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Biomedical subjects

J E May

Publications and source records attributed to J E May.

At least 19 recordsLinked to original sources
PubMed2001

A characterisation of long-term depression induced by metabotropic glutamate receptor activation in the rat hippocampus in vitro.

1. In the CA1 region of hippocampal slices prepared from juvenile (12- to 18-day-old) rats, activation of group I metabotropic L-glutamate (mGlu) receptors by the specific agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) induces a form of long-term depression (LTD) of excitatory synaptic transmission. 2. We have used a variety of electrophysiological techniques applied to CA1 neurones in hippocampal slices and from pyramidal cells in dissociated hippocampal cultures to investigate the Ca2+ dependence and locus of expression of DHPG-induced LTD. 3. In patch-clamp experiments from hippocampal slices, bath application of DHPG induced a depression of synaptically evoked responses that persisted for the duration of the recording (up to 2 h after commencing washout of DHPG) in 27 of 29 neurones investigated. 4. DHPG-induced LTD was associated with an increase in both the paired-pulse facilitation ratio and the coefficient of variation of EPSCs. 5. Using dendritic recording, there was a decrease in EPSC success rate (number of trials that elicited a detectable response) but no change in potency (mean EPSC amplitude excluding failures) associated with DHPG-induced LTD. 6. In experiments using dissociated hippocampal cultures, application of DHPG elicited a persistent decrease in the frequency of tetrodotoxin-resistant miniature EPSCs but no change in the amplitude of such events. 7. DHPG-induced LTD was not blocked by intracellular application of the calcium chelator BAPTA. It was also unaffected when intracellular calcium stores were depleted by perfusion with thapsigargin. Furthermore, when synaptic transmission was blocked by perfusing with Ca2+-free medium, DHPG application reliably induced LTD. 8. These data suggest that DHPG-induced LTD is Ca2+ independent and is expressed presynaptically.

Animals↗
PubMed2000

The effect of additional shots on the vaccine administration process: results of a time-motion study in 2 settings.

CONTEXT: The introduction of combination vaccines to the pediatric regimen offers the possibility of reducing the number of injections required to reach full vaccination status. Fewer injections benefit the patient/child and the parent/caregiver, and the healthcare provider may benefit from savings in personnel time associated with vaccine administration. To date, however, these savings have not been quantified. OBJECTIVE: To study the vaccine administration process in a managed care environment. STUDY DESIGN: We studied 2 settings in which vaccinations were administered: (1) a devoted injection room and (2) the examination room as part of the well-child examination. For each setting, we documented the vaccine administration process, identified vaccine-related activities, and quantified the time savings in each activity by reductions in the number of shots. PATIENTS AND METHODS: For vaccine recipients younger than 2 years, time-motion data on vaccine-related activities in 2 managed care settings were collected by a professional industrial engineering consultant. Activity time data by the number of shots administered were analyzed using linear regression adjusting for patient age. RESULTS: We observed 276 vaccination visits (137 in an examination room, and 139 in an injection room). Total nurse time associated with vaccine administration decreased by 2.4 and 1.7 minutes per shot eliminated in the examination room setting (P = .006) and in the injection room setting (P < .001), respectively. Significant time savings were realized for activities associated with vaccine preparation, vaccine injection, and administrative duties. In addition, infant crying time decreased by 1.0 and 0.4 minutes per shot eliminated in the examination room and injection room settings, respectively (P < or = .001 for both). CONCLUSIONS: Significant reductions in vaccine administration time could be achieved by eliminating injections during a well-child regimen.

Child Health Services↗
PubMed1989

Prevalence of dyskinesia and related movement disorders in a developmentally disabled population.

The prevalences and inter-relationships of five types of movement disorders were evaluated in a large, developmentally disabled (DD) population (n = 1227); prevalence was evaluated with regard to severity, age, gender and antipsychotic-drug (APD) exposure. Dyskinesia was found in 48% of the sample, dystonia in 29%, akathisia in 13%, Parkinsonism in 3% and paroxysms in 4%. Many persons had more than one symptom so that 72% had one or more of the five target symptoms. Although the five movement-disorder categories were not mutually exclusive, analysis supported the individuality of the categories as defined in this study. The prevalences of dyskinesia and Parkinsonism were considerably greater than those in the general population. On the other hand, the prevalence of dyskinesia was similar to that reported for psychiatric and institutionalized geriatric populations. Parkinsonism increased with age and male gender, while dyskinesia increased with age and female gender. APD-exposure was significantly correlated only with akathisia.

Adolescent↗
PubMed1988

Dyskinesia, antipsychotic-drug exposure and risk factors in a developmentally-disabled population.

The relation between antipsychotic drug (APD) exposure and the prevalence of dyskinesia (DK) was examined in a large, developmentally-disabled (DD) population. Using qualitative data in a cross-sectional, retrospective design, the drug-exposed group was systematically compared with a non-drug-exposed group, controlling for age and gender. When the population was evaluated with no regard to APD-exposure, age and female gender were significant risk factors, as in many prior studies. When APD-exposure was considered, it proved to be a complex variable dependent on the recency of exposure to APD, and the outcome depended on the method of analysis: when APD-exposure was considered as a binomial variable (yes/no), the relationship between APD and DK was not significant; when APD-exposure was controlled for recency of exposure, however, a significant relationship between APD and DK was demonstrated (p less than 0.01) although the relationship accounted for less than 3% of the variance. Analysis of the relation between DK-prevalence and recency-of-APD-exposure revealed a pattern of diminished prevalence during APD use and increased prevalence during early withdrawal.

Adolescent↗
PubMed1980

Carcinoma of the lung: a clinical review.

Records of 702 patients with carcinoma of the lung seen from 1960 through 1970 were reviewed. The efficacy of various diagnostic and therapeutic procedures was assessed. Salient findings were as follows: Biopsy of nonpalpable ipsilateral supraclavicular lymph nodes was positive for carcinoma in 63 of 286 patients (22%). Even more surprising, biopsy of nonpalpable contralateral supraclavicular lymph nodes was positive for carcinoma in 9 of 38 patients (24%). Accordingly, the importance of biopsy of nonpalpable supraclavicular nodes is to be stressed. Squamous cell carcinoma was the most common type, but adenocarcinoma was more common in women and nonsmokers. Among the 702 patients, 48 (6.8%) were nonsmokers. The 5-year survival for 92 patients treated by lobectomy was 21%; the 5-year survival for 77 patients treated by pneumonectomy was 19%; the 5-year survival among 18 patients have resection of the chest wall in addition to resection of the primary lesion was 22%. Of 12 patients with small cell carcinoma of the lung treated by resection, there was 1 5-year survivor. The overall 5-year survival in the 702 patients was 6.6%.

Adenocarcinoma↗
PubMed1977

Urachal remnants: benign or malignant?

Two cases are presented with cystoscopically visible cystic urachal remnants. The initial clinical findings, including bladder biopsies, were remarkably similar. Partial cystectomy with removal of the urachal cord alone clarified the actual disease. The inability to separate the malignant and the benign urachal lesion by other means suggests the necessity of total surgical extirpation. Perhaps this approach may result in an improvement in the generally poor prognosis for urachal carcinoma.

Adenocarcinoma↗
PubMed1975

Studies of the biologic effects of selective C4 deficiency.

The role of the several pathways of complement activation in mediating a number of the biologic activities of complement has been examined in an animal model, the C4-deficient guinea pig. It has been shown that the presence of an intact classic pathway (C1, 4, 2) is requisite for damage of antibody-sensitized mammalian cell membranes and for the development of thrombocytopenia and the hypercoagulable state following in vivo endotoxin administration. Both the classic and alternate pathways participate in defense against the lethal effects of endotoxin, in opsonization and lysis of bacteria and in mediation of the events of inflammation.

Antigen-Antibody Complex↗
PubMed1973

A new complement-mediated cytolytic mechanism--the C1-bypass activation pathway.

A new cytolytic pathway is described whereby cells sensitized with cytotoxic antibody can be specifically lysed in the complete absence of intact, classical complement pathway function. Evaluation of this model with sera deficient in the 4th (C4), 2nd (C2), and 6th (C6) components of complement has revealed that this new lytic mechanism, termed the C1-bypass activation pathway, is initiated by the antibody-mediated activation of C1. Utilizing components of the previously described alternate complement pathway, this pathway bypasses C4 and C2 to activate the third to ninth components of complement (C3-9) with induction of membrane damage.

Animals↗
PubMed1973

Interactions of the classical and alternate complement pathway with endotoxin lipopolysaccharide. Effect on platelets and blood coagulation.

The contributions of the classical and alternate pathways of complement activation to the biological effects of endotoxin have been examined in the guinea pig, with particular reference to thrombocytopenia, leukopenia, and the development of the hypercoagulable state. Injection of endotoxin into normal guinea pigs led to a 95% fall in the level of circulating platelets within 15 min as well as a fall in circulating granulocytes. C4-deficient guinea pigs, known to have a complete block in the activity of the classical complement pathway, but with the alternate pathway intact, sustained no fall in platelets. The development of granulocytopenia proceeded normally. Endotoxin did activate the alternate complement pathway in C4D guinea pigs, as evidenced by the fall in C3-9 titers. With restoration of serum C4 levels, endotoxin-induced thrombocytopenia was observed in C4D animals. Thus, function of the classical complement pathway was an absolute requirement for the development of thrombocytopenia. Experiments performed in cobra venom factor (CVF)-treated normal guinea pigs, with normal levels of C1, C4, and C2, but with less than 1% of serum C3-9 demonstrated the importance of the late components in the development of thrombocytopenia but not leukopenia.C4-deficient guinea pigs had normal clotting times demonstrating that C4 was not required for normal clotting. In addition, development of the hypercoagulable state, evidenced by a marked shortening of the clotting time, was not observed on injection of endotoxin into C4D animals. Therefore, development of the hypercoagulable state paralleled the development of thrombocytopenia and required function of the classical complement pathway. Again, the importance of the late components of complement was emphasized by the failure of CVF-treated normal animals to develop hypercoagulability. These results demonstrate that endotoxin is capable of activating both the classical and alternate complement pathways in guinea pigs but that function of the classical pathway is an absolute requirement for the development of thrombocytopenia and the hypercoagulable state.

Animals↗