Effects of different perfusates on functional parameters of isolated perfused dog kidneys.

BACKGROUND: The isolated perfused canine kidney has been established as a valid model for conducting both renal physiology and transplantation research. This model is of particular importance for developing new strategies to improve graft function after renal transplantation. In the present study, a newly developed method using isolated haemoperfused porcine kidneys was adapted for use in canine kidneys. In contrast to haemoperfusion, synthetic perfusion media can be standardized and can prevent the initiation of blood-mediated reperfusion reactions. Thus, an additional aim was to determine whether blood could be replaced by synthetic cell-free perfusion solutions. METHODS: Canine kidneys (n = 30) were harvested from donors euthanized in veterinary practices for causes unrelated to the present study. The kidneys were isolated and perfused with autologous blood or cell-free synthetic electrolyte buffer (Tyrode solution). During perfusion, we monitored renal perfusate flow (RPF), glomerular filtration rate (GFR), electrolyte and glucose reabsorption, oxygen consumption and urine concentration. RESULTS: Changes in perfusion medium did not affect the RPF. In contrast, GFR, urine concentration and oxygen consumption were significantly higher, whereas fractional excretion of sodium and glucose were significantly lower in blood- than in Tyrode-perfused kidneys. CONCLUSIONS: This system offers a simple model for studying whole-organ functional alterations after acute renal ischaemia. Renal function indicators were below values reported during in vivo physiological conditions. These functions were better conserved when kidneys were perfused with autologous blood than with Tyrode.     

Acquired dyschromatopsia in combined exposure to solvents and alcohol

Hypothesis: Does occupational exposure to solvents in combination with alcohol intake give rise to acquired color vision defects? Method: A total of 138 individuals exposed to solvents (toluene, xylene, trichloroethylene, tetrachloroethylene) were examined using Lanthony’s D-15 test and compared with 100 nonexposed controls. The extent of color vision loss was quantitatively assessed based on Bowman’s color confusion index (CCI). A cumulative exposure index was calculated from the hours of exposure per day and the years of exposure. In 30 persons who were exposed to trichloroethylene and tetrachloroethylene, urinary trichloroacetic acid was assessed as a parameter of exposure. Alcohol intake was calculated as based on interviews of patients in grams of ethyl alcohol per week. Results: Individuals who consumed more than 250 g alcohol/week and were simultaneously exposed to solvents showed a significantly elevated CCI (P = 0.0044). No significant correlation emerged between trichloroacetid acid excretion in the urine or the cumulative exposure index and the CCI. Conclusion: The combination of alcohol intake and occupational exposure to solvents discloses the risk of acquired subclinical color vision defects.     

Postictal Language Dysfunction in Patients with Right or Bilateral Hemispheric Language Localization

Summary: Purpose : As shown previously, when temporal lobe complex partial seizures (TLCPS) originate from the language dominant hemisphere, patients cannot read a test phrase correctly within 60 s of the end of the ictal discharge. We wished to assess whether postictal language testing results discordant with this pattern identified patients with non-left (right hemisphere or mixed) language dominance.
Methods : Since 1988, all patients undergoing video/EEG monitoring at our institution have been given a test phrase to read aloud as soon as a seizure is detected. Inclusion criteria for this study were (a) postictal language testing within 60 s of seizure end for at least one TLCPS, (b) >90% seizure reduction after anterior temporal lobectomy with 2-year minimum follow- follow- up, and (c) language localization by either intracarotid amobarbital test (IAT) or direct electrical stimulation of left hemisphere cortex.
Results : Two hundred twenty-four seizures in 64 patients were analyzed. Discordant postictal language patterns were noted in 10 of 11 patients with IAT documented non-left language dominance and in 15 of 53 with left dominance (p = 0.006; sensitivity 90.9%, specificity 71.7%).
Conclusions : Postictal language testing accurately identifies patients with non-left language dominance and may be useful in selecting appropriate patients for IAT.     

Quantitative and comparative study of haematoporphyrin-derived photosensitizers on a murine tumour model

Eight commercially available HPD-photosensitizers intended for photodynamic therapy were tested in a murine tumour model with regard to their therapeutic efficacy. The regrowth delay of the fibrosarcoma SSK-2 on the mouse C3H, Neuherberg-line, was determined 3, 24, 48 and 72 h after injection of the drugs (dose: 9 mg kg^–1 body weight). The corresponding pharmacodynamics, as measured by regrowth delay, were approximated by an exponential function and the characterizing coefficients derived. These coefficients served to quantify the photodynamic properties of the drugs.The pharmacodynamics of five substances were compared with those obtained fluorometrically. The latter showed shorter decay constants than the therapy-correlated substances which indicates different metabolic behaviour of the therapeutic and diagnostically useful fluorescent components of haematoporphyrin-derived photosensitizers.     

A correlation with type of sulfonamide resistance gene in Escherichia coli and synergy between trimethoprim and sulfamethoxazole.

Plasmids carrying type I or II sulfonamide-resistance (Sur) genes were evaluated for their effect on synergy between trimethoprim (Tmp) and sulfamethoxyzole (Smx) in E. coli. Strain J53 containing each of three plasmids (R1, pSa, and R388) with the type I Sur gene displayed a synergistic response to Tmp/Smx; strain LE392 containing a plasmid (RSF1010) with the type II Sur gene displayed no synergy. The difference in synergy between type I and type II Sur genes might be explained by the difference in amount of resistant enzyme produced.     

Evaluation of the impedance tonometers TGDc-01 and iCare according to the international ocular tonometer standards ISO 8612

BACKGROUND: Two new tonometers have been introduced that are based on the impedance principle. Both the TGDc-01 (transpalpebral measurement) and the iCare (corneal measurement) do not require corneal anaesthesia. The present work presents an evaluation of both devices. METHODS: Comparative measurements using one of the new tonometers and applanation tonometry were performed by one investigator according to the international standard for ocular tonometer (ISO 8612). Measurements were performed on 445 eyes without corneal pathology from 243 patients. Six measurements were performed for iCare and 3 for TGDc, immediately followed by 3 applanation tonometry measurements. RESULTS: The correlation coefficient with respect to applanation tonometry was 0.81 for TGDc and 0.95 for iCare. TGDc-01 measurements showed an average deviation of 3.1 +/- 2.6 mmHg to those of Perkins applanation tonometry. The maximum difference was 28.7 mmHg below and 9.8 mmHg above the results of applanation tonometry. iCare showed an average deviation of 2.5 +/- 1.1 mmHg to Goldmann tonometry. The maximum difference was 14.5 mmHg below and 9.8 mmHg above. CONCLUSIONS: The results of both new tonometers showed a good correlation with the reference applanation tonometric methods, but the strict requirements of ISO 8612 are not fulfilled by either tonometer at present. Additionally, transpalpebral measurements with the TGDc-01 showed unacceptably high variability.     

PET examination of [11C]NNC 687 and [11C]NNC 756 as new radioligands for the D1-dopamine receptor

The benzazepines NNC 687 and NNC 756 have in animal studies been described as selective D₁-dopamine receptor antagonists. Both compounds have been labeled with¹¹C for examination by positron emission tomography (PET). In the present study central receptor binding was studied in monkeys and healthy men. After IV injection of both radioligands in Cynomolgus monkeys radioactivity accumulated markedly in the striatum, a region with a high density of D₁-dopamine receptors. This striatal uptake was displaced by high doses of the selective D₁-antagonist SCH 23390 (2 mg/kg) but not by the 5HT₂-antagonist ketanserin (1.5 mg/kg) or the selective D₂-antagonist raclopride (3 mg/kg). The cortical uptake after injection of [¹¹C]NNC 687 was not reduced in displacement experiments with ketanserin. The cortical uptake of [¹¹C]NNC 756 was reduced in displacement and protection experiments with ketanserin by 24–28% (1.5 mg/kg), whereas no reduction could be demonstrated on striatal uptake. In healthy males both compounds accumulated markedly in the striatum. For [¹¹C]NNC 687 the ratio of radioactivity in the putamen to cerebellum was about 1.5. For [¹¹C]NNC 756 the ratio was about 5. This ratio of 5 for [¹¹C]NNC 756 is the highest obtained so far for PET radioligands for the D₁-dopamine receptor.