Deep single-cell RNA-seq data clustering with graph prototypical contrastive learning.

MOTIVATION: Single-cell RNA sequencing enables researchers to study cellular heterogeneity at single-cell level. To this end, identifying cell types of cells with clustering techniques becomes an important task for downstream analysis. However, challenges of scRNA-seq data such as pervasive dropout phenomena hinder obtaining robust clustering outputs. Although existing studies try to alleviate these problems, they fall short of fully leveraging the relationship information and mainly rely on reconstruction-based losses that highly depend on the data quality, which is sometimes noisy. RESULTS: This work proposes a graph-based prototypical contrastive learning method, named scGPCL. Specifically, scGPCL encodes the cell representations using Graph Neural Networks on cell-gene graph that captures the relational information inherent in scRNA-seq data and introduces prototypical contrastive learning to learn cell representations by pushing apart semantically dissimilar pairs and pulling together similar ones. Through extensive experiments on both simulated and real scRNA-seq data, we demonstrate the effectiveness and efficiency of scGPCL. AVAILABILITY AND IMPLEMENTATION: Code is available at https://github.com/Junseok0207/scGPCL.

Successful electrode insertion for spinal cord stimulation after balloon adhesiolysis in a patient with epidural adhesion - A case report.

BACKGROUND: Spinal cord stimulation (SCS) can be successfully performed using highly developed implantation techniques. However, anatomical barriers, such as epidural adhesion, may impede placing the electrode for SCS in an adequate position. CASE: A 60-year-old female who had SCS with an electrode at the T9-10 level removed because she had a wound infection at the back incision site. After the wound infection was completely resolved, we tried to re-insert the SCS electrode. However, it was difficult to advance it up to the T11 level due to epidural adhesion. We performed a combined epidural adhesiolysis using balloon decompression with an inflatable balloon catheter. After that, the SCS lead was successfully placed up to the T11 level, and implantation of SCS was performed. CONCLUSIONS: When a patient has epidural adhesion, an epidural adhesiolysis with an inflatable balloon catheter may help the insertion of the SCS electrode in the epidural space.

Transversus abdominis plane block as a sole anesthetic technique for evacuation of rectus abdominis muscle hematoma - A case report.

BACKGROUND: Transversus abdominis plane (TAP) blocks have been used for analgesia in various abdominal surgeries. However, a TAP block as the sole anesthetic method for surgery has rarely been reported. CASE: A 33-year-old breastfeeding primipara woman was admitted to the hospital due to a rectus abdominis muscle hematoma. Because the patient refused other anesthetic methods, evacuation of the hematoma was performed under an ultrasound-guided bilateral TAP block. A 23-gauge needle was inserted in an in-plane method using a linear ultrasound probe. An injection of 10 ml of 2% lidocaine was made to the right lateral TAP and the left lateral TAP. After confirming the sensory blockade of the T10 to T12 dermatomes, surgery was performed successfully. The patient's condition stabilized during the surgery. Breastfeeding was performed on the day of surgery. CONCLUSIONS: The evacuation of an abdominal wall hematoma in a breastfeeding patient was successfully performed under a bilateral TAP block.

Transforaminal Epidural Balloon Adhesiolysis via a Contralateral Interlaminar Retrograde Foraminal Approach: A Retrospective Analysis and Technical Considerations.

Several treatment modalities have been proposed for foraminal stenosis, but the treatment options remain unsatisfactory. Previous studies have shown that transforaminal balloon adhesiolysis may be effective in patients with refractory lumbar foraminal stenosis. However, in patients with a high iliac crest, balloon catheter insertion may be difficult via a conventional transforaminal approach (particularly targeting the L5-S1 foramen). It has been reported that an epidural catheter can be placed easily by a contralateral interlaminar retrograde foraminal approach. Therefore, we applied this approach to L5-S1 transforaminal balloon adhesiolysis in patients with a high iliac crest. We retrospectively analyzed data from 22 patients who underwent combined epidural adhesiolysis and balloon decompression (balloon adhesiolysis) using the novel foraminal balloon catheter via a contralateral interlaminar retrograde foraminal approach. The pain intensity significantly decreased over the three-month period after balloon adhesiolysis (p < 0.001). There were no complications associated with the balloon procedure. The present study suggests that balloon adhesiolysis for L5-S1 foramen via a contralateral interlaminar retrograde foraminal approach may be an effective alternative for patients with a high iliac crest and refractory lumbar radicular pain due to lumbar foraminal stenosis. In addition, detailed procedural aspects are described here.

Comparison between cerebral state index and bispectral index during desflurane anesthesia.

BACKGROUND: Cerebral state index (CSI) is an anesthesia depth monitor alternative to bispectral index (BIS). Published comparative studies have used propofol or sevoflurane. However, studies using desflurane have not been reported yet. Different volatile anesthetics have different electroencephalography signatures. The performance of CSI may be different in desflurane anesthesia. Therefore, the objective of this study was to compare CSI and BIS during desflurane anesthesia. METHODS: Thirty-three patients were recruited. Desflurane and remifentanil were used to maintain general anesthesia. BIS and CSI were recorded simultaneously every minute. End-tidal concentration of desflurane was maintained at 4% from the beginning of surgery for 5 minutes. Pairwise data of CSI and BIS were obtained five times at one-minute intervals. This process was repeated in the order of 6%, 8%, and 10%. RESULTS: BIS and CSI were negatively correlated with the end-tidal concentration of desflurane with a similar degree of correlation (correlation coefficient BIS: -0.847, CSI: -0.844). The relationship between CSI and BIS had a good linearity with a slope close to 1 (R2 = 0.905, slope = 1.01). For the relationship between CSI and BIS at each end-tidal concentration of desflurane, CSI and BIS showed good linearity in 4% and 10% (R2 = 0.559, 0.540). However, the linearity and slope were decreased in 6% and 8% (R2 = 0.163, 0.014). CONCLUSIONS: CSI showed an equivalent degree of overall performance compared to BIS in desflurane anesthesia. Accounting for previous literature, CSI can be used as a good substitute for BIS regardless of the kind of anesthetics used.

The effects of adjuvant intrathecal fentanyl on postoperative pain and rebound pain for anorectal surgery under saddle anesthesia.

BACKGROUND: Intrathecal opioid has been known to enhance the quality and prolong the duration of spinal anesthesia, as well as to reduce postoperative pain. The purpose of this study was to evaluate postoperative analgesic characteristics of intrathecal fentanyl for the first 48 hours after anorectal surgery under saddle anesthesia. METHODS: Eighty patients were recruited in our study. Forty patients were randomly allocated to group B that received 0.5% bupivacaine 5 mg with 0.3 ml normal saline. The other 40 patients were assigned to group BF which was given 0.5% bupivacaine 5 mg with fentanyl 15 µg. The primary outcome variable was a numeric rating scale (NRS) at six hours postoperatively. Secondary outcomes included changes in the NRS score between one and 48 hours postoperatively, consumption of rescue analgesics, and the frequency of rebound pain. RESULTS: Group BF exhibited a lower mean NRS score at postoperative six hours compared to group B (P < 0.001). However, the mean NRS score was not different after postoperative six hours between the two groups. The median consumption of rescue analgesics in group BF was less than that of group B (P = 0.028) and the frequency of rebound pain decreased in group BF when compared to group B (P = 0.021). The levels of sensory block were S1 dermatome and motor block scores were 0 for both groups. There was no significant difference in adverse effects between the groups. CONCLUSIONS: Intrathecal fentanyl 15 µg for anorectal surgery under saddle anesthesia led to an improved pain score for the first six hours after surgery and decreased postoperative analgesic use. Rebound pain diminished with intrathecal fentanyl and adverse effects did not increase.

Airway obstruction by dissection of the inner layer of a reinforced endotracheal tube in a patient with Ludwig's angina: A case report.

Intraoperative airway obstruction is perplexing to anesthesiologists because the patient may fall into danger rapidly. A 74-year-old woman underwent an emergency incision and drainage for a deep neck infection of dental origin. She was orally intubated with a 6. 0 mm internal diameter reinforced endotracheal tube by video laryngoscope using volatile induction and maintenance anesthesia (VIMA) with sevoflurane, fentanyl (100 µg), and succinylcholine (75 mg). During surgery, peak inspiratory pressure increased from 22 to 38 cmH2O and plateau pressure increased from 20 to 28 cmH2O. We maintained anesthesia because we were unable to access the airway, which was covered with surgical drapes, and tidal volume was delivered. At the end of surgery, we found a longitudinal fold inside the tube with a fiberoptic bronchoscope. The patient was reintubated with another tube and ventilation immediately improved. We recognized that the tube was obstructed due to dissection of the inner layer.