic acid effects the growth, differentiation and apoptosis of normal human myeloid progenitors derived from purified CD34+ bone marrow cells.

We have previously shown that all-trans retinoic acid (ATRA) increases the number of CFU-GM colonies grown from unseparated human bone marrow cells with crude sources of colony stimulating factors. In this study, we further characterized the effect of ATRA on the growth of CFU-GM stimulated by individual cytokines from multiple samples of CD34+ enriched or purified human bone marrow cells. The number of IL-3- or GM-CSF-induced CFU-GM with 3 x 10(-7) M ATRA was 3.25+/-1.13, and 2.17+/-0.8-fold greater respectively, compared to controls without ATRA, while G-CSF had no effect and the ratio of colony-induced with or without ATRA was 1.06+/-0.17 (P = 0.00012). No colonies grew with ATRA + IL-6 or ATRA without a cytokine. Maximum enhancing effect on IL-3-induced CFU-GM occurred when ATRA was added on day 2, gradually diminished when delaying ATRA, and in cultures of day 9 or older adding ATRA had no effect. In 14 days liquid cultures of purified CD34+ cells with IL-3, ATRA increased the number of myeloid differentiated cells to 91-95%, compared to 37-70% with IL-3 alone. In addition, the number of apoptotic cells using the annexin V method increased after 14 days from 5.1% with IL-3 to 17.1% with IL-3 + ATRA and by the TUNEL in situ method from 10-26% to 60-95%, respectively. This study demonstrates that ATRA consistently enhances the growth of myeloid progenitors from CD34+ cells. This effect is dependent on the stimulating cytokine, suggesting the myeloid cells responding to ATRA are the less mature CFU-GMs that are targets of IL-3 and GM-CSF and not the G-CSF-responding mature progenitors. The growth stimulation by ATRA and IL-3 is also associated with granulocyte differentiation and increased apoptosis. These studies further suggest a potential role of pharmacological doses of ATRA on the development of normal human hematopoietic cells.

Antigens, CD34↗
PubMed2000

Safety of intravenous gadolinium (Gd-BOPTA) infusion in patients with renal insufficiency.

The safety of gadolinium (Gd-benzyloxypropionictetra-acetate [BOPTA] dimeglumine) infusion was evaluated in 32 patients with severe or moderate chronic renal failure in a prospective, randomized, double-blind, placebo-controlled study. Renal failure was defined as severe if creatinine clearance was between 10 and 29 mL/min, and as moderate if creatinine clearance was between 30 and 60 mL/min. Serum creatinine level and 24-hour urine samples for creatinine clearance were followed up serially for 7 days after the administration of either gadolinium (Gd-BOPTA dimeglumine), 0.2 mmol/kg, or a saline infusion. No patient experienced a significant change in renal function, defined as an increase in serum creatinine level greater than 0.5 mg/dL more than baseline, and no patient required hospitalization or dialysis during the study period. Gadolinium (Gd-BOPTA dimeglumine) appears to be well tolerated in patients with moderate to severe renal failure.

Contrast Media↗
PubMed2000

Systematic biases in measured PM10 values with U.S. Environmental Protection Agency-approved samplers at Owens Lake, California.

From 1993 through 1998, Wedding or Graseby high-volume PM10 samplers were collocated with tapered element oscillating microbalance (TEOM) samplers at three sites at Owens Lake, CA. The study area is heavily impacted by windblown dust from the dry Owens Lake bed, which was exposed as a result of water diversions to the city of Los Angeles. A dichotomous (dichot) sampler and three collocated Partisol samplers were added in 1995 and 1999, respectively. U.S. Environmental Protection Agency (EPA) operating procedures were followed for all samplers, except for a Wedding sampler that was not cleaned for the purpose of this study. On average, the TEOM and Partisol samplers agreed to within 6%, and the dichot, Graseby, and Wedding samplers measured lower PM10 concentrations by about 10, 25, and 35%, respectively. Surprisingly, the "clean" Wedding sampler consistently measured the same concentration as the "dirty" Wedding sampler through 85 runs without cleaning. The finding that the Graseby and Wedding high-volume PM10 samplers read consistently lower than the TEOM, Partisol, and dichot samplers at Owens Lake is consistent with PM10 sampler comparisons done in other fugitive dust areas, and with wind tunnel tests showing that sampler cut points can be significantly lower than 10 microns under certain conditions. However, these results are opposite of the bias found for TEOM samplers in areas that have significant amounts of volatile particles, where the TEOM reads low due to the vaporization of particles on the TEOM's heated filter. Coarse particles like fugitive dust are relatively unaffected by the filter temperature. This study shows that in the absence of volatile particles and in the presence of fugitive dust, a different systematic bias of up to 35% exists between samplers using dichot inlets and high-volume samplers, which may cause the Graseby and Wedding PM10 samplers to undermeasure PM10 by up to 35% when the PM10 is predominantly from coarse particulate sources.

Air Pollution↗
PubMed2000

Acute renal failure after cardiopulmonary bypass: a possible association with drugs of the fibrate group.

BACKGROUND: Renal failure is a recognized, but infrequent, complication following cardiac surgery. The causes for this condition are multifactorial, and a major concern is that the occurrence of postoperative acute renal failure is still associated with a high mortality rate. METHODS AND MATERIALS: We report unexpected acute renal failure occurring in 4 patients after uncomplicated cardiac surgery. Each patient was taking a fibric acid derivative at the time of surgery. Renal failure occurred rapidly within 3 days of surgery and was associated with increased concentrations of skeletal muscle-derived creatine kinase (CK). One patient developed myoglobinuria, and another developed a malignant hyperthermia-like syndrome. CONCLUSIONS: These cases show that patients receiving lipid lowering medications could be at higher risk of developing acute renal failure after cardiac surgery. This association merits careful evaluation in large prospective studies and, if proved, would suggest that patients taking either statins or fibrates should discontinue doing so before cardiac surgery.

Acute Kidney Injury↗
PubMed2000

sucker encodes a zebrafish Endothelin-1 required for ventral pharyngeal arch development.

Mutation of sucker (suc) disrupts development of the lower jaw and other ventral cartilages in pharyngeal segments of the zebrafish head. Our sequencing, cosegregation and rescue results indicate that suc encodes an Endothelin-1 (Et-1). Like mouse and chick Et-1, suc/et-1 is expressed in a central core of arch paraxial mesoderm and in arch epithelia, both surface ectoderm and pharyngeal endoderm, but not in skeletogenic neural crest. Long before chondrogenesis, suc/et-1 mutant embryos have severe defects in ventral arch neural crest expression of dHAND, dlx2, msxE, gsc, dlx3 and EphA3 in the anterior arches. Dorsal expression patterns are unaffected. Later in development, suc/et-1 mutant embryos display defects in mesodermal and endodermal tissues of the pharynx. Ventral premyogenic condensations fail to express myoD, which correlates with a ventral muscle defect. Further, expression of shh in endoderm of the first pharyngeal pouch fails to extend as far laterally as in wild types. We use mosaic analyses to show that suc/et-1 functions nonautonomously in neural crest cells, and is thus required in the environment of postmigratory neural crest cells to specify ventral arch fates. Our mosaic analyses further show that suc/et-1 nonautonomously functions in mesendoderm for ventral arch muscle formation. Collectively our results support a model for dorsoventral patterning of the gnathostome pharyngeal arches in which Et-1 in the environment of the postmigratory cranial neural crest specifies the lower jaw and other ventral arch fates.

Amino Acid Sequence↗
PubMed2000

An evaluation of ICNP intervention axes as terminology model components.

In this paper we evaluate selected axes of the International Classification of Nursing Practice (ICNP) as terminology model components for nursing actions by dissecting and categorizing two data sets of term phrases (Patient Care Data Set and Home Health Care Classification). Second, we critically analyze the relationships between the ICNP axes and terminology model components used to formally define procedures (including nursing actions) in SNOMED RT. Our findings demonstrate that the semantic categories represented by the ICNP intervention axes are relevant sources for terminology model components for nursing actions. In addition, our findings suggest that only minimal additions or extensions to the current semantic links of SNOMED RT are needed to support the formal definition of nursing actions such as those contained in PCDS and HHCC.

Models, Theoretical↗