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Biomedical subjects

C McCormick

Publications and source records attributed to C McCormick.

At least 37 records · Page 2Linked to original sources
PubMed1996

Missed opportunities for vaccination in Chitungwiza, Zimbabwe 1995: a service deficiency which can easily be eliminated.

OBJECTIVES: Missed opportunities for vaccination occur when a child or woman who is eligible for a vaccination visits a health facility but fails to receive that vaccination. Our study attempted to determine the extent and reasons for missed opportunities occurring in an urban setting in Zimbabwe. DESIGN: This study was carried out using the standard WHO EPI protocol for ascertaining missed opportunities for vaccination. SETTING: All four health clinics in Chitungwiza City. SUBJECTS: All appropriate clients (children < 2 years and women of childbearing age) exiting each facility. RESULTS: The study revealed a global missed opportunity rate of six pc for children and 55pc for women of childbearing age. Missed opportunities occurred more frequently when children attended curative services and when women of childbearing age attended preventive services. CONCLUSIONS: Vaccination services can be improved by making all vaccines available and by screening children and women at all contacts with health services. Additionally, all women should receive and be encouraged to carry a tetanus toxoid vaccination card when visiting a health facility. In all cases, a vial of vaccine should be opened even if only one child or woman is eligible for vaccination, in accordance with Ministry of Health policy.

Adolescent↗
PubMed1995

Activity of interferon alpha, interleukin 6 and insulin in the regulation of differentiation in A549 alveolar carcinoma cells.

The differentiation of A549, a human tumour cell line from type II pneumocytes, can be induced by a crude fibroblast-derived factor (FDF) isolated from the conditioned medium of glucocorticoid-treated lung fibroblasts. In the present report, we have used alkaline phosphatase as a differentiation marker to investigate the activity of a number of growth factors as potential candidates for this paracrine activity. This showed that insulin, interleukin 6 (IL-6), and interferon alpha (IFN-alpha) could simulate the activity of conditioned medium. Their effects were dexamethasone (DX) dependent, additive and reversible with a half-life of 1 week. Transforming growth factor alpha and beta, IL-1 alpha and epidermal growth factor, were all inhibitory, and inhibition was opposed, partially or completely, by DX. The most potent inducer was IL-6, but as DX was shown to decrease the concentration of IL-6 in lung fibroblast-conditioned medium it seems an unlikely candidate for FDF. Unlike FDF, all of the positive-acting factors were shown to induce plasminogen activator. FDF has also been shown to be active in the absence of DX. This suggests that differentiation-inducing activity may be present in several paracrine factors, but that so far a candidate for FDF has not been identified.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1994

Comparison of magnetic resonance imaging and computed tomographic discography in the assessment of lumbar disc degeneration.

Eighteen patients with chronic low back pain were studied with magnetic resonance imaging (MRI) and computed tomographic (CT) discography. Each study was classified as being normal, showing early disc degenerative changes including annular tear, showing established disc degeneration or disc herniation. There was comparable information in over 90% of the MRI studies when compared to CT discography, without reliance on pain provocation or carrying out an invasive procedure. The axial and sagittal T1 weighted images were used to exclude other causes of pain, such as foraminal stenosis and disc herniation. The mid-sagittal T2 weighted image used in this study was considered to be, in part, responsible for the underestimation of disc degeneration because it did not allow visualization of the lateral aspects of the discs.

Humans↗
PubMed1994

Clonal analysis of three morphologically distinct lymphomas occurring in the same patient.

AIMS: To determine whether three morphologically distinct lymphomas (mucosa associated lymphoid tissue (MALT) lymphoma, monocytoid B cell lymphoma, and large cell anaplastic lymphoma), which occurred in the same patient, were in fact three morphological variants of the same lymphoproliferative process. METHODS: Previously described methods of clonal analysis using the polymerase chain reaction (PCR) were used to determine the pattern of rearrangements of the immunoglobulin heavy chain gene and the T cell receptor beta and T cell receptor gamma chain genes in the three lymphomas. RESULTS: All three morphological entities had identical patterns of gene rearrangements. CONCLUSIONS: This finding confirms the association between MALT lymphoma and monocytoid B cell lymphoma, and also provides evidence that large cell anaplastic lymphoma may not only arise de novo but may also be an end stage morphological picture in lymphoma progression.

Colonic Neoplasms↗
PubMed1992

Spinal abnormalities in young fast bowlers.

The action of fast bowling in the game of cricket is known to cause injuries to the lumbar spine. We studied a group of 16- to 18-year-old fast bowlers, selected for special training in Western Australia. All 24 had MR scans of the spine, 22 had radiographs and CT scans; in 20 the bowling technique was analysed biomechanically. There was a high incidence of back pain and this was always associated with a radiological abnormality. Pars interarticularis defects were diagnosed in 54% and intervertebral disc degeneration in 63%. Bowling actions which involved counter-rotation were associated with a higher incidence of both injuries.

Adolescent↗
PubMed1990

Trisomy 4 in a case of acute undifferentiated myeloblastic leukemia with hand-mirror cells.

A case of acute undifferentiated myelocytic leukemic with trisomy 4 is described. The patient is a 61-year-old woman who developed leukemia 4 1/2 years after receiving radiation therapy for uterine carcinoma. Many leukemic cells exhibited hand-mirror configuration after the bone marrow aspirate was left at room temperature overnight. The relationship between trisomy 4 and hand-mirror cells in acute myelocytic leukemia is unknown.

Bone Marrow Examination↗
PubMed1988

Pyogenic cervical osteomyelitis presenting as a massive prevertebral abscess in a patient with rheumatoid arthritis.

Pre-existing rheumatoid arthritis appeared to have masked the diagnosis and contributed to a succession of hazardous events in a 58-year-old man with pyogenic cervical osteomyelitis. A massive prevertebral abscess and near asphyxiation finally led to the diagnosis of an indolent Staphylococcus aureus infection in a course marked by antecedent staphylococcal sepsis, a series of dangerous cervical spine chiropractic manipulations in the presence of advanced bony destruction, and, ultimately, cervical spine bony collapse and gibbus formation. The absence of myelopathy despite long-standing progressive advanced destruction is noteworthy. The roentgenologic documentation of this progression was unique. This appears to be the first fully documented case of cervical spine osteomyelitis presenting as a prevertebral abscess in a patient with rheumatoid arthritis.

Abscess↗
PubMed1983

Inability of dimethyl sulfoxide and 5-fluorouracil to open the blood-brain barrier.

The inability of most chemotherapeutic agents to adequately penetrate the blood-brain barrier (BBB), in either normal brain or tumor-infiltrated brain, is a major factor limiting the use of chemotherapy in central nervous system malignancy. This barrier, however, can be opened in a reversible manner by the intra-arterial administration of hyperosmotic agents such as mannitol. It has been suggested that the intravenous administration of dimethyl sulfoxide (DMSO) or 5-fluorouracil (5-FU) can accomplish the same thing in a less invasive manner. We have not been able to confirm these findings. DMSO was administered to 25 rats intravenously at concentrations ranging from 25 to 90% or into the internal carotid artery at a concentration of 30%. The penetration of methotrexate, Evans blue-albumin, and hexosaminidase A was then evaluated at intervals ranging from 1.5 to 3.5 hours after administration. Significant barrier opening was not observed in animals receiving intravenous DMSO. Barrier modification, albeit generally modest, was obtained in animals receiving intracarotid DMSO, but this may have been the result of grand mal seizures, inasmuch as 5 of 6 of these animals had such seizures. Several of the animals receiving i.v. DMSO also had seizures, and all animals developed varying degrees of hematuria. Similarly, 5-FU was administered at a dose of 30 mg/kg i.v. and the permeability of the BBB to either Evans blue-albumin or methotrexate was evaluated. No increased permeability of the BBB to these two markers was observed. In summary, osmotic BBB opening in our hands remains the most consistent and reliable means available to open the BBB in a reversible fashion. Neither intravenous DMSO nor 5-FU seems to increase the delivery of chemotherapy or protein tracer to the central nervous system, and the use of DMSO can result in seizures and hematuria.

Animals↗
PubMedDate not supplied

Herpes simplex virus: discovering the link between heparan sulphate and hereditary bone tumours.

To gain entry into the host, viruses use host cell surface molecules that normally serve as receptors for other ligands. Herpes simplex virus type 1 (HSV-1) uses heparan sulphate (HS) glycosaminoglycans (GAGs) as receptors for initial attachment to the host cell surface. HS GAGs are both ubiquitous and structurally diverse, and normally serve as critical mediators of interactions between the cell and the extracellular environment. We have used the HS binding ability of HSV-1 to identify the function of a cellular gene, EXT1, which is involved in HS polymerisation. Cellular factors that affect virus growth and replication are often key regulators of the cell cycle and EXT1 is no different-humans with inherited mutations in EXT1 have developmental defects that lead to bone tumours (hereditary multiple exostoses, HME) and sometimes chondrosarcomas. Thus, as a result of using HSV-1 as a molecular probe, a functionally orphaned disease gene now has a defined function. These findings highlight the utility of viruses for investigating important cellular processes.

Cell Line↗
PubMedDate not supplied

Pharmacokinetic and dose tolerability study of ADD 94057 in comedicated patients with partial seizures.

ADD 94057, a metabolite of fluzinamide, manufactured by the A. H. Robins Company, blocks chemically- and electrically-induced seizures in animals. The primary objective of this open add-on study was to evaluate patient tolerability of ADD 94057 at ascending target plasma concentrations. Nine subjects with medically refractory seizures were receiving phenytoin (PHT, 3), carbamazepine (CBZ, 3), or both (3). A pharmacokinetic profile after a single oral 400-mg dose of ADD 94057 was used to calculate ADD 94057 dosages. After a 4-week baseline period, patients were treated for 4 weeks with weekly ADD 94057 dosage escalations. Two patients completed the study at their assigned highest dosage level; the other patients finished the study at lower dosages. The patients receiving PHT (but not CBZ) tolerated higher plasma concentrations of ADD 94057 than did patients receiving CBZ, alone or in combination with PHT. Adverse experiences included headache, ataxia, blurred vision, diplopia, dizziness, lightheadedness, and mild confusion. Eight of nine patients had reductions in seizure frequency from baseline.

Administration, Oral↗