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Biomedical subjects

O Gutierrez

Publications and source records attributed to O Gutierrez.

33 records · Page 2Linked to original sources

Uptake and release of glucose by the human kidney. Postabsorptive rates and responses to epinephrine.

Despite ample evidence that the kidney can both produce and use appreciable amounts of glucose, the human kidney is generally regarded as playing a minor role in glucose homeostasis. This view is based on measurements of arteriorenal vein glucose concentrations indicating little or no net release of glucose. However, inferences from net balance measurements do not take into consideration the simultaneous release and uptake of glucose by the kidney. Therefore, to assess the contribution of release and uptake of glucose by the human kidney to overall entry and removal of plasma glucose, we used a combination of balance and isotope techniques to measure renal glucose net balance, fractional extraction, uptake and release as well as overall plasma glucose appearance and disposal in 10 normal volunteers under basal postabsorptive conditions and during a 3-h epinephrine infusion. In the basal postabsorptive state, there was small but significant net output of glucose by the kidney (66 +/- 22 mumol.min-1, P = 0.016). However, since renal glucose fractional extraction averaged 2.9 +/- 0.3%, there was considerable renal glucose uptake (2.3 +/- 0.2 mumol.kg-1.min-1) which accounted for 20.2 +/- 1.7% of systemic glucose disposal (11.4 +/- 0.5 mumol.kg-1.min-1). Renal glucose release (3.2 +/- 0.2 mumol.kg-1.min-1) accounted for 27.8 +/- 2.1% of systemic glucose appearance (11.4 +/- 0.5 mumol.kg-1.min-1). Epinephrine infusion, which increased plasma epinephrine to levels observed during hypoglycemia (3722 +/- 453 pmol/liter) increased renal glucose release nearly twofold (5.2 +/- 0.5 vs 2.8 +/- 0.1 mol.kg-1.min-1, P = 0.01) so that at the end of the infusion, renal glucose release accounted for 40.3 +/- 5.5% of systemic glucose appearance and essentially all of the increase in systemic glucose appearance. These observations suggest an important role for the human kidney in glucose homeostasis.

Adult↗

Hepatocellular carcinoma presenting with intractable diarrhea. A radiologic-pathologic correlation.

A 44-year-old woman with hepatocellular carcinoma presented with intractable watery diarrhea and her condition was evaluated angiographically. Surgical ablation of the tumor resulted in complete resolution of the diarrhea. The tumor cells of the hepatocellular carcinoma were found to contain vasoactive intestinal polypeptide, gastrin, and prostaglandinlike immunoactivity. To our knowledge, this is the first report of such an association.

Adult↗

[Histologic aspect of the human gastric mucosa: relation to gastrin and somatostatin cells and the intraluminal secretion of these peptides].

Fifty-eight subjects including controls, patients with duodenal ulcer, non-operated or treated with a superselective vagotomy underwent endoscopic fundic and antral biopsies. Histologic classification of the two mucosae was performed. We examined the relationship between the histologic grade of gastritis in the two mucosae, then between the histologic aspect of the antral mucosa and antral gastrin-and somatostatin-cell densities, the basal intraluminal secretion of gastrin and somatostatin. There was a significant correlation between the histologic aspect of fundic or antral mucosa and the age of patients, except in the case of vagotomized patients. Fundic and antral histologic patterns were also correlated in each patient, except for vagotomized. Gastrin and somatostatin cell densities showed no variation in function of the degree of inflammation of non atrophic gastritis. These cell densities showed a tendency to decrease in atrophic gastritis, especially when intestinal metaplasia was present. Intraluminal gastrin secretion was increased in patients with mild atrophic gastritis (p less than 0.05 to p less than 0.02) in comparison with those whose histology was roughly normal. It was also increased in severe atrophic gastritis. The highest intraluminal secretion of somatostatin was observed in patients with mild atrophic gastritis while this secretion fell noticeably in those showing severe atrophic gastritis, as compared to the other groups. This work seems to suggest a relationship between intraluminal peptides and the evolution of gastritis. While results are still preliminary, they do not indicate that these peptides, thus released, play any pathophysiologic role.

Adolescent↗

Leiomyosarcoma of the inferior vena cava (IVC) with intracardiac extension.

A case of leiomyosarcoma of the inferior vena cava showed extension into the right atrium and the right ventricle. Chest roentgenograms, inferior vena cavogram and computed tomography suggested the correct diagnosis and established the extent of involvement. The tumour was successfully removed from the heart with subsequent significant symptomatic relief.

Angiography↗

Radiology of aortic dissection: pitfalls in diagnosis.

The diagnosis of aortic dissection can be made with certainty when computed tomography or aortography reveals two lumina and a intimal flap between them. If the false lumen is thrombosed, the differential diagnosis between dissection and aneurysm with intraluminal thrombus is difficult. High resolution computed tomography with dynamic scanning seems more effective in differentiating these two entities than aortography. Two illustrative cases are presented.

Aged↗

Epithelial cell proliferation in human fundic and antral mucosae. Influence of superselective vagotomy and relationship with gastritis.

Epithelial cell proliferation in the fundic and antral mucosae was studied in 19 duodenal ulcer patients, 11 patients having undergone fundic superselective vagotomy for duodenal ulcer, and 10 controls. This was achieved through in vitro incorporation of tritiated thymidine in mucosal biopsies and radioautography. Except for increased fundic mucosal height, duodenal ulcer patients did not differ from controls for all parameters studied. In vagotomized patients, as compared to the other two groups, the labeling index was significantly enhanced in the innervated antral mucosa where atrophic gastritis developed, but there was no change in the labeling index and no worsening of mucosal inflammation in the denervated fundic mucosa. The only abnormality in the latter was a striking expansion, towards the surface, of the proliferative area within the fundic pit. The labeling indices and the degree of gastritis in gastric mucosae are significantly correlated in control and duodenal ulcer patients. After superselective vagotomy, this correlation still existed in antral mucosa (r = 0.88, P less than 0.001) but not in fundic mucosa. If findings in antral mucosa, after superselective vagotomy, seemed related to gastritis lesions, those in fundic mucosa were not and may indicate an alteration due to the vagotomy per se.

Adolescent↗

A simple device to aid impalement of cells using conventional microelectrode drives.

Consistent penetration of cell membranes by micropipettes is facilitated by using electrode accelerators or high velocity step drives. Notwithstanding, much intracellular work is still done with conventional mechanical or hydraulic drives; cell membrane penetration is achieved by means of gentle taps on any convenient part of the set up. A remote control device is described which performs this function and is compact enough to be fixed on either the microelectrode holder or the preparation mounting. It consists of a small magnetized rod freely suspended in a pot-core coil. A current pulse through the coil jolts the rod; the inertial reaction of the coil frame provides the sudden movement required by the micropipette tip to overcome the elastic resistance of the cell membrane.

Animals↗

Early evaluation of coronary artery bypass grafts: CT or selective angiography.

A prospective study was performed in 27 patients to compare the value of computed tomography and selective angiography in assessing coronary artery graft patency in the early post-operative period. The sensitivity of CT to graft patency was 85% with no falsely patent determinations. Dynamic CT was not found useful in predicting graft stenosis. There were no complications associated with CT studies, and two related to selective angiography. It is concluded that CT is the procedure of choice for graft evaluation in the early post-operative period; but that angiography is mandatory for the assessment of late symptom recurrence. A review is made of the results described in previous series.

Blood Vessel Prosthesis↗