Orbital angular momentum in the near-field of a fork grating.

Light beams with Orbital Angular Momentum (OAM) are explored in applications from microscopy to quantum communication, while the Talbot effect revives in applications from atomic systems to x-ray phase contrast interferometry. We evidence the topological charge of an OAM carrying THz beam in the near-field of a binary amplitude fork-grating by means of the Talbot effect, which we show to persist over several fundamental Talbot lengths. We measure and analyze the evolution of the diffracted beam behind the fork grating in Fourier domain to recover the typical donut-shaped power distribution, and we compare experimental data to simulations. We isolate the inherent phase vortex using the Fourier phase retrieval method. To complement the analysis, we assess the OAM diffraction orders of a fork grating in the far-field using a cylindrical lens.

Epidemiology, management and outcomes of Cryptococcus gattii infections: A 22-year cohort.

BACKGROUND: Cryptococcus gattii is a globally endemic pathogen causing disease in apparently immune-competent hosts. We describe a 22-year cohort study from Australia's Northern Territory to evaluate trends in epidemiology and management, and outcome predictors. METHODS: A retrospective cohort study of all C. gattii infections at the northern Australian referral hospital 1996-2018 was conducted. Cases were defined as confirmed (culture-positive) or probable. Demographic, clinical and outcome data were extracted from medical records. RESULTS: 45 individuals with C. gattii infection were included: 44 Aboriginal Australians; 35 with confirmed infection; none HIV positive out of 38 tested. Multifocal disease (pulmonary and central nervous system) occurred in 20/45 (44%). Nine people (20%) died within 12 months of diagnosis, five attributed directly to C. gattii. Significant residual disability was evident in 4/36 (11%) survivors. Predictors of mortality included: treatment before the year 2002 (4/11 versus 1/34); interruption to induction therapy (2/8 versus 3/37) and end-stage kidney disease (2/5 versus 3/40). Prolonged antifungal therapy was the standard approach in this cohort, with median treatment duration being 425 days (IQR 166-715). Ten individuals had adjunctive lung resection surgery for large pulmonary cryptococcomas (median diameter 6cm [range 2.2-10cm], versus 2.8cm [1.2-9cm] in those managed non-operatively). One died post-operatively, and 7 had thoracic surgical complications, but ultimately 9/10 (90%) treated surgically were cured compared with 10/15 (67%) who did not have lung surgery. Four patients were diagnosed with immune reconstitution inflammatory syndrome which was associated with age <40 years, brain cryptococcomas, high cerebrospinal fluid pressure, and serum cryptococcal antigen titre >1:512. CONCLUSION: C. gattii infection remains a challenging condition but treatment outcomes have significantly improved over 2 decades, with eradication of infection the norm. Adjunctive surgery for the management of bulky pulmonary C. gattii infection appears to increase the likelihood of durable cure and likely reduces the required duration of antifungal therapy.

Retrieving the Talbot length of arbitrary 2D gratings.

The Talbot effect has been revived in many fields of modern optics. As a key number of self-imaging, the fundamental Talbot length plays a crucial role in many applications. However, the inspection of the Talbot carpet for determining the Talbot length is applicable only if the 2D field distribution behind the grating is represented by a 1D cross section. In this Letter, we show an effective way to overcome this limitation to explore the self-imaging of gratings with complex 2D periodicities. For that purpose, the near-field diffraction is analyzed using the Pearson correlation coefficient of the intensity distribution in Fourier space. We report results on linear, ring, and spiral gratings.

Single-Pulse Measurement of Orbital Angular Momentum Generated by Microring Lasers.

Optical beams with helical phase fronts carry orbital angular momentum (OAM). To exploit this property in integrated photonics, micrometer-scale devices that generate beams with well-defined OAM are needed. Consequently, lasers based on microring resonators decorated with azimuthal grating elements have been investigated. However, future development of such devices requires better methods to determine their OAM, as current approaches are challenging to implement and interpret. If a simple and more sensitive technique were available, OAM microring lasers could be better understood and further improved. In particular, despite most devices being pulsed, their OAM output has been assumed to be constant. OAM fluctuations, which are detrimental for applications, need to be quantified. Here, we fabricate quantum-dot microring lasers and demonstrate a simple measurement method that can straightforwardly determine the magnitude and sign of the OAM down to the level of individual laser pulses. We exploit a Fourier microscope with a cylindrical lens and then investigate three types of microring lasers: with circular symmetry, with "blazed" grating elements, and with unidirectional rotational modes. Our results confirm that previous measurement techniques obscured key details about the OAM generation. For example, while time-averaged OAM from our unidirectional laser is very similar to our blazed grating device, single-pulse measurements show that detrimental effects of mode competition are almost entirely suppressed in the former. Nevertheless, even in this case, the OAM output exhibits shot-to-shot fluctuations. Thus, our approach reveals important details in the underlying device operation that can aid in the improvement of micrometer-scale sources with pure OAM output.

Evolutionary origins of the placental expression of chromosome 19 cluster galectins and their complex dysregulation in preeclampsia.

INTRODUCTION: The dysregulation of maternal-fetal immune tolerance is one of the proposed mechanisms leading to preeclampsia. Galectins are key regulator proteins of the immune response in vertebrates and maternal-fetal immune tolerance in eutherian mammals. Previously we found that three genes in a Chr19 cluster encoding for human placental galectin-13 (PP13), galectin-14 and galectin-16 emerged during primate evolution and may confer immune tolerance to the semi-allogeneic fetus. MATERIALS AND METHODS: This study involved various methodologies for gene and protein expression profiling, genomic DNA methylation analyses, functional assays on differentiating trophoblasts including gene silencing, luciferase reporter and methylation assays. These methods were applied on placental specimens, umbilical cord blood cells, primary trophoblasts and BeWo cells. Genomic DNA sequences were analyzed for transposable elements, transcription factor binding sites and evolutionary conservation. RESULTS AND DISCUSSION: The villous trophoblastic expression of Chr19 cluster galectin genes is developmentally regulated by DNA methylation and induced by key transcription factors of villous placental development during trophoblast fusion and differentiation. This latter mechanism arose via the co-option of binding sites for these transcription factors through promoter evolution and the insertion of an anthropoid-specific L1PREC2 transposable element into the 5' untranslated region of an ancestral gene followed by gene duplication events. Among placental Chr19 cluster galectin genes, the expression of LGALS13 and LGALS14 is down-regulated in preterm severe preeclampsia associated with SGA. We reveal that this phenomenon is partly originated from the dysregulated expression of key transcription factors controlling trophoblastic functions and galectin gene expression. In addition, the differential DNA methylation of these genes was also observed in preterm preeclampsia irrespective of SGA. CONCLUSIONS: These findings reveal the evolutionary origins of the placental expression of Chr19 cluster galectins. The complex dysregulation of these genes in preeclampsia may alter immune tolerance mechanisms at the maternal-fetal interface.

Detection of Mycobacterium leprae by PCR testing of sputa from a patient with pulmonary cryptococcus coinfection in northern Australia.

A case of fever, sepsis, and chest lesions evident on a computed tomography scan of an indigenous man in northern Australia following burns to the feet is described. Sputum PCR testing revealed Mycobacterium leprae, and a fine-needle aspirate of the chest lesions demonstrated Cryptococcus coinfection.

Feasibility of latent tuberculosis infection diagnosis by interferon-γ release assay remote from testing facilities.

Although the tuberculin skin test (TST) has been the mainstay of the diagnosis of latent tuberculosis infection (LTBI) for many decades, interferon-gamma release assays (IGRAs) are gaining acceptance and are more specific for this diagnosis. The characteristics of one such IGRA, the QuantiFERON-TB Gold Whole Blood In-Tube, make it feasible for use in a remote setting. This study performed 62 IGRAs with this test on individuals testing positive by TST, in a clinical setting over 3,000 km from the testing laboratory. Of these, 42 patients (68%) recorded negative results, 19 (31%) were positive, with only 1 result (2%) indeterminate. Negative, and therefore discordant in this study, test results were more common in those known to have been previously vaccinated with bacille Calmette-Guérin. These results are consistent with other reports, indicating that this approach to testing is logistically feasible, and has the potential to complement LTBI screening to assist tuberculosis control programs in settings remote from the testing laboratory.

Does aminoglycoside therapy cause significant acute kidney injury in febrile neutropenia?

Owing to concern about aminoglycoside-related acute kidney injury (AKI) in therapy for febrile neutropenia, the aim of this study was to ascertain the incidence, severity and persistence of AKI secondary to aminoglycoside use for febrile neutropenia at an adult tertiary referral hospital. All admitted adults with neutropenia in a 27-month period were reviewed. Cases of febrile neutropenia due to chemotherapy who received an aminoglycoside were identified and renal function was assessed up to Day 30 after aminoglycoside administration. Transient renal impairment (TRI) was defined as any temporary rise in serum creatinine of >44 µmol/L within 30 days; and persistent, significant renal impairment (PSRI) was defined as an elevation of serum creatinine of >44 µmol/L at Day 30, or death from renal failure or need for dialysis. The Acute Kidney Injury Network (AKIN) stage for all episodes was also determined. Amongst 554 episodes of neutropenia, 148 episodes of chemotherapy-related febrile neutropenia with aminoglycoside treatment were identified. PSRI occurred in six episodes [4.1%; 95% confidence interval (CI) 1.9-8.6%] and TRI occurred in seven episodes (4.7%; 95% CI 2.3-9.4%). No PSRI was attributable to aminoglycoside therapy alone (0%; 95% CI 0-3.2%). Severe sepsis was the main cause of PSRI. Aminoglycoside therapy was the main contributing cause of TRI in two episodes (1.4%; 95% CI 0.2-5.3%). In conclusion, PSRI is a rare complication of aminoglycoside therapy for febrile neutropenia at this institution. AKIN stage 1 AKI is a common complication of febrile neutropenia episodes in which aminoglycosides are administered.

Primary neoplasms of the small bowel.

Primary neoplasms of the small bowel are unusual and constitute 1-5% of all gastrointestinal tract neoplasms. Preoperative diagnostic difficulties, frequent dissemination at the time of the diagnosis, and poor prognosis are characteristic of this pathology. During a period of 26 years we treated 61 patients with tumors of the small bowel, 44 malignant and 18 benign (1 patient had both). The most common symptoms were abdominal pain (62%), weight loss (41%), and gastro-intestinal bleeding (31%). More than half of the patients were treated as emergencies and among the remaining, the most useful diagnostic test was the small intestinal barium study. Seventeen patients were operated on for intestinal obstruction, 6 of them due to intussusception of the tumor, while 8 other patients presented with perforation and 7 with massive gastrointestinal bleeding. Leiomyoma was the most frequent benign lesion. Among malignancies lymphoma was encountered in 38.6%, followed by adenocarcinoma (29.6%) and leiomyosarcoma (22.8%). Lymphoma was predominant among Sephardic Jews. Curative procedures were attempted in all but one of the benign cases and in 21 of the malignant cases. At the time of surgery metastases were present in 23 patients. The postoperative mortality was high (20% and 14% in the benign and malignant groups, respectively) most probably due to the high incidence of emergency surgery in a high risk population. The prognosis of the malignant tumors was poor with a 5-year survival of 18%. Their disappointing course seems to be related to late diagnosis because of nonspecific symptoms and difficulty in bringing the tumor to the fore. Hopefully, a greater awareness will lead to an earlier diagnosis and improve the prognosis.

Benign cystic mesothelioma of the peritoneum: the occurrence of an adult entity in a child.

Benign cystic mesothelioma of the peritoneum is considered a disease of adulthood occurring predominantly in women. We report a case of benign cystic mesothelioma of the peritoneum in an 11-year-old boy. The innumerable cystic lesions that varied in size occupied the entire peritoneal cavity. He underwent two laparotomies in a period of 15 months during which a partial removal of the tumor was performed. Four years after the second operation the child is well and active, despite significant tumor tissue left behind after the first two operations. The management of this disease is discussed, and the importance of a conservative approach minimizing the number of laparotomies and avoiding radical surgical intervention especially in childhood is emphasized.

Secretory breast cancer in childhood and adolescence: report of a case and review of the literature.

A 17-year-old boy underwent a wide partial mastectomy with axillary dissection for secretory breast cancer, followed by low grade irradiation (30 Gy). There were no axillary lymph node metastases. Hormone receptor assay of the tumor was positive for progesterone and negative for estrogen. There was no local recurrence or sign of dissemination after nearly 5 years. Literature search revealed 21 cases of secretory breast cancer in childhood and adolescence; in only 2 cases was the hormonal status studied. We report an additional case and review the literature.

Penetration of aminoglycosides into human peritoneal tissue.

Each of 30 patients underwent elective laparotomy following administration of a single intravenous dose of amikacin, netilmicin or tobramycin. Therapeutic concentrations of amikacin were achieved in peritoneal tissue in 10/10 patients. Only 13/20 samples from patients receiving the other two antibiotics showed antibacterial activity. Our data suggest that the penetrability of tobramycin (53%) and amikacin (39%) into the uninflamed peritoneal tissue is superior to that of netilmicin (16%).

The incidence and significance of serum hCG and CEA in patients with gastrointestinal malignant tumors.

Beta-human chorionic gonadotropin (hCG) is normally produced and secreted by trophoblastic cells in pregnancy, by tumors arising from those cells and by a wide variety of tumors of nonendocrine origin. Gonadotropin is produced and secreted by various tissues (stomach, pancreas, ovary, etc.) and the incidence of ectopic secretion varies between 0 and 43%. Our report is an attempt to evaluate the incidence of high plasma beta hCG levels in 101 patients with gastrointestinal malignant tumors. The results revealed negative beta hCG in the control samples, while in the studied patients 41 were positive for beta hCG (44.4%). Three samples from oesophagus squamous cell carcinoma were positive. Twenty-five out of 69 with colorectal carcinoma had raised serum beta hCG (36.8%). Gastric carcinoma showed positive beta hCG in 52% of the patients. Among all the patients high beta hCG levels were far more common in those with positive lymphnodes (P less than 0.05). The beta hCG levels decreased with colorectal carcinoma tumor size and with smaller tumors there was the probability of increasing positive serum measurements (P less than 0.05). The patients with adenocarcinoma of the stomach showed good statistical correlation between stages of the disease at the operation time to beta hCG levels. In our opinion this serological assay will become one of the markers to be added to our armamentarium in the evaluation of patients with gastrointestinal malignant tumors.

Penetration of third-generation cephalosporins into human peritoneal tissue.

Each of 40 patients underwent elective laparotomy following administration of a single 1.0-gram intravenous dose of ceftizoxime, ceftriaxone, cefoperazone or cefotaxime. Therapeutic concentrations of cefoperazone and ceftriaxone were achieved in peritoneal tissue in 20/20 patients. Only 9/20 samples from patients receiving the other two antibiotics had detectable antibiotic activity. The antibiotic concentration in peritoneal fluid (7 samples) was 2.36-11.15 times higher than that of concurrently obtained peritoneal tissue. When adjusted for the in vitro susceptibility (MIC) of potential peritoneal pathogens, our data suggest that ceftriaxone and cefoperazone may be preferable to other third-generation cephalosporins for the prophylaxis and therapy of intraabdominal infection.

Paget's disease of the male breast.

Histologically proved Paget's disease of the breast with negative hormonal receptor assay in a 73-year-old man induced a review of the 27 valuable cases of the literature. Our patient is disease-free, eight years after treatment by modified radical mastectomy and adjuvant irradiation. Peak incidence of the disease is between 50 and 70 years of age. The most frequent presenting signs reported are ulcerations and eczematous lesions of the nipple (71.4%) with discharge and bleeding in 39.3% of the cases. Other findings are a palpable mass (42.8%) and involved axillary lymph nodes (53.5%). The treatment of choice is shown to be radical or modified radical mastectomy with adjuvant radiotherapy. To date, no proof exists of the value of hormone receptors assays and routine adjuvant hormone therapy is not practiced.