Secure polarization-independent subcarrier quantum key distribution in optical fiber channel using BB84 protocol with a strong reference.

A quantum key distribution system based on the subcarrier wave modulation method has been demonstrated which employs the BB84 protocol with a strong reference to generate secure bits at a rate of 16.5 kbit/s with an error of 0.5% over an optical channel of 10 dB loss, and 18 bits/s with an error of 0.75% over 25 dB of channel loss. To the best of our knowledge, these results represent the highest channel loss reported for secure quantum key distribution using the subcarrier wave approach. A passive unidirectional scheme has been used to compensate for the polarization dependence of the phase modulators in the receiver module, which resulted in a high visibility of 98.8%. The system is thus fully insensitive to polarization fluctuations and robust to environmental changes, making the approach promising for use in optical telecommunication networks. Further improvements in secure key rate and transmission distance can be achieved by implementing the decoy states protocol or by optimizing the mean photon number used in line with experimental parameters.

Carcinoid tumour of the kidney in a Chinese woman presenting with loin pain.

Renal carcinoid tumours are uncommon. The aetiology is not yet fully understood and there is still no useful diagnostic tool for detecting them. We report our experience managing a Chinese woman with a primary renal carcinoid tumour.

Inhibition of MAP kinase kinase (MEK) results in an anti-inflammatory response in vivo.

The MAP kinase pathway has been well-characterized as a cascade of sequential protein phosphorylation events leading to the upregulation of a variety of genes in response to growth factors and mitogens. We are interested in the role of these kinases in inflammation and have thus examined their activity in vivo using TPA-induced ear edema in the mouse as a model of inflammation. We show that the activities of both ERK-1 and ERK-2 are upregulated in this model in response to TPA. Increased levels of ERK phosphorylation are measurable as early as 15 min poststimulation and reach a level 8-fold over controls at 4 h. In contrast, minimal activation of JNK or p38 is observed. Topical treatment of ears with the MEK inhibitor, U0126, prevents ERK phosphorylation and ear swelling in a dose-dependent manner in this model. These results suggest that the MEK/ERK pathway is important during an inflammatory response in vivo.

Fine needle aspiration cytology of epithelial-myoepithelial carcinoma of salivary glands. A report of three cases.

BACKGROUND: Epithelial-myoepithelial carcinoma is a rare, low grade malignant tumor of the salivary glands. Histologically, it has a biphasic cellular composition and exhibits a high degree of differentiation. The fine needle aspiration cytology of this rare tumor is rarely described in the literature. CASES: We report the fine needle aspiration cytology of three epithelial-myoepithelial carcinomas, arising in the right parotid, left parotid and minor salivary gland of the hard palate. Cytology showed a biphasic population consisting of cells of ductal epithelial and myoepithelial origin arranged in small clusters and sheets. The myoepithelial cells had small, uniform nuclei; ample, clear cytoplasm and distinct cell borders, while the ductal epithelial cells had larger, mildly pleomorphic nuclei and scanty cytoplasm. These ductal cells tended to form tubules among background sheets of clear myoepithelial cells. This feature, if present, was an important diagnostic clue. Hyaline material surrounding cell clusters and focal adenoid cystic carcinoma-like areas with orangeophilic globules were also not uncommon. CONCLUSION: While the cytologic appearance of epithelial-myoepithelial carcinoma may closely mimic that of other salivary gland tumors, such as adenoid cystic carcinoma, pleomorphic adenoma and basal cell adenoma, certain peculiar cytologic features may allow a distinction to be made on fine needle aspiration biopsy.

Fine needle aspiration cytology of myxopapillary ependymoma. A case report.

BACKGROUND: Myxopapillary ependymoma is a variant of ependymoma that usually occurs in the sacrococcygeal region. Histologically, it is characterized by arborizing papillary fronds of capillaries with mucinous stroma rimmed by ependymal cells. The fine needle aspiration cytology of this rare tumor is rarely described in the literature. CASE: We report the fine needle aspiration cytology of a primary sacrococcygeal myxopapillary ependymoma occurring in a 18-year-old female. Cytology showed "fernlike" papillae and globules of mucinous and myxoid substance containing central capillaries. These structures were rimmed by one to several layers of mitotically inactive, mildly pleomorphic cuboidal to columnar cells with occasional pseudonuclear cytoplasmic inclusions. Some of these ependymal cells sent fibrillary processes toward the capillaries, suggestive of perivascular pseudorosettes. There were also numerous isolated tumor cells in the background. CONCLUSION: Because of the prominent mucinous elements and papillary fronds, myxopapillary ependymoma may mimic other myxoid or papillary tumors cytologically. Recognition of the characteristic cytologic features may allow a distinction to be made on fine needle aspiration biopsy.

Conservative treatment of low grade squamous intraepithelial lesions (LSIL) of the cervix.

OBJECTIVE: To assess the accuracy of the cervical smear and colposcopy in diagnosing low grade squamous intraepithelial lesions (LSIL), and the natural history of LSIL. METHOD: The cytological, colposcopic and histological findings of 145 patients with a smear diagnosis of LSIL were compared, and the final outcome studied. RESULTS: The diagnosis of LSIL either by cytology alone or in combination with colposcopy was associated with a rate of overdiagnosis of 11.7% and 6.9%, respectively, and a rate of underdiagnosis of 31.0% and 26.2%, respectively. Spontaneous regression of lesions occurred in 81.1% of patients with proven LSIL, with regression within 24 months in 4/5 of cases. CONCLUSIONS: The degree of dysplasia shown in the cervical smear correlated poorly with histology. All patients with cervical smear showing LSIL should have colposcopy and colposcopic-directed biopsy to exclude the presence of more advanced lesions. In the absence of some serious lesions, it is then acceptable to observe the patient for 24 months before adopting definite treatment, as spontaneous regression is common.

ASCUS and AGUS criteria. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: The conference participants addressed the following issues: (1) reporting of equivocal diagnoses, (2) strategies to minimize the use of such diagnoses, (3) morphologic criteria, and (4) management of women with equivocal diagnoses. CONSENSUS POSITION: Equivocal diagnoses should be minimized, to the extent possible, by emphasizing cytologist education and training, improved specimen collection and quality assurance monitoring of individual and laboratory diagnosis rates. Cases fulfilling criteria for other diagnostic entities should not be included in the equivocal category. Regardless of the term utilized, an equivocal diagnosis should be qualified in some manner to indicate that the diagnosis defines a patient at increased risk of a lesion, particularly for those cases which raise concern about a possible high grade lesion. Qualification of an equivocal diagnosis can also be accomplished by appending laboratory statistics of the likelihood of various clinical outcomes or recommendations for patient follow-up. In contrast to favoring a reactive process versus squamous intraepithelial lesion (SIL), a more rationale approach to qualification of atypical squamous cells of undetermined significance may be to separate cases equivocal for low grade SIL from those suspicious for high grade SIL. With regard to glandular lesions, the conference participants expressed unanimous support for the separation of adenocarcinoma in situ (AIS) from atypical endocervical cells of undetermined significance when sufficient criteria are present. However, the diagnosis of a precursor lesion to AIS, endocervical glandular dysplasia, was controversial. The majority of conference participants discourage the use of such terms as mild glandular dysplasia and low grade glandular dysplasia for cytologic diagnoses. ONGOING ISSUES: Conference participants agreed that a term reflecting diagnostic uncertainty is necessary to communicate findings that are equivocal. However, participants could not agree on the wording of such a term. Opinions differed as to: (1) use of atypical, abnormal or morphologic changes to describe cell changes, (2) whether the diagnosis should indicate a squamous or glandular origin of the cells in question when this determination can be made, and (3) the value of defining morphologic criteria for such a diagnosis. The debate over terminology, as well as morphologic criteria, is ongoing, and the readership is invited to communicate opinions to Acta Cytologica. Management of women with equivocal diagnoses varies widely from locale to locale and may differ based on how the equivocal diagnosis is qualified. Findings insufficient for the diagnosis of a high grade lesion may warrant more aggressive follow-up than cases equivocal for a low grade lesion. Where sensitivity of detection of lesions is of paramount importance, follow-up will generally consist of more frequent cytology screening or colposcopy and biopsy. However, in some countries it is considered unethical to have a high percentage of false positive diagnoses, which result in overtreatment and an unnecessary burden for women participating in cervical screening. Future studies may provide a morphologic, or perhaps molecular, basis for distinguishing true precursors of neoplasia from minor lesions of no significant clinical import; this would allow a more coherent and rational approach to diagnosis and management of women with equivocal cytologic findings.

Terminology. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: Differences in type, structure, quality of health care systems and availability of resources influence reporting systems. In most countries, individual systems have a long history of usage that might preclude adoption of a uniform terminology worldwide. CONSENSUS POSITION: It is desirable but unrealistic at this time to aim for a unified terminology worldwide. It should be the stated objective of the International Academy of Cytology to serve as an umbrella organization for various terminologies and enhance mutual understanding and cooperation. Translation tables of equivalent terms have been created to allow increased communication. Consensus has been achieved in defining essential elements required of any terminology system: (1) the report must be text based: numerical Papanicolaou class designations alone are inadequate; (2) an assessment of the adequacy of the sample should be included; and (3) the diagnosis must address the primary purpose of cervical cytology: to indicate the presence or absence of epithelial abnormalities. Incorporating additional elements within a terminology system may be more or less appropriate, depending on the setting in which the system is used. ONGOING ISSUES: Despite the cited problems in adopting a uniform terminology worldwide, a single system would have many advantages in terms of communication and research and may be a long-term goal worth pursuing. Countries are invited to present their individual national terminology systems and participate in an ongoing dialogue, critically evaluating the advantages and disadvantages of all systems.

Medicolegal affairs. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: Increasing litigation over alleged false negative cervical cytologic (CC) smears threatens the viability of this test for cervical cancer detection. The problem appears to be largely American but is beginning to appear in some other countries. In the vast majority of cases there is either a settlement or jury verdict for the plaintiff based largely on the testimony of expert witnesses. Cases are judged on an individual basis without significant consideration of the general performance of the CC smear in laboratories operating in compliance with a wide array of laboratory regulations and with documented and comprehensive quality control practices in place. It is acknowledged that there are problem laboratories and cytology practitioners. There is an emerging issue of automated preparation and screening devices and issues of informed patient consent. CONSENSUS POSITION: Cytology professionals have done an extraordinary and commendable job of educating the public about the benefits of the CC smear. We have been less successful and conscientious about explaining and defining the limitations of the CC test. There is a need for public and professional education as to the benefits and limitations of the CC smear for cervical cancer detection. The process suggested is to work with women's groups, public health agencies, government agencies, and state and national legislatures and to coordinate professional committees working on liability issues. Contextual information could be included with the CC smear report to indicate that a negative report confers a low probability of developing cervical cancer. It is suggested that appropriate language and a menu of statements be developed. Increased efforts should be directed to physician education with respect to informed consent concerning the benefits and limitations of CC smear testing and the application of new technology to improve smear accuracy. The process should include development of appropriate statements on the use of alternative technology. The profession should develop "process guidelines" for review of CC smears in the context of possible litigation, including standardized methods for blind slide review of smears that reduce or eliminate context and outcome bias. It is suggested that review panels be anonymous, that the process be standardized and that there be limitations on liability for participating organizations. Professional cytopathology and pathology societies should formulate acceptable guidelines for expert witnesses. The standards should be applicable to both defendant and plaintiff experts. All materials to the extent practical, including consultant opinions, should be available for peer review. Professional cytopathology and pathology societies should monitor expert testimony for objectivity and scientific accuracy. ONGOING ISSUES: For the near future, litigation will continue to focus on false negative CC smears on a case-by-case basis. Laboratories and individuals can reduce the risk of malpractice liability by directing their attention to proactive quality control and quality assurance methods. In the final analysis, consumer education about the benefits and limitations of the test is key to limiting malpractice claims. To stem the tide of continued medicolegal challenges to the integrity of cytology practice, the cytology community has now focused its efforts on developing and utilizing standards that convey to patients, attorneys and cytologists the contemporary status of and reasonable expectations for the practice of cytology. Guidelines such as those for uniform reporting terminology and clinical management of cervical abnormalities form the basis of cytology practice standards on which legal standards of practice can be based. Consensus conference reports, clinical management trials and scientifically valid studies of false negative rates that analyze the type, frequency and cause of missed cases represent sounder methods of establishing defensible

Cutaneous epithelioid angiosarcoma: a potential diagnostic trap for cytopathologists.

We report on the cytologic features of a rare case of cutaneous epithelioid angiosarcoma of the scalp occurring in a 65-yr-old Chinese male. The prominent epithelioid features may cytologically mimic poorly-differentiated carcinoma, malignant melanoma, and even epithelioid sarcoma. Recognition of subtle cytologic features of vasoproliferation, immunohistochemical demonstration of endothelial markers, and ultrastructural examination are necessary before a final conclusion may be drawn.

Diagnostic significance and possible pitfalls of nuclear grooves in extrathyroid cytology.

The diagnostic significance of grooved nuclei in the cytology of extrathyroid lesions is not well-described in the literature. Isolated cases of metastatic adult granulosa cell tumor, reactive mesothelial hyperplasia, Langerhans' cell histiocytosis, recurrent renal cell carcinoma, and round cell liposarcoma were reviewed, and their cytologic features were discussed. While nuclear grooving can be present to a different extent in all these conditions, the significance of this feature in diagnostic cytology varies. The integration of clinical information, radiologic findings, different morphologic features, and immunohistochemistry is necessary before a final conclusion is reached.

Cytologic Diagnosis of "CASTLE" of thyroid gland: report of a case with histologic correlation.

We report on the cytologic and histologic features of a rare form of lymphoepithelioma-like carcinoma of the thyroid i.e., carcinoma showing thymus-like element (CASTLE). Sixteen cases of cervical lymph node aspirates with metastatic nasopharyngeal carcinoma are also reviewed. While it is important to recognize CASTLE of the thyroid because of its distinctly good prognosis, its cytologic features closely resemble those in metastatic nasopharyngeal carcinoma.

A melanoma cell line sensitive to expression of a fusion protein binding the retinoblastoma protein family pocket domain.

An established melanoma cell line (MM96L) was transfected with selectable plasmid constructs encoding either whole SV40 large T antigen, or beta-galactosidase fusions with the retinoblastoma protein (Rb)-binding region of SV40 large T antigen and a nonbinding mutant derivative of it. Both of the beta-galactosidase fusions also encoded the large T nuclear targeting signal. Transcription of inserted genes was regulated through a Zn+2-inducible metallothionein IA promoter, which provides tight but not absolute control of expression. Only the wild-type large T segment fusion was functionally active in the binding of Rb protein. Stable lines derived from primary transfectants with the expression plasmid encoding the mutant large T segment fusion showed a normal FACS scan profile, a normal growth rate, and (upon induction) high levels of nuclear staining for beta-galactosidase. However, cells transfected with the wild-type (Rb-binding) large T segment fusion grew slowly, with surviving clones assuming a predominantly tetraploid karyotype and relatively much lower levels of beta-galactosidase activity upon Zn+2 induction. The latter cells, but not those transfected with the corresponding non-Rb-binding fusion construct, also exhibited elevated cell death and apoptosis in response to the inducer Zn+2. These results implied that expression of an Rb-binding protein has deleterious effects on the melanoma cell line growth and may reflect a role for Rb of a related pocket protein in maintaining the differentiation state of these transformed cells.

Renal abnormalities and an altered inflammatory response in mice lacking cyclooxygenase II.

Prostaglandins have wide-ranging effects in the body and are thought to be important mediators of inflammation. Cyclooxygenase (COX) plays a key regulatory role in prostaglandin synthesis, and occurs in both constitutive (COX-1) and inducible (COX-2) isoforms. COX-1 is thought to provide cytoprotective effects, whereas COX-2 is both inducible and the major isoform of inflammatory cells. Reduction of prostaglandin production by inhibition of cyclooxygenases appears to be the main mechanism of action of most non-steroidal anti-inflammatory drugs (NSAIDS). Here we present an animal model of COX-2 deficiency that was generated by gene targeting. Defects in null mice correlating with reduced viability included renal alterations, characteristic of renal dysplasia (100% penetrance), and cardiac fibrosis (50% penetrance). Female Cox-2-/- mice were infertile. COX-2 deficiency failed to alter inflammatory responses in several standard models, but striking mitigation of endotoxin-induced hepatocellular cytotoxicity was observed.

Ultrasound guided transperineal prostatic aspiration biopsy: experience in Hong Kong.

OBJECTIVE: The purpose of this study is to correlate the result of the ultrasound guided transperineal aspiration biopsy with the clinical findings. MATERIALS AND METHODS: We retrospectively studied 27 patients who had been subjected to ultrasound guided transperineal prostatic aspiration biopsy in our institution during the period 1990 to 1992. The patients were divided into two groups: Group A--those with clinically palpable nodules on digital examination, and Group B--those without palpable nodule but with clinical evidence of prostatic enlargement and/or bladder outlet obstruction. RESULTS: There were 8 biopsy proven cancers, 4 of them were palpable lesions while the other 4 were clinically non-palpable. The overall positive predictive value was 29.6%; this increased to 40% if the lesions were palpable but decreased to 23.5% if the lesions were non-palpable. CONCLUSION: The overall positive predictive value of this technique was found to be consistent with other studies using different methods of biopsies. The positive predictive value was increased if the abnormality was clinically palpable. This technique was also found to be safe and no significant complication was observed in these patients.

Assessment of cell proliferation in hydatidiform mole using monoclonal antibody MIB1 to Ki-67 antigen.

AIMS: To assess the role of Ki67 immunoreactivity in predicting the clinical progress of hydatidiform mole. METHODS: Tissue from 87 hydatidiform moles, 11 normal first trimester placentas, 11 normal term placentas and 17 spontaneous abortions were examined for expression of Ki67 antigen, using the monoclonal antibody MIB1. RESULTS: Ki67 immunoreactivity was significantly higher in the tissue from normal first trimester placentas than in that from normal term placentas and spontaneous abortions. Among the 87 patients with hydatidiform moles studied, 20 developed persistent gestational trophoblastic disease and required subsequent treatment. There was no statistically significant difference in the Ki67 index between the 20 patients who developed persistent disease and those who did not. CONCLUSION: Hydatidiform moles which give rise to persistent trophoblastic disease do not have a higher proliferative rate than those which do not. The Ki67 index is not useful for predicting the prognosis of molar pregnancies.