bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transverse folds of rectum: Anatomic study and clinical implications
Authors: Shafik Ahmed , Doss Sameh , Ali Yehia Ahmed , Shafik Ali A. 
Published: August 2002

AbstractThere are controversies with respect to the location, number, and function of the transverse folds of the rectum (TFR), probably because their physioanatomic aspects have not been fully investigated. The purpose of this communication was to study the anatomic and histologic structure of the TFR aiming at elucidation of their function in the light of their structure. The TFR were studied morphologically and histologically in 18 cadavers (10 male, 8 female) with a mean age of 36.6 ± 10.4 (SD) years. Barium enema studies were also performed in 36 volunteers (20 male, 16 female; mean age 38.6 ± 15.2 [SD] years). The number of TFR varied, the commonest findings being two and three. In a few cases, TFR were absent or exceeded three in number. Most folds extended beyond the middle of the rectal lumen; a few were narrow. They were thick at the base and tapered gradually. Microscopically, the TFR contained circular and longitudinal smooth muscle fibers; they were rarely purely mucosal. TFR varied in location dividing the rectum into compartments; an alternating side‐to‐side arrangement allows for a wavy movement of the stool in the rectum. The wavy movement, compartmental division, and the shelving action of the TFR are suggested to retard stool movement in the rectum so as to allow time for fecal sampling (stool or gas) and for impulses to reach the conscious level to decide whether or not to defecate. Further studies are needed to investigate the role of the TFR in clinical practice. Clin. Anat. 14:196–203, 2001. © 2001 Wiley‐Liss, Inc.
Acute renal failure requiring dialysis after percutaneous coronary interventions
Authors: Gruberg Luis , Mehran Roxana , Dangas George , Mintz Gary S. , Waksman Ron , Kent Kenneth M. , Pichard Augusto D. , Satler Lowell F. , Wu Hongsheng , Leon Martin B. 
Published: August 2002

AbstractAcute renal failure requiring dialysis is a rare but serious complication after percutaneous coronary interventions (PCI), associated with high in‐hospital mortality and poor long‐term survival. We have analyzed the incidence, resource utilization, short‐ and long‐term outcomes, and predictors of dialysis after percutaneous coronary interventions. We studied 51 consecutive patients who were not on dialysis on admission and developed acute renal failure that required in‐hospital dialysis after PCI in comparison to the 7,690 patients who did not require dialysis after PCI. Patients who required dialysis were older, with a higher incidence of hypertension, diabetes, prior bypass surgery, chronic renal failure, and a significantly lower left ventricular ejection fraction. Despite similar angiographic success, these patients had a higher incidence of in‐hospital mortality (27.5% vs. 1.0%, P < 0.0001), non–Q‐wave myocardial infarction (45.7% vs. 14.6%, P < 0.0001), vascular and bleeding complications, and longer hospitalization. At 1‐year follow‐up, mortality (54.5% vs. 6.4%, P < 0.0001), myocardial infarction (4.5% vs. 1.6%, P = 0.006), and event‐free survival (38.6% vs. 72.0%, P < 0.0001) were significantly worse in patients who required dialysis compared to patients who did not. Multivariate analysis revealed in‐hospital dialysis and an increase in baseline serum creatinine levels as the most important predictors of in‐hospital and long‐term mortality. Thus, acute renal failure that requires dialysis after percutaneous coronary interventions is associated with very high in‐hospital and 1‐year mortality rates and a dramatic increase in hospital resource utilization. Cathet Cardiovasc Intervent 2001;52:409–416. © 2001 Wiley‐Liss, Inc.
Impact of coronary plaque morphology as assessed by IVUS computer‐aided analysis on mechanisms of balloon angioplasty and stenting
Authors: Garot Philippe , Pelle Gabriel , Teiger Emmanuel , Belarbi Abdel , Aptecar Eduardo , Boudali Lotfi , Dubois‐Randé Jean Luc , Dupouy Patrick 
Published: August 2002

AbstractThis study was performed in order to quantitate structural coronary plaque modifications after balloon angioplasty and stenting and to evaluate the impact of plaque morphology on the mechanisms of lumen enlargement during angioplasty. Plaque morphology was studied by computer‐aided analysis of 60 cross‐sectional intravascular ultrasound (IVUS) images of the target lesion in 20 patients undergoing percutaneous coronary angioplasty. Based on a computer‐aided video densitometry classification of plaque morphology, three groups of plaques were defined based on the slope value of a fifth polynomial regression of the plaque gray‐level distribution. In groups A and B, balloon angioplasty provided significant increases in lumen area (P < 0.0001) and vessel area (P < 0.05) without a reduction in plaque area; neither parameter increased in group C. In group A, stenting was associated with an additional lumen enlargement (P < 0.0001) due to plaque reduction (P < 0.05). In groups B and C, stenting further increased lumen area (P < 0.0001) by improving vessel area (P < 0.001) but without plaque reduction. Balloon angioplasty and stenting provided a significant decrease in plaque area in group A as compared to groups B (P < 0.05) and C (P < 0.01). Finally, vessel area improvement was greater in group B than in groups A (P < 0.01) and C (P < 0.05). The mechanisms underlying lumen enlargement after coronary angioplasty are highly dependent on plaque morphology as defined by an IVUS computer‐aided analysis and may differ between balloon angioplasty and stenting. Cathet Cardiovasc Intervent 2001;52:449–456. © 2001 Wiley‐Liss, Inc.
Transcatheter closure of atrial septal defect using Amplatzer septal occluder in Chinese adults
Authors: Lee Chi‐hang , Kwok On‐hing , Fan Katherine , Chau Elaine , Yip Alex , Chow Wing‐hing 
Published: August 2002

AbstractAmplatzer septal occluder (AGA Med. Co., USA) is a novel device for occlusion of atrial septal defect. We present our experience of transcatheter closure of atrial septal defects using Amplatzer septal occluder in 45 adult Chinese patients (age range 18–69 years). The size of atrial septal defect varied from 14–28 (23 ± 4) mm. Cardiac catheterization revealed a pulmonary‐to‐systemic shunt ratio ranging from 1.4–2.8 (mean 2.0 ± 0.4). The procedure was successful in 44 (98%) patients. Displacement of the device requiring surgical removal occurred in one (2%) patient and minor wound complication occurred in two (4%) patients. Total procedure time was 67 ± 16 minutes and the fluoroscopy time was 25 ± 8 min. Immediate post‐procedure and pre‐discharge echocardiography revealed complete abolition of shunt in 42 (93%) and trivial residual shunt in 3 (7%) patients. The average follow‐up period was 16 ± 6 months (range 2 months to 3 years) months. None of the patients had developed other major complication at follow‐up. Cathet Cardiovasc Intervent 2001;52:373–377. © 2001 Wiley‐Liss, Inc.
Overestimation of stent delivery balloon diameters by manufacturers' compliance tables: A quantitative coronary analysis of Duet and NIR stent implantation
Authors: Hehrlein Christoph , DeVries Jennifer J. , Wood Todd A. , Haller Scott D. , Arab Amina , Kloostra Ann C. , Lauer Michael A. , Fischell Tim A. 
Published: August 2002

AbstractAlthough manufacturers' compliance tables of stent delivery balloons indicate the diameter of the balloon at a given inflation pressure, it is unclear whether these data correlate with in vivo true intracoronary balloon diameters (TBDs). The TBDs of two new‐generation balloon‐expandable stent delivery systems (Duet and NIR) were measured by quantitative coronary analysis (QCA) in 100 consecutive patients. The manufacturers' stated balloon diameter (BD) of the stent delivery systems overestimated the TBD in 94% ± 4% of patients receiving both Duet or NIR stent implantations. In only 6% of the patients, the TBD matched the manufacturers' stated balloon diameter. There was no underestimation of TBDs by both manufacturers' compliance tables. The Duet tables overestimated TBDs by 14% ± 8% (range, 1%–36%), the NIR tables by 18% ± 8% (range, 1%–41%), P < 0.05, Duet vs. NIR, respectively. When the manufacturers' data were corrected for the differences in reporting data from in vitro tests, i.e., balloon compliance data with or without the stent, the degree of overestimation of diameters was similar for Duet and NIR stent delivery balloons (14% ± 8% vs. 13% ± 7%, Duet vs. NIR; P = NS). Manufacturers' compliance tables of both the Duet and NIR stent delivery balloon systems significantly overestimate the true intracoronary balloon diameter. The manufacturers' of stent delivery balloons should clearly state on the box, if balloon compliance data were derived from in vitro bench testing, which phantoms were used for compliance analysis, and that the tables may overestimate the true intracoronary balloon diameter. The findings of the present study have important clinical implications with respect to performing coronary stent implantation with precision. Cathet Cardiovasc Intervent 2001;53:474–478. © 2001 Wiley‐Liss, Inc.
Determination of the absolute configuration of bicyclo[3.3.1]nonane‐2,7‐dione by circular dichroism spectroscopy and chemical correlation
Authors: Butkus Eugenius , Stončius Sigitas , Žilinskas Albinas 
Published: August 2002

AbstractA study of the enantiomers of bicyclo[3.3.1]nonane‐2,7‐dione, a chiral molecule containing two carbonyl chromophores, was performed. Enantiomers of this structure were obtained by HPLC resolution and the (+)‐(1R,5S)‐enantiomer by enantiospecific synthesis from(+)‐(1S,5S)‐bicyclo[3.3.1]nonane‐2,6‐dione. The title structure is an interesting molecule to demonstrate the validity of the octant rule. The location of the major chair–chair conformer into octants placing each chromophore into the origin of the octants led to the opposite configuration assignments. In order to prove unequivocally absolute configuration, enantiospecific synthesis of the title compound was carried out. The kinetic resolution of racemic bicyclo[3.3.1]nonane‐2,6‐dione using baker's yeast afforded (+)‐(1S,5S)‐2,6‐dione. Employing a reaction sequence analogous to one developed earlier by us with racemic substrates led to carbonyl group shift giving enantiomerically pure (+)‐(1R,5S)‐bicyclo[3.3.1]nonane‐2,7‐dione. The absolute configuration of the investigated compound was established by combined use of the octant rule and chemical correlation. Chirality 13:694–698, 2001. © 2001 Wiley‐Liss, Inc.
Spectroscopic studies of enantiomeric discrimination in jet‐cooled chiral complexes
Authors: Le Barbu K. , Zehnacker A. , Lahmani F. , Mons M. , Piuzzi F. , Dimicoli I. 
Published: August 2002

AbstractVan der Waals complexes formed between chiral molecules in the isolated gas phase were studied by combining supersonic expansion techniques with laser spectroscopy. The weakly bound diastereoisomers formed between a chiral secondary alcohol, butan‐2‐ol, and a chiral aromatic derivative such as 2‐naphthyl‐1‐ethanol or 1‐phenylethanol used as a resolving agent were discriminated on the basis of the spectral shifts of the UV S0‐S1 transition of the chromophore. Ground‐state depletion spectroscopy (hole burning) has shown that, while only one structure was detected for the 1‐phenylethanol/butan‐2‐ol homochiral complex, the heterochiral complex is trapped in the jet under two different conformations. Two isomers have also been shown for each diastereoisomeric pair of the 2‐naphthyl‐1‐ethanol/butan‐2‐ol complexes. Using a semiempirical potential model, these isomeric forms were related to calculated structures which exhibit a folded or extended geometry depending on the solvent conformation (anti or gauche). The relative binding energy of the complexes involving R‐1‐phenylethanol and R‐ or S‐butan‐2‐ol were obtained from fragmentation threshold measurements following two‐color photoionization. Comparison of the diastereoisomers exhibiting a similar spectral signature shows that the homochiral pair is more stable than the heterochiral one by about 0.7 kcal/mol. The fragmentation threshold has been shown to depend on the jet‐cooled isomer and this result addresses the role of conformational control in enantioselective interactions. Chirality 13:715–721, 2001. © 2001 Wiley‐Liss, Inc.
Highly enantioselective asymmetric autocatalysis of 2‐alkenyl‐ and 2‐vinyl‐5‐pyrimidyl alkanols with significant amplification of enantiomeric excess
Authors: Sato Itaru , Yanagi Tomotaka , Soai Kenso 
Published: August 2002

Abstract2‐Alkenyl‐ and 2‐vinyl‐5‐pyrimidyl alkanols are highly enantioselective asymmetric autocatalysts with significant amplification of enantiomeric excess in the enantioselective addition of diisopropylzinc to 2‐alkenyl‐ and 2‐vinylpyrimidine‐5‐carbaldehydes. Consecutive asymmetric autocatalysis starting from 7% ee increases the ee of pyrimidyl alkanol up to 99% without the need for any other chiral auxillary. Chirality 14:166–168, 2002.© 2002 Wiley‐Liss, Inc.
Synthesis of 11‐cis‐locked bicyclo[5.1.0]octanyl retinal and an enantioselective binding to bovine opsin
Authors: Fujimoto Yukari , Xie Rongyuan , Tully Sarah E. , Berova Nina , Nakanishi Koji 
Published: August 2002

AbstractBoth enantiomers of 13‐(E) and 13‐(Z) isomers of 11‐cis‐locked bicyclo[5.1.0]octanyl retinal were prepared by an improved synthesis and incubated with bovine opsin. The synthesis also establishes the absolute configuration of the enantiomers. Only one of the enantiomers binds to opsin, thus showing the steric restrictions regarding the middle polyene moiety of the retinoid molecule; this is in sharp contrast to the known leniency of the ring moiety binding site of retinoids. However, although one enantiomer is incorporated into the pigment, the circular dichroic spectrum of the pigment incorporating the bound enantiomer yields only a very weak Cotton effect, showing that, once incorporated, the bicyclo[5.1.0]octanyl chromophore is flattened by the opsin binding site. The titled retinoid was synthesized for study of the absolute conformation of the retinal pigment in rhodopsin. Chirality 14:340–346, 2002. © 2002 Wiley‐Liss, Inc.
Disposition of venlafaxine enantiomers in rats with hepatic encephalopathy after chronic drug treatment
Authors: Wikell Cecilia , Eap Chin B. , Josefsson Martin , Apelqvist Gustav , Ahlner Johan , Baumann Pierre , Bengtsson Finn 
Published: August 2002

AbstractPortacaval shunted (PCS) rats, a model of hepatic encephalopathy, and control animals were administered racemic venlafaxine for 14 days (10 mg/kg). The levels of the S‐ and R‐enantiomers and the S/R‐enantiomer ratios of venlafaxine and its metabolites were assessed by an enantiomer‐selective chromatographic assay in serum, brain parenchyma, and brain dialysate of both groups. Higher levels of the S‐ and R‐enantiomers of venlafaxine were found in serum and brain of PCS vs. normal rats (median values of S‐ and R‐venlafaxine in serum: 290 and 201 nM in PCS; 97 and 66 nM in normal rats; median values of S‐ and R‐venlafaxine in cortex: 956 and 939 nM in PCS; 357 and 318 nM in normal rats). Interestingly, similar S/R‐venlafaxine ratios were observed in PCS and normal rats both in serum (S/R = 1.4) and brain compartments (S/R = l.0–1.1). These findings may have clinical relevance for the safety of venlafaxine in chronic hepatic encephalopathy. Chirality 14:347–350, 2002. © 2002 Wiley‐Liss, Inc.
Stereoselective effects of (R)‐ and (S)‐carvedilol in humans
Authors: Stoschitzky Kurt , Koshucharova Gergana , Lercher Peter , Maier Robert , Sakotnik Andrea , Klein Werner , Liebmann Peter M. , Lindner Wolfgang 
Published: August 2002

AbstractCarvedilol is currently used as the racemic mixture, (R,S)‐carvedilol, consisting of equal amounts of (R)‐carvedilol, an alpha‐blocker, and (S)‐carvedilol, an alpha‐ and beta‐blocker, which have never been tested in their optically pure forms in human subjects. We performed a randomized, double‐blind, placebo‐controlled, crossover study in 12 healthy male volunteers. Subjects received single oral doses of 25 mg (R,S)‐carvedilol, 12.5 mg (R)‐carvedilol, 12.5 mg (S)‐carvedilol, and placebo at 8 AM as well as at 8 PM. Exercise was performed at 11 AM, and heart rate and blood pressure were measured at rest and after 10 min of exercise. Urine was collected between 10 AM and 6 PM, as well as between 10 PM and 6 AM, and the amounts of urinary 6‐hydroxy‐melatonin sulfate (aMT6s) were determined by RIA. Compared to placebo, (R)‐carvedilol increased heart rate during exercise (+4%, P < 0.05) and recovery (+10%, P < 0.05); (S)‐carvedilol decreased heart rate during exercise (−14%, P < 0.05) and recovery (−6%, P < 0.05), and systolic blood pressure during exercise (−12%, P < 0.05); (R,S)‐carvedilol decreased heart rate during exercise (−11%, P < 0.05), and systolic blood pressure at rest (−7%, P < 0.05) and during exercise (−10%, P < 0.05). None of the agents had any significant effect on the release of aMT6s. Our results indicate that only (S)‐carvedilol causes beta‐blockade, whereas (R)‐carvedilol appears to increase sympathetic tone, presumably as a physiological reaction to the decrease of blood pressure caused by alpha‐blockade. None of the drugs had any influence on melatonin release. The weak clinical net effect of beta‐blockade of (R,S)‐carvedilol at rest might be one reason why this drug causes fewer side effects than other beta‐blockers, such as a reduction of nocturnal melatonin release. Chirality 13:342–346, 2001. © 2001 Wiley‐Liss, Inc.
Central nervous system metastasis from nasopharyngeal carcinoma
Authors: Ngan Roger K. C. , Yiu Harry H. Y. , Cheng Harold K. M. , Chan John K. C. , Sin Vai‐Chong , Lau Wai‐Hon 
Published: August 2002

AbstractBACKGROUNDCentral nervous system (CNS) metastasis from nasopharyngeal carcinoma (NPC) is an extremely rare occurrence, although direct intracranial invasion is not infrequent in patients with NPC at a locally advanced stage. Only five other patients have been reported in detail in the English literature.METHODSThe clinical records of two such patients with NPC who were diagnosed with metastasis to the spinal cord (intradural) and to the occipital lobe, respectively, were reviewed. The literature was searched for a review of similar incidents.RESULTSBoth patients had locally advanced disease at the time of presentation and were treated with neoadjuvant chemotherapy and radical radiotherapy. The CNS metastases in both patients were accompanied by disease recurrences in multiple sites after a prolonged period of clinical remission. Spread through cerebral spinal fluid was postulated for the patient with spinal cord metastasis, and hematogenous spread was postulated for the patient with brain metastasis. Aggressive surgical resection with or without postoperative radiotherapy conferred reasonable survival and symptom control. The patient with brain metastasis died 6 months later of lung metastasis, whereas the other patient is still alive 40 months from the diagnosis of spinal metastasis.CONCLUSIONSGood symptom control and disease control can be achieved for patients with CNS metastasis after surgery with or without radiotherapy. After aggressive therapy, the ultimate survival depends on control of extracranial disease. Cancer 2002;94:398–405. © 2002 American Cancer Society.
A quantitative morphometric analysis of rat spinal cord remyelination following transplantation of allogenic Schwann cells
Authors: Lankford Karen L. , Imaizumi Toshio , Honmou Osamu , Kocsis Jeffery D. 
Published: August 2002

AbstractQuantitative morphometric techniques were used to assess the extent and pattern of remyelination produced by transplanting allogenic Schwann cells into demyelinated lesions in adult rat spinal cords. The effects of donor age, prior culturing of donor cells, prior lesioning of donor nerves, and host immunosuppression were evaluated by transplanting suspensions of 30,000 acutely dissociated or cultured Schwann cells from neonatal, young adult, or aged adult rat sciatic nerves into X‐irradiation and ethidium bromide‐induced demyelinated dorsal column lesions, with or without co‐transplantation of neonatal optic nerve astrocytes. Three weeks after transplantation, spinal cords were processed for histological analysis. Under all Schwann cell transplant protocols, large areas containing many Schwann cell‐like myelinated axon profiles could be readily observed throughout most of the lesion length. Within these “myelin‐rich” regions, the vast majority of detectable axons showed a peripheral‐like pattern of myelination. However, interaxonal spacing also increased, resulting in densities of myelinated axons that were more similar to peripheral nerve than intact dorsal columns. Freshly isolated Schwann cells remyelinated more axonal length than cultured Schwann cells, and cells from younger donors remyelinated slightly more axon length than cells from older donors, but all Schwann cell transplant protocols remyelinated tens of thousands of millimeters of axon length and remyelinated axons at similar densities. These results indicate that Schwann cells prepared under a variety of conditions are capable of eliciting remyelination, but that the density of remyelinated axons is much lower than the myelinated axon density in intact spinal cords. J. Comp. Neurol. 443:259–274, 2002. © 2002 Wiley‐Liss, Inc.
Polygenic expression of somatostatin in the sturgeon Acipenser transmontanus: Molecular cloning and distribution of the mRNAs encoding two somatostatin precursors
Authors: Trabucchi Michele , Tostivint Hervé , Lihrmann Isabelle , Sollars Cristina , Vallarino Mauro , Dores Robert M. , Vaudry Hubert 
Published: August 2002

AbstractThe sequence of somatostatin‐14 (SS1) has been strongly preserved throughout the evolution of vertebrates from agnathans to mammals. In Acipenseridae (sturgeons), two isoforms of somatostatin have been characterized to date: somatostatin‐14 has been identified from the gastrointestinal tract of the pallid sturgeon Scaphirhynchus albus and [Pro2]somatostatin‐14 has been identified from the pituitary of the Russian sturgeon Acipenser gueldenstaedti. In the present study, we report the cloning of two distinct somatostatin cDNAs from the brain of the sturgeon Acipenser transmontanus. One of the cDNAs encodes a 116‐amino acid protein (PSS1) that contains the SS1 sequence at its C‐terminal extremity and, thus, is clearly orthologous to other vertebrate PSS1. The other cDNA encodes a 111‐amino acid protein that contains the somatostatin variant [Pro2]somatostatin‐14 at its C‐terminal extremity. This second precursor exhibits more than 67% identity with the recently characterized lungfish PSS2 and goldfish PSS2. Reverse transcriptase‐polymerase chain reaction analysis revealed that PSS1 is expressed in the central nervous system, the pancreas and the gut, whereas PSS2 is found in the central nervous system but not in the digestive system. In situ hybridization histochemistry showed that the PSS1 and PSS2 genes are differently expressed in numerous regions of the sturgeon brain. Interestingly, PSS1 and PSS2 mRNAs are present in the hypothalamus suggesting that, in sturgeon, both SS1 and SS2 may play hypophysiotropic functions. The PSS2 mRNA but not the PSS1 mRNA was found in the intermediate lobe of the pituitary. The present data demonstrate that two somatostatin genes are expressed in the sturgeon brain: one precursor generates somatostatin‐14 and the other one gives rise to a [Pro2]somatostatin‐14 variant, which is orthologous to goldfish, lungfish, and frog SS2. J. Comp. Neurol. 443:332–345, 2002. © 2002 Wiley‐Liss, Inc.