Thelaziasis as an uncommon cause of giant papillary conjunctivitis.

INTRODUCTION: We report a local human case of Thelazia callipaeda eye infection in a 49-year-old lady with history of fly contact in Hong Kong. CASE DESCRIPTION: A 49-year-old lady presented with right eye foreign body sensation for one month. She recalled a fly being stuck onto her right upper eyelashes with mascara when she went hiking in a forest trail in Hong Kong. On assessment there were a lot of giant papillae on palpebral conjunctiva. Three living worms crawling on conjunctiva were discovered and removed in total. The worms were identified as Thelazia callipaeda by morphology and molecular sequencing. After removal, her symptoms resolved completely. CONCLUSION: Human thelaziasis is probably under-reported in many countries. The presence of giant papillary conjunctivitis in non-contact lens wearers should alert clinicians to the possibility of thelaziasis in patients with compatible exposure history in endemic regions. Ophthalmologists should increase their awareness towards this uncommon disease and should not wrongly attributed the symptoms to allergic conjunctivitis.

A stepwise approach to control an outbreak and ongoing transmission of methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit.

BACKGROUND: Preventing methicillin-resistant Staphylococcus aureus (MRSA) transmission in health care facilities where MRSA is endemic is challenging yet critical. OBJECTIVE: We sought to determine the effectiveness of 2 bundles of interventions for preventing MRSA transmission in a neonatal intensive care unit (NICU). METHODS: This retrospective cohort study included infants admitted to our NICU between September 1, 2004, and March 31, 2009. Following a MRSA outbreak between September 2004 and September 2005, preventing ongoing MRSA transmission remained a challenge. In July 2006, bundle-I, including culture-based active surveillance, preemptive contact precaution for up to 72 hours for new admissions, and cohorting assignment of direct caregivers was introduced for eradicating MRSA transmission. Bundle-II began in April 2007 and included bundle-1 measures except that the real-time polymerase chain reaction test replaced culture for the detection of MRSA. RESULTS: This study identified 218 infants who developed MRSA infection or colonization and 151 instances of MRSA transmission during the study period. After instituting bundle-II, the transmission rate declined from 2.9 to 2.1 per 1000 patient-days-at-risk (incidence rate ratio, 1.4; 95% confidence interval: 0.9-2.2), and hospital-acquired MRSA infections declined from 1.3 to 0.5 per 1000 patient-days-at-risk (incidence rate ratio, 2.5; 95% confidence interval: 1.1-5.8). CONCLUSION: Despite an increasing incidence of MRSA in community settings, preventing MRSA transmission within a NICU is achievable through implementation of optimal intervention strategies.

Neonatal cord blood subsets and cytokine response to bacterial antigens.

We compared lymphocyte subsets and cytokine responses to bacteria among term, preterm infants, and adults. Lymphocyte subset percentages in cord blood (22 preterm, 27 term neonates) and peripheral blood from 21 adults and cytokine/chemokine interleukin (IL)-6, IL-8, IL-10, IL-12, interferon gamma (IFN gamma) responses to Escherichia coli, group B Streptococcus (GBS), Staphylococcus epidermidis, and Lactobacillus plantarum (Lp299v) were assessed by flow cytometry. Preterm compared with term infants had increased CD8 (+) T cells (p = 0.02) and reduced naïve CD4 (+) T cells (p < 0.0001). Memory T and natural killer (NK) T cells were reduced (p < 0.001) in neonates; NK and CD56 (+)161 (+) NK cells were increased (p < 0.001). CD56 (+)CD8 (+) NK cells were higher in preterm compared with term infants. Despite individual exceptions, cytokine responses in neonates were weaker than adults except for IL-8 response to E. coli in preterm and IL-12 response to Lp299v in term infants. IL-10 responses were weaker in preterm (p = 0.01) and term (p = 0.005) infants to S. epidermidis and to E. coli (p = 0.03 for both) compared with adults. Differences in regulatory subpopulations of NK and T cells between neonates and adults and term compared with preterm infants were observed. These differences rather than intrinsic functional deficiency may account for neonatal cytokine responses to bacteria.

Maitake beta-glucan enhances umbilical cord blood stem cell transplantation in the NOD/SCID mouse.

Beta glucans are cell wall constituents of yeast, fungi and bacteria, as well as mushrooms and barley. Glucans are not expressed on mammalian cells and are recognized as pathogen-associated molecular patterns (PAMPS) by pattern recognition receptors (PRR). Beta glucans have potential activity as biological response modifiers for hematopoiesis and enhancement of bone marrow recovery after injury. We have reported that Maitake beta glucan (MBG) enhanced mouse bone marrow (BMC) and human umbilical cord blood (CB) cell granulocyte-monocyte colony forming unit (GM-CFU) activity in vitro and protected GM-CFU forming stem cells from doxorubicin (DOX) toxicity. The objective of this study was to determine the effects of MBG on expansion of phenotypically distinct subpopulations of progenitor and stem cells in CB from full-term infants cultured ex vivo and on homing and engraftment in vivo in the nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse. MBG promoted a greater expansion of CD34+CD33+CD38- human committed hematopoietic progenitor (HPC) cells compared to the conventional stem cell culture medium (P = 0.002 by ANOVA). CD34+CXCR4+CD38- early, uncommitted human hematopoietic stem cell (HSC) numbers showed a trend towards increase in response to MBG. The fate of CD34+ enriched CB cells after injection into the sublethally irradiated NOS/SCID mouse was evaluated after retrieval of xenografted human CB from marrow and spleen by flow cytometric analysis. Oral administration of MBG to recipient NOS/SCID mice led to enhanced homing at 3 days and engraftment at 6 days in mouse bone marrow (P = 0.002 and P = 0.0005, respectively) compared to control mice. More CD34+ human CB cells were also retrieved from mouse spleen in MBG treated mice at 6 days after transplantation. The studies suggest that MBG promotes hematopoiesis through effects on CD34+ progenitor cell expansion ex vivo and when given to the transplant recipient could enhance CD34+ precursor cell homing and support engraftment.

Cytokine expression in response to bacterial antigens in preterm and term infant cord blood monocytes.

BACKGROUND: Neonatal susceptibility to bacterial infection is associated with an immature immune system, but the role of different bacterial antigens in specific responses is largely unknown. OBJECTIVE: To evaluate differences in intracellular cytokine response to physiologically relevant bacterial antigens in term and preterm infants as compared with adults. METHODS: Cord blood samples from preterm and term neonates and adult peripheral blood samples were cultured ex vivo with and without whole heat-killed bacteria. Intracellular leukocyte production of interleukin (IL)-6, IL-10, IL-12, and IL-8 responses was assessed by flow cytometry. RESULTS: Monocytes were the primary producers of all mediators. Escherichia coli was the most potent stimulant. Lactobacillus plantarum 299v activated fewer monocytes as compared with E. coli for all responses (p < 0.05), except for IL-12 in term neonates. IL-6 response to Staphylococcus epidermidis was lower in both groups of neonates as compared with adults (p = 0.023 and p = 0.001). IL-8 response to S. epidermidis was lower in term as compared with preterm neonates and adults (p = 0.003). IL-10 response to group B streptococci was lower in term neonates as compared with adults and higher in preterm as compared with term neonates (p = 0.015). CONCLUSIONS: Monocytes from term neonates compared to preterm neonates show a downregulated anti-inflammatory response to specific bacteria. High neonatal response to pathogenic E. coli in the preterm infant could cause uncontrolled inflammatory response, while lower IL-6 response to S. epidermidis in neonates may indicate a basis for vulnerability to S. epidermidis infection.

Enhancement of umbilical cord blood cell hematopoiesis by maitake beta-glucan is mediated by granulocyte colony-stimulating factor production.

Maitake beta-glucan (MBG) is an extract from the fruit body of the Grifola frondosa mushroom that is being widely used to treat cancer in Asia. We have previously reported that MBG enhances mouse bone marrow cell (BMC) hematopoiesis in vitro and protects BMC from doxorubicin (DOX) toxicity. In the current study, we investigated the ability of MBG to enhance hematopoiesis and to reduce the toxic effects of DOX on fresh human umbilical cord blood (CB) cells. MBG treatment significantly enhanced the colony formation unit (CFU) response of granulocytes-macrophages (CFU-GM response) over the whole dose range of 12.5 to 100 microg/ml (P < 0.05). The addition of MBG to DOX-treated CB cells significantly protected granulocyte-macrophage colony formation from the toxicity of DOX, which otherwise produced strong hematopoietic repression. MBG also partially replaced recombinant human granulocyte colony-stimulating factor (rhG-CSF), as shown by a significant augmentation of the CFU-GM response in the absence of rhG-CSF. We found that MBG induces granulocyte colony-stimulating factor (G-CSF) production in CB CD33+ monocytes, as detected by intracellular cytokine flow cytometric assessment. In contrast, we found that adult peripheral blood monocytes did not produce a significant G-CSF response to MBG, whereas both adult and CB monocytes produced G-CSF in response to lipopolysaccharide. These studies provide the first evidence that MBG induces hematopoietic stem cell proliferation and differentiation of CFU-GM in umbilical CB cells and acts directly to induce G-CSF.

Isolation of nuclei from label-retaining cells and measurement of their turnover rates in rat colon.

We describe here a new technique for isolating nuclei from long-term label-retaining cells (LRCs), a subpopulation enriched with stem cells from colon, and for measuring their proliferation rates in vivo. A double-label approach was developed, combining the use of bromodeoxyuridine (BrdU) and (2)H(2)O. Male Fisher 344 rats were administered BrdU in drinking water continuously for 2-8 wk. BrdU was then discontinued (BrdU washout), and animals (n = 33) were switched to (2)H(2)O in drinking water and killed after 2, 4, and 8 wk. Nuclei from BrdU-positive cells (LRCs) were collected by flow cytometry. The percentages of LRCs were 7 and 3.8% after 4 and 8 wk of BrdU washout, respectively. Turnover rates of LRCs were measured on the basis of deuterium incorporation from (2)H(2)O into DNA of LRC nuclei, as determined by mass spectrometry. The proliferation rate of the LRCs collected was 0.33-0.90% per day (half-life of 77-210 days). Significant contamination from other potentially long-lived colon cells was excluded. In conclusion, this double-labeling method allows both physical isolation of nuclei from colon epithelial LRCs and measurement of their in vivo proliferation rates. Use of this approach may allow better understanding of mechanisms by which agents induce or protect against colon carcinogenesis.