Energy-efficient 0.26-Tb/s coherent-optical OFDM transmission using photonic-integrated all-optical discrete Fourier transform.

We propose a novel energy-efficient coherent-optical OFDM transmission scheme based on hybrid optical-electronic signal processing. We demonstrate transmission of a 0.26-Tb/s OFDM superchannel, consisting of 13 x 20-Gb/s polarization-multiplexed QPSK subcarrier channels, over 400-km standard single-mode fiber (SSMF) with BER less than 6.3x10(-4) using all-optical Fourier transform processing and electronic 7-tap blind digital equalization per subchannel. We further explore long-haul transmission over up to 960 km SSMF and show that the electronic signal processing is capable of compensating chromatic dispersion up to 16,000 ps/nm using only 15 taps per subchannel, even in the presence of strong inter-carrier interference.

Linear phase-and-frequency-modulated photonic links using optical discriminators.

We report our experimental results for linear analog optical links that use phase or frequency modulation and optical discrimination. The discriminators are based on two architectures: a cascaded MZI FIR lattice filter and a ring assisted MZI (RAMZI) IIR filter. For both types of discriminators, we demonstrate > 6 dB improvement in the link's third-order output intercept point (OIP3) over a MZM link. We show that the links have low second-order distortion when using balanced detection. Using high optical power, we demonstrate an OIP3 of 39.2 dBm. We also demonstrate 4.3dB improvement in signal compression.

All-optical OFDM transmission of 7 x 5-Gb/s data over 84-km standard single-mode fiber without dispersion compensation and time gating using a photonic-integrated optical DFT device.

We implement dispersion-tolerant and time-gating-free all-optical OFDM transmission using a photonic-integrated discrete Fourier transform (DFT) device. We show that 35-Gb/s OFDM data having near-unity spectral efficiency can be transmitted all-optically with 1-dB dispersion margin of ~1000 ps/nm. The passive-optical DFT circuit is implemented using multi-mode interference (MMI) couplers on a high index-contrast silica integrated-optic platform. We also propose a photonic DFT circuit based on an NxN MMI device capable of simultaneous channelization of OFDM signals into N subcarriers.

Long-haul transmission of 35-Gb/s all-optical OFDM signal without using tunable dispersion compensation and time gating.

We propose that the optical OFDM technique using all optical discrete Fourier transform (DFT) has potential as a viable alternative for upgrading long-haul optical transmission systems towards 100-Gb/s. We demonstrate transmission of 35-Gb/s (7 x 5 Gb/s NRZ-OOK) all-optical OFDM signal over ~2000-km dispersion-managed span without using tunable dispersion compensation and time gating. We achieve bit error ratio of 1.2x10(-3) (7x10(-3)) for transmission over 1980-km (2310-km) all-EDFA amplified span consisting of standard single mode fiber (SSMF) and dispersion compensating fiber (DCF). We also study the nonlinear penalty impacting the all-optical OFDM transmission and discuss potential method for its mitigation.

All-optical XOR and XNOR operations at86.4 Gb/s using a pair of semiconductor optical amplifier Mach-Zehnder interferometers.

We propose a method for increased-speed all-optical XOR operation using semiconductor optical amplifiers. We demonstrate XOR and XNOR operations at 86.4 Gb/s using a pair of photonic-integrated semiconductor optical amplifier Mach-Zehnder interferometers.

A hybrid electroabsorption modulator device for generation of high spectral-efficiency optical modulation formats.

We report a novel hybrid integrated optic device consisting of AlGaInAs/InP electroabsorption modulators and a four-arm silica-on-silicon planar lightwave circuit optical interferometer. The device is designed for generation of high spectral efficiency optical modulation formats. We demonstrate generation of 21.4 Gb/s quadrature phase shift keyed optical signals with electrical data drives of 2V(pp) amplitudes, achieving a bit error rate of 10(-9) with the required optical signal to noise ratio of ~18 dB in a 0.1 nm resolution bandwidth.

Urinary hypoxanthine and pseudouridine as indicators of tumor development in mesothelioma-transplanted nude mice.

A human mesothelioma was heterotransplanted to nude mice, and the urinary excretions of hypoxanthine, xanthine, pseudouridine, orotic acid, 7-methylguanine, and 1-methylhypoxanthine have been followed before and after the tumor transplantation. The compounds were measured by means of isotachophoresis, which has been found a rapid and precise method. The tumor reached maximum size within 30 days, and at this time a significantly increased excretion of pseudouridine and hypoxanthine was observed. Tumor growth was stopped by chemotherapy (vincristine, cyclophosphamide, prednisolone, and Adriamycin), and corresponding to this, a decrease occurred in both pseudouridine and hypoxanthine excretion to normal values.

Antibodies to Pneumocystis carinii in Danish blood donors and AIDS patients with and without Pneumocystis carinii pneumonia.

Sera from 1) 8 AIDS patients with Pneumocystitis carinii pneumonia, 2) 13 HIV antibody-positive patients, 9 with AIDS and 4 with AIDS-related symptoms, all 13 without Pneumocystis carinii pneumonia, and 3) 36 healthy male blood donors, all HIV antibody negative, were examined for antibodies against Pneumocystis carinii using the indirect immunofluorescence antibody technique. Seven (87%) out of eight sera from group 1, 12 (92%) out of 13 sera from group 2, and 35 (97%) out of 36 sera from group 3 were positive. There was no significant difference between group 1 and 2, and group 2 and 3. The difference between group 1 and group 3 was significant (p = 0.03).

Bacteriological autopsy. I. A methodological study.

The two aims of this investigation were: 1. To compare a swab culture technique with an imprint method in bacteriological autopsy. 2. To examine the influence of body manipulation on culture. Specimens were taken from the lungs and the spleen in 42 autopsies. For imprint a piece of sterile blotting paper was used. Point 1. Good qualitative agreement was found between the two methods. Print cultures enabled a quantitation at low numbers of bacteria. However, in most cases when growth was present the colonies were confluent, which did not allow counting. The lung cultures were 67%/69% positive (swab/print). For the spleen, the positive rate was 21%/42% (swab/print). In the cases representing the difference, only a few colonies grew on the print plates. Culture by means of a swab was found to give the same information as culture by imprint. Swabs are easier to handle but should be processed within a couple of hours. Point 2. In ten autopsies, cultures were taken with organs in situ after the organ block was removed and after an ordinary autopsy had been performed. A scoring system was used to compare the results. There was a clear correlation between positive cultures and manipulation of the organs. The specimens should be taken with the organs in situ.

Bacteriological autopsy. II. Comparison of a group of cancer patients with a control group.

A study of the results of bacteriological autopsy in a group of cancer patients compared with a control group was carried out. Autopsy was performed on 42 bodies within 24 hours of death. Thirty-two patients had died with a cancer and the remaining ten had died of cardiovascular disease. Tissue for microscopy and material and culture were taken from the same sites. The results of the inoculations were semiquantified, resulting in a culture score, and the results of the microscopy were classified according to presence of bacteria and kind of inflammation. Furthermore, grading was done according to the degree of inflammation and whether bacteria were seen at microscopy. The culture scores were significantly higher in the cancer group than in the control group. We found a significant correlation between score and presence of acute inflammation. Likewise, a significant correlation was found between score and presence of bacteria at microscopy. As a difference between the cancer group and the control group was seen, further research on bacteriological autopsy seems worthwhile.

Localization of monocyte chemotactic and activating factor (MCAF/MCP-1) in psoriasis.

The monocyte chemotactic protein-1 (MCAF) also termed MCP-1, a strong chemotactic factor towards monocytes, is produced by several cell types present in the skin. The in situ presence of MCAF/MCP-1 protein in the skin has, however, not yet been established. Using immunohistochemical techniques we have investigated the distribution of MCAF in skin from patients with different types of psoriasis and normal healthy volunteers. We report the novel finding that psoriasis has strong positive immunostaining for MCAF located to all the layers of the epidermis, except the stratum granulosum, in pustular, guttate and chronic plaque psoriasis. In the dermis, infiltrating cells in the perivascular aggregates and the blood vessels stained positive for MCAF. No significant differences were observed between the different subtypes of psoriasis except that strongly positive infiltrating cells were observed in the epidermal pustules in pustular psoriasis. In normals positive staining was observed in all the layers of the epidermis and in a few perivascular cells and blood vessels in the dermis. Where present in normal and diseased skin, eccrine ducts of sweat glands and sebaceous glands stained positive for MCAF. Arrector pili muscles were in all cases negative. These findings are consistent with a role for MCAF in attracting inflammatory cells, including monocytes, into the skin in psoriasis.

Lymphangioleiomyomatosis. Is fine needle aspiration cytodiagnosis possible?

Lymphangioleiomyomatosis is a rare condition characterized by a proliferation of the smooth muscle cells, mainly in the lymphatic system, giving rise to blockage of the thoracic duct with chylothorax and chyloascites. This condition was seen in a 34-year-old woman with an abdominal tumor that was subjected to fine needle aspiration. The cytologic diagnosis of this neoplasm is difficult since the cellularity and the cytologic picture indicate malignancy. The organoid configuration together with the chylus formation gave an important clue to the correct diagnosis, which, however, was not made until after a biopsy was performed and the cytologic and histologic findings were combined. The cytologic, histologic and electron microscopic findings are presented.

Urid acid accumulated in isolated kidney grafts: an assessment of agonal ischaemia.

Hypoxanthine-xanthine washed out from kidney tissue during preservation has previously been found to be a reliable measure of the in vitro assessment of the deleterious effect of ischaemia on the functional regenerative ability of the graft. We have now studied the question: can uric acid accumulation in the isolated kidney graft be employed as a retrospective measure of the agonal ischaemia? We have found that uric acid alone accumulates in renal tissue during the agonal phase, in an amount that remains unchanged during the subsequent in vitro ischaemia. The determination of hypoxanthine-xanthine and uric acid in kidney perfusate samples during preservation must thus be presumed to be an optimal clinical-chemical method of assessing the graft ischaemia.

[Inflammatory pseudotumor--differential diagnosis in lung tumor in a child]. / Inflammatorisk pseudotumor--en differentialdiagnose ved lungetumor hos b|rn.

A case of a twelve-year-old girl with a big solid tumour in the right lung is presented. As malignancy could not be excluded, she was operated. A lobectomy was performed. Frozen section showed no malignancy. Histology showed inflammatory pseudotumour, which is a rare but important benign lung tumour in childhood. The recommended treatment is conservative resection.

[Outbreak of serogroup C meningococcal disease among teenagers in Randers--preventive measures and examination of the meningococcal carrier conditions]. / Udbrud af serogruppe C-meningokoksygdom blandt teenagere i Randers--profylaktiske foranstaltninger og undersøgelse af meningokokboerertilstanden.

An outbreak involving 20 cases of serogroup C meningococcal disease, predominantly among teenagers, occurred over a seven-month period in the Randers area of Denmark. The cases were caused by a serogroup C:2a:P1.2 sulphonamide-resistant strain. The available evidence was against the transmission being related to particular schools. The outbreak was experienced as three clusters. At two schools involved in the first and the third cluster of the outbreak, 351 students were examined regarding pharyngeal carriage of meningococci, 282 of whom were tested again 17 weeks later; 308 students attending two similar schools in a nearby area were examined once. The majority of strains isolated from group C carriers in the high-risk area were serologically indistinguishable from the outbreak strain (13/14 = 95%), but less often sulphonamide-resistant (5/13 = 38%). In both areas, the overall carrier rate (30%), the overall group C rate (3%) and, the carrier rate for the outbreak strain (1%) were the same. The attack rate for the outbreak strain differed significantly: 1/40 in the high-risk area versus 1/2.500 in the normal risk area. No conditions that might explain this difference were revealed. Immediately after recognition of the first and the third cluster, 780 and 13,300 students, respectively, were vaccinated with meningococcal polysaccharide vaccine A+C. It was concluded that the definition of target groups for vaccination should be liberal, because the "at risk" population may be difficult to recognize at the onset of an outbreak.

Gene expression signatures for colorectal cancer microsatellite status and HNPCC.

The majority of microsatellite instable (MSI) colorectal cancers are sporadic, but a subset belongs to the syndrome hereditary non-polyposis colorectal cancer (HNPCC). Microsatellite instability is caused by dysfunction of the mismatch repair (MMR) system that leads to a mutator phenotype, and MSI is correlated to prognosis and response to chemotherapy. Gene expression signatures as predictive markers are being developed for many cancers, and the identification of a signature for MMR deficiency would be of interest both clinically and biologically. To address this issue, we profiled the gene expression of 101 stage II and III colorectal cancers (34 MSI, 67 microsatellite stable (MSS)) using high-density oligonucleotide microarrays. From these data, we constructed a nine-gene signature capable of separating the mismatch repair proficient and deficient tumours. Subsequently, we demonstrated the robustness of the signature by transferring it to a real-time RT-PCR platform. Using this platform, the signature was validated on an independent test set consisting of 47 tumours (10 MSI, 37 MSS), of which 45 were correctly classified. In a second step, we constructed a signature capable of separating MMR-deficient tumours into sporadic MSI and HNPCC cases, and validated this by a mathematical cross-validation approach. The demonstration that this two-step classification approach can identify MSI as well as HNPCC cases merits further gene expression studies to identify prognostic signatures.