The Diaphragm Challenged by Acid‐Base Imbalance
Bibliographic record
Abstract
Respiratory and Metabolic Acidosis can result from a variety of diseases and be sensed by receptors in the respiratory control system. But acid/base imbalance also directly affects the performance of the principal muscle of respiration, the diaphragm (D). In this presentation we provide an overview of the in vitro (rat) and in vivo (dog) D responses to four challenges: Uncompensated/Compensated respiratory acidosis (HC/CHC) and Uncompensated/Compensated Metabolic Acidosis (MA/CMA). Our findings revealed that HC reduced the force of tetanic contraction (FC) in both rat and dog Ds. This phenomenon is often seen in human subjects as well. CHC also reduced the FC of the rat D but less that HC. Both MA and CMA reduced the FC in both rat and dog Ds. We found decreases in FC are due to decreases in peak twitch tensions and increases in ½ relaxation time (1/2RT). We found that in the rat D neither HC, MA, nor CMA reduced ATP or PCr. Further, we found that methylxanthines, neostigmine, isoproterenol acted to attenuate the decreases in FC, each by different mechanisms. But first a glance at how decreased pH i per se can affect striated muscle: (1)Increased binding of Ca ++ by the sarcoplasmic reticulum (SR) and decreased rate of Ca ++ uptake and release per impulse. The first would prolong twitch ½ RT. (2)ATPase activity is decreased and Ca ++ concentration requirement for myofibril activation is increased. (3) K + leaks from the cell, hyperpolarizing the cell and reducing membrane excitability. This work was performed when S. Howell and Ch. Roussos were at Meakins‐Christie Laboratories, McGill University. Support: NIH (HL RO1‐50712‐14; MRC, Canada, Quebec Thoracic Society.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".