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Biomedical subjects

B Sina

Publications and source records attributed to B Sina.

At least 19 recordsLinked to original sources
PubMed2000

Corrigendum

Explore the source record for details and available documents.

Journal Article↗
PubMed2000

Laboratory and field evaluation of polymerase chain reaction-based forensic DNA profiling for use in identification of human blood meal sources of Aedes aegypti (Diptera: Culicidae).

We modified polymerase chain reaction (PCR)-based forensic DNA profiling for field studies on the feeding behavior of Aedes aegypti, the principal mosquito vector of dengue virus. Human DNA was extracted from oral swabs of human subjects and from blood-engorged mosquitoes, DNA was quantified by slot blot, and alleles at variable number tandem repeats and three short tandem repeats loci were amplified by PCR. Alleles were separated electrophoretically and then visualized by silver staining. A custom software program was written to match DNA fingerprints of potential human hosts to allelic profiles detected in engorged mosquitoes, and to calculate error rates for identification of human hosts of single and multiple-host blood meals. At 29 degrees C in the laboratory, human DNA recovered from mosquito blood meals declined an average of 67% 8 h after feeding and 90% after 24 h. We obtained complete allelic profiles from seven of 10 mosquitoes collected after 24 h. In a field trial, complete DNA profiles were obtained successfully for 43 people living in a rural village in south central Thailand and for 20 of 100 Ae. aegypti that contained blood and were collected in those peoples' homes. Blood imbibed from more than one person was detected in 45% (9 of 20) of the meals. Sixty-five percent of the meals contained blood from nonresidents of the house in which the mosquito was collected or from people who were not profiled; data consistent with the hypothesis that human movement is important for the spread of dengue virus within and among communities. When using alleles at four loci, all of the Thais and nine members spanning three generations of a Chinese-American family had unique allelic profiles. Error rates from classifying possible multiple-host meals as single-host meals were low (1-8%), with the highest error associated with closely related people. Results from our laboratory and field studies indicated that DNA profiling can be used to study the details and epidemiological implications of Ae. aegypti blood-feeding behavior.

Aedes↗
PubMed1999

Solitary mastocytoma arising at a hepatitis B vaccination site.

On the first day of life, a healthy infant was given a recombinant hepatitis B vaccine. Over the following year, a 3 by 4.5 cm, well-defined, erythematous patch with an overlying white, reticulated, smaller plaque gradually appeared on her thigh at the vaccination site. Darier's sign was elicited at the site. Examination of a biopsy specimen showed an upper dermal mast cell infiltrate. This is the first reported case of a solitary mastocytoma appearing in a vaccination site.

Biopsy↗
PubMed1997

Metastatic inflammatory carcinoma of the rectum: tumor spread by three routes.

We report a case of a patient with adenocarcinoma of the rectum with inflammatory metastases to the skin who was treated with radiation therapy and subsequently developed lymphatic obstruction with resultant extensive lymphedema of the lower extremities. Histopathologic examination and immunohistochemistry showed intralymphatic, intravascular, and interstitial malignant cells in the dermis. To our knowledge, this is the second reported case of inflammatory carcinoma arising from metastatic carcinoma of the rectum. However, tumor cell spread to the skin by three routes has not previously been demonstrated.

Adenocarcinoma↗
PubMed1995

Cutaneous eruptions from suramin. A clinical and histopathologic study of 60 patients.

BACKGROUND AND DESIGN: During a trial of suramin for advanced solid tumors, a high rate of cutaneous adverse reactions was observed. We present a prospective study, describing the clinical, histopathologic, histochemical, and immunochemical findings of the cutaneous reactions observed in 60 patients treated with suramin. RESULTS: Forty-nine (82%) of the 60 patients studied experienced at least one cutaneous reaction attributable to suramin therapy. Although morbilliform reactions predominated, a wide variety of eruptions was observed. Most reactions occurred within the first 24 hours of therapy and were self-limited despite continued drug infusion. Distinctive cutaneous findings included scaling erythematous papules (suramin keratoses) and a predilection of many eruptions for previously sun-exposed areas. Six patients experienced severe cutaneous reactions, but no patient permanently withdrew from therapy because of cutaneous toxic reactions. Common histopathologic findings included hyperkeratosis, parakeratosis, spongiosis, acanthosis, exocytosis, apoptosis, a perivascular lymphohistiocytic infiltrate, upper dermal edema, and increased dermal mucin. Staining with S100 antigen was markedly positive in several specimens. Only trace amounts of suramin were detected in skin samples tested with high-pressure liquid chromatography. CONCLUSIONS: The incidence of cutaneous toxic reactions from suramin greatly exceeds that seen with other medications. A wide spectrum of skin manifestations were observed, including suramin keratoses and UV recall, although serious reactions were infrequent. Cutaneous toxic reactions neither predicted nor correlated with other toxic reactions from suramin. Suramin may soon become more widely used; practitioners should be aware of the high incidence and wide spectrum of cutaneous toxic reactions to this drug.

Adult↗
PubMed1992

Probing behaviour and sporozoite delivery by Anopheles stephensi infected with Plasmodium berghei.

We observed that Plasmodium berghei sporozoite-infected Anopheles stephensi was not impaired in its ability to locate blood on a host. When probing rats, infected mosquitoes took as long as non-infected mosquitoes to locate blood. Contrary to previous suggestions, infective mosquitoes delivered sporozoites into mineral oil even after extensively probing a vertebrate host. We observed that, in mosquitoes having probed a host, both the mean number of sporozoites ejected over 3 min into oil (35.9 v. 31.7 sporozoites) and the proportion of mosquitoes delivering sporozoites (60% v. 50%) were similar to mosquitoes not having probed. We then developed a model of sporozoite delivery, taking into account observations that sporozoites are clumped in the lumen of the glands as well as upon delivery, and that output is uneven and inconsistent. We conclude that clumping optimizes transmission, if a threshold of infection exists and the mean number of sporozoites per clump is greater than the threshold.

Animals↗
PubMed1992

Fibrous mastocytoma in a patient with generalized cutaneous mastocytosis.

A 57-year-old woman with cutaneous mastocytosis of 23 years duration developed a hyperpigmented abdominal plaque composed of confluent indurated papules that enlarged for a period of 1 year to 12 x 8 cm. Biopsy showed dermal infiltration by closely packed spindle-shaped mast cells, fibroblasts, collagen, and scattered lymphocytes, predominantly T-suppressor cells. Electron microscopy showed close contact between mast cells, fibroblasts, and lymphocytes. Piecemeal mast cell degranulation and extrusion of mast cell granules was seen, with rare mast cell granules in fibroblasts, and collagen fibers in peripheral and perinuclear endoplasmic reticulum of mast cells. the term Fibrous mastocytoma is suggested for this tumor-like dermal fibrosis, possibly induced by lymphokines.

Biopsy↗
PubMed1992

Generalized elastophagocytic granuloma.

The case of an eighty-three-year-old woman with the sudden onset of a generalized pruritic eruption is reported. The skin lesions resembled disseminated subacute lupus erythematosus on clinical examination, but actinic granuloma or annular elastolytic giant cell granuloma was seen in biopsy specimens of the lesions. Our case was differentiated from generalized granuloma annulare by the distinct zoning of elastolysis and the distribution of giant cells.

Aged↗
PubMed1990

Non-CS pre-erythrocytic protective antigens.

Three novel non-CS antigens have been identified on P. falciparum and P. berghei sporozoites and exoerythrocytic parasites. CSP-2 is a sporozoite surface protein common to P. falciparum and P. berghei that elicits antibody-mediated protection, and is also found within P. berghei EE parasites. LSA is a P. falciparum EE-specific antigen localized within the parasitophorous vacuole. LSA-2 is a P. berghei EE-specific antigen, localized on the parasitophorous vacuole membrane, that protected mice to P. berghei sporozoite challenge, and elicited cytotoxic T cells that killed P. berghei EE parasites in vitro.

Amino Acid Sequence↗