Selective complexation of divalent cations by a cyclic α,ß-peptoid hexamer: a spectroscopic and computational study.

We describe the qualitative and quantitative analysis of the complexation properties towards cations of a cyclic peptoid hexamer composed of alternating α- and ß-peptoid monomers, which bear exclusively chiral (S)-phenylethyl side chains (spe) that have no noticeable chelating properties. The binding of a series of monovalent and divalent cations was assessed by 1H NMR, circular dichroism, fluorescence and molecular modelling. In contrast to previous studies on cations binding by 18-membered α-cyclopeptoid hexamers, the 21-membered cyclopeptoid cP1 did not complex monovalent cations (Na+, K+, Ag+) but showed selectivity for divalent cations (Ca2+, Ba2+, Sr2+ and Mg2+). Hexacoordinated C-3 symmetrical complexes were demonstrated for divalent cations with ionic radii around 1 Å (Ca2+ and Ba2+), while 5-coordination is preferred for divalent cations with larger (Ba2+) or smaller ionic radii (Mg2+).

Location of adrenal medullary pheochromocytoma by I-123 metaiodobenzylguanidine SPECT.

This is a retrospective study evaluating the efficacy of SPECT in the location of pheochromocytoma. Thirty patients with a suspected pheochromocytoma underwent I-123 metaiodobenzylguanidine (I-123 MIBG) SPECT 4 and 22 hours after intravenous injection of 370 MBq I-123 MIBG. SPECT was compared with planar scintigraphy, CT scanning, histology, and clinical course. Twenty-two-hour I-123 MIBG SPECT correctly identified 10 patients with adrenal medullary pheochromocytoma and correctly excluded pheochromocytoma in 19 patients. The sensitivity of the 22-hour MIBG SPECT was 1.00 and the specificity was 0.95. The positive predictive value was 0.95 and the negative predictive value was 1.00. In 16 patients, planar scintigraphy was compared with SPECT. SPECT located normal adrenal glands and tumors with greater confidence in three dimensions, but the patients with adrenal medullary pheochromocytoma were all correctly identified by planar scintigraphy. The results of SPECT and CT agreed in 29 of 30 patients (96.7%). I-123 MIBG SPECT for the location of pheochromocytoma has a high sensitivity, specificity, and positive and negative predictive values. I-123 MIBG SPECT or CT scanning alone were equally good for locating adrenal medullary pheochromocytoma but the combination of MIBG SPECT and CT makes it possible to distinguish between functioning and nonfunctioning adenomas. I-123 MIBG SPECT may be used alone or in combination with planar scintigraphy when three-dimensional location of a lesion is wanted.

[Patient assessment in ambulatory surgery. A questionnaire study]. / Patientevaluering af sammedagskirurgi. En enqueteundersøgelse.

In our department, from the beginning of December 1994 to the end of February 1995, we operated upon a selected group of 199 patients, hospitalized as day surgery patients. Each patient was given a questionnaire to fill in after discharge. We asked them to evaluate day surgery from the consumer's point of view. We did not record any data which could identify the single patient. We received 158 questionnaires (79%) of which 151 were accepted. One hundred and seven patients (71%) found day surgery acceptable and a good alternative to conventional hospitalization, 82% preferred having the same doctor and primary nursing during the treatment. One hundred and sixteen patients were discharged as planned (77%). There were no serious complications. Provided that patients are carefully selected, we find day surgery a highly satisfactory method of management which is safe and efficient.

Renal and extrarenal clearance of 99mTc-MAG3: a comparison with 125I-OIH and 51Cr-EDTA in patients representing all levels of glomerular filtration rate.

. This investigation was undertaken in order to determine whether the clearance of technetium-99m mercaptoacetyltriglycine (99mTc-MAG3) is more closely correlated to the clearance of iodine-125 orthoiodohippurate (125I-OIH) than to the clearance of chromium-51 ethylene diamine tetra-acetate (51Cr-EDTA) and whether there is a clinically significant extrarenal clearance of 99mTc-MAG3 . Fifty-one patients with a glomerular filtration rate (GFR) of 4-132ml/min were studied. After a simultaneous single injection of the three tracers, plasma clearance was measured from blood samples 0-5h post injection (p.i.) (0-24h in patients with GFR<15ml/min). Renal plasma clearance was measured 0-5h p.i. The ratio between the renal plasma clearance of 99mTc-MAG3 and 125I-OIH was 0.57. The ratio between the renal plasma clearance of 99mTc-MAG3 and 51Cr-EDTA was 2.57. The coefficient of variation (CV) of the 99mTc-MAG3/125I-OIH ratio was significantly smaller than the CV of the 99mTc-MAG3/51Cr-EDTA ratio (13.4% versus 31.2%). The corresponding plasma clearance ratios were 0.59 (CV=14.8%) and 2.48 (CV=27.0%). Plasma clearance overestimated renal plasma clearance by 7.0ml/min (5.4%) for 99mTc-MAG3 and by 4.1ml/min (8.4%) for 51Cr-EDTA. The difference in plasma and renal plasma clearance of 125I-OIH of 5.5ml/min did not reach statistical significance. Red blood cell binding of 99mTc-MAG3, 125I-OIH and 51Cr-EDTA was 2.0%, 14.6% and 0.2%, respectively. Protein binding of 99mTc-MAG3, 125I-OIH and 51Cr-EDTA was 86.3%, 61.1% and 5.9%, respectively. The volume of distribution of 99mTc-MAG3, 125I-OIH and 51Cr-EDTA was 16.3%, 27.0% and 19.4% of body weight. In conclusion, the clearances of 99mTc-MAG3 and 125I-OIH are more closely correlated than is the clearance of 99mTc-MAG3 with GFR. Extrarenal clearance of 99mTc-MAG3 is relatively smaller than extrarenal clearance of 51Cr-EDTA. Thus, plasma clearance of 99mTc-MAG3 can be used as a measure of renal tubular function.

99mTc-MAG3 kinetics in the normal pig. A comparison to 131I-OIH and 125I-iothalamate after single injection and during continuous infusion.

An invasive comparative study of some pharmacokinetic aspects of 99mTc-mercaptoacetyltriglycine (MAG3), 131I-orthoiodohippurate (OIH), and 125I-iothalamate (iothalamate) was performed in six pigs 0-150 min after a simultaneous single injection (SI) and during a subsequent 90 min of continuous infusion (CI). The total plasma clearance and the renal clearance of MAG3 were about 75% that of OIH. The renal clearance of MAG3 was about 2 1/2 times the glomerular filtration rate. The distribution volume of MAG3 was 71% that of iothalamate and only 47% that of OIH. There was a significant hepatic plasma clearance of MAG3 of 5.9 ml min-1 and 3.9% of the injected dose was excreted in the bile. HPLC analysis revealed that technetium was excreted in urine and bile mainly labelled to MAG3. The average red blood cell (RBC) binding after single injection/during continuous infusion was 1.0%/2.3% for MAG3, 13.5%/9.0% for OIH, and 3.1%/5.3% for iothalamate. The binding of OIH to RBC in arterial blood increased from 8% at 1 min post-injection to 21% at 150 min post-injection. The RBC binding was higher in the renal vein, indicating incomplete back diffusion from RBC to plasma. The protein binding was 90% for MAG3, 49% for OIH and 16% for iothalamate. The renal plasma extraction of MAG3 was constant but significantly smaller after SI (0.54) than during CI (0.62). Following SI, the renal plasma extraction of OIH decreased continuously from 0.85 to 0.52, 3-150 min post-injection. On the average there was no significant difference in renal plasma extraction after SI and during CI of either OIH (0.72 versus 0.77) or iothalamate (0.26 versus 0.27). It is concluded that MAG3 is preferential to OIH as a tracer for renal function studies using a single injection technique mainly due to the constant renal extraction of MAG3.

Detection of rhinorrhoea by cisternography in combination with single photon emission tomography, following lumbar injection of iodine-123-labelled albumin.

Eight patients were examined. Seven had verified rhinorrhoea and six had had one or more episodes of pneumococcal meningitis. In four of the patients a fistula could not be visualized by computed tomography. All eight patients had injections of iodine-123-labelled albumin by lumbar puncture. Tomoscintigraphy (SPET) was performed 3, 6 and 8-9 h after injection. After 6-8 h we were able to demonstrate a fistula in seven of the patients with verified rhinorrhoea and the findings were confirmed by a subsequent operation. In one of the patients we were not able to visualize any leak of cerebrospinal fluid into the nasal cavity. This patient was not operated upon and we were not able to verify the findings in this patient. The operated patients all did well after the operation with no relapse of meningitis. In conclusion, SPECT-cisternography after intralumbar injection of iodine-123-labelled albumin is a valuable diagnostic tool for the detection of small fistulae in patients with rhinorrhea.

Peripartum cardiomyopathy.

Peripartum cardiomyopathy is a rare form of heart disease with a high mortality rate. We report a case, refractory to intensive medical treatment, with a fatal issue 5 months post partum. In recent years the literature has provided examples of the beneficial effect of immunosuppressive therapy, either Azathioprine combined with prednisone, or prednisone alone.

The effect of dietary protein content upon growth in a genetically heterogeneous population of mice.

The effect of different dietary protein contents (19.3%, 14.9%, 11.0% and 5.7%) on weight gain was investigated in a genetically heterogeneous population of mice. Significant difference in weight gain was found only in the early growth period and was due mainly to the reduced weight gain of mice fed the diet with the lowest protein content. Feeding the mice low protein diets during the growth period did not affect reproductive performance.

Detection of early "significant" antibody responses in paired sera by the use of an automated bovine parainfluenza-3 hemagglutination-inhibition system.

An automated bovine parainfluenza-3 hemagglutination-inhibition system was used to detect small increases (15--20%) in specific antibody titer between paired bovine sera collected three days apart. Automated and manual parainfluenza-3 hemagglutination-inhibition test procedures were compared as methods for the serologic diagnosis of parainfluenza-3 infection. Fifteen daily serum specimens from each of three animals were analyzed as various possible manual-test and automated-test serum pairs. With the sera from two of the animals, considered to be parainfluenza-3 hemagglutination-inhibition-positive, the manual microtiter test procedure made 18 (69%) false negative diagnoses when using the standard manual-test criteria for "evidence of infection." When a 20% titer increase between three-day serum pairs was considered "serologically significant," the automated system made three (17%) false-negative diagnoses. At a 15% "serologically significant" increase, no false-negative diagnosis was made. The utilization of automated serology for the routine diagnosis of disease should permit treatment and control measures to be initiated early, thereby reducing losses due to infectious disease.