Biomedical subjects
Publications and source records attributed to C Cox.
In a study of home care in six European countries, researchers from Columbia University found that home care is generally an entitlement provided on a public basis. Programs differ from country to country, but this right is a common thread in care of the elderly.
This study investigated the effect of citric acid application on periodontally involved root surfaces. Forty periodontally involved teeth were randomly divided into four groups of ten teeth each: no treatment, citric acid treatment, root planing alone, and root planing in conjunction with citric acid treatment. Ten nondiseased, untreated teeth served as controls. After treatment, each tooth was split along its long axis; half was examined under light microscopy and half under scanning electron microscopy (part II of the paper). Light microscopy revealed that the effects obtained by scaling and root planing were not altered after citric acid application. Moreover, the cementum layer was not entirely removed without careful and thorough planing of the root surface. Citric acid application alone had no effect on the diseased root surface. Citric acid did not penetrate the dentinal tubules, nor did it alter the collagen content of the roots obtained by scaling and root planing.
Myelodysplastic features and myeloperoxidase (MPO) deficiency have been investigated in a series of 336 cases of de novo acute myeloid leukemia (AML) to clarify their impact on the outcome of such patients and to compare with the previous results from the literature. Dysplastic features were defined according to the FAB criteria. Trilineage disease (TLD) was observed in 11.6% of patients (39 cases), and the complete remission rate (CR) was 56.4% for TLD patients compared to 74.4% for patients without any dysplastic features (p = 0.03). The effects of dysgranulopoiesis (DysM) alone or in combination were assessed using a logistic regression analysis. This analysis revealed that only DysG had any effect on CR rate (p = 0.013). The CR rate for patients with DysG was 56.6% and 71.5% for patients without DysG. We were unable to find any correlation between MPO deficiency, dysplastic features and CR rate. Cytogenetic analysis could be assessed for 119 patients. For patients with DysG, 10 karyotypes were normal and 20 were abnormal compared to 48 normal and 41 abnormal for patients without DysG (p = 0.05). We conclude that the presence of DysG in de novo AML exerts a negative effect on the ability to achieve a CR and is related to a higher frequency of cytogenetic abnormalities.
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We consider a regression to the mean problem with a very large sample for the first measurement and relatively small subsample for the second measurement, selected on the basis of the initial measurement. This is a situation that often occurs in screening trials. We propose to estimate the unselected population mean and variance from the first measurement in the larger sample. Using these estimates, the correlation between the two measurements, as well as an effect of treatment, can be estimated in simple and explicit form. Under the condition that the size of the subsample is of a smaller order, the new estimators for all the four parameters are as asymptotically efficient as the usual maximum likelihood estimators. Tests based on this new approach are also discussed. An illustration from a cholesterol screening study is included.
BACKGROUND: Exogenous pulmonary surfactants are administered into the trachea either to prevent respiratory distress syndrome in premature infants or to treat it. In a randomized, multicenter trial, we compared the results of surfactant therapy initiated as prophylaxis with the results of rescue therapy with surfactant. METHODS: Before birth, 479 infants with an estimated gestational age of less than 30 weeks were randomly assigned to receive surfactant as prophylaxis (n = 235) or rescue therapy (n = 244). The infants in the prophylaxis group received a 90-mg intratracheal dose of an exogenous calf-lung surfactant extract at the time of delivery, whereas the infants in the rescue-therapy group received 90 mg of the surfactant several hours after delivery if the fractional inspiratory oxygen concentration was at least 0.40 or if the mean airway pressure was at least 0.686 kPa (7 cm of water), or both. Infants in both groups received additional doses of surfactant at intervals of 12 to 24 hours if these criteria were met. RESULTS: The proportion of infants surviving until discharge to their homes was significantly higher in the prophylaxis group than in the rescue-therapy group (88 vs. 80 percent, P = 0.028). This difference was due primarily to the longer survival of very premature infants (less than or equal to 26 weeks' gestation) in the prophylaxis group than in the rescue-therapy group (75 vs. 54 percent, P = 0.006). According to proportional-hazards regression analysis, the distribution of survival times was better for all infants in the prophylaxis group (P = 0.007) and for the subgroup of infants in the prophylaxis group who were delivered at 26 weeks' gestation or earlier (P = 0.0048). Infants in the prophylaxis group who were delivered at 26 weeks' gestation or earlier had a lower incidence of pneumothorax than similar infants in the rescue-therapy group (7 vs. 18 percent, P = 0.03). CONCLUSIONS: We found a significant advantage to the administration of the initial dose of surfactant as prophylaxis rather than as rescue therapy in very premature infants.
Finding a screening test to evaluate patients with cancer for occult metastatic disease, as well as imaging all known disease, is a goal of research efforts. Twenty-nine evaluable patients with deeply invasive (stage I), regional nodal (stage II), or systemic (stage III) melanoma underwent imaging by administration of a preparation of the antimelanoma antibody labeled with technetium 99m. Scan results indicated that 28 of 32 confirmed metastatic sites were imaged with this technique (88% sensitivity). Analysis of the individual positive sites revealed that nodal basins and visceral metastases accounted for the highest percentage of metastatic sites imaged, with 14 (88%) of 16 nodal basin metastases and all four visceral metastases being detected through imaging. Occult nodal disease was detected in the iliac nodal chain in two of the 29 patients. The imaging of benign tumors and nodal basins not containing disease accounted for a confirmed false-positive rate of 21%. Three (10%) of the 29 scan results were confirmed to be false-negative. In vivo tumor localization with monoclonal antibodies showed a sensitivity similar to that of other roentgenographic procedures for identifying metastatic disease and was useful in two of three patients in identifying occult iliac nodal disease, a region that is difficult to evaluate with physical examination and other imaging modalities.
A cell culture technique was developed to investigate submicroscopic lymph node metastases in patients with stage 1 or 2 malignant melanoma. Lymph nodes were isolated from standard dissections and bivalved. Half of the node was evaluated by routine histopathologic examination, while the other half was processed and placed into tissue culture. Three hundred twenty-three lymph nodes were collected from 41 patients. The cell culture technique identified 155 of 323 lymph nodes containing micrometastases, while only 20 of 323 lymph nodes tested positive with routine histochemical processing. Nine patients were upgraded from stage 1 or 2 to stage 3 disease after micrometastases were identified in lymph node cultures. Identification of melanoma was confirmed by cytologic examination, immunohistologic staining, and the presence of GD3 ganglioside and 250-kd glycoprotein melanoma-associated antigens. This study provides evidence that the culture of lymph nodes is a sensitive method for the detection of micrometastases. In addition, this procedure may change prognosis and identify candidates for adjuvant therapies.
A Bladder Cancer Flow Cytometry Network study has been carried out to further identify and quantify sources of inter- and intra-laboratory variability. Replicate samples containing four mixtures of peripheral blood lymphocytes and aneuploid cell lines were distributed together with reference standards to six laboratories. The samples were stained for DNA using propidium iodide, with each laboratory using its own staining protocol. Two of each of the four sample types and a reference standard were analyzed by each laboratory on 3 separate days to obtain cellular DNA distributions. DNA index (DI) and hyperdiploid fraction (HDF) were calculated for each histogram using an automated technique. The results showed significant inter- and intra-laboratory differences. Results were evaluated by a two-way analysis of variance to estimate components of the overall variation attributable to individual sources. Error variation was found to be the major component of random variation. Specimen means were also compared for each laboratory. No significant differences were noted in mean DI for similar specimens; however, agreement in HDF between similar specimens was lacking in most laboratories. Prediction intervals were computed to estimate the range of values expected for a single specimen based on the analysis of the previous six. Prediction intervals for DI were quite good while those for HDF were troublesome due to wide variation. The results of these studies indicate that intra- and inter-laboratory variability are high enough that results for a single sample may not be sufficiently precise to allow comparison to results obtained in other laboratories.(ABSTRACT TRUNCATED AT 250 WORDS)
Tumor spread or recurrence in the axilla is usually treated with nodal dissections. At times disease recurrence is uncontrolled, causing significant morbidity including pain, bleeding, lymphedema, and neurologic symptoms. Previously, forequarter amputation has been the treatment for this problem, resulting in a significant cosmetic and functional deficit. This report describes a novel myocutaneous flap that can be used to cover soft tissue defects after major disarticulations of the upper extremity. The deltoid myocutaneous flap has been used to successfully treat three patients with uncontrolled tumors in the axilla and preserve the shoulder structures to lessen the functional deficit.
An attempt was made to verify a report (Liboff et al. 1987) that a unique combination of DC and AC magnetic field exposures at room temperature results in a 3-fold increase in 45Ca2+ uptake by human lymphocytes in vitro. Exposures at "resonance condition", as well as at frequencies and amplitudes above and below the reported effective exposure conditions, were without effect, as were exposures at 37 degrees C. Treatment with ionomycin (0.25 microM), a positive control, resulted in a highly significant increase 45Ca2+ uptake. Some experiments were performed simultaneously by different investigators. Their results did not differ significantly. All experiments were conducted "double blindly".
Prostatic tissue was obtained from 36 patients at two study locations and assayed for azithromycin by HPLC or bioassay. The mean concentration of azithromycin in human prostatic tissue (2.54 micrograms/ml) 14 h after 500 mg oral dosing (two 250 mg doses 12 h apart) was much greater than plasma concentrations (less than or equal to 0.1 micrograms/ml). Azithromycin was slowly eliminated from prostatic tissue (half-life 60 h) and a mean concentration of 0.62 micrograms/ml remained 137 h after dosing.
Lymphoscintigraphy was performed on 82 patients with melanoma registered at the University Melanoma Clinic. From these data, precise lymphatic drainage basins could be drawn for the head, neck, shoulder, and trunk. These drawings differed significantly from the classic anatomic studies, providing a functional look at the cutaneous lymphatic drainage. This new method correlates much better with clinical experiences and demonstrates much larger areas of ambiguous drainage than previously reported. Data from the lymphoscintigrams also emphasize the individuality of cutaneous lymphatic flow. The implications of these data in planning elective node dissections for intermediate thickness melanomas are obvious, since it is estimated that up to 59% of the dissections for trunk and head and neck primary melanomas may be misdirected if based on classic anatomic studies. The data indicate that all patients with head, neck, and shoulder lesions should undergo lymphoscintigraphy to define possible drainage basins at risk for metastatic disease. Similarly, truncal lesions require scintigrams except when they are within four well-defined areas with an extremely low probability of ambiguous drainage. Lesions in these areas show very reliable and predictable drainage to a single nodal group.
Liebeskind et al. reported that ultrasound from a diagnostic ultrasound unit caused an increase in cell transformation of in vitro C3H cells. The objective of this study was to attempt verification of this result, using the same cell line and a similar ultrasound exposure regimen. Four experiments were undertaken, each involving an ultrasound, X-ray (positive control) and sham exposure regimen. There was no increase in cell transformation frequency with the ultrasound exposure, but a small and statistically significant increase with the X-ray regimen.
Nonhuman primates are known to be susceptible to many of the arthritides that afflict humans. Psoriatic like spondyloarthropathies have been reported in gorillas and skeletal hyperostosis in gibbons, rhesus monkeys, and gorillas, and additional cases of both of these conditions occurring in drills (baboons) are noted in this report. One western lowland gorilla and two rhesus monkeys with clinical features consistent with ankylosing spondylitis have been documented previously. Two additional nonhuman primate species with radiographic evidence of ankylosing spondylitis are described. A siamang (gibbon) and two drills (baboons) with the classic radiographic features of ankylosing spondylitis, namely a bamboo spine and sacroiliac joint fusion, are reported.
The bone marrow smears of 18 confirmed cases of MDS were analyzed carefully for the presence of "hypergranular type III blasts", defined as more than 20 fine azurophil primary granules per cells. The concordance was close to 80% among 5 observers. Thirty-nine percent (7 cases) were reclassified as RAEB-t rather than RAEB. The presence of these hypergranular blasts was not suggestive of increased differentiation but rather leukemic cells. The reassignment of cases altered the median survival for the various subcategories, providing a clearer separation with the introduction of type III blasts than without utilizing these cells which were separated from the promyelocyte family. The introduction of this new blast cell definition in a larger series of patients is recommended to confirm these preliminary observations.
1. Platelet-derived growth factor (PDGF), administered daily for 5 days and every other day for 9 additional days or the day of wounding and the following day, caused dose dependent (0.2, 1.0 or 5.0 micrograms PDGF/wound) increased granulation tissue. 2. The two day 5.0 micrograms treatment resulted in a 73% increase and the multi-day treatment resulted in a 52% increase of alkaline phosphatase activity three days after wounding. 3. Multi-day treatment resulted in significant increases in protein synthesis (132%), vimentin content (160%) and excised wound weight (76%) three days after wounding. 4. These results indicate that limited administration of PDGF alters wound healing although multiple applications provoke a more dramatic response.
In 1984 Stella et al. reported that each of 10 patients exposed to therapeutic ultrasound had a statistically significant increase in sister chromatid exchanges (SCEs) at mid- and end of therapy; there was a wide range of clinical symptoms (e.g., elbow epicondylitis to knee arthrosis) in this set of patients. In the present study, a set of 4 patients each with some diagnosis recommending therapeutic ultrasound was similarly tested for SCE induction; an additional set of 4 healthy persons underwent sham-therapeutic ultrasound exposures. For both sets of subjects (patients, nonpatients) there was no increase in the frequency of SCEs.