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Biomedical subjects

A Bagheri

Publications and source records attributed to A Bagheri.

18 recordsLinked to original sources

The application and properties of composite sorbents of inorganic ion exchangers and polyacrylonitrile binding matrix.

A description is given of the preparation and properties of potassium hexacyanocobalt (II) ferrate (II) (KCFC) and the composite, potassium hexacyanocobalt (II) ferrate (II)-polyacrylonitrile (KCFC-PAN). The materials were dried at high temperatures and characterized by chemical analysis, scanning electron microscope, X-ray diffraction, inductively coupled plasma and infrared. The ion exchange of alkaline earth metals and molybdenum on a nonstoichiometric compound K(2)[CoFe(CN)(6)] and its PAN based absorber was examined by batch methods. The adsorption of molybdenum from aqueous solutions on KCFC-PAN was investigated and optimized as a function of equilibration time and pH. The materials which were dried at optimum high temperature of 110 degrees C were found to be stable in water, dilute acids, alkaline solutions and relatively high temperature. The distribution coefficient values K(d) for alkaline earth metals, followed the same trend of increase for both sets of absorbers studied, i.e. Ba(2+)>Sr(2+)>Ca(2+)>Mg(2+), which closely resembles to the order of the size of the hydrated cations. However, the K(d) values show a significant increase for PAN based absorbers in comparison to KCFC absorbers.

Acrylic Resins↗

Ion exchangers in radioactive waste management: natural Iranian zeolites.

Five samples of natural zeolites from different parts of Iran were chosen for this study. In order to characterize and determine their structures, X-ray diffraction and infrared spectrometry were carried out for each sample. The selective absorption properties of each zeolite were found by calculating the distribution coefficient (K(d)) of various simulated wastes which were prepared by spiking the radionuclides with (131)I, (99)Mo, (153)Sm, (140)La and (147)Nd. All the zeolite samples used in this study had extremely high absorption value towards (140)La; clinoptolite from Mianeh and analsite from Ghalehkhargoshi showed good absorption for (147)Nd; clinoptolite from Semnan and clinoptolite from Firozkoh showed high absorption for (153)Sm; mesolite from Arababad Tabas showed good absorption for (99)Mo; and finally mesolite from Arababad Tabas, clinoptolite from Semnan and clinoptolite from Firozkoh could be used to selectively absorb (131)I from the stimulated waste which was prepared. The natural zeolites chosen for these studies show a similar pattern to those synthetic ion exchangers in the literature and in some cases an extremely high selectivity towards certain radioactive elements. Hence the binary separation of radioactive elements could easily be carried out. Furthermore, these zeolites, which are naturally occurring ion exchangers, are viable economically and extremely useful alternatives in this industry.

Absorption↗

Organ transplantation laws in Asian countries: a comparative study.

Legal tools are a necessity in organ procurement to allow transplant surgeons to remove organs from potential sources. In some countries the organ transplantation law may not only increase the organ retrieval rate, but may also decrease the number of transplantations. Reassessing the impact of organ transplantation laws on the application of transplant technology is therefore an emerging issue. This article discusses organ transplantation laws in eight Asian countries: Japan, Korea, India, Iran, Philippines, Saudi Arabia, Singapore, and Turkey. The organ transplantation laws of each of these countries were compared in terms of how they address the issues of definition of death; donor consent; the role of family and surrogate decision making; age limitation for organ donation; organ trade and donor compensation; and the organ procurement model.

Asia↗

Bilateral recession-resection surgery for convergent strabismus fixus associated with high myopia.

The authors report two patients with more than 20 diopters of myopia, severely restricted abduction, and more than 90Delta of acquired esotropia. Marked axial elongation of the globes was present. Each underwent large bilateral medial rectus recessions and bilateral lateral rectus resections. The deviations were significantly reduced and abduction improved with combined horizontal recession-resection surgery on both eyes.

Esotropia↗

Prenatal development of the alveolar bone of human deciduous incisors and canines.

The formation of the human alveolar process around the incisors and canines is a hitherto unreported aspect of fetal oral development. The question is how, where, and when the alveolar process is formed. The purpose of this study was to elucidate the questions where and when and hence to analyze the pattern of formation of the alveolar bone around developing human deciduous canine and incisor teeth. The study was conducted with material selected from a sample of 61 normal human fetuses, legally or spontaneously aborted. Fertilization ages ranged from 9 to 22 weeks, crown-rump Length from 25 to 205 mm, and foot length from 4 to 34 mm. From this material, 7 maxillae and 10 mandibles were selected for the study according to developmental stages of the canines and incisors and according to the orientation of the histological sections. The skeletal investigation consisted of macroscopic and microscopic analysis of the mandibles and maxillae. The investigations revealed the absence of bone between the central and lateral incisors in the mandibles and maxillae of fetuses below the ages of 21 and 22 weeks, respectively. In three specimens, alveolar bone between the central and lateral incisors was recorded (21, 21, and 22 weeks of fertilization). Absence of bone labial to the canine was recorded in all fetuses investigated. In all other regions, alveolar bone occurred as a regular finding. The present study has shown that alveolar bone formation is strictly coordinated with tooth formation. Alveolar bone occurs later in the area labial to the canine and in the region between the central and lateral incisors than it does in other areas associated with the incisor/canine regions. Knowledge of this pattern in the formation of the alveolar process seems to be of importance for a future elucidation of how the alveolar process is initially formed.

Alveolar Process↗

Psychiatric problems among Iranian immigrants in Canada.

The number of Iranian immigrants in Canada has been increasing since 1979. This study is the result of a review of 111 charts of Iranian patients who were referred for psychiatric treatment between 1985 and 1988. Ninety-eight percent of them arrived in Canada after the Iranian revolution, which started in 1979, and the Iran-Iraq war of 1980. Ten percent were experiencing trauma as a result of their involvement with the revolutionary government or the war. The symptoms were in accordance with the DSM-III-R criteria for post-traumatic stress disorder. Sixty percent met the criteria for adjustment disorder with depressed or anxious mood. Six percent had been subjected to physical and psychological torture and confinement. This is the first study that looks at the prevalence of psychiatric illness among Iranians and illustrates the effect of migration and displacement in the integrity of the psychic life of this population.

Canada↗

Increased germ cell degeneration during postprophase of meiosis is related to increased serum follicle-stimulating hormone concentrations and reduced daily sperm production in aged men.

Aged men, known to have high serum gonadotropin levels and reduced spermatogenic potential, were used to study the relationship between serum follicle-stimulating hormone (FSH) and germ cell degeneration. Serum hormones were measured from blood obtained at autopsy. Phase-contrast cytometry was used to enumerate germ cells in homogenates of fixed testes from 13 younger (24-51 yr) and 14 aged (69-90 yr) men. The developmental steps of spermatogenesis during which germ cells degenerate were determined by comparing potential daily sperm production based on primary spermatocytes with daily sperm production based on two different types of spermatids. During spermiogenesis, there was no significant degeneration in the younger or aged men. During postprophase of meiosis, aged men had more (p less than 0.01) germ cell degeneration, significantly lower (p less than 0.05) serum testosterone, and greater (p less than 0.01) serum FSH than did younger men. Germ cell degeneration during postprophase of meiosis was negatively correlated (p less than 0.01) to daily sperm production and significantly (p less than 0.01) related to serum concentrations of FSH. As revealed in these aged men, meiotic germ cell degeneration has a direct effect on daily sperm production and is significantly related to serum FSH concentrations.

Adult↗

An analysis of the relationship between the cellular distribution and the rate of turnover for the separate classes of unoccupied, noncovalently occupied, and covalently occupied insulin receptor.

To further investigate insulin's role in regulating the turnover of insulin receptor during down-regulation in 3T3-L1 adipocytes, the relationship between the cellular distribution and turnover of unoccupied, noncovalently occupied, and covalently occupied receptor was examined. At steady-state 12% of the unoccupied receptors and 46% of covalently occupied receptors are intracellular. The apparent first-order rate constant (Kapp) for turnover of the total pool of covalently occupied receptors (0.16 h-1) is 3.8-fold higher than that for unoccupied receptors (0.042 h-1). When unlabeled insulin is added, identical values for both Kapp (0.10 h-1) and distribution (26% internal) are measured for noncovalently and covalently occupied receptors. The rate constant (Kdeg), describing the relative sensitivity of internalized receptor to degradation, is identical (0.36-0.41 h-1) for unoccupied, noncovalently occupied, and permanently occupied pools of internal receptor. Mechanisms for down-regulation postulating: (a) an occupancy-dependent alteration in the conformation of internal receptor increasing receptor sensitivity to internal proteases, (b) a preferential sorting of internal occupied receptor to degradative pathways, or (c) induction of intracellular proteases by insulin, would all reflect a substantial change in Kdeg for occupied receptor and thus are unlikely mechanisms by which insulin increases the rate of receptor turnover. The turnover of insulin receptor in 3T3-L1 adipocytes is regulated primarily by its intracellular concentration and not by the state of occupancy of internalized receptor.

Adipose Tissue↗

Muscle fiber selectivity of Trichinella spiralis and Trichinella pseudospiralis (1983).

The biceps, semimembranosus, biceps femoris, and soleus muscles of female Rockland Wistar mice infected with either 1,000 Trichinella spiralis or 1,000 Trichinella pseudospiralis larvae were removed on days 12, 14, 16, and 18 post-infection (PI), sectioned and stained histochemically for their myosin ATPase activity. Light microscopic examination of the sections revealed that larvae of T. spiralis invade only the slow twitch muscle fibers, and those of T. pseudospiralis invade both the fast twitch and the slow twitch fibers. In sections obtained from mice infected with either parasite and killed on days 16 and 18 PI, identification of the majority of the infected fibers as fast twitch or slow twitch was not possible due to pathological modification of infected fibers.

Adenosine Triphosphatases↗

Metabolism of androsterone and 5 alpha-androstane-3 alpha,17 beta-diol in human lung tissue and in pulmonary endothelial cells in culture.

The metabolism of [3H]androsterone and [3H] 5 alpha-androstane-3 alpha,17 beta-diol ( [3H] 3 alpha-diol) was studied in slices of human lung tissue and cultures of human pulmonary artery endothelial cells. Lung tissue metabolized [3H]androsterone (0.25 microM) to 5 alpha-androstane-3,17-dione (30.3 pmol 100 mg-1 tissue h-1), isoandrosterone (0.7 pmol 100 mg-1 tissue h-1), 5 alpha-dihydrotestosterone (5 alpha-DHT; 0.1 pmol 100 mg-1 tissue h-1), 3 alpha-diol (0.1 pmol 100 mg-1 tissue h-1), and two polar metabolites. Pulmonary arterial endothelial cells produced the same metabolites of [3H]androsterone (0.083 microM), with the exception of the polar compounds [5 alpha-androstane-3,17-dione (1.3 pmol mg-1 protein h-1), isoandrosterone (0.1 pmol mg-1 protein h-1), 5 alpha-DHT (0.2 pmol mg-1 protein h-1), and 3 alpha-diol (0.2 pmol mg-1 protein h-1)]. Thus, the principal metabolite of [3H]androsterone in both lung tissue and endothelial cells was 5 alpha-androstane-3,17-dione. Human lung tissue metabolized [3H]3 alpha-diol (0.28 microM) to 5 alpha-DHT (8.8 pmol 100 mg-1 tissue h-1), androsterone (2.2 pmol 100 mg-1 tissue h-1), 5 alpha-androstane-3,17-dione (0.8 pmol 100 mg-1 tissue h-1), isoandrosterone (0.1 pmol 100 mg-1 tissue h-1), and four polar metabolites (0.2 pmol 100 mg-1 tissue h-1). 5 alpha-DHT was the principal metabolite of [3H]3 alpha-diol within the first hour of incubation, but the concentration of this androgen declined thereafter to 3.6 pmol 100 mg-1 tissue after 4 h of incubation. This decline was correlated with increased 5 alpha-androstane-3,17-dione synthesis (6.7 pmol 100 mg-1 tissue 4 h-1). Androsterone formation from [3H]3 alpha-diol, however, was linear with time of incubation for 4 h (8.9 pmol 100 mg-1 tissue 4 h-1). The formation of these products demonstrates that the principal 5 alpha-reduced-C19-steroid-metabolizing enzymes in human lung are 3 alpha-hydroxysteroid oxidoreductase.

Adolescent↗

Physicians' confusion demonstrated by competency requests.

A study was performed at a Veteran's Administration (VA) Hospital of the requests for competency evaluations made by medical and surgical services to a psychiatric consultant service. Since less than half the requests were found to be appropriate and specific, this study emphasizes the need for forensic psychiatrists to educate our nonpsychiatric colleagues about the problems engendered by confusion regarding competency. To do so, psychiatrists as well as other physicians and mental health professionals must be trained in discriminating between different types of competencies and the criteria appropriate for each. Because of continuing legal developments, it is becoming increasingly essential to be precise not only about the specific purpose for a competency request but also about the criteria necessary for evaluating different types of competencies. Forensic psychiatrists could play an important role in the education process to clarify the confusion. This study highlights the need for clarity and education concerning competency issues.

Adult↗

Competence to give informed consent for medical procedures.

This study shows that referrals to psychiatry for evaluation for competence to give informed consent generally were made on patients who refused medical treatment. In this sample of referred patients, the only patients found to be incompetent to give informed consent were those with organic brain syndromes. No one with either schizophrenia or depression was found to be incompetent. It is possible that schizophrenic and depressed patients may generally be competent to give informed consent to medical treatment. This finding might be true notwithstanding the fact that many such patients have been found in other studies to be incompetent to consent to voluntary psychiatric treatment. For example, a patient may have delusions that others can read his mind and thoughts, but he still can understand that he needs dialysis for renal failure. Alternatively, it may be relatively rare that an emergency procedure is necessary before a patient's psychosis can be brought under control and consequently internists and surgeons themselves may prefer to wait. The significance of the results is unclear. Because of active interest in the doctrine of informed consent for psychiatric and medical patients by both physicians and attorneys and the few studies within this population, there is a strong need for more study regarding competence to give informed consent. Further study is especially important for psychotic patients for whom psychiatric consultation is not requested.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Dacryoadenitis as the earliest presenting manifestation of systemic Wegener's granulomatosis.

PURPOSE: To report a case presenting with dacryoadenitis as the earliest manifestation of systemic Wegener's granulomatosis (WG). DESIGN: Observational case report. METHODS: A 41-year-old woman initially presented symptoms of bilateral dacryoadenitis. She subsequently developed upper and lower respiratory tract involvement, scleritis and keratitis. RESULTS: Cytoplasmic antineutrophil antibody (c-ANCA) titer was positive. The lacrimal gland and lung biopsies were consistent with WG. The patient responded well to cyclophosphamide and prednisolone. CONCLUSIONS: Dacryoadenitis maybe the earliestpresenting manifestation of WG andprompt immunosuppressive chemotherapy may control it preventing the limited disease from progressing to a complete form and reducing its morbidity and mortality.

Adult↗

Cerebrospinal fluid leakage during dacryocystorhinostomy in a patient with meningoencephalocele.

PURPOSE: To report a rare case of cerebrospinal fluid leakage during dacryocystorhinostomy in a patient with Mobius syndrome and meningoencephalocele and to explain our experience in the management of this complication. METHODS: A 9-year-old girl with a history of surgically repaired fronto-ethmoidal meningoencephalocele and bilateral canthopexy was diagnosed with Mobius syndrome and underwent sequential bilateral dacryocystorhinostomy and silicone intubation because of dysgenesis of the lacrimal drainage pathway. RESULTS: Both dacryocystorhinostomies resulted in cerebrospinal fluid leakage, which spontaneously ceased with conservative management. CONCLUSIONS: Dacryocystorhinostomy surgery in patients with a history of trauma or surgery or congenital defects around the base of the nose or lacrimal system may rarely result in cerebrospinal fluid leakage; thus an ophthalmologist should be familiar with its management.

Cerebrospinal Fluid Rhinorrhea↗