Mitochondrial complex I activity in microglia sustains neuroinflammation

Sustained smouldering, or low-grade activation, of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis1. Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells2. However, how these metabolic features act to perpetuate inflammation of the central nervous system is unclear. Here, using a multiomics approach, we identify a molecular signature that sustains the activation of microglia through mitochondrial complex I activity driving reverse electron transport and the production of reactive oxygen species. Mechanistically, blocking complex I in pro-inflammatory microglia protects the central nervous system against neurotoxic damage and improves functional outcomes in an animal disease model in vivo. Complex I activity in microglia is a potential therapeutic target to foster neuroprotection in chronic inflammatory disorders of the central nervous system3.

Inflammation and poverty as individual and combined predictors of 15-year mortality risk in middle aged and older adults in the US

Background

Chronic systemic inflammation and poverty are both linked to an increased mortality risk. The goal of this study was to determine if there is a synergistic effect of the presence of inflammation and poverty on the 15-year risk of all-cause, heart disease and cancer mortality among US adults.

Methods

We analyzed the nationally representative National Health and Nutrition Examination Survey (NHANES) 1999 to 2002 with linked records to the National Death Index through the date December 31, 2019. Among adults aged 40 and older, 15-year mortality risk associated with inflammation, C-reactive protein (CRP), and poverty was assessed in Cox regressions. All-cause, heart disease and cancer mortality were the outcomes.

Results

Individuals with elevated CRP at 1.0 mg/dL and poverty were at greater risk of 15-year adjusted, all-cause mortality (HR = 2.45; 95% CI 1.64, 3.67) than individuals with low CRP and were above poverty. For individuals with just one at risk characteristic, low inflammation/poverty (HR = 1.58; 95% CI 1.30, 1.93), inflammation/above poverty (HR = 1.59; 95% CI 1.31, 1.93) the mortality risk was essentially the same and substantially lower than the risk for adults with both. Individuals with both elevated inflammation and living in poverty experience a 15-year heart disease mortality risk elevated by 127% and 15-year cancer mortality elevated by 196%.

Discussion

This study extends the past research showing an increased mortality risk for poverty and systemic inflammation to indicate that there is a potential synergistic effect for increased mortality risk when an adult has both increased inflammation and is living in poverty.

Mitochondrial reverse electron transport in myeloid cells perpetuates neuroinflammation

Sustained smouldering, or low grade, activation of myeloid cells is a common hallmark of several chronic neurological diseases, including multiple sclerosis (MS) 1 . Distinct metabolic and mitochondrial features guide the activation and the diverse functional states of myeloid cells 2 . However, how these metabolic features act to perpetuate neuroinflammation is currently unknown. Using a multiomics approach, we identified a new molecular signature that perpetuates the activation of myeloid cells through mitochondrial complex II (CII) and I (CI) activity driving reverse electron transport (RET) and the production of reactive oxygen species (ROS). Blocking RET in pro-inflammatory myeloid cells protected the central nervous system (CNS) against neurotoxic damage and improved functional outcomes in animal disease models in vivo . Our data show that RET in myeloid cells is a potential new therapeutic target to foster neuroprotection in smouldering inflammatory CNS disorders 3 .

The Prevalence and Management of Synchronous Prostate and Rectal Cancer

PURPOSE/OBJECTIVE(S)

Synchronous prostate and rectal cancer is rare and guidelines for co-management are not well established. This case series explores the prevalence of synchronous diagnosis and different treatment paradigms to propose a standardized approach to management.

MATERIALS/METHODS

We retrospectively reviewed all radiation treatments between 1/2017 and 12/2022 for curative intent treatment to both prostate and rectal cancer. Synchronous was defined as rectal or prostate cancer diagnosed within a 6-month period of each other. We collected baseline characteristics and treatment paradigms including the sequencing of chemoradiation (CRT), chemotherapy (CT), prostate boost, and surgery.

RESULTS

There were 10 out of 2204 total treated patients with prostate or rectal primary noted to have a synchronous diagnosis (0.45%). Table 1 shows characteristics and treatment approach for all patients with 50% receiving CRT and 50% CT alone first. At a median FU of 21.4 months, 2 patients did not complete therapy due to patient choice and both had progression of disease (POD). After completion of CRT, 6 patients underwent rectal surgery with 2 pathological complete response, and 2 patients proceeded with a Watch and Wait approach with clinical complete response on MRI. Prostate boost was delivered equally as often pre-surgery as post-surgery with both SBRT, EBRT and Seed Implant used. There was no grade 3+ RT related toxicity in the patients who completed all therapy.

CONCLUSION

This series represents one of the largest synchronous prostate and rectal cancer cohorts treated with curative intent. Future collaborative work is needed to develop guidelines in the treatment of synchronous prostate and rectal cancers. Although a rare diagnosis, the heterogeneity of approaches has led us to propose a standardized approach to management of synchronous diagnosis with upfront chemotherapy followed by EBRT inclusive of prostate and rectum followed by boost via brachytherapy (SBRT in non-candidates).

40-year-old woman • fever • rash • arthralgia • Dx?

► Fever ► rash ►arthralgia.

The Impact of Virtual Interviews on Recruitment and Implicit Bias

BACKGROUND AND OBJECTIVES

The COVID-19 pandemic accelerated virtual residency interview adoption. The impact of virtual interviews on program directors' (PD) National Residency Matching Program (NRMP) Match satisfaction, their future interview plans, and their perceptions about virtual interviews' influence on bias are unknown. We report the results of a survey of family medicine (FM) PDs about these topics after mandatory virtual interviews in 2020-2021.

METHODS

A national survey of all FM PDs was conducted in April 2021 (n=619). The response rate was 46.37% (n=287). Questions asked whether PDs conducted virtual interviews, as well as PDs' general perceptions of virtual interviews' impact on administrative burden, diversity and bias; PD's ability to communicate program culture and assess applicants' alignment with program values; PD's satisfaction with Match results; and plans for interview structure postpandemic.

RESULTS

Two hundred forty-four (93.1%) respondents performed only virtual interviews; 83.9% (n=220) conducting virtual interviews were satisfied with Match results, with no difference between programs with all virtual interviews vs others (OR 1.2, P=.994). PDs who communicated program values and involved residents in virtual interviews experienced higher Match satisfaction (OR 7.6, P<.001; OR 4.21, P=.001). PDs concerned about virtual interviews increasing bias against minorities before 2020 were still concerned after (OR 8.81, P<.001) and had lower Match satisfaction (OR 0.24, P=.001).

CONCLUSIONS

Most FM PDs conducted entirely virtual interviews in 2020 and were satisfied with the Match. Interview processes including residents and conveying residency culture increased Match satisfaction. PDs are concerned about bias in virtual interviews, but more investigation about bias is needed.

Family Medicine Musculoskeletal Medicine Education: A CERA Study

Background and Objectives: Musculoskeletal (MSK) concerns constitute up to 40% of primary care outpatient visits. Despite Accreditation Council for Graduate Medical Education (ACGME) family medicine program requirements for musculoskeletal medicine and sports medicine training, previous studies have shown that family medicine residency graduates do not have adequate training to manage common musculoskeletal conditions. Factors for this may include deficiencies in education at both the undergraduate and graduate medical education training levels. Methods: A Council of Academic Family Medicine Educational Research Alliance survey of 287 family medicine program directors assessed the current state of the delivery of musculoskeletal medicine education. Opinions were gathered on the scope and delivery of training requirements as well as potential areas for further curricular attention. Results: Two hundred eighty-seven program directors responded to the survey (response rate 41.53%). Most (72.60%) were in university based or affiliated programs and had a fellowship-trained primary care sports medicine physician (59.85%) curricular lead. A majority (77.4%) did not feel that PGY-1 residents enter residency with the physical exam skills needed to evaluate common musculoskeletal (MSK) conditions , and most (81.15%) did not feel that there should be changes to the current ACGME requirements. An area highlighted for further investment is faculty development in point-of-care ultrasound (39.85%). Conclusions: Although program directors believe that current ACGME MSK curricular requirements are likely appropriate, they do not feel residents arrive with the examination skills needed to evaluate common MSK conditions.Therefore, further attention can be given to medical student education in musculoskeletal exam skills prior to residency. Future research should develop objective measures using multiple assessors—students, residents, teaching faculty, and patients—to assess both the baseline and graduating competency in MSK medicine of our residents.

COVID-19 Post-acute Sequelae Among Adults: 12 Month Mortality Risk

Background: There are concerns regarding post-acute sequelae of COVID-19, but it is unclear whether COVID-19 poses a significant downstream mortality risk. The objective was to determine the relationship between COVID-19 infection and 12-month mortality after recovery from the initial episode of COVID-19 in adult patients. Methods: An analysis of electronic health records (EHR) was performed for a cohort of 13,638 patients, including COVID-19 positive and a comparison group of COVID-19 negative patients, who were followed for 12 months post COVID-19 episode at one health system. Both COVID-19 positive patients and COVID-19 negative patients were PCR validated. COVID-19 positive patients were classified as severe if they were hospitalized within the first 30 days of the date of their initial positive test. The 12-month risk of mortality was assessed in unadjusted Cox regressions and those adjusted for age, sex, race and comorbidities. Separate subgroup analyses were conducted for (a) patients aged 65 and older and (b) those <65 years. Results: Of the 13,638 patients included in this cohort, 178 had severe COVID-19, 246 had mild/moderate COVID-19, and 13,214 were COVID-19 negative. In the cohort, 2,686 died in the 12-month period. The 12-month adjusted all-cause mortality risk was significantly higher for patients with severe COVID-19 compared to both COVID-19 negative patients (HR 2.50; 95% CI 2.02, 3.09) and mild COVID-19 patients (HR 1.87; 95% CI 1.28, 2.74). The vast majority of deaths (79.5%) were for causes other than respiratory or cardiovascular conditions. Among patients aged <65 years, the pattern was similar but the mortality risk for patients with severe COVID-19 was increased compared to both COVID-19 negative patients (HR 3.33; 95% CI 2.35, 4.73) and mild COVID-19 patients (HR 2.83; 95% CI 1.59, 5.04). Patients aged 65 and older with severe COVID-19 were also at increased 12-month mortality risk compared to COVID-19 negative patients (HR 2.17; 95% CI 1.66, 2.84) but not mild COVID-19 patients (HR 1.41; 95% CI 0.84, 2.34). Discussion: Patients with a COVID-19 hospitalization were at significantly increased risk for future mortality. In a time when nearly all COVID-19 hospitalizations are preventable this study points to an important and under-investigated sequela of COVID-19 and the corresponding need for prevention.

Vocal Cord Dysfunction: Rapid Evidence Review

Vocal cord dysfunction (i.e., vocal cords closing when they should be opening, particularly during inspiration) should be suspected in patients presenting with inspiratory stridor or wheezing; sudden, severe dyspnea (without hypoxia, tachypnea, or increased work of breathing); throat or chest tightness; and anxiety, particularly in females. Common triggers include exercise, asthma, gastroesophageal reflux disease, postnasal drip, upper or lower respiratory tract infection, and irritants. Nasolaryngoscopy and pulmonary function testing, with provocative exercise and methacholine, can help diagnose vocal cord dysfunction and are helpful to evaluate for other etiologies. Conditions that can trigger vocal cord dysfunction should be optimally treated, particularly asthma, gastroesophageal reflux disease, and postnasal drip, while avoiding potential irritants. Therapeutic breathing maneuvers and vocal cord relaxation techniques are first-line therapy for dyspnea that occurs with vocal cord dysfunction. A subset of vocal cord dysfunction leads to dysphonia, as opposed to dyspnea, secondary to abnormal laryngeal muscle spasms (vocal cord closure is less severe). OnabotulinumtoxinA injections may be helpful for spasmodic dysphonia and for treating dyspnea in certain cases, although evidence is limited.

Case Report: Can Inhaled Adenosine Attenuate COVID-19?

This case report demonstrates a small repetition of the case series carried out in Italy wherein inhaled adenosine was administered to patients experiencing severe and worsening coronavirus disease-2019 (COVID-19). The two cases are important not only because they were the first of their type in the United States, but also because both patients were DNR/DNI and were therefore expected to die. Study repetition is vitally important in medicine. New work in pharmacology hypothesizes that adenosine-regulator proteins may play a role in the pathogenesis of COVID-19 infection. Furthermore, adenosine, by interacting with cell receptor sites, has pluripotent effects upon inflammatory cells, is anti-inflammatory, and is important in tissue hypoxia signaling. Inhaled adenosine is potentially safe; thousands have received it for asthmatic challenge testing. The effects of adenosine in these two cases were rapid, positive, and fit the pharmacologic hypotheses (as seen in prior work in this journal) and support its role as a therapeutic nucleoside.

An End-to-End Solution for Automatic Contouring of Tumor Region in Intraoperative Images of Breast Lumpectomy

Breast-conserving surgery, also known as lumpectomy, is an early stage breast cancer treatment that aims to spare as much healthy breast tissue as possible. A risk associated with lumpectomy is the presence of cancer positive margins post operation. Surgical navigation has been shown to reduce cancer positive margins but requires manual segmentation of the tumor intraoperatively. In this paper, we propose an end-to-end solution for automatic contouring of breast tumor from intraoperative ultrasound images using two convolutional neural network architectures, the U-Net and residual U-Net. The networks are trained on annotated intraoperative breast ultrasound images and evaluated on the quality of predicted segmentations. This work brings us one step closer to providing surgeons with an automated surgical navigation system that helps reduce cancer-positive margins during lumpectomy.

A-07 The Potential Impact of Nuclear History of Micronesia in Neuropsychological Functioning

Objective

As a result of 67 nuclear tests in the Marshall Islands between 1946 and 1958, inhabitants of Micronesia exposed to radiation exhibited chronic health issues and birth defects that persist to this day. This patient’s presentation may be an example of the continued residual impact of nuclear testing in Micronesia and demonstrates the importance of historical and biological factors when considering differential diagnoses.

Method

Patient is a six-year-old Micronesian male referred for assessment of psychological functioning. He was developmentally delayed since birth, exhibited unusual facial features, and previously diagnosed with Autism Spectrum Disorder (ASD). Presenting problems included speech delays, limited attention span, difficulty coping with challenges, narrow interests, impulsivity, difficulties interacting with peers, and toileting issues (i.e., defecating on the floor). Mother immigrated to Hawaii from Micronesia in 2006 and primarily speaks Chuukese. While pregnant, mother was on medications for diabetes, hospitalized with high blood pressure, and chewed tobacco daily. Patient experienced some difficulties during the neonatal period.

Results

Average nonverbal intelligence; moderately low receptive single word vocabulary; possible somatization, tendency to withdraw, and atypical behavior; problems with functional communication and daily living activities; and learning-related problems at school. Probability of autism within the Possibly/Very Likely range. Age-inappropriate projective drawings, with indications of potential genetic or developmental dysfunction.

Conclusions

Patient was diagnosed with ASD, with accompanying language impairment. Due to family history of radiation exposure in Micronesia and prenatal concerns, a rule out of other neurodevelopmental disorders and various genetic conditions were considered.

Abstract PD4-10: 18F-fluoroestradiol (FES) and 18F-fluorodeoxyglucose (FDG) PET imaging in staging extent of disease in metastatic lobular breast cancer

Background: The histology and pattern of spread in lobular breast cancer has presented challenges in estimating extent of disease and identifying treatment options. 18F-FES is an estrogen analogue PET imaging tracer which measures tumor ER expression at multiple tumor sites simultaneously and predicts response to endocrine therapy. We analyzed FES-PET and FDG-PET SUV uptake in patients with metastatic lobular and ductal carcinoma to identify sites of tumor and responsiveness to therapy.

Methods: We retrospectively reviewed FES and FDG SUV uptake between ER+ lobular (n = 36) and ductal (n= 173, including 6 men) metastatic breast cancer patients enrolled in various institutional studies. Up to 3 lesions in each patient were evaluated by FES SUVmax and/or FDG SUVmax for a total of 475 lesions in FES images and 462 lesions in FDG images. Classification into three categories (low FDG, high FDG/high FES, and high FDG/low FES) was generated using recursive portioning with 5-fold internal cross validation. Using a Pearson Chi-squared test, we compared degree of uptake in FES and FDG between lobular and ductal carcinomas. We used linear mixed effects model to assess association of FES SULmean3 (Lean body mass adjusted SUV) and FDG SULmean3 with histology. Overall survival (OS), from time of FES-PET scan to death, and progression free survival (PFS) was evaluated between classification groups in both histologies using Kaplan-Meier curves and Cox model.

Results: In patients with metastatic breast cancer, 72 patients had low FDG, 96 had high FES/high FDG, and 41 with high FES/low FDG. Lobular lesions tended to have a higher proportion of patients in the risk group with lower FDG (42% vs 33%) and a lower proportion in the risk group with high FDG/low FES (11% vs 21%) but the difference was not statistically significant (p = 0.32). Mean (range) FES SULmean3 and FDG SULmax3 respectively for ductal was 1.38 (0.10, 6.7) and 3.17 (0.88, 12.26) and for lobular was 1.42 (0.34, 3.43) and 3.13 (1.04, 13.87). There was no significant difference between in FES SULmean3 and FDG SULmax3 between histologies. Following FES-PET imaging, patients with lobular carcinomas and low FDG demonstrated a higher median survival time (7.7 years) compared to high FDG/low FES (4.3 years) and high FDG/high FES (2.6 years). Similarly, patients with ductal carcinomas and low FDG had an improved median survival time (5.6 years) compared to both high FDG/high FES (2.9 years) and high FDG/low FES (2.5 years). However, the interaction between histology and the FDG/FES classifications was not significant (p = 0.86). Across a variety of tumor sites, lobular histology can be detected by both FES and FDG with no difference between the imaging modalities.

Conclusions: In the metastatic setting, quantitative FES and FDG can be used to discriminate indolent and aggressive phenotypes in both lobular and ductal breast cancer. A greater proportion of lobular carcinoma lesions had higher FES/lower FDG and would be anticipated to be more sensitive to endocrine therapy. Further prospective trials are needed to confirm the utility of FES to stage extent of disease in metastatic breast cancer.

Citation Format: Manohar PM, Peterson LM, Wu V, Jenkins IC, Novakova-Jiresova A, Specht JM, Link JM, Krohn KA, Kinahan PE, Mankoff DA, Linden HM. 18F-fluoroestradiol (FES) and 18F-fluorodeoxyglucose (FDG) PET imaging in staging extent of disease in metastatic lobular breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD4-10.

The Pregnant Patient: Managing Common Acute Medical Problems

Women often see their primary care physicians for common acute conditions during pregnancy. These conditions may be caused by pregnancy (obstetric problems) or worsened by pregnancy (obstetrically aggravated problems), or they may require special consideration during pregnancy because of maternal or fetal risks (nonobstetric problems). Primary care physicians should know the differential diagnosis for common conditions during pregnancy and recognize the important findings of obstetric and urgent nonobstetric problems. The family physician can evaluate and treat most nonobstetric problems, although obstetric problems require referral to a primary maternity care clinician. A tiered approach, including routinely looking for all-cause red flag symptoms and signs, while remaining aware of estimated gestational age, allows for high-quality care and shared decision making between the family physician and the pregnant patient. When treating common causes of nausea and epigastric pain/gastroesophageal reflux, lifestyle modifications are considered the safest and first-choice therapy, followed by well-established low-risk therapies, such as vitamin B6 (pyridoxine) and doxylamine for nausea, and antacids not containing salicylates (found in bismuth combination products) for gastroesophageal reflux. Other common conditions during pregnancy are best treated with low-risk therapies, such as using antihistamines or topical steroids for rashes, first-generation cephalosporins or amoxicillin for cystitis, and physical therapy and acetaminophen for low back pain and headaches.

Colibactin biosynthesis and biological activity depend on the rare aminomalonyl polyketide precursor

The as-yet unidentified E. coli metabolite colibactin induces DNA damage in eukaryotic cells and promotes tumorigenesis. Its wide distribution in pathogenic and probiotic strains has raised great interest in its structure and biosynthesis. Here we show that colibactin formation involves a rare aminomalonyl unit used as a building block.

The organization of colposcopy services in Ontario: recommended framework

OBJECTIVE

The purpose of this guideline is to help ensure the provision of high-quality colposcopy practices in the province of Ontario, including those conducted as diagnostic procedures in follow-up to an abnormal cervical screening test.

METHODS

This document updates the recommendations published in the 2008 colposcopy guideline from Cancer Care Ontario, The Optimum Organization for the Delivery of Colposcopy Service in Ontario. A systematic review of guidelines was conducted to evaluate the existing evidence and recommendations concerning these key aspects of colposcopy: □ Training, qualification, accreditation, and maintenance of competence□ Practice setting requirements□ Operational practice□ Quality indicators and outcomes.

RESULTS

This guideline provides recommendations on training and maintenance of competence for colposcopists in the practice settings in which colposcopic evaluation and treatments are conducted. It also provides recommendations on operational issues and quality indicators for colposcopy.

CONCLUSIONS

This updated guideline is intended to support quality improvement for colposcopy for all indications, including the follow-up of an abnormal cervical screening test and work-up for lower genital tract lesions that are not clearly malignant. The recommendations contained in this document are intended for clinicians and institutions performing colposcopy in Ontario, and for policymakers and program planners involved in the delivery of colposcopy services.

Biomarkers in transplantation: Prospective, blinded measurement of predictive value for the flow cytometry crossmatch after negative antiglobulin crossmatch in kidney transplantation

This prospective, blinded observational study was conducted to measure the predictive value the of flow cytometric crossmatch for biopsy-proven acute rejection, graft loss, or death following kidney transplantation. Patients were selected for renal transplantation on the basis of a conventional antihuman globulin cytotoxic T-cell crossmatch. Flow crossmatch was performed simultaneously, but the results were not disclosed to the transplant team. A total of 257 kidney transplant recipients were enrolled in the study; 78 patients experienced biopsy-proven rejection in the first post-transplant year, and 41 patients lost their graft or died during the period of follow-up (mean: 2046 days). Kaplan-Meier estimates of rejection, graft loss, or patient death did not differ between subjects with a positive or negative flow crossmatch. Cox analyses showed no influence of the flow crossmatch on the risk of biopsy-proven acute rejection (P = 0.987). The sensitivity and specificity of the flow crossmatch for prediction of biopsy-proven rejection were 0.128 and 0.883, and the positive and negative post-test probabilities were 0.323 and 0.301, respectively. The magnitude of the channel shift did not influence the multivariate Cox regression model. The area under the receiver operating characteristic curve of the flow crossmatch was 0.483 (P = 0.71) and 0.572 (P = 0.38), respectively for the living and cadaver transplant recipients, indicating no discriminative value in this study population. Flow crossmatch appears to have no significant incremental value in predicting biopsy-proven acute rejection, graft loss, or death following kidney transplantation in patients who have a negative antihuman globulin cytotoxic T-cell crossmatch against their donor.

CRF2 receptor activation prevents colorectal distension induced visceral pain and spinal ERK1/2 phosphorylation in rats

BACKGROUND AND AIMS

Activation of corticotropin releasing factor 1 (CRF1) receptors is involved in stress related responses and visceral pain, while activation of CRF2 receptors dampens the endocrine and some behavioural stress responses. We hypothesised that CRF2 receptor activation may influence visceral pain induced by colorectal distension (CRD) in conscious rats, and assessed the possible sites and mechanisms of action.

METHODS

Male Sprague-Dawley rats were exposed to CRDs (60 mm Hg, 10 minutes twice, with a 10 minute rest interval). Visceromotor responses (VMR) were measured by electromyography or visual observation. Spinal (L6-S1) extracellular signal regulated kinase 1/2 (ERK 1/2) activation following in vivo CRD and CRF2 receptor gene expression in the T13-S1 dorsal root ganglia (DRG) and spinal cord were determined. Inferior splanchnic afferent (ISA) activity to CRD (0.4 ml, 20 seconds) was assessed by electrophysiological recording in an in vitro ISA nerve-inferior mesenteric artery (intra-arterial)-colorectal preparation.

RESULTS

In controls, VMR to the second CRD was mean 31 (SEM 4)% higher than that of the first (p<0.05). The selective CRF2 agonist, human urocortin 2 (hUcn 2, at 10 and 20 microg/kg), injected intravenous after the first distension, prevented sensitisation and reduced the second response by 8 (1)% and 30 (5)% (p<0.05) compared with the first response, respectively. RT-PCR detected CRF2 receptor gene expression in the DRG and spinal cord. CRD (60 mm Hg for 10 minutes) induced phosphorylation of ERK 1/2 in neurones of lumbosacral laminae I and IIo and the response was dampened by intravenous hUcn 2. CRD, in vitro, induced robust ISA spike activity that was dose dependently blunted by hUcn 2 (1-3 microg, intra-arterially). The CRF2 receptor antagonist, astressin2-B (200 microg/kg subcutaneously or 20 microg intra-arterially) blocked the hUcn 2 inhibitory effects in vivo and in vitro.

CONCLUSIONS

Peripheral injection of hUcn 2 blunts CRD induced visceral pain, colonic afferent, and spinal L6-S1 ERK 1/2 activity through CRF2 receptor activation in rats.

Determination of polymorphic forms of ranitidine–HCl by DRIFTS and XRPD

The identification, characterization and quantification of crystal forms are becoming increasingly important within the pharmaceutical industry. A combination of different physical analytical techniques is usually necessary for this task. In this work solid-state techniques, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and X-ray powder diffractometry (XRPD) were combined to analyze polymorphic purity of crystalline ranitidine-HCl, an antiulcer drug, H2 receptor antagonists. A series of 12 different mixtures of Form 1 and 2 was prepared by geometric mixing and their DRIFT spectra and XRD powder patterns were obtained and analyzed, either alone or combined together, using Artificial Neural Networks (ANNs). A standard feed-forward network, with back-propagation rule and with multi layer perceptron architecture (MPL) was chosen. A working range of 1.0-100% (w/w) of crystal Form 2 in Form 1 was established with a minimum quantifiable level (MQL) of 5.2% and limit of detection of 1.5% (w/w). The results demonstrate that DRIFTS combined with XRPD may be successfully used to distinguish between the ranitidine-HCl polymorphs and to quantify the composition of binary mixtures of the two.

Alloimmunization and erythrocyte autoimmunization in transfusion-dependent thalassemia patients of predominantly asian descent

The development of hemolytic alloantibodies and erythrocyte autoantibodies complicates transfusion therapy in thalassemia patients. The frequency, causes, and prevention of this phenomena among 64 transfused thalassemia patients (75% Asian) were evaluated. The effect of red blood cell (RBC) phenotypic differences between donors (mostly white) and Asian recipients on the frequency of alloimmunization was determined. Additional transfusion and patient immune factors were examined. 14 (22%) of 64 patients (75% Asian) became alloimmunized. A mismatched RBC phenotype between the white population, comprising the majority of the donor pool, and that of the Asian recipients, was found for K, c, S, and Fyb antigens, which accounts for 38% of the alloantibodies among Asian patients. Patients who had a splenectomy had a higher rate of alloimmunization than patients who did not have a splenectomy (36% vs 12.8%; P =.06). Erythrocyte autoantibodies, as determined by a positive Coombs test, developed in 25% or 16 of the 64 patients, thereby causing severe hemolytic anemia in 3 of 16 patients. Of these 16, 11 antibodies were typed immunoglobulin G [IgG], and 5 were typed IgM. Autoimmunization was associated with alloimmunization and with the absence of spleen (44% and 56%, respectively). Transfused RBCs had abnormal deformability profiles, more prominent in the patients without a spleen, which possibly stimulated antibody production. Transfusion of phenotypically matched blood for the Rh and Kell (leukodepleted in 92%) systems compared to blood phenotypically matched for the standard ABO-D system (leukodepleted in 60%) proved to be effective in preventing alloimmunization (2.8% vs 33%; P =.0005). Alloimmunization and autoimmunization are common, serious complications in Asian thalassemia patients, who are affected by donor-recipient RBC antigen mismatch and immunological factors.

Stability of polymorphic forms of ranitidine hydrochloride

Ranitidine-HCl can exist in two different polymorphic forms: form I (m.p. 134-140 degrees C) and form II (m.p. 140-144 degrees C). In the present study the stability of form I of ranitidine-HCl to a selection of powder pretreatments, to reflect conditions which might occur in manufacturing procedures, and also to a limited range of storage conditions was investigated. The original samples of form I and form II used were characterised by X-ray powder diffraction (XRPD), hot stage microscopy (HSM) and differential scanning calorimetry (DSC). A quantitative XRPD method for determining the fraction of form II in the presence of form I was used. XRPD data were analysed using regression techniques and artificial neural networks (ANN). The quantitative XRPD technique was then used to monitor the relative proportion of form II in each treated sample. Pretreatments of form I included (i) mixing with form II or with common excipients (ii) compression and grinding (iii) contact with solvents (followed by drying) before storage. Storage conditions involved three temperatures (20 degrees C, 30 degrees C, 42 degrees C) and three relative humidities (45% RH; 55% RH; 75% RH). Samples were stored for a period of 6 months. A limited factorial design was used. No increase in the form II:form I ratio was observed in the following pretreatment processes: introduction of form II nuclei into form I; introduction of excipients to form I; compression of form I powder at 5 and 15 tons; normal mixing and grinding processes; addition of isopropanol (IPA) or water/IPA mix followed by drying. In the pretreatment process where water was added to form I powder (with most or all of the powder dissolving), drying of the liquefied mass led to a mix of form I and form II. On storage at room temperature (20-30 degrees C), low relative humidity (45-55% RH), and in an air-tight container there was no increase in the form II:form I ratio. Storage of form I/form II mixes, particularly at high humidity, resulted in a preferential loss of form II (compared to form I). Loss was greater at 30 degrees C/75% RH than at 20 degrees C/75% RH. Form II was also preferentially lost under low humidity conditions created by a saturated solution of potassium carbonate (45% RH) at the elevated temperature of 42 degrees C. This environment was shown to be acidic.

Ranitidine hydrochloride X-ray assay using a neural network

A simple X-ray powder diffractometric (XRD) method with artificial neural networks (ANNs) for data modelling was developed to recognize and quantify two crystal modifications of ranitidine HCl in mixtures and thus, provide information about the solid state of the bulk drug. The method was also used to quantify ranitidine HCl from tablets in the presence of other components. An ANN consisting of three layers of neurons was trained by using a back-propagation learning rule. A sigmoid output function was used in the hidden layer to facilitate non-linear fitting. Unlike other techniques the ANN method described here employed pattern recognition on the entire XRD pattern. Correct classification was mainly influenced by the XRD pattern resolution. It was shown that data transformations improved the quantitative performance when the XRD patterns were not contaminated by other components. Only smoothed X-ray diffractograms were required to distinguish between the two crystalline forms in a mixture. In the case of ranitidine-HCl quantification from tablets, where significant interference with tablet excipients was present, better results were obtained without data transformations. The trained ANN perfectly quantified ranitidine HCI polymorphic forms from mixtures (mean sum of squared error was less than 0.02%) and ranitidine HCl form 1 from tablets (recovery = 98.65). Excellent quantification performance of the ANN analysis. demonstrated in this study, serves as an indication of the broad potential of neural networks in pattern analysis. While the system described has been developed to interpret XRD patterns, peak detection has implications in every chemical application where the recognition of peak-shaped signals in analytical data is important.