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EEG findings in senile dementia and normal aging.

EEG findings in 62 patients with senile dementia of alzheimer type (SDA), 22 patients with multi-infarct dementia (MID) and 90 controls of same age and sex were studied. The SDA patients differed significantly from the controls in EEG normality, over-all disturbance, dominant occipital, rhythm, accentuation of theta and delta, fluctuations in alertness, paroxysmal activity and H-reaction. Even the least severely affected SDA patients differed significantly from the controls in all EEG variables except paroxysmal activity. With increasing degree intellectual impairment in the SDA group the dominant occipital rhythm became slower. The MID group differed from the controls in all EEG parameters including asymmetric findings. The EEG findings of the SDA patients differed significantly from those of the MID patients only in asymmetric findings which were more common in the MID patients. 29% of the normal elderly people had EEG alterations, Abnormalities were mild. Asymmetric findings, mainly theta activity in left temporal region were common. H-reaction (occipital driving response greater than or equal to 18 c/s) was well preserved in the controls. EEG is valuable in differentiation of dementia patients from normal elderly people, but differentiation between MID and SDA is not reliable by using EEG, only.

Aged↗

Diagnostic value of the strand displacement amplification method compared to those of Roche Amplicor PCR and culture for detecting mycobacteria in sputum samples.

We compared the ability of the semiautomated BDProbeTec-SDA system, which uses the strand displacement amplification (SDA) method, with that of the Roche Amplicor-PCR system and the Septi-Chek AFB culture system to directly detect Mycobacterium tuberculosis complex (MTB) and other mycobacteria in sputum samples. A total of 530 sputum samples from 299 patients were examined in this study. Of the 530 samples, 129 were culture positive for acid-fast bacilli with the Septi-Chek AFB system; 95 for MTB, 29 for M. avium-M. intracellulare complex (MAC), and 5 for other mycobacteria. The BDProbeTec-SDA system detected 90 of the 95 samples culture positive for MTB (sensitivity, 94.7%), and the Amplicor-PCR system detected 85 of the 95 samples culture positive for MTB (sensitivity, 89.5%). The specificity of each system, based on the clinical diagnosis, was 99.8% for SDA and 100% for PCR, respectively. Among the 29 samples culture positive for MAC, the BDProbeTec-SDA system detected MAC in 24 samples (sensitivity, 82.8%), whereas the Amplicor-PCR system detected MAC in 23 samples (sensitivity, 79.3%). The specificities of the systems were 98.3 and 100%, respectively. The high degrees of sensitivity and specificity of the BDProbeTec-SDA system suggest that it should be very useful in clinical laboratories for the rapid detection of mycobacteria in sputum samples.

Bacteriological Techniques↗

CHROMagar Candida as the sole primary medium for isolation of yeasts and as a source medium for the rapid-assimilation-of-trehalose test.

The chromogenic medium BBL CHROMagar Candida (CAC) was evaluated as a sole primary medium for the isolation of yeasts from clinical specimens in which yeasts are the primary concern. Additionally, the reliability of the rapid-assimilation-of-trehalose (RAT) test in yielding correct results with isolates taken from CAC was assessed. A total of 270 throat, urine, and genital (TUG) specimens were streaked onto CAC, Sabouraud dextrose agar (SDA), inhibitory mold agar (IMA), and Mycosel (MYC). A total of 69 blood culture broths that were smear positive for yeast were streaked onto CAC and SDA. A 1-h RAT test (NCCLS M35-A) was performed simultaneously on isolates from CAC and SDA. A total of 112 TUG specimens yielded yeast colonies (CAC, 111 colonies; IMA, 105; SDA, 103; MYC, 91). The 69 blood culture yeasts grew on both CAC and SDA. Mixed cultures of yeasts were detected on 11 CAC plates but were unrecognized on other media. Colonies suspected of being C. glabrata on 32 CAC plates were all RAT test positive and confirmed to be C. glabrata; of 59 colonies with various characteristics of color and morphology on CAC, none were RAT positive, and all were conventionally identified as yeasts other than C. glabrata (sensitivity and specificity, 100%). The same isolates from SDA tested for RAT produced six false negatives and no false positives (sensitivity, 81%; specificity, 100%). The results show that CAC can be used as the sole primary medium for recovery of yeasts from clinical specimens. Additionally, isolates grown on CAC yield excellent results with the RAT test utilized in this study.

Candida↗

Should Chlamydia trachomatis confirmation make you cross? Performance of collection kits tested across three nucleic acid amplification test platforms.

OBJECTIVE: To investigate the feasibility of confirming initially reactive nucleic acid amplification assays for Chlamydia trachomatis (CT) by cross testing on a second molecular platform. The three platforms investigated were Aptima Combo 2 assay (AC2), Cobas Amplicor CT test (PCR) and ProbeTec ET CT assay (SDA). METHODS: Serial dilutions of a CT culture were prepared in 0.9% saline; used to prepare simulated swab samples for all three platforms, and tested as in the manufacturer's instructions. For the cross testing investigation, 1 ml of the simulated swab samples prepared in each of the three collection kits was transferred into the appropriate collection kit for the second platform. RESULTS: AC2 demonstrated a higher analytical sensitivity than the SDA and PCR assays. Upon cross testing AC2 again demonstrated a superior performance to the SDA and PCR assays even when testing swab samples originally prepared in the SDA and PCR transport medium. The SDA assay was inhibited by the addition of transport medium from both the AC2 and PCR assays. CONCLUSION: The analytical sensitivity of the three assays is not identical, therefore confirming initially reactive samples on a second platform may prove to be difficult. However, the higher sensitivity of the AC2 assay could allow its use as a confirmatory assay for reactive swab samples collected in the SDA and PCR transport medium.

Chlamydia Infections↗

BD ProbeTec ET assay for the diagnosis of gonorrhoea in a high-risk population: a protocol for replacing traditional microscopy and culture techniques.

OBJECTIVES: To evaluate the Neisseria gonorrhoeae Becton Dickinson (BD) ProbeTec strand displacement assay (SDA) on female endocervical swab and male first void urine against culture for Neisseria gonorrhoeae on female endocervical and urethral swab for the diagnosis of N gonorrhoeae infection in genitourinary medicine (GUM) attendees. To determine an algorithm for implementation of N gonorrhoeae infection screening by SDA in these patients taking account of the desirability of having a N gonorrhoeae isolate in people with N gonorrhoeae infection. METHODS: Initially, 1582 patients attending the GUM clinic were tested for N gonorrhoeae infection by SDA and routine microscopy, and culture. On the basis of the results, a protocol for diagnosis of N gonorrhoeae infection by SDA, with culture specimens only from patients with a listed risk factor for acquiring N gonorrhoeae infection, was devised and implemented. A post implementation audit was done to assess the effectiveness of this protocol for routine service use. RESULTS: There was good concurrence between the N gonorrhoeae SDA and culture results with a N gonorrhoeae infection prevalence rate of 3.4% by both methods. All men and 85% of women with N gonorrhoeae infection had an identifiable risk factor for acquiring infection. Overall, 38% men and 60% women attending the GUM clinic had this listed risk factor for acquiring N gonorrhoeae. Post implementation audit confirmed the initial findings. CONCLUSION: Nucleic acid amplification techniques like the SDA are sensitive and specific for diagnosis of N gonorrhoeae. We were able to list certain risk factors, which were predictive of those patients most likely to have N gonorrhoeae infection. To obtain timely sensitivity data, a culture specimen should also be submitted at the same time from patients deemed to have a listed risk factor for acquiring Neisseria gonorrhoeae infection.

Bacteriological Techniques↗

Inspiratory muscle strength and endurance in steroid-dependent asthma.

The adverse effect of long-term steroid treatment on respiratory muscle function remains controversial. We evaluated inspiratory muscle strength and endurance in steroid-dependent asthmatics in comparison with other asthmatics or with patients with chronic obstructive pulmonary disease exhibiting a comparable level of lung hyperinflation. Inspiratory muscle function was assessed by maximal inspiratory pressure (Pimax) and by an incremental inspiratory threshold loading test in 19 patients who had had steroid-dependent asthma (SDA) requiring a mean daily dose of 20.7 +/- 0.8 mg prednisone for 5 +/- 1.4 yr. They were compared with 16 healthy control subjects, 30 patients with COPD, and 16 patients with non-steroid-dependent asthma (NSDA). Pimax as percentage of predicted values (%Pimax) was not significantly different in patients with SDA (77 +/- 5%) or NSDA (83 +/- 6%) than in control subjects (93 +/- 4%). In contrast, %Pimax was lower in patients with COPD (59 +/- 4.4%) than in those with SDA or NSDA (p < 0.05) or the control subjects (p < 0.0001). A significant correlation was found between %Pimax and hyperinflation assessed by the FRC/TLC ratio (r = 0.42; p < 0.001). Inspiratory endurance, defined as the ratio of maximal peak inspiratory pressure sustained for 2 min to individual Pimax (Plim2/Pimax), was significantly lower in the SDA (43 +/- 3%; p < 0.0001), NSDA (65 +/- 4%; p = 0.01), and COPD (55 +/- 3%; p < 0.0001) groups than in the control group (76 +/- 2%). Plim2/Pimax was also lower in patients with SDA than in those with COPD (p = 0.0073) or NSDA (p < 0.0001). Hyperinflation plays a major role in inspiratory muscle dysfunction associated with obstructive lung disorders, but the finding of a significantly decreased endurance in patients with SDA when compared with patients with COPD, despite a lower level of hyperinflation in the former group, points to a deleterious effect of long-term corticosteroid treatment on inspiratory muscle function in asthmatics.

Asthma↗

On the nature of pre-freeze mortality in insects: water balance, ion homeostasis and energy charge in the adults of Pyrrhocoris apterus.

Three acclimation groups [i.e. non-diapause (LD), diapause (SD) and diapause, cold-acclimated (SDA)] of the adult bugs Pyrrhocoris apterus differed markedly in their levels of chill tolerance. Survival time at a sub-zero, but non-freezing, temperature of -5 degrees C (Lt50) extended from 7.6 days, through 35.6 days, to >60 days in the LD, SD and SDA insects, respectively. The time necessary for recovery after chill-coma increased linearly with the increasing time of exposure to -5 degrees C, and the steepness of the slope of linear regression decreased in the order LD>SD>SDA. The capacity to prevent/counteract leakage of Na(+) down the electrochemical gradient (from haemolymph to tissues) during the exposure to -5 degrees C increased in the order LD<SD<SDA. As a result, the rates of counteractive outward movement of K(+), and of the E(K) dissipation, decreased in the same order. The least chill-tolerant insects (LD) showed the highest rate of body-water loss. Most of the water was lost from the haemolymph compartment. The ability to regulate a certain fraction of ion pools into the hindgut fluid was the highest in the SDA group, medium in the SD group and missing in the LD group. The adenylate energy charge in the fat body cells was constant in all three groups. The total pools of ATP, ADP and AMP, however, decreased in the SD and SDA groups but remained constant in the LD group. The inability of insects to maintain ion gradients at sub-zero temperature is discussed as an important cause of pre-freeze mortality.

Acclimatization↗

Molecular testing (strand displacement assay) for identification of urethral gonorrhoea in men: can it replace culture as the gold standard?

The objective was to evaluate the performance of Becton Dickinson's BD Probe Tec(TM) (BDPT) strand displacement amplification (SDA) test for the detection of Neisseria gonorrhoeae on urethral specimens from men with urethritis compared with conventional culture and to show that SDA improves the diagnostic yield of gonorrhoea infections (GC). Anonymized retrospective testing of stored urethral swab samples from men attending genitourinary services in East London was performed using SDA. The prevalence of GC culture positive infections in this sample was 20/152 (13%). The sensitivity, specificity, positive predictive value and negative predictive value for the BDPT-SDA system compared with culture were 100%, 95%, 77% and 100%, respectively. In this study population, the BDPT-SDA assay was a highly sensitive and specific test for the diagnosis of N. gonorrhoeae from urethral swabs in men. Therefore, SDA can be used to complement culture in the diagnosis of N. gonorrhoeae infection. No ethics committee approval was obtained as all samples were anonymized.

Bacterial Typing Techniques↗

Isolation and properties of sialodacryoadenitis virus of rats.

Pathogenic agents were isolated from affected salivary glands of rats with sialodacryoadenitis (SDA) by means of intercerebral inoculation to newborn mice and inoculation to primary rat kidney cell cultures. The properties of these isolates, irrespective of the isolation techniques, were in general agreement with that of SDA virus strain 681, and they were identified as SDA virus. In addition to the known properties, following characteristics were noticed: (1) Particles of SDA virus bore two different long and short surface projections. (2) Some antigenic differences were observed between the present isolate 930-10 and the strain 681. (3) It was suggested that SDA virus grew better at 35 degrees C than at 31 degrees, 33 degrees, 37 degrees or 39 degrees C. (4) SDA virus did not propagate in DBT cells.

Animals↗

[Diagnostic and therapeutic problems in adult onset Still's disease (data of a long-term follow-up)].

15 patients with Still's disease of adults (SDA) were followed up for 17 years maximum. The disease showed a principal clinical-laboratory syndrome observed both in SDA debut and exacerbations (recurrences). Clinical manifestations of SDA do not arise stereotypically causing difficulties in its nosological interpretation. SDA course is represented by three variants: monophasic (monocyclic), recurrent and chronic persisting with development of destructive arthritis. Use of nonsteroid antiinflammatory drugs is analysed, indications to administration of glucocorticoids and basic treatment are listed. Reversibility of systemic SDA manifestations except the articular one is shown. About half of the patients develop chronic destructive arthritis. In active SDA, renal amyloidosis and chronic renal failure may develop with lethal outcome.

Adolescent↗

Potential role of 5-HT2 and D2 receptor interaction in the atypical antipsychotic action of the novel succimide derivative, perospirone.

The pharmacological profile of the novel serotonin-dopamine antagonists (SDA)-type antipsychotic, perospirone, was compared with other SDA and typical antipsychotics, and a potential role of 5-HT2 and D2 receptor interaction in the atypical antipsychotic property of SDA was discussed based on the findings with selective 5-HT2 antagonists. Our study revealed that perospirone, like other SDA, differed from the typical antipsychotics by exhibiting 1) putative anxiolytic and/or antidepressant actions in some animal models (e.g., conditioned fear stress-induced freezing model and rat social interaction), 2) reduced extrapyramidal side effects (EPS) liability (catalepsy and bradykinesia induction), 3) weaker blocking actions at striatal D2 receptors as revealed by c-fos expression and dopamine turnover and 4) lower propensity to induce supersensitivity of dopamine receptors after repeated treatments (e.g., dopamine agonist-induced stereotyped behavior and vacuous chewing movement). The 5-HT2 antagonists mimicked the action of SDA antipsychotics in the animal models of mood disorder. In addition, combined treatments of 5-HT2 antagonists with typical antipsychotic could attenuate EPS induction and striatal c-fos expression associated with D2 receptor blockade, and could prevent the sensitization of D1 receptor function after repeated treatments. These findings suggest that the blockage of 5-HT2 receptors contributes to the broad efficacy profile of SDA (i.e., antipsychotic and mood stabilizing actions) and may counteract the D2 (and/or D1) blocking activities of antipsychotics in the striatum to reduce EPS.

Animals↗

Simultaneous strand displacement amplification and fluorescence polarization detection of Chlamydia trachomatis DNA.

Strand displacement amplification (SDA) is an isothermal DNA amplification technology that uses a restriction enzyme and polymerase. We have developed a target-specific method which allows simultaneous SDA and detection in a homogeneous format. This is accomplished by including a detector oligodeoxynucleotide labeled with 5-(4,6-dichlorotriazin-2-yl)amino fluorescein in the SDA reaction. Fluorescence polarization is used to monitor hybridization of the detector probe to the amplification product as it rises in concentration during SDA. We have demonstrated real-time SDA detection for the cryptic plasmid of Chlamydia trachomatis with high sensitivity in only 30 min.

Base Sequence↗

Quantitative reverse transcription strand displacement amplification: quantitation of nucleic acids using an isothermal amplification technique.

Recent advances in nucleic acid amplification techniques have allowed for quantitation of viral nucleic acid levels in clinical specimens. The most prevalent testing is carried out for HIV viral load. Strand displacement amplification (SDA) is an isothermal DNA amplification system utilizing a restriction enzyme and a DNA polymerase with strand displacement properties. SDA was adapted for quantitative RNA amplification (QRT-SDA) of an HIV gag sequence by including AMV reverse transcriptase, a quantitative control sequence, and 32P-labeled detector oligonucleotides for the HIV and the control sequences. We have also improved the amplification efficiency by including the single-strand binding protein from gene 32 of T4 bacteriophage (T4gp32) to enhance strand displacement replication. In a preliminary analytical demonstration of the technique, RT-SDA was quantitative to within twofold over a range of 500-500,000 transcripts that were generated from a plasmid bearing an HIV gag sequence. QRT-SDA potentially represents a convenient alternative for viral load testing in a clinical setting.

Base Sequence↗

The medial and lateral cell groups of the sexually dimorphic area of the gerbil hypothalamus are essential for male sex behavior and act via separate pathways.

Male reptiles, birds and mammals do not copulate if the medial preoptic area (MPOA) is destroyed but the MPOA cell groups necessary for male sexual behavior were not known. Here, two cell groups essential for copulation are identified in the sexually dimorphic area (SDA) of the gerbil (Meriones unguiculatus) MPOA. Bilateral cell-body lesions of either the medial or lateral SDA eliminated mating in sexually experienced male gerbils given testosterone. Nearby MPOA lesions did not. The medial and lateral SDA affect sex behavior via separate pathways since lesioning the medial SDA on one side of the brain and the lateral SDA on the other did not stop sexual behavior.

Animals↗

Effects of dietary soybean protein levels on metabolic response of the southern catfish, Silurus meridionalis.

A closed respirometer was used to measure oxygen consumption of the southern catfish Silurus meridionalis fed with six isonitrogenous (48% crude protein) diets replacing 0%, 13%, 26%, 39%, 52% and 65% fish meal (FM) protein by soybean meal (SBM) protein, in order to investigate the effects of dietary soybean protein level (SPL) (replacing FM) on metabolic rates of the southern catfish. The results showed that there were no significant differences in routine metabolism among dietary treatments. Either the total metabolic rate or specific dynamic action (SDA) was positively correlated with assimilated food energy at each diet, respectively (P<0.05). The SDA coefficient (means the energy spent in metabolism per unit of assimilated dietary energy) significantly increased with increasing dietary SPL (P<0.05). Fish fed the diet with 13% SPL had a significantly lower SDA coefficient (0.1528) than fish fed the diet with 52% or 65% SPL (0.1826 or 0.1932) (P<0.05). However, there were no significant differences in SDA coefficient among fish fed the diets with 13%, 26% and 39% SPL (P>0.05). Results of the present study suggested that an imbalance of essential amino acids at higher dietary SPL resulted in more energy channeled into metabolism, and subsequently increased the SDA coefficient.

Animal Feed↗

Effects of prey type on specific dynamic action, growth, and mass conversion efficiencies in the horned frog, Ceratophrys cranwelli.

To be most energetically profitable, predators should ingest prey with the maximal nutritional benefit while minimizing the cost of processing. Therefore, when determining the quality of prey items, both the cost of processing and nutritional content must be considered. Specific dynamic action (SDA), the increase in metabolic rate associated with feeding in animals, is a significant processing cost that represents the total cost of digestion and assimilation of nutrients from prey. We examined the effects of an invertebrate diet (earthworms) and a vertebrate diet (newborn mice) on mass conversion efficiencies, growth, and SDA in the Chacoan horned frog, Ceratophrys cranwelli. We found the earthworm diet to be significantly lower in lipid, protein, and energy content when compared to the diet of newborn mice. Growth and mass conversion efficiencies were significantly higher in frogs fed newborn mice. However, mean SDA did not differ between frogs fed the two diets, a finding that contradicts many studies that indicate SDA increases with the protein content of the meal. Together, our results indicate that future studies evaluating the effect of meal type on bioenergetics of herpetofauna are warranted and may provide significant insight into the underlying factors driving SDA.

Animal Nutritional Physiological Phenomena↗

Replacement of dietary fish oil for Atlantic salmon parr (Salmo salar L.) with a stearidonic acid containing oil has no effect on omega-3 long-chain polyunsaturated fatty acid concentrations.

The worldwide increase in aquaculture production and the concurrent decrease of wild fish stocks has made the replacement of fish oil in aquafeeds an industry priority. Oil from a plant source Echium plantagineum L., Boraginaceae, has high levels of stearidonic acid (SDA, 18:4omega3, 14%) a biosynthetic precursor of omega-3 long-chain (> or =C(20)) polyunsaturated fatty acids (omega3 LC-PUFA). Atlantic salmon (Salmo salar L.) parr were fed a control fish oil diet (FO) or one of 3 experimental diets with 100% canola oil (CO) 100% SDA oil (SO), and a 1:1 mix of CO and SDA oil (MX) for 42 days. There were no differences in the growth or feed efficiency between the four diets. However, there were significant differences in the fatty acid (FA) profiles of the red and white muscle tissues. Significantly higher amounts of SDA, eicosapentaenoic acid (20:5omega3, EPA), docosahexaenoic acid (22:6omega3, DHA) and total omega3 FA occurred in both red and white muscle tissues of fish fed SO and FO compared with those fed CO. Feeding SO diet resulted in omega3 LC-PUFA amounts in the white and red muscle being comparable to the FO diet. This study shows that absolute concentration (mug/g) of EPA, DHA and total omega3 have been maintained over 6 weeks for Atlantic salmon fed 14% SDA oil. The balance between increased biosynthesis and retention of omega3 LC-PUFA to maintain the concentrations observed in the SO fed fish remains to be conclusively determined, and further studies are needed to ascertain this.

Animals↗

Postprandial responses in the African rhombig egg eater (Dasypeltis scabra).

The African rhombic egg eater (Dasypeltis scabra) is a colubrid snake feeding exclusively on bird eggs. Frequency of feeding is governed by the seasonal availability of bird eggs; i.e., long fasting intervals change with relatively short periods when plenty of food is available. Intermittent feeding snakes show a remarkable postprandial increase of metabolic rate and digestive organ size. The postprandial increase in metabolic rate (specific dynamic action, SDA) in snakes is affected by meal size, temperature, and meal composition. A major portion of SDA in snakes is allocated to gastric function and the breakdown of the meal. We hypothesize that SDA in egg eaters is lower than in other snake species, because egg eaters feed on "liquid" food that does not require enzymatic breakdown in the stomach. We also hypothesized that other components of the postprandial response of egg eaters (e.g., size changes of the intestine and the liver) do not differ from other snakes. The standard metabolic rate and metabolic response to feeding were measured using closed-chamber respirometry. Size changes of small intestine and liver were measured using high-resolution transcutaneous ultrasonography. Standard metabolic rates of fasting egg eaters were in the same range of mass specific values as known from other snakes. Within 24h after feeding, oxygen consumption doubled and peaked at 2 days after feeding. At the same time, the size of the small intestine and the cross-sectional diameter of the liver increased. Within 2 days after feeding, the size of the mucosal epithelium doubled its thickness. Liver size increased significantly within 24h reaching maximum size 2-4 days after feeding. The size of both organs returned to fasting values within 7-10 days after feeding. The postprandial response of African rhombic egg eaters shows the same pattern and dynamics as known from other snake species. However, the factorial increase of metabolic rate during SDA is the lowest reported for any snake. A comparison with literature data supports the idea that SDA is mainly determined by gastric function and that it is low in egg eaters because they do not have to break down solid meals in the stomach as other snake species do.

Animals↗