Apnea during moderate to deep sedation using continuous infusion of remimazolam compared to propofol and dexmedetomidine: A retrospective observational study

Remimazolam's rapid onset and offset make it an innovative sedative for use during regional anesthesia. However, its respiratory safety profile is not well understood. We compared the continuous infusion of remimazolam with commonly used sedatives, propofol and dexmedetomidine, after regional anesthesia. In this retrospective study, the incidence of apnea (>10 seconds) was assessed in patients who underwent orthopedic surgery under regional anesthesia and received moderate to deep sedation using continuous infusion of remimazolam (group R: 0.1 mg/kg in 2 minutes followed by 0.5 mg/kg/hr). The incidence was compared with that of propofol (group P: 2-3 μg/mL target-controlled infusion) and dexmedetomidine (group D: 1 μg/kg in 10 minutes followed by 0.4-1 μg/kg/hr). Propensity score weighted multivariable logistic regression model was utilized to determine the effects of the sedative agents on the incidence of apnea. A total of 634 (191, 278, and 165 in group R, P, and D) cases were included in the final analysis. The incidence of apnea was 63.9%, 67.3%, and 48.5% in group R, P, and D, respectively. The adjusted odds ratios for apnea were 2.33 (95% CI, 1.50 to 3.61) and 2.50 (95% CI, 1.63 to 3.85) in group R and P, compared to group D. The incidence of apnea in patients receiving moderate to deep sedation using continuous infusion of remimazolam with dosage suggested in the current study was over 60%. Therefore, careful titration and respiratory monitoring is warranted.

Impact of changes in clinical practice guidelines for intra-articular injection treatments for knee osteoarthritis on public interest and social media

OBJECTIVE

To summarize changes in recommendations for injection treatments for knee osteoarthritis (OA) in current clinical practice guidelines (CPGs) and to assess whether these changes have affected public interest according to Google data and content in YouTube videos.

DESIGN

A literature search to identify CPGs revised since 2019 that provide recommendations regarding the five intra-articular injection treatments for knee OA (corticosteroid [CS], hyaluronic acid [HA], stem cell [SC], platelet-rich plasma [PRP], and botulinum toxin [BT]) was conducted to assess perspective changes for each treatment. Data from Google Trends were examined to identify changes in search volume from 2004 to 2021 using a join-point regression model. Relevant YouTube videos were divided into those uploaded before and after changes in CPGs and compared according to degrees of recommendation for each treatment to identify the effect of changes in CPGs on video production.

RESULTS

All eight identified CPGs released after 2019 recommended HA and CS use. Most CPGs were the first to state a neutral or opposing stance concerning the use of SC, PRP, or BT. Interestingly, relative searches on Google for SC, PRP, and BT has increased greater than those for CS and HA. YouTube videos produced after CPGs changed continue to recommend SC, PRP, and BT as much as those produced before CPGs were revised.

CONCLUSIONS

Although knee OA CPGs have changed, public interest and healthcare information providers on YouTube have not reacted to this shift. Improved methods to propagate updates to CPGs warrant consideration.

Rhizobium meliloti nodulation genes allow Agrobacterium tumefaciens and Escherichia coli to form pseudonodules on alfalfa

Regions of the Rhizobium meliloti symbiotic plasmid (20 to 40 kilobase pairs long) containing nodulation (nod) genes were transferred to Agrobacterium tumefaciens or Escherichia coli by conjugation. The A. tumefaciens and E. coli transconjugants elicited root hair curling and the formation of ineffective pseudonodules on inoculated alfalfa plants. A tumefaciens elicited pseudonodules formed at a variable frequency, ranging from 15 to 45%, irrespective of the presence of the Ti plasmid. These pseudonodules developed characteristic nodule meristems, and in some nodules, infection threads were found within the interior of nodules. Infrequently, infection threads penetrated deformed root hairs, but these threads were found only in a minority of nodules. There was no evidence of bacterial release from the infection threads. In addition to being found within threads, agrobacteria were also found in intercellular spaces and within nodule cells that had senesced . In the latter case, the bacteria appeared to invade the nodule cells independently of infection threads and degenerated at the same time as the senescing host cells. No peribacteroid membranes enclosed any agrobacteria , and no bacteroid differentiation was observed. In contrast to the A. tumefaciens-induced pseudonodules , the E. coli-induced pseudonodules were completely devoid of bacteria; infection threads were not found to penetrate root hairs or within nodules. Our results suggest that relatively few Rhizobium genes are involved in the earliest stages of nodulation, and that curling of root hairs and penetration of bacteria via root hair infection threads are not prerequisites for nodule meristem formation in alfalfa.

Ultrastructural analysis of ineffective alfalfa nodules formed by nif::Tn5 mutants of Rhizobium meliloti

Ineffective alfalfa nodules formed by Rhizobium meliloti nif::Tn5 mutants were examined by light and electron microscopy. R. meliloti nifH::Tn5 mutants formed nodules that were similar in structure to wild-type nodules except that nifH- bacteroids accumulated a compact, electron-dense body. In contrast to nodules induced by wild type and nifH mutants, nifDK- R. meliloti mutants induced nodules which contained numerous starch grains and prematurely senescent bacteroids. In addition, meristematic activity in nifDK- nodules ceased significantly earlier than in nifH- nodules. All mutant nodules exhibited elevated levels of rough endoplasmic reticulum and Golgi membranes compared to wild-type nodule cells. These elevated levels may reflect either a response to nitrogen starvation in the ineffective nodules or an abnormal synthesis and export of nodule-specific proteins during later developmental stages.

Structural studies of alfalfa roots infected with nodulation mutants of Rhizobium meliloti

Alfalfa roots infected with four nodulation defective (Nod-) mutants of Rhizobium meliloti which were generated by transposon Tn5 mutagenesis were examined by light and electron microscopy. In one class of Nod- mutants, which we can nonreactive, the bacteria did not induce root hair curling or penetrate host cells. In a second class of Nod- mutants, which we call reactive, the bacteria induced some root hair curling and entered root epidermal cells, although no infection threads were formed. In addition, reactive Nod- mutants induced extensive root hair proliferation and hypertrophied roots. This study presents the details of the phenotype of the association between each mutant strain and alfalfa roots.