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Biomedical subjects

J Prichard

Publications and source records attributed to J Prichard.

At least 19 recordsLinked to original sources
PubMed2001

A longitudinal study comparing scaling, osseous surgery, and modified Widman procedures: results after 5 years.

BACKGROUND: Scaling and root planing, osseous surgery, and modified Widman procedures are effective methods for treating periodontal diseases. Studies have been carried out to determine if these procedures are more effective than others in reducing clinical probing depths, while maintaining clinical attachment levels. The purpose of this report is to present 5-year results from a longitudinal study comparing scaling and root planing (SRP), osseous surgery (OS), and modified Widman (MW) therapies. The study has been completed for 12 years. METHODS: Sixteen adult patients with moderate to advanced periodontal disease were treated with initial scaling and oral hygiene procedures in a private practice. Posthygiene data were used to compare changes in plaque and gingival indices, probing depth (PD), clinical attachment levels (CAL), and recession. Frequency distributions were used to compare changes at individual sites. The first published report was from baseline to one year. This follow-up report is from baseline through 5 years. RESULTS: At 5 years, there were significant decreases in gingival and plaque scores. For the 3 procedures, there were significant decreases in baseline 4 to 6 mm PD (P<0.0001); however, there were no differences between the methods. Similar findings were noted for PD initially greater than 7 mm. At 5 years, OS had the greatest number of 1 to 3 mm sites (332 sites, 73.2%), while MW had the fewest number of 4 to 6 mm PD (98 sites, 21.8%). SRP had the fewest 7 mm and greater sites (15 sites, 3.4%). At 5 years, CAL loss for 1 to 3 mm PD was statistically significant for the 3 procedures. There were slight gains in CAL for 4 to 6 mm probing depths. These gains were not significant. Similar findings were seen for CAL for probing depths greater than 7 mm. OS had the greatest number of sites losing more than 2 mm of CAL (64 sites), followed by SRP (21 sites) and MW (34 sites), respectively. CONCLUSIONS: This 5-year clinical trial demonstrates that with good patient maintenance excellent clinical results can be achieved with various methods of treatment. Within the limits of this study, SRP, OS, and MW were effective at reducing probing depths with slight changes in clinical attachment levels.

Adult↗
PubMed2000

Fine-needle aspiration cytology of low-grade fibromyxoid sarcoma of the renal capsule (capsuloma).

We report on the fine-needle aspiration (FNA) findings of a low-grade fibromyxoid sarcoma arising from the renal capsule in a 70-yr-old male. Cytologic examination revealed a spindle-cell and myxoid lesion characterized by microtissue fragments of delicate spindle-shaped cells and thin-walled capillary-type channels enmeshed in metachromatically staining myxoid material, best appreciated in Diff-Quik-stained smears. The spindle cells had slightly elongated, bland, oval to tapered nuclei. Based on the FNA diagnosis, the renal mass was resected, which revealed a hypocellular to moderately cellular, spindle-shaped neoplasm showing alternating hypercellular fibrous foci with hypocellular myxoid areas arranged in a swirling growth pattern, characteristic of low-grade fibromyxoid sarcoma. We believe that this is the first report of a low-grade fibromyxoid sarcoma arising in the renal capsule (capsuloma), as well as the first capsuloma diagnosed by FNA biopsy. Differential diagnoses of other sarcomas arising from the kidney and nearby retroperitoneal region are discussed, as well as other entities that might enter into the differential diagnosis of this low-grade sarcoma.

Aged↗
PubMed1995

Secular trends in mortality from asthma in children and young adults: Republic of Ireland, 1970-91.

Trends in mortality attributed to asthma in children (0-14 years) and young adults (15-44 years) and the age group 5-34 years were examined for the Republic of Ireland over the period 1970-91. Childhood mortality rates were low with no clear trend. A recent rise in asthma mortality was observed in the 5-34 year olds but not in the 15-44 year age group. More detailed examination of these rates revealed that the rise in mortality in the 5-34 year olds derived from the age band 25-34 years. This increase is masked in the 15-44 year age group by wide fluctuations in mortality in the age band 35-44 years. A similar discrepancy in asthma mortality trends for the 15-44 and 5-34 year age groups has been reported in Britain. Possible reasons for the recent rise in asthma mortality in the 25-34 year age group are discussed.

Adolescent↗
PubMed1994

A comparison of the benefits of roller pump versus constrained vortex pump in adult open-heart operations utilizing outcomes research.

The purpose of this study was to compare roller pump and centrifugal pump technologies in routine adult open-heart operations to demonstrate the usefulness of applying a proven method of uniform risk stratification (outcomes research). Objective and readily available preoperative patient data was collected retrospectively on 102 non-randomized and consecutive adult open-heart operations. Group 1 consisted of 51 adult open-heart operations utilizing a roller pump for arterial blood perfusion. Group 2 consisted of 51 adult open-heart procedures utilizing a constrained vortex pump for arterial blood perfusion. A comparison between the frequency of occurrence of 53 different preoperative risk factors in the roller pump group and the centrifugal pump group found no statistically significant differences (p < 0.05). Outcome data for the roller pump and centrifugal pump groups included such data comparisons as intensive care unit length of stay (LOS), post operative LOS, total LOS, total patient charge, reimbursement, morbidity, and mortality, which revealed no statistically significant differences (p < 0.05). Further comparison studies of roller pumps versus centrifugal pumps for arterial blood perfusion should incorporate this kind of comprehensive data comparison and analysis to reasonably assure that both pump groups are very similar before outcomes research is performed.

Cardiopulmonary Bypass↗
PubMed1991

Lactate rise detected by 1H NMR in human visual cortex during physiologic stimulation.

Brain lactate concentration is usually assumed to be stable except when pathologic conditions cause a mismatch between glycolysis and respiration. Using newly developed 1H NMR spectroscopic techniques that allow measurement of lactate in vivo, we detected lactate elevations of 0.3-0.9 mM in human visual cortex during physiologic photic stimulation. The maximum rise appeared in the first few minutes; thereafter lactate concentration declined while stimulation continued. The results are consistent with a transient excess of glycolysis over respiration in the visual cortex, occurring as a normal response to stimulation in the physiologic range.

Energy Metabolism↗
PubMed1989

Pulmonary disease following allogeneic bone marrow transplantation.

Bone marrow transplantation is the treatment of choice of many haematological disorders but its success is limited by two major complications, graft-versus-host disease (GVHD) and pulmonary disorders. Of the first 31 patients transplanted at St. James's Hospital (1984-1986) 16 (52%) had a successful outcome. Of the 15 patients who died, two died of GVHD and one of recurrent leukaemia. All others had severe pulmonary disease either causing death directly (9 cases) or contributing to death from toxic encephalopathy, carditis or recurrent leukaemia (1 case each). The principal forms of pulmonary disease were cytomegalovirus pneumonitis (4 cases), acute haemorrhagic pulmonary oedema (4 cases) and pneumocystis carinii pneumonia (2 cases). There were single cases of staphylococcal pneumonia and idiopathic pulmonary fibrosis. Aspergillus was a second pathogen in two cases. Pulmonary damage due to conditioning chemoradiotherapy and to GVHD probably underlies this high incidence of pulmonary disease. T-cell depletion to limit the incidence of GVHD together with increased prophylaxis against CMV and pneumocystis carinii will probably substantially reduce these complications in the near future.

Adolescent↗
PubMed1988

A longitudinal study comparing scaling, osseous surgery and modified Widman procedures. Results after one year.

The purpose of this study was to compare, longitudinally, the effectiveness of scaling and root planing, osseous surgery, and the modified Widman procedures. The study was carried out in a private practice setting. Sixteen adult patients with moderate to advanced adult periodontitis were treated with initial scaling and oral hygiene procedures. Posthygiene data were used for comparison of changes in probing depth, clinical attachment levels and gingival recession. The initial examination data were used to compare changes in plaque and gingival indices. Frequency distributions were used to compare changes that occurred at individual sites. At one year, plaque and gingival indices were significantly reduced when compared with the initial examination. At one year, shallow pockets (1-3 mm) were reduced when compared to posthygiene. Four- to six-millimeter pockets were significantly reduced by the three procedures. Osseous surgery and modified Widman had significantly greater pocket reduction when compared with scaling. For pockets greater than 7 mm, osseous surgery and the modified Widman had significantly greater reduction when compared with scaling. For pockets 1-3 mm at one year osseous surgery had significantly greater clinical attachment loss when compared with scaling. For 4-6 mm pockets at one year, the three procedures had slight gains in clinical attachment levels. The results were similar for pockets with greater than 7 mm. Interproximal soft tissue craters were measured for six postoperative weeks. Initially, the modified Widman had a higher percentage of soft tissue craters when compared with osseous surgery. At six weeks, however, there were no significant differences when the surgical procedures were compared. Recession was measured at each examination. Recession for 1-3 mm pockets at one year was greater for osseous surgery when compared with scaling and the modified Widman. Recession for 4-6 mm and greater than 7 pockets was greater for the surgical procedures than scaling. The results from this study indicate that with three-month maintenance recalls, both the modified Widman and osseous surgery are effective for pocket reduction, and each will produce a slight gain of clinical attachment over one year. Scaling was effective at maintaining attachment levels but was not as effective in reducing pocket depth.

Adult↗
PubMed1986

131-I coupled to monoclonal antibodies as therapeutic agents for neuroectodermally derived tumors: fact or fiction?

It has been suggested that monoclonal antibodies may be useful in targeting cytotoxic compounds to tumor cells. We have explored their use in targeting 131-I to highly radiosensitive primitive neural tumors such as neuroblastoma and pineoblastomas. Two routes of administration have been employed, intravenous and intrathecal. Our current experience in using radiolabelled antibodies is described, indicating toxicities seen and any therapeutic benefit observed. The results of the study suggest that if targeted radiation has a role in the treatment of these malignancies, it will be restricted to the eradication of small tumor masses from the body.

Animals↗
PubMed1984

Preliminary observations on magnetic resonance imaging in refractory epilepsy.

We are studying the use of magnetic resonance (MR) imaging in localization of epileptogenic foci in patients with medically refractory partial epilepsy. Imaging is performed using a prototype resistive unit operating at 0.15 T. All studies include 7 mm axial sections obtained with a partial saturation sequence (TR = 200 msec) in which signals are recovered with a spin echo (TE = 11 msec) and images reconstructed using a modified 2D Fourier transform technique. Since the temporal lobe and limbic system are the commonest site of seizure foci in this group of patients, examinations were performed with the plane of section parallel to the temporal horns of the lateral ventricles. Consensus interpretations by a radiologist, neurologist and neurosurgeon have recognized findings considered possibly abnormal in six of 11 epilepsy patients and none of six normal volunteers. These preliminary results indicate that further study is warranted in this group of patients. Critical evaluation of such findings must be carried out in a larger group including normals and patients with a variety of neurologic disorders.

Adolescent↗
PubMed1975

Relationship between membrane potential and external potassium in human glioblastoma cells in tissue culture.

Cells from a human glioblastoma (TC 526) maintained in tissue culture for ten years had a mean membrane potential of 27 +/- 0.9 mV at an external potassium concentration [Ko] of 5.3 mM. When [Ko] was varied between 2.5 and 5.3 mM, membrane potential changes were close to those predicted by the Nernst equation. At higher [Ko], the Nernstian slope was approached only in the presence of 10(-5) M ouabain, which did not affect membrane potential at a [Ko] of 5.3 mM. An electrogenic sodium pump activated by high [Ko] could explain these findings; such a mechanism has been demonstrated in other tissues.

Biological Transport, Active↗
PubMed1975

Reticulum cell sarcoma: an effector cell in antibody-dependent cell-mediated immunity.

A transplantable, murine reticulum cell sarcoma is described which exhibits the cytologic, adherence, and phagocytic properties of macrophages. It forms specific rosettes with erythrocytes in the presence of the corresponding anti-serum. The ascites cells mediate antibody-dependent cellular immunity as assayed by release of radioactivity from 51Cr-labeled erythrocytes. The contribution of contaminating host cells in the cytotoxic reaction was ruled out by growing the tumor in F1 mice and removing the host cells by anti-H2 serum and complement. The tumor cells have receptors for IgG2a and IgG2b immunoglobulins. The availability of a pure population of effector cells in the immune system allows study of the biochemical processes pursuant to lysis of foreign cells.

Animals↗