Background: Transanal surgery facilitates organ preservation in select patients with benign and early malignant rectal lesions to avoid the functional consequences of radical surgery. The transanal endoscopic microsurgery (TEM) platform created a standard for local excision with lower margin positivity and recurrence rates than traditional transanal excision. The single-port robot (SP r) presents a promising alternative transanal platform.
View Article and Find Full Text PDFBackground: The transanal abdominal transanal radical proctosigmoidectomy was developed in 1984 as a sphincter preservation surgery in patients with low rectal cancers after preoperative radiation therapy. While serving as a catalyst for disruptive sphincter preservation surgery, it continues to be used and evolve. With the controversy over safety and local recurrence in other sphincter-preserving surgery, review of transanal abdominal transanal radical proctosigmoidectomy long-term oncologic outcomes is warranted.
View Article and Find Full Text PDFNarrated in this article are accounts of the many contributions Howard P. Roffwarg, MD, made to the field of sleep research and sleep medicine across his entire professional career as a student, a mentor, a leader in the Sleep Research Society, a sleep medicine clinician, and a scientist who performed experimental investigations in humans and animals. Dr Roffwarg was the originator of what is known as the "Ontogenetic Hypothesis" of sleep.
View Article and Find Full Text PDFBackground: The challenge of performing a good total mesorectal excision (TME) dissection, particularly in the distal 1/3 of the rectum, has spurred interest in new techniques. Robotic surgery is advocated by some, and more recently, a "new" approach, the transanal total mesorectal excision, has been popularized to address this problem. While great interest in this technique exists, little long-term outcome data are available.
View Article and Find Full Text PDFBackground: Transanal abdominal transanal proctectomy is a sphincter-preserving procedure designed to avoid colostomy in patients with cancer in the distal third of the rectum. Oncologic outcomes of this procedure have been established. However, data regarding patient satisfaction and quality of life are scant.
View Article and Find Full Text PDFIntroduction: Natural orifice transluminal endoscopic surgery (NOTES) represents the ultimate expression of minimally invasive surgery. We have developed and present here an initial feasibility and safety study of transanal total mesorectal excision (TME) with splenic flexure release, high ligation of the IMA and IMV, and side-to-end coloanal anastomosis with temporary diverting ileostomy for rectal cancer.
Methods: A program of full NOTES TME resection with release of the splenic flexure, high ligation of the IMA/IMV, with side-to-end coloanal anastomosis was performed transanally from December 2013 to July 2014.
Introduction: Single-port (SP) surgery has been characterized as having limited applicability regarding procedure, disease, and patient characteristics. There is a question if SP procedures offer disadvantages or advantages to multiport (MP) colorectal surgery. We hypothesize that SP is equivalent to MP and is a safe alternative in the full spectrum of colorectal disease and procedures.
View Article and Find Full Text PDFThe sublaterodorsal nucleus (SLD) in the pons of the rat is a locus supporting short-latency induction of a REM sleep-like state following local application of a GABAA receptor antagonist or kainate, glutamate receptor agonist. One putatively relevant source of these neurotransmitters is from the region of the deep mesencephalic nucleus (DpMe) just ventrolateral to the periaquiductal gray, termed the dorsal DpMe (dDpMe). Here, the amino acid neurotransmitter innervation of SLD from dDpMe was studied utilizing anterograde tract-tracing with biotinylated dextranamine (BDA) and fluorescence immunohistochemistry visualized with laser scanning confocal microscopy.
View Article and Find Full Text PDFThe oral pontine reticular formation (PnO) of rat is one region identified in the brainstem as a rapid eye movement (REM) sleep induction zone. Microinjection of GABA(A) receptor antagonists into PnO induces a long lasting increase in REM sleep, which is similar to that produced by cholinergic agonists. We previously showed that this REM sleep-induction can be completely blocked by a muscarinic antagonist, indicating that the REM sleep-inducing effect of GABA(A) receptor antagonism is dependent upon the local cholinergic system.
View Article and Find Full Text PDFBackground: Ideal treatment of rectal cancer includes controlling the cancer; minimizing trauma, morbidity, and mortality; and avoiding a colostomy with preservation of adequate function. These goals become more challenging the further distal in the rectum the cancer is located. We sought to determine whether minimally invasive sphincter-preservation surgery (SPS) can accomplish good cancer control, maintaining sphincter function with minimal morbidity and mortality in rectal cancers of the distal 3 cm after receiving neoadjuvant chemoradiotherapy.
View Article and Find Full Text PDFBackground: Transanal endoscopic microsurgery (TEM) is a minimally invasive treatment used to excise a variety of rectal lesions. Potential overstretching of the sphincter's musculature due to dilation of the anal canal to allow placement of a 40-mm-wide scope combined with partial resection of the rectum and subsequent loss of rectal volume creates a concern regarding anorectal function postoperatively. Data regarding patient satisfaction with anorectal function and quality of life after TEM are scant.
View Article and Find Full Text PDFIt has been reported that non-subtype-selective GABAA receptor antagonists injected into the nucleus pontis oralis (PnO) of rats induced long-lasting increases in REM sleep. Characteristics of these REM sleep increases were identical to those resulting from injection of muscarinic cholinergic agonists. Both actions were blocked by the muscarinic antagonist, atropine.
View Article and Find Full Text PDFPharmacological manipulations of gamma-aminobutyric acid (GABA) neurotransmission in the nucleus pontis oralis (PnO) of the rat brainstem produce alterations in sleep/wake behavior. Local applications of GABA(A) receptor antagonists and agonists increase REM sleep and wake, respectively. These findings support a role for GABAergic mechanisms of the PnO in the control of arousal state.
View Article and Find Full Text PDFNeoadjuvant therapy is widely accepted as the current standard of care for localized rectal cancer. Downstaging of disease has been significantly improved and pathological complete response rates (pCR) which were historically below 10% with preoperative radiation alone, now range from 15% to 30% with preoperative chemo-radiation. While the availability of new chemotherapeutic drugs (Irinotecan, Oxaliplatin, etc.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
November 2008
There is considerable debate on the optimum approach to neoadjuvant therapy in rectal cancer. This review of major published studies of short-course preoperative radiation and the more conventional approach of long-course neoadjuvant chemoradiation was undertaken in an effort to understand the potential advantages and disadvantages of each of these approaches. Studies were evaluated with regard to patient selection, clinical outcomes, and toxicities.
View Article and Find Full Text PDFThe genes Kcnc1 and Kcnc3 encode the subunits for the fast-activating/fast-deactivating, voltage-gated potassium channels Kv3.1 and Kv3.3, which are expressed in several brain regions known to be involved in the regulation of the sleep-wake cycle.
View Article and Find Full Text PDFBackground: Patients with major comorbidities often are denied laparoscopic colorectal resections because they are thought to be at too "high risk." Paradoxically, these patients generally have the most to gain from a minimally invasive surgical approach. This study aimed to examine the feasibility and safety of laparoscopic colorectal resection to determine whether it is contraindicated for "high-risk" patients.
View Article and Find Full Text PDFLong-lasting increases in REM sleep are induced in the rat following injection of small amounts of muscarinic receptor agonists into the caudal oral pontine reticular formation. By injecting carbachol at the beginning of the light period or beginning of the dark period, we sought to determine whether the muscarinic, REM sleep induction is influenced by the time of day it is initiated. We found that carbachol is more effective at increasing REM sleep when administered at the beginning of the dark in 87% of the cases.
View Article and Find Full Text PDFSleep-wake behavior is tightly controlled in many animal species, suggesting genetically encoded, homeostatic control mechanisms that determine arousal-state dynamics. We reported that two voltage-gated potassium channels, Kv3.1 and Kv3.
View Article and Find Full Text PDFMicroinjection of adenosine A1 receptor agonist or an inhibitor of adenylyl cyclase into the caudal, oral pontine reticular formation (PnOc) of the rat induces a long-lasting increase in REM sleep. Here, we report significant inhibition of forskolin-stimulated cAMP in dissected pontine tissue slices containing the PnOc incubated with the A1 receptor agonist, cyclohexaladenosine (10(-8) M). These data are consistent with adenosine A1 receptor agonist actions on REM sleep mediated through inhibition of cAMP.
View Article and Find Full Text PDFBackground: Heightened interest in minimally invasive surgery and the expanding use of radiation therapy presents surgeons with new challenges. While conventional surgery in the irradiated pelvis represents a significant technical obstacle, indications for laparoscopic colorectal surgery are currently being defined. The purpose of this study is to examine the efficacy of laparoscopic surgery in the irradiated field.
View Article and Find Full Text PDFHeme is an essential prosthetic group or substrate for many proteins, including hemoglobin, and hemo enzymes such as nitric oxide synthase, soluble guanylyl cyclase, and heme oxygenase (HO). HO is responsible for the breakdown of heme into equimolar amounts of biliverdin, iron, and carbon monoxide, the latter of which is thought to play a role in the regulation of vascular tone. It is not clear whether the source of heme for cardiovascular functions is derived from uptake from the extracellular milieu or synthesis.
View Article and Find Full Text PDFCan J Physiol Pharmacol
April 2004
During the last decade, heme oxygenase (HO) and carbon monoxide (CO) have garnered substantial research interest in terms of cell and organ regulation, especially as they bear on the central nervous system, organ transplantation, and the cardiovascular system. While the enzymatic mechanism, substrates, and products of HO are well known, it is not clear whether the cardiovascular system derives its supply of the heme substrate through de novo synthesis or uptake from the extracellular milieu. The objective of the present study was to test the latter possibility in rat aorta and to determine the influence of plasma proteins that bind heme in vivo, viz.
View Article and Find Full Text PDFExp Biol Med (Maywood)
May 2003
Carbon monoxide (CO), formed during heme oxygenase (HO)-catalyzed oxidation of heme, has been proposed to play a complementary role with nitric oxide in the regulation of placental hemodynamics. The objective of this study was to elucidate HO enzymatic activity and HO-1 (inducible) and HO-2 (constitutive) protein content in the microsomal subcellular fraction of homogenate of selected regions of placenta from normotensive and mild pre-eclamptic pregnancies. HO enzymatic activity was measured under optimized conditions by gas chromatography using CO formation as an index of activity, and HO-1 and HO-2 protein content were determined by Western immunoblot analysis.
View Article and Find Full Text PDFIn a previous study using microsomes from human lymphoblastoid cell lines (HLCL) containing single cDNA-expressed human cytochrome P450 (P450) enzymes, human P450 enzymes were identified that are susceptible to mechanism-based inactivation by the porphyrinogenic xenobiotics, 3-[(arylthio)ethyl]sydnone (TTMS), 3,5-diethoxycarbonyl-1,4-dihydro-2,6-dimethyl-4-ethylpyridine (4-ethylDDC) and allylisopropylacetamide (AIA). In this study, we tested the hypothesis that N-alkylprotoporphyrin IX (N-alkylPP) formation following interaction of porphyrinogenic xenobiotics with single cDNA-expressed human P450 enzymes in microsomes from HLCL would occur only with P450 enzymes that had undergone mechanism-based inactivation. In a previous study, when 4-ethylDDC and NADPH interacted with human liver microsomes possessing elevated levels of CYP1A2 and 2C9, N-ethylprotoporphyrin IX (N-ethylPP) was not formed despite the fact that it was formed in microsomes from baculovirus-infected insect cell lines (BIICL) containing either CYP1A2 or 2C9.
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