The Effect of a Regimen of Antifungal Cream Use on Episodes of Acute Adenolymphangitis (ADL) among Lymphedema Patients: An Application Using Marginal Structural Models

Episodes of adenolymphangitis (ADL) are a recurrent clinical aspect of lymphatic filariasis (LF) and a risk factor for progression of lymphedema. Inter-digital entry lesions, often found on the web spaces between the toes of those suffering from lymphedema, have been shown to contribute to the occurrence of ADL episodes. Use of antifungal cream on lesions is often promoted as a critical component of lymphedema management. Our objective was to estimate the observed effect of antifungal cream use on ADL episodes according to treatment regimen among a cohort of lymphedema patients enrolled in a morbidity management program. We estimated this effect using marginal structural models for time varying confounding. In this longitudinal study, we estimate that for every one-unit increase in the number of times one was compliant to cream use through 12 months, there was a 23% (RR = 0.77 (0.62, 0.96)) decrease in the number of ADL episodes at 18 months, however the RR’s were not statistically significant at other study time points. Traditionally adjusted models produced a non-significant RR closer to the null at all time points. This is the first study to estimate the effect of a regimen of antifungal cream on the frequency of ADL episodes. This study also highlights the importance of the consideration and proper handling of time-varying confounders in longitudinal observational studies.

Postnatal ultrasound reliability in cerebellar vermis assessment

BACKGROUND

Cerebellar growth in late gestation is impeded by prematurity which may adversely affect neurocognitive development. Assessment of cerebellar growth should be easily attainable, reliable and reproducible.

OBJECTIVE

To assess the reliability of linear sonographic cerebellar vermis measurement.

METHOD

Cranial ultrasounds of 110 infants ranging from 24 to 41 weeks' gestation were retrospectively reviewed. Cerebellar vermian height, craniocaudal diameter and superior and inferior vermis widths were independently measured on the first midline sagittal image by three neonatal sonologists of varying experience. Interobserver and intraobserver reliability were calculated using the intraclass correlation coefficient (ICC) (2 way mixed model, SPSS V.15.0).

RESULTS

61 images were technically adequate. Interobserver ICCs (95% CI) were: cerebellar vermian height 0.88 (0.82 to 0.92); craniocaudal diameter 0.91 (0.86 to 0.94); superior vermis width 0.84 (0.77 to 0.89); inferior vermis width 0.92 (0.89 to 0.95). Intraobserver ICCs were similar.

CONCLUSION

With adequate images, linear ultrasound measurements of cerebellar vermis are reliable.

Predictors of compliance with a mass drug administration programme for lymphatic filariasis in Orissa State, India 2008

OBJECTIVES

To assess the performance of an educational campaign to increase adherence to a mass-administered DEC regimen against lymphatic filariasis (LF) in Orissa, and to identify factors that could enhance future campaigns.

METHOD

Randomized cluster survey, comparing areas that did and did not receive the educational campaign, using a household coverage survey and knowledge, attitudes and practices (KAP) survey.

RESULTS

LF MDA coverage for the entire population (n = 3449) was 56% (95% CI: 50.0-61.9). There was no statistical difference between the areas that did and did not receive the educational campaign. The most common barriers to adherence were fear of medication side effects (47.4%) and lack of recognition of one's risk for LF (15.8%). Modifiable, statistically significant, multivariable predictors of adherence were knowing that DEC prevents LF (aOR = 2.6, 95% CI: 1.4-5.1), knowing that mosquitoes transmit LF (aOR = 1.9, 95% CI: 1.1-3.2), and knowing both about the mass drug administration (MDA) in advance and that mosquitoes transmit LF (aOR = 5.4, 95% CI: 2.8-10.4).

CONCLUSIONS

India needs to increase compliance with MDA programmes to reach its goal of interrupting LF transmission. Promoting a simple public health message before MDA distribution, which takes into account barriers to and predictors of adherence, could raise compliance with the LF MDA programme.

Effect of total plasma homocysteine on cervical dysplasia risk

We investigated whether total plasma homocysteine (tHcy) is associated with risk for cervical intraepithelial neoplasia (CIN). tHcy was evaluated, along with numerous risk factors for CIN and biochemical indexes of nutrients, in a previously reported study population of 294 subjects with CIN and 170 female controls without CIN. tHcy was significantly higher in cases than in controls (9.1 vs. 8.3 mumol/l, p = 0.002). Human papillomavirus type 16 infection [odds ratio (OR) = 6.7], oral contraceptive use (OR = 6.0), parity (OR = 2.2), and cigarette smoking (OR = 1.9) were significantly associated with CIN after adjustment for each other and for age, number of sexual partners, and plasma tHcy, folate, iron, and zinc. Human papillomavirus type 16 positivity increased risk for CIN more when tHcy was > 9.12 mumol/l (OR = 4.7) than when it was < or = 9.12 mumol/l (OR = 3.0). Cigarette use increased risk for CIN when tHcy was > 9.12 mumol/l (OR = 3.9), but not when tHcy was < or = 9.12 mumol/l (OR = 1.5). Parity increased risk for CIN more when tHcy was > 9.12 mumol/l (OR = 4.0) than when tHcy was < or = 9.12 mumol/l (OR = 2.0). These results suggest that elevated plasma tHcy is a risk factor for cervical dysplasia and that it enhances the effects of other risk factors. It is unknown whether tHcy is serving as a marker of folate deficiency or is acting through other mechanisms.

Adrenocortical secretion of dehydroepiandrosterone in healthy women: highly variable response to adrenocorticotropin

Excess adrenal androgen (AA) levels are observed in 25--50% of women with the polycystic ovary syndrome (PCOS), and AA excess in PCOS may represent selection bias. Thus, it is possible that AA secretion among the general population is highly variable, and that those women who are predisposed to secreting greater amounts of AA have a greater probability of having PCOS. We now hypothesize that the levels of AAs are highly variable among normal nonhyperandrogenic women, and that this heterogeneity is the result of a variable response of AAs to ACTH stimulation. To test this hypothesis we prospectively studied the response of dehydroepiandrosterone (DHA) and cortisol (F) to a 60-min acute stimulation with ACTH-(1--24) in 56 healthy eumenorrheic nonhirsute healthy women with a mean age of 28.9 yr (range, 20--37 yr.) and a mean body mass index (BMI) of 29.2 kg/m(2) (18.2--46.2 kg/m(2)). Baseline samples and poststimulation samples were assayed for DHA and F. The basal and ACTH-stimulated levels of DHA, but not those of F, were negatively correlated with age, although neither the basal nor ACTH-stimulated responses of DHA and F varied with BMI. After controlling for age, the basal F level was negatively correlated to its net increment (i.e. Delta F; r = -0.54; P < 0.001), whereas there was no significant relationship between basal DHA and Delta DHA. We also compared the intersubject variability (coefficient of variation) for basal and stimulated levels of DHA and F. For basal (DHA(0)), 60 min (DHA(60)), and net increment in (Delta DHA) DHA levels, the coefficients of variation were 67.9%, 61.4%, and 76.0%, respectively; for F(0), F(60), and Delta F, they were 40.4%, 16.9%, and 31.3%, respectively. The variance in Delta DHA was significantly higher, and the variance in F(60) was significantly lower than that in all other variables; DHA(0), DHA(60), F(0), and Delta F had similar variances. In conclusion, in our population of healthy reproductive-aged women we observed that both basal and ACTH-stimulated levels of DHA after ACTH-(1--24) stimulation had significantly greater intersubject variance (approximately 60--70%) compared with the basal and poststimulation levels of F (approximately 15--40%). These data support the hypothesis that among normal women, AA (i.e. DHA) levels are highly variable compared to those of F. In addition, the intersubject variability in DHA levels is at least in part due to a variable response of AAs to ACTH stimulation. Whether the AA excess frequently observed in PCOS is due to the greater risk of those women with higher AA levels, basally and after ACTH stimulation, remains to be confirmed.

A prevalence study of hepatitis A virus infection in a migrant community: Is hepatitis A vaccine indicated?

BACKGROUND

The Advisory Committee on Immunization Practices recommends routine hepatitis A vaccination of children living in communities with high rates of hepatitis A. Rates among children living in migrant farm worker families are unknown.

METHODS

Participants recruited from the 1243 migrant children aged 2 to 18 years in Okeechobee County, Florida, were administered a questionnaire. A blood sample was taken for testing for antibodies to hepatitis A virus (anti-HAV), and hepatitis A vaccine was administered.

RESULTS

Of 244 (20%) participating children, 125 (51%) were anti-HAV-positive. Seropositivity increased with age from 34% (2- to 5-year-olds) to 81% (>/=14-year-olds) (P <.0001). In multivariate analysis, age (odds ratio [OR] = 1.2/year; 95% CI = 1.1 to 1.3), having a Mexican-born father (OR = 12.2; 95% CI = 2.2 to 227.9), and age on moving to the United States (OR = 1.3/year; 95% CI = 1.0 to 1.6) were independently associated with anti-HAV positivity. Among US-born children aged 2 to 5 years who had never left the United States, 33% were anti-HAV-positive.

CONCLUSIONS

Anti-HAV prevalence among migrant children in Okeechobee County, including the youngest US-born children, is high, indicating ongoing transmission of HAV. Children in this and other US migrant communities may benefit from hepatitis A vaccination.

Correlates of total plasma homocysteine: folic acid, copper, and cervical dysplasia

We examined correlates of total plasma homocysteine (tHcy) in 294 subjects with cervical intraepithelial neoplasia and 170 control subjects. Associations of tHcy with risk factors for cervical intraepithelial neoplasia and 24-h intakes and biochemical indices of nutrients were examined. Plasma and red blood cell folate and plasma B(12) were strong inverse correlates of tHcy (r = -0.35, -0. 31, and -0.27, respectively). Plasma copper and severity of dysplasia were positively correlated with tHcy (r = 0.14 and 0.21, respectively). A stepwise regression model that included red blood cell folate, plasma copper, grade of dysplasia, ethnicity, intake of polyunsaturated fatty acids, plasma vitamin B(12), intake of fat, and oral contraceptive use explained 29% of the variation in tHcy. Two hundred thirty-five subjects with cervical intraepithelial neoplasia were randomized to receive folic acid (10 mg/d) or placebo for 6 mo. After 2, 4, and 6 mo, mean tHcy in the folate-supplemented group (7.2 +/- 1.8, 7.0 +/- 1.9, and 7.0 +/- 2.3 micromol/L, respectively) was significantly lower than baseline and the placebo group at 2, 4, and 6 mo (8.9 +/- 3.1, 8.4 +/- 3.0, and 8.9 +/- 3.1 micromol/L, respectively). Supplementation lowered tHcy even in subjects in the highest quintile of baseline folate. Folate, vitamin B(12), copper, and severity of dysplasia are associated with tHcy. Folate supplementation significantly lowers tHcy even in folate-replete subjects.

Behavioral and neurochemical effects of the dopamine transporter ligand 4-chlorobenztropine alone and in combination with cocaine in vivo

The current studies evaluated the novel diphenylmethoxytropane analog 4-chlorobenztropine (4-Cl-BZT), cocaine, and combinations of the two drugs for their abilities to stimulate locomotor activity, produce cocaine-like discriminative stimulus effects, and elevate extracellular dopamine (DA) in the nucleus accumbens (NAc) as measured by in vivo microdialysis. Peripherally administered cocaine was approximately twice as efficacious as 4-Cl-BZT as a locomotor stimulant and was behaviorally active at a lower dose than was 4-Cl-BZT. Cocaine also was more efficacious than 4-Cl-BZT in producing discriminative-stimulus effects in rats trained to discriminate i.p. injections of 10 mg/kg cocaine from saline. The time course of behavioral activation differed markedly between the two drugs, with much shorter onset and duration of locomotor stimulant effects for cocaine relative to 4-Cl-BZT. Similarly, i.p. cocaine (10 and 40 mg/kg) induced a pronounced, rapid, and short-lived increase in DA in the NAc, whereas i.p. 4-Cl-BZT was effective only at the higher dose and produced a more gradual, modest, and sustained (>/=2 h) elevation in accumbens DA. In contrast to i.p. administration, local infusion of 4-Cl-BZT (1-100 microM) into the NAc through the microdialysis probe elevated extracellular DA to a much greater extent than did local cocaine (nearly 2000% of baseline maximally for 4-Cl-BZT versus 400% of baseline for cocaine) and displayed a much longer duration of action than cocaine. However, when microinjected bilaterally into the NAc at 30 or 300 nmol/side, cocaine remained a more efficacious locomotor stimulant than 4-Cl-BZT. Finally, pretreatment with i.p. 4-Cl-BZT dose dependently enhanced the locomotor stimulant, discriminative stimulus effects, and NAc DA response to a subsequent low-dose i.p. cocaine challenge. The diphenylmethoxytropane analog also facilitated the emergence of stereotyped behavior and convulsions induced by high-dose cocaine. The current results demonstrate that DA transporter ligands that do not share the neurochemical and behavioral profiles of cocaine nevertheless may enhance the effects of cocaine in vivo.

Necessary role for ventral tegmental area adenylate cyclase and protein kinase A in induction of behavioral sensitization to intraventral tegmental area amphetamine

In the present study, we investigated the effects of selective activation or inhibition of ventral tegmental area (VTA) adenylate cyclase (AC) and protein kinase A (PKA) on long-term sensitization induced by repeated intra-VTA or peripheral amphetamine (AMPH). Selective inhibition of AC by SQ 22,536 (9-(tetrahydro-2-furanyl)-9H-purin-6-amine; 100 nmol/side bilateral into VTA) had no effect on acute basal locomotion but attenuated the locomotor stimulation induced by acute i.p. AMPH (1.5 mg/kg). Coinjection of SQ 22,536 (100 nmol/side) fully blocked the sensitization induced by repeated intra-VTA AMPH (15 nmol/side) but had no detectable effect on the sensitization induced by repeated i. p. AMPH. Persistent activation of AC by intra-VTA cholera toxin (500 ng/side) modestly increased acute locomotion and induced a robust sensitization to i.p. AMPH challenge 10 days after the last of three repeated VTA microinjections. Selective inhibition of PKA by Rp-adenosine-3',5'-cyclic monophosphothioate triethylamine (Rp-cAMPS; 25 nmol/side) had no effect on acute basal or AMPH-stimulated locomotion. Coinjection of Rp-cAMPS (25 nmol/side) fully blocked the sensitization induced by repeated intra-VTA AMPH but had no effect on sensitization induced by repeated i.p. AMPH. Intra-VTA microinjection of the selective PKA activator Sp-adenosine-3',5'-cyclic monophosphothioate triethylamine (Sp-cAMPS; 25-100 nmol/side) dose-dependently stimulated acute locomotion and exerted synergistic effects on locomotor activity when coinfused into the VTA with AMPH but had no detectable effect on acute i.p. AMPH-induced locomotion. Repeated intra-VTA Sp-cAMPS did not induce sensitization to AMPH challenge but potentiated the sensitization induced by repeated i.p. AMPH. These results suggest that VTA cAMP signal transduction is necessary for the induction of persistent sensitization to intra-VTA amphetamine and that peripheral and intra-VTA AMPH may not induce behavioral sensitization by identical mechanisms.

Intractable diarrhea from cytomegalovirus enterocolitis in an immunocompetent infant

Infection with cytomegalovirus (CMV) in infants can be congenital or perinatal. Infected infants may be asymptomatic or present with pneumonia, rash, hepatosplenomegaly, or encephalitis.1 In the presence of an immunodeficiency, severe and sometimes fatal disease may occur. To our knowledge, CMV has not been identified previously as a cause of intractable diarrhea of infancy. We report the case of a 5-week-old immunocompetent infant with intractable diarrhea attributable to CMV-induced enterocolitis. Recognition of this infection and initiation of ganciclovir therapy was associated with a rapid improvement and resolution of the diarrhea.

The effect of a self-monitoring tool on self-efficacy, health beliefs, and adherence in patients receiving hemodialysis

OBJECTIVE

Assess the effectiveness of a self-monitoring tool on perceptions of self-efficacy, health beliefs, and adherence in patients receiving hemodialysis.

DESIGN

A monthly intervention using a pretest, posttest design over a 6-month period. Both the treatment and control groups were randomly selected and received surveys to assess health beliefs, perceptions of self-efficacy for performing specific healthful behaviors, and renal diet knowledge at baseline, before intervention, and 6 months later. The treatment group also received monthly feedback of monthly phosphorus levels and interdialytic weight gains.

SETTING

A university hospital-based 43-chair ambulatory dialysis center.

SUBJECTS

Forty patients with end-stage renal disease (25 men and 15 women, age 26 to 78 years), on chronic hemodialysis for at least 2 months and with a history of noncompliance with phosphorus and/or fluid restrictions for 1 or more months.

MAIN OUTCOME MEASURES

Self-efficacy, health beliefs, knowledge, biochemical, and demographic variables were analyzed. Analysis of variance tests of repeated measures were used to examine relationships between adherence with phosphorus and fluid restrictions to health beliefs and perceptions of self-efficacy after training in self-monitoring.

RESULTS

Overall, there were no significant improvements in adherence with phosphorus and fluid restrictions between the two groups, although a comparison within the groups revealed the treatment group had a statistically significant decrease in mean phosphorus levels of 7.14 to 6.22 mg/dL (P = .005) from baseline to month 3. However, because this value was not maintained, it was not statistically significant. No significant differences existed between the two groups for health beliefs and perceptions of self-efficacy. Knowledge scores in the treatment group, however, improved significantly as compared to the control group (P = .008) and was a significant increase from baseline (P = . 002). In the control group, all scores fell slightly but this difference was not significant.

CONCLUSIONS

The benefits of patient self-monitoring and behavioral contracting upon adherence in patients on hemodialysis are inconclusive, as serum phosphorus and interdialytic weight gains did not differ between the two groups. The interventional tools also appeared to have little effect on perceptions of self-efficacy and health beliefs. Trends of improvement, however, did exist for phosphorus within the treatment group and subjects in this group had a statistically significant increase in knowledge scores over time. Additional research using repeated measures design is needed to explore the effects of increased frequency and duration of an intervention on the attainment of patient clinical outcome measures.

Androgen response to hypothalamic-pituitary-adrenal stimulation with naloxone in women with myotonic muscular dystrophy

Myotonic muscular dystrophy (MMD) is a disease of autosomal dominant inheritance characterized by multisystem disease, including myotonia, muscle-wasting and weakness of all muscular tissues, and endocrine abnormalities attributed to a genetic abnormality causing a defective cAMP-dependent kinase. We have previously reported that MMD patients demonstrate ACTH hypersecretion after endogenous CRH release stimulated by naloxone administration while manifesting a normal cortisol (F) response. Additionally, others have reported a reduced adrenal androgen (AA) response to exogenous ACTH administration in MMD patients. As ACTH stimulates the secretion of both AAs and F, it is possible that the discordant relationship of these hormones in MMD patients results from a defect of adrenocortical ACTH receptor function or postreceptor signaling or subsequent biochemical events. Furthermore, the molecular abnormality seen in MMD patients may suggest that the mechanism underlying the frequently observed discordances in the secretion of glucocorticoids and AAs (e.g. adrenarche, surgical trauma, severe burns, or intermittent glucocorticoid administration) are explainable solely via an alteration in the function of the ACTH receptor or postreceptor signaling. To ascertain whether the responses of F and AAs to endogenous ACTH diverged in this disorder, we prospectively studied the responses of these hormones to naloxone-stimulated CRH release in nine premenopausal women with MMD and seven healthy age and weight-matched control women. After naloxone infusion (125 micrograms/kg, i.v.), blood sampling was performed at baseline (i.e. -5 min) and at 30 and 60 min. In addition to the absolute hormone level at each time, we calculated the net increment (i.e. change) at 30 and 60 min and the area under the curve (AUC) for F, ACTH, dehydroepiandrosterone (DHA), and androstenedione (A4). Consistent with our previous study, MMD patients demonstrated higher ACTH levels at all sampling times except [minud]5 min. AUC analysis revealed the ACTHAUC values were significantly higher in MMD than in control women (457 +/- 346 vs. 157 +/- 123 pmol/min.L; P < 0.03), whereas the FAUC response did not differ between MMD and controls (13860 +/- 3473 vs. 13375 +/- 3465 nmol/min.L; P > 0.5). Despite the greater ACTH secretion, the baseline circulating dehydroepiandrosterone sulfate levels were significantly lower in MMD compared with control women (18 +/- 23 vs. 61 +/- 23 mumol/L; P < 0.002). The serum concentrations of A4 at baseline, 30 min, and 60 min and DHA levels at 30 and 60 min were also significantly lower in MMD vs. control women. Additionally, the A4AUC and DHAAUC values were significantly lower in MMD patients than in controls. Furthermore, the net response of DHA at 60 min to the endogenous ACTH increase was also reduced in MMD patients compared with that in control subjects (2.3 +/- 2.1 vs. 5.6 +/- 2.6 nmol/L; P < 0.02). In conclusion, in addition to ACTH hypersecretion to CRH-mediated stimuli, these data suggest that MMD patients have a defect in the adrenocortical response to ACTH, reflected in normal F and reduced DHA and A4 secretion. Whether this defect is inherent to the disease or simply reflects adaptive changes to chronic disease remains to be demonstrated. However, it is possible that further studies of the response of MMD patients to ACTH may reveal a mechanism that explains the frequently observed dichotomy in the secretion of glucocorticoids and AAs.

Adrenal androgen excess in the polycystic ovary syndrome: sensitivity and responsivity of the hypothalamic-pituitary-adrenal axis

Over 50% of patients with the polycystic ovary syndrome (PCOS) demonstrate excess levels of adrenal androgens (AAs), particularly dehydroepiandrosterone sulfate (DHS). Nonetheless, the mechanism for the AA excess remains unclear. It has been noted that in PCOS the pituitary and ovarian responses to their respective trophic factors (i.e. GnRH and LH, respectively) are exaggerated. Similarly, we have postulated that excess AAs in PCOS arises from dysfunction of the hypothalamic-pituitary-adrenal axis, due to 1) exaggerated pituitary secretion of ACTH in response to hypothalamic CRH, 2) excess sensitivity/responsivity of AAs to ACTH stimulation, or 3) both. To test this hypothesis we studied 12 PCOS patients with AA excess (HI-DHS; DHS, > 8.1 mumol/L or 3000 ng/mL), 12 PCOS patients without AA excess (LO-DHS; DHS, < 7.5 mumol/L or 2750 ng/mL), and 11 controls (normal subjects). Each subject underwent an acute 90-min ovine CRH stimulation test (1 microgram/kg) and an 8-h incremental i.v. stimulation with ACTH-(1-24) at doses ranging from 20-2880 ng/1.5 m2.h) with a final bolus of 0.25 mg. All patient groups had similar mean body mass indexes and ages, and both tests were performed in the morning during the follicular phase (days 3-10) of the same menstrual cycle, separated by 48-96 h. During the acute ovine CRH stimulation test, no significant differences in the net maximal response (i.e. change from baseline to peak level) for ACTH, dehydroepiandrosterone (DHA), androstenedione (A4), or cortisol (F) or for the DHA/ACTH, A4/ACTH, or F/ACTH ratios was observed. Nonetheless, the net response of DHA/F and the areas under the curve (AUCs) for DHA and DHA/F indicated a greater response for HI-DHS vs. LO-DHS or normal subjects. The AUC for A4 and A4/F and the delta A4/delta F ratio (delta = net maximum change) indicated that HI-DHS and LO-DHS had similar responses, which were greater than that of the normal subjects, although the difference between LO-DHS patients and normal subjects reached significance only for the AUC of the A4 response. No difference in the sensitivity (i.e. threshold or minimal stimulatory dose) to ACTH was noted between the groups for any of the steroids measured. Nonetheless, the average dose of ACTH-(1-24) required for a threshold response was higher for DHA than for F and A4 in all groups. No difference in mean responsivity (slope of response to incremental ACTH stimulation) was observed for DHA and F between study groups, whereas the responsivity of A4 was higher in HI-DHS patients than in normal or LO-DHS women. The net maximal and the overall (i.e. AUC) responses of DHA were greater for HI-DHS than for normal or LO-DHS women. The response of A4 and the delta A4/delta F ratio were greater for HI-DHS patients than for LO-DHS patients or normal subjects. Alternatively, HI-DHS and LO-DHS patients had similar overall responses (i.e. AUC) for A4 or A4/F, although both were greater than those of normal subjects. The relative differences in response to incremental ACTH stimulation between steroids was consistent for all subject groups studied, i.e. A4 > F or DHA. In conclusion, our data suggest that AA excess in PCOS patients is related to an exaggerated secretory response of the adrenal cortex for DHA and A4, but not to an altered pituitary responsivity to CRH or to increased sensitivity of these AAs to ACTH stimulation. Whether the increased responsivity to ACTH for these steroids is secondary to increased zonae reticularis mass or to differences in P450c17 alpha activity, particularly of the delta 4 pathway, remains to be determined.

Role of the ovary in the adrenal androgen excess of hyperandrogenic women

OBJECTIVE

To test the hypothesis that ovarian hormones in women with hyperandrogenism alter adrenocortical steroidogenesis.

DESIGN

Combination of two prospective studies.

SETTING

Academic medical centers.

PATIENT(S)

Eighteen hyperandrogenic patients demonstrating hirsutism with either hyperandrogenemia, oligomenorrhea, or both. Eighteen healthy nonhirsute eumenorrheic untreated women served as controls.

INTERVENTIONS

Blood sampling basally and after acute adrenal stimulation with ACTH, before and after 20-24 weeks of leuprolide administration. Nine patients also received 0.625 mg/d of oral conjugated esterified estrogens and 10 mg of medroxyprogesterone acetate days 1-12 of the month (i.e., estrogen replacement therapy [ERT]), whereas the remaining nine did not.

MAIN OUTCOME MEASURE(S)

Before and after the administration of the GnRH agonist (GnRH-a), the basal concentrations of DHEAS; and the levels of androstenedione (A4), DHEA, androstenediol, 11 beta-hydroxyandrostenedione (11-OHA4), and cortisol before and 60 minutes after acute adrenal stimulation, were measured.

RESULT(S)

Levels of DHEAS, androstenediol, and 11-OHA4 decreased by 15%-30%, regardless of whether patients initially had or did not have DHEAS excess. However, only hyperandrogenic patients with elevated levels of DHEAS showed a significant decrease in basal DHEA levels. No statistically significant difference in the response of either androgen to ACTH (1-24) stimulation was noted with ovarian suppression, regardless of initial DHEAS level or use of ERT.

CONCLUSION(S)

We found no evidence that ovarian hormone secretion affected adrenal steroidogenesis, and those women with the highest adrenal androgen levels had the least response to GnRH-a suppression. These findings further support the concept of an intrinsic, and possibly primary, abnormality of adrenocortical steroidogenesis in a subset of hyperandrogenic women that is independent of ovarian abnormalities.

Predictors of stroke complicating carotid artery stenting

BACKGROUND

The evolving technique of carotid stenting is being evaluated as an alternative to endarterectomy. Identification of the factors that predispose a patient to neurological complications would facilitate further refinement of the technique and optimize patient selection.

METHODS AND RESULTS

We analyzed the impact of various clinical, morphological, and procedural determinants on the development of procedural strokes in 231 patients who underwent elective (primary) stenting of 271 extracranial carotid arteries. The mean age of the patients was 68.7+/-10 years, 165 (71%) were males, and 139 (60%) had symptoms attributed to the lesion treated. This series represented a high-risk subset with 164 patients (71%) having significant coronary artery disease, 91 (39%) having bilateral disease, and 28 (12%) having contralateral carotid occlusion. Of the treated vessels, 59 (22%) had prior carotid endarterectomy, 66 (24%) had ulcerated plaques, and 87 (32%) had calcified lesions. Only 37 treated vessels (14%) would have been eligible for inclusion in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). There were 17 (6.2%) minor and 2 (0.7%) major strokes during and within 30 days of the procedure. NASCET-eligible patients had a low (2.7%) risk of procedural strokes after carotid stenting. The results of multivariate analysis revealed advanced age (P=.006) and presence of long or multiple stenoses (P=.006) as independent predictors of procedural strokes.

CONCLUSIONS

During this procedural developmental phase of carotid stenting, neurological complications were highly dependent on patient selection. Advanced age and long or multiple stenoses were independent predictors of procedural stroke.

Pinealocyte ultrastructure in mutant mice that lack sympathetic innervation to the pineal gland

Pinealocyte synaptic ribbons (SR) and dense-cored vesicles (DCV) were quantitated in mice that have developmental deficiencies in the sympathetic innervation of the pineal gland due to a null mutation for the p75 low-affinity NGF receptor (NGFR). SR exhibited a significant increase whereas there was a significant decline in the frequency of DCV in mutant mice. These findings support the hypothesis that pinealocyte SR and DCV are regulated by neural mechanisms associated with sympathetic system. Ultrastructural characteristics of pinealocytes in mutants included degenerative changes that culminated in the breakdown of cellular components and the accumulation of flocculent-containing vesicles within the cytoplasm. Ribosomal lamellar complexes were also commonly seen in pinealocytes of mutant rats. Although the mutant pineal gland exhibited signs of metabolic imbalances, the cytoarchitecture of the gland (e.g., vascular compartment) and differentiation of the cells were generally unaffected by developmental deficiencies in the gland's innervation.

Enriched immune-environment of blood-brain barrier deficient areas of normal adult rats

The circumventricular organs (CVOs) in the brain are without a blood-brain barrier (BBB) and as such directly exposed to blood plasma constituents and blood-borne pathogens. In light of previous studies showing discrepancies regarding the immunocompetence of these organs, we initiated the present study to provide a comprehensive immunohistochemical analysis of the cellular expression of immune-associated antigens within the pineal gland, area postrema and the subfornical organ. In all CVOs, subpopulations of cells morphologically similar to complement receptor type 3 immunoreactive microglial/macrophage cells expressed major histocompatibility complex (MHC) class II antigen, leucocyte common antigen (LCA/CD45), as well as CD4 and ED1 antigen. Based on morphological criteria the MHC class II antigen expressing cells could be grouped into a major population of classical parenchymal and perivascular ramified microglial cells and a minor population presenting itself as scattered or small groups of rounded macrophage-like cells. CD4 and ED1 antigen were expressed by both cell types. CD45 was preferentially expressed by macrophage-like cells. MHC class I antigen was expressed by the vascular endothelium in both BBB-protected and BBB-deficient areas and was additionally present as a lattice-like network throughout the BBB-deficient parenchyma in all CVOs. The results suggest that the BBB-free areas of the brain besides being constantly surveyed by blood-borne macrophages, possess an intrinsic immune surveillance system based on resting and activated microglial cells, which may function as a non-endothelial, cellular barrier against blood-borne pathogens.

Frequency of extra-cardiac activity and its effect on 99Tcm-MIBI cardiac SPET interpretation

There are limited published data concerning the frequency and relative intensity of abdominal activity on 99Tcm-methoxyisobutyl isonitrile (99Tcm-MIBI) myocardial perfusion scans and its effect on interpretation. We undertook a blinded prospective study to evaluate (1) the frequency and intensity of abdominal activity on single photon emission tomography (SPET) scans, (2) its effect on separate evaluation of rest and stress SPET images, and (3) its effect on clinical interpretation. Patients undergoing one-day rest-stress 99Tcm-MIBI scans were randomized to receive 99Tcm-MIBI obtained from one of two radiopharmacies. The rest plus exercise or rest plus intravenous dipyridamole scans of 303 patients were scored separately by three physicians for (1) intensity of abdominal activity and (2) its effect on scan evaluation. Nuclear reports generated independently of the blinded evaluation were reviewed to assess the effect of abdominal activity on clinical interpretation. There were no statistical differences between pharmacies. Abdominal activity was uncommon on the exercise but common on the rest and dipyridamole scans. The exercise scans differed from the rest and dipyridamole scans in the subgroups: intensity of abdominal activity equal to myocardium, and greater than myocardium (P < 0.001). There was no difference between the rest and dipyridamole scans. The effect on evaluation was moderate in 5% of the exercise, 46% of the dipyridamole and 37% of the rest scans, and severe in 1% of the exercise, 3% of the dipyridamole and 12% of the rest scans. Rest differed from exercise (P < 0.001) and from dipyridamole (P < 0.05). There was no difference between the dipyridamole and exercise scans. Based on the clinical reports, abdominal activity was a limitation to scan interpretation for 20 patients; in 5, the inferior wall could not be evaluated. Although abdominal activity was frequently observed on both the dipyridamole and rest scans, it was a limitation to clinical interpretation in a small fraction of the patients.

A multidimensional evaluation of a nursing information-literacy program

The goal of an information-literacy program is to develop student skills in locating, evaluating, and applying information for use in critical thinking and problem solving. This paper describes a multidimensional evaluation process for determining nursing students' growth in cognitive and affective domains. Results indicate improvement in student skills as a result of a nursing information-literacy program. Multidimensional evaluation produces a well-rounded picture of student progress based on formal measurement as well as informal feedback. Developing new educational programs can be a time-consuming challenge. It is important, when expending so much effort, to ensure that the goals of the new program are achieved and benefits to students demonstrated. A multidimensional approach to evaluation can help to accomplish those ends. In 1988, The University of Northern Colorado School of Nursing began working with a librarian to integrate an information-literacy component, entitled Pathways to Information Literacy, into the curriculum. This article describes the program and discusses how a multidimensional evaluation process was used to assess program effectiveness. The evaluation process not only helped to measure the effectiveness of the program but also allowed the instructors to use several different approaches to evaluation.

Regulation of synaptic ribbons in rat pineal gland explants by norepinephrine and sympathetic neurons in a co-culture model

The hypothesis that synaptic ribbons in the mammalian pinealocyte are influenced by adrenergic mechanisms was tested in the present study using a co-culture model of pineal glands and superior cervical ganglia from neonatal rats. Pineal gland explants survived and showed a high degree of differentiation when cultured for up to 30 days regardless of the presence or absence of superior cervical ganglia. Pineal glands also had neurotrophic properties promoting the survival and neurite extension from superior cervical ganglia. Synaptic ribbons were a common ultrastructural feature in all pineal cultures. There was a significant decline in synaptic ribbon numbers when co-cultured with superior cervical ganglia for both 7 and 30 days. A similar significant decrease in synaptic ribbon frequency was observed after treatment of pineal explants with norepinephrine (10(-5 )M) for both 7 and 30 days. These findings are consistent with the hypothesis that neural mechanisms play an important role in regulating synaptic ribbon numbers, at least during early development. The study also illustrates the utility of pineal gland-superior cervical ganglia co-cultures as a model for future investigations of neuron-target interactions in the pineal.

Neurotrophic effects of the pineal gland: role of non-neuronal cells in co-cultures of the pineal gland and superior cervical ganglia

The pineal gland (PG) is a source of several trophic factors. In this study, PG and superior cervical ganglia (SCG) from Sprague-Dawley neonates (1-day-old) were co-cultured to test the hypothesis that endogenous release of PG NGF (or an NGF-like cytokine) is sufficient to promote survival of SCG neurons. Neuronal density of SCG neurons was significantly enhanced when co-cultured with PG for 7 days compared to SCG cultured alone. SCG survival and neurite formation in PG co-cultures was less than in SCG treated with exogenous NGF (100 ng/ml). The neurotrophic effect of PG co-cultures was abolished when 1% anti-NGF was added to the medium. Co-cultures of SCG neurons with established 7-day PG cultures induced extensive SCG neurite formation within 24 hr compared to SCG co-cultured with 1-day PG cultures. This suggests that PG neurotrophic effects are due to PG non-neuronal cells (nnc) that proliferate to confluency by 7 days in culture. S-antigen-positive pinealocytes did not proliferate in culture. There was decreased SCG survival when neurons were seeded onto PG cultures that had been previously killed by drying, which suggests that the neurotrophic effects of nnc are not substrate-dependent. Immunocytochemical characterization of PG nnc revealed a heterogenous mixture of astrocytes, macrophage/microglia, and fibroblasts. These findings support the hypothesis that NGF is actively secreted by PG and that nnc are the principal source of this neurotophin.

Effect of leuprolide acetate in patients with moderate to severe functional bowel disease. Double-blind, placebo-controlled study

Moderate to severe functional bowel disease results in debilitating abdominal pain, nausea, intermittent vomiting, early satiety, bloating, abdominal distension, and/or altered bowel habits. Because it occurs approximately 20-30 times more frequently in women than in men and its symptoms often coincide with the menstrual cycle, we hypothesized that reproductive steroids may antagonize diseased nerves of the gastrointestinal tract, enhancing the expression of symptoms. No effective or consistent therapy has existed for these patients. We prospectively investigated the effect of a gonadotropin-releasing hormone analog, leuprolide acetate, in 30 women with symptoms of moderate to severe functional bowel disease. The study was phase II, randomized, double blind, and placebo controlled. Lupron Depot 3.75 mg (which delivers a continuous low dose of drug for one month) or placebo were given intramuscularly monthly for three months. Symptom scores were assessed at each four-week visit. Follicle-stimulating hormone, luteinizing hormone, estradiol, and progesterone levels were assessed before and after therapy. Patients treated with low-dose leuprolide improved progressively and significantly in scores for nausea, vomiting, bloating, abdominal pain, and early satiety, and for overall symptoms (P < 0.01-0.05). All hormone levels decreased significantly (P < 0.05) except luteinizing hormone (P = 0.054).

Immunocytochemical and electron-microscopic characterization of macrophage/microglia cells and expression of class II major histocompatibility complex in the pineal gland of the rat

Interstitial cells in the pineal gland of the rat were characterized immunocytochemically using the monoclonal antibodies MRC OX-42 and ED1 for macrophages/microglia, and MRC OX-6, which recognizes major histocompatibility complex (MHC) class II antigen. A polyclonal antibody against GFAP was used to identify astrocytes. Cells immunopositive for OX-42 and/or ED1 were distributed throughout the gland; they extended processes primarily along the perivascular spaces and occasionally within the parenchyma of the gland. Ultrastructurally, these OX-42-positive cells were characterized by a nucleus with sparse heterochromatin and cytoplasmic vacuoles/lysosomes. Cells expressing MHC class II antigen had a distribution and morphology similar to OX-42-immunopositive cells, suggesting that pineal macrophages/microglia play a role as antigen-presenting cells. GFAP-positive astrocytes were concentrated at the proximal end of the pineal where the pineal stalk enters the gland. The occurrence of antigen-presenting cells in this circumventricular neuroendocrine gland has important functional implications as these cells may be mediators of neuroimmunomodulatory mechanisms, and involved in certain disease states such as autoimmune pinealitis.

Immunocytochemical demonstration of nerve growth factor (NGF) receptor in the pineal gland: effect of NGF on pinealocyte neurite formation

Nerve growth factor receptor immunoreactivity (NGFRI) in the pineal gland was examined both light and electron microscopically using the monoclonal antibody 192IgG. NGFRI was located on sympathetic fibers and on perivascular cells resembling macrophage/microglia. A pineal gland dispersed cell culture model confirmed the presence of NGFRI in cells that exhibited processes of varying lengths and were distributed among pinealocytes and other flat cells. Pinealocytes in dispersed cell culture were identified immunocytochemically by their expression of S-antigen, their round shape and small size and their tendency to extend neurites in the direction of the flat cells in culture. The length of pinealocyte neurites showed a significant increase when cultured in the presence of NGF (25 ng/ml), suggesting that trophic factors, mediated by these macrophage/microglial cells, are important to the morphogenesis of these neuroendocrine cells. Neurotrophic activation of these neuroendocrine macrophage/microglia may have neuro-immunomodulatory implications leading to expression of proteins encoded by the major histocompatibility complex.

Experimental autoimmune pinealitis in the rat: ultrastructure and quantitative immunocytochemical characterization of mononuclear infiltrate and MHC class II expression

Lewis rats immunized with Peptide M (an oligopeptide epitope of the S-antigen protein) developed experimental autoimmune uveoretinitis (EAU) and experimental autoimmune pinealitis (EAP). Temporal changes in mononuclear infiltrate to the pineal gland were quantitated by computer image analysis of sections immunostained with monoclonal antibodies to specific mononuclear populations. T helper/inducer cells (W3/25+) and monocyte/macrophages (OX-42+) were elevated during the early phases of inflammation (day 15) while cytotoxic/suppressor T cells (OX-8+) were elevated at days 15 and 21. Expression of MHC class II (OX-6) was markedly enhanced on pineal glia, but was not present on vascular endothelia during EAP. Ultrastructurally, many capillaries exhibited thickenings of the endothelia and basal lamina. EAP had little effect on the fine structure of pinealocytes and glia and there was little evidence of cellular destruction by day 21, in contrast to the extensive retinal destruction resulting from EAU. These findings suggest fundamental differences between EAU and EAP related to mechanisms of antigen processing/recognition in autoimmune diseases. Our study further indicates the importance of EAP as a model to investigate neuroendocrine-immune interactions.

The major calmodulin-binding protein in rabbit parietal cells is Ca2+/calmodulin-dependent protein kinase II

Parietal cell secretion can be stimulated by both histaminergic and cholinergic agonists. We have recently found that inhibition of calmodulin-dependent protein kinase II (CaMK II) activity can abolish cholinergic but not histaminergic stimulation of parietal cell secretion (Am. J. Physiol. 262:G118-122). We have investigated the presence of calmodulin-binding proteins and CaMK II in isolated rabbit parietal cells. Calmodulin-binding proteins with apparent molecular masses of 50, 60, 85, 100, and 240 kDa were observed. The major calmodulin-binding species was a 50 kDa band which was enriched in 50,000 g. microsomal membranes. The 50 kDa calmodulin binding comigrated with immunoreactivity for CaMK II. Partial purification of the microsomal CaMK II demonstrated a 250 kDa oligomer. The results demonstrate that CaMK II is the major calmodulin-binding protein in parietal cells and is associated primarily with light microsomal membranes.

Pinealocyte synaptic ribbons and neuroendocrine function

A comparative study of pinealocyte synaptic ribbons (SR) revealed two predominant populations exhibiting either a rod/ribbon shape (SRr) or a spherical/punctate shape (SRsp). Species-specific differences were found in the abundance of SR, the ratio of SRr/SRsp, and the occurrence of SR in ribbon fields. The close topographical relationship of SR to the plasma membrane and the numerical changes that occurred with changes in metabolism of the pinealocytes suggest that SR have important vesicle-mediated interactions with the cell membrane. Experiments designed to clarify the relationship between SR and pineal neuroendocrine function revealed a positive correlation between SR numbers and indole intermediates during pineal development in the rat, and increased SR frequency after denervation of the rat pineal gland or administration of the beta-adrenergic agonist, isoproterenol. These data are consistent with the hypothesis that SR function is linked to receptor mechanisms regulating indoleamine production in the pineal gland.

An inhibitor of Ca2+/calmodulin-dependent protein kinase II, KN-62, inhibits cholinergic-stimulated parietal cell secretion

Cholinergic stimulation of parietal cell secretion is mediated by an increase in intracellular calcium. KN-62, a selective inhibitor of Ca2+/calmodulin-dependent protein kinase II (CaMK II), has recently been synthesized (Tokomitsu et al. J. Biol. Chem. 265: 4315-4320, 1990). To define the role of CaMK II in parietal cell secretion, we determined the effects of KN-62 on secretagogue-stimulated acid secretion in isolated rabbit parietal cells. Pretreatment of parietal cells with KN-62 resulted in the inhibition of carbachol-stimulated [14C]aminopyrine uptake over a concentration range of 3 to 60 microM (IC50 of 20 microM). KN-62 (60 microM) reduced carbachol-stimulated aminopyrine uptake to unstimulated levels. KN-62 did not alter carbachol-stimulated increases in cytoplasmic free Ca2+ concentration. High concentrations of KN-62 (60 microM) elicited a small decrease in aminopyrine uptake stimulated by forskolin, but did not significantly inhibit histamine stimulation. A potent CaMK II activity was identified in total membrane from parietal cells. These results suggest that CaMK II may mediate cholinergic-stimulated parietal cell secretion.

Cardiac manifestations of Weber-Christian disease: report and review of the literature

A patient with chronic systemic Weber-Christian disease who was treated with hydroxychloroquine developed cardiac dilatation with congestive heart failure. Endomyocardial biopsy demonstrated myocyte degeneration and interstitial fibrosis, but no typical features of chloroquine induced cardiomyopathy. Clinical symptoms of congestive heart failure also were recognized in 7 of the 11 reported autopsy cases of Weber-Christian disease having cardiac involvement. This involvement can affect the pericardium and the myocardium.

Pineal gland transplants into the cerebral hemisphere of newborn rats: a study of the blood brain barrier and innervation

Pineal glands from neonatal (0-1 day) Long-Evans black-hooded rats were transplanted into the cerebral hemispheres of litter mates for periods of 1 to 5.5 months. Grafts exhibited differentiated pinealocytes that were intensely immunoreactive for serotonin. Transplant vasculature was permeable to endogenous IgG, comprised fenestrated endothelia with wide pericapillary spaces typical of in situ glands, and had a volume density intermediate to that of surrounding cortex and in situ pineals. Along the periphery, transplant capillaries tended to have continuous endothelia similar to those of host cortex. This peripheral zone was impermeable to endogenous IgG and appeared to increase in size in older grafts. The presence of noradrenergic-like fibers within the perivascular compartment suggested that transplants were innervated by peripheral sympathetic neurons from the superior cervical ganglia. In animals which had been superior cervical ganglionectomized, noradrenergic-like fibers were absent or degenerating. Neural regulation of transplant metabolic activity was suggested by the increased frequency of pinealocyte synaptic ribbons in denervated grafts. These findings are consistent with the hypothesis that factors from both graft and host influence vasculature physiology and differentiation in neural transplants. Furthermore, grafts appeared to receive appropriate neural input from the peripheral sympathetic system.

Circadian analysis of mononuclear cells in the rat following pinealectomy and superior cervical ganglionectomy

The role of the pineal gland and adrenocorticosteroids in circadian rhythmicity of immune function was investigated in Sprague-Dawley rats that either had been pinealectomized (PX) or had undergone superior cervical ganglionectomy (SCGX), which functionally denervates the pineal. For both experiments, conducted between August and October, rats were entrained to a 10-h light:14-h dark cycle and fed ad libitum. The circadian rhythm in monocytes (ANOVA, p less than .01 for Control + Sham + PX samples) tended to parallel that of plasma corticosteroid levels (ANOVA, p less than .01) with the peak during early dark and the nadir at early light. In comparison, suppressor/cytotoxic T cells and B cells tended to be more frequent during early light with minimum levels during early dark (ANOVA, p less than .05 and .01, respectively, for Control + Sham + PX samples). Natural killer (NK) activity in control animals varied significantly (ANOVA, p less than .05) over the light:dark cycle with peak activity during early dark in the SCGX experiment, but was only slightly elevated during late dark in the PX experiment. PX animals exhibited increased frequency of NK cells, but only in samples collected during the day (t test, p less than .05). This effect was not observed in sham-operated PX controls and in SCGX animals. Neither PX nor SCGX had a significant (ANOVA) effect on plasma corticosterone levels. These observations in the rat are consistent with findings in mice and humans that corticosteroids play an important general role in circadian rhythmicity of immune functions. In contrast, the present study suggests that pineal gland influence of immune function(s) is more specific and that pineal gland interaction with NK cells has a circadian component.

A circannual cycle in pinealocyte synaptic ribbons in the hibernating and seasonally reproductive 13-lined ground squirrel (Spermophilus tridecemlineatus)

Pinealocyte synaptic ribbons (SR) in the 13-lined ground squirrel were quantified at monthly intervals over a one-year period spanning the hibernating and reproductive cycles of these animals. SR numbers were high (70-90/20,000 microns2) during periods of activity and reproductive quiescence (May-October). With the onset of hibernation (November-December) there was a rapid 6 to 7-fold reduction in SR frequency. During arousal (January-February) and sexual maturation (March-April) there was a gradual increase in SR frequency. The winter decline in SR frequency is consistent with the decline in pineal melatonin during hibernation and supports the hypothesis that pinealocyte SR play an important role in the neurotransduction of melatonin biosynthesis.

Ultrastructure and organization of circumventricular organs and endolymphatic tubules in the treefrog, Hyla versicolor

The morphology and anatomical relationship of the paraphysis, anterior choroid plexus, and endolymphatic tubules of Hyla versicolor suggest that these structures may act as a functional unit to regulate composition of the cerebrospinal fluid (CSF). Ependymal cells of both the paraphysis and the choroid plexus exhibit ultrastructural features (an extensive microvillar border, large intercellular spaces containing an amorphous material, and apically located mitochondria) which indicate active exchange between the blood and CSF. Mast cells (which may play a role in regulating vascular permeability) also occur on the brush border. The tubules of the endolymphatic sacs were found to lie in close relation with the dorsal portion of the paraphysis. The endolymphatic organ is known to play a role in systemic buffering during respiratory acidosis and may influence Na/K fluxes via calcium release. The association of the paraphysis with the endolymphatic tubules may therefore represent an important mechanism for ion regulation in the CSF of amphibians. The ultrastructure of the pineal organ agrees with descriptions for other species. No pineal stalk was present. Photoreceptor inner and outer segments project into a central lumen continuous with the third ventricle. Outer segments show signs of disorganization. Photoreceptor/neural dendrite contacts involve synaptic ribbons and conventional synapses.

Day-night differences in the vesicle populations of nerve terminals in the rat and chick pineal gland

Day-night differences in the ultrastructure of pineal neuronal elements were quantitated in the rat and the chick--two species that exhibit important differences in adrenergic control of melatonin synthesis. Area densities of small clear vesicles (40-60 nm) and small dense-cored vesicles (40-60 nm) in nerve terminals were significantly reduced during the night in the rat. In the chick, there were no day-night differences in the frequency of clear vesicles, but the number of small dense-cored vesicles tended to be greater at night. There was no effect of day-night sampling on area densities of large dense-cored vesicles (80-120 nm) in either species. These findings are consistent with biochemical evidence for day-night species differences in the adrenergic control of pineal function.

Delayed redistribution in thallium 201 SPECT myocardial perfusion studies

Stress 201Tl myocardial perfusion studies are useful in differentiating viable, reversibly ischemic from infarcted myocardium. A perfusion defect that shows redistribution 2 to 4 h after 201Tl injection is diagnostic of ischemia, while a fixed defect suggests infarction. However, occasional patients with a fixed defect at 4 h have redistribution at 24 h. This study evaluates the frequency and significance of this delayed redistribution with SPECT 201Tl. Patients with either no or incomplete redistribution at 4 h had repeat imaging 18 to 48 h later. Delayed redistribution was seen in 8/26 (31 percent). Four had incomplete and four had no redistribution at 4 h. Delayed redistribution with SPECT 201Tl is more common than generally appreciated, and we recommend delayed images in patients with fixed perfusion defects or incomplete redistribution at 4-h imaging, particularly in patients with previous infarctions for whom a revascularization procedure is being considered.

Effects of isoproterenol on synaptic ribbons in pinealocytes of the rat and C57BL/6J mouse

Synaptic ribbons (SR) in melatonin-deficient pinealocytes of the C57BL/6J mouse were quantitatively compared to SR in pinealocytes of the rat after beta-adrenergic receptor activation by isoproterenol. Two populations of SR comprising synaptic spherules (SRsp) and synaptic rods (SRr) were described in both the mouse and the rat, but species differences existed in the ratio of SRr to SRsp. Isoproterenol caused a significant increase in frequency of SR of the rat but had little or no effect on SR populations in the mouse. It is unlikely that beta-adrenergic receptors are absent on mouse pinealocytes or were not activated since isoproterenol elevated plasma renin concentrations indicating activation of beta-adrenergic receptors. Furthermore the pineal of both species receives heavy sympathetic input. These findings indicate that the role and regulation of pinealocyte SR are complex and are functionally linked to beta-adrenergic receptors as well as other mechanisms related to the production of melatonin.

Day-night variability in acid phosphatase activity of pineal gland macrophages

Acid phosphatase (ACP) activity was investigated in the photoreceptive pineal gland of the goldfish by both light and electron microscopy. Intraluminal macrophages exhibited the greatest ACP reactivity that was generally confined to lysosomal bodies containing membranous debris. Quantitative light microscopic evaluation revealed significantly higher ACP reactivity in animals collected at mid-light compared to those collected at mid-dark suggesting that functional activities of macrophages in this photoneuroendocrine organ are cyclical over the 24-h photoperiod. Day-night differences in macrophage ACP activity may reflect rhythmic renewal and shedding of photoreceptor outer segment membranes.

Electrophysiology and ultrastructure of eustachian ridge from cat right atrium: a comparison with SA node

Intracellular microelectrode and electron microscopic techniques were used to investigate and correlate the electrophysiology of subsidiary pacemaker activity with the presence of cells having ultrastructural characteristics of pacemaker cells i.e. P cells, in Eustachian ridge tissue isolated from cat right atrium. In addition, the electrophysiological characteristics of subsidiary pacemaker activity and the ultrastructural characteristics of P cells in Eustachian ridge were compared to those of SA node obtained from the same hearts. Action potential recordings and morphological analysis were restricted to the endocardial site of earliest activation. Electrophysiological recordings revealed that spontaneously active Eustachian ridge tissues generate slow response action potentials with pacemaker characteristics similar, although not identical, to those of SA node. These included a relatively steep diastolic slope, low maximum diastolic potential (-70 mV), rate of rise (5.5 V/s), take-off potential (-52.5 mV), a relatively large overshoot potential (+7.7 mV) and a spontaneous cycle length (948 ms) about twice as long as SA node (434 ms). Morphological analysis revealed cells with ultrastructural characteristics of P cells, that were restricted to the endocardial site of earliest pacemaker activation. Morphological measurements indicate that Eustachian ridge P cells are not significantly different from P cells in SA node of the same hearts. However, Eustachian ridge P cells exhibit a unique apposition of subsarcolemmal cisternae between cells not seen in SA node. We conclude that pacemaker cells within the Eustachian ridge generate stable, spontaneous activity via slow response pacemaker action potentials. Cells responsible for this subsidiary pacemaker activity are most likely P cell types that are similar, although not identical, to P cells in SA node.

Pinealocyte dense-cored vesicles and synaptic ribbons: a correlative ultrastructural-biochemical investigation in rats and mice

Dense-cored vesicles (DCV) and synaptic ribbons (SR) were quantified in the pineal gland of the rat (Sprague-Dawley) and mouse (Sasco/ICR strain), and day/night differences in frequency of these organelles correlated with levels of indoles determined by high performance liquid chromatography (HPLC). There were significant day/night differences in levels of serotonin (5HT), 5-hydroxyindole acetic acid (5HIAA), N-acetyl-5HT, and melatonin in the rat gland. Melatonin and N-acetyl-5HT were not detectable in the mouse gland sampled every 4 h over the light:dark cycle. The concentrations of 5HT and 5HIAA (ng/microgram protein) were similar in light-adapted rats and mice, but these indoles did not exhibit a circadian rhythm in the mouse gland. Correlative ultrastructural/biochemical results suggest that DCV do not contain physiologically important stores of 5HT since 1) the mouse gland contains the same number of DCV as the rat during the daytime, but only one-tenth the levels of 5HT, 2) day/night 5HT levels do not vary in the mouse gland, but there is a significant nocturnal decline in DCV numbers, and 3) 5HT levels in the rat gland decline at night when DCV numbers increase. Numbers of SR were significantly elevated at night in the rat and mouse, and the frequency of this organelle was similar in both species. However, ribbon-type SR predominated in rat pinealocytes, whereas SR in the mouse were almost exclusively spherical in shape. Day/night differences in SR numbers in the mouse gland suggest that cellular mechanisms regulating the frequency of this organelle do not involve factors related to indole metabolism. Because of the lack of photoperiodic effects on indole metabolism in the mouse pineal gland, this species is a potentially important model to study the functional relationship of pinealocyte organelles to cyclical changes in pineal products other than indoles (e.g., peptide/protein factors).

The assessment of contractile reserve after thrombolytic therapy for acute myocardial infarction

"Stunned" myocardium prevents the assessment of myocardial salvage after streptokinase. In order to unmask "stunning," we sought to evaluate left ventricular inotropic contractile reserve of patients after streptokinase. Radionuclide ventriculograms were obtained in 75 consecutive patients 2 weeks after myocardial infarction, at rest and during intravenous isoproterenol infusion. Resting and isoproterenol-stressed ejection fractions were compared in the patent and closed-infarct vessel groups. Although there was no difference in the resting ejection fractions between the patent group (0.48 +/- 0.02) and the closed group (0.48 +/- 0.02), isoproterenol increased the ejection fractions in the patent group (increase 0.14 +/- 0.01) significantly more than in the closed group (increase 0.06 +/- 0.01) (p less than 0.0001). Thus, despite identical resting ventricular function, the greater inotropic contractile reserve in the patent infarct vessel group suggests that restoration of blood flow in acute myocardial infarction salvages myocardium.

Temperature dependence of protein transport across lymphatic endothelium in vitro

The purpose of the work was to develop an in vitro model for the study of lymphatic endothelium and to determine, using this model, whether or not a cytoplasmic process may be involved in transendothelial transport. Segments of canine renal hilar lymphatics were dissected clean, cannulated at both ends, and transferred to a perfusion chamber for measurement of transendothelial protein transport and for ultrastructural tracer studies. The segments were subsequently processed for light and electron microscopy. By both structural and functional criteria the lymphatics were judged to have retained their integrity. At 37 degrees C, 36 lymphatics showed a mean rate of protein transport of 3.51 +/- 0.45 (SEM) micrograms/min per cm2 of lymphatic endothelium. The rate was influenced by the temperature of the system, being significantly reduced by 49% +/- 4.8, 31% +/- 5.3, and 29% +/- 3.9 when the temperature was lowered to 4 degrees, 24 degrees, and 30 degrees C, respectively. When the temperature was raised to 40 degrees C, the rate was significantly increased by 48% +/- 12.2. The vesicular system and the intercellular regions in vessels with increased or reduced rates of transport were analyzed quantitatively to ascertain whether the rate changes could be correlated with ultrastructurally demonstrable changes in either of these postulated pathways. No significant changes in junctional or vesicular parameters were found between the control lymphatics and those perfused at 24 degrees, 30 degrees, and 40 degrees C. At 4 degrees C, the temperature at which the rate of protein transport was maximally reduced, vesicular size decreased, and the number of free cytoplasmic vesicles increased, whereas the number associated with the abluminal and luminal surfaces decreased. We concluded that isolated perfused lymphatic segments transport protein at a relatively constant rate under control conditions, and that this transendothelial transport comprises both temperature-dependent and temperature-independent mechanisms. The findings were considered in terms of the different theories of lymph formation and were interpreted as providing support for the vesicular theory.

Capacity of deoxycytidine to selectively antagonize cytotoxicity of 5-halogenated analogs of deoxycytidine without loss of antiherpetic activity

Enzyme kinetic studies from this laboratory (M. Dobersen and S. Greer, Biochemistry 17:920-928, 1978) suggested that deoxycytidine could antagonize the toxicity of 5-halogenated analogs of deoxycytidine without interfering with their antiviral activity. Antagonism by deoxycytidine of the toxicity of 5-chlorodeoxycytidine without impairing its anti-herpes simplex virus type 2 activity is demonstrated in the present studies. Tetrahydrouridine, an inhibitor of cytidine deaminase, was utilized. The high Km for deoxycytidine (0.6 mM) with respect to the herpes pyrimidine nucleoside kinase as compared with the low Km for 5-chlorodeoxycytidine (1.1 microM) accounts for the absence of antagonism of the antiviral activity. The high Km for 5-chlorodeoxycytidine (56 microM) as compared with the low Km of deoxycytidine (2 microM) with respect to mammalian deoxycytidine kinase accounts, in great part, for the antagonism of toxicity. In addition, antagonism of toxicity by deoxycytidine is the result of factors other than the kinetic parameters of nucleoside kinases, as indicated by its antagonism of the cytotoxicity of 5-chlorodeoxyuridine. This may be attributed to replenishment of low dCTP pools, diminished because of effector inhibition of ribonucleoside diphosphate reductase by Cl-dUTP. Resistance of the herpes-encoded enzymes to effector control may also play a role in the selective antagonism. Cell culture studies with high concentrations of tetrahydrouridine and 2'-deoxytetrahydrouridine suggest that competition by deoxycytidine for deaminases may not play a major role. The fact that deoxycytidine antagonizes the toxicity of chlorodeoxyuridine also argues against competition for the deaminases as a major reason for its effect. Limited studies with a topical herpes simplex virus type 2 infection system indicate heightened efficacy of 5-chlorodeoxycytidine (and tetrahydrouridine) when deoxycytidine is coadministered. The concepts of selective antagonism of a chemotherapeutic agent derived from these studies may be applied to other approaches that extent beyond viral chemotherapy.

The morphology of canine lymphatic valves

The architecture of 60 valves from thoracic ducts and from renal hilar and mesenteric collecting lymph vessels of dogs were studied by scanning electron microscopy as well as by light and transmission electron microscopy. All of the valves seen in hilar and mesenteric lymph vessels and most of those studied in the thoracic duct were bicuspid. An occasional tricuspid and one monocuspid valve was seen in the thoracic duct. The semilunar cusps of the valves extended from the vessel wall, to which they were attached, towards the valve outlet where adjacent cusps fused. Coincident to the area of fusion was the formation of mesenteric-like folds or buttresses that anchored the cusps to the vessel wall. These folds extended 50-100 micrometers beyond the cusp margins on the outflow side of the valve. The attachments of the cusps, buttresses, and vessel wall to one another resulted in the formation of postvalvular sinuses, such that raised intraluminal pressure downstream to valve areas would distend the sinuses, causing leaflet apposition and hence valvular closure. The morphology of the valves was such that they were not considered to provide any significant impediment to the antegrade flow of lymph.

Left ventricular function in sickle cell anemia: a noninvasive evaluation

There is controversy in the medical literature regarding the significance of "sickle cell cardiomyopathy." In an attempt to clarify this, we studied 14 patients with sickle cell anemia (age range 16 to 36 years) using simultaneous echocardiography and phonocardiography. The values of systolic time intervals and echocardiographic indices of left ventricular performance were similar to those reported for normal subjects and those with comparable degrees of anemia. We confirm a previous report of normal left ventricular function at rest in patients with sickle cell anemia and concur with the suggestion that a concomitant heart disease be considered in these patients when cardiac failure supervenes.

Devic's syndrome and systemic lupus erythematosus: a case report with necropsy

Systemic lupus erythematosus (SLE) rarely occurs coincident with demyelinating disease and, to our knowledge, only one previous case of Devic's syndrome with SLE has been reported.