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Biomedical subjects

H J Landy

Publications and source records attributed to H J Landy.

At least 37 records · Page 2Linked to original sources
PubMed1994

Retreatment of intracranial gliomas.

Although intracranial gliomas carry a poor long-term prognosis, retreatment at the time of tumor progression may prolong survival and maintain or improve the quality of life. Thirty-three patients who underwent retreatment with surgery, radiotherapy, and chemotherapy were reviewed retrospectively. Median survival after initiation of retreatment was 8 months for glioblastoma, 13 months for anaplastic astrocytoma, 22 months for astrocytoma, and 47 months for oligodendroglioma/mixed glioma. Survival was significantly better for younger patients and for those with better functional status. One third of patients were neurologically improved by surgery. Surgical morbidity was minimal (2.1%); there was no surgical mortality. Chemotherapy and radiotherapy produced expected adverse reactions. Retreatment of intracranial gliomas carries acceptable risk and is beneficial in selected patients. Decisions regarding retreatment must be carefully individualized with consideration of the quality of life and the wishes of the patient and family.

Adult↗
PubMed1994

Abdominal rescue using the vacuum extractor after entrapment of the aftercoming head.

BACKGROUND: Fetal replacement into the uterus for ceasarean delivery after failed vaginal delivery has been reported for both vertex and breech presentations. Although an option, this mode of delivery frequently is the last maneuver to deliver a viable infant after other methods to allow vaginal delivery have failed. We report the adjunctive use of a vacuum extractor to facilitate abdominal rescue after entrapment of the aftercoming head during an attempted vaginal breech delivery. CASE: A multiparous woman presented at term with two fetal feet bulging through the membranes at the introitus. During vaginal breech delivery, the aftercoming head became entrapped. Unsuccessful maneuvers to facilitate descent included Dührssen incisions, the Mauriceau maneuver, placement of Piper forceps, and halothane administration. At emergency ceasarean delivery, the infant was pushed upward from below, and rapid, successful delivery of a 2530-g neonate was accomplished with assistance by a vacuum extractor. Apgar scores were 3, 6, and 7 at 1, 5, and 10 minutes, respectively. Umbilical artery blood gas revealed a pH of 7.18 and base excess of -6. A head sonogram and electroencephalogram were normal. Both mother and infant were discharged without complications. CONCLUSION: After entrapment of the aftercoming head during attempted vaginal breech delivery, use of the vacuum extractor may expedite the abdominal rescue and ceasarean.

Adult↗
PubMed1994

Pulmonary artery sarcoma in a pregnant woman: report of a case.

BACKGROUND: We report the case of a 23-year-old pregnant woman with hemoptysis, cor pulmonale, and pulmonary artery sarcoma. The physiologic changes of pregnancy may have unmasked the pulmonary lesion. CASE: A 23-year-old woman presented at 28 weeks' gestation with acute onset of hemoptysis and dyspnea. A hilar mass was noted and a pulmonary embolus was diagnosed. Biopsy of the hilar mass was nondiagnostic. Emergency cesarean delivery was performed because of rapid clinical deterioration and an acute loss of fetal heart tones. Both mother and infant died. Autopsy of the mother demonstrated a large pulmonary artery sarcoma with metastases to both lungs and terminal bacterial bronchopneumonia. CONCLUSION: Hemodynamic changes of pregnancy may have unmasked the pulmonary lesion in this case. Pulmonary artery sarcoma is an extremely rare tumor.

Adult↗
PubMed1993

Comprehensive evaluation of left hemisphere type I schizencephaly.

We report the neuropsychological, magnetic resonance imaging, electroencephalographic telemetry, and sodium amytal test findings of a 32-year-old, left-handed man with unilateral left hemisphere type I schizencephaly. The patient was referred for treatment of medically refractory left temporal complex partial seizures that developed at age 26 years. Sodium amytal testing revealed complete incorporation of speech and language function by the right hemisphere. Detailed neuropsychological evaluation indicated average to above-average performance on all measures of language skills, judgment and reasoning, visuospatial abilities, and memory function. This case demonstrates that extensive but lateralized neuronal migration disorders can be associated with complete reorganization and full recovery of function by the contralateral hemisphere. Furthermore, this case supports the view that the degree of recovery is greatest when compensatory mechanisms are activated antenatally.

Adult↗
PubMed1993

Effects of vagal nerve stimulation on laryngeal function.

Functional electrical stimulation is a developing methodology that shows significant potential in the management of peripheral neuromuscular deficits. Potential applications in the head and neck area, including control of bilateral vocal fold paralysis and spasmodic dysphonia, have recently been explored. Despite promising early results, very little is known about the mechanisms of action or the long-term effects of electrical stimulation on human laryngeal function. Recent development of implantable vagal nerve stimulators as a method to control intractable seizures in individuals who have not responded to medication provides a unique opportunity to study its effect on the normal human larynx. Laryngeal and vocal function testing was studied on five individuals who had undergone vagal nerve stimulator implants for intractable seizures. Consistent abduction/adduction of the left vocal fold was achieved at 20 and 40 Hz, respectively. Higher levels of electrical stimulation produced hemispasm of the larynx. Results were consistent with studies in the literature of recurrent laryngeal nerve stimulation in animal and human models. The vagus nerve provides relatively easy access for implantation of electrodes to provide electrical stimulation to the muscles of the larynx. Vagal nerve stimulation may prove efficacious in the treatment of movement disorders of the larynx; further study is needed.

Adult↗
PubMed1993

Vagus nerve stimulation for complex partial seizures: surgical technique, safety, and efficacy.

Electrical stimulation of the vagus nerve has shown efficacy in controlling seizures in experimental models, and early clinical trials have suggested possible benefit in humans. Eleven patients with complex partial seizures were subjected to implantation of vagus nerve stimulators. Electrode contacts embedded in silicone rubber spirals were placed on the left vagus nerve in the low cervical area. A transcutaneously programmable stimulator module was placed in an infraclavicular subcutaneous pocket and connected to the electrode. One patient required replacement of the system due to electrode fracture. Another patient developed delayed ipsilateral vocal-cord paralysis; the technique was then modified to allow more tolerance for postoperative nerve edema. A third patient showed asymptomatic vocal-cord paresis on immediate postoperative laryngoscopy. Vagus nerve stimulation produces transient vocal-cord dysfunction while the current is on. Nine patients were randomly assigned to receive either high- or low-current stimulation, and seizure frequency was recorded. The high-current stimulation group showed a median reduction in seizure frequency of 27.7% compared to the preimplantation baseline, while the low-current stimulation group showed a median increase of 6.3%. This difference approached statistical significance. The entire population then received maximally tolerable stimulation. The high-current stimulation group showed a further 14.3% reduction, while the low-current stimulation group showed a 25.4% reduction compared to the blinded period. The efficacy of vagus nerve stimulation seemed to depend on stimulus parameters, and a cumulative effect was evident. These results are encouraging, and further study of this modality as an adjunct treatment for epilepsy is warranted.

Adult↗
PubMed1993

A non-hemorrhagic manifestation of vasa previa: a clinicopathologic case report.

BACKGROUND: The rare entity of vasa previa occurs when fetal vessels lying between the amniotic and chorionic membranes cross the cervical os. This report presents a case that was associated with vessel compression and concomitant adverse effects on fetal hemodynamics. CASE: A 23-year-old nulliparous woman at 36 weeks' gestation developed persistent, progressive severe variable decelerations several hours after spontaneous rupture of the membranes, resulting in a decision to perform a cesarean. At delivery, fetal vessels were noted in the membranes near the cervical os, leading into a marginally inserted cord. The decelerations were attributed to compression of the unprotected umbilical arteries by the fetal head. CONCLUSION: Vasa previa often results in fetal death and may be associated with fetal hemorrhage, but lack of bleeding does not exclude the existence of vasa previa. Altered fetal hemodynamics from varying degrees of vessel compression by the presenting part during labor may result in hypoxia and acidosis. A high index of suspicion is necessary to make the diagnosis and institute proper, timely management.

Adult↗
PubMed1992

Temporal lobectomy for seizures associated with unilateral schizencephaly.

Schizencephaly is characterized by unilateral or bilateral cerebral clefts associated with neurologic deficits and epilepsy. Most commonly schizencephaly is attributed to abnormal neuronal migration, and these malformations are well visualized by current neuroimaging techniques. This report describes a patient with unilateral schizencephaly and poorly controlled complex partial seizures who was found to have a temporal lobe seizure focus; anterior temporal lobectomy produced nearly complete control of the seizures. Despite the extensive malformation, relatively restricted resection was of significant benefit. The principles of seizure focus localization and resection are applicable to the management of patients with schizencephaly.

Adult↗
PubMed1992

Computer controlled stereotaxic radiotherapy system.

A computer-controlled stereotaxic radiotherapy system based on a low-frequency magnetic field technology integrated with a single fixation point stereotaxic guide has been designed and instituted. The magnetic field, generated in space by a special field source located in the accelerator gantry, is digitized in real time by a field sensor that is six degree-of-freedom measurement device. As this sensor is an integral part of the patient stereotaxic halo, the patient position (x, y, z) and orientation (azimuth, elevation, roll) within the accelerator frame of reference are always known. Six parameters--three coordinates and three Euler space angles--are continuously transmitted to a computer where they are analyzed and compared with the stereotaxic parameters of the target point. Hence, the system facilitates rapid and accurate patient set-up for stereotaxic treatment as well as monitoring of patient during the subsequent irradiation session. The stereotaxic system has been developed to promote the integration of diagnostic and therapeutic procedures, with the specific aim of integrating CT and/or MR aided tumor localization and long term (4- to 7-week) fractionated radiotherapy of small intracranial and ocular lesions.

Electromagnetic Phenomena↗
PubMed1992

Obstetric performance in patients with the lupus anticoagulant and/or anticardiolipin antibodies.

Antiphospholipid antibodies, notably the lupus anticoagulant and anticardiolipin antibodies, are associated with recurrent fetal wastage, pregnancy complications, and thromboses. Aggressive medical treatment using aspirin and steroids has been recommended. Fifty-one patients with antiphospholipid antibodies, only four with underlying connective tissue disorders, were followed through 53 pregnancies. Aggressive therapy was used in 33 pregnancies, 90.9% of which resulted in successful obstetric outcomes, a highly statistically significant difference compared with previous pregnancies in the same patients. Most pregnancies among nine patients receiving single-agent therapy (aspirin or steroids alone) and eight patients not treated also had successful outcomes. A 48.6% complication rate was found in association with therapy, particularly gestational diabetes mellitus. There was no statistical correlation between dose or duration of therapy and development of treatment-related complications. Although a subgroup of patients with antiphospholipid antibodies will benefit from aggressive therapy, the high complication rate warrants close observation.

Adrenal Cortex Hormones↗
PubMed1991

Intraoperative ultrasonography and cortical mapping for removal of deep cerebral tumors.

Stereotactic biopsies of brain tumors have recently become frequent, but prognosis may be improved by more aggressive surgery for primary and metastatic tumors. This report describes techniques for debulking and removal of deep cerebral tumors that are commonly subjected only to biopsy. With the use of intraoperative cranial ultrasonography and cortical mapping, five gliomas were debulked and three metastatic lesions were grossly totally removed. No complications occurred, and the patients with metastatic disease had striking neurologic improvement. Deep cerebral tumors may be treated aggressively with appropriate surgical techniques in selected patients.

Adolescent↗
PubMed1990

Small-field stereotactic external-beam radiation therapy of intracranial lesions: fractionated treatment with a fixed-halo immobilization device.

Current techniques of stereotactic, small-field, external-beam irradiation with linear accelerators require treatment with a single fraction or only a few fractions of radiation with large single doses per fraction. Using a radiolucent halo that remained affixed to the cranium with skin-piercing screws, the authors treated 24 patients with a multifraction technique for benign and malignant brain lesions. The objective of this study was to ascertain the feasibility of maintaining the halo in place for a prolonged, multifraction course of treatment, not to assess treatment efficacy. The halo was affixed for multifraction treatments lasting 19-58 days (mean, 38.7 days; median, 40.0 days) and delivered in 16-31 fractions (mean, 24.9 fractions; median, 25.5 fractions). Two of 24 patients experienced superficial skin infection at the site of fixation, but no other significant acute or chronic toxicity attributable to the stereotactic halo was observed. The authors conclude that stereotactic, small-field, precision irradiation can be accomplished with multiple fractions as well as with a single fraction.

Adolescent↗
PubMed1989

Herpes simplex virus.

Genital herpes simplex infection remains an infectious disease having widespread consequences for both adult and neonatal populations. Physicians must understand that the psychologic impact of genital HSV infections frequently is more disabling than the physical manifestations. Sensitivity, compassion, and support are necessary from members of the medical community, and psychologic counseling may help patients cope with HSV and all its implications. Similarly, physicians must downplay the hysteria that has been associated with herpesvirus infections, emerging as a result of intense media coverage in the 1970s and 1980s. Minimizing the number of cases of neonatal herpes through identification of infected women during parturition continues to be important. Recent guidelines suggest a rationale for the management of women at risk for genital HSV. Nevertheless, until newer immunologic and serologic techniques become clinically reliable and allow a correct and rapid diagnosis of herpes simplex infection, identification of the infected woman in labor must be made using detailed clinical history, physical examination, and viral culture.

Acyclovir↗
PubMed1988

Acardiac fetus in a triplet pregnancy.

The acardiac monster represents one of the most severe but rare congenital anomalies. It occurs only in multiple gestations associated with vascular anastomoses between the affected fetus and its co-twin. The prenatal diagnosis of an acardiac fetus must be suspected in any multiple gestation in which cardiac activity cannot be documented sonographically in a growing fetus. We report an acardiac fetus occurring in a spontaneously conceived triplet pregnancy. A review of the literature, including pathogenetic theories and sonographic reports, is discussed.

Abnormalities, Severe Teratoid↗
PubMed1988

MR characterization of brain and brain tumor response to radiotherapy.

This paper describes our experience in using the T1 and T2 relaxation times for quantitative evaluation of brain and brain tumor response to radiation therapy. Twenty-two computed T1 and 22 computed T2 images were obtained from 66 routine inversion-recovery and spin-echo magnetic resonance (MR) brain scans. The relaxation times of the brain tissues, determined from the computed images, were examined as a function of the absorbed dose. Statistical evaluation of the results showed no significant difference between the relaxation times of irradiated and not irradiated tissues, including tumor and normal white matter. Influence of the magnetic field strength and imaging techniques on the computed T1 and T2 values was confirmed. We conclude that the relaxation time values, as obtained today using conventional MR scanner and standard software, are not specific enough to warrant a correct assessment of the acute radiation effect on the brain tissues.

Adolescent↗