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Biomedical subjects

Iftikhar Ahmed

Publications and source records attributed to Iftikhar Ahmed.

At least 19 recordsLinked to original sources
PubMed2006

A novel highly boron tolerant bacterium, Bacillus boroniphilus sp. nov., isolated from soil, that requires boron for its growth.

Three strains of gram-positive, motile, rod-shaped and boron (B)-tolerant bacterium were isolated from naturally B containing soil of Hisarcik area in the Kutahya Province, Turkey. The strains, designated as T-14A, T-15Z(T) and T-17s, produced spherical or ellipsoidal endospores in a terminal bulging sporangium. The strains required B for the growth and can tolerate more than 450 mM B. These also tolerated up to 7.0% (w/v) NaCl in the presence of 50 mM B in agar medium but grew optimally without NaCl. The temperature range for growth was 16-37 degrees C (optimal of 30 degrees C), whereas the pH range was 6.5-9.0 (optimal of 7.5-8.5). The DNA G + C content was 41.1-42.2 mol% and the predominant cellular fatty acid was iso-C(15:0). The major respiratory quinone system was detected as MK-7 and the diamino acid of the peptidoglycan was meso-diaminopimelic acid. Based on phenotypic and chemotaxonomic characteristics, phylogenetic analysis of 16S rRNA gene sequences data and DNA-DNA re-association values, we concluded that the three strains belong to a novel species of the genus Bacillus, the type strain of which is T-15Z(T) and for which we proposed the name, B. boroniphilus sp. nov. (DSM 17376(T) = IAM 15287(T) = ATCC BAA-1204(T)).

Bacillus↗
PubMed2006

Livedoid vasculopathy: further evidence for procoagulant pathogenesis.

OBJECTIVE: To further characterize the clinical and pathologic features, disease associations, and laboratory abnormalities of livedoid vasculopathy. DESIGN: Retrospective study of patients identified from our institutional database from January 1, 1990, to December 31, 2000. SETTING: Tertiary care institution. Patients Forty-five patients with biopsy-proved livedoid vasculopathy. MAIN OUTCOME MEASURES: Clinical presentation, histopathologic diagnosis, results of testing for coagulation abnormalities, and assessment of vascular status. RESULTS: Thirty-two patients (71.1%) were female (mean age, 45 years; age range, 10-85 years). Bilateral lower extremity disease occurred in 36 patients (80.0%), ulceration in 31 (68.9%), and atrophie blanche in 32 (71.1%). In patients tested, transcutaneous oximetry measurements were decreased in 20 (74.1%) of 27, and factor V Leiden mutation (heterozygous) was noted in 2 (22.2%) of 9, decreased activity for protein C or protein S in 2 (13.3%) of 15, prothrombin G20210A gene mutation in 1 (8.3%) of 12, and lupus anticoagulant in 5 (17.9%) of 28. Anticardiolipin antibodies were present in 8 (28.6%) of 28 patients, and elevated homocysteine levels in 3 (14.3%) of 21. Intraluminal thrombosis was observed in 44 (97.8%) of 45 skin biopsy specimens. Direct immunofluorescence disclosed multiple vascular conjugates in 31 (86.1%) of 36 biopsy specimens. CONCLUSIONS: Livedoid vasculopathy was predominantly bilateral, affected the lower extremities, and was associated with ulceration and atrophie blanche. Histologic evidence of intraluminal thrombosis was observed in almost all biopsy specimens reviewed. Laboratory testing revealed numerous heterogeneous coagulation abnormalities, providing further evidence of procoagulant mechanisms.

Adolescent↗
PubMed2006

Diffuse dermal angiomatosis of the breast.

BACKGROUND: Diffuse dermal angiomatosis is rare and usually considered a variant of reactive angioendotheliomatosis. It generally involves the extremities of patients with severe vascular disease and other comorbidities. Two patients with breast involvement have been described; however, neither had a relevant medical history or a vaso-occlusive disorder, but both had large pendulous breasts, and 1 was positive for IgM anticardiolipin and antinuclear antibodies. OBSERVATIONS: A 53-year-old woman had a reticulated, erythematous plaque with superficial ulceration and underlying tender nodules on her left breast. She had a history of cardiovascular disease and was a heavy smoker. Biopsy of the lesion showed diffuse proliferation of additional endothelial cells and small bland vessels within the papillary and upper reticular dermis. Angiography showed almost complete occlusion of the subclavian artery proximally. Diffuse dermal angiomatosis was diagnosed. With isotretinoin therapy, the lesions improved. One month later, after percutaneous subclavian arterial revascularization, the lesion resolved completely. A literature review suggested that a history of heavy smoking, in addition to a history of vascular disease, may be important in the pathogenesis of diffuse dermal angiomatosis. CONCLUSIONS: Clinical acumen is crucial to diagnose diffuse angiomatosis of the breast. Appropriate treatment to alleviate hypoxia may improve the patient's condition.

Angiomatosis↗
PubMed2006

Post-injection involutional lipoatrophy: Ultrastructural evidence for an activated macrophage phenotype and macrophage related involution of adipocytes.

We describe a 53-year-old white female with distinctive clinical and histologic changes of involutional lipoatrophy on the right elbow that developed 6 months following a steroid injection to the site. Morphologically, immunohistochemically and ultrastructurally macrophages were seen in close proximity to the altered adipocytes. The macrophages displayed an activated phenotype and were observed engulfing segments of altered adipose and stromal tissue. Other inflammatory cells were lacking and up-regulation of the intra-epidermal Langerhan cells and dermal dendrocytic populations were not observed suggesting non-immune causal mechanisms in the disease process. We believe that the progression model of involutional lipoatrophy is similar to that of glomerulonephritis in which macrophage accumulation can result from non-immune mechanisms such as trauma and lead to the production of several cytokines that induce tissue injury and subsequent fibrosis and sclerosis.

Adipocytes↗
PubMed2006

Adenocarcinoma of mammary-like glands of the vulva: Report of a case and review of the literature.

Mammary-like glands are a poorly recognized structure of normal vulvar skin. Adenocarcinomas arising from these glands are rare and represent a distinct clinicopathologic entity that must be distinguished from metastatic tumors. We reviewed 19 cases reported in the literature and describe a 51-year-old patient with a long-standing nodule on her right interlabial sulcus. Excisional biopsy and Mohs micrographic surgery demonstrated an infiltrating adenocarcinoma of the mammary-like glands involving the dermis and subcutis. On review of all 20 cases, the mean age at diagnosis was 59.6 years, the labia majora were involved in 13 cases (65%), and the mean lesional size was 2.5 cm. The tumor's histologic patterns varied greatly, although the histomorphologic similarity among this neoplasm, sweat gland carcinomas, and invasive extramammary Paget disease suggested a morphologic spectrum among these tumors. Criteria for establishing the diagnosis of adenocarcinoma of mammary-like glands include identifying transition zones between normal mammary-like glands and adenocarcinomatous areas. This tumor is best categorized as a locally aggressive neoplasm with a low risk for widespread metastasis. Use of aggressive surgical therapeutic regimens, particularly in the case of tumors localized to the skin, must be reassessed, especially given the likelihood of long-term morbidity with such regimens. In our patient, successful Mohs micrographic surgery suggests that alternate management may be adopted for tumors localized to the skin, especially in elderly patients.

Adenocarcinoma↗
PubMed2006

In situ hybridization in cutaneous deep fungal infections: a valuable diagnostic adjunct to fungal morphology and tissue cultures.

Dimorphic fungal infections (histoplasmosis, blastomycosis, coccidioidomycosis, and cryptococcosis) can occur in immunocompromised and healthy individuals. Cutaneous involvement is often secondary and may be the presenting sign of systemic disease. These ominous infections are frequently clinically indistinct, and patient prognosis is influenced by a timely diagnosis and treatment. Morphologic differentiation between these organisms is not definitive, and tissue cultures represent the diagnostic gold standard in current day practice. However, tissue cultures are rarely obtained and merely represent an afterthought in seemingly unsuspecting cases. Furthermore, when performed, they may take several days or weeks for completion. In situ hybridization (ISH) utilizing oligonucleotide probes directed against fungal ribosomal RNA is a rapid and accurate assay for the identification of dimorphic fungi in paraffin-embedded tissue sections. We present five patients in whom ISH both prospectively and retrospectively confirmed the presence of a cutaneous infection (histoplasmosis, blastomycosis, coccidioidomycosis, and cryptococcosis). In all of the skin sections analyzed, dimorphic fungi were morphologically apparent but not diagnostically discernible. In summary, ISH is a valuable tool in the prompt diagnosis of cutaneous deep fungal infections.

Adult↗
PubMed2006

Angiosarcoma arising in a lymphedematous abdominal pannus with histologic features reminiscent of Kaposi's sarcoma: report of a case and review of the literature.

BACKGROUND: Despite common endothelial origins, angiosarcoma and Kaposi's sarcoma are clinically and histologically distinct vascular proliferations. The development of angiosarcoma in a chronically edematous abdominal pannus is extremely uncommon. Similarly, tumors with the combined histologic features of angiosarcoma and Kaposi's sarcoma have rarely been described. METHODS: We reviewed the literature on angiosarcoma arising in a lymphedematous abdominal pannus and evaluated an 81-year-old morbidly obese woman who had profound, long-standing edema of the lower abdominal wall in which an aggressive vascular tumor developed. RESULTS: Three clinically similar cases were identified in the literature. All patients were women who generally experienced rapid disease progression. In addition, in our patient, sequential cutaneous sampling from different lesional sites demonstrated disparate histologic changes, ranging from those of classic Kaposi's sarcoma to high-grade angiosarcoma, to areas with combined features of the two tumors. A polymerase chain reaction performed on lesional tissue was negative for human herpesvirus-8 DNA. CONCLUSION: It is important to note that angiosarcoma may develop in the abdomen in association with chronic lymphedema, as demonstrated by the cases noted in this report. In addition, our case highlights the difficulty in differentiating histologically angiosarcoma from Kaposi's sarcoma in some situations, and demonstrates the value of close clinicopathologic correlation and sequential tissue sampling in evaluating problematic cases.

Abdomen↗
PubMed2006

Unusual palmoplantar blistering in the setting of hemodialysis: a case report and review of the dermatoses associated with hemodialysis.

We describe a 70-year-old White female on maintenance high-flux hemodialysis for chronic renal insufficiency with an abrupt onset of asymptomatic palmoplantar blisters. The lesions were tense, noninflamed and 0.2-1.0 cm in dimension. Concomitant photo-distributed blistering of the dorsal hands and forearms was not present. A cutaneous biopsy demonstrated nonspecific histological and direct immunofluorescent findings. Serum indirect immunofluorescence and tissue cultures for bacteria, fungi and viruses were negative. Fecal porphyrins were normal but an elevated plasma uroporphyrin level of 17.0 microg/dL (normal: < 1.0 microg/dL) was observed. The duration of each hemodialysis treatment, which the patient had continued to receive three times per week, was changed from 2 to 2.5 h. Within 2 weeks no new blisters occurred. Within 6 weeks complete clinical and biochemical remission was noted. During this time course no topical steroid or antifungal therapy was employed nor was the patient's oral medication regimen altered.

Aged↗
PubMed2006

Wilms' tumour: a comparison of surgical aspects in patients with or without pre-operative chemotherapy.

OBJECTIVE: To compare the technical aspects of Wilms' tumour (WT) surgery in patients with and without pre-operative chemotherapy. DESIGN: Quasi-experimental. PLACE AND DURATION OF STUDY: Military Hospital (MH) and Combined Military Hospital (CMH), Rawalpindi, from January 1999 to December 2004. PATIENTS AND METHODS: Patients of WT, presenting between January 1999 and December 2001, were treated, using the NWTSG protocol, with primary surgery (group I). Between January 2001 and December 2004, WT patients were treated according to SIOP protocol, with pre-operative chemotherapy followed by surgery (group II). Volume reduction with chemotherapy, duration of surgery, rupture of tumour, extent of excision, adherence and damage to surrounding structures, blood loss, complications, stay in hospital and event-free survival (EFS) were compared in the two groups. RESULTS: Out of 22 patients in group I, 19 (86.4%) underwent primary surgery. Of the 23 patients in group II, 21 (91.3%) received pre-operative chemotherapy followed by surgery. Average volume reduction in this group was 54% with chemotherapy. Difference in duration of surgery and blood loss was significantly low in group II (p=0.003 and p < 0.001, respectively). In group I, rupture (6 vs 2), adherence (14 vs 10) and damage to surrounding structures (5 vs 2) were more. Complete macroscopic excision was possible in 90.5% of WT in group II as compared to 73.7% in group I. Immediate postoperative complications and length of hospital stay were similar in both groups. There was no difference in EFS. CONCLUSION: Pre-operative chemotherapy makes it technically easier and safer to operate, without jeopardizing the final outcome.

Antineoplastic Agents↗
PubMed2005

Subcutaneous sarcoidosis: is it a specific subset of cutaneous sarcoidosis frequently associated with systemic disease?

BACKGROUND: Skin is involved in 25% of cases of sarcoidosis. The lesions are specific and nonspecific depending on the presence or absence of granulomas, respectively. Specific lesions are not thought to have prognostic significance and are not associated with systemic disease. OBJECTIVE: We sought to evaluate for the presence or absence of systemic disease in patients with subcutaneous sarcoidosis. METHODS: With diagnostic criteria of subcutaneous sarcoidosis, 33 cases were identified in the literature and 21 cases in our institutional database. A retrospective clinical and pathologic review of these cases was conducted. RESULTS: Subcutaneous sarcoidosis is characterized by a peak incidence during the fourth decade; female predisposition; asymptomatic to slightly tender lesions typically involving the upper extremities; cutaneous lesional clustering and multiplicity; autoimmune disease associations at time of diagnosis in a subset of cases; systemic disease associations at diagnosis in most patients, typically consisting of bilateral hilar adenopathy; and a favorable response to oral corticosteroid therapy. LIMITATIONS: Retrospective analysis with inadequate documentation of therapeutic regimens and their responses in some cases is a limitation of this study. CONCLUSIONS: The confirmatory diagnosis of subcutaneous sarcoidosis depends on identifying pannicular noninfectious sarcoidal or epithelioid granulomas with minimal lymphocytic inflammation. Subcutaneous sarcoidosis is the only specific subset of cutaneous sarcoidosis frequently associated with systemic disease.

Humans↗
PubMed2005

Effectiveness of intravenous immunoglobulin therapy for skin disease other than toxic epidermal necrolysis: a retrospective review of Mayo Clinic experience.

OBJECTIVE: To examine retrospectively the use and effectiveness of intravenous immunoglobulin (IVIg) treatment of various skin diseases, primarily immunobullous disease. PATIENTS AND METHODS: We identified patients who had received IVIg therapy for skin disease between 1996 and 2003 at the Mayo Clinic in Rochester, Minn, Scottsdale, Ariz, and Jacksonville, Fla, and retrospectively reviewed their medical records. RESULTS: Eighteen patients were treated with IVIg for various skin diseases: immunobullous disease in 11 adults (pemphigus vulgaris [7 patients], bullous pemphigold [3], and cicatricial pemphigoid [1]); dermatomyositis (2); mixed connective tissue disease (1); chronic urticaria (1); scleromyxedema (1); leukocytoclastic vasculitis (1); and linear IgA bullous disease (1). Responses of patients by type of disease were as follows: pemphigus vulgaris, 1 partial response (PR) and 6 no response (NR); bullous pemphigoid, 1 complete response (CR) and 2 NR; cicatricial pemphigoid, 1 NR; dermatomyositis, 1 CR and 1 PR; mixed connective tissue disease, 1 CR; chronic urticaria, 1 CR; scleromyxedema, 1 CR; leukocytoclastic vasculitis, 1 PR; and linear IgA bullous disease, 1 CR. Six patients (33%) experienced CR, 3 (17%) had PR, and 9 (50%) had NR to IVIg therapy. All 9 nonresponders were adult patients with immunobullous disease. CONCLUSION: Although this was a retrospective study of a small cohort of a mixture of patients, the findings emphasize that our experience with IVIg treatment for skin disease, particularly immunobullous disease, is less favorable than that reported previously. Further studies are needed to verify the efficacy of IVIg for skin disease.

Adolescent↗
PubMed2005

Pili trianguli et canaliculi is a defect of inner root sheath keratinization: ultrastructural observations of anomalous tonofilament organization in a case.

A 4-year-old Caucasian girl with pili trianguli et canaliculi had distinctive findings. These included unique ultrastructural alterations consisting of tonofilament-desmosomal detachment and tonofilament clumping within inner root sheath cells. We believe that the hair anomaly in this condition may be due to a compromised cytoskeleton with subsequent configurational changes of the inner root sheath. Despite these configurational changes keratinization of the inner root sheath occurs. As inner root sheath keratinization typically precedes keratinization of the hair shaft, the abnormally configured inner root sheath determines the surface characteristics of the hair shaft in pili trianguli et canaliculi.

Child, Preschool↗
PubMed2004

Persistent hyperinsulinemic hypoglycemia of infancy - nesidioblastosis.

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) or nesidioblastosis is a rare condition presenting with severe hypoglycemia. Prompt diagnosis and early pancreatectomy can save many of them, in spite of the magnitude of surgery. We present two cases in which near total pancreatectomy was performed with favourable outcome. Both patients are normoglycemic, with one requiring pancreatic enzyme supplements.

Congenital Hyperinsulinism↗
PubMed2004

Management of multifocal primary cutaneous CD30 anaplastic large cell lymphoma.

Primary cutaneous CD30(+) anaplastic large cell lymphoma in adults is rare, but the prognosis is generally excellent. Skin lesions may be localized or, less commonly, multifocal. Although not extensively reported, multifocal primary cutaneous anaplastic large cell lymphoma tends to relapse after systemic chemotherapy and is generally considered more prone to progress to extracutaneous involvement than the localized disease. We report the case of a 21-year-old woman with primary cutaneous CD30(+) anaplastic large cell lymphoma manifesting as widespread papules and nodules. Despite remaining localized to the skin, the disease relapsed after multiple chemotherapy regimens and autologous stem-cell transplantation. Treatment with an experimental anti-CD30 monoclonal antibody was successful. Review of this case and similar cases illustrates that traditional combination chemotherapy may not be best. Newer treatments, including anti-CD30 monoclonal antibodies, show promise. However, further study is needed to develop optimal therapeutic strategies.

Adult↗
PubMed2004

Erythema multiforme associated with phenytoin and cranial radiation therapy: a report of three patients and review of the literature.

BACKGROUND: Intracranial malignancies (primary and metastatic) are often complicated by seizure activity. Phenytoin (Dilantin) is typically employed as prophylactic anticonvulsant in this setting. Uncommonly, erythema multiforme (EM) can develop in such patients at the port site during or soon after cranial radiation and can rapidly progress to EM major. Herein, in addition to a comprehensive literature review of this entity, three additional patients are presented. The acronym 'EMPACT' is suggested (E: erythema; M: multiforme; associated with P: phenytoin; A: and; C: cranial, radiation; T: therapy) to best describe this disorder. METHODS: An extensive review of the English medical literature through the National Library of Medicine (PUBMED) was performed to identify patients who had received or continued to receive radiation therapy while on phenytoin. A total of 24 patients were identified and clinical information of varying detail was available in all cases. Clinical and histological information on three additional patients seen at two institutions (Rochester Methodist Hospital, Rochester, MN, and Fairview-University Medical Center, Minneapolis, MN) by the authors were also compiled. RESULTS: The mean age was 44 years (range: 23-67) and no sexual predisposition was noted. All patients had taken phenytoin for variable time periods (range 16-80 days; mean: 40) and were on the medication when the skin lesions first appeared. These lesions developed within the port site during the radiation treatments (11 cases) or soon after (nine cases) its completion (mean: 16 days; range: 2-35). Subsequent disease evolution to EM major occurred in all cases (Stevens-Johnsons syndrome developed in 73% of patients). No relationship was identified between the extent and the severity of the skin lesions with the phenytoin and radiation dosages and with the histologic type and origin of the intracranial malignancy. None of the patients demonstrated the requisite features of the 'Dilantin hypersensitivity syndrome'. Although, a systemic steroid taper was employed in 10 out of the 14 patients before the development of the skin lesions, the subsequent progression of the skin lesions was not influenced by the use of systemic steroid therapy. Complete recovery occurred in all but two patients typically within 1-8 weeks of discontinuation of phenytoin. CONCLUSIONS: The need for prophylactic anticonvulsant therapy especially utilizing phenytoin in patients undergoing cranial radiation therapy should be assessed on a case by case basis. If anticonvulsants are employed, then they must be administered with caution, and all cutaneous reactions developing subsequently within the radiation site must be promptly evaluated with a high index of suspicion for erythema multiforme.

Anticonvulsants↗
PubMed2004

Direct agglutination test with urine samples for the diagnosis of visceral leishmaniasis.

A new direct agglutination test (DAT) for use with urine samples for the diagnosis of visceral leishmaniasis (VL) has been developed and compared with the conventional DAT with serum samples and our previously reported enzyme-linked immunosorbent assay (ELISA) with urine samples (urine ELISA). The new DAT, in which anti-human IgG was used as enhancing antibody, was tested with urine samples from 75 VL patients and 225 non-VL patients and healthy people. The sensitivity of the new DAT (90.7%), was almost the same as that of the conventional DAT (91.0%) and the urine ELISA (93.3%). The specificity of the new DAT (96.4%) was nearly identical with that of the urine ELISA (97.3%). A urine-based DAT has several advantages over the conventional DAT: sample collection is non-invasive and it can process larger numbers of samples with smaller amounts of antigen.

Adult↗