Biomedical subjects

M Gartner

Publications and source records attributed to M Gartner.

At least 19 recordsLinked to original sources

PubMed2004

Assessment of medial olivocochlear system function in pre-term and full-term newborns using a rapid test of transient otoacoustic emissions.

This study was conducted to investigate maturation of the medial olivocochlear efferent system (MOCS) in pre- and full-term neonates using Quickscreen (Otodynamics Ltd) and to confirm previous findings on transient otoacoustic emission (TEOAE) suppression in neonates. MOCS maturation was investigated in 46 neonates born at the Chaim Sheba Medical Center, Tel Hashomer, Israel, using Quickscreen. All neonates were normal with no family history of general or auditory disease and no risk factors for hearing impairment. MOCS function appears gradually in human pre-term neonates and is considered to reach maturity shortly after term birth. The clinical value of MOCS testing in specific populations of newborns at risk for hearing and/or brainstem function can be legitimately raised as activation of the MOCS clearly alters cochlear output. The present results can be interpreted to support the testing of infants at risk of developing abnormal MOCS function using a commercially available rapid TEOAE measurement system.

Acoustic Stimulation↗

PubMed2002

Changes in fat distribution (WHR) and body weight across the menstrual cycle.

The aim of the present study was to analyze changes of the body weight and waist-to-hip ratio during menstrual cycle, with special respect to changes around ovulation. 32 healthy young women ranging in age between 19 and 30 years (X = 23.5) were enrolled in the study. Beside a basal anthropometric investigation (stature, weight, BMI, waist circumference, hip circumference, fat percentage, waist to hip ratio) the probands were instructed to take body weight, waist and hip circumference and basal body temperature every morning by themselves over a whole cycle. Three proband groups according to cycle length (average, short and long) were defined and eight hormonal contraceptive users served as controls. It turned out that body weight increased only slightly during the second cycle half in all proband groups. A marked decrease of WHR around the time of ovulation was found in the proband group who exhibited average cycle length and a successful ovulation could be assumed. Evolutionary and physiological explanations are discussed.

Adaptation, Physiological↗

PubMed2001

Synthesis and biochemical investigation of scyphostatin analogues as inhibitors of neutral sphingomyelinase.

The sphingolipid ceramide is considered to be an important intracellular mediator. However, many aspects of its action and the role of several different ceramide generating sphingomyelinases are still unclear. Recently, we reported on the synthesis of the first selective irreversible inhibitor of the neutral sphingomyelinase (N-SMase), as well as the identification of Manumycin A and some of its analogues as irreversible inhibitors of N-SMase. For the development of pharmacologically interesting competitive inhibitors of N-SMase, structure-activity studies are essential. Herein we show the synthesis and enzymatic investigation of two scyphostatin analogues 3a and 3b, revealing the importance of the primary hydroxy group in compound 2 for N-SMase inhibition.

Amides↗

PubMed1999

Cerebral metabolism of the remote area after epilepsy surgery.

To clarify whether epilepsy surgery improves cerebral metabolism, pre- and postoperative positron emission tomography (PET) scans were performed, with special reference to hypometabolism outside the resected epileptogenic zones in nine patients (8 males, 1 female) with medically intractable complex partial seizures and multiple hypometabolic zones. Seven patients underwent unilateral anterior temporal lobectomy, one patient underwent selective amygdalohippocampectomy, and one patient underwent parieto-occipital cortical resection and anterior temporal lobectomy. PET scans were obtained at least 6 months after surgery. Eight patients became seizure-free, and one patient had fewer than three seizures per year. Four patients showed improved glucose metabolism in the formerly hypometabolic zones, which were remote to the surgical site and ipsilateral to the epileptogenic foci. Five patients, who showed bilateral temporal hypometabolism preoperatively, had contralateral temporal hypometabolism after surgery. The relative glucose uptake in four of these patients showed increased metabolism of the adjacent lobes ipsilateral to the surgical site. The lobes that showed increased glucose metabolism after surgery were mostly frontal. Hypometabolism is reversible in the ipsilateral remote area, and may be caused by inhibition via the intercortical pathway. Contralateral temporal hypometabolic zones that persist after surgery may be caused by a different mechanism, and neither indicate the presence of seizure foci nor affect the seizure outcome.

Adolescent↗

PubMed1997

Effects of hypothermia on cochlear micromechanical properties in humans.

The aim of the present experiment was to investigate the influence of hypothermia on transient evoked otoacoustic emissions (TEOAEs) in humans. Hypothermic alterations were brought about directly by cooling the cardiovascular system of young children during open heart bypass surgery. This condition caused TEOAE levels to decrease with a significant positive correlation between total and frequency band TEOAE amplitudes during cooling. TEOAEs were totally abolished at tympanic temperatures around 30 degrees C, without it being possible to find differences in TEOAE alteration among the frequency components. During rewarming, the changes reversed and TEOAEs returned to their initial prehypothermia status, although sometimes only partially. Despite large possible metabolic changes caused by this hypothermic condition at various levels, it is concluded that the motile properties of outer hair cells (OHCs), that are related to TEOAEs, are temperature-sensitive. The total suppression found in deep hypothermia (above 30 degrees C) could conceivably be attributable to a process involving a temperature-dependent energy source.

Auditory Threshold↗

PubMed1995

Seizure control and extent of mesial temporal resection.

Controversy exists about the extent of mesial temporal lobe resection that improves seizure control in patients with temporal lobe epilepsy. In this retrospective study, 70 patients with mesial temporal seizure activity (without evidence of tumor or vascular malformation) were surgically treated and followed for at least 2 years. The extent of mesial temporal resection was based on the findings of interictal and ictal discharges using depth electrodes, which were inserted preoperatively or intraoperatively by the orthogonal approach to the amygdaloid and hippocampal regions. Only the amygdala was resected along with the limited lateral neocortex if no epileptiform activity involved the hippocampus. The amount of hippocampal excision was determined by the extent of interictal seizure activity. The following groups became seizure free: all 8 patients with only amygdalar resection; 6 of 10 patients with amygdalar and < or = 1 cm hippocampal resection; 23 of 38 with 1-2 cm hippocampal removal, and 11 of 14 with > 2 cm hippocampal excision. In cases where there was no hippocampal resection, neuropsychological outcome compared favorably with controls. Our results suggest that although most patients with temporal lobe epilepsy require hippocampal resection of varying degrees, there is a subset in whom the amygdala may be the crucial element of a mesial temporal epileptogenic network. These patients can undergo a surgical resection sparing the hippocampus without compromising seizure outcome.

Adult↗

PubMed1995

Surgical management of epilepsy associated with developmental anomalies of the brain.

BACKGROUND: Disorders as the central nervous system forms during the pre-, peri-, or postnatal periods may cause developmental anomalies of the brain. Such maldevelopment, ranging from slight to severe disturbances, appears to be the mechanism for causing childhood seizure disorders. However, the surgical treatment of these lesions responsible for intractable partial seizures remains undefined. METHOD: Twenty-two patients (8 males, 14 females) with chronic seizure disorders associated with structural lesions of the brain related to developmental anomalies were surgically treated (1983 to 1990). Imaging studies, intraoperative findings, and histology showed 12 lesions in the temporal lobe, 1 in the frontal lobe, and 9 of multilobular involvement. All patients had preoperative prolonged electroencephalography with sphenoidal electrodes. Sixteen patients had intraoperative electrocorticography. All underwent craniotomy and total excision of the epileptogenic zone unless the speech or motor cortex was involved. RESULTS: Results of postoperative seizure control during the follow-up period (mean 5.5 years) were excellent (seizure-free) in 12 patients (including four with complete and eight with incomplete excision of the structural lesion), good in seven, fair in two, and poor in one. CONCLUSION: Seizure control is possible for patients with total excision of the epileptogenic zone, even including those with incomplete excision of a structural lesion caused by developmental brain anomalies.

Adolescent↗

PubMed1995

Lesionectomy versus electrophysiologically guided resection for temporal lobe tumors manifesting with complex partial seizures.

Complex partial seizures associated with tumors and other mass lesions are readily diagnosed by modern imaging techniques but their optimum surgical treatment remains unresolved. Lesionectomy has been reported to produce seizure outcomes equal to outcomes after resection that ablates the epileptogenic cortex with the lesion. However, some evidence suggests that when the lesion is in the temporal lobe, simple excision of the tumor or lesion more often fails to control seizures. After retrospectively reviewing the records of 30 patients with complex partial seizures and temporal lobe tumors who underwent surgical treatment at the University of Cincinnati hospitals (1985-1992), the authors divided them into two groups: Group A (16 patients) underwent lesionectomy only and Group B (14 patients) received surgical treatment for seizures with electroencephalographic delineation of the epileptogenic zone and resection of the lesion. Seizure control was best achieved in Group B patients with 13 (92.8%) seizure free at follow up (mean 52 months). Only three (18.8%) of the Group A patients became seizure free after lesionectomy at follow up (mean 33 months). In eight Group A patients, who underwent temporal lobectomy as a second procedure after lesionectomy failed to control seizures, five (62.5%) became seizure free. Group B patients had a longer duration of seizures and were more likely to have lesions smaller than 2.5 cm compared with Group A. Analysis of covariance demonstrated that the differences in outcome between the groups remained significant even with adjustment for the variation in duration of seizures (p = 0.0006) and size of tumor (p = 0.0001). Based on this study, the authors found that the probable relief from seizures caused by a temporal lobe lesion is greater if the region of epileptogenicity, usually the amygdalohippocampal complex, is resected along with the tumor in a temporal lobectomy.

Adolescent↗

PubMed1993

The shorthand vertical mattress stitch: evaluation of a new suture technique.

The shorthand vertical mattress suture is a new suture technique that provides the same amount of wound eversion in less time than the classic method. A randomized, prospective clinical trial was designed to test this hypothesis in a University-affiliated community hospital. Thirty patients who presented to the emergency department with traumatic lacerations requiring primary closure were eligible for this study. Wounds involving the hands, feet, or face were excluded. Patients meeting inclusion criteria were allocated randomly to have either shorthand or classic vertical mattress sutures. Wound information was collected on data sheets and included physician training level, repair time, number of knots placed, and degree of wound-edge eversion for each suture technique. Subjects were then asked to return to the emergency department in 7 to 10 days for wound assessment and suture removal. Thirty-six lacerations to the scalp, trunk, and extremities were evaluated. Shorthand vertical mattress sutures were used on 20 wounds (56%) and classic mattress sutures were used on 16 (44%) wounds. The shorthand stitch provided the same amount of wound eversion in half the time as the classic technique. No infectious complications, delayed wound healing, or cosmetic problems were observed with the shorthand technique. The shorthand vertical mattress stitch described is an efficient, alternative method for laceration repair without compromising wound eversion or cosmetic results.

Adult↗

PubMed1993

Seizure control after surgery on cerebral arteriovenous malformations.

Prediction of seizure control after surgery on cerebral arteriovenous malformations (AVM's) is currently unavailable. Between 1982 and 1990, 54 patients (30 males, 24 females) with epilepsy caused by a supratentorial cerebral AVM, without prior manifestation of intracranial hemorrhage, were surgically treated. Patients ranged in age from 11 to 59 years at seizure onset and from 13 to 70 years at surgery; the duration of seizure history ranged from several months to 27 years. The AVM's were located in the temporal (17 cases), frontal (15), parietal (10), rolandic (two), and occipital (two) regions; eight were multilobular. All patients underwent preoperative electroencephalography, intraoperative electrocorticography, and total excision of the AVM; additional cortical excision was performed in 25 cases. Remote seizure foci were identified in the ipsilateral mesial temporal structure in 10 patients with AVM's located in the lateral or posterior temporal lobe and in one with an AVM in the anterior frontal region. Two patients required a second operation to remove a remote seizure focus. Among the 54 patients, there were no operative deaths. After surgical treatment, two patients developed hemiparesis, one had contralateral paresthesia of limbs, two suffered partial visual field defects, and five experienced temporary speech disturbances. Postoperative results of seizure control during follow-up study (mean duration 4.8 years) were excellent in 38 patients (70.4%), good in 10 (18.5%), fair in five (9.3%), and poor in one (1.9%). Results appear to correlate with age at seizure onset, duration of seizures, location of lesions, and cortical excision. Excellent results were shown in 18 (60%) of 30 patients whose age at seizure onset was 30 years or less and in 20 (83.3%) of 24 whose age at seizure onset was greater than 30 years. Eighteen (90%) of 20 patients had excellent results when seizure duration was 1 year or less; only 25% of these underwent cortical excision. Twelve (71%) of the 17 temporal AVM's were associated with demonstrable epileptic foci. Secondary epileptogenesis can occur in humans with supratentorial cerebral AVM's; cortical excision in selected patients can improve the outcome of seizure control. Early surgery of a cerebral AVM in young patients presenting with epilepsy is an important consideration.

Adolescent↗

PubMed1993

The nursing plan: innovative home health documentation.

In order to improve documentation, a home health agency task force analyzed and revised its current nursing care plan system. Nurses in the five-county service area were involved in all aspects of the development. The system combines nursing interventions and patient outcomes with the overall physician plan to generate a totally computerized treatment plan.

Diffusion of Innovation↗

PubMed1992

A strategy for growth in home care. The clinical nurse specialist.

One of the most challenging problems that faces today's home healthcare providers is how to deliver quality care within the constraints imposed by changing population, limited resources, and regulations. This problem is particularly apparent to those who provide rural healthcare. Use of the clinical nurse specialist can promote quality care while facilitating the development and expansion of home health services.

Consultants↗

PubMed1992

Home care aide evaluation. Assuring competency & quality.

Supervision and evaluation of the direct care provider can be a costly and time-consuming activity. A comprehensive process to coordinate the various aspects of the home care aide evaluation is a creative solution for the efficient use of supervisory and staff time, paperwork reduction, and cost containment.

Caregivers↗

PubMed1991

Noise and medial olivocochlear system in humans.

Evoked otoacoustic emissions (EOAE) and sound evoked olivocochlear feedback were performed in 200 subjects (noise induced hearing loss (NIHL), n = 109; sensori-neural hearing loss (SNHL), n = 91). Intensity of EOAE is greater in NIHL than in SNHL. This result does not seem to be related to the medial olivocochlear system since sound olivocochlear feedback was not significantly different between the two groups. No correlations were seen between temporary threshold shifts (TTS) and sound-olivocochlear feedback in the NIHL group.

Acoustic Stimulation↗

PubMed1990

Blood lactate during constant-load exercise at aerobic and anaerobic thresholds.

Venous blood lactate concentrations [1ab] were measured every 30 s in five athletes performing prolonged exercise at three constant intensities: the aerobic threshold (Thaer), the anaerobic threshold (Than) and at a work rate (IWR) intermediate between Thaer and Than. Measurements of oxygen consumption (VO2) and heart rate (HR) were made every min. Most of the subjects maintained constant intensity exercise for 45 min at Thaer and IWR, but at Than none could exercise for more than 30 min. Relationships between variations in [1ab] and concomitant changes in VO2 or HR were not statistically significant. Depending on the exercise intensity (Thaer, IWR, or Than) several different patterns of change in [1ab] have been identified. Subjects did not necessarily show the same pattern at comparable exercise intensities. Averaging [1ab] as a function of relative exercise intensity masked spatial and temporal characteristics of individual curves so that a common pattern could not be discerned at any of the three exercise levels studied. The differences among the subjects are better described on individual [1ab] curves when sampling has been made at time intervals sufficiently small to resolve individual characteristics.

Aerobiosis↗

PubMed1990

Comparative lactate kinetics after short and prolonged submaximal exercise.

Arterial blood lactate concentrations were determined in two groups of eleven males before, during and after near 2 W.kg body mass-1 bicycle exercise. One group of subjects cycled for 3 min, whereas the second group exercised for 60 min. All the lactate curves during recovery could be fitted to a bi-exponential time function consisting of a rapidly increasing and a slowly decreasing component. This typical evolution pattern indicates that the two-compartment model which has been proposed to represent the movements of lactate after short exercise applies also to recovery from prolonged exercise. Lengthening exercise duration decreased (respectively 10% and 28%) the value of both velocity constants of the fits to the lactate recovery curves, with the difference (28%) being statistically significant for the velocity constant describing the slowly decreasing part of the curves. This result indicates that extending exercise from 3 to 60 min impairs the ability to remove lactate after the exercise.

Adult↗

PubMed1990

Lactate removal ability and graded exercise in humans.

Venous lactate concentrations of nine athletes were recorded every 5 s before, during, and after graded exercise beginning at a work rate of 0 W with an increase of 50 W every 4th min. The continuous model proposed by Hughson et al. (J. Appl. Physiol. 62: 1975-1981, 1987) was well fitted with the individual blood lactate concentration vs. work rate curves obtained during exercise. Time courses of lactate concentrations during recovery were accurately described by a sum of two exponential functions. Significant direct linear relationships were found between the velocity constant (gamma 2 nu) of the slowly decreasing exponential term of the recovery curves and the times into the exercise when a lactate concentration of 2.5 mmol/l was reached. There was a significant inverse correlation between gamma 2 nu and the rate of lactate increase during the last step of the exercise. In terms of the functional meaning given to gamma 2 nu, these relationships indicate that the shift to higher work rates of the increase of the blood lactate concentration during graded exercise in fit or trained athletes, when compared with less fit or untrained ones, is associated with a higher ability to remove lactate during the recovery. The results suggest that the lactate removal ability plays an important role in the evolution pattern of blood lactate concentrations during graded exercise.

Adolescent↗

PubMed1990

Age-related changes in evoked otoacoustic emissions.

Outer hair cells of the organ of Corti play an important part in the genesis of evoked otoacoustic emissions (EOAEs), which are related to cochlear biomechanics. The aim of this study was to investigate the age factor in relation to EOAEs in 166 ears of subjects between 6 weeks and 83 years of age. The results show that when age increases, the presence of EOAEs by age group and the frequency peak in spectral analysis decrease, and EOAE threshold increases. Thus, there is an effect of age upon EOAEs, and it seems linked with alteration of cochlear biomechanics and/or hair cell loss. Such an effect has to be taken into consideration when EOAEs are used in clinical applications, and limits the use of EOAEs in older subjects.

Adolescent↗