Combined Targeted Muscle Reinnervation With Regenerative Peripheral Nerve Interfaces Decreases Long-Term Narcotic Use in Amputees: A Case Control Study

PURPOSE

Combined targeted muscle reinnervation with regenerative peripheral nerve interfaces ("TMRpni") is a recently described nerve management strategy that leverages beneficial elements of targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) techniques. This study aimed to evaluate the effect of TMRpni on long-term opioid consumption after amputation. We hypothesize that TMRpni decreases chronic opioid consumption in amputees.

METHODS

This is a retrospective cohort study of all patients who underwent TMRpni between 2019 and 2021. These patients were age-matched at a 1:1 ratio with a control group of patients who underwent amputation without TMRpni. Statistical analysis was performed using SPSS Version 28.0.

RESULTS

Thirty-one age-matched pairs of patients in the TMRpni and control groups were included. At 30 days after surgery, there was no significant difference in number of patients who required an additional refill of their opioid prescriptions (45% vs 55%, P = 0.45) or patients who continued to actively use opioids (36% vs 42%, P = 0.60). However, at 90 days after surgery, there was a significantly lower number of patients from the TMRpni group who reported continued opioid use compared with the control group (10% vs 32%, P = 0.03).

CONCLUSIONS

This study demonstrates that TMRpni may translate to decreased rates of chronic opiate use. Continued study is indicated to optimize TMRpni techniques and patient selection and to determine its long-term efficacy.

Evaluation of Conflict of Interest in Consulting Fee Payments in Plastic Surgery and Related Specialties

BACKGROUND

The Physician Payments Sunshine Act was enacted to increase transparency regarding physician and industry financial interests. Consulting fee payments constitute a large proportion of these financial relationships. The authors hypothesized that there are discrepancies among industry-derived consulting payments to medical and surgical specialties. The purpose of this study was to evaluate the distribution of consulting fee payments to plastic surgery and related specialties.

METHODS

This cross-sectional study used the publicly available Centers for Medicare & Medicaid Services Open Payments Program database for 2018. Consulting fee payments to physicians practicing in dermatology, internal medicine, neurosurgery, orthopedic surgery, otolaryngology, and plastic surgery were isolated and analyzed to identify discrepancies in consulting payments among these specialties and within plastic surgery.

RESULTS

A total of $250,518,240 was paid in consulting fees to specialties analyzed, with the largest average payment made to orthopedic surgeons and neurosurgeons. Nearly half of physicians were paid at least $5000 for consulting fees in 2018. Most payments were not associated with contextual information. Among U.S. plastic surgeons, 4.2% held financial relationships with corporations and were likely to be paid more when consulting for small companies.

CONCLUSIONS

Consulting payments make up a large proportion of payments included in the Open Payments Database. Although sex, state, company type, and sole proprietorship did not correlate with higher pay, plastic surgeons who consulted for small companies were paid more per payment than those working for large companies. Future studies are warranted to determine whether these industry financial relationships impact physician behavior.

Preinjury Social Determinants of Health Disparities Predict Postinjury Psychosocial Conditions in Adult Traumatic Brachial Plexus Injuries

BACKGROUND

Adult traumatic brachial plexus injuries (TBPIs) are life-altering events that can have detrimental effects on a patient's quality of life.

OBJECTIVE

To examine how social determinants of health (SDOH) disparities influence the risk of developing new psychosocial conditions after TBPIs in previously psychiatric-naïve patients.

METHODS

Between January 2010 and June 2019, a retrospective analysis was performed using PearlDiver's Mariner, an all-payer claims database, to create 3 cohorts: TBPI disparity cohort: patients with TBPI and presence of at least 1 SDOH disparity before injury, TBPI without disparity cohort: patients with TBPI and the absence of any SDOH disparity, and control cohort: patients without TBPIs.

RESULTS

The matched population analyzed in this study consisted of 1176 patients who were equally represented in the TBPI disparity cohort (n = 392, 33.33%), TBPI without disparity cohort (n = 392, 33.33%), and control cohort (n = 392, 33.33%). A total of 301 patients developed any psychosocial condition with 4 years of their injury. Patients in the TBPI disparity cohort had significantly higher rates of developing any psychosocial condition (31.12%, P < .0005), depression (22.70%, P = .0032), anxiety (18.62%, P = .0203), drug abuse (7.91%, P = .0060), and alcohol abuse (4.85%, P = .03499) when compared with the other cohorts. Furthermore, the disparity cohort carried a significantly increased risk of developing any psychosocial condition (hazard ratio 1.42, 95% CI 1.09-1.86). The rates of suicide attempt, post-traumatic stress disorder, and divorce did not significantly differ between groups.

CONCLUSION

TBPI patients with SDOH disparities are at increased risk of developing new-onset psychosocial conditions, such as depression, anxiety, drug abuse, and alcohol abuse. Level of Evidence: Prognostic Level III.

Does Facial Fracture Management Require Opioids? A Pilot Trial of a Narcotic-Minimizing Analgesia Protocol for Operative Facial Trauma

Opioid minimization in the acute postoperative phase is timely in the era of the opioid epidemic. The authors hypothesize that patients with facial trauma receiving multimodal, narcotic-minimizing pain management in the perioperative period will consume fewer morphine milligram equivalents (MMEs) while maintaining adequate pain control compared with a traditional analgesia protocol. An IRB-approved pilot study evaluating isolated facial trauma patients compared 10 consecutive prospective patients of a narcotic-minimizing pain protocol beginning in August 2020 with a retrospective, chart-reviewed cohort of 10 consecutive patients before protocol implementation. The protocol was comprised of multimodal nonopioid pharmacotherapy given preoperatively (acetaminophen, celecoxib, and pregabalin). Postoperatively, patients received intravenous (IV) ketorolac, scheduled acetaminophen, ibuprofen, and gabapentin. Oxycodone was reserved for severe uncontrolled pain. The control group had no standardized protocol, though opioids were ad libitum. Consumed MMEs and verbal Numeric Rating Scale (vNRS) pain scores (0-10) were prospectively tracked and compared with retrospective data. Descriptive and inferential statistics were run. At all recorded postoperative intervals, narcotic-minimizing subjects consumed significantly fewer MMEs than controls [0-8 h, 21.5 versus 63.5 ( P = 0.002); 8-16 h, 4.9 versus 20.6 ( P = 0.02); 16-24 h, 3.3 versus 13.9 ( P = 0.03); total 29.5 versus 98.0 ( P = 0.003)]. At all recorded postoperative intervals, narcotic-minimizing subjects reported less pain (vNRS) than controls (0-8 h, 7.7 versus 8.1; 8-16 h, 4.4 versus 8.0; 16-24 h 4.3 versus 6.9); significance was achieved at the 8 to 16-hour time point ( P = 0.006). A multimodal, opioid-sparing analgesia protocol significantly reduces opioid use in perioperative facial trauma management without sacrificing satisfactory pain control for patients.

A Guide to Industry Payments and an Algorithm for Their Management

BACKGROUND

The Open Payments database was created to increase transparency of industry payment relationships within medicine. The current literature often examines only 1 year of the database. In this study, the authors use 5 years of data to show trends among industry payments to plastic surgeons from 2014 to 2018. In addition, the authors lay out the basics of conflict-of-interest reporting for the new plastic surgeon. Finally, the authors suggest an algorithm for the responsible management of industry relationships.

METHODS

This study analyzed nonresearch payments made to plastic surgeons from January 1, 2014, to December 31, 2018. Descriptive statistics were calculated using R Statistical Software and visualized using Tableau.

RESULTS

A total of 304,663 payments totaling $140,889,747 were made to 8148 plastic surgeons; 41 percent ($58.28 million) was paid to 50 plastic surgeons in the form of royalty or license payments. With royalties excluded, average and median payments were $276 and $25. The average yearly total per physician was $2028. Of the 14 payment categories, 95 percent of the total amount paid was attributable payments in one of six categories. Seven hundred thirty companies reported payments to plastic surgeons from 2014 to 2018; 15 companies (2 percent) were responsible for 80 percent ($66.34 million) of the total sum paid. Allergan was responsible for $24.45 million (29.6 percent) of this amount.

CONCLUSIONS

Although discussions on the proper management of industry relationships continue to evolve, the data in this study illustrate the importance of managing industry relationships. The simple guidelines suggested create a basis for managing industry relationships in the career of the everyday plastic surgeon.

Delayed Septal Perforation as a Complication of COVID-19: A Case Report

BACKGROUND

There are increasing reports of the effects of SARS-CoV-2 on olfactory function, with a significant number of patients reporting anosmia as a symptom. However, our knowledge and understanding of the virus's complete impact on the nose remains poor. This report describes a unique patient case to demonstrate how COVID-19 may be associated with rhinoplasty complications such as septal perforation.

CASE REPORT

This is a case report of a previously healthy patient who underwent septorhinoplasty in 2018. She had frequent follow-up including intranasal examinations without evidence of the septal perforation for the 2 years following her operation. In March 2020, the patient was noted to have symptoms suggestive of COVID-19, but testing was not recommended by the pediatrician. Soon after her symptoms resolved, she experienced a sudden onset of whistling and physical examination revealed a perforation in the septum which rapidly enlarged over the ensuing weeks. She tested positive for the COVID-19 antibody. After confirming that she no longer had an active infection via antigen testing, she underwent repair of her septal perforation without complications.

CONCLUSION

This case report illustrates a septorhinoplasty complication that may be associated with COVID-19. Further study into this virus's impact on vascularity and wound healing, specifically in the nose, is recommended.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Industry Payments by Allergan, Inc to Plastic Surgery and Related Specialties in 2018

In 2014, payments to medical providers from drug/device manufacturers were made public through the Open Payments Database. Although previous studies have used the Open Payments Database to describe relationships between specialties and industry, few have evaluated specific companies and the effect of their contributions. As a large contributor to industry payments in plastic surgery, Allergan, Inc represents a significant source of potential financial conflicts of interest in the field. In this study, we aimed to describe the quantity, type, and specific products associated with Allergan's payments to both plastic surgeons and physicians of other specialties. In 2018, Allergan paid a total of $48,484,163 in 397,225 payments to 90,386 physicians. Psychiatry and neurology received $11,867,861 in payments, the largest of any specialty, whereas internal medicine received the largest number of individual payments. Plastic surgeons made the most per physician ($3025). Most payments made to plastic surgeons were categorized as "gifts." Payments made in relation to Botox were predominantly made to neurologists, whereas most payments attributed to Natrelle breast implants were made to plastic surgeons (74.4%). Surprisingly, 18.2% of Natrelle payments were made to family medicine physicians. Further study is needed to fully understand the implications of the financial contributions revealed in this study.

Novel Use of a Closed Liposuction System: Treatment of an Acute Morel-Lavallée Lesion of the Upper Extremity

Morel-Lavallée lesions (MLL) are closed post-traumatic soft tissue shear injuries that occur between fascial planes and may result in tissue loss. Current treatment options for MLL include percutaneous drainage and open irrigation and debridement. A few cases of suction-assisted lipectomy (SAL) have been described for subacute and chronic MLL of the lower extremity. We present the first case report of using a closed SAL system to treat an acute MLL of the upper extremity. A 78-year-old female with right forearm MLL presented after blunt force trauma while on apixaban. After inpatient monitoring and anticoagulant drug clearance, a closed system SAL was performed to evacuate the hematoma and prevent ischemia of overlying soft tissues. Treatment outcomes were measured by clinical exam and CT imaging. Pre-operative diagnostic CT scan demonstrated a 4.8 x 6.6 x 13 cm fluid collection between fascial layers of the right forearm. SAL resulted in the evacuation of 300 cc of coagulated blood. Post-operative CT imaging of the right upper extremity did not show any measurable fluid collection. Clinical exam demonstrated resolution of swelling and soft tissue compromise. The patient reported significant pain reduction, resumed her anticoagulation, and was discharged home. There were no notable complications at her three month post-operative visit. Consideration of a constant low-pressure SAL system can successfully treat MLL in the acute period. This system is relatively minimally invasive, results in faster healing times compared to open debridement, and still results in effective hematoma evacuation.

Regeneration of Functional, Full-Thickness Skin With Minimal Donor Site Contribution Using Autologous Homologous Skin Construct

Autologous skin grafts (autografts) remain the gold standard in the treatment of skin loss. For extensive wounds or burns, however, identifying adequate donor sites can be the limiting factor. Additionally, donor sites are associated with pain, risk of infection, and poor cosmetic outcomes. Many skin substitutes have been engineered as alternatives to traditional autografts. These substitutes, however, all leave something to be desired either functionally or cosmetically. This report describes the use of a new technology, autologous homologous skin constructs, to regenerate full-thickness skin grafts that maintain functional polarity, allowing important components of skin such as glands and hair follicles to regenerate. These grafts only require small samples of full-thickness skin from the patient, decreasing issues of donor site availability.

Lifestyle and Self-Management by Those Who Live It: Patients Engaging Patients in a Chronic Disease Model

BACKGROUND

Patients pursuing organ transplantation have complex medical needs, undergo comprehensive evaluation for possible listing, and require extensive education. However, transplant patients and their supports frequently report the need for more lifestyle and self-management strategies for living with organ transplantation.

OBJECTIVES

First, to explore feasibility of a successful, patient-run transplant lifestyle educational group (Transplant Living Community), designed to complement medical care and integrated into the clinical setting; and second, to report the major themes of patients' and supports' qualitative and quantitative feedback regarding the group.

METHODS

Informal programmatic review and patient satisfaction surveys.

RESULTS

A total of 1862 patient satisfaction surveys were disseminated and 823 were returned (response rate, 44.2%). Patients and their supports reported positive feedback regarding the group, including appreciation that the volunteer was a transplant recipient and gratitude for the lifestyle information. Five areas were associated with the success of Transplant Living Community: 1) a "champion" dedicated to the program and its successful integration into a multidisciplinary team; 2) a health care environment receptive to integration of a patient-led group with ongoing community development; 3) a high level of visibility to physicians and staff, patients, and supports; 4) a clearly presented and manageable lifestyle plan ("Play Your ACES"(a) [Attitude, Compliance, Exercise, and Support]), and 5) a strong volunteer structure with thoughtful training with the ultimate objective of volunteers taking ownership of the program.

CONCLUSION

It is feasible to integrate a sustainable patient-led lifestyle and self-management educational group into a busy tertiary care clinic for patients with complex chronic illnesses.

Training Advanced Practice Providers to Collect Functional Outcomes After Fragility Fractures

Objective:

The objective of this study was to determine whether advanced practice providers could learn to collect objective functional assessment data accurately and efficiently with commercially available devices that measure kinematics and kinetics (Nintendo Wii Balance Board [WBB] and Level Belt [LB]) to aid in the assessment of fall risk and outcomes after fragility fractures.

Methods:

Nine advanced practice providers participated in a 1-hour clinical assessment tools (CATs) training session on equipment use, providing standardized instructions, and practice of the testing procedures. Afterward, they participated in a skills demonstration evaluation and completed a postsession survey.

Results:

Participants successfully achieved a mean of 18.22 (standard deviation 1.56) of 20 performance measures. Of the incomplete or omitted tasks, the majority (10 of 16) occurred within the first of 3 CATs activities. Postsession survey results revealed that 9 of 9 participants reported that the 1 hour provided for training on the CATs was sufficient. All participants reported that after the training, they felt confident they could reliably carry out the tasks to test patients on both the WBB and the LB. The majority of participants reported that they believed that the WBB (7 of 9) and LB (8 out of 9) would be good assets to clinics in assessing patient functionality after fragility fractures.

Conclusion:

These results indicate that advanced practice providers can confidently learn and effectively test patients with the WBB and LB within 1 hour of training. In the future, adoption of CATs in the clinical setting may allow for objective, easy-to-use, portable, noninvasive, and relatively inexpensive measures to assess functional outcomes in patients with fragility fracture.

Effect of estrogen on growth and apoptosis in esophageal adenocarcinoma cells

The epidemiology of esophageal adenocarcinoma demonstrates a strong gender bias with a sex ratio of 8-9:1 in favor of males. A potential explanation for this is that estrogen might protect against esophageal adenocarcinoma. Estrogen has previously been shown to stimulate apoptosis in esophageal squamous cancer cells. However, the effect of estrogen on esophageal adenocarcinoma cells has not been determined. We used immunoblotting analysis to determine the expression of estrogen receptors, cell adhesion marker E-cadherin, and proliferation marker Ki-67 in cell lines derived from esophageal adenocarcinoma (OE-19, OE-33) and Barrett's esophagus (QhTRT, ChTRT, GihTRT). Estrogen and selective estrogen receptor modulator (SERM)-dependent effects on cell growth were determined by the CellTiter-96 Aqueous Proliferation Assay. Apoptosis was determined by Annexin V/Propidium Iodide cell labeling and flow cytometry. We detected that physiological and supra-physiological concentrations of 17β-estradiol and SERM decreased cell growth in esophageal adenocarcinoma cells. In Barrett's esophagus cells (QhTRT, ChTRT), decreased growth was also detected in response to estrogen/SERM. The level of estrogen receptor expression in the cell lines correlated with the level of anti-growth effects induced by the receptor agonists. Flow cytometry analysis confirmed estrogen/SERM stimulated apoptosis in esophageal adenocarcinoma cells. Estrogen/SERM treatments were associated with a decrease in the expression of Ki-67 and an increase in E-cadherin expression in esophageal adenocarcinoma cells. This study suggests that esophageal adenocarcinoma and Barrett's esophagus cells respond to treatment with selective estrogen receptor ligands, resulting in decreased cell growth and apoptosis. Further research to explore potential therapeutic applications is warranted.

Is atropine needed with ketamine sedation? A prospective, randomised, double blind study

OBJECTIVE

To compare atropine with placebo as an adjunct to ketamine sedation in children undergoing minor painful procedures. Outcome measures included hypersalivation, side effect profile, parental/patient satisfaction, and procedural success rate.

METHODS

Children aged between 1 and 16 years of age requiring ketamine procedural sedation in a tertiary emergency department were randomised to receive 0.01 mg/kg of atropine or placebo. All received 4 mg/kg of intramuscular ketamine. Tolerance and sedation scores were recorded throughout the procedure. Side effects were recorded from the start of sedation until discharge. Parental and patient satisfaction scores were obtained at discharge and three to five days after the procedure, with the opportunity to report side effects encountered at home.

RESULTS

A total of 83 patients aged 13 months to 14.5 years (median age 3.4 years) were enrolled over a 16 month period. Hypersalivation occurred in 11.4% of patients given atropine compared with 30.8% given placebo (odds ratio (OR) 0.29, 95% confidence interval (CI) 0.09 to 0.91). A transient rash was observed in 22.7% of the atropine group compared with 5.1% of the placebo group (OR 5.44, 95% CI 1.11 to 26.6). Vomiting during recovery occurred in 9.1% of atropine patients compared with 25.6% of placebo patients (OR 0.29, 95% CI 0.09 to 1.02). There was a trend towards better tolerance in the placebo group. No patient experienced serious side effects.

CONCLUSION

Ketamine sedation was successful and well tolerated in all cases. The use of atropine as an adjunct for intramuscular ketamine sedation in children significantly reduces hypersalivation and may lower the incidence of post-procedural vomiting. Atropine is associated with a higher incidence of a transient rash. No serious adverse events were noted.

Association between antenatal cytokine production and the development of atopy and asthma at age 6 years

BACKGROUND

Various lines of evidence suggest that antenatal factors are important in determining susceptibility to atopy and asthma. One possible mechanism is cytokines, production of which in the placenta is high throughout gestation and which protect placental integrity via control of local immunological homoeostasis. We investigated antenatal cytokine concentrations in a prospective birth cohort, intensively monitored for atopy and asthma outcomes at age 6 years.

METHODS

Cryopreserved cord-blood serum samples from 407 children were assayed for interleukins 4, 5, 6, 10, 12, and 13, interferon gamma, and tumour necrosis factor alpha (TNFalpha). Associations between family, antenatal, and perinatal factors, cord-blood cytokine concentrations, and atopy or asthma outcomes were analysed by logistic regression. Causal effects of cytokines on outcomes were estimated by propensity scores based on family, antenatal, and perinatal factors.

FINDINGS

Detectable cord-blood concentrations of interleukin 4 and interferon gamma were each associated with lower risk of physician-diagnosed asthma (adjusted odds ratios 0.60 [95% CI 0.37-0.99] and 0.60 [0.37-0.97] respectively), current asthma (0.59 [0.33-1.00] and 0.39 [0.22-0.71]), and current wheeze (0.55 [0.32-0.93] and 0.52 [0.31-0.90]) and atopy (sensitisation to some inhalant allergens) outcomes at 6 years. High concentrations of TNFalpha were associated with lower risk of atopy but not with asthma risk. These associations were broadly unaltered by propensity-score adjustment. Maternal smoking was associated with higher risk of both wheeze at 6 years and lower concentrations of interleukin 4 and interferon gamma in cord blood.

INTERPRETATION

The mechanism underlying attenuated T-helper-1/T-helper-2 cytokine production in high-risk children also apparently operates in control of cytokine production in the fetoplacental unit. The finding that this mechanism is dysregulated by maternal smoking suggests it is a target for antenatal environmental factors relevant to asthma aetiology.

Reciprocal patterns of allergen-induced GATA-3 expression in peripheral blood mononuclear cells from atopics vs. non-atopics

BACKGROUND

T helper (Th)2 cytokines are considered to play a central role in the induction and expression of allergic disease. However, the relative importance of individual cytokines is unclear, and overall disease pathogenesis appears to involve the coordinate activities of a range of Th2 cytokines acting in sequence or in parallel. The present study examines an alternative approach to the study of cytokine gene function in atopy, focusing instead upon T cell transcription factors (TFs) which play a role in the regulation of multiple cytokine genes.

OBJECTIVE

To investigate the allergen-induced expression of the TF GATA-3 and c-Maf in peripheral blood mononuclear cells (PBMCs) and in cytokine-driven Th polarization.

METHODS

PBMC from house dust mite (HDM)-atopic and non-atopics were stimulated in vitro with allergen or anti-CD3/IL-2. TF expression was analysed by semiquantitative RT-PCR and major findings were validated by real-time PCR. Cell separations were performed to analyse the contribution of CD45RO+ cells. CD4+ cord blood cells were Th1 or Th2 polarized in vitro by exogenous cytokines and TF expression analysed by Northern blot and real-time PCR. Results We demonstrate for the first time that during differentiation of CD4+ CD45RA+ naïve human T cells towards Th2 commitment, and during allergen-specific reactivation of peripheral CD4+ CD45RO+ Th2 memory cells in established atopics, expression of the Th2-associated TF GATA-3 is rapidly up-regulated, whereas T cells from non-atopics display equally rapid GATA-3 down-regulation under identical conditions of allergen stimulation.

CONCLUSION

These findings identify Th2-associated TFs as key determinants of the atopic phenotype, suggesting their unique potential as therapeutic targets for disease control.

"Bystander" amplification of PBMC cytokine responses to seasonal allergen in polysensitized atopic children

BACKGROUND

Atopic children show increased expression and production of the Th2-associated cytokines IL-4, IL-5, IL-13, and IL-9 from PBMCs after stimulation with allergen, but it has previously not been clearly determined whether the Th2-cytokine production is restricted to the inhalant allergen the child is sensitized to, and whether perennial or seasonal allergens induce different cytokine responses. Our purpose was to determine whether in vitro Th2 cytokine production is specific to the sensitizing allergen, and to compare the cytokine responses to a perennial and a seasonal allergen in monosensitized and polysensitized children.

METHODS

Using semiquantitative RT-PCR, we analyzed the expression of the cytokines IL-4, IL-5, IL-13, IL-9, IL-10, and IFN-gamma after stimulation of PBMCs with house-dust-mite (HDM) or ryegrass allergen. The cells were sampled from groups of 6-year-old children sensitized to either HDM (n=20) or ryegrass (n=24), or to both allergens (n=20), as well as from a nonatopic group (n=20).

RESULTS

After stimulation with HDM allergen, PBMCs from children sensitized only to HDM expressed increased mRNA levels of the Th2 cytokines, but not of IL-10 and IFN-gamma, whereas ryegrass stimulation did not result in increased cytokine expression. PBMCs from children sensitized to HDM and ryegrass expressed increased Th2 cytokines after stimulation with either of the two allergens. In contrast, PBMCs from children sensitized only to ryegrass did not express increased levels after stimulation with either of the allergens.

CONCLUSIONS

The expression of Th2 cytokines after in vitro stimulation of PBMCs from atopic children is specific to the sensitizing allergen, indicating that atopic status per se does not affect the type of T-cell response. In addition, T cells specific to seasonal allergens circulate in the blood out of season only if the child is concomitantly sensitized to a perennial allergen.

Promoter analysis of the murine T-cell protein tyrosine phosphatase gene

The T-cell protein tyrosine phosphatase (TC PTP) is expressed ubiquitously at all stages of mammalian development. However, mRNA levels fluctuate in a cell-cycle-dependent manner, reaching peak levels in late G1, and rapidly decreasing in S phase. Furthermore, TC PTP being present in higher amounts in lymphoid tissues, we have recently shown that it is essential for proper maintenance of both the bone marrow micro-environment and B- and T-cell functions. In order to better understand the elements controlling the expression pattern of this gene, we have isolated and characterized approx. 4kb of the murine TC PTP promoter. DNA sequencing of the proximal 5' region revealed the absence of both TATAA and CAAT boxes. Primer extension analysis and S1 nuclease mapping techniques identified multiple transcription initiation sites. Functional promoter activity was determined using transfection experiments of promoter deletion constructs fused to a CAT reporter construct. Our results indicate that the minimal promoter sequence required for functional expression is contained within the first 147bp of the TC PTP promoter. In addition, consistent with the cell-cycle-dependent expression of TC PTP, we localized a domain between 492 and 1976bp from the transcription initiation site through which repression occurs. In conclusion, although initiator-driven transcription allows for ubiquitous expression of TC PTP, we define general transcription motifs present within the promoter that may mediate specific modulations of the TC PTP gene.