Effect of high frequency repetitive transcranial magnetic stimulation (rTMS) on the balance and the white matter integrity in patients with relapsing-remitting multiple sclerosis: A long-term follow-up study

OBJECTIVES

Repetitive Transcranial Magnetic Stimulation (rTMS) is considered as a safe and non-invasive developing technique used as a therapeutic method for patients with Relapsing-Remitting Multiple Sclerosis (RRMS) who suffer from disturbances in gait and balance. The aim of our study is to evaluate the long-term effect of high frequency rTMS as a therapeutic option for truncal ataxia in RRMS patients and to assess its impact on the integrity of the white matter (WMI), measured in the form of anisotropy metrics using diffusion tensor imaging (DTI).

METHODS

The study was conducted in two phases: phase I; a randomized, single-blind, sham-controlled phase and phase II was a 12 months longitudinal open-label prospective phase. Phase I of the trial involved the randomization of 43 patients with RRMS and truncal ataxia to either real (n = 20) or sham (n = 19) rTMS (2 participants from each treatment group were excluded from the study; one developed a relapse before treatment, 2 declined to participate, and one did not show up). Phase II involved providing 12 actual treatments cycles to all patients; each cycle length is 4 weeks, repeated four times on a trimonthly basis, forming a total of 48 sessions. DTI was used for assessment of the WMI. All patients performed DTI 3 times: Imaging sessions were conducted at the screening visit, at the end of phase I, and after the last session in phase II for the first, second and third sessions respectively. A figure-of-8-shape coil, employing rTMS protocol and located over the cerebellum, was used. rTMS protocol is formed of 20 trains formed of 50 stimuli with 20 s apart (5 Hz of 80 % of resting Motor Threshold "MT"). The Berg Balance Scale (BBS), Time up and go (TUG) test, and 10-m walk test (10MWT) were first evaluated at the start of each cycle and just after the final rTMS session.

RESULTS

The genuine rTMS group's 10MWT, TUG, and BBS showed substantial improvement (p < 0.01), which is continued to be improved throughout the study Timeline, with a significant difference observed following the final rTMS session (P< 0.001). A longitudinal increase in FA was observed in both the Cerebello-Thalamo-Cortical (CTC) and Cortico-Ponto-Cerebellar (CPC) bilateral, as indicated by means of Fractional Anisotropy (FA) measures (p < 0.05).

CONCLUSION

In ataxic RRMS patients, high frequency rTMS over the cerebellum has a long-term beneficial impact on both balance and WMI.

HNF1α upregulation and promoter hypermethylation as a cause of glucose dysregulation: a case-control study of Kashmiri MODY population

AIM

HNF1α transcription factor regulates a network of genes involved in the development of β-cells and also serves as a model for transcription defects in pancreatic β-cells; mutations in this gene cause MODY. The goal of this study was to assess the promoter methylation and expression profile of the most common MODY causing gene, HNF1α, in Kashmiri MODY patients, as factors responsible for glucose dysregulation, as no such study had been performed on MODY patients in Kashmir previously.

METHODS

The study included 85 Kashmiri subjects. Samples were extracted for DNA and RNA using standard protocols. The HNF1α promoter methylation profile was assessed by bisulfite conversion of the DNA followed by MSP, whereas qPCR was used for expression analysis.

RESULTS

The expression of HNF1α was found to be upregulated (p value 0.0349*) in majority of MODY (60%) and T1D (72%) cases (p value 0.0349*). HNF1α expression was 1.33-fold higher in MODY cases with hypermethylated HNF1α promoters (p value 0.0360*). HNF1α expression was upregulated by 2.3-fold in MODY patients with HbA1c levels > 7% (p value 0.0025**). MODY cases with FBS levels > 7.7 mmol/l were upregulated by 0.646-fold than those with FBS levels ≤ 7.7 mmol/l (p value 0.0161*).

CONCLUSION

In this study, we found that as glucose dysregulation progresses, blood FBS, RBS, and HbA1c levels rise, and that at higher levels, HNF1α expression rises as well. From the results obtained, we may conclude that HNF1α is strongly upregulated in MODY, thus indicating the deleterious effect of over expression of HNF1α gene on glucose regulation.

Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28}  cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25}  cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

Forensic psychiatry in Pakistan: Where next following the Supreme Court judgement

Introduction

No statutory mental health services exist for justice-involved individuals in Pakistan. The lack of expertise in forensic psychiatry serves to deny individuals with mental illness the critical support needed for mental healthcare and adequate court dispositions with serious unintended consequences including capital punishment for those who could otherwise be deemed treatment and not punishment worthy. A landmark judgement by the Supreme Court of Pakistan in February 2021 criticized the lack of forensic psychiatry expertise in Pakistan and directing the development of forensic mental health services and forensic psychiatry training in Pakistan.

Objectives

The key objectives are: 1. Understanding the timeline of how justice invloved individuals are manged by psychiatric services 2. The importance of the Supreme Court of Pakistan Judgement in affecting change 3. Highlights on how Queen’s University will enhance forensic psychiatry in Pakistan

Methods

A literature review and personal networking facilitated the collection of important data in how justice invloved individuals are supported in Pakistan. The author has published and presented to Pakistani psychiatrists and the Pakistani judiciary on this topic. Queen’s University is aiming to implement a 3-year plan to develop an online curriculum and certificate course to help train the trainers.

Results

In the Pakistan’s most populous province, Punjab, prevalence rates for psychotic illnesses (3.7%), major depression (10%), and personality disorders (65%) among men with higher rates for psychotic disorders (4.0%) and major depression (12%) among women.

Conclusions

In conclusion there is a dire need to develop forensic psychiatry in Pakistan and other low/middle income countries.

Disclosure

No significant relationships.

Treatment and comorbidities of patients with erectile dysfunction before and during COVID-19 in the United States: A real-world data analysis

Introduction

Objectives

Methods

Results

Conclusions

Disclosure

[External Dacryocystorhinostomy--Analysis of Patient Material of the University Hospital Halle from 2000 to 2011]

BACKGROUND

The aim of this retrospective study was to collect additional data on the long-term success (LTS) of external dacryocystorhinostomy (ext-DCR) and the impact of pre-, intra- and postoperative factors on the surgical outcome. This was intended to increase the precision of the indication for DCR.

METHOD

A retrospective, non-comparative study was conducted on 637 ext-DCR due to dacryocystitis performed at the Department of Ophthalmology, University Hospital Halle. This included all surgical interventions on patients of at least 11 years of age. Using standardised questionnaires and patient records, 60.75 % (n = 387) of patients were surveyed. Follow-up was 1.0 to 12.0 years (mean, 4.0 years).

RESULTS

Analysis of patient satisfaction showed satisfactory (20.2 %) and very satisfactory (74.2 %) results. LTS was 94.4 % (n = 365). Factors negatively influencing postoperative outcome were prior surgical interventions of nose and/or sinus, previous ext-DCR and transcanalicular lacrimal surgery. Surgical outcome was positively influenced by lacrimal sac size and lacrimal stenting. Large saccus lacrimales and use of monocanalicular intubates improved LTS.

CONCLUSIONS

LTS of ext-DCR shows very good results, thus underlining its superiority to other surgical approaches. Special attention should be paid to diseases and previous surgical interventions on the nose and/or sinus that effect the lacrimal duct system. Therefore, a special committee of ENT physicians and ophthalmologists has been established at the Department of Ophthalmology, University Hospital Halle. From the surgical point of view, it is important to create an adequate mucosal anastomosis using lacrimal and nasal mucosa. Restoration is possible with lacrimal stent materials. The indication for ext-DCR was restricted by competition with transcanalicular endoscopic interventions to preserve physiological lacrimal drainage.

The oxysterol receptor LXRβ protects against DSS- and TNBS-induced colitis in mice

We examined the function of the oxysterol receptors (LXRs) in inflammatory bowel disease (IBD) through studying dextran sodium sulfate (DSS)- and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice and by elucidating molecular mechanisms underlying their anti-inflammatory action. We observed that Lxr-deficient mice are more susceptible to colitis. Clinical indicators of colitis including weight loss, diarrhea and blood in feces appeared earlier and were more severe in Lxr-deficient mice and particularly LXRβ protected against symptoms of colitis. Addition of an LXR agonist led to faster recovery and increased survival. In contrast, Lxr-deficient mice showed slower recovery and decreased survival. In Lxr-deficient mice, inflammatory cytokines and chemokines were increased together with increased infiltration of immune cells in the colon epithelium. Activation of LXRs strongly suppressed expression of inflammatory mediators including TNFα. While LXRα had anti-inflammatory effects in CD11b(+) immune cell populations, LXRβ in addition had anti-inflammatory effects in colon epithelial cells. Lack of LXRβ also induced CD4(+)/CD3(+) immune cell recruitment to the inflamed colon. Expression of both LXRA and LXRB was significantly suppressed in inflamed colon from subjects with IBD compared with non-inflamed colon. Taken together, our observations suggest that the LXRs could provide interesting targets to reduce the inflammatory responses in IBD.

Identification of patients with low-risk pulmonary embolism suitable for outpatient treatment using the pulmonary embolism severity index (PESI)

BACKGROUND

There is increasing evidence that outpatient treatment of patients with low-risk stable pulmonary embolism (PE) is safe, effective and potentially reduces costs. It is not clear how many patients presenting to an Irish Emergency Department (ED) are potentially suitable for outpatient management.

AIMS

To identify how many patients presenting to our ED over a 1-year period who were diagnosed with acute PE are potentially suitable for outpatient treatment.

METHODS

A retrospective observational study was conducted over a 1-year period. Clinical notes for patients who had a positive computed tomographic pulmonary angiogram (CTPA) within 24 h of presentation to the ED were examined to risk stratify the patients according to the pulmonary embolism severity index (PESI).

RESULTS

Forty-seven patients who presented to our ED were diagnosed with a PE. Clinical notes were missing for 3 cases, and 44 cases were analysed further. The mean age was 64.3 (±16.8 SD) years and 24 (54.5 %, 95 % CI 40-68.3 %) were males. Six patients (13.6 %, 95 % CI 6.4-26.7 %) had a background of cancer. Fifteen cases (34.1 %, 95 % CI 21.9-48.7 %) were deemed to be low risk as they were categorised as PESI risk class I or II. Our study found that 61/420 (14.5 %, 95 % CI 11.5-18.2) of CTPAs done were positive for PE.

CONCLUSION

This study suggests that a significant percentage of patients diagnosed with acute PE are low risk as per PESI and therefore potentially suitable for outpatient management.

Evaluation of Balloon Occlusion Test for Giant Brain Aneurysms under Local Anaesthesia

We describe our experience in balloon test occlusion for giant carotid or basilar aneurysms under hypotension. Twenty-four patients underwent balloon test occlusion (BTO) during the year 2008. Only patients showed absence of any neurological deficits after 20 minutes under normal tension then another 20 minutes under hypotension were considered tolerable for occlusion of the parent artery. Of the 24 patients, four (16.67%) had deficits at normal tension and two (8.33%) had deficits at hypotensive phase. None of the 18 (75%) patients who clinically tolerated test occlusion and had parent artery sacrifice show any complication at follow-up period of two years. Two patients with clinical intolerability underwent carotid artery sacrifice after STA-MCA bypass without sequelae. Balloon test occlusion with hypotension is a useful, competent and simple technique in the evaluation of tolerance to parent artery occlusion in case of giant and complex intracranial aneurysms.

Prenatal diagnosis of chorionicity in twins

The aim of this audit was to assess the accuracy of transabdominal ultrasound scan in predicting chorionicity in twin pregnancies in our unit. The presence or absence of lambda sign, T-sign, dividing membrane thickness and number of placentae were used to determine chorionicity. We retrospectively analysed these antenatal markers in 268 sets of twins delivered over a 5 year period and compared it with the postpartum placental histology and neonatal gender. Of 268 twin deliveries, 204 (76%) had both chorionicity and placental histology to compare. 67 of 84 (80%) were correctly diagnosed antenatally as monochorionic and 137 of 151 (91%) as dichorionic. In 31 cases (15%) the ultrasound diagnosis of chorionicity didn't match placental histology. Seventeen were thought to be monochorionic antenatally but were confirmed dichorionic on placental histology. Overall chorionicity was correctly diagnosed in 171/204 (84%) using transabdominal ultrasound scan (USS) in all trimesters. However the sensitivity and specificity of USS was much higher for dichorionic twins when carried out before 14 weeks of gestation.

Sclerosing mesenteritis presenting with complete small bowel obstruction, abdominal mass and hydronephrosis

Sclerosing mesenteritis is an uncommon and poorly understood inflammatory condition of the bowel mesentery which can often be confused with neoplasia, Crohn's disease and other inflammatory conditions. We describe a case of complete small bowel obstruction and right sided hydronephrosis due to sclerosing mesenteritis.

The Immediate Management of the Patient with Rupture: Open Versus Endovascular repair (IMPROVE) aneurysm trial--ISRCTN 48334791 IMPROVE trialists

BACKGROUND

Systematic reviews have suggested a survival advantage for patients with ruptured abdominal aortic aneurysm (AAA), who are managed by endovascular repair. These reviews are based on single centre experiences of selected patients.

OBJECTIVE

To determine whether a policy of endovascular repair improves the survival of all patients with ruptured AAA.

METHODS

A randomized controlled trial, IMPROVE (ISRCTN 48334791) will randomize patients with a clinical diagnosis of rAAA, made in hospital, either to immediate CT scan and endovascular repair whenever anatomically suitable (endovascular first), or to open repair, with CT scan being optional (normal care), The trial is set on a background of guidelines for emergency care, CT scanning and anaesthesia, which incorporate the protocol of permissive hypotension. Recruitment started in October 2009 and 600 patients are required to show a 14% survival benefit at 30 days (primary outcome) for the endovascular first policy. Recruitment will be from the UK and Europe. Secondary outcomes include 24h, in-hospital and 1 year survival, complications, major morbidities, costs and quality of life.

DISCUSSION

This is a "real life" trial that will answer the fundamental relevant clinical dilemma, namely, do patients who present with ruptured AAA derive benefit from treatment in a system, which offers a preferential strategy of endovascular repair? The trial addresses whether the anticipated reduced mortality and morbidity associated with endovascular repair is offset by the relatively greater ease of access and speed to conventional surgery. This issue is pivotal to future patient care and provision of services.

Evaluation of the need for endoscopy to identify low-risk patients presenting with an acute upper gastrointestinal bleed suitable for early discharge

AIMS

To audit the safety of differing protocol-driven early-discharge policies, from two sites, for low-risk acute upper gastrointestinal (GI) bleeding and determine if default early (<24 h) in-patient endoscopy is necessary.

METHODS

All patients with low-risk acute upper GI bleeding presenting to two separate hospital sites in Leeds from August 2002 to March 2005 were identified. Both hospitals operate nurse-led process-driven protocols for discharge within 24 h, but only one includes default endoscopy. Relevant information was obtained from patients' notes, patient administration systems, discharge letters and endoscopy records.

RESULTS

120 patients were admitted to site A and 74 to site B. Median length of stay on the clinical decisions unit was 12.6 h at site A and 9.4 h at site B (p = 0.045). Oesophagogastroduodenoscopy was performed on 89/120 (74%) patients at site A compared with only 7/74 (9%) at site B (p<0.001). Six of 120 (5%) patients from site A were admitted to hospital for further observation compared with 6/74 (8%) from site B (p = 0.38). Of the remaining patients, all were discharged within 24 h, and 8/114 (7%) at site A vs 17/68 (25%) at site B were given hospital clinic follow-up (p<0.001). None of the 194 patients had further bleeding or complications within 30 days.

CONCLUSIONS

Patients admitted with a low-risk acute upper GI bleeding can be managed safely by a nurse-led process-driven protocol, based on readily available clinical and laboratory variables, with early discharge <24 h. Avoiding in-patient endoscopy appears to be safe but at the price of greater clinic follow-up.

An audit of referral practice for patients with impacted palatal canines and the impact of referral guidelines

OBJECTIVE

To assess referral practice for patients presenting with impacted palatal maxillary canines, and to develop and evaluate the effectiveness of referral guidelines.

DESIGN

Prospective clinical audit.

SETTING

Southend and Basildon district general hospitals.

SUBJECTS AND METHODS

The 'gold' standard was identified as regular dental attenders with unerupted palatal canines being referred by 12 years old, with a wait of no longer than 20 weeks from referral to assessment. Data were collected and compared to the defined standard. An algorithm outlining the correct management was developed and distributed to all local dentists. The cycle was repeated for a similar time period.

RESULTS

Ninety-eight per cent of patients were seen within 20 weeks during both cycles while the referrals increased from 85 to 109 patients. The percentage of patients referred by 12 years of age increased from 16.5% to 27% (p = 0.09). During the first cycle 82% of patients presented with retained deciduous maxillary canines. This was reduced to 76% during the second cycle (p = 0.29).

CONCLUSION

Referral practice was generally poor when compared to the recommended good practice. More patients were referred after distribution of the guidelines, but the percentage referred by the recommended age was not statistically significantly improved.

Relationship of visceral fat distribution to angiographically assessed coronary artery disease: results in subjects with or without diabetes or impaired glucose tolerance

BACKGROUND AND AIM

To evaluate the relationship between the degree of coronary artery disease (CAD) and the amount of visceral fat deposition in a mixed population of CAD patients with or without diabetes or impaired glucose tolerance (IGT), and with different body weights.

METHODS AND RESULTS

A total of 55 patients undergoing coronary angiography (43 men and 12 women with a mean age of 58.9 +/- 1.1 years, range 37-70, and a mean body mass index [BMI] of 27.9 +/- 0.4, range 21.3-38.7) were studied in order to establish whether the coronary damage exclusively depends on intra-abdominal adipose tissue per se, or may be influenced by the coexistence of diabetes or IGT. Twenty-one subjects were non-diabetic, 13 had type 2 diabetes, and 21 IGT. Hypertension was found in 47% and dyslipidemia in 55%; 69% were smokers. The angiographic evaluation of CAD was made using the method of Gensini, and computed tomography (CT) was used to estimate the amount of visceral adipose tissue (VAT) based on a single scan at L4 level. Clinical, anthropometric, biochemical and hormonal variables, as well as smoking and alcohol consumption were determined. In the study population as a whole, the coronary score did not correlate with VAT, but only with smoking. However, both univariate and multivariate regression analysis showed that CAD significantly correlated with VAT in the non-diabetic patients, particularly in those with VAT of > 130 cm2. This correlation did not appear in the diabetic or IGT patients, nor when the group of patients with VAT > 130 cm2 was extended to include diabetic or IGT patients. No relationship was found between CAD and BMI or the other considered variables.

CONCLUSIONS

In a mixed population of CAD patients with or without diabetes, CAD correlates with VAT only in the absence of diabetes or IGT, and especially when VAT exceeds 130 cm2 at an L4 CT scan, regardless of weight or obesity. Diabetes or IGT therefore seem to contribute towards the development of CAD regardless of the amount of VAT.

Ulcerative terminal ileitis after BCG therapy for bladder carcinoma

AIM

We evaluated the aetiology of ulcerative ileitis in a 77-year-old patient receiving BCG therapy for recurring bladder carcinoma.

METHODS AND RESULTS

Histological examination, laboratory data and the clinical history allowed us to exclude a classical cause such as Crohn's disease, tuberculosis or ischaemia. The important locoregional reaction suggests a BCG ileitis of the terminal ileum. Intestinal BCG ileitis has been exceptionally described after BCG vaccination.

CONCLUSION

Our observation of ulcerative ileitis indicates that a digestive tract location is possible as a reaction to BCG therapy.

Microbubble retention and failed macular hole surgery

This case reports a possible new cause of failed macular hole surgery. Standard macular hole surgery with removal of epiretinal membranes, 16% C3F8, and strict postoperative prone positioning was performed on a patient with stage 4 macular hole. Macular hole surgery failed with retention of a microbubble of C3F8 within the macular hole during the follow-up period. Retention of a microbubble within a macular hole may prevent closure of the hole and be a previously unrecognized cause of failed macular hole surgery.

External versus internal approach to the removal of metallic intraocular foreign bodies

OBJECTIVE

To review the management of metallic intraocular foreign bodies (IOFB) at a single institution and to compare the use of internal and external approaches for their removal.

SUBJECTS AND METHODS

A retrospective review was conducted on 70 eyes from 70 patients who underwent surgical removal of a metallic IOFB with either an internal (vitrectomy followed by forceps or internal magnet use) or external approach (large electromagnet) by seven vitreoretinal surgeons at a single institution between 1973 and 1996. Visual acuity and complications occurring with the two approaches were the main outcome measures studied.

RESULTS

Overall, patients showed significant improvement in visual acuity following surgical intervention (P < 0.001) despite widely varying surgical techniques. When the authors compared patients treated with an external versus an internal approach they found no statistically significant difference with regard to visual outcome and a trend toward a higher rate of postoperative endophthalmitis in the external approach group.

CONCLUSION

Surgical removal of metallic IOFB results in significant visual improvement. The external approach to the removal of magnetic metallic IOFB remains a viable treatment option in select cases.

Revision hip arthroplasty activity in a single UK health region: an audit of 1265 cases

Revision hip arthroplasty is an operation which is steadily increasing in number and can often be technically challenging. We have utilised a regional hip register (the Trent Regional Arthroplasty Study) to analyse the epidemiology of revision hip arthroplasties in a single UK health region. The study shows that of the large number (1265) of procedures performed over a 7-year period (1991-1997), the majority were performed by general orthopaedic surgeons, with 91 different surgeons performing the operation and only two surgeons performing more than 20 procedures per year. Of more than 100 prosthetic combinations used for the procedure, the Charnley prosthesis was the most common (38.3% of acetabular revisions and 37.5% of femoral revisions). The same component was also the most commonly explanted (43%). There was an even geographical spread across the region with revision hip arthroplasty being performed in all hospitals with an orthopaedic in-patient facility. Prospective audit of this large and varied cohort is necessary to determine differences in outcome (if any) between 'specialist' hip surgeons and general orthopaedic surgeons.

The SCID mouse: an experimental model for endometriosis

The purpose of this study was to validate the suitability of the severe combined immunodeficient (SCID) mouse as an experimental model for endometriosis, by defining the morphological and histological features of induced endometrial implants, and characterizing specific biochemical properties of these implants. Human secretory endometrial tissues were injected into the peritoneal cavity of SCID/SCID CB17 mature female mice. Successful peritoneal implantation was observed in 55 of 57 (96.5%) SCID mice and consisted of circumscribed elevated nodules. Haematoxylin-eosin staining of implanting lesions demonstrated the presence of endometrial glandular tissue in a mixed background of stromal and inflammatory cells. When progesterone was administered to mice, epithelial glands underwent well-defined secretory changes. Immunohistochemical analysis using polyclonal human pan-cytokeratin antibodies demonstrated selective positive staining in the glandular epithelium of the human implants with none in the surrounding stroma. In-situ hybridization analysis using complement component 3 cDNA radiolabelled riboprobes yielded significantly more intense signals in glands compared to stroma. As human endometrial implants in SCID mice were shown to retain specific histological, functional and biochemical properties, we conclude that the SCID mouse is an attractive animal model for the study of endometriosis.

Tracheal deviation as a sign in ill patients: beware ipsilateral pathology

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Tissue-specific and androgen-repressible regulation of the rat dehydroepiandrosterone sulfotransferase gene promoter

Dehydroepiandrosterone sulfotransferase (Std) catalyzes sulfonation of androgenic steroids and certain aromatic procarcinogens. In rats, this enzyme is selectively expressed in the liver, and its expression is strongly repressed by androgens. DNase I footprinting and electrophoretic mobility shift analyses revealed two hepatocyte nuclear factor-1 (HNF1), three CCAAT/enhancer-binding protein (C/EBP), and one consensus palindromic thyroid hormone response elements within the first 215 base pairs (bp) of the promoter sequence of rat Std. This promoter is normally inactive in fibroblast-derived NIH 3T3 cells. However, overexpression of HNF1 and C/EBP resulted in synergistic activation of the Std promoter in this cell type, indicating essential roles of these two trans-regulators in liver-selective expression of the rat Std gene. On the other hand, point mutations at any one of five cis elements proximal to the -215 bp region markedly reduced reporter gene expression, suggesting that all of these sites are important for overall promoter function. Androgenic repression of the Std gene in rat liver can be recapitulated in androgen receptor (AR)-negative HepG2 hepatoma cells after cotransfection with an AR expression plasmid. Functional assay of a nested set of 5'-deleted promoters mapped the negative androgen response region between positions -235 and -310. Antibody supershift and oligonucleotide competition identified three OCT-1 and two C/EBP elements between bp -231 and -292. An additional OCT-1 site was found to overlap with a C/EBP element at the -262/-252 position. Mutational inactivation of any one of five cis elements within the -231/-292 region abolished negative androgen response. However, none of these cis elements showed DNase I protection by recombinant AR in footprinting assay, suggesting the absence of a direct AR-DNA interaction. Thus, these studies on rat Std promoter function indicate that (i) HNF1 and C/EBP are responsible for liver specificity of the rat Std gene; (ii) androgenic repression of the gene requires the presence of all of the OCT-1 and C/EBP elements between positions -231 and -292; and (iii) AR may exert its negative regulatory effect indirectly through transcriptional interference of OCT-1 and C/EBP rather than through a direct DNA-AR interaction.