Search PubMed⌕ Search

Biomedical subjects

A Rowe

Publications and source records attributed to A Rowe.

At least 19 recordsLinked to original sources
PubMed1999

Percutaneous gastrojejunostomy in amyotrophic lateral sclerosis.

We have performed a retrospective review of the use of a percutaneous gastrojejunostomy in patients with amyotrophic lateral sclerosis (ALS). Forty-one patients with initial bulbar manifestations of ALS and 32 patients with initial limb manifestations underwent a percutaneous gastrojejunostomy under fluoroscopic control using the Rankin gastrojejunostomy tube. Survival characteristics were compared with 86 bulbar onsetting and 207 limb onsetting ALS patients who did not require nutritional support. The 30-day mortality rate was 9.6% (respiratory death in three bulbar onsetting patients and four limb onsetting patients) and the 30 day morbidity rate was 4.1% (one operative site infection and intraperitoneal leakage in two patients). The most frequent long-term complication was the requirement for tube changing (blockage in six; dislodgment in two). Gastric reflux was not described amongst the treated patients. Overall survivorship (symptom onset to death) was less in the bulbar onsetting patients receiving a gastrojejunostomy tube than in the control population (median survival 22.0 vs. 33.7 months, respectively, P=0.005). As a group, the median survivorship for limb onsetting patients was not different for those receiving a gastrojejunostomy than for those who did not. However, a significant reduction in survival was observed in limb onsetting patients receiving a gastrojejunostomy early in the course of their disease (P=0.001) compared to those with a longer duration prior to the procedure. This was not observed in the bulbar onsetting patients. In both patient populations, no relationship was observed between survival post-gastrojejunostomy and the severity of pulmonary involvement at the time of the intervention, serum chloride, or age at onset. These studies demonstrate that a percutaneous gastrojejunostomy is a well-tolerated and safe alternative technique for enteral nutritional support in ALS patients. It also offers the advantage of not requiring either a general anaesthetic at the time of the procedure or instrumentation through the oropharynx. We have also observed that limb onsetting patients requiring a gastrojejunostomy early in the course of their illness are in a distinctive, less favorable, prognostic group.

Adult↗
PubMed1999

3D coronary artery imaging with phase reordering for improved scan efficiency.

Three-dimensional (3D) coronary imaging has the potential to overcome problems resulting from vessel tortuosity and to reduce partial volume effects. With these techniques, however, acquisition times are long and respiratory motion artifacts problematical. This work describes the development of a method that applies phase encode reordering to 3D acquisitions, allowing larger navigator acceptance windows to be used, with a consequent reduction in acquisition time. This method is compared with navigator acceptance window methods (the acceptance-rejection algorithm and the diminishing variance algorithm) and the retrospective respiratory gating technique, both in vitro and in vivo. The use of phase reordering with a 10 mm acceptance window provided a significant increase in scan efficiency over a non-reordered 5 mm method (P<0.001) with no significant change in image quality, and a significant increase in image quality compared with a non-reordered image acquired in the same time (P<0.05). A significant improvement in both image quality and scan efficiency was demonstrated over the retrospective respiratory gating method (P<0.05).

Adult↗
PubMed1999

Spatial working memory in Asperger's syndrome and in patients with focal frontal and temporal lobe lesions.

Spatial working memory (SWM) was investigated in 15 patients with Asperger's syndrome (AS) comparing their performance to 18 age- and IQ-matched control subjects. An additional comparison was made with 20 unilateral frontal excision patients [9 right (RFL); 11 left (LFL)] and with 38 unilateral temporal lobectomy patients [18 right (RTL); 18 left (LTL)], the frontal and temporal lobe patients having separate matched control groups. SWM was tested using the Executive Golf Task, a test that also measures spatial strategy formation. The AS group showed a substantial deficit on SWM, but no impairment in strategy formation. The LFL showed the same pattern of impairment, but with a less substantial deficit. The RFL group showed a large deficit, but some of this was accounted for by a strategy formation impairment. Of the temporal lobe lesions groups, only the RTL group was impaired on SWM, but this group showed normal strategy formation. It was concluded that the SWM deficit in AS may reflect a more general difficulty in accessing different types of representations in order to guide voluntary behavior, providing at least a partial explanation for the executive deficits found in AS.

Adolescent↗
PubMed1999

Cytoadherence, pathogenesis and the infected red cell surface in Plasmodium falciparum.

The particular virulence of Plasmodium falciparum compared with the other malaria species which naturally infect humans is thought to be due to the way in which the parasite modifies the surface of the infected red cell. Approximately 16 hours into the asexual cycle, parasite encoded proteins appear on the red cell surface which mediate adherence to a variety of host tissues. Binding of infected red cells to vascular endothelium, a process which occurs in all infections, is thought to be an important factor in the pathogenesis of severe disease where concentration of organisms in particular organs such as the brain occurs. Binding to uninfected red cells to form erythrocyte rosettes, a property of some isolates, is linked to disease severity. Here we summarise the data on the molecular basis of these interactions on both the host and parasite surfaces and review the evidence for the involvement of particular receptors in specific disease syndromes. Finally we discuss the relevance of these data to the development of new treatments for malaria.

Animals↗
PubMed1999

Itchy folliculitis and human immunodeficiency virus infection: clinicopathological and immunological features, pathogenesis and treatment.

The predominant itchy folliculitis associated with human immunodeficiency virus (HIV) infection appears to be an eosinophilic folliculitis (EF). This is characterized by lytic degeneration of sebaceous glands and an inflammatory infiltrate in which eosinophils and CD8+ T lymphocytes predominate. All patients have low CD4 counts and present late on in their HIV disease. Lesional distribution is mainly truncal, with a significant proportion also having facial involvement. Our prospective survey has shown that it is impossible to differentiate clinically between infective folliculitis and EF, and we recommend therefore that all cases are biopsied. We review the clinicopathological and immunological aspects of HIV-associated itchy folliculitis, in particular HIV-associated EF as well as current theories on pathogenesis and treatment. We suggest that HIV-associated EF is an autoimmune disease with the sebocyte or some constituent of sebum acting as the autoantigen.

AIDS-Related Opportunistic Infections↗
PubMed1999

Sequential changes in trace metal, metallothionein and calmodulin concentrations in healing skin wounds.

Metalloenzymes have an important role in repair and regenerative processes in skin wounds. Demands for different enzymes vary according to the phase in the healing cascade and constituent events. Sequential changes in the concentrations of calcium, copper, magnesium and zinc were studied in the incisional wound model in the rat over a 10 d period. Copper levels remained low (< 10 microg/g dry weight) throughout, but calcium, magnesium and zinc increased from wounding and peaked at about 5 d at a time of high inflammation, granulation tissue formation and epidermal cell proliferation. Metal concentrations declined to normal by 7 d when inflammation had regressed, re-epithelialisation of the wound site was complete and the 'normalisation' phase had commenced. Although the wound was overtly healed by 10 d, the epidermis was still moderately hyperplastic. In view of competitive binding of trace metals at membrane receptors and carrier proteins, the ratios or balance between these trace metals was examined and the significance is discussed. Using immunocytochemistry, we demonstrated increases in metallothionein immunoreactivity as an indication of zinc and copper activity in the papillary dermis and in basal epidermal cells near the wound margin 1-5 d after wounding. This is consistent with metalloenzyme requirements in inflammation and fibrogenesis. Calmodulin, a major cytosolic calcium binding protein was highest in maturing keratinocytes and in sebaceous gland cells of normal skin; it was notably more abundant in the epidermis near the wound margin and in re-epithelialising areas at a time when local calcium levels were highest.

Animals↗
PubMed1999

Depletion of cutaneous peptidergic innervation in HIV-associated xerosis.

Severe xerosis occurs in approximately 20% of human immunodeficiency virus seropositive patients. Changes in cutaneous innervation have been found in various inflammatory skin diseases and in xerotic skin in familial amyloid. We have therefore carried out a quantitative examination of the cutaneous peptidergic innervation in human immunodeficiency virus-associated xerosis. Immunohistochemistry and image analysis quantitation were used to compare total cutaneous innervation (protein gene product 9.5), calcitonin gene-related peptide, substance P, and vasoactive intestinal peptide peptidergic fibers, at two sites in the skin of human immunodeficiency virus-associated xerosis patients (upper arm, n = 12; upper leg, n = 11) and site-matched seronegative controls (upper arm, n = 10; upper leg, n = 10). Measurement of lengths of fibers of each type was carried out for each subject in the epidermis and papillary dermis, and around the sweat glands. Immunostained mast cells in these areas were counted. Epidermal integrity and maturation were assessed by immunostaining for involucrin. There were significant (Mann-Whitney U test; p < 0.02) decreases in total lengths of protein gene product 9.5 fibers in both epidermis/papillary dermis and sweat gland fields; of calcitonin gene-related peptide innervation in the epidermis/papillary dermis; and of substance P innervation of the sweat glands. There were no differences in the distribution of mast cells, or in the epidermal expression of involucrin. Depletion of the calcitonin gene-related peptide innervation may affect the nutrient blood supply of the upper dermis, and the integrity and function of basal epidermis and Langerhans cells. Diminished substance P innervation of the sweat glands may affect their secretory activity. Both of these changes may be implicated in the development of xerosis.

Adult↗
PubMed1999

Effects of a 2-hour cheerleading practice on dynamic postural stability, knee laxity, and hamstring extensibility.

STUDY DESIGN: One group; pretest, posttest design. OBJECTIVE: To assess the effect of a 2-hour cheerleading practice on the anterior knee laxity, hamstring extensibility, and dynamic postural stability (preferred stance leg during vision-denied unilateral stance) of 17 nonimpaired members of a college cheerleading team (8 females, 9 males; 18-25 years old). BACKGROUND: Anterior knee laxity and hamstring extensibility increase following exercise. The relationship between exercise induced anterior knee laxity, hamstring extensibility, and dynamic postural stability, however, has not been examined. METHODS AND MEASURES: Pre- and postpractice measurements were compared using paired t tests and Bonferroni's correction for multiple comparisons. A 3 x 2 analysis of variance (force level applied to the arthrometer by condition) and Tukey honest significant difference post hoc test were used to evaluate specific arthrometer force level by condition effects (P < .05). RESULTS: Mean laxity at 133 N and hamstring extensibility increased (mean +/- SD) 1.5 +/- 1 mm and 3 +/- 4 degrees, respectively, following practice. Mean medial-lateral stabiliometer platform angulation (frontal plane position) moved medially following practice (2.9 +/- 3 degrees) and produced a weak correlation with increased knee laxity (r = 0.58). Hamstring extensibility did not significantly relate to stabiliometry or knee laxity variables. CONCLUSIONS: The relationship between the medially directed platform angulation and the increase in anterior knee laxity following cheerleading practice suggests a relationship between subtalar joint position and anterior cruciate ligament strain.

Adolescent↗
PubMed1998

Interleukin-4 and the interleukin-4 receptor in allergic contact dermatitis.

Cutaneous immune responses involving T helper (TH) type 1 (TH1) and type 2 (TH2) T cells, characterised by secretion of interferon-gamma (Ifn-gamma) and interleukin-4 (IL-4), respectively, have both been reported in allergic contact dermatitis (ACD). We used immunohistochemistry to localize expression of IL-4 in ACD lesions and unaffected skin. Atopic dermatitis (AD) and psoriasis biopsies provided positive and negative IL-4 immunoreactivity controls. To investigate the role of IL-4 in ACD, we investigated expression of IL-4 receptors in ACD, AD and psoriatic skin. IL-4 immunoreactivity was found in cells in the dermal infiltrate in 3 out of 7 ACD lesions, but not in unaffected skin from these patients. IL-4 immunoreactivity was found in the dermal infiltrate of all lesional and unaffected AD biopsies, but in none of the psoriatic biopsies. IL-4 receptor alpha chain immunoreactivity, associated with dermal mast cells, was found in all patients. Local expression of IL-4 in ACD indicates either TH2 or TH0 immunoregulation in some allergic contact dermatitis lesions. Our findings do not support exclusive TH1 or TH2 cutaneous immune responses in ACD. Expression of IL-4 receptors by cutaneous mast cells provides a route through which local effects of IL-4 might be mediated.

Biopsy↗
PubMed1997

Retinoid X receptors.

Retinoids are metabolites of retinol (vitamin A), which act as signalling molecules in embryogenesis and as stimulators of cellular differentiation. The potency of retinoids as differentiating agents has led to their successful use in treating skin diseases and some forms of cancer. The retinoid X receptors (RXRs) are receptors for the vitamin A metabolite 9-cis retinoic acid, and they are members of the steroid/thyroid hormone receptor superfamily of DNA binding nuclear hormone receptor. The RXRs are also cofactors required for transcription activated by some other members of the steroid/thyroid hormone receptor superfamily, including the all-trans retinoic acid, thyroid hormone, vitamin D and peroxisome proliferator-activated receptors. The biological importance of the RXRs has been demonstrated in recent genetic studies which have shown that some RXR null mutations in mice have phenotypic effects similar to vitamin A deficiency.

Animals↗
PubMed1997

Constitutive endothelial and inducible nitric oxide synthase in inflammatory dermatoses.

We have used immunohistochemistry to localize the expression of the constitutive endothelial and inducible forms of the enzyme nitric oxide synthase (NOS) in skin from involved and uninvolved sites in patients with atopic dermatitis (AD) and allergic contact dermatitis (CD). Endothelial NOS (eNOS) immunoreactivity was localized to vascular endothelium in the dermis of both involved and uninvolved skin from all patients. Inducible NOS (iNOS) immunoreactivity was found to be closely associated with the upper dermal microvasculature in all the involved AD biopsies, but only in two of 10 uninvolved AD biopsies. CD biopsies were taken from 10 positive skin patch test sites and iNOS immunoreactivity was detected in all of these. iNOS immunoreactivity was detected in only one of the negative patch test biopsies. Both the extent and intensity of iNOS immunoreactivity was lower in CD than in AD skin lesions. The presence of eNOS in the skin is necessary for constitutive NO-mediated dilatation of the dermal vasculature. Induction of iNOS in the dermal endothelium and in perivascular inflammatory cells may be significant with respect to the roles of NO in both the vasodilatory component of the inflammatory response and in the modulation of immune responses in the skin.

Dermatitis, Allergic Contact↗
PubMed1997

Endoscopic management of pancreatic pseudocysts.

Pancreatic pseudocyst is a major complication of acute and chronic pancreatitis. Surgical drainage, the mainstay of therapy for this condition, is associated with 5% mortality, 25% morbidity, and 10% recurrence rates. Efforts to improve these figures and reduce the typically long hospitalizations have brought about percutaneous and endoscopic drainages. This article describes the endoscopic techniques and attempts to summarize their results based on a literature review. Before endoscopic drainage is carried out, other cystic lesions must be excluded with clinical history, computed tomography findings, and perhaps cyst fluid CEA content and cytology. Endoscopic techniques include wide transmural incision, transmural puncture and stenting, and transpapillary stenting. Either transgastric or transduodenal drainages can be carried out depending on the proximity of the pseudocyst to the gastrointestinal lumen. Endosonography has become an integral part of the transmural procedure because it can help diagnose cystic neoplasms, localize pseudocysts, detect submucosal vessels, and measure the cyst to mucosal distance for transmural punctures. Temporary nasocystic drains are often used to complement stenting during the initial treatment phase. Overall, the endoscopic experience in expert hands is associated with 94% initial technical success, 90% cyst resolution, and 16% recurrence rates. Additional nonendoscopic interventions, mostly surgical, are necessary in 17% of patients. Complication rate is 20%, with < 1% mortality. These data suggest that endoscopic drainage should become an accepted modality in the treatment of pseudocysts. Because of significant technical difficulty and potential risks, endoscopic drainages should only be carried out by experienced endoscopists and at well-equipped facilities.

Adult↗
PubMed1997

[Cholesterol in beef, pork, chicken and their products commercialized in Maringá, Paraná, Brazil].

A rapid method developed by Al-Hasani et al. with modifications for cholesterol determination was applied in samples of beef, pork, chicken and meat products. Analyses of cholesterol were performed by capillary gas chromatography. The obtained results showed that chicken presented higher concentration (126.96 to 188.29 mg/100 g) of cholesterol in comparison to beef and pork and similar to meat products, except bovine liver that presented 265.03 mg/100 g. Cholesterol values of beef and pork samples were considered low due to the absence of superficial fat in meat samples.

Animals↗
PubMed1996

Investigations into the molecular size and shape of tomato extensin.

The molecular characteristics of soluble extensin from tomato have been investigated. An apparent molecular mass greater than 240 kDa has been previously observed with the shape-dependent method of gel-filtration chromatography [Brownleader and Dey (1993) Planta (Berlin) 191, 457-469]. Tomato extensin is a heavily glycosylated protein that does not migrate into SDS/polyacrylamide gels. This shape-dependent behaviour raises doubts about agreement between the observed apparent mass and the absolute value. The molecular mass measured with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) was 72.3 kDa, with no evidence of any other species except a doubly charged ion. The sample was therefore considered to be monodisperse under the conditions used. Electron microscopy of soluble extensin showed the presence of particles 40-50 nm in length and 2.0-2.5 nm in width. A minority of these particles showed a central 'kink'. A number of smaller and generally wider particles (20 nm x 2-4 nm) were considered to be folded monomers and larger particles were thought to be dimers. Sedimentation analysis showed that extensin exists in a rapid monomer-dimer equilibrium in the concentration range and buffer used. Sedimentation equilibrium data gave a Kd of 8.5 microM and sedimentation velocity data generated a Kd between 1 and 10 microM. The concentration dependence of the measured sedimentation coefficient was used, together with hydrodynamic bead modelling, to define plausible shapes for monomer and dimer. This suggests that monomeric extensin is an elongated rod of length 40 nm and width 2 nm, which forms staggered dimers of average length 50 nm and width 3 nm. Extensin is an integral component of the primary cell wall. The physical characteristics (size, shape and form) of the rod-like extensin have been evaluated in this paper so that the role that extensin plays in primary cell wall architecture and during plant disease resistance can be more fully understood.

Cells, Cultured↗
PubMed1995

Expression of the chicken retinoid X receptor-gamma gene in migrating cranial neural crest cells.

We have used in situ hybridisation to whole chick embryos with digoxygenin-labelled probes to investigate the distribution of RXR-gamma transcripts during neural crest cell migration in the developing head and the anterior of the trunk (the vagal region), where neural crest cells make a substantial contribution. We have found that RXR-gamma transcripts are a good marker for migrating neural crest cells in the chick embryo. RXR-gamma transcripts were first detected in cells that had recently emerged from the neural crest, providing an earlier marker for neural crest cells than the HNK-1 epitope. The pattern of RXR-gamma transcript distribution is dynamic in the developing chick head, and changes in a pattern which is coincident with the migration of cells containing RXR-gamma transcripts and the gradual restriction of RXR-gamma transcripts to specific differentiating neural crest derivatives. Transcripts appeared to be present initially in migrating neural crest cells thoughout the developing head, but gradually became restricted to some crest-derived populations and absent from others. By stage 15, RXR-gamma transcripts were not detectable in neural-crest-derived ectomesenchymal cells, although they were still found in cells contributing to the cranial ganglia and their roots.

Animals↗
PubMed1995

Plasmodium falciparum rosetting is associated with malaria severity in Kenya.

Rosette formation in 154 fresh Plasmodium falciparum isolates from Kenyan children with mild (n = 54), moderate (n = 64), or severe (n = 36) malaria was studied to determine whether the ability to form rosettes in vitro is correlated with malaria severity. There was a wide distribution of rosette frequencies within each clinical category; however, a clear trend towards higher rosette frequency with increasing severity of disease was seen, with the median rosette frequency of the mild-malaria group (1%; range, 0 to 82%) being significantly lower than those of the moderate-malaria group (5%; range, 0 to 45%; Mann-Whitney U test, P < 0.02) and the severe-malaria group (7%; range, 0 to 97%; Mann-Whitney U test, P < 0.003). Within the severe-malaria category there was no difference in rosetting among isolates from cerebral malaria patients or those with other forms of severe malaria. We also examined the ABO blood groups of the patients from whom isolates were obtained and found that isolates from group O patients (median rosette frequency, 2%; range 0 to 45%) rosetted less well than those from group A (median, 7%; range 0 to 82%; Mann-Whitney U test, P < 0.01) or group AB (median, 11%; range 0 to 94%; Mann-Whitney U test, P < 0.03). We therefore confirm that rosetting is associated with severe malaria and provide further evidence that rosetting is influenced by ABO blood group type. Whether rosetting itself plays a direct role in the pathogenesis of severe malaria or is a marker for some other causal factor remains unknown.

ABO Blood-Group System↗