Surgical stress attenuates reflex heart rate response to hypotension

Purpose

The baroreflex-mediated increase in heart rate (HR) in response to acute reduction of systolic blood pressure (SBP) was studied in order to assess whether the changes in arterial baroreflex sensitivity depend on the intensity of surgical stress, and location of visceral and somatic stimulation during surgery.

Methods

Patients were divided into visceral stimulation groups [upper (n = 30) and lower (n = 30) abdominal surgery] and somatic stimulation groups [upper (n = 25) and lower (n = 25) limbs, and chest wall (n = 25) surgery]. Acute hypotension as a baroreflex depressor test was induced by prostaglandin E₁ (PGE₁) 10 min before surgical incision (control) and during surgical manipulation under isoflurane-N₂O anaesthesia or isoflurane-N₂O-fentanyl anaesthesia. Plasma level of ACTH was measured in an additional 40 patients who underwent upper abdominal surgery.

Results

During upper abdominal surgery, the heart rate baroreflex sensitivity (ΔHR/ΔSBP) was depressed from-0.47 ± 0.05 (control) to -0.01 ± 0.04 (P < 0.05). The reflex heart rate baroreflex sensitivity remained unchanged and was similar among the remaining groups of patients. The concentration of ACTH increased from 12.5 ± 1.0 (control) to 343 ± 78.6 pg·ml^?1 (P < 0.05) with isoflurane-N₂O anaesthesia but did not change with isoflurane-N₂O-fentanyl anaesthesia during upper abdominal surgery.

Conclusion

Upper abdominal surgery is associated with the most stressful stimulation to attenuate heart rate baroreflex sensitivity. Integrity of the baroreflex can be preserved by adding opioids to supplement inhalation anaesthesia.     

Spatiotemporal characteristics of the neural activities processing consonant/dissonant tones in melody

To identify neural correlates underlying melody processing, we measured MEG responses elicited by keynote and out-of-key tones at the end of musical phrases. These melodies were newly composed and unknown to the subjects. Significant enlargements of N1m/P2m peaks at about 120–160 ms were observed in response to dissonant (out-of-key) tones compared to those in response to consonant (keynote) tones. The equivalent current dipoles (ECD) of the N1m were localized in areas centered at bilateral primary auditory cortices in the superior surface of the temporal lobe. Following the N1m/P2m, a late component occurring at 280–530 ms was observed. As the latency proceeded, the location of ECD sources of the late component shifted in the right hemisphere, but not in the left hemisphere, from the supratemporal auditory cortex to a posterior inferior auditory association cortex around the superior temporal sulcus (STS). The grand mean locations of the ECDs for consonant and dissonant tones were separated at a peak period of 380–410 ms of the late component but converged to the same region around the STS in the last period of 440–530 ms. These observations suggest that the neural activities generating the N1m component in the bilateral auditory cortices may play a role in automatic detection of tonality mismatch based on the pitch analysis. The activities of the late component around the posterior part of the right STS are thought to be involved in the analysis of pitch-sequence, such as how the pitch changes temporally, as a pre-process of melody perception.     

PRIMARY PULMONARY ARTERY SARCOMA. Report of Two Autopsy Cases Studied by Immunohistochemistry and Electron Microscopy, and Review of 110 Cases Reported in the Literature

Two cases of primary pulmonary artery sarcoma are reported. The patient in the first case was a 61-year-old male with a two-year history of cough and exertional dyspnea, who died of intractable cardiac failure two months after admission without establishment of a diagnosis related to the etiology of cardiac failure. Autopsy revealed a sessile tumor within the pulmonary trunk and a solitary metastatic lesion in the lung. Histologic, immunohistocyto-chemical and electron microscopic studies were performed and a diagnosis of malignant mesenchymoma was made. The patient in the second case was a 32-year-old male complaining of exertional dyspnea and back pain. Radiologic studies indicated a mediastinal tumor involving the pulmonary artery. Exploratory thoracotomy revealed that the mediastinal mass arose from the left pulmonary artery. He died of respiratory failure 26 months after onset of his initial symptoms. Histologic, immunocytochemical and electron microscopic studies of both surgical and autopsy materials revealed a malignant fibrous histiocytoma. One hundred ten previously reported cases of this tumor are reviewed, and its clinicopathologic and morphologic features and probable histogenesis are discussed. ACTA PATHOL JPN 38: 883∼896, 1988.     

Levels of oxidative stress and redox-related molecules in the placenta in preeclampsia and fetal growth restriction

Recent evidence suggests that oxidative stress is involved in the pathophysiology of preeclampsia. Using immunohistochemistry and Western blotting, we investigated the oxidative stress- and redox-related molecules, such as 8-hydroxy-2-deoxyguanosine (8-OHdG), 4-hydroxynonenal (4-HNE), thioredoxin (TRX) and redox factor-1 (ref-1) in the placenta in preeclampsia, intrauterine growth restriction (IUGR), preeclampsia + IUGR and in normal pregnancy. Using immunohistochemistry, the level of 8-OHdG was significantly higher in IUGR (P=0.012) or preeclampsia + IUGR (P=0.0021) than in normal pregnancy, while TRX expression was significantly higher in preeclampsia (P=0.045), and ref-1 expression was significantly higher in preeclampsia (P=0.017), IUGR (P=0.016) and preeclampsia + IUGR (P=0.0038) than in normal pregnancy. The levels of 4-HNE did not differ significantly between either preeclampsia or IUGR and normal pregnancy. A significant positive correlation was observed between TRX and ref-1 expressions in both normal (=0.52) and complicated (=0.43) pregnancies. Using Western blotting, ref-1 expression tended to be higher in complicated pregnancies than in normal pregnancy (P=0.09). These results suggest that oxidative DNA damage is increased in IUGR and that redox function is enhanced in both preeclampsia and IUGR compared with normal pregnancy.     

Essential role of active nuclear transport in apoptosis

Background : Apoptosis is defined by chromatin condensation, nuclear fragmentation and the formation of apoptotic bodies. Because apoptotic signals are transmitted through a common pathway that includes the target steps of death-driving ICE-family proteases and anti-cell death protein Bcl-2 in the cytoplasm, the signals must be transferred from the cytoplasm to the nucleus, at least to induce the apoptotic manifestation of the nucleus. Small signal molecules might diffuse across nuclear pores, but larger molecules are transported by active mechanisms requiring ATP and GTP hydrolysis. It is not known whether apoptotic signals are transmitted into the nucleus by the mechanisms of active nuclear transport.
Results : To test the possibility that active nuclear transport is involved in apoptotic signal transmission, we have analysed the effects of molecules that inhibit active nuclear transport on apoptosis. Wheat germ agglutinin (WGA), excess amounts of p10 protein, Ran-GTPγS complex, and anti-PTAC58 antibody, which all inhibit active nuclear transport when exogenously microinjected, prevent Fas-induced apoptotic nuclear manifestation. WGA also prevents apoptotic nuclear change promoted by microinjected active CPP32β/Yama protease (an ICE family member), which plays an essential role in most apoptosis.
Conclusions : The results presented here strongly suggest that active nuclear transport is essential for apoptotic signal transduction.     

Twenty seven nucleotide deletion within exon 11 of the erythrocyte band 3 gene in Indonesian ovalocytosis

Summary We here report the molecular characterization of an Indonesian ovalocytosis. The analysis of genomic gene by polymerase chain reaction shows that the individual has two amplified products from a region encompassing exon 11 of the erythrocyte band 3 gene. The sequence of the larger product matched completely with that of normal individuals. In the sequence of the smaller product, 27 nucleotides within exon 11 disappeared. The deletion removes a total of nine amino acids in the boundary of cytoplasmic and membrane domains of band 3 protein, a membrane anion transporter protein. This is the first report to confirm the heterogeneous presence of an altered membrane band 3 protein in Indonesian ovalocytosis.     

Quantitative Analysis of Human Immunodeficiency Virus Type 1 DNA Dynamics by Real-Time PCR: Integration Efficiency in Stimulated and Unstimulated Peripheral Blood Mononuclear Cells

We established a set of real-time PCR assay to accurately quantify human immunodeficiency virus type 1 (HIV-1) DNA in infected cells. Using this assay we were able to measure the strong-stop, full-length/ 1-LTR circle, 2-LTR circle, and integrated forms of viral DNA, and the data provided was quite consistent with the characteristics of mutant viruses in early phase of infection. Since our assay is particularly applicable to quantify the integrated DNA in small scale of samples, we measured the level of integrated DNA in wild-type virus (WT)- or Vpr-defective virus (Vpr)-infected peripheral blood mononuclear cells (PBMC), and examined whether quiescent condition of the PBMC influences integration step of HIV-1. Under stimulating condition approximately 25% of total viral DNA was in integrated form in either WT- or Vpr-infected cells. In contrast, under unstimulated condition the level of integration efficiency was not significantly reduced in WT-infected cells, while this efficiency was severely impaired in the absence of vpr gene. This result clearly demonstrated a crucial role of the Vpr for nuclear localization and subsequent integration of viral DNA in nondividing cells. Therefore, our assay is useful for analyzing the events in early phase of HIV-1 infection under various conditions.