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Biomedical subjects

E Anyanwu

Publications and source records attributed to E Anyanwu.

At least 19 recordsLinked to original sources
PubMed2002

Antibodies to neuron-specific antigens in children with autism: possible cross-reaction with encephalitogenic proteins from milk, Chlamydia pneumoniae and Streptococcus group A.

We measured autoantibodies against nine different neuron-specific antigens and three cross-reactive peptides in the sera of autistic subjects and healthy controls by means of enzyme-linked immunosorbent assay (ELISA) testing. The antigens were myelin basic protein (MBP), myelin-associated glycoprotein (MAG), ganglioside (GM1), sulfatide (SULF), chondroitin sulfate (CONSO4), myelin oligodendrocyte glycoprotein (MOG), alpha,beta-crystallin (alpha,beta-CRYS), neurofilament proteins (NAFP), tubulin and three cross-reactive peptides, Chlamydia pneumoniae (CPP), streptococcal M protein (STM6P) and milk butyrophilin (BTN). Autistic children showed the highest levels of IgG, IgM and IgA antibodies against all neurologic antigens as well as the three cross-reactive peptides. These antibodies are specific because immune absorption demonstrated that only neuron-specific antigens or their cross-reactive epitopes could significantly reduce antibody levels. These antibodies may have been synthesized as a result of an alteration in the blood-brain barrier. This barrier promotes access of preexisting T-cells and central nervous system antigens to immunocompetent cells, which may start a vicious cycle. These results suggest a mechanism by which bacterial infections and milk antigens may modulate autoimmune responses in autism.

Antigens↗
PubMed1999

Evaluation of the laboratory and environmental factors that induce seizures in photosensitive epilepsy.

This paper evaluates the laboratory and environmental factors that induce seizures in photosensitive epileptic patients. The aims are (i) to identify those factors that trigger seizures so that the patients could take preventive measures, (ii) to advise the patients on appropriate preventive measures that could be taken to avoid spontaneous seizures. Thirty-six photosensitive epileptic patients were studied. The electroencephalographic laboratory seizure-inducing factors identified were intermittent photic stimulation (IPS), flickering lights from both the TV and the visual display unit (VDU) at various flashes per second, grid patterns (vertical, horizontal lines, squares, black and white lines) of various cycles per degree, and blank screens. In the environmental factor investigation, 10 out of 36 patients had series of seizures induced by narrow stripes of black and white, or white and red striped coloured dresses especially, when stepping outdoors on sunny days. Other environmental factors identified include moving escalators; 'moving' trees, bushes, and houses when travelling in a vehicle, including trains; faceted patterns in the bathroom windows with light passing through; swirling light patterns especially on displayed objects of black and white colours; telegraphic post, gantry post, and luminance variance when stepping outdoors from the dark in bright sunlight. The effective preventive measures were: (i) patients should occlude one eye when travelling in a vehicle or using computers or when stepping outdoors on a sunny day, or when there are various patterns before them, (ii) patients should sit at least 3 metres away from the TV when watching a programme, (iii) they should avoid any object that transmits luminance variance; if this is not possible, they should occlude one eye.

Adolescent↗
PubMed1997

Mental imagery of photic stimulation provokes paroxysmal EEG activity in a photosensitive patient who self-induces seizures.

This article reports a case of a 14 year-old male photosensitive epileptic patient who was able to induce fits subjectively by the mental imagery of the effective visual stimuli. The patient underwent a comprehensive electroencephalographic (EEG) examination including hyperventilation. The basic EEG showed abnormalities. Intermittent photic (IPS) and pattern stimulations (PtnS), evoked photo and pattern paroxysmal responses (PPRs) within a wide range of frequencies for 2-50 flashes per second (fps) and 0.5-6 cycles per degree (cdp) respectively. The patient was able to reconstruct the PPRs mentally on exposure to the effective stimuli of 25 and 50 fps, and 2.0 and 3.25 cpd respectively. His cognitive functions were not affected when exposed to photostimulation. However, on exposure to pattern stimulation, he became totally confused and his consciousness was impaired. These findings showed that self-induction of fits in photosensitive epilepsy is a mental phenomenon which takes place with or without loss of cognitive function depending on the rate and frequency of the physical and 'imagined' stimuli.

Adolescent↗
PubMed1997

Bitemporal hemianopia in photosensitive epilepsy: a case study.

This paper reports the occurrence of bilateral hemianopia in a 16 year old male who was having unusual seizures accompanied by severe migrainous headaches and loss of vision while watching a television programme and while playing with the computer. Electrophysiological tests not only confirmed his photo and pattern sensitivity, but also showed that he had bitemporal hemianopia. Hence, his basic EEG showed a great deal of abnormality including generalised spike and wave activity which was more marked in the temporal regions. The patient showed classical occipital spikes on exposure to 25 and 50 Hz of intermittent photic stimulation. Pattern sensitivity test evoked photo paroxysmal response within the range of 2-4.5 cycles per degree (cpd). The visual evoked response to binocular flash stimulation produced N2 at 74 ms, P2 at 112-118 ms and N3 at 168 ms. P2 amplitude was 15-17 uV. Monocular right stimulation produced N2 at 72 ms, P2 at 122-124 ms. Monocular left stimulation produced N2 at 82 ms, P2 at 120-124 ms of 14 uV and N3 at 178 ms. Pattern reversal stimulation produced some abnormality. Poor phase reversals were mainly seen to the left occiput with right eye stimulation and poor phase reversals to the right occiput with left eye stimulation. The pattern responses were of normal latency but showed a marked hemispheric asymmetry. The reduction of the response in the left hemisphere with right eye stimulation and the reduction in the right hemisphere with left eye stimulation would suggest the presence of bitemporal field deficit.

Adolescent↗
PubMed1996

Protein-tyrosine phosphatase 1B is a negative regulator of insulin- and insulin-like growth factor-I-stimulated signaling.

To understand the physiological role of protein-tyrosine phosphatase 1B (PTPase 1B) in insulin and insulin-like growth factor-I (IGF-I) signaling, we established clonal cell lines overexpressing wild type or inactive mutant (C215S) PTPase 1B in cells overexpressing insulin (Hirc) or IGF-I (CIGFR) receptors. PTPase 1B overexpression in transfected cells was verified by immunoblot analysis with a monoclonal PTPase 1B antibody. Subfractionation of parental cells demonstrated that greater than 90% of PTPase activity was localized in the Triton X-100-soluble particulate (P1) cell fraction. PTPase activity in the P1 fraction of cells overexpressing wild type PTPase 1B was 3-6-fold higher than parental cells but was unaltered in all fractions from C215S PTPase 1B-containing cells. The overexpression of wild type and C215S PTPase 1B had no effects on intrinsic receptor kinase activity, growth rate, or general cell morphology. The effects of PTPase 1B overexpression on cellular protein tyrosine phosphorylation were examined by anti-phosphotyrosine immunoblot analysis. No differences were apparent under basal conditions, but hormone-stimulated receptor autophosphorylation and/or insulin receptor substrate tyrosine phosphorylation were inhibited in cells overexpressing wild type PTPase 1B and increased in cells expressing mutant PTPase 1B, in comparison with parental cells. Metabolic signaling, assessed by ligand-stimulated [14C]glucose incorporation into glycogen, was also inhibited in cells overexpressing active PTPase 1B and enhanced in cells containing C215S PTPase 1B. These data strongly suggest that PTPase 1B acts as a negative regulator of insulin and IGF-I signaling.

Amino Acid Sequence↗
PubMed1996

Visually-evoked pattern and photomyoclonic responses in video game and television epilepsy: case reports.

This research paper reports a case study of two male photosensitive epileptic patients, aged 14 and 16 years old respectively, whose epileptic seizures were often triggered by the flickers from television and video games respectively. The 14-year old patient had no family history of epilepsy, while the 16 year old had a family history of epilepsy. A comprehensive electroencephalogram (EEG), including hyperventilation, intermittent photic stimulation (IPS) and pattern stimulation were carried out on them and EEG abnormalities including photoparoxysmal responses (PPR) and generalized myoclonic responses were evoked. A thorough analysis of the EEG morphology of the myclonic responses and the clinical manifestations showed evidence of two separate entitles of seizures namely: visually evoked pattern-myoclonic responses (PTMR) and visually evoked photomyoclonic responses (PMR). PTMR was independent of flash rate and occurred before a PPR and at the same time as the flash rate, while PMR occurred after the PPR and was dependent on flash rate. These findings suggest that "Video Game" epilepsy is probably a pattern sensitive epilepsy, electronic screen being the source of the triggering patterns; hence, the morphology and the family histories and the myoclonic phenomena differ from those of pure photosensitive epilepsy.

Adolescent↗
PubMed1994

Pulmonary metastasectomy as secondary treatment for testicular tumors.

Patients presenting with synchronous and metachronous metastases of nonseminomatous testicular tumors are candidates for pulmonary metastasectomy after receiving definitive primary treatment, which includes semicastration, eventually retroperitoneal lymphadenectomy, and definitely chemotherapy. One hundred four such patients (age, 14 to 79 years; median age, 27 years) underwent pulmonary metastasectomy from 1972 to 1990, representing 15.8% of the pulmonary metastasectomies performed during the same period. Of the 117 operations performed, eight were repeat operations. Median sternotomy, posterolateral and, later, transverse thoracotomies were the standard surgical approaches used to remove the single and multiple metastases randomly distributed in both lungs. Wedge resections and atypical segmentectomies (66%), lobectomies (15%), anatomic segmentectomies (9%), pneumonectomies (3%), bilobectomies (3%), and mediastinal lymphadenectomies (65.4%) were the various procedures performed. Of the 104 patients, metastasectomy was complete in 80 and incomplete in 24. The 30-day mortality was 2.0%. Life table analysis revealed a survival rate of 77%, 70%, 66%, and 59% at 1, 2, 3, and 5 years, respectively. Of all prognostic factors examined, complete resection of the metastases seems to be the most significant factor influencing the prognosis.

Adolescent↗
PubMed1994

Genotypic evaluation of ocular pathologies in sickle cell diseases.

Sickle cell disease patients are known to manifest different types of ocular problems. These problems include proliferative and non-proliferative retinopathies, and refractive errors. The distribution of these pathologic and refractive problems among the sickle cell genotypes is analyzed according to the individual genotypes. Data collected from a total of 63 sickle cell disease patients who responded to the questionnaires shows that fifty-six percent (35) are males and forty-four percent (28) are females. The genotype distributions are: SS, 55% (34); SC, 33% (21); S-Thal, 11% (7); while 2% (1), is AS-genotype. Overall findings show that severe ophthalmic abnormalities were reported by approximately 90% of the respondents with sickle cell disease. The majority of sickle cell disease patients in this research show consistent susceptibility to both fungal and bacterial infections with varying degree of refractive errors. It is observed that refractive errors are prevalent in SC and S-Thal sickle cell genotypes, while the severity of anemia and painful crises are more prevalent in SS and S-Thal genotypes. Systemic ocular problems are also prevalent among the SC and S-Thal disease genotypes.

Adolescent↗
PubMed1993

Tumor presence at resection boundaries and lymph-node metastasis in bronchial carcinoma patients.

A prospective study was performed analyzing the bronchial resection boundaries of 120 patients operated on for lung carcinoma. The resection boundary, maximum tumor diameter, distance between tumor and resection boundary, and lymph-node stage were analyzed by serial sections of the surgical specimens (lobes and lungs). The following results were obtained: 20/120 cases (17%) displayed microscopic tumor invasion of the resection boundary (R1 status), most frequently adenocarcinoma (21%). The R1 status was closely associated with the distance between tumor and resection boundary and postsurgical lymph-node state (pN stage): all 8 tumors excised at distance 1 mm or less from the bronchial resection boundary revealed bronchial submucous tumor growth, whereas none of the tumors located more than 20 mm from the resection boundary was found to display tumor invasion of the bronchial boundary. Curative resection was noted in all 40 tumors operated at pNO stage and in only 11 cases (69%) of tumors with distant lymph-node metastases (pN3 stage). No relationship between tumor infiltration of the resection boundary and type of resection was seen. The data indicate that a) intra-operative control of bronchial resection boundaries is necessary in all lung-carcinoma patients with central tumor localization less than 20 mm from the proposed resection boundary; b) a "safety distance" between resection boundary and tumor boundary is of specific importance in bronchial carcinoma with lymph-node metastases.

Adenocarcinoma↗
PubMed1993

The involvement of taurine in the action mechanism of sodium valproate (VPA) in the treatment of epilepsy.

Several lines of evidence have shown that sodium valproate (VPA) mechanism of action in the therapy of epilepsy is based on the phenomena of its interaction with neurotransmitters (GABA), receptor sites and ion channels (1). However, there is no conclusive evidence to show the extent of VPA interactions with other neurotransmitters in the brain. Based on this fact, taurine (an amino acid 'neurotransmitter') found distributed in the brain the visual system may probably be involved in the drug action mechanism of VPA. The application of taurine in experimental and human epilepsy started over thirty years ago (2,3) and it has been known to possess some mild anticonvulsant activity in both humans and experimental animal models (4). This review, therefore, will attempt to draw together all the available information on the involvement of taurine in epilepsy and its possible association with the action mechanism of VPA in suppressing epileptic seizures. Structural and physiological distribution of taurine in the brain will be discussed. Its association with the phenomena of VPA action in epilepsy will be cited. Its neurotransmitter candidacy, involvement in ocular pathology, receptor sites and modulatory activity will be dealt with in relation to valproate action in the therapy of epilepsy.

Brain↗
PubMed1993

The frequency distribution of ocular disease by age in Imo State Nigeria.

BACKGROUND: A total of 600 'first-time served' patients with confirmed ocular pathologies visited our clinic between 1987 and 1988. METHODS: These patients and their ocular diseases were classified according to age, sex, and employment. Gender mix was 53.5 percent male, 46.5 percent female. RESULTS: Of the total disease conditions, 42 percent fell within the 0-30 age group, 44 percent fell within the 31-60 age group and 14 percent fell between 61-90. The relative incidence of ocular disease within this clinic population was: 32.8 percent conjunctivitis; 28.8 percent cataract; 15.5 percent glaucoma; 11.5 percent pterygium; 1.8 percent optic atrophy; and 9.5 percent other. CONCLUSIONS: Caution is made to generalize these data to the population at large since those without financial means were not represented in this study.

Adolescent↗
PubMed1985

[Indications for operative intervention in acute and acute recurring lung embolism].

From 1973 to 1983 10 patients suffering from pulmonary embolism were seen at our clinic. All 10 underwent cardiopulmonary bypass and embolectomy of the pulmonary truncus and its branches including exploration of the right heart. 6 patients survived. The embolectomy of the pulmonary artery was supplemented by clipping the inferior vena cava. In chronic recurrent pulmonary embolism we only performed the clipping procedure of the inferior vena cava.

Acute Disease↗
PubMed1984

Morphological hazards of deuterium oxide as a cardioplegic agent.

To determine the cardio-protective effect of heavy water on the ischemic myocardium, a thoracotomy was performed on 18 mongrel dogs. The animals were connected to the extracorporeal circulation in a standardized experimental procedure. Following total cardiopulmonary bypass, 2,000 ml of a standard cardioplegic solution (LK 352) was infused at the aortic root of 10 dogs, which served as controls (group I), and the same solution containing 20% of 99.8% deuterium oxide was given at the aortic root of the remaining animals (group II). At the end of 60 minutes of ischemia, 1,000 ml of the solutions was again administered at the aortic root of the corresponding animals. Myocardial biopsies were taken from the apex of the left ventricle of each dog before cardiopulmonary bypass, immediately after the infusion of the cardioplegic solutions, following 90 minutes of ischemia, and after 30 minutes of reperfusion, and studied ultrastructurally. Whereas the ultrastructure of the myocardium of group I was well preserved at the end of the ischemic period, deuterium-oxide-treated hearts showed extensive focal and global myofilamentolysis and lysis of whole myocytes. Structural damage to glycogen, nuclear chromatin dispersal, severe intracellular edema and complete rupture of the intercalated discs were characteristic findings. At the end of ischemia, all the hearts of group I could be resuscitated. During the ischemia, all the hearts of group II developed into stone hearts. Biochemical studies on a second series showed a higher ATP depletion and a significantly higher lactate accumulation in group II than in group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Surgery of coarctation of the aorta: a nine-year review of 253 patients.

From 1973 to 1982, 253 patients--164 males and 89 females--underwent an operation for coarctation of the aorta in our clinic. Of the patients 72.3% presented with a circumscribed lesion and 58.5% with associated congenital cardiovascular defects. Resection with end-to-end anastomosis was performed in 138 patients (54.5%). Seventy-four patients (29.3%) had vascular graft prosthesis, 1.2% underwent the Clagett's operation, 9.1%, the indirect isthmoplasty and the rest (5.9%), the subclavian flap plastic. Ventricular fibrillation led to the intraoperative death of 3 infants with associated intracardiac and multiple somatic defects. The operative mortality was high in children under 15 months (13.2%), 1% in all the others taken together and 0% in all cases without concomitant lesions. Paraplegia occurred in only one patients (0.4%). One hundred twenty-eight patients were followed-up over a mean period of 3.6 years. The systolic and diastolic pressures decreased by a mean of 30 mmHg and 15 mmHg respectively. Eighty-seven patients (68%) had normal blood pressure at the time of examination. The rest (41 patients) had persistent postoperative hypertension necessitating medical management. The surgical technique elected did not influence the level and incidence of persistent postoperative hypertension, rather the level of the preoperative systolic right arm-to-leg pressure gradient (SPG) related closely to the incidence of persistent hypertension. Thirty patients (23.4%), among whom were 24 children under 10 years--some of them with preductal hypoplasia--presented with an SPG above 20 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

The influence of non-coronary collateral blood supply on the electively arrested heart during ischemia and reperfusion.

To study the influence of non-coronary collateral blood circulation (NCCBC) on the integrity of the ischemic myocardium a right-sided thoracotomy was performed on 15 anesthetized dogs. Following a total cardiopulmonary bypass (CPB), ventricular fibrillation was induced, during which 2,000 ml calcium-free cardioplegic solution LK 352 was given at the aortic root over an 8-10 min period. Precautions were taken to prevent retrograde blood flow into the coronary system via the coronary sinus. After 90 min of ischemia, ten of the dog hearts were reperfused with systemic blood for the next 30 min. Transmural biopsies were taken from the apex of the left ventricle at the following intervals: (1) before CPB, (2) immediately after the infusion of LK 352, (3) following 90 min of ischemia, (4) after 5 min, (5) after 15 min, and finally (6) after 30 min of reperfusion and were then studied ultrastructurally. The presence of NCCBC was documented by the observation of erythrocyte-filled blood vessels in the biopsies corresponding to nos. 2 and 3 of the above. To assess the degree of ischemic injury and the extent of myocardial recovery during reperfusion, a scoring system based on a semiquantitative assessment of the characteristic morphological changes was used. The average result of the separately assessed subendo- and subepicardial layers represented the score, which was plotted on the ischemic injury and the recovery scale, thus making a direct comparison of the hearts possible. All the hearts generously supplied with blood via extracoronary routes during ischemia showed minimal and reversible ischemic injuries. They recovered more quickly and more completely following reperfusion than those hearts without NCCBC. From these results we conclude that despite its warming-up effect on the myocardium and its tendency to wash out the cardioplegic solution, the NCCBC generally protects the myocardium from serious ischemic injuries and shortens the period of recuperation during the reperfusion.

Animals↗