Acute erythroleukemia: evaluation of 48 cases with reference to classification, cell proliferation, cytogenetics, and prognosis

We evaluated 48 archival cases of acute erythroleukemia and divided them into 3 groups: M6a, corresponding to the traditional French-American-British M6 category; M6b, which is pure erythroleukemia; and M6c, in which myeloblasts and pronormoblasts each account for more than 30% of cells by the French-American-British exclusion criteria. No significant differences were noted among the subtypes for ratio of males to females; age; or exposure to toxins, alcohol, or both. However, compared with the patients in the M6a group, patients in the M6b and M6c groups demonstrated a statistically significant increase in cytogenetic aberrations, proliferation markers (proliferating cell nuclear antigen and Ki67), and ringed (type III) sideroblasts. Marked survival differences were noted between the M6a (30.1 +/- 29.5 months) and M6b (3.15 +/- 4.2 months) groups, with patients in the M6c group demonstrating an intermediate prognosis (10.5 +/- 12.7 months). Chemotherapeutic regimens induced remission in all treated patients in the M6a and M6c groups but did not appear to affect the M6b group. However, the patients in the M6c group remained in remission for a significantly shorter period of time than did patients in the M6a group. Overall, survival appeared to depend on the ratio of pronormoblasts to myeloblasts at diagnosis and demonstrated a rapid decline with increasing pronormoblast and decreasing myeloblast counts. We must, therefore, devise chemotherapeutic regimens that target both blastic components of this disease.     

The association of intra-abdominal infection and abdominal wound dehiscence

Concurrent infection is a risk factor for abdominal wound dehiscence. We reviewed our experience with fascial dehiscence to determine the incidence and to identify prognostic factors for associated intra-abdominal infection. Over a 7-year period, 107 patients with abdominal wound dehiscence were identified. Seventeen were managed nonoperatively, and 90 underwent exploratory laparotomy, 43 of whom had no intra-abdominal pathology and 47 of whom had intra-abdominal infections. Demographic factors, comorbid diseases, and potential indicators of systemic infection did not distinguish patients with intra-abdominal infection from those without. Patients with an intra-abdominal infection were more likely to have undergone an emergency operation (74% vs 48%; P < 0.02), an operation on the colon (55% vs 25%; P < 0.005), or an operation with a higher wound classification (P < 0.02). Mortality was higher in patients with intra-abdominal infection than in those without (44% vs 20%; P < 0.02). Wound dehiscence after emergent operations, and operations with a higher wound classification, especially those involving the colon, should raise concern for intra-abdominal infection. Thorough abdominal exploration should be performed at the time of dehiscence repair. Before nonoperative management is chosen, intra-abdominal infection should be excluded.     

Design criteria for high-temperature steels strengthened with vanadium nitride

Fe-8-12Cr ferritomartensitic steels are widely used in the power generation, petrochemical and nuclear industries where they are subject to high operating temperatures and stresses. Resistance to creep deformation is therefore a critical materials property. One method of providing creep resistance is to precipitate a fine homogeneous distribution of vanadium nitride (VN) particles in the matrix. Maximizing this precipitation hardening effect requires a high nitrogen content, but this could cause gas bubble formation during conventional fabrication processes. It is therefore necessary to determine how much N can be added without encountering such problems. Phase stability calculations, using Thermo-Calc, were carried out to find high-N compositions to optimize the fraction of VN and the fabrication route for obtaining fine particles. Several experimental compositions, including nine high-nitrogen alloys, were fabricated as ingots; out of these, two exhibited porosity Thermo-Calc predicts that, in all of the high-nitrogen alloys, nitrogen gas is a stable phase around the solidus temperature. It is evident that porosity cannot simply be predicted from the presence of the gas phase on the equilibrium diagram. However, detailed analysis of the equilibrium phases predicted in these alloys, including their variation with composition, allowed a porosity criterion to be obtained. This criterion links porosity formation to the nature of the liquid-to-solid transformation. Further calculations were carried out to predict the dependence of gas phase evolution on both composition and pressure. Thermodynamic calculations are a valuable tool for the design of these industrially important alloys. Input from experimental data has enabled the refinement of the initial design criteria such that it should now be possible to propose compositions with high VN hardening but without the risk of porosity. This paper was presented at the International Symposium on User Aspects of Phase Diagrams, Materials Solutions Conference and Exposition. Columbus, Ohio, 18–20 October, 2004.     

Management of early-stage epithelial ovarian cancer

"Early" epithelial ovarian carcinoma encompasses a spectrum of patients with diseases that have markedly different survivals, ranging from indolent lesions truly confined to the ovary to high-grade lesions that have a significant chance of occult metastasis at the time of diagnosis. The basic principles of management rest on an adequate primary surgical procedure that removes all gross disease and accurately assesses the sites at risk for metastasis with a comprehensive staging laparotomy. After a comprehensive staging laparotomy, patients can be stratified into low-risk and high-risk groups. Those with low-risk disease have such a low risk of recurrence that the toxicity of adjuvant therapy is not warranted. Although patients with high-risk disease have a high enough of a risk of recurrence to justify consideration of adjuvant therapy, their ultimate prognosis may be determined more by an accurate determination of the stage of disease rather than by currently available, marginally effective or ineffective therapy. Patients who are thought to have early stage disease on the basis of inadequate staging procedures either should undergo a restaging laparotomy or receive therapy for the possibility of occult advanced disease.     

Electromyographic and neuromuscular variables in post-polio subjects

OBJECTIVE: Post-polio subjects experience functional deterioration many years after developing acute poliomyelitis and have been shown previously to have a deficit in strength recovery after isometric activity. This study characterized the size and stability of the motor units in a group of post-polio subjects with macro and single fiber electromyography (EMG) and correlated these variables with isometric strength, endurance, "work capacity," and strength recovery after fatiguing isometric exercise. DESIGN: A cohort of 12 post-polio subjects was tested for neuromuscular function. Electromyographic variables were determined on a separate day. SETTING: Volunteers were recruited from the community and tested in our neuromuscular research laboratory. SUBJECTS: A volunteer sample was obtained from advertisements. All subjects acknowledged post-polio syndrome symptoms. MAIN OUTCOME MEASURES: Neuromuscular variables were isometric knee extension peak torque, endurance (time to exhaustion) at 40% of maximal torque, tension time index, and recovery of torque at 10 minutes. Electromyographic variables were macro EMG and single fiber EMG (percent blocking and jitter). RESULTS: Macro EMG amplitude was ninefold the control value, and both jitter and blocking were greatly increased in comparison to control values. Isometric strength significantly (p < .05) correlated negatively with macro EMG amplitude. CONCLUSIONS: The weakest subjects had the greatest number of muscle fibers within the motor unit (as measured by macro EMG amplitude). Jitter and blocking did not correlate with neuromuscular function.     

Epidemiology of infection with Epstein-Barr virus types 1 and 2: lessons from the study of a T-cell-immunocompromised hemophilic cohort

In apparent contrast to earlier work on Epstein-Barr virus (EBV) carriage in the general Caucasian population, in vitro virus isolations from human immunodeficiency virus (HIV)-positive male homosexual cohorts have shown frequent examples of multiple EBV infection and an overall prevalence of type 2 EBV strains exceeding 30%. Here we ask to what extent these findings might hold true in another T-cell-immunocompromised cohort, HIV-positive hemophilic patients. Resident EBV strains were rescued within lymphoblastoid cell lines derived from the blood and throat washings of 39 such individuals, using the same in vitro protocols of virus isolation as for the homosexual cohort. A mean of 19 independent cell lines was made per patient, and in each case the resident virus was characterized by PCR-based viral genomic analysis and by immunoblotting to reveal the viral "EBNAprint." By these criteria a significant proportion (14 of 39) of the hemophilic cohort carried more than one EBV strain, suggesting that T-cell impairment does indeed sensitize virus carriers to reinfection with new strains of exogenously transmitted virus. However, the overall incidence of type 2 EBV infection was 10%, which is close to that observed in the earlier work with healthy carriers and substantially lower than that seen in HIV-positive homosexuals. We infer that type 2 EBV is relatively rare in the general Caucasian population but has become endemic in the homosexual community.     

Fetal heart rate patterns in postasphyxiated fetal lambs with brain damage

OBJECTIVE: We previously showed that in asphyxiated fetal lambs the duration of hypotension correlated well with the severity of histologic damage to the brain, whereas the duration of bradycardia did not. This study compares fetal heart rate patterns with the degree of histologic damage to the brain. STUDY DESIGN: Twelve chronically instrumented near-term fetal lambs were subjected to asphyxia by umbilical cord occlusion until fetal arterial pH was <6. 9 and base excess was <-20 mEq/L. An additional 4 fetuses served as sham-asphyxia controls. Fetal heart rate (from electrocardiogram), arterial blood pressure, fetal breathing movements, and electrocorticogram were continuously monitored before, during, and for 72 hours after asphyxia. Fetal brain histologic features were categorized as mild (group 1, n = 5), moderate (group 2, n = 4), and severe (group 3, n = 3). Long-term fetal heart rate variability expressed as amplitude range was assessed visually every 5 minutes from 30 minutes before asphyxia until 2 hours of recovery and at 6, 12, 24, 48, and 72 hours of recovery. RESULTS: Long-term fetal heart rate variability amplitude decreased from 32 +/- 17 beats/min (mean +/- SEM) preocclusion to 4 +/- 13 beats/min at the end of occlusion (P <.001) without significant differences among the 3 groups. During 10 to 45 minutes of recovery, the long-term variability of group 1 was significantly greater than that of groups 2 and 3. At 24 to 72 hours of recovery, the long-term variability of groups 1 and 2 was significantly higher than that of group 3, which was almost 0. The "checkmark" and sinusoidal fetal heart rate patterns were observed during the recovery period in groups 2 and 3. CONCLUSIONS: Decreased long-term fetal heart rate variability and the "checkmark" and sinusoidal fetal heart rate patterns were indicators of the severity of asphyxial histologic damage in the fetal brain.     

Paramagnetic 1H-NMR relaxation probes of stereoselectivity in metalloporphyrin catalyzed olefin epoxidation

Enantioselective catalytic epoxidation of olefins is an important problem from both practical and mechanistic points of view. The origins of chiral induction by asymmetric porphyrin and salen complexes were investigated by FT-NMR T1 relaxation techniques. A new chiral vaulted porphyrin (1) that carries (S)-binaphthyl-L-alanine straps across both faces of the porphyrin macrocycle was synthesized and characterized. (R)-styrene oxide was obtained in > 90% ee in the initial stages of styrene epoxidation with F5PhIO catalyzed by 1-Fe(III)Cl. The transition state for olefin epoxidation with high-valent metal-oxo species was modeled by coordinating epoxides to paramagnetic copper complexes of the corresponding ligands. The epoxide enantiomer that better fit the chiral cavity of the catalyst, as revealed by T1 relaxation measurements, was also the major product of catalytic olefin epoxidation. These results are consistent with the "lock-and-key" mechanism of asymmetric catalysis by metalloporphyrins. The copper complex of a chiral salen ligand showed no differentiation in terms of T1 relaxation rates between the enantiomers of cis-beta-methylstyrene oxide in contrast to the high enantioselectivity observed for catalytic epoxidation.     

Restoring palatal tooth loss with composite resin, aided by increased vertical height

The Mini-Mental-State Examination (MMSE) is widely used as a screening tool for dementia in epidemiological studies. Its applicability in population-based studies is nevertheless limited by its low specificity. The effect of age and educational level have been usually ignored when cut-off scores have been selected. The aim of this study was to evaluate the effect of age and educational level on the MMSE scores in a representative sample of subjects older than 70 and provide adjusted normalised data according to these two variables, after excluding subjects with dementia or cognitive decline. Population-based, cross-sectional and longitudinal study of a representative cohort of 1367 subjects older than 70. All subjects with suspected dementia or cognitive decline received a neurological evaluation where clinical and etiological diagnosis were established. Normal MMSE scores, as defined by the 10th percentile, varied significantly across age and educational level groups. Exclusion of demented or cognitively declined patients from the reference population reduced the variability and "range of normality", but this remained excessively high in the older and less educated groups. The use of different cut-off points for each age and educational level groups may improve the specificity and applicability of the MMSE in population-based epidemiological studies. However, the wide amplitude of the range of normality suggests that different approaches, other than this vibariate analysis, may prove more adequate in the selection of cut-off scores for the MMSE.     

Periodic orbits: a new language for neuronal dynamics

A new nonlinear dynamical analysis is applied to complex behavior from neuronal systems. The conceptual foundation of this analysis is the abstraction of observed neuronal activities into a dynamical landscape characterized by a hierarchy of "unstable periodic orbits" (UPOs). UPOs are rigorously identified in data sets representative of three different levels of organization in mammalian brain. An analysis based on UPOs affords a novel alternative method of decoding, predicting, and controlling these neuronal systems.