Pseudorandom phase-only encoding of real-time spatial light modulators

We previously proposed a method of mapping full-complex spatial modulations into phase-only modulations. The Fourier transform of the encoded modulations approximates that of the original complex modulations. The amplitude of each pixel is encoded by the property that the amplitude of a random-phasor sum is reduced corresponding to its standard deviation. Pseudorandom encoding is designed for phase-only spatial light modulators that produce 360° phase shifts. Because such devices are rare, experiments are performed with a 326°modulator composed of two In Focus model TVT6000 liquid-crystal displays. Qualitative agreement with theory is achieved despite several nonideal properties of the modulator.

Phase I and pharmacologic study of 9-aminocamptothecin given by 72-hour infusion in adult cancer patients

PURPOSE

To conduct a phase I and pharmacologic study of the new topoisomerase I inhibitor, 9-aminocamptothecin (9-AC).

PATIENTS AND MATERIALS

A 72-hour infusion of 9-AC was administered every 14 days to 48 solid-tumor patients at doses of 5 to 59 microg/m2/h without granulocyte colony-stimulating factor (G-CSF) and 47 to 74 microg/m2/h with G-CSF.

RESULTS

Without G-CSF, two of eight patients who received 47 microg/m2/h had dose-limiting neutropenia in their initial cycle, as did both patients who received 59 microg/m2/h (with a platelet count < 25,000/microL in one). With G-CSF, zero of seven patients treated with 47 microg/m2/h had dose-limiting neutropenia in their first cycle, while dose-limiting neutropenia occurred in six of 14 patients (with platelet count < 25,000/microL in five) entered at 59 microg/m2/h. Among 39 patients entered at > or = 25 microg/m2/h 9-AC with or without G-CSF, fatigue, diarrhea, and nausea/vomiting of grade 2 severity ultimately occurred in 54%, 30%, and 38%, respectively, while grade 3 toxicities of each type occurred in 8% of patients. Steady-state 9-AC lactone concentration (Css) increased linearly from 0.89 to 10.6 nmol/L, and correlated strongly with leukopenia ( r = .85).

CONCLUSION

The recommended phase II dose of 9-AC given by 72-hour infusion every 2 weeks is 35 microg/m2/h without G-CSF or 47 microg/m2/h with G-CSF support. Dose escalation in individual patients may be possible according to their tolerance.

The development and initial validation of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index for systemic lupus erythematosus

OBJECTIVE

To develop and perform an initial validation of a damage index for systemic lupus erythematosus (SLE).

METHODS

A list of items considered to reflect damage in SLE was generated through a nominal group process. A consensus as to which items to be included in an index was reached, together with rules for ascertainment. Each center submitted 2 assessments, 5 years apart, on 2 patients with active and 2 with inactive disease, of whom 1 had increased damage and the other had stable disease. Analysis of variance was used to test the factors physician, time, amount of damage, and activity status.

RESULTS

Nineteen physicians completed the damage index on 42 case scenarios. The analysis revealed that the damage index could identify changes in damage seen in patients with both active and inactive disease. Patients who had active disease at both time points had a higher increase in damage. There was good agreement among the physicians on the assessment of damage in these patients.

CONCLUSION

This damage index for SLE records damage occurring in patients with SLE regardless of its cause. The index was demonstrated to have content, face, criterion, and discriminant validity.

Gastrin-releasing peptide receptor signaling resulting in growth inhibition

We demonstrate that gastrin-releasing peptide (GRP) can inhibit the proliferation of human immortal nontumorigenic (184-B5) mammary epithelial cells ectopically expressing the human GRP receptor. Growth of Balb 3T3 cells ectopically expressing relatively high levels of the GRP receptor was also inhibited by GRP; however, growth of transfectants expressing lower levels of the receptor was not inhibited. Compared with Balb 3T3 cells, mammary epithelial cells could be rendered sensitive to growth inhibition by GRP by the expression of fewer GRP receptors. GRP also stimulated DNA synthesis in quiescent, serum-starved Balb 3T3 transfectants. In clones that were sensitive to growth inhibition by GRP by virtue of their expression of relatively high levels of the GRP receptor, the dose-response curve of GRP-stimulated DNA synthesis was bell shaped. This is consistent with our conclusion that the growth-inhibiting activity of GRP required the activation of a relatively large pool of receptors in Balb 3T3 cells. Significantly, prostaglandin H synthase inhibitors, which block the production of prostaglandins from arachidonic acid, reduced GRP-inhibitory effects on DNA synthesis. We also compared a number of GRP-stimulated signaling pathways in Balb 3T3 clones that were sensitive or insensitive to growth inhibition by GRP, including cAMP formation, phospholipase C activation, calcium mobilization, and arachidonic acid formation. Taken together, these results demonstrate a novel GRP receptor-coupled signal pathway promoting growth inhibition in which prostaglandin H synthase plays a significant role.

[Determination of metronidazole in serum by HPLC]

This paper report a sensitive and rapid method for the determination of metronidazole (MTZ) using theophylline as the internal standard. High performance liquid chromatograph model 344 (Beckman) with a 254 nm wavelength UV detector and YWG-C18H37 column (10 microns, 250 x 4.6 mm) was used. To the serum sample 200 microliters, 100 microliters phosphate buffer (0.8 mol/L, pH 7.5) was added, then extracted with 3 ml chloroform containing 5% isopropyl alcohol. The organic layer was removed and evaporated to dryness under an air stream in a 40 degrees C water bath. The residue was dissolved in 30 microliters mobile phase and 20 microliters injected. The mobile phase of water-methanol (73:27) was pumped at 1.0 ml/min through the column. The detector operated at 0.005 aufs. The retention times for MTZ and theophylline were 5.78 and 6.81 min respectively. Standard curve was linear in the concentration range of 0.3125 to 20 mg/L. The detection limit in serum was 0.02 mg/L. Extraction recovery was 77%-82%; method recovery 99%-102%; withinday RSD less than 3.0%; inter-day RSD less than 3.5%.

Bacterial expression of neutralizing mouse monoclonal antibody Fab fragments to Hantaan virus

We amplified by polymerase chain reaction the heavy and light chain antibody genes of two mouse hybridomas secreting neutralizing monoclonal antibodies (MAbs) to the G1 or G2 envelope proteins of Hantaan virus, cloned them into the phagemid vector pComb3, and expressed them in bacteria to yield Fab fragments. Expressed Fab fragments had the same antigenic specificities for Hantaan and Seoul viruses as the complete parent MAbs and were able to neutralize Hantaan virus in plaque-reduction neutralization assays. The authentic MAb to G2 (HCO2) could passively protect hamsters from challenge with Hantaan virus when neutralizing antibody titers of at least 1:10 were detected in the animals' sera just prior to challenge. In contrast, although 1:10 neutralization titers were also detected in hamsters receiving passively transferred, Escherichia coli-expressed HCO2 Fab, these animals were not protected from infection with Hantaan virus. Similarly, passive transfer of the HCO2 Mab on Days 1 through 4 after infection prevented antigen deposition in hamster lungs and kidneys but passive transfer of the recombinant HCO2 Fab did not. The results suggest that although neutralization by IgG antibodies correlates with protection in hamsters, the same may not be true for neutralizing Fab fragments.

Random phase encoding of composite fully complex filters

The mapping of complex-valued functions onto phase-only spatial light modulators is examined. Random phase encoding effectively adds amplitude control to the phase-only filter and can be used to trade off systematic errors of the phase-only filter for random errors. This is illustrated for the problem of recognizing a threedimensional object from arbitrary views. The complex-valued composite filters that constitute a filter bank design are encoded by phase-only and pseudorandom methods. The best recognition probabilities are achieved by blending the two methods so that only the smallest amplitudes are randomly encoded.

Health status instruments / utilities

Rheumatologists and other interested professionals at the OMERACT II conference formed small groups to discuss whether it was sensible to use a generic health status instrument in musculoskeletal disease trials. These instruments promise the possibility of comparison of health status between disease states. However, data is lacking on validity of the current generation of instruments to support their use. Participants had little personal experience with these instruments. After inspection, many voiced strong concerns over comprehensiveness and responsiveness. Many dimensions of health relevant for patients with this group of diseases were felt to be underrepresented. The dimension of adverse effects was universally absent, although this is more a problem of state of the art in trial methodology than a problem of these measures. Although there is little data, the small number of response categories in the dimensions covered, plus the lack of comprehensiveness, make it likely that responsiveness will be low. Further research, especially the adoption of one or more generic measures alongside specific measures, both in trials and in observational studies, is necessary to validate and improve the current generic measures. Until that time, valid conclusions and health policy regarding musculoskeletal diseases cannot be based on generic measures of health status.

Primary structure of hepatocyte nuclear factor/forkhead homologue 4 and characterization of gene expression in the developing respiratory and reproductive epithelium

Members of the winged helix/forkhead family of transcription factors are believed to play a role in cell-specific gene expression. A cDNA encoding a member of this family of proteins, termed hepatocyte nuclear factor/forkhead homologue 4 (HFH-4), has been isolated from rat lung and rat testis cDNA libraries. This cDNA contains an open reading frame of 421 amino acids with a conserved DNA binding domain and several potential transactivating regions. During murine lung development, a single species of HFH-4-specific transcript (2.4 kb long) is first detected precisely at the start of the late pseudoglandular stage (embryonic day 14.5) and, by in situ hybridization, is specifically localized to the proximal pulmonary epithelium. The unique temporal and spatial pattern of HFH-4 gene expression in the developing lung defines this protein as a marker for the initiation of bronchial epithelial cell differentiation and suggests that it may play an important role in cell fate determination during lung development. In addition to expression in the pulmonary epithelium, RNA blot analysis reveals 2.4-kb HFH-4 transcripts in the testis and oviduct. By using mice with genetic defects in spermatogenesis, HFH-4 expression in the testis is found to be associated with the appearance of haploid germ cells and in situ hybridization studies indicate that HFH-4 expression is confined to stages I-VII of spermatogenesis. This pattern of HFH-4 gene expression during the early stages of differentiation of haploid germ cells suggests that HFH-4 may play a role in regulating stage-specific gene expression and cell-fate determination during lung development and in spermatogenesis.

A brief introduction to the critical reading of the clinical literature

Clinicians are bombarded by reports of new diagnostic tests or treatments for patients with spine problems. To provide the best possible patient care, clinicians need to be able to critically appraise the results of such studies for validity and relevance to patient care. Important questions to be asked of any description of diagnostic or treatment studies are the following questions: 1) Are the patients described in detail so that you can decide whether they are comparable to those that you see in your practice? 2) Are the treatments or assessments described well enough so that you could provide the same for your patients? 3) Was a clinically relevant endpoint measured? 4) Is there an appropriate comparison group? 5) Are potential sources of bias appropriately attended to? 6) Are the results clinically significant?

Approximating fully complex spatial modulation with pseudorandom phase-only modulation

Any desired diffraction pattern can be produced in the Fourier plane by the specification of a corresponding input-plane transparency. Complex-valued transmittance is generally required, but in practice phase-only transmittance is used. Many design procedures use numerically intensive, constrained optimization. We instead introduce a noniterative procedure that directly translates the desired but unavailable complex transparency into an appropriate phase transparency. At each pixel the value of phase is pseudorandomly selected from a random distribution whose standard deviation is specified by the desired amplitude. We also derive statistical expressions and use them to evaluate the approximation errors between the desired and achieved diffraction patterns.

Antigenic and molecular characterization of hantavirus isolates from China

Hemorrhagic fever with renal syndrome (HFRS) is caused by certain viruses in the genus Hantavirus, family Bunyaviridae, and is a major public health problem in China. By using molecular and serological tests, we characterized 15 hantaviruses isolated either from patients with HFRS or from rodents captured in endemic areas of China. By cross plaque-reduction neutralization tests performed with rabbit immune sera, we identified two serologically distinct groups of viruses, comprised of those related to Hantaan virus, and those related to Seoul virus. To study the genetic relationships among these viruses, we amplified a 330 base pair region of the medium (M) genome segment of each isolate by reverse transcription and polymerase chain reaction (PCR) and compared the nucleotide sequences to those of other, well-characterized hantaviruses. In addition, we PCR-amplified and analyzed the entire coding region of the small (S) genome segment of each isolate by restriction enzyme digestion with a battery of enzymes. The results of our genetic analyses of both the M and S segments of these isolates confirmed our serological data, indicating that Hantaan and Seoul viruses co-circulate in endemic disease regions of China. We constructed a phylogenetic tree based on multiple alignment of the partial M segment sequences. The resulting dendrogram distinguished three genetic subtypes of Hantaan viruses and one type of Seoul virus.

Lateral inhibition: inherent recurrent processes in coherent optical propagation

Processes that are analogous to the neural process of recurrent lateral inhibition can be found in optical systems that consist of a shift-invariant system and a Fabry-Perot cavity. The properties of the optical recurrent system are derived and demonstrated by computer simulation. The simulation shows that optical lateral inhibition can be used to enhance the outline of an amplitude object and to make phase-only objects directly detectable and visible. The optical recurrent system is compared with frequency-plane spatial filtering. Requirements and practical limitations for the design of an optical recurrent system are also discussed.

Comparison of three techniques to inflate the bronchial cuff of left polyvinylchloride double-lumen tubes

Correct inflation of the cuff of any breathing tube is important; overinflation can damage the mucosa of the tracheobronchial tree and underinflation will cause a leak. Three different techniques to determine cuff seal/leak during inflation of the bronchial cuff of left double-lumen endobronchial tubes (DLT) were each evaluated in 10 patients. DLT size was chosen from a formula based on the patient's height and sex. In the first technique, designated the positive pressure technique of bronchial cuff inflation (PPT), the bronchial side of the DLT is pressurized during connection of the tracheal side to a beaker of water. Air bubbles will appear in the beaker in the absence of bronchial seal. The second technique, designated the CO2 analysis technique of bronchial cuff inflation (CAT), is based on analysis of CO2 content of gas sampled from the tracheal side of the DLT during ventilation of its bronchial side. When the bronchus is sealed, the normal CO2 waveform changes to a flat line. In the third technique, designated the negative pressure technique of bronchial cuff inflation (NPT), suction is applied to the tracheal side of the DLT. The absence of bronchial seal will result in collapse of the reservoir bag within a breathing system connected to the bronchial side of the tube. The bronchial sealing volumes were 1.1 +/- 0.9 mL, 0.9 +/- 0.7 mL, and 0.3 +/- 0.4 mL (mean +/- SD) when measured with the PPT, CAT, and NPT, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular and antigenic characterization of HV114, a hantavirus isolated from a patient with haemorrhagic fever with renal syndrome in China

The relationship of a Hantaan-like virus (HV114), isolated from a patient with haemorrhagic fever with renal syndrome in Hubei Province, People's Republic of China, to other pathogenic hantaviruses was evaluated by cross-neutralization studies and nucleotide sequence analysis of the M genome segment. Plaque reduction neutralization assays indicated that HV114 is closely related to prototype Hantaan (HTN) virus, strain 76-118, which was originally isolated from an Apodemus field mouse in Korea. Comparison of the M genome segments of HTN 76-118 and HV114 revealed sequence identity of 84.7% and 95.4% for nucleotides and deduced amino acids, respectively. These data demonstrate that HV114 and 76-118 are two closely related but different isolates of HTN virus, establishing the scientific basis for testing and future use in China of a recombinant vaccine expressing the genome of HTN virus strain 76-118.

Compression of bright optical pulses by dark solitons

We show that bright optical pulses can be compressed in the wavelength region of normal group-velocity dispersion by using dark optical solitons. Various cases of the pulse compression are studied numerically for dark soliton pulses with a background of finite temporal duration.

Epidermal growth factor activates phospholipase C in rat hepatocytes via a different mechanism from that in A431 or rat1hER cells

Epidermal growth factor (EGF) can stimulate inositol lipid hydrolysis in rat hepatocytes and can accelerate GTP/GDP exchange in hepatic membranes. Both of these responses can be abolished by pretreatment with pertussis toxin, suggesting that EGF may regulate phospholipase C (PLC) activity via a guanine nucleotide-binding regulatory protein (G protein) in liver cells. In contrast, in A431 human epidermoid carcinoma cells EGF can induce a rapid phosphorylation of PLC-gamma on tyrosine residues that increases the activity of immunoprecipitated PLC-gamma, suggesting that tyrosine phosphorylation of PLC-gamma may be the mechanism for EGF-stimulated inositol trisphosphate production in these cells. To determine the importance of the phosphorylation of PLC-gamma on tyrosine residues in a system where the EGF receptor apparently couples to a G protein, the effect of EGF on tyrosine phosphorylation of PLC-gamma was examined in rat hepatocytes. PLC-gamma was immunoprecipitated from cell lysates with a PLC-gamma antiserum and its tyrosine phosphorylation state was determined using both Western blot analysis with phosphotyrosine antibodies and direct measurement of phosphorylated amino acids. The results were compared with analogous experiments performed with A431 cells and another cultured cell line expressing high levels of human EGF receptors, Rat1hER fibroblasts. Although the amount of PLC-gamma in rat hepatocytes is similar to that in A431 cells and slightly higher than that in Rat1hER cells, EGF causes a barely detectable increase in the phosphorylation of PLC-gamma on tyrosine in hepatocytes, whereas it stimulates a significant degree of phosphorylation of PLC-gamma on tyrosine in Rat1hER or A431 cells. Pretreatment of hepatocytes with pertussis toxin abolishes the ability of EGF to activate PLC, as determined by an increase in intracellular Ca2+, but has no effect on the small amount of phosphate incorporated into tyrosine residues on the PLC-gamma protein, demonstrating that this low level of PLC-gamma phosphorylation does not correlate with changes in PLC activity. The data suggest that phosphorylation of PLC-gamma on tyrosine is not important for EGF-enhanced PLC activity in hepatocytes. This conclusion implies that EGF may use a mechanism to regulate PLC activity in hepatocytes that is different from that used in cultured cells expressing high levels of EGF receptors.