Search PubMed⌕ Search

Biomedical subjects

A N Srivastava

Publications and source records attributed to A N Srivastava.

At least 19 recordsLinked to original sources
PubMed2006

Role of different etiological factors in progression of cervical intraepithelial neoplasia.

Implication of high risk-human Papillomavirus in the process of cervical carcinogenesis is well documented. However, carcinogenesis in the cervix is recognized as multifactorial and other unknown etiological factors are also presumed to contribute to development of cancer. The present communication was aimed to investigate the role of risk factors such as age, parity, cervical lesions, and gynecological symptoms in the progression of the intra-epithelial cervical neoplasia. The study followed 571 cytologically diagnosed cases of high-grade squamous intraepithelial lesions (HSIL) during 35 yr of cytological screening, which is in progress at Gynae OPD of Queen Mary's Hospital of the University since April 1971 and until June 2005, a total of 33,658 cervical smears have been cytologically evaluated. Analysis of different risk factors in 571 HSIL cases revealed high parity coupled with increasing age to play a significant role in the progression of SIL. Further aggravated cervical lesions such as suspicious and unhealthy cervix and persistent vaginal discharge were found to be contributing factor in the progression of SIL. All these factors were predominantly seen in 35 cases of severe dysplasia that have shown progression from moderate dysplasia. The study indicates that women of high parity, especially with high age, are more prone to progression of SIL and hence this group needs mandatory cytological evaluation. Further adequate treatment of mild cervical lesions and persistent vaginal discharge is necessary to avoid the aggravation of the lesion/symptom and subsequent progression of dysplasia.

Adult↗
PubMed2006

The role of mast cells and eosinophils in chronic gastritis.

The role of mast cells and eosinophils in influencing the pathology of chronic gastritis remains unclear. We attempted to study the relationship between endoscopy and the mast cell and eosinophil infiltrate. We also studied the role of gene polymorphisms, Helicobacter pylori density and the CagA antibody status in influencing the mast cell and eosinophil infiltrate. One hundred and twenty consecutive patients were studied. Endoscopic evaluation was done and 3 antral biopsies were taken from each patient and were assessed for eosinophilic and mast cell infiltration, H. pylori density and the density of the other inflammatory cells as per the revised Sydney system. Cytokine gene polymorphisms (IL-1beta, IL-1RA and TNF-alpha) were done on the DNA extracted from the peripheral blood by PCR-RFLP. ELISA was done on the patients' serum for the anti-CagA antibody titres. Nodularity is strongly associated with the presence and density of eosinophils on biopsy (P < 0.05). Eosinophil density is strongly associated with the density of H. pylori, neutrophils, lymphocytes, plasma cells, atrophy, ulceration, foveolitis and lymphoid follicles. The mast cell density is not associated with any of the other histopathological variables. Gene polymorphisms and the CagA antibody titres have no relationship to the mast cell and eosinophil density. Eighty-one patients showed positive anti-CagA antibody titres but there was no association with the eosinophilic or the mast cell infiltrate. It is likely that eosinophilic infiltration is influenced by the H. pylori density but the CagA protein has no role to play in influencing the grade of the eosinophilic infiltrate in the Indian context. Cytokine gene proinflammatory polymorphisms have no role to play in influencing the eosinophilic or the mast cell response. It is likely that other mediators are involved in the inflammatory cell responses.

Adolescent↗
PubMed2004

Papillary renal cell carcinoma in a child.

AIM: To report a case of papillary renal cell carcinoma in a pediatric patient. METHOD: A seven-year-old boy complained of hematuria for one year. CT scan showed a mass in the middle zone of the right kidney. Radical nephrectomy was performed without incident. RESULT: Histology of the specimen showed papillary renal cell carcinoma. As the tumor was stage one, no chemotherapy was offered. At follow-up after 6 months the child was without recurrence or metastases. CONCLUSIONS: Papillary renal cell carcinoma is an uncommon kidney tumor in children and in its early stages it can be cured by nephrectomy alone.

Carcinoma, Papillary↗
PubMed2002

Unusual solitary osteochondroma of the mandibular ramus.

Mandibular osteochondromas, although rare, predominantly involve the condyloid and coronoid processes. An extremely rare case arising from the inner aspect of the gonion is reported here. Only one such case has been reported in the literature so far. Despite being very slow growing and having a benign course, histopathological examination showed reactive changes that may be confused with sarcomatous transformation. We advocate surgical excision using a combined external and internal approach followed by regular post-operative review. The relevant literature has been reviewed but various surgical approaches as advocated in the past have not been found suitable.

Female↗
PubMed2000

Overexpression of p53 protein in gallbladder carcinoma in North India.

AIMS: p53 mutations are one of the most frequent genetic alterations in human cancers and are thought to play a role in pathogenesis of several malignancies. Overexpression of p53 in gallbladder cancer has not previously been reported from North India which has one of the highest incidence of this malignancy in the world. The present work is aimed at studying the overexpression of p53 in gallbladder carcinoma occurring in North India. METHODS: p53 overexpression by immunohistochemistry was studied in 20 operative specimens of gallbladder carcinoma. The clinico-pathological observations of these patients were correlated with the extent of p53 overexpression. RESULTS: Seventy per cent (14/20) of specimens of gallbladder carcinoma overexpressed p53 protein. There was a significant correlation between presence of gallstones, T stage, grade of tumour and liver invasion with p53 overexpression. There was no significant correlation with other factors studied viz. age, sex, nodal status and histological type. CONCLUSIONS: The results show a strong association between gallstones and p53 protein overexpression in gallbladder carcinoma. The causal relationship in this association, however, still remains unproven.

Adult↗
PubMed1995

Detection of human papillomavirus DNA sequences in cancer of the urinary bladder by in situ hybridisation and polymerase chain reaction.

OBJECTIVE: To evaluate the prevalence of "high risk" human papillomavirus type 16 (HPV 16) in transitional cell carcinoma of the urinary bladder. MATERIALS AND METHODS: The study included 10 biopsy specimens from male patients of transitional cell carcinoma of the urinary bladder for the detection of HPV DNA sequences. Specimens were collected from the Urology Clinic of the K.G. Medical College Hospital, Lucknow, India. Detection of HPV DNA was carried out by tissue in situ hybridisation (a single copy gene localisation method) using 3H-labelled HPV DNA probe and also by polymerase chain reaction (PCR) techniques using primers to HPV 16 upstream regulatory region (URR). RESULTS: Out of 10 cases of transitional cell carcinoma of the urinary bladder, "high risk" HPV 16 DNA was detected only in one (10%) by using in situ hybridisation whereas two cases (20%) were found to be positive by polymerase chain reaction. CONCLUSION: Our results suggest that the rare occurrence of HPV in bladder carcinoma may not have a causal relation with the viral infection.

Base Sequence↗
PubMed1995

Predicting conditional probability distributions: a connectionist approach.

Most traditional prediction techniques deliver a single point, usually the mean of a probability distribution. For multimodal processes, instead of predicting the mean, it is important to predict the full distribution. This article presents a new connectionist method to predict the conditional probability distribution in response to an input. The main idea is to transform the problem from a regression problem to a classification problem. The conditional probability distribution network can perform both direct predictions and iterated predictions, the latter task being specific for time series problems. We compare this new method to fuzzy logic and discuss important differences, and also demonstrate the architecture on two time series. The first is the benchmark laser series used in the Santa Fe competition, a deterministic chaotic system. The second is a time series from a Markov process which exhibits structure on two time scales. The network produces multimodal predictions for this series. We compare the predictions of the network with a nearest-neighbor predictor and find that the conditional probability network is more than twice as likely a model.

Neural Networks, Computer↗
PubMed1995

Nonlinear gated experts for time series: discovering regimes and avoiding overfitting.

In the analysis and prediction of real-world systems, two of the key problems are nonstationarity (often in the form of switching between regimes) and overfitting (particularly serious for noisy processes). This article addresses these problems using gated experts, consisting of a (nonlinear) gating network, and several (also nonlinear) competing experts. Each expert learns to predict the conditional mean, and each expert adapts its width to match the noise level in its regime. The gating network learns to predict the probability of each expert, given the input. This article focuses on the case where the gating network bases its decision on information from the inputs. This can be contrasted to hidden Markov models where the decision is based on the previous state(s) (i.e. on the output of the gating network at the previous time step), as well as to averaging over several predictors. In contrast, gated experts soft-partition the input space, only learning to model their region. This article discusses the underlying statistical assumptions, derives the weight update rules, and compares the performance of gated experts to standard methods on three time series: (1) a computer-generated series, obtained by randomly switching between two nonlinear processes; (2) a time series from the Santa Fe Time Series Competition (the light intensity of a laser in chaotic state); and (3) the daily electricity demand of France, a real-world multivariate problem with structure on several time scales. The main results are: (1) the gating network correctly discovers the different regimes of the process; (2) the widths associated with each expert are important for the segmentation task (and they can be used to characterize the sub-processes); and (3) there is less overfitting compared to single networks (homogeneous multilayer perceptrons), since the experts learn to match their variances to the (local) noise levels. This can be viewed as matching the local complexity of the model to the local complexity of the data.

Computers↗
PubMed1995

Wilms' tumour : a clinicopathologic study with special reference to its morphologic variants.

Twenty five cases of Wilms' tumour were studied with special reference to their morphological variations. Wilms' tumour constituted 7.6% of all the malignant tumours of childhood and 50% of renal malignancies. Male/female ratio was 4:1; the mean age being 3.5 years. Left side was commonly involved (60.9%) center dot bilateral involvement in one case (4.3%). Morphologic study revealed triphasic pattern in 60% cases, biphasic (epithelial + stromal) in 12% and monophasic pattern in 28%. Other features observed were myxomatous degeneration, rhabdomyoblasts, calcification and squamous epithelial pearls seen in 20%, 12%, 8% and 4% respectively.

Adolescent↗
PubMed1994

Tumours of the male urogenital tract: a clinicopathologic study.

The present communication deals with the study of 388 tumours of the male urogenital tract diagnosed histopathologically during the period of 1984 to 1990. Of these 12 (3.09%) were benign and the rest 376 (96.91%) malignant. The incidence of malignant growths of male urogenital tract was 8.71% of all the malignancies or 14.19% of all cancers in males. Renal tumours constituted 10.64% of all the malignant tumours of male urogenital tract or 1.51% of all the male cancers. Morphological variants were renal cell carcinoma (37.5%), Wilms' tumour (47.5%), transitional cell carcinoma (7.5%), papillary cystic adenocarcinoma (3.5%), leiomyosarcoma (2.5%), metastatic from thyroid (2.5%). The mean age of the cases for renal cell carcinoma was 50.3 years and for Wilms' tumour 3.5 years. Urinary bladder cancer comprised 29.52% of all the malignancies of male urogenital tract or 4.19% of all malignant growths in males. The average age of the patients was 53.9 years. Transitional cell carcinoma was the commonest type of tumour (91.9%). Primary malignant tumours of the testis constituted 0.95% of all the malignancies, 1.55% of all male cancers, 10.9% of all malignancies of male urogenital tract or 18.3% of all the malignant growths of male genital tract. The mean age of the patients was 40.6 years. Seminoma was the commonest -46.34% of all the testicular tumours. The incidence of prostatic cancer was 1.81% of all cancers, 2.95% of all malignancies in males or 20.74% of all malignancies of male urogenital tract or 34.82% of malignancies of male genital tract.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Trace elements in the endometrium of infertile women.

Some essential trace elements were estimated in endometrium of regularly menstruating fertile women and in women with infertility due to cervical factors. The distribution of the trace elements zinc, copper, iron, selenium and manganese at any particular phase of cycle remains more or less semilier between control (i.e. fertile) and infertile (primary and secondary) subjects.

Adult↗
PubMed1983

Sarcocystosis in man: a report of two cases.

Two cases of sarcocystis infestation in living humans are reported. Both presented with discharging sinuses; one on the lower extremity, the other gluteal. Microscopical examination of excised sinus tissue revealed characteristic cysts of the parasite. In none of the cases was the parasite's presence previously suspected. The significance of this parasite is discussed in relationship to these and previously reported cases.

Adult↗
PubMed1975

Clinical study of Volkmann's ischemic contracture of the upper limb.

A clinical study of Volkmann's ischemic contracture of the forearm has been presented. The total incidence was 0.105 percent of all orthopedic cases. Mostly it occurred in males (77.5 percent), mostly in the second or third decade of life. Most patients lived in rural areas, reflecting prevailing socioeconomic conditions.

Compartment Syndromes↗
PubMedDate not supplied

Incisional skin metastasis of a squamous cell cervical carcinoma 3.5 years after radical treatment--a case report.

Metastatic carcinoma in an abdominal wall incision from internal malignant neoplasm is an uncommon and often a preterminal event. Most commonly metastatic skin incisional cancers have been reported with cancers of colon, kidney, and bladder. Incisional metastasis from postoperative case of carcinoma cervix is very rare. It has been reported in few patients with adenocarcinoma and poorly differentiated histopathology, more so at drain site postoperatively. We report a postoperative case of squamous cell carcinoma cervix FIGO stage IIA in a patient who after 3.5 years of completion of radical treatment (postoperative external and intravaginal radiation therapy) developed incisional skin metastasis followed by extensive subcutaneous metastasis in the vulval region. She received salvage chemotherapy; however, she did not show any response and finally succumbed to the disease. The outcome of patients with incisional skin metastasis is usually poor as they are often associated with locoregional recurrence. The intent of treatment remains palliation either by radiation/chemotherapy/surgery alone or in combinations. As far as we know, this is the first case of squamous cell carcinoma cervix stage IIA having incisional scar recurrence 3.5 years after postoperative radiotherapy.

Adult↗