Effects of tryptophan supplementation on plasma tryptophan and related hormone levels in heifers and dairy cows.

This study was conducted to investigate the effects of rumen-protected tryptophan (125 g tryptophan per day) in heifers and dairy cows. Blood samples from dairy cows and heifers were collected for 24h in 3-h intervals on the day before tryptophan supplementation, on day 2, 5 and 7 of tryptophan supplementation, and in heifers additionally on d 14 after tryptophan supplementation was ceased. Plasma tryptophan, melatonin, serotonin, and prolactin concentrations were determined. Tryptophan plasma concentrations on d 5 were augmented at day (11:00 h) and nighttime (02:00 h), (P<0.05) in response to tryptophan supplementation in heifers by 119% and in dairy cows by 47%, respectively, as compared with d 0. Melatonin increased (P<0.05) in response to tryptophan supplementation in heifers, but not in cows. The effect of tryptophan supplementation on plasma tryptophan and melatonin was reversible as demonstrated in heifers on d 14 after cessation of tryptophan supplementation. Serotonin and prolactin in plasma did not respond to tryptophan supplementation. However, milk yield during morning milking increased significantly in tryptophan supplemented cows on d 1, 3 and 4 as compared to the day before tryptophan supplementation. Additional blood samples were taken during afternoon milking in cows at 1-min intervals for the analyses of oxytocin and prolactin on the day before the start and on d 7 of tryptophan supplementation. Milk flow curves were recorded during milking. No effect of tryptophan supplementation on the milking related release of oxytocin and prolactin and on any characteristic of milk flow was observed. In conclusion, tryptophan supplementation caused increased plasma tryptophan in cows and heifers and plasma melatonin in heifers. However, plasma serotonin, prolactin and oxytocin release in cows remained unchanged by tryptophan supplementation. Milk yield at morning milking increased slightly and transiently in response to tryptophan supplementation.

Arachidonic acid metabolism in isolated gastric mucous and parietal cells.

Arachidonic acid metabolism was studied in isolated gastric mucous and parietal cells. During a 90 min incubation, mucous cells incorporated [1-14C]arachidonic acid (4.5 mumol/l) into triacylglycerols (500 pmol/mg protein), phosphatidylcholine (520), phosphatidylethanolamine (290) and phosphatidylinositol (100). 230 pmol/mg protein was recovered as 14CO2 and 130 pmol/mg protein in the form of unidentified water-soluble metabolites. The incorporation rates were linearly related with arachidonic acid concentration up to 10 mumol/l. Neither equimolar concentrations of oleic acid, palmitic acid and linoleic acid nor prostaglandin E2 (1 mumol/l) or indomethacin (10 mumol/l) affected incorporation. During prolonged incubation incorporated arachidonic acid was transferred from triacylglycerols and phosphatidylcholine to phosphatidylethanolamine. Upon subcellular fractionation most of the incorporated arachidonic acid was found in the microsomal fraction. Compared with mucous cells, parietal cells incorporated arachidonic acid less quickly into phospholipids, but utilized it more efficiently for energy metabolism. In conclusion gastric cells show a highly dynamic metabolism of arachidonic acid which is qualitatively similar but quantitatively different between cell types.

In vivo incorporation of lipoic acid enantiomers and homologues in the pyruvate dehydrogenase complex from Escherichia coli.

The strain Escherichia coli JRG26, which has a defect in the lipoic acid biosynthesis, was cultivated in the presence of R-lipoic acid, S-lipoic acid, RS-dithiolane-3-caproic acid, RS-bisnorlipoic acid, and RS-tetranorlipoic acid, respectively. With the exception of the last compound the strain was able to grow with all these substances. R-lipoic acid was the most efficient factor, concentrations of 10 ng/l were sufficient to support growth of the cells, while 10(4)-fold to 10(7)-fold higher concentrations were necessary for the other compounds. The specific catalytic activity of the pyruvate dehydrogenase complex isolated from the cells grown on RS-dithiolane-3-caproic acid was only slightly lower than from cells grown on R-lipoic acid. With RS bisnorlipoic acid the specific activity was one third compared to that of the native enzyme complex. The incorporation of the RS-bisnorlipoic acid into the pyruvate dehydrogenase could directly be demonstrated by polyclonal antibodies directed against R-lipoic acid and RS-bisnorlipoic acid, both conjugated to BSA. Western blot analysis showed that the antibodies against the R-lipoic acid reacted specifically with the E2 component of pyruvate dehydrogenase complex purified from cells grown on this factor, while antibodies against RS-bisnorlipoic acid reacted with the enzyme complex isolated from cells grown in the presence of this compound.

Oral lichen planus (OLP), oral lichenoid lesions (OLL), oral dysplasia, and oral cancer: retrospective analysis of clinicopathological data from 2002-2011.

INTRODUCTION: This 10-year retrospective study analyzed the incidence of malignant transformation of oral lichen planus (OLP). The study also included dysplasia and oral lichenoid lesion (OLL) in the initial biopsy as a potential differential diagnosis. MATERIAL AND METHODS: A total of 692 scalpel biopsies were taken from 542 patients (207 [38.2%] men and 335 [61.8%] women). Clinical and histopathological parameters were analyzed. RESULTS: The parameters gender (p = 0.022) and smoking behavior (p < 0.001) were significantly associated with the severity of diagnosis. Mucosal lesions with an ulcerative appearance (p = 0.006) and those located on the floor of the mouth (p < 0.001) showed significantly higher degrees of dysplasia or were diagnosed as oral squamous cell carcinoma (OSCC). Smoking and joint disease appeared to be significant risk factors. Treatment with tretinoin in different concentrations (0.005-0.02%) significantly improved diagnosis. Twelve patients (8 female, 4 male) showed malignant transformation to OSCC within an average period of 1.58 years. The malignant transformation rate (MTR) was higher for OLL (4.4%) than OLP (1.2%). If the first biopsy showed intraepithelial neoplasia, the risk of developing OSCC increased (by 3.5% for squamous intraepithelial neoplasia (SIN) II and by 6.7% for SIN III). CONCLUSION: Although we cannot rule out that OLP is a premalignant oral condition, we can confirm that OLP had the lowest MTR of all diagnoses.

1-Naphthol conjugation in isolated cells from liver, jejunum, ileum, colon and kidney of the guinea pig.

Cells from liver, jejunum, ileum, colon and kidney of the guinea pig were freshly prepared by standard isolation procedures. Cells were incubated in the presence of several concentrations of 1(14C)-naphthol, and formation of 1-naphthol glucuronide and 1-naphthol sulphate was assessed at various times by thin layer chromatography. Cells from all five tissues conjugated 1-naphthol. The velocity of conjugation was fastest in jejunals cells (2.9 nmole/mg prot X min) followed by cells from liver, ileum, colon and kidney (0.2 nmole/mg prot X min). The apparent Km-values for glucuronidation ranged from 17 microM to 32 microM, and those for sulphation from 15 microM to 35 microM. Each tissue had a specific conjugation pattern. The two extremes were kidney cells, which had a glucuronidation/sulphation ratio in excess of 10, and colon cells which had a ratio of 0.38. The data suggest that these tissues possess different levels of 1-naphthol-conjugating enzymes, which resemble with regard to their apparent substrate affinities.

Interaction of alpha-lipoic acid enantiomers and homologues with the enzyme components of the mammalian pyruvate dehydrogenase complex.

Lipoic acid (alpha-lipoic acid, thioctic acid) is applied as a therapeutic agent in various diseases accompanied by polyneuropathia such as diabetes mellitus. The stereoselectivity and specificity of lipoic acid for the pyruvate dehydrogenase complex and its component enzymes from different sources has been studied. The dihydrolipoamide dehydrogenase component from pig heart has a clear preference for R-lipoic acid, a substrate which reacts 24 times faster than the S-enantiomer. Selectivity is more at the stage of the catalytic reaction than of binding. The Michaelis constants of both enantiomers are comparable (Km = 3.7 and 5.5 mM for R- and S-lipoic acid, respectively) and the S-enantiomer inhibits the R-lipoic acid dependent reaction with an inhibition constant similar to its Michaelis constant. When three lipoic acid homologues were tested, RS-1,2-dithiolane-3-caproic acid was one carbon atom longer than lipoic acid, while RS-bisnorlipoic acid and RS-tetranorlipoic acid were two and four carbon atoms shorter, respectively. All are poor substrates but bind to and inhibit the enzyme with an affinity similar to that of S-lipoic acid. No essential differences with respect to its reaction with lipoic acid enantiomers and homologues exist between free and complex-bound dihydrolipoamide dehydrogenase. Dihydrolipoamide dehydrogenase from human renal carcinoma has a higher Michaelis constant for R-lipoic acid (Km = 18 mM) and does not accept the S-enantiomer as a substrate. Both enantiomers of lipoic acid are inhibitors of the overall reaction of the bovine pyruvate dehydrogenase complex, but stimulate the respective enzyme complexes from rat as well as from Escherichia coli. The S-enantiomer is the stronger inhibitor, the R-enantiomer the better activator. The two enantiomers have no influence on the partial reaction of the bovine pyruvate dehydrogenase component, but do inhibit this enzyme component from rat kidney. The implications of these results are discussed.

Pharmacokinetic-pharmacodynamic modeling of testosterone and luteinizing hormone suppression by cetrorelix in healthy volunteers.

Cetrorelix (CET), a potent luteinizing hormone-releasing hormone (LH-RH) antagonist, was recently approved for the prevention of premature ovulation in patients undergoing a controlled ovarian stimulation (COS), followed by oocyte pickup and assisted reproductive techniques (ART), and is currently under clinical trials for benign prostate hyperplasia, endometriosis, and tumors sensitive to sex hormones. CET suppresses luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T) in men. The purpose of this study was to evaluate the pharmacokinetics and absolute bioavailability of 3 mg intravenously and subcutaneously administered CET in healthy male and female volunteers and to develop a pharmacokinetic-pharmacodynamic (PK-PD) model to link the plasma concentrations of CET to the T and LH suppression in males. Following intravenous (IV) (n = 5) and subcutaneous (SC) (n = 6) administration of CET acetate, CET and hormone plasma levels were measured by radioimmunoassay (RIA) and enzyme immunoassay (EIA) methods, respectively. Pharmacokinetics of CET was explained by a three-compartment model for the IV route and by a two-compartment model with first-order absorption for the SC route. Average absolute bioavailability after SC administration was 85%. There were no differences in the pharmacokinetics between male and female subjects (ANOVA, p > 0.05). Single IV and SC doses of CET caused immediate and distinct suppression of LH, FSH, and T levels by 80%, 45% and 95% of their baseline levels, respectively. The duration of hormone suppression was longer for the SC route. An indirect-response PK-PD Emax model was developed to link the measured CET plasma concentrations with the respective T or LH levels. In addition, the circadian rhythm of T levels was accounted by including a cosine function in a second separate PD model. The PD model with cosine function was applied to T baseline levels as well as to the suppressed concentrations after CET dosing. The two models adequately described the PK-PD relationship between plasma levels of CET and T suppression following IV and SC dosing. The EC50 values (mean +/- SD) for the suppression of T were similar (p > 0.05) between the two routes of administration and the two models.

The use of the Cell Saver in transoral maxillofacial surgery: a preliminary report.

In a prospective study with 18 patients, the Cell Saver was used in transoral operations. Blood cultures were taken immediately before retransfusion, 15 min, 2 and 24 h after retransfusion. As a clinical consequence we noticed a higher increase in temperature because of the transient bacteraemia. Other negative clinical consequences were not observed. If adequate antibiotic prophylaxis is used with careful patient selection, we think that the Cell Saver can even be used in transoral operations, although the number of observations is too small to allow definitive conclusions.

Complications following arthroscopy of the temporomandibular joint: analysis covering a 10-year period (451 arthroscopies).

451 arthroscopies of the temporomandibular joint (TMJ) have been performed on 373 patients during 10 years of clinical experience. The complication rate was low (1.77%). Most complications were transient, consisting mainly of temporary deficits of the 5th and 7th cranial nerves. No patient required arthrotomy because of complications, but one patient had to undergo angiography and embolization of a traumatic aneurysm of the superficial temporal artery secondary to arthroscopy.

Development of the frontal sinus following bilateral fronto-orbital osteotomies.

The presence of frontal sinuses following bilateral fronto-orbital advancement is discussed controversially in the literature. In a retrospective study, 33 patients (18 male and 15 female) were operated on between 1982 and 1993, with at least one year postoperative follow-up and with a minimum age of 6 years at the end of the follow-up period following bilateral fronto-orbital remodelling, were included. The average age at which the procedure was performed was 29 months with a minimum of 3 months and a maximum of 7.8 years. The study presented shows a pneumatization of the frontal sinus in 72.7% of 33 patients following bilateral fronto-orbital advancement. The first radiographic signs of sinus development were detected between the ages of 4 and 11, average 8.3 years. There were no statistically proven correlations between frontal sinus pneumatization and age at operation or the amount of advancement or sex of the patients. Surgical enlargement of the cranium by frontal advancement with adequate stabilization results in an enlargement of the neurocranium, thereby decreasing pressure on the inner frontal cortex and allowing frontal sinus pneumatization to proceed normally. Hence, the development of a frontal sinus may be a reflection of the effectiveness of the surgical therapy.

The pterygoid hamulus as a pain-inducing factor. A report of a case and a radiographic study.

A case is reported of a patient suffering from untraceable pain in the palate. The hyperplastic pterygoid hamulus appeared to be the cause of his discomfort. A computed tomography study on 20 adult patients revealed a wide variation in the anatomy of this region, but a fairly consistent pattern in the left-right relationship in the same patient.

Stability analysis of fixed points via chaos control.

This paper reviews recent advances in the application of chaos control techniques to the stability analysis of two-dimensional dynamical systems. We demonstrate how the system's response to one or multiple feedback controllers can be utilized to calculate the characteristic multipliers associated with an unstable periodic orbit. The experimental results, obtained for a single and two coupled diode resonators, agree well with the presented theory. (c) 1997 American Institute of Physics.

Stochastic resonance in coupled nonlinear dynamic elements.

We investigate the response of a linear chain of diffusively coupled diode resonators under the influence of thermal noise. We also examine the connection between spatiotemporal stochastic resonance and the presence of kink-antikink pairs in the array. The interplay of nucleation rates and kink speeds is briefly addressed. The experimental results are supplemented with simulations on a coupled map lattice. We furthermore present analytical results for the synchronization and signal processing properties of a Phi(4) field theory and explore the effects of various forms of nonlinear coupling. (c) 1998 American Institute of Physics.

Pregnancy and Birth After a Two-Step PGD: Polar Body Diagnosis for Hemophilia A and Array CGH on Trophectoderm Cells for Chromosomal Aberrations.

Objective: To demonstrate that a PGD program can be successfully established after the 2011 verdict of the German Bundestag concerning PGD. Material and Method: Eight years previously, the couple had had a daughter who suffered from clinically manifest hemophilia A due to an unbalanced X-inactivation, as well as microdeletion syndrome resulting in severe physical and mental disability. The couple wished to have a second child but refused the idea of a "trial" pregnancy. Given the indications for both, it was necessary to carry out polar body diagnosis (PBD) to rule out hemophilia A and, during the same cycle, a subsequent PGD on the blastocysts to rule out genetic aberrations. The PBD and PGD (trophectoderm biopsy, TEB) were performed after high-dosage ovarian stimulation and ICSI fertilization of the oocytes. A blastocyst was successfully transferred on day 6. Results: The patient conceived immediately. The pregnancy developed normally and the patient gave birth to a girl in the 40th week of pregnancy. Post-natal examinations showed that the baby is free from hemophilia A and is developing normally both physically and mentally. Conclusion: Establishment of a PGD program is now possible after legalization of PGD in Germany. It is possible to apply two investigative techniques in a single treatment cycle if multifactorial diagnosis is required.

A conserved ubiquitin ligase of the nuclear envelope/endoplasmic reticulum that functions in both ER-associated and Matalpha2 repressor degradation.

Substrate discrimination in the ubiquitin-proteasome system is believed to be dictated by specific combinations of ubiquitin-protein ligases (E3s) and ubiquitin-conjugating enzymes (E2s). Here we identify Doa10/Ssm4 as a yeast E3 that is embedded in the endoplasmic reticulum (ER)/nuclear envelope yet can target the soluble transcription factor Matalpha2. Doa10 contains an unusual RING finger, which has ubiquitin-ligase activity in vitro and is essential in vivo for degradation of alpha2 via its Deg1 degradation signal. Doa10 functions with two E2s, Ubc6 and Ubc7, to ubiquitinate Deg1-bearing substrates, and it is also required for the degradation of at least one ER membrane protein. Interestingly, different short-lived ER proteins show distinct requirements for Doa10 and another ER-localized E3, Hrd1. Nevertheless, the two E3s overlap in function: A doa10Delta hrd1Delta mutant is far more sensitive to cadmium relative to either single mutant and displays strong constitutive induction of the unfolded protein response; this suggests a role for both E3s in eliminating aberrant ER proteins. The likely human ortholog of DOA10 is in the cri-du-chat syndrome critical region on chromosome 5p, suggesting that defective ubiquitin ligation might contribute to this common genetic disorder.

[Serum lipase and amylase activity after endoscopic retrograde pancreatography (author's transl)]. / Lipase- und Amylaseaktivität im Serum nach endoskopischer retrograder Pankreatikographie

Serum activities of lipase and amylase were measured in 11 patients at short time intervals (-10 min; + 10, 30, 60 min; 2,3,4,6,8,24,48 hours) after an endoscopic retrograde pancreatography. Lipase activity increased rapidly in 9 patients in 10 min after the contrast instillation and obtained its maximum at the first hour of investigation. Amylase activity elevation occurred in 5 patients only and was significantly lower than that of lipase with a flat peak at 1-6 hours.