Electrochemical degradation of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in groundwater.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) represent hazardous pollutants and are frequently detected in the environment, e.g. in contaminated groundwater. PFASs are persistent to biodegradation and conventional oxidation processes such as ozonation. In this study electrochemical degradation of PFASs on boron-doped diamond (BDD) electrodes is demonstrated. Experiments were performed with model solutions and contaminated groundwater with a dissolved organic carbon (DOC) content of 13 mg/L. The perfluorinated carboxylic acids (PFCAs) perfluorobutanoate, perfluoropentanoate, perfluorohexanoate, perfluoroheptanoate and perfluorooctanoate, and the perfluorinated sulfonic acids (PFSAs) perfluorobutane sulfonate, perfluorohexane sulfonate, perfluorooctane sulfonate and 6:2 fluorotelomer sulfonate were detected in the groundwater samples. At PFAS concentrations ranging from 0.26 to 34 mg/L (0.7 to 79 µM), the degradation of PFASs was achieved despite of the high DOC background. Pseudo first-order kinetic constants of PFSA degradation increased with the increase of carbon chain length. Fluoride formation as well as the generation of PFCAs with shortened chain lengths was observed. Inorganic byproducts such as perchlorate were also formed and have to be considered in further process optimization.

Oral bioavailability of P-glycoprotein substrate drugs do not differ between ABCB1-1Δ and ABCB1 wild type dogs.

Previous studies have indicated that intestinal P-glycoprotein (P-gp) limits the oral bioavailability of substrate drugs and alters systemic pharmacokinetics. In this study, dogs lacking functional P-gp were used to determine the contribution of P-gp to the oral bioavailability and systemic pharmacokinetics of several P-gp substrate drugs. The P-gp substrates quinidine, loperamide, nelfinavir, cyclosporin and the control (non P-gp substrate) drug diazepam were individually administered intravenously and per os to ABCB1-1Δ dogs, which have a P-gp null phenotype and ABCB1 wildtype dogs. ABCB1-1Δ dogs have been shown to have greater brain penetration of P-gp substrates, but limited information is available regarding oral bioavailability of P-gp substrate drugs in this animal model. Plasma drug concentration vs. time curves were generated and pharmacokinetic parameters were calculated for each drug. There were no differences in oral bioavailability between ABCB1-1Δ dogs and ABCB1 wildtype dogs for any of the drugs studied, suggesting that intestinal P-gp does not significantly affect intestinal absorption of these particular substrate drugs in ABCB1-1Δ dogs. However, small sample sizes and individual variability in CYP enzyme activity may have affected the power of the study to detect the impact of P-gp on oral bioavailability.

Natural attenuation of chloroethenes: identification of sequential reductive/oxidative biodegradation by microcosm studies.

A different lines of evidence approach for investigation of biodegradation processes at a chloroethene contaminated site showed well corresponding results of pollutant profiles, redox zonation, characterisation of autochthonic microflora and microcosm studies. In particular microcosm studies allowed identification of the predominating degradation pathways. Perchloroethene and trichloroethene are reductively chlorinated to mainly cis-1,2-dichloroethene (cDCE) under anaerobic conditions. Further reductive degradation to vinyl chloride (VC) is restricted to a distinct strongly anaerobic zone in the plume. Addition of high amounts of sediment material (80 vol%) to groundwater microcosms enabled reductive dechlorination without amendment with further auxiliary substrates. Reductive dechlorination was not irreversibly hindered by initially high nitrate concentrations and initially high oxidation-reduction potential. The products of anaerobic degradation cDCE and VC are subsequently aerobically mineralised, even when only low oxygen concentrations are available. Anaerobic oxidative degradation could not be proven in this study.

Disruption of DMD and deletion of ACSL4 causing developmental delay, hypotonia, and multiple congenital anomalies.

We have studied a male patient with significant developmental delay, growth failure, hypotonia, girdle weakness, microcephaly, and multiple congenital anomalies including atrial (ASD) and ventricular (VSD) septal defects. Detailed cytogenetic and molecular analyses revealed three de novo X chromosome aberrations and a karyotype 46,Y,der(X)inv(X) (p11.4q11.2)inv(X)(q11.2q21.32 approximately q22.2)del(X)(q22.3q22.3) was determined. The three X chromosome aberrations in the patient include: a pericentric inversion (inv 1) that disrupted the Duchenne muscular dystrophy (DMD) gene, dystrophin, at Xp11.4; an Xq11.2q21.32 approximately q22.2 paracentric inversion (inv 2) putatively affecting no genes; and an interstitial deletion at Xq22.3 that results in functional nullisomy of several known genes, including a gene previously associated with X-linked nonsyndromic mental retardation, acyl-CoA synthetase long chain family member 4 (ACSL4). These findings suggest that the disruption of DMD and the absence of ACSL4 in the patient are responsible for neuromuscular disease and cognitive impairment.

LC-MS/MS detection of peroxynitrite-derived 3-nitrotyrosine in rat microvessels.

3-Nitrotyrosine (3NT) is used as a biomarker of nitrative pathology caused by peroxynitrite (PN), myeloperoxidase (MPO)-, and/or eosinophil peroxidase (EPO)-dependent nitrite oxidation. 3NT measurements in biological materials are usually based on either antibody staining, HPLC detection, or GC detection methodologies. In this report, a procedure is described for the measurement of 3NT and tyrosine (TYR) by LC-MS/MS that is simple, direct, and sensitive. Though highly specialized in its use as an assay, LC-MS/MS technology is available in many research centers in academia and industry. The critical assay for 3NT was linear below 100 ng/ml and the limit of detection was below 100 pg/ml. Regarding protein digested samples, we found that MRM was most selective with 133.1 m/z as the daughter ion. In comparison, LC-ECD was 100 times less sensitive. Basal levels of 3NT in extracted digests of rat brain homogenate were easily detected by LC-MS/MS, but were below detection by LC-ECD. The LC-MS/MS assay was used to detect 3NT in rat brain homogenate that was filtered through a 180 micron nylon mesh. Three fractions were collected and examined by phase contrast microscopy. The mass ratio (3NT/TYR) of 3NT in fractions of large vessel enrichment, microvessel enrichment, and vessel depletion was 0.6 ng/mg, 1.2 ng/mg, and 0.2 ng/mg, respectively. Ultimately, we found that the basal 3NT/TYR mass ratio as determined by LC-MS/MS was six times greater in microvessel-enriched brain tissue vs. tissue devoid of microvessels.

[Sonographic diagnosis of enlarged parathyroid glands in hyperparathyroidism (author's transl)]. / Sonographische Diagnostik vergrösserter Nebenschilddrüsen beim Hyperparathyreoidismus.

Fifty-nine patients suspected clinically of having primary or tertiary hyperparathyroidism have been examined since 1978 in order to localize enlarged parathyroid glands. With glands larger than 5 mm. this proved successful in about 90% of those situated in the neck. The sonographic features of enlarged parathyroid glands are poor echoes, smooth margins and the typical position on the medial and posterior surface of the thyroid gland. A requirement for diagnostic success is the use of modern compound apparatus with digital convertors and focussed high resolution probes.

[The value of sonography in the differential diagnosis of pseudotumours of the kidney (author's transl)]. / Bedeutung der Sonographie für die Differentialdiagnostik von Pseudotumoren der Niere.

Two hundred and three patients with urographic appearances suspicious of a space-occupying lesion were examined by sonography. Seventy-nine showed normal results; there were 65 cysts, 20 malignant lesions, 20 pseudo-tumours and 19 with other abnormalities such as hydronephrosis, urolithiasis and inflammatory lesions. Pseudotumours are due to varients of the structure of the kidney, which resemble space-occupying lesions in the excretory urogram. The sonogram shows them as low echo, centrally protruding structures arising from the edge of the parenchyma. Angiographically they are islands of parenchyma with normal vessels. Sonography has proved to be a necessary complement to excretion urography and provides a more certain indication for renal arteriography. Angiography can be limited to changes in the parenchyma, since sonography is able to define cystic processes.

[Pain reduction in peripheral arteriographies of the upper and lower extremities in a double blind test. Lidocain/ioglicinate versus metrizamide (author's transl)]. / Schmerzreduktion bei peripheren Arteriographien der oberen und unteren Extremität im Doppelblindversuch. Lidocain/loglicinat gegen Metrizamid.

36 aortofemoral and 18 brachial angiographies effected under standardized conditions in a double blind test in approximately two equal parts with Lidocain/Ioglicinate and Metrizamide, respectively, were evaluated with regard to vascular pain and sensation of heat during the examination. With the femoralis angiograms reduction of vascular pain was on the average somewhat greater, although this could not be established statistically when using Metrizamide. In the case of the angiogram of the arm, pain was on the average equally low in both cases. Of the 14 patients who had received injections of both contrast media in varying succession at intervals of 20 minutes, 6 patients considered the Metrizamide injection to be more agreeable, whereas 2 preferred the Lidocain/Ioglicinate injection and 6 patients did not notice any significant difference. The average sensation of heat during contrast medium visualisation of the legs and arms was equal with both substances. Lidocain/Ioglicinate and Metrizamide are approximately equally well suited for peripheral angiography of arms and legs, rendering narcosis and strapping down of the extremities unneccessary in normal cases.

[Efficacy of intra-arterial lidocaine in the control of pain in arteriography of the arm and leg (author's transl)]. / Effektivität von intraarteriellem Lidocain in der Schmerzbekämpfung bei Arm- und Beinarteriographien.

The efficacy of addition of lidocaine to the conventional contrast medium has been statistically verified by the results of angiography of 342 legs and 25 arms. The investigation is painless or only slightly painful for most patients but the feeling of heat cannot be eliminated. A higher dose of lidocaine and the preliminary injection of Valium certainly improve the results of the investigation slightly, but give rise to a higher incidence of side-effects (fall in blood pressure, sleepiness). Serious complication have not been observed even in the large number of patients with risk factors.

[The angiographic diagnosis of islet cell tumours. Results in 34 patients (author's transl)]. / Angiographische Diagnostik bei Inselzelltumoren. Ergebnisse bei 34 Patienten.

Between 1965 and 1979, 34 patients with organic hyperinsulinism were examined angiographically. By observing the following points it should be possible to diagnose tumours greater than 1 cm, whatever their position in the pancreas: 1) Use of high performance generators and tubes which permit one to employ fine focus, low kv and high mAs. 2) Optimum imaging systems (carbon fibre table top, high intensity screens). 3) Selective catheterisation, large quantities of contrast per unit time and adequate duration of the filming sequence. 4) Pharmacoangiography and subtractions may be valuable in some cases.

[Alleviation of pain via lidocain in peripheral arteriography. Further experiences (author's transl)]. / Schmerzreduktion durch Lidocain bei der peripheren Arteriographie. Weitere Erfahrungen.

On comparing an ionic contrast medium with a contrast medium containing one or two mg Lidocain/ml contrast medium, the one with the higher Lidocain addition was found to be most effective in respect of pain alleviation. The feeling of flush could not be favourably influenced. The use of a higher dose of Lidocain in the contrast medium may involve more pronounced circulatory reactions, such as drop in blood pressure and enhanced pulse rate. Besides, the rate of side effects compared with the use of the pure contrast medium and contrast medium with one mg Lidocain/ml CM will be increased. For this reason, it is not recommended to add more than 1 mg/ml Lidocain to the contrast medium. In most cases, repeat examinations can be effected without any risk with 1 mg Lidocain/ml contrast medium. No absolute contraindications were found in the application to outpatients and risk patients. Relative contraindication exists in patients with bradycardia and bradyarrhythmia. Following preliminary injection of a vasodilatory substance, the Lidocain/contrast medium mixture is well suited for arteriography in the arm.

[Carcinoid of the digestive tract. Diagnostic possibilities (author's transl)]. / Karzinoide des Verdauungstrakts. Diagnostische Möglichkeiten.

Special features which enable preoperative differential diagnosis are dealt with in detail with reference to 44 patient with carcinoid of the digestive tract. Carcinoid of the appendix becomes noticable early with signs of acute or chronic appendicitis and in 94% of cases is operated on in good time. Angiography of the superior mesenteric artery shows a characteristic stellate figure in the mesenterium in carcinoid of the small intestine. In contrast to the primary tumor, liver metastases show intense vascularization in the angiogram. A rise in urinary excretion of 5-hydroxyindole acetic acid is pathognomonic for carcinoid, its determination permits the checking of operative radicality and shows the appearance of metastases early.

[Investigations on pain reduction during peripheral angiography (author's transl)]. / Untersuchungen zur Schmerzverminderung bei der Extremitätenangiographie.

An attempt was made to reduce pain during femoral angiography by adding 1 mg. of Lidocaine/ml. contrast medium in the course of 95 examinations. In a further 87 patients, Diazepam was injected intravenously before the injection of the contrast-Lidocaine mixture. Pain and the feeling of heat was compared with a control group who received contrast medium with 10% physiological saline. There was a highly significant reduction in pain sensation as a result of Lidocaine; pain was further reduced by additional Diazepam, which also reduced heat sensation, but resulted in a fall in blood pressure. High risk patients did not suffer any significant complications. Lidocaine is well suited for out patients, but Diazepam requires a longer period of observation. General anaesthesia has been used only if patients insisted on it or if there was known contrast reaction.

[Lymphographic investigations of oedema of the extremities following reconstructive vascular surgery in the femoro-popliteal territory (author's transl)]. / Lymphangiographische Untersuchungen zum Extremitätenödem nach rekonstruktiven Gefässeingriffen im Femoropoplitealbereich.

In 37 patients, oedema of the legs was observed following successful femoro-popliteal surgery; lymphangiograms were performed between the third and ninth post-operative days and the intact lymph vessels at the knee and at the groin were counted. In 27 patients there was partial to total disruption of the lymphatic vessels. There was a clear correlation between the degree of swelling of the leg and thigh with the number of not divided lymphatic vessels at the knee and groin. In the presence of more than three intact lymph vessels, swelling amounted to only 1 to 2 cm., whereas if all lymph vessels had been divided, swelling amounted to 7 cm. Extensive soft tissue trauma and repeat surgery resulted in a greater reduction in intact lymph vessels and correspondingly more oedema than was found with more conservative surgery and after initial operations. The pre-operative condition of the arteries, the presence of venous disease and the postoperative blood-flow in the leg had no influence on postoperative oedema. In order to avoid post-operative lymphoedema, it is necessary to preserve the lymphatics during surgery. Marked oedema requires treatment consisting of compression bandages and medicaments.

[Angiographic diagnosis of small intestine carcinoids (author's transl)]. / Angiographische Diagnostik der Dünndarmkarzinoide.

A report is given on two cases of metastasizing ileum carcinoid in which the arteriography of the superior mesenteric artery and the hepatic artery lead to a correct diagnosis while no clear result could be obtained by conventional X-ray examinations (gastrointestinal passage and Irigoscopy of the colon). In the first case, the vascular alterations in the lower ileum, combined with numerous hyper-vascularized metastases in the liver allowed to diagnose the primary tumor and to determine its type. In the second case, a correct diagnosis could be made alone bacuse of the specific vascular alterations indicating the carcinoid which was growing by infiltration (vascular star, missing parenchymatous charge, belated venous drainage, in the tumor region). In one case, a second primary tumor whose growth was accompanied only by little infiltration could be early diagnosed. All diagnoses were confirmed by surgical and anatomicopathological findings. In order to ameliorate the prognosis, bad until now, by an earlier diagnosis, arteriography should be used whenever a (metastasizing) small intestine carcinoid is suspected.

[Mediastinal angiography. A helpful method to evaluate to operability of mediastinal and lung tumors (author's transl)]. / Mediastinale Phlebographie: Eine wertvolle Entscheidungshilfe zur Operabilitätsbeurteilung und Operationsplanung von Lungen- und Mediastinaltumoren.

Preoperative mediastinal angiography, as a simple method, shows alterations of pulmonary and venous mediastinal circulation. It enables the surgeon to evaluate the operability of malignant thoracic neoplasms without performance of other diagnostic procedure with a higher rate of complications, e.g. mediastinoscopy or explorative thoractomy.

[Renal perfusion during experimental hyper-acute rejection. 133-xenon perfusion compared with microscopy and angiography (author's transl)]. / Nierenperfusion bei hyperakuter xenogener abstrssung im Tierversuch. 133-Xenon-Durchblutung im Vergleich zur Mikroskopie und Angiographie.

Twenty-two cat kidneys and 11 pig kidneys were incorporated into canine circulatory systems. The delayed hyper-acute and hyper-acute rejections produced by these models were studied with respect to blood flow and blood distribution with an intra-arterial 133-xenon wash-out technique at intervals of 7-30 minutes until the death of the kidney at 40 minutes to twelve hours. In addition, magnification angiograms and serial cortical biopsies were obtained for continuous histological study of the rejection phenomenon. At the beginning of the rejection process, there is a reduction in blood-flow through the cortex. During delayed hyper-acute rejection, cortical flow could no longer be demonstrated 180 minutes after the period of flow maximum. After A.L.G. treatment of dogs, rejection could be delayed for ten to twelve hours. Magnification angiograms showed characteristic changes consisting of irregular segmental and interlobar arteries, occlusion of small cortical vessels and focal contrast accumulation in the renal cortex. The changes in blood-flow and blood distribution measured with 133-xenon and the vascular findings on the angiogram could be correlated with the microscopic findings. Serial estimations of blood flow and blood distribution with the xenon blood wash-out technique permit differentiation between shock kidney and rejection following renal transplantation.

[An approximation for improving the accuracy of compartmental analysis after intravenous 133Xe]. / Näherungsverfahren zur Erhöhung der Genauigkeit der Kompartmentanalyse nach i.v. 122Xe-Applikation

Perfusion of transplanted kidneys is studied in our clinic by intravenous injection of 133Xe with subsequent graphic compartmental analysis of time-activity curves. Where there is poor perfusion of the renal cortex, it is not possible to obtain a half-value time for the first compartment--which is the significant measure for specific blood flow -- since few points are available for the tail end of the curve. A correction is described which produces an approximation to a bolus, based on the time-activity curve of the expired air. If this is applied to the proximal part of the time-activity curve, with respect to background activity, compartmental analysis can be performed with a higher degree of accuracy in the calculation of renal perfusion.