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Biomedical subjects

S N Malik

Publications and source records attributed to S N Malik.

9 recordsLinked to original sources
PubMed2001

Retinal ischemia and embolism. Etiologies and outcomes based on a prospective study.

OBJECTIVES: To identify the most likely mechanisms of retinal ischemia and embolism in a hospital-referred population, and to determine the frequency of recurrent vascular events during the 3-month period following initial presentation. METHODS: Consecutive patients presenting to 2 tertiary medical centers and their outpatient clinics were prospectively enrolled over a 22-month period. Eligible patients presented with histories of transient or permanent monocular visual loss, or had evidence of asymptomatic retinal embolism on routine ophthalmological examination. They underwent a rapid and standardized evaluation that included imaging studies as well as blood tests, and follow-up was obtained at 1 and 3 months. RESULTS: Seventy-seven patients were enrolled. Enrollment diagnoses consisted of amaurosis fugax (n = 32), asymptomatic retinal embolism (n = 34), and central or branch retinal artery occlusion (n = 11). Eight different presumed etiologies of retinal artery distribution embolism or hypoperfusion were identified. Extracranial internal carotid artery occlusion or more than 50% stenosis was observed in 17/77 (22.1%) cases, making it the largest etiologic subgroup. Uncommon but treatable conditions were identified in 8/77 (10.4%) patients, and an etiologic diagnosis could not be made in 35/77 (45.5%) patients. Recurrent events occurred in, respectively, 14/77 (18.2%) and 6/73 (8.2%) patients at the 1- and 3-month follow-ups. They included 2 infarcts and 2 deaths; ischemic events of the retina were more common than those involving the brain. CONCLUSION: Severe stenosis of the extracranial internal carotid artery is the most common identified condition associated with retinal ischemia and embolism, but a variety of other, potentially treatable, conditions can be diagnosed if appropriate and specific evaluations are conducted. The frequency of recurrent vascular ischemic events is highest during the 1st month of follow-up and decreases during the 2nd and 3rd months. Recurrences range from relatively innocuous episodes of amaurosis fugax to vascular death.

Adult↗
PubMed1999

Monitoring patients for bladder neoplasms: what can be expected of urinary cytology consultations in clinical practice.

OBJECTIVES: To determine what practitioners could reasonably expect from urinary cytology (UC) consultations by analyzing their role in our clinical practice. METHODS: Reports of 227 consecutive interpretations on 130 patients collected during a 13-month period were correlated with all available follow-up information. RESULTS: In our practice, UC consultations can predict the presence of bladder carcinoma in nearly 90% of patients, the major mitigating factor being the absence of tumor cells in specimens from patients harboring bladder neoplasms. High-grade neoplasms are most reliably detected with UC. Very low grade neoplasms are difficult to detect, primarily because the cells of these lesions lack features of carcinoma. Significant interobserver variation did not occur. CONCLUSIONS: Pathology consultations based on UC can be associated with high diagnostic yields provided that certain factors are understood. These include that (a) the clinical import of diagnostic terms may vary among observers and should be mutually understood in individual practice settings; (b) UC specimens may not contain tumor cells even when patients have bladder cancer; (c) correlative information may be difficult to obtain and thus seem to inflate calculations for false-positive results; (d) interobserver variation can be reduced if cytopathologists use limited and uniform diagnostic terms; and (e) a high level of diagnostic expertise from cytopathologists should be expected.

False Negative Reactions↗
PubMed1975

Effect of surfactants on absorption through membranes III: effects of dioctyl sodium sulfosuccinate and poloxalene on absorption of a poorly absorbable drug, phenolsulfonphthalein, in rats.

The influence of dioctyl sodium sulfosuccinate and poloxalene on the GI absorption of phenolsulfonphthalein in the rat was studied. Urinary excretion data after oral administration of the drug to intact rats and loss of the drug from the whole small intestine as a loop were both utilized to assess the effect of the surfactants on absorption. Dioctyl sodium sulfosuccinate markedly increased the absorption of the drug, and the extent was dependent on the surfactant concentration. Maximum effect was observed at the reported ED50 in rats, of the surfactant as a fecal softener. The mechanism responsible for absorption enhancement seems to be an alteration of the permeability of the intestinal membrane. Micellar complexation between the drug and the surfactant resulted in a lesser increase in absorption at the higher surfactant concentrations. Poloxalene did not increase drug absorption, but higher concentrations caused a decrease in absorption due to micellar entrapments of the drug molecules. The influence of dioctyl sodium sulfosuccinate on the peritoneal absorption of the drug was also investigated. Lower doses of the surfactant increased absorption of the drug by altering the membrane permeability. Higher doses decreased absorption due to unavailability of the drug molecules entrapped in the micelles.

Animals↗
PubMedDate not supplied

Benign cellular changes in Pap smears. Causes and significance.

OBJECTIVE: We reviewed consecutive cases classified as benign cellular changes (BCC) over a four-month period. STUDY DESIGN: Cases classified as BCC were retrieved from the cytology files. A search was carried out to identify the previous Pap smears and concomitant cervical biopsies. RESULTS: One thousand one hundred three cases (23% of our gynecologic smears) were classified as BCC. Ninety-two patients (8.3%) underwent concurrent cervical biopsies. Specific infections accounted for 8% of BCC cases; reactive changes accounted for 92%. Of the biopsy specimens, 8.3% had no significant pathologic change. The most common biopsy diagnoses were cervicitis (31.5%), immature squamous metaplasia (16.3%) and reserve cell hyperplasia (10.8%). Miscellaneous benign diagnoses accounted for 21.7%. Cervical intraepithelial neoplasia (CIN) 1/human papillomavirus (HPV) was present in 14% of cases. All patients with biopsy diagnoses of CIN 1 had at least two previous abnormal Pap smears. Previous biopsy reports were available for review in 127 (12%) of the 1,103 patients. Of these 127 cases, 53.5% had a previous diagnosis of CIN/HPV; 9.4% had invasive carcinoma. A benign diagnosis was reported in 36.5%. CONCLUSION: The majority of BCC cases are due to reactive and inflammatory processes. In patients with a previous history of CIN, BCC may be of some significance. In patients with no significant prior cervical abnormalities, a Pap smear classified as BCC represents a reactive process.

Biopsy↗
PubMedDate not supplied

Do qualifiers of ASCUS distinguish between low- and high-risk patients?

OBJECTIVE: To evaluate the qualification of a Pap smear classified as atypical squamous cells of undetermined significance (ASCUS) favor reactive or neoplasia as recommended by the Bethesda System. STUDY DESIGN: The smears from 105 concurrent patients with a cytologic diagnosis of ASCUS not otherwise qualified were reviewed and subclassified as ASCUS favor reactive, low grade squamous intraepithelial lesion (LSIL) or high grade squamous intraepithelial lesion (HSIL) based on the Bethesda System criteria. The cervical biopsy diagnoses were correlated. RESULTS: Of the 105 cases classified as ASCUS, 37 were subclassified as favor reactive, 51 as favor LSIL and 17 as favor HSIL on cytologic review. In the ASCUS favor reactive group, 19 (51%) had reactive changes on biopsy, 17 (46%) had cervical intraepithelial neoplasia (CIN) 1, and 1 (2%) had CIN 3. A total of 48% patients had CIN. In the favor LSIL group, there was CIN 1 in 28 cases (55%), CIN 2 or 3 in 12 (23%) and benign changes in 11 (22%) on biopsy. Seventy-eight percent had CIN. In the 17 cases classified as ASCUS favor HSIL group, all had CIN. CONCLUSION: Of the total 105 cases of ASCUS, 71% had CIN, 29% had reactive changes on follow-up biopsies, and 48% of patients in the ASCUS favor reactive group had CIN. Qualifiers of ASCUS have questionable utility in patient management.

Adolescent↗
PubMedDate not supplied

Mesenchymal chondrosarcoma of the cerebellum.

Mesenchymal chondrosarcoma is a rare malignant neoplasm of bone and soft tissues. An unique case is described of an 8-year-old child with a midline cerebellar lesion. Pertinent clinical and radiologic findings along with histopathologic features are described. To our knowledge, this is the first case of mesenchymal chondrosarcoma arising in the cerebellar parenchyma of a child.

Cerebellar Neoplasms↗