Effects of paced respiration on anxiety reduction in a clinical population

The purpose of this study was to examine the effects of paced respiration on autonomic and self-report indices of affect within a clinical population. Thirty-six alcohol-dependent inpatients scoring high in trait anxiety were randomly assigned to either a pacing or attention control group. The paced subjects received 10 minutes of slow-breathing training during the first experimental session, while control subjects simply counted the pacing tones. In a second session, paced subjects were asked to breathe at the same lowered rate (10 cycles per minute) on their own, while the remaining subjects were instructed to relax. Prior to and following each session, self-ratings of tension level and state anxiety were collected. As expected, paced subjects evidenced greater reductions in self-rated tension, state anxiety, and skin conductance levels compared to the control subjects. It was concluded that respiratory pacing is an easily learned self-control strategy and potentially may be a useful therapeutic tool.     

Effects of paced respiration on anxiety reduction in a clinical population

The purpose of this study was to examine the effects of paced respiration on autonomic and self-report indices of affect within a clinical population. Thirty-six alcohol-dependent inpatients scoring high in trait anxiety were randomly assigned to either a pacing or attention control group. The paced subjects received 10 minutes of slow-breathing training during the first experimental session, while control subjects simply counted the pacing tones. In a second session, paced subjects were asked to breathe at the same lowered rate (10 cycles per minute) on their own, while the remaining subjects were instructed to relax. Prior to and following each session, self-ratings of tension level and state anxiety were collected. As expected, paced subjects evidenced greater reductions in self-rated tension, state anxiety, and skin conductance levels compared to the control subjects. It was concluded that respiratory pacing is an easily learned self-control strategy and potentially may be a useful therapeutic tool.This project was supported by Veterans Administration Medical Health Services Research and Development funds awarded to the first author.     

Severe impairment of nucleotide synthesis through inhibition of mitochondrial respiration

Since de-novo synthesis of pyrimidine nucleotides is coupled to the mitochondrial respiratory chain (RC) via dehydroorotic acid dehydrogenase (DHODH), respiratory chain dysfunction should impair pyrimidine synthesis. To investigate this, we used specific RC inhibitors, Antimycin A and Rotenone, to treat primary human keratinocytes and 143B cells, a human osteosarcoma cell line, in culture. This resulted in severe impairment of de novo pyrimidine nucleotide synthesis. The effects of RC inhibition were not restricted to pyrimidine synthesis, but concerned purine nucleotides, too. While the total amount of purine nucleotides was not diminished, they were significantly broken down from triphosphates to monophosphates, reflecting impaired mitochondrial ATP regeneration. The effect of Rotenone was similar to that of Antimycin A. This was surprising since Rotenone inhibits complex I of the respiratory chain, which is upstream of ubiquinone where DHODH interacts with the RC. In order to avoid unspecific effects of Rotenone, we examined the consequences of a mitochondrial DNA mutation that causes a specific complex I defect. The effect was much less pronounced than with Rotenone, suggesting that complex I inhibiton cannot fully explain the marked effect of Rotenone on pyrimidine nucleotide synthesis.     

Plant species richness regulates soil respiration through changes in productivity

Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of diversity on soil respiration. We hypothesized that plant diversity could affect soil respiration in two ways. On the one hand, more diverse plant communities have been shown to promote plant productivity, which could increase soil respiration. On the other hand, the nutrient concentration in the biomass produced has been shown to decrease with diversity, which could counteract the production-induced increase in soil respiration. Our results clearly show that soil respiration increased with species richness. Detailed analysis revealed that this effect was not due to differences in species composition. In general, soil respiration in mixtures was higher than would be expected from the monocultures. Path analysis revealed that species richness predominantly regulates soil respiration through changes in productivity. No evidence supporting the hypothesized negative effect of lower N concentration on soil respiration was found. We conclude that shifts in productivity are the main mechanism by which changes in plant diversity may affect soil respiration.     

Treatment of the chronic pain patient.

A small percentage of patients with persistent pain are sufficiently angry, demanding, and manipulative to require the negotiation of an explicit treatment and/or management contract. The very few studies in this field suggest that pain is both a function of and a stimulus to abnormal illness behavior, thus requiring special attention to therapeutic "ground rules." Treatment requires an unequivocal assertion by the patient that he wishes to get better and is willing to work at doing so; the specification of clearcut goals and the means of working towards them ("pacing behavior"); and the possible use of electrical neurostimulation and/or weak analgesics for pain control. Explicit understanding of mutual expectations and the patient's and doctor's "rights" is also helpful in fostering goodwill and desirable results.     

Chronic pain as a reticular formation syndrome

Evidence was previously presented to support the thesis that chronic pain is activated by neuronal elements that make up the multisynaptic short axon core of the reticular system (Andy and Peeler 1985). The present thesis, that chronic pain is a reticular formation syndrome, is based on a retrospective analysis of four patients with chronic pain who were successfully treated with a lesion in the anterior thalamus and stimulation electrode implants in the posterior thalamus and pontomesencephalic brain stem. The reticular formation was the common underlying anatomic substrate at those three sites. In addition to chronic pain, all the patients had other symptoms attributable to other body organs and systems. The number and type of symptoms that made up the syndrome differed between patients. Symptoms making up the core of the syndrome were pain, anxiety, nervousness, insomnia, and depression. Experimental and clinical findings are briefly presented to demonstrate the various reticular formation sites, pragmatically considered "reticular functional systems," from which symptoms may arise. It is hypothesized that the symptoms are recruited by a low threshold "pain oscillator" that is generated at one reticular site and subsequently permeates the rest of the reticular system. Therapeutic stimulation inactivates the low threshold system by "jamming" it.