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.

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.

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.

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.

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.

Cancer family syndrome of Lynch.

This report describes a family in whom eight cancers (six colonic and two endometrial) occurred in seven relatives. The colonic cancer was diagnosed in five of the six affected patients at an unusually young age, had a predilection for the proximal colon, and was of the mucinous type in four patients. Polyposis was not found in any colon. The occurrence of cancer in this kindred is characteristic of the "cancer family syndrome" of Lynch.

Choledochoduodenostomy for benign and malignant biliary tract diseases.

Although nonsurgical alternative treatments for primary or retained common bile duct stones--such as dissolution of gallstones with deoxycholic acids and, especially endoscopic papillotomy--have become available, choledochoduodenostomy (CDS) has been used with increasing frequency over the past decade, with extension of the indications for its use. We report our experience with side-to-side CDS in 116 patients with benign (65 patients) and malignant (46 patients) biliary diseases. Even though the mean age of our patients with benign disease--patients who underwent urgent operations because of obstructive jaundice (74%), liver damage (approximately 60%), and other biliary complications--was 66.8 years, the perioperative mortality was 3.07% and the long-term follow-up results were excellent with no biliary complications. In regard to the controversy about the use of CDS in malignant biliary obstructions, our experience shows that none of the 42 patients had any complication due to malignant invasion of the stoma, and only one patient had ascending cholangitis; the perioperative mortality in this group was 8.6%. In our opinion, CDS is a relatively safe, definitive procedure for treatment of benign and malignant biliary diseases, with good long-term results in high-risk, aged patients.

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.

Primary resection with colocolostomy for obstructive carcinoma of the left side of the colon.

Between 1970 and 1982, 147 patients were operated on for obstructing carcinoma of the colon at our institution. Of these, 25 patients with obstructing carcinoma of the left side of the colon were treated by emergency primary resection with colocolostomy. Three patients who had primary resection died postoperatively, two of them from myocardial infarction and one, a 66 year old patient with liver metastasis, from sepsis. One patient had an anastomotic leak and underwent a proximal diverting colostomy. Results of this form of treatment have been good, and we advocate the procedure for selected groups of patients.

Choledochoduodenostomy for benign biliary tract disease in the elderly.

Endoscopic sphincterotomy is an available nonoperative alternative treatment for recurrent or residual common bile duct stones. Nevertheless, immediate, intraoperative and definitive treatment is needed in patients with common duct stones and other pathologies that are prone to develop into such complications, which is important especially in aged high-risk patients during recurrent operations and nonoperative instrumental interventions. To evaluate the safety of choledochoduodenostomy in elderly patients, we reviewed our experience with 55 patients over the age of 70 years with benign biliary tract diseases. Even though the majority of patients (69%) had obstructive jaundice and were operated on urgently, there was one death (1.8%) due to cardiac failure, and nine (16.3%) early postoperative complications including subphrenic abscess, disruption of wound and pneumonia (one case of each), wound infection (three cases) and urinary tract infections (three cases). There were no complications related to the procedure itself. In a follow-up period of one to 12 years, neither cholangitis nor sump syndrome were documented.

[Acute intestinal occlusion caused by phytobezoar in Israel. Role of oranges and persimmons]. / L'occlusion intestinale aiguë par phytobézoards en Israël. Rôle de l'orange et du persimmon.

Forty-one patients were operated upon for acute intestinal obstruction secondary to the presence of phytobezoars, 34 of these patients (83%) having a history of previous gastric surgery for ulcer. The etiologic factor in 44% of cases was oranges and in 56% persimmons (Kakis). Treatment was by enterotomy in 27 patients (65,85%) and by "milking" in 14 (34,15%). Postoperative mortality was 2,44% (1 case). Recurrence was noted in three cases (7,3%) including one with an ileocutaneous fistula, treatment being by enterotomy in 2 cases and "milking" in the third patient. First intention intestinal resection was never required. Five patients required several admissions for subacute obstruction treated conservatively. These findings suggest that gastric surgery predisposes to intestinal obstruction by phytobezoar. Careful exploration of the digestive tube and particularly the stomach should avoid postoperative relapse, while prevention depends on a dietary regimen avoiding excessive intake of foods rich in cellulose, particularly oranges and persimmon fruit.

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.

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.

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.