A synthetic retinoic acid receptor γ antagonist (7C)-loaded nanoparticle enhances bone morphogenetic protein-induced bone regeneration in a rat spinal fusion model

BACKGROUND CONTEXT

Bone morphogenetic proteins (BMPs) have potent osteoinductivity and have been applied clinically for challenging musculoskeletal conditions. However, the supraphysiological doses of BMPs used in clinical settings cause various side effects that prevent widespread use, and therefore the BMP dosage needs to be reduced.

PURPOSE

To address this problem, we synthesized 7C, a retinoic acid receptor γ antagonist-loaded nanoparticle (NP), and investigated its potential application in BMP-based bone regeneration therapy using a rat spinal fusion model.

STUDY DESIGN

An experimental animal study.

METHODS

Fifty-three male 8-week-old Sprague-Dawley rats underwent posterolateral spinal fusion and were divided into the following five treatment groups: (1) no recombinant human (rh)BMP-2 and blank-NP (Control), (2) no rhBMP-2 and 1 μg 7C-NP (7C group), (3) low-dose rhBMP-2 (0.5 μg) and 1 μg blank-NP (L-BMP group), (4) low-dose rhBMP-2 (0.5 μg) and 1 μg 7C-NP (L-BMP + 7C group), and (5) high-dose rhBMP-2 (5.0 μg) and 1 μg blank-NP (H-BMP group). Micro-computed tomography and histologic analysis were performed 2 and 6 weeks after the surgery.

RESULTS

The spinal fusion rates of the Control and 7C groups were both 0%, and those of the L-BMP, L-BMP + 7C, and H-BMP groups were 55.6%, 94.4%, and 100%, respectively. The L-BMP + 7C group markedly promoted cartilaginous tissue formation during BMP-induced endochondral bone formation that resulted in a significantly better spinal fusion rate and bone formation than in the L-BMP group. Although spinal fusion was slower in the L-BMP + 7C group, the L-BMP + 7C group formed a spinal fusion mass with better bone quality than the spinal fusion mass in the H-BMP group.

CONCLUSIONS

The combined use of 7C-NP with rhBMP-2 in a rat posterolateral lumbar fusion model increased spinal fusion rate and new bone volume without deteriorating the quality of newly formed bone.

CLINICAL SIGNIFICANCE

7C-NP potentiates BMP-2-induced bone regeneration and has the potential for efficient bone regeneration with low-dose BMP-2, which can reduce the dose-dependent side effects of BMP-2 in clinical settings.

Risk factors for insufficient ultrasound-guided supraclavicular brachial plexus block

PURPOSE

Ultrasound-guided supraclavicular brachial plexus block (SCBPB) is performed by surgeons for upper limb anesthesia; however, certain patients need additional local anesthesia. This study aimed to identify risk factors for additional local anesthetic injection requirements.

METHODS

In total, 269 patients receiving ultrasound-guided SCBPB were enrolled. Patient age, sex, body mass index, anesthetic drug dose, surgeon expertise (hand surgeon or resident), tourniquet time, comorbidities (diabetes mellitus and mental disorders), and preoperative blood pressure representing anxiety were compared between the additional local anesthesia and no additional local anesthesia groups matched for background using propensity scores. Receiver operating characteristic analysis was performed to determine risk factor cut-off values with the highest predictive potential.

RESULTS

Of 269 patients, 41 (15.2%) required additional intraoperative local anesthesia. Among surgical sites, elbow surgery showed the highest prevalence of the need for additional local anesthesia (17/41, 41%). A high body mass index and high systolic blood pressure before surgery were identified as risk factors for additional intraoperative local anesthesia requirement. Furthermore, systolic blood pressure > 170 mmHg (area under the curve, 0.66) predicted the need for intraoperative local anesthesia with 36% sensitivity, 89% specificity, 37.5% positive predictive value, and 88.6% negative predictive value. The median systolic blood pressure was significantly greater in patients requiring additional local anesthesia than in those not requiring it [151 (139-171) mmHg vs. 145 (127-155) mmHg; P = 0.026].

CONCLUSION

Elbow surgery, obesity, and high systolic blood pressure (> 170 mmHg) before surgery are predictive of additional intraoperative local anesthesia requirement.

LEVEL OF EVIDENCE

Prognostic Level III.

Upregulation of HNF-1β during experimental acute kidney injury plays a crucial role in renal tubule regeneration

Hepatocyte nuclear factor-1β (HNF-1β) is a transcription factor expressed in the kidney, liver, pancreas, and other organs. Mutations of HNF-1β cause maturity-onset diabetes of the young type 5 (MODY5). The aims of this study were to investigate the functional roles of the HNF-1β/suppressor of cytokine signaling-3 (SOCS-3) pathway in tubule damage after acute kidney injury (AKI) both in vivo and in vitro and to examine the effect of HNF-1β on renal tubule formation. To clarify the significance of the HNF-1β/SOCS-3 pathway in AKI, we used a rat ischemia/reperfusion (I/R) AKI model and cultured renal tubular cells (NRK-52E cells). Western blot analysis showed that HNF-1β and polycystic kidney disease 2 (PKD2) expressions were increased at 3-12 h and 12-24 h after I/R, respectively. The expression level of SOCS-3 was decreased at 3-48 h. Immunohistological examination revealed that expression of HNF-1β was increased in proximal tubules. Overexpression of HNF-1β resulted in decreased SOCS-3 expression, activation of signal transducer and activator of transcription 3 (STAT3) and Erk, and increased [(3)H]thymidine uptake in the presence of hepatocyte growth factor. Furthermore, tubule formation in three-dimensional gels was inhibited by dominant-negative HNF-1β. Our study shows that HNF-1β is upregulated after AKI in proximal tubular cells and that HNF-1β controls cellular proliferation and tubule formation by regulating SOCS-3 expression and STAT3/Erk activation. Therefore, the current study unravels the physiological and pathological significance of the HNF-1β pathway in AKI.

Long-term assessment of fecal incontinence after lateral internal sphincterotomy

BACKGROUND

Lateral internal sphincterotomy (LIS) can cause fecal incontinence. The aim of this study was to evaluate this sequelae after long-term follow-up of patients treated by LIS and to identify possible associated factors.

METHODS

Data were retrospectively collected for patients with chronic anal fissure who had LIS between 1994 and 1997. Continence was assessed according to the incontinence score (IS) obtained by medical record review and telephone questionnaire. Statistical analysis was performed using by Student's t test for qualitative variables and chi-square test for qualitative variables.

RESULTS

All 68 patients evaluated had healed after fissure surgery. None of these patients had preoperative fecal incontinence neither recurrence at the time of follow-up. At a mean follow-up of 66.6 months (range, 30-84 months), 7 patients (10.2%) were incontinent (mean IS=8.2; range, 5-16) and none had recovered continence at the time of follow-up. There was no significant difference between patients with and without fecal incontinence relative to gender age, hemorrhoidectomy combined with LIS, or vaginal delivery.

CONCLUSIONS

Incontinence due to LIS does not recover after long-term follow-up and appears to be an independent cause of fecal incontinence.

[A state of confusion following cerebral angiography with iopamidol: a case report]

A 59-year-old male in a state of confusion following cerebral angiography with iopamidol was reported. He was admitted to our hospital for right upper monoparesis. MRI demonstrated multiple cerebral infarction. The patient had undergone angiographies with iopamidol, of which a total of 100 ml had been used. After the examination, the patient showed perseveration, continuing to say the same sentence and 30 minutes later he entered a state of confusion. He recovered completely from this consciousness disturbance after 30 hours. No lesion except for the old infarction was demonstrated on CT and MRI. Confusion in this case was assumed to be a toxic reaction caused by the contrast agent.