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Biomedical subjects

M Harris

Publications and source records attributed to M Harris.

At least 325 records · Page 18Linked to original sources

Undiagnosed fractures in severely injured children and young adults. Identification with technetium imaging.

A whole-body bone scan was performed to search for undetected fractures in forty-eight patients who had multiple injuries or a head injury, or both, and who were less than twenty-two years old. The study took place from January 1991 to July 1992. Radiographs had been made of all areas of suspected skeletal trauma at the time of admission. Follow-up plain radiographs were made of all areas where unexpected abnormal tracer activity was noted. Forty-two of these areas were noted in eighteen skeletally immature patients and fifty-two, in twelve skeletally mature patients. Nineteen previously unrecognized fractures were identified in the subsequent radiographic analysis. Four skeletally immature and two skeletally mature patients had an alteration in treatment on the basis of the identification of a previously undiagnosed injury. Each of these six patients had a cast applied. A fracture was identified three weeks or more after the injury in two skeletally mature patients. These fractures would have been treated (one with a cast and the other with open reduction and internal fixation) if they had been diagnosed earlier. We believe that this analysis demonstrates the usefulness of technetium radionucleotide bone-imaging, as an adjuvant to the orthopaedic examination, in the identification of undiagnosed musculoskeletal injuries in a patient who is less that twenty-two years old and who has sustained a head injury or multiple injuries, or both.

Adolescent↗

Oxygen free radicals in idiopathic facial pain.

Chronic idiopathic oro-facial pain has become a common complaint, resulting increasingly in referral to the pain clinics world-wide, about 90% of the psychologically stress-related patients of the psychiatric clinic of Eastman Dental Hospital, London have been found to have associated idiopathic oro-facial pain. Psychological stress may produce a situation where oxidative stress might enhance the production of free radicals, especially OH radicals, in human biological fluids. Furthermore, it has been suggested that. OH radicals are responsible for the production of many systemic and local tissue injury diseases which may initially manifest as pain syndrome. It has been suggested that the oxygen free radical production of sailcloth, 2,3-dihydroxybenzoic acid (DHB) is a biological marker for the detection and quantification of OH radicals. Analyses of plasma samples collected from patients with chronic idiopathic orofacial pain and an equal number of age and sex matched control subjects revealed that the patient group had significantly increased evidence for circulating levels of 2,3-DHB after aspirin ingestion than control subjects. There was no significant difference in 2,5-DHB levels between the two groups. The urine samples from the same individuals showed evidence of measurable amounts of 2,3 and 2,5-DHB in both pre- and post-aspirin samples. These results suggest that OFRs may be involved in the aetiology of pain in patients that present with facial pain.

Adult↗

Utilisation rates of primary care services in an emergency department.

Rates of patients attending for primary care reasons at the emergency department of Campbelltown Hospital were estimated to identify trends in utilisation, reasons for attendance and social characteristics. The proportion of 'primary care' patients attending the emergency department is increasing. The reasons for the increase are not known and require further investigation.

Adolescent↗

GM-1 ganglioside administration combined with physical therapy restores ambulation in humans with chronic spinal cord injury.

In a randomized double-blind cross-over study, humans with chronic spinal cord injury received ganglioside GM-1 or placebo for 2 months. GM-1, administered intravenously at a dose of 100 mg, 6 days a week, resulted in a statistically significant improvement of motor scores (P < 0.05), whether administered before or after 2 months of placebo. There was no placebo effect on motor scores. Subjects who received GM-1 before placebo maintained their improvement during the placebo phase. Subjects who received GM-1 ambulated with a reciprocal gait, using orthotics, for longer distances and at a faster rate whether the drug was administered before or after placebo. These results constitute the first finding that any chemical substance improves locomotion in human chronic spinal cord injury.

Adult↗

Evidence for multi-site closure of the neural tube in humans.

Four separate initiation sites for neural tube (NT) fusion have been demonstrated recently in mice and other experimental animals. We evaluated the question of whether the multisite model vs. the traditional single-site model of NT closure provided the best explanation for neural tube defects (NTDs) in humans. Evidence for segmental vs. continuous NT closure was obtained by review of our recent clinical cases of NTDs and previous medical literature. With the multi-site NT closure model, we find that the majority of NTDs can be explained by failure of fusion of one of the closures or their contiguous neuropores. We hypothesize that: Anencephaly results from failure of closure 2 for meroacranium and closures 2 and 4 for holoacranium. Spina-bifida cystica results from failure of rostral and/or caudal closure 1 fusion. Craniorachischisis results from failure of closures 2, 4, and 1. Closure 3 non-fusion is rare, presenting as a midfacial cleft extending from the upper lip through the frontal area ("facioschisis"). Frontal and parietal cephaloceles occur at the sites of the junctions of the cranial closures 3-2 and 2-4 (the prosencephalic and mesencephalic neuropores). Occipital cephaloceles result from incomplete membrane fusion of closure 4. In humans, the most caudal NT may have a 5th closure site involving L2 to S2. Closure below S2 is by secondary neurulation. Evidence for multi-site NT closure is apparent in clinical cases of NTDs, as well as in previous epidemiological studies, empiric recurrence risk studies, and pathological studies. Genetic variations of NT closures sites occur in mice and are evident in humans, e.g., familial NTDs with Sikh heritage (closure 4 and rostral 1), Meckel-Gruber syndrome (closure 4), and Walker-Warburg syndrome (2-4 neuropore, closure 4). Environmental and teratogenic exposures frequently affect specific closure sites, e.g., folate deficiency (closures 2, 4, and caudal 1) and valproic acid (closure 5 and canalization). Classification of NTDs by closure site is recommended for all studies of NTDs in humans.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Patterns of cancer in the families of children with soft tissue sarcoma.

BACKGROUND: Childhood soft tissue sarcomas are known to occur in a number of genetic syndromes. This study assesses the proportion of soft tissue sarcoma diagnosed in childhood associated with genetic predisposition to cancer. METHODS: Information on the occurrence of neoplastic disease was collected for 151 of 179 families of a population-based series of children with soft tissue sarcoma. RESULTS: Considering the index child as the proband, 5 of the 151 families manifested the classic Li-Fraumeni cancer family syndrome according to standard criteria and a further 10 families showed features consistent with the syndrome. One proband had double primary syndrome cancers. One other family had a sibling pair of childhood cancers, seven families had cancer which had occurred in childhood in other relatives, and three families had adult-onset sarcomas in more distant relatives. In another 16 families, one parent or the other had developed a possible syndrome cancer, or had developed cancer when younger than 60 years of age. Two families showed striking clusters of stomach cancer. Five case children were thought to have been affected with neurofibromatosis. CONCLUSIONS: Genetic predisposition to cancer was thought to be present in 7% to 33% of families interviewed.

Child↗

Temporomandibular joint and orofacial pain: clinical and medicolegal management problems.

Idiopathic pain in the face, temporomandibular joint (TMJ), and teeth is common but varied in its duration and severity. Many cases respond to informed reassurance or simple physical therapy using an occlusal splint. Those that do not should be referred for specialist management by medication, and where necessary, arthroscopy or occasionally arthrotomy. Awareness of the underlying psychogenic factors is important at all levels of management, particularly as some patients will benefit from the support of a liaison psychiatrist. The failure to recognise these factors, together with prolonged unsuccessful physical or surgical therapy can render the pain intractable or incite certain patients to seek relief through litigation.

Antidepressive Agents, Tricyclic↗

Comparative potencies of Aroclors 1232, 1242, 1248, 1254, and 1260 in male Wistar rats--assessment of the toxic equivalency factor (TEF) approach for polychlorinated biphenyls (PCBs).

Immature male Wistar rats were treated with several different doses of the commercial polychlorinated biphenyls (PCBs) Aroclors 1232, 1242, 1248, 1254, and 1260 (10, 40, 160, 480, and 2000 mg/kg) and the effects on body weight gain, thymic atrophy, and the induction of hepatic microsomal aryl hydrocarbon hydroxylase (AHH), ethoxyresorufin O-deethylase (EROD), and pentoxyresorufin O-deethylase (PROD) activities were measured 14 days after treatment. A significant inhibition in body weight gain was observed only in rats treated with high doses of Aroclors 1232 and 1248 and thymic atrophy was not observed for any of the Aroclors. All the Aroclors caused a dose-dependent increase in hepatic microsomal AHH, EROD, and PROD activities. The corresponding ED50 values for the induction of AHH-EROD activities varied from 51 to 678 mg/kg. Aroclor 1260 was the least active inducer of the P4501A1-mediated enzyme activities. In contrast, Aroclor 1260 was a potent inducer of PROD activity (ED50 = 37 mg/kg), but Aroclors 1232, 1242, 1248, and 1254 did not induce 50% of the maximal response at the highest dose used in this experiment (2000/kg). Previous studies have quantitated the levels of those PCB congeners which induce AHH or EROD activities in Aroclors 1232, 1242, 1254, and 1260 and their potencies or toxic equivalency factors (TEFs) relative to that of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) have also been estimated or experimentally determined. Using highly conservative TEF values it was demonstrated that the calculated ED50s for the Aroclors as inducers of AHH and EROD activity were significantly lower than the observed ED50 values.2

Animals↗

Osmotic stress variants in Chinese hamster cells.

Stable variants resistant to hypertonic stress have been obtained from V79 cells by one-step selection in media supplemented with graded concentrations of NaCl. Such variants retain a potential for resistance when isolated and propagated in isotonic media. On replating in graded NaCl, a family of dose-response curves is obtained, rising in level of resistance according to the degree of hypertonicity used to isolate the variants initially. In hybrids between variants and sensitive cells, phenotypic expression of resistance to hypertonic NaCl is recessive. Stable variants can also be isolated by one-step selection in media made hypertonic with D-mannitol. Clonal sublines selected with mannitol, as well as those obtained with NaCl, are resistant to both types of hypertonic media. Fluctuation tests in media supplemented with NaCl show that resistance arises spontaneously and at random, with measured rates of variation that depend on the concentration of NaCl used for selection. Treatment of sensitive cells with 5-azacytidine increases the frequency of resistant variants in assays with high levels of added NaCl but is less effective when selection is performed at lower concentrations. Exposure to ethyl methane sulfonate has little or no effect on variant frequency.

Animals↗

Plymouth randomized trial of cardiotocogram only versus ST waveform plus cardiotocogram for intrapartum monitoring in 2400 cases.

OBJECTIVE: The physiology of changes in the ST waveform of the fetal electrocardiogram has been elucidated in extensive animal and human observational studies. A combination of heart rate and ST waveform analysis might improve the predictive value of intrapartum monitoring. Our purpose was to compare operative intervention and neonatal outcome in labors monitored by the conventional cardiotocogram with those monitored by ST waveform plus the cardiotocogram. STUDY DESIGN: A prospective, randomized clinical trial was performed on 2434 high-risk labors in a district general hospital in Plymouth, England. Statistical analysis was performed by Student t test and chi 2 analysis. RESULTS: There was a 46% reduction (p < 0.001, odds ratio 1.85 [1.35-2.66]) in operative deliveries for "fetal distress" and a trend to less metabolic acidosis (p = 0.09, odds ratio 0.38 [0.13-1.07]) and fewer low 5-minute Apgar scores (p = 0.12, odds ratio 0.62 [0.35-1.08]) in the ST waveform plus cardiotocogram arm. CONCLUSIONS: ST waveform analysis discriminates cardiotocogram changes in labor, and the protocol for interpretation is safe. Further randomized studies are warranted.

Blood Gas Analysis↗

In vitro cell aggregation and cell adhesion molecules in Crohn's disease.

BACKGROUND: Lack of a suitable model has hindered efforts to understand inflammation and granuloma formation in Crohn's disease. METHODS: Granulomalike aggregates of circulating mononuclear cells are produced in vitro by cultures of cells with polyacrylamide beads. To identify features of in vitro aggregates, which are similar to tissue granulomas of Crohn's disease, the gross morphology and immunohistological appearance of the aggregates produced with peripheral blood mononuclear cells from patients with Crohn's disease were analyzed, and the size of in vitro aggregates was correlated with clinical activity of the disease. Blocking antibodies were used to evaluate the role of cell-adhesion molecules in the formation of in vitro aggregates. RESULTS: The size of in vitro aggregates correlates very significantly with clinical activity (P < 0.001). In active Crohn's disease, in vitro aggregates show immunohistological features of hypersensitivity type granulomas. Blocking antibodies against leukocyte function associated antigen LFA-2 (CD2), LFA-3 (CD58), and Mac-1 (CD11b/CD18) inhibit in vitro aggregate formation. CONCLUSION: In vitro aggregates model in vivo granulomas in size and organization. Cell adhesion molecules like CD2, CD58, and CD11b/CD18 may be involved in granuloma-formation of Crohn's disease.

Antigens, CD↗

Wilms' tumor in the Li-Fraumeni cancer family syndrome.

Scrutiny of the family pedigrees of a population-based series of 176 children diagnosed with Wilms' tumor between 1954 and 1990, along with a review of the literature on the Li-Fraumeni cancer family syndrome, indicate that Wilms' tumor may be an uncommon component of the syndrome and that a small proportion of children with Wilms' tumor may be members of Li-Fraumeni syndrome (LFS) families.

Adolescent↗

Temporomandibular joint synovial fluid analysis.

A method for the estimation of the synovial fluid volume of the temporomandibular joint (TMJ) is described. Patients are administered 1.2 g of aspirin and the concentration of salicylate in plasma and in saline aspirates of the TMJ is measured by a sensitive high performance liquid chromatography assay. The ratio of the concentration of salicylate in the saline aspirate to that in the plasma allows the volume of the synovial fluid to be calculated. The method would also allow the determination of the concentration and the absolute amount of putative mediators of pathology in the upper joint.

Adolescent↗

A retrospective study of 66 titanium cranioplasties.

A review was undertaken to assess the outcome of treatment in 66 patients for whom a titanium prosthesis was provided for the repair of a calvarium defect. While many aspects were satisfactory, certain disappointing features led to a prospective pilot study which enabled the following problems to be identified: (a) poor communication between neurosurgeon and prosthetist; (b) difficulties in establishing the margins of the defect; (c) orientation of the prosthesis, and (d) marginal retention. All were overcome with an agreed protocol.

Esthetics↗

Central giant cell granulomas of the jaws regress with calcitonin therapy.

Aggressive central giant cell granulomas may be eliminated by administering human calcitonin 0.5 mg (100 iu) deep subcutaneously for 1 year. This avoids the need for mutilating surgery or radiotherapy in growing children. Aggressive recurrent peripheral lesions (the giant cell epulis) can also be treated by excision after calcitonin therapy. These giant cell granulomas should be redefined as osteoclast granulomas, and the aneurysmal bone cyst, the cystic osteoclast granuloma. However the stimulus for the disturbance in the osteo progenitor spindle cell needs to be defined.

Adolescent↗