Biomedical subjects

M Lee

Publications and source records attributed to M Lee.

At least 595 records · Page 33Linked to original sources

PubMed1995

Immunological factors and risk of infection in plateau phase myeloma.

AIMS: A series of patients with myeloma were investigated to assess whether immunological risk factors predisposing to serious infection could be identified. METHODS: Patients (n = 102) with predominantly plateau phase myeloma were monitored prospectively for infections. Immunological parameters including total non-paraprotein immunoglobulins and specific antibody titres were measured in all patients and compared with a control population of healthy individuals of a similar age; response to immunisation with Pneumovax II, tetanus and diphtheria toxoids and IgG subclasses were measured in a subgroup of 41 patients. Other characteristics investigated for any association with infection included age, sex, paraprotein type, disease stage, and chemotherapy. RESULTS: Specific antibody titres to pneumococcal capsular polysaccharides and tetanus and diphtheria toxoids were significantly reduced compared with the control population. Low antipneumococcal and anti Escherichia coli titres correlated with risk of serious infection and low anti-pneumococcal titres with severity of non-paraprotein immunosuppression. In 41 immunised patients responses to Pneumovax II, tetanus and diphtheria toxoids were poor; IgG subclass levels were significantly reduced and a poor IgG response to Pneumovax II immunisation was associated with an increased risk of septicaemia and low IgG2 levels. The overall serious infection rate was 0.92 infections per patient year and was four times higher during periods of active disease (1.90) compared with plateau phase myeloma (0.49). The predominant site of infection was the respiratory tract. Clinical and laboratory parameters showed only male sex and reduced non-paraprotein IgG and IgA levels to be significantly associated with at least one serious infection. CONCLUSIONS: A subgroup of patients with myeloma with poor IgG responses to exogenous antigens, who are at increased risk of serious infection, can be identified and may benefit from replacement immunoglobulin therapy to reduce the risk of infection.

Aged↗

PubMed1995

Acquired Chiari-I malformation and hydromyelia secondary to a giant craniopharyngioma.

Hydromyelia, or hydrosyringomyelia is frequently associated with the Chiari I malformation of the cerebellar tonsils. Descent of the cerebellar tonsils is considered a congenital anomaly with a few reports of 'acquired' Chiari I malformation. We report a patient with a giant craniopharyngioma and hydrocephalus who at presentation had a concomitant Chiari I malformation and hydromyelia. The patient underwent gross total resection of the tumor and, with no further treatment, demonstrated spontaneous resolution of the Chiari I malformation and hydromyelia during the postoperative period. This suggests that the Chiari I malformation and the resulting hydromyelia were 'acquired', and were caused by an intracranial mass effect. This provides further evidence for an associative mechanism of cerebellar tonsillar descent and the development of hydromyelia.

Arnold-Chiari Malformation↗

PubMed1995

Complications of fourth-ventricular shunts.

Fourth-ventricular shunting is commonly used to treat symptomatic posterior fossa cysts of the Dandy-Walker malformation and trapped fourth ventricle. Although the benefits of this procedure have been widely reported, there is a paucity of data on the pitfalls of posterior fossa shunting in the neurosurgical literature. During the 4-year period from July 1989 to June 1993, we placed fourth-ventricular shunts in 12 patients. Remarkably, 5 patients suffered complications related to posterior fossa catheter placement (42% rate). Three of these patients developed new cranial nerve dysfunction caused by direct injury to the floor of the fourth ventricle, 1 patient suffered an intracystic hemorrhage and acute shunt malfunction, and 1 patient had the catheter tip in the brainstem on postoperative studies without new neurological deficit. We conclude that placement of fourth-ventricular shunts can be fraught with complications which we believe is related to technique. We propose that altering the trajectory of the ventricular catheter from our usual midline technique to a more lateral position will lessen the chances for injury to the floor of the fourth ventricle. In this manner we hope to decrease our incidence of complications for this procedure.

Adult↗

PubMed1995

Fibrinogen and factor VIII, but not factor VII, are associated with measures of subclinical cardiovascular disease in the elderly. Results from The Cardiovascular Health Study.

No studies have examined the associations of coagulation factor levels with measures of subclinical cardiovascular disease (CVD) in the elderly. The Cardiovascular Health Study (CHS) is a prospective, population-based cohort study of CVD in persons older than 65 years. At the baseline examination, we measured fibrinogen, factor VII, and factor VIII levels in 5024 of the 5201 participants of the CHS and examined the associations of these coagulation factors with measures of subclinical CVD in a cross-sectional analysis. Subclinical CVD measures were based on electrocardiography, carotid ultrasonography, echocardiography, and ankle-arm blood pressure measurements (AAI). For analyses, we used the full cohort as well as two mutually exclusive subgroups: those with prevalent clinical CVD at baseline and those without. Fibrinogen and to a lesser extent factor VIII showed positive associations with a variety of subclinical CVD measures. In age-adjusted analyses, fibrinogen and factor VIII were significantly associated with 8 of 10 measures. In multivariate analyses, fibrinogen was significantly associated with carotid artery stenosis, internal (but not common) carotid artery wall thickness, and AAI. Factor VIII was associated with abnormal wall motion and AAI in the full cohort only. Factor VII was not consistently associated with subclinical disease measures. In bivariate analyses that included data from all three groups, there were 5 positive subclinical disease associations and 5 negative associations for factor VII. In multivariate analyses, there were no significant associations between factor VII and subclinical CVD in the full cohort or in either subgroup. We conclude that in these cross-sectional analyses, fibrinogen and to a lesser extent factor VIII are associated with subclinical CVD in the elderly, even in those without symptoms or a history of clinical CVD. Factor VII, however, was not associated with subclinical CVD in the elderly.

Aged↗

PubMed1995

Individual social skills training and co-worker training for supported employees with dual sensory impairment. Two case examples.

Two case studies examined the efficacy of two social enhancement procedures--individual social skills training (SST) and co-worker intervention for two employees with dual sensory impairment who were working in competitive employment settings but who were socially isolated from contact with their nondisabled co-workers. A variety of measures, including direct behavioral observations and social validation ratings, examined social interaction and the formation of social networks in the workplace. Results showed that the number and duration of social interactions improved with each of the social enhancement programs. Social validation data and anecdotal reports indicated that the employees with disabilities became more socially competent, interactive, and included in the social network of the workplace. Interestingly, SST followed by co-worker training resulted in greater increases in social responding as compared to co-worker training followed by SST.

Adult↗

PubMed1995

Elevation of microtubule-associated protein tau in the cerebrospinal fluid of patients with Alzheimer's disease.

Currently, there is no biochemical marker clinically available to test for the presence of Alzheimer's disease (AD). Recent studies suggest that the core component of AD-associated neurofibrillary tangles (NFTs), the microtubule-associated protein tau, might be present in CSF. This study focuses on establishing both the presence of tau in CSF and its potential utility in the diagnosis of AD. We obtained CSF from 181 individuals; 71 of these were diagnosed as having probable AD by NINCDS-ADRDA criteria. The remaining 110 individuals were divided into three groups: (1) age-matched demented non-AD patients (n = 25), (2) neurologic controls (n = 59), and (3) other controls (n = 26). We developed a sensitive enzyme-linked immunosorbent tau assay using monoclonal antibodies prepared against recombinant human tau. We confirmed specificity of the antibodies by a combination of immunoprecipitation and immunoblot results. By this assay we measured that the AD population has a mean level of tau 50% greater than the non-AD dementia patients. Comparing AD patients with all other groups, the difference in tau levels as analyzed by one-way ANOVA is highly statistically significant (p < 0.001). Postmortem analysis of two AD patients with high levels of CSF tau revealed a high density of NFTs in the hippocampus. There was no significant correlation between tau and age in the non-AD groups. This study suggests that CSF tau is elevated in AD and might be a useful aid in antemortem diagnosis.

Aged↗

PubMed1995

Modern management of spinal tuberculosis.

The resurgence of pulmonary tuberculosis in the United States has been paralleled by a concomitant rise in tuberculosis of the spine (Pott's disease). The appearance of drug-resistant strains of tuberculosis, infection in large numbers of immunocompromised hosts, newer imaging modalities, and the development of more effective spinal reconstruction techniques have raised important issues regarding the management of Pott's disease. In spite of this, there has been little published recently on the modern management of Pott's disease in developed countries. We report our experience with the management of 20 patients with Pott's disease in the past 5 years, 16 of whom were admitted during the last 18 months of this retrospective study. The mean patient age was 49 years. Sixteen (80%) were men. Nineteen (95%) had a positive tuberculin skin test, and 13 (65%) had pulmonary tuberculosis. Symptoms consisted of spinal pain, weakness, sensory complaints, and flank mass in order of decreasing frequency. Ten patients were neurologically intact; the remainder had motor deficits of variable severity. The thoracic spine was involved in 13 patients, the lumbar spine was involved in 4, the cervical spine was involved in 2, and the thoracolumbar spine was involved in 1. Spinal deformity was present in 11 patients, spinal epidural compression was present in 13, and a paraspinal mass was present in 18. Operative indications included motor deficits, spinal deformity, nondiagnostic computer tomographic-guided needle biopsy, and noncompliance with, or lack of, response to medical therapy. Eleven patients underwent operations. Six patients had vertebrectomy and bone grafting with posterior instrumentation when indicated; three had laminectomy, debridement, and abscess drainage; one had laminectomy and posterior instrumentation; and one had paraspinal abscess drainage. Two patients have died; the remainder have been monitored for at least 1 year and are neurologically improved or normal without residual infection. The average angulation decreased from 31 to 24 degrees by the follow-up examination. In selected patients, early operative treatment with instrumentation, when indicated, minimizes neurological deterioration and spinal deformity, allows early ambulation, and results in excellent neurological outcome.

Adult↗

PubMed1995

Brain stem mapping: neurophysiological localization of motor nuclei on the floor of the fourth ventricle.

We have improved upon a brain stem mapping technique that can be used to locate cranial motor nuclei on the floor of the fourth ventricle. This technique helped to intraoperatively locate the facial colliculus and the motor nuclei of cranial nerves IX/X and XII in 14 patients undergoing removal of brain stem tumors. The motor nuclei of these cranial nerves are usually located relative to specific anatomic landmarks on the ventricular floor. These landmarks were not evident in most patients studied because of the distorting effects of the tumor. Different points of the floor of the fourth ventricle were electrically stimulated while electromyographic responses were recorded with electrodes inserted in the orbicularis oculi and orbicularis oris muscles, the lateral posterior pharyngeal wall, and the intrinsic muscles of tongue. Mapping was performed before and after tumor resection. The technique was found to be useful for locating cranial motor nuclei before tumor resection. It enabled surgeons to avoid damaging the nuclei when entering the brain stem. This technique, however, has certain limitations. Because this is a mapping technique, not a monitoring technique, continuous monitoring during tumor resection was unavailable. Also, the presence of a muscle response after tumor resection did not always indicate preservation of immediate postoperative function (7 days after surgery) because damage to the corticobulbar tract and/or the underlying neural circuitry was not detectable by mapping. Further research is needed to determine the point of stimulation in the functional motor circuitry and the relationship between intraoperative recordings and postoperative function in the long term.

Adolescent↗

PubMed1995

Induction of 73-kDa and 90-kDa heat shock protein expression in HL60 cells during differentiation.

We investigated the expression of heat shock proteins HSP73 and HSP90 in human promyelocytic line HL60 during their differentiation induced by phorbor ester and all trans retinoic acid (ATRA). Polyclonal antibodies which had been raised against HSPs purified from bovine brains were used to detect human HSPs. Semiquantitation of HSPs was performed by immunoblotting. Induction of monocytoid and granulocytoid differentiation with phorbor ester and ATRA was accompanied by increased expression of HSP73 and HSP90 with distinct kinetics. Increased expression of both HSPs was confirmed by immunocytochemical studies. Our results suggest that HSP73 and HSP90 may be involved in differentiation of HL60 cells.

Animals↗

PubMed1995

Successful hematopoietic reconstitution with granulocyte colony-stimulating factor in a patient with hypoplastic acute myelogenous leukemia.

We describe a 68-year-old Japanese male with hypoplastic acute myelogenous leukemia (AML) who achieved complete hematological reconstitution following granulocyte colony-stimulating factor (G-CSF) administration. The patient had pancytopenia and the bone marrow was hypocellular with 19 to 36% peroxidase-positive blasts without morphological abnormalities suggestive of myelodysplasia. After receiving G-CSF as a supportive therapy for pneumonia, the blood count became normal and the bone marrow was normocellular with less than 5% of blasts. Without subsequent chemotherapy, he relapsed as a form of overt leukemia and died of pneumonia. Chemotherapy may be necessary to maintain remission in hypoplastic AML after hematopoietic reconstitution by G-CSF.

Aged↗

PubMed1995

Assessment of training-induced autonomic adaptations in athletes with spectral analysis of cardiovascular variability signals.

The purpose of this study was to assess the adaptive effects of endurance training on autonomic functions in athletes with spectral analysis of cardiovascular variability signals. Continuous ECG, arterial blood pressure (ABP), and respiratory signals were recorded from 15 athletes (VO2max > 55 ml/(kg.min)) and 15 nonathletes (VO2max < 45 ml/(kg.min)) in the sitting position during controlled respiration (tidal volume 700 ml and 15 cycles/min). The autonomic functions were assessed by the normalized low-frequency power (LF power: 0.06-0.14 Hz) and high-frequency power (HF power: the region of the respiratory frequency based on respiratory spectrum) obtained from the autospectra of the RR interval, systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) variability signals. The spontaneous baroreflex sensitivity (BRS) was evaluated by the moduli, BRSLF and BRSHF, of the transfer function between the RR interval and SAP variability in LF and HF bands. The resting HR in athletes was significantly lower than that in nonathletes. In the case of RR interval spectra, the HF power was significantly higher in athletes than in nonathletes, whereas the LF power was significantly lower in athletes than in nonahtletes. These differences might reflect an alteration of sympathovagal interaction with a predominance of parasympathetic activity. However, there was no significant difference in the LF power of SAP and DAP autospectra, reflecting the sympathetic vascular control. The BRSLF and BRSHF were significantly higher in athletes as compared with nonathletes. These results indicate that endurance training induces autonomic imbalance (i.e., the enhanced vagal activities/the attenuated sympathetic tone), which may in part contribute to the resting bradycardia and an increase in the spontaneous BRS in athletes.

Adaptation, Physiological↗

PubMed1995

Beta cell-specific expression of retroviral mRNAs and group-specific antigen and the development of beta cell-specific autoimmunity in non-obese diabetic mice.

Non-obese diabetic (NOD) mice spontaneously develop autoimmune type 1 diabetes. Earlier studies have shown that retroviruses appear to be associated with the development of the disease in these animals. This investigation was initiated to determine whether any retroviral genes are specifically expressed in pancreatic beta cells from NOD mice, in contrast to their non-diabetic, parental strain, ICR mice. Host chromosomal DNAs from pancreatic islets, kidneys, hearts, and stomachs of NOD and ICR mice contained an equal amount of A-type retroviral genome (DNA); however, A-type retroviral gag, pol, and env mRNAs were detected in only the pancreatic islets from NOD mice. Furthermore, group-specific retroviral antigen (p73 of A-type--gag gene product) was found by immunofluorescent staining using anti-p73 antibody in only pancreatic beta cells from NOD mice. On the basis of these observations, we suggest that tissue and strain differences in transcription of the retroviral genome and beta cell-specific expression of A-type retroviral group-specific antigen p73 in NOD mice may be involved in the initiation of beta cell-specific autoimmunity leading to type 1 diabetes in these animals.

Animals↗

PubMed1995

Intramedullary spinal cord lipomas.

Spinal cord lipomas are rare lesions, accounting for approximately 1% of all spinal cord tumors. True intramedullary spinal cord lipomas are extremely rare and are represented in the literature as scattered, single case reports. The authors present a series of six patients with intramedullary spinal cord lipomas managed at our institution from July, 1985 to July, 1993. The patients' ages ranged from 8 to 45 years. Four patients presented with newly diagnosed tumors and two had undergone previous surgery. Patients usually presented with long histories of disability followed by rapid progression of their symptoms. Most patients were in poor neurological condition on presentation. Presenting symptoms included spinal pain, dysesthetic sensory changes, gait difficulties, weakness, and incontinence. Three patients had cervical tumors, two had cervicothoracic tumors, and one patient had a thoracic tumor. Diagnostic studies, including magnetic resonance imaging, were obtained in all patients. No patient exhibited any form of spinal dysraphism or had a dural defect. All patients underwent decompressive, subtotal resections of 40% to 70% of their lesions. Follow-up times ranged from 12 to 96 months. All patients had resolution of their pain, but they generally showed no neurological improvement. As of their most recent follow-up visit, none of the patients was neurologically normal; three can function independently, although with neurological deficits. The other three patients cannot function independently and have severe neurological deficits. The authors conclude that patients with intramedullary spinal cord lipoma who present with significant neurological compromise have a very poor prognosis with regard to neurological function and generally show no improvement with surgical resection.

Adolescent↗

PubMed1995

Immunoblot analysis for serum antibodies to Pneumocystis carinii by age and intensity of infection in rats.

The present study aims to observe changing patterns of serum antibody to Pneumocystis carinii in normal rats of different ages and in immunosuppressed rats. The serum IgG antibody was observed by immunoblotting with crude antigen of P. carinii which were purified from the lungs of infected rats. The crude antigens separated in SDS-PAGE resolved more than 20 protein bands from 20 to 200 kDa. Of them, 40-45, 50-55, 116 and 200 kDa bands were major antigens of P. carinii. Most of the normal rats of up to 4 weeks had the antibodies reacting the 4 bands, but none of 8-week-old rats revealed the specific antibody. After the rats grew for 40 weeks, all were found to have the antibody in their serum. Same pattern of serum antibody level by age was found in ELISA. When immunosuppressed rats became heavily infected, the antibody in their serum decreased distinctively. The present results suggest that antibodies in normal newborn rats are transferred from their mother and lowered up to 8 weeks. Thereafter, the levels of the antibodies begin to increase by natural exposure to P. carinii. It was also confirmed that the intensity of P. carinii infection is inversely related with levels of serum antibodies.

Aging↗

PubMed1995

[Clinical study of photodynamic therapy for laryngeal cancer].

Photodynamic therapy (PDT) is an innovative treatment involving the use of a photosensitizer and low powered laser to selectively destroy tumor cells. In the head and neck, its application to laryngeal papilloma, metastatic tumor and oral cancer have been reported but our report on PDT for laryngeal cancer is the only clinical report in Japan. At present, we treat laryngeal cancer by PDT using argon and excimer dye lasers such as the HpD. In the present study, we assessed the utility and safety of PDT and investigated long-term prognosis after this therapy. The subjects were 12 patients with laryngeal cancer who underwent PDT between February 1988 and October 1993. Among them, ten with cancer of the vocal cords underwent PDT as the primary treatment and two underwent PDT because of recurrence after radiotherapy. Under local anesthesia, PDT was performed using a video endoscope (Pentax EB2000). The optimal dose from an argon dye laser was set at 200-500 mW/cm2 of continuous waves for 20 minutes and that from the excimer dye laser was set at 200 J/cm2 of pulse waves (3-4 mJ/pulse, 30-40 Hz). The argon dye laser used was the Fujinon PDT developed by Fuji Photo Optical Co., Ltd. The excimer dye laser used was a product of Hamamatsu Photonics Co., Ltd. 1) Effect of PDT The effect of PDT as a primary treatment for ten patients was classified as CR in eight and PR in two cases, the CR rate being 80.0%. When evaluated only for T1 patients, the results were classified as CR in eight and PR in one. The patient whose response was classified as PR had refused repeated PDT. CR was maintained for five and 13 months in the two patients who underwent PDT as a secondary treatment after radiotherapy. CR was obtained in 83.3% of all patients studied. 2) Duration of the effect of PDT and long-term prognosis The patients were followed up for 14 to 71 months. The longest duration of CR achieved by PDT monotherapy was 65 months. Among the patients who underwent PDT as a primary treatment, one developed local recurrence and underwent radiotherapy. However, the prognosis was uneventful in all other patients. CR after PDT monotherapy was maintained for 42 months in one T3 patient. Two patients with a history of previous treatment thereafter relapsed and underwent total laryngectomy. The larynx could be conserved in 83.3% of all patients. However, it could be conserved in 100% of patients who underwent PDT as a primary treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗

PubMed1995

Litigation by patients as third party beneficiaries of payor-provider contracts.

"No third party beneficiaries" clauses, if drafted with care, can offer some measure of protection to providers. Although courts may give minimal weight to "boilerplate" clauses in determining contractual intent, a more detailed and substantive clause may be more persuasive. In drafting such clauses, however, care should be taken to clearly state the specific intentions of the parties, including the scope and purposes of the contract, the identity of the intended beneficiaries, and the classes of persons that are to be excluded as beneficiaries (e.g., HMO enrollees).

Contract Services↗

PubMed1995

Effectiveness of a cytokine restraining agent (CRA (TM)) in attenuating disuse deconditioning induced by hindlimb unloading in rats.

Spaceflight alters many immune responses and among the regulatory components of an organisms response system that have been to be affected by spaceflight is the cytokine network. Spaceflight, as well as ground-based model systems of spaceflight, have been shown to affect the production and activation of various cytokines including interleukins (IL) and tumor necrosis factor (TNF). Levels of urinary IL-2 are elevated on the first day of spaceflight and again after returning from space. Most results from ground-based studies in rodents indicate either no alterations in cytokines or decreased levels. Results from this experiment indicate that HP 228, a potent cytokine restraining agent (CRA (TM)) was effective in attentuating many of the disuse deconditioning changes induced by the ground-based hindlimb suspension model that simulates weightlessness in rats. HP 228 is a novel heptapeptide with unnatural amino acids and can effectively restrain lipopolysaccharide (LPS)-induced increased levels of several key cytokines, including plasma TNF alpha, IL-1 beta and IL-6. HP 228 has also been shown to be effective in several rodent models of pain, inflammation and LPS-induced lethality, as well as in reducing inducible nitric oxide synthase.

Animals↗

PubMed1995

Effects of putative cannabinoid receptor ligands, anandamide and 2-arachidonyl-glycerol, on immune function in B6C3F1 mouse splenocytes.

Anandamide (arachidonylethanolamide), isolated from the porcine brain, and 2-arachidonyl-glycerol (2-Ara-Gl), derived from the canine gut, are two recently identified putative endogenous cannabinoid receptor ligands. Both ligands have been reported to possess binding affinity for cannabinoid receptor subtypes, CB1 and CB2. The objective of the present studies was to investigate the immunomodulatory effects of both of these ligands in B6C3F1 mouse splenocytes. 2-Ara-Gl produced a marked and dose-related inhibition of the mixed lymphocyte response, anti-CD3 mAb-induced T-cell proliferation and LPS-induced B-cell proliferation, whereas having no inhibitory effect on phorbol-12-myristate-13-acetate/ionomycin-induced cell proliferation. Interestingly, the inhibitory effects by 2-Ara-Gl on proliferation were at least dependent in part on cell density. At high cell density, 2-Ara-Gl enhanced lymphoproliferation whereas exhibiting marked inhibitory activity at low cell density. Similarly, in vitro primary immunoglobulin M antibody-forming cell responses which are dependent on high cell density also were found to be enhanced by 2-Ara-Gl. Conversely, anandamide exhibited no inhibitory effects on cell proliferative responses to stimulation by anti-CD3 mAb, lipopolysaccharide or phorbol-12-myristate-13-acetate/ionomycin treatment. Anandamide also showed no effect on the in vitro sheep erythrocyte antibody-forming cell response. Although shown previously to markedly inhibit forskolin-stimulated cyclic AMP accumulation, 2-Ara-Gl exhibited no effect on basal adenylate cyclase activity in splenocytes. Additionally, anandamide showed negligible inhibitory effects at extremely high concentrations on forskolin-stimulated adenylate cyclase activity and no effect on basal adenylate cyclase activity in splenocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗