Phospholipase A2 levels in acute chest syndrome of sickle cell disease

Acute chest syndrome (ACS) is associated with significant morbidity and is the leading cause of death in patients with sickle cell disease (SCD). Recent reports suggest that bone marrow fat embolism can be detected in many cases of severe ACS. Secretory phospholipase A2 (sPLA2) is an important inflammatory mediator and liberates free fatty acids, which are felt to be responsible for the acute lung injury of the fat embolism syndrome. We measured SPLA2 levels in 35 SCD patients during 20 admissions for ACS, 10 admissions for vaso-occlusive crisis, and during 12 clinic visits when patients were at the steady state. Eleven non-SCD patients with pneumonia were also evaluated. To determine if there was a relationship between sPLA2 and the severity of ACS we correlated SPLA2 levels with the clinical course of the patient. In comparison with normal controls (mean = 3.1 +/- 1.1 ng/mL), the non- SCD patients with pneumonia (mean = 68.6 +/- 82.9 ng/mL) and all three SCD patient groups had an elevation of SPLA2 (steady state mean = 10.0 +/- 8.4 ng/mL; vaso-occlusive crisis mean = 23.7 +/- 40.5 ng/mL; ACS mean = 336 +/- 209 ng/mL). In patients with ACS sPLA2 levels were 100- fold greater than normal control values, 35 times greater than values in SCD patients at baseline, and five times greater than non-SCD patients with pneumonia. The degree of SPLA2 elevation in ACS correlated with three different measures of clinical severity and, in patients followed sequentially, the rise in SPLA2 coincided with the onset of ACS. The dramatic elevation of SPLA2 in patients with ACS but not in patients with vaso-occlusive crisis or non-SCD patients with pneumonia and the correlation between levels of SPLA2 and clinical severity suggest a role for SPLA2 in the diagnosis and, perhaps, in the pathophysiology of patients with ACS.     

Clinical presentation, karyotypic characterization, and treatment outcome of childhood acute lymphoblastic leukemia with a near-haploid or hypodiploid less than 45 line

Cytogenetic and DNA flow cytometric analyses of leukemic cells from 2,184 children with newly diagnosed acute lymphoblastic leukemia (ALL) identified 27 cases (1.2%) that had a hypodiploid line with fewer than 45 chromosomes per cell. Had cytogenetic techniques been used alone, seven cases would have been missed, compared with five if only flow cytometry had been used. For comparative purposes, the 27 cases were divided into three groups: near-haploid (n = 10), hypodiploid 30-40 (n = 9), and hypodiploid 41-44 (n = 8). Blast cells from patients with near-haploid ALL lacked structural chromosomal abnormalities; showed nonrandom retention of two copies of chromosomes 8, 10, 14, 18, 21, and the sex chromosomes; and had a second leukemic line with exactly twice the number of chromosomes or DNA content. Karyotypic analysis of the hypodiploid 30-40 and hypodiploid 41-44 groups disclosed structural abnormalities in the stemline or sideline of most of the well-banded cases; those in the latter group were similar to findings in cases with 45 chromosomes. As in the near-haploid group, chromosome 21 and the sex chromosomes were preferentially retained in the hypodiploid 30-40 and 41-44 cases. Except for a slight excess of female patients in the near-haploid group and an older age at diagnosis in the hypodiploid 30-40 cases, there were no initial clinical features that distinguished these patients from the general ALL population. Despite intensive treatment and short follow-up, 17 of the 27 patients have relapsed. This study suggests that the poor treatment responsiveness of hypodiploid ALL is not limited to the more than 80% of the patients who have 45 chromosomes per leukemic cell and demonstrates that cytogenetic and flow cytometric analyses are complementary in the evaluation of children with ALL.     

Isochromosomes in childhood acute lymphoblastic leukemia: a collaborative study of 83 cases.

Cytogenetic analysis of leukemic cells from 2,805 children with newly diagnosed acute lymphoblastic leukemia (ALL) identified 83 cases (3%) that had a stemline with at least one isochromosome. The i(9q) was present in 28 (1%), the i(17q) in 23 (0.8%), and the i(7q) in 23 (0.8%). Other isochromosomes--i(21q), i(6p), i(1q), i(8q), or i(Xq)--were found in only 12 cases (0.4%). The isochromosome cases were more likely than were other ALL cases to have a pre-B immunophenotype (38% v 25%, P = .02) and leukemic cell hyperdiploidy greater than 50 (37% v 24%, P = .02); five cases had both features. The i(9q) was associated with age greater than 10 years (P less than .05) and the pre-B immunophenotype (P = .05); both the i(17q) and i(7q) had high frequencies of hyperdiploidy greater than 50 (P less than .0001 and P = .05, respectively). The t(1;19)(q23;p13) was a common feature (23%) in cases with the i(9q), i(7q), i(6p), or i(1q). These findings establish the i(9q), i(17q), and i(7q) as nonrandom chromosomal abnormalities in ALL. The prognostic significance of the presence of isochromosome(s) remains to be determined.     

Review: Head and neck squamous cell carcinoma in sub-Saharan Africa

Aim

Review the literature from 1990 to 2013 to determine known anatomic sites, risk factors, treatments, and outcomes of head and neck squamous cell carcinoma (HNSCC) in sub-Saharan Africa.

Methods

Using a systematic search strategy, literature pertaining to HNSCC in sub-Saharan Africa was reviewed and patient demographics, anatomic sites, histology, stage, treatment, and outcomes were abstracted. The contributions of human immunodeficiency virus (HIV), human papillomavirus (HPV) and behavioural risk factors to HNSCC in the region were assessed.

Results

Of the 342 papers identified, 46 were utilized for review, including 8611 patients. In sub-Saharan Africa, the oropharyngeal/oral cavity was found to be the most common site, with 7750 cases (90% of all cases). Few papers distinguished oropharyngeal from oral cavity, making identification of possible HPV-associated oropharyngeal squamous cell carcinoma (SCC) difficult. SCC of the nasopharynx, nasal cavity, or paranasal sinuses was identified in 410 patients (4.8% of all cases). Laryngeal SCC was found in 385 patients (4.5% of all cases), and only 66 patients (0.8% of all cases) with hypopharyngeal SCC were identified. In 862 patients with data available, 43% used tobacco and 42% used alcohol, and reported use varied widely and was more common in laryngeal SCC than that of the oropharyngeal/oral cavity. Toombak and kola nut use was reported to be higher in patients with HNSCC. Several papers reported HIV-positive patients with HNSCC, but it was not possible to determine HNSCC prevalence in HIV-positive compared to negative patients. Reports of treatment and outcomes were rare.

Conclusions

The oropharyngeal/oral cavity was by far the most commonly reported site of HNSCC reported in sub-Saharan Africa. The roles of risk factors in HNSCC incidence in sub-Saharan Africa were difficult to delineate from the available studies, but a majority of patients did not use tobacco and alcohol.     

The nature of noncholinergic membrane potential responses to transmural stimulation in guinea pig ileum.

The effect of substance P antagonism on membrane potential responses to transmural nerve stimulation in the presence of atropine was examined in circular smooth muscle of the guinea pig ileum. Intracellular recordings of membrane potential responses recorded 3-5 mm oral to the transmural stimulus consisted of an inhibitory junction potential followed by two distinct depolarizations referred to as early and late excitatory junction potentials. Substance P antagonism was achieved by desensitization with high doses of substance P or use of the antagonist Spantide (Sigma Chemical Co., St. Louis, MO). Substance P antagonism had no effect on the amplitude of the inhibitory junction potential, caused an increase in the latter portion of the early excitatory junction potential, and abolished the late excitatory junction potential. The excitatory junction potential potentiated by substance P receptor antagonism was associated with a decrease in membrane resistance, increased in amplitude with conditioning hyperpolarizations to the estimated equilibrium potential for K+, and was blocked by the Cl-/HCO3- exchange inhibitor DIDS or prolonged perfusion with low-chloride solution. These studies suggest that a noncholinergic, non-substance P neurotransmitter is released from enteric motoneurons that produces excitation through an increase in smooth muscle chloride conductance.     

Clinical features and outcome of T-cell acute lymphoblastic leukemia in childhood with respect to alterations at the TAL1 locus: a Pediatric Oncology Group study

Alteration of the TAL1 locus is the most common nonrandom genetic defect in childhood T-cell acute lymphoblastic leukemia (T-ALL). To determine if rearrangements of the TAL1 proto-oncogene confer a distinct leukemic phenotype, we studied leukemic peripheral blood or bone marrow samples from 182 children with newly diagnosed T-ALL enrolled on Pediatric Oncology Group treatment protocols. Forty-eight (26%) of the samples had a local rearrangement of the TAL1 locus. Demographic and clinical features were compared for patient subgroups with and without TAL1 rearrangements. The only clinical correlates that were significantly associated with TAL1 gene rearrangements were higher white blood cell count (P = .017) and higher hemoglobin (P = .007) at diagnosis. Immunophenotypically, samples with altered TAL1 were more likely to be CD2+ (P = .001) and lack CD10 (cALLa) expression (P = .007) than those without the rearrangement. There was a trend toward improved event-free survival (EFS) in patients with TAL1 rearrangements (4-year EFS was 44% +/- 7% for patients without the rearrangements v 59% +/- 11% for those with rearrangements), but the difference was not significant (P = .34). The role of TAL1 in leukemogenesis has yet to be clearly defined, and the prognostic significance of TAL1 gene rearrangements in T-ALL deserves further study.     

An analysis of clinical and laboratory features of acute lymphocytic leukemias with emphasis on 35 children with pre-B leukemia

In 35 of 191 patients with acute lymphocytic leukemia (ALL) malignant cells were similar in phenotype to B-lymphocyte precursors. Both these patients' lymphoblasts and normal pre-B-cells contain cytoplasmic immunoglobulin (Ig) mu heavy chains, but have no surface Ig. In patients with pre-B leukemias, lymphoblasts containing cytoplasmic mu chains alone were often accompanied by cells of identical morphology that expressed no Ig and less frequently by lymphoblasts bearing scant amounts of surface mu. This spectrum of cellular Ig expression suggests that "null," pre-B, and intermediate pre-B/B ALLs represent closely related malignancies with complete or partial arrests at different stages of maturation. When pre-B, B, T, and "null" cell categories of ALL were compared for 22 different clinical and laboratory features, including remission rate and short-term remission duration, no statistical differences were observed between the pre-B and "null" groups. These early results suggest that pre-B-cell leukemias represents a relatively good prognostic subclass of ALL, do not require more intensive treatment than that proven to be effective for "null" cell ALL, and should be distinguished from the less common, but more clinically aggressive, B-cell subclass of ALL. Longer follow-up will be required to confirm these preliminary conclusions.     

Clinics in diagnostic imaging (162). Meckel’s diverticulum

A 28-year-old Chinese man presented with acute bleeding per rectum. Computed tomography showed a posterior outpouching arising from the distal ileum. The outpouching had hyperaemic walls, but no active contrast extravasation was detected. Technetium-99m pertechnetate scintigraphy showed focal areas of abnormal uptake in the right side of the pelvis, superior and posterior to the urinary bladder. These areas of uptake appeared simultaneously with the gastric uptake and demonstrated gradual increase in intensity on subsequent images. The diagnosis of Meckel’s diverticulum was confirmed on surgery and the lesion was resected. The clinical and imaging features of Meckel’s diverticulum are discussed.