Misrepresentation of publications by applicants for radiology fellowships: is it a problem?

In light of the recently described experimental technique of in vivo bone reconstitution with biotechnologic methods (from bone marrow stromal cells) and the prefabrication flap procedures, the possibility to obtain autologous bone growth in a myocutaneous flap, thus creating a composite osteomyocutaneous preformed flap, is postulated. Human bone marrow stromal cells were delivered into the latissimus dorsi of athymic mice by a porous hydroxyapatite ceramic model. Eight weeks after the implantation, histologic examination revealed the presence of spongious bone tissue. A simple myocutaneous flap was thus transformed into a composite osteomyocutaneous flap. This flap is called the biotechnologic prefabricated flap, because it was the result of ex vivo expanded osteogenic precursor cells and in vivo bone tissue neoformation. The shape of the bone flap was exactly the same as the shape of the ceramic model used. A possible clinical application may be the correction of skeletal defects. The advantages of this procedure are simple surgical execution, the possibility of preshaping the graft to the exact characteristics of the defect, and the availability of autogenous donor tissue without donor site morbidity.     

Molecular typing of Borrelia burgdorferi from Lyme disease patients by PCR-restriction fragment length polymorphism analysis

Ninety-three Borrelia burgdorferi isolates obtained from erythema migrans lesions or blood of Lyme disease patients in Westchester County, N.Y., between 1991 and 1994 were characterized by PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the 16S-23S rRNA gene spacer. All isolates could be classified into three distinct RFLP types. Among the 82 skin biopsy isolates studied, 21 (25.6%) were type 1, 37 (45.1%) were type 2, and 21 (25.6%) were type 3. Three (3.7%) cultures contained a mixture of two isolates with distinct RFLP types. The 11 isolates cultured from blood showed a similar predominance of RFLP type 2 (6 of 11; 54.5%) relative to types 1 (2 of 11; 18.2%) and 3 (3 of 11; 27.3%). For one patient both skin and blood isolates were cultured, and RFLP analysis revealed that these isolates differed from one another. This study demonstrates that there is genotypic heterogeneity in B. burgdorferi strains infecting Lyme disease patients, and this typing approach may allow differentiation of isolates with various degrees of pathogenic potential.     

Phase I trial of intravenous carboplatin and cyclosporin A in refractory gynecologic cancer patients

Our objective was to determine the maximum tolerated dose of cyclosporin A (CsA) delivered as a loading dose (LD) and continuous i.v. infusion (CI) in combination with carboplatin in patients with refractory gynecologic cancers. Twenty-nine heavily pretreated patients (25 ovarian epithelial, 2 cervical, and 2 endometrial carcinomas) received 113 cycles of CsA and carboplatin from September 1989 to September 1991. Twenty-four of these 29 carcinomas were strictly defined to be platinum resistant. CsA was administered as a LD escalated from 6 to 10 mg/kg followed by a 24-h CI from 2.5 to 14.5 mg/kg/day. Carboplatin was targeted to an area under the time versus concentration curve (AUC) of 6 mg/ml x min and was not dose escalated. Whole-blood CsA concentrations (fluorescence polarization immunoassay) at the maximum tolerated dose (10 mg/kg LD, 14.5 mg/kg/day CI) ranged from 2.4 to 3.0 microgram/ml over 12 h. Estimated median carboplatin AUC, based on calculated carboplatin clearance, was 7.9 mg/ml x min. The dose-limiting toxicity of the combination of CsA and carboplatin was grade 4 thrombocytopenia. Grade 3 or 4 thrombocytopenia occurred in 35% of the patients, which could be explained by the effects of carboplatin (AUC of 6 mg/ml x min) alone. Overall, neutropenia occurred in 24% of the patients and anemia in 17% of the patients. Grade 3 or 4 nausea or vomiting was noted in 10 and 14% of the patients, respectively. Grade 3 hypertension during CsA administration occurred in 14% of the patients. No grade 3 or 4 nephrotoxicity was seen in this trial. Three objective responses were noted: one complete response (11 months) and one partial response (5 months), both in potentially platinum-sensitive patients with platinum-free intervals of only 9 months each. One platinum-resistant patient had a partial response for 21 months. Five additional patients experienced >75% reduction of CA-125 or a return to a normal CA-125 titer. We concluded that whole-blood CsA concentrations of >3.0 microgram/ml (as seen when CsA is used as a modulator of multidrug resistance) were not achievable in this combination with carboplatin in this population of heavily pretreated gynecologic cancer patients. However, because CsA is used in this trial as a chemosensitizer in platinum-sensitive tumors and as a chemomodulator of platinum resistance, we targeted a CsA concentration of >1.0 microgram/ml, which was achieved. The CsA dose recommended for a Phase II trial of this combination is 10 mg/kg LD and 11.6 mg/kg/day CI, which results in blood CsA concentrations ranging from 1.2 to 1.3 microgram/ml over 12 h. Responses in this population of refractory gynecologic cancer patients are unusual, and these encouraging results form the basis for a Phase II trial of this combination.     

Superposition turbo TCM for multirate broadcast

Bergmans and Cover identified the capacity region of the Gaussian degraded broadcast channel, where different receivers observe the transmitted signal with different signal-to-noise ratios. This letter presents a superposition turbo-coding scheme that performs within 1 dB of the capacity region boundary of the degraded broadcast channel at a bit-error rate of 10/sup -5/.     

开放源代码与开放性标准之辨

长期以来，技术供应商在使用“开放”一词的同时，也在滥用它。因此，现在轮到技术用户大量使用开放一词，也就不足为奇了。如今，“开放”一词已经和软件源代码、工业标准、开发商社团和各种许可模型等四个完全不同的技术术语联系在一起。而这四个技术术语经常被人们以含糊的方式混为一谈。软件源代码、工业标准、开发商社团和许可模型都在发挥着各自的作用。但重要的是应该了解到，其中每一种技术指的是什么、不是什么。在这四种技术中，开放性标准最为关键，因为你今天做出的选择不应该妨碍你明天做出另外一种选择。这就是开放性标准的全…     

Optical mapping approaches to molecular genomics

Gunshot injury causes a complex of changes in perinecrotic area covering all tissue structures of skin which is discussed as a systemic organ disintegration, including disintegration of dermal differons. Connective tissue regeneration is reflected by a determined process. Replacement of a defect with granulation tissue should be considered as a reparative regeneration. Peculiarities of fibroblasts proliferation and differentiation in perinecrotic area indicate the prevalence of regenerative histogenesis features.     

The immediate and late allergic response to segmental bronchopulmonary provocation in asthma

The response to antigen is an important factor in the development of airway inflammation. Segmental bronchoprovocation (SBP) with antigen and subsequent bronchoalveolar lavage (BAL) have provided valuable insight into the mechanisms of allergic inflammation. To determine the features of allergic airway response in asthma, 19 subjects with mild asthma underwent antigen SBP in a dose-dependent manner. The amount of antigen used in SBP was 0 (saline), and 1, 5, or 20% of the antigen dose required to drop the FEV1 by 20% (APD20). BAL was done at 5 min and 48 h after SBP. BAL histamine levels increased modestly 5 min after antigen SBP. At 48 h, there was a marked increase in eosinophils and IL-5 concentration even in airway segments where the release of histamine was small. Moreover, eosinophils correlated with IL-5 levels at 48 h (r = 0.63; p < 0.001), but not with BAL histamine concentrations at 5 min. GM-CSF levels did not increase after antigen SBP and did not correlate with eosinophils. These observations indicate that asthmatic subjects can develop a dose-dependent response to antigen SBP that is characterized by a modest increase in histamine immediately after antigen exposure, and marked eosinophilia, which appears proportionately greater than the histamine response and relatively greater than what is seen in allergic nonasthmatic subjects. This feature might be important to the eventual development of airway inflammation in asthma.     

The design, synthesis and transmembrane transport studies of a biomimetic sterol-based ion channel

A model sterol-based ion channel was rationally designed and synthesized. The potential ion channel is comprised of a tartrate-derived crown ether to which six steroids are appended. Macromolecule 1a was incorporated into phospholipid vesicles and shown to facilitate the transmembrane transport of sodium and lithium ions using alkali metal NMR spectroscopy.