Shotgun metagenome sequencing of a Sudanese toombak snuff tobacco: genetic attributes of a high tobacco-specific nitrosamine containing smokeless tobacco product.

The most alarming aspect of the Sudanese toombak smokeless tobacco is that it contains high levels of highly toxic tobacco-specific nitrosamines (TSNAs). Understanding the microbiology of toombak is of relevance because TSNAs are an indirect result of microbial-mediated nitrate reductions. We conducted shotgun metagenomic sequencing on a toombak product for which relevant features are presented here. The microbiota was composed of over 99% Bacteria. The most abundant taxa included Actinobacteria, specifically the genera Enteractinococcus and Corynebacterium, while Firmicutes were represented by the family Bacillaceae and the genus Staphylococcus. Selected gene targets were nitrate reduction and transport, antimicrobial resistance, and other genetic transference mechanisms. Canonical nitrate reduction and transport genes (i.e. nar) were found for Enteractinococcus and Corynebacterium while various species of Staphylococcus exhibited a notable number of antimicrobial resistance and genetic transference genes. The nitrate reduction activity of the microbiota in toombak is suspected to be a contributing factor to its high levels of TSNAs. Additionally, the presence of antimicrobial resistance and transference genes could contribute to deleterious effects on oral and gastrointestinal health of the end user. Overall, the high toxicity and increased incidences of cancer and oral disease of toombak users warrants further investigation into the microbiology of toombak.

Placenta accreta: Elective versus emergent delivery as a major predictor of blood loss.

OBJECTIVE: To compare blood loss and the use for blood transfusion between elective (planned) and emergent cesarean hysterectomy performed for placenta accreta by a single, multidisciplinary team and to present the team's pre-operative evaluation and the surgical technique. STUDY DESIGN: Prospective cohort study at a single tertiary care center. Maternal and neonatal outcomes were compared between elective and emergent delivery of pregnancies complicated by placenta accreta. The primary outcomes were the need for blood transfusion and the number of units transfused. RESULTS: A total of 28 cases of confirmed placenta accreta underwent peripartum hysterectomy, including 22 as elective and 6 as emergent. Eleven out of 22 (50%) subjects in the elective group received blood transfusion, while all subjects in the emergency group required transfusion (p = 0.03). More importantly, the number of units of packed red blood cells transfused was only 1.90 (±2.20) units in the elective cases compared to 7.83 (±4.90) units in cases performed emergently (p = 0.03). CONCLUSION: Elective cesarean hysterectomy for this indication using a clearly outlined surgical approach is associated with significantly lower blood loss and hence less need for transfusion, compared to its emergent counterpart.

The scientific basis of tobacco product regulation.

This report presents the conclusions and recommendations of TobReg from its fourth meeting, where the Study Group deliberated on a number of topics in the field of tobacco product regulation and produced the following advisory notes and recommendations: an advisory note on smokeless tobacco products: health effects, implications for harm reduction and research needs; an advisory note on 'fire safer' cigarettes: approaches to reduced ignition propensity; a recommendation on mandated lowering of toxicants in cigarette smoke: tobacco-specific nitrosamines and selected other constituents; and a recommendation on cigarette machine smoking regimens. The four sections of this report address these four issues, and the Study Group's recommendations are set out at the end of each section. Its overall recommendations are summarized in section 5.

Gene frequencies of the HPA-1 platelet antigen alleles in the Lebanese population.

The objective was to study the gene frequencies of HPA-1 in the Lebanese population for the first time. The aims of this study were to assess the prevalence of 1a and 1b HPA-1 alleles in healthy Lebanese individuals and compare with the international literature. Human platelet antigen (HPA) systems are involved in alloimmunization, organ transplantation rejection and the development of cardiovascular disease. Of several classified HPA systems, HPA-1 specifically has been considered to be the most important antigenic system implicated in the Caucasian population. This specific gene has never been investigated in our population. DNA was extracted from specimens collected from 205 healthy unrelated Lebanese individuals and tested, using a reverse hybridization polymerase chain reaction (PCR) assay, for the prevalence of 1a and 1b HPA-1 alleles. Genotypes 1a/1a, 1a/1b, and 1b/1b were assigned accordingly. We observed that the 1a/1a genotype was the most prevalent (65.85%) followed by 1a/1b (30.24%) and 1b/1b (3.91%) with allelic frequencies for 1a and 1b of 0.81 and 0.19, respectively. As compared with other ethnic groups, the Lebanese population was found to have a relatively high prevalence of the HPA-1b, which may predispose to a higher risk of alloimmunization. This report is the first to study the prevalence of the HPA-1 system in the Lebanese population and serves as a template for future clinical research involving platelet disorders and cardiovascular diseases.

Distribution of killer cell immunoglobulin-like receptors genotypes in the Lebanese population.

This study represents the first report on the distribution of 16 Killer cell Immunoglobulin-like Receptors (KIR) genes in 120 unrelated healthy Lebanese individuals. We observed that 2DL2 frequency (61%) comes second highest after South Asians (64%) and 2DL5 frequency (58.3%) is the second highest reported so far after the South Asians (74%). Interestingly, a large number of AA1 genotype individuals with no loci for activating KIR and three completely new BB profiles not previously reported were found in our population with a group A : group B haplotypes ratio of 1.3:1. The frequency of the KIR loci suggests that the Lebanese population shares common general features with the Caucasoid populations studied before, but still has its own unique decreased or increased frequencies of several loci.

Post-adenoidectomy inflammatory pseudotumor.

PROBLEM: Inflammatory pseudotumor is a rare pathology in the head and neck area. Multiple post-adenoidectomy complications have been described in the literature without alluding to such an entity. METHOD: A case report of an inflammatory pseudotumor following an adenoidectomy. MAIN RESULTS: Pseudotumor of the nasopharynx should be added to the list of possible complications of adenoidectomy. CONCLUSION: Inflammatory pseudotumor of the nasopharynx is a rare complication that confronts the otolaryngologist and the pathologist with a diagnostic challenge. Surgical excision remains the best therapeutic option.

Lateral cervical bronchogenic cyst: an unusual cause of a lump in the neck.

BACKGROUND: Congenital cysts of the neck in children are not uncommon. Most of these are thyroglossal, branchial cleft, or less commonly, thymic cysts. Bronchial cysts rarely are initially seen as a neck mass. METHODS: Use of an illustrative case of a bronchogenic cyst initially seen as an upper lateral neck mass. CONCLUSIONS: We emphasize that although ectopic bronchogenic cysts are rare lesions of the head and neck, especially in the upper lateral neck, they should be included in the differential diagnosis in the evaluation of congenital neck cysts.

Scrotal calcinosis: is it idiopathic?

Idiopathic calcinosis of the scrotum is a rare condition, and its pathogenesis remains unknown. We recently examined 3 patients in whom scrotal epidermoid cysts in varying stages of inflammation coexisted with scrotal calcinosis. Some cysts revealed calcification of their keratin contents with little evidence of active inflammation. Other cysts showed rupture of their epithelial walls associated with the presence of keratin fibers and calcium granules in the surrounding dermis. We found that this disorder is not idiopathic and that epidermal inclusion cysts constitute the basic abnormality.

Lebanese population: prevalence of the erythrocyte phenotypes.

STUDY OBJECTIVES: This survey was designed to be a descriptive study of the erythrocyte phenotype prevalence in Lebanon. The general aim was to provide transfusion centers and blood banks with the occurrence of the nation's erythrocyte phenotypes in the population they are serving. The results were descriptively compared to Caucasians. SUBJECTS AND METHODS: 632 blood samples were collected from the Lebanese population in the 5 muhafazats (regions). Of which, 350 samples were extensively phenotyped for the blood group systems ABO, Kell, Kidd, Duffy, MNS, Lewis, Lutheran and P; and 282 samples were selectively phenotyped for Fy(a), Fy(b) and Kp(a). Additionally, 3064 random blood donors were studied for the ABO and D blood groups. MAIN RESULTS: With respect to the blood group phenotypes, the Lebanese are similar to the Caucasian population with the exception of rr, Le(b), Le (a-b-), Fy (a-b-), M+N+S-s+ and M-N-S-s+. CONCLUSION: It is of scientific cognizance and interest that the Lebanese erythrocyte phenotypes closely resemble that of the Caucasians: nevertheless, certain novel differences are present, and possibly, there exists a phenotype that attributes to admixture of the African gene in a Middle Eastern population.

A familial case of recurrent hydatidiform molar pregnancies with biparental genomic contribution.

Hydatidiform mole is a benign trophoblastic neoplasia characterized by an abnormal development of the embryo and proliferation of placental villi. Using microsatellite markers amplified by the polymerase chain reaction, we have performed a genetic study on eight independent molar tissues occurring in two sisters. Karyotype and genotype data demonstrate a diploid and biparental constitution in seven of the analyzed moles suggesting a common mechanism underlying the etiology of the various molar pregnancies in this family. The data reported here suggest that complete and partial hydatidiform moles are not always separate entities and that women with familial recurrent hydatidiform moles are homozygous for an autosomal recessive mutation.

Papillary serous carcinoma of the ovary following prolonged tamoxifen treatment.

We present a patient with breast cancer who developed papillary serous adenocarcinoma of the ovary after 13 years of tamoxifen use. The possible association is explored and the literature is reviewed.

Fine-needle aspiration of the mediastinum: a clinical, radiologic, cytologic, and histologic study of 42 cases.

Forty-two fine-needle aspirates (FNA) of the mediastinum were reviewed from 1984-1995. The clinical, radiologic, pathologic, and cytologic material was studied. Twenty-five males and 17 females had an age range from 10-72 yr and a mean of 41 yr. Common complaints were chest pain, dyspnea, and cough. Thirty-eight tumors were in the anterior/superior mediastinum. Fifty-seven percent were primary neoplasms (Hodgkin's lymphoma, 7; non-Hodgkin's lymphoma, 6; thymoma, 3; germ-cell tumor, 3; thymic carcinoid and angiosarcoma, 1 each; and malignant not otherwise specified, 3). Twenty-four percent were metastatic tumors (carcinoma, 9; and sarcoma, 1). Twelve percent were benign conditions (granulomatous disease, 2; multinodular goiter, 1; extramedullary hematopoesis, 1; and one thymic cyst). Seven percent were inconclusive. FNA yielded adequate tissue for diagnosis in 83% and a correct diagnosis in 86%. There was one false-negative and no false-positive diagnosis. FNA is a useful tool for accurate tissue diagnosis of mediastinal masses.

Dural osteochondroma: case report, review of the literature and proposal of a new classification.

Complete excision of a dural osteochondroma is presented. Upon reviewing the literature we noted that basal and convexity osteochondromas, although considered as a single pathological entity, differ in epidemiology, pathogenesis, management and natural history. A new classification is proposed.

Cranial osteomas: their classification and management. Report on a giant osteoma and review of the literature.

BACKGROUND: Cranial osteomas are regarded by some as very common; yet their classification, symptomatology, and management have been neglected. METHODS: We report on a giant enostotic convexity osteoma and have reviewed the medical literature. RESULTS: A new comprehensive classification for cranial osteomas is proposed: (1) intraparenchymal, (2) dural, (3) skull base, and (4) skull vault. The latter is in turn, subdivided into exostotic and enostotic variants. Three symptom producing enostotic convexity osteomas have been reported in the world literature. We also describe a giant enostotic skull vault osteoma and propose an original surgical technique used to successfully resect this unusual tumor. CONCLUSIONS: Most cranial osteomas are asymptomatic and need not be resected. Those that are symptomatic should be managed properly. Their excision, if nor properly performed, may lead to unforeseen cerebral complications.

Dendritic cell tumors associated with low-grade B-cell malignancies. Report of three cases.

Indeterminate and interdigitating cell tumors are rare proliferations of immunoregulatory cells that demonstrate morphologic, immunologic, and ultrastructural features similar to their cells of origin. Although an association of lymphoproliferative disease with Langerhans' cell histiocytosis is well described, only sporadic cases of non-Langerhans' dendritic cell proliferations have been published. The authors describe three patients with low grade B-cell lymphoproliferative disease who developed subsequent indeterminate cell or interdigitating cell tumors. When the two cases of indeterminate cell tumor are added to those previously described in the literature, it appears that 4 of 13 cases (31%) are associated with a history of low grade B-cell malignancy. Possible explanations for the relationship between these two disorders are discussed.

Liesegang-like rings in fine needle aspirates of renal/perirenal hemorrhagic cysts.

Periodic structures with equally spaced radial striations, identified as Liesegang-like rings, were encountered in fine needle aspirates of two patients' hemorrhagic renal/perirenal cysts. The patients, one 60 and the other 39 years old, had acute right-flank pain; both underwent nephrectomy. The ring structures ranged in size from 8 microns to 200 microns in diameter and had regularly striated double walls. Histochemical and immunoperoxidase tests for iron, calcium, mucopolysaccharides, amyloid, keratin and hemoglobin performed on the tissue sections of the resected specimens gave negative results. With electron microscopy, the ring structures of one of the cases displayed a fine fibrillary composition. Since these Liesegang-like structures may be mistaken for parasites or necrotic tissue, pathologists should be aware of them. To our knowledge, this is the first report of Liesegang-like rings in the cytology literature.