Associations between Proportion of Plasma Phospholipid Fatty Acids, Depressive Symptoms and Major Depressive Disorder. Cross-Sectional Analyses from the AGES Reykjavik Study.

BACKGROUND: Deficits in n-3 fatty acids may be associated with depression. However, data are scarce from older adults who are at greater risk of poor dietary intake and of developing depression. OBJECTIVE: To investigate proportion of plasma phospholipid fatty acids with respect to depressive symptoms and major depressive disorder in community dwelling older adults. METHODS: Cross-sectional analyses of 1571 participants in the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study aged 67-93 years. Depressive symptoms were measured using the 15-item Geriatric Depression Scale (GDS-15). Major depressive disorder was assessed according to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria using the Mini-International Neuropsychiatric Interview (MINI). RESULTS: Depressive symptoms were observed in 195 (12.4%) subjects and there were 27 (1.7%) cases of major depressive disorder. Participants with depressive symptoms were less educated, more likely to be smokers, less physically active and consumed cod liver oil less frequently. Difference in GDS-15 scores by tertiles of n-3 fatty acid proportion was not significant. Proportion of long chain n-3 fatty acids (Eicosapentaenoic- + Docosahexaenoic acid) were inversely related to major depressive disorder, (tertile 2 vs. tertile 1) OR: 0.31 (95% CI: 0.11, 0.86); tertile 3 vs. tertile 1, OR: 0.45 (95% CI: 0.17, 1.21). CONCLUSION: In our cross sectional analyses low proportions of long chain n-3 fatty acids in plasma phospholipids appear to be associated with increased risk of major depressive disorder. However, the results from this study warrant further investigation in prospective setting with sufficiently long follow-up.

Effect of Cranberry Extract on the Frequency of Bacteriuria in Dogs with Acute Thoracolumbar Disk Herniation: A Randomized Controlled Clinical Trial.

BACKGROUND: Dogs with spinal cord injury are at increased risk of developing bacteriuria due to increased residual urine volume. Cranberry extract inhibits binding of E. coli to uroepithelial cells, potentially reducing risk of bacteriuria. HYPOTHESIS: Cranberry extract reduces risk of bacteriuria in dogs after acute TL-IVDH. ANIMALS: Client-owned dogs with acute onset TL-IVDH causing nonambulatory status. METHODS: Randomized, placebo-controlled, blinded, prospective clinical trial. Dogs with acute TL-IVDH were recruited 48 hours postoperatively and randomized to receive cranberry extract or placebo in a masked fashion. Urine cultures and neurological examinations were performed 2, 4, and 6 weeks postoperatively. The number of dogs with bacteriuria (all bacterial species) and bacteriuria (E. coli) were primary and secondary outcome measures and were evaluated using chi-squared test. Urine antiadhesion activity (AAA) was measured in a subset (N = 47) and examined in a secondary analysis evaluating additional risk factors for bacteriuria. RESULTS: Bacteriuria was detected 17 times in 94 dogs (6 placebo, 11 cranberry, P = .12). There were 7 E. coli. positive cultures (1 placebo, 6 cranberry, P = .09). Dogs in both groups had positive urine AAA (14/21: placebo, 16/26: cranberry), and dogs with urine AAA had significantly fewer E. coli positive cultures (n = 1) than dogs without it (n = 4) (P = .047). CONCLUSIONS AND CLINICAL IMPORTANCE: This clinical trial did not show a benefit of oral cranberry extract but had low power. Cranberry extract supplementation did not impact urine AAA, but a possible association between urine AAA and lower risk of E. coli bacteriuria was identified. Other doses could be investigated.

Arterialized venous bicarbonate is associated with lower bone mineral density and an increased rate of bone loss in older men and women.

CONTEXT: Higher dietary net acid loads have been associated with increased bone resorption, reduced bone mineral density (BMD), and increased fracture risk. OBJECTIVE: The objective was to compare bicarbonate (HCO3) measured in arterialized venous blood samples to skeletal outcomes. DESIGN: Arterialized venous samples collected from participants in the Health, Aging and Body Composition (Health ABC) Study were compared to BMD and rate of bone loss. SETTING: The setting was a community-based observational cohort. PARTICIPANTS: A total of 2287 men and women age 74 ± 3 years participated. INTERVENTION: Arterialized venous blood was obtained at the year 3 study visit and analyzed for pH and pCO2. HCO3 was determined using the Henderson-Hasselbalch equation. MAIN OUTCOME MEASURE: BMD was measured at the hip by dual-energy x-ray absorptiometry at the year 1 (baseline) and year 3 study visits. RESULTS: Plasma HCO3 was positively associated with BMD at both year 1 (P = .001) and year 3 (P = .001) in models adjusted for age, race, sex, clinic site, smoking, weight, and estimated glomerular filtration rate. Plasma HCO3 was inversely associated with rate of bone loss at the total hip over the 2.1 ± 0.3 (mean ± SD) years between the two bone density measurements (P < .001). Across quartiles of plasma HCO3, the rate of change in BMD over the 2.1 years ranged from a loss of 0.72%/y in the lowest quartile to a gain of 0.15%/y in the highest quartile of HCO3. CONCLUSIONS: Arterialized plasma HCO3 was associated positively with cross-sectional BMD and inversely with the rate of bone loss, implying that systemic acid-base status is an important determinant of skeletal health during aging. Ongoing bone loss was linearly related to arterialized HCO3, even after adjustment for age and renal function. Further research in this area may have major public health implications because reducing dietary net acid load is possible through dietary intervention or through supplementation with alkaline potassium compounds.

Polyunsaturated fatty acids in relation to incident mobility disability and decline in gait speed; the Age, Gene/Environment Susceptibility-Reykjavik Study.

BACKGROUND/OBJECTIVES: Low intake of long chain polyunsaturated fatty acids (PUFAs) are associated with physical disability; however, prospective studies of circulating PUFAs are scarce. We examined associations between plasma phospholipid n-3 and n-6 PUFAs with risk of incident mobility disability and gait speed decline. SUBJECTS/METHODS: Data are from a subgroup of the Age, Gene/Environment Susceptibility-Reykjavik Study, a population-based study of risk factors for disease and disability in old age. In this subgroup (n = 556, mean age 75.1 ± 5.0 years, 47.5% men), plasma phospholipid PUFAs were assessed at baseline using gas chromatography. Mobility disability and usual gait speed were assessed at baseline and after 5.2 ± 0.2 years. Mobility disability was defined as the following: having much difficulty, or being unable to walk 500 m or climb up 10 steps; decline in gait speed was defined as change ⩾ 0.10 m/s. Logistic regression analyses were performed to determine associations between sex-specific s.d. increments in PUFAs with risk of incident mobility disability and gait speed decline. Odds ratios (95% confidence intervals) adjusted for demographics, follow-up time, risk factors and serum vitamin D were reported. RESULTS: In women, but not men, every s.d. increment increase of total n-3 PUFAs and docosahexaenoic acid (DHA) was associated with lower mobility disability risk, odds ratio 0.48 (0.25; 0.93) and odds ratio 0.45 (0.24; 0.83), respectively. There was no association between n-6 PUFAs and the risk of incident mobility disability or gait speed decline. CONCLUSIONS: Higher concentrations of n-3 PUFAs and, particularly, DHA may protect women from impaired mobility but does not appear to have such an effect in men.

Validity of retrospective diet history: assessing recall of midlife diet using food frequency questionnaire in later life.

OBJECTIVES: Limited information exists on the validity of dietary information given by elderly people on their past diet. Here we test the relative validity of a food frequency questionnaire asking older persons about their midlife diet. DESIGN: Retrospective food intake of 56-72-year-old subjects was estimated using a food frequency questionnaire designed for the AGES-Reykjavik Study (AGES-FFQ), an epidemiological study of older individuals. Results were compared with detailed dietary data gathered from the same individuals 18-19 years previously, i.e., in midlife, as part of a national cohort. Spearman correlation and cross-classifications were used to assess the ability of the AGES-FFQ to rank subjects according to their intake. SETTING: Nationwide, Iceland. PARTICIPANTS: Subjects, born 1937-1952 (n=174), who participated in the 1990 Icelandic National Dietary Survey. MEASUREMENTS: Dietary intake, estimated by the AGES-FFQ (2008-2009), and dietary history obtained from the 1990 Icelandic National Dietary Survey as a reference method. RESULTS: The strongest correlation between the AGES-FFQ and the reference method was found for cod liver oil, r=0.53, p<0.001 and r=0.56, p<0.001, for men and women, respectively. For men the corresponding correlation coefficient for milk and dairy products was r=0.43, p<0.001. The correlation coefficients were lower but within a reasonably acceptable range (r=0.26-0.40) for meat, fish and potatoes for both genders, as well as fresh fruits and milk/dairy products for women and whole-wheat bread, oatmeal/muesli and blood/liver-sausage for men. No correlation was found between the AGES-FFQ and the dietary history for rye bread and vegetable consumption. Subjects were categorized into five groups according to level of consumption by the two methods. Cross-classification showed that 16-59% were classified into same group and 43-91% into same or adjacent group, 0-14% were grossly misclassified into opposite groups. CONCLUSION: The AGES-FFQ on midlife diet was found suitable to rank individuals by their intake of several important food groups.

Absolute kinetic characterization of 17-beta-estradiol as a radical-scavenging, antioxidant synergist.

We directly measured the absolute reactivity of 17-beta-estradiol (E2) and several phenolic model compounds for E2 toward t-butoxy radical (t-BuO*) by nanosecond time-resolved optical spectroscopy. Compared to other phenols, E2 is a moderate, but not strong deactivator of oxyradicals. The absolute bimolecular rate constant for H-atom transfer from E2 to t-BuO* is 1.3 +/- 0.3 x 10(9) M(-1) x s(-1) (23 degrees C, benzene). We estimate the O-H bond strength of 17-beta-estradiol to be approximately 85 +/- 2 kcal/mol and calculate the reaction rate constant of E2 toward peroxy radical to be 10(5) M(-1) x s(-1) at 37 degrees C. The conjugate phenoxy radical of 17-beta-estradiol, E2O*, is unusually reactive toward alpha-tocopherol and ascorbate by H-atom transfer in homogeneous solution (10(8)-10(9) M(-1) x s(-1)). Our findings suggest that E2 functions in vivo as a highly localized, synergistic biological antioxidant. This may partly explain the clinical effectiveness of ovarian steroids in delaying the manifestations of Alzheimer's Disease as well as in protecting against cardiovascular pathologies. In the absence of complementary antioxidant synergists, E2O* is expected to be a pro-oxidant.

Green tea catechins partially protect DNA from (.)OH radical-induced strand breaks and base damage through fast chemical repair of DNA radicals.

The catechins, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG) are believed to be active constituents of green tea accounting for the reported chemoprevention of certain cancers. The molecular mechanisms by which the measured low concentrations (ca. micromolar) of catechins in humans can reduce the incidence of carcinogenesis is not clear. Using an in vitro plasmid DNA system and radiolytically generating reactive oxygen species (ROS) under constant scavenging conditions, we have shown that all four catechins, when present at low concentrations, ameliorate free radical damage sustained by DNA. A reduction in both prompt DNA single-strand breaks and residual damage to the DNA bases, detected by subsequent incubation with the DNA glycosylases formamidopyrimidine (FPG), endonuclease III (EndoIII) and 5' AP endonuclease exonuclease III (ExoIII), was observed. EGCG was found to be the most active of the catechins, with effects seen at micromolar concentrations. Combined fast-reaction chemistry studies support a mechanism of electron transfer (or H-atom transfer) from catechins to ROS-induced radical sites on the DNA. These results support an antioxidant role for catechins in their direct interaction with DNA radicals.

The association between adolescent spirituality and voluntary sexual activity.

PURPOSE: The purpose of this study was to describe the spectrum of adolescent spirituality and to determine the association between dimensions of spirituality and voluntary sexual activity (VSA) in adolescents. DESIGN: A sample of 141 consecutive youth aged 11-25 years presenting to an urban, hospital-based adolescent medicine clinic completed a 153-item instrument assessing sociodemographics, psychosocial parameters, and eight specific aspects of spirituality including: (1) religious attendance, (2) religious importance, (3) intrinsic and (4) extrinsic religious motivation, (5) belief in God, (6) belief in divine support, (7) existential aspects of spirituality, and (8) spiritual interconnectedness. Adolescents were also asked about VSA. RESULTS: Sixty-one percent of respondents were African-American and 67.4%, female; mean age was 16.0+/-2.4 years. Adolescent religious attendance was equally distributed across the categories from "none" to "weekly or greater" attendance. Over 90% felt religion was somewhat important in their lives. Over 85% reported belief in God. Fifty-six percent of respondents reported a history of VSA. Greater importance of religion (p = 0.035) and higher spiritual interconnectedness with friends (p = 0.033) were inversely associated with VSA. A multiple logistic regression model including age, gender, race, socioeconomic status, and specific denomination of religious faith, importance of religion, and spiritual interconnectedness found that spiritual interconnectedness with friends (OR = 0.92, 95% CI = 0.85, 0.99) and age (OR = 1.75, 95% CI = 1.34, 2.28) were independent predictors of VSA. CONCLUSIONS: Spirituality is a common facet of adolescents' lives. Younger age and higher spiritual interconnectedness, particularly interconnectedness among spiritual friends, are independently associated with a lower likelihood of VSA.

Multiple conformations of an intercalated (-)-(7S,8R,9S, 10R)-N6-[10-(7,8,9,10-tetrahydrobenzo[a]pyrenyl)]-2'-deoxyadenosyl adduct in the N-ras codon 61 sequence.

The structure of the (-)-(7S,8R,9S,10R)-N6-[10-(7,8,9, 10-tetrahydrobenzo[a]pyrenyl)]-2'-deoxyadenosyl adduct at A7 of 5'-d(CGGACAAGAAG)-3'.5'-d(CTTCTTGTCCG)-3', derived from trans addition of the exocyclic N6-amino group of dA to (-)-(7S,8R,9R, 10S)-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene [(-)-DE2], was determined using molecular dynamics simulations restrained by 532 NOEs from 1H NMR. This was named the SRSR(61,3) adduct, derived from the N-rasprotooncogene at and adjacent to the nucleotides encoding amino acid 61 (underlined) of the p21 gene product. The solution structure of this adduct was best described as a mixture of two conformations in rapid equilibrium on the NMR time scale. The two populations differed in the pseudorotation angle of the sugar ring for the 5'-neighboring base A6, as determined from scalar coupling data. One population, estimated to be present at 53%, had the A6 deoxyribose in the C2'-endo conformation, while in the second conformation the A6 deoxyribose was in the C3'-endo conformation. NOEs between C5, A6, and SRSRA7 were either disrupted or weakened, as were those in the complementary strand between C15, T16, and T17. Major groove NOEs were observed between the benzo[a]pyrene aromatic protons, H1, H2, H3, H4, H5, and H6, and T16 CH3. Minor groove NOEs were observed between H1, H2, and H3 of benzo[a]pyrene and T16 H1' and H2' and T17 H1' and H2'. The benzo[a]pyrene protons H10, H11, and H12 showed NOEs to A6 H1', H2', and H2". The chemical shifts of the pyrenyl moiety were dispersed over a 1.9 ppm range. Upfield chemical shifts of 2.4 ppm for T16 N3H, 1.1 ppm for T17 N3H, 1.3 and 1.0 ppm for T16 H6 and CH3, 0.85 ppm for T16 H1', and 0.80 and 0.90 ppm for C15 H2' and H2" were observed. These observations were consistent with intercalation of the pyrenyl moiety toward the 5' direction of SRSRA7. The results were compared to the isomeric SRSR(61,2) adduct [I. S. Zegar, S. J. Kim, T. N. Johansen, P. J. Horton, C. M. Harris, T. M. Harris, and M. P. Stone (1996) Biochemistry 35, 6212-6224] and revealed the role of DNA sequence in modulating the conformation of this benzo[a]pyrene adduct.

Vitamin E and vitamin C supplement use and risk of all-cause and coronary heart disease mortality in older persons: the Established Populations for Epidemiologic Studies of the Elderly.

We examined vitamin E and vitamin C supplement use in relation to mortality risk and whether vitamin C enhanced the effects of vitamin E in 11,178 persons aged 67-105 y who participated in the Established Populations for Epidemiologic Studies of the Elderly in 1984-1993. Participants were asked to report all nonprescription drugs currently used, including vitamin supplements. Persons were defined as users of these supplements if they reported individual vitamin E and/or vitamin C use, not part of a multivitamin. During the follow-up period there were 3490 deaths. Use of vitamin E reduced the risk of all-cause mortality [relative risk (RR) = 0.66; 95% CI: 0.53, 0.83] and risk of coronary disease mortality (RR = 0.53; 95% CI: 0.34, 0.84). Use of vitamin E at two points in time was also associated with reduced risk of total mortality compared with that in persons who did not use any vitamin supplements. Effects were strongest for coronary heart disease mortality (RR = 0.37; 95% CI: 0.15, 0.90). The RR for cancer mortality was 0.41 (95% CI: 0.15, 1.08). Simultaneous use of vitamins E and C was associated with a lower risk of total mortality (RR = 0.58; 95% CI: 0.42, 0.79) and coronary mortality (RR = 0.47; 95% CI: 0.25, 0.87). Adjustment for alcohol use, smoking history, aspirin use, and medical conditions did not substantially alter these findings. These findings are consistent with those for younger persons and suggest protective effects of vitamin E supplements in the elderly.

Major groove (S)-alpha-(N6-adenyl)styrene oxide adducts in an oligodeoxynucleotide containing the human N-ras codon 61 sequence: conformations of the S(61,2) and S(61,3) sequence isomers from 1H NMR.

The (S)-alpha-(N6-adenyl)styrene oxide adducts at positions X6 in d(CGGACXAGAAG). d(CTTCTTGTCCG) and X7 in d(CGGACAXGAAG).d(CTTCTTGTCCG), incorporating codons 60, 61 (underlined), and 62 of the human n-ras protooncogene, were examined by 1H NMR. These were the S(61,2) and S(61,3) adducts. Chemical shift perturbations were in the 3'-direction from the sites of adduction; upfield changes associated with the styrene aromatic ring current were noted for S-SOA6 H2 and H1', T16 N3H, H6, and CH3 resonances in the S(61,2) oligomer. In the S(61,3) oligomer, S-SOA7 H1', T16 H1', C15 N4Ha, and H5 shifted upfield. The styrene aromatic rings flipped rapidly on the NMR time scale; under these conditions the ortho and meta aromatic protons were equivalent. A sequence effect, in which the S(61,2) adduct equilibrated between two conformers, while the S(61,3) adduct exhibited only a single conformation, was observed. Potential energy minimization of the S(61,2) adduct major conformation yielded a structure in which the styrene ring was oriented in the 3'-direction and interacted primarily with the complementary strand. For the S(61,3) adduct, 291 restraints were obtained from NOE data at three mixing times using relaxation matrix analysis. The emergent structures refined to an average rms difference of 1.3 A, determined by pairwise analysis. These were compared to NOE intensity data; the calculated sixth root residual index was 9.2 x 10-2 at 250 ms. In the refined structure, the styrene ring was also oriented in the 3'-direction and interacted with the complementary strand. The minor conformation of the S(61,2) adduct was not identified. These results contrasted with the diastereomeric R(61,2) and R(61,3) adducts, which underwent slow ring flips on the NMR time scale and for which small sequence effects involving the minimum energy conformation of the styrene ring were observed.

Do older women use estrogen replacement? Data from the Duke Established Populations for Epidemiologic Studies of the Elderly (EPESE)

OBJECTIVES: The primary purpose of this study was to determine the prevalence of current and past estrogen use among older, community-dwelling, postmenopausal women. The secondary purpose was to describe factors associated with estrogen use in this population. DESIGN: A survey. SETTING: The Piedmont region of North Carolina. PARTICIPANTS: The sample included 2602 community-dwelling women over the age of 65 who were interviewed for the Duke Established Populations for Epidemiologic Studies of the Elderly (EPESE). MEASUREMENTS: Current and past use of estrogen. RESULTS: Of the women surveyed, 6.1% reported current estrogen use, and 18.5% reported past use. Approximately half of the participants reported using estrogen for more than 2 years. Multivariate analysis demonstrated that current estrogen users were younger, more affluent, had smaller families, and were more likely to be white and to live in an urban area than were never users. Current users were also more likely to drink alcohol and to take calcium supplements; and compared with past estrogen users, they were more likely to be white, have smaller families, and to drink alcohol. CONCLUSION: Estrogen replacement therapy is used by a small minority of older women, especially blacks. Moreover, although women with some risk factors for osteoporosis are more likely to use estrogen, the chief determinants of estrogen utilization are socioeconomic.

Platelet-activating factor biosynthesis in rat vascular smooth muscle cells.

The ability of platelet-activating factor (PAF) receptor antagonists to protect rats from the cardiovascular collapse induced by large doses of endothelin 1 led us to examine the capacity of rat cultured vascular smooth muscle cells to produce PAF and also to evaluate its potential functional roles in this cell type. Adenosine triphosphate and the vasoactive peptides, endothelin 1, angiotensin II, and arginine vasopressin, each elicited an increase in the PAF level in extracts of rat cultured vascular smooth muscle cells as determined by bioassay. PAF was not detectable (above 20 fmol/mg protein) in the supernatants of these cells. The identity of the bioactivity as PAF was confirmed by GC/MS which indicated that more than 80% of the PAF was 1-O-hexadecyl-2-acetyl-3-sn-glyceryl-phosphorylcholine. Exogenous PAF (100 nM) elicited increases in intracellular calcium that were inhibited by WEB 2086 (10 microM). Endothelin 1, at a concentration which stimulated PAF synthesis, (1 nM), elicited increases in intracellular calcium levels that were not inhibited by WEB 2086 (10 microM). Thus, endogenous PAF is unlikely to be involved in the endothelin-1-induced calcium increases. Although WEB 2086 (3-100 microM) inhibited concentration dependently fetal calf serum (10% v/v) induced [3H]-thymidine incorporation, reaching a maximum effect at 30 microM of 40-50% reduction, in parallel experiments WEB 2086 had no effect on serum-induced increases in cell numbers. We conclude that PAF is produced and retained by cultured rat vascular smooth muscle and that it is unlikely to contribute to the signaling of increases in intracellular calcium or proliferation.

The pharmacologic evaluation of locomotor activity versus inflammatory parameters in rat adjuvant arthritis.

Adjuvant-induced arthritis (AA) is an experimental model of inflammatory joint disease in the rat which mimics rheumatoid arthritis. Although paw inflammation (e.g., swelling) is commonly used to monitor the efficacy of antiarthritic drugs, a reduction in locomotor function may provide a more sensitive evaluation of "functional disability" in AA rats. The purpose of the present study was to investigate the effect of dietary therapy with prednisolone or ibuprofen on locomotor activity as well as arthritic symptoms in established AA (days 20-42). AA rats demonstrated an increase in arthritis scores, spleen weights, fibrinogen, and WBC along with a reduction in locomotor function. Prednisolone (2 mg/kg/day) exhibited a positive therapeutic effect on all these parameters. Ibuprofen (50 mg/kg/day) consistently lowered arthritis scores and fibrinogen; however, locomotor function only improved on day 35. In conclusion, the measurement of locomotor activity in concert with other experimental parameters may provide a more meaningful evaluation of disease severity or improvement in AA.

Expression cloning of an adenylate cyclase-coupled calcitonin receptor.

A calcitonin receptor complementary DNA (cDNA) was cloned by expression of a cDNA library from a porcine kidney epithelial cell line in COS cells. The 482-amino acid receptor has high affinity for salmon calcitonin (dissociation constant Kd approximately 6 nM) and is functionally coupled to increases in intracellular cyclic adenosine monophosphate (cAMP). The receptor shows no sequence similarity to other reported G protein-coupled receptors but is homologous to the parathyroid hormone-parathyroid hormone-related peptide (PTH-PTHrP) receptor, indicating that the receptors for these hormones, which regulate calcium homeostasis, represent a new family of G protein-coupled receptors.

Wanted, psychiatric technician. Assessing decision-making skills.

Psychiatric technicians are becoming increasingly important in the inpatient psychiatric setting, yet few educational programs properly prepare students for this demanding role. By structuring interviews around practical, real life dilemmas faced by technicians, the interviewer can establish which applicants are best suited for the job, thus helping to improve satisfaction and retention.

An intracerebroventricular perfusion system developed for the study of centrally acting antihypertensive drugs in the rat.

A method for the complete construction and employment of an intracerebroventricular perfusion system for the rat brain is described. Rats maintained on the system for up to 7 hr displayed no detectable change in cardiovascular status. Penetration of intracerebroventricular-administered methylene blue dye into all areas of the cerebroventricles demonstrated the accessibility of the injection volume throughout the ventricular system. The hypotensive and bradycardic response produced by a 1.5-microgram/kg dose of clonidine (a centrally active antihypertensive agent) administered via the intracerebroventricular implant was of considerably greater magnitude and duration than an equivalent intravenous dose. Administration of [3H]-labeled clonidine via the intracerebroventricular implant resulted in relatively minor accumulation of the drug into peripheral organs, when compared to that found in the brain. These supportive data suggest the general applicability of this approach for studying the selective central effects of pharmacologic agents in a relatively inexpensive and easily procured laboratory animal.

An alternative phototherapy light combination.

Combinations of fluorescent lamps for phototherapy were evaluated in order to select one that maximizes blue light content (400 to 500 nanometers) for most effective photodegradation of bilirubin, maintains acceptable color balance for observing infant skin color, and requires minimal lamp replacement for low maintenance cost. The combination that best achieves these objectives consists of four special blue (Westinghouse F20T12-BB) and four broad spectrum (Verd-A-Ray F20T12-CC) lamps that produce blue radiation in excess of an array of eight conventional blue lamps, a spectrum closely approximating that of natural light, and at least 80% of the original blue radiation after 2,100 hours of use.