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S W Carmichael

Publications and source records attributed to S W Carmichael.

72 records · Page 4Linked to original sources
PubMed1982

Bilateral secretory responses of the adrenal medulla during stimulation of hypothalamic or mesencephalic sites.

Bilateral secretion of epinephrine and/or norepinephrine from adrenal medullae occurred in 76% of cats studied following unilateral electrical stimulation of sites in the hypothalamus or rostral mesencephalon. Responses were generally greater on the ipsilateral side. In most experiments, epinephrine alone or both epinephrine and norepinephrine outputs were increased. In only two experiments norepinephrine output was increased. Stimulation of most hypothalamic sites that evoked bilateral secretion was accompanied by an increase in blood pressure. Stimulation of effective sites in the mesencephalon was not generally accompanied by blood pressure changes.

Adrenal Medulla↗
PubMed1982

Evidence that cytoplasmic birefringence is a normal feature of rat adrenal chromaffin cells.

The rat adrenal medulla was fixed by isobaric whole-body perfusion with glutaraldehyde. Specimens treated with anisotropic stains exhibited a diffuse cytoplasmic birefringence. Evidence is presented that birefringence is not only associated with "dark" cell formation, but may be a normal feature of fixed chromaffin cells. It is suggested that the birefringence is caused by the fixed contents of the chromaffin vesicles and/or the microtrabecular lattice recently described in rat chromaffin cells.

Adrenal Medulla↗
PubMed1980

Ultrastructural demonstration of Mg-ATPase activity of the chromaffin granule.

Histochemical evidence for magnesium-activated-ATPase activity of chromaffin granules in the hamster adrenal medulla is presented. A modified Wachstein-Meisel medium, using 40 mM magnesium, was employed. Not all chromaffin granules were reactive, but the reaction product was more noticable on noradrenaline granules than adrenaline granules. Presumtive exocytotic sites were very reactive. Small vesicles, elongated-granules, lysosomes, the plasma membrane, the endoplasmic reticulum, and mitochondria were also reactive.

Adenosine Triphosphatases↗
PubMed1980

Uptake of nucleotides and catecholamines by chromaffin granules from pig and horse adrenal medulla.

The uptake of nucleotides and catecholamines into chromaffin granules from adrenals of pigs and horses is similar to that previously seen in bovine chromaffin granules. The rate of [3H]ATP uptake at 2 mM-ATP concentration was 0.42 +/- 0.06 and 0.15 +/- 0.02 nmol/mg protein/min for pig and horse granules, respectively. The apparent Km's were 1.37 mM for pig granules, 0.89 mM for horse granules, and 1.2 mM for ox granules. The sensitivity of the uptake for nucleotides and catecholamine to specific inhibitors was found to be similar in granules from pig and ox, indicating that the same mechanisms of uptake are involved in both species.

Adenosine Triphosphate↗
PubMed1980

Bilateral three-headed biceps brachii muscles.

The body of an 83 year old, Caucasian man was found to have bilaterally symmetrical, 3 headed biceps brachii muscles. Each third had a humeral origin and inserted into a common tendon of insertion with the long and short heads of the same side. This is a significant variation from the norm because of the bilaterality of its existence and because the third heads were of considerable size, each being about half the weight of the ipsilateral long or short head. As expected, innervation and vascular supply were from the musculocutaneous nerve and brachial artery, respectively.

Aged↗
PubMed1979

Clinical anatomy of the lumbosacral complex.

The clinical anatomy of the lumbosacral region has been presented to show the complexity of spinal pathology. Individual structures are described, but emphasis is placed on understanding the concept of the entire functional unit and how alteration can lead to pain and disability.

Adenosine Triphosphatases↗
PubMed1979

Perfusion fixation of the newborn opossum: equipment and techniques.

A 30-gauge cannula was used to perfuse fixative through the fragile heart of a newborn opossum. The cannula was gently maneuvered into the heart and held in place with a specially designed manipulator. The flow rate of the fixative was regulated with an infusion set connected to the cannula.

Animals↗
PubMed1978

Direct connections between mitochondria and catecholamine-storage vesicles demonstrated by high voltage electron microscopy in rat adrenal medulla.

Tubular channels from mitochondria to catecholamine-storage vesicles have been demonstrated in thick sections of adrenal medullary tissue from hypoglycemia-stressed rats by the use of the high voltage electron microscope. The function of these connections is not presently known although they may serve as channels for the transport of materials such as high-energy nucleotides from one organelle to the other. The present study has examined only the adrenal medulla, but it should be considered that such connections may also exist in other neural cells and possibly other cells in which there is intracellular transport of ATP.

Adrenal Medulla↗
PubMed1978

High-voltage electron microscopy of adrenal medulla: direct connections between mitochondria and catecholamine-storage vesicles.

A high-voltage electron microscopic study of adrenal medullary cells from hypoglycemia-stressed rats revealed the existence of tubular channels which create a luminal continuity between the mitochondrial compartment and the catecholamine-storage vesicles. It is suggested that these channels allow for the transfer of materials such as high-energy nucleotides between the mitochondria and the catecholamine-storage vesicles without an intervening membrane.

Adrenal Medulla↗
PubMed1976

Sex determination of the lesser bushbaby (Galago senegalensis).

The gross anatomy of the external genitalia of newborn to adult lesser Galago was described. The penis is perpendicular to the body wall at birth and by about 8 wk of age the testes have descended into the scrotum. In the adult male the testes are permanently descended, the scrotum sessile, the penis is oriented obliquely rostral, and the genitalia are covered by luxuriant pelage. In the young female, the clitoris is also perpendicular to the body wall and the labia and vaginal orifice, although not obvious, are located at its caudal base. In the adult female, the clitoris remains perpendicular, is slender, essentially devoid of fur, and has the urethral opening in its tip. The labia and vaginal orifice are at its caudal base, obscured by fur. Effective and reliable methods for differentiating males from females were outlined.

Animals↗
PubMed1975

Electron microscopy of the adrenal medulla of the newborn dog under hypothermia and asphyxia.

The left adrenal medullas of 20 (5 litters of 4) day-old dogs were studied with the electron microscope. The right adrenal medullas of the same animals had been examined by fluorescence microscopy and the results reported previously. In each litter one animal served as a coenothermic (37 degrees C) and one a hypothermic control (15 degrees C). The third animal (at 37 degrees C) was asphyxiated until twice its time of last gasp (about 32 min) and the fourth was cooled to 15 degrees C and asphyxiated for the same length of time as the third animal. The induction of hypothermia (to 15 degrees C) in unanesthetized puppies results in a decrease (32%) in dense-cored granules, an enlargement of mitochondria, and slight dilation of the endoplasmic reticulum. In coenothermic puppies asphyxiation to twice the time of last gasp is accompanied by the following changes: loss of dense-cored granules (52%); swelling of nuclei; clumping and marginal aggregation of nuclear chromatin material; dilation of the endoplasmic reticulum; swelling, loss of cristae and rarefaction of the matrices of mitochondria. The changes in some cells were greater than others. Many of these changes are considered to demonstrate anoxic damage. Under the conditions of the present experiments, hypothermia protected most of the adrenal medullary cells from anoxic damage.

Adrenal Medulla↗
PubMedDate not supplied

MR imaging of knee hyaline cartilage: evaluation of two- and three-dimensional sequences.

Magnetic resonance (MR) imaging of cadaveric knees was performed to determine optimal sequences for visualization of hyaline cartilage. Full-thickness cartilage lesions ranging in diameter from 1 to 5 mm and a partial-thickness cartilage lesion 15 mm in diameter were created in the femoral articular surfaces of three cadaveric knees. The knees were then imaged with a 1.5-T imager with various two-dimensional and high-resolution three-dimensional (3D) techniques. After imaging, the knee specimens were sectioned for evaluation. Measurements of cartilage thickness in fast spin-echo images correlated best with those in the gross specimen. Diffuse areas of cartilage thinning were also most accurately identified with fast spin-echo images. Small, focal cartilage defects were best delineated in 3D SPGR (spoiled GRASS [gradient-recalled acquisition in the steady state]) images.

Cadaver↗