bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alternative Surgical Exposure of the Rat Heart in vivo Using a Simple Abdominal Approach
Authors: Huikeshoven M. , van den Brink A. , Beek J.F. 
Published: April 2003

Access to the heart in laboratory rats is usually performed via a median sternotomy or a lateral thoracotomy. An alternative, less traumatic approach to the in vivo rat heart with improved survival is described. The technique uses an upper median laparotomy extending alongside the xyphoid bone. The xyphoid bone is retracted in a rostral direction, and a T-shaped cut is made in the diaphragm thus opening the thoracic cavity. Using a retractor the opening in the diaphragm is spread and the heart is exposed. We performed this abdominal approach in 23 anaesthetised and mechanically ventilated (for 2 h) rats and found physiologic intra-operative haemodynamics, a good postoperative recovery and 0% mortality.
Long-Term Effects of Vitamin B<sub>12</sub>, Folate, and Vitamin B<sub>6</sub> Supplements in Elderly People with Normal Serum Vitamin B<sub>12</sub> Concentrations
Authors: Henning Bernhard F. , Tepel Martin , Riezler Reiner , Naurath Hans J. 
Published: April 2003

<i>Background:</i> In the elderly, deficiencies of folate, cobalamin (vitamin B<sub>12</sub>) and pyridoxal phosphate (vitamin B<sub>6</sub>) are common. The metabolites homocysteine, methylmalonic acid, 2-methylcitric acid and cystathionine have been reported to be sensitive markers of these vitamin deficiencies. <i>Objective:</i> The long-term (269 days) effect of an intramuscular vitamin supplement containing 1 mg vitamin B<sub>12</sub>, 1.1 mg folate, and 5 mg vitamin B<sub>6</sub> on serum concentrations of homocysteine (tHcy), methylmalonic acid (MMA), 2-methylcitric acid (2-MCA), and cystathionine (Cysta) was studied in 49 elderly subjects with normal levels of vitamin B<sub>12</sub>. <i>Methods:</i> Vitamin supplement was administered 8 times over a 21-day period, metabolite concentrations were measured until day 269 (e.g. 248 days after the end of vitamin supplementation). <i>Results:</i> From day 0 to 21, the serum levels of the 3 vitamins increased significantly, after cessation of supplementation the levels returned to baseline within the follow-up period. The MMA, 2-MCA and tHcy levels decreased during the treatment period significantly and did not reach baseline values within the 248-day period. Cysta levels did not differ significantly from baseline, either during or after treatment. <i>Conclusion:</i> MMA and 2-MCA levels rather reflect the availability of vitamins, especially cobalamin, than the actual serum levels. Since deficiencies of folate, cobalamin and pyridoxal phosphate in the elderly may cause hyerhomocysteinemia and hence may have unfavorable effects on mental performance, determination of MMA and 2-MCA levels in elderly patients with mental disturbances may be a cost-effective measure to improve or maintain mental performance.
Cardiovascular Responses to Lower Body Negative Pressure in the Elderly: Role of Reduced Leg Compliance
Authors: Tsutsui Yuka , Sagawa Sueko , Yamauchi Katsuya , Endo Yutaka , Yamazaki Fumio , Shiraki Keizo 
Published: April 2003

<i>Background:</i> It is warranted to test the hypothesis that the orthostatic tolerance does not diminish in the aging process per se in healthy individuals. <i>Objective:</i> The purpose of the present study was to examine the effects of aging on cardiovascular response and baroreflex sensitivity during lower body negative pressure (LBNP) with a special reference to leg compliance. <i>Methods:</i> Fifteen healthy old male subjects [mean age 68.2 ± (SE) 0.8 years] and 22 young male subjects [mean age 21.4 ± (SE) 0.3 years] underwent a 21-min bout of ramped LBNP (from 0 to –60 mm Hg, 10 mm Hg each for 3 min). Heart rate (HR), blood pressure, stroke volume (SV), forearm blood flow, and leg volume were measured throughout the experimental period. The arterial baroreflex sensitivity was calculated from spontaneous changes in beat-to-beat arterial pressure and HR during LBNP. <i>Results:</i> The leg compliance was lower, and the orthostatic tolerance index was higher in old than in young participants. The LBNP-associated increases in leg volume and HR and the decreases in SV were lower in old subjects, suggesting that the reduction of venous return was less in magnitude in old subjects during LBNP. The baseline value of baroreflex sensitivity evaluated by the sequence analysis was smaller, and no LBNP-related change was observed in old subjects, whereas a gradual LBNP-related reduction was observed in young subjects. The slope of regression between ΔSV and change in forearm vascular resistance during LBNP was identical in both age groups. <i>Conclusions:</i> We conclude that: (1) aging per se does not increase the intolerance to orthostatic stress induced by LBNP; (2) a low magnitude of venous return reduction during LBNP contributes to a higher tolerance in the old because of lower leg compliance, and (3) the sensitivity of baroreflex control of the HR is attenuated in the old; however, there is no deterioration of the sensitivity of the peripheral vasoconstriction during LBNP.
Effect of Heparin on Activated Partial Thromboplastin Time in Patients Undergoing Gynecologic or Obstetric Surgery
Authors: Watanabe Takashi , Minakami Hisanori , Sakata Yoichi , Obara Hiromi , Wada Tomoaki , Onagawa Tamaho , Sato Ikuo 
Published: April 2003

The exaggerated prolongation of the activated partial thromboplastin time (APTT) by heparin prophylaxis for postoperative thromboembolism may cause bleeding complications. We examined the effects of various doses of unfractionated heparin on the APTT in patients who underwent a gynecologic or obstetric operation. A total of 68 patients who underwent a gynecologic operation (n = 47) or a cesarean section (n = 21) with risk factors for thromboembolism received a continuous intravenous infusion of unfractionated heparin (110–285 IU/kg/day) after surgery until the patient was mobilized the next day. A group of 61 postoperative patients who did not receive heparin served as controls. The APTT was measured in these 129 patients preoperatively and on postoperative day 1. A clinical deep vein thrombosis occurred in only 1 patient, who was in the control group. No bleeding complications occurred in any patient. The percent change in the APTT was significantly correlated with the dose of heparin administered (p < 0.001). Compared with the control group, the mean APTT was not prolonged in the patients who received heparin at 110–149 IU/kg/day. It was prolonged significantly in the patients who received heparin at greater than 150 IU/kg/day. An exaggerated prolongation of the APTT, defined as an APTT greater than 150% of the preoperative value, was found in 0 of 32 patients in the 110–149 IU/kg/day group, 1 of 28 patients (3.6%) in the 150–199 IU/kg/day group and 2 of 8 patients (25%) in the 200–285 IU/kg/day group. The continuous postoperative administration of intravenous heparin at less than 200 IU/kg/day does not result in an exaggerated prolongation of the APTT.
Effect of p53 Polymorphism on the Susceptibility of Cervical Cancer
Authors: Yang Yuh-Cheng , Chang Chih-Long , Chen Mong-Liang 
Published: April 2003

Using PCR amplification followed by confirmation with <i>Bst</i>U I restriction enzyme digestion, the p53 Pro sequence was determined in tissues from 88 normal cervices, in 184 cervical swabs with mildly abnormal Pap smear, in 50 squamous cell cervical carcinoma specimens, and in 30 cervical adenocarcinoma samples. The frequencies for homozygous proline (Pro-72), homozygous arginine (Arg-72), and heterozygous proline/arginine (Pro/Arg-72) were 23% (n = 20), 28% (n = 25), and 49% (n = 43), respectively, in normal cervices; 24% (n = 45), 28% (n = 51), and 48% (n = 88), respectively, in samples with mild dyskaryotic changes in Pap smears; 26% (n = 13), 28% (n = 14), and 46% (n = 23), respectively, in squamous cell carcinomas, and 33.3% (n = 26), 46.2% (n = 36), and 20.5% (n = 16), respectively, in adenocarcinomas. In the present study, we have found that p53 polymorphism may have a role in the development of adenocarcinoma but not squamous cell carcinoma. The arginine-encoding allele may thus be an important factor affecting host susceptibility to the development of adenocarcinoma.
Correlation between Grade III Placenta and Plasma Antithrombin III Activity in Full Term Pregnancy
Authors: Asakura Hirobumi , Ohshita Tomoko , Suzuki Shunji , Araki Tsutomu 
Published: April 2003

We evaluated whether the presence of a grade III placenta correlates with blood hypercoagulability in pregnancy between 37 and 39 weeks of gestation. The placenta was graded by ultrasound in 155 healthy full-term women and the plasma levels of antithrombin III (AT III) activity, thrombin-antithrombin complex (TAT) and D-dimer were correlated with each placental grade. AT III activity levels tended to decrease with advancing placental grade from I to III (p < 0.05). D-dimer showed the same tendency while TAT did not. The incidence of reduced AT III activity levels (<70%) in women with a grade III placenta was about twice those in women with a grade II or I placenta, and that of AT III <80% was 3-fold greater. We concluded that the presence of a grade III placenta in full-term pregnancies correlates with blood hypercoagulability.
Differential Levels of Interleukin 6 in Maternal and Cord Sera and Placenta in Women with Pre-Eclampsia
Authors: Al-Othman Saed , Omu Alexander E. , Diejomaoh F.M.E. , Al-Yatama Magda , Al-Qattan Fawzia 
Published: April 2003

<i>Background:</i> Interleukin 6 (IL-6) is a T helper 2 cytokine with a variety of properties including pro-inflammatory characteristics. It has, therefore, been implicated in the pathophysiology of abnormal pregnancies. <i>Objective:</i> To investigate the association between IL-6 and pre-eclampsia by estimating the differential levels of IL-6 in maternal and cord serum and supernatant of homogenized placental tissue. <i>Methods:</i> 50 primigravidae with pre-eclampsia and 50 matched normotensive primigravidae served as controls. At delivery, maternal and cord blood were collected and the serum extracted. Placental blocks were homogenized and sonicated in RPMI solution and the supernatant collected. The total protein concentration was determined and IL-6 levels assayed with an ELISA technique. <i>Results:</i> Placental IL-6 (170 and 186 pg/mg protein) was threefold that in the maternal (64 and 58 pg/mg protein) and cord serum (63 and 72 pg/mg protein; p < 0.01). There was no significant difference in the mean IL-6 levels in maternal and cord serum or placenta in both pre-eclamptic women and normotensive controls nor in pre-eclamptic patients with babies with intra-uterine growth restriction or in pre-eclamptic patients with babies with an appropriate birth weight and in normotensive controls. <i>Conclusion:</i> There are no differences in the maternal and cord sera and placental levels of IL-6 in pre-eclamptic and normotensive women, indicating that IL-6 may not have a role in the pathophysiology of pre-eclampsia.
Prediction of the Effect of Metformin Treatment in Patients with Polycystic Ovary Syndrome
Authors: Vrbíková J. , Hill M. , Stárka L. , Vondra K. 
Published: April 2003

The objective of the study was to find predictors of a successful therapy with metformin in polycystic ovary syndrome. 24 women with polycystic ovary syndrome were examined (oral glucose tolerance test and gonadotropin-releasing hormone analogue test) before and after a 6-month course of metformin (1 g/day). In 58% of the women, a significant improvement in the menstrual cycle pattern was observed. After a treatment course, a significant reduction in gonadotropin-releasing hormone analogue stimulated levels of testosterone (p < 0.05), free testosterone index (p < 0.01), luteinizing hormone (p < 0.05), and estradiol (p < 0.01) was found. The best prediction of the improvement in menstrual cyclicity after metformin was achieved with a combination of basal values of 17-hydroxyprogesterone, testosterone, sex hormone binding globulin, and androstenedione. These variables correctly classified 86.7% of the responders. The best predictor of changes in the index of free testosterone after metformin treatment was the combination of estradiol and androstenedione in the gonadotropin-releasing hormone analogue test, with basal testosterone correctly classifying 91.7% of the subjects.
Chlamydienscreening: Ist das Nachweisproblem gelöst?
Authors: Niederhauser C. , Honegger C. , Kaempf L. 
Published: April 2003

<i>Fragestellung:</i> Vor dem Hintergrund diskrepanter Nachweisraten von <i>Chlamydia trachomatis</i> bei Frauen mit Verdacht auf eine genitale Infektion wurden im Routinebetrieb drei verschiedene Testsysteme miteinander verglichen. <i>Methode:</i> Bei 594 Frauen wurden Zervixproben entnommen und jeweils eine Polymerasekettenreaktion (PCR) und zwei Immunofluoreszenztests (Chlamyset und Chlamydia direct IF) für den Nachweis von <i>C. trachomatis</i> durchgeführt. War einer dieser drei Tests positiv, wurde zusätzlich das auf die beiden Objektträger (IF-Tests) aufgetragene Material abgekratzt und davon eine PCR durchgeführt. <i>Ergebnisse:</i> Bei 15 von 594 Patientinnen liessen sich die Chlamydien im Zervixabstrich nachweisen. 14 dieser 15 «richtig»-positiven Proben waren mit der PCR positiv, 13 bzw. 8 mit den IFs der Firma Orion und der Firma Biomérieux. Mit dem IF-Test der Firma Orion waren zusätzlich 37 Proben falsch-positiv. <i>Schlussfolgerungen:</i> Der PCR-Test hat sowohl eine hohe Sensitivität als auch eine hohe Spezifität, wobei die Sensitivität durch eine bessere Probenvorbereitung noch optimiert werden kann. Der IF-Test der Firma Biomérieux hat eine gute Spezifität, leider aber eine geringe Sensitivität. Der IF-Test der Firma Orion hat eine sehr hohe Rate an falsch-positiven Resultaten. Zusammenfassend ist zu bemerken, dass die PCR das Potential hat, für den Nachweis von <i>C. trachomatis</i> zu einem neuen Goldstandard zu werden.
Rapid Production of Recombinant Allergens in <i>Nicotiana benthamiana</i> and Their Impact on Diagnosis and Therapy
Authors: Breiteneder H. , Krebitz M. , Wiedermann U. , Wagner B. , Essl D. , Steinkellner H. , Turpen T.H. , Ebner C. , Buck D. , Niggemann B. , Scheiner O. 
Published: April 2003

<i>Background:</i> Type I allergies are immunological disorders that afflict a quarter of the world’s population. Recombinant allergens have improved the diagnosis of allergic diseases and allow the formulation of new therapeutic approaches. Over 50% of all allergens are of plant origin. <i>Objective:</i> We have applied a novel method of overexpressing plant allergens in the tobacco-related species <i>Nicotiana benthamiana.</i><i>Method:</i> This method is based on the use of a chimeric tobacco mosaic virus that harbors a foreign gene sequence and directs its transcription after the infection of the host plant. <i>Results:</i> We have expressed the model allergen Bet v 1, the major birch pollen allergen, and two <i>Hevea brasiliensis</i> latex allergens, the spina-bifida-associated allergens Hev b 1 and Hev b 3, in <i>N. benthamiana</i> using such a viral vector. Bet v 1, Hev b 1 and Hev b 3 produced by this method were recognized by patients’ IgE suggesting that the plant-produced allergens were properly folded. Nonpurified Bet v 1 expressed in <i>N. benthamiana</i> leaves had the same immunogenicity as purified Bet v 1 expressed in <i>Escherichia coli</i> or natural Bet v 1 when tested in a murine model of type I allergy. <i>Conclusion:</i> We conclude that this plant expression system offers a viable alternative to fermentation-based production of allergens in bacteria or yeasts.
Differential Effects of Enalapril and Irbesartan in Experimental Papillary Necrosis
Authors: Garber Sandra L. , Mirochnik Yelena , Arruda Jose A.L. , Dunea George , Slobodskoy Leonid 
Published: April 2003

This study was undertaken to determine whether angiotensin receptor blockers are as renoprotective as angiotensin-converting enzyme inhibitors in an experimental model of chronic interstitial renal disease. Groups of rats received one of the following treatments for 1 week: (1) enalapril, (2) diltiazem, (3) a cocktail of hydralazine, reserpine, and hydrochlorothiazide, or (4) irbesartan (an AT<sub>1</sub> antagonist). The animals were injected with bromoethylamine (200 mg/kg), and antihypertensive treatment continued for 1 month. All drugs were effective in lowering the mean arterial pressure. The bromoethylamine-treated rats developed albuminuria and sustained a 40–50% decrease in creatinine clearance. Enalapril and irbesartan reduced albuminuria, but only enalapril partially prevented the decline in creatinine clearance and lowered the number of ED-1-positive cells. Diltiazem and cocktail had no effect on proteinuria, creatinine clearance, or ED-1 cells. In this experimental model, the effects of enalapril and irbesartan were not identical. Both drugs reduced proteinuria, but enalapril was more effective in protecting the renal function. The fact that the AT<sub>1</sub> antagonist protected against albuminuria but did not affect the clearance of creatinine implies that the results seen with angiotensin-converting enzyme inhibition may be in part due to an effect on angiotensin II via AT<sub>2</sub> receptor blockade or through an effect on bradykinin.
Does Gonadotropin-Releasing Hormone in the Cerebrospinal Fluid Modulate Luteinizing Hormone Release?
Authors: Skinner Donal C. , Caraty Alain , Evans Neil P. 
Published: April 2003

The function of gonadotropin-releasing hormone (GnRH) in the cerebrospinal fluid (CSF) is unknown. This study on ovariectomized ewes investigated whether CSF-GnRH has a role in modulating luteinizing hormone (LH) secretion either through an ultrashort-loop feedback system to affect GnRH secretion or to directly act on the pituitary gland after entering the hypothalamo-hypophysial portal system. In the first experiment, a 3-hour continuous infusion of exogenous GnRH (700 or 7 pg/min; n = 8) was administered into the third ventricle through a permanent indwelling cannula. Jugular LH concentrations were measured as an estimate of the activity of the GnRH ‘pulse generator’. To assess the potential for a direct involvement of CSF-GnRH in pituitary stimulation of LH secretion, ewes were also implanted with a cannula to collect hypophysial portal blood. In a first investigation, radioactive (2 × 10<sup>6</sup> cpm <sup>125</sup>I-GnRH; n = 3) GnRH was injected into the third ventricle, and the amount of radioactivity present in the portal and jugular blood after the injection measured. In a second investigation, cold GnRH was infused (400 pg/min; n = 3) into the third ventricle for 2 h, and portal and jugular blood collected for the determination of GnRH and LH concentrations, respectively. In the first experiment, neither rate of infusion of GnRH into the third ventricle had any effect on the mean interpulse interval, nadir, pulse amplitude or circulating level of systemic LH, suggesting that CSF-GnRH is not a component of an ultrashort-loop feedback system for GnRH. Furthermore, in the second experiment, despite extremely low levels of radioactivity (maximum: 120 cpm/ml) being detected in hypophysial portal blood (which may not have been intact decapeptide), in the second part of this experiment, no radioimmunoassayable GnRH associated with the period of infusion could be measured. These data demonstate in ewes that little, if any, CSF-GnRH reaches the hypophysial portal blood, and this compartment of GnRH does not, thus, directly affect the pituitary gland. The present study strongly suggests, therefore, that CSF-GnRH does not modulate LH secretion. Whether this compartment of GnRH is involved in sexual behavior remains to be established.
Role of Vasoactive Intestinal Peptide and 5-HT<sub>2</sub> Receptor Subtype in Serotonin Stimulation of Basal and Thyrotropin-Releasing-Hormone- Induced Prolactin Release in vitro from Rat Pituitary Cells
Authors: Apfelbaum Marta E. 
Published: April 2003

We have previously demonstrated that 5-HT stimulates not only basal but also thyrotropin-releasing-hormone (TRH)-induced prolactin (PRL) release by acting directly at the pituitary gland level. In the present report, the participation of an autoparacrine action of VIP in the stimulatory effects of 5-HT and the involvement of the 5-HT<sub>2</sub> receptor type in mediating serotonin-induced PRL release have been examined. Cultured anterior pituitary cells from ovariectomized adult rats were incubated for 1 h in 1 ml of T<sub>3</sub>-supplemented medium with or without the test substances. The results obtained in the presence of T<sub>3</sub> confirm our previous observations, since treatment of the cells with 5-HT caused dose-dependent increases in basal PRL release, with an approximate EC<sub>50</sub> of 3.68 × 10<sup>–8</sup> <i>M</i>, and led to a significant potentiation (1.3-fold) of the TRH-induced PRL release. In order to evaluate the possible participation of vasoactive intestinal peptide (VIP) as mediator of the effects of 5-HT on PRL release, cells were incubated in the presence of 5-HT alone (3–1,000 n<i>M</i>) or 100 n<i>M</i> 5-HT plus 30 n<i>M</i> TRH, with or without 200 n<i>M</i> VIP antagonist (VIP-At): [D,4-Cl-Ph<sup>6</sup>,Leu<sup>17</sup>]VIP. VIP-At partially inhibited the release of PRL induced by 5-HT, both basal and TRHstimulated release. The stimulatory effect of 5-HT, however, was not eliminated by VIP-At, since the PRL released in response to 5-HT was still over the respective control ones. These results further support the findings suggesting that 5-HT acts directly at pituitary level by stimulating PRL release. Addition of the 5-HT<sub>2</sub> receptor antagonist, ketanserin (1 µ<i>M</i>) into the incubation medium resulted in the loss of cellular responsiveness to 5-HT, preventing not only the stimulatory effect of 5-HT on the basal but also on the TRH-induced PRL release. In conclusion, the results further strengthen the possibility that 5-HT increases the basal PRL release and potentiates the stimulatory effect of TRH by acting directly at the level of the lactotropes. These effects are not simply a consequence of autoparacrine action of VIP. In addition, it was shown that ketanserin completely antagonizes PRL response to 5-HT, indicating the involvement of the 5-HT<sub>2</sub> receptor type in mediating PRL release.