Screening, Brief Intervention and Referral to Treatment (SBIRT): An examination of health disparities.

Risky substance use can lead to a variety of negative health outcomes, yet treatment is often underutilized by historically minoritized racial/ethnic groups. Screening, Brief Intervention and Referral to Treatment (SBIRT) is effective in changing substance use patterns across diverse settings and for diverse demographic groups. However, few studies have focused on whether individuals receive the appropriate level of care based on screening criteria. The purpose of this study was to investigate intervention match/mismatch and factors (e.g., service site, gender, race, ethnicity, age, socio-economic status) that predicted the likelihood of being matched/mismatched to an intervention. A sample of N = 3412 were available for analyses and logistic regressions were performed to examine the relationship between matching/mismatching to an intervention and other factors. Of participants, 2222 (65%) were matched to an intervention and 1190 (35%) were mismatched to an intervention. Being older, Hispanic, and receiving SBIRT by health-teams designed to reduce health disparities was related to increased odds of being mismatched. Exploratory results suggested that across predictors, individuals were more likely to receive a lesser intervention than their screening score indicated. Most clients were matched well to intervention as based on screening score. When mismatch occurred, a lower level of care was given. Staff may benefit from attending to more client engagement so that clients return for more intensive interventions; and agencies may need more resources to facilitate client access to services.

Ultrasound guided subcostal transversus abdominis plane (TAP) infiltration with liposomal bupivacaine for patients undergoing robotic assisted hysterectomy: A prospective randomized controlled study.

INTRODUCTION: Optimal pain control after major surgery contributes to a patient's recovery and satisfaction. The use of liposomal bupivacaine in subcostal transversus abdominis plane (TAP) blocks for postoperative pain control after robot assisted abdominal surgery has yet to be studied. METHODS: We conducted a prospective randomized controlled observer-blinded study comparing bilateral subcostal TAP blocks with bupivacaine to bilateral subcostal TAP blocks with liposomal bupivacaine. These were performed prior to the patient undergoing robot assisted hysterectomy. The patients' pain scores, opioid use, side effects, and satisfaction were followed for 72h after injection. RESULTS: Total opioid use in the first 72h after injection was significantly decreased in the group that received liposomal bupivacaine compared to bupivacaine. Patients in the liposomal bupivacaine group had significantly lower maximal pain scores at all time periods studied as well as decreased incidence of nausea/vomiting. There was a trend toward decreased length of stay in the liposomal bupivacaine group. CONCLUSION: Subcostal TAP blocks with liposomal bupivacaine decreased the total opioid requirement for the first 72h after robot assisted hysterectomy when compared to subcostal TAP blocks with bupivacaine.

Colchicine and/or Naltrexone for Hospitalized COVID-19 Patients Not Requiring High Levels of Ventilatory Support (COLTREXONE): A Prospective, Randomized, Open-Label Trial.

We assessed the efficacy and safety of colchicine and low-dose naltrexone (LDN), alone and in combination, in preventing progression to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this prospective, randomized, open-label trial, colchicine and LDN were compared to standard of care (SOC) in patients hospitalized with SARS-CoV-2 not requiring high levels of ventilatory support. Patients were randomly assigned to colchicine alone, LDN alone, colchicine/LDN in combination, or SOC. The primary outcome was time to disease recovery. Secondary outcomes included total time hospitalized, study enrollment, level of care, oxygen support, and adverse events.  One-hundred and thirty-seven patients were randomized (Nc = 34, Nc+ldn = 33, Nldn = 35, Nsoc = 35). Eighty-four patients (61%) achieved disease recovery by day 5. There was no significant difference in the proportion of patients who experienced the primary efficacy outcome among those who received colchicine, LDN, or between the four study arms.Patients receiving colchicine had a shorter length of enrollment but not a significant reduction in the length of stay. Diarrhea was the most common adverse reaction. In adults hospitalized with SARS-CoV-2 not requiring high-level ventilatory support, colchicine and LDN, alone and in combination, were not associated with significant reductions in progression to severe disease.

Motivational interviewing for family planning and reducing risky sexual behavior among incarcerated men nearing release: A randomized controlled pilot study.

Incarcerated men are at high risk for sexually transmitted infections (STIs) and unintended partner pregnancy postrelease. Limited research has been invested in developing and testing treatments targeting risky sexual behavior and unwanted pregnancy for this at-risk population. Motivational interviewing (MI) is a promising behavioral intervention for decreasing risky sexual behaviors. This study assessed the feasibility and acceptability of MI for family planning and risky sexual behaviors with incarcerated men nearing release. Preliminary efficacy of the MI intervention was also compared to an educational control group. Thirty-two men were assessed at baseline and randomized to one 90-min session. Assessment occurred 2 months after release. MI was feasibly administered, and participants were highly satisfied with both treatments. In addition, those who received MI reported higher rates of condom use with casual partners, higher rates of partner use of hormonal contraceptives, and slightly higher rates of sex that was protected against pregnancy. Increases are readiness to discuss family planning with sexual partners, as well as reported frequency of these discussions, and increases in family planning knowledge were also found in those randomized to MI. The findings from this study indicate the need to further assess MI with this population with a full-scale clinical trial. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Epidemiological and clinical characteristics of patients with COVID-19 in Islamic Republic of Iran.

Background: Coronavirus disease 2019 (COVID-19) is a worldwide public health emergency. Aims: This study aimed to investigate the epidemiological and clinical characteristics of patients with COVID-19 in Saveh city, Islamic Republic of Iran in 2020. Methods: In this descriptive analytical research, 3181 patients suspected of having COVID-19 who visited Saveh medical centres were investigated. Patients were confirmed with COVID-19 using polymerase chain reaction testing. Data on sociodemographic, epidemiological and clinical characteristics of the patients were collected using a validated form through interviews and medical records. The chi-squared, t and Fisher exact tests were used to assess differences in sociodemographic, epidemiological and clinical characteristics between patients with positive and negative polymerase chain reaction results. Logistic regression analysis was used to examine the association between independent variables and death from COVID-19. Results: About half the patients (48.3%) had a history of chronic disease. Diabetes (16.2%), high blood pressure (14.8%) and cardiovascular disease (12.4%) were the most prevalent chronic diseases among patients who were confirmed positive for COVID-19. Risk factors for death among confirmed COVID-19 patients were: intubation (odds ratio (OR) = 8.97; 95% confidence interval (CI): 5.15-15.63), age ≥ 80 years (OR = 5.81; 95% CI: 1.91-17.60), oxygen saturation < 93% (OR = 2.48; 95% CI: 1.51-4.08), diabetes (OR = 1.88; 95% CI: 1.00-3.54) and shortness of breath (OR = 1.70; 95% CI: 1.02-2.82). Conclusion: Given the greater risks of contracting and dying from COVID-19 in certain groups of patients, health education programmes targeting these groups are recommended.

Evaluation and comparison of vitamin A supplementation with standard therapies in the treatment of patients with COVID-19.

Background: Incomplete data are often presented for determining the role of vitamin A supplement therapy for improving treatment outcomes in patients with COVID-19. Aims: We compared treatment effects between a group that received vitamin A added to the standard COVID-19 treatment and another group that received the standard drug treatment alone. Methods: Participants in this triple-blind controlled trial comprised 182 COVID-19 outpatients in Saveh City, Markazi Province, Islamic Republic of Iran, in 2020. Patients were randomly divided into experimental (n = 91) and control (n = 91) groups. Patients in the control group received the national standard treatment for COVID-19 (hydroxychloroquine), and those in the intervention group received 25 000 IU/d oral vitamin A for 10 days in addition to the standard treatment recommended by the national protocol. We evaluated the clinical symptoms, paraclinical criteria, and hospitalization status before and after 10 days of interventions. Results: The treatment groups did not differ significantly in clinical and paraclinical symptoms before the intervention. However, clinical symptoms such as fever, body ache, weakness and fatigue, paraclinical symptoms, white blood cell count, and C-reactive protein showed significantly greater decreases in the experimental group 10 days post-intervention compared with the standard treatment alone (P < 0.05). Conclusion: Vitamin A supplementation demonstrated efficacy in improving some clinical and paraclinical symptoms in patients with COVID-19. Future studies should evaluate vitamin A supplementation with a larger sample size and compare different dosages, especially in hospitalized patients.

Motivational interviewing to reduce risky sexual behaviors among at-risk male youth: A randomized controlled pilot study.

BACKGROUND: Despite male youth taking more sexual risks that lead to unwanted partner pregnancy and/or sexually transmitted infections (STIs), research evaluating interventions for risky sex has focused almost exclusively on adolescent and adult females. With STIs among male youth on the rise, behavioral interventions that target risky sex among male youth are needed. PURPOSE: A randomized controlled pilot study was conducted to examine the feasibility and acceptability of two manualized behavioral interventions for sexually active male youth. METHODS: Sexually active at-risk male youth (N = 27) were recruited and randomized to receive one session of motivational interviewing (MI) or didactic educational counseling (DEC). Assessment interviews were conducted prior to and 3 months following the intervention session. RESULTS: Support for the feasibility and acceptability of delivering behavioral interventions to reduce risky sexual behaviors among at-risk male youth was found. Compared to participants in DEC at follow-up, participants in MI reported having significantly fewer sexual encounters with casual partners, used substances at the time of sex significantly less often with all partners and casual partners, and reported fewer incidents of using substances at the time of sex without a condom with all partners. Conversely, participants who received MI used substances at the time of sex with main partners and used substances at the time of sex without a condom more often with main partners at follow-up compared to participants who received DEC. CONCLUSIONS: Results of the pilot study support conducting a larger randomized controlled trial to examine treatment effects. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A psychometric assessment of the Brief Situational Confidence Questionnaire for Marijuana (BSCQ-M) in juvenile justice-involved youth.

Cannabis refusal self-efficacy, defined as confidence in the ability to refuse cannabis or to avoid cannabis use, is associated with decreased cannabis use. Juvenile justice-involved youth are at high risk for cannabis use and may have lower refusal self-efficacy. While court-involved, non-incarcerated (CINI) and incarcerated youth are groups that are both at high-risk for cannabis use, the experience of incarceration may impact the measurement of refusal self-efficacy for cannabis. The factor structure, measurement invariance, and concurrent validity of the Brief Situational Confidence Questionnaire for Cannabis (BSCQ-M) was assessed among CINI (n = 148) and incarcerated (n = 199) youth (80.7% male, Mage = 16.3). Confirmatory factor analyses indicated that a correlated 3-factor model including positive/good times, negative internal, and negative external situational factors best fit the data. Multigroup measurement invariance testing revealed that the BSCQ-M demonstrated configural, metric, scalar, and residual invariance across CINI and incarcerated samples, indicating measurement invariance across the two groups. Negative binomial regressions revealed that BSCQ-M scores were significantly negatively associated with concurrent cannabis use. Results suggest that the BSCQ-M is a brief, psychometrically sound measure of refusal self-efficacy for cannabis among juvenile justice-involved youth that can be utilized with both CINI and incarcerated youth.

Oral self-care behavior and its influencing factors in a sample of school children from Central Iran.

BACKGROUND: Oral health is an important part of public health and crucial to health promotion and enhancing the quality of life. This research examined childhood oral self-care behavior and their related factors using extended Theory of Planned Behavior (TPB). METHOD: This cross-sectional study was conducted on 368 sixth-grade elementary school students in Saveh city, Iran, in 2019. The students were selected using a random multi-stage sampling method. The instrument included the socio-demographic questions, TPB constructs, and action and coping plan items. Data were analyzed by SPSS software (Version 21) at alpha level p ≤ 0.05. RESULT: Overall, 24 (6.6%) students have never used toothbrushes, 222 (62.7%) have never used dental floss, and 298 (82.7%) students have never used mouthwash. The stepwise multiple linear regression analysis results indicated that the TPB with action and coping planning constructs had better predictive power than the original model. In the final model, coping planning (ß = .28), intention (ß = .24), action planning (ß = .23), and perceived behavior control (ß = .15) were the most important predictors of oral self-care behavior. CONCLUSION: The results indicated that the oral self-care behavior status in Iranian elementary students was not favorable, and the extended model of the TPB with action and coping plan constructs were significant predictors of self-care behavior. Therefore, these findings emphasize the need for expanding educational interventions based on the extended model of the TPB to improve the oral self-care behavior of students.

Intravenous Dexmedetomidine as an Adjunct to Neuraxial Anesthesia in Cesarean Delivery: A Retrospective Chart Review.

BACKGROUND: Dexmedetomidine is a selective α-2 agonist commonly used for sedation that has been used in obstetric anesthesia for multimodal labor analgesia, postcesarean delivery analgesia, and perioperative shivering. This study evaluated the role of intravenous dexmedetomidine to provide rescue analgesia and/or sedation during cesarean delivery under neuraxial anesthesia. METHODS: We conducted a single-center, retrospective cohort study of all parturients undergoing cesarean delivery under neuraxial anesthesia between December 1, 2018, and November 30, 2019, who required supplemental analgesia during the procedure. Patients were divided into two groups: patients who received intravenous dexmedetomidine (Dexmed group) and patients who received adjunct medications such as fentanyl, midazolam, ketamine, and nitrous oxide (Standard group). Primary outcome was incidence of conversion to general anesthesia. RESULTS: During the study period, 107 patients received adjunct medications. There was no difference in conversion to general anesthesia between the Dexmed group and the Standard group (6% (4/62) vs. 9% (4/45); p=0.718). In the Dexmed group, the mean dexmedetomidine dose received was 37 µg (range 10 to 140 µg). While the use of inotropic/vasopressor medications was common and similar in both groups, there was an increase in the incidence of bradycardia (Dexmed 15% vs. Standard 2%; p=0.042) but not hypotension (Dexmed 24% vs. Standard 24%; p=1.00) in the Dexmed group. CONCLUSION: In patients who required supplemental analgesia for cesarean delivery, those who received dexmedetomidine versus other medications had a similar rate of conversion to general anesthesia, a statistically significant increase in bradycardia, but no difference in the incidence of hypotension.

New Q Waves and T-Wave Inversions Following Endovascular Surgery Lead to Diagnosis of Clinically Silent Myocardial Infarction Despite Negative Preoperative Cardiovascular Risk Evaluation: A Case Report.

In this case, a 79-year-old male presented with new anteroseptal Q waves and T-wave inversions across the precordial leads following an otherwise uneventful endovascular repair of his thoracoabdominal aortic aneurysm. The patient had no history of cardiac disease and had undergone a dobutamine stress echocardiogram within the preceding 6 months that showed no evidence of inducible ischemia. Nevertheless, routine postoperative electrocardiogram (EKG) revealed new Q waves and T-wave inversions and transthoracic echocardiogram that demonstrated akinesis of the left ventricle (LV) apex with chronic-appearing apical thrombus. We will further discuss preoperative evaluation of cardiovascular risk along with postoperative interpretation of EKG abnormalities.

The Brief Situational Confidence Questionnaire for alcohol: A psychometric assessment with incarcerated youth.

The factor structure, measurement invariance, validity, reliability, and stability of scores on the Brief Situational Confidence Questionnaire (BSCQ) were evaluated for use with incarcerated youth. The BSCQ is an 8-item measure that assesses self-efficacy to resist alcohol use in tempting situations. The brevity of the measure may make it a useful tool for clinicians and researchers in a forensic setting. Analyses were conducted with 2 separate samples (N = 205 and N = 189) of incarcerated youth (M age = 16.90 and 17.12 years, respectively; 88% and 86% male). Based on prior theory and confirmatory factor analyses (CFAs), results indicated that a correlated 2-factor model best fit the data. Multisample CFAs suggested that BSCQ scores demonstrated configural and metric invariance across our 2 samples. Further, the BSCQ scores demonstrated sufficient test-retest stability in Samples 1 and 2 (Pearson's r = .66, .55) and internal consistency (Cronbach's α = .84 and .86, respectively). Negative binomial regressions showed that the overall BSCQ scores were significantly associated with concurrent alcohol use (number of drinking days, number of heavy drinking days, average drinks per week) and significantly predicted future alcohol use. Scores on the BSCQ demonstrated sufficient stability, internal consistency, and validity, and the 2-factor structure was largely invariant across 2 separate samples of incarcerated youth. Given its brevity, the BSCQ may provide valid and reliable scores to use with this population when time and resources are scarce. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Intracytoplasmic sperm injection (ICSI) with transmission of a ring(Y) chromosome and ovotesticular disorder of sex development in offspring.

We present a newborn infant with ovotesticular disorder of sex development and sex chromosome mosaicism with a supernumerary ring(Y), and a normal female cell line (47,XXr(Y)[10]/46,XX[40]. The ring (Y) was inherited from the child's father, and was transmitted following assisted reproductive technology and intracytoplasmic sperm injection (ICSI). The father presented with infertility and oligospermia, but cytogenetic analysis had not been carried out as part of the infertility workup. The Y containing cell line had not been seen on amniocentesis, which had shown a 46,XX apparently normal female karyotype in all cells studied. Molecular analysis using polymorphic probes from the X chromosome demonstrated that the 47,XXr(Y) cell line in the child was consistent with inheritance from the father, following meiosis I paternal non-disjunction. This report underscores the need to obtain chromosome analysis in couples with infertility who undergo assisted reproduction.

Gene expression alterations in cryptorchid males using spermatozoal microarray analysis.

OBJECTIVE: To identify differential spermatozoal gene expression patterns using microarray between controls and patients with cryptorchidism. DESIGN: Prospective laboratory analysis. SETTING: Pediatric urology clinic and laboratory of an academic hospital in the United States. PATIENT(S): Ten control patients and 12 cryptorchid males (8 unilateral, 4 bilateral). INTERVENTION(S): Ejaculates were collected and motile sperm were isolated by Percoll centrifugation, total RNA was extracted and verified using sperm-specific reverse transcriptase-polymerase chain reaction (RT-PCR). Biotin-labeled amplified RNA was hybridized to Affymetrix Human Genome Focus arrays. Differentially expressed genes were identified using permutation t-test. MAIN OUTCOME MEASURE(S): Semen analyses and differential spermatozoal gene expression patterns measured by microarray. RESULT(S): Mean semen volume was not different between control and patients with cryptorchidism. Mean sperm density was significantly decreased between control, unilateral, and bilateral cryptorchid samples (110 vs. 87 vs. 16 million/mL). From the microarray expression data, we identified 43 genes differentially expressed between the two groups. Thirty-eight genes were significantly underexpressed in the cryptorchid samples including many transcriptional factors (cul3, prm1, hspcd35) and a testis-specific cell-adhesion gene (tpx-1) involved in germ cell maturation and sperm tail formation. An antiapoptotic gene (TNFAIP3) was highly overexpressed in the cryptorchid samples. CONCLUSION(S): Gene expression profiles offer insight into the diverse alterations that occur in cryptorchidism. The observed changes in spermatozoal expression of transcriptional and antiapoptotic genes may result in poor seminal parameters in formerly cryptorchid males.

Lipid signaling changes in smooth muscle remodeling associated with partial urinary bladder outlet obstruction.

AIMS: Hypertrophy of the urinary bladder smooth muscle (detrusor) is associated with partial bladder outlet obstruction (PBOO). Hypertrophied detrusor smooth muscle (DSM) reveals altered contractile characteristics. In this study, we analyzed the lipid-dependent signaling system that includes phospholipase A2 in PBOO-induced DSM remodeling and hypertrophy to determine whether the release of arachidonic acid (AA) from phospholipid is altered in the detrusor. METHODS: Partial bladder outlet obstruction (PBOO) was produced by partial ligation of the urethra in New Zealand white rabbits. Two weeks after the surgery, the bladder function was studied by keeping the rabbits in metabolic cages for 24 hr. Bladders were removed from rabbits that had bladder dysfunction (increased urinary frequency and decreased void volume) and the DSM separated from mucosa and serosa. The isolated smooth muscle was incubated with [3H] AA to equilibrate the cytoplasmic AA. The level of AA release was compared with the level obtained with 2-week sham-operated rabbits. RESULTS: The rate of AA release was high in DSM from bladders with PBOO-induced hypertrophy. Carbachol stimulated AA release in control DSM but DSM from obstructed rabbits revealed no further increase from the elevated basal AA release. The half-maximal concentration of carbachol that was required to stimulate AA release from control samples of detrusor was 35 microM. CONCLUSIONS: The increased levels of AA release that are observed in this tissue after PBOO indicate the activation of phospholipase A2. The finding that carbachol could induce contraction, but not an increase in AA, indicates that the carbachol-induced contraction in the obstructed bladders is independent of lipid signaling pathways that involve AA. It is possible that the increased rate of arachidonic acid release from obstructed bladders correlates with the enhanced rates of prostaglandin production reported by other investigators from the same tissue.

Activation of the calcineurin pathway is associated with detrusor decompensation: a potential therapeutic target.

PURPOSE: We hypothesized that the calcineurin pathway mediated some of the complex remodeling process that allows a bladder subjected to partial outlet obstruction to adapt to its new workload. Atrial natriuretic factor mRNA expression served as a marker of calcineurin activation. MATERIALS AND METHODS: A total of 16 New Zealand White rabbits underwent surgical creation of partial outlet obstruction, followed by randomization to receive cyclosporin A (20 mg/kg intramuscularly twice daily) or no additional treatment for 14 days. Three animals underwent 2 weeks of partial bladder outlet obstruction followed by bladder biopsy and the reversal of obstruction. RESULTS: Atrial natriuretic factor expression was seen only in bladders with severe hypertrophy and it disappeared with the reversal of outlet obstruction. Cyclosporin A treatment resulted in a decrease in atrial natriuretic factor mRNA expression (p <0.05) and a marked shift in myosin heavy chain A-to-B ratios toward normal (p <0.01) and an increase in smooth muscle cross sectional area (p <0.05). Bladder mass decreased 40% but did not attain statistical significance (p = 0.08). CONCLUSIONS: The calcineurin pathway has a significant role in bladder wall hypertrophy following partial outlet obstruction. Bladder hypertrophy could not be fully prevented by cyclosporin A, suggesting that multiple signaling pathways are involved in this pathophysiology. The expression of myosin heavy chain AB isoforms is regulated in part by the calcineurin pathway.

Partial bladder outlet obstruction selectively abolishes protein kinase C induced contraction of rabbit detrusor smooth muscle.

PURPOSE: Despite the acute onset, partial bladder outlet obstruction in the rabbit induces detrusor remodeling similar to that in men with benign prostatic hyperplasia in terms of its impact on structural and functional alterations in smooth muscle. We determined if partial bladder outlet obstruction induced remodeling alters the protein kinase C signaling pathway that leads to contraction. MATERIALS AND METHODS: Smooth muscle from control animals and those subjected to 2 weeks of partial bladder outlet obstruction were mounted for isometric force recording, measurement of myosin light chain phosphorylation and levels of adducin phosphorylation. Bladder muscle strips were stimulated by phorbol dibutyrate or carbachol in the presence and absence of bisindolylmaleimide-1. RESULTS: Smooth muscle strips from animals subjected to partial bladder outlet obstruction showed little to no increase in stress in response to phorbol dibutyrate and no increase in myosin light chain phosphorylation levels. Muscle strips from control animals produced a robust contraction with concomitant increases in myosin light chain phosphorylation. Inhibition of protein kinase C by bisindolylmaleimide-1 significantly depressed carbachol induced contractions of muscle strips from control animals but it had no effect on carbachol induced contractions of muscle strips from outlet obstructed animals. Phorbol dibutyrate increased phospho-adducin levels in muscle strips from the 2 animal sources, suggesting that protein kinase C could be activated. CONCLUSIONS: We propose that partial bladder outlet obstruction does not alter protein kinase C activation, but rather abolishes or uncouples the pathway(s) downstream of protein kinase C, leading to contraction. Loss of this pathway may contribute to the loss of normal voiding behavior and the resultant decompensated state.

Urethral strictures incident to bicycle motocross racing.

A dramatic shift from traditional team to alternative or "extreme" sports has given rise to a new generation of nontraditional athletes and sports-related injuries in the pediatric population. We present a case of 2 brothers who developed urethral strictures believed incident to BMX racing. We address current demographics and the general presentation and course of treatment to aid both the pediatric urologist and the general practitioner in prompt and proper diagnosis.

Partial bladder outlet obstruction abolishes the receptor- and G protein-dependent increase in calcium sensitivity in rabbit bladder smooth muscle.

Partial bladder outlet obstruction (PBOO) alters the function of the whole bladder and produces specific alterations in the contractility of the bladder smooth muscle cell. The goal of this study was to test the hypothesis that PBOO affects smooth muscle contraction at the level of the receptor- and G protein-dependent increase in myofilament Ca2+ sensitivity. To address this question, we used alpha-toxin-permeabilized strips of bladder smooth muscle from control animals and animals subjected to 2 wk of PBOO. Increasing free [Ca2+] increased force in permeabilized strips from control animals; the addition of 10 microM carbachol and 10 microM GTP increased both the Ca2+ sensitivity of the contractions and the maximal levels of force attained. In contrast, although increases in [Ca2+] increased force in permeabilized strips from PBOO animals, the addition of carbachol and GTP had no additional effects. Myosin light chain phosphorylation levels increased with [Ca2+], and although they tended to be higher in strips from PBOO animals, they did not reach statistical significance. Assessment of G protein activity from both animal models suggests this is not a site responsible for the loss of carbachol and GTP enhancement of myofilament Ca2+ sensitivity. The addition of phorbol dibutyrate increased the Ca2+ sensitivity of force development in strips from both animal models, suggesting that an alteration in PKC signaling is not involved. Our results are consistent with the hypothesis that PBOO decreases receptor-mediated myofilament calcium sensitization and that the site of action is downstream from either the G proteins or PKC.