Richard Cheng

Electroacupuncture Elevates Blood Cortisol Levels in Naive Horses; Sham Treatment has no Effect

It was hypothesized that electroacupuncture releases beta-endorphin and ACTH from the pituitary. Since ACTH induces the release of cortisol from the adrenal glands, blood cortisol level should be enhanced by electroacupuncture. The present result shows that the blood cortisol levels of horses are significantly increased after 30 min of electroacupuncture treatment while the sham treatment (control) shows an insignificant effect.

Dexamethasone partially reduces and 2% saline-treatment abolished electroacupuncture analgesia: These findings implicate pituitary endorphins

Abstract Dexamethasone, a cortisol analogue which inhibits ACTH and endorphin release in a negative feedback system, partially reduces electroacupuncture analgesia (EAA) in mice. In addition, mice forced to drink 2% saline for 3 days (this reduces pituitary endorphin levels) had a complete loss of EAA. These two experiments support our previous finding that hypophysectomy abolishes EAA. Altogether, these results implicate pituitary endorphins in EAA.

PAIN THRESHOLD AND BRAIN ENDORPHIN LEVELS IN GENETICALLY OBESE (ob/ob) AND OPIATE RECEPTOR DEFICIENT (CXBK) MICE

Genetically obese (ob/ob) mice have a higher pain threshold than control mice. CXBK mice, which are deficient in opiate receptors, have a similar pain threshold to controls. There was no significant difference in the brain levels of opiate peptides or methionine enkephalin in genetically obese (ob/ob), opiate receptor deficient (CXBK) or control mice. These results suggest that the excessive eating behavior of genetically obese (ob/ob) mice is not associated with altered brain levels of endorphins. The elevated levels of pituitary brain endorphins in obese (ob/ob) mice may be responsible for their high pain thresholds. The presence of an opiate receptor assayable substance other than methionine enkephalin and B-endorphin in the brain extracts of each of these species is indicated.

Relationship between retinal blood flow and arterial oxygen

Vascular reactivity, the response of the vessels to a vasoactive stimulus such as hypoxia and hyperoxia, can be used to assess the vascular range of adjustment in which the vessels are able to compensate for changes in PO2 . Previous studies in the retina have not accurately quantified retinal vascular responses and precisely targeted multiple PaO2 stimuli at the same time as controlling the level of carbon dioxide, thus precluding them from modelling the relationship between retinal blood flow and oxygen. The present study modelled the relationship between retinal blood flow and PaO2 , showing them to be a combined linear and hyperbolic function. This model demonstrates that the resting tonus of the vessels is at the mid‐point and that they have great vascular range of adjustment, compensating for decreases in oxygen above a P ETC O2 of 32–37 mmHg but being limited below this threshold.

Retinal Blood Flow and Vascular Reactivity in Chronic Smokers

PURPOSE The aim of this study was to investigate the impact of cigarette smoking in otherwise healthy young individuals on retinal blood flow (RBF) and vascular reactivity (RVR). METHODS An automated gas flow controller (RespirAct) was used to achieve normoxic hypercapnia in 10 nonsmokers (mean age 28.9; SD 4.6 years) and nine smokers (mean age 27.55; SD 4.7 years). Retinal blood flow measurements were obtained using a prototype Doppler spectral-domain optical coherence tomographer (SD-OCT) and bidirectional laser Doppler velocimetry and simultaneous vessel densitometry during baseline, normoxic hypercapnia, and recovery. Group mean PETCO2 (end-tidal partial pressure of CO2) was increased by 15.9% in the nonsmoking group and by 15.7% in the smoking group, with a concomitant increase in PETO2 (end-tidal partial pressure of O2) by approximately 1.5% to 2% in both groups. RESULTS In nonsmokers, retinal arteriolar diameter (P < 0.0001), centerline velocity (P = 0.0004), and blood flow (P < 0.0001) significantly increased during normoxic hypercapnia. Similarly, the venous area (P = 0.0418), venous velocity (P = 0.0068), and total venous RBF (P < 0.0001), as measured by the prototype Doppler SD-OCT, significantly increased. In smokers, normoxic hypercapnia resulted in a significant increase in velocity (P = 0.0019), flow (P = 0.0029), and total venous RBF (P = 0.002). Comparing smokers and nonsmokers, the percentage change in arteriolar diameter (P = 0.0379) and blood flow (P = 0.0101) was significantly lower in the smoking group. There was no significant difference in baseline PETCO2 level between smokers and nonsmokers. CONCLUSIONS Retinal vascular reactivity in response to normoxic hypercapnia is significantly reduced in young, healthy smokers compared with nonsmokers.

Human prefrontal cortical response to the meditative state: a spectroscopy study.

ABSTRACT The effect of Qigong meditation on the hemodynamics of the prefrontal cortex was investigated by spectroscopy with a single-wavelength probe (650 nm) and confirmed by standard near-infrared spectroscopy with a dual-wavelength probe. Deoxyhemoglobin changes were recorded with the single-wavelength probe over the left prefrontal cortex during meditation by Qigong practitioners, and non-practitioners instructed in the technique. Practitioners showed a significant decrease in deoxyhemoglobin levels suggesting an increase in prefrontal activation during meditation. The results were confirmed in a second set of experiments with the standard dual-wavelength probe, in which significant differences in the decrease in deoxyhemoglobin and increase in oxyhemoglobin concentrations were observed in practitioners as compared with non-practitioners. The study thus provides evidence that Qigong meditation has a significant effect on prefrontal activation.

THE ANTIPEPTIDASES INCREASE ELECTROACUPUNCTURE ANALGESIA AND SHOW PREDICTABLE HYPALGESIC EFFECTS ON MICE WITH CONGENITALLY ABNORMAL ENDORPHIN SYSTEMS

Summary To test the hypothesis that antipeptidases produce hypalgesia by protecting endorphins from enzymatic degradation, we test the effect of D-leucine and D-phenylalanine on mice with congenitally abnormal endorphin systems. In three strains of mice antipeptidase hypalgesia ranks in the order of Ob/Ob > b6AF1/J > CXBK. This correlates with the endorphin abnormalities in these mice: Ob/Ob high in pituitary beta-endorphin and CXBK low in opiate receptors. In addition, antipeptidases significantly increases electroacupuncture hypalgesia in b6AF1/J mice. All the above hypalgesia are reversed by naloxone.

ELECTROACUPUNCTURE HYPALGESIA IS ENHANCED IN MORPHINE DEPENDENT MICE; SHOWING NO CROSS-TOLERANCE AND REDUCING SIGNS OF WITHDRAWAL

Summary Electroacupuncture hypalgesia was significantly enhanced in addicted B6AF1/J mice during morphine tolerance as compared to those non-addicted mice. This result indicates that electroacupuncture hypalgesia shows no cross-tolerance with morphine. In addition, electroacupuncture reduces signs of withdrawal in 6 out of 12 mice.

NK-92 Cytotoxicity Against Cancer Stem Cells in Hematologic Malignancies

The discovery that many cancers are driven by a rare population of cancer stem cells has raised new questions as to how the immune system recognizes these cells. There is evidence to support an immunophenotypically defined stem cell in acute myeloid leukemia and multiple myeloma, two common hematologic malignancies. While chemotherapy can cure a minority of AML patients, multiple myeloma is generally incurable with this approach. However, allogeneic stem cell transplantation is the most effective therapy for AML implying an important role for the graft-versus-leukemia effect while multiple myeloma is typically treated with autologous bone marrow transplantation. One novel emerging therapeutic approach is the use of immune effector cell lines that have a broad tumour killing capacity such as NK-92. Here we review the role of NK-92 in the recognition and killing of cancer stem cells in leukemia and multiple myeloma and outline the application of clonogenic cytotoxicity assays to study these immunologic interactions.