Biomedical subjects
Publications and source records attributed to B D Wright.
We report a case of septic abortion with intact fetal membranes caused by Campylobacter fetus subsp. fetus in an 18-year-old woman who was 9 1/2 weeks pregnant.
The Functional Independence Measure (FIM) records the severity of disability of rehabilitation patients. The necessarily curvilinear relationship between the finite range of recorded FIM raw scores and the conceptually infinite range of additive disability measures is resolved through Rasch analysis. The analysis of admission and discharge FIM ratings of 14,799 patients shows that the 18 FIM items define two statistically and clinically different indicators. Thirteen items define disability in motor functions. Five items define disability in cognitive functions. Additive measures for each indicator have the same characteristics at admission and discharge, so that these measures can be used to assess change in patient status.
This study evaluated the extent to which rehabilitation outcomes and resource use can be predicted by functional status measures. Linear measures of motor and cognitive function were derived from the Functional Independence Measure for a sample of 27,699 patients undergoing initial rehabilitation. Admission functional status was consistently related to discharge function and length of stay, though the strength of these associations varied with impairment. Motor function was a stronger predictor of length of stay than was cognitive function for all impairments. However, the unique contribution of cognitive function was apparent for specific impairment groups. The predicted variance at discharge in motor function averaged 55%, 70% in cognitive function, and 20% in length of stay. These results support the use of functional status measures in the development of rehabilitation resource use models. Recommendations for future research are proposed.
This study was conducted to scale the Functional Independence Measure (FIM) with Rasch Analysis and to determine the similarity of scaled measures across impairment groups. The results show that the FIM contains two fundamental subsets of items: one measures motor and the second measures cognitive function. Rasch analysis of the Uniform Data System for Medical Rehabilitation patient sample yielded interval measures of motor and cognitive functions. The validity of the FIM was supported by the patterns of item difficulties across impairment groups. Adequate clinical precision of the FIM was demonstrated, though suggestions for improvement emerged. The frequency of misfit between patients and the performance scales varied across impairment groups, but was acceptable. The results of this project will enable clinicians and researchers to plan cost-effective treatment by providing a valid measure of disability.
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Previous studies suggest that kinesin heavy chain (KHC) is associated with ER-derived membranes that accumulate in the mitotic apparatus in cells of early sea urchin embryos (Wright, B. D., J. H. Henson, K. P. Wedaman, P. J. Willy, J. N. Morand, and J. M. Scholey. 1991. J. Cell Biol. 113:817-833). Here, we report that the microinjection of KHC-specific antibodies into these cells has no effect on mitosis or ER membrane organization, even though one such antibody, SUK4, blocks kinesin-driven motility in vitro and in mammalian cells. Microinjected SUK4 was localized to early mitotic figures, suggesting that it is able to access kinesin in spindles. In contrast to KHC-specific antibodies, two antibodies that react with kinesin-like proteins (KLPs), namely CHO1 and HD, disrupted mitosis and prevented subsequent cell division. CHO1 is thought to exert this effect by blocking the activity of a 110-kD KLP. The relevant target of HD, which was raised against the KHC motor domain, is unknown; HD may disrupt mitosis by interfering with an essential spindle KLP but not with KHC itself, as preabsorption of HD with KHC did not alter its ability to block mitosis. These data indicate that some KLPs have essential mitotic functions in early sea urchin embryos but KHC itself does not.
The functional independence measure (FIM) is used to determine the degree of disability that patients experience and the progress that they make through programs of medical rehabilitation. Rasch analysis is a statistical technique for constructing interval measures from ordinal data that was applied to derive FIM measures. The major factors that are taken into account to produce FIM measures are the relative difficulty in performance of FIM items and the ability of the persons tested. Our analyses showed the relative difficulties that patients experienced in performing items in the FIM. There were two dominant patterns of difficulty, one for motor FIM items and the other for cognitive FIM items. The patterns were consistent across impairment groups, although not identical. Of the motor items, eating and grooming were easiest whereas stair climbing, tub/shower transfers and locomotion were most difficult. Of the cognitive items, expression and comprehension were easiest and problem solving was the most difficult. The patterns of difficulty in performing FIM items are illustrated by analysis of the following impairment groups: for motor items, orthopedic conditions, stroke with left hemiparesis and spinal cord dysfunction; for cognitive items, orthopedic conditions, brain dysfunction, stroke with right hemiparesis and spinal cord dysfunction. By understanding patterns of difficulty in performing FIM items according to types of impairment and levels of function, clinicians may more precisely design treatment programs, use services and predict outcomes of medical rehabilitation.
Sea urchin gametes and early embryos have proven to be a useful system for studying the roles of microtubule (MT)-associated motors in axonemal motility and cytoplasmic MT-based movements in dividing cells. In this brief article, known and potential sea urchin MT motors are listed and their possible biological functions are discussed.
A case is reported where atropine sulphate eye drops increased the frequency of fits in a child suffering regular akinetic seizures. This increase was marked and observed during two separate courses of eye drops. This is discussed with reference to previous reports of central nervous toxicity after the use of topical atropine sulphate.
We have recently used domain-specific monoclonal antibodies (mAbs) to immunofluorescently localize kinesin to vesicle-like structures in the cytoplasm of sea urchin coelomocytes. In order to characterize further these localization patterns we have examined the distribution of kinesin with respect to the arrangement of microtubules (MTs) and various organelles. In double-label experiments involving the immunofluorescent staining of kinesin (using a mixture of the mAbs SUK2, 4 and 5), MTs were labeled with an antiserum against sea urchin tubulin, the endoplasmic reticulum (ER) was labeled with an antiserum against a luminal calsequestrin-like protein, the Golgi apparatus was labeled with rhodamine-wheat germ agglutinin (WGA) or NBD-ceramide, mitochondria were labeled with rhodamine 123, endosomes were labeled with Texas Red-ovalbumin, and lysosomes were labeled with Lucifer yellow or acridine orange. Kinesin-labeled vesicle-like structures were found in the same regions of the cells as MTs and the ER, being widely distributed in motile cells, but restricted to the perinuclear regions of stationary cells. There also appeared to be a correlation between the distribution of endosomes and kinesin staining in a subpopulation of cells. The kinesin binding structures were found occasionally to align in linear arrays, consistent with the idea that kinesin may transport ER and endosomes along linear MT tracks. No clear correlations were observed between the kinesin staining and the distribution of mitochondria, the Golgi apparatus or lysosomes, suggesting that kinesin may specifically associate with only a subclass of organelles in coelomocytes.
Kinesin was previously immunolocalized to mitotic apparatuses (MAs) of early sea urchin blastomeres (Scholey, J.M., M.E. Porter, P.M. Grissom, and J.R. McIntosh. 1985. Nature [Lond.]. 318:483-486). Here we report evidence that this MA-associated motor protein is a conventional membrane-bound kinesin, rather than a kinesin-like protein. Our evidence includes the observation that the deduced amino acid sequence of this sea urchin kinesin heavy chain is characteristic of a conventional kinesin. In addition, immunolocalizations using antibodies that distinguish kinesin from kinesin-like proteins confirm that conventional kinesin is concentrated in MAs. Finally, our immunocytochemical data further suggest that conventional kinesin is associated with membranes which accumulate in MAs and interphase asters of early sea urchin embryos, and with vesicles that are distributed in the perinuclear region of coelomocytes. Thus kinesin may function as a microtubule-based vesicle motor in some MAs, as well as in the interphase cytoplasm.
Quantitative observations are based on counting observed events or levels of performance. Meaningful measurement is based on the arithmetical properties of interval scales. The Rasch measurement model provides the necessary and sufficient means to transform ordinal counts into linear measures. Imperfect unidimensionality and other threats to linear measurement can be assessed by means of fit statistics. The Rasch model is being successfully applied to rating scales.
The volatile anesthetic halothane, when present at fertilization, dose-dependently increases the incidence of abnormally developing sea urchin embryos at the first cell division. Microscopic examinations of eggs stained with aceto-orcein or the DNA fluorochrome bisbenzimide and direct observations on isolated sperm aster complexes show that halothane induces polyspermy (multiple sperm entry) when present at fertilization. Experimental evidence suggests that anesthetic-induced polyspermy involves impairment of both the fast (electrically mediated) and slow (morphological) blocks to multiple sperm entry. These observations clearly show that relatively brief exposures to halothane at fertilization cause polyspermy and that this effect is almost certainly responsible for the ensuing abnormal development observed at the first cell division.
When unfertilized sea urchin eggs are pretreated with the bisbenzimide DNA-specific fluorochrome Hoechst 33342, then washed and fertilized, a single sperm bound to the egg surface becomes intensely fluorescent. The location of the fluorescent sperm on the egg surface coincides exactly with the epicenter of the cortical reaction and the site at which the insemination cone subsequently appears. These observations, coupled with studies of eggs treated with quercetin to prevent fusion, as well as eggs made polyspermic by halothane exposure, indicate that the sperm acquires fluorescence as a consequence of fusion with the fluorochrome preloaded egg. Using a modification of this technique, we have found that cytoplasmic continuity between the sperm and egg is established at 4-8 sec after the onset of the sperm-induced conductance increase in the egg.
The volatile anesthetic halothane rapidly and dose-dependently induces the acrosome reaction in sperm of the sea urchin Lytechinus variegatus. The reaction occurs equally well in artificial sea water containing 10 mM Ca2+ and in low (less than 100 microM)-Ca2+ media. The anesthetic-induced acrosome reaction can be prevented by pretreating sperm with EGTA, lanthanum, or procaine. In contrast, the Ca2+ channel blockers D-600, verapamil, diltiazem, and nitrendipene do not prevent the reaction. Acrosomal processes induced by halothane are ultrastructurally identical to those induced by egg jelly, the natural inducer of the acrosome reaction. These results suggest that Ca2+ in low quantity is required for the anesthetic-induced acrosome reaction and may be derived from internal sources. Enflurane, isoflurane, and methoxyflurane also induce the acrosome reaction, indicating that volatile anesthetics may be useful in studying ion changes accompanying sperm activation.
We have developed a procedure for isolating intact sperm asters in quantity from fertilized sea urchin eggs. This procedure is based on detergent-extraction methods developed previously for the bulk isolation of mitotic apparatuses. Using this protocol it is possible to isolate sperm asters as soon as they appear in the fertilized egg or at any subsequent point in their brief existence.
A questionnaire to measure the activity level of people with visual handicaps was developed in which separate components of activity are measured: "independence" and "difficulty" in performing various activities, "felt loss" in not performing the activities, and "motivation to learn" the activities. The responses of 129 veterans who completed this questionnaire were analyzed. Attempts were made to determine the reliability and validity of the scales. The questionnaire can be regarded as useful to evaluate both what patients are specifically taught and how that training effects activities not specifically taught.
The incidence of sea urchin embryos developing abnormally after their exposure to equimolar concentrations of halothane, enflurane, and methoxyflurane has been determined. Halothane concentrations in the 0.6-1.25 mM range caused 18-96% of the embryos to undergo abnormal cleavage at the first cell division. This is important because embryos exhibiting atypical cleavage patterns at the first cell division eventually involute and die before reaching gastrulation. Over the same range of concentrations, enflurane and methoxyflurane have minimal effects on development. However, when exposed to 2.5 mM methoxyflurane, nearly 40% of the cells did not fertilize. These results show that volatile anesthetic agents have decidedly different effects on development and suggest that the incidence of abnormal development may not correlate directly with the anesthetic potency of inhalational agents.