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Biomedical subjects

L L Lloyd

Publications and source records attributed to L L Lloyd.

At least 19 recordsLinked to original sources
PubMed2000

Laparoscopic anterior lumbar fusion.

PURPOSE: To assess the feasibility and complications of the laparoscopic approach to anterior lumbar fusion and to evaluate the ability of metoclopramide in conjunction with preoperative bowel preparation and early oral feeding to decrease postoperative ileus and reduce the length of hospital stay. PATIENTS AND METHODS: Laparoscopic anterior lumbar fusion was performed on 30 patients with persistent back pain between September 1997 and March 1999. All patients received metoclopramide 10 mg intravenously preoperatively and every 6 hours postoperatively, then 10 mg orally every 8 hours for 7 days. An experienced laparoscopic surgeon exposed the disc space, and lumbar fusion was performed by a neurosurgeon or an orthopedic surgeon. RESULTS: One procedure in an obese patient was converted to open surgery. The average operating time for the remaining patients was 2 hours 23 minutes. The average estimated blood loss was 75 mL. The only intraoperative complication was a trocar injury to the bladder. The average hospital stay was 2.3 days. CONCLUSION: In properly selected patients, laparoscopic anterior lumbar fusion with metoclopramide, preoperative bowel preparation, and early oral feeding results in a short hospital stay and yields better cosmetic results than traditional surgery.

Adult↗
PubMed2000

Effects of modified orthography on the identification of printed words.

Research has shown that instructional methods involving pairing pictures with print interfere with identification of written words. Preliminary evidence, however, indicates that use of modified orthography (where a line drawing is superimposed upon the printed word) may be effective for reading instruction with individuals who have mental retardation. In the present study, we used a single-subject parallel treatments design with 4 adults who had moderate to severe mental retardation. They received reading instruction under two conditions--traditional and modified orthography. Results showed that traditional orthography was a more effective method for word identification. The relative advantage of modified orthography over traditional orthography for individuals with mental retardation was not supported.

Adult↗
PubMed1998

Comparison of graphic symbol learning in individuals with aphasia and right hemisphere brain damage.

This study compared the differences in performance on recognition of graphic symbols across time by individuals with aphasia, individuals with right-hemisphere brain damage, and neurologically normal adults. The subjects, seen individually, learned 40 Blissymbols. The symbols were selected so that the effects of symbol translucency and complexity on the recognition of graphic symbols could be examined. A paired-associate learning paradigm was used to teach the symbol-referent pairs to subjects. The results indicated that individuals with aphasia and neurologically normal adults do not differ significantly in recognition of graphic symbols. However, individuals with right-hemisphere damage recognized fewer symbols compared to individuals with aphasia and normal adults, suggesting that they have difficulty in associative learning of graphic symbols. Additionally, translucency was found to be a potent factor in the recognition of Blissymbols by all groups. The finding that individuals with severe chronic aphasia can learn and retain graphic symbols has significant clinical implications for aphasia rehabilitation.

Aged↗
PubMed1997

Platelet-derived growth factor mediates angiotensin II-induced DNA synthesis in vascular smooth muscle cells.

In order to elucidate the mechanism of angiotensin II (ANG II)-induced proliferation in vascular smooth muscle cells in culture, growth rates and 3H-thymidine incorporation into DNA in response to ANG II treatment were examined in cultured rat aortic smooth muscle cells. ANG II-treated and control cells were exposed to the ANG II receptor antagonists [Sar1, Val5, Ala8]-ANG II (Sar) and DUP753 and to antibody against platelet-derived growth factor (PDGF). In growing cells, ANG II acted as a moderate mitogen, inducing an increase in growth rate during the first two days of treatment. ANG II induced a marked increase in 3H-thymidine incorporation in cultured vascular smooth muscle cells. The effect was blocked by the ANG II inhibitors Sar and DUP753 and by the PDGF antibody. ANG II was able to stimulate vascular smooth muscle growth in cell culture. The effect seemed to be mediated, at least in part, by PDGF. These results are in agreement with a possible role of ANG II in promoting vascular growth in physiological and/or pathological situations.

Angiotensin II↗
PubMed1996

Interactions between angiotensin II and adenosine 3':5'-cyclic monophosphate in the regulation of amino acid transport by vascular smooth muscle cells.

The regulation of amino acid transport by angiotensin II (AII) and cyclic AMP (cAMP) was assessed in cultured vascular smooth muscle cells, using a nonmetabolizable amino acid, alpha-[3H]aminoisobutyric acid (AIB). An exposure time in excess of 2 h was required for AII to elicit a stimulatory response, the magnitude of which increased in a time-dependent manner for 12 h. AII-induced transport was blocked by [1-sarcosine, 8-isoleucine]AII, a competitive inhibitor of AII binding. The effect of AII was not abolished by downregulation protein kinase C with phorbol 12,13-dibutyrate or by use of a protein kinase C inhibitor, suggesting that transport in response to AII can be mediated by a protein kinase C independent pathway. In contrast, the elimination of calcium from the incubation medium reduced AII-stimulated AIB uptake. The calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide partially inhibited AIB uptake in response to AII, suggesting that calmodulin may be involved in the modulation of AII-stimulated amino acid transport. AIB transport was also increased by elevating intracellular cAMP levels via beta-adrenergic receptor stimulation, the use of a cAMP analog (N6-monobutyryl cAMP), or a phosphodiesterase inhibitor (3-isobutyl-1-methylxanthine) or by direct stimulation of adenylate cyclase with forskolin. cAMP-induced AIB transport was evident within 10 min and peaked within 1 h. At 1 h AII enhanced cAMP-stimulated AIB transport. A possible mechanism for this effect is suggested by the observation that AII potentiated cAMP production in response to isoproterenol and 3-isobutyl-1-methylxanthine.

1-Methyl-3-isobutylxanthine↗
PubMed1993

Effects of initial element teaching in a story-telling context on Blissymbol acquisition and generalization.

Blissymbolics is a graphic symbol system used by individuals with little or no functional speech. The purpose of this study was to determine the effects of initial teaching of semantic elements on compound Blissymbol acquisition, retention, and generalization in a story-telling context. The subjects included 40 preschool children with normal cognitive abilities (mean chronological age = 45 months) who were assigned to one of two groups. Group I was taught elements before being taught compounds that contained these elements. Group II was taught elements before being taught compounds consisting of elements that were not taught previously. In addition, both groups received instruction in a second set of compounds that were taught directly, that is, without first being taught the elements. The teaching procedures and materials were socially validated by experts in Blissymbol instruction. Results indicate that the initial teaching of elements did not contribute to compound acquisition and retention, but did facilitate generalization to untrained compound Blissymbols. The results are discussed in terms of considerations for selecting an initial lexicon and Blissymbol teaching and research.

Child, Preschool↗
PubMed1992

Effects of configuration on the paired-associate learning of blissymbols by preschool children with normal cognitive abilities.

Translucency appears to be a potent variable in the learning of Blissymbols by preschool children with normal cognitive abilities. Complexity does not appear to influence learning for these individuals when there is a concurrent condition of high translucency. However, a condition of high complexity seems to enhance the learnability of Blissmbols having low translucency. For the present experiment, an attempt was made to determine if symbol configuration affects the learning of highly complex Blissymbols that bear little relationship to their referents. A paired-associate learning paradigm was used to present 30 Blissymbols to 20 cognitively normal preschool children. These symbols were evenly divided into superimposed and nonsuperimposed groups. Results indicated that the children learned more superimposed symbols than their nonsuperimposed counterparts. The implications of this finding for the teaching of Blissymbols are discussed.

Child Language↗
PubMed1992

A reversed-phase HPLC method for measurement of 5-hydroxymethyl furfuraldehyde and furfuraldehyde in processed juices.

An HPLC method using a reversed-phase macroreticular PLRP-S column and phosphate buffer as eluent is described for the analysis of L-ascorbic acid degradation products, 5-hydroxymethyl furfuraldehyde and furfuraldehyde, in processed fruit juices. Measurement of the levels of 5-HMF and furfuraldehyde in citrus juices against time showed the presence of 5-HMF (0.45 mg l-1) even at zero time. An assessment on the effect of the additives on the formation of 5-HMF of reconstituted single-strength orange juice showed virtually the same results for all the samples stored at 4 degrees C and 20 degrees C, irrespective of the additive. For citrus juice samples which had been subjected to accelerated degradation, those that showed the highest decomposition of L-ascorbic acid, produced the highest level of 5-HMF. The presence of furfuraldehyde in any of the samples was not detected, probably due to the fact that furfuraldehyde was formed in such small amounts which are below the minimum detectability limit of the method (0.050 mg l-1).

Acetates↗
PubMed1991

Oligonucleotide analysis by anion exchange HPLC.

The ability to resolve and purify synthetic oligonucleotides by high performance anion exchange chromatography was evaluated using two wide pore polymeric HPLC matrices. The materials used are rigid macroporous copolymers which have a fully quaternised polyethyleneimine coating to provide a strong anion exchange, quaternary amine, functionality. Oligomers of poly(rA), poly(rC) and RNA produced by alkaline hydrolysis of the polymers were chromatographed to evaluate the selectivity of the system prior to the analysis of synthetic oligonucleotides produced using a commercial oligonucleotide synthesizer.

Base Sequence↗
PubMed1990

The comparative translucency of initial lexical items represented in five graphic symbol systems and sets.

The comparative translucency within and across five aided augmentative and alternative symbol systems or sets (Blissymbols, Picsyms, PIC, PCS, and Rebus) for symbols representing three parts of speech (nouns, verbs, and modifiers) was investigated. A sample of 41 items representing an initial lexicon was rated by undergraduate college students on a 7-point scale of iconicity. Results indicate that translucency varies among systems or sets and among parts of speech. Rebus and PCS were the most translucent overall; however, a number of Blissymbolics, Picsyms, and PIC symbols were also rated as highly translucent. Caution is indicated in extrapolating results to young or retarded learners because of the influence of normal adult knowledge and experience on translucency ratings. Care must also be taken in extrapolating to more advanced lexicons containing larger, more developmentally advanced vocabularies.

Adult↗
PubMed1984

Non-speech communication symbols and systems: where have we been and where are we going?

During the past quarter century, and especially during the past decade, we have seen the emergence of various non-speech communication symbols and systems as viable means of communication by and with severely handicapped individuals. A brief overview of the full range of both aided (static or graphic) and unaided (dynamic or manual) non-speech symbols and systems is presented. A hierarchy of difficulty, cognitive requisites, approximation to English (or other natural languages), abstraction, acceptance, etc. is considered. Advantages of non-speech communication are related to general input simplification, response production, receptive language/auditory processing, stimulus processing/stimulus association, and symbolic representation. The advantages of vocabulary limits and attentional facilitation for intervention with severely handicapped individuals are discussed. Major research issues are also explored.

Attention↗
PubMed1983

Amer-Ind transparency.

Objective and reliable transparency comprehension results have been obtained on the citation form of the 193 Amer-Ind signals as presented in the original Amerind Video Dictionary. Transparency ratings, as determined by three different scoring criteria, as well as the most common errors, are presented. While transparency (42-50%) was considerably less than what has been suggested in previous reports (80-88%) it was, nevertheless, well above what has been reported for signs from American Sign Language. Transparency of repetitive signals was significantly higher than that reported for kinetic and static signals. The implications for clinical practice are discussed.

Adult↗
PubMed1983

The effects of presentation modality upon learning in a comprehension task using oral, manual, and dual mode stimulus cues.

Interest in how and why the use of nonspeech symbols such as manual signs facilitates the communication development of language-handicapped individuals has been growing. One question of interest is whether comprehension is facilitated because manual sign cues are in the same stimulus modality (visual) as the objects or events to which they refer, in contrast to oral cues, which are in a different modality (auditory). Another question is, when total communication (words and manual signs) is used, which modality, visual or auditory, actually controls responding? Previous analogue research with normal adults has not controlled for representational iconicity and/or has utilized tasks different than those used with handicapped populations. In this study, 15 undergraduate students were trained to a criterion to identify abstract forms in response to manual sign, CVC nonsense syllables, or combined manual sign plus CVC nonsense syllables. Signed English signs normally representing common objects were matched to the abstract forms. Results from learning probes indicated that performance improved significantly following training for all types of labels. Performance on learning probes of responses to manual labels was significantly poorer than performance on probes of responses to oral labels, to manual labels previously used in combined labels, and to oral labels previously used in combined labels. However, there was no difference in performance among these latter three conditions. These results suggest that the facilitative effects of manual sign labels upon comprehension found in other research may be due to the iconic relationship between signs and their referents.

Adult↗
PubMed1983

The influence of production mode on the recall of signs in normal adult subjects.

Preliminary evidence has suggested that signs produced with contact between the two hands or between the hand and body are learned more readily than signs produced without such contact. Using a paradigm that eliminated the possibly confounding variables of previous studies, the effect of production mode on sign acquisition and recall was investigated with normal young adults. Results indicated that contact signs were acquired more readily than noncontact signs by one of two subject groups. More contact than noncontact signs were produced correctly during recall. Recall at 1 week was equivalent to that at same day for contact signs, but same-day recall was greater than 1-week recall for noncontact signs. Examination of responses that were correct except for a contact/noncontact discrepancy suggested that contact was added more often than it was deleted from signs during recall. These findings are discussed in terms of the role of tactile feedback in learning and memory and their potential application to teaching signs to nonverbal children.

Adult↗
PubMed1982

Gesture recognition in patients with aphasia.

This study focuses on the controversial issue of the integrity of gestural communication abilities in subjects with aphasia. To define the ability of subjects to interpret symbolic gestures, an Amer-Ind Recognition Test (ART) was developed which required no verbal response from the examiner or the subject. The relationships between impairment of Amer-Ind signal recognition and (a) severity of aphasia, (b) listening and talking abilities and (c) the type of response picture used were investigated. Whether subjects more often chose related foils than unrelated foils in a forced-choice format was also examined. Two training tests and the ART are described. Results from administration to 15 aphasic subjects indicated that: (a) all subjects performed equally well, regardless of their aphasia severity classification; (b) action picture recognition was related to listening ability; (c) action pictures were easier to identify than object pictures; and (d) on error responses, subjects overwhelmingly chose related over unrelated foils. The possibility that gestural abilities were relatively well preserved among the subjects tested, in the presence of a wide range of listening and talking deficits, is also discussed.

Adult↗