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Biomedical subjects

D Martin

Publications and source records attributed to D Martin.

At least 469 records · Page 26Linked to original sources
PubMed1994

Invasive pneumococcal disease in a pediatric population, Auckland, New Zealand.

Streptococcus pneumoniae is one of the major invasive pathogens in childhood. The increasing worldwide prevalence of penicillin-resistant strains makes management of invasive infections difficult and underscores the need for effective vaccines. Currently available vaccines are of limited value in the pediatric age group. Trials are taking place to evaluate conjugated pneumococcal vaccines and in view of this it is important to establish local epidemiology of pneumococcal disease. The aims of this population-based study were to review all of the cases of invasive pneumococcal disease occurring during a 9-year period (1984 to 1992) in Auckland, New Zealand. Through the use of laboratory records and hospital discharge codes, 413 isolates from 407 patients were found. Age-specific incidence for all invasive disease was 22.0/100,000 for children less than 15 years old but 56.0/100,000 for children less than 5 years old (chi 2 Yates corrected 18.20; P = 0.001). Two-thirds were less than 2 years old. The rates were higher in Maori and Pacific Island children than in Caucasian children. A total of 70 isolates from 68 patients with meningitis occurred. The majority were less than 5 years old (incidence of meningitis was 10.0/100,000) and 84% were less than 2 years old. The overall mortality from meningitis was 4.3%. Of the 129 isolates serogrouped or serotyped, 14, 6 and 19 accounted for 23%, 16% and 16%, respectively, of cases. Although 98% of serotypes identified would be covered by the currently available 23-valent vaccine, two-thirds of the children affected by these isolates would be unprotected because of poor immunogenicity of polysaccharide vaccines in children less than 2 years old.

Adolescent↗
PubMed1994

Identification and intervention for urinary incontinence by community physicians and geriatric assessment teams.

OBJECTIVE: To determine the difference in the recognition and intervention/referral rates for urinary incontinence (UI) by out-patient Geriatric Assessment Units (GAUs) and private physicians in community-based practices (CMDs). DESIGN: A multi-site, randomized, controlled study where block randomization was utilized to assign subjects 65 years of age and older to either a GAU or a CMD for assessment. SETTING: One academic and three hospital-based GAUs and CMDs in private practice in a large metropolitan area. PARTICIPANTS: Three hundred sixty-four community-dwelling frail men (14%) and women (86%) with a mean age of 75 years. MEASUREMENTS: The independent variable was the type of out patient care, either CMD or GAU, to which the subjects were randomized. The dependent variables were recognition of UI by the health care providers and intervention or referral for the problem of UI once it was identified. Instruments included a structured in-home interview performed before randomization designed to uncover health problems such as urinary incontinence, as well as a medical record review form used post-assessment to ascertain recognition rates and intervention for UI by CMDS and GAUs. Both of the instruments were developed and piloted by the investigators in a preliminary study. MAIN RESULTS: Of the 364 subjects, 151 (41.5%) reported UI during the in-home interviews. Recognition rates for UI were significantly better for GAUs (48 of 81, 59.3%) than CMDs (11 of 70, 15.7%) (P < 0.001). This was true for mild (< 3 times/week) 44.2% vs 2.1% (P < 0.000005) as well as severe UI (> 3 times/week) 86.2% vs 43.5% (P = 0.00111) for GAUs and CMDs, respectively. There were no significant differences in the rate of referral/intervention for recognized cases of UI by GAUs or CMDs. GAUs referred/treated five (21.7%) cases of mild UI and 10 (40%) cases of severe UI while CMDs referred/treated three (30%) cases of severe UI but did not offer intervention for the one recognized case of mild UI. GAUs were more likely to refer to Continence Programs (12, 25%) compared with CMDs who were more likely to refer (3, 100%) to a urologist. A majority of the subjects with UI did not receive treatment or referral for their problem (8, 72.7% CMDs and 33, 68.6% of GAUs). CONCLUSIONS: GAUs out performed CMDs in the identification of subjects with both mild and severe UI. However, the intervention/referral rates were low for both GAUs and CMDs. The outcome of this study points to the need for increased emphasis on UI in curriculum preparing physicians and other health providers as well as the need for continuing education for those already in practice.

Aged↗
PubMed1994

Electrical proarrhythmia with procainamide: a new ICD-drug interaction.

A 78-year-old man with a transvenous cardioverter defibrillator system developed frequent shocks during oral procainamide therapy. Electrophysiologic evaluation demonstrated failure to terminate ventricular tachycardia with maximal energy shocks, but consistent termination by low energy discharges. Procainamide had no effect upon the defibrillation threshold. The failure of therapy with disopyramide and mexiletine to reproduce this observation suggests either a previously unreported electrophysiologic effect of, or idiosyncratic response to, procainamide.

Aged↗
PubMed1994

Hyperdense basilar artery. An early computed tomography sign of thrombosis.

Noncontrast computed tomographic scans (CT scans) may show a hyperdense basilar artery before a brainstem infarct is visualized. This early sign should assist clinicians in confirming the diagnosis of basilar artery thrombosis. In a review of admission records of 750 patients with acute cerebrovascular disease from July 1991 to June 1993, at Saint Louis University Hospital, 20 patients were identified with clinical signs of nonlacunar, vertebrobasilar distribution infarction. Eight of these had pontomesencephalic ischemia. Their neuroimaging studies and medical records were evaluated. Four patients with acute clinical signs of pontomesencephalic infarction were found to have a hyperdense basilar artery on CT scans. The scans of 2 patients were excluded because of dolichoectasia; in the other 2 patients, the basilar artery appeared normal on the CT scan. The hyperdense basilar artery was detected within the early hours of neurological symptoms and often was the only detectable abnormality on the scan. In 3 patients extensive brainstem infarcts subsequently developed and they died. Basilar artery thrombosis was confirmed by pathological study in all these patients. In the fourth patient basilar artery occlusion and a large pontine infarct were evident by magnetic resonance imaging and angiography. A hyperdense basilar artery is a common feature on CT scans of patients presenting with an early clinical diagnosis of thrombosis. Untreated, the hyperintense basilar artery often portends a poor prognosis. Its ready recognition should guide further interventional studies and treatment.

Adult↗
PubMed1994

Influence of exercise and fiber type on antioxidant enzyme activity in rat skeletal muscle.

These experiments examined the influence of exercise intensity and duration on antioxidant enzyme activity in locomotor muscles differing in fiber type composition. Nine groups of female Sprague-Dawley rats (age 120 days) exercised 4 days/wk on a motor-driven treadmill for 10 wk. The impact of three levels of exercise intensity (low, moderate, and high: approximately 55, approximately 65, and approximately 75% of maximal oxygen consumption, respectively) and exercise duration (30, 60, and 90 min/day) was assessed. Sedentary animals served as controls. Oxidative capacity in the soleus and white and red gastrocnemius was assessed by measurement of citrate synthase (CS) activity, and antioxidant capacity was evaluated by assay of total superoxide dismutase, catalase, and total glutathione peroxidase (GPX) activities. In all muscles, CS activity increased as a function of exercise duration. Furthermore, in the soleus and white gastrocnemius, the magnitude of the training-induced increase in CS activity was directly related to exercise intensity. In contrast, the peak increase in CS activity in the red gastrocnemius was relatively independent of exercise intensity. Catalase activity was not increased (P > 0.05) in any muscle with training. Training-induced changes in superoxide dismutase and GPX activities were muscle specific; specifically, exercise training significantly (P < 0.05) increased superoxide dismutase activity in the soleus as a function of exercise duration up to 60 min/day. Conversely, training-induced significant (P < 0.05) increases in GPX activity occurred in red gastrocnemius only; the magnitude of the GPX increase was directly related to exercise duration but relatively independent of intensity. These data demonstrate that exercise training-induced changes in muscle antioxidant enzymes are muscle specific.

Animals↗
PubMed1994

Novel tenascin variants with a distinctive pattern of expression in the avian embryo.

Previous studies have shown that several forms of the glycoprotein tenascin are present in the embryonic extracellular matrix. These forms are the result of alternative splicing, which generates tenascin variants with different numbers of fibronectin type III repeats. We have used degenerate primers and PCR to isolate a novel tenascin exon from an avian genomic library. Genomic clones contained a sequence encoding a fibronectin type III repeat that corresponds to repeat 'C' from the variable domain of human tenascin. To demonstrate that tenascin containing repeat 'C' is actually synthesized by avian cells, a monospecific antiserum was raised against a repeat 'C' fusion protein. This antiserum recognized a novel high-molecular-weight variant on immunoblots of tenascin isolated from chicken embryo fibroblast-conditioned medium, and stained tendons on frozen sections of chicken embryos. A cDNA probe specific for mRNA encoding repeat 'C' was used for in situ hybridization. This probe hybridized in a subset of the embryonic tissues labelled with a universal tenascin probe, including tendons, ligaments and mesenchyme at sites of epithelial-mesenchymal interactions. Finally, we provide evidence that additional fibronectin type III repeats, one corresponding to a recently discovered human repeat as well as one entirely novel sequence, also exists in chicken tenascin mRNA. These data indicate that tenascin is present in the embryonic matrix in a multitude of forms and that these forms have distinctive distributions that may reflect more than one function for tenascin in development.

Amino Acid Sequence↗
PubMed1994

[Anterior interosseous flap].

An anatomical study which was carried out on 44 upper limbs of fresh cadavers has enabled us to describe a new flap based on the superior perforating branch of the anterior interosseous artery: "the anterior interosseous flap". The anterior interosseous artery participates in the vascularization of the dorsal aspect of the distal two-third of the forearm by providing two perforating branches, "the superior and the inferior perforating branches". The superior perforating branch of the anterior interosseous artery, pedicle of the flap, perforates the interosseous membrane 10 +/- 2 cm above the radio-carpal joint and runs in the septum between the extensor pollicis longus and brevis muscles accompanied by two venae comitantes. The calibre of the artery at its origin varies from 0.9 to 1.5 mm. During its course, the artery gives 5 to 7 septocutaneous branches to reach the overlying skin in the posterior aspect of the distal two-thirds of the forearm. It also gives 3 to 5 osseous branches spreading over the dorsal aspect of the distal third of the radius and several muscle branches to the abductor pollicis longus, extensor pollicis longus and brevis, extensor indicis and extensor digitorum muscles. The inferior perforating branch of the anterior interosseous artery generally perforates the interosseous membrane 4 to 5 cm above the radio-carpal joint. After giving a medial branch which anastomoses with the posterior interosseous artery (in 42 out of 44 cases) the inferior perforating branch of the anterior interosseous artery always runs distally to join the dorsal vascular network of the wrist which is rich enough to produce a retrograde arterial blood flow. This flap can be used as an island flap (with a retrograde or a direct blood flow) or a free flap. The surgical procedure of the retrograde island flap consists in raising the cutaneous or compound flap based on the superior perforating branch, division of the interosseous membrane and ligature of the anterior interosseous trunk proximally. The flap is vascularized by a retrograde blood flow through the dorsal (or volar or both) vascular network of the wrist. Theoretically, the most distal point of rotation of the flap is located at the level of the luno-capitate joint and the pedicle is long enough to allow the most distal point of the flap to reach the DIP joint of the finger.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1994

[The "extreme" brachial flap: a distal pedicled use of an external brachial flap. Preliminary report].

The authors present a new application of the procedure they called the "reverse flow YV pedicle extension" which allows a very distal pedicled mobilisation of the lateral arm flap. Until now, only the distally based lateral arm flap and the ulnar recurrent fascicutaneous island flap could to be transferred distally but reached only the proximal third of the forearm. In our experience these flaps did not seem to be very reliable. Lengthening of the lateral arm flap pedicle using the lateral triceps artery (branch arising from the profunda brachii artery) allows the lateral arm flap to be transferred beyond the distal third of the forearm. This so-called "extreme" lateral arm flap has advantages and disadvantages which are discussed in this paper. We consider cutaneous or osteocutaneous reconstructions of the forearm to be the best indication for this flap. Our first clinical case is reported.

Accidents, Traffic↗
PubMed1994

[Reverse flow YV pedicle extension: a method of doubling the arc of rotation of a flap under certain conditions].

The authors present a new surgical procedure which allows the transfer of pedicled flaps distally to the origin of their vascular pedicle. They call this procedure the "reverse-flow YV pedicle extension of a flap". The idea is to raise a flap distally on a branch of a Y-like vascular bifurcation. The section of the trunk of the bifurcation turns the Y-into a V-vascular pattern, which allows distal mobilisation of the flap on the remaining branch of the V. The distal range of transposition of the flap can reach twice the length of one bifurcation of the flap. The arterial blood supply is provided by reverse-flow through the attached remaining branch of the V. Venous drainage is ensured as in a distally based pedicled flap. Up until now, the authors have performed six different applications of this procedure: arterial lengthening of a latissimus dorsi flap pedicled on the circumflex scapular artery for coverage of the vertex (a venous anastomosis is required in this case; lengthening of the submental vein in very distal transfers of a submental flap; lengthening of an arteriovenous pedicle: transfer of the anterior interosseous flap which can reach the PIP joint of long digits, transfer of an amputated digit on to the adjacent stump, distal transfer of a medial plantar flap allowing it to reach the tip of the toes, transfer of the lateral arm flap on to the triceps branch of the profunda brachii artery. This flap can reach the metacarpal area of the hand. This procedure seems to very usefully replace microsurgical techniques in many circumstances in which, until now, they would have been necessary. Further applications will be discussed.

Female↗
PubMed1994

[The transplantation of syngeneic Schwann cells in medullary lesions: results, limitations and perspectives].

After a central nervous system (CNS) injury, there is only an "abortive regeneration" of axons, while injured axons regenerate vividly in the peripheral nervous system (PNS). This difference is due, at least in part, to the existence in the periphery of Schwann cells and of growth promoting proteins they synthetize. One strategy to promote regrowth of central axons can be therefore, to modify (i.e. "peripheralize") the microenvironment by transplanting biologically active Schwann cells into the lesion site. In a rat model of traumatic paraplegia by inflation of a subdural microballoon, we performed syngeneic transplants of Schwann cells. These cells are cultured from adult dorsal root ganglia and can be kept in vitro for several months. They are transplanted in the injured spinal cord. The grafted Schwann cells are well integrated in the host tissue without detectable inflammatory reaction. Cystic cavitation and astrogliosis are reduced in grafted animals as compared to injured, non-grafted animals. The transplant is invaded by abundant, mainly unmyelinated axons which are immunoreactive for substance P, VIP or CGRP, i.e. transmitters known to be present in DRG afferents. Supraspinal afferents containing 5HT, TH or CCK accumulate at the rostral margin of the graft. Experimental procedures trying to stimulate the invasion of the graft by descending fibers, i.e. by inducing a chemoattraction are therefore of crucial importance for functional recovery.

Animals↗
PubMed1994

[Transsexualism: surgical aspects. An experience of the plastic surgical unit's in Bordeaux].

After briefly reviewing the history of transsexual surgery, the authors explain their technical choices and present their experience based on a series of 19 patients, 11 male transsexuals and 8 female transsexuals. The results are analysed. The potential complications of surgery in female transsexuals are those of microsurgical techniques aggravated by treatment with testosterone, as well as urethral fistulae and strictures. In addition to prevention of thromboses, the authors palliate these complications by ulnar elongation of the radial forearm flap in order to minimise the factors responsible for urethral fistulae, combined with enlargement of this flap to decrease the risk of stricture. The complications in male transsexuals essentially consist of rectoneovaginal fistulae. Problems of the depth of the neovagina are also important. Two rectoneovaginal fistulae were observed in this series of 11 patients, both treated medically. The unit's experience in this field will be continued in order to further improve the results.

Adult↗
PubMed1994

Treatment of deeply infiltrating endometriosis.

Deep endometriosis has been defined as endometriosis infiltrating deeper than 5 mm under the peritoneum. A model for the development and propagation of endometriosis is presented. Subtle and non-pigmented lesions are suggested to occur intermittently in all women. Infiltration occurs generally to a few millimeters of depth only, and these lesions become typical, burnt out lesions. In some 20% of women, severe endometriosis develops either as deeply infiltrating disease or as cystic ovarian disease. Arguments are given to consider deep endometriosis and cystic ovarian endometriosis as two specific entities of endometriotic disease. A possible causal relationship with dioxin pollution is discussed. Diagnosis of deep endometriosis is made by clinical examination and palpation during surgery. Clinical examination during menstruation and CA-125 concentrations in plasma are useful to help in the diagnosis of smaller deep lesions. Surgical excision can be carried out by laparoscopy, laparotomy or vaginally using sharp dissection, electrosurgery or with the use of a CO2 laser. Excision is the treatment of choice because of a high pregnancy rate, a complete cure of pain in most women, and a low recurrence rate. Medical treatment is probably less effective to treat infertility, but highly effective in relieving pelvic pain. Medical therapy, by luteinizing hormone-releasing hormone agonists, danazol, or gestrinone, also seems useful as a pretreatment for surgery. The choice of treatment will therefore depend on the local expertise with minimal invasive surgery, certainly if a first excision has been incomplete and pain symptoms recur.

Endometriosis↗
PubMed1993

The neuroprotective agent riluzole inhibits release of glutamate and aspartate from slices of hippocampal area CA1.

Riluzole is believed to exert its anticonvulsant and neuroprotective actions by reducing glutamate release. This study demonstrated that 10-30 microM riluzole reduces the K(+)-evoked release of glutamate and aspartate from slices of hippocampal area CA1. Only higher concentrations reduced gamma-aminobutyrate (GABA) release. These actions of riluzole were not occluded by tetrodotoxin. Riluzole did not diminish the ability of glutamate analogues to depolarize CA1 pyramidal cells, as determined from grease-gap recordings. Therefore the anticonvulsant and neuroprotective actions of riluzole in the hippocampus may be at least partly explained by its ability to inhibit glutamate/aspartate release from synaptic terminals.

Animals↗
PubMed1993

Emergence of NK1.1+ cells as effectors of IFN-gamma dependent immunity to Toxoplasma gondii in MHC class I-deficient mice.

CD8+ T lymphocytes have been reported to play a major role in the protective immune response against acute infection with Toxoplasma gondii. In order to further assess the role of CD8+ cells in resistance against this protozoan we examined the ability of beta 2m-deficient mice, which fail to express MHC class I molecules and peripheral CD8+ lymphocytes, to survive tachyzoite challenge following vaccination with an attenuated parasite mutant. Surprisingly, vaccination of beta 2m-deficient mice induced strong resistance to lethal challenge, with > 50% surviving beyond 3 months. Vaccinated beta 2m-deficient mice, but not control heterozygotes, showed a five- to six-fold expansion in spleen cell number and approximately 40% of the splenocytes were found to express the NK markers NK1.1 and asialo GM1. Spleen cells from the vaccinated beta 2m-deficient animals failed to kill either infected host cells or the NK target YAC-1. However, high levels of IFN-gamma were secreted when the cells were cultured in vitro with soluble T. gondii lysate, and this response was abolished by NK1.1+ but not CD4+ and CD8+ lymphocyte depletion, implicating the NK1.1+ population as the major source of IFN-gamma. More importantly, vaccine-induced immunity in beta 2m-deficient mice was completely abrogated by in vivo administration of antibody to NK1.1, asialo GM1, or IFN-gamma. Together, the data suggest that in class I-deficient mice vaccinated against T. gondii, the absence of CD8+ effector cells is compensated for by the emergence of a population of NK1.1+ and asialo GM1+ cells which lack cytolytic activity, and that the protective action of these cells against the parasite is attributable to IFN-gamma production. The induction of this novel NK population may provide an approach for controlling opportunistic infections in immunocompromised hosts.

Animals↗
PubMed1993

Interleukin-1 mediates the behavioral hyperalgesia produced by lithium chloride and endotoxin.

The sickness-inducing agents lithium chloride (LiCl) and lipopolysaccharide (LPS) produce a long-lasting facilitation of the nociceptive tailflick reflex. Many of the behavioral and physiological changes produced by illness are mediated by interleukin-1 (IL-1) released from monocytes stimulated by the pathogenic substance. Monocytes also produce an IL-1 receptor antagonist (IL-1ra) which has been sequenced and cloned. The present experiments report that IL-1 can itself produce hyperalgesia as assessed by tailflick to radiant heat, and that recombinant IL-1ra blocks the hyperalgesia produced by LiCl and LPS.

Animals↗