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L Cruz

Publications and source records attributed to L Cruz.

49 records · Page 3Linked to original sources
PubMed1986

Immunoreactive dynorphin B in sacral primary afferent fibers of the cat.

Immunocytochemical analysis of the distribution of dynorphin B terminals in the sacral spinal cord of the cat revealed a pattern of staining very similar to that produced with antisera directed against the primary afferent derived, putative neurotransmitter, vasoactive intestinal polypeptide. Labeled axons and terminals were concentrated in lamina I and V and there was dense fiber staining in the tract of Lissauer. Of particular interest was the presence of immunoreactive axons in attached dorsal rootlets. To specifically focus on the possibility that some of the sacral primary afferent fibers are dynorphin-immunoreactive, we first tried to increase perikaryal labeling in the sacral dorsal root ganglia by topical treatment with colchicine. This did not produce immunoreactive labeling of cell bodies in the ganglia. Unilateral multiple dorsal rhizotomy (L5 to coccygeal 1), however, significantly decreased the staining of dynorphin-immunoreactive axons and terminals in the tract of Lissauer and in the dorsal horn of sacral segments ipsilateral to the deafferentation. No changes were detected in the lumbar cord. Finally, radioimmunoassay of caudal lumbar and sacral dorsal root ganglia was performed. Measurable immunoreactivity was found in all ganglia assayed, but, consistent with the histochemical analysis, sacral ganglia contained the highest concentration of immunoreactive dynorphin B. These data indicate that a significant component of the sacral spinal cord dynorphin terminal immunoreactivity derives from primary afferent fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Multiple opioid peptides and the modulation of pain: immunohistochemical analysis of dynorphin and enkephalin in the trigeminal nucleus caudalis and spinal cord of the cat.

Using immunocytochemistry, we have identified important differences in the distribution of immunoreactive dynorphin and enkephalin cells and terminals in the trigeminal nucleus caudalis and in the spinal dorsal horn of the cat. Dynorphin immunoreactive processes are more closely associated with those regions of cord that process nociceptive information, specifically laminae I and V. Enkephalin neurons and terminals are more widespread. Based on the staining pattern with an antiserum to the octapeptide-metenkephalin-arg-gly-leu, we suggest that the dense enkephalin terminal immunoreactivity in the inner part of the substantia gelatinosa derives from cells in lamina III. There are also significant differences in the anatomical relationship of the two opioid peptides with the organization of parasympathetic autonomic preganglionic neurons. The functional significance of these observations must await physiological analysis; nevertheless, it is almost certain that differences will be found and that these will be important in understanding the mechanisms through which exogenous opiates and a variety of descending control systems exert their effects on spinal cord neurons.

Animals↗
PubMedDate not supplied

Water enema computed tomography (WE-CT) in the local staging of low colorectal neoplasms: comparison with transrectal ultrasound.

BACKGROUND: To determine the accuracy of computed tomography performed with a water enema application (WE-CT) in the local staging of low colorectal neoplasms and to compare the results with those of transrectal ultrasonography (TRUS). METHODS: Forty patients with low colorectal tumors were evaluated prospectively by CT with the simultaneous administration of a lukewarm rectal enema (0.5-1.5 L). Thin slices (5 mm) and intravenous application of iodinated contrast media were routinely used. TRUS was performed in 18 patients. Tumor size, location, and staging according to the TNM classification of the UICC were registered. Tumors were classified as < T3 (T1 or T2) or as T3 or T4. For staging peritumoral lymph node metastases on WE-CT, two criteria of positivity were tested: N+ if at least one peritumoral node > or 5 mm in diameter was seen (reading A); N+ if at least one peritumoral node > or = 5 mm or three peritumoral nodes < 5 mm were identified (reading B). RESULTS: For the tumor staging, WE-CT showed a sensitivity of 90%, a specificity of 73%, a positive predictive value (PPV) of 90%, a negative predictive value (NPV) of 73%, and an accuracy of 85%. For TRUS, the results were sensitivity of 73%, specificity of 29%, PPV of 62%, NPV of 40%, and an accuracy of 39%. Concerning nodal staging with WE-CT, results were superior when reading A was used: sensitivity = 84%, specificity = 83%, PPV = 73%, NPV = 91%, and accuracy = 84%. TRUS showed a sensitivity of 29%, specificity of 100%, PPV of 100%, NPV of 67%, and an accuracy of 71%. CONCLUSION: WE-CT is a reliable technique for the local staging of low colorectal tumors that can be superior to TRUS. For diagnosis of peritumoral metastatic lymph nodes on WE-CT, the 5-mm diameter cutoff value is the most appropriate size criterion.

Adenocarcinoma↗