A rapid luminescent assay for measuring cytochrome P450 activity in individual larval Culex pipiens complex mosquitoes (Diptera: Culicidae).

Multiple assays are available to measure P450 activity in insects, including mosquitoes; however, each of these assays has drawbacks in terms of the number of mosquitoes required, specificity, sensitivity, cost, and/or time required to prepare active enzyme homogenates. In this study, a commercially available luminescent assay, P450-Glo, was modified and evaluated to measure P450 activity from the gut of a single larva after removal of the gut contents. We also compared this assay to an earlier developed fluorescent assay. After optimization of assay conditions, the P450-Glo assay held considerable promise to be used as an effective, inexpensive, high-throughput, and sensitive screening assay to measure P450 activities in single mosquitoes. Furthermore, we tested the utility of the single gut assay using the pyrethroid resistant Marin strain of Culex pipiens pipiens form molestus and the pyrethroid sensitive CQ-1 strain of Cx. pipiens quinqefasciatus. We observed on average 1.8-fold higher levels of P450 activity in the resistant mosquitoes in comparison to the sensitive mosquitoes. Additionally, consistent with our previous findings, distribution plots of P450 activity showed 33% of individual Marin mosquitoes had higher P450 activities than the highest activity displayed by a CQ-1 mosquito. The assay platform is highly flexible in terms of choice of tissue, method of preparation, isozyme specificity, and sample quantity and thus could easily be adapted to be used for other arthropod species.

A cross-linguistic study of grammatical morphology in Spanish- and English-speaking agrammatic patients.

To account for cross-linguistic differences in agrammatism, Bates and her colleagues have employed the Competition Model, proposing that the cue validity and cue costs of a grammatical morpheme in a particular language will directly affect how agrammatism is manifested. Using Goodglass et al.'s (1993) Morphosyntax Battery in English and a translated version in Spanish, we analyzed the use of equivalent grammatical structures in production and comprehension by agrammatic speakers of the two languages. Wilcoxon signed-rank tests revealed that the relative order of difficulty in both production and comprehension of various grammatical morphemes was the same for both Spanish- and English-speaking agrammatic patients, with two exceptions (1) the Spanish-speaking agrammatics were relatively better at producing subject-verb agreement, and (2) the Spanish speakers were significantly worse at comprehending both active and passive voice sentences. The Competition Model can explain the performance differences regarding subject-verb agreement and comprehension of active voice sentences, but it cannot account for the differences seen in comprehending passive voice sentences.

Coherence violations and propositional usage in the narratives of fluent aphasics.

Aphasic patients have been generally assumed to produce coherent narratives, despite their numerous surface structure deficits. The current study is designed to analyze three types of coherence violations (i.e., information gaps, repetitions of propositions, and irrelevant propositions) in the narratives of mildly impaired conduction, anomic, and Wernicke's aphasics. Results reveal that the three aphasic groups produce qualitatively different patterns of coherence violations. It is hypothesized that these coherence violations reflect adaptive strategies used by the aphasic patients to compensate for their underlying impairments. While the anomic and conduction aphasics appear to compensate for surface structure deficits, the Wernicke's aphasics seem to have an underlying coherence deficit.

Comparison of morphology and syntax in free narrative and structured tests: fluent vs. nonfluent aphasics.

Seven agrammatic Broca's and seven paragrammatic conduction aphasics were evaluated on a free narrative story elicitation test and on a structured, cross-modal morphology and syntax battery (MSB). The latter permitted comparison of the same set of morphosyntactic forms in both production and comprehension. Results suggests distinctive oral production profiles, with agrammatics inferior to paragrammatics in use of auxiliaries, verb inflection and passive word order. Only agrammatics commonly omitted articles or main verbs. The use of noun plurals and possessives did not discriminate between the groups. The two groups did not differ in level of performance on MSB comprehension subtests, and the order of difficulty among the comprehension subtests was unrelated to their difficulty for production. This suggests that the source of agrammatic production errors is independent of comprehension errors. The production of targeted constructions on the MSB, an easily scored instrument, closely paralleled production in free narrative.

Thermographic imaging of myofascial trigger points: a follow-up study.

Thermographic evaluation was performed on 11 adult volunteers with myofascial trigger points and on 11 asymptomatic controls. Infrared thermography was used to obtain a series of images to compare the sensory referral areas of myofascial trigger points with their thermal referral patterns. A series of images was then taken at, and distal to, the sensory referral area of each trigger point during quantitative compression of the trigger point, and dynamic temperature changes were monitored. Asymmetric thermal patterns were observed at all trigger points in the sensory referral area and distal to the referred area before compression. The thermal referral areas showed a reduction in temperature from precompression levels during compression. When similar but asymptomatic areas were compressed, no significant changes in temperature were noted at distal sites.

Role of the calpain system in muscle growth.

Muscle protein degradation has an important role in rate of muscle growth. It has been difficult to develop procedures for measuring rate of muscle protein degradation in living animals, and most studies have used in vitro systems and muscle strips to determine rate of protein degradation. The relationship between results obtained by using muscle strips and rate of muscle protein turnover in living animals is unclear because these strips are in negative nitrogen balance and often develop hypoxic cores. Also, rate of protein degradation is usually estimated by release of labeled amino acids, which reflects an average rate of degradation of all cellular proteins and does not distinguish between rates of degradation of different groups of proteins such as the sarcoplasmic and the myofibrillar proteins in muscle. A number of studies have suggested that the calpain system initiates turnover of myofibrillar proteins, which are the major group of proteins in striated muscle, by making specific cleavages that release thick and thin filaments from the surface of the myofibril and large polypeptide fragments from some of the other myofibrillar proteins. The calpains do not degrade myofibrillar proteins to small peptides or to amino acids, and they cause no bulk degradation of sarcoplasmic proteins. Hence, the calpains are not directly responsible for release of amino acids during muscle protein turnover. Activity of the calpains in living cells is regulated by calpastatin and Ca2+, but the nature of this regulation is still unclear.

Immunolocalization of the calpains and calpastatin in human and bovine platelets.

The structure of human platelets differs from that of bovine platelets in that human platelets have a surface-connected canalicular system that bovine platelets lack. Platelets are one of the richest known sources of the calpains, and the calpains have been implicated in many of the specific cleavages of cytoskeletal and surface-receptor proteins that occur during platelet activation and aggregation. Several studies have reported that human platelets are rich in mu-calpain and contain less m-calpain, whereas bovine platelets contain principally m-calpain and almost no mu-calpain. The immunolocalization studies reported here show that calpastatin is distributed throughout the cytosol of both human and bovine platelets and that calpain is located throughout the interior of human platelets. Calpain in bovine platelets is located primarily in alpha-granules, however. Because bovine platelets contain predominantly m-calpain and because alpha-granules are translocated to the platelet surface during activation, bovine m-calpain may be responsible for the specific cleavages of platelet surface proteins such as glycoprotein Ib that occur during platelet activation and at extracellular Ca2+ concentrations high enough to activate m-calpain.

Altered metabolic enzyme activities in fast and slow twitch muscles due to induced sciatic neuropathy in the rat.

A pilot study was conducted to examine enzymatic and metabolic alterations in end organs as a consequence of neuropathy. Silastic pellets were implanted transverse to the sciatic nerve of rats. Neurobehavioral evaluations based on hind limb gait were conducted at 2 and 4 weeks postoperatively. Four-week values demonstrated facilitated utilization of the neuropathic limb in three of five animals, as compared to the normal contralateral limb and normal animals. Nerve electrophysiology and quantitative muscle enzymology were observed at 4 weeks postoperatively. Relative to control animals, the experimental group exhibited decreased nerve conduction velocity, decreased glycolytic enzyme activity in both fast and slow twitch muscle and increased malate dehydrogenase activity in the flexor digitorum longus (FDL). Muscle weight/body weight ratios for control and experimental animals suggest an increase for experimental animals, especially of the FDL. This change was not due to increased muscle proteins for the experimental group as determined on homogenates. Muscle homogenate protein values were actually significantly lower than those of the control group for FDL and soleus. For this reason, when enzyme activities were compared on an equal protein basis, most significant differences were obscured. Only aldolase remained significantly less for the experimental group (p less than 0.01). It is concluded that muscle metabolism is subject to change when confronted with mildly neuropathic innervation. Of particular interest is the uniform direction of change. Both fast and slow twitch muscles exhibited a metabolic shift in the direction of slow twitch muscle.

Effect of information about role and outcome on alcoholics' attributional processes.

Alcoholics attributed an alcoholic's behavior to internal or dispositional factors. Alcoholics identified more closely with alcoholics who could succeed and nonalcoholics who failed than with nonalcoholics who could succeed and alcoholics who failed.