Geometric morphometric study of population variation in indigenous southern African crania

Much of our understanding of population variation in southern Africa is derived from traditional morphometric research. In the search for new perspectives, this paper reports on new geometric morphometric data examining cranial variation in 12 modern human populations from southern Africa. In total, 298 male Bantu-speaking individuals were studied. In addition, a small Khoisan (Khoikhoi and San) series was also examined. The purpose of this study was to investigate Khoisan-Bantu morphological similarities and differences, and to examine variation within both the Bantu-speaking and Khoisan populations. The three-dimensional coordinates of 96 landmarks were analyzed, using the shape-analysis software morphologika. Interpopulation variation was examined by calculating Procrustes distances between groups; a cluster analysis was then used to summarize phenetic relationships. A principal components analysis explored the relationships between populations; shape differences were visualized and explored using three-dimensional rendered models, and further interpreted using thin-plate splines. Morphological differences are present within and between the crania of Bantu-speaking and Khoisan individuals. The Khoisan demonstrate features (e.g., a pentagonoid vault, more rounded forehead contour, and a small and less prognathic face) that clearly distinguish them from Bantu-speaking populations. Although southern African Bantu-speaking populations are clearly closely related, they show population-specific features (e.g., the crania of more southerly populations (Xhosa, Southern Sotho, and Zulu) are characteristically more brachycephalic and less prognathic). This study suggests that differential admixture with adjacent Khoisan peoples has contributed to diversity within southern African Bantu-speaking populations.

Flattening of the interventricular septum (D-shaped left ventricle) in addition to high right ventricular tracer uptake and increased right ventricular volume found on gated SPECT studies strongly correlates with right ventricular overload

BACKGROUND

Flattening of the interventricular septum (D-shaped left ventricle) detected during echocardiographic examination is correlated with significant right ventricular (RV) overload. There are no reports of this finding with cardiac gated single photon emission computed tomography (SPECT) imaging. We report an observational study correlating this finding with the presence of RV overload.

METHODS AND RESULTS

Retrospectively, we compared 8 cases with flattening of the interventricular septum on cardiac gated SPECT imaging for which echocardiographic correlations and clinical data were available regarding the presence of RV overload. All patients but 1 had pulmonary hypertension ranging from 42 to 52 mm Hg measured by echocardiographic Doppler studies. All patients but 1 had reasons for RV overload (chronic obstructive pulmonary disease in 3, history of atrial septal defect in 3, pulmonary embolism in 1, and obstructive sleep apnea in 1). Septal flattening present on gated SPECT images was seen in 50% of the cases by echocardiography. Other signs of RV overload (RV enlargement, RV hypertrophy) were observed by echocardiography in 5 patients and by the gated SPECT in 7 patients.

CONCLUSION

The presence of interventricular septal flattening on gated SPECT studies correlates with RV overload and should be routinely assessed during interpretation of gated SPECT studies.

Sexual dimorphism and discriminant function sexing in indigenous South African crania

This study aimed to examine sexual dimorphism in, and to produce a practical discriminant function for determining the sex of indigenous, Bantu-speaking, South African crania. The types of data to be used were a small number of traditional, or mathematically transformed three-dimensional, linear measurements, comparable to those in use by most physical and forensic anthropologists. The samples to be examined, separately and pooled, were of the Cape Nguni, Natal Nguni and Sotho subgroups. In addition, three local populations ('tribes'--Zulu, Xhosa and Southern Sotho) within these subgroups were also studied. Univariate male/female ratios indicate significant sexual dimorphism in the pooled South African crania. Canonical variates analysis of the pooled sample showed that facial width is the strongest discriminating morphometric variable; cranial length and basi-bregmatic height are the next most significant features. Eight measurements derived from the three-dimensional data were used to produce a series of discriminant functions for sex determination in the pooled sample, for which an accuracy of 77-80% was attained. Analysis of the calvaria and face, separately, has shown that the sex of damaged material can be diagnosed with a reasonable degree of accuracy (75-76%). The new functions for the pooled indigenous South African sample provide improved sex discrimination accuracy compared to those obtained by employing the commonly utilised statistics of Giles & Elliot (1963), even when a modified sectioning point is used. Functions calculated for the separate local populations gave variable and fairly low improvements in sexing accuracy. As the subdivisions at all levels are at present quite rapidly disappearing in South Africa, for most purposes it is now best to simply apply the pooled data functions for sexing crania.

Three-dimensional technology for linear morphological studies: a re-examination of cranial variation in four southern African indigenous populations

In order to compare linear dimensions made by traditional anthropometric techniques, and those obtained from three-dimensional coordinates, samples of four indigenous southern African populations were analysed. Linear measurements were obtained using mathematically transformed, three-dimensional landmark data on 207 male crania of Cape Nguni, Natal Nguni, Sotho and Shangaan. Univariate comparisons for accuracy of the transformed linear data were made with those in a traditional linear study by de Villiers (The Skull of the South African Negro: A Biometrical and Morphological Study. Witwatersrand University Press, Johannesburg) on similar samples and equivalent landmarks. Comparisons were not made with her Penrose (Ann Eugenics 18 (1954) 337) analysis as an apparently anomalous 'shape'-'size' statistic was found. The univariate comparisons demonstrated that accurate linear measurements could be derived from three-dimensional data, showing that it is possible to simultaneously obtain data for three-dimensional geometric 'shape' and linear interlandmark analyses. Using Penrose and canonical variates analyses of the transformed three-dimensional interlandmark measurements, similar population distances were found for the four indigenous southern African populations. The inter-population distance relationships took the form of three separated pairs of distances, with the within-pair distances very similar in size. The cranial features of the four populations were found to be overall very similar morphometrically. However the populations were each shown by CVA to have population specific features, and using discriminant analyses 50% or more of the individual crania (with the exception of the Sotho) could be referred to their correct populations.

Factors affecting the quantitative liver-spleen scan in normal individuals

The quantitative liver-spleen scan (QLSS) can estimate the functional hepatic mass and the organ volumes by precise measurement of sulfur colloid (SC) distribution. The normal range determined in prior studies was estimated from patients with absence of chronic liver disease in which intense fasting appeared to produce slightly abnormal values. This study was to determine the effect of fasting or fed status and colloid particle size on quantitative measurements from the QLSS in a small cohort of normal individuals. Twelve persons without any medical problems had QLSS taken twice, 2 weeks apart, one fasting and one postprandial. Patients were scanned after injection of 5-6 mCi of SC; six patients were given solution A (5- to 12-microm particle size) and six patients solution B (2- to 12-microm particle size). SPECT and planar analysis were performed. SC distribution of total counts between the liver and the spleen {[L/(L + S)]t ratio}, liver-spleen index (LSI), and liver-bone marrow index (LBI) were calculated. The perfused hepatic mass (PHM) is the average of the LSI and LBI. Spleen and liver volumes are expressed as milliliters per pound ideal body weight (IBW). Results showed that the liver and spleen volumes (solution B postprandial, 9.27 +/- 2.48 and 1.47 +/- 0.57 ml/lb IBW, respectively) and LBI were not affected by the type of SC solution or by ingestion status. L/(L + S) total and pixel count ratios were significantly higher for solution B and postprandial studies. [L/(L + S)]t, LSI, and PHM increased significantly (P < 0.05) from fasting to postprandial for solution A (0.71 +/- 0.13 vs 0.79 +/- 0.08, 80 +/- 14 vs 91 +/- 8, and 102 +/- 10 vs 106 +/- 8, respectively) and for solution B (0.81 +/- 0.05 vs 0.90 +/- 0.02, 86 +/- 4 vs 95 +/- 3, and 101 +/- 5 vs 110 +/- 3). Neither fasting nor postprandial LSI and PHM were significantly different between solution A and solution B. We conclude the following. (1) The QLSS functional indices in "true" normal patients fall within the previously reported normal range. (2) Calculated liver and spleen volumes are not altered by fasting or sulfur colloid particle size. (3) Fasting significantly decreased the [L/(L + S)]t, LSI, and PHM. (4) A postprandial scan may be preferable since the normal values for [L/(L + S)]t, LSI, and PHM are greater, with a narrower range, than fasting values.

Use of Yttrium-90 TheraSphere for the treatment of unresectable hepatocellular carcinoma

This is a retrospective analysis of a new treatment modality, intra-arterial administration of Yttrium-90 TheraSphere, for unresectable hepatocellular carcinoma (HCC). Patients with HCC not amenable to surgical treatment who had satisfactory physiological function without comorbid disease or significant pulmonary shunting were eligible for treatment. Patients were categorized into complete, partial, or no response based on serum alpha-fetoprotein (AFP) levels and CT or MRI imaging. Fourteen patients were considered candidates for treatment. Three patients were excluded due to significant hepatopulmonary shunting. Eleven patients were treated with TheraSphere. One patient (9%) had a complete response, eight patients (78%) had a partial response, and two patients (18%) showed no response. Partial and complete responders with AFP-associated HCC demonstrated a median decrease in AFP levels of 79 per cent at 73 days. No patients developed liver toxicity nor died due to treatment. Five patients (45%) died of progressive disease at a median of 7 months post-treatment. Six patients (54%) were alive at a median of 11 months (range, 9 to 20 months). Okuda stage 2 and 3 patients showed a median survival of 11 months and 7 months, respectively. Yttrium-90 TheraSphere treatment for unresectable hepatocellular carcinoma is well tolerated and appears to extend survival.

Use of Yttriurn-90 TheraSphere for the Treatment of Unresectable Hepatocellular Carcinoma

This is a retrospective analysis of a new treatment modality, intra-arterial administration of Yttrium-90 TheraSphere, for unresectable hepatocellular carcinoma (HCC). Patients with HCC not amenable to surgical treatment who had satisfactory physiological function without comorbid disease or significant pulmonary shunting were eligible for treatment. Patients were categorized into complete, partial, or no response based on serum alpha-fetoprotein (AFP) levels and CT or MRI imaging. Fourteen patients were considered candidates for treatment. Three patients were excluded due to significant hepatopulmonary shunting. Eleven patients were treated with TheraSphere. One patient (9%) had a complete response, eight patients (78%) had a partial response, and two patients (18%) showed no response. Partial and complete responders with AFP-associated HCC demonstrated a median decrease in AFP levels of 79 per cent at 73 days. No patients developed liver toxicity nor died due to treatment. Five patients (45%) died of progressive disease at a median of 7 months post-treatment. Six patients (54%) were alive at a median of 11 months (range, 9 to 20 months). Okuda stage 2 and 3 patients showed a median survival of 11 months and 7 months, respectively. Yttrium-90 TheraSphere treatment for unresectable hepatocellular carcinoma is well tolerated and appears to extend survival.

Color duplex sonographic findings in human vertebral arteries during cervical rotation

PURPOSE

The aims of this study were to determine whether vertebral artery blood flow velocity changes during contralateral cervical rotation, to determine the extent of rotation necessary to affect the velocity, and to find direct evidence of stretching or compression of the vertebral arteries during cervical rotation.

METHODS

Color duplex sonography was used to measure the blood flow velocities and diameters of the vertebral arteries in 20 patients. Measurements were taken with the patients' heads in the neutral position and at 10 degrees increments of contralateral neck rotation (determined using a cervical range of motion goniometer) to the end-range.

RESULTS

The data showed no significant change in the mean blood flow velocity for the entire study population during cervical rotation. However, there were marked changes in the blood flow velocities in 7 vertebral arteries toward the end-range of rotation. No arteries displayed any evidence of major stretching of the arterial walls, although localized compression of 2 arteries was observed.

CONCLUSIONS

The results of this study suggest that vertebral arteries are usually unaffected by contralateral cervical rotation and that Doppler sonography may provide an indirect assessment of mechanical stresses to the arterial wall.

Relative sensitivity of Tc-99m WBC versus In-111 WBC in a patient with Crohn disease and steroid use

Numerous studies have shown that chemotaxis is affected by certain antibiotics and steroids. The authors present the case of a patient with Crohn disease relapse with multiple small-bowel fistulae and mesenteric abscesses. Whereas the Tc-99m WBC scan failed to show the intra-abdominal inflammatory foci, an In-111 WBC scan performed within a week delineated the abscesses very well, and these were later confirmed at surgery. This case is presented not only to illustrate the relative sensitivities of a Tc-99m WBC versus an In-111 WBC scan, but also to discuss the impediment to polymorphonuclear chemotaxis by steroids, which may be a contributory factor to the sensitivities of the different radiopharmaceuticals selected for detection of intra-abdominal septic foci.

Relative sensitivity of Tc-99m WBC versus In-111 WBC in a patient with Crohn's disease on steroids

Numerous studies have shown that chemotaxis is affected by certain antibiotics and steroids. A patient had Crohn's disease in relapse with multiple small bowel fistulae and mesenteric abscesses. Although the Tc-99m WBC scan did not show the intra-abdominal inflammatory foci, an In-111 WBC scan performed within a week delineated the abscesses and these were later confirmed at surgery. This case is being presented not only to show the relative sensitivities of a Tc-99m WBC vs. an In-111 WBC scan, but also to discuss the impediment to polymorphonuclear leukocyte chemotaxis by steroids, which may be a contributory factor to the sensitivities of the different radiopharmaceuticals selected for detection of intra-abdominal septic foci.

The 'urogenital diaphragm', external urethral sphincter and radical prostatectomy

BACKGROUND

The present study was performed to determine whether a 'urogenital diaphram' exists, to examine the true nature of the striated external urethral sphincter and to evaluate whether the standard technique for radical prostatectomy damages the external sphincter.

METHODS

Fifty radical prostatectomies were performed using optical magnification and the dorsal bunching technique, and the external sphincter was carefully examined. Ten human cadavers and one 5-year-old baboon were dissected with longitudinal (sagittal) and transverse sections being taken through the prostate apex, membranous and bulbar urethrae. During the standard technique for dorsal vein control during radical prostatectomy, the tissue incorporated within the ligature was examined for striated muscle.

RESULTS

No 'urogenital diaphragm' could be demonstrated in any human or baboon tissue. The striated external urethral sphincter is a cylinder of muscle surrounding the membranous urethra, extending from the perineal membrane to the prostate and continuing over the prostate as part of the anterior fibromuscular stroma. Striated muscle was present in the ligated material from the dorsal venous complex.

CONCLUSIONS

The 'urogenital diaphragm' is a myth. The standard technique of radical prostatectomy significantly damages the external sphincter.

Adaptation in the vertebral column: a comparative study of patterns of metameric variation in mice and men

In this paper we examine metamerism in the vertebral column of certain mammals from the perspectives of development and adaptation. To this end we examine the patterns of metameric variation of dimensions of the neural (vertebral) canal, vertebral body and spinous process in man and inbred strains of mice. The data from inbred strains of mice indicate that variability in dimensions within a strain reflects the temporal ordering and nature of developmental influences on vertebral morphogenesis. Differences between strains parallel the within-strain findings. These findings are attributed to somatic and neural influences on morphogenesis. Comparisons between mice and man indicate that these same influences can be invoked to explain and interpret the mosaic nature of vertebral column evolution. These findings lead us to conclude that different vertebral elements and levels are subject to different interactions of evolutionary and morphogenetic influences. The study of these influences and their interactions should prove fruitful in developing an understanding of the relationship between adaptation, development, growth and function in the skeleton generally.

Morphological survey of the cervicothoracic junctional region

STUDY DESIGN

Vertebral morphology of the cervicothoracic junctional region was studied using the C6 to T4 vertebrae from 51 disarticulated skeletons (26 males and 25 females).

OBJECTIVES

Orientation of the facet joint pair relative to the plane of the superior endplate and the sagittal reference was recorded. A vertebral index was developed to compare the superior endplate surface area with the posterior vertebral body height.

SUMMARY OF BACKGROUND DATA

Vertebral morphometry was recorded for comparison with the limited published data for this region.

METHODS

The disc-facet angle was measured using a zygapophysial endplate protractor and the facet angle recorded from computer-aided digitizing of photographs of each segment. Vertebral dimensions were measured using Mitutoyo digital calipers.

RESULTS

A marked change in disc-facet angle from C6 to T1 was recorded, with the incidence of right versus left asymmetry highest at the T1 level. The incidence of facet angle asymmetry greater than 10 degrees was 24% at C6, 18% at C7, and 16% at T1. The vertebral index indicated no significant gender difference.

CONCLUSION

Consistent with other junctional regions of the spine, the cervicothoracic transition has significant morphological variations.

Gastric emptying is impaired in patients with spinal cord injury

OBJECTIVES

The rate and completeness of gastric emptying (GE) are major determinants of the bioavailability of oral medication, and the efficiency of gastric emptying is highly dependent on an intact central nervous system. Hence, in spinal cord injury (SCI), an impairment in gastric emptying could significantly diminish drug efficacy.

METHODS

We evaluated posture-dependent (seated and supine) gastric emptying of an isotopically-labeled liquid meal in six quadriplegic subjects. The time-course profile of the gastric elimination of a radionuclide was followed for up to 120 min using serial anterior scintigraphy, and the disappearance of radioactivity from the stomach was described by both a mono- and biexponential fit of raw data. A half-time of gastric emptying (GEt1/2) was estimated from each curve and compared to GEt1/2 derived from able-bodied (intact neuraxis) experimental and historic control populations.

RESULTS

The mean GEt1/2 in quadriplegic subjects (monoexponential curve fit) was significantly increased to 43.4 +/- 26.0 min in seated SCI subjects (95% CI 13.5-73.2, p < 0.05) and to 50.5 +/- 48.0 min in supine SCI subjects compared to supine experimental and historic control values of 10.1 +/- 8.8 min (95% CI 2.3-18.0, p < 0.05) or 12.0 +/- 3.0 min (95% CI 9.4-14.8, p < 0.05), respectively. A small, non-significant trend towards an increased rate of GE (decreased GEt1/2) was observed in seated SCI subjects.

CONCLUSIONS

We conclude that gastric emptying is impaired in subjects with cervical SCI. Comparative studies of gastric emptying in subjects with SCI should incorporate concurrently studied, control subjects and employ experimental methods that are not constrained by truncated data collection periods. The convention of forcing GE data to conform to a monoexponential pattern of evacuation ignores time-dependent multiphasic patterns of GE and does not support serendipity.

Analysis of nutrient hepatic blood flow after 8-mm versus 16-mm portacaval H-grafts in a prospective randomized trial

BACKGROUND

In previous unrandomized studies, we demonstrated that patients undergoing 8-mm diameter portacaval H-grafts with collateral ablation (partial shunts) have lower rates of portasystemic encephalopathy (PSE) postoperatively than patients undergoing total portacaval shunts. We postulated that nutrient hepatic blood flow was greater after partial shunts because 8-mm grafts preserved some portal flow.

METHODS

To test this hypothesis, we analyzed hepatic hemodynamics in 18 of 30 randomized patients who consented to be studied after complete operative recovery, grouped according to shunt size. We measured nutrient hepatic blood flow using 99m-Tc-Mebrofenin tracer elimination kinetics, and fractionated it into its portal venous and hepatic arterial components. PSE was assessed by blinded observers. Stepwise logistic regression was used to select the variable that best predicted encephalopathy. From 1989 to 1993, we conducted a randomized, prospective trial of partial (8 mm) versus total (16 mm) portacaval H-grafts. Group differences were compared using one-way analysis of variance (ANOVA).

RESULTS

Hepatic encephalopathy occurred in 2 of 10 patients with partial shunts versus 5 of 8 patients with total shunts. Nutrient hepatic blood flow was significantly higher for partial shunts compared with total shunts (403 +/- 601 versus 243 +/- 17mL/min). Three variables--nutrient hepatic blood flow, portal blood flow, and hepatic arterial flow--were analyzed by stepwise logistic regression. Nutrient hepatic blood flow was selected as the best predictor of hepatic encephalopathy. In this series, PSE did not occur in any patient with more than 325 mL/min of nutrient hepatic blood flow.

CONCLUSION

These findings provide a physiologic basis for clinical observations demonstrating a lower incidence of PSE with partial shunts and indicates the superiority of partial over total shunts. Partial shunts, by preserving portal flow, maintain higher nutrient hepatic blood flow than total shunts and thus minimize PSE rates.

Comparison of thallium-201 single-photon emission computed tomographic scintigraphy with intravenous dipyridamole and arm exercise

In patients who cannot perform treadmill exercise, both intravenous dipyridamole and arm exercise have been used with thallium-201 scintigraphy to detect significant coronary artery disease. However, no study has directly evaluated the results of intravenous dipyridamole and arm exercise thallium scintigraphy as compared with coronary angiography. It was the purpose of this study to compare intravenous dipyridamole and arm exercise thallium-201 single-photon emission computed tomographic (SPECT) scintigraphy for detection of significant coronary artery disease in patients who could not perform treadmill exercise. Data are presented for both intravenous dipyridamole and arm exercise thallium-201 SPECT scintigraphy in 18 men who could not perform treadmill exercise, and results are compared with those of coronary angiography. Ten of 11 (91%) patients with significant coronary artery disease were identified correctly, and the results of intravenous dipyridamole and arm exercise thallium scintigraphy were comparable. In patients without significant coronary artery disease, intravenous dipyridamole thallium images were interpreted correctly. However, initial arm exercise thallium images demonstrated a fixed inferior wall defect in two of seven patients without significant coronary artery disease. Images in one of these patients could not be retrieved from tape for further analysis. Review of the images in the other patient demonstrated relatively high background radioactivity, and when the images were displayed without background subtraction, the inferior wall was correctly interpreted as normal. We conclude that results of intravenous dipyridamole and arm exercise thallium-201 SPECT scintigraphy are comparable.

The role of zygapophysial joint orientation and uncinate processes in controlling motion in the cervical spine

Five linear and 2 angular measurements on each of C3 to T1 in a sample of 67 human skeletons were used to examine 3 hypotheses about the function of uncinate processes and zygapophysial joints in the cervical vertebral column. The material was sexed and each vertebra was rated for pathological changes. The effects of gender and pathology on the measures was assessed. The upper 4 vertebrae studied had the largest disc-facet angles, supporting the view that the articular facet orientation is responsible for the greater intervertebral disc translation occurring during sagittal motion in the neck. These upper 4 vertebrae also have the largest uncinate processes, and this observation supports the hypothesis that uncinate processes function to guide and control the anteroposterior translation which occurs during sagittal motion. The 3rd hypothesis that uncinate processes function to facilitate axial rotation is not supported by the recorded interfacet angles which appear to promote axial rotation only in the lower 4 vertebrae. Two further hypothesis are suggested. First, that the interfacet angle is responsible for controlling how strictly lateral flexion and axial rotation are coupled in cervical motion segments. Second, the suggestion is made that the high frequency of pathological change seen at the disc margins of the middle cervical vertebrae may be a result of the unusual combination of disc-facet and interfacet angles permitting more degrees of freedom than the cervical intervertebral discs can withstand.