Morphometric assessment of spleen dimensions and its determinants among individuals living in Arba Minch town, southern Ethiopia.

INTRODUCTION: The spleen is a vital lymphoid soft organ that demands constant attention from the clinical point of view. It is a multi-dimensional organ that enlarges in its all dimensions during some disease condition. The detection of the spleen by palpation is not an indicator of an enlarged spleen because normal spleen may be palpable. Therefore, this study aimed to assess the morphometry of spleen dimensions and its determinants among individuals living in Arba Minch town by sonographic examinations. METHODS AND MATERIALS: Community-based cross-sectional study was conducted in Arba Minch town from February 1 to March 30, 2020. Seven hundred and eight study participants were selected using a multi-stage systematic random sampling technique. Data were checked for completeness, edited, coded and entered into Epi-Data version 3.1 and exported to STATA software version 16 for analysis. RESULT: The mean splenic length, width, thickness and volume were 10.24 cm, 4.79 cm, 3.93 cm, and 109.34 cm3, respectively. The mean spleen length, width, thickness and volumes among males were 10.64 cm, 4.92 cm, 4.05 cm and 119.81 cm3 and among females were 9.75 cm, 4.63 cm, 3.78 cm and 96.50 cm3 respectively. As age increased by one year the mean spleen length, width, thickness and volume was decreased by 0.032 cm, 0.018 cm 0.004 cm and 0.012 cm respectively. As height increased by 1 cm the mean spleen width and volume were increased by 0.096 cm and 0.052 cm respectively. As we go from male to female the mean spleen length decreased by 0.294 cm. CONCLUSION: The spleen dimensions were higher in males than females. Splenic length was determined by age & sex, the spleen width was determined by age & height, the spleen volume was determined by age & height and the spleen thickness was determined by age.

Validation of 2d ultrasound and volume estimation formulae for volume assessment of kidneys and spleens: an in-vitro study / alidación de la fórmula de estimación de volumen y ultrasonido 2D para la evaluación del volumen de los riñones y el bazo: un estudio in vitro

The accuracy of internal organ volume estimation done with ultrasound (US) was found to be multifactorial. Hence, we aimed to describe and validate the volume assessment of ultrasound and standard volume estimation formulae for different shaped intra-abdominal organs using spleens and kidneys.Dissected cadaveric kidneys (n=25) and spleens (n=29) were scanned to obtain linear measurements and ultrasound auto-generated volumes (USV). Linear measurements were used to calculate the volumes manually with ellipsoid, prolate, and Lambert volume estimating formulae. The actual volumes (AV) of organs were obtained by the water displacement method. Volume assessment accuracy of USV and different formulae were compared by comparing bias, precision and Bland-Altman plot analysis. The US linear and volume measurement procedure was reliable with high inter and intra-observer agreements (linear: Chronbach's α=0.983 to 0.934; volumes: Chronbach's α=0.989). USV estimates were accurate with a high correlation to AV and low estimation bias (-5.9%). Also, prolate (bias=-0.75%) and ellipsoid formulae (bias=-3.75%) were reliable with a negligible bias in estimated volumes. Contrary, the Lambert formula was unreliable due to a high bias (41.6%). For all evaluated methods, the estimation error found to be related to the organ size (T=3.483; p=0.001), mainly when the assessed organ is larger than 50 ml. Also, the shape related estimation error found to be related to the volume estimation formula used.This study has validated the USV for kidney and splenic volume assessments while describing volume-calculating formula employed, organ size and shape as significant contributors for volume estimation accuracy.

Se encontró que la precisión de la estimación del volumen de órganos internos realizada con ultrasonido (US) es multifactorial. El objetivo fue describir y validar la evaluación de volumen mediante ecografía y las fórmulas estándar de estimación de volumen para órganos intraabdominales de diferentes formas utilizando bazos y riñones.Se evaluaron riñones cadavéricos disecados (n = 25) y bazos (n = 29) para obtener medidas lineales y volúmenes autogenerados por ultrasonido (USV). Se utilizaron medidas lineales para calcular los volúmenes manualmente con fórmulas de estimación de volumen elipsoide, prolate y Lambert. Los volúmenes reales (AV) de los órganos se obtuvieron mediante el método de desplazamiento de agua. Se comparó la precisión de la evaluación del volumen de USV y diferentes fórmulas comparando el sesgo, la precisión y el análisis de la gráfica de Bland-Altman. El procedimiento de medición lineal y de volumen mediante US fue confiable con alta concordancia inter e intraobservadores (lineal: α de Chronbach = 0,983 a 0,934; volúmenes: α de Chronbach = 0,989). Las estimaciones de USV fueron precisas con una alta correlación con AV y un bajo sesgo de estimación (-5,9%). Además, las fórmulas prolate (sesgo= -0,75%) y elipsoide (sesgo = -3,75%) fueron confiables con un sesgo insignificante en los volúmenes estimados. Por el contrario, la fórmula de Lambert no fue confiable debido a un alto sesgo (41,6%). Para todos los métodos evaluados, se encontró que el error de estimación estaba relacionado con el tamaño del órgano (T = 3.483; p = 0.001), principalmente cuando el órgano evaluado es mayor de 50 ml. Además, se encontró que el error de estimación de forma está relacionado con la fórmula de estimación de volumen utilizada.Este estudio ha validado el USV para evaluaciones de volumen renal y esplénico al mismo tiempo que describe la fórmula de cálculo de volumen empleada, el tamaño y la forma de los órganos como contribuyentes significativos de la precisión de la estimación de volumen.

Safety of natural anthraquinone emodin: an assessment in mice.

BACKGROUND: Emodin, a natural anthraquinone, has shown potential as an effective therapeutic agent in the treatment of many diseases including cancer. However, its clinical development is hindered by uncertainties surrounding its potential toxicity. The primary purpose of this study was to uncover any potential toxic properties of emodin in mice at doses that have been shown to have efficacy in our cancer studies. In addition, we sought to assess the time course of emodin clearance when administered both intraperitoneally (I.P.) and orally (P.O.) in order to begin to establish effective dosing intervals. METHODS: We performed a subchronic (12 week) toxicity study using 3 different doses of emodin (~ 20 mg/kg, 40 mg/kg, and 80 mg/kg) infused into the AIN-76A diet of male and female C57BL/6 mice (n = 5/group/sex). Body weight and composition were assessed following the 12-week feeding regime. Tissues were harvested and assessed for gross pathological changes and blood was collected for a complete blood count and evaluation of alanine transaminase (ALT), aspartate transaminase (AST) and creatinine. For the pharmacokinetic study, emodin was delivered intraperitoneally I.P. or P.O. at 20 mg/kg or 40 mg/kg doses to male and female mice (n = 4/group/sex/time-point) and circulating levels of emodin were determined at 1, 4 and 12 h following administration via liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis. RESULTS: We found that 12 weeks of low (20 mg/kg), medium (40 mg/kg), or high (80 mg/kg) emodin feeding did not cause pathophysiological perturbations in major organs. We also found that glucuronidated emodin peaks at 1 h for both I.P. and P.O. administered emodin and is eliminated by 12 h. Interestingly, female mice appear to metabolize emodin at a faster rate than male mice as evidenced by greater levels of glucuronidated emodin at the 1 h time-point (40 mg/kg for both I.P. and P.O. and 20 mg/kg I.P.) and the 4-h time-point (20 mg/kg I.P.). CONCLUSIONS: In summary, our studies establish that 1) emodin is safe for use in both male and female mice when given at 20, 40, and 80 mg/kg doses for 12 weeks and 2) sex differences should be considered when establishing dosing intervals for emodin treatment.

Ultrasound assessment of normal liver, spleen, and kidney dimensions in southwest Nigerian children: a bedside formula for sonologists.

BACKGROUND: Knowledge of the normal sizes of the liver, spleen, and kidneys is important to radiologists when assessing for pathology using ultrasound scan. The need for a local determination of a easy-to-use formula for estimating the expected normal sonographic dimensions of these organs in children in order to serve as baseline when assessing them for pathology cannot be over emphasized. PURPOSE: To determine ultrasonographic sizes of the liver, spleen, and kidneys among primary school children in southwestern Nigeria and correlate these with anthropometric measures to provide local reference data and an easy-to-use formula for assessing these organs for pathology in clinical practice. MATERIAL AND METHODS: This is an observational, cross-sectional study using 1000 public primary school children in Ogbomoso. Sonographic dimensions of their liver, spleen, and both kidneys with anthropometric parameters were obtained and correlated. Data were analyzed using SPSS version 20. RESULTS: The liver span was higher in boys than in girls (P = 0.048) while the left lobe of the liver was higher in girls than in boys (P = 0.003). The spleen length was higher in boys than in girls (P = 0.011). There was no gender difference in kidney dimensions (P > 0.05). All anthropometric measures correlated significantly (P < 0.001) with organ dimensions. Body surface area is the strongest predictor of the liver and kidney sizes (P < 0.001) and height for spleen size (P < 0.001). CONCLUSION: Nomograms for the liver, spleen, and kidneys and regression equations for estimating the dimensions of these organs were formulated based on the best multivariate correlates.

Sonographic assessment of liver and spleen size based on age, height, and weight: evaluation of Jordanian children.

BACKGROUND: The growth of the liver and spleen is a dynamic process in children, and is related to the somatic parameters of the child, and may be affected by many diseases in children. It is of paramount importance to have standard reference values for the size of these organs for diagnostic and prognostic purposes. The aim of our study was to provide practical and reliable normal reference values for the size of the liver and spleen in children and to correlate the values with age, height, and weight. METHODS: Three hundred fifteen children (142 boys and 173 girls) were prospectively examined by ultrasound due to problems unrelated to the liver or spleen. All of the subjects had normal sonographic appearance of their organs. The ages of the subjects ranged from newborns to 14 years. The liver and spleen size was correlated with age, height, and weight. The spleen size was compared with previous internationally published data. RESULTS: There was no statistical significant difference in the size of the liver and spleen between boys and girls (P>0.05). There was steady increase in the size of the liver and spleen, with good correlation with age and all the somatic parameters. The spleen size was in close proximity to those previously reported in the literature. CONCLUSIONS: Standard spleen and liver size reference values were obtained by ultrasound for Jordanian children and were in concordance with international values.

Variability of Spleen and Mesenteric Lymph Node in Control Cynomolgus Monkeys ( Macaca fascicularis) from Nonclinical Safety Studies: A Retrospective Assessment.

We assessed the variability of spleen and mesenteric lymph node (MLN) microscopic observations and the correlations of these observations with other study data from 478 control cynomolgus monkeys from 53 routine nonclinical safety studies. Spleen weight parameters (absolute and relative to body or brain weights) were highly variable both within a control group on an individual study (up to 5.11-fold) and among animals with the same light microscopic observation. Grades for microscopic observations were also highly variable. The most frequent microscopic observations for spleen were changes in the size and number of germinal centers (58%), acidophilic (hyaline) material in lymphoid follicles (52%), and compound lymphoid follicles (20%). The most frequent microscopic observations in the MLN were eosinophil infiltrates (90%), changes in size and number of germinal centers (42%), and brown pigment (21%). The only meaningful relationships ( r2 > 0.3) were positive correlations between reticuloendothelial hyperplasia and malarial pigment in the spleen and between each of these observations and spleen weight parameters. We conclude that determination of test article-related effects on the immune system in routine monkey toxicology studies requires careful consideration and a weight-of-evidence approach due to the low numbers of animals/group, the inherent variability in spleen and MLN parameters, and the infrequent correlation among immune system-related end points.

Smaller size of high metabolic rate organs explains lower resting energy expenditure in Asian-Indian Than Chinese men.

BACKGROUND: In Singapore, the obesity prevalence is disproportionately higher in the Asian-Indians and Malays than the Chinese. Lower resting energy expenditure (REE) may be a contributory factor. OBJECTIVE: We explored the association between ethnicity and REE in Chinese, Asian-Indian and Malay men living in Singapore and determined the influence of body composition, mass/volume of high metabolic rate organs, represented by brain volume and trunk fat-free mass (FFM), and physical activity on ethnic differences. DESIGN: Two hundred and forty-four men from Singapore (n=100 Chinese, 70 Asian-Indians and 74 Malays), aged 21-40 years and body mass index of 18.5-30.0 kg m(-2), were recruited in this cross-sectional study. REE was assessed by indirect calorimetry and body composition by dual-energy X-ray absorptiometry. Brain volume was measured by magnetic resonance imaging. Physical activity was assessed by the Singapore Prospective Study Program Physical Activity Questionnaire. RESULTS: REE was significantly lower in Asian-Indians compared with that in Chinese after adjusting for body weight. FFM (total, trunk and limb) and total fat mass were important predictors of REE across all ethnic groups. Brain volume was positively associated with REE only in Malays. Moderate and vigorous physical activity was positively associated with REE only in Asian-Indians and Malays. The difference in REE between Asian-Indians and Chinese was attenuated but remained statistically significant after adjustment for total FFM (59±20 kcal per day), fat mass (67±20 kcal per day) and brain volume (54±22 kcal per day). The association between REE and ethnicity was no longer statistically significant after total FFM was replaced by trunk FFM (which includes heart, liver, kidney and spleen) but not when it was replaced by limb FFM (skeletal muscle). CONCLUSIONS: We have demonstrated a lower REE in Asian-Indians compared with Chinese who may contribute to the higher rates of obesity in the former. This difference could be accounted for by differences in metabolically active organs.

Ultrasonographic assessment of splenic volume and its correlation with body parameters in a Jordanian population.

OBJECTIVES: To estimate normal linear dimensions and volume of spleen in Jordanians using ultrasonography, and to correlate splenic volume with age and body parameters: height, weight, body surface area (BSA), and body mass index (BMI). METHODS: A prospective pilot study was conducted on 205 volunteers (115 males and 90 females) not known to have any conditions likely to be associated with splenomegaly. The study was performed at the Radiology Department, Jordanian University Hospital, Amman, Jordan, between December 2013 and August 2014. All linear dimensions of spleen were measured, and splenic volume (index) was calculated using the standard prolate ellipsoid formula (length × width × depth × 0.523). The splenic volume was then analyzed with age and body parameters using the Pearson's correlation coefficient. RESULTS: The mean (± SD) splenic dimensions were 10.72±1.37 cm in length, 7.40±1.52 cm in width, 4.40±1.47 cm in depth, and 184.15±79.56 cm3 in volume. Men had larger spleens than women (p less than 0.0001). Age had no significant effect on spleen volume (r=0.11, p=0.12). There was a significant moderate positive correlation (p less than 0.0001), using Pearson's correlation coefficient, between the spleen volume, and other parameters (height, weight, BSA, and BMI), with correlation coefficients exceeding 0.3. CONCLUSION: A local reference of spleen dimensions was established with a different range of values reported previously.

Carcinogenicity assessment of the pan-caspase inhibitor, emricasan, in Tg.rasH2 mice.

Emricasan, formerly IDN-6556, is a small molecule currently being evaluated in clinical trials to reduce hepatic injury and liver fibrosis. Since emricasan is an irreversible pan-caspase inhibitor that potently inhibits caspase-mediated apoptosis and inflammation, its carcinogenic potential was evaluated in a humanized mouse model. Tg.rasH2 mice received LabDiet formulated with 0, 10, 25, and 75mg/kg/day of emricasan, for 26weeks. At terminal sacrifice, blood was collected for clinical pathology analysis and tissues were collected, processed, and evaluated microscopically. There were no treatment related deaths or overt signs of toxicity for the duration of the study. There was no evidence of a carcinogenic effect in the peripheral blood leukocyte counts. Liver microgranulomas, which are background lesions, were slightly increased, especially in males. Increases in the incidence of the activated germinal centers were seen in the spleens and mesenteric lymph nodes of males and females, and in the mandibular lymph nodes of male mice. Atrophy of ovaries and testicular degeneration were also seen in emricasan treated animals. Although several non-neoplastic lesions were observed, there was no evidence of emricasan-related tumor formation in any tissue. In addition, the non-neoplastic lesions were not considered pre-neoplastic. Thus, emricasan is not considered carcinogenic.

Sonographic Assessment of the Normal Dimensions of Liver, Spleen, and Kidney in Healthy Children at Tertiary Care Hospital.

Background Ultrasonography is one of the most common imaging modality to measure dimensions of visceral organs in children. However, the normal limit of size of visceral organs according to age and body habitus has not been specified in the standard textbooks. This might result in under detection of organomegaly in pediatrics population. Objective The objective of this study was to determine the normal range of dimensions for the liver, spleen, and kidney in healthy children. Method This is prospective cross-sectional, hospital-based study done at Tertiary-care teaching hospital. Participants included 272 pediatric subjects (152 male and 120 female) with normal physical or sonographic findings who were examined because of problems unrelated to the measured organs. The subjects were one month to 15 year (180 months) old. All measured organs were sonographically normal. Relationships of the dimensions of these organs with sex, age, body weight and height were investigated. Limits of normal dimensions of these organs were defined. Result Normal length of liver, kidneys and spleen were obtained sonographically for 272 children (152 male [55.9%] and 120 female [44.1%]) in the age group from 1 months to 15 (180 months) years. The mean age was 45.78 months (SD, 44.73). The measured dimensions of all these organs showed highest correlation with height and age so the descriptive analysis of the organ dimensions (mean, minimum, and maximum values, SD and 5th and 95th percentiles) were expressed in 10 age groups along with height range of the included children. The mean length of right kidney was shorter than the left kidney length, and the difference was statistically significant (p = 0.001). Conclusion This study provides practical and comprehensive guide to the normal visceral organ dimension in pediatric population. The normal range limit of the liver, spleen, and kidney determined in this study could be used as a reference in daily practice in local radiology clinics.

Assessment of toxicological effects of blood microsampling in the vehicle dosed adult rat.

UNLABELLED: Historically, satellite groups are often used for rodent toxicokinetic profiling because of the haematological consequences of blood sampling. If microsampling is shown to be toxicologically benign, its adoption in rat studies would enable comparison of exposure and toxicity in individual animals (as happens in non-rodent studies) as well as obviating need for satellite groups. METHODS: Groups of 10 male (200-300g) and female (150-250g) rats aged 10weeks were vehicle dosed and either left unsampled, conventional blood volume sampled (6×200µL) or microsampled (6×32µL) on Days 1 and 14. At termination on Day 15, clinical pathology plus liver and spleen weights and histopathology were obtained. RESULTS: All clinical pathology parameters were within background range. However, compared to unsampled controls, conventional volume sampled rats showed a statistically significant (p<0.001) decrease in haemaglobin, haematocrit and red blood cell count, an increase in reticulocytes (at least p<0.01), increased AST and GLDH and, in males only, an increase in monocytes and neutrophils. In contrast, microsampled animals showed no changes except for a slight, toxicologically insignificant decrease in haemoglobin concentration (15.0g/dL compared to the unsampled group mean of 14.4g/dL) in females (p<0.05) and a small increase in monocytes (p<0.05) in males. CONCLUSION: Microsampling of adult rats is possible without adverse toxicological consequences.

Ultrasonographic assessment of the spleen in 60 healthy sheep.

AIM: To evaluate the sonographic appearance, size, location and shape of the spleen in 60 healthy sheep. METHODS: A 7.5 MHz linear scanner was used to examine the location, extent and appearance of the spleen from the left side of the sheep, in intercostal spaces (ICS) 8-12 and caudal of the last rib. RESULTS: The ultrasonographic appearance of the splenic parenchyma was homogeneous with a thin, smooth echogenic capsule. The spleen could be visualized in intercostal spaces 9-12 in all sheep, in intercostal space 8 in 25/60 sheep (42%) and caudal of the last rib in 24/60 sheep (40%). In intercostal spaces 8-12 and caudal of the last rib the spleen was visible in 16/60 sheep (27 %). The distance from the dorsal margin of the spleen to the spinous processes of the thoracic vertebrae was greatest in the 8th intercostal space: mean 19.32 (SD 2.76) cm and smallest in the 12th intercostal space: mean 6.61 (SD 1.94) cm. The dorsoventral splenic extent was greatest in the 11th intercostal space: mean 13.69 (SD 2.2) cm and smallest in the 8th intercostal space: mean 7.13 (SD 2.5) cm. The thickness of the spleen ranged from 21 (SD 9.0) mm in the 8th intercostal space to 49 (SD 7.0) mm in the 11th intercostal space. The mean vessel diameter was 1.9 (SD 0.7) mm. Spleen size did not correlate with age, body weight, or thoracic and abdominal circumference. CONCLUSIONS: Ultrasonography is a useful, straightforward and non-invasive method for evaluation of the spleen in sheep. CLINICAL RELEVANCE: These findings provide information which can be used as a reference for sonographic spleen examination and diagnosis of splenic lesions in sheep.

Brain and high metabolic rate organ mass: contributions to resting energy expenditure beyond fat-free mass.

BACKGROUND: The degree to which interindividual variation in the mass of select high metabolic rate organs (HMROs) mediates variability in resting energy expenditure (REE) is unknown. OBJECTIVE: The objective was to investigate how much REE variability is explained by differences in HMRO mass in adults and whether age, sex, and race independently predict REE after adjustment for HMRO. DESIGN: A cross-sectional evaluation of 55 women [30 African Americans aged 48.7 +/- 22.2 y (mean +/- SD) and 25 whites aged 46.4 +/- 17.7 y] and 32 men (8 African Americans aged 34.3 +/- 18.2 y and 24 whites aged 51.3 +/- 20.6 y) was conducted. Liver, kidney, spleen, heart, and brain masses were measured by magnetic resonance imaging, and fat and fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry. REE was measured by indirect calorimetry. RESULTS: REE estimated from age (P = 0.001), race (P = 0.006), sex (P = 0.31), fat (P = 0.001), and FFM (P < 0.001) accounted for 70% (adjusted (2)) of the variability in REE. The addition of trunk HMRO (P = 0.001) and brain (P = 0.006) to the model increased the explained variance to 75% and rendered the contributions of age, sex, and race statistically nonsignificant, whereas fat and FFM continued to make significant contributions (both P < 0.05). The addition of brain to the model rendered the intercept (69 kcal . kg(-1) . d(-1)) consistent with zero, which indicated zero REE for zero body mass. CONCLUSIONS: Relatively small interindividual variation in HMRO mass significantly affects REE and reduces the role of age, race, and sex in explaining REE. Decreases in REE with increasing age may be partly related to age-associated changes in the relative size of FFM components.

An assessment of the accuracy of hepatic and splenic size based upon a clinician's physical examination, a radiologist's impression and the actual liver and spleen volumes calculated by CT scanning.

OBJECTIVES: In this study, a radiologist's impression of liver and spleen size based on computed tomography (CT) images, calculated liver and spleen volumes as determined radiologically, and findings of a hepatologist were compared. METHODS: One hundred and ninety-four consecutive subjects seen by a hepatologist were evaluated clinically and radiologically. Liver and spleen volumes were calculated based on CT images and compared to radiologist's impression and to expected liver volume based on body weight. Covariate analysis was used to determine the relationships between different variables, and a value of P < 0.05 was considered to be significant. RESULTS: Liver volume calculated on the basis of CT scans correlated to liver size based on the hepatologist's clinical exam but not to the radiologist's impression of liver size. In contrast, spleen volume based on CT scans, splenic size based upon radiologist's impression, and clinician's assessment all correlated well. CONCLUSIONS: A variety of biases determine and/or affect the radiologist's assessment of liver size but not of splenic size.

Assessment of rabbit spleen size using ultrasonography.

Assessment of spleen size using the ultrasonography has become a standard practice in human. However, the assessment is not established method in experimental animals. To establish the index to assess the spleen size using ultrasonography, we measured the cross-section image of rabbit spleen during endotoxin shock. The image of the cross-section was appeared as triangle, and the height of the triangular image was defined as the spleen index. This spleen index showed strong correlation with the spleen weight. In conclusion, this method is suitable for observation of changes in rabbit spleen size and may reduce the number of rabbit in the longitudinal studies.

Effects of altitude on spleen volume: sonographic assessment.

PURPOSE: To use sonography to determine changes that may arise in splenic volume in humans from regions of lower altitude who begin to live in regions of higher altitude. MATERIALS AND METHODS: The study was conducted in the Turkish province of Agri, at an altitude of 1750 m and included 108 healthy, nonsmoking, disease-free volunteers who had moved from regions at an altitude lower than 500 m. Length, width, and thickness of the spleen were measured using sonography. Splenic volume was calculated using the following standard ellipsoid formula: length x width x thickness x 0.523. Sonographic assessments were repeated at 3 and 6 months along with other blood tests, including hemoglobin, hematocrit, and platelet levels. RESULTS: The mean +/- SD splenic volume was 299 +/- 97 cm(3) (range, 116-574 cm(3)). At 3 and 6 months, the splenic volumes decreased significantly compared to their initial values (p < 0.05). An increase in hemoglobin, hematocrit, and platelet count was observed in all subjects. CONCLUSION: Our data show that splenic volume in healthy individuals who begins to live at high altitudes decreases gradually.

Small organs with a high metabolic rate explain lower resting energy expenditure in African American than in white adults.

BACKGROUND: African Americans have a lower resting energy expenditure (REE) relative to fat-free mass (FFM) than do whites. Whether the composition of FFM at the organ-tissue level differs between African Americans and whites and, if so, whether that difference could account for differences by race in REE are unknown. OBJECTIVE: The objectives were to quantify FFM in vivo in women and men at the organ-tissue level and to ascertain whether the mass of specific high-metabolic-rate organs and tissues differs between African Americans and whites and, if so, whether that difference can account for differences in REE. DESIGN: The study was a cross-sectional evaluation of 64 women (n = 34 African Americans, 30 whites) and 35 men (n = 8 African Americans, 27 whites). Magnetic resonance imaging measures of liver, kidney, heart, spleen, brain, skeletal muscle, and adipose tissue and dual-energy X-ray absorptiometry measures of fat and FFM were acquired. REE was measured by using indirect calorimetry. RESULTS: The mass of selected high-metabolic-rate organs (sum of liver, heart, spleen, kidneys, and brain) after adjustment for fat, FFM, sex, and age was significantly (P < 0.001) smaller in African Americans than in whites (3.1 and 3.4 kg, respectively; x +/- SEE difference: 0.30 +/- 0.06 kg). In a multiple regression analysis with fat, FFM, sex, age, and race as predictors of REE, the addition of the total mass rendered race nonsignificant. CONCLUSIONS: Racial differences in REE were reduced by >50% and were no longer significant when the mass of specific high-metabolic-rate organs was considered. Differences in FFM composition may be responsible for the reported REE differences.

Ultrasound assessment of spleen size in collegiate athletes.

OBJECTIVES: To determine normal spleen dimensions in a healthy collegiate athletic population. METHODS: 631 Division I collegiate athletes from one university participated in the study. During pre-participation examinations, demographic data collected were collected from volunteer athletes including sex, race, measurement of height and weight, and age. Subjects also completed a medical history form to determine any history of mononucleosis infection, platelet disorder, sickle cell disease (or trait), thalassaemia, or recent viral symptoms. Subjects then underwent a limited abdominal ultrasound examination, where splenic length and width were recorded. RESULTS: Mean (SD) splenic length was 10.65 (1.55) cm and width, 5.16 (1.21) cm. Men had larger spleens than women (p<0.001). White subjects had larger spleens than African-American subjects (p<0.001). A previous history of infectious mononucleosis or the presence of recent cold symptoms had no significant affect on spleen size. In more than 7% of athletes, baseline spleen size met current criteria for splenomegaly. CONCLUSIONS: There is a wide range of normal spleen size among collegiate athletes. Average spleen size was larger in men and white athletes than in women and black athletes. A single ultrasound examination for determination of splenomegaly is of limited value in this population.

Sonographic assessment of the normal limits and percentile curves of liver, spleen, and kidney dimensions in healthy school-aged children.

OBJECTIVE: The purpose of this study was to determine the normal standards of liver, spleen, and kidney dimensions and the relationship of each with sex, age, body weight, height, body mass index, and body surface area in healthy school-aged children. METHODS: Seven hundred twelve healthy school-aged children (7-15 years) in 2 neighboring cities, including rural areas and city centers, were evaluated prospectively. Sex, age, weight, height, body mass index, and body surface area were determined for each case. Organ dimensions were measured 3 times, and the mean values were recorded. All measured organs had a normal position, shape, and echo texture. The children were separated into 5 groups according to body weight. RESULTS: There were no significant differences in organ dimensions with respect to sex (P > .05). The mean right kidney length was shorter than the left kidney length, and the difference was significant (P = .009). Body weight showed the best correlation with liver, spleen, and kidney dimensions. The results were also supported by the variance and covariance of the correlation coefficients. CONCLUSIONS: The normal limits of the liver, spleen, and kidneys are important parameters during a sonographic examination. This study revealed that organ dimensions showed the best correlation with body weight. To our knowledge, in clinical practice there are no pediatric organ dimension percentile graphs for interpretation of sonographic examinations. We hope this study contributes to daily practice in radiology clinics.