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C Stringer

Publications and source records attributed to C Stringer.

12 recordsLinked to original sources
PubMed1999

Comparing frontal cranial profiles in archaic and modern homo by morphometric analysis.

Archaic and modern human frontal bones are known to be quite distinct externally, by both conventional visual and metric evaluation. Internally this area of the skull has been considerably less well-studied. Here we present results from a comparison of interior, as well as exterior, frontal bone profiles from CT scans of five mid-Pleistocene and Neanderthal crania and 16 modern humans. Analysis was by a new morphometric method, Procrustes analysis of semi-landmarks, that permits the statistical comparison of curves between landmarks. As expected, we found substantial external differences between archaic and modern samples, differences that are mainly confined to the region around the brow ridge. However, in the inner median-sagittal profile, the shape remained remarkably stable over all 21 specimens. This implies that no significant alteration in this region has taken place over a period of a half-million years or more of evolution, even as considerable external change occurred within the hominid clade spanning several species. This confirms that the forms of the inner and outer aspects of the human frontal bone are determined by entirely independent factors, and further indicates unexpected stability in anterior brain morphology over the period during which modern human cognitive capacities emerged. Anat Rec (New Anat): 257:217-224, 1999.

Biometry↗
PubMed1998

Rare temporal bone pathology of the Singa calvaria from Sudan.

Evidence has recently accumulated that the Singa calvaria from Sudan probably dates from Oxygen Isotope Stage 6 (>130 ka). Morphological studies have indicated a mixture of archaic and more modern human traits, but such analyses are complicated by the possibility that the vault is pathologically deformed, although the exact etiology has not been established. Now computed tomography (CT) has revealed that the right temporal bone lacks the structures of the bony labyrinth. The most likely cause of this rare pathological condition appears to be labyrinthine ossification, in which newly deposited bone obliterates the inner ear spaces following an infectious disease or occlusion of the labyrinthine blood supply. A possible cause of vascular compromise could have been the presence of an expanding acoustic neuroma in the internal acoustic meatus, which is suggested by a significantly wider right meatus compared with the left side. Interestingly, labyrinthine ossification is also consistent with the controversial diagnosis that an anemia caused the characteristic diploic widening at the parietal bosses, because prime etiological factors of ossification are among the common complications of some of these blood diseases. CT examination of the vault and a review of the literature suggest that a blood disorder may well have caused the unusual parietal morphology. Given the nature of these pathological conditions, the Singa individual must have experienced a period of considerable disability. The morphological evidence from the normal bony labyrinth on the left side and from the CT evaluation of the vault is consistent with the interpretation of Singa as a late archaic hominid or an early representative of Homo sapiens drawn from a population which might be directly ancestral to modern humans.

Animals↗
PubMed1997

A comparative study of stereolithographically modelled skulls of Petralona and Broken Hill: implications for future studies of middle Pleistocene hominid evolution.

Computer generated three-dimensional stereolithographic models of middle Pleistocene skulls from Petralona and Broken Hill are described and compared. The anterior cranial fossae of these models are also compared with that of another middle Pleistocene skull, Arago 21. Stereolithographic modelling reproduces not only the outer surfaces of skulls, but also features within the substance of the bones, and details of the internal braincase. The skulls of Petralona and, to a somewhat lesser degree, Broken Hill are extremely pneumatized. Previously undescribed features associated with pneumatization are detailed, along with their possible functional significance, polarity, and potential for understanding hominid cranial variation. Petralona and Broken Hill also exhibit a dramatic suite of cerebral features that is probably related to extensive pneumatization of the skull, namely frontal lobes that are tilted and located behind rather than over the orbits, laterally flared temporal lobes, marked occipital projection, and basal location of the cerebellum. Comparison of the anterior cranial fossae of Petralona, Broken Hill, and Arago 21 suggests that external resemblance of skulls may not always correlate with endocranial similarity. We believe that stereolithographic reconstructions have the potential for helping to resolve difficult questions about the origins of Neanderthal and anatomically modern people.

Animals↗
PubMed1994

Liver biopsy and nursing intervention.

A liver biopsy is valuable in evaluating for liver disease. A biopsy is often the determining factor for final diagnosis. The Mengbini Klatskin and Tru-Cut needles are types of biopsy needles used in the GI department at the University of Rochester. The choice is based on the personal preference of the physician or on the type of biopsy. The RN's role in the GI department includes pre- and post-procedure planning, assistance during the procedure, patient and family education, and emotional support. It is important to develop a trusting rapport with patients undergoing a liver biopsy. In addition, confident assistance with the procedure and correct positioning of the patient lead to a successful procedure as well as to an uneventful recovery. In searching the literature, the authors found little current information to assist nurses in the assessment of patients about to undergo a liver biopsy. In this article, the authors present some recommendations from experience to assist others in providing quality patient care for liver biopsy procedures.

Biopsy, Needle↗
PubMed1993

CD44 expression on murine tissues.

CD44 is a cell surface glycoprotein found on lymphoid and epithelial cells. Its primary function on lymphocytes and macrophages is to mediate interaction with endothelium, while its function on epithelial cells is not known. The protein has many different forms, generated by alternative mRNA splicing and by post-translational modification, which may mediate different functions. During previous work on murine lung tumor cells, mAb 133-13A was isolated and shown to recognize a surface glycoprotein, P100, of 90-100 x 10(3) M(r). Amino acid sequence analysis of purified P100 indicates that it is CD44. Since few data exist to indicate which forms of CD44 are present in different normal tissues, mAb 133-13A was used to analyze CD44 expression in mouse tissue. Quantitative data on the distribution of CD44(P100) in mice show that spleen, thymus, liver, intestine, uterus and choroid of the eye are major sites of expression. In addition, epithelia of adrenals, esophagus and trachea are CD44(P100) positive. Previous work on human cell lines has implicated a high molecular mass (130-160 x 10(3) M(r)) form of the glycoprotein as the form expressed in epithelial cells and carcinomas. Isolation of CD44 proteins from lymphoid tissues in the mouse indicate that, as in human lymphoid tissue, the low molecular mass form (80-90 x 10(3) M(r)) is predominately expressed. These data show that both small (approximately 81 x 10(3) M(r)) and large forms of the glycoprotein are expressed in basal epithelia of esophagus and trachea and in salivary gland, while only the small form is expressed in epithelium of the adrenal cortex and in the murine lung and mammary carcinomas studied. While these data cannot distinguish between specific splice variants, they show that the large forms of CD44 are minor components in normal tissue and seem to be found only in basal epithelium. The CD44 of low M(r) found in epithelial tissues is probably associated with lymphoid cell types in the tissues.

Amino Acid Sequence↗
PubMed1992

Thrombomodulin is preferentially expressed in Balb/c lung microvessels.

Previously, two rat monoclonal antibodies where developed which bind distinct epitopes on a murine glycoprotein, P112, which is expressed primarily in lung capillary endothelium. In this paper we show that P112 is identical to the endothelial anticoagulant protein, thrombomodulin (TM). Several lines of evidence support this conclusion. First, amino acid analysis of P112 shows a high degree of homology to TM, and both molecules exhibit the same mobility in gel electrophoresis. Second, P112 and TM share reactivity for two different monoclonal antibodies. Third, purified P112, like TM, acts as a cofactor for protein C activation. Finally, two cDNA clones identified with P112 polyclonal antiserum contain sequence identity with the known TM cDNA sequence. Quantitative analysis of TM (P112) expression using a two-site monoclonal antibody assay demonstrates that significantly higher levels of TM are found in lung in comparison with other highly vascularized organs, i.e. the kidney and liver. Quantitative Northern blot data coincides with the two-site assay data and demonstrates that the high level of TM expression in lung is not due to preferential binding of the monoclonal antibodies to lung TM but rather to increased production of TM mRNA in the lung relative to other highly vascularized organs. It is suggested that expression of TM is highest in cells from continuous endothelium.

Animals↗