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PubMed1983

IgA nephropathy. Correlation of clinical and histologic features.

The clinical and histologic features of 81 patients with IgA nephropathy were analyzed. Azotemia was present in 32 per cent of the patients, proteinuria was present in 88 per cent, and gross or microscopic hematuria was present in all of the patients tested. The median age of histologic diagnosis was 27 years. The median age at onset of clinical signs was 20 years. There was no increased incidence in any HLA-A or -B antigen within the patient population over our control population. All patients had glomerular mesangial IgA deposition (by definition) greater than or equal to IgG or IgM. Histologic changes were quantitated and ranged from normal to necrotizing and/or crescentic glomerulonephritis. Many patients (48 per cent) had mild or moderate generalized glomerlular hypercellularity. Nonparametric statistical analysis showed strong correlations among patient age at histologic diagnosis, creatinine, proteinuria, global glomerular sclerosis, and interstital fibrosis. Our analysis suggests that IgA nephropathy is an indolent disease generally beginning in childhood. It is a cause of renal insufficiency in a significant number of patients. Interpretation of this series and other reported studies suggests that most cases of IgA nephropathy in the United States are best considered idiopathic but that hereditary and secondary forms may exist.

Adolescent↗

PubMed1981

125I radioimmunoassay of delta-9-tetrahydrocannabinol in blood and plasma with a solid-phase second-antibody separation method.

In this sensitive and specific radioimmunoassay for delta-9-tetrahydrocannabinol, an iodinated tracer with high specific activity and a solid-phase separation are used. Within-run coefficients of variation for 5.0 and 30.0 microgram/L concentrations were 7.8 and 4.2% for plasma and 14 and 10.6% for hemolyzed blood specimens, respectively. Day-to-day coefficients of variations ranged from 7.3 to 13.6% (for 7.6 to 33.0 microgram/L concentrations) for plasma and 13.4 to 18.1% (3.0 to 52.1 microgram/L) for hemolyzed blood specimens. Data for time after start of smoking of a standard THC-containing cigarette vs the concentration of delta-9-tetrahydrocannabinol in the plasma were similar to those obtained by others. Positive plasma specimens from the smoking study were analyzed by gas chromatography-mass spectrometry and by our radioimmunoassay. Nonparametric statistical comparison and linear regression (r2 = 0.972) showed that results by the two methods of analysis correlate well. The sensitivity of the assay was at least 0.3 microgram/L for plasma, 1.1 microgram/L for hemolyzed blood.

Adult↗

PubMed1982

Major histologic types of cancers of the gum and mouth, esophagus, larynx, and lung by sex and by income level.

Incidence rates by income level were computed for squamous cell carcinomas of the gum and mouth, larynx, and esophagus and for squamous cell carcinoma, small cell carcinoma, and adenocarcinoma of the lung in white males and females aged 35--64 years, with the use of data for the nine geographic areas of the Third National Cancer Survey and the 1970 U.S. census. Within sex, age, and geographic area groups, patterns of cancer incidence by income level were analyzed by use of a nonparametric statistical method. Higher rates for males than for females were found for every histologic type studied, and the ratio of male-to-female rates increased with age (especially for squamous cell carcinomas of the larynx and lung). A strong inverse relation to income level was found for all of the histologic types studied in males and for squamous cell carcinomas of the gum and mouth and esophagus and small cell carcinoma of the lung in females. These findings are discussed with reference to patterns of smoking and alcohol use by sex and social class.

Adult↗

PubMedDate not supplied

The photometric latex test for rheumatoid factors in patients with rheumatoid arthritis. II. Clinical evaluation.

The photometric latex test (PLT) for the detection of rheumatoid factors has been clinically evaluated. PLT titers have been closely studied in relation to clinical and laboratory parameters by means of parametric and nonparametric statistical methods. An analysis of the sensitized sheep cell test (SSC) titers has also been undertaken. The subjects comprised 377 patients with rheumatoid arthritis (RA) and 120 controls. The medical data recorded included sex, age, diagnosis, anatomical stage, functional class, duration and course of the disease, presence of the American Rheumatism Association (ARA) criteria, blood sedimentation rate, red and white blood counts, haemoglobin concentration, total protein content, serum protein levels, and SSC and PLT titers. A multivariate stepwise regression analysis with eight normally distributed variables was made. In accordance with previous findings, a significant correlation was shown to exist between the serum protein levels and the development of the RA when the anatomical stage, functional class and course of the disease were used as parameters of disease activity. In the RA patients there was also correlation between the serologic titers and the serum protein levels, and the anatomical stage, functional class and course of the disease, and the sedimentation rate, thus showing that titers can also serve as a measure of the inflammatory process. There was a significant correlation between the number of ARA criteria and the titers in the RA patients but not in the controls. The course of the disease correlated with the serum titers and other inflammatory parameters, a finding showing that the course of the disease is an important diagnostic parameter with possible prognostic value. Correlation was also demonstrated between the white blood count and the titers. It is concluded that the sedimentation rate, albumin and gamma-globulin levels, and PLT titer are the best parameters of disease activity. The titer values are not only of diagnostic importance but have prognostic value as regards the severity of the disease.

Adolescent↗

PubMed1984

Six approaches to routine quantification of human monoclonal immunoglobulin M compared.

Six routine techniques for the determination of monoclonal IgM are compared: standard electrophoresis, the Technicon AIP system, Hyland laser nephelometry, Beckman Immunochemistry System, Behring laser nephelometry, and radial immunodiffusion. The data are evaluated by use of a nonparametric statistical analysis of variance by ranks (Friedman test) and Wilcoxon's test. The 27 sera containing monoclonal IgM that we studied yielded different results by the various techniques. Sera from a "reference" population of 15 subjects having above-normal polyclonal IgM yielded identical results for all techniques. These statistical findings agree with the biophysical mechanisms involved in the various ways of quantifying IgM. We conclude that these different systems are equivalent for estimating polyclonal IgM, but cannot (and should not) yield identical values when used in monoclonal IgM evaluations. Results for monoclonal IgM must be interpreted in terms of the molecular forms and immunological specificities of the assayed IgM.

Antibodies, Monoclonal↗

PubMed1983

Glutamate and spreading depression in chick retina.

This work is centered on the involvement of glutamate in spreading depression. Chick eye cup preparations bathed with Ringer solution at 28 degrees C were used. For chemical stimulation KCl was increased and glutamate was added to the Ringer solution. The occurrence of spreading depression was detected by visual observation of the optical changes accompanying the phenomenon. Enzymatic method based on the fluorescence of the reduced form of nicotinamide adenine dinucleotide was used for glutamate dosage in the Ringer's samples. The investigations proceeded under six different experimental conditions, and the results were analysed by nonparametric statistical methods. No correlation was found between spreading depression and glutamate outflux. The glutamate hypothesis to account for spreading depression was discussed, and experimental situations involving glutamate, K+ and Cl- were indicated that proved unfavorable to the incidence of the reaction.

Animals↗

PubMed1982

Radioimmunoassay for phencyclidine (PCP) in serum.

This accurate, sensitive radioimmunoassay for determining phencyclidine concentrations in serum specimens involves the use of anti-phencyclidine sera, 0.1 mL of serum specimen, an iodinated tracer, and a solid-phase separation. Phencyclidine metabolites do not show significant cross reactivity, but several phencyclidine analogs do cross react. Within-run coefficients of variation for human and dog serum ranged from 2.5 to 13% for concentrations from 2.0 to 500 micrograms/L. Day-to-day coefficients of variation for human and dog serum ranged from 4.3 to 16.7% for concentrations ranging from 2.0 to 90.0 micrograms/L. The sensitivity of the radioimmunoassay is less than 0.5 micrograms/L. Thirty serum specimens from two dogs given 1 mg of phencyclidine per kilogram body weight were analyzed by radioimmunoassay and a gas-chromatographic method. Nonparametric statistical comparison and linear regression showed that results from the two procedures correlate well (r2 = 0.952). Concentration-time data from the two dogs are presented to illustrate the utility of the radioimmunoassay for examining phencyclidine disposition.

Animals↗

PubMed1980

Antitumor activity of Corynebacterium parvum and retinyl palmitate used in combination on the Lewis lung carcinoma.

The effects of Corynebacterium parvum and retinyl palmitate given at various levels, schedules, and routes of administration on primary Lewis lung carcinoma and its metastases have been evaluated in C57BL/6J mice given s.c. inoculations of 5 X 10(5) tumor cells. Single i.v., but not i.p., s.c., or i.m., administration of C. parvum (0.35 mg/mouse given on Days 0, 1, or 3) reduced growth of tumor and prolonged survival time. Retinyl palmitate (3000 IU/mouse/day) given alone i.p. either before, after, or both before and after tumor inoculation showed no effect on tumor growth, survival of mice, or lung metastases. The combination of retinyl palmitate i.p. (6 daily injections of 1500 IU/mouse after tumor implantation) and C. parvum (0.175 mg/mouse) given i.v. resulted in an increase in life span over control of 146% and appeared to be therapeutically synergistic. This combination produced 90-day cures in about 20% of the treated animals, all of which were found to be tumor free. Two nonparametric statistical procedures, the Kruskal-Wallis and the Dunn test, were used to assess the effects of treatments on survival time and tumor growth and may be generally applicable to animal tumor studies. They provide multiple comparisons of different treatments and allow the inclusion of long-term survivors into the analysis.

Animals↗

PubMed1995

[Kinetic distribution of cyclosporine after single dose subcutaneous administration; experimental study in rats].

Adequate dose of cyclosporin A shows immunosuppressor effect, and low toxicity. The doses reported previously ranged from 2.5 to 25 mg/kg every 24, 48 hours and even 7 days. Routes for cyclosporin A administration are subcutaneous or intramuscular preferentially. In the present study, cyclosporin A (CSA) single dose subcultaneous was administered to 21 Wistar-Furth rats, adult, males, weighing 350-450g. The animals were divided in 3 groups receiving 2.5 mg/kg (group 1), 5.0 mg/kg (group 2) and 10.0 mg/kg (group 3). Blood samples were collected at 1, 4, 8, 12, 24, 48 and 72 hours after drug collection into plastic tubes containing sodium EDTA. Blood cyclosporin A levels were determined by a commercially available radioimmunoassay kit (Sandoz RIE Kit Basel) after whole hemolysis using liquid nitrogen. Cyclosporin A blood concentrations vs time curve were plotted (log C vs t). Two compartment open model was applied to estimate the kinetic parameters as t(1/2) beta e beta. A model independent calculation was applied to estimate the kinetic parameters as AUCT, CIT and Vd. Initially, parametric and nonparametric tests were applied. Due to the high dispositional variability, nonparametric statistics (Wilcoxon's test) was applied for analysis of results obtained. Based on data obtained in the present study the authors suggest linear pharmacokinetics where Cmax AUCT showed proportional increases with the dose administered, remaining unchanged the Kinetic parameters as t(1/2) B,B, CIT and Vd.

Analysis of Variance↗

PubMed1994

[Comparative study of lipids, apoproteins and lipoproteins in patients with coronary disease and in a control population].

We carried out a comparative study of various lipid parameters (apo AI and B, LpAI, Lp(a) and LpBCIII) in coronary heart disease patients (19 males and 4 females, mean age 61 +/- 11 years) and in controls (18 males and 14 females, mean age 55 +/- 3 years) selected so that cholesterol and triglycerides levels be beneath 6 and 2.3 mmol/l in both populations. Apo AI and B were analysed by immunonephelometry and lipoparticles by electroimmunodiffusion. Nonparametric statistics tests were performed on account of the small numbers in both groups. Our study confirms the protective effect of Lp AI but did not show an obvious superiority of Lp AI quantification compared to apo AI. It highlights the interest of Lp(a) as an independent and additional risk factor for atherogenesis: no obvious correlation with any other lipidic parameter was demonstrated. An increase in Lp(a) beyond 0.30 g/l increases atherogenic risk 2.5 fold. We did not show any benefit of LpBCIII quantification in 'normolipemic' coronary patients. In conclusion, a discriminant analysis including the apo B/apo AI and apo B/LpAI ratios and Lp(a) allows an accurate classification of 67% of the patients.

Apolipoproteins A↗

PubMed1995

Age as a factor in critical care unit admissions.

BACKGROUND: Although the aged occupy a high proportion of critical care beds nationwide, few multicenter studies have been undertaken to specifically determine physician attitudes toward the elderly in a critical care setting. We attempt to determine the importance of patient age as a factor in the admission of acutely ill medical patients to critical care units. METHODS: In response to a hypothetical case scenario, physicians were asked to admit one of two patients to a last available critical care unit bed. An accompanying questionnaire was used to gain a ranking of several admission factors as compared with age, and to gain demographic data regarding the study population. Data were subjected to nonparametric statistical analysis. RESULTS: When age was the only difference between two patients in a hypothetical case scenario, 80.7% of respondents chose the younger patient (age 56 years) for admission, 13.2% chose the older patient (age 82 years), and 6.2% abstained. Following the provision of more detailed medical and social information, however, only 53.5% chose the younger patient, 41.2% chose the older patient, and 5.3% continued to abstain. In a ranking of several admission factors, age was found to be of less importance than severity of presenting illness, previous medical history, and do not resuscitate status, but of more importance than patient motivation, ability to contribute to society, family support, and ability to pay for care. When asked if they supported a definitive age criterion that would restrict all patients over a certain age from access to critical care units, 95.1% responded that they did not. CONCLUSIONS: Age is a factor considered by physicians in the admission of acutely ill medical patients to critical care units. Other medical and social factors, however, can affect the impact of patient age on treatment decisions. Further study and discussion are needed to clarify the appropriate role of age and other factors in critical care unit admissions.

Age Factors↗

PubMed1994

A cautionary note on applying scores in stratified data.

When rank tests are used to analyze stratified data, three methods for assigning scores to the observations have been proposed: (S) independently within each stratum (see Lehmann, 1975, Nonparametrics: Statistical Methods Based on Ranks; San Francisco: Holden-Day); (A) after aligning the observations within each stratum and then pooling the aligned observations (Hodges and Lehmann, 1962, Annals of Mathematical Statistics 33, 482-497); and (P) after pooling the observations across all strata (that is, without alignment) (Mantel, 1963, Journal of the American Statistical Association 58, 690-700; Mantel and Ciminera, 1979, Cancer Research 39, 4308-4315). Test statistics are formed for each method by combining the stratum-specific linear rank tests using the assigned scores. We show that method P is sensitive to the score function used in the case of two moderately sized strata. In general, we recommend methods S and A for use with moderate to large-sized strata.

Biometry↗

PubMed1994

Possible improvement in uteroplacental blood flow during atrial natriuretic peptide infusion in preeclampsia.

OBJECTIVE: To study the effects of low doses of the hormone atrial natriuretic peptide (ANP) on uteroplacental blood flow in patients with preeclampsia. METHODS: Eleven women with preeclampsia were infused intravenously with ANP (10 ng/kg/minute). Uteroplacental blood flow index was measured using dynamic placental scintigraphy with indium-113m. Regional blood flows were assessed by pulsed Doppler ultrasound and expressed as pulsatility index (PI). Hemodynamic measurements and blood sampling for peripheral venous plasma analysis of cyclic guanosine monophosphate (cGMP), an ANP second messenger, were performed before and after 30 minutes of infusion. Nonparametric statistics were used. RESULTS: The uteroplacental blood flow index increased by 28% (-2 to 58%; mean and 95% confidence interval). The Doppler findings were unaffected. Mean arterial blood pressure decreased from 112 (108-117) to 108 (103-114) mmHg (P < .01). Cyclic GMP increased significantly from 9.2 (6.2-12.3) to 17.4 (12.3-22.6) nmol/L (P < .01). Subjects exhibiting a substantial increase in uteroplacental blood flow index (25% or more) demonstrated a significantly greater cGMP response (P < .01) than those who did not (6% or less increase). CONCLUSION: A tendency to an increased uteroplacental blood flow index combined with minor blood pressure reduction after ANP infusion suggest the possibility of uteroplacental vasodilatation.

Adult↗

PubMedDate not supplied

[The comparative characteristics and receptor mechanism of the effect of adenosine-receptor agonists in total cerebral ischemia].

The duration of gasping has no normal distribution, so nonparametric statistic criteria should be used. Three adenosine receptor agonists have a highly cerebro-protective effect which decreases in the order: N-ethylcarboxamide adenosine > > cyclohexyl adenosine > adenosine. Theophylline completely blocks these effects. Thus, they act through adenosine receptors. Adenosine receptor agonist are likely to protect themselves neurons.

Adenosine↗

PubMed1994

Efficient strategies for genomic searching using the affected-pedigree-member method of linkage analysis.

The affected-pedigree-member (APM) method of linkage analysis is a nonparametric statistic that tests for nonrandom cosegregation of a disease and marker loci. The APM statistic is based on the observation that if a marker locus is near a disease-susceptibility locus, then affected individuals within a family should be more similar at the marker locus than is expected by chance. The APM statistic measures marker similarity in terms of identity by state (IBS) of marker alleles; that is, two alleles are IBS if they are the same, regardless of their ancestral origin. Since the APM statistic measures increased marker similarity, it makes no assumptions concerning how the disease is inherited; this can be an advantage when dealing with complex diseases for which the mode of inheritance is difficult to determine. We investigate here the power of the APM statistic to detect linkage in the context of a genomewide search. In such a search, the APM statistic is evaluated at a grid of markers. Then regions with high APM statistics are investigated more thoroughly by typing more markers in the region. Using simulated data, we investigate various search strategies and recommend an optimal search strategy that maximizes the power to detect linkage while minimizing the false-positive rate and number of markers. We determine an optimal series of three increasing cut-points and an independent criterion for significance.

Female↗

PubMed1994

Age- and joint-specific risk of initial heterotopic ossification in patients who have fibrodysplasia ossificans progressiva.

Using data from a survey of 44 patients who have fibrodysplasia ossificans progressiva, age- and joint-specific risks of new joint involvement were estimated using parametric and nonparametric statistical methods. Regions in which the risk of heterotopic ossification appears to remain constant with age include the neck, spine, shoulders, elbows, and ankles. Regions with apparently increasing risk include the jaw, wrists, hips, and knees. This analysis allows clinicians to estimate the risk of new involvement for any joint at any patient age, as well as the fraction of patients with uninvolved joints at any age. The variation of ossification risk by joint provides a clinically useful guide to the patterns of progression of the disease. Such a guide will help in planning for individual patient needs, as well as anticipating auxiliary social services and rehabilitation programs.

Adolescent↗

PubMed1993

Cosmetic result of lower midline laparotomy wounds: polybutester and nylon skin suture in a randomized clinical trial.

OBJECTIVE: To compare the cosmetic outcome of lower midline laparotomy scars using either nylon or polybutester suture for skin closure. METHODS: A randomized clinical trial compared polybutester skin suture with nylon for lower midline laparotomy wounds in 50 women undergoing gynecologic surgery. Scar hypertrophy, scar width, scar color, the presence of cross-hatching marks, and a total score were assessed in all patients at 18 months following surgery and compared by nonparametric statistical tests. RESULTS: The wounds closed with polybutester suture were significantly less hypertrophic than those closed with nylon. Regardless of the suture material used, the lower part of the laparotomy scar showed an inferior cosmetic result compared with the upper part underneath the umbilicus for scar hypertrophy, scar width, and the total scar score. CONCLUSIONS: Polybutester skin suture diminishes the risk of hypertrophic scarring because of its special properties allowing it to adapt to changing tensions in the wound. Increased closure tension of the skin in the midline region above the pubic bone may be caused by a relative immobility of the skin. Scar cosmetics in this area may be improved by extra subcuticular suture support.

Cicatrix↗

PubMed1995

Lymphatic air embolism: a new hypothesis regarding the pathogenesis of neonatal systemic air embolism.

Objective. Neonatal systemic air embolism (NSAE) has been thought to result from introduction of air into the pulmonary veins through hypothesized alveolar-capillary fistula. The objective of this paper is to reassess the distribution of intravascular air visualized radiographically in this entity. Based on these data, an alternative theory for the pathogenesis of NSAE is proposed. Materials and methods. Four cases from our institutions and 21 additional reviewable published radiographs of NSAE were evaluated for the presence and location of intravascular air. Nonparametric statistical analysis was performed to determine if the predominance of intravascular air was venous or arterial in location, and to determine the presence or absence of pulmonary interstitial emphysema (PIE), pneumothorax, pneumomediastinum, and pneumopericardium. Results. Isolated systemic venous air was present significantly more often than isolated systemic arterial air (p < 0.0005). In addition, the presence of isolated right-sided cardiac air was found significantly more often than air within left heart chambers alone (p < 0.0005). PIE in patients with NSAE was found to be statistically more prevalent than pneumomediastinum or pneumopericardium, though similar in prevalence to pneumothorax. Conclusion. Our data support the hypothesis that intravascular air in NSAE is predominantly venous in location. PIE was found to be a very common associated finding in NSAE. Based on our current knowledge of pulmonary lymphatics, radiographic anatomy, and the lymphatic location of PIE, we propose that air within the pulmonary lymphatic system (PIE) gains access to the systemic venous system via lymphatic ducts, which results in the clinical entity NSAE. This readily explains the venous predominance of air in NSAE.

Embolism, Air↗