Genome erosion and evidence for an intracellular niche - exploring the biology of mycoplasmas in Atlantic salmon.

Mycoplasmas are the smallest autonomously self-replicating life form on the planet. Members of this bacterial genus are known to parasitise a wide array of metazoans including vertebrates. Whilst much research has been significant targeted at parasitic mammalian mycoplasmas, very little is known about their role in other vertebrates. In the current study, we aim to explore the biology of mycoplasmas in Atlantic Salmon, a species of major significance for aquaculture, including cellular niche, genome size structure and gene content. Using fluorescent in-situ hybridisation (FISH), mycoplasmas were targeted in epithelial tissues across the digestive tract (stomach, pyloric caecum and midgut) from different development stages (eggs, parr, subadult) of farmed Atlantic salmon (Salmo salar), and we present evidence for an intracellular niche for some of the microbes visualised. Via shotgun metagenomic sequencing, a nearly complete, albeit small, genome (~0.57 MB) as assembled from a farmed Atlantic salmon subadult. Phylogenetic analysis of the recovered genome revealed taxonomic proximity to other salmon derived mycoplasmas, as well as to the human pathogen Mycoplasma penetrans (~1.36 Mb). We annotated coding sequences and identified riboflavin pathway encoding genes and sugar transporters, the former potentially consistent with micronutrient provisioning in salmonid development. Our study provides insights into mucosal adherence, the cellular niche and gene catalog of Mycoplasma in the gut ecosystem of the Atlantic salmon, suggesting a high dependency of this minimalist bacterium on its host. Further study is required to explore and functional role of Mycoplasma in the nutrition and development of its salmonid host.

Adaptation of a health literacy screener for computerized, self-administered use by U.S. adults.

Objective: Health literacy is a critical health determinant, for which few computerized, self-administered assessments exist. This study adapted and tested the reliability of the Newest Vital Sign© (NVS) as a computerized, self-administered health literacy screener. Methods: Phase one involved 33 participants to create response options for a computerized, self-administered NVS (C-NVS). Phase two was a randomized crossover trial to test the consistency of C-NVS and original, interviewer-administered NVS (I-NVS) scores in 89 participants. Results: Linear mixed-effects regression model results showed a significant carryover effect (p < .001). Crossover trial data from time 1 showed that participants who initially received the C-NVS had significantly higher average scores (M = 5.7, SD = 0.6) than participants who received the I-NVS (M = 4.5, SD = 1.5; t(87) = 5.25, p < .001). Exploratory analysis results showed that when the washout period was longer than 33 days (75th percentile) the carryover effect was not statistically significant (p = .077). Conclusion and innovation: Findings suggest learning can occur when health literacy screeners are administered more than once in less than a month's time and computerized, self-administered health literacy screeners may produce ceiling effects. A universal precautions approach to health literacy therefore remains germane.

Caregiver strain among North American parents of children from the Autism Treatment Network Registry Call-Back Study.

LAY ABSTRACT: Caregiver strain is the adverse impact that parents of children with emotional and behavioral issues including autism often experience (e.g. negative consequences of caregiving such as financial strain and social isolation; negative feelings that are internal to the caregiver such as worry and guilt; and negative feelings directed toward the child such as anger or resentment). This study showed that on average caregiver strain did not significantly change in North American parents of children with autism during a 2-year period. Improved caregiver strain was linked to improved child functioning and behavior. Routine assessment of caregiver strain and referral to evidence-based programming and supports may help alleviate some of the burden that families of children with autism commonly experience.

Long-term effects of D-003, a mixture of high molecular weight acids from sugarcane wax, on bones of ovariectomized rats: a one year study.

This study was done to determine the long-term effect of D-003 on bones of ovariectomized (ovx) rats distrib-uted in 4 groups: a false-operated and three groups of ovx rats: one treated with the vehicle and two with D-003 (5 and 250 mg/kg). D-003 significantly prevented, in a dose-dependent fashion, the trabecular bone volume (TBV), trabecular number (TbN) and trabecular thickness (TbTh) reduction induced in ovx rats and the increase of trabecular separation (TbSp) osteoclast number (OcN) and osteoclast surface (OcS/BS) increased in the positive controls versus the sham group. It is concluded that D-003 administered for 12 months prevented bone loss and decreased bone resorption in ovx rats, without evidences of impaired bone quality.

Treatment with the mitochondrial-targeted antioxidant peptide SS-31 rescues neurovascular coupling responses and cerebrovascular endothelial function and improves cognition in aged mice.

Moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling has an essential role in maintenance of healthy cognitive function. In advanced age, increased oxidative stress and cerebromicrovascular endothelial dysfunction impair neurovascular coupling, likely contributing to age-related decline of higher cortical functions. There is increasing evidence showing that mitochondrial oxidative stress plays a critical role in a range of age-related cellular impairments, but its role in neurovascular uncoupling remains unexplored. This study was designed to test the hypothesis that attenuation of mitochondrial oxidative stress may exert beneficial effects on neurovascular coupling responses in aging. To test this hypothesis, 24-month-old C57BL/6 mice were treated with a cell-permeable, mitochondria-targeted antioxidant peptide (SS-31; 10 mg kg-1  day-1 , i.p.) or vehicle for 2 weeks. Neurovascular coupling was assessed by measuring CBF responses (laser speckle contrast imaging) evoked by contralateral whisker stimulation. We found that neurovascular coupling responses were significantly impaired in aged mice. Treatment with SS-31 significantly improved neurovascular coupling responses by increasing NO-mediated cerebromicrovascular dilation, which was associated with significantly improved spatial working memory, motor skill learning, and gait coordination. These findings are paralleled by the protective effects of SS-31 on mitochondrial production of reactive oxygen species and mitochondrial respiration in cultured cerebromicrovascular endothelial cells derived from aged animals. Thus, mitochondrial oxidative stress contributes to age-related cerebromicrovascular dysfunction, exacerbating cognitive decline. We propose that mitochondria-targeted antioxidants may be considered for pharmacological microvascular protection for the prevention/treatment of age-related vascular cognitive impairment (VCI).

Long-term carcinogenicity of D-003, a mixture of high molecular weight acids from sugarcane wax, in Sprague Dawley rats: a 24 months study.

D-003 is a mixture of high molecular weight sugarcane wax aliphatic primary acids with cholesterol-lowering, anti-platelet and antioxidant effects. This study investigated the long-term oral toxicity and carcinogenicity of D-003 in Sprague Dawley rats of both sexes, randomly distributed into four groups: a control group, treated only with the vehicle, and three treated with D-003 (50, 500 and 1500 mg/kg). All treatments were given orally for 24 months. Mortality (survival analysis), clinical symptoms, weight gain, food consumption, organ weights, time-to-tumour or tumour incidence data were not shown between group differences or trends. With the exception of serum cholesterol levels, lower in D-003-treated groups (500 and 1500 mg/kg) than in the controls, no other difference in blood indicators was found. D-003 did not increase the frequency of neoplastic and non-neoplastic lesions compared with the controls. The occurrence of all malignant and mammary tumours in D-003-treated females was lower than in the controls. The lesions observed were consistent with spontaneous lesions reported in this species. In conclusion, D-003 is not toxic or carcinogenic when given orally to Sprague Dawley rats up to 1500 mg/kg for 2 years, and 1500 mg/kg was a not-observable effect dose.

Urinary Incontinence, Incident Parkinsonism, and Parkinson's Disease Pathology in Older Adults.

OBJECTIVE: To test the hypothesis that urinary incontinence (UI) is associated with incident parkinsonism in older adults. METHODS: We used data from 2,617 older persons without dementia. Assessment included baseline self-report UI and annual structured exam which assessed parkinsonian signs, motor performances, cognitive function, and self-report disabilities. We used a series of Cox proportional hazards models to examine the association of UI with parkinsonism and adverse health outcomes and a mixed-effect model to examine the association of UI with the annual rate of cognitive decline. In decedents, regression models were used to examine if UI proximate to death was related to postmortem indices of neuropathologies. RESULTS: At baseline, more than 45% of participants reported some degree of UI. Over an average of nearly 8 years of follow-up, UI was associated with incident parkinsonism (hazard ratio [HR] = 1.07, 95% CI = 1.02, 1.12), death (HR = 1.07, 95% CI = 1.03, 1.11), incident ADL disability (HR = 1.11, 95% CI = 1.07, 1.16), and incident mobility disability (HR = 1.07, 95% CI = 1.02, 1.13). UI was not related to incident MCI (HR = 1.02, 95% CI = 0.97, 1.07), incident AD dementia (HR = 1.00, 95% CI = 0.95, 1.05) or to the rate of cognitive decline (Estimate = -.002, standard error = .002, p = .167). In 1,024 decedents with brain autopsy, UI proximate to death was related to PD pathology (Lewy body pathology and nigral neuronal loss), but not Alzheimer's disease pathology or other age-related neuropathologies. CONCLUSION: UI in older adults is associated with incident parkinsonism and may identify older adults at risk for accumulating PD brain pathology.

Insulin-like growth factor 1 deficiency exacerbates hypertension-induced cerebral microhemorrhages in mice, mimicking the aging phenotype.

Clinical and experimental studies show that aging exacerbates hypertension-induced cerebral microhemorrhages (CMHs), which progressively impair neuronal function. There is growing evidence that aging promotes insulin-like growth factor 1 (IGF-1) deficiency, which compromises multiple aspects of cerebromicrovascular and brain health. To determine the role of IGF-1 deficiency in the pathogenesis of CMHs, we induced hypertension in mice with liver-specific knockdown of IGF-1 (Igf1f/f  + TBG-Cre-AAV8) and control mice by angiotensin II plus l-NAME treatment. In IGF-1-deficient mice, the same level of hypertension led to significantly earlier onset and increased incidence and neurological consequences of CMHs, as compared to control mice, as shown by neurological examination, gait analysis, and histological assessment of CMHs in serial brain sections. Previous studies showed that in aging, increased oxidative stress-mediated matrix metalloprotease (MMP) activation importantly contributes to the pathogenesis of CMHs. Thus, it is significant that hypertension-induced cerebrovascular oxidative stress and MMP activation were increased in IGF-1-deficient mice. We found that IGF-1 deficiency impaired hypertension-induced adaptive media hypertrophy and extracellular matrix remodeling, which together with the increased MMP activation likely also contributes to increased fragility of intracerebral arterioles. Collectively, IGF-1 deficiency promotes the pathogenesis of CMHs, mimicking the aging phenotype, which likely contribute to its deleterious effect on cognitive function. Therapeutic strategies that upregulate IGF-1 signaling in the cerebral vessels and/or reduce microvascular oxidative stress, and MMP activation may be useful for the prevention of CMHs, protecting cognitive function in high-risk elderly patients.

Effect of D-004, a lipid extract from the Cuban royal palm fruit, on atypical prostate hyperplasia induced by phenylephrine in rats.

BACKGROUND AND OBJECTIVE: Benign prostatic hyperplasia (BPH) is a non-malignant enlargement of the prostate that results in obstructive lower urinary tract symptoms. Saw palmetto (Serenoa repens), the dwarf American palm (Arecaceae family), is commonly used to treat BPH. The Cuban royal palm (Roystonea regia) also belongs to the Arecaceae family, and 200-400mg of D-004, a lipid extract from its fruits, administered orally for 14 days has been shown to prevent testosterone- but not dihydrotestosterone-induced prostatic hyperplasia in rats. D-004 (125-250 microg/mL) added to preparations of rat vas deferens caused a marked, dose-dependent and significant inhibition of noradrenaline-induced smooth muscle contraction, a response mediated through alpha(1)-adrenoceptors, and was more effective in these respects than Saw palmetto. However, the in vivo effects of D-004 and Saw palmetto on the hypertensive response induced by noradrenaline were modest (albeit significant), and neither treatment affected resting blood pressure or heart rate in rats. The differential effects of D-004 in in vitro and in vivo models could be related to a differential affinity for adrenoceptor subtypes or to different bioavailabilities in vascular and urogenital targets. Phenylephrine injected into rodents induces prostatic hyperplasia with all the characteristic morphological changes of the condition but does not result in enlargement of the prostate. Therefore, this phenylephrine-induced change in rat prostate tissue is called atypical prostatic hyperplasia. It serves as an in vivo model of prostatic hyperplasia induced by stimulation of alpha(1)-adrenoceptors. The objective of this study was to determine whether D-004 can inhibit induction of atypical prostatic hyperplasia by phenylephrine in rats. METHODS: Rats were randomly distributed into five groups (ten rats/group). One group was a negative control and received oral vehicle only. The other four groups were injected subcutaneously with phenylephrine (2 mg/kg): of these groups, one was a positive control receiving the vehicle, and the other three groups were treated with D-004 or Saw palmetto (both 400 mg/kg) or tamsulosin 0.4 mg/kg. All active treatments were given orally for 28 days. After completion of treatment, rats were placed unrestrained in metabolic cages and micturition studies were performed. The rats were later killed and their prostates removed and weighed. Prostate samples were processed for histological study, with histological changes being assessed according to a scoring system. Bodyweight was measured at baseline and at weekly intervals. RESULTS: Histological examination of positive control rats revealed features of atypical prostatic hyperplasia, with piling-up, papillary and cribiform patterns and budding-out of epithelial cells. Micturition assessment revealed that phenylephrine significantly lowered both the total volume of urine in 1 hour and the volume per micturition; the latter was considered the main efficacy variable. D-004 and Saw palmetto extracts significantly prevented this reduction in volume per micturition by 70.5% and 68.6%, respectively, while tamsulosin totally abolished the reduction in micturition induced by phenylephrine (100% inhibition). Tamsulosin, D-004 and Saw palmetto significantly reduced the histological changes of atypical prostatic hyperplasia induced by phenylephrine by 73.1%, 61.2% and 50.0%, respectively. CONCLUSIONS: Administration of D-004 resulted in marked and significant prevention of phenylephrine-induced impairment of micturition and histological changes in rat prostate. These findings indicate that, in vivo, D-004 effectively opposes these responses to phenylephrine, which are mediated through urogenital alpha(1)-adrenoceptors. In this respect, D-004 was moderately more effective than Saw palmetto, a phytotherapeutic standard used to treat BPH, but less effective than tamsulosin, a selective alpha(1A)-adrenoceptor antagonist.

Comparison of the effects of D-003, a mixture of high-molecular-weight aliphatic acids from sugarcane wax, and pravastatin on bones and osteoclast apoptosis of ovariectomized rats.

The mevalonate pathway is relevant in bone cells. Statins inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the key enzyme of this route, stimulating osteoblast differentiation and activity. Pravastatin increases bone formation markers in postmenopausal women and bone density in diabetics. D-003 is a mixture of high-molecular-weight acids purified from sugarcane wax which inhibits cholesterol biosynthesis through HMG-CoA reductase regulation, preventing bone loss in osteoporosis induced with ovariectomy and prednisolone in rats. We investigated the effects of D-003 (50 mg/kg) and pravastatin (20 mg/kg) orally administered for 12 weeks to ovariectomized rats. Female rats were randomized in four groups (10 rats/group): two control groups treated with the vehicle, one false-operated (sham) and another ovariectomized (positive control), while two other groups received D-003 or pravastatin. Bone resorption and formation was studied through histomorphometry and apoptosis through immunohistochemistry. D-003 and pravastatin significantly (p < 0.001) prevented the changes of trabecular bone versus ovariectomized rats and (p < 0.001) the increase of the surface and number of osteoclasts versus ovariectomized controls. D-003 and pravastatin, however, did not modify osteoblast surfaces, a bone formation marker D-003 and pravastatin increased osteoclast apoptosis and reduced (p < 0.05) osteoblast and osteocyte apoptosis versus ovariectomized controls; D-003 was more effective (p < 0.05) than pravastatin. In conclusion, D-003 (50 mg/kg) orally administered for 12 weeks prevented bone loss and bone resorption in ovariectomized rats, increasing osteoclast apoptosis. The preventive effects of D-003 on bone loss and resorption in ovariectomized rats are comparable to those of pravastatin. Both drugs inhibited osteoblast apoptosis but failed to change osteoblast surface. The effects of D-003 on bone cell apoptosis were greater than those of pravastatin. Therefore, D-003 could be used to prevent or treat bone loss in postmenopausal women, but further animal studies and clinical trials are required to confirm the clinical relevance of this potential effect.

Oral acute and subchronic toxicity of D-004, a lipid extract from Roystonea regia fruits, in rats.

D-004 is a lipid extract obtained from Cuban royal palm (Rosytonea regia) fruits, consisting of a mixture of fatty acids and esters. D-004 has shown protective effects on prostate hyperplasia induced by testosterone in rodents. We report the results of two studies investigating the acute and subchronic oral toxicity of D004 in rats. Oral acute toxicity of D-004 (2,000 mg/kg) was investigated in Sprague Dawley rats according to the acute toxic class method, and the results showed that D-004 oral acute toxicity was practically absent, being defined as unclassified. In the subchronic study, rats were orally treated with D-004 at 500, 1,000 and 2,000 mg/kg for 90 days. No evidence of treatment-related toxicity was detected. Thus, analysis of body weight gain, clinical observations, blood biochemistry, hematology, organ weight ratios and histopathological data did not show significant differences between control and treated groups. We conclude that D-004 orally administered to rats was safe and that no drug-related toxicity was detected even at the highest dose investigated in both acute and subchronic (2,000 mg/kg) studies. Thus, this dose can be considered as a nonobservable-effect dose in rats.

Effects of D-003 (5-200 mg/kg), a mixture of high molecular weight aliphatic acids from sugarcane wax, on bones and bone cell apoptosis in ovariectomized rats.

The mevalonate pathway is crucial for osteoclast function. D-003 is a mixture of high molecular weight acids purified from sugarcane wax, which inhibits cholesterol biosynthesis through HMG-CoA reductase regulation. D-003 administered at 50 and 200 mg/kg for 12 weeks prevented bone loss in ovariectomized rats, increasing osteoclast apoptosis. The present study investigated whether the effects of D-003 on bone resorption and osteoclast apoptosis are dose-dependent. Rats were randomized into seven groups (10 rats/group): two control groups orally treated with the vehicle, one false-operated (sham) and another ovariectomized group (positive control), while another four groups received D-003 (5, 25, 50 and 200 mg/kg). The effects on bone resorption and formation were studied through histomorphometry and the effects on apoptosis through immunohistochemistry. D-003 (5-200 mg/kg) dose-dependently and significantly prevented (p < 0.001) changes in trabecular bone and increase in osteoclast surface and number versus ovariectomized controls, leaving osteoblast surfaces unchanged. Across the dose range, D-003 significantly increased (p < 0.05) osteoclast apoptosis in a dose-dependent manner and reduced (p < 0.05) osteoblast and osteocyte apoptosis versus ovariectomized controls, but these effects did not show dose dependence. In conclusion, D-003 (5-200 mg/kg) orally administered at for 12 weeks prevented bone loss and bone resorption and increased osteoclast apoptosis in ovariectomized rats in a dose-dependent manner. These results are consistent with previous data, showing that D-003 administered at relatively low doses prevents bone loss induced with ovariectomy, which could be useful to prevent or treat bone loss in postmenopausal women. Further experimental and clinical studies, however, are needed to confirm these findings.

Effect of D-004, a lipid extract from Cuban royal palm fruit, on histological changes of prostate hyperplasia induced with testosterone in rats.

Benign prostatic hyperplasia (BPH) is the nonmalignant, uncontrolled growth of prostate gland cells and stroma leading to difficulty in urinating. Lipid extracts from Saw palmetto (Arecaceae) fruits are used to treat BPH. The Cuban royal palm (Roystonea regia) is a member of this family and D-004, a lipid extract from its fruits, prevents prostate hyperplasia (PH) induced with testosterone, as opposed to dihydrotestosterone, in rodents. This study investigated whether D-004 could prevent the histological features of testosterone-induced PH in rats. Rats were distributed into six groups (10 rats per group): A negative control group receiving subcutaneous injections of soy oil and treated with vehicle, and five groups injected subcutaneously with testosterone and treated with the vehicle (positive control), D-004 (100, 200 and 400 mg/kg) or Saw palmetto (400 mg/kg). Treatments were given orally for 14 days. At sacrifice, prostates were removed and processed for light microscopy. The histopathological findings of PH were assessed according to a score-chart protocol. D-004 200 and 400 mg/kg, but not 100 mg/kg, significantly and moderately in a dose-dependent manner prevented prostate enlargement and the testosterone-induced histological changes. Compared with positive controls, D-004 200 and 400 mg/kg inhibited prostate size increases and the histological score up to 56.1% and 60.7%, respectively, while Saw palmetto 400 mg/kg reduced such variables by 45.8% and 49.0%, respectively. The effects of D-004 400 mg/kg on the histological changes, not on prostate size, were greater (p < 0.05) than those of Saw palmetto. D-004 and Saw palmetto did not affect body weight values. In conclusion, D-004 200 and 400 mg/kg administered orally for 14 days prevented the increase of prostate size and the testosterone-induced histological changes in rats, its effects being comparable or mildly better than those of Saw palmetto. These results extend previous data showing preventive effects of D-004 on testosterone-induced prostate enlargement with in rodents, and further studies are required to explore the mechanisms underlying such effects.

IGF-1 deficiency impairs neurovascular coupling in mice: implications for cerebromicrovascular aging.

Aging is associated with marked deficiency in circulating IGF-1, which has been shown to contribute to age-related cognitive decline. Impairment of moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of age-related cognitive impairment. To establish the link between IGF-1 deficiency and cerebromicrovascular impairment, neurovascular coupling mechanisms were studied in a novel mouse model of IGF-1 deficiency (Igf1(f/f) -TBG-Cre-AAV8) and accelerated vascular aging. We found that IGF-1-deficient mice exhibit neurovascular uncoupling and show a deficit in hippocampal-dependent spatial memory test, mimicking the aging phenotype. IGF-1 deficiency significantly impaired cerebromicrovascular endothelial function decreasing NO mediation of neurovascular coupling. IGF-1 deficiency also impaired glutamate-mediated CBF responses, likely due to dysregulation of astrocytic expression of metabotropic glutamate receptors and impairing mediation of CBF responses by eicosanoid gliotransmitters. Collectively, we demonstrate that IGF-1 deficiency promotes cerebromicrovascular dysfunction and neurovascular uncoupling mimicking the aging phenotype, which are likely to contribute to cognitive impairment.

Acquired immunodeficiency syndrome in children: report of the Centers for Disease Control National Surveillance, 1982 to 1985.

Since national surveillance for acquired immunodeficiency syndrome (AIDS) began in 1981, the Centers for Disease Control (CDC) has received reports of more than 20,000 cases of AIDS in the United States. As of December 31, 1985, 307 of these cases had been diagnosed in children younger than 13 years of age. The number of cases is increasing rapidly. The number of cases reported in 1985 more than doubled those reported in 1984. The major risk factors in children for acquiring infection with the causative agent, human immunodeficiency virus (HIV), were having a mother known to be infected and/or at increased risk for infection and receiving a transfusion of blood or blood products. Of the 307 children with AIDS, 73% were reported from one of four states: New York, New Jersey, Florida, and California. Most AIDS cases in children occur in black or Hispanic infants and toddlers. The estimated incubation period for AIDS in children has increased each surveillance year, with the longest incubation exceeding 7 years. The prognosis for children with AIDS is poor and infants less than 1 year of age have the shortest survival time following diagnosis. Continued national surveillance for AIDS is mandatory for establishing effective prevention programs to control the spread of the disease. The CDC encourages all health care personnel to report cases of AIDS to their public health departments.

Ras-GRF, the activator of Ras, is expressed preferentially in mature neurons of the central nervous system.

In rodents, the Ras-specific guanine-nucleotide exchange factor (Ras-GRF) is expressed in different areas of the brain and, at a reduced level, also in the spinal cord. No expression of the 140 kDa Ras-GRF was detected in dorsal root ganglia and all other tissues tested. Analysis of primary cultures derived from brain reveals that this exchange factor is only present in neurons of the central nervous system. In primary hippocampal cultures, the expression of Ras-GRF increases in parallel with the onset of a neuronal network and in the whole brain it increases sharply after birth.

Protective effect of D-003 on experimental spinal cord ischemia in rabbits.

D-003 is a natural mixture of long chain aliphatic acids isolated and purified from sugar cane wax. It possesses antiplatelet and antithrombotic effects as well as decreases plasma and serum levels of thromboxane B(2) (TxB(2)), meanwhile significantly and markedly raises prostacyclin (PgI(2)) levels in rats. This study was undertaken to investigate the effects of D-003 on spinal cord injury in rabbits. New Zealand rabbits were treated during 10 days with D-003 (25 and 200 mg kg(-1)) and ASA (2 mg kg(-1)) before spinal cord ischemia. Animals were subjected to 20 min of aortic occlusion and 24h of reperfusion. Clinical symptoms and histopathological changes of spinal cord were observed. The PgI(2) levels in thoracic aorta were quantified by bioassay. D-003 (25 and 200 mg kg(-1)) significantly increased the mean scores reached 4h after reperfusion, although no dose relation was observed. Twenty-four hours after reperfusion, no deaths occurred in both sham and D-003 treated groups, meanwhile in positive controls and ASA the mortality rate was 38.5% and 7.69% respectively. In addition, 100% of sham, 69% and 77% of rabbits treated with D-003 at 25 and 200 mg kg(-1), respectively, did not show histopathological changes. By the contrary, 100% of positive control animals showed severe damage and ASA-treated rabbits showed only a partial protection. Animals treated with both doses of D-003 showed PgI(2) levels significantly larger than those of positive and negative controls, an effect dose-related, while ASA 2 mg kg(-1) did not change PgI(2) values. The increase of PgI(2) levels achieved in the D-003 treated animals could be an important mechanism in the protection against the spinal cord ischemia.

Interference of levamisole with Forssman shock.

The anti-helminthic drug levamisole has been used as an adjunct in the treatment of some immunologic defects including cancer. Recently, it has been shown that this drug inhibits thromboxane synthetase as well. Since Forssman shock in guinea pig is used as a model for pulmonary thromboembolism involving thromboxane A2, we studied the interference of levamisole with bronchoconstriction, thrombocytopenia, endothelial cells and pulmonary damage induced by Forssman antiserum. Levamisole inhibited dose-dependently the pathological changes produced by Forssman antiserum raising the possibility that levamisole may be effective for the treatment of pulmonary thromboembolism in man.

Comparison of DNA migrations in two clamped homogeneous electric field chambers of different sizes. Relation between sample thickness and electrophoresis time.

We present here a method to compare the mathematical descriptions of DNA migration per pulse as a function of pulse time. It is based on obtaining robust estimates and variances of DNA reorientation time, migration velocities during and after DNA reorientation; and on the statistical comparisons of these estimates. We demonstrated an equal description for the migration per pulse of each DNA molecule separated under identical conditions in clamped homogeneous electric field (CHEF) and miniCHEF chambers. However, miniCHEF resolved the patterns in shorter times, because it uses thinner samples. The relationship between sample thickness and CHEF run time is also presented.

Effect of policosanol on intimal thickening in rabbit cuffed carotid artery.

We studied the effect of policosanol on smooth muscle cell proliferation in the cuffed carotid artery of the rabbit. Policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane wax, with cholesterol lowering effects proved in experimental models and patients with type II hypercholesterolemia. It acts by inhibiting cholesterol biosynthesis. The positioning of a nonocclusive silicone collar around the rabbit carotid artery results in the formation of a neointima. We wished to determine whether policosanol orally administered prevented intimal thickening. Collars were placed around the left carotid for 15 days. The contralateral artery was sham operated. We included three experimental groups: a control received vehicle and two others policosanol at 5 and 25 mg Kg until sacrificed. Samples of arteries were examined by light and electron microscopy. To evaluate intimal thickening the cross-sectional area of intima and media were measured. Neointima was significantly reduced in policosanol-treated animals compared with controls. The smooth muscle cell proliferation was studied by the immunohistochemical detection of proliferating cell nuclear antigen and a significant reduction was observed in policosanol treated rabbits. It is concluded that policosanol has a protective effect on the neointima formation in this experimental model.