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Biomedical subjects

M Lehman

Publications and source records attributed to M Lehman.

17 recordsLinked to original sources
PubMed2005

SNAT expression in rat placenta.

Amino acid transport System A (SysA) activity is present within the rodent and human placentas. Inhibition of this transport system is associated with fetal growth retardation. Several cDNAs encoding SysA transport proteins have been discovered, and their presence documented within the human placenta. We have demonstrated the presence of mRNA encoding three of these transporters, SNAT1, 2, and 4 within the rat placenta over the final third of gestation. Abundance of these mRNA species increases from day 14 to day 20 of gestation. Immunohistochemistry demonstrates the presence of SNAT1 and 2 within the placental labyrinth at both days 14 and 20. Transport proteins are also present within marginal giant cells and, for SNAT1, within fetal endothelium. In conclusion, several proteins capable of SysA transport activity are present within the rodent placenta. mRNA expression increases over the final third of gestation, coincident with the period of greatest need for fetal amino acid delivery.

Amino Acid Transport System A↗
PubMed2001

Cold water swim stress increases the expression of neurotensin mRNA in the lateral hypothalamus and medial preoptic regions of the rat brain.

Stress-induced analgesia is a well-documented phenomenon that occurs in all mammalian species. Forced cold water swim produces a type of stress-induced analgesia that is independent of mu opioid receptors. The neuropeptide neurotensin (NT) has been implicated in mu opioid-independent analgesia (MOIA), but the circuitry of this system is largely unknown. The medial preoptic area (MPO) and lateral hypothalamus (LH) are two regions that are known to modulate pain processing. These two regions also contain neurotensinergic projections to the periaqueductal gray, a region that has been shown to produce MOIA upon injection of NT. The goal of this study was to determine if cold water swim (CWS) stress, which produces MOIA, activates the NT-ergic systems in these two regions. In situ hybridization results indicate that CWS increases the level of NT mRNA within neurons in the MPO and LH, suggesting that these two regions are activated during this process.

Animals↗
PubMed2000

Female clear cell adenocarcinoma arising within a urethral diverticulum.

Clear cell adenocarcinomas arising from female urethral diverticulae are rare. The optimal management of this clinical entity is uncertain. Two cases managed by a combination of surgery and XRT (radiotherapy) are presented. The common histopathological findings and treatment options are highlighted. Individualized patient management in a multi-disciplinary setting is recommended.

Adenocarcinoma, Clear Cell↗
PubMed1993

[The Relative Complexity Index beta: value of each parameter].

The French health policy PMSI project (Program for a Medical Information System) is mainly aimed at development of cost analysis based on diagnosis related groups. An indicator of the relative costs of anaesthetics, the relative complexity index (ICR beta), was defined as the result of a computation of different indexes of surgical and anaesthetic procedures such as duration, patients ASA status, degree of emergency, stay in the recovery room. The aims of this study were 1) to analyze relative part of each index in ICR beta value and in ICR beta variance and 2) to assess the value of ICR beta as a cost or a complexity index. The study included 14,435 anaesthetics analyzed with the Dunn and Clarks multiple linear regression. Mean ICR beta was 267.28. The duration of the procedure accounted for 46% of the ICR beta value and surgery for 25%. The anaesthesia and the recovery accounted for 15% of the ICR beta value, but only for 0.0341 and 0.0347 respectively of the ICR beta variance. The product of the surgical procedure index by the ASA status index accounted for 0.259 of the ICR beta variance and the duration index for 0.650. The comparison of homogeneous groups with regard to the surgical procedure shows that intravenous anaesthesia accounts for 12.4% of the ICR beta value, inhalational anaesthesia for 13.84%, but exceeds 15% for regional anaesthesia (44.5% for caudal anaesthesia). For appendectomies (n = 114) duration index is still an important parameter in ICR beta variance (delta R2 = 0.354) but equivalent to the emergency index (delta R2 = 0.363).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1991

Tracing SCN graft efferents with Dil.

The suprachiasmatic nuclei (SCN) regulate circadian rhythmicity in many biological and behavioral responses. Hamsters are made permanently arrhythmic by bilateral destruction of the SCN. Circadian locomotor rhythmicity is restored by fetal tissue transplants placed in the 3rd ventricle (3V). If intact animals are implanted with fetal SCN grafts, they maintain locomotor activity rhythms when the host SCN are subsequently destroyed. The mechanism(s) whereby the SCN (either grafted or in situ) regulate locomotor rhythmicity is not known. Evidence from other graft models point to the possibility of efferents to appropriate targets in the host. In the present study, efferent connections of transplanted fetal SCN were examined using the carbocyanine dye, Dil. Intact or SCN-lesioned animals were sacrificed 7 or 40 days after receiving fetal SCN grafts into 3V. Dil crystals were placed on the grafts in fixed brains which were then incubated for 3-6 weeks before sectioning. Sections bearing Dil-labelled efferents from the graft were photographed and then stained for immunoreactive VIP and NP cells to locate donor SCN. Although labelled efferents were observed in a majority of the grafts, most were confined to the limits of the graft. The few labelled efferents that entered the host tissue when the graft seemed to merge with the host did not extend very far regardless of whether the graft contained immunohistochemical evidence for donor SCN or not. The observation of limited graft-host connectivity suggests either that a limited number of efferents is sufficient to support circadian locomotor rhythmicity, or that the mechanism mediating restoration of function entails a diffusible substance.

Animals↗
PubMed1989

Surgical indications in children with cerebral palsy.

We have presented our approach to the surgical consideration for the upper extremities of a child with cerebral palsy. This is basically a coordinated approach involving many team members, and is the only way to achieve predictable postoperative results.

Cerebral Palsy↗
PubMed1988

Effects of aging and hypertension on endothelium-dependent vascular relaxation in rat carotid artery.

We evaluated the effects of aging and hypertension on endothelium-dependent relaxation of rat common carotid arteries using 14-week-old (young) and 11-month-old (old) Wistar-Kyoto rats (WKY) and age-matched spontaneously hypertensive rats (SHR). Isometric tension of common carotid artery ring segments was measured. With a resting tension of 2.0 g determined from the baseline tension-contraction curves, precontraction was induced by 10(-5) M 5-hydroxytryptamine and endothelium-dependent relaxation was measured by application of either acetylcholine or adenosine 5'-triphosphate (ATP). Mean arterial blood pressure was 73.1 +/- 3.0 mm Hg in WKY and 110.0 +/- 3.1 mm Hg in SHR. These baseline values were significantly different. Acetylcholine-induced maximal relaxations were 70.1 +/- 2.6% of the 5-hydroxytryptamine-induced contraction in young WKY, 45.6 +/- 2.1% in old WKY, 35.1 +/- 1.8% in young SHR, and 21.4 +/- 2.5% in old SHR. On the other hand, ATP-induced relaxations were 52.0 +/- 3.2%, 35.7 +/- 3.8%, 21.7 +/- 3.5%, and 17.0 +/- 1.8% in the groups, respectively. Acetylcholine-induced relaxations were significantly different between WKY and SHR, young and old, independently. On the other hand, ATP-induced relaxations were also significantly different between young and old WKY, although no significant difference was observed between young and old SHR. The fact that endothelium-dependent relaxation of a cephalic artery is impaired in old rats and in hypertensive rats suggests that aging and hypertension are risk factors that may augment the disturbance of the cerebral circulation in pathologic conditions.

Acetylcholine↗
PubMed1986

Long-term follow-up on tendon transfers to the extensors of the wrist and fingers in patients with cerebral palsy.

Thirty-eight patients with cerebral palsy had tendon transfers to improve extension of the wrist and fingers. The 10 patients who had poor hand placement, sensibility, or motor control failed to improve in functional grasp or release. The remaining 28 patients, with better preoperative criteria, had improved function. On long-term follow-up, 5 of the 12 patients with transfers to the wrist extensor had extension contractures with difficulty in release, and in seventeen patients transfers to the finger extensors resulted in improved finger extension and release, with no sacrifice in the ability to grasp.

Adolescent↗
PubMed1986

Spinal curvature, hand dominance and prolonged upper-extremity use of wheelchair-dependent DMD patients.

A study of 26 wheelchair-dependent patients with Duchenne muscular dystrophy aged between 11 and 23 years (average 16.5 years) showed no correlation between handedness or prolonged use of one upper extremity and convexity of the spinal curve. Severe, untreated scoliosis results in loss of function. A straight, stable spine allows patients to use their upper extremities functionally rather than for supporting the trunk.

Adolescent↗
PubMed1986

Barrier disruption in the major cerebral arteries during the acute stage after experimental subarachnoid hemorrhage.

The effects of experimental subarachnoid hemorrhage (SAH) on the blood-arterial wall barrier in the basilar arteries were studied during the acute stage after SAH. SAH was induced in rats by injecting fresh autologous blood into the cisterna magna. Horseradish peroxidase (HRP) was given intravenously before killing the animals to assess the integrity of the barrier. In the basilar arteries taken from the animals that were killed 30 minutes after the cisternal injection of either mock cerebrospinal fluid or arterial blood, HRP reaction products were diffusely observed in the subendothelial spaces and smooth muscle layers. At 5 hours after the blood injection, no permeation of HRP into the subendothelial space was observed. Endothelial cell transcytosis seemed to be the important mechanism for HRP permeation into the subendothelial space rather than the opening of interendothelial junctions. The disruption of the blood-arterial wall barrier in the major cerebral arteries after SAH may be involved in the pathogenesis of vasospasm.

Animals↗
PubMed1981

The surgical anatomy of the interosseous ligament of the subtalar joint as it relates to clubfoot surgery.

Confusion exists as to the exact anatomical description of the interosseous ligament of the subtalar joint. An effort was made through anatomical dissections to elucidate the exact boundaries of this tiny ligament. It is the authors' belief that in some resistant clubfeet, unless this ligament is transected completely, a full correction of the clubfoot deformity will not be obtained and a less than satisfying result, or a recurrent clubfoot deformity, may be the sequela.

Ankle Joint↗
PubMedDate not supplied

Is concurrent chemotherapy and radiotherapy the new standard of care for locally advanced cervical cancer?

The results of five multi-institutional randomized controlled trials demonstrating a survival advantage for the concurrent administration of chemotherapy and radiotherapy in the management of cervix cancer represented the first major advance in the management of this malignancy in many years and prompted many practitioners to alter their pattern of practice. More recently, the results of the National Cancer Institute of Canada (NCIC) trial demonstrating no survival benefit when combined modality therapy is compared with optimally delivered radiotherapy, has led many to question the strength of the evidence supporting the adoption of combined modality therapy as the standard therapy for cervix cancer and in particular the magnitude of the benefit derived from the addition of chemotherapy to an optimally delivered radiotherapy regimen. This review paper will critically examine the evidence presented in the literature indicating a benefit for the use of combined modality therapy, discuss possible reasons why the conclusions of negative trials such as the NCIC study differ from those of the other studies and highlight those aspects of the use of combined modality therapy that require further evaluation.

Adult↗
PubMedDate not supplied

Arthrodesis of the paralytic shoulder.

Five children, aged 7-15 years, with brachial palsies and flail shoulders, had fusions performed. Four of the five had improved function; however, there was progressive loss of fused abduction position over time.

Adolescent↗