PubMed Health⌕ Search

Biomedical subjects

A K Haque

Publications and source records attributed to A K Haque.

At least 55 records · Page 3Linked to original sources
PubMed1991

Pathology of carcinoma of lung: an update on current concepts.

The incidence of mortality of lung cancer continues to increase worldwide in spite of considerable advances in diagnostic techniques and therapeutic modalities. The incidence of adenocarcinoma appears to have increased, and that of squamous cell carcinoma to have decreased, over the last few decades. The neuroendocrine tumors of the lung are emerging as a better defined group, with at least four subtypes being recognized in the spectrum ranging from typical carcinoid tumor to small cell undifferentiated carcinoma. Staging of lung tumors has also undergone major changes as new treatment modalities have become available. Pathologists are using sophisticated immunohistochemical and ultrastructural examination to categorize the tumors more accurately for appropriate therapy, follow-up, and survival studies.

Adenocarcinoma↗
PubMed1991

The pitted duodenal bulb.

The radiologic, endoscopic, and histologic findings in two patients with flaskshaped or collar-button collections of barium in the duodenum are presented. These abnormal mucosal depressions, which may be related to inflammation, were seen endoscopically and identified radiographically and have not been reported previously.

Aged↗
PubMed1990

Effect of hemodynamic factors on atherosclerosis in the abdominal aorta.

The distribution pattern of atherosclerotic plaques in the human abdominal aorta is examined using autopsy specimens. The location of the plaques is found to be dominant where flow separation may occur in the abdominal aorta based on hemodynamic theory. This observation provides strong support for the role of flow separation with subsequent platelet aggregation in atherogenesis. The severity of plaque formed in the anterior inferior wall of the abdominal aorta is found to be affected by the branching angles of the renal arteries as deduced from experimental results using glass tube models.

Aorta, Abdominal↗
PubMed1990

The pathology and pathophysiology of mycobacterial infections.

Classic tuberculosis is the result of infection with the human strain of Mycobacterium tuberculosis, and atypical tuberculosis is the result of infection with atypical mycobacteria. The pathology and course of the disease depend on the sensitivity of the host. Primary tuberculosis is the first infection in an unsensitized host, and secondary, postprimary, or chronic tuberculosis results from reactivation of previously acquired infection or, rarely, reinfection of a sensitized host. The pathology of infection with M avium-intracellulare in patients with acquired immunodeficiency syndrome (AIDS) is different from that of tuberculosis; formation of noncaseating lesions and a marked macrophage response resemble changes seen in lepromatous leprosy. These infections in patients with AIDS are predominantly extrapulmonary.

Humans↗
PubMed1990

Disseminated Conidiobolus infection with endocarditis in a cocaine abuser.

A crack cocaine abuser developed disseminated infection caused by a species of Conidiobolus not known to cause disease in vertebrates. The fungus gained entry via skin abrasions on the lower extremities, spread through the hematogenous route, and caused endocarditis. There was evidence of fungal infection in the lungs, heart, kidneys, skeletal muscles, and brain. An additional complication was extensive rhabdomyolysis, with a marked elevation of creatine kinase of up to 1.2 million U/L.

Adult↗
PubMed1989

Transformation of lung cells from inhalation of radon daughters in dwellings: a preliminary study.

There is now world-wide concern for the quantification of lung cancer risk due to indoor radon, but the recent estimates are based on epidemiological studies of miners alone. The present attempt is a preliminary study of the alteration of lung stem cells irradiated by alpha particles emitted by radon daughters. Local energy deposited has been calculated for alpha particles, emitted from radon daughters lining the mucous layer in the respiratory tracts. This calculation has then been followed by dose evaluation and estimation of transformation of lung cells as a function of age. Mean life span of the stem cells was varied between 5 and 45 years to simulate living conditions in different environments. The cumulative fraction of transformed cells after 40 and 70 years has been calculated for radon concentration in the range 23-230 Bq/m3. Increase of the fraction of transformed cells with radon concentration was exponential. It has been assumed that causes other than radiation increase the rate of cell death of mature and stem lung cells, and hence the turnover of stem cells to replace them. It is concluded that the rate of transformation of cells is small for low radon concentration even late in age for non-polluted environments. For radon concentrations of 50 and 100 Bq/m3 the fractions of transformed cells are 0.2 and 6 per cent, respectively for an exposure time of 70 years.

Age Factors↗
PubMed1989

Local energy deposited for alpha particles emitted from inhaled radon daughters.

An analytical method has been developed to calculate the local energy deposited by alpha particles emitted from radon daughters deposited on the mucus surface in the lung airways. For the particular cases of 218Po (Ra A) and 214Bi (Ra C'), microdose spectra have been evaluated in test spheres of 1 micron diameter which were taken to lie within airways of diameters 18,000, 3,500 and 600 microns. In each case, the contributions of the near and far wall were computed separately. The average microdosimetric parameters yF and yD have also been calculated. For the two smaller airways, yF and yD values were found to be about 110 and 135 keV microns-1 for 218Po and about 87 and 107 keV microns-1 for 214Bi respectively. The corresponding values were about 10% higher for the largest airway.

Alpha Particles↗
PubMed1989

Disseminated cytomegalovirus infection presenting with acalculous cholecystitis and acute pancreatitis.

Disseminated cytomegalovirus (CMV) infection occurs predominantly in immunocompromised hosts. Symptomatic CMV cholecystitis and pancreatitis are quite rare, and, to our knowledge, there are no reports of these occurring simultaneously. We describe a patient with a history of chronic myelogenous leukemia (treated with chemotherapy) who presented with recurrent unexplained fevers and an acute abdomen. At surgery, cholecystitis and pancreatitis were found, and a cholecystectomy was performed. The patient developed disseminated intravascular coagulation, eventual sepsis, and multiorgan failure. At autopsy, widespread disseminated CMV infection was found, with CMV-associated foci of acute inflammation and necrosis in the pancreas and in the surgically resected gallbladder. A review of our autopsy files revealed only one renal transplant patient with CMV inclusions and chronic pancreatitis. No pancreatitis was seen in 27 patients with acquired immunodeficiency syndrome. Cytomegalovirus should be considered as a possible cause of pancreatitis and cholecystitis in immunocompromised patients.

Acute Disease↗
PubMed1988

Main factors affecting the calculation of radiation dose to the lung from inhalation of radon daughters.

The radiation dose to the lung due to inhalation of radon daughter products has been computed with improved data on lung models, aerosol parameters, deposition and clearance mechanisms. The effects of the following factors on the dose calculated for dwellings have been considered in detail: (a) the diffusion coefficient of the unattached daughter products; (b) the activity median diameter (AMD) of the aerosol size distribution; (c) room ventilation rate; (d) air flow rate in the respiratory tracts; (e) lung morphometry; and (f) effect of phase of the tissue-equivalent medium on the stopping power and range for alpha particles. It has been found that realistic changes in values of some factors change the dose rate by a factor of 2. By adopting likely values, it is calculated that annual dose rates in the fifth bronchial generation are typically 4.3 and 1.8 mGy year-1, at the epithelial surface and 20 microns depth, respectively, for a person exposed to a radon concentration of 23 Bq m-3, the average value for U.K. dwellings.

Aerosols↗
PubMed1988

Glutathione S-transferase isoenzymes in human lung tumors.

In the present studies we have compared the levels of glutathione (GSH) and GSH-related enzymes in lung tumors and corresponding normal tissues obtained from the same individuals. We have also immunologically quantitated the relative amounts of glutathione S-transferase pi (or GST-P) type antigen in tumors and adjacent normal tissues from five patients. GST activities towards 1-chloro-2,4-dinitrobenzene (CDNB) and ethacrynic acid were found to be elevated in tumors from two out of five patients (patients #1 and 4), whereas the activity towards these substrates was markedly suppressed in the tumor tissue from one of the patients (#5). Immunotitration and Western blot studies using antibodies raised against pi-type GST isoenzymes of human lung and placenta indicated induction of GST pi-type isoenzyme in tumors from patients #1 and 4 and suppression of this isoenzyme in tumor from patient #5. The tumors from patients #2 and 3 did not show any increase in GST activity or GST pi-type antigen. Except for the tumor from patient #5, the GSH content was higher in the tumors from other patients. GSH reductase activity was found to be elevated in tumors of all the patients examined in this study. These results indicate that GSH and GSH related enzymes are differentially altered in lung tumors and GSH levels and GST pi- or GST-P-type isoenzyme(s) are not uniformly elevated in all tumors.

Carcinoma↗
PubMed1988

Asbestos bodies in children's lungs. An association with sudden infant death syndrome and bronchopulmonary dysplasia.

Lungs from 46 autopsied children (age range, 1 to 27 months) were examined for asbestos bodies using a bleach-digestion extraction technique. Ten (21.7%) of 46 children had asbestos bodies in their lungs. Of these ten children, seven were diagnosed with sudden infant death syndrome, and three were diagnosed with bronchopulmonary dysplasia. Thus, 46.6% of children with sudden infant death syndrome and 42.8% of children with bronchopulmonary dysplasia had asbestos bodies. Impaired lung-clearing mechanisms due to either abnormal lung physiology or reorganization of pulmonary architecture may be significant in the formation of asbestos bodies. Additionally, children with asbestos bodies may have been exposed to higher ambient levels of asbestos and other pollutants.

Asbestosis↗
PubMed1987

Cavernous lymphangioma of the duodenum: case report and review of the literature.

Lymphangiomas of the gastrointestinal tract are extremely rare benign tumors. There have been 39 cases of solitary intestinal lymphangiomas reported, 8 of which were found in the duodenum; only 3 of these were seen radiographically. A case of cavernous lymphangioma of the duodenum is presented, the roentgenographic and pathologic findings are described, and the literature is reviewed.

Duodenal Neoplasms↗
PubMed1987

Influence of the physical state and straggling on the computation of the radiation dose due to radon daughters deposited in the lung.

The effect of the physical state (phase) of the absorbing medium and the energy straggling of the alpha particles on the calculation of the radiation dose due to the daughter products of radon deposited in the lung have been studied in detail. The stopping power data for alpha particles in water and water vapour have been used. It has been found that the effect of straggling on the stopping power calculations is small, and therefore its contribution to dose calculations is negligible. The phase effect has been found to be dependent on the energy of the alpha particles and the depth in the medium. If the stopping power of water vapour is used instead of that for liquid water, the dose may be overestimated by 5-20 and 1-11% for 6 and 7.7 MeV alpha particles, respectively, at the beginning of alpha range, and underestimated by 15 and 40% respectively for the above energies at the end of the range.

Dose-Response Relationship, Radiation↗
PubMed1986

Xanthogranulomatous abscess of a mullerian duct remnant. A rare lesion of the rectum and anus.

A rare example of xanthogranulomatous inflammatory mass and abscess of a Mullerian duct remnant involving the anorectal area is reported. A barium enema showed a bilobed precoccygeal mass of moderate size involving the posterior aspect of the distal rectum. Computed tomography (CT) showed two nonfatty, round masses, one of which contained a small central cystic area. The other mass had a homogeneous appearance and was believed to be in the wall of the rectum. The pathologic specimen showed organizing abscesses and a chronic xanthogranulomatous inflammation in tissue compatible with urogenital tissue, presumably a Mullerian duct remnant. This is the first documented report of anorectal xanthogranulomatous abscess in a Mullerian duct remnant with radiologic findings and histopathologic correlation. Though rare, this lesion should be considered in the differential diagnosis of extrinsic and intramural rectal masses seen on barium enema and CT examinations.

Abscess↗
PubMed1986

A solution to declining autopsy rates--the Decedent Affairs Office.

Can the decline in autopsy rates be reversed by solving logistical problems that impede or deter permissions and arrangements? The authors report an increase in the autopsy rate at their institution after a Decedent Affairs Office was established. Furthermore, the time between death and autopsy has been greatly narrowed, thus providing optimal tissue for diagnosis. As an additional benefit, the number of organ donations has also risen.

Autopsy↗