Mediterranean springs: Keystone ecosystems and biodiversity refugia threatened by global change

Mediterranean spring ecosystems are unique habitats at the interface between surface water and groundwater. These ecosystems support a remarkable array of biodiversity and provide important ecological functions and ecosystem services. Spring ecosystems are influenced by abiotic, biotic, and anthropogenic factors such as the lithology of their draining aquifers, their climate, and the land use of their recharge area, all of which affect the water chemistry of the aquifer and the spring discharges. One of the most relevant characteristics of spring ecosystems is the temporal stability of environmental conditions, including physicochemical features of the spring water, across seasons and years. This stability allows a wide range of species to benefit from these ecosystems (particularly during dry periods), fostering an unusually high number of endemic species. However, global change poses important threats to these freshwater ecosystems. Changes in temperature, evapotranspiration, and precipitation patterns can alter the water balance and chemistry of spring water. Eutrophication due to agricultural practices and emergent pollutants, such as pharmaceuticals, personal care products, and pesticides, is also a growing concern for the preservation of spring biodiversity. Here, we provide a synthesis of the main characteristics and functioning of Mediterranean spring ecosystems. We then describe their ecological value and biodiversity patterns and highlight the main risks these ecosystems face. Moreover, we identify existing knowledge gaps to guide future research in order to fully uncover the hidden biodiversity within these habitats and understand the main drivers that govern them. Finally, we provide a brief summary of recommended actions that should be taken to effectively manage and preserve Mediterranean spring ecosystems for future generations. Even though studies on Mediterranean spring ecosystems are still scarce, our review shows there are sufficient data to conclude that their future viability as functional ecosystems is under severe threat.

Senolytics dasatinib and quercetin in idiopathic pulmonary fibrosis: results of a phase I, single-blind, single-center, randomized, placebo-controlled pilot trial on feasibility and tolerability

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is an age-related, chronic, irreversible fibrotic lung disease. IPF is associated with increased senescent cells burden, which may be alleviated with administration of senescent cell targeting drugs termed 'senolytics'. We previously conducted an open-label single-arm pilot study of the senolytic combination of dasatinib and quercetin (D + Q) in patients with IPF but lack of control group limited interpretation and next-stage trial planning. The primary objective of this confirmatory randomized placebo-controlled pilot trial (RCT; NCT02874989) was to report adverse events with D + Q and inform study feasibility for future efficacy trials.

METHODS

Twelve participants with IPF aged >50 years were blinded and randomized at a 1:1 ratio to either receive three weeks of D + Q (D: 100 mg/d and Q: 1250 mg/d, three consecutive days per week) or matching placebo.

FINDINGS

All participants completed the scheduled drug dosing regimen (108/108 doses) and planned assessments (60/60). While the placebo arm reported fewer overall non-serious AEs (65 vs 22), there were no serious adverse events related to D + Q. Most AEs in the D + Q arm are common in IPF patients or anticipated side effects of D. Sleep disturbances and anxiety were disproportionately represented in the D + Q arm (4/6 vs 0/6). Frailty, pulmonary, or physical function were explored before and after intermittent D + Q; though under-powered to evaluate change, these measures do not appear to differ meaningfully between groups.

INTERPRETATION

Intermittently-dosed D + Q in patients with IPF is feasible and generally well-tolerated. Further prospective studies, such as a larger RCT, are needed to confirm the safety and efficacy of D + Q in patients with IPF.

FUNDING

This work was supported by National Institutes of Health grants R33AG61456 (JLK, TT), Robert and Arlene Kogod (JLK, TT), the Connor Fund (JLK, TT), Robert J. and Theresa W. Ryan (JLK, TT), and the Noaber Foundation (JLK, TT) San Antonio Claude D. Pepper Older Americans Independence Center's (OAIC)Pilot/Exploratory Studies Core (PESC) Grant (AMN, NM); NIHK01 AG059837 (JNJ), P30 AG021332 (SBK, JNJ); NIHR37 AG013925 (JLK), the Connor Group (JLK), Glenn/AFAR BIG Award (JLK), Robert J. and Theresa W. Ryan (JLK), and the Noaber and Ted Nash Long Life Foundations (JLK).

Senolytics in idiopathic pulmonary fibrosis: Results from a first-in-human, open-label, pilot study

Background

Cellular senescence is a key mechanism that drives age-related diseases, but has yet to be targeted therapeutically in humans. Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal cellular senescence-associated disease. Selectively ablating senescent cells using dasatinib plus quercetin (DQ) alleviates IPF-related dysfunction in bleomycin-administered mice.

Methods

A two-center, open-label study of intermittent DQ (D:100 mg/day, Q:1250 mg/day, three-days/week over three-weeks) was conducted in participants with IPF (n = 14) to evaluate feasibility of implementing a senolytic intervention. The primary endpoints were retention rates and completion rates for planned clinical assessments. Secondary endpoints were safety and change in functional and reported health measures. Associations with the senescence-associated secretory phenotype (SASP) were explored.

Findings

Fourteen patients with stable IPF were recruited. The retention rate was 100% with no DQ discontinuation; planned clinical assessments were complete in 13/14 participants. One serious adverse event was reported. Non-serious events were primarily mild-moderate, with respiratory symptoms (n = 16 total events), skin irritation/bruising (n = 14), and gastrointestinal discomfort (n = 12) being most frequent. Physical function evaluated as 6-min walk distance, 4-m gait speed, and chair-stands time was significantly and clinically-meaningfully improved (p < .05). Pulmonary function, clinical chemistries, frailty index (FI-LAB), and reported health were unchanged. DQ effects on circulat.ing SASP factors were inconclusive, but correlations were observed between change in function and change in SASP-related matrix-remodeling proteins, microRNAs, and pro-inflammatory cytokines (23/48 markers r ≥ 0.50).

Interpretation

Our first-in-humans open-label pilot supports study feasibility and provides initial evidence that senolytics may alleviate physical dysfunction in IPF, warranting evaluation of DQ in larger randomized controlled trials for senescence-related diseases.

ClinicalTrials.gov identifier: NCT02874989 (posted 2016–2018).

Effects of bronchoscopy on lung function in asthmatics

BACKGROUND

To better understand the changes in pulmonary physiology related to asthma severity following bronchoscopy, we performed scheduled pre- and post-procedure spirometry on subjects undergoing bronchoscopy in our research program.

METHODS

Control subjects and asthma subjects were recruited for bronchoscopy. On the day of bronchoscopy, subjects underwent spirometry pre-bronchoscopy and then up to three sets within 2 hour following the completion of bronchoscopy. A subset of patients had a second bronchoscopy after 2 weeks of treatment with oral prednisolone (40mg daily).

RESULTS

A total of 92 subjects had at least one bronchoscopy (12 control subjects, 56 nonsevere asthma (NSA), 24 severe asthma (SA)). The SA and NSA groups had similar decreases in forced expiratory volume in 1 second (FEV1) (-20±13% vs.-19±16%, p = 0.92) and forced vital capacity (FVC) (-20±12% vs.-20±14%, p = 0.80), but no change in FEV1/FVC ratio. The control and NSA group had more rapid recovery of both FEV1 and FVC by 2 hour compared to the SA group (p = 0.01). In the subset of 36 subjects (22 NSA, 14 SA) who underwent a second bronchoscopy following the administration of oral prednisolone for 14 days, steroids resulted in more rapid recovery of lung function (p < 0.04).

CONCLUSION

Following bronchoscopy the lung function of NSA subjects recovered more quickly than SA subjects. Treatment with oral corticosteroids was associated with a quicker recovery of FEV1 which suggests an inflammatory mechanism for these changes in lung compliance.

Effect of antenatal betamethasone administration on rat cerebellar expression of type la metabotropic glutamate receptors (mGluRla) and anxiety-like behavior in the elevated plus maze

Preclinical studies indicate that endogenous or exogenous glucocorticoids acting during the pre- or postnatal periods produce a significant Purkinje cell dendritic atrophy, especially during late postnatal ages. The present authors hypothesized that the underlying sub- strate that may contribute in part to this morphological change is the under-expression of the metabotropic glutamate la receptor (mGluRl a) because its expression is correlated with Purkinje cell dendritic outgrowth. Therefore, in the current study, they analyzed the impact of antenatal betamethasone on the immunoreactive expression of the mGluR 1 a and on anxiety-like behavior in the elevated plus maze (EPM). Pregnant rats were randomly divided into two experimental groups: control (CONT) and betamethasone-treated (BET). At gestational day 20 (G20), BET rats were subcutaneously injected with a solution of 170 μg.kg(-1) of betamethasone, and CONT animals received a similar volume of saline. At postnatal days 22 (P22) and P52, BET and CONT offspring were evaluated behaviorally in the EPM, and their cerebella were immunohistochemically processed. Contrary to the uthors' expected results, animals that were prenatally treated with a single course of betamethasone did not exhibit under-expression of mGluRl a or behavioral changes consistent with anxiety-like behaviors.

Predictors of response to tiotropium versus salmeterol in asthmatic adults

BACKGROUND

Tiotropium has activity as an asthma controller. However, predictors of a positive response to tiotropium have not been described.

OBJECTIVE

We sought to describe individual and differential responses of asthmatic patients to salmeterol and tiotropium when added to an inhaled corticosteroid, as well as predictors of a positive clinical response.

METHODS

Data from the double-blind, 3-way, crossover National Heart, Lung, and Blood Institute's Asthma Clinical Research Network's Tiotropium Bromide as an Alternative to Increased Inhaled Glucocorticoid in Patients Inadequately Controlled on a Lower Dose of Inhaled Corticosteroid (ClinicalTrials.gov number, NCT00565266) trial were analyzed for individual and differential treatment responses to salmeterol and tiotropium and predictors of a positive response to the end points FEV1, morning peak expiratory flow (PEF), and asthma control days (ACDs).

RESULTS

Although approximately equal numbers of patients showed a differential response to salmeterol and tiotropium in terms of morning PEF (n = 90 and 78, respectively) and ACDs (n = 49 and 53, respectively), more showed a differential response to tiotropium for FEV1 (n = 104) than salmeterol (n = 62). An acute response to a short-acting bronchodilator, especially albuterol, predicted a positive clinical response to tiotropium for FEV1 (odds ratio, 4.08; 95% CI, 2.00-8.31; P < .001) and morning PEF (odds ratio, 2.12; 95% CI, 1.12-4.01; P = 0.021), as did a decreased FEV1/forced vital capacity ratio (FEV1 response increased 0.39% of baseline for every 1% decrease in FEV1/forced vital capacity ratio). Higher cholinergic tone was also a predictor, whereas ethnicity, sex, atopy, IgE level, sputum eosinophil count, fraction of exhaled nitric oxide, asthma duration, and body mass index were not.

CONCLUSION

Although these results require confirmation, predictors of a positive clinical response to tiotropium include a positive response to albuterol and airway obstruction, factors that could help identify appropriate patients for this therapy.

Comparison of physician-, biomarker-, and symptom-based strategies for adjustment of inhaled corticosteroid therapy in adults with asthma: the BASALT randomized controlled trial

CONTEXT

No consensus exists for adjusting inhaled corticosteroid therapy in patients with asthma. Approaches include adjustment at outpatient visits guided by physician assessment of asthma control (symptoms, rescue therapy, pulmonary function), based on exhaled nitric oxide, or on a day-to-day basis guided by symptoms.

OBJECTIVE

To determine if adjustment of inhaled corticosteroid therapy based on exhaled nitric oxide or day-to-day symptoms is superior to guideline-informed, physician assessment-based adjustment in preventing treatment failure in adults with mild to moderate asthma.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, parallel, 3-group, placebo-controlled, multiply-blinded trial of 342 adults with mild to moderate asthma controlled by low-dose inhaled corticosteroid therapy (n = 114 assigned to physician assessment-based adjustment [101 completed], n = 115 to biomarker-based [exhaled nitric oxide] adjustment [92 completed], and n = 113 to symptom-based adjustment [97 completed]), the Best Adjustment Strategy for Asthma in the Long Term (BASALT) trial was conducted by the Asthma Clinical Research Network at 10 academic medical centers in the United States for 9 months between June 2007 and July 2010.

INTERVENTIONS

For physician assessment-based adjustment and biomarker-based (exhaled nitric oxide) adjustment, the dose of inhaled corticosteroids was adjusted every 6 weeks; for symptom-based adjustment, inhaled corticosteroids were taken with each albuterol rescue use.

MAIN OUTCOME MEASURE

The primary outcome was time to treatment failure.

RESULTS

There were no significant differences in time to treatment failure. The 9-month Kaplan-Meier failure rates were 22% (97.5% CI, 14%-33%; 24 events) for physician assessment-based adjustment, 20% (97.5% CI, 13%-30%; 21 events) for biomarker-based adjustment, and 15% (97.5% CI, 9%-25%; 16 events) for symptom-based adjustment. The hazard ratio for physician assessment-based adjustment vs biomarker-based adjustment was 1.2 (97.5% CI, 0.6-2.3). The hazard ratio for physician assessment-based adjustment vs symptom-based adjustment was 1.6 (97.5% CI, 0.8-3.3).

CONCLUSION

Among adults with mild to moderate persistent asthma controlled with low-dose inhaled corticosteroid therapy, the use of either biomarker-based or symptom-based adjustment of inhaled corticosteroids was not superior to physician assessment-based adjustment of inhaled corticosteroids in time to treatment failure.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00495157.

Retrospective look at change in brain natriuretic peptide values in ambulatory patients with chronic heart failure

BACKGROUND

There is significant interest in the role of B-type natriuretic peptide (BNP) guided therapy for outpatient congestive heart failure (CHF) patients. The objective of this study was to see if the percentage change in BNP levels can predict CHF hospitalisations or death.

METHODS

We retrospectively reviewed the records of CHF patients who had BNP levels drawn on two clinic visits. Patients were divided into two groups, those with a 70% or greater increase in the BNP values and those in whom the BNP value either decreased or did not increase by 70%. Primary outcome measured was the need for hospitalisation for CHF or death within 6 months of the second clinic visit.

RESULTS

One hundred and fourteen (114) paired BNP measurements were included in the analysis. Of these, 26 had > 70% increase in BNP while 88 did not. Hospitalisations for CHF or death at 6 months were significantly higher in the former group than the latter (p = 0.04). On multivariate regression analysis significant change in BNP remained a predictor of adverse outcomes.

CONCLUSIONS

In stable outpatients with CHF, > 70% increase in BNP is an independent risk factor for CHF hospitalisations or death at 6 months.

Tiotropium bromide step-up therapy for adults with uncontrolled asthma

BACKGROUND

Long-acting beta-agonist (LABA) therapy improves symptoms in patients whose asthma is poorly controlled by an inhaled glucocorticoid alone. Alternative treatments for adults with uncontrolled asthma are needed.

METHODS

In a three-way, double-blind, triple-dummy crossover trial involving 210 patients with asthma, we evaluated the addition of tiotropium bromide (a long-acting anticholinergic agent approved for the treatment of chronic obstructive pulmonary disease but not asthma) to an inhaled glucocorticoid, as compared with a doubling of the dose of the inhaled glucocorticoid (primary superiority comparison) or the addition of the LABA salmeterol (secondary noninferiority comparison).

RESULTS

The use of tiotropium resulted in a superior primary outcome, as compared with a doubling of the dose of an inhaled glucocorticoid, as assessed by measuring the morning peak expiratory flow (PEF), with a mean difference of 25.8 liters per minute (P<0.001) and superiority in most secondary outcomes, including evening PEF, with a difference of 35.3 liters per minute (P<0.001); the proportion of asthma-control days, with a difference of 0.079 (P=0.01); the forced expiratory volume in 1 second (FEV1) before bronchodilation, with a difference of 0.10 liters (P=0.004); and daily symptom scores, with a difference of -0.11 points (P<0.001). The addition of tiotropium was also noninferior to the addition of salmeterol for all assessed outcomes and increased the prebronchodilator FEV1 more than did salmeterol, with a difference of 0.11 liters (P=0.003).

CONCLUSIONS

When added to an inhaled glucocorticoid, tiotropium improved symptoms and lung function in patients with inadequately controlled asthma. Its effects appeared to be equivalent to those with the addition of salmeterol. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT00565266.).

[Prophylaxis of postoperative endophthalmitis with intracameral cefuroxime: a five years' experience]

PURPOSE

To present the outcomes of prophylaxis of postoperative endophthalmitis following cataract surgery with intracameral Cefuroxime.

METHOD

A retrospective study was done on 4281 eyes that underwent cataract surgery from October 2003 to September 2008. All patients underwent phacoemulsification cataract surgery. All cases received an injection of 0.1 ml intracameral Cefuroxime (1 mg) at the end of surgery except those patients allergic to penicillin and cephalosporin until September 2007 and thereafter only those with demonstrated allergy to cefuroxime.

RESULTS

The rate of postoperative endophthalmitis was 0.11% (5 cases). Four of them had a positive culture. We found no evidence of clinical ocular toxicity.

CONCLUSIONS

Intracameral cefuroxime works very well for reducing the incidence of postoperative endophthalmitis. It appears safe to use and is easy to prepare.

Incidence and risk factors associated with urinary tract infection in diabetic patients with and without asymptomatic bacteriuria

In order to compare the incidence of symptomatic urinary tract infection (UTI) in diabetic patients with and without asymptomatic bacteriuria (ASB), and to identify other risk factors for these infections, 289 females and 168 males were studied over a 12-month period. Symptomatic UTI occurred in 69.2% of patients with ASB (67.6% female and 76.5% male) versus 9.8% without ASB (14.9% female and 2.6% male). ASB and urinary incontinence were associated with symptomatic UTI in both women and men. Other risk factors included previous antimicrobial treatment and macrovascular complications in women and obesity and prostatic syndrome in men. The presence of ASB was found to be the major risk factor for developing symptomatic urinary tract infection. Further prospective randomized clinical trials of diabetic patients with risk factors for UTI who are receiving or not receiving treatment may be considered.

Differential expression of TRAIL and TRAIL receptors in allergic asthmatics following segmental antigen challenge: evidence for a role of TRAIL in eosinophil survival

Asthma is a chronic lung disease exhibiting airway obstruction, hyperresponsiveness, and inflammation, characterized by the infiltration of eosinophils into the airways and the underlying tissue. Prolonged eosinophilic inflammation depends on the balance between the cell's inherent tendency to undergo apoptosis and the local eosinophil-viability enhancing activity. TRAIL, a member of the TNF family, induces apoptosis in most transformed cells; however, its role in health and disease remains unknown. To test the hypothesis that Ag-induced inflammation is associated with TRAIL/TRAIL-R interactions, we used a segmental Ag challenge (SAC) model in ragweed-allergic asthmatics and nonasthmatic patients and analyzed bronchoalveolar lavage (BAL) material for 2 wk. In asthmatic patients, the level of TRAIL in BAL fluid dramatically increased 24 h after SAC, which significantly correlated with BAL eosinophil counts. Immunohistochemical analysis of bronchial biopsies from asthmatic patients demonstrated that TRAIL staining was increased in epithelial, airway smooth muscle, and vascular smooth muscle cells and throughout the interstitial tissue after SAC. This was confirmed by quantitative immunocytochemical image analysis of BAL eosinophils and alveolar macrophages, which demonstrated that expression levels of TRAIL and DcR2 increased, whereas expression levels of the TRAIL-Rs DR4 and DR5 decreased in asthmatic subjects after SAC. We also determined that TRAIL prolongs eosinophil survival ex vivo. These data provide the first in vivo evidence that TRAIL expression is increased in asthmatics following Ag provocation and suggest that modulation of TRAIL and TRAIL-R interactions may play a crucial role in promoting eosinophil survival in asthma.

Effects of six diterpenes on macrophage eicosanoid biosynthesis

Six diterpenes (three clerodanes, two abietanes and one rosane) were tested for interactions with the cyclooxygenase and 5-lipoxygenase pathways of arachidonate metabolism and for effects of nitric oxide production. Two abietane diterpenes, aethiopinone and 11,12-dihydroxy-6-oxo-8,11,13-abietatriene and the rosane lagascatriol showed a remarkable effect on COX-1 pathway of PGE2 release in calcium ionophore A23187-stimulated peritoneal macrophages. Only the two latter diterpenes showed inhibition on COX-2 pathway of PGE2 release in E. coli LPS-stimulated peritoneal macrophages. In addition, all compounds assayed were inhibitors of LTC4 release with IC50 < or = 10 microM. Clerodane diterpenes were inactive in COX assay. None of the diterpenes assayed, except 11,12-dihydroxy-6-oxo-8,11,13-abietatriene, affected NO production. The results obtained suggest that the cellular mechanisms of action of some of these substances may involve inhibition of cyclooxygenase/lipoxygenase pathways and nitric oxide production.

Effects of furocoumarins from Cachrys trifida on some macrophage functions

Phytochemical and biological studies aimed at the discovery and development of novel antiinflammatory agents from natural sources have been conducted in our laboratory for a number of years. In this communication, three naturally occurring furocoumarins (imperatorin, isoimperatorin and prantschimgin) were evaluated as potential inhibitors of some macrophage functions involved in the inflammatory process. These furocoumarins have been tested in two experimental systems: ionophore-stimulated mouse peritoneal macrophages serve as a source of cyclooxygenase-1 and 5-lipoxygenase, and mouse peritoneal macrophages stimulated with E. coli lipopolysaccharide are the means of testing for anti-cyclooxygenase-2 and nitric-oxidesynthase activity. All above-mentioned furocoumarins showed significant effect on 5-lipoxygenase (leukotriene C4) with IC50 values of < 15 microM. Imperatorin and isoimperatorin exhibited strong-to-medium inhibition on cyclooxygenase-1- and cyclooxygenase-2-catalysed prostaglandin E2 release, with inhibition percentages similar to those of the reference drugs, indometacin and nimesulide, respectively. Of the three furocoumarins, only imperatorin caused a significant reduction of nitric oxide generation. Imperatorin and isoimperatorin can be classified as dual inhibitors, since it was evident that both cyclooxygenase and lipoxygenase pathways of arachidonate metabolism were inhibited by these compounds. However, selective inhibition of the 5-lipoxygenase pathway is suggested to be the primary target of action of prantschimgin.

A five-year report on experience in the detection of pheochromocytoma

OBJECTIVE

The purpose of the study is to identify biochemical tests that are good predictors for the diagnosis of pheochromocytoma in patients at hypertension.

SETTING

Review of data from of 3826 patients studied over a 5-year period, between 1994 and 1998, at the University Hospital Virgen de la Arrixaca, Murcia, Spain.

DESIGN AND METHODS

A retrospective study for the diagnosis of pheochromocytoma of 24-h urinary free catecholamines (norepinephrine, epinephrine, and dopamine) measured by high-performance liquid chromatography (HPLC)-electrochemical detector (ECD), total metanephrines (MNt), and vanillylmandelic acid measured by spectrophotometric methods.

RESULTS

During this period, 57 patients were found to have pheochromocytoma, being 47 sporadic, 9 with multiple endocrine neoplasia type 2A, and 1 with neurofibromatosis. In all patients multiple endocrine neoplasia type 2A the tumor were bilateral but only in four of the sporadic tumor group (p < 0.0001, Fisher's exact test). MNt was determined to be the best discriminator of hypertension and pheochromocytoma. It scored a sensitivity of 94.7% (95% confidence interval, 88.3-99.9%), a specificity of 95.3% (89.5-99.9%), and thus had the best negative predictive value of 99.9% (99.8-99.9%), and this biochemical test also had the best positive predictive value of 23.3% (10.8-59.9%). When combining both MNt and norephinephrine, the positive predictive value to increases to 85.6% (65.3-95.6%).

CONCLUSION

Urinary 24-h MNt excretion level is the best single biochemical test for screening and, in combination with norephinephrine, is diagnostic of the presence of pheochromocytoma.

Purkinje cell impairment induced by early movement restriction

In the present work the effects of movement restriction imposed during the early postweaning period on both Purkinje cell dendritic development and exploratory behavior were analyzed. Male and female Sprague-Dawley albino rats were reared either in isolated-restricted or social-standard environments from postnatal day 18 to 30. On the 31st postnatal day, all rats were behaviorally evaluated by the open-field test and then sacrificed under deep ether anesthesia. Vermian cerebellar sections were later stained with the Golgi-Cox-Sholl method and the Purkinje cell dendritic morphology was quantified under light microscopy. The results indicate that early somatomotor restriction severely impairs both exploratory behavior and Purkinje cell dendritic growth.

[Validity of clinical tests to confirm or exclude the diagnosis of acute myocardial infarction]

BACKGROUND

To know the clinical usefulness of the diagnostic tests habitually used to diagnose an acute myocardial infarction (MI), in a group of patients in which this diagnosis is clinically highly suspected.

PATIENTS AND METHODS

A cross sectional study was designed. The sample (n = 114) was randomized and selected by term and specific of days from the patients attending the Emergency Service at Elda General Hospital (Alicante, Spain) in a year period. The method we used was is a validity study, making 2 x 2 tables. The clinical outcome was the gold standard and was cross matched with some of the clinical criteria habitually used to diagnose acute myocardial infarction: thoracic pain character, irradiation, ECG findings and CK-MB levels.

RESULTS

Clinical suspicion of MI was confirmed in only 27.8% (IC--95%: 19.3-36.3). The best validity indexes of clinical usefulness to confirm the MI diagnosis were obtained from ECG findings (CP+ = infinity) and CK-MB (CP+ = 24.2 at the end of the observational period and CP = 17.9 at the beginning). The best negative clinical validity indexes were CK values obtained at the end of the observational period (CP- = 0.07) and the ECT findings obtained at the end of the observational period (CP- = 0.10).

CONCLUSION

Clinical carefulness is essential to avoid a diagnostic mistakes in MI patients, since the symptoms we used as a diagnostic guide do not offer good validity indexes. Changes in ECG or CK-MB levels could confirm the MI diagnosis but normal findings in both tests did not discard this diagnosis. We should keep the possibility of a mistake till the end of the observational period.

A comparison of the personality profiles of internal medicine residents, physician role models, and the general population

PURPOSE

To compare personality profiles of internal medicine residents with those of the general population and positive role models in medicine.

METHOD

A widely used personality inventory, NEO PI-R, which measures five major personality factors and 30 important personality facets, was administered in 1998 to 104 physicians in internal medicine residency and earlier to a nationwide sample of 188 physicians selected as positive role models in medicine.

RESULTS

The internal medicine residents, compared with the general population, were more likely to be attentive, to have deeper intellectual curiosity, to have higher aspiration levels, to have more vivid imaginations, to be more receptive to their emotions, to be interested in mental stimulation, and to think carefully before acting. The residents, compared with role models in medicine, were less eager to face challenges, less able to control their impulses, less able to cope with adversity, less easygoing, and less relaxed, but were more likely to crave excitement.

CONCLUSION

Internal medicine residents and positive role models in medicine have some distinct personal qualities. Understanding the qualities of successful physicians can be helpful in career counseling of medical students and young physicians.

Early social isolation decreases the expression of calbindin D-28k in rat cerebellar Purkinje cells

The main objective of this study was to analyze the effects of early social isolation on the expression of calbindin D-28k (CAD-28k) in cerebellar Purkinje cells. Sprague-Dawley rats were reared either in isolation (IC) or socially housed conditions (SC) from postnatal days 18-32. Half of the rats of each group were sacrificed at 32 days of age and the cerebella processed for immunocytochemical labeling against CAD-28k. The remaining IC animals were housed under standard conditions for re-socialization between postnatal days 32 and 62. The results indicate that Purkinje cells of rats reared under early isolation show a marked loss of CAD-28k immunoreactivity, and that this deficiency is recovered by later social interaction, although the thickness of the molecular layer remains reduced.

Carotid occlusive disease: primary care of patients with or without symptoms

Of the half-million strokes that occur each year in the United States, 20 to 30% can be directly linked to carotid occlusive disease. The degree of stenosis involving the carotid bifurcation is an important predictor of stroke risk. Asymptomatic disease may be diagnosed on routine physical exam or screening of the carotid bifurcation in patients with risk factors for ischemic strokes. Symptomatic disease includes transient ischemic attacks, stroke in evolution, and complete stroke. Duplex ultrasound scanning is the standard test for the initial evaluation of carotid artery disease. Patients undergoing surgery should also have magnetic resonance angiography or an angiogram of the carotid vessels. Stroke prevention includes lifestyle modification such as cessation of smoking, strict dietary and medical management of hyperlipidemia, diabetes, and hypertension. Antiplatelet, anticoagulant, and thrombolytic therapy can be used where indicated.

A preliminary study of the reliability of immediate vs. delayed interviews of cardiac arrest witnesses

INTRODUCTION

Methods to characterize the interval between a collapse from cardiac arrest until a 911 call is made have not yet been developed.

OBJECTIVE

To determine the concordance of cardiac arrest data obtained by two methods: an immediate nurse interview of out-of-hospital cardiac arrest (OHCA) witnesses, and a follow-up phone interview performed two weeks later.

METHODS

This was a prospective study of OHCA witnesses dating from January 1997 to May 1998. Witnesses were briefly interviewed at the time of emergency department presentation, and two weeks later a more lengthy structured phone interview was performed. The authors identified key data elements: 1) was the arrest witnessed? (Wit); 2) was CPR administered prior to EMS arrival? (BCPR); 3) was the first call placed to 911? (c911); and 4) was the estimated collapse to call interval <4 minutes? (ECCI). The analysis utilized Cohen's kappa statistic and Spearman's correlation coefficient.

RESULTS

A convenience sample of 42 matched pairs of OHCA cases was analyzed. Kappa statistics for agreement between methods were: 1) Wit(kappa = 0.750), 2) BCPR(kappa = 0.892), 3) c911 (kappa = 0.892), and 4) ECCI(kappa = 0.571, Spearman's 0.528).

CONCLUSION

There is good to excellent agreement between immediate and phone interview data retrieval methods. Phone interviews appear to yield data comparable to that with the more difficult and expensive, direct interview method.

Ensheathing glia transplants promote dorsal root regeneration and spinal reflex restitution after multiple lumbar rhizotomy

Previously, we have shown that transplants of olfactory bulb ensheathing cells promoted regeneration of transected dorsal roots into the spinal cord. In this study, we assessed the ability of regenerating axons to make functional connections in the cord. Dorsal roots L3 to L6 were sectioned close to their entrance into the spinal cord and reapposed after injecting a suspension of ensheathing cells into each dorsal root entry zone (Group G). Afferent regeneration into the cord and recovery of spinal reflexes were compared with animals that received no injection (Group S) or culture medium without cells (Group C). Electrophysiological tests, to measure nerve conduction and spinal reflexes (H response and withdrawal reflex) evoked by stimulation of afferents of the sciatic nerve, were performed. At 14 days after surgery, H response was found in only 1 of 7 rats of Group G, and withdrawal reflexes were absent from all animals. At 60 days, the H response reappeared in 7 of 10 rats of Group G, and 1 of 5 of each of Groups C and S. The withdrawal reflex recovered in 4 of 10 rats of Group G, but in none of Groups C and S. Immunohistochemical labeling for calcitonin gene-related peptide (CGRP) in rats of Group G showed immunoreactive fibers entering the dorsal horn from sectioned roots, although at lower density than in the contralateral side. In conclusion, transplanted ensheathing cells promoted central regeneration and functional reconnection of regenerating sensory afferents.

Synergistic effect of MNU and DMBA in mammary carcinogenesis and H-ras activation in female Sprague-Dawley rats

The combined application of N-methyl-N-nitrosourea (MNU) and 7,12-dimethylbenz[alpha]anthracene (DMBA) was compared with the administration of each carcinogen alone as to the effectiveness of the induction of mammary carcinomas and the influence of H-ras oncogene activation in female Sprague-Dawley rats. At 50 days of age, group 1 received 30 mg/kg MNU intraperitoneally (i.p.), group 2 received 30 mg/kg DMBA i.p., group 3 received 60 mg/kg MNU i.p., group 4 received 60 mg/ kg DMBA i.p., group 5 received 30 mg/kg MNU followed by 30 mg/kg DMBA i.p., group 6 received 30 mg/kg MNU i.p. and then 30 mg/kg DMBA intravenously (i.v.) and group 7 remained untreated. Animals were killed when the largest mammary tumor reached 1-2 cm in diameter or were necropsied when they were 30 weeks of age. MNU i.p. produced no deaths (groups 1 and 3), however, the i.p. administration of DMBA induced death due to peritonitis (groups 2, 4 and 5), whereas the i.v. administration of DMBA suppressed the death (group 6). All of the tumors produced by MNU were adenocarcinomas of mammary origin. In contrast, DMBA produced tumors of other than mammary origin. The combined treatment with DMBA and MNU increased the mammary carcinogenic effect; it significantly increased the mean number of mammary cancers per rat. With either carcinogen alone and in combination, the mammary carcinomas produced identical adenocarcinoma histology. Of the mammary carcinomas induced by the combined application of MNU and DMBA (group 6), all 11 tumors from five rats showed the GGA to GAA transitional mutation in H-ras codon 12 (38%) and all 18 tumors from the other 10 rats remained as wild-type. An H-ras point mutation at codon 61 was not detected.

Pharmacokinetics and retinal toxicity of intravitreal liposome-encapsulated 5-fluorouridine

BACKGROUND

Fluoropyrimidines may be effective in preventing proliferative vitreoretinopathy after repair of complicated retinal detachments. Liposome encapsulation of these antiproliferative drugs may extend the intravitreal half-life and increase their efficacy.

METHODS

The current study evaluated the pharmacokinetic behavior of intravitreally injected 5-fluorouridine (5-FUR), free and encapsulated in liposomes, either conventionally or coated with collagen into 25 New Zealand rabbits. Additionally, we investigated the retinal toxicity of intravitreal injections of 100, 250 and 500 microg as well as 1 mg 5-FUR as free drug or encapsulated in liposomes in the rabbit eye.

RESULTS

The half-life of free 5-FUR after liposome injection into the vitreous cavity was 18.17+/-2.43 h, considerably longer than the half-life of free 5-FUR (0.82 h). Electrophysiologic tests did not show any changes in latency and a-wave amplitude and minimal changes in the b-wave amplitude. Histopathologic studies revealed integrity of the inner limiting membrane, and mild vacuolization in the outer retina.

CONCLUSION

Encapsulation of 5-FUR within liposomes markedly increases its intravitreal half-life. Our study suggests that liposome-encapsulated 5-FUR is not toxic to the retina even at doses of 1 mg.

Effects of subchronic inhalation of vaporized plastic cement on exploratory behavior and Purkinje cell differentiation in the rat

In the present study, the effects of preweaning cement vapor inhalation on exploratory behavior and cerebellar Purkinje cell differentiation were assessed. Sprague-Dawley albino rats were daily exposed to glue vapors between postnatal d 2 and 21. At postnatal d 22, all animals were submitted to the open-field test in order to evaluate their exploratory behavior. Then they were sacrificed, their brains dissected out, and cerebella stained according to the Golgi-Cox-Sholl procedure. Purkinje cells sampled from parasagittal sections of the cerebellar vermis were drawn under camera lucida and their dendritic domain was determined. The collected data indicate that glue solvent inhalation impairs both Purkinje cell differentiation and locomotor exploratory behavior.

[Diagnostic efficiency of biological markers of alcohol consumption for the detection of excessive drinkers]

The objective of our study was to test the usefulness of some biological markers of alcoholism to detect heavy drinkers, using a structured interview with a 7-day memory as this is currently considered the most reliable technique for determining alcohol consumption. A transversal, observational study was designed with a sample representative of the working population of the province of Alicante seen by the Ibermutua medical service. Participants were selected randomly and classified according to region and sex. The total sample include 1,033 subjects (644 men and 389 women, mean age 36 +/- 11.7 years). Of these 13.5 were heavy drinkers (> 40 g. of alcohol per day), 23.3 moderates drinkers (20-40 g. alcohol per day). Average consumption of alcohol was from 26 g/day + 29.9 grams. In order to quantify the random error, the confidence interval was set at 95. The methods used to test the biological markers were 2 x 2 tables and the calculation of indicators of sensitivity (S). specificity (E), positive predictive value (Vp+), negative predictive value (Vp-) and effectiveness. The highest S was obtained by associating various markers (65.5%), followed by GGT with 53.9%. The GGT/ALP quotient obtained an E of 95.9% and an AST of 92.2%. The GGT/ALP quotient achieved the best effectiveness (85%) and Vp+ (36.2%) and the association of markers the best Vp-at 92.9%, followed by GGT at 91.3%. In spite of the fact that the markers studied do not meet the conditions required to be considered acceptable as screening (S and E > 80%), their use seems appropriate if their limitations are kept in mind (many false negatives). As the GGT/ALP quotient has the highest E, there are few false positives. In order to decrease the number of false negatives, an evaluation of GGT or marker association can be done for those with negative values. In order to resolve the disadvantages of Vp+, the best solution is to order tests for groups of markers that are most prevalent in heavy drinkers.

Nitrendipine and enalapril in the treatment of diabetic hypertensive patients with microalbuminuria

A trial to study the efficacy, safety and tolerability of nitrendipine and enalapril in the treatment of diabetic hypertensive patients with microalbuminuria (MA) was performed to compare the effects of both drugs in the prevention of the renal impairment. Twenty-eight valid patients [13 with nitrendipine (N) and 15 with enalapril (E) with NIDDM, hypertension (diastolic blood pressure between 90 to 114 mm Hg) and MA (urinary albumin between 30 to 300 mg/24 hr) were recruited in a double blind, randomized trial. Following a placebo run-in period of two to four weeks, all eligible patients were randomly allocated to either N or E treatment. Treatment lasted six months, with two different visits at three and six months in which blood pressure (BP), heart rate (HR), renal function and MA were measured. No statistically significant differences on BP and metabolic parameters were found between both treatment groups. The geometric mean of final glomerular filtration rate (GFR) in the N group was 34.5% higher than in the E group, while the reduction on MA was most important in the E group. Eleven patients reported adverse events (AEs) and there were four dropouts, three of them due to AEs. We conclude that both treatments are a good choice for treating diabetic hypertensive patients with early altered renal function, as they reduce BP without altering metabolic parameters, increase GFR and reduce MA with a low frequency of AEs.

Cardiovascular and respiratory adjustments in normal volunteers during modified exercise tests in comparison to standard exercise tests

Sixteen normal, non-smoking first year medical students underwent four standard exercise tests, while cardiovascular (heart rate and blood pressure) and pulmonary (respiratory rate, tidal volume and oxygen consumption) adjustments were being monitored. Maximal exercise level for all tests were defined following the Jones scale. No variation was noted in respiratory rate among the four exercise tests. The cycle ergometry (CE), hand ergometry (HE), and treadmill (TM) exercise tests produced progressive increases of the various parameters as expected, although target maximal heart rates were not reached in most cases secondary to muscle fatigue. The step test (ST) approximated the physiological parameter changes noted in these three tests during the early stages of exercise, but levelled off after 3 minutes, probably due to lack of incremental load. The ST took the longest time to reach maximal level of exercise parameters, and recorded the lowest tidal volume increase. The same subjects underwent a modified step test (MST1) by adding 1 kg sandbags every 3 min to backpacks worn by the subjects, to provide incremental load. This modification provided a slight increase in the parameters measured, but still plateaued after 3 min. Another set of 18 normal, non-smoking medical students underwent bicycle ergometry and two other modified exercise tests. The modified step test two (MST2) was similar to our initial MST1, except that the sandbags added every 3 min were not fixed at 1 kg but were also incremental (1, 2, 3 and 4 kg). The other test (Ramp test or RT) required the subjects to walk up and down a ramp, which entailed not only the addition of incremental weights of sandbags every 3 min, but also increasing the elevation of the ramp at each stage. Data analysis showed that these two tests showed almost similar changes in cardiovascular and respiratory adjustments in the subjects, compared to the standard bicycle ergometry. These pilot studies showed that low-cost modified step tests may be utilized to approximate the expensive standard treadmill and bicycle exercise tests. More studies on larger populations have to be done to validate these results.

Effects of preweaning sensorimotor stimulation on behavioral and neuronal development in motor and visual cortex of the rat

The present study investigates the effects of early sensorimotor stimulation on behavioral and neuronal cytodifferentiation in motor and visual cortex of lactating rats. Seventy-two male and female Sprague-Dawley albino rats were systematically submitted to environmental stimulation during the early postnatal period (postnatal days 5-21). On postnatal day 22, four behavioral tests were performed (open field, narrow path crossing, hind limb support and ascending on a rope). In order to evaluate dynamic neuronal changes induced by sensorimotor enrichment, brains were stained through the Golgi-Cox-Sholl method. Morphometric studies were carried out in pyramidal neurons located in motor and visual cortical layers II and III, by measuring their basal dendritic length and branching. Further, wide cortical field studies were performed with the aim of evaluating the degree of development reached by clusters of pyramidal cells. The results indicate that sensorimotor stimulation carried out during the suckling period produced a significant increase in neuronal cytodifferentiation as observed in single cell studies. However, collective neuronal evaluations yielded less significant results. Consistently, rats exposed to enriched environments showed a better performance in behavioral adaptive responses.

Effects of preweaning environmental stimulation on neuronal and behavioral impairment produced by undernutrition

The present study investigates the effects of sensorimotor stimulation on the basal dendrogenesis of superficial cerebrocortical neurons and the accomplishment in the associated exploratory behavior in rats simultaneously exposed to nutritional deprivation. Sprague-Dawley albino rats were submitted to nutritional-environmental influences from birth to the 21st postnatal day. Exploratory behavior was assessed by the evaluation of locomotor activity in the open-field apparatus. In order to evaluate changes in neuronal morphology induced by nutritional-environmental variables, brains were stained according to the Golgi-Cox-Sholl procedure. Dendritic development was assessed under camera lucida by measuring basal dendritic branching of layer II and III pyramidal neurons, located in the dorsomedial region of the visual cortex of the rat. Morphometrical analysis revealed that both basal dendritic length and branching were significantly reduced by undernutrition. In contrast, environmental stimulation during the suckling period compensated for the neuronal impairment produced by protein-calorie deprivation. An improvement was also observed in exploratory behavior although to a lesser degree, as shown by the open field test data. In conclusion, the present results indicate that sensorimotor stimulation applied during the period of fastest rate of cortical cytodifferentiation compensates for neuronal and behavioral impairment produced by undernutrition.

[The validity of the separate determination of total cholesterol in the primary prevention of coronary risk]

BACKGROUND

The aim of this study was to validate total cholesterol (TC) determination in the primary prevention of coronary risk and evaluate the prevalence of low HDL cholesterol (HDL-C) levels at the different TC cut-off points to thereby determine the TC level at which HDL-C determination is of interest.

METHODS

The atherogenic index was used as the reference method in TC evaluation with the values of low HDL-C levels being evaluated at the following TC cut-off points: 160, 180, 200, 220, 240, 250, and 300 mg/dl (4.44; 4.66; 5.18; 5.70; 6.22; 6.48; 7.77 mmol/l). According to the results of the Framingham study the atherogenic index or the existence of low HDL-C levels were considered as abnormal. The sample included 4,162 workers from the province of Alicante (Spain) selected by consecutive sampling and opportunistic search in January and February, 1993. Validity was calculated with confidence interval of 95%.

RESULTS

The atherogenic index was high in 43.7% of the sample, ranging from 6% in the population with TC lower than 160 mg/dl (4.14 mmol/l) to 76.4% in those oscillating between 250-299 mg/dl (6.48-7.76 mmol/l). Low HDL-C levels were detected in 20.1% with a prevalence ranging from 38.8% in those with a TC of less than 160 mg/dl (4.14 mmol/l) to 11.9% in those with TC > or = 250 mg/dl (> or = 6.48 mmol/l). The cut-off points for low TC had high sensitivity (S) and low specificity (SP) (160 mg/dl [4.14 mmol/l]: S = 91.1%, SP = 11.5%; 180 mg/dl [4.66 mmol/l]: S = 95.2%, SP = 30.2%). The highest TC points presented very low S and very high SP (250 mg/dl [6.48 mmol/l]: S = 46.3%, SP = 87.7%; 300 mg/dl [6.48 mmol/l]: S = 7.4%, SP = 97%).

CONCLUSIONS

The HDL-cholesterol should be determined in people with a total cholesterol of less than 200 mg/dl (5.18 mmol/l) since, in this group there is an important percentage of individuals with an altered atherogenic index and low HDL-C levels.

Effects of sensitization on vasoactive intestinal polypeptide-induced relaxation and its concentration and binding in guinea-pig airways

We investigated the relaxant effect of vasoactive intestinal polypeptide (VIP) in trachea and lung parenchyma from normal and sensitized guinea-pigs. A technique by which drug access was restricted to either the mucosal or the adventitial surface of tracheal rings was used. In intact trachea, concentration-response curves for VIP entering from the mucosal surface (pD2 = 6.61 +/- 0.06) were displaced to the right compared with those for adventitial entry (pD2 = 6.78 +/- 0.04). Epithelium removal produced a leftward shift (approximately 2.8-fold) in the mucosal VIP concentration-response curve. Sensitization did not alter the responsiveness (maximal effect) or sensitivity (pD2 values) of tracheal rings to VIP irrespective of the surface of drug entry and of the absence or presence of epithelium. VIP-induced relaxation of normal and sensitized lung strips was also similar. Sensitization resulted in a significant decrease in tracheal VIP content (from 2.16 +/- 0.07 in normal to 0.60 +/- 0.08 nmol/mg protein in sensitized trachea; P < 0.05; n = 7) whereas the affinity of both high- and low-affinity binding sites for VIP increased as compared to that of normal trachea. Differences were not found in the binding capacities of normal and sensitized trachea. VIP content and binding did not differ in normal and sensitized lung. In conclusion, immunological sensitization produced changes in VIP tracheal content and binding but neither VIP-induced relaxation of isolated airways nor the influence of epithelium in this response was altered.

Environmental deprivation delays the maturation of motor pyramids during the early postnatal period

The effects of environmental deterioration upon the development of motor cortex was studied in 30 Sprague-Dawley albino rats during lactation (1st-18th postnatal days). The use of Golgi-Cox-Sholl methodology allowed qualitative and particularly quantitative evaluations since impregnation of neurons take place at random without any selectivity. Morphometric studies were assessed by measuring layers II-III pyramidal neurons, basal dendritic branching, under camera lucida. Early environmental impoverishment results in a highly significant decrease in the number and length of peripherical branches and terminal dendrites. These results extend previous observations made predominantly in non-motor cortices which indicate that during early postnatal life restrictions or enrichments of the environment may be associated with quantitative changes in the differentiation of cerebrocortical neurons. It is of upmost importance to consider that the potential effects of different types of epigenetic cues are highly selective since pyramids of pups subjected to mild nutritional manipulation during the same developmental period remained unaffected.

Relaxation by calcium antagonists of potassium-contracted trachea from normal and sensitized guinea-pigs: influence of epithelium and the surface of drug entry

A technique by which drug access was restricted to either the mucosal or the adventitial surface of tracheal rings, isolated from normal (unsensitized) or sensitized guinea-pigs, was used to study the role of the epithelium in the relaxation produced by calcium antagonists (verapamil, nifedipine, cinnarizine and flunarizine) of K(+)-induced contraction. In trachea from normal guinea-pigs, the relaxation to verapamil for unrestricted or mucosal drug entry was reduced in the absence of epithelium, whereas the relaxation produced by nifedipine, cinnarizine or flunarizine was unchanged. In sensitized trachea, the relaxation elicited by the calcium antagonists tested was similar in intact and epithelium-denuded tracheal rings irrespective of the surface of drug entry. These results confirm that the epithelium influences the relaxation to verapamil. This modulatory effect is absent in sensitized trachea and is not shared by other calcium antagonists.

Role of endothelium in the responses to noradrenaline in normal and sensitized guinea-pig aorta

1. The pharmacological reactivity of sensitized blood vessels has been less studied than that of the airways. Aorta rings were obtained from normal (non-sensitized) and actively sensitized guinea-pigs, and prepared for isometric recording of tension changes. 2. Noradrenaline (10 nM-0.1 mM), histamine (0.1 microM-0.1 mM) and KCl (10-100 mM) produced concentration-related contractions of normal tissues. Removal of endothelium resulted in a marked leftward and upward shift of the concentration-response curve for noradrenaline but it did not alter histamine- or KCl-induced responses. Pretreatment with L-NG-nitroarginine (L-NOARG, 30 microM), haemoglobin (5 microM) or ibuprofen (10 microM) enhanced noradrenaline-induced responses without affecting those to histamine or KCl. 3. Removal of endothelium or pretreatment with L-NOARG or ibuprofen did not alter agonist-induced responses in sensitized tissues. Acetylcholine (1 microM)-induced relaxation of the contraction produced by noradrenaline (1 microM) in intact rings was diminished in sensitized compared to normal tissues. 4. Neuronal uptake and release of [3H]-noradrenaline did not differ in normal and sensitized tissues. 5. Loss of the modulatory role of endothelium and other mechanisms may be involved in the hyperreactivity of sensitized guinea-pig aorta.

Early life environmental deterioration, nutrition and ontogenesis of the motor cortex in the rat: a Golgi study

Sprague-Dawley albino rats were subjected to an experimental paradigm in which environmental and nutritional variables were studied from birth to day 18. The use of Golgi-Cox-Sholl methodology allowed quantitative evaluations of neurons which were randomly impregnated with metallic mercury after fixation in a mercury salt. The nutritional treatment employed did not significantly influence the cytoplasmatic differentiation of cortical neurons although it was able to induce gross morphological modifications in body weight and size. By contrast, an impoverished surrounding during a limited period of time had a profound effect on the basal dendritic tree. The evidence presented here suggests the importance of the preweaning environment on the development of neural appendages. Motor pyramids of pups housed in deteriorated conditions underwent a progressive decrement in the length and number of peripheral branches and terminal dendrites. A decreased rate of cortical differentiation was also observed in overnourished pups as a result of reducing the litter size. This regressive event, can probably be attributed to social and sensory-motor limitations of the experimental group. However, to confirm this possibility, further research is required.

cDNA cloning and sequence analysis of human pancreatic procarboxypeptidase A1

Using polyclonal antibodies raised against human pancreatic procarboxypeptidases, a full-length cDNA coding for an A-type proenzyme was isolated from a lambda gt11 human pancreatic library. This cDNA contains standard 3' and 5' flanking regions, a poly(A)+ tail and a central region of 1260 nucleotides coding for a protein of 419 amino acids. On the basis of sequence comparisons, the human protein was classified as a procarboxypeptidase A1 which is very similar to the previously described A1 forms from rat and bovine pancreatic glands. The presence of the amino acid sequences assumed to be of importance for the zymogen inhibition by its activation segment, primarily on the basis of the recently reported crystal structure of the B form, further supports the proposed classification.

Frequency domain models of the EEG

The structure of the normal resting EEG crosspectrum SVV(omega) is analyzed using complex multivariate statistics. Exploratory data analysis with Principal Component Analysis (PCA) is followed by hypothesis testing and computer simulations related to possible neural generators. The SVV(omega) of 211 normal individuals (ages 5 to 97) may be decomposed into two types of processes: the xi process with spatial isotropicity reflecting diffuse, correlated cortical generators with radial symmetry, and processes that seem to be generated by more spatially concentrated, correlated sources. The latter are reflected as spectral peaks such as the process. The eigenvectors of the xi process are the Spherical Harmonic Functions which explains the recurring pattern of maps characteristic of the spatial PCA of qEEG data. A new method for estimating sources in the frequency domain which fits dipoles to the whole crosspectrum is applied to explain the characteristics of the localized sources.

Response to noradrenaline and histamine in normal and sensitized guinea pig aorta and its relation to endothelium

Pharmacological reactivity of sensitized blood vessels has been less studied than that of airways. Aorta rings were obtained from normal and actively sensitized guinea pigs and prepared for isometric recording of tension changes. Noradrenaline (10 nM-10 microM), histamine (0.1 microM-0.1 mM) and KCl (10-100 mM) produced concentration-related contractions of normal tissues. Removal of endothelium resulted in a marked left upward shift of the concentration-response curve to noradrenaline but it did not alter histamine- or KCl-induced responses. Pretreatment with ibuprofen (10 microM) or L-NG-nitroarginine (L-NOARG, 3.3 microM) enhanced noradrenaline-induced responses without affecting those to histamine or KCl. Removal of endothelium or pretreatment with ibuprofen or L-NOARG did not alter agonist-induced responses in sensitized tissues. Neuronal uptake and release of [3H]-noradrenaline did not differ in normal and sensitized tissues. Loss of the modulatory role of endothelium and other mechanisms may be involved in the hyperreactivity of sensitized guinea pig aorta.

Conservation of the sequence of the Alzheimer's disease amyloid peptide in dog, polar bear and five other mammals by cross-species polymerase chain reaction analysis

Neuritic plaque and cerebrovascular amyloid deposits have been detected in the aged monkey, dog, and polar bear and have rarely been found in aged rodents (Biochem. Biophy. Res. Commun., 12 (1984) 885-890; Proc. Natl. Acad. Sci. U.S.A., 82 (1985) 4245-4249). To determine if the primary structure of the 42-43 residue amyloid peptide is conserved in species that accumulate plaques, the region of the amyloid precursor protein (APP) cDNA that encodes the peptide region was amplified by the polymerase chain reaction and sequenced. The deduced amino acid sequence was compared to those species where amyloid accumulation has not been detected. The DNA sequences of dog, polar bear, rabbit, cow, sheep, pig and guinea pig were compared and a phylogenetic tree was generated. We conclude that the amino acid sequence of dog and polar bear and other mammals which may form amyloid plaques is conserved and the species where amyloid has not been detected (mouse, rat) may be evolutionarily a distinct group. In addition, the predicted secondary structure of mouse and rat amyloid that differs from that of amyloid bearing species is its lack of propensity to form a beta sheeted structure. Thus, a cross-species examination of the amyloid peptide may suggest what is essential for amyloid deposition.