The stromal cell line S17 supports the growth of lipopolysaccharide-stimulated CBA/N spleen cell colonies in vitro.

The expression of an X-linked defect in the CBA/N strain of mice has been found to result in a number of immune abnormalities. These include low responsiveness to antigens and a greatly reduced ability to respond to many of the common B cell mitogens. An in vitro manifestation of this condition is the virtual inability of CBA/N B cells to form colonies in lipopolysaccharide (LPS)-containing semisolid agar cultures. In this report we show evidence that the colony-forming ability of CBA/N spleen cells can be effectively restored by the bone marrow stromal-derived cell line S17. Spleen cells from 4-5-week-old homozygous CBA/N female mice were grown in double-layer agar cultures containing S17 feeder layers. Control cultures contained the fibroblast-like cell line 95.17 or were treated with medium alone. It was found that at an input cell concentration of 10(4) cells per plate, CBA/N colony formation was increased from a frequency of approximately 1 in 5,000 to 1 in 50 total splenic cells. Studies with purified surface immunoglobulin-positive cells indicate the direct involvement of S17 in this process. The CBA/N colonies formed were dependent on the presence of a mitogen (LPS) and secreted detectable amounts of IgM. Major implications of these findings and the application of this assay system to study the CBA/N defect have been discussed.     

Safety and efficacy of simultaneous bilateral 25-gauge lens-sparing vitrectomy for vascularly active stage 4 retinopathy of prematurity

Purpose

To report the safety and efficacy of simultaneous bilateral 25-gauge lens-sparing vitrectomy for vascularly active stage 4 retinopathy of prematurity (ROP).

Methods

Retrospective, noncomparative, consecutive case series. Twenty eyes of 10 babies who presented with vascularly active stage 4 ROP in both the eyes underwent simultaneous bilateral 25-gauge lens-sparing vitrectomy. After completing surgery for one eye, the other eye was re-prepped as performed before starting any new case of a different patient and an entire new set of disposable 25-gauge instruments were used. During the post-operative period parents were advised to keep separate eye drops for each eye and to wash their hands in between switching the eyes to put the drops.

Results

The mean follow-up was 8.7 months (range 4–17 months). None of the cases developed any signs of infection. The anatomic success rate for stage 4a was 100% (11/11 eyes) and for stage 4b was 8/9 eyes (89%).

Conclusion

These results show that simultaneous bilateral 25-gauge lens-sparing vitrectomy for stage 4 ROP is a safe and effective procedure with a good outcome provided both eyes of the baby are treated as eyes of two different patients.     

Outcomes of Intra- and Extraocular Retinoblastomas from a Single Institute in South India

Aim: To report treatment outcomes of intra- and extraocular retinoblastomas seen at Aravind Eye Hospital, Coimbatore, South India.

Methods: Retrospective case series from January 2006 to December 2011 involving 106 babies. Clinical records were reviewed and data collected on presenting signs, gender, age, family history, ocular findings and treatment outcomes. All eyes were classified using the International Retinoblastoma Classification.

Results: The mean follow up was 35.4 months (range 1–75 months, SD 20.2, median 33 months). The mean age of presentation was 20.8 months (range 5 days to 120 months). There were 68 unilateral and 38 bilateral cases. Globe salvage rates were 100% for group A (11 eyes), B (16 eyes) and C (2 eyes). For group D, eye salvage rate was 29.5% (10/34 eyes). Survival rate of orbital retinoblastoma in our study was 55.5% (5/9 cases) at a mean follow up of 33.6 months. The overall patient survival rate was 89.6% with 11 deaths (10.4%). The commonest cause of death (7/11) was distant metastasis due to refusal to take initial treatment.

Conclusion: Greater improvement in patient survival can be achieved not only by early treatment of intraocular disease but also to convince patients to accept treatments including enucleation in this part of the world.     

Identification of Polybacterial Communities in Patients with Postoperative,Posttraumatic, and Endogenous Endophthalmitis through 16S rRNA Gene Libraries

Endophthalmitis is a potential vision-threatening complication following surgical procedures (postoperative endophthalmitis [POE]), trauma (posttraumatic endophthalmitis [PTE]), and bacteremic seeding of the eye from a distant infection site (endogenous endophthalmitis [EE]). Several studies have revealed the polybacterial characteristics of endophthalmitis, which make the administration of antibiotics to treat the disease challenging. However, until now, the polybacterial communities of POE, PTE, and EE have not been precisely studied. Hence, the present study was designed to identify the bacterial community of endophthalmitis through 16S rRNA gene libraries. Of the 40 intraocular samples tested, 30 libraries were constructed with bacterial nested-PCR-positive samples. The obtained recombinant clones were screened through amplified rRNA gene restriction analysis (ARDRA) to identify unique clones. The multiple types of ARDRA patterns (P = 0.345) and diverse bacterial sequences (P = 0.277) within the libraries revealed the polybacterial nature of infection in POE, PTE, and EE. Moreover, to the best of our knowledge, this is the first report on polybacterial infection in EE. Gram-positive bacteria, including Bacillus spp. (n = 19), Streptococcus spp. (n = 18), Staphylococcus spp. (n = 6), Exiguobacterium spp. (n = 3), Gemella spp. (n = 2), Enterococcus spp. (n = 2), a Lysinibacillus sp. (n = 1), a Clostridium sp. (n = 1), and a Nocardia sp. (n = 1), and Gram-negative bacteria, including Serratia spp. (n = 18), Pseudomonas spp. (n = 10), Enterobacter spp. (n = 8), Acinetobacter spp. (n = 3), Pantoea spp. (n = 3), a Haemophilus sp. (n = 1), and a Massilia sp. (n = 1), were identified. Interestingly, among them, 10 bacterial species were not previously reported to be associated with endophthalmitis or other ocular infections. Besides, the presence of 4 unidentifiable clones suggests the possibility of novel organisms that might cause eye infections. Therefore, it is recommended that, in addition to the polybacterial nature of POE, PTE, and EE infections, the spectrum of the pathogenic bacterial community identified in this work should be considered while administering antibiotic therapy in suspected endophthalmitis cases.     

Mechanisms of defective erythropoiesis and anemia in pediatric acute lymphoblastic leukemia (ALL)

Anemia frequently accompanies the diagnosis of acute lymphoblastic leukemia (ALL) in children and is considered to be one of the most common clinical complications of the disease. In addition, a low hemoglobin (Hb) level is often responsible for fatigue and other associated symptoms that cause a decline in the quality of life of these children. Traditionally, a number of contributing factors such as overcrowding of the marrow, coexisting infections, and nutritional deficits have been used to explain this phenomenon. However, recent advances in in vivo modeling and real-time ultrastructural analytical techniques have enabled researchers to examine leukemic bone marrow (BM) microenvironment more closely and helped to build mechanistic models of this process. Importantly, data from these studies show that in the majority of cases, the required stem cell populations and the erythropoietic growth mechanisms remain intact in leukemia. In this report, we aim to review the current state of knowledge regarding the cellular and molecular mechanisms implicated in the altered erythropoiesis at the time of diagnosis of leukemia. We propose that further understanding of the mechanisms of anemia in leukemia may help to manage some of its clinical consequences more effectively as well as to yield key insight into the process of leukemogenesis itself.     

Immune reconstitution inflammatory syndrome in HIV-infected patients with and without prior tuberculosis

We conducted a nested case-control study in a cohort of patients initiating antiretroviral therapy (ART) to identify risk factors and common manifestations of immune reconstitution inflammatory syndrome (IRIS) and to validate the Robertson criteria for IRIS prediction. HIV-infected patients at the Tuberculosis Research Centre clinics, Chennai and Madurai, India, initiating ART between July 2004 and June 2005 were prospectively studied. Of 97 patients (62% men, median age 32 years, median CD4 count 63 cells/μL) included, 34 developed IRIS. IRIS was more common in patients with a prior history of tuberculosis (74% versus 52%, P = 0.04), median time to development was 46 days and the sensitivity and specificity of the Robertson criteria to predict IRIS were 91% and 22%, respectively. In this population, IRIS was a common event, more so among patients with prior tuberculosis, and neither the rate of CD4 increase nor the Robertson criteria were useful in predicting its development.