Isolation, identification, and screening of biosurfactant-producing and hydrocarbon-degrading bacteria from oil and gas industrial waste

Qatar is one of the biggest oil and gas producers in the world, coupled with it is challenging environmental conditions (high average temperature: >40 °C, low annual rainfall: 46.71 mm, and high annual evaporation rate: 2200 mm) harbors diverse microbial communities that are novel and robust, with the potential to biodegrade hydrocarbons. In this study, we collected hydrocarbon contaminated sludge, wastewater and soil samples from oil and gas industries in Qatar. Twenty-six bacterial strains were isolated in the laboratory from these samples using high saline conditions and crude oil as the sole carbon source. A total of 15 different bacterial genera were identified in our study that have not been widely reported in the literature or studied for their usage in the biodegradation of hydrocarbons. Interestingly, some of the bacteria that were identified belonged to the same genus however, demonstrated variable growth rates and biosurfactant production. This indicates the possibility of niche specialization and specific evolution to acquire competitive traits for better survival. The most potent strain EXS14, identified as Marinobacter sp., showed the highest growth rate in the oil-containing medium as well as the highest biosurfactant production. When this strain was further tested for biodegradation of hydrocarbons, the results showed that it was able to degrade 90 to 100% of low and medium molecular weight hydrocarbons and 60 to 80% of high molecular weight (C35 to C50) hydrocarbons. This study offers many promising leads for future studies of microbial species and their application for the treatment of hydrocarbon contaminated wastewater and soil in the region and in other areas with similar environmental conditions.

Rhino-orbito-cerebral mucormycosis: patient characteristics in pre-COVID-19 and COVID-19 period

Background: Rhino-orbito-cerebral-mucormycosis (ROCM), a rare and potentially fatal disease was seen in increasing numbers during the COVID-19 pandemic. This study describes and compares the patient characteristics and outcomes in COVID-19 associated mucormycosis (CAM) and non-COVID-19 mucormycosis (non-CAM). Methodology: CAM patients (24 cases) were recruited from the COVID-19 period and non-CAM (24 controls) from the pre-COVID-19 period. Clinical data of the CAM group was collected retrospectively with 3 month outcomes prospectively. The non-CAM group data was collected retrospectively. Patient characteristics were compared and risk factors for mortality in ROCM were assessed. Results: Orbital symptoms [altered vision, restricted eye movements, ptosis] and intracranial involvement were higher in CAM patients on presentation. Similarly, the radiological involvement of orbit (orbital apex, superior orbital fissure) and intracranial cavity (intracranial thrombosis, cavernous sinus) was also higher in CAM patients. Newly detected diabetes was found only in CAM patients (29.2%). Although univariate analysis suggested an increased mortality risk in ROCM patients with orbital involvement, the multivariate analysis showed no increased risk with any of the parameters assessed, including COVID-19 positivity. Conclusions: Compared to the non-CAM, the disease presentation was severe in CAM with higher frequency of orbital and intracranial involvement. However, with early detection and treatment, the short term survival was comparable in both groups.

Effect of Foot Reflexology on Reduction of Labour Pain Among Primigravida Mothers

BACKGROUND

Reflexology may help induce labour and reduce pain during childbirth. Fear of pain associated with childbirth leads to increase in the irregular use of cesarean method.

PURPOSE

This study was performed to evaluate the effect of reflexology on relieving labour pain and assess the recipient's opinion regarding foot reflexology.

SETTING

The study taken place in the labour room, Amrita Institute of Medical Sciences, Kerala, South India.

PARTICIPANTS

50 primigravida patients experiencing labour.

RESEARCH DESIGN

A quasi-experimental study design was used. Subjects were selected by convenience sampling technique with the first 25 patients allocated to the experimental group and the successive 25 primigravida mothers to a time-control group, to avoid data contamination.

INTERVENTION

Intervention consisted of foot reflexology applied by a trained therapist to five pressure points of both feet that correspond to the uterus. Total intervention time lasted 20 minutes. Control group rested quietly for 20 minutes to serve as a time control.

MAIN OUTCOME MEASURES

Pain associated with labour was recorded on a visual analogue scale immediately prior to intervention, and at 20- and 40-minutes postintervention. Patient satisfaction with reflexology treatment was recorded.

RESULTS

Mean baseline pain score in foot reflexology group was significantly reduced across the study timeframe relative to control group (p < .001). Post hoc tests confirmed a reduction in labour pain at both the 20-min (p < .001, 95%CI 0.764-1.796) and 40-min (p < .001, 95%CI 0.643-1.677) time points. Eighty-one per cent of patients would recommend reflexology during labour.

CONCLUSION

The findings showed that foot reflexology was effective in relief of labour pain, with a high degree of patient satisfaction in primigravida mothers.

Noncanonical effector functions of the T-memory-like T-PLL cell are shaped by cooperative TCL1A and TCR signaling

T-cell prolymphocytic leukemia (T-PLL) is a poor-prognostic neoplasm. Differentiation stage and immune-effector functions of the underlying tumor cell are insufficiently characterized. Constitutive activation of the T-cell leukemia 1A (TCL1A) oncogene distinguishes the (pre)leukemic cell from regular postthymic T cells. We assessed activation-response patterns of the T-PLL lymphocyte and interrogated the modulatory impact by TCL1A. Immunophenotypic and gene expression profiles revealed a unique spectrum of memory-type differentiation of T-PLL with predominant central-memory stages and frequent noncanonical patterns. Virtually all T-PLL expressed a T-cell receptor (TCR) and/or CD28-coreceptor without overrepresentation of specific TCR clonotypes. The highly activated leukemic cells also revealed losses of negative-regulatory TCR coreceptors (eg, CTLA4). TCR stimulation of T-PLL cells evoked higher-than-normal cell-cycle transition and profiles of cytokine release that resembled those of normal memory T cells. More activated phenotypes and higher TCL1A correlated with inferior clinical outcomes. TCL1A was linked to the marked resistance of T-PLL to activation- and FAS-induced cell death. Enforced TCL1A enhanced phospho-activation of TCR kinases, second-messenger generation, and JAK/STAT or NFAT transcriptional responses. This reduced the input thresholds for IL-2 secretion in a sensitizer-like fashion. Mice of TCL1A-initiated protracted T-PLL development resembled such features. When equipped with epitope-defined TCRs or chimeric antigen receptors, these Lckpr-hTCL1Atg T cells gained a leukemogenic growth advantage in scenarios of receptor stimulation. Overall, we propose a model of T-PLL pathogenesis in which TCL1A enhances TCR signals and drives the accumulation of death-resistant memory-type cells that use amplified low-level stimulatory input, and whose loss of negative coregulators additionally maintains their activated state. Treatment rationales are provided by combined interception in TCR and survival signaling.

Health professionals' views about who would benefit from using a closed-loop system: a qualitative study

AIM

To explore health professionals' views about who would benefit from using a closed-loop system and who should be prioritized for access to the technology in routine clinical care.

METHODS

Health professionals (n = 22) delivering the Closed Loop from Onset in type 1 Diabetes (CLOuD) trial were interviewed after they had ≥ 6 months' experience supporting participants using a closed-loop system. Data were analysed thematically.

RESULTS

Interviewees described holding strong assumptions about the types of people who would use the technology effectively prior to the trial. Interviewees described changing their views as a result of observing individuals engaging with the closed-loop system in ways they had not anticipated. This included educated, technologically competent individuals who over-interacted with the system in ways which could compromise glycaemic control. Other individuals, who health professionals assumed would struggle to understand and use the technology, were reported to have benefitted from it because they stood back and allowed the system to operate without interference. Interviewees concluded that individual, family and psychological attributes cannot be used as pre-selection criteria and, ideally, all individuals should be given the chance to try the technology. However, it was recognized that clinical guidelines will be needed to inform difficult decisions about treatment allocation (and withdrawal), with young children and infants being considered priority groups.

CONCLUSIONS

To ensure fair and equitable access to closed-loop systems, prejudicial assumptions held by health professionals may need to be addressed. To support their decision-making, clinical guidelines need to be made available in a timely manner.

Identifying factors that influence the '6-hour target' in the Emergency Department by applying Regression Analysis

AIM

To determine factors within the Emergency Department (ED) that have maximum influence on the '6-hour target'.

METHODS

Regression Analysis methodology employed to analyse the influence of 9 ED variables on the '6-hour target' compliance.

RESULTS

The number of patients waiting to be seen an ED physician at 8pm exerts maximum influence on the '6-hour target' (r = -0.581, p<0.05).

CONCLUSION

The '6-hour target' compliance rises with lesser number of patients waiting to be seen by an ED physician at 8pm. Also, the '6-hour target' compliance rises by increasing the number of ED Registrar working hours and the number of ED SHO working hours per day.

Ethyl pyruvate, a modulator of dendritic cell activation and survival (INM1P.437)

Danger Signals induce dendritic cells (DCs) to mature and present antigen in a pro-inflammatory context. When remaining immature however, DCs confer tolerance. Hence the need for new protocols inducing tolerogenic DCs. We assessed the effects of ethyl pyruvate (EP), ester derivative of pyruvate with anti-inflammatory properties, on DC responses. We found that EP (10mM) abolished pro-inflammatory cytokine induction (IL-12, TNFa, IL-6) by the TLR ligand and strong DC activator LPS in bone marrow-derived dendritic cells (BMDCs) at 8, 24, 48 and 72h post-stimulation. Furthermore, EP inhibited the IFN-I response and the anti-inflammatory cytokine IL-10 induced by LPS stimulation. Determining the effects of EP on BMDC viability with a dose titration response showed that EP (10mM) strongly inhibited in vitro DC activation without inducing death. Moreover, EP could prevent LPS-induced killing that normally occurs 72h post-stimulation. EP also decreased the up-regulation of BMDC surface MHC-II and co-stimulatory molecules, suggesting a role in inhibiting antigen presentation. Investigating the mechanism of action, EP decreased Erk and JNK phosphorylation but not p38 phosphorylation. Our results indicate that EP inhibits most of the biological responses of DCs to LPS. We are currently examining further the molecular mechanisms of EP’s action in BMDCs to highlight novel targets to inhibit DC activation.

Clinical effectiveness of a sedation protocol minimizing benzodiazepine infusions and favoring early dexmedetomidine: a before-after study

Introduction

Randomized controlled trials suggest clinical outcomes may be improved with dexmedetomidine as compared with benzodiazepines; however, further study and validation are needed. The objective of this study was to determine the clinical effectiveness of a sedation protocol minimizing benzodiazepine use in favor of early dexmedetomidine.

Methods

We conducted a before-after study including adult surgical and medical intensive care unit (ICU) patients requiring mechanical ventilation and continuous sedation for at least 24 hours. The before phase included consecutive patients admitted between 1 April 2011 and 31 August 31 2011. Subsequently, the protocol was modified to minimize use of benzodiazepines in favor of early dexmedetomidine through a multidisciplinary approach, and staff education was provided. The after phase included consecutive eligible patients between 1 May 2012 and 31 October 2012.

Results

A total of 199 patients were included, with 97 patients in the before phase and 102 in the after phase. Baseline characteristics were well balanced between groups. Use of midazolam as initial sedation (58% versus 27%, P <0.0001) or at any point during the ICU stay (76% versus 48%, P <0.0001) was significantly reduced in the after phase. Dexmedetomidine use as initial sedation (2% versus 39%, P <0.0001) or at any point during the ICU stay (39% versus 82%, P <0.0001) significantly increased. Both the prevalence (81% versus 93%, P =0.013) and median percentage of days with delirium (55% (interquartile range (IQR), 18 to 83) versus 71% (IQR, 45 to 100), P =0.001) were increased in the after phase. The median duration of mechanical ventilation was significantly reduced in the after phase (110 (IQR, 59 to 192) hours versus 74.5 (IQR, 42 to 148) hours, P =0.029), and significantly fewer patients required tracheostomy (20% versus 9%, P =0.040). The median ICU length of stay was 8 (IQR, 4 to 12) days in the before phase and 6 (IQR, 3 to 11) days in the after phase (P =0.252).

Conclusions

Implementing a sedation protocol that targeted light sedation and reduced benzodiazepine use led to significant improvements in the duration of mechanical ventilation and the requirement for tracheostomy, despite increases in the prevalence and duration of ICU delirium.

Ethyl pyruvate, an inhibitor of high-mobility group box 1 (HMGB1) release, modulates dendritic cell activation and survival (TRAN3P.897)

Dendritic cells (DCs) activated by stimulatory danger signals initiate the detrimental anti-graft immune responses that lead to transplant rejection. High-mobility group box1 (HMGB1) is a nuclear DNA-binding protein that signals danger if released, contributing to DC activation and acute allograft rejection. Preventing HMGB1 release is a way to block its effects, promoting less active DCs. Here we assessed the effects of ethyl pyruvate (EP), proposed to potentially prevent HMGB1 release from cells, on DC responses. We found that EP (10mM) abolished pro-inflammatory cytokine (IL-12, IL-6 and TNFa) and IL-10 induction by the strong DC stimulus LPS in myeloid bone marrow-derived dendritic cells (BMDCs). EP also significantly decreased BMDC surface MHC expression, suggesting a possible role in inhibiting antigen presentation. We also determined EP effects on BMDC viability and found that EP strongly inhibited in vitro DC activation without inducing death. Furthermore, EP could prevent LPS-induced apoptosis that normally occurs 72h post-stimulation. Moreover, EP suppressed DC responses to other TLR stimuli including CpGs and R848. Our results indicate that EP inhibits most of the biological responses of DCs to LPS and other TLR stimuli. We are investigating the link between EP and HMGB1 release prevention from BMDCs. Testing the effect of HMGB1 blockade on DC activation will highlight a novel target to induce tolerogenic DCs and prolong solid organ graft survival.

IL-4 suppresses the responses to TLR7 and TLR9 stimulation and increases the permissiveness to retroviral infection of murine conventional dendritic cells

Th2-inducing pathological conditions such as parasitic diseases increase susceptibility to viral infections through yet unclear mechanisms. We have previously reported that IL-4, a pivotal Th2 cytokine, suppresses the response of murine bone-marrow-derived conventional dendritic cells (cDCs) and splenic DCs to Type I interferons (IFNs). Here, we analyzed cDC responses to TLR7 and TLR9 ligands, R848 and CpGs, respectively. We found that IL-4 suppressed the gene expression of IFNβ and IFN-responsive genes (IRGs) upon TLR7 and TLR9 stimulation. IL-4 also inhibited IFN-dependent MHC Class I expression and amplification of IFN signaling pathways triggered upon TLR stimulation, as indicated by the suppression of IRF7 and STAT2. Moreover, IL-4 suppressed TLR7- and TLR9-induced cDC production of pro-inflammatory cytokines such as TNFα, IL-12p70 and IL-6 by inhibiting IFN-dependent and NFκB-dependent responses. IL-4 similarly suppressed TLR responses in splenic DCs. IL-4 inhibition of IRGs and pro-inflammatory cytokine production upon TLR7 and TLR9 stimulation was STAT6-dependent, since DCs from STAT6-KO mice were resistant to the IL-4 suppression. Analysis of SOCS molecules (SOCS1, −2 and −3) showed that IL-4 induces SOCS1 and SOCS2 in a STAT6 dependent manner and suggest that IL-4 suppression could be mediated by SOCS molecules, in particular SOCS2. IL-4 also decreased the IFN response and increased permissiveness to viral infection of cDCs exposed to a HIV-based lentivirus. Our results indicate that IL-4 modulates and counteracts pro-inflammatory stimulation induced by TLR7 and TLR9 and it may negatively affect responses against viruses and intracellular parasites.

Myeloid dendritic cells from B6.NZM Sle1/Sle2/Sle3 lupus-prone mice express an IFN signature that precedes disease onset

Patients with systemic lupus erythematosus show an overexpression of type I IFN-responsive genes that is referred to as "IFN signature." We found that B6.NZMSle1/Sle2/Sle3 (Sle1,2,3) lupus-prone mice also express an IFN signature compared with non-autoimmune C57BL/6 mice. In vitro, myeloid dendritic cells (mDCs) (GM-CSF bone marrow-derived dendritic cells; BMDCs) from Sle1,2,3 mice constitutively overexpressed IFN-responsive genes such as IFN-β, Oas-3, Mx-1, ISG-15, and CXCL10 and members of the IFN signaling pathway STAT1, STAT2, and IRF7. The IFN signature was similar in Sle1,2,3 BMDCs from young, pre-autoimmune mice and from mice with high titers of autoantibodies, suggesting that the IFN signature in mDCs precedes disease onset and is independent from the autoantibodies. Sle1,2,3 BMDCs hyperresponded to stimulation with IFN-α and the TLR7 and TLR9 agonists R848 and CpGs. We propose that this hyperresponse is induced by the IFN signature and only partially contributes to the signature, as oligonucleotides inhibitory for TLR7 and TLR9 only partially suppressed the constitutive IFN signature, and pre-exposure to IFN-α induced the same hyperresponse in wild-type BMDCs as in Sle1,2,3 BMDCs. In vivo, mDCs and to a lesser extent T and B cells from young prediseased Sle1,2,3 mice also expressed the IFN signature, although they lacked the strength that BMDCs showed in vitro. Sle1,2,3 plasmacytoid DCs expressed the IFN signature in vitro but not in vivo, suggesting that mDCs may be more relevant before disease onset. We propose that Sle1,2,3 mice are useful tools to study the role of the IFN signature in lupus pathogenesis.

Type I IFN Signature in plasmacytoid dendritic cells from young Sle 1,2,3 lupus prone mice. (171.1)

The importance of the Type I Interferon (IFN) Signature in systemic lupus erythmatosus is well documented in patients and mouse models. We have earlier observed a distinct IFN gene Signature in the myeloid dendritic cells (mDC) of young Sle 1,2,3 lupus prone mice. In this study, we grew bone-marrow precursors in the presence of Flt3L to generate plasmacytoid dendritic cells (pDC) and analyzed the IFN Signature. The percentage of pDCs generated in culture did not differ between the Sle and the control C57BL/6 (B6) mice. We sorted pDCs (B220+CD11c+) and mDCs (CD11c+CD11b+) from the culture and analyzed the constitutive expression of IFN responsive genes (IFNb, IRF7, ISG15, Mx-1 and CXCL10) by real-time RT-PCR as sign of IFN Signature. There was minimal IFNb expression in both B6 and Sle pDCs; while the IFNb expression in mDCs was higher and much higher in Sle vs B6 mDCs like we observe in cultures supplemented with GMCSF. IRF7 gene expression was higher in pDCs than mDCs and much higher in Sle pDCs. The expression of the other genes in pDCs was lower than in mDCs in both strains, although in Sle pDCs their expression was higher than in B6 pDCs. Our results indicate that plasmacytoid DCs from young pre-diseased Sle1,2,3 lupus prone mice express an IFN Signature similarly to lupus myeloid DCs. Moreover, these results highlight the important role for IRF7 in the activation of lupus pDCs and suggest a probable mechanism for the hyper-activation of the IFN Signature in lupus.

Role of PAMPs and DAMPs in Graft Rejection (126.6)

Dendritic cells (DCs) induce immunity or tolerance depending on the presence of danger signals. LPS is a danger signal with multiple effects on DCs, besides activation. Unpublished results from our lab show that LPS induces DC death in vitro and in vivo. It has also been reported that DCs treated with LPS during their development remained immature and induced T cell anergy. LPS triggers TLR4, a PRR also stimulated by endogenous danger signals, like HMGB1, released during tissue damage. We used a mouse transplant model to determine the effects of simultaneous exposure to LPS and endogenous danger signals, released during engraftment, on DC functions and graft survival. We used the single minor male-specific H-Y antigen mismatch. We transplanted skin of male C57BL/6 mice onto syngeneic female recipients. We administered 4 i.p. injections of 12.5ug/mouse of LPS or PBS every other day. Control mice rejected male skin graft in 24-34 days, as expected, while mice treated with LPS did not reject the graft until 64 days or later. Studying the DCs migrating out of the graft, we found a sharp decrease of DCs 48 hours post transplant and the DC loss was more severe after LPS. LPS also decreased the number of DCs with high surface expression of MHC class II. These findings suggest that the combination of endogenous danger signals released during engraftment and LPS are either killing the DCs or preventing them from maturing thus allowing for tolerance of the male skin graft.

SOCS molecules are upregulated during IL-4-induced inhibition of Type I interferon responses in murine myeloid dendritic cells. (57.23)

We have previously reported that IL-4 suppresses the response of murine myeloid dendritic cells (mDCs) to Type I interferons (IFN). We are now investigating the molecular mechanisms of this inhibition in myeloid bone marrow-derived DCs (BMDCs). We have found that sub-optimal doses of IL-4 (down to 0.25ng/mL) can still suppress IFN-a induced gene expression and phosphorylation of STAT1 and STAT2, suggesting that IL-4 acts at the level or upstream of STAT molecules in the Type I IFN signaling pathway. IL-4 suppresses when administered before and also after Type I IFN stimulation and it inhibits the response of DCs to the autocrine IFN-b that is induced upon IFN-a stimulation, acting on its positive feedback loop. The inhibition of protein synthesis by Cyclohexamide (CHX) abrogated the suppressive effects of IL-4 indicating that IL-4 represses Type I IFN signaling through the upregulation of a protein. We then tested the expression of the SOCS molecules as immediate candidates that negatively regulate Type I IFN signaling and are regulated at the transcription level. The gene expression of SOCS-1was highly induced by IL-4 treatment and was synergistically upregulated in the presence of IL-4 and IFN-a; the levels drastically went down when DCs were pretreated with CHX, suggesting that SOCS-1 maybe one of the key players in suppressing the IFN responses. We are currently testing this hypothesis by silencing SOCS-1 expression in DCs.

Intrinsic interferon signature in myeloid dendritic cells from lupus-prone mice precedes disease onset (47.1)

Systemic Lupus Erythematosus (SLE) patients over-express Type I Interferon (IFN) responsive genes but the cellular source of this IFN Signature is unclear. We found that ex vivo dendritic cells (DCs) from Sle1,2,3 lupus-prone mice express the IFN Signature. To test if the IFN Signature was intrinsic to DCs, we grew myeloid DCs in vitro from bone marrow in GM-CSF medium (BMDCs), and found that IFN responsive genes, analyzed by real-time RT-PCR, are constitutively over-expressed in Sle1,2,3 BMDCs as compared to non-autoimmune C57BL/6 BMDCs: expression of IFN-b, signaling molecules IRF-7, STAT1 and STAT2, and IFN responsive genes ISG-15, IL-15, Oas-3 and Mx1, was significantly higher in lupus BMDCs than in C57BL/6 BMDCs in absence of any stimulation. The IFN Signature was similar in BMDCs from mice negative for autoAbs and from mice with high autoAb titers, suggesting that the IFN Signature precedes disease onset and is not affected by the autoimmune process. Sle1,2,3 BMDCs were hyper-sensitive to nucleic acids CpGs and R848, confirming a role for TLR7 and TLR9 in lupus pathogenesis. However, treatment with oligonucleotide sequences inhibitory for TLR7/TLR9 did not suppress the constitutive over-expression of IFN responsive genes, indicating that DC IFN Signature is independent from chronic exposure to TLR7/9 ligands. We suggest that myeloid DCs are a source of IFN Signature in Sle1,2,3 mice and have an intrinsic dysregulation in the IFN signaling/response.

Primitive Neuroectodermal Tumor of the Uterus

A case of primitive neuroectodermal tumor arising in the uterine corpus of a 43-year-old woman is presented. The tumor mass was 13.3 cm and extended to the uterine serosa, endocervical stroma, and left adnexa. Histologically, the tumor was composed of small blue cells with scant cytoplasm, indistinct cell borders, hyperchromatic round nuclei, and inconspicuous nucleoli focally forming pseudorosettes, suggestive of neuroectodermal origin. The tumor cells displayed strong immunoreactivity for CD99 and FLI1. Cytogenetic fluorescence in situ hybridization study revealed presence of an EWS-FLI1 fusion gene. To the best of our knowledge, this is the first case of primitive neuroectodermal tumor of the uterus with diagnosis confirmed by FLI1 immunohistochemical labeling and demonstration of t (11; 22) by fluorescence in situ hybridization.

Lymphocytic colitis treated with proctocolectomy and ileal J-pouch-anal anastomosis: report of a case

PURPOSE

We present a case of severe diarrhea caused by lymphocytic colitis and concurrent celiac sprue in a patient who did not respond to maximal medical therapy and required surgery.

METHODS

The patient was initially treated with fecal diversion via an end ileostomy. Six months later, she underwent colectomy and one-stage ileal J-pouch-anal anastomosis.

RESULTS

Notably, the characteristic microscopic changes of lymphocytic colitis were still present at the time of colectomy despite diversion.

CONCLUSION

Colectomy with continent reconstruction is an option for treatment of patients with lymphocytic colitis refractory to medical therapy.

Acute promyelocytic leukemia. New methods in diagnosis and treatment

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia characterized by hypergranular leukemic cells, bleeding diathesis and t(15; 17) translocation. The t(15; 17) translocation leads to the production of the PML-RAR alpha fusion protein which plays a vital role in the pathogenesis of APL by arresting normal differentiation of myeloid precursors. However, in the presence of high concentrations of all-trans-retinoic acid (ATRA), the PML-RAR alpha fusion protein serves to stimulate cell differentiation. The diagnosis of APL and the detection of residual disease are based on the t(15; 17) translocation. Treatment with a combination of ATRA and anthracycline-AraC chemotherapy has shown a higher rate of complete remission in APL. We report the case of a 71-year-old male with the rare microgranular variant of APL to illustrate these findings. The patient was treated with a combination of ATRA and Daunorubicin-AraC chemotherapy and achieved complete remission. He developed retinoic acid syndrome as a complication of therapy with ATRA. The methods for diagnosis, the molecular mechanisms in the oncogenesis of APL, rationale of treatment of APL with ATRA, complications of therapy and the new concepts in the treatment of ATRA-resistant APL are discussed.

Invariant characterization of neural systems

It is shown that the invariant integral, viz., the Kolmogorov second entropy, is eminently suited to characterize EEG quantitatively. The estimation obtained for a "clinically normal" brain is compared with a previous result obtained from the EEG of a person under epileptic seizure.