Development of quinolone resistance and prevalence of different virulence genes among Shigella flexneri and Shigella dysenteriae in environmental water samples.

The purpose of this study was to find out the mechanism of quinolone resistance in Shigella sp. isolated from environmental water samples from various parts of Kolkata, India. Out of 196 Shigella sp. isolated from 2014 to 2017, we selected 32 Shigella isolates for antimicrobial susceptibility tests. The minimum inhibitory concentrations (MIC) for quinolones ranged from 30 to 50 µg ml-1 for ofloxacin, 5-20 µg ml-1 for ciprofloxacin and 20-30 µg ml-1 for norfloxacin. A few amino acid changes were found in quinolone resistance determining region (QRDR) of gyrA. Mutations in gyrA lead to a higher increment of MIC of quinolones. Among the plasmid-mediated (PMQR) quinolone resistance genes investigated, qnrB and aac(6')-lb-cr genes were found in all isolates. qnrA and qnrS were found in 25% and 62% of the isolates, respectively. ipaH gene was found in all of the isolates followed by the presence of other virulence genes ial, sen and stx1. Almost all the isolates having high MICs showed efflux pump activity in drug accumulation assay. All the mechanisms may or may not be present in a single strain. Several types of efflux pumps, presence of PMQR genes and mutations in drug target site of QRDR region may play the crucial role for resistance in our isolates.

Spin glass like transition and the exchange bias effect in Co3O4 nanoparticles anchored onto graphene sheets.

We have synthesized Co3O4 nanoparticles having 40 nm average size, which are anchored on reduced graphene oxide. X-ray diffraction, FESEM, TEM and Raman spectroscopy are performed for the characterization. The temperature dependence of field cooled (FC) and zero field cooled (ZFC) magnetization curves exhibits antiferromagnetic (AFM) transition around ∼30 K, as observed for bulk Co3O4. The exchange bias effect is observed below ∼30 K. A significant change in the exchange bias effect is noted around ∼8 K, which is close to a spin-glass-like transition. The spin-glass-like phase has been confirmed by the memory effects observed by different experimental protocols. The possible origin of exchange bias is discussed in the manuscript.

A phase II study (ARCHER 1042) to evaluate prophylactic treatment of dacomitinib-induced dermatologic and gastrointestinal adverse events in advanced non-small-cell lung cancer.

BACKGROUND: ARCHER 1042, a randomized phase II trial, explored the impact of prophylactic treatment on select dermatologic adverse events of interest (SDAEI), diarrhea, and mucositis associated with dacomitinib, an oral irreversible pan-human epidermal growth factor receptor (HER) inhibitor, in development for advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Patients with advanced NSCLC treated with dacomitinib were enrolled in two cohorts. Cohort I patients were randomized 1:1 to receive oral doxycycline or placebo (4 weeks). Cohort II patients received oral VSL#3 probiotic plus topical alclometasone. Primary end points for Cohorts I and II were incidence of all grade and grade ≥2 SDAEI in the first 8 weeks of treatment and quality of life (QoL) assessed by the Skindex-16 survey. Additional primary end points for Cohort II were incidence of all grade and grade ≥2 diarrhea and mucositis in the first 8 weeks of treatment; QoL regarding diarrhea and mucositis incidence was assessed by the modified-Oral Mucositis Daily Questionnaire. RESULTS: Cohort I randomized 114 evaluable patients: 56 in the doxycycline arm, 58 in the placebo arm. Cohort II enrolled 59 evaluable patients. Doxycycline significantly reduced the incidence of grade ≥2 SDAEI by 50% (P = 0.016) compared with placebo. The incidence of all grade SDAEI was lower with doxycycline than with placebo but did not reach statistical significance. Doxycycline was associated with less deterioration in QoL compared with placebo. Alclometasone was associated with less deterioration in QoL compared with placebo but did not statistically significantly reduce the incidence of all grade or grade ≥2 SDAEI. VSL#3 did not reduce the incidence of all grade or grade ≥2 diarrhea and did not impact mucositis scores. CONCLUSIONS: Doxycycline was effective as a prophylactic treatment for dacomitinib-induced grade ≥2 SDAEI. Both doxycycline and alclometasone reduced the negative impact in patient-reported dermatologic AEs. The probiotic was not effective for preventing diarrhea or mucositis.

A phase II trial of dacomitinib, an oral pan-human EGF receptor (HER) inhibitor, as first-line treatment in recurrent and/or metastatic squamous-cell carcinoma of the head and neck.

BACKGROUND: An open-label, multicenter, single-arm phase II trial was conducted to investigate the clinical activity of dacomitinib in recurrent/metastatic squamous-cell carcinoma of the head and neck (RM-SCCHN). PATIENTS AND METHODS: Eligible patients were administered dacomitinib at 45 mg orally daily, in 21-day cycles. Primary end point was objective response rate. RESULTS: Sixty-nine patients were enrolled with a median age of 62 years. Among response-evaluable patients, 8 [12.7%, 95% confidence interval (CI) 5.6% to 23.5%] achieved a partial response and 36 (57.1%) had stable disease, lasting ≥24 weeks in 9 patients (14.3%). The median progression-free survival (PFS) was 12.1 weeks and the median overall survival (OS) was 34.6 weeks. Most adverse events (AEs) were tolerable. The most common grade 3 or higher treatment-related AEs were diarrhea (15.9%), acneiform dermatitis (8.7%), and fatigue (8.7%). Treatment-related AEs led to at least one dose interruption in 28 (40.6%) patients and dose reductions in 26 (37.7%). Permanent treatment discontinuation occurred in 8 (11.6%) patients due to treatment-related AEs. CONCLUSIONS: Dacomitinib demonstrated clinical activity in RM-SCCHN, and the primary end point of this study was met. The toxicity profile of this agent was generally manageable with dose interruptions and adjustments.

The effects of SCF/G-CSF prestimulation on radiation sensitivity and engraftment in nonmyeloablated murine hosts.

OBJECTIVE: Previous studies have shown improved engraftment in a murine model when granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) were administered for 5 days prior to irradiation, with significant levels of engraftment in the growth factor-preconditioned group even at very low radiation doses. We sought to explore the mechanisms behind this effect. METHODS: The radiation sensitivity of mice with or without 5 days of prestimulation with G-CSF (200 microg/kg/d) and SCF (50 microg/kg/d) was compared. To further evaluate whether growth factor prestimulation enhances engraftment by mobilization of hematopoietic progenitors into peripheral blood, thus creating less endogenous competition within the marrow compartment, female mice were pretreated with 5 days of G-CSF/SCF or control diluent. Engraftment of 40 x 10(6) peripheral blood stem cells (PBSCs) harvested from G-CSF/SCF-mobilized male mice was compared in the two recipient groups. RESULTS: There was no difference in survival between the pretreated and control mice at the radiation doses tested. Additionally, there was no significant difference in the recovery of blood counts, bone marrow cellularity, colony-forming unit (CFU) content, or stem cell numbers assessed 4 months later in a competitive repopulation model. Engraftment levels of male cells did not differ between G-CSF/SCF-pretreated and control recipients, and could be detected in 30% of recipients at 20-24 weeks (4/12 in each group) at overall levels of 0.1-1%. CONCLUSIONS: The enhanced engraftment in cytokine pretreated recipients is unlikely to be due to increased endogenous stem-cell killing or to the creation of endogenous marrow "space" by egress of endogenous stem cells after cytokine prestimulation.

In vivo persistence of retrovirally transduced murine long-term repopulating cells is not limited by expression of foreign gene products in the fully or minimally myeloablated setting.

Many nonmalignant hematologic disorders could potentially be treated by genetic correction of as few as 5-10% of target lineage cells. However, immune system clearance of cells expressing gene products perceived as foreign could be limiting. There is evidence that tolerance to foreign proteins can result when myeloablative conditioning is used, but this limits the overall applicability of such techniques. Therefore, we sought to evaluate the engraftment of hematopoietic stem cells carrying a foreign transgene after low-dose irradiation by comparing in vivo survival of murine long-term repopulating cells (LTRC) transduced with either a retroviral vector expressing the bacterial neomycin phosphotransferase gene (neo) or a vector containing neo gene sequences but modified to prevent protein expression (nonexpression). First, marrow cells from congenic donors were transduced with either vector and transplanted into recipients treated with standard dose irradiation of 800 rads. High-level engraftment and gene marking resulted, without differences in the marking levels or pattern of persistence of the cells between cells transduced with either vector. Low-dose irradiation at 100 rads was tested using higher cell doses. Marking levels as high as 10% overall were obtained, again with no differences between mice receiving cells transduced with the neo versus the nonexpression vectors. To investigate a potentially more immunogenic protein, marrow cells were transduced with a vector containing the green fluorescent protein (GFP) gene, and their persistence was studied in recipient mice receiving 100 rads. Stable GFP expression in 5-10% of circulating cells was observed long term. We conclude that even with very low dose conditioning, engraftment by genetically modified LTRC cells at clinically significant levels can be achieved without evidence for clearance of cells known to be expressing immunogenic proteins.

Invasive aspergillosis in human immunodeficiency virus-infected children.

BACKGROUND: Aspergillosis is an uncommon yet serious opportunistic infection in patients with AIDS. It has been extensively reported in HIV-infected adult patients. To our knowledge there are no studies that describe the epidemiology, clinical manifestations and outcome of aspergillosis in a large HIV-infected pediatric population. METHODS: We reviewed the records of all 473 HIV-infected children followed in the Pediatric Branch of the National Cancer Institute for 9 years from 1987 through 1995 for the presence of Aspergillus infection. RESULTS: Seven (1.5%) patients developed invasive aspergillosis during the study period. All patients had low CD4 counts reflecting severe immunosuppression. Sustained neutropenia (> 7 days) or corticosteroid therapy as a predisposing factor for invasive aspergillosis was encountered in only two patients (28%). Invasive pulmonary aspergillosis developed in five patients and cutaneous aspergillosis in two. The most common presenting features in patients with pulmonary aspergillosis were fever, cough and dyspnea. Patients with cutaneous aspergillosis were diagnosed during life and successfully treated with amphotericin B and surgery, whereas diagnosis of pulmonary aspergillosis was made clinically in only one patient. CONCLUSIONS: Aspergillosis is an uncommon but highly lethal opportunistic infection in HIV-infected children. Invasive pulmonary aspergillosis should be considered in the differential diagnosis in febrile, HIV-infected children with persistent pulmonary infiltrates.

Successful pregnancy after total body irradiation and bone marrow transplantation for acute leukaemia.

We report successful pregnancies in two young women (aged 24 and 20 years) following allogeneic bone marrow transplantation (BMT) for acute non-lymphoblastic leukaemia. Conditioning therapy consisted of cyclophosphamide (120 mg/kg) and total body irradiation (TBI, 12 Gy) in 2 Gy fractions once daily for 6 days or twice daily for 3 days. Graft-versus-host disease prophylaxis was with methotrexate alone. Both women were amenorrhoeic after BMT and gonadal testing indicated hypergonadotrophic hypogonadism. Both women had normal pregnancies (2 years and 5 years after BMT) resulting in normal healthy infants. Previously successful pregnancy has been reported after TBI in three women in whom the TBI dose was less than 8 Gy. Our cases illustrate that normal outcome of pregnancy is possible at even higher doses of TBI.

Allogeneic bone marrow transplantation for children with acute lymphoblastic leukemia conditioned with busulfan, cyclophosphamide and melphalan.

Children with acute lymphoblastic leukemia (ALL) undergoing allogeneic bone marrow transplantation (BMT) using total body irradiation (TBI)-containing conditioning regimens are at risk of substantial late sequelae affecting growth and endocrine functions. This has lead to the use of non-TBI or chemotherapy conditioning regimens for ALL patients in many centers. However, it is unknown whether chemotherapy conditioning results in improved antileukemic efficacy or reduced transplant-related toxicity. We report our experience using a chemotherapy conditioning regimen (busulfan (Bu), cyclophosphamide (CY) and melphalan (Mel)) in 26 consecutively enrolled children with ALL (group I). At a median follow-up of 58 months, event-free survival (EFS) for Bu/CY/Mel-treated patients was 27% (+/- 8.7), while the leukemic relapse rate was 49% (+/- 13). Regimen-related toxicity was severe in these patients: overall treatment-related mortality was 42%, while 50% of patients had interstitial pneumonitis and 35% of patients had severe hemorrhagic cystitis. A historical control group of 25 consecutively enrolled patients, mostly treated with TBI-containing regimens (group II), had an EFS of 36% (+/- 9.6%) and a leukaemic relapse rate of 45% (+/- 11) at a median follow-up of 117 months. We conclude that the Bu/CY/Mel conditioning regimen leads to severe transplant-related toxicity and did not significantly improve leukemic relapse rates.

Factors affecting hair regrowth after bone marrow transplantation.

Permanent alopecia after BMT has been reported as a side-effect associated with GVHD or after busulphan conditioning therapy, primarily in adults. We have reviewed children undergoing BMT to document the frequency of incomplete hair regrowth and to evaluate factors associated with this problem. Hair regrowth was studied in 74 children who survived > 6 months following BMT undertaken for malignant and non-malignant diseases. Alopecia was categorised as severe (< 50% of pre-transplant status), moderate (50-75%) or mild (> 75% but less than normal). Overall, 18 (24.3%) of 74 patients had mild (n = 5), moderate (n = 4) or severe (n = 9) alopecia. Risk factors for alopecia were presence of chronic GVHD (67%; p < 0.001), older age (p < 0.001) and prior cranial irradiation (42%; p = 0.03). Alopecia occurred in children receiving either busulphan (31%) or total body irradiation (16%; p = 0.15) as conditioning therapy. The highest frequency was seen in patients conditioned with busulphan with or without melphalan and who received prior cranial irradiation and/or developed chronic GVHD (75%). These data indicate that alopecia after BMT in children is a significant problem and confirm, in children, the previously noted association between alopecia and chronic GVHD and busulphan. Further risk factors of older age and prior cranial irradiation are identified. Consideration needs to be given to the use of an alternative to busulphan in children who are of older age, have received prior cranial irradiation and/or are at increased risk of GVHD.

Epidemic iatrogenic Acinetobacter spp. meningitis following administration of intrathecal methotrexate.

We report the first outbreak of Acinetobacter species meningitis in a group of children with acute leukaemia following the administration of intrathecal chemotherapy. Eight of twenty patients receiving methotrexate injections on a single day developed signs and symptoms of meningitis within 18 h of treatment, and cases were clustered by time of administration. A cohort study comparing case and non-case patients did not identify any specific host factor associated with meningitis. Acinetobacter calcoaceticus var anitratus was isolated from the cerebrospinal fluid (CSF) of five patients; three patients died. Our investigation determined that the methotrexate was extrinsically contaminated by reused needles, used for reconstitution and administration, which had been inadequately sterilized. Acinetobacter calcoaceticus var anitratus was isolated from an autoclaved needle and a vial of methotrexate used for chemotherapy; these and the clinical isolates had similar antibiograms. After introduction of single-use disposable needles no subsequent cases occurred.

Limitations of the therapeutic regimens for myelodysplastic syndrome.

Thirty patients of myelodysplastic syndrome (MDS) were treated over a period of 2 yr using 3 different treatment regimens. Twelve patients received hydroxyurea, 4 were given low dose cytosine arabinoside and 14 others were treated with an aggressive acute myeloid leukaemia (AML) induction regimen. A low complete remission was obtained in the first 2 groups (17 and 25% respectively), whereas 9 (64%) patients attained complete remission with the AML induction regimen. Remission in the latter group was associated with prolonged and severe pancytopenia requiring intensive support. Patients in all the 3 groups had a short duration of remission culminating in death with progressive marrow failure or evolution to AML, indicating the limitations of the current treatment strategies for MDS and highlighting the need for exploring newer therapeutic approaches.

Spontaneous complete remission in acute lymphoblastic leukaemia.

Case records of 78 patients of acute lymphoblastic leukemia have been reviewed. Complete remission occurred in seven cases following an episode of septicemia and supportive care.

Acute lymphoblastic leukemia in childhood: treatment, results and prognostic factors.

Two hundred and nine children (20 years and below) diagnosed as acute lymphoblastic leukemia between January 1980 and December 1983 were retrospectively analysed to evaluate the clinical features, prognostic factors and the results of therapy. One hundred and eighty one evaluable patients were treated with three different chemotherapy regimens consisting of vincristine and prednisolone (Group-A), vincristine, prednisolone and L-asparaginase (Group B-60 patients), and vincristine, prednisolone and adriamycin (Group C-81 patients). Complete remission was achieved in 152 (84%) patients, remission induction being 75 percent, 85 percent and 88 percent in Group A, B and C respectively. At a median follow-up of 36 months the disease free survival for complete responders was 35.5 patient. The disease-free survival for Group A, B and C was 20 percent, 47 percent 34 percent respectively indicating the superiority of a three drug regimen over the conventional two drug regimen. Patients at standard risk in each group had significantly better survival when compared to those at high risk. A 3-drug treatment regimen was superior to the 2-drug regimen and a low initial leucocyte count was an important favourable prognostic factor.

Cytotoxic therapy. Role of durable venous access.

Aggressive chemotherapy regimens and supportive measures in haemato-oncology patients demand reliable venous access. Experience with this method in India has been limited. During a period of six months, we have used 42 subclavian indwelling catheters and 31 cubital Cavafix long lines. The mean age of patients in the two groups was 32 years and 7 years respectively. Subclavian catheters had a median duration of catheter placement of 46 days (range 4-145) and total 1494 catheter days, while cubital longlines yielded a median duration of insertion of 14 days (range 4-27) and total 508 catheter days. Catheter related complications were infection in 25% of patients, thrombophlebitis in 22%, blockade in 12% and misplacement in 17% in both groups taken together. The patients and families were extremely satisfied with the devices. Our experience supports further use of durable venous access in cancer patients. Implanted central venous catheters should be preferred whenever feasible.

Oral and dental phenotype of dyskeratosis congenita.

Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome that is characterized by lacey reticular hyperpigmentation of the skin, dystrophic nails, mucous membrane leukoplakia and pancytopenia. Diagnosis may be delayed until clinical signs are apparent. Severe pancytopenia frequently causes early mortality of DC patients, who have an increased risk of developing oropharyngeal squamous cell carcinoma. Several case reports have described oral changes in DC, which include oral leukoplakia, increased dental caries, hypodontia, thin enamel structure, aggressive periodontitis, intraoral brown pigmentation, tooth loss, taurodontism and blunted roots. We determined the prevalence of these previously reported findings in a cohort of 17 patients with DC and 23 family members. The most common oral changes in DC patients were oral leukoplakia (65% of the entire DC population), decreased root/crown ratio (75% with sufficient tooth development) and mild taurodontism (57% with sufficient tooth development). From the clinical perspective, a diagnosis of DC or other inherited bone marrow failure syndrome should be considered in young persons with oral leukoplakia, particularly those with no history of smoking. Multiple permanent teeth with decreased root/crown ratios further suggest DC.