Biomedical subjects

R A Adams

Publications and source records attributed to R A Adams.

At least 19 recordsLinked to original sources

PubMed2006

Association analysis of the chromosome 4p-located G protein-coupled receptor 78 (GPR78) gene in bipolar affective disorder and schizophrenia.

The orphan G protein-coupled receptor 78 (GPR78) gene lies within a region of chromosome 4p where we have previously shown linkage to bipolar affective disorder (BPAD) in a large Scottish family. GPR78 was screened for single-nucleotide polymorphisms (SNPs) and a linkage disequilibrium map was constructed. Six tagging SNPs were selected and tested for association on a sample of 377 BPAD, 392 schizophrenia (SCZ) and 470 control individuals. Using standard chi(2) statistics and a backwards logistic regression approach to adjust for the effect of sex, SNP rs1282, located approximately 3 kb upstream of the coding region, was identified as a potentially important variant in SCZ (chi(2) P=0.044; LRT P=0.065). When the analysis was restricted to females, the strength of association increased to an uncorrected allele P-value of 0.015 (odds ratios (OR)=1.688, 95% confidence intervals (CI): 1.104-2.581) and uncorrected genotype P-value of 0.015 (OR=5.991, 95% CI: 1.545-23.232). Under the recessive model, the genotype P-value improved further to 0.005 (OR=5.618, 95% CI: 1.460-21.617) and remained significant after correcting for multiple testing (P=0.017). No single-marker association was detected in the SCZ males, in the BPAD individuals or with any other SNP. Haplotype analysis of the case-control samples revealed several global and individual haplotypes, with P-values <0.05, all but one of which contained SNP rs1282. After correcting for multiple testing, two haplotypes remained significant in both the female BPAD individuals (P=0.038 and 0.032) and in the full sample of affected female individuals (P=0.044 and 0.033). Our results provide preliminary evidence for the involvement of GPR78 in susceptibility to BPAD and SCZ in the Scottish population.

Bipolar Disorder↗

PubMed2006

Role of leucocytes in damage to the vascular endothelium during ischaemia-reperfusion injury.

During this investigation, a model of tourniquet-induced forearm ischaemia-reperfusion injury is employed to investigate the role of leucocytes in damage to the vascular endothelium during ischaemia-reperfusion injury. Leucocyte entrapment is investigated by measuring the concentration of leucocytes in venous blood leaving the arm. Neutrophil and monocyte leucocyte subpopulations are isolated by density gradient centrifugation techniques. Cell surface expression of CD11b and the intracellular production of hydrogen peroxide are measured via flow cytometry. Plasma concentrations of elastase and von Willebrand factor (vWF) are measured using enzyme-linked immunosorbemt assay (ELISA) techniques. During ischaemia-reperfusion, there was an increase in CD11b cell surface expression on neutrophils (P=0.040) and monocytes (P=0.049), and a decrease in peripheral blood leucocytes (P=0.019). There was an increase in the intracellular production of hydrogen peroxide by leucocyte subpopulations (P=0.027 [neutrophils], P=0.091 [monocytes]) and in the plasma elastase concentration (P=0.05). There was also a trend to increasing plasma concentration of vWF (P=0.0562), which was measured as a marker of endothelial damage. Ischaemia-reperfusion results in increased adhesiveness, entrapment and activation of leucocytes. Even following a mild ischaemic insult, this leucocyte response was followed immediately by evidence of endothelial damage. These results may have important implications for understanding the development of chronic diseases that involve mild ischaemic episodes.

Adult↗

PubMed2005

Coonrad-Morrey total elbow arthroplasty for tumours of the distal humerus and elbow.

We reviewed 20 patients who had undergone a Coonrad-Morrey total elbow arthroplasty after resection of a primary or metastatic tumour from the elbow or distal humerus between 1980 and 2002. Eighteen patients underwent reconstruction for palliative treatment with restoration of function after intralesional surgery and two after excision of a primary bone tumour. The mean follow-up was 30 months (1 to 192). Five patients (25%) were alive at the final follow-up; 14 (70%) had died of their disease and one of unrelated causes. Local control was achieved in 15 patients (75%). The mean Mayo Elbow Performance Score improved from 22 (5 to 45) to 75 points (55 to 95). Four reconstructions (20%) failed and required revision. Seven patients (35%) had early complications, the most frequent being nerve injury (25%). There were no infections or wound complications although 18 patients (90%) had radiotherapy, chemotherapy or both. The Coonrad-Morrey total elbow arthroplasty provides good relief from pain and a good functional outcome after resection of tumours of the elbow. The rates of complications involving local recurrence of tumour (25%) and nerve injury (25%) are of concern.

Aged↗

PubMed2001

The impact of psychological disturbances on immediate memory.

The current study tested the hypothesis that attention mediates the impact of psychological disturbances (i.e. depression, loss of self-control, and bizarre thinking) on immediate memory. A hypothesized model, in which psychological disturbances indirectly impacted immediate memory via attention, was tested using structural equations modeling (EQS). The participants included heterogeneous groups of brain-damaged and psychiatric subjects both with and without age-corrected observed variables. These groups did not vary with regard to the relationships within the model, and all models had good fit indices [comparative fit index (CFI)>0.98]. Competing models with paths directly from psychological disturbances to verbal, spatial, and general immediate memory were not significant, and these competing models did not result in a better fitting model. Therefore, the best fitting, most parsimonious model was the hypothesized one. These results corroborate the hypothesis of an indirect relationship between psychological disturbances and immediate memory via attention.

Journal Article↗

PubMed2000

A conservative femoral replacement for total hip arthroplasty. A prospective study.

Between 1985 and 1993, 146 patients (162 hips) had total hip replacement (THR) using a conservative uncemented femoral component. The mean age of the patients was 50.8 years and the mean follow-up was 6.2 years (2 to 13). One patient was lost to follow-up, one died within two years of surgery and one had a revision procedure after a fracture sustained in a road-traffic accident. For the remaining 159, Kaplan-Meier survival analysis was calculated for the incidence of revision because of mechanical loosening or osteolysis. Survival without mechanical loosening at both five and ten years was 98.2%. Survival without osteolysis was 99% at five and 91% at ten years. The Harris hip score improved from a mean of 66.3 before to 90.4 at follow-up. Of particular note is the lack of thigh pain in this group. Radiological analysis showed that 139 stems (88%) had no measurable subsidence, 8 (5%) had less than 2 mm and 12 (7%) had more than 2 mm. Two of the eight and one of the 12 were revised for mechanical loosening. Nine hips were revised for late loosening associated with osteolysis. No reaming of the femoral canal was associated with statistically significant less blood loss compared with a comparable control group of uncemented implants (p < 0.0001). Our study suggests that using a conservative femoral implant does not protect against wear debris but the reliable mechanical stability (98.2%) makes this an attractive design of implant particularly for young patients.

Adult↗

PubMed2000

Soluble adhesion molecules in clinical ischaemic injury.

BACKGROUND: Neutrophil adhesion is a prerequisite for ischaemic injury. In vitro research has shown that soluble adhesion molecules have an inhibitory effect on neutrophil binding AIMS: To determine whether the circulating forms of adhesion molecules are consumed during skeletal muscle ischaemic injury in man. METHODS: The response of the circulating forms of adhesion molecules ICAM-1 (intercellular adhesion molecule-1) and L-selectin to ischaemia and reperfusion was investigated in 23 patients during surgery involving aortic cross-clamping and in 20 volunteers with tourniquet-induced forearm ischaemia. RESULTS: In the aortic model the levels of circulating ICAM-1 fell from an initial value of 250 +/- 20 to 210 +/- 13 ng/ml (p < 0.05) and soluble L-selectin fell from 642 +/- 62 to 487 +/- 49 ng/ml during ischaemia (p < 0.05). There was a similar pattern of reduced levels of circulating adhesion molecules in the model of forearm ischaemia. However the recovery of these molecules during the reperfusion period differed between the two models. CONCLUSIONS: Soluble L-selectin and soluble ICAM-1 appear to be utilised during clinical models of ischaemia. This supports previous in vitro studies suggesting a role in competitive inhibition and these circulating molecules may be clinically important inhibitors of leukocyte adhesion.

Aged↗

PubMed1999

Maternal stress in caring for children with feeding disabilities: implications for health care providers.

The purposes of this study were to compare the stress experienced by mothers of children with feeding disorders to the stress experienced by mothers of children with other childhood disabilities, to compare the stress experienced by mothers of children who are tube-fed with that of mothers of children with disabilities who do not require tube feeding, to ascertain the types of stressors that mothers in both groups experience, and to determine their coping resources. Subjects were mothers of children with disabilities who had recently been discharged or were receiving outpatient care from a private rehabilitation facility in a Midwestern city. The Short Form of the Questionnaire on Resources and Stress instrument and open-ended questions developed by the researchers were used. Results were analyzed using analysis of variance. Results indicate that mothers of children requiring tube feeding experienced significantly greater stress than mothers of children with disabilities who do not require tube feedings. Mothers of children requiring tube feeding also receive less support from family and friends. To assist dietitians, other health care professionals, and university instructors in developing family-centered treatment programs, we recommend including fathers, friends, or relatives in the care and feeding process; discovering ways to include the tube-fed child in family mealtime activities; increasing public awareness of tube-feeding issues; organizing support groups; and educating dietetics students about the unique stresses experienced by mothers of children who are tube-fed.

Adolescent↗

PubMed1999

Examination of a rheological profile for blood using micropore filters.

Various techniques have been used to assess the flow properties of blood and blood cells in a range of clinical situations. Filtration through microfilters offers a single technique for measuring the flow properties of all cellular components of blood in one experiment but depends on an assumed ability to recognize cells that make up <10% of leucocytes. The remaining leucocytes, labelled fast leucocytes, were previously presumed to be lymphocytes and granulocytes. This study confirmed the identities of these fast leucocytes as those of lymphocytes and granulocytes in undiluted blood. The transit time for lymphocytes (1.2 s) and granulocytes (1.6 s) is close to that recorded for fast leucocytes (1.7 s). The resistance of each type of blood cell to flow through 5 microm filters was defined in this study as the product of the concentration of that cell in blood and its transit time through a pore in the filter. The total resistance to flow of healthy blood through the filter is 4.46 x 10(7) s/ml and is attributed to plasma (2.7%), red cells (25.9%), fast leucocytes (25.3%) and slow leucocytes (46.1%). In a cohort of 21 men with peripheral arterial disease the total resistance was increased to 7.82 x 10(7) s/ml and attributed to plasma (1.5%), red cells (14.5%), fast leucocytes (21.0%) and slow leucocytes (63.00%). This analysis therefore provides a single test for assessing the flow properties of all the cellular components of blood and plasma.

Blood Viscosity↗

PubMed1999

Instability of the elbow treated with semiconstrained total elbow arthroplasty.

The results of nineteen semiconstrained modified Coonrad-Morrey total elbow arthroplasties performed in nineteen patients to treat instability were evaluated at an average of seventy-two months (range, twenty-five to 128 months) postoperatively. Preoperatively, all patients had either a flail elbow or gross instability of the elbow that prevented useful function of the extremity. The instability of sixteen elbows was the result of a traumatic injury or of the treatment of such an injury. The most recent result was satisfactory for sixteen elbows and unsatisfactory for three. The average overall Mayo elbow performance score increased from 44 points preoperatively to 86 points postoperatively. At the most recent follow-up examination, no elbow was unstable. The average arc of flexion was from 25 degrees (range, 0 to 60 degrees) to 128 degrees (range, 30 to 142 degrees), which represented a 58-degree increase from the preoperative average arc. Sixteen patients had little or no pain after the arthroplasty. There were four complications in four patients. Three complications (loosening of the humeral component in one patient and a fracture of the ulnar component in two) occurred postoperatively; all three were treated with a revision procedure. The other complication (a fracture of the olecranon) occurred intraoperatively and was treated with tension-band fixation; the most recent outcome was not affected. Radiographically, one patient had complete (type-V) radiolucency about the humeral component. None of the nine patients for whom true anteroposterior radiographs were available had evidence of wear of the bushings. The bone graft behind the anterior flange of the humeral prosthesis was mature in fourteen elbows, incomplete in two, and resorbed in two. One patient was excluded from this analysis because radiographs were not available. Instability of the elbow resulting in the inability to use the extremity is a challenging clinical situation. However, in patients who are more than sixty years old and in selected patients who are less than sixty years old but who have extensive loss of bone as a result of severe injury, have had multiple operations, or have rheumatoid arthritis, total elbow arthroplasty with a linked, semiconstrained prosthesis reestablishes a mobile, stable joint without premature loosening or failure of the components. In our experience, the use of customized implants, maintenance of the muscular attachments to the epicondyles, and reconstruction of the epicondyles to the implant were unnecessary.

Arthroplasty, Replacement↗

PubMed1998

Total elbow arthroplasty in primary osteoarthritis of the elbow.

Primary osteoarthritis of the elbow is an infrequent condition typically managed by some form of debridement. There is no comment in the literature regarding prosthetic replacement for this condition. We report 5 patients (mean age, 68), with a minimum assessment of 3 years (range, 37-125 years) after total elbow arthroplasty. Complications in 4 patients included subluxation, fracture of a humeral component with particulate synovitis, heterotopic ossification, recurrent osteophyte formation, and transient ulnar neuropathy. Although revision was required in 2 of the 5, currently all experience had satisfactory outcomes. While replacement has proven ultimately to be a successful option for this high-demand patient group because of the high complication rate, we do not recommend replacement unless alternate operative options are deemed unacceptable.

Aged↗

PubMed1998

Rheological properties and function of blood cells in stored bank blood and salvaged blood.

The technique involving filtration of diluted blood enables the separate analysis of the flow properties of different cell subpopulations. This study was designed to assess the changes occurring in the flow properties and function of blood cells in stored bank blood and salvaged blood compared to patient blood in a given clinical situation. We measured hydrogen peroxide production by neutrophils and the filterability, through 5 microm Nucleopore filters, of isolated red blood cells and of diluted blood. Samples were obtained from patients undergoing aortic surgery and blood intended for transfusion: either salvaged during surgery or stored bank blood. Both salvaged and bank blood were much less filterable than patient blood, with reduced deformability of both red and white blood cells. However, salvaged blood contained highly activated neutrophils with a prolonged transit time of the 'fast-flowing' cells in the analysis compared to bank blood. Bank blood contained significantly more particles which acted as pore-blockers. Cells in bank and salvaged blood therefore have markedly abnormal flow and biochemical properties compared to patient blood.

Blood Banks↗

PubMed1998

Infection after total elbow arthroplasty.

The purpose of this study was to review our experience with the treatment of twenty-five infections (in twenty-five patients) after total elbow arthroplasty and to examine indications for salvage of the prosthesis compared with those for resection arthroplasty. The patients were divided into three groups on the basis of treatment. Group I comprised fourteen patients who were managed with multiple, extensive irrigation and debridement procedures with retention of the original components. The primary indication for retention of the prosthesis was evidence that it was well fixed as determined both radiographically and intraoperatively. Group II comprised six patients who had removal of the prosthesis and debridement followed by immediate or staged reimplantation. Group III comprised five patients who were managed with resection arthroplasty. The infection was successfully eradicated in seven of the fourteen elbows that had salvage of the prosthesis with irrigation and debridement. The results were strongly dependent on the causative organism; attempts at debridement failed in the four elbows that were infected with Staphylococcus epidermidis compared with three of the ten that were infected with another organism. Four of the six patients in Group II had successful reimplantation of a prosthesis; in three, the infection had been caused by an organism other than Staphylococcus epidermidis. Only one of the three patients who had a Staphylococcus epidermidis infection had a successful reimplantation. None of the five patients who had a resection arthroplasty had signs of infection at the latest follow-up examination. We concluded that salvage of the prosthesis with extensive irrigation and debridement in the presence of an infection about the elbow can be reasonably successful if the infecting organism is not Staphylococcus epidermidis and if the components are well fixed. When removal of the components is warranted, staged reimplantation can also be highly successful when the infecting organism is not Staphylococcus epidermidis. However, the repeated operations necessary to retain a prosthesis and the high rates of complications seen with this approach--and the relatively good rates of satisfaction obtained with resection arthroplasty--suggest that resection arthroplasty remains the procedure of choice in medically frail patients or in patients for whom function of the elbow is less of a concern.

Adult↗

PubMed1998

Body elimination attitude and occupation.

16 food service personnel and 20 bank employees scored significantly higher (indicating greater disgust) on the Templer, King, Brooner, and Corgiat 1984 Body Elimination Attitude Scale than 46 nursing personnel and 15 sewage workers.

Adult↗

PubMed1997

Total elbow arthroplasty: revision with use of a non-custom semiconstrained prosthesis.

The results of revision elbow arthroplasty with use of the semiconstrained Mayo-modified Coonrad implant in forty-one patients were reviewed retrospectively. The average duration of follow-up was six years (range, two to thirteen years). At the time of the latest follow-up evaluation, thirty-eight patients were able to perform activities of daily living, one had a stiff elbow because of heterotopic ossification, one had weakness secondary to an injury of the radial nerve, and one had an unstable elbow after removal of the prosthesis because of recurrent aseptic loosening. Fourteen patients sustained either a fracture or a perforation of the cortex at the time of removal of the primary implant. Three of these patients had an injury of the radial nerve; the injury was due to extravasation of the cement from a cortical defect in two of them and was sustained during removal of the cement in one. Eight patients had an intraoperative or postoperative complication that necessitated additional operative intervention. Postoperatively, twenty-two patients had complete relief of pain and sixteen had mild discomfort. Three patients remained disabled: one, because of pain secondary to loosening of the component; one, because of a pre-existing nerve injury; and one, because of the residual effects of an intraoperative injury of the radial nerve. The average Mayo elbow performance score was 87 +/- 16 points at the latest follow-up evaluation, compared with 44 +/- 17 points preoperatively (p < 0.0001). Revision elbow arthroplasty restored function to the patients who had had a failed prosthesis without infection.

Adult↗

PubMed1996

Neutrophil elastase, von Willebrand factor, soluble thrombomodulin and percutaneous oxygen in peripheral atherosclerosis.

OBJECTIVES: To test the hypothesis that endothelial cell damage and hypoxia are related to the activity of neutrophil elastase in patients with peripheral atherosclerosis. DESIGN: A cross-sectional serological study in a tertiary referral, University Hospital. MATERIALS: Venous blood was obtained from 22 patients with peripheral vascular disease and an equal number of age and sex matched controls. METHODS: Neutrophil elastase and two markers of endothelial cell damage (von Willebrand factor and soluble thrombomodulin) were measured in plasma by ELISA. Hypoxia was measured by percutaneous oxygen (by oximeter) at the dorsum of the foot. RESULTS: Patients had higher von Willebrand factor, higher soluble thrombomodulin and higher elastase but lower percutaneous oxygen (all p < 0.001). In the patient's group, there were significant inverse correlates between von Willebrand factor and percutaneous oxygen (p = 0.004) and between soluble thrombomodulin and percutaneous oxygen (p = 0.011) while elastase correlated positively with soluble thrombomodulin (p = 0.023). CONCLUSIONS: Our data support the hypothesis that release of elastase from activated neutrophils relates to endothelial cell damage. This may contribute to hypoxia and may result in the deterioration in clinically assessed atherosclerosis.

Arteriosclerosis↗

PubMed1995

Semiconstrained elbow replacement for distal humeral nonunion.

We have reviewed 36 of 39 consecutive patients with an average age of 68 years who had semiconstrained elbow replacement for distal humeral nonunion at an average follow-up of 50.4 months (24 to 127). Of these, 31 (86%) had satisfactory results, three (8%) had fair, and two (6%) had poor results; 32 patients (88%) had moderate or severe pain before and 91% had no or only mild discomfort after the procedure. Motion had improved from a mean arc of 29 degrees to 103 degrees before operation to 16 degrees to 127 degrees after surgery. All five flail extremities were stable at last assessment. There were seven complications (18%): two patients had deep infection, two had particulate synovitis, two had ulnar neuropathy and one had worn polyethylene bushes. Five of these seven, excluding the two with transient nueropathy, required reoperation (13%). Joint replacement arthroplasty can be a safe and reliable treatment for this difficult clinical condition, seen most commonly in elderly patients. This is a significant advance, since repeated osteosynthesis has been shown to be ineffective in most patients.

Activities of Daily Living↗

PubMed1993

Gangliosides elicit a T-cell independent antibody response.

Antibodies to glycolipids have recently been found to be elevated in a substantial proportion of patients with motor neuron diseases, various neuropathies and classical ALS. Several features of these antibody responses suggest that they may be produced by a T-cell independent B lymphocyte response: (1) antibodies are predominantly of IgM class; (2) antibodies against gangliosides are directed against the carbohydrate component of the gangliosides; and (3) antiganglioside antibodies are difficult to suppress. In this study we have asked whether gangliosides can induce T-independent responses, in T-cell deficient and T-cell competent mice. Homozygous nude mice (nu/nu), which lack T-cells, and heterozygous controls (nu/+) with intact T-cells, were immunized and rechallenged with the ganglioside GM1 in liposomes. Antibodies were measured by an ELISA method. Both nude mice and controls produced high titers of IgM class antibodies to the ganglioside GM1. The antibody titers peaked by 7 days after each immunization and declined by 14 days. The maximum titer rose progressively after each immunization. No significant amount of IgG antibody to GM1 was produced by either nu/nu or nu/+ mice, even after repeated immunization. These results suggest that gangliosides elicit prominent T-cell-independent antibody responses. The implications of these findings for neurologic disorders associated with anti-ganglioside antibodies are discussed.

Animals↗

PubMed1993

Transferrin-binding ability of invasive and commensal isolates of Haemophilus spp.

Haemophilus influenzae type b expresses an inducible siderophore-independent iron-acquisition system that depends on a direct interaction between human transferrin and specific iron-regulated transferrin-binding outer-membrane proteins. To evaluate the importance of this iron-acquisition system amongst haemophili, 156 isolates of Haemophilus spp. (78 commensal isolates and 78 isolates from invasive infections) were examined for their ability to bind transferrin. Of the 78 invasive isolates, all of which were H. influenzae type b, 71 (91%) were capable of binding transferrin, with 57 (73%) binding transferrin constitutively (i.e., even when grown in an iron-sufficient medium). In contrast, only 11 (14%) of the commensal isolates bound transferrin constitutively, with a further 16 (21%) binding transferrin only after growth in an iron-deficient medium. Of the 27 commensal strains that were capable of binding transferrin, 12 were H. parainfluenzae biotype III, 14 were non-typable H. influenzae, and one was H. parahaemolyticus. None of the H. influenzae type b invasive or commensal isolates showed evidence of siderophore production, but 50 (66%) of the remaining 76 commensal isolates appeared to produce an iron chelator. Thus, while not a universal characteristic, detectable transferrin-binding was associated strongly with H. influenzae type b isolates from invasive infections, and was also recognised for the first time in isolates of H. parainfluenzae and H. parahaemolyticus.

Bacteremia↗