Rate dependent left bundle branch block: the pattern of myocardial perfusion SPECT

We report myocardial perfusion SPECT pattern in four subsequentpatients with rate dependent left bundle branch block(LBBB). Three females and one male (aged 48, 51, 63 and 67years) were studied. None of the patients had history of typicalchest pain and all suffered from atypical chest pain or dyspneaon exertion. All patients were tested for baseline and serial heartrate, blood pressure, and electrocardiogram recordings. Theexercise treadmill tests (ETT) were carried out under the strictsupervision of a cardiologist, a nuclear medicine physician andclose availability of an expert cardio-pulmonary resuscitation teamand cardiac care unit within just few seconds. Maximal stress test(at least 85% of calculated heart rate, following development ofLBBB) was achieved in all four patients according to standardBruce protocol. No adverse cardiac events were noted and allETT stress protocols terminated completely and safely. Myocardialperfusion SPECT imaging showed no evidence of reversibleperfusion defects. The only patient with past history of exerciseinduced LBBB showed nonreversible perfusion defects in theseptal and anteroseptal regions and mild LV cavity dilatation. Thelimited number of patients enrolled in our study does not allow us todraw a definite conclusion. Despite the presence of false-positivedefects in myocardial perfusion SPECT in patients with sustained  LBBB, such a finding is not a consistent finding in patients withrate dependent or exercised-induced LBBB, unlike that which weexpected to see. Maybe it is possible to continue ETT for thosepatients undergoing myocardial perfusion scintigraphy and developingrate dependent LBBB.We report myocardial perfusion SPECT pattern in four subsequentpatients with rate dependent left bundle branch block(LBBB). Three females and one male (aged 48, 51, 63 and 67years) were studied. None of the patients had history of typicalchest pain and all suffered from atypical chest pain or dyspneaon exertion. All patients were tested for baseline and serial heartrate, blood pressure, and electrocardiogram recordings. Theexercise treadmill tests (ETT) were carried out under the strictsupervision of a cardiologist, a nuclear medicine physician andclose availability of an expert cardio-pulmonary resuscitation teamand cardiac care unit within just few seconds. Maximal stress test(at least 85% of calculated heart rate, following development ofLBBB) was achieved in all four patients according to standardBruce protocol. No adverse cardiac events were noted and allETT stress protocols terminated completely and safely. Myocardialperfusion SPECT imaging showed no evidence of reversibleperfusion defects. The only patient with past history of exerciseinduced LBBB showed nonreversible perfusion defects in theseptal and anteroseptal regions and mild LV cavity dilatation. Thelimited number of patients enrolled in our study does not allow us todraw a definite conclusion. Despite the presence of false-positivedefects in myocardial perfusion SPECT in patients with sustained  LBBB, such a finding is not a consistent finding in patients withrate dependent or exercised-induced LBBB, unlike that which weexpected to see. Maybe it is possible to continue ETT for thosepatients undergoing myocardial perfusion scintigraphy and developingrate dependent LBBB

Subcutaneous implantable cardioverter-defibrillator placement in a patient with a preexisting transvenous implantable cardioverter-defibrillator

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml

Analysis of polymorphic marker rs9384 located in the GCDH gene region associated with glutaricaciduria type 1.

زمینه و هدف: گلوتاریک اسید یوریای نوع 1 نوعی اختلال متابولیکی عصبی می باشد که در اثر جهش در ژن رمز کننده آنزیم گلوتاریل کوآدهیدروژناز (GCDH) ایجاد می شود. اصولاً تعیین توالی به منظور شناسایی جهش ‌های نقطه ای و دیگر تنوعات توالی موجود در این ژن استفاده می‌شود که بسیار وقت ‌گیر و پر هزینه می ‌باشد. روش دیگر بررسی پیوستگی با استفاده از مارکرهای چند شکلی مانند چند شکلی های تک نوکلئوتیدی (SNP) است که برای تعیین افراد ناقل و همچنین تشخیص پیش از تولد در خانواده‌های دارای فرد مبتلا به کار می ‌رود. در پایگاه‌ های داده تعداد زیادی از مارکرهای SNP برای ناحیه ژنی GCDH معرفی شده است. در مطالعه حاضر خصوصیات و همچنین اطلاع دهندگی مارکر rs9384 واقع در ناحیه ژنی GCDH مورد بررسی قرار گرفت. روش بررسی: مارکر rs9384 در 100 فرد سالم غیر خویشاوند با روش ARMS PCR با بهره گیری از پرایمرهای جدید طراحی شده تعیین ژنوتیپ شد. در این مطالعه تخمین فراوانی آللی و درجه هتروزیگوسیتی با استفاده از پایگاه GenePop انجام شد؛ همچنین از نرم ‌افزار Power Marker برای تخمین وجود تعادل هاردی واینبرگ و میزان محتوی اطلاع دهندگی چند شکلی (PIC) استفاده شد. یافته ها: نتایج حاصل از این مطالعه بیانگر فراوانی آللی مینور (MAF) 0/34، درجه هتروزیگوسیتی 0/53 و مقدار 0/35=PIC برای مارکر rs9384 در جمعیت مورد مطالعه بود. به علاوه بررسی تعادل هاردی واینبرگ نشان داد که جمعیت برای این مارکر در تعادل می‌ باشد. نتیجه گیری: در مجموع با توجه به نتایج به دست آمده از مطالعه حاضر می‌ توان مارکر rs9384 را به عنوان یک مارکر تک نوکلئوتیدی مناسب جهت تشخیص مولکولی گلوتاریک اسید یوریای نوع 1 در جمعیت اصفهان به عنوان نمونه‌ ای از جمعیت ایرانی معرفی کرد

Visual Evoked Potential Findings in Patients with Dyslexia

Purpose: The aim of this study was to compare the Visual Evoked Potential (VEP) findings in patients with dyslexia and in normal individuals.Patients and Methods: In this case-control study, we evaluated 26 eyes from 13 dyslexic patients over the period of 2018-2022. The control group consisted of 26 eyes from 13 age- and sex-matched healthy individuals. VEP was recorded for both the case and control groups. We compared the latency (in milliseconds) and amplitude of the VEP P100 peak between the patients and the controls.Results: The mean latency of the VEP P100 peak was significantly higher in the patient group, measuring 108.92 ± 3.84 milliseconds, compared to 97.46 ± 2.8 milliseconds in the control group (P < 0.01). Additionally, the mean amplitude of the VEP, P100 peak in the case group was significantly lower, at 2.96 ± 1.12 microvolts, in contrast to 6.38 ± 1.6 microvolts observed in the control group (P < 0.01).Conclusion: Based on the findings of this study, it is concluded that dyslexia may influence the visual pathway of the visual system, leading to changes that could potentially be evaluated using VEP testing

Test-retest reliability of transcarpal sensory NCV method for diagnosis of carpal tunnel syndrome

Background: Carpal Tunnel Syndrome (CTS) is the most frequent entrapment neuropathy affecting the upper extremity. There are a variety of electrodiagnostic methods available for documenting median neuropathy in CTS. In some studies, determining the sensory NCV across the palm-wrist segment has been introduced as the most sensitive diagnostic procedure for CTS. The aim of this study was to investigate the test-retest reliability of transcarpal median sensory NCV method for the diagnosis of CTS. Materials and Methods: Twenty-three patients with clinical symptoms of CTS were tested two times by two different practitioners in one session and again by the first practitioner after one week. Stimulation of the median nerve was performed in the wrist and palm, with a conduction distance maximum of 7 cm, reliabilities of median nerves sensory nerve action potential latencies with stimulation at wrist and palm (W-SNAP, P-SNAP) and its transcarpal NCV were assessed with intraclass correlation coefficient (ICC). Results: Comparison of the obtained values, which were done by two practitioners in one session showed ICC of W-SNAP latency, P-SNAP latency and transcarpal NCV of 0.93, 0.88 and 0.87, respectively and values that were done by one practitioner in two sessions with one-week interval showed ICC of 0.60, 0.50 and 0.47, respectively. Conclusion: Our findings suggest excellent interpractitioner test-retest reliability of transcarpal median sensory NCV method for diagnosing CTS

Mre11–Rad50–Nbs1-dependent processing of DNA breaks generates oligonucleotides that stimulate ATM activity

DNA double-strand breaks (DSBs) can be processed by the Mre11–Rad50–Nbs1 (MRN) complex, which is essential to promote ataxia telangiectasia-mutated (ATM) activation. However, the molecular mechanisms linking MRN activity to ATM are not fully understood. Here, using Xenopus laevis egg extract we show that MRN-dependent processing of DSBs leads to the accumulation of short single-stranded DNA oligonucleotides (ssDNA oligos). The MRN complex isolated from the extract containing DSBs is bound to ssDNA oligos and stimulates ATM activity. Elimination of ssDNA oligos results in rapid extinction of ATM activity. Significantly, ssDNA oligos can be isolated from human cells damaged with ionizing radiation and injection of small synthetic ssDNA oligos into undamaged cells also induces ATM activation. These results suggest that MRN-dependent generation of ssDNA oligos, which constitute a unique signal of ongoing DSB repair not encountered in normal DNA metabolism, stimulates ATM activity