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Biomedical subjects

P Menon

Publications and source records attributed to P Menon.

At least 19 recordsLinked to original sources

Imiquimod therapy for molluscum contagiosum.

BACKGROUND: Molluscum contagiosum virus (MCV) is a large double-stranded DNA virus that is a member of the family Poxviridae, and which has a worldwide distribution. As with other poxviruses, MCV does not appear to develop latency but evades the immune system through the production of viral specific proteins. OBJECTIVE: To evaluate the therapeutic efficacy of imiquimod 5% cream for MCV. METHODS: Thirteen children >5 and <10 years old, 19 immune-competent adults and four adults with advanced, but stable HIV-1 disease with >10 MCV lesions were treated with topical 5% imiquimod cream three times weekly for up to 16 weeks. RESULTS: Fourteen of 19 immune-competent adults, four of four adults with HIV-1 disease, and six of 13 children had resolution of their MCV lesions in <16 weeks of imiquimod therapy. Children tended to have more pruritus and inflammatory reactions with imiquimod, although most treated lesions appeared to respond. The development of new MCV lesions resulted in a lower overall resolution of the lesions in children. Imiquimod appeared to be the most efficacious in patients with HIV-1 disease and in the genital area in immune-competent adults. CONCLUSION: Although topical imiquimod appears to have some efficacy in the therapy of MCV, in children the pruritus correlated relatively well with the development of new lesions. In adults, areas that would be expected to have better penetration appeared to respond more consistently. Although the HIV-1-positive patients had the largest clinical lesions at the onset of therapy, as a group they had the best overall response to therapy.

AIDS-Related Opportunistic Infections↗

Preliminary observations on lymphocyte subpopulations in HIV seropositive & HIV seronegative tuberculosis patients in Pune, India.

CD4 and CD8 lymphocyte counts were determined in 59 HIV seropositive and 41 HIV seronegative newly diagnosed tuberculosis patients in Pune. There were significant differences in the CD4 counts and CD4/CD8 ratios between HIV seropositive and HIV seronegative tuberculosis patients. Majority of the HIV seropositive patients had a CD4 count less than 500 cells/cu.mm, whereas among the HIV seronegative patients, majority had a CD4 count more than 500 cells/cu.mm. In HIV seropositive patients with extrapulmonary and pulmonary tuberculosis, the CD4 counts were lower than in those who had only pulmonary or extrapulmonary tuberculosis. There was no significant differences in the CD8 counts between HIV seropositive and HIV seronegative tuberculosis patients, except for patients with pulmonary cavity, where the CD8 counts were significantly higher in HIV seropositive tuberculosis patients. In HIV seropositive individuals with pulmonary tuberculosis, the CD8 counts in those with pulmonary cavity were higher than in those without any pulmonary cavity. Absence of cavitation and presence of pulmonary with extrapulmonary tuberculosis occurred when immune activation was at a lower level.

Adult↗

Sampling density compensation in MRI: rationale and an iterative numerical solution.

Data collection of MRI which is sampled nonuniformly in k-space is often interpolated onto a Cartesian grid for fast reconstruction. The collected data must be properly weighted before interpolation, for accurate reconstruction. We propose a criterion for choosing the weighting function necessary to compensate for nonuniform sampling density. A numerical iterative method to find a weighting function that meets that criterion is also given. This method uses only the coordinates of the sampled data; unlike previous methods, it does not require knowledge of the trajectories and can easily handle trajectories that "cross" in k-space. Moreover, the method can handle sampling patterns that are undersampled in some regions of k-space and does not require a post-gridding density correction. Weighting functions for various data collection strategies are shown. Synthesized and collected in vivo data also illustrate aspects of this method.

Anisotropy↗

Effects of interleaf order for spiral MRI of dynamic processes.

The effects of the temporal order in which spiral interleaves are collected are discussed, in the context of artifacts from moving or changing objects. Simulations and in vivo experiments demonstrate the properties of four different ordering methods. Specific applications discussed include cardiac and interventional magnetic resonance imaging, as well as inflow and contrast-enhanced magnetic resonance angiography.

Artifacts↗

Unusual vascular dysplasia presenting as an intra-abdominal catastrophe.

A case of severe, generalised vascular dysplasia presenting as an intra-abdominal catastrophe is reported. Associated clinical features included cutis marmorata telangiectatica congenita, congenital glaucoma, hypertension, and focal fits. The case has been reported in view of its rarity and nature of presentation.

Abdominal Pain↗

Adjuvant therapy with hyaluronidase prior to excision of dermatofibrosarcoma protuberans.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) are uncommon, low grade cutaneous malignancies, which rarely metastasize. Although surgery is the main therapy for these tumors, they commonly recur in spite of wide excisions. Hyaluronidase (HD) has been used both intralesionally as well as intravenously as an adjuvant in therapy of both epithelial and mesenchymal malignancies to decrease local spread, to potentiate differentiation induced apoptosis, and to potentiate the tissue penetration of chemotherapeutic agents. In addition, there is a long history of intralesional HD use without significant complications. The biologic characteristics of DFSP including the observation that hyaluronic acid is commonly present and sometimes is increased in these tumors and the known effects of HD therapy in other malignancies suggested to us that HD pretreatment may be a helpful adjuvant in the surgical management of DFSPs. Following diagnostic biopsy of a recurrent DFSP, the patient was treated for 4 weeks with intralesional HD injections. RESULTS: Based on margins necessary for complete excision from past studies, this patient had decreased margin width and thus had a postoperative wound size less than was expected. The patient has had no evidence of recurrence at 24 months follow-up.

Chemotherapy, Adjuvant↗

Pretreatment with intralesional hyaluronidase prior to excision of dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSPs) are an uncommon malignancy that commonly recur, but rarely metastasize. The origin of DFSPs is controversial; however, they stain with the progenitor marker CD34. DFSPs usually show increased stromal mucin, mainly hyaluronic acid (HA). HA increases cellular proliferation, delays differentiation and increases cellular motion. We evaluated the pretreatment of DFSPs with intralesional injections of hyaluronidase (HD) prior to the surgical excision. Five of nine cases of DFSPs were pretreated with HD. In HD-pretreated cases the margins for excision of the residual tumor were reduced. HD pretreatment also decreased CD34 staining and increased polarizable collagen in the residual tumor.

Adult↗

Cutaneous epithelioid schwannomas: a rare variant of a benign peripheral nerve sheath tumor.

Although benign epithelioid peripheral nerve sheath tumors have been described, they are rare, and benign epithelioid schwannomas have not yet been established as a specific histologic variant. We present four cases of tumors which we believe would meet criteria to be classified as benign epithelioid schwannomas. Biopsy specimens obtained from four different patients were examined with routine and immunohistochemical staining. All the tumors were well-circumscribed lesions that were surrounded by a capsule containing EMA-positive cells. The cellular component was composed of epithelioid cells, in which there was a lack of mitotic activity. Immunohistochemical studies showed the tumor cells were S-100 protein and Leu 7 positive and HMB-45 negative. In addition, type IV collagen encircled individual cells within the tumor, indicating a continuous basal lamina. We report a group of cutaneous epithelioid schwannomas. Although the presence of such tumors is not unexpected, this diagnosis may not be initially considered because of this rare cytologic feature.

Adult↗

Hawaii Poison Center data reveals a need for increasing hazard awareness about household products.

This study examined for the fiscal years 1995-1996 and 1996-1997, the frequency of calls to Hawaii Poison Center related to household products and pesticides poisoning, the frequency of the source of calls (professional versus layperson), and the patient's age distribution. The data was compared with the data recorded in 1989 which was reported earlier in the literature. We found the most frequent calls were from general public (6 to 8 times) and were related to household products (30% in 1996-97, 39% in 1995-96, and 39% in 1989) involving children less than 5 years of age. Results strongly suggest the need for increasing the awareness of hazards related to household products amongst the general public.

Adolescent↗

Neurocristic cutaneous hamartoma: a distinctive dermal melanocytosis with an unknown malignant potential.

Neurocristic hamartomas (NCHs) result from aberrant development of the neuromesenchyme. In addition to a dermal melanocytic component, these tumors can contain neurosustentacular and fibrogenic components and can undergo malignant transformation. Although NCHs have many features in common with other dermal melanocytic neoplasms, including cellular blue nevi and some congenital nevi, they have distinctive clinical and histologic features. We present a case report of a 27-year-old white woman with an NCH of the scalp. The clinical, histologic, and immunohistochemical features are compared with those of other dermal melanocytic neoplasms. The NCH contained epithelioid pigmented melanocytes positive for S-100 and HMB45, within which there were well-circumscribed nodules of S-100+/Leu 7+/HMB45- cells surrounded by a capsule composed of spindle cells positive for epithelial membrane antigen. The stromal cells throughout the tumor were diffusely CD34 positive, and hair follicles were decreased and dystrophic within the tumor. NCHs represent neoplastic dysplasia that involves not only melanocytic cells but also neurosustentacular and fibrocytic effector cells. The histologic and immunohistochemical features, along with the decreased and dystrophic hair follicles, suggest that the abnormalities in the mesenchyme are significant and result from the contribution of neural crest cells to the cellular and matrix components of the mesenchyme.

Adult↗

Child development: vulnerability and resilience.

Many of the challenges facing children now are a function of changing times, including increase in urbanization, political violence, changing family forms, and in some areas decreased supplies of adequate food. This review focuses particularly on those changes in which children are the victims and which induce new threats for them, rather than on problems such as child disability or mental illness. The outcome variables of interest in this paper are dimensions of children's psychosocial development, including cognitive development, psychological adjustment and aggression, whereas the companion paper in this issue (Caldwell P., Child survival: vulnerability and resilience in adversity in the European past and the contemporary Third World, Soc. Sci. Med.) [1] focuses on physical aspects of children's development. The risks that are hurdles in the process of development of a young child begin from conception and carry on into later life. To address them all would be impossible; thus, in order to do justice to the issues at hand, we have chosen those risks that, in our view, are important in a child's psychosocial development in developing countries. This paper will thus provide a discussion of the concepts of risk and resilience, then apply these concepts to the analysis of three examples of risk faced by children today: nutritional threats (e.g. malnutrition due to decline in breastfeeding); family dynamics and types of family forms (e.g. child fostering and non-traditional families); and experiences of violence (domestic or political). In each case, the same four questions will be addressed: what are the consequences of the risk factor for children, what are the etiologies and conditions of risk, are there any children who seem to cope with the risk factor successfully and what are some of the protective factors, and what interventions or programs would help support these children?

Adolescent↗

Passive cigarette smoke-challenge studies: increase in bronchial hyperreactivity.

Degree and duration of bronchial hyperreactivity (BHR) after environmental tobacco smoke (ETS) inhalation was assessed in 31 smoke-sensitive subjects with asthma who exhibited lower airway symptoms on ETS exposure (group I) and 39 smoke-sensitive subjects without asthma who manifested only upper airway symptoms on cigarette-smoke exposure (group II). Subjects were challenged with ETS for 4 hours in a static-test chamber. The atmosphere was continuously monitored for airborne particulate levels (800 cpm), total suspended particulates (1266 +/- 283 micrograms/m3), and airborne nicotine levels (226 +/- 49 micrograms/m2). Methacholine challenges were performed before and serially after cigarette-smoke exposure, and the provocative dose causing a 20% fall in FEV1 was determined. Five of the 31 smoke-sensitive subjects with asthma and none of the smoke-sensitive subjects without asthma reacted to cigarette-smoke challenge (greater than or equal to 20% fall from baseline FEV1). Thirty-two percent (10/31) of the subjects with asthma demonstrated increased BHR at 6 hours, 29% (9/31) at 24 hours, and 13% (4/31) up to day 14 after ETS challenge. Of the subjects without asthma, 18% (7/39) demonstrated increased BHR at 6 hours, 10% (4/39) at 24 hours, and 8% (3/39) at 3 weeks. These studies demonstrated an increase in BHR after cigarette-smoke challenge in a number of study subjects (although they were clinically asymptomatic) and suggest that prolonged subclinical airway inflammation can occur in the absence of demonstrable change in airway caliber on exposure to ETS.

Adolescent↗

Comparison of cockroach allergenic activity in whole body and fecal extracts.

Previous studies have established cockroach allergens as important sensitizing agents in the induction/exacerbation of urban asthma. The present investigation compared saline extracts of American cockroach (Periplaneta americana) whole bodies and feces and German cockroach (Blattella germanica) whole bodies and feces as important sources of allergens. All extracts were tested before or after gel filtration on Sephadex G-75 columns (fraction 2) as previously described. Skin test studies of 69 subjects with asthma with extracts of American or German cockroaches demonstrated a significant correlation of reactivity to whole body and fecal extracts for both species. Direct RASTs of 13 sera from cockroach skin test-positive subjects were generally greater to both German whole body extracts (GWBEs) and German fecal extracts (GFEs) as compared to American whole body and fecal extracts. There was a good correlation of RAST reactivity to GWBE with GFE. RAST inhibition demonstrated that GFE contained most of the allergenic activity present in GWBE. These studies demonstrate the allergenic similarities of cockroach whole body and fecal extracts and suggest that cockroach feces are an important sensitizing agent in atopic asthma.

Allergens↗

Mortality of fecal bacteria in seawater.

We propose a method for determining the mortality rate for allochthonous bacteria released in aquatic environments without interference due to the loss of culturability in specific culture media. This method consists of following the disappearance of radioactivity from the trichloroacetic acid-insoluble fraction in water samples to which [3H]thymidine-prelabeled allochthonous bacteria have been added. In coastal seawater, we found that the actual rate of disappearance of fecal bacteria was 1 order of magnitude lower than the rate of loss of culturability on specific media. Minor adaptation of the procedure may facilitate assessment of the effect of protozoan grazing and bacteriophage lysis on the overall bacterial mortality rate.

Colony Count, Microbial↗

Skin test reactivity to whole body and fecal extracts of American (Periplaneta americana) and German (Blatella germanica) cockroaches in atopic asthmatics.

Forty-six atopic asthmatic subjects aged 3 to 58 years attending the allergy clinic of a university hospital were evaluated for prick skin test reactivity with commercially available extracts of cockroach (CCE) and house dust (HD). Additionally, skin testing was performed with American cockroach whole body (AWBE) and fecal extracts (AFE) as well as German cockroach whole body (GWBE) and fecal extracts (GFE) prepared in our laboratory. Commercial cockroach extract was prepared from American, German, and Oriental cockroach whole bodies. Skin test reactivity to the different extracts were as follows: 83% to HD, 70% to CCE, 70% to AWBE and/or GWBE, 63% to AWBE, 57% to GWBE, 63% to AFE and/or GFE, 52% to AFE, 50% to GFE, 48% to both AWBE and GWBE, and 39% to both AFE and GFE. The subjects with positive skin tests to AWBE and/or GWBE (70%) were the same individuals who showed skin test reactivity to CCE (70%). Subjects from lower income families (less than $10,000) had a significantly higher skin test reactivity to cockroach allergens than those from families with an annual income of $11,000 to $24,000 (P = .04). These results demonstrate the significance of cockroach sensitization in atopic asthmatics, suggest the importance of fecal cockroach allergens, and support earlier observations of shared interspecies allergens between American and German cockroach whole bodies.

Adolescent↗