Dosing Variability and Clinical Outcomes of Oxybutynin: A Pediatric Cohort of Patients With Neurogenic Bladder

Background

Despite the therapeutic advancements of the last several decades, neurogenic bladder remains a significant source of morbidity for patients with a spinal pathology. Oxybutynin is a mainstay of treatment in pediatric populations despite significant side effects and highly variable bioavailability.

Objectives

To characterize the use of oxybutynin in a cohort of pediatric patients with neurogenic bladder.

Methods

Retrospective data were collected of dosing, drug interactions, and urodynamics parameters in the 100 consecutive patients in a spinal differences clinic who had an appointment between October 7, 2015, and December 30, 2015. In addition to descriptive statistics, a linear regression model of oxybutynin dose versus age and sex was developed to examine the impact of age on dosing variability.

Results

One hundred patients (52% female) with a median age of 6.8 years were included. The median daily dose of oxybutynin was 0.36 mg/kg (interquartile range, 0.28-0.54 mg/kg). Of the 48 patients with a recent urodynamics study, 13 had a detrusor leak point pressure (DLPP) greater than the typical cutoff of 40 cm H₂O, indicating a need for management escalation. However, of these 13 patients, 38% were already on or exceeding oxybutynin's maximum recommended dose.

Conclusion

The wide dosing variability and high DLPPs despite maximal dosing indicate a need for further investigation of oxybutynin's bioavailability in this population compared to its side effects and clinical outcomes. If variability in response to the medication is due to differences in bioavailability, then a precision-dosing model based on patient genomics could be developed for oxybutynin.

Transurethral reconstruction of fossa navicularis strictures with dorsal inlay buccal mucosa graft urethroplasty

PURPOSE

To describe a single stage, glans-sparing urethroplasty technique for fossa navicularis strictures using a transurethral dorsal inlay buccal mucosa graft.

METHODS

We conducted a retrospective review of a prospectively maintained urethral stricture database to identify all fossa navicularis strictures reconstructed with a single stage, transurethral dorsal inlay buccal mucosa graft urethroplasty (5/2015-6/2020). Primary outcomes were anatomic success, defined as the ability to pass a 17 Fr flexible cystoscope, and functional success, defined as the lack of obstructive voiding symptoms and no need for further procedures. Secondary outcomes were postoperative complications and patient satisfaction.

RESULTS

Sixteen patients were included. Mean age was 63.1 years (43.9-75.6) and mean stricture length was 1.7 cm (1.4-2.0). Stricture etiology included internal trauma (62.5%), idiopathic (25.0%), and lichen sclerosus (12.5%). Prior endoscopic procedures were done in 75% of patients. Over a median follow-up of 28.8 months (IQR 17.6-38.0), anatomic success was 15/16 (93.8%) and functional success was 16/16 (100%). The single anatomic recurrence was at 4.2 months postoperatively. No additional procedures were required. Urinary tract infection occurred in 25% (4/16). There were no instances of de novo erectile dysfunction, chordee, or wound infection. All patients would recommend urethroplasty to others and all patients were either very satisfied (83.3%) or satisfied (16.7%) with the procedure. Penile sensitivity was unchanged in 83.3%, increased in 8.3% and decreased in 8.3%.

CONCLUSION

Transurethral dorsal inlay buccal mucosa graft urethroplasty is a viable option for reconstruction of fossa navicularis strictures that avoids splitting the glans and results in excellent cosmesis.

Defining risk for low reticuloruminal pH during the diet transition period in a commercial feedlot in western Canada

The objective of the current study was to measure reticuloruminal pH in cattle in a commercial feedlot setting to determine the incidence and extent of low reticuloruminal pH for steers and heifers as they transition to a high-concentrate finishing diet. Reticuloruminal pH was measured in 16 "mixed breed" steers (4 steers/pen with 4 pens) and 16 "mixed breed" heifers (4 heifers/pen with 4 pens) housed in commercial feedlot pens, with 227 ± 13 and 249 ± 6 cattle/pen cohort steers and heifers, respectively, for the diet transition period. Cattle were transitioned from a diet of 53.5% forage and 46.5% concentrate to a diet of 9.5% forage and 90.5% concentrate on a DM basis using a 40-d transition with 5 dietary steps with the diets containing 41.4, 44.8, 49.8, 52.5, 55.1, and 64.0% nonfibrous carbohydrate. In addition, wheat replaced barley as the grain source during the dietary transition. Reticuloruminal pH was measured using orally administered pH measurement devices that were retrieved at slaughter. Data were analyzed using a mixed model including the fixed effects of sex, diet, and the 2-way interaction to evaluate the effect of diet and sex and with the fixed effects of sex, diet, and day relative to each dietary change along with the 2- and 3-way interactions to evaluate temporal responses as a result of diet change. A repeated measures statement was included for the effect of day. Both the mean and minimum reticuloruminal pH values decreased as the proportion of concentrate in the diet increased ( < 0.001). The area and duration that pH was <5.6 increased with greater inclusion of concentrate in the diet ( < 0.001). The number of cattle experiencing low reticuloruminal pH, defined as pH < 5.6 for >180 min, increased with increasing concentrate, and by the end of the 40-d dietary transition, 83% of the cattle had experienced at least 1 bout of low reticuloruminal pH, with most experiencing between 1 and 3 bouts/diet. These data are interpreted to suggest that cattle are at high risk for experiencing low reticuloruminal pH during the dietary transition but that the extent of low reticuloruminal pH is mild. Moreover, the data suggest that the risk for low reticuloruminal pH increases with increasing proportion of concentrate in the diet. The results also suggest that susceptibility to low reticuloruminal pH may differ between steers and heifers.

Do blood donors read and understand screening educational materials?

BACKGROUND

Blood donors with high-risk behaviors may not self-defer because they failed to read or understand the screening educational materials.

STUDY DESIGN AND METHODS

In 1993, a total of 34,726 allogeneic donors responded to an anonymous mail survey of 50,162 donors that inquired about demographics, donor status, amount of the donor educational materials read, new HIV knowledge gained, and donors' opinions on the length and difficulty of materials.

RESULTS

Although 78 percent reported reading all materials, only 32 percent indicated reading carefully; 34 percent learned new information about HIV and 95 percent perceived the materials as easy to understand. First-time donors were more likely to read carefully (OR, 7.9) and gain more HIV knowledge from the materials (OR, 1.9) than repeat donors. Minority, less educated, screening test-reactive, and HIV test-seeking donors reported reading the materials more carefully and learning more about HIV than their respective counterparts. Donors with less education, those with reactive screening tests, those seeking HIV test results, and those not reporting a risk behavior were more likely to find the materials difficult to understand.

CONCLUSION

Most donors reported skimming and not having difficulty understanding the educational materials. Some donors may be aware that they should not donate or are failing to assimilate the information in the materials. Methods to present information more clearly and concisely are clearly needed. However, some high-risk donors may still continue donating no matter how improved the educational materials are.

Inverted lithotomy

An inexpensive plywood device to support the patient for supine or prone operations involving the rectum is described.

The ultrastructure of a porcine hereditary lymphoma with some observations on cell cultures and enzyme cytochemistry

Ultrastructural studies have been made on affected tissues and cell cultures established from an hereditary lymphosarcoma of Large White pigs. Certain hydrolytic and lysosomal enzymes have been investigated at light microscope level in tumour cells and in cells established in culture. Morphological, behavioural and enzymatic characteristics indicate that two types of surface-adherent cells persist in primary cultures established from the marrow of affected pigs, namely macrophages and myeloid cells. The latter show an initial tendency to colonial growth which disappears in subsequent passages. In nearly all cases the tumour is considered to be a poorly differentiated lymphocytic lymphosarcoma. There is, however, considerable variation in cellular components and tumour-cell differentiation, and on purely morphological grounds one case might be considered to be an histiocytic i.e. macrophage lymphoma. Intra-nuclear bodies were observed in one case and occasional cytoplasmic virus-like particles were seen in both fresh tissues and cultured cells. In older pigs tumorous lymph nodes often show a cellular depletion associated with an increase of fibroreticular stroma.

Photodisintegration of 16O and 63Cu by Photons of Variable Energy

Proton capture reactions in light nuclei provide ?-radiation with energy controllable by variation of proton energy. The radiation from proton capture by 7Li has been used to investigate the (?,n) reactions in 16O and 63Cu over an energy range of 300 keV around 17�7 MeV. No resonant behaviour was observed in 16O. A variation in the 63Cu photoneutron cross section is interpreted as the combined effect of many unresolved levels.

Energy Resolution of ?-Radiation up to 18 MeV by Sodium Iodide Scintillation Counters

The pulse-height distributions to be expected from scintillation counters using thallium-activated sodium iodide crystals have been investigated for ?-radiation of energies 6, 12, and 18 MeV. with two sizes of cylindrical crystal (2�5 cm. long by 2�5 cm. diameter and 7�5 cm. long by 4 cm. diameter). A Monte Carlo calculation of the partial shower process by which photons are absorbed in the crystals has given the probability distributions of ionization energy from homogeneous incident photons. The spreading of the distributions by statistical effects in the photomultiplier has been measured using light flashes of constant integrated intensity from a rotating mirror. The curves predicted by combining these two factors are compared with experimental pulse-height distributions for ?-radiation from proton bombardment of fluorine, boron, and lithium.