Fish consumption and school grades in Swedish adolescents: a study of the large general population.

AIM: To study the associations between fish intake and academic achievement as cognitive parameter among Swedish adolescents. METHODS: In 2000, a questionnaire including respiratory items, socioeconomic conditions and dietary information was mailed to all schoolchildren (n = 18 158), aged 15 and living in Västra Götaland region of Sweden. The questionnaire was returned by 10 837 subjects. One year later, the total school grades for each subject who had completed the questionnaire and who included their full personal identification number were obtained from the national registers. Multiple linear regression models were applied to evaluate the association between fish intake and academic grades among 9448 schoolchildren, while adjusting for potential confounders, e.g. parents' education. RESULTS: Grades were higher in subjects with fish consumption once a week compared with subjects with fish consumption of less than once a week (reference group) [increment in estimate 14.5, 95% confidence interval (CI) 11.8-17.1]. Grades were even higher in subjects with fish consumption of more than once a week compared with the reference group (increment in estimate 19.9, 95% CI 16.5-23.3). In the model stratified for parents' education, there were still higher grades among subjects with frequent fish intake in all educational strata (p < 0.01). CONCLUSION: Frequent fish intake among schoolchildren may provide benefits in terms of academic achievement.

Morphology of chronic lymphocytic leukemia and its relationship to survival.

The morphology of lymphocytes in blood and bone marrow from patients with chronic lymphocytic leukemia was studied; blood lymphocyte morphology was related to survival. Three primary morphologic groups emerged. Group 1 was characterized by small to medium-sized lymphocytes with narrow rims of cytoplasm and coarsely clumped nuclear chromatin. In group II the predominant lymphocytes were large with abundant cytoplasm. Group III was characterized by a heterogeneous population of lymphocytes with characteristics of both groups I and II. Clinical features of the patients were studied, and B and T typing of the lymphocytes was done. The median survival in group I was 26+ months; in group II 46+ months; and in group III 50+ months. Our data are at variance with previous reports and suggest that survival in patients with large lymphocytes is longer than in those with small lymphocytes.

Bis-cationic heteroaromatics as macrofilaricides: synthesis of bis-amidine and bis-guanylhydrazone derivatives of substituted imidazo[1,2-a]pyridines.

A series of guanylhydrazone, amidine, and hydrazone derivatives of 2-phenylimidazo[1,2-a]pyridine have been prepared and evaluated for macrofilarial activity against Acanthocheilonema viteae and Brugia pahangi in jirds. Compounds with 4',6-bis-substitution by cyclic guanylhydrazone groups show activity. 4',6-Bis-amidines show some activity but are more toxic; 4'- or 6-monosubstituted compounds are inactive. 2,6-Bis-substituted compounds lacking the phenyl ring are inactive. 4',6-Bis-substituted compounds having additional double bonds inserted between the heterocyclic ring and the phenyl ring or between the substituent and the ring system show reduced activity.

Cationic antiprotozoal drugs. Trypanocidal activity of 2-(4'-formylphenyl)imidazo[1,2-a]pyridinium guanylhydrazones and related derivatives of quaternary heteroaromatic compounds.

A series of quaternary 2-phenylimidazo[1,2-a]pyridinum salts has been prepared and evaluated for antiparasitic activity. Primary attention was focused on derivatives with amido, substituted hydrazone, and heterocyclic functionality at the para position of the phenyl substituent. Guanylhydrazones and N-substituted guanylhydrazones of the 4'-formyl-substituted compounds are very active against the blood state Trypanosoma rhodesiense in mice by subcutaneous or oral administration. The most potent compounds attain 100% survival for 30 days at doses of less than 1.0 mg/kg (sc) and greater than 5.0 mg/kg (po). Weaker activity is noted for certain other 4'-substituents such as carboxamidines and carboxamide oximes. Considerable variation in structure, including replacing of the imidazo [1,2-a]pyridinium ring by other cationic heterocyclic rings and insertion of linking groups between the heterocyclic ring and phenyl group, can be done, and a high level of activity is maintained. Relationships between these structural changes and biological activity are discussed.

The function of a colloid in liver cold-storage preservation.

The value of colloid in preservation of the liver by cold storage has not yet been fully clarified. Therefore, we studied the effects of colloid on cell swelling, liver weight, and bile production after cold storage in rat liver tissue slices and isolated rabbit liver. In rat liver tissue slices cold-stored for 24 hr in UW solution, total tissue water (TTW) was the same as in the control freshly unpreserved tissue and omitting the colloid (hydroxyethyl starch) from the UW solution did not affect the TTW. However, after cold storage for 24 hr in Perfadex, TTW was markedly increased (by 100%, P less than 0.001). Omitting the colloid in this solution, dextran, or replacing it with hydroxyethyl starch, did not affect this increase in TTW. Thus, the hypothermia-induced cell swelling evident after preservation in Perfadex was not prevented by colloid. Rabbit liver cold-stored in UW solution for 24 hr lost 15.4 +/- 4.7% of weight, but omitting the colloid from UW solution decreased this weight loss to 3.1 +/- 3% (P less than 0.01). In contrast, rabbit livers cold-preserved in colloid-free Perfadex gained 23.3 +/- 5.7% in weight. Adding colloid, either dextran or hydroxyethyl starch, decreased significantly this weight gain, to 9 +/- 3.7% and 10.4 +/- 1.8%, respectively (P less than 0.01), probably as a result of colloid osmotic pressure, preventing the interstitial edema. Rabbit livers preserved for 24 hr in UW solution, with or without colloid, produced the same amount of bile as control unpreserved livers. In contrast, livers preserved in colloid-free Perfadex for 24 hr had a markedly impaired bile production (3.9 +/- 0.9 ml/100 g) as compared with control livers (15.5 +/- 2.6 ml/100 g, P less than 0.01). Colloid partially restored this impaired bile production, to 8 +/- 1.4 mg/100 g by dextran and to 8.5 +/- 1.7 ml/100 g by hydroxyethyl starch, respectively (P less than 0.01). Thus, although colloids do not prevent the hypothermia-induced cell swelling, they prevent the development of interstitial edema, and, hence, improve the liver function.

A new dextran 40-based solution for liver preservation.

UW solution is at present the most efficient solution for preservation of livers for transplantation. We have developed an alternative solution based on dextran instead of hydroxyethyl starch and without raffinose, allopurinol, magnesium sulfate, insulin, penicillin, or dexamethasone, which all are used in UW solution. In addition, 62.5 mM potassium in UW solution is replaced with sodium. We tested this new solution for liver preservation using the isolated perfused rabbit liver. We found that livers preserved in the UW solution for 24 or 48 hr lost 11.6 +/- 2.6% and 16.8 +/- 2.0% of the prepreservation weight, respectively, as a sign of organ shrinkage (P less than 0.001). In contrast, no change in liver weight was observed after preservation in the new dextran-based solution. Similarly, no change in total tissue water of the rat liver slices was seen after preservation in the new solution. Furthermore, livers preserved for 24 hr in the UW solution or the new solution produced the same amount of bile as unpreserved livers. However, after preservation in the UW solution for 48 hr, bile production was reduced by 65% (P less than 0.05). In contrast, livers preserved for 48 hr in the new solution showed no reduction in bile production. We conclude that our new solution significantly improves long-term liver preservation, and with this modified solution, 48-hr preservation may be safe.

Improvement of liver preservation quality with UW solution by chlorpromazine pretreatment of the donor in an experimental model.

We investigated the effect of donor pretreatment with chlorpromazine (CPZ), in rabbit livers cold-stored in University of Wisconsin (UW) cold storage solution for 48 hr. Three groups of livers were investigated: livers flushed with Perfadex and immediately thereafter reperfused on an isolated circuit (controls), and livers cold stored in UW solution for 48 hr, with or without donor pretreatment with CPZ, 3 mg/kg. After preservation, reperfusion was performed in vitro, using an isolated circuit (IPL). The reperfusion medium consisted of an oxygenated Krebs-Henseleit bicarbonate solution supplemented with 5 mM glucose, 50 mg/L of streptomycin and penicillin G, and 3.5% Dextran 60 for oncotic support. Livers that were not pretreated with CPZ produced 5.3 +/- 1.2 ml bile/100 g (mean +/- SD) during 2 hr of IPL reperfusion. CPZ donor pretreatment significantly improved the bile flow to 17.1 +/- 6.9 ml (P less than 0.01, Wilcoxon). This figure was not different from that in control livers without a storage period (18.3 +/- 3.8 ml). Alanine aspartate aminotransferase (ASAT) released into the perfusate was measured, and levels were increasing during 2 hr of reperfusion. ASAT values were moderately increased in the preserved groups compared with controls (P less than 0.01), with no discernible differences between livers with and without CPZ pretreatment. It is concluded that CPZ pretreatment of the donor improves preservation quality, as evidenced by improved bile formation. The present results suggest that 48 hr cold storage in UW solution may be safe for clinical preservation, if donors are pretreated with chlorpromazine.

An analysis of the components in UW solution using the isolated perfused rabbit liver.

The isolated perfused rabbit liver model has been used to determine the essential components of the UW solution for hepatic preservation by simple cold storage. Livers were stored on ice for 48 hr after initial flushing with the solution being tested, and then reperfused at 38 degrees C in an isolated perfusion circuit; bile flow and enzyme (SGOT, SGPT, and LDH) release during a 2-hr period were recorded. All solutions tested contained phosphate (25 mM) as a buffer and magnesium sulfate (5 mM). Sodium can be substituted for potassium without adverse effects. Lactobionate, raffinose and glutathione cannot be omitted; all other components can be eliminated without altering the effectiveness of the solution in this model.

Preservation of the canine liver for 24-48 hours using simple cold storage with UW solution.

The results of a series of 29 orthotopic liver transplants in the dog are described. The livers were preserved in a new cold storage fluid, UW solution, and were successfully transplanted after periods of storage of 24, 30, 36, and 48 hr. All six animals transplanted after 24 hr survived beyond 5 days after transplantation and had excellent graft function. Four of six survived for at least 5 days after 30 hr of cold storage, and five of five after 36 hr. Five of six consecutive dogs that received transplants that had been cold-stored for 48 hr survived for 5 or more days. This solution represents a substantial advance over all existing cold storage solutions for liver preservation.

The "critical colloid dose" in studies of reticuloendothelial function.

The [99mTc]sulfur colloid distribution in rat organs was investigated after the administration of different amounts of colloid particles. Saturation of the liver and spleen was not observed. Blood clearance was significantly reduced 15 min after injection above approximately 3 X 10(9) particles per kg body weight. With an increasing number of injected particles, lung uptake increased and bone marrow uptake decreased. Microfiltration studies showed that the colloid is unaffected by dilution with saline but may be affected after incubation in normal rat plasma. We conclude that the distribution of [99Tc]sulfur colloid in organs varies with the number of injected particles and therefore, is not dependent upon the blood flow to the reticuloendothelial organs alone. The "critical colloid dose" may differ among the reticuloendothelial organs and cannot, therefore, be evaluated by blood clearance measurements alone. The considerable influence of the number of injected colloid particles on bone marrow uptake should also be recognized when carrying out dosimetric calculations.

Cryptosporidial enteritis and pneumocystis pneumonia in a homosexual man.

The case of a 44-year-old homosexual man with cryptosporidial enteritis associated with multiple opportunistic infections and increased T-suppressor cells is reported. This case calls attention to cryptosporidia as the cause of unremitting diarrhea in homosexual men with the syndrome of opportunistic infectious disease associated with acquired immunodeficiency.

Bone marrow aspiration and trephine biopsy. An approach to a thorough study.

Recent advances in the treatment of hematologic malignancies have been paralleled by renewed interest on the part of pathologists and hematologists in methods of obtaining and preparing bone marrow for diagnostic studies. A thorough bone marrow morphologic study involves examination of peripheral blood smears, direct, particle, and buffy coat bone marrow smears, trephine biopsy imprints, particle and trephine biopsy sections, and marrow volumetric data. The information obtained from the study of these various specimens is complementary. Frequently it is a combination of clues gathered from examination of several different preparations that leads to a correct diagnosis. Utilization of biopsy material by the methods described provides complete, accurate and reproducible information and minimizes the necessity for repeating a biopsy for morphologic diagnosis or ancillary studies.

Synthesis and evaluation of 2-diazo-3,3,3-trifluopropanoyl derivatives of colchicine and podophyllotoxin as photoaffinity labels: reactivity, photochemistry, and tubulin binding.

Derivatives of the tubulin polymerization inhibitors colchicine and podophyllotoxin bearing the photoreactive 2-diazo-3,3,3-trifluoropropanoyl (DTFP) group were synthesized for evaluation as potential photoaffinity labels of the tubulin binding site. All labels were assayed for their ability to inhibit tubulin polymerization, and N-DTFP-deacetylthiocolchicine was shown to competitively inhibit tubulin-colchicine binding with a Ki of 4-5 microM. The tubulin off-rate of this analog was similar to that of podophyllotoxin, rather than to the relatively irreversibly bound colchicine. Photochemical solvent insertion reactions of the labels were investigated. Radioactive samples of the two most active labels were prepared and used in initial protein-labeling experiments, during which the fractional occupancy of tubulin and extent of covalent incorporation were determined. A rearrangement of DTFP amides was encountered which is relevant to the utility of this moiety for use in synthesis of photoaffinity labels.

On-line capillary electrophoresis with mass spectrometry detection for the analysis of carbohydrates after derivatization with 8-aminonaphthalene-1,3,6-trisulfonic acid.

Capillary electrophoresis (CE) with mass spectrometry (MS) detection is an ideal tool for analytical use, which combines a nano quantity assay with mass determination. Carbohydrate analysis has always been a challenge because of the inherent structural complexity and the lack of a chromophore, unless derivatization is used. Here we use the derivatization of carbohydrates with a fluorophore, 8-aminonaphthalene-1,3,6-trisulfonic acid (ANTS). This chromophore has two advantages, first, it facilitates UV and fluorescence detection and, second, it introduces negative charge to the analyte, which enhances zone electrophoretic separation. In this study, CE combined with negative ion electrospray MS (ESI-MS) was evaluated for the on-line analysis of ANTS labeled carbohydrates and cellulose fragments. The CE system was connected to the MS by a sheath-liquid electrospray arrangement. The ANTS reagent and Dextrin-15, which contains oligomers of maltose, were used as model samples for ESI-MS optimization in flow-injection-MS and CE-MS modes, respectively. Various sheath-liquid compositions regarding organic modifier (isopropanol, methanol, or acetonitrile) and electrolyte (acetic acid-formic acid, ammonium acetate, or triethylamine) were studied. The response as well as the analyte charge state distribution was found to be dependent on the composition and the orifice voltage. Low-pH conditions with isopropanol as organic modifier were sensitive, stable, and the most favorable for analysis.

Synthesis and anticancer screening of 2-indolyl 5-(1,2,3,6-tetrahydropyridyl) ketones.

Several derivatives of 2-indolyl 5-(1,2,3,6-tetrahydropyridyl) ketone with various substituents on the pyridine nitrogen and with or without a benzenesulfonyl group on the indole nitrogen were synthesized and characterized by spectroscopic and analytical data. Only one showed erratic but confirmed activity in the P-388 screen. The other derivatives were inactive in the L-1210 leukemia screen.

Statistical choice of standard samples and precision of analysis in emission spectroscopy.

An approach utilizing mathematical statistics to aid the choice of standard concentrations in emission spectroscopy is presented. The method is applied to the analysis of isoformed samples by the tape method. Some other possible applications (eg. X-ray, fluorescence, absorption photometry) are briefly discussed.