Three-dimensional shifting selectivity of random phase encoding in volume holograms

We analyze and demonstrate the three-dimensional shifting selectivity of volume holograms based on random phase encoding with ground glass. Under weak coupling, the diffraction characteristic is caused by the phase difference between the reference and the reading light. We find that the shifting selectivity is different for different shifting directions, which include laterally horizontal, laterally vertical, and longitudinal directions. The shifting selectivity depends on the diameter of the region of illumination on the random phase plate, the thickness of the hologram, and the distance between them.

Precise Measurement of Thermal-Induced Refractive-Index Change in BaTiO(3) on the Basis of Anisotropic Self-Diffraction

We propose a method for precise measurement of the temperature-dependent refractive-index change in BaTiO(3) by use of anisotropic self-diffraction (ASD). In this method the refractive-index change corresponds to the angle deviation of the diffraction pattern. Because only the geometry of the ASD is used for measuring, the precision of measurement is independent of crystal thickness and environmental perturbation. The accuracy of the refractive-index change achieved is 10(-4) when the resolution of the measurement of the angle is ~0.04 degrees . Both the theory and the experiment are demonstrated.

Unilateral congenital third cranial nerve palsy with central nervous system anomalies: report of two cases

The third nerve palsies are not uncommon in adults and are usually the result of vascular or compressive lesions. However, they are uncommon in children and are usually congenital. Congenital oculomotor nerve palsies were generally thought to exist in isolation without associated abnormalities; however, there have been conflicting reports in the literature as to the associations of congenital oculomotor palsies. In this report, we present 2 cases of congenital third cranial nerve palsy with neurological deficits and central nervous system abnormalities. The first patient had initial presentations of inequality in pupil size, exodeviation of the affected eye, and extreme hypotropia of the contralateral eye, which was also complicated by profound neurological deficits. Magnetic resonance imaging (MRI) scans disclosed hypoplasia of the right midbrain and corpus callosum. The second patient presented with an exodeviated right eye, and pupils non-reactive to light since birth. Computed tomography scans showed ventricular dilatation and absence of the septum pellucidum, which is compatible with septo-optic dysplasia (de Morsier syndrome). The clinical courses are presented, and we also review the literature concerning congenital third cranial nerve palsy associated with central nervous system anomalies.

High levels of interleukin-8, soluble CD4 and soluble CD8 in bullous pemphigoid blister fluid. The relationship between local cytokine production and lesional T-cell activities

BACKGROUND

Bullous pemphigoid (BP) is an inflammatory subepidermal blistering disease associated with autoantibodies that recognize hemidesmosomal proteins. In addition to autoantibodies, the cell-mediated immune reaction is considered to play an important part in blister formation. Objectives To investigate some T-cell activation markers and inflammatory cytokines in the blister fluid and sera of patients with BP.

METHODS

We measured soluble CD4 (sCD4) and soluble CD8 (sCD8), which have been, respectively, associated with CD4 and CD8 T-cell activation. Enzyme-linked immunosorbent assays were also used to quantify the production of the leucocyte chemoattractant interleukin (IL) -8 and of the cytokines IL-1alpha, IL-1beta, IL-6, IL-10 and tumour necrosis factor-alpha in the blister fluid and sera of 11 patients with BP.

RESULTS

The mean +/- SD level of sCD4 in patients' blisters (42.4 +/- 25.0 units mL-1) was significantly elevated (P < 0.005) compared with that in their sera (11.2 +/- 8.9) and that in the suction blisters of 10 healthy people (11.4 +/- 5.4; P < 0.005). Mean +/- SD IL-8 concentrations in BP blisters (4683.6 +/- 3878.1 pg mL-1) were much higher than those in their sera (17.1 +/- 18.9; P < 0.001), and were very significantly elevated (P < 0.005) in comparison with those in suction blisters of healthy persons (512 +/- 292). sCD4 levels in BP blisters were inversely related to IL-10 levels (P = 0. 03, r2 = 0.85), IL-8 levels were positively related to sCD8 levels (P = 0.01, r2 = 0.54), and IL-1beta levels were positively related to sCD8 concentrations (P < 0.005, r2 = 0.65).

CONCLUSIONS

The correlations suggest that there is a delicately orchestrated network of cytokines and cell-mediated immunity operating in BP blisters.

Shift-tolerance property of an optical double-random phase-encoding encryption system

We investigate the shift-tolerance property of the decrypting phase mask in an optical double-random phase-encoding encryption system. A simple method for improving the shift tolerance of the phase mask is proposed. We demonstrate how the robustness to data loss of the encrypted image extends the shift tolerance of the decrypting phase mask. The signal-to-noise ratio is calculated. Both a computer simulation and an experiment are presented.

Assessment of a three-dimensional operating system with skill tests in a pelvic trainer

OBJECTIVES

To compare the performance of laparoscopic skill assisted by a traditional two-dimensional (2D) and a three-dimensional (3D) endoscopic video system in a pelvic trainer.

MATERIALS AND METHODS

The 3D imaging system (DeepVision((R)), Automated Medical Products Corp.) consists of a traditional single lens optic laparoscope, a light source, an endoscopic camera (Stryker), a DeepVision processor and a DeepVision monitor. The 2D images could be obtained with the same system without turning on the DeepVision processor. Thirty-four medical personnel with no laparoscopic surgical experience were enrolled to perform two skill tests, the object-pick-up and spatial orientation test in a trainer box. They were randomly divided into two groups, one group performed the test under 2D conditions first and 3D later, and another group performed the test under 3D conditions first and 2D later. The duration needed to complete the skill tests was recorded and the differences on performance time under 2D and 3D conditions were calculated for each participant. Two-way ANOVA was used to analyze the statistic difference on the performance time in two conditions.

RESULTS

The duration needed to complete the initial skill tests was similar among 2D and 3D conditions. For both tests, the average performance time decreased significantly for the second attempt regardless of 2D or 3D conditions. Statistic analysis disclosed significant difference for learning factor (p < 0.001 for object-pick-up test and p < 0.01 for spatial orientation test), but no significant difference between 2D and 3D conditions (p = 0.276 for object-pick-up test and p = 0.327 for spatial orientation test).

CONCLUSION

A significant decrease of the performance time at the second attempt reflected the importance of a learning process in laparoscopic surgery. It appears that no significant benefits were obtained by this 3D operating system for surgeons without laparoscopic surgical experience.

Cavitational ultrasonic surgical aspiration for the treatment of vaginal intraepithelial neoplasia

OBJECTIVE

The aim of this study is to determine whether cavitational ultrasonic surgical aspiration (CUSA) is effective and safe for treating vaginal intraepithelial neoplasia (VAIN).

METHODS

We conducted a retrospective chart review of 46 patients who were treated with CUSA for VAIN in a single gynecologic oncology practice between 1981 and 1999.

RESULTS

At initial presentation, 39% of treated patients had grade I VAIN, 20% had grade II, and 41% had grade III. The mean duration of follow-up from initial CUSA treatment was 21 months. Twenty-nine patients (63%) were initially treated with CUSA, 7 patients (15%) with laser vaporization, 7 patients (15%) with surveillance by Papanicolaou smear, 1 patient (2%) with partial vaginectomy, 1 patient (2%) with 5-fluorouracil, and 1 patient (2%) with loop excision. Patients initially treated with CUSA had a higher percentage of grade III VAIN at diagnosis (48%) than did patients initially treated with other methods (29%). A significantly greater proportion of patients initially treated with CUSA had no recurrence of VAIN (66%) compared with patients initially treated with other methods (0%) (P < 0.0001). A significantly greater proportion of patients who were treated for recurrent disease with CUSA had no further recurrence (52%) compared with patients treated for recurrent disease with other methods (9%) (P < 0.001). No patient treated with CUSA reported adverse effects; 7 patients treated with other methods reported dysuria, burning, and pain.

CONCLUSION

These initial data suggest that CUSA is a safe and effective method for treating VAIN and may be an appropriate treatment for many patients.

Double phase conjugation with orthogonally polarized beams in a BaTiO(3) crystal

We have demonstrated experimentally the simultaneous self-conjugation of extraordinarily and ordinarily polarized light waves (lambda=514 nm), with the polarization state preserved, in a Ce:BaTiO(3) crystal. Conjugate o waves originate from coupling between o and e waves by means of a circular photogalvanic effect. The conjugator also takes advantage of the Ce:BaTiO(3) crystal, for which it is easy to generate an extraordinary conjugate beam by photorefractive backscattering. This beam of light is necessary for double phase conjugation.

Pharmacoeconomic considerations in treating ovarian cancer

Ovarian cancer is the leading cause of death in women with gynaecological cancers. The most common type of ovarian cancer is epithelial ovarian cancer. Referred to as the 'silent' killer, this disease is difficult to detect because of the lack of specific symptoms. The majority of women who have ovarian cancer are diagnosed in the advanced stages. While the exact cause of ovarian cancer remains elusive, it is believed that the events relating to incessant ovulatory function play a major role in the development of this disease. Long term prognosis of women with ovarian cancer remains grim. Although ovarian cancer is highly responsive to chemotherapy, most women will develop persistent or recurrent disease after primary treatment. The standard front-line treatment is paclitaxel in combination with a platinum-based agent; however, toxicities associated with paclitaxel must be weighed against the clinical benefit. The economic issues associated with the treatment of ovarian cancer involve costs of chemotherapy agents and management of supportive care. Patient preferences and quality-of-life issues are also of major importance because of the short survival benefit for most patients. Therefore, quality of life must be maximised alongside efforts to prolong survival. More research is necessary to determine what trade-offs (e.g. adverse effects of treatment) patients are willing to make for modest gains in survival.

A comparison of C/B ratios from studies using receiver operating characteristic curve analysis

In receiver operating characteristic (ROC) curve analysis, the optimal cutoff value for a diagnostic test can be found on the ROC curve where the slope of the curve is equal to (C/B) x (1-p[D])/p[D], where p[D] is the disease prevalence and C/B is the ratio of net costs of treating nondiseased individuals to net benefits of treating diseased individuals. We conducted a structured review of the medical literature to examine C/B ratios found in ROC curve analysis. Only two studies were found in which a C/B ratio was explicitly calculated; in another 11 studies, a C/B ratio was based on a so-called holistic estimate, an all-encompassing educated estimate of the relative costs and benefits relevant to the clinical situation. The C/B ratios ranged from 0.0025 (tuberculosis screening) to 2.7 (teeth restoration for carious lesions). Clinical scenarios that are directly life threatening but curable had C/B ratios of less than 0.05. This analysis led us to construct a table of ordered C/B ratios that may be used by investigators to approximate C/B ratios for other clinical situations in order to establish cutpoints for new diagnostic tests.

Two-dimensional shifting tolerance of a volume-holographic correlator

A simple method for simulating two-dimensional (2-D) distributions of the diffraction lights of a volume-holographic-type VanderLugt correlator is proposed and demonstrated. The simulation results are similar to those of the corresponding experiments, and only a few dozen points are sampled from both the input and the reading patterns. We show that the shifting tolerance to the reading pattern is a result of Bragg degeneracy and is not isotropic. The Bragg degeneracy generates different degrees of cross talk between the horizontal and the vertical directions. With the method we further simulate the 2-D shifting tolerance of the volume-holographic correlator. The simulation results offer a clear picture of the diffraction in a transmission volume hologram used as an optical spatial correlator.

Optical symmetry filtering by use of anisotropic self-diffraction in BaTiO3 crystals

We propose what we believe to be a novel and simple method for optical symmetry filtering, using anisotropic self-diffraction in BaTiO(3) crystals. This method allows us to distinguish a centrosymmetric pattern from a noncentrosymmetric pattern easily with scale invariance. It is self-referential; no extra reference element is required. Both the theory and the experiment are demonstrated.

OEIS complex (omphalocele-exstrophy-imperforate anus-spinal defects) in monozygotic twins

The omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex is a consistent and recognizable pattern of midline abdominal and pelvic defects. It is rare, affecting 1 in 200,000 to 400,000 pregnancies and is even rarer in twin gestations. This is an autopsy study of OEIS complex in monozygotic twins after pregnancy termination at 20 weeks of gestation. Unremarkable family history but concordance of monozygotic twins for the defects may support the theory that early malformation complexes, e.g., OEIS, and monozygotic twinning are manifestations of the same disturbance of early blastogenesis.

Correlation of prenatal ultrasound diagnosis and pathologic findings in fetal anomalies

This retrospective study compared the prenatal ultrasound (US) diagnosis with autopsy findings in 61 intact fetuses following induced abortion and 36 fragmented fetuses from dilatation and evacuation (D&E). In intact fetuses, complete agreement between US diagnosis and autopsy findings was achieved in 65.6% of cases in the central nervous system (CNS) and 47.5% in other somatic organ systems (SOS). There were major differences between US and autopsy findings involving the CNS in 6.5% of cases and SOS in 27.9%. Correlation was better for evaluation of renal anomalies (complete agreement in 63.6% of 11 suspected cases, 2 false-positive and no false-negative cases) than congenital heart disease (complete agreement in 27.3% of 11 suspected cases, 5 false-positive and 3 false-negative cases). In D&E specimens, a prenatal diagnosis of neural tube defect (NTD) was confirmed in 90% of cases. However, due to fragmentation of fetal parts, the US diagnosis in the CNS could not be confirmed totally (69.4%) or partially (2.8%) in fetuses with chromosomal abnormalities (ChA) or multiple congenital anomalies (MCA). Nonetheless, the US diagnosis of SOS was confirmed in six cases on D&E, including Meckel-Gruber syndrome, cystic hygroma, renal agenesis with contralateral renal dysplasia, cardiac defect, fetal hydrops, and tracheal atresia. Our results show that a thorough autopsy of an intact fetus after abortion is necessary to confirm prenatal diagnosis and allow proper management and counseling. The pathologic examination of D&E specimens can reliably confirm the US diagnosis of NTD, but it is very limited in identifying other fetal anomalies.

Epicutaneous administration of hapten through patch application augments TH2 responses which can downregulate the elicitation of murine contact hypersensitivity

BACKGROUND AND OBJECTIVE

Allergic contact dermatitis and its animal model, contact hypersensitivity (CHS), have long been documented as type 1 T-cell-predominant immune responses. Although type 1/type 2 T-cell deviation has been repeatedly demonstrated to play an important role in many human diseases and their animal models, the potential of tilting type 1/type 2 T-cell differentiation of CHS by modulating the manner of administration and dosage of hapten remains unexplored. This study examined the effect of these two factors on type 1/type 2 balance of CHS.

METHODS

ELISA methods for detection of isotypes of hapten-specific antibodies and cytokine profiles of in vitro reactivation culture as well as ear-swelling assay were used to indicate type 1 or type 2 T-cell immune responses.

RESULTS

In this paper, it was demonstrated that dosage of hapten has no effect on the type 1/ type 2 T-cell balance of CHS, whereas epicutaneous administration of hapten through patch application could tilt the type 1/type 2 balance to decrease type 1 and to augment type 2 T-cell responses. Patch application-induced modulation is still effective in ever-sensitized mice and the augmented type 2 T-cell responses are persistent and increase progressively in strength after repeated immunizations. Moreover, it was demonstrated that the augmented type 2 T-cell response can downregulate the elicitation of CHS. The major mediating cells of the enhanced type 2 T-cell responses were determined to be CD4+ T cells (TH2 cells).

CONCLUSIONS

These data show that epicutaneous administration of hapten through patch application augments TH2 response which can downregulate the elicitation of murine CHS. This exploration may contribute to the understanding of regulatory mechanisms involved in contact allergy.

Photorefractive Incoherent-to-Coherent Optical Converter Based on Anisotropic Self-Diffraction in BaTiO(3)

A photorefractive incoherent-to-coherent optical converter (PICOC) is demonstrated; conversion is accomplished by anisotropic self-diffraction in BaTiO(3). The setup of the PICOC is easy, and only two writing beams are required. The diffraction efficiency reaches 50%, and the resolution is 22 line pairs (lp)/mm in a typical-size crystal. Further, the resolution reaches 40 lp/mm when a BaTiO(3):Rh crystal of thickness 1.2 mm is used, and the diffraction efficiency is as high as 51%. The resolution of the PICOC can be increased effectively by reduction of the crystal thickness with no penalty for low diffraction efficiency.

Outbreak of Pseudomonas fluorescens bacteremia among oncology patients

From 7 to 24 March 1997, four patients developed Pseudomonas fluorescens bacteremia at the hospital; one on the oncology ward and the other three in the chemotherapy room. These patients all had underlying malignancies and had the Port-A-Cath (Smiths Industries Medical Systems, Deltec, Inc., St. Paul, Minn.) implants. Three patients had primary bacteremia, and one had Port-A-Cath-related infection. None of these patients had received a blood transfusion before the episodes of bacteremia. All patients recovered: two received antimicrobial agents with in vitro activity against the isolates, and the other two did not have any antibiotic treatment. A total of eight blood isolates were recovered from these patients during the febrile episodes that occurred several minutes after the infusion of chemotherapeutic agents via the Port-A-Cath. These isolates were initially identified as P. fluorescens or Pseudomonas putida (four), Burkholderia (Ralstonia) pickettii (three), and a non-glucose-fermenting gram-negative bacillus (one) by routine biochemical methods and the Vitek GNI card. These isolates were later identified as P. fluorescens on the basis of the characteristic cellular fatty acid chromatogram and the results of supplemental biochemical tests. The identification of identical antibiotypes by the E test and the random amplified polymorphic DNA patterns generated by arbitrarily primed PCR of the isolates showed that the outbreak was caused by a single clone of P. fluorescens. Surveillance cultures of the possibly contaminated infusion fluids and disinfectants, which were performed 7 days after recognition of the last infected patient, failed to isolate P. fluorescens. This report of a small outbreak caused by P. fluorescens suggests that timely, accurate identification of unusual nosocomial pathogens is crucial for early initiation of an epidemiological investigation and timely control of an outbreak.

Cloacal dysgenesis sequence: observations in four patients including three fetuses of second trimester gestation

Cloacal dysgenesis is a rare malformation sequence. We studied cloacal dysgenesis in four fetuses, including three at 18-22 weeks of gestation. All four fetuses showed a smooth perineum with absence of anal, urethral, and/or vaginal openings. The urinary bladder was dilated in 3 cases. The labia majora and minora were absent in the two female fetuses; the scrotum and penis were absent in one male fetus and hypoplastic in the second. The kidneys were either absent (1 case), dysplastic (1 case), or hydronephrotic (1 case). Normal kidneys were seen in a fetus of 20-22 weeks gestation in whom the urinary obstruction was alleviated by a vesicocolonic fistula. This fetus did not have pulmonary hypoplasia. Severe renal anomaly and pulmonary hypoplasia are the limiting factors for the survival of infants born with cloacal dysgenesis. The unique observation of normal kidneys and lungs in one of our fetuses, despite anhydramnios, suggests that the effect of oligohydramnios on lung development may be limited early in gestation, at least up to 20-22 weeks. It may also indirectly support the theory that there are factors other than oligohydramnios that interfere with early lung development, such as reduced production of a pulmonary growth factor by the kidney or reduced proline production by malformed kidneys, that may cause decreased collagen formation and result in hypoplastic lung mesenchyme.

Antenatal diagnosis of lethal skeletal dysplasias

Lethal skeletal dysplasias (LSD) are a heterogeneous group of rare but important genetic disorders characterized by abnormal growth and development of bone and cartilage. We describe the diagnosis and outcome of 29 cases of lethal skeletal dysplasias evaluated between January 1989 and December 1996 at the University of Maryland Medical Center and the Ultrasound Institute of Baltimore. Two cases presented at delivery with no prenatal care while the remaining 27 cases were identified by antenatal sonography. Final diagnoses included thanatophoric dysplasia (14), osteogenesis imperfecta, type II (6), achondrogenesis (2), short rib syndromes (3), campomelic syndrome (2), atelosteogenesis (1), and no evidence of a skeletal dysplasia (1). Twenty out of 27 pregnancies were terminated with an average at detection of 21.6 weeks. The other 7 pregnancies that went on to deliver had an average age at detection of 29.2 weeks. Fetal abnormalities in the terminated pregnancies were identified at a significantly earlier gestational age (P = 0.0016) than the pregnancies that continued. While the identification of LSD by sonography was excellent (26/27), only 13/27 (48%) were given an accurate specific antenatal diagnosis. In 8/14 (57%) cases with an inaccurate or nonspecific diagnosis there was a significant or crucial change in the genetic counseling. Thus, while antenatal sonography is an excellent method for discovering LSD, clinical examination, radiographs, and autopsy are mandatory for making a specific diagnosis.

Is hereditary site-specific ovarian cancer a distinct genetic condition?

It is not clear if hereditary site-specific ovarian cancer exists as a genetic entity distinct from the hereditary breast-ovarian cancer syndrome. We have identified a large Ashkenazi Jewish kindred with 8 cases of ovarian carcinoma and no cases of breast cancer. Initially, linkage analysis for this kindred generated a negative LOD score to BRCA1, but subsequent mutation and haplotype analysis of key individuals demonstrated a BRCA1 185delAG mutation segregating with all but 1 of the ovarian cancer cases. This observation has important implications for genetic counselling of families with site-specific ovarian cancer. Hereditary site-specific ovarian cancer is likely to be a variant of the hereditary breast-ovarian cancer syndrome, attributable to either BRCA1 or BRCA2. We consider women from these families to be at increased risk of breast cancer and counsel them accordingly.

Pulmonary capillary hemangiomatosis: radiographic appearance

Pulmonary capillary hemangiomatosis is a rare disorder that is characterized pathologically by formation of capillaries along alveolar walls that may ultimately invade the pulmonary parenchyma and pulmonary arteries. The clinic presentation overlaps that of primary pulmonary hypertension, but the natural history of pulmonary capillary hemangiomatosis is one of rapid deterioration. The typical radiographic appearance is a diffuse bilateral reticulonodular pattern associated with enlarged central pulmonary arteries.