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Biomedical subjects

J Martin

Publications and source records attributed to J Martin.

At least 217 records · Page 12Linked to original sources
PubMed2000

Reinfusion of mediastinal blood after heart surgery.

BACKGROUND: Several authors studying autotransfusion of shed mediastinal blood in patients undergoing heart operations have published conflicting results regarding reduction of the need for homologous blood transfusion. The effect on coagulation parameters is also unclear. METHODS: In a prospective randomized study, 198 patients who underwent coronary artery bypass grafting or a valvular operation were divided into 2 groups: a group with autotransfusion of shed mediastinal blood after an operation and a control group. Continuous reinfusion of mediastinal blood was done until no drainage was present or for a period of 12 hours after the operation. The amount of blood lost and autotransfused, the number of homologous blood products transfused, and the coagulation parameters were monitored. RESULTS: The number of patients requiring homologous blood transfusion was significantly different between the 2 groups (54/98 [55%] in autotransfused patients vs 73/100 [73%] in the control group, P =.01). The number of re-explorations for excessive bleeding was similar in the 2 groups (7/98 [7.1%] vs 8/100 [8%]), but the amount of blood collected postoperatively was higher in the autotransfused patients compared with control patients (1200 +/- 201 mL vs 758 +/- 152 mL, P =.0007). Coagulation parameters analyzed and complication rates were similar in the 2 groups after the operations. CONCLUSION: Autotransfusion of shed mediastinal blood reduces the need for homologous blood transfusion in patients undergoing various cardiac operations. The cause of increased shed blood in patients undergoing autotransfusion remains unclear.

Analysis of Variance↗
PubMed2000

Behavior and neurocognitive performance in children aged 5-10 years who snore compared to controls.

Sleep disordered breathing in children is a common but largely underdiagnosed problem. It ranges in severity from primary snoring to obstructive sleep apnea syndrome (OSAS). Preliminary evidence suggests that children with severe OSAS show reduced neurocognitive performance, however, less is known about children who snore but do not have severe upper airway obstruction. Participants included 16 children referred to the Ear, Nose and Throat/Respiratory departments of a Children's Hospital for evaluation of snoring and 16 non-snoring controls aged 5-10 years. Overnight polysomnography (PSG) was carried out in 13 children who snored and 13 controls. The PSG confirmed the presence of primary snoring in seven and very mild OSAS (as evidenced by chest wall paradox) in eight children referred for snoring while controls showed a normal sleep pattern. To test for group differences in neurocognitive functioning and behavior, children underwent one day of testing during which measures of intelligence, memory, attention, social competency, and problematic behavior were collected. Compared to controls, children who snored showed significantly impaired attention and, although within the normal range, lower memory and intelligence scores. No significant group differences were observed for social competency and problematic behavior. These findings suggest that neurocognitive performance is reduced in children who snore but are otherwise healthy and who do not have severe OSAS. They further imply that the impact of mild sleep disordered breathing on daytime functioning may be more significant than previously realized with subsequent implications for successful academic and developmental progress.

Analysis of Variance↗
PubMed2000

Primary T-cell lymphoma of the brain in children: a case report and literature review.

Described here are the clinical features and results of treatment in a 10-year-old Saudi Arabian girl with primary T-cell lymphoma of the central nervous system. At presentation the patient had nystagmus and ataxia. The diagnosis was established by tissue biopsy obtained from the cerebellum. Therapy included cranio-spinal irradiation and combination chemotherapy of a systemic high dose of methotrexate, cytosine, arabinoside, and L-asparaginase. Remission was obtained easily but was interrupted by a local intracranial relapse 57 months after diagnosis (37 months after cessation of therapy; at present the patient is still alive and receiving palliative treatment). This report is warranted because of the rarity of this condition in children.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Circadian rhythms of agitation in institutionalized patients with Alzheimer's disease.

Agitation is a common problem in institutionalized patients with Alzheimer's disease (AD). "Sundowning," or agitation that occurs primarily in the evening, is estimated to occur in 10-25% of nursing home patients. The current study examined circadian patterns of agitation in 85 patients with AD living in nursing homes in the San Diego, California, area. Agitation was assessed using behavioral ratings collected every 15 minutes over 3 days, and activity and light exposure data were collected continuously using Actillume recorders. A five-parameter extension of the traditional cosine function was used to describe the circadian rhythms. The mean acrophase for agitation was 14:38, although there was considerable variability in the agitation rhythms displayed by the patients. Agitation rhythms were more robust than activity rhythms. Surprisingly, only 2 patients (2.4%) were "sundowners." In general, patients were exposed to very low levels of illumination, with higher illumination during the night being associated with less robust agitation rhythms with higher rhythm minima (i.e., some agitation present throughout the day and night). Seasonality was examined; however, there were no consistent seasonal patterns found. This is the largest study to date to examine agitation rhythms using behavioral observations over multiple 24 h periods. The results suggest that, although sundowning is uncommon, agitation appears to have a strong circadian component in most patients that is related to light exposure, sleep, and medication use. Further research into the understanding of agitation rhythms is needed to examine the potential effects of interventions targeting sleep and circadian rhythms.

Activity Cycles↗
PubMed2000

The interview with the donor's family before postmortem cornea procurement.

PURPOSE: Asking the family of a deceased patient to consider eye donation is one of the most difficult aspects of the donation process. The aim of this prospective study was to describe the content of interviews with the families of potential donors and to analyze their reactions to improve the process of eye donation. METHODS: We consecutively met with 151 families of suitable corneal donors at the Rouen University Hospital. All interviews with donor families were analyzed using a preestablished questionnaire. RESULTS: In only 17.9% of cases was the family aware of the potential donor's last will. In 77.7% of these cases, the patient wished to donate. Procurement rate was 71.5%. This acceptance was mostly facilitated by the awareness and motivation of the hospital staff, the experience of the physician, and the 13.3-h period of time allowed after the donor's death. The commitment on the part of the ophthalmologist to carry out optimal anatomical restoration was a very important point for 32% of families who accepted donation. Twenty-one percent of families asked for a delay for reflection. This delay helped to obtain a positive response in 72.7% of cases and even sometimes helped families to reconsider a previously negative position (14% of initial refusals). CONCLUSION: We demonstrate that a high positive response (71.5%) can be obtained from the donor's family when a trained and motivated group manages the post-mortem cornea donation request.

Adult↗
PubMed2000

Radiographic fracture assessments: which ones can we reliably make?

OBJECTIVE: To identify the fracture characteristics that can be reliably assessed by analysis of plain radiographs of tibial plateau fractures. DESIGN: Radiographic review study. PARTICIPANTS: Five orthopaedic traumatologists served as observers. INTERVENTION: Observers made assessments based on the radiographs of fifty-six tibial plateau fractures. Precise definitions of the assessments to be made were agreed on by all observers. The tested assessments included raters' abilities to identify and locate fracture lines, identify the presence of fracture displacement and comminution, make quantitative measurements of displacement, and characterize qualitative features of fractures. For thirty-eight of the fractures that had a computed tomography (CT) scan available, assessments were repeated using both radiographs and CT scans. MAIN OUTCOME MEASURES: To characterize interobserver reliability, percentage agreement and kappa statistics were calculated for categorical variables, and intraclass correlation coefficients (ICC) were calculated for noncategorical variables. RESULTS: Reliability of the assessments varied widely. Determining the location of fracture lines had the greatest reliability, whereas the subjective assessments of fracture stability and energy showed the poorest reliability. Although the ICCs for quantitative measurements approached acceptable levels, the tolerance limits were extremely wide. The addition of a CT scan improved the reliability of most assessments, but not to a statistically significant degree. CONCLUSIONS: Many basic radiographic interpretations relied on in making treatment decisions are made variably by observers. Using experienced raters and precise definitions of fracture assessments does not guarantee a high level of agreement. Discrete assessments have higher interrater agreements than do more qualitative assessments. Quantitative measures have wide tolerance limits and, therefore, probably cannot be used reproducibly to classify fractures or make treatment decisions. We conclude the reliability of fracture classification is limited by raters' abilities to agree on basic radiographic assessments.

Humans↗
PubMed2000

Intercontinental karyotypic differentiation of Chironomus entis Shobanov, a Holarctic member of the C. plumosus group (Diptera, Chironomidae).

Analysis of banding sequences of polytene chromosomes in Palearctic (Russian) and Nearctic (North American) Chironomus entis shows strong karyotype divergence between populations on the two continents. Four out of seven chromosomal arms in the North American C. entis karyotype are characterized by sequences found only in the Nearctic. In total, 44 banding sequences are now known for this species across the Holarctic, including 22 exclusively Palearctic, 6 Holarctic, and 16 exclusively Nearctic sequences. The degree of cytogenetic differentiation between Palearctic and Nearctic C. entis populations is an order of magnitude greater than differentiation among populations within either continent, but is only one third as great as the cytogenetic distance between the sibling species C. entis and C. plumosus. C. entis is the only sibling species of C. plumosus uncovered during cytological identification of Chironomus species from more than 50 North American lakes, indicating that the plumosus sibling-species group is much smaller in the Nearctic than in the Palearctic, where a dozen sibling species are known. Cytogenetic distance values calculated between Nearctic and Palearctic representatives of both C. entis and its sibling species C. plumosus are similar, but result from different patterns of karyotype divergence. New World C. entis is distinguished from Old World populations by the 16 uniquely Nearctic sequences, four of which occur in the homozygous state. In contrast, North American C. plumosus has fewer uniquely Nearctic sequences, and only one that occurs as a homozygote. However, four chromosomal arms in C. plumosus that are polymorphic in the Palearctic show fixation, or near fixation, of Holarctic sequences in the Nearctic C. plumosus karyotype. Thus, both the fixation of Holarctic sequences, and the occurrence or fixation of distinctly Nearctic sequences, contribute significantly to karyotype divergence. Patterns of karyotype divergence in Palearctic and Nearctic populations of different Holarctic chironomid species are discussed relative to intercontinental cytogenetic differentiation in other dipterans.

Animals↗
PubMed2000

Vascular protection: A novel nonangiogenic cardiovascular role for vascular endothelial growth factor.

There is widespread interest in the use of the angiogenic cytokine, vascular endothelial growth factor (VEGF), for the treatment of cardiovascular disease. The main paradigm for VEGF cardiovascular therapy is the stimulation of "therapeutic angiogenesis" in ischemic myocardial and peripheral vascular limb disease. In this review, approaches to VEGF therapy based on the therapeutic angiogenesis model are critically assessed, and the alternative mechanism of vascular protection is advanced. Vascular protection is defined as the VEGF-induced enhancement of endothelial functions that mediate the inhibition of vascular smooth muscle cell proliferation, enhanced endothelial cell survival, suppression of thrombosis, and anti-inflammatory effects. VEGF-induced synthesis of NO and prostacyclin are both likely to be key mediators of VEGF-dependent vascular protection. Investigation into vascular protection should help us to gain insight into the underlying mechanisms of the cardiovascular actions of VEGF and should prove valuable in the development of novel therapeutic approaches based on local VEGF gene delivery.

Animals↗
PubMed2000

Social network mapping with transplant recipients.

Social support can have great influence on health, well-being, and general quality of life To promote awareness of the social network that surrounds each transplant recipient, transplant social workers are now using the Social Network Map as an intervention. Because perceptions of availability and accessibility of support are key elements in the use of social network resources, awakening an individual's awareness of available resources is a significant first step in enhancing social support and, ultimately, quality of life. The Social Network Map is used to establish dialogue regarding individuals' needs and sources of support, and then how the support system can meet those needs. Transplant social workers thus foster active use of those people in transplant recipients' networks who can meet the particular needs recipients identify.

Adult↗
PubMed2000

Thyroid function tests: often justified in the acutely ill.

It is claimed that inappropriate requesting of thyroid function tests (TFTs) is common in acutely ill patients. Consecutive inpatient TFTs (n = 129) were assessed in relation to clinical history and common symptoms and signs of thyroid disease. Requests were justified in 69% of cases, most commonly on the basis of atrial fibrillation and/or tachycardia. There were no clear reasons for requesting TFTs in the remaining cases, although the yield of abnormal results in these patients was similar to that in those with justified requests. Thyroid stimulating hormone (TSH) concentration was increased (median 7.5 mU/L, range 4.8-38.6 mU/L) in 22 patients, six of whom had biochemical and/or clinical evidence of hypothyroidism (previously undiagnosed) and five of whom had pre-existing hypothyroidism. Of the remaining 11 patients with increased TSH levels, three were confirmed to have compensated hypothyroidism; non-thyroidal illness (NTI) (including the effect of drugs) accounted for four cases. In four patients (one of whom died during the admission) follow-up was not possible. Of six patients with reduced TSH concentration (range <0.05-0.35 mU/L), one was thyrotoxic on carbimazole, one was receiving thyroxine for hypothyroidism, one had NTI and three were lost to follow-up (two of whom died during their admission). Manifestations of thyroid disease are protean and often subtle, and TFTs are thus clinically justified in many unwell inpatients. Although NTI contributes to some cases of abnormal TSH levels, a significant number of TFT abnormalities are consistent with underlying thyroid abnormality requiring investigation/treatment.

Acute Disease↗
PubMed2000

Transfer of telemedical support to Cornwall from a national telemedicine network during a solar eclipse.

During late 1998 and early 1999, planning officers in Cornwall predicted a huge increase in summer visitors to the county to observe the August solar eclipse. There was the possibility that a mass gathering in Cornwall could overload existing arrangements for handling accident and emergency patients. We therefore set up a telemedicine system to support the county's minor injury units (MIUs) from hospitals throughout the UK. Six main hospital accident and emergency departments outside Cornwall with existing links to their own MIUs were twinned with 10 of the 11 MIUs in Cornwall before the expected date of the gathering. The network was live for nine days, starting four days before the eclipse, and 2045 patients were seen in the 10 MIUs. There were 93 telemedicine calls from the 10 MIUs, involving 91 patients. Overall, 4.6% of the patients required a telemedicine consultation. Fifty-seven calls were made during working hours. Thirty-four patients were referred for further management, of whom 18 were referred on the same day. The transfer of telemedical support to a national network was successful.

Emergency Medical Services↗
PubMed2000

Technology evaluation of a USA-Mexico health information system for epidemiological surveillance of Mexican migrant workers.

From 1994 through 1996, federal, state, and nongovernmental organizations in Mexico and in the United States of America developed and piloted a Binational Health Information System for Epidemiological Surveillance of Mexican migrant workers. The system allowed data exchange for epidemiological surveillance between the state of Guanajuato in Mexico and the Commonwealth (state) of Pennsylvania in the United States, for case detection, prevention, and treatment, through shared contact investigation and case management of communicable diseases. The target population consisted of migrant workers traveling between Guanajuato and Pennsylvania to work mainly in the mushroom industry, and their sexual partners in their Mexican communities of origin. Computerized migrant health information modules were set up in Guanajuato and in Pennsylvania. Patient information and epidemiological surveillance data were encrypted and communicated electronically between the modules, using the WONDER communications system of the U.S. Centers for Disease Control and Prevention. Evaluation of the Guanajuato-Pennsylvania Binational Health Information System showed that major barriers to binational epidemiological surveillance and control are: a) lack of communication binationally; b) interrupted medical care due to migration; c) inconsistent diagnosis and treatment criteria between the two countries; d) lack of referral clinical records from one country to the other; and e) deficient legal regulations concerning binational clinical data transfer. To our knowledge, this is the first project that has successfully demonstrated the technological feasibility of a binational disease control system linking a state in the interior of one country with a state in the interior of another country, rather than just states in the border region. The project also advanced the understanding of health service organizational issues that facilitate or hinder communication, outreach, disease prevention, and organization of health care services for migrant workers in both Mexico and the United States. Despite the unprecedented success and potential bilateral benefits demonstrated by this project, serious structural and organizational deficits in the public health systems of both countries must be addressed before epidemiological surveillance can be achieved binationally.

Information Systems↗
PubMed2000

Diagnosis and treatment of a fractured third phalanx in a Masai giraffe (Giraffe camelopardalis tippelskirchi).

A 10-yr-old male Masai giraffe (Giraffe camelopardalis tippelskirchi) presented with acute right forelimb lameness. Radiographs revealed a fracture of the medial claw of the distal phalanx penetrating into the distal interphalangeal joint. The giraffe was sedated while it was standing in a chute, and a wooden "hoof block" was applied to the lateral claw of the same limb. The animal was no longer lame 3 days after the procedure. Subsequent treatments included vitamin E, phenylbutazone, and glycosaminoglycans. For 7 wk it was maintained in a small holding yard on packed sand during the day and on deep sand during the night. The hoof block slowly wore down, and at 7 wk, it was placed back on concrete in the evening. At 8 wk, the block had completely worn off and the animal was no longer lame, but radiographs indicated minimal fracture healing. Radiographs performed at 7 mo indicated that there was still a radiolucent zone at the fracture line but calcification was evident at the margins of the fracture.

Animal Diseases↗
PubMed2000

Group II chaperonins as mediators of cytosolic protein folding.

Protein folding and assembly in the cell requires the assistance of molecular chaperones. These components prevent off-pathway folding reactions that lead to aggregation. They are also critical factors in organismal stress physiology, protecting cells against heat shock and providing thermotolerance. Among this important protein family are chaperonins. They form large cylindrical double ring complexes with a central cavity where protein binding and folding takes place in an ATP-dependent manner. Recently, components functionally related to the eubacterial and organellar chaperonins have been found in the cytosol of archaebacteria and of eukaryotic cells. Based on their sequences and structural features, they have been classified as group II chaperonins, to distinguish them from the group I chaperonins occurring in bacteria. Of particular interest in the group II family is the eukaryotic CCT complex, whose function in protein folding and assembly has been demonstrated mainly for the cytoskeletal proteins tubulin and actin. Together with the Hsp70 chaperone system, it can be considered as an essential helper factor to facilitate the folding of native proteins in the eukaryotic cytosol. Recent structural data have opened the path to a molecular understanding of group II chaperonins and have helped to define their role in cellular protein folding.

Animals↗