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Biomedical subjects

S Hunt

Publications and source records attributed to S Hunt.

At least 145 records · Page 8Linked to original sources
PubMed1979

Abnormal deoxyribose metabolites in the urine of a child with a possible new inborn error of metabolism.

The urinary extract of a child investigated because of strabismus was found to contain large amounts of a compound which was identified using gas chromatography/mass spectrometry as 2-deoxyerythropentono-1,4-lactone. This lactone has not been observed previously in urinary extracts. When ion-exchange chromatography was used to isolate the organic acids from urine, the major peaks obtained by gas chromatography were shown to be 2-deoxyerythropentonic acid, 2-deoxyerythropentono-1,5-lactone and 2-deoxyerythropentono-1,4,lactone. Another abnormal metabolite, 2-deoxyribitol, was also excreted by the patient although this compound could not be detected in the urine of normal children. It is proposed that these unusual compounds accumulate in the urine of this child as a result of a defect in the catabolism of 2-deoxyribose.

Deoxyribose↗
PubMed1979

The structure and compositon of the love dart (gypsobelum) in Helix pomatia.

The love dart of the snail Helix pomatia is a four-bladed, hollow spicule of calcium carbonate. The calcium carbonate is largely in the form of microcrystalline aragonite, the crystals being not more than 0.5 micrometer in size but assembled into sheets or blocks of much greater size. Protein occurs in the dart structure as an external sheath, as a lining to the tubular core and as a matrix component of the mineral phase. Comparisons with the molluscan shell are drawn and a rationale for the architecture suggested.

Amino Acids↗
PubMed1979

Probable transmission of Toxoplasma gondii by organ transplantation.

Two heart transplant recipients developed toxoplasmosis shortly after surgery. As neither recipient had serologic evidence of exposure to Toxoplasma gondii before transplantation, infection was acquired from an exogenous source. Of the possible modes of transmission of Toxoplasma to the recipients, infection by the oral route or through transfusion of blood or blood products seems remote. Since both heart donors had serologic evidence of recently acquired toxoplasma infection at the time of transplantation and the myocardium is known to be infected with the organism during acute infection, we considered these facts to be a strong implication that the donors' hearts were the most likely source of toxoplasma infection in the recipients.

Adult↗
PubMed1979

Circulating levels of vasoactive intestinal polypeptide in liver disease.

In animals, the effects of vasoactive intestinal polypeptide (VIP) include peripheral vasodilation, hyperdynamic circulation, hyperglycemia, and hyperventilation. Because these phenomena are noted in patients with cirrhosis, it has been postulated that VIP might be escaping hepatic inactivation and entering the systemic circulatory system and contributing to these abnormalities. The major purpose of this study is to establish whether or not VIP levels are elevated in patients with cirrhosis. Additional goals are to determine if VIP levels are elevated in acute liver disease and in chronic illnesses with secondary liver involvement. The data demonstrate that patients with cirrhosis and those with acute liver disease or chronic illnesses with secondary hepatic involvement have a wide range of VIP levels with mean values significantly above that of normal individuals and patients with chronic illness and no liver involvement.

Acute Disease↗
PubMed1978

Some observations on the binding patterns of alpha-bungarotoxin in the central nervous system of the rat.

Patterns of alpha-bungarotoxin (alphaBuTX) binding within the brain of the rat have been studied following one of the two procedures: (1) the intraventricular injection of 125I-labeled toxin followed by a survival period of 1--8 days before aldehyde perfusion, or (2) the incubation of fresh cryostat sections of brain tissue in dilute solutions of radioactive toxin. Appropriate controls with nicotine, curare, atropine and native alphaBuTX established that specific nature of the binding. The principal observations were that toxin binding sites are predominantly associated with central areas of the brain in direct receipt of sensory inputs (the main and accessory olfactory bulbs, superior colliculus, ventral lateral geniculate nucleus, cochlear nuclei, the substantia gelatinosa of the spinal cord and spinal trigeminal nucleus, the principal sensory nucleus of the trigeminal, and the dorsal column nuclei) and with limbic areas of the brain (hippocampus, amygdala, olfactory tubercle, medial mammillary nucleus, and the dorsal tegmental nucleus of Gudden). Toxin was not found to bind to cranial motor nuclei with the exception of the dorsal motor nucleus of the vagus and the nucleus ambiguus. The discrete distribution of clusters of silver grains within the granule layer of cerebellar folia I, IX, and X is described as well as the heavy labeling of the inferior and accessory olivary nuclei. In many areas of the brain silver grains were found to overlie cell bodies. It is suggested that this may reflect the presence of both membrane-bound toxin and internalized ligand following initial binding to a membrane receptor site. An attempt was made to correlate the localization of toxin binding sites with the terminal distributions of previously described cholinergic pathways. There appears to be a reasonably good agreement between the distribution of toxin receptors and proposed sites of cholinergic transmission within the hippocampus, interpeduncular nucleus and cerebellum. In most other cases however, lack of data precluded such correlations. The anatomical relationship of alphaBuTX binding activity and neurotransmitters other than acetylcholine is also considered.

Animals↗
PubMed1977

Localization of reducing group activity in the structural protein ribbons of the egg capsule of the gastropod mollusc Buccinum undatum L.

Egg capsules of the gastropod molluse Buccinum undatum L. show a staining reaction with silver-methenamine reagent with prior treatment with periodate. The reactivity is specifically localized on the striated structural protein ribbons which form the capsule walls. The staining is in the region of ribbon most resistant to chemical degradation and where the constituent protein monomers are believed to overlap and be cross-linked. Since the proteins contain little cysteine it is likely that the staining originates in aldehyde groups. Staining is abolished by borohydride reduction. It is suggested that the aldehyde groups are a locus of stabilization and cross-linking since previous work has also shown association of an aldehyde secretion with hardening of the capsules.

Aldehydes↗
PubMed1977

Successful retransplantation of the human heart.

Cardiac retransplantation has been performed in five patients at Stanford University Medical Center. Long-term survival and rehabilitation have been achieved in two cases. In the first case retransplantation was performed 57 days after the initial procedure because of persistent acute graft rejection. The second patient underwent retransplantation 27 months postoperatively because of documented accelerated graft atherosclerosis. The major indications for cardiac retransplantation consist of intractable acute rejection and late postoperative graft atherosclerosis. These complications should prompt consideration of cardiac retransplantation in carefully selected cases.

Adolescent↗
PubMed1977

Evidence for common and distinct determinants of colon carcinoembryonic antigen, colon carcinoma antigen-III, and molecules with carcinoembryonic antigen activity isolated from breast and ovarian cancer.

This study was designed to answer the question, do molecules with carcinoembryonic antigen (CEA) activity from colon, breast, and ovarian cancer differ? Extracts of two breast and three ovarian cancers with CEA activity were compared to three colon cancer CEA preparations and to the related antigen, colon carcinoma antigen-III, in terms of lectin- and antiserum-binding properties. With the use of Farr-type radioimmunoassays with the lectins, concanavalin A and wheat germ agglutinin, the iodinated colon CEA and CEA-like preparations from breast and ovarian cancer all showed distinctly different patterns of binding. Specificity of binding was confirmed by inhibition studies with the relevant monosaccharides. Similarly, with antisera prepared against colon CEA, colon carcinoma antigen-III, or breast CEA, it was shown that, although all preparations shared some antigens, unique antigenic determinants were also present on all preparations. These data are consistent with the concept of a series of closely related CEA and CEA-like molecules with distinct characteristics for each tissue source of CEA.

Antibodies, Neoplasm↗
PubMed1976

Fine structure of the dogfish egg case: a unique collagenous material.

The fine structure of the dogfish egg case is described with special reference to the highly ordered, unique, collagen-containing fibrils. The outer layer of the case wall contains densely packed, amorphous granules, rich in tyrosine while approximately 98% of the thickness of the case is built up from orthogonally stacked laminae of closely packed, collagen-containing fibrils. These fibrils show a paracrystalline three-dimensional construction. A model for the structure of the B band of the fibril is proposed, based on appearances in transverse sections of different thickness and on two projection seen in longitudinal sections. The transverse projection of the unit cell appears to be a square lattice with sides approximately 110 A possibly containing a pseudocell with sides (see article). The structure of these fibrils is discussed in relation to those of rat tail tendon collagen.

Animals↗
PubMed1976

An unusual type of secretory cell in the ventral pedal gland of the gastropod mollusc Buccinum undatum L.

The ventral pedal gland in the foot of the mature female whelk Buccinum undatum L. consists of a shallow pouch containing a layer of elongated cells which partially penetrate a basement membrane overlying layers of smooth muscle. This glandular epithelium contains acid mucopolysaccharide cells, ciliated and interstitial cells as well as the upper part of a new type of subepidermal gland cell. These gland cells consist of an elongated extracellular tubular duct formed by an invagination of the cell membrane and lined by numerous microvilli. Into this duct are discharged packets of a densely staining secretion. The secretion packets are produced in Golgi regions around the nuclei of the cells and are passed up through the cell to the base of the duct through or along an extensive assemblage of microtubules. The secretion packets show organized internal structure and may contain aromatic aldehydes and protein associated with the sclerotization of the egg capsules, which pass through the gland after leaving the genital tract.

Animals↗
PubMed1976

Effect of transducer placement on echocardiographic mitral valve systolic motion.

The influence of transducer position and angulation upon the mitral systolic echo was studied in 100 presumably healthy females. Echocardiographic studies were performed from the second, third, fourth and fifth intercostal spaces (ICS). The role of the sound beam's path relative to cardiac motion was assessed by analyzing the recorded mitral valve pattern as a function of transducer orientation, independent of the absolute ICS used. With the transducer directed caudally when both mitral leaflets and left atrium were recorded, holosystolic or midsystolic posterior motion of the mitral valve leaflet echo was seen in 59% of the subjects. These patterns, recorded this way, were not related to phonocardiographic signs suggesting mitral valve prolapse. Best correlation with phonocardiographic findings was obtained when the echocardiographic examination was performed with the transducer either perpendicular to the chest in the sagittal plane, or pointing slightly cephalad ('perpendicular' position). With the transducer in 'perpendicular' position, both holosystolic and midsystolic posterior motion of the mitral systolic echo, deviating more than 2 mm from a line joining the C and D points, were highly related statistically to phonocardiographic findings suggesting mitral valve prolapse. This study demonstrates that transducer position and angulation on the chest wall are important determinants of echocardiographic appearance of mitral valve during systole. Only the 'perpendicular' transducer position should be used when analyzing echocardiograms for the presence of mitral valve prolapse.

Echocardiography↗
PubMed1975

The fine structure of the epidermis of two species of salmonid fish, the Atlantic salmon (Salmo salar L.). and the brown trout (Salmo trutta L.)

The fine structure of epidermal mucous cells of two species of salmonid fish has been described. Mucous cells are, next to filament-containing cells, the most commonly encountered cells in fish epidermis. The development of the cells as they progress to the periphery has been characterised. They are initially difficult to distinguish from filament-containing cells: later, they can be recognised by the presence of much smooth-surfaced E.R. The mucigenesis and the subsequent secretion of mucus has been observed and it is essentially comparable to that which occurs in the mucous cells of the mammalian intestine. The mucous layer of the epidermal surface seems to mainly comprise of the products of these mucous cells and the "cuticle" seen in other species has not yet been observed in the salmonid species investigated here.

Animals↗
PubMed1975

The fine structure of the epidermis of two species of salmonid fish, the Atlantic salmon (Salmo salar l.) and the brown trout (Salmo trutta L.). I. General organization and filament-containing cells.

The fine structure of the epidermis or two species of salmonid fish has been described. Gross characteristics have been noted along with many apparent differences in the epidermis of different body regions of the fish. The major cell type is the filament-containing cell and this has been described in detail. The major inclusions of the cell are the tonofilaments. Differences in basal, mid-epidermal and periphal filament-c0ntaingcells have been characterized. Comparisons of fish epidermis with that of other vertebrates has been made.

Animals↗