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PubMed1980

Distribution of eyeblink amplitude recorded by an electrode hookup: re-examination.

The present experiment was run to re-examine the distributional properties of the eyeblink amplitude elicited by a burst of 110-dB white noise, recorded by an electrode hookup as recommended in our previous report (Yamada, Yamasaki, & Miyata, 1979). 103 volunteers, 54 males and 49 females, were tested. Analysis showed that the amplitudes were distributed normally when a logarithmic transformation was performed but not when the raw scores were used. We conclude that the amplitude of the startle eyeblink reflex has a log-normal distribution property.

Acoustic Stimulation↗

PubMed1985

Incidence of finger pattern types and pattern intensity in a Spanish population (Tierra de Campos).

The incidence of finger pattern types and the pattern intensity distribution in a Spanish sample (417 males and 416 females) drawn from the geographical area of Tierra de Campos have been studied. Sexual and bilateral differences for both dermatoglyphic traits were explored by means of chi 2-test and Mann-Whitney U-test, showing significant differences in all cases, excepting the sexual difference between left hands for pattern intensity. Kolmogorov test for distribution normality showed that pattern intensity was not normally distributed, being the distributions right skewed because of the low frequency of classes with fewer triradii. The results obtained in Tierra de Campos were compared with those observed in other Spanish and Portuguese populations, showing more heterogeneity in the pattern types than in pattern intensity. This could imply that arches account for the main source of variation between populations. Moreover, pattern type frequencies and pattern intensity in Tierra de Campos are, as expected, within the variation ranges of Southeuropean-Mediterranean populations and Caucasians as a whole, although the incidence of radial loops is located in the lower extremes of the corresponding variation ranges.

Dermatoglyphics↗

PubMed1994

[Computerized tomography measurement of torsion angle of the lower extremities].

The precise evaluation of post-traumatic deformities is indispensable when planning a corrective osteotomy. Torsional angles of the lower extremities of 186 patients were measured using CT. The mean age of the studied population was 34 years (18-80). It consisted of 131 men and 55 women. All patients had sustained a fracture of at least one of the leg's bony segments. The normal femoral (n = 293) inward torsion measured 23.47 degrees +/- 17.16 degrees (mean +/- 2 SD). Normal tibia (n = 263) outward torsion was 34.03 degrees +/- 17.22 degrees. The intraindividual torsional differences were not normally distributed. Normal femoral (n = 103) intraindividual torsional difference measured 11 degrees (95% percentile) and 15 degrees (99% percentile), with a median of 4 degrees. The tibiae (n = 76) showed a normal intraindividual torsional difference of 12 degrees (95% percentile) and 15 degrees (99% percentile). Right tibiae showed a statistically significant greater outward rotation when compared to their left counterpart (P < 0.001). No correlation to sex could be established. Preoperative planning of a corrective osteotomy should include the geometric evaluation of all four bony segments of the leg. Intraindividual torsional differences must be considered. A corrective osteotomy appears to be unnecessary with a torsional difference smaller than 15 degrees in the femora and smaller than 15 degrees in the tibiae.

Adolescent↗

PubMed1988

Models of hepatic elimination: comparison of stochastic models to describe residence time distributions and to predict the influence of drug distribution, enzyme heterogeneity, and systemic recycling on hepatic elimination.

The residence time distribution of noneliminated solutes in the liver can be represented by a variety of stochastic models. The dispersion model (closed and mixed boundary conditions), gamma distribution, log normal distribution and normal distribution models were used to describe output concentration-time profiles after bolus injections into the liver of labeled erythrocytes and albumin. The dispersion model and log normal distribution model provide the best representation of the data and give similar estimates of relative dispersion and availability for varying hepatocellular enzyme activity. The availability of solutes eliminated from the liver by first-order kinetics is determined by the residence time distribution of the solute in the liver and not on events occurring in the liver when a uniform enzyme distribution is assumed. Both enzyme heterogeneity (axial or transverse) and hepatocyte permeability may affect solute availability. A more complex model accounting for enzyme distribution and the micromixing of solute within the liver is required for solutes undergoing saturable kinetics.

Biological Transport↗

PubMed1994

Non-normality of distribution of Glasgow Coma Scores and Revised Trauma Scores.

STUDY OBJECTIVE: Inferential and descriptive statistics continue to be used incorrectly when analyzing biomedical data. Glasgow Coma Score (GCS) and Revised Trauma Score (RTS) data have recently been described and analyzed using parametric statistical methods in several studies despite the ordinal nature of these data scales. The objective of this study was to determine whether GCS and RTS data are normally distributed, despite their ordinal nature. HYPOTHESIS: Neither GCS nor RTS data are normally distributed. DESIGN: A retrospective review of GCS and RTS data obtained at a medical school teaching and county hospital that is a Level I trauma center. PARTICIPANTS: Patients who met criteria for trauma team activation at the hospital. METHODS: GCS and RTS data distributions were compared to a standard normal distribution using the chi 2 goodness of fit test. RESULTS: GCS and RTS data distributions differed significantly from the normal distribution for all data sets examined. CONCLUSION: Parametric statistical descriptors and inferential methods are inappropriate for use with GCS and RTS data. Ordinal data should be tested for normality before statistical analysis with parametric statistical methods.

Chi-Square Distribution↗

PubMed1988

Quantitative genetic analysis of bi-iliac breadth.

Bi-iliac breadth, the frontal maximum diameter between right and left iliac crests, was measured in 1,547 male and 2,085 female residents of a rural area in Japan. All subjects were over 14 years of age. The bi-iliac breadth showed an increase related to age but little sex difference. Modification of age and sex variations from the measured value was obtained by calculation of the score, represented by arithmetical means and standard deviations. Distribution of these scores appeared to be binomial, and since binomial distribution approaches normal distribution when n is large, it is presumed that this trait gains normal distribution. Thus variation of bi-iliac breadth in subjects 20-79 years of age enables us to analyze inheritance. No significant difference was found between husband and wife in the correlation coefficients or between father and daughter (0.13 +/- 0.08). Significant differences were found as follows: father-son (0.35 +/- 0.05) (P less than 0.001), mother-son (0.28 +/- 0.05) (P less than 0.001), and mother-daughter (0.28 +/- 0.06) (P less than 0.001). There was no indication of maternal or paternal effects, since no significant difference was found in father-child and mother-child correlation coefficients. It is concluded that bi-iliac breadth is a quantitative genetic trait under control of polygenes on autosomes. Regression coefficient of child on midparental value was 0.55 +/- 0.05, approximately twice the means of four pairs of correlation coefficients between parent-offspring. Narrowly, heritability was estimated as 0.54 approximately 0.55. Contribution of dominance to total variance was small (VD = 0.11), in contrast to the larger additive genetic variance (VA = 0.54).

Adolescent↗

PubMed1989

Role of bandpass filters in optimizing the value of the signal-averaged electrocardiogram as a predictor of the results of programmed stimulation.

Normal values for the signal-averaged electrocardiogram (SAECG) at 11 different high-pass filter settings were obtained from 100 normal subjects (group I). The filtered QRS duration and the duration of low amplitude signals less than 40 microV, but not the root mean square voltage of the last 40 ms (RMS40), showed normal distribution. A normal distribution for RMS40 could be obtained by transforming each value to its natural logarithm. The normal values were used in a systematic approach to optimize the accuracy of the SAECG to predict the results of programmed stimulation in 80 patients with spontaneous nonsustained ventricular tachycardia (VT). Fifty-two patients with no inducible VT (group II) and 28 patients with inducible sustained monomorphic VT (group III) were investigated. The 3 SAECG parameters at each high-pass filter in groups II and III were categorized as normal or abnormal and were evaluated singly or in combinations of 2 or 3. There was no combination that provided a sensitivity greater than 82% that could also be obtained by single determinations of low amplitude signals less than 40 microV at 25 to 40 Hz or RMS40 at 40 Hz. On the other hand, there were 267 different combinations that provided a maximal specificity of 98%. The best total predictive accuracy of a single parameter was 85%, provided by RMS40 at 40 or 60 Hz. The total predictive accuracy could be improved to 89% by 1 of 32 different combinations. The top combinations were mostly in triplets and included SAECG parameters recorded at different high-pass filter settings. The only 2 paired combinations with the best total predictive accuracy were RMS40 at 20 or 25 Hz paired with RMS40 at 40 Hz. Frequencies at both ends of the analyzed high-pass filter settings (less than 20 Hz and greater than 60 Hz) were not represented in the top predictive combinations. The SAECG parameters analyzed at 40 Hz were most frequently represented in the top predictive combinations, suggesting that the SAECG may have the best predictive accuracy at this filter setting. In summary, the combination of SAECG parameters analyzed at different filter settings can enhance the accuracy of the technique as a screening test for the results of programmed stimulation in patients with spontaneous nonsustained VT.

Adult↗

PubMed1986

Beta-cell dysfunction, rather than insulin insensitivity, is the primary defect in familial type 2 diabetes.

Continuous infusion of glucose with model assessment was used to measure glucose tolerance, beta-cell function, and insulin sensitivity in 154 first-degree relatives of 55 patients with type-2 diabetes. The plasma glucose achieved at 1 h was normally distributed in normal control subjects, but 31 (20%) of relatives of type-2 diabetics had values above the normal distribution mean +2 SD. Insulin secretion, assessed from the first or second phase plasma-C-peptide responses, was significantly lower in the glucose-intolerant relatives than in normoglycaemic relatives of similar sex, age, and obesity. beta-cell function, estimated by means of model analysis, was severely impaired in the glucose-intolerant relatives but was not impaired in the normoglycaemic relatives (geometric mean 41% and 109% of normal beta-cell response, respectively). Reduced beta-cell function was found with all degrees of glucose intolerance, whereas only the more severely hyperglycaemic relatives had impaired insulin sensitivity. This suggests that the primary defect in familial type-2 diabetes is beta-cell dysfunction.

Adult↗

PubMed1993

Microautoradiographic analysis of the normal organ distribution of radioiodinated single-chain Fv and other immunoglobulin forms.

In previous studies, we have compared the immunochemical properties, the in vivo pharmacokinetics, and the tumor penetrance of a radioiodinated single-chain Fv (sFv) in comparison with other immunoglobulin (Ig) forms (intact IgG, F(ab')2, and Fab') (Cancer Res., 51: 6363-6371, 1991). Biodistribution studies demonstrated a higher percent injected dose/g in the liver and spleen for the intact IgG and F(ab')2. Renal uptake was observed with the Fab' and F(ab')2, whereas the sFv demonstrated no specific localization in either of these organs. The 125I-labeled sFv also demonstrated a more even distribution throughout the tumor xenografts as compared to the other Ig forms (Cancer Res., 52: 3402-3408, 1992). Subsequent studies utilizing the sFv conjugated with a radiometal (177Lu) demonstrated that the sFv was being metabolized by the kidney, and a significantly higher percent injected dose/g was obtained with a 177Lu-labeled sFv as compared to a 125I-labeled sFv (Cancer Res., 52: 6413-6417, 1992). These previous studies indicated the potential utility of radioiodinated sFv and other Ig fragments for use in radioimmunoguided surgery with a hand-held probe, diagnostic imaging, and possibly therapy. The present study compares the distribution in normal tissues of the 4 Ig forms of monoclonal antibody (MAb) CC49, which is directed against a pancarcinoma antigen (tumor-associated glycoprotein-72). 125I-labeled sFv, Fab', F(ab')2, and IgG of MAb CC49 were administered to athymic mice either bearing or not bearing the tumor-associated glycoprotein-72 positive human colon carcinoma xenograft (LS-174T). At various intervals following the i.v. injection of the Ig forms, the liver, spleen, kidneys, and lungs were removed for autoradiographic analyses. Dramatic differences were observed in the kidney; the IgG was found only in the renal vasculature, whereas the Fab', F(ab')2, and sFv showed a high density of grains in the cortical tubules. In the liver, the IgG and F(ab')2 were found in association with hepatocytes, Kupffer cells, and in the sinusoids; the Fab' and sFv were primarily associated with the Kupffer cells. In the spleen, the Ig forms localized to the marginal zones surrounding the lymphoid follicles. No specific accumulation of grains for any of the Ig forms was observed in the lung. In each of the tissues, the clearance rates were related to the size of the Ig form. The localization in the liver and spleen was determined to be antigen-mediated.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1991

[Individual and average weight requirements of pharmaceutical preparations].

Authors studied the weight deviations allowed by non-statistically constructed individual and average weight requirements of Pharmacopoeas under consideration of normal Gaussian distribution. Normality was examined on a given suppository product and has been established, that in this case theoretically the hypothesis of normal distribution is not valid. For this reason deviation characteristics calculated according to the severest and the lightest Pharmacopoean requirements have been presented, i.e. the lower limit (if the deviation is less than this limit, the preparation meets the requirements by all means), and the upper limit (if the deviation is larger than this limit, the preparation definitively does not meet the requirements) respectively. Moreover, deviation characteristics calculated for continuous Gaussian distribution and for discrete distribution with few elements (representing a good approximation of the former) are given in the paper. On the basis of these results authors suggested to modernize the requirements of Pharmacopoeas and to continue research work in this direction.

Dosage Forms↗

PubMed1988

Regional capillary and myocyte distribution in normal and exercise trained male and female rat hearts.

Adult Sprague-Dawley male and female rats were exercise trained for five months by either treadmill running or swimming. Significant differences in left ventricular regional capillary density and myocyte cross-sectional area were found. In control rats the epicardial regions had greater capillary density than endocardial regions. Endocardial myocyte cross-sectional areas were greater than those of epicardial myocytes in both sexes. Male rats had larger endocardial myocytes and larger hearts than females. After exercise training, myocyte size increased in the epicardial region but not in the endocardial region, while capillary density increased significantly only in the endocardial region. Similar changes were seen in both male and female rats with comparable degrees of exercise induced hypertrophy. These data suggest that exercise training "normalizes" the distribution of capillaries in the myocardium. Capillary density increased only in the regions where myocyte cross-sectional area did not increase. Further, the effects of exercise on male and female rat hearts is not different when the degree of exercise induced hypertrophy is similar.

Animals↗

PubMed1984

A study of body hair density and distribution in normal women.

The distribution and density of terminal hair growth have been studied in 19 different body regions in 100 normal women of fertile age and 25 normal postmenopausal women. In accordance with earlier investigations an age-dependent variation in hair growth pattern was observed. None of the women in either group had terminal hair growth on the cheek, and on the breast region hair was limited to a small circumareolar area. Whereas facial terminal hair growth appeared to be less common than that reported in earlier studies of women from other countries, the frequency of terminal hair in other regions was found to be significantly higher in the Norwegian women. No difference in hair growth pattern between blondes and brunettes could be detected.

Adolescent↗

PubMed1995

Calculation of trough:peak ratio of antihypertensive treatment from ambulatory blood pressure: methodological aspects.

OBJECTIVE: To address several methodological questions related to calculation of trough:peak ratio from 24 h ambulatory blood pressure (BP) recordings. METHODS: Data from patients with mild essential hypertension who were included in parallel group (n = 280) or cross-over studies (n = 39) were pooled. 24 h ambulatory BP recordings were available after 2- to 4-week washout from treatment and at the end of a 4- to 8-week period of treatment with calcium antagonists (n = 143), angiotensin converting enzyme inhibitors (n = 103) or placebo (73 patients from parallel group studies and 39 from a cross-over study). Each recording started between 0900 and 1000 h, immediately after the drug or placebo intake during the treatment phase. BP was measured at 15 min intervals during the day and at 15-20 min intervals during the night. Peak changes were calculated from systolic BP and diastolic BP 2-8 h after drug intake, and trough changes from readings taken during the last 4 h of the 24 h. RESULTS: Peak changes induced by drug treatment were progressively reduced when data were averaged over 1, 2, 4 and 6 h. BP reproducibility showed a concomitant increase and the best compromise between correct estimate of peak changes and reproducibility was the average of the adjacent 2 h with the maximal BP fall. Peak and trough (average of last 2 h) changes showed a normal distribution, whereas trough:peak ratios showed non-normal distributions, large scatters and many individual values with no pharmacodynamic significance (namely, much above unity and below zero). Selecting responders to treatment reduced the dispersion and made the trough:peak ratio distribution normal. There was no correlation between trough:peak ratios and changes in BP variability (standard deviation of 24 h mean) induced by treatment. Placebo administration caused no trough but a modest peak fall. Peak changes during placebo also showed a wide scatter and a non-normal distribution, which makes correction with respect to average peak placebo data inappropriate in parallel-group studies. However, placebo correction may be performed for each subject in cross-over studies, leading to a reduction in peak changes and an increase in trough:peak ratio values. CONCLUSIONS: When the trough:peak ratio is assessed from ambulatory BP, peak and trough changes should preferably be computed over a 2 h time window. To remove values with no pharmacodynamic significance, the analysis should preferably be conducted only in responders to treatment at peak. Although placebo is accompanied by some peak effect, placebo correction might be appropriate only for individual subjects in cross-over studies.

Antihypertensive Agents↗

PubMed1983

Immunohistochemical studies of amyloid P component distribution in normal human skin.

The distribution of amyloid P component (AP) in normal human skin was investigated by a light and electron microscopic immunoperoxidase technique, using antibodies to serum amyloid P component (SAP). AP, or an immunologically cross-reactive protein, was found to be specifically localized to the microfibrils of papillary oxytalan fibers and to the peripheral microfibrillar mantle surrounding the elastin core of mature elastic fibers in the reticular dermis; collagen fibers were not stained with anti-SAP. AP was not detected in the dermal-epidermal basement membrane or in the basement membranes surrounding dermal papillary blood vessels and eccrine structures. These findings, which establish the detailed distribution of normal tissue AP in the skin, provide a basis for further studies of the function and behavior of this protein in health and disease.

Amyloid↗

PubMed1997

Log-normality of distribution of occupational exposure concentrations to cobalt.

In evaluating occupational exposures, the daily exposure levels of a worker are generally assumed to be distributed log-normally between days. When there are many workers in a job group, the individual worker's arithmetic means are assumed to be distributed log-normally. Using the cobalt exposure data in a hard metal factory, these assumptions were examined with the Shapiro-Wilk W test. The hypothesis of log-normality was accepted in all cases, while the hypothesis of normality was rejected in some cases.

Cobalt↗

PubMed1978

A comparative study of the buoyant density distribution of normal and malignant lymphocytes.

Density distribution patterns of normal and malignant lymphocytes were compared following centrifugation to equilibrium on linear density gradients. For normal lymphocytes differences in the distribution patterns were observed between: (1) B and T cells, (2) central and peripheral cells, and (3) resting and activated cells. The findings suggested that cell density is determined by cell lineage the degree of differentiation and the stage of functional activation. Marked differences in the density distribution profiles were also observed among certain types of morphologically distinguishable lymphoproliferations. To some extent density analyses enabled the discrimination between CLL, follicular lymphomas and lymphoblastic lymphomas as well as between O-ALL and T-ALL. Density profiles of malignant lymphocytes failed to disclose any features specific for malignancies. But they revealed some similarities with distinct subsets of normal lymphocytes, i.e. between: (1) CLL and bone marrow lymphoid cells, (2) follicular lymphomas and follicular centre cells, and (3) lymphoblastic lymphomas and activated lymphocytes. These findings are further evidence supporting the hypothesis that the malignant transformation of phenotypically different lymphoproliferations takes place at different levels of lymphocyte differentiation.

B-Lymphocytes↗

PubMed1989

Microvascular distribution in normal human synovium.

The distribution of vessels in normal human synovium has been investigated using frozen sections and staining with Ulex Europaeus lectin by an indirect immunoperoxidase technique. The presence of a vascular net close to the tissue surface was confirmed. Quantitative analysis showed the majority of vessel profiles to be small venules with a peak density 25-100 microns beneath the tissue surface. A smaller number of capillaries was present with a peak density within 25 microns of the tissue surface. It is suggested that important functions of the numerous venules seen in synovium may include the provision of a source of fresh monocytes to replace surface macrophages and provision of nutrients for the surface layer of cells as a whole, and that the density of the vascular net may reflect angiogenic signals from this cell layer.

Anthropometry↗

PubMed1983

Intrauterine growth retardation detected in several species by non-normal birthweight distributions.

The statistical distribution of birthweights in 64 litters of pigs, 48 litters of dogs, 59 litters of rabbits, 130 litters of rats and 46 litters of mice was examined. Birthweight followed a Gaussian or normal distribution in about two-thirds of the litters inspected, as judged visually using a normal probability plot, and by the W-test statistic. In the remainder, a single outlying observation in an otherwise normal sample was detected by Dixon's test, and/or a separate sub-population of low birthweight animals could be identified by fitting two normal populations to the observed samples. In the non-Gaussian litters, the average proportion of affected members was 40% of the litter. These results suggest that growth-retarded neonates should not be regarded simply as the tail-end of a normal distribution.

Animals↗