Detailed mapping of CGRP mRNA expression in the rat central nervous system: Comparison with previous immunocytochemical findings

The localization of CGRP mRNA in neurons of the rat brain and spinal cord was assessed by in situ hybridization histochemistry (ISH) using a radiolabeled synthetic 57-mer oiigodeoxynucleotide probe complementary to the rat prepro CGRP mRNA. Results were compared with previously published findings of CGRP-immunoreactive (CGRP-IR) cell bodies revealed by an indirect immunofluorescence technique. The highest numbers of CGRP mRNA expressing neurons as well as the greatest intensity of staining were found in the lateral hypothalamic area, the parabrachial nuclei, and among the cranial motor nuclei, especially in the nuclei of the 7th and 12th nerve and the ambiguus nucleus, which is generally in good agreement with findings assessed by immunocytochemistry (ICH). However, some mismatches between the localizaton of the peptide by ICH and the localization of the CGRP mRNA were also observed. Thus, ISH was not able to confirm CGRP-IR in cells of the amygdaloid complex and parts of the medial hypothalamus, the central gray, and the inferior colliculus, but ISH revealed considerably more CGRP mRNA expressing cells in the lateral hypothalamic area, arcuate nucleus, posterior and peripeduncular thalamic nuclei, and all cranial motor nuclei than CGRP-IR containing cells found by ICH. Moreover, ISH also revealed CGRP mRNA synthesis in the nucleus of the lateral olfactory tract and in the perihypoglossal nuclei that were devoid of CGRP-IR. The reasons for the observed mismatches still remain to be elucidated; however, intracerebroventricular colchicine pretreatment used to increase immunocytochemical signals also might have induced or suppressed gene expression in certain brain regions in an unpredictable matter. On the other hand, detection of only the mRNA in a certain region does not necessarily mean that also the active peptide is synthesized there.     

S100 protein-immunoreactive primary sensory neurons in the trigeminal and dorsal root ganglia of the rat

The cell body size (cross-sectional area) of S100-immunoreactive (-ir) primary neurons was measured in the trigeminal (TG) and lumbar dorsal root ganglia (DRG). About a half of neurons exhibited S100-immunoreactivity (-ir) in the DRG (44.0%) and TG (59.0%). DRG neurons with cell bodies >1200 μm² mostly exhibited S100-ir (96.5%), whereas S100-ir DRG neurons <600 μm² were rare (8.0%). 36.6% of DRG neurons in the cell size range 600–1200 μm² showed the ir. TG neurons >800 μm² mostly exhibited S100-ir (93.1%), whereas those <400 μm² were devoid of it (positive cells 10.5%). 58.3% of TG cells in the range 400–800 μm² contained S100-ir. Double-immunofluorescence method revealed the co-expression of S100 and other calcium-binding proteins. Parvalbumin-ir neurons mostly exhibited S100-ir in the DRG (97.4%) and TG (97.0%). The co-expression of S100 and calbindin D-28k was very rare in the DRG, because the DRG contained few calbindin D-28k-ir neurons. Unlike in the DRG, numerous neurons co-expressed S100- and calbindin D-28k-ir in the TG. Most calbindin D-28k-ir TG neurons were also immunoreactive for S100 (90.7%). Sub-populations of calretinin (CR)-ir neurons co-expressed S100-ir in both the DRG (68%) and TG (50.0%). Virtually all CR-ir neurons >1400 μm² co-expressed S100-ir in the DRG (100%) and TG (95.9%). CR-ir neurons <800 μm² were rarely exhibited S100-ir (DRG 18.0%, TG 21.9%). 71.3 and 60.5% of CR-ir neurons in the range 800–1400 μm² co-expressed S100-ir in the DRG and TG, respectively. The present study indicates that S100 is closely correlated to the primary neuronal cell size in the DRG and TG.     

Internal mammary artery bypass: thirteen years of experience. Influence of angina and survival in 5125 patients.

Internal mammary artery (IMA) bypass to the anterior descending coronary artery (ADA) was performed in 5125 patients from January 1978 to December 1990. The average age of patients was 68 years; males accounted for 68% (3485 patients) and 82% (4203) were NYHA Class III. Left ventricular function was impaired (ejection fraction < 40%) in 68% (3485 patients). The average number of additional saphenous vein graft (SVG) per patient was 2.2. Operative mortality was 1.8%. Mediastinitis occurred in 51 patients (1.0%). Reoperation for bleeding was necessary in 56 patients (1.1%). Perioperative myocardial infarction was seen in 102 patients (2.0%) and neurological complications occurred in 51 patients (1%). Repeat coronary angiography was performed in 1414 patients (28%) and demonstrated a patency rate of 96% in IMA grafts and 75% in SVG grafts (p < 0.001). Survival at 13 years was 80% from all causes and 90% when non-cardiac deaths were excluded. Recurrence of angina occurred in 768 patients (15%) and reoperation or PTCA was performed in 61 (1.2%). During the same time period, 2345 patients underwent coronary artery bypass utilizing solely SVG. Survival at 13 years was 68% from all causes and 78% when non-cardiac deaths were excluded (p < 0.001). Recurrent angina was present in 727 patients (31%) (< 0.001). This data suggests that long-term probability of cumulative survival and occlusion free survival were significantly greater and the probability of recurrent angina and reoperative CABG and death from cardiac causes were significantly less in the IMA patients and should be the conduit of choice in coronary bypass surgery.