Sperm competition in yellow dung flies: No consistent effect of sperm size.

The male competition for fertilization that results from female multiple mating promotes the evolution of increased sperm numbers and can impact sperm morphology, with theory predicting that longer sperm can at times be advantageous during sperm competition. If so, males with longer sperm should sire more offspring than competitors with shorter sperm. Few studies have directly tested this prediction, and findings are inconsistent. Here we assessed whether longer sperm provide a competitive advantage in the yellow dung fly (Scathophaga stercoraria; Diptera: Scathophagidae). Initially, we let brothers with different temperature-mediated mean sperm lengths compete - thus minimizing confounding effects of genetic background - and found no clear advantage of longer sperm. We then used flies from lines subjected to bidirectional selection on phenoloxidase activity that had shown correlated evolutionary responses in sperm and female spermathecal duct lengths. This experiment also yielded no main effect of sperm size on siring success. Instead, there was a trend for a shorter-sperm advantage, but only when competing in females with longer spermathecal ducts. Our data corroborated many previously reported findings (last-male precedence, effects of copula duration and body size), suggesting our failure to find sperm size effects is not inherently due to our experimental protocols. We conclude that longer sperm are not competitively superior in yellow dung flies under most circumstances, and that, consistent with previous work, in this species competitive fertilization success is primarily determined by the relative numbers of sperm competing.

Selective imitation impairments differentially interact with language processing.

Whether motor and linguistic representations of actions share common neural structures has recently been the focus of an animated debate in cognitive neuroscience. Group studies with brain-damaged patients reported association patterns of praxic and linguistic deficits whereas single case studies documented double dissociations between the correct execution of gestures and their comprehension in verbal contexts. When the relationship between language and imitation was investigated, each ability was analysed as a unique process without distinguishing between possible subprocesses. However, recent cognitive models can be successfully used to account for these inconsistencies in the extant literature. In the present study, in 57 patients with left brain damage, we tested whether a deficit at imitating either meaningful or meaningless gestures differentially impinges on three distinct linguistic abilities (comprehension, naming and repetition). Based on the dual-pathway models, we predicted that praxic and linguistic performance would be associated when meaningful gestures are processed, and would dissociate for meaningless gestures. We used partial correlations to assess the association between patients' scores while accounting for potential confounding effects of aspecific factors such age, education and lesion size. We found that imitation of meaningful gestures significantly correlated with patients' performance on naming and repetition (but not on comprehension). This was not the case for the imitation of meaningless gestures. Moreover, voxel-based lesion-symptom mapping analysis revealed that damage to the angular gyrus specifically affected imitation of meaningless gestures, independent of patients' performance on linguistic tests. Instead, damage to the supramarginal gyrus affected not only imitation of meaningful gestures, but also patients' performance on naming and repetition. Our findings clarify the apparent conflict between associations and dissociations patterns previously observed in neuropsychological studies, and suggest that motor experience and language can interact when the two domains conceptually overlap.

Vitamin D levels and bone mineral density: are LH levels involved in the pathogenesis of bone impairment in hypogonadal men?

BACKGROUND: Osteoporosis is a major public health problem also in men and it recognizes hypogonadism as a major cause. AIMS: To investigate the possible pathogenetic mechanisms on bone impairment in male hypogonadism and on its improvement in response to testosterone replacement treatment (TRT). METHODS: We retrospectively investigated the hormonal profile and bone mineral density (BMD), evaluated by DXA, in 17 middle-aged hypogonadal men treated for at least 5 years with TRT, compared with 21 recently diagnosed untreated hypogonadal males and 18 age- and BMI-matched healthy subjects. RESULTS: No significant differences in clinical, biochemical and densitometric parameters were found among the three groups, with the exception of 25-OH vitamin D levels that were significantly higher in healthy subjects compared with hypogonadal patients. Untreated patients affected by central hypogonadism, despite similar hormonal levels, displayed significantly lower BMD and decreased LH and 25-OH vitamin D levels, compared with patients with primary hypogonadism. Among the treated patients, BMD parameters were similar regardless of the formulation of TRT. CONCLUSIONS: A recent history of central hypogonadism, compared with primary hypogonadism, appears to adversely affect bone health independently of gonadal steroids levels. This could be due to lower LH levels and consequent reduction of vitamin D 25-hydroxylation in the testis.

Effects of testosterone replacement therapy on bone metabolism in male post-surgical hypogonadotropic hypogonadism: focus on the role of androgen receptor CAG polymorphism.

INTRODUCTION AND AIM: The relationship between androgen receptor (AR) CAG polymorphism and bone metabolism is highly controversial. We, therefore, aimed to evaluate the independent role of AR CAG repeat polymorphism on bone metabolism improvement induced by testosterone replacement therapy (TRT) in male post-surgical hypogonadotropic hypogonadism, a condition frequently associated with hypopituitarism and in which the effects of TRT have to be distinguished from those resulting from concomitant administration of pituitary function replacing hormones. METHODS: 12 men affected by post-surgical hypogonadotropic hypogonadism [mean duration of hypogonadism 8.3 ± 2.05 (SD) months] were retrospectively assessed before and after TRT (from 74 to 84 weeks after the beginning of therapy). The following measures were studied: parameters of bone metabolism [serum markers and bone mineral density (BMD)], pituitary dependent hormones and genetic analysis (AR CAG repeat number). RESULTS: Total testosterone, estradiol, free T4 (FT4) and insulin-like growth factor-1 (IGF-1) increased between the two phases, while follicle stimulating hormone (FSH) decreased. While serum markers did not vary significantly between the two phases, BMD improved slightly but significantly in all the studied sites. The number of CAG triplets correlated negatively and significantly with all the variations (Δ-) of BMDs. Conversely, Δ-testosterone correlated positively and significantly with all studied Δ-BMDs, while Δ-FSH, Δ-estradiol, Δ-FT4, and Δ-IGF-1 did not correlate significantly with any of the Δ-BMDs. Multiple linear regression analysis, after correction for Δ-testosterone, showed that CAG repeat length was negatively and significantly associated with ∆-BMD of all measured sites. CONCLUSIONS: Our data suggest that, in post-surgical male hypogonadotropic hypogonadism, shorter AR CAG tract is independently associated with greater TRT-induced improvement of BMD.

Have androgen receptor gene CAG and GGC repeat polymorphisms an effect on sperm motility in infertile men?

Androgens and a normal androgen receptor (AR) are required for normal spermatogenesis. We investigated polyglutamine (CAG) and a polyglycine (GGC) tract in Italian men with defective spermatogenesis. We studied a group of 40 infertile men with spermatogenesis failure without Y-chromosome microdeletions compared with 60 normozoospermic ones. The distributions of both polymorphisms, within the normal range of Caucasian populations, were similar among infertile men and controls. Nonetheless, we observed that the frequency comparison of each CAG allele showed a statistical difference in the allele CAG 22; GGC 17 was the more predominant allele in infertile men than in controls. Moreover, to investigate the hypothesis that semen characteristics are perturbed by androgen receptor allele variants, we tried to detect a link between triplets and sperm motility in all subjects (cases plus controls). Subjects were subdivided into three groups, based on calculated allele frequencies. A significantly decreased motility, related to a longer CAG and GGC tracts, and marked differences between the groups exist for both polymorphisms. Our data highlight a probable relationship between the allele CAG 22/GGC 17 and a defective spermatogenesis in infertile men, suggesting that these polymorphisms might have an important effect on AR function.

The ability of CBCL DSM-oriented scales to predict DSM-IV diagnoses in a referred sample of children and adolescents.

The majority of studies examining associations between clinical-diagnostic and empirical-quantitative approaches have concentrated only on the target diagnosis without taking into account any possible co-variation of psychopathological traits, which is intrinsic to child psychopathology. The ability of child behaviour checklist (CBCL) DSM-oriented scales (DOSs) to predict target and other DSM diagnoses, taking into consideration the covariation of psychopathological traits, was analysed by logistic regression analysis. Corresponding odds ratio (OR) was used as indicator of the strength of the relationship between the clinical score in DOSs and the presence of DSM-IV diagnoses. Logistic regression allowed us to consider multiple scales simultaneously, thus addressing the problem of co-occurrence of psychopathological traits, and to include gender and age as covariates. The sample consisted of 360 children and adolescents aged 6-16 years, consecutively referred for behavioural and emotional problems. As a whole, the CBCL DOSs seem to be more specific but with a weaker association with DSM-IV diagnoses than syndrome scales, and with some distinctive features: clinical scores in the anxiety DOS suggest a diagnosis of both anxiety and mood disorder; clinical scores in the somatic problems DOS are very strong and specific predictors for diagnosis of separation anxiety disorder; clinical scores in the oppositional defiant problems DOS are not only predictors of the oppositional defiant disorder but are also strong predictors of generalized anxiety disorder; clinical scores in the conduct problems DOS are a specific and strong predictor for oppositional defiant disorder. Results confirm the clinical usefulness of CBCL and suggest using both syndrome and DOS scales for a complete and accurate assessment of children and adolescents.

Action-related properties shape object representations in the ventral stream.

The principles driving the organization of the ventral object-processing stream remain unknown. Here, we show that stimulus-specific repetition suppression (RS) in one region of the ventral stream is biased according to motor-relevant properties of objects. Quantitative analysis confirmed that this result was not confounded with similarity in visual shape. A similar pattern of biases in RS according to motor-relevant properties of objects was observed in dorsal stream regions in the left hemisphere. These findings suggest that neural specificity for "tools" in the ventral stream is driven by similarity metrics computed over motor-relevant information represented in dorsal structures. Support for this view is provided by converging results from functional connectivity analyses of the fMRI data and a separate neuropsychological study. More generally, these data suggest that a basic organizing principle giving rise to "category specificity" in the ventral stream may involve similarity metrics computed over information represented elsewhere in the brain.

Action performance and action-word understanding: evidence of double dissociations in left-damaged patients.

It has been proposed that language and action representational systems overlap when the tasks used to assess them involve the same stimuli and require abilities acquired at similarly early developmental stage. We matched variables at task and stimulus level to test this hypothesis in a group of 12 left-damaged patients (and 17 controls). At the patients' group level, we replicated previously reported correlations between linguistic and nonlinguistic tasks. When performances were analysed individually, however, double dissociations were observed between the ability to imitate pantomimes and the ability to produce and comprehend the corresponding action verbs, as well as between the ability to use tools and the ability to comprehend the corresponding tool nouns. These findings suggest that processing action words is independent of the ability to produce the associated object-directed actions. Double dissociations were also found between the ability to comprehend action verbs and the ability to comprehend tool nouns. Moreover, action and tool naming showed differential effects of age of acquisition, suggesting that the two word categories meet the lexical organization by word class (nouns and verbs), even when related to identical action concept. Dissociations at behavioural level are supported by anatomical dissociations shown in the analysis of patients' lesions.

Pathological classification of DCIS and planning of therapeutic management.

BACKGROUND: Ductal intraepitelial neoplasia (DIN) represents a spectrum of disease that may progress from usual hyperplasia to ductal carcinoma in situ (DCIS) grade 3. The aim of the study was to asses the correlation between the DIN classification and the surgical treatment including sentinel lymph node biopsy (SLNB). PATIENTS AND METHODS: In this retrospective study, 229 patients with DIN had undergone conservative or radical surgical treatment and SLNB in cases of DIN1C-DIN3. RESULTS: Breast conservative surgery was the definitive treatment in 80% of the cases. The H&E evaluation of excised sentinel nodes was negative for metastatic disease; nevertheless the immunohistochemical (IHC) evaluation revealed the presence of metastatic cells in 6 patients (3.7%). CONCLUSION: In cases of DIN lesions SLNB is not indicated. The only reason SLNB should be considered is when there is an evidence of invasive foci at definitive histology or when radical mastectomy is proposed.

[Regional cerebral blood flow changes in Parkinson's disease: correlation with disease duration]. / Cambios de la perfusión cerebral en la enfermedad de Parkinson: relación con la duración de los síntomas.

INTRODUCTION: Changes in regional cerebral blood flow (rCBF) have been reported in idiopathic Parkinson's disease (PD). Nonetheless, their typical pattern still remains controversial regarding some features, such as basal ganglia involvement and the main cortical regions affected. Functional neuroimaging makes it possible to identify the brain dysfunctions of the neural circuits underlying the disease. Voxel-based analysis methods make it possible to increase the reliability of the results. OBJECTIVE: To assess the rCBF changes in patients with PD and their relation with disease duration. MATERIALS AND METHODS: Thirty PD adult patients without dementia underwent evaluation with (99m)Tc-ECD SPECT. SPM5 was used for statistical comparison with 25 normal controls of similar ages. The disease course duration in years was added as a covariate. Additionally, patients with a 6-year evolution or less and those with more than 6 years were compared separately with normal controls. RESULTS: Significant hypoperfusion was detected in bilateral premotor and posterior parietal cortex and increase of perfusion was present in the cerebellum. These changes correlated with the years of evolution of the illness. Patients with longer evolution also presented thalamic, subthalamic and basal ganglia hypoperfusion. CONCLUSIONS: We describe rCBF changes in PD in neural circuits related with control of movements. These changes are more manifest in patients with a longer duration of the disease.

Fatty aspirin: a new perspective in the prevention of dementia of Alzheimer's type?

Alzheimer's disease (AD) leads to a dramatic decline in cognitive abilities and memory. A more modest disruption of memory often occurs in normal aging and the same circuits that are devastated through degeneration in AD are vulnerable to sub-lethal age-related changes that alter synaptic transmission. There are numerous indications that aberrant plasticity is critically involved in Alzheimer's. Is ageing itself the major risk factor for AD? Is AD an acceleration of normal ageing? We assume that the ability of the brain is to modify its own structural organization and functioning which is liable to become impaired in ageing until it becomes dramatically impaired in Alzheimer's. Moreover, ageing can compromise the conversion of dietary alpha-linolenic acid (ALA) to docosahexaenoic acid (DHA). DHA regulates synaptogenesis and affects the synaptic structure, and synapse density is reduced in ageing. DHA and newly identified DHA-derived messenger, neuroprotecting D1 (NPD1), protect synapses and decrease the number of activated microglia in the hippocampal system. Delaying AD onset by a few years would reduce the number of the cases of dementia in the community. DHA (and NPD1?) and aspirin induce brain-derived neurotrophic factor (BDNF) protein expression and this protein has a crucial role in neuronal survival. The authors--in view of the increased neuroinflammatory reaction frequently observed during normal brain ageing--suggest the long-term use of "fatty aspirin", an association of DHA and/or NPD1 and aspirin (or nitroaspirin), to postpone, or prevent, the structural neurodegeneration of the brain.

What is the role of motor simulation in action and object recognition? Evidence from apraxia.

An important issue in contemporary cognitive neuroscience concerns the role of motor production processes in perceptual and conceptual analysis. To address this issue, we studied the performance of a large group of unilateral stroke patients across a range of tasks using the same set of common manipulable objects. All patients (n = 37) were tested for their ability to demonstrate the use of the objects, recognize the objects, recognize the corresponding object-associated pantomimes, and imitate those same pantomimes. At the group level we observed reliable correlations between object use and pantomime recognition, object use and object recognition, and pantomime imitation and pantomime recognition. At the single-case level, we document that the ability to recognize actions and objects dissociates from the ability to use those same objects. These data are problematic for the hypothesis that motor processes are constitutively involved in the recognition of actions and objects and frame new questions about the inferences that are merited by recent findings in cognitive neuroscience.

Degraded semantic knowledge and accurate object use.

In the present paper we report the performance on object use and on semantic tasks of two patients, D.L. with probable semantic dementia, and A.M. with an atypical onset of dementia of Alzheimer, assessed twice two years apart. In particular, we investigated whether the patients' ability to use objects degraded as a function of their semantic knowledge about those objects. Results from the two assessments in 2002 and in 2004 confirmed that both patients had a selective loss of the lexical-semantic knowledge, despite a relative preservation of the other cognitive abilities including object use. This pattern of results suggests that semantic knowledge is not necessarily involved in the correct use of objects.

[Radon exposition preliminary research in a Sicilian territory]. / Esposizione a radon indagine preliminare su un territorio siciliano.

Radon toxicity on human body is well known from along (in 1988 radon has been classified as first type carcinogen, after only to tobacco's smoke, as cause of lung's cancer). Based on known scientific data, preliminary study has been conducted by the AA. It concerns radon exposition on inhabitants living in a Sicilian territory featured by previous seismic events: the territory and the town of Montevago. The project has been sponsored by ARPA Palermo. The territory of Montevago has been divided in several areas in order to assign detectors homogeneously, to begin the environmental sampling. In the period between May and October 2006, instruments has been calibrated and standardization of the procedure has been completed, in collaboration with Centro Studi Nucleare Enrico Fermi del Dipartimento di Ingegneria Nucleare del Politecnico di Milano. The values obtained result in European range.

Responses to selection on phenoloxidase activity in yellow dung flies.

Maintaining an immune system is costly. Resource allocation to immunity should therefore trade off against other fitness components. Numerous studies have found phenotypic trade-offs after immune challenge, but few have investigated genetic correlations between immune components and other traits. Furthermore, empirical evidence for the costs of maintaining an innate immune system in the absence of challenges is rare. We examined responses to artificial selection on phenoloxidase (PO) activity, an important part of the insect innate defense against multicellular pathogens, in yellow dung flies, Scathophaga stercoraria (L.). After 15 generations of successful selection on PO activity, we measured reproductive characters: clutch size, egg hatching rates, adult emergence rates, and adult longevity. We found no evidence for negative genetic correlations between PO activity and reproduction. In fact, flies of lines selected for increased PO activity had larger first clutches, and flies of lines selected for decreased PO activity had smaller ones. However, flies from high-PO lines died earlier than did low-PO flies when no food was available; that is, there is a survival cost of running at high PO levels in the absence of challenge. Variation in resource acquisition or use may lead to positive genetic correlations between PO and fertility and fecundity. The negative correlation between PO and longevity under starvation may indicate that variation for resource acquisition is maintained by a cost of acquisition, based on a genotype-environment interaction.

Mindray BC-6800 body fluid mode, performance of nucleated cells, and differential count in ascitic and pleural fluids.

INTRODUCTION: An accurate and rapid analysis of cells in body fluids (BFs) is important for diagnosis and follow-up in many pathological conditions. We evaluated the analytical performance of the module BF Mindray BC-6800 (BC-6800-BF) for cytometric analysis of ascitic and pleural fluids. METHODS: A total of 99 ascitic and 45 pleural samples were collected and assessed with BC-6800-BF and optical microscopy. This study also includes the evaluation of limit blank (LoB), limit detection (LoD), limit quantitation, (LoQ), carryover, linearity, and diagnostic concordance between the two methods. RESULTS: For TC-BF, LoB was 1 × 10(6) cells/L, LoD was 3 × 10(6) cells/L, and LoQ was 4 × 10(6) cells/L. Linearity was excellent (r(2) = 0.99) and carryover was negligible. TC-BF performed with the two methods showed Pearson's correlation of 0.99 (P < 0.0001), Passing-Bablok regression y = 1.04x - 1.17, and bias 33.7 cells. In ascitic fluids, polymorphonuclear cells (PMN) showed an area under curve (AUC) of 0.98 (P < 0.0001). In pleural fluids, mononuclear cells (MN) and PMN % displayed an AUC of 0.79 (P < 0.0001) and 0.93 (P < 0.0001), respectively. CONCLUSIONS: BC-6800-BF in ascitic and pleural fluids offers rapid and accurate cell and differential counts in clinically relevant concentration ranges. The use of BC-6800-BF may allow to replace routine optical counting, except for samples displaying abnormal cell counts or abnormal DIFF scattergram.

Energy metabolism of thoracic surgical patients in the early postoperative period. Effect of posture.

STUDY OBJECTIVE: To determine the effect of elective thoracic surgery on energy metabolism and gas exchange and to evaluate whether the 30-degree sitting position would affect these variables. DESIGN: Prospective, unblinded, controlled study. SETTING: Surgical ICU in a university hospital. PATIENTS: Twenty-two adult patients undergoing elective pulmonary resection. INTERVENTIONS: Posture change from supine to 30-degree sitting position. MEASUREMENTS AND RESULTS: Oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory quotient (RQ), and energy expenditure (EE) were measured by means of computerized indirect calorimetry before and after surgery. Heart rate and respiratory frequency were measured continuously during gas exchange measurement. Blood gases were analyzed with an automated blood gas analyzer. Preoperatively, altering position did not affect energy metabolism, gas exchange, and cardiopulmonary variables. Postoperatively, the measured EE was 116% of the expected value. Mean EE and VO2 values for each position were higher than the preoperative values for the corresponding postures (p<0.05 for each position), while VCO2 increased only in the supine position (p<0.05). Mean percent increases in EE, VO2, and VCO2 were significantly lower in the 30-degree sitting position than in the supine position (EE: 7.9+/-2.7% vs 14.4+/-2.3%; p<0.001; VO2: 9.0+/-3.0% vs 16.4+/- 2.6%; p<0.001; VCO2: 3.2+/-2.1% vs 6.5+/-1.4%: p<0.05). Arterial oxygen tension and all the physiologic indexes of gas exchange for each position were worse than the preoperative values for the corresponding postures (p<0.05 for each position). Mean arterial pressure, heart rate, and respiratory frequency for each position were higher than the preoperative values for the corresponding postures (p<0.05 for each position). No changes in mean values of these variables occurred between the two positions postoperatively. CONCLUSIONS: The early postoperative period of patients undergoing elective thoracic surgery is characterized by a condition of impaired gas exchange and by a hypermetabolic state. Hypermetabolism can be partly mitigated by assuming the 30-degree sitting position.

Verapamil acute administration: a new dynamic test in hyperprolactinemic states.

We studied the effect of acute administration of the calcium-channel blocker verapamil (VER) in 27 patients with tumoral hyperprolactinemia ([THPRL] prolactinomas and pseudoprolactinomas). We also studied the effect of VER in seven patients with idiopathic hyperprolactinemia (IHPRL) and a small group of patients with normal prolactin (PRL) levels and minimal incidental anomalies shown by magnetic resonance imaging (MRI). The study was performed on 2 separate days: on the first day, all subjects received VER, and on the second they received placebo. Acute administration of VER evoked a remarkable increase in serum PRL in IHPRL (as in normal healthy subjects used as controls), but no response was shown in THPRL, with no overlap between the two conditions. Acute administration of VER stimulated PRL secretion in patients with minimal incidental lesions shown by MRI; however, this increase was smaller in patients whose PRL level consistently reached the upper-normal limit. Although the meaning of such minimal anomalies shown by MRI is unknown, this could suggest that the test is precociously altered. To further elucidate the action of VER on lactotropes, we investigated the effect of VER given intravenously (IV) and compared different oral formulations in healthy subjects. Our data show that the VER test is effective in distinguishing between THPRL and IHPRL, but unfortunately, like other tests, it is not able to individualize patients in whom THPRL is the result of diminished dopaminergic tone (pseudoprolactinoma). From a pathophysiological point of view, calcium influx would appear less important in PRL regulation in chronic disorders of PRL secretion. VER given IV did not stimulate PRL release in normal subjects. This suggests that IV administration could produce a peak with an inadequate duration or that oral formulations may act also by metabolites formed on first-pass metabolism in the liver.

When pain is not fully explained by organic lesion: a psychiatric perspective on chronic pain patients.

Recent literature demonstrates the relationship between psychopathology and medically unexplained pain, even if the results of several studies show a high degree of variability. The present study was planned with the aim of analysing both the possible relationship between the level (low/high) of organicity and the presence of psychopathology, and the degree to which these differences are related to methodological problems. Between 1998 and 2000, four hundred and thirty six consecutive patients seen at the Pisa Pain Therapy and Palliative Care Unit were requested to fill in a questionnaire, the GHQ-12, to screen the subjects probably with (GHQ-12>3) or without (GHQ-123 than the medically unexplained pain group. These results confirm that methodology is an important factor that could modify results in psychiatric research. Both medically unexplained pain and the presence of psychopathology are significantly correlated with sex, and age: females and young patients have a higher prevalence of psychopathology and of medically unexplained pain. Our results suggest that in the correlation between the low organicity of pain and psychopathology, the age and sex play a relevant role.

Evaluation of the efficacy of intrathecal nimodipine in canine models of chronic cerebral vasospasm.

Previous studies have examined whether calcium antagonists given sublingually, intravenously, or orally affect an experimentally induced vasospasm. This study was designed primarily to determine the efficacy of nimodipine given intracisternally in reversing the cerebral vasospasm produced in dogs by the injection of 4 ml of autogenous blood into the cisterna magna. The magnitude of the vasospasm and the vascular response to nimodipine were determined arteriographically. One group of animals was studied acutely to determine the dose and pharmacodynamic effects of intrathecal nimodipine, a second group was studied 1 to 4 days after the intrathecal injection of blood, and a third group was studied 3 to 6 days after successive injections of cisternal blood given 48 hours apart. Some animals were studied further 24 hours after the nimodipine treatment. Intrathecal administration of 4 ml of 10(-3) M nimodipine promptly and completely reversed the cerebral vasospasm in all groups. This effect lasted at least 4 hours but had disappeared by 24 hours. The intrathecal administration of nimodipine produced a transient drop in blood pressure. In contrast, nimodipine given sublingually (0.28 to 0.58 mg/kg) or intravenously (0.1 mg/kg) produced a persistent hypotensive effect without affecting the vasospasm. The results show that the presence of nimodipine in the cerebrospinal fluid will reverse the blood-induced vasospasm, and suggest that this calcium antagonist administered intrathecally would be an effective emergency treatment of cerebral arterial spasm.