Evaluation of the role of black carbon in attenuating bioaccumulation of polycyclic aromatic hydrocarbons from field-contaminated sediments

The significance of black carbon (BC) for the bioavailability of polycyclic aromatic hydrocarbons (PAHs) was examined by using historically contaminated intact sediment cores in laboratory exposure experiments with the deposit-feeding amphipod Monoporeia affinis. Log values of amphipod biota-sediment accumulation factors (BSAFs) were significantly related to log BC, whereas log BSAFs were related to log octanol-water partition coefficients only in background sediments containing less BC. In the background sediments, the BSAF for polycyclic aromatic hydrocarbons (PAHs) was 1 to 2 for phenanthrene, with lower values for more hydrophobic PAHs, indicating an increase in nonequilibrium conditions with increasing PAH molecular size. For the near-equilibrated phenanthrene and fluoranthene, higher BSAFs were measured during exposure to background sediments, with BSAF decreasing to <0.1 in contaminated sediments in the Stockholm waterways. In situ caged mussels (Dreissena polymorpha) exhibited field BSAF values (relative to sediment-trap-collected suspended matter) for polychlorinated biphenyls (PCBs) of 0.1 to 0.4, but for PAHs of similar hydrophobicity and molecular size, the field BSAFs were much lower and in the range 0.002 to 0.05. This PAH-PCB dichotomy is consistent with recently reported much stronger binding to diesel soot (a form of BC) for PAHs than for PCBs of equal hydrophobicities. Lower BSAFs for the near-equilibrated PAHs (phenanthrene and fluoranthene) in the urban sediments relative to the background sediments were consistent with the larger presence of BC in the urban sediments. This study provides the first linked BSAF-BC field data that supports a causal relationship between strong soot sorption and reduced bioavailability for PAHs.     

Chest and abdominal CT during extracorporeal membrane oxygenation: Clinical benefits in diagnosis and treatment

RATIONALE AND OBJECTIVE: This study aims to evaluate the clinical usefulness of thoracic and abdominal computed tomography (CT) as an adjunct to bedside diagnostic imaging in patients on extracorporeal membrane oxygenation (ECMO) therapy because of severe acute respiratory failure. MATERIALS AND METHODS: Imaging records for 118 consecutive thoracic and abdominal CT examinations performed in 63 patients (22 neonates, 15 children, and 26 adults) on ECMO therapy during an 8-year period were retrospectively reviewed. Reported CT findings were compared with concurrent bedside radiographs and ultrasounds. The clinical importance and effect on treatment of each CT finding was determined by reviewing the medical records. RESULTS: CT showed 30 clinically important complications in 20 different patients that directly impacted on the treatment, but were not diagnosed with bedside imaging. Of the 30 complications, 15 (50%) were surgically treated, 11 (37%) required percutaneous invasive procedures, and 4 (13%) were managed conservatively. Despite the serious complications, 13 of 20 patients (65%) survived. CONCLUSION: Both chest and abdominal CT have an important clinical role in patients on ECMO therapy because of acute respiratory failure, as a complement to bedside imaging, to exclude or show complications and expedite early invasive treatment, when needed.     

Assessment of genetic susceptibility to ethanol intoxication in mice

Increased use of gene manipulation in mice (e.g., targeted or random mutagenesis) has been accompanied by increased reliance on a very few rapid and simple behavioral assays, each of which aspires to model a human behavioral domain. Yet, each assay comprises multiple traits, influenced by multiple genetic factors. Motor incoordination (ataxia), a common characteristic of many neurological disorders, may reflect disordered balance, muscle strength, proprioception, and/or patterned gait. Impaired motor performance can confound interpretation of behavioral assays of learning and memory, exploration, motivation, and sensory competence. The rotarod is one of the most commonly used tests to measure coordination in mice. We show here that exactly how the rotarod test is performed can markedly alter the apparent patterns of genetic influence both in undrugged performance and sensitivity to ethanol intoxication. However, when tested with well chosen parameters, the accelerating rotarod test showed very high inter- and intralaboratory reliability. Depending on test conditions, ethanol can either disrupt or enhance performance in some strains. Genetic contribution to performance on the accelerating versus the fixed-speed rotarod assay can be completely dissociated under some test conditions, and multiple test parameters are needed to assess the range of genetic influence adequately.     

Vitamin A intake is low among pregnant women in central Java,Indonesia

From 1996-1998, a longitudinal study on nutritional status during pregnancy was carried out in Purworejo District, Central Java, Indonesia. Dietary intake was assessed in each trimester using six 24-hour recalls, and analyzed cross-sectionally among 493 women. The proportion of women below the Indonesian RDI for vitamin A (700 RE) ranged from 83% in the first trimester to 76% in the third. Regardless of total vitamin A intake, plant sources contributed 64-79% in all three trimesters. The contribution from animal and fortified sources was generally lower throughout pregnancy for those with low education compared to those with high education. Significant risk factors for having a low vitamin A intake (< FAO/WHO basal RDI, 370 RE) in the second and third trimesters were fewer than six years of education, low socio-economic status, a low energy intake, and a low vitamin A intake in the previous trimester. Home gardening and chicken-raising were not positively associated with vitamin A intakes. Given the large percentage of women with inadequate vitamin A intakes, further strategies are needed to increase the vitamin A intake of all pregnant women in this area.     

Facilitation and inhibition of male rat ejaculatory behaviour by the respective 5-HT1A and 5-HT1B receptor agonists 8-OH-DPAT and anpirtoline,as evidenced by use of the corresponding new and selective receptor antagonists NAD-299 and NAS-181

1. Ejaculatory problems and anorgasmia are well-known side-effects of the SSRI antidepressants, and a pharmacologically induced increase in serotonergic neurotransmission inhibits ejaculatory behaviour in the rat. In the present study the role of 5-HT_1A and 5-HT_1B receptors in the mediation of male rat ejaculatory behaviour was examined by use of selective agonists and antagonists acting at these 5-HT receptor subtypes.
2. The 5-HT_1A receptor agonist 8-OH-DPAT (0.25–4.00 μmol kg⁻¹ s.c.) produced an expected facilitation of the male rat ejaculatory behaviour, and this effect was fully antagonized by pretreatment with the new selective 5-HT_1A receptor antagonist (R)-3-N,N-dicyclobutylamino-8-fluoro-3,4-dihydro-2H-1-benzopyran-5-carboxamide hydrogen (2R,3R) tartrate monohydrate (NAD-299) (1.0 μmol kg⁻¹ s.c.). NAD-299 by itself (0.75–3.00 μmol kg⁻¹ s.c.) did not affect the male rat ejaculatory behaviour.
3. The 5-HT_1B receptor agonist anpirtoline (0.25–4.00 μmol kg⁻¹ s.c.) produced a dose-dependent inhibition of the male rat ejaculatory behaviour, and this effect was fully antagonized by pretreatment with the 5-HT_1B receptor antagonist isamoltane (16 μmol kg⁻¹ s.c.) as well as by the new and selective antagonist (R)-(+)-2-(3-morpholinomethyl-2H-chromene-8-yl)oxymethylmorpholino methansulphonate (NAS-181) (16 μmol kg⁻¹ s.c.). Isamoltane (1.0–16.0 μmol kg⁻¹ s.c.) and NAD-181 (1.0–16.0 μmol kg⁻¹ s.c.) had no, or weakly facilitatory effects on the male rat ejaculatory behaviour. The non-selective 5-HT₁ receptor antagonist (−)-pindolol (8 μmol kg⁻¹ s.c.), did not antagonize the inhibition produced by anpirtoline.
4. The present results demonstrate opposite effects, facilitation and inhibition, of male rat ejaculatory behaviour by stimulation of 5-HT_1A and 5-HT_1B receptors, respectively, suggesting that the SSRI-induced inhibition of male ejaculatory dysfunction is due to 5-HT_1B receptor stimulation.

     

The magnitudes of litter size and sex effects on brain growth of BALB/c mice

In a sample of 67 litters of genetically uniform BALB/c mice, litter size before weaning, which ranged from 2 to 11 animals, had a strong negative and approximately linear effect on body and brain sizes at 100 days after birth. For both males and females, the difference between litters of 11 and 2 was about 3.7 g body weight and 42 mg brain weight. The difference in brain weights was similar to effects produced by severe protein-calorie undernutrition in the postnatal suckling period. The relationship between body weight and brain weight was approximately linear and the fit was not improved significantly by including a nonlinear term or using the allometric equation. The allometric exponent was approximately .35, which is close to values commonly observed for populations of mice having large genetic variability. Although the slopes of the equations relating brain size to body size were similar for males and females, females had substantially larger brains than their male littermates. When males and females were equated statistically for body weight, the brains of females averaged about 32 mg heavier. Statistical considerations in making these estimates are discussed.     

Loss of renomedullary interstitial cells in Brattleboro rats after vasopressin treatment

Previous studies have shown a disappearance of interstitial cells from the renal medulla of rats with hereditary diabetes insipidus (Brattleboro) when the animals were treated with vasopressin in high doses. The present study was undertaken to elucidate the mechanisms behind this cell loss. The disappearance of interstitial cells from the renal medulla of Brattleboro rats was quantitatively determined by electron microscopic stereology after various types of treatment. A considerable decrease in the volume density of interstitial cells was induced by the administration of either 8-arginine vasopressin or 1-desamino-8-D-arginine vasopressin. This lesion of the interstitial cells was not prevented by the simultaneous administration of oxytocin. Even a 48-hour period of water deprivation also resulted in a slight decrease in the volume density of interstitial cells. The results indicate that the observed loss of renal medullary interstitial cells is not a direct effect of the hormone on the cells but probably secondary to the marked increase in the renal medullary solute (urea) concentration. The fact that animals with hardly any renomedullary interstitial cells concentrated their urine to a virtually normal level shows that these cells cannot play an important role in the concentrating mechanism. The interstitial cells recovered rapidly when the vasopressin treatment was discontinued, but it could not be determined whether this was due to local proliferation or to the immigration of cells from extrarenal tissue.     

Wegener granulomatosis in children and young adults

This retrospective study reports seven children and three young adults (aged 11–30 years) who suffered from Wegener granulomatosis. Nine represent consecutive patients admitted to the Division of Nephrology over a period of 23 years. All patients had respiratory tract symptoms and renal involvement on admission. In several patients infiltrates on chest X-ray developed within 2 weeks of onset of symptoms. All patients survived. The median observation period was 9 years (range 13 months to 23 years). One patient progressed to end-stage renal disease. Nine patients initially received cyclophosphamide and steroids. After a median period of 9 months (range 6–31 months) the cyclophosphamide was replaced by azathioprine. Relapses occurred after a median of 28 months (range 4–120 months) in 80% of patients, in six of the eight patients causing a definite decrease in kidney function. We believe that early diagnosis and initiation of therapy reduce the extent of organ damage. Since relapses are frequent, these patients should be evaluated frequently. Received: 18 December 1997 / Revised: 1 December 1998 / Accepted: 2 December 1998     

Feeding problems in an affluent society. Follow-up at four years of age in children with early refusal to eat

Twenty-four children, previously investigated at 3-12 months of age for refusal to eat during at least four weeks with no apparent medical cause, were followed up prospectively and reinvestigated at four years of age. Comparisons were made with 38 controls, selected from the same child health care districts. Information was obtained from parental interviews, medical records and assessments by a speech therapist. At four years of age, 17 of the 24 children with early refusal to eat (71%) were reported by the parents to still have feeding problems and 10 (42%) were reported as hyperactive. Compared to the controls, the children with early refusal to eat seemed to have an equally good prognosis with respect to health, growth and development, but were at risk of later problems with their eating patterns and behaviour.     

Increased dopamine turnover in the ventral striatum by 8-OH-DPAT administration in the rat

The administration of the 5-HT1A agonist 8-OH-DPAT (0.8 mumols kg-1 s.c.-40 min) produced an increase in dopamine (DA) turnover, estimated by the quotient (DOPAC + HVA) DA-1, in the ventral striatum of the rat. No statistically significant effects were obtained in the dorsal striatum. The accumulation of 3-MT in pargyline-treated animals (375 mumols kg-1 s.c.-60 min) was not affected by 8-OH-DPAT treatment (0.15-2.4 mumols kg-1 s.c.-30 min). These findings indicate that 8-OH-DPAT has weak antagonist properties at striatal DA receptors in normal rats. Both the 5-HT1A agonist flesinoxan (0.06-17.8 mumos kg-1 s.c. -50 min) and the mixed 5-HT1 and 5-HT2 agonist 5-MeODMT (1.6-26.0 mumols kg-1 s.c.-50 min) produced a decrease in forebrain 5-HTP accumulation (striatum and neocortex), following decarboxylase inhibition by means of NSD-1015 in reserpine treated rats, indicating stimulation of central 5-HT receptors by these two compounds. At the same time, the DOPA accumulation by the ventral striatum was decreased by flesinoxan and increased by 5-MeODMT treatment. These observations show that, under these conditions, the decrease in DA synthesis is not directly coupled to the decreased 5-HT synthesis produced by flesinoxan, as previously demonstrated for 8-OH-DPAT. Taken together with previous observations, the present results suggest that 8-OH-DPAT, depending on the experimental conditions, is an agonist or antagonist at striatal DA receptors, in all probability due to partial DA receptor agonist properties of the compound.