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Research Interests: Biology, Cell Biology, Development, Medicine, Biological Sciences, and 12 moreCell Differentiation, Cartilage, Animals, Embryonic Stem Cell, Gel Permeation Chromatography, Hyaluronic Acid, Proteoglycans, Glycosaminoglycans, Chondrogenesis, Molecular weight, Chick embryo, and Medical and Health Sciences
Research Interests: Chemistry, Biology, Cell Biology, Medicine, Biological Sciences, and 15 moreCartilage, Animals, Biochemical, Proteins, Gel Permeation Chromatography, CHEMICAL SCIENCES, Proteoglycans, Chondrogenesis, Limb Development, Molecular weight, Sulfates, Extremities, Sodium Dodecyl Sulfate, Chick embryo, and Medical and Health Sciences
Analyses of brains from six infants whose birth weights were "small for gestational age" (SGA) and ten infants whose birth weights were ‘appropriate for gestational age" (AGA) show the cerebellum to be the area of the brain... more
Analyses of brains from six infants whose birth weights were "small for gestational age" (SGA) and ten infants whose birth weights were ‘appropriate for gestational age" (AGA) show the cerebellum to be the area of the brain most greatly affected by intrauterine underdevelopment. The SGA cerebellar weight was reduced 37% and cellularity 35%, compared to reductions of only 21% and 19% for weight and cellularity in the remainder of the brain. The myelin lipids, cerebroside and sulfatide, were significantly reduced (p < .01) in concentration or total quantity in the brains of SGA infants, in contrast to phospholipids, cholesterol, and gangliosides which did not show a similar reduction. Galactolipid sulfotransferase activity, important in sulfatide formation, was also significantly reduced (p < .01) in the brains from SGA infants.
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A two stage assay procedure has been developed for the estimation of dihydroxyacetone (DHN). DHA is at first phosphorylated to dihydroxyacetone phosphate (DHAP) by glycerokinase (GK) and ATP at pH 8.5. The DHAP formed is then measured... more
A two stage assay procedure has been developed for the estimation of dihydroxyacetone (DHN). DHA is at first phosphorylated to dihydroxyacetone phosphate (DHAP) by glycerokinase (GK) and ATP at pH 8.5. The DHAP formed is then measured enzymatically using glycerol-3P dehydrogenase (GDH) and NADH at pH 7.6. The sensitivity of this method is found to be adequate for both routine
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Fibroblasts from a proband with Ehlers-Danlos syndrome type VII synthesized approximately equal amounts of normal and shortened pro alpha 2(I) chains of type I procollagen. Nuclease S1 probe protection experiments with mRNA demonstrated... more
Fibroblasts from a proband with Ehlers-Danlos syndrome type VII synthesized approximately equal amounts of normal and shortened pro alpha 2(I) chains of type I procollagen. Nuclease S1 probe protection experiments with mRNA demonstrated that the pro alpha 2(I) chains were shortened because of a deletion of most or all of the 54 nucleotides in exon 6, the exon that contains codons for the cleavage site for procollagen N-proteinase. Sequencing of genomic clones revealed a single-base mutation that converted the first nucleotide of intron 6 from G to A. Therefore, the mutation was a change, in the -GT-consensus splice site, that produced efficient exon skipping. Allele-specific oligonucleotide hybridizations demonstrated that the proband's mother, father, and brother did not have the mutation. Therefore, the mutation was a sporadic one. Analysis of potential 5' splice sites in the 5' end of intron 6 indicated that none had favorable values by the two commonly employed techniques for evaluating such sites. The proband is the fourth reported proband with Ehlers-Danlos syndrome VII with a single-base mutation that causes skipping of exon 6 in the splicing of RNA from either the COL1A1 gene or COL1A2 gene. No other mutations in the two type I procollagen genes have been found in the syndrome. Therefore, such mutations may be a common cause of the phenotype. The primers developed should be useful in screening for the same or similar mutations causing the disease.
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The medical humanities, an umbrella term for the fields of ethics, social science, and fine arts, are increasingly recognized as an important component of medical education. Since the Flexner report, the primacy of science and... more
The medical humanities, an umbrella term for the fields of ethics, social science, and fine arts, are increasingly recognized as an important component of medical education. Since the Flexner report, the primacy of science and evidence-based medicine has replaced subjectivity and nuance. While this has been critical for standardization of care and patient safety, an exclusive emphasis on science in undergraduate medical education can devalue more humanistic pursuits. Modern medicine is now plagued with burnout, pandemics, and societal ills that permeate into medicine. Addressing these requires a thoughtful, holistic approach where we extend our sights beyond strict evidence-based medicine.
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Limb-bud proteoglycans are heterogeneous molecules which vary in their chemical and physical properties with development. This report describes proteoglycan intermediates (PG-I) that predominate in stage-34 limbs, and compares them with... more
Limb-bud proteoglycans are heterogeneous molecules which vary in their chemical and physical properties with development. This report describes proteoglycan intermediates (PG-I) that predominate in stage-34 limbs, and compares them with proteoglycan aggregates (PG-A) in stage-38 limbs. We analysed proteoglycans and their components extracted with guanidinium chloride by subjecting them to density gradient centrifugation, molecular sieve chromatography, electrophoretic separation, and selective enzymatic degradation. PG-I and PG-A have similar chondroitin sulphate composition, amino sugars, chondroitin sulphate side-chain length, glycoprotein link factors, and hyaluronic acid binding capacity, and both cross react with antisera prepared against cartilage-specific chick sternal proteoglycans. However, PG-I has lower molecular weight, lower buoyant density, and fewer chondroitin sulphate side chains on the protein core. The PG-I in the developing limb can be considered a mixture of sma...
Research Interests: Biochemistry, Biology, Development, Medicine, Biological Sciences, and 13 moreCartilage, Animals, P-glycoprotein, Gel Permeation Chromatography, Hyaluronic Acid, Proteoglycans, Time Factors, Centrifugation, Molecular weight, Chondroitin Sulphate, Extremities, Chick embryo, and Medical and Health Sciences
Research Interests: Chemistry, Medicine, Cartilage, Pubmed, Animals, and 4 moreHyaluronic Acid, Proteoglycans, Extremities, and Chick embryo
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Research Interests: Developmental Biology, Biology, Scanning Electron Microscopy, Cell Biology, Transmission Electron Microscopy, and 11 moreMedicine, Extracellular Matrix, Biological Sciences, Cartilage, Animals, Proteoglycans, Glycosaminoglycans, Notochord, Chondrogenesis, Chick embryo, and Medical and Health Sciences
The effects of mechanical stress on the metabolism of dog femoral head cartilage have been investigated. The model involves exercising the dog on a treadmill for an 8-month period and isolating the cartilage proteoglycans from three... more
The effects of mechanical stress on the metabolism of dog femoral head cartilage have been investigated. The model involves exercising the dog on a treadmill for an 8-month period and isolating the cartilage proteoglycans from three different anatomical regions of the femoral head. These regions are 1) the articulating area, which shows degenerative changes, 2) the area surrounding the articulating area, and 3) the non-articulating area. The hexosamine analysis of cartilage from the exercised animals, indicates 43% and 21% decreases in regions 1 and 2, respectively, while in region 3 no significant change was observed. The size of the proteoglycan aggregates and monomers also decreased with exercise in regions 1 and 2, and the cartilage from these two regions also incorporated more radioactive sulfate, suggesting a possible attempt to repair the degenerative alterations. The proteoglycan monomer (D1) from the articulating region of exercised dogs failed to interact with hyaluronic acid, while the monomers from other regions in the same animal did interact. Glycosaminoglycan chains from region 1 were smaller than in the control tissue, and there was an increase in chondroitin-4-sulfate synthesis. The results of the present study indicate that the cartilage from the articulating area and the surrounding area resist mechanical deformation by increasing synthetic activity. These observations suggest that the exercised animal can be a valuable model and provide increased understanding of the mechanism of cartilage degeneration.
Research Interests: Chemistry, Biomedical Engineering, Medicine, Dogs, Anatomy, and 14 moreCartilage, Animals, Male, Connective tissue, Glycosaminoglycan, Gel Permeation Chromatography, Clinical Sciences, Proteoglycans, Glycosaminoglycans, Mechanical Stress, Articular Cartilage Wear, Chondroitin Sulfate, Hexosamines, and physical exertion
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Horseshoe kidney (HSK), the most common type of congenital renal fusion anomaly, is characterized by ectopia, malrotation, and altered vascular changes. Horseshoe kidney in this case is atypical because of multiple ureters, arteries, and... more
Horseshoe kidney (HSK), the most common type of congenital renal fusion anomaly, is characterized by ectopia, malrotation, and altered vascular changes. Horseshoe kidney in this case is atypical because of multiple ureters, arteries, and veins, as well as how they originated and formed. During the routine dissection of 83-year-old male donor who died of respiratory failure, we observed the presence of horseshoe kidney in which the lower lobes of the left and right kidneys were connected by an isthmus below the level of inferior mesenteric artery (IMA). Furthermore, the presence of arterial, venous, and ureteric anomalies was also observed; these were sequentially dissected and are described here.
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The intervertebral discs of a young (age, 3 years) and an old (age, 8 years) dog were isolated as motion segments and cyclically stressed in physiologic nondestructive axial compression loads. Chemical analysis of the matrix of the... more
The intervertebral discs of a young (age, 3 years) and an old (age, 8 years) dog were isolated as motion segments and cyclically stressed in physiologic nondestructive axial compression loads. Chemical analysis of the matrix of the annulus fibrosus revealed a shift in proteoglycan molecular size from larger to smaller moieties for the older dog but not for the younger. These preliminary results may indicate an age-related inability of the disc to tolerate cyclic stress.
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... Hexosamines were determined by the Elson and Morgan22 method as modified by Antonopoulos et al.23, Gel chromatography was performed at room temperature (22°C) using Sepharose 2B (Phar-macia Fine Chemicals, Uppsala, Sweden) columns... more
... Hexosamines were determined by the Elson and Morgan22 method as modified by Antonopoulos et al.23, Gel chromatography was performed at room temperature (22°C) using Sepharose 2B (Phar-macia Fine Chemicals, Uppsala, Sweden) columns (0.4 x 100 cm). ...
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Several years ago, we in my laboratory and a number of investigators elsewhere decided to address an intriguing question: Why do some families have osteogenesis imperfecta (01), the genetic disease characterized by extreme brittleness of... more
Several years ago, we in my laboratory and a number of investigators elsewhere decided to address an intriguing question: Why do some families have osteogenesis imperfecta (01), the genetic disease characterized by extreme brittleness of bone? The answer that has been ...
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The obturator nerve (L2–L4) is a branch of the lumbar plexus that supplies sensation and adductor muscles of the medial aspect of the thigh. A unilateral variation in the course of the left obturator nerve was observed while exposing the... more
The obturator nerve (L2–L4) is a branch of the lumbar plexus that supplies sensation and adductor muscles of the medial aspect of the thigh. A unilateral variation in the course of the left obturator nerve was observed while exposing the components of the pelvis and lumbar plexus during cadaveric dissection. Although the course of the obturator nerve is often consistent, variations in pelvic vascular and nervous structures do exist, and clinicians should be aware of the possibility of encountering less common presentations of the obturator nerve. Knowledge of alternative course of obturator nerve has a significant impact during pelvic surgery, addressing pelvic fractures resulting from trauma or osteoporosis and approaches to regional anesthesia. To the best of our knowledge, this is the first report on the uncommon course of obturator nerve through an independent osseus tunnel in the pelvic bone. © Int J Anat Var (IJAV). 2013; 6: 133–135.
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... Anatomy. 2008; 2: 6771. [9] Harish K, Gopinath KS. Sternalis muscle: importance in surgery of the breast. Surg Radiol Anat. 2003; 25: 311314. [10] Sadler T. Langman's Medical Embryology. 11th Ed., Maryland, Lippincott... more
... Anatomy. 2008; 2: 6771. [9] Harish K, Gopinath KS. Sternalis muscle: importance in surgery of the breast. Surg Radiol Anat. 2003; 25: 311314. [10] Sadler T. Langman's Medical Embryology. 11th Ed., Maryland, Lippincott Williams and Wilkins. 2010; 143149. ...
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Atypical branches of the aortic arch (AA) occur frequently but are poorly explained. In an 82-year-old Caucasian male cadaver who died of coronary artery disease with severe aortic stenosis, the left vertebral artery (LVA) originated from... more
Atypical branches of the aortic arch (AA) occur frequently but are poorly explained. In an 82-year-old Caucasian male cadaver who died of coronary artery disease with severe aortic stenosis, the left vertebral artery (LVA) originated from the AA between the common carotid and subclavian arteries. The prevertebral part of LVA was narrower and entered the C5 transverse foramen. The right vertebral artery (RVA) from the right subclavian was wider than LVA suggesting compensation to the cerebral circulation. An unusual LVA may be asymptomatic; however, it is important in neck and supraaortic arch surgery and in non-invasive neck procedures. Vertebral arteries (VAs) are formed by development of longitudinal anastomoses linking the cervical intersegmental arteries, which regress except the seventh that becomes the proximal subclavian artery, the point of origin of the adult VA. Persistence of the 6th dorsal intersegmental artery might account for LVA arising from AA proximal to the subcla...
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Much of the fused pelvic kidney (pancake kidney) described in the literature are complicated by coexisting anomalies of other organ system and vasculature. During a routine anatomical dissection of a 69 year-old male we found a fused... more
Much of the fused pelvic kidney (pancake kidney) described in the literature are complicated by coexisting anomalies of other organ system and vasculature. During a routine anatomical dissection of a 69 year-old male we found a fused pelvic kidney without vascular or other organ system defects. A detailed dissection of the entire body showed normal anatomical features except pancreatic cancer and related lymph nodes. Further dissection of the pelvic kidney showed presence of right and left accessory renal arteries; however the remaining vasculature was normal. Possible embryological causes of pelvic kidney and clinical consequences of this anomaly are discussed.
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The pedagogical approach for both didactic and laboratory teaching of anatomy has changed in the last 25 years and continues to evolve; however, assessment of student anatomical knowledge has not changed despite the awareness of... more
The pedagogical approach for both didactic and laboratory teaching of anatomy has changed in the last 25 years and continues to evolve; however, assessment of student anatomical knowledge has not changed despite the awareness of Bloom's taxonomy. For economic reasons most schools rely on multiple choice questions (MCQ) that test knowledge mastered while competences such as critical thinking and skill development are not typically assessed. In contrast, open-ended question (OEQ) examinations demand knowledge construction and a higher order of thinking, but more time is required from the faculty to score the constructed responses. This study compares performances on MCQ and OEQ examinations administered to a small group of incoming first year medical students in a preparatory (enrichment) anatomy course that covered the thorax and abdomen. In the thorax module, the OEQ examination score was lower than the MCQ examination score; however, in the abdomen module, the OEQ examination score improved compared to the thorax OEQ score. Many students attributed their improved performance to a change from simple memorization (superficial learning) for cued responses to conceptual understanding (deeper learning) for constructed responses. The results support the view that assessment with OEQs, which requires in depth knowledge, would result in student better performance in the examination. Anat Sci Educ. © 2017 American Association of Anatomists.