Biomedical subjects

R K Gupta

Publications and source records attributed to R K Gupta.

At least 883 records · Page 49Linked to original sources

PubMedDate not supplied

Fine-catheter aspiration cytology of peritoneal cavity improves decision-making about difficult cases of acute abdominal pain.

Fine-catheter aspiration cytology of the peritoneal cavity was successfully undertaken in 25 of 27 hospital inpatients with acute abdominal pain because it was not clear whether they required urgent laparotomy. Cytological specimens were prepared by the cyto-sieve technique. The main test criterion was the percentage of neutrophils in the peritoneal cell sample. The decision before the test about urgent laparotomy was correct in 14 of the 27 patients, whereas the decision after the test was correct in 26 of the 27 patients (p = 0.001). 4 patients were saved unnecessary laparotomy and 8 further delay in laparotomy.

Abdomen, Acute↗

PubMedDate not supplied

Determination of protein loading in biodegradable polymer microspheres containing tetanus toxoid.

Various methods to determine loading of vaccine in biodegradable polymer microspheres encapsulating tetanus toxoid were evaluated. The microspheres were composed of poly (D-lactic acid) (PLA) and poly (DL-lactic-co-glycolic acid) (PLGA). Dissolution of microspheres in organic solvents such as methylene chloride, chloroform, or dimethyl sulfoxide and extraction of vaccine antigen or total protein with phosphate buffered saline gave variable results which depended upon the characteristics of the microspheres, such as type of polymer, excipients used in the microspheres and formulation conditions. Microspheres made from low molecular weight PLGA polymer and showing a large burst release exhibited up to 25% extraction of antigen whereas microspheres made from PLA microspheres with low burst release showed < 1% extraction. Extraction of total protein with 0.1 N NaOH and 5% sodium dodecyl sulfate showed results similar to those obtained with organic solvent extraction method. Partial digestion of microspheres with 6 N HCl at 60 degrees C for 20 h resulted in approximately 30% loss in TT protein by micro-bicinchoninic acid (BCA) assay. The major problem with this method was strong reactions in the micro-BCA assay of stabilizers, particularly sugars (glucose, sucrose) used in the microsphere formulations. Complete digestion of microspheres with 6 N HCl at 110 degrees C for 20 h or with 13.5 N NaOH at 121 degrees C for 1 h and quantitation of amino acids by a modified ninhydrin assay showed reproducible results on the protein loading in the microspheres. However, this method was affected by the presence of stabilizers, such as gelatin, which contain amino acids. Further, sucrose concentrations higher than 10% caused interference in the ninhydrin assay on samples hydrolyzed with 6 N HCl. In contrast, hydrolysis with 13.5 N NaOH did not show any interference by sucrose. Stabilizers used outside the microspheres for lyophilization purposes may be removed by washing the microspheres before loading determination or by dialysis but stabilizers used inside the microspheres would still cause interference. For reliable determination of total protein in the microspheres containing vaccines, we suggest complete digestion of microspheres with acid or base followed by amino acid analysis by colorimeteric assays such as ninhydrin method or using amino acid analyzers. The method needs to be optimized for each type of formulation to eliminate interference by the excipients. Alternatively, total protein nitrogen in the microspheres may be determined by the Kjel-dahl method if no amino acids or other nitrogen containing stabilizer is used inside the microspheres.

Antigens, Bacterial↗

PubMedDate not supplied

Differences in the immunogenicity of native and formalinized cross reacting material (CRM197) of diphtheria toxin in mice and guinea pigs and their implications on the development and control of diphtheria vaccine based on CRMs.

Immunogenicity of native and formalinized cross reacting material (CRM197) of diphtheria toxin (DTx) was assessed in mice and guinea pigs. For the primary response, mice produced similar levels of diphtheria toxoid (DTxd) IgG antibodies to both native and formalinized preparations of CRM197 though the antibody levels were significantly lower than those elicited by conventional DTxd (P < 0.05). In contrast, guinea pigs showed significantly higher levels of DTxd IgG antibodies to the formalinized CRM197 preparation than the native preparation (P < 0.001) after single injection. These differences in the immunogenicity of mice and guinea pigs to native and formalinized CRM197 preparations have implications for the development and control of diphtheria or other vaccines involving the use of CRMs.

Animals↗

PubMedDate not supplied

Rational approaches to reduce adverse reactions in man to vaccines containing tetanus and diphtheria toxoids.

Adverse reactions to routine vaccines are obstacles to the mass vaccination campaigns. Though the absolute safety of any injectable vaccine cannot be guaranteed, the adverse side effects to vaccines can be minimized by practicing existing scientific knowledge. Adverse side effects to tetanus and diphtheria toxoids have been known for many years and there have been ways to minimize these reactions. These procedures did not get wide acceptance, because the current partially purified tetanus and diphtheria vaccines meet the regulatory requirements and the manufacturers are reluctant to change the established procedures of production due to the amount of work involved in the regulatory issues under the current Good Manufacturing Practices (GMP). Due to the recent epidemic of diphtheria in the independent states of the former Soviet Union, and its potential for spread to other European Countries, vaccination campaigns with tetanus and diphtheria vaccines received a new boost with several international agencies. In this report, we review the causes for adverse reactions to tetanus and diphtheria vaccines and offer practical suggestions for minimizing these reactions. The major issues in minimizing adverse reactions to these vaccines include: (1) purifying the toxins before detoxification as the reactogenic accessory antigens get covalently bound to the toxins during detoxification; (2) either using well-tolerated adjuvants which do not elicit the production of antigenic specific IgE antibodies responsible for adverse reactions or by using non-adjuvanted highly immunogenic polymerized antigens; (3) checking the status of immunity by recently developed rapid serological methods or by the Schick skin-test for diphtheria to avoid allergic or Arthus-type reactions. These approaches are applicable to industrial scales and would result in a pure, less reactogenic and better characterized toxoids antigens which would be more suitable for combined vaccines comprising highly purified acellular pertussis components, polysaccharide-protein conjugates and other antigens.

Adjuvants, Immunologic↗

PubMedDate not supplied

Ambient air pollution and chronic respiratory morbidity in Delhi.

The authors conducted a cross-sectional study among residents of Delhi to determine the role of ambient air pollution in chronic respiratory morbidity in Delhi. The authors selected a random, stratified sample (N = 4,171) of permanent residents who were 18+ y of age and who lived near 1 of the 9 permanent air quality monitoring stations in the city. Air-quality data for the past 10 y were obtained; data were based on the differences in total suspended particulates, and the study areas were categorized into lower- and higher-pollution zones. A standardized questionnaire was administered, clinical examination was carried out, and spirometry followed. The authors assessed chronic respiratory morbidity by (a) prevalence of chronic respiratory symptoms (i.e., chronic cough, phlegm, breathlessness, and wheezing) and airway diseases (i.e., chronic obstructive pulmonary disease/chronic bronchitis and bronchial asthma); and (b) lung function results in asymptomatic nonsmoking subjects in the two pollution zones. A multiple logistic regression identified the determinants of chronic symptoms. Smoking, male sex, increasing age, and lower socioeconomic status were strong independent risk factors for occurrence of chronic respiratory symptoms. In the comparison of nonsmoking residents of lower- and higher-pollution zones--stratified according to socioeconomic levels and sex--chronic cough, chronic phlegm, and dyspnea (but not wheezing) were significantly more common in the higher-pollution zone in only some of the strata. Furthermore, prevalence rates of bronchial asthma, chronic obstructive pulmonary disease, and chronic bronchitis among residents in the two pollution zones were not significantly different. Nonetheless, lung function of asymptomatic nonsmokers was consistently and significantly better among both male and female residents of the lower-pollution zone.

Adolescent↗

PubMedDate not supplied

MR imaging of intracranial tuberculomas.

Eight patients with intracranial tuberculomas were studied with CT and magnetic resonance (MR) imaging. Large, ring enhancing, solid lesions on CT showed low intensity on T2-weighted images and intermediate intensity on T1-weighted images. Small lesions, with ring enhancement on CT, showed central bright signal on T2-weighted images with a peripheral low intensity rim surrounded by high intensity edema. The MR imaging features of the tuberculomas were found to be distinct from those of abscesses, metastases, and gliomas.

Adolescent↗

PubMedDate not supplied

Craniospinal enterogenous cyst: MR findings.

An enterogenous cyst of the craniocervical region producing anterior medullary compression is reported. The patient presented with quadriparesis with greater involvement of the upper limbs. Computed tomography showed a high attenuation intradural extramedullary mass located anteriorly. Magnetic resonance imaging demonstrated a high intensity mass extending from the pontomedullary junction to the second cervical vertebra, flattening the medulla and upper cervical cord. Complete recovery ensued following total excision of the cyst.

Adult↗

PubMedDate not supplied

Differentiation of calcification from chronic hemorrhage with corrected gradient echo phase imaging.

PURPOSE: The purpose of the current study was to prospectively evaluate the role of corrected gradient echo phase imaging in differentiation of calcified granuloma from chronic hemorrhage. METHOD: Eighty-five patients with single/multiple calcifications and hemorrhages irrespective of their location were studied with corrected gradient echo phase imaging. In all the cases, CT was used as the gold standard for the presence/absence of calcification. RESULTS: All calcified lesions showed positive phase, whereas chronic hemorrhages showed negative phase in all cases. Five calcified lesions showed no phase shift at TE =15 ms and positive shift at TE = 35 ms. Heterogeneous phase shift was observed in three calcified lesions at TE = 35 ms; all three lesions showed positive phase shift at TE = 15 ms. There was no site-specific problem in differentiation of calcification from chronic hemorrhage including in the basal ganglia. CONCLUSION: We conclude that calcified granuloma can be easily differentiated from chronic hemorrhage with corrected gradient echo phase imaging, which may obviate the need for CT for its confirmation.

Adolescent↗

PubMedDate not supplied

Magnetic resonance imaging evaluation of focal computed tomography abnormality in epilepsy.

Sixty-seven patients with epilepsy and isolated enhancing computed tomography (CT) scan lesion were studied with magnetic resonance imaging (MRI). Fifty-six patients (83.5%) had partial seizures and 11 (16.4%) had generalized seizures. Four distinct groups were identified by MRI: nonspecific 16 cases (23.8%), tuberculoma 38 cases (56.7%), cysticercosis 12 cases (17.9%), and abscess 1 case (1.4%). Patients in the non-specific group had lesions that were hyperintense on T2 images and hypointense or isointense on T1 images. Such lesions resolved completely in 5 months with serial MRIs while the patients were receiving antiepileptic drugs (AEDs). Virologic studies, including cerebrospinal fluid (CSF) serology, are suggested for patients with such MRI lesions.

Brain↗

PubMedDate not supplied

Scan-negative neurocysticercosis.

An 11-year-old child was diagnosed as having benign intracranial hypertension on basis of clinical examination and normal CT scan. Magnetic resonance imaging demonstrated multiple lesions in both cerebral hemispheres, some of which showed nodular scolex characteristic of cysticerci.

Animals↗

PubMedDate not supplied

31P nuclear magnetic resonance and saturation transfer studies of the isolated perfused rat kidney.

Previous studies using 31P nuclear magnetic resonance (NMR) saturation transfer techniques to quantitate the energy metabolism of the kidney have often resulted in estimates of adenosine triphosphate (ATP) turnover which are much lower than those predicted from the renal oxygen consumption and reasonable values of the P/O ratio. We measured the ATP turnover in isolated perfused kidneys of rats, using 31P NMR saturation transfer and a new procedure for quantitation of the intracellular Pi concentration. The estimated turnover rates of ATP were higher than previously reported. The P/O ratios calculated on the basis of these rates of ATP turnover and rates of renal oxygen consumption reported in the literature were within the range of theoretically possible values. Thus, 31P NMR saturation transfer can be used to quantitate the ATP turnover in the isolated perfused rat kidney.

Adenosine Triphosphate↗

PubMedDate not supplied

Fine needle aspiration cytodiagnosis of primary squamous cell carcinoma of the gallbladder. Report of two cases.

BACKGROUND: Cytologic descriptions of the diagnosis of the rare primary carcinoma of the gallbladder are sparse. The obstacles to the diagnosis are ascribed to vague symptoms and inaccessibility of the gallbladder to biopsy. We describe two cases of primary squamous cell carcinoma of the gallbladder that were diagnosed using fine needle aspiration (FNA) cytology. CASES: Both patients were elderly females with vague symptoms of abdominal pain, jaundice, loss of weight, anorexia and mild fever. Imaging studies showed enlargement of the gallbladder with a soft tissue mass in the fundus and abnormally thickened wall, indicative of a tumor. Also, in case 1, gallstones and enlarged, matted paraaortic and porta hepatis lymph nodes were present. FNA of the gallbladder was done after selection of a suitable puncture site and needle positioning, which was confirmed by computed tomography. The aspirated material was collected as needle and syringe washings, and from half the material filter preparations were made and stained for cytologic study, while the remainder was used for making cell blocks for histologic study. Both cases showed cytohistologic features of a moderately well differentiated, necrotizing squamous cell carcinoma characterized by keratinizing malignant cells with orangeophilic cytoplasm. In both cases immunostaining for high-molecular-weight keratins (AE1/AE3) and cytokeratin (CAM 5.2) was positive, while staining for carcinoembryonic antigen, B72.3 and other markers was negative. CONCLUSION: This study further confirmed that with the widespread use of more-sophisticated imaging techniques, the gallbladder is becoming more readily accessible to visualization. In view of this, FNA cytodiagnosis holds promise as a noninvasive technique in the diagnosis of gallbladder neoplasms.

Aged↗

PubMedDate not supplied

Fine needle aspiration cytology in xanthogranulomatous cholecystitis, gallbladder adenocarcinoma and coexistent lesions.

OBJECTIVE: To evaluate the diagnostic efficacy of fine needle aspiration cytology (FNAC) in gallbladder mass lesions and to explore the possibility of overlooking malignancy in coexistent adenocarcinoma with xanthogranulomatous cholecystitis (XGC) on fine needle aspiration smears. STUDY DESIGN: In a retrospective, seven-year study, ultrasound-guided needle aspirates from 25 histologically proven cases of gallbladder adenocarcinoma, 11 cases of gallbladder adenocarcinoma associated with XGC and 20 cases of XGC were evaluated for the presence of mesotheliumlike, foam, inflammatory and multinucleate giant cells; pink, granular background; bile; and degenerated cells, along with atypical or frankly malignant cells. Detailed clinical findings were retrieved from the records. RESULTS: The overall sensitivity of detecting carcinoma was 90.63% and specificity 94.74%. The sensitivity of detecting malignancy was 80% when adenocarcinoma was associated with XGC. CONCLUSION: FNAC plays an important role in making the preoperative diagnosis of adenocarcinoma, XGC and coexistent lesions. The probability of detecting malignancy is greater than with XGC in coexistent lesions. Thus, a preoperative FNAC diagnosis would help in determining the urgency of treatment and in planning for the surgical procedure in gallbladder lesions.

Adenocarcinoma↗

PubMedDate not supplied

Fine needle aspiration cytodiagnosis of leiomyosarcoma of the breast. A case report.

BACKGROUND: Leiomyosarcoma of the breast is a rare tumor. Here we present a case in an elderly female in which the diagnosis was suggested from an aspirate sample. CASE: An 80-year-old female presented with an irregular, firm mass in the left breast of a few months' duration. In view of the clinical suspicion of a tumor, fine needle aspiration was performed. It showed a large number of dissociated cells and compact sheets of spindly and round cells with pleomorphic, hyperchromatic and anaplastic nuclei; mitoses; nucleoli; and somewhat-vacuolated, eosinophilic cytoplasm. Examination of the cell block, tumor tissue and immunostaining further suggested the cytologic impression of a leiomyosarcoma. CONCLUSION: Although leiomyosarcoma of the breast is very rare, fine needle aspiration cytology may allow the diagnosis to be suggested. Correlation with cell block findings and the application of appropriate immunostains as an adjuvant to standard cytologic and histologic stains may allow a more confident diagnosis.

Aged↗

PubMedDate not supplied

Fine needle aspiration cytology of cutaneous and subcutaneous metastatic deposits from epithelial malignancies. An analysis of 146 cases.

OBJECTIVE: To analyze cases suggestive of cutaneous/subcutaneous metastatic deposits from a known carcinoma or as the first manifestation of an unknown carcinoma using fine needle aspiration cytology (FNAC). STUDY DESIGN: The study group consisted of 146 patients (86 males and 60 females) ranging in age from 34 to 82 years. In 135 cases there was a previous history of carcinoma, and in these cases FNAC showed the tumor to be similar to the carcinoma that had been treated by surgery and/or radiotherapy. In 11 patients no tumor had been found previously, and the site of the unknown primary was suggested by immunostaining. Aspirations were performed using a 22-gauge needle. The material was collected in 30% ethyl alcohol, and filter preparations and cell blocks were made. RESULTS: The size of metastatic nodules ranged from 1.5 to 2 cm. The sites of metastases were on the chest wall (n = 35), back (n = 8), abdomen (including umbilicus) (n = 46), head and neck (n = 35), upper extremity (n = 12), lower extremity ((n = 6), penile skin (n = 1) and vulva (n = 3). The sites of known primary carcinomas were breast (n = 39), lung (n = 35), gastrointestinal tract (n = 38), endometrium (n = 2), cervix (n = 3), urinary tract (n = 4), prostate (n = 3), hand (n = 1), scalp (n = 1), tongue (n = 1), brain (n = 1), ear (n = 3) and ovary (n = 4). The sites of primary carcinomas unknown at the time of aspiration and found after FNAC were the gastrointestinal tract (n = 3), lung (n = 2), prostate (n = 1), breast (n = 3), liver (n = 1) and kidney (n = 1). No false negatives or positives were observed, and no second primary tumors were found. Cytologic preparations were sufficient for diagnosis and typing in tumors with a known primary tumor. Immunostaining was helpful in establishing a diagnosis of carcinoma and in determining the likely primary site in tumors with unknown primaries. CONCLUSION: Cutaneous and subcutaneous metastatic deposits from previously known carcinomas can be diagnosed rapidly and accurately utilizing FNAC. A combination of FNAC and immunostaining may also help define the site of an unknown primary.

Adenocarcinoma, Papillary↗

PubMedDate not supplied

Fine needle aspiration cytodiagnosis of sialadenitis with crystalloids.

OBJECTIVE: To assess the utility of fine needle aspiration cytology in the diagnosis of sialadenitis with crystalloid formation in four patients that presented with a swelling of the parotid gland. STUDY DESIGN: The swelling was aspirated in all the cases using a 22-gauge needle, and aspirates were submitted as needle and syringe washings in a cytology fixative (30% ethyl alcohol in physiologic saline). From these washings filter preparations were made on Sartorius or Gelman filters (pore size, 3 microns) and stained by the Papanicolaou method. Additionally, cell block preparations were made from the aspirate. After processing, sections were cut and stained by hematoxylin-eosin, Prussian blue, alcian blue, mucicarmine, and Von Kossa and congo red stain. No air-dried smears were made, and no electron microscopic studies were done. RESULTS: Stained cytologic preparations and cell blocks showed numerous nonbirefringent crystalloids of varying sizes and shapes appearing as rectangles, needles, squares and rods mixed with neutrophils and rare multinucleated giant cells. No salivary gland components were seen, and all special staining was negative. CONCLUSION: Fine needle aspiration cytology not only provided an accurate diagnosis of sialadenitis with crystalloids but also resulted in adopting conservative management and avoiding unnecessary surgery.

Adolescent↗

PubMedDate not supplied

Xanthogranulomatous cholecystitis. Fine needle aspiration cytology in 17 cases.

OBJECTIVE: To establish morphologic features of xanthogranulomatous cholecystitis (XGC) on fine needle aspiration cytology (FNAC). STUDY DESIGN: In a retrospective, five-year study, ultrasound-guided fine needle aspirates from 17 cases of histologically proven XGC were examined for the presence of histiocytes, foam cells, inflammatory cells, multinucleate giant cells, bile, cholesterol crystals, degenerate cells, normal columnar epithelial cells, capillary endothelial cells and a pink granular background. RESULTS: The presence of histiocytes, foam cells, multinucleate giant cells, bile and a mixed population of inflammatory cells in varying proportions on a background of pink, granular debris was characteristic of XGC. However, pleomorphism in reactive histiocytes can occasionally raise the suspicion of malignancy, necessitating a comprehensive evaluation of the overall cytologic findings. CONCLUSION: XGC has characteristic cytologic features that can be used to differentiate it from malignancy, which XGC can mimic clinically and radiologically. Preoperative FNAC in such cases would help to guide the surgeon toward a correct surgical approach.

Bile↗

PubMedDate not supplied

Fine needle aspiration cytodiagnosis of primary and metastatic squamous cell carcinoma of the breast.

OBJECTIVE: To assess the diagnosis of squamous cell carcinoma involving the breast by fine needle aspiration cytology in four cases (two primary and two metastatic). STUDY DESIGN: All patients were women between the ages of 42 and 74 years. The aspiration findings were confirmed by cell blocks of the aspirates, biopsy and/or comparison of the tissue from the previous primary. The aspirate was obtained using multiple passes in the breast masses while maintaining negative pressure. RESULTS: The cytohistologic features in all cases were characterized by numerous malignant squamous cells with hyperchromatic, enlarged, dense nuclei; thickened nuclear membranes; coarse chromatin; abundant eosinophilic, keratinizing glassy cytoplasm; and a necrotizing background with keratin debris. The diagnostic value of immunocytochemical study was considered questionable despite immunopositivity for cytokeratin and epithelial membrane antigen and negative staining for carcinoembryonic antigen and B72.3 in all cases. CONCLUSION: The identification of malignant squamous cells in breast aspirates is an important observation. Such cells, when seen as the predominant ones in an aspirate, should prompt a search for other sources of a primary tumor before a diagnosis of squamous cell carcinoma of the breast is accepted.

Adolescent↗