Mechanisms of blood homeostasis: lineage tracking and a neutral model of cell populations in rhesus macaques

Background

How a potentially diverse population of hematopoietic stem cells (HSCs) differentiates and proliferates to supply more than 10¹¹ mature blood cells every day in humans remains a key biological question. We investigated this process by quantitatively analyzing the clonal structure of peripheral blood that is generated by a population of transplanted lentivirus-marked HSCs in myeloablated rhesus macaques. Each transplanted HSC generates a clonal lineage of cells in the peripheral blood that is then detected and quantified through deep sequencing of the viral vector integration sites (VIS) common within each lineage. This approach allowed us to observe, over a period of 4-12 years, hundreds of distinct clonal lineages.

Results

While the distinct clone sizes varied by three orders of magnitude, we found that collectively, they form a steady-state clone size-distribution with a distinctive shape. Steady-state solutions of our model show that the predicted clone size-distribution is sensitive to only two combinations of parameters. By fitting the measured clone size-distributions to our mechanistic model, we estimate both the effective HSC differentiation rate and the number of active HSCs.

Conclusions

Our concise mathematical model shows how slow HSC differentiation followed by fast progenitor growth can be responsible for the observed broad clone size-distribution. Although all cells are assumed to be statistically identical, analogous to a neutral theory for the different clone lineages, our mathematical approach captures the intrinsic variability in the times to HSC differentiation after transplantation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12915-015-0191-8) contains supplementary material, which is available to authorized users.

Confirmation of TTC8 as a disease gene for nonsyndromic autosomal recessive retinitis pigmentosa (RP51)

Nonsyndromic retinitis pigmentosa (RP) is genetically highly heterogeneous, with >100 disease genes identified. However, mutations in these genes explain only 60% of all RP cases. Blood samples were collected from 12 members of an autosomal recessive RP family. Whole genome homozygosity mapping and haplotype analysis placed the RP locus in this family at chromosome 14q31.3. Whole-exome sequencing (WES) in proband revealed a mutation in TTC8, which was flagged as most likely candidate gene by bioinformatic analysis. TTC8 is mutated in Bardet-Biedl syndrome 8 (BBS8), and once reported previously in a family with nonsyndromic RP. Sequencing of amplified products of exon 13 of TTC8 validated c.1347G>C (p.Gln449His), a novel change that affects the final nucleotide of exon 13 and might deleteriously affect splicing. This mutation segregated completely with the disease in the family and was not observed in 100 ethnically matched controls from same population. This represents second report of a TTC8 mutation in nonsyndromic RP, thus confirming the identity of TTC8 as causative gene for RP51.

MARKER ASSISTED EVALUATION OF MORPHOLOGICAL AND GENETIC ATTRIBUTES OF SUB-POPULATIONS OF NILI-RAVI BUFFALO: A VULNERABLE DAIRY TYPE RIVERINE BREED OF INDIA

In the present study, we report the distribution of true to type and atypical Nili-Ravi buffalo, a vulnerable dairy type riverine breed of North India and its underlying genetic structure. Out of total investigated buffaloes 73.5% had bilateral wall eyes while 5.4% had unilateral wall eyes and 21.1% had no wall eyes. 41.15% of Nili-Ravi buffaloes maintained in the breeding farm were having typical true to the type characteristics (both eyes walled, white markings in forehead, muzzle/chin, all the four legs and tail) while only 28.5% of Nili-Ravi buffaloes were true to the type under field conditions. Genotypic data were generated in four groups of Nili-Ravi buffalo (FMTNR--Typical Nili-Ravi from farm; FMANR--Atypical Nili-Ravi from farm; FDTNR--Typical Nili-Ravi from field; FDANR--Atypical Nili-Ravi from field) at 16 microsatellite loci. Comparative genetic analysis of various groups of Nili-Ravi buffaloes with Murrah revealed significant between group differences with an estimated global F(ST) of 0.063. Pair-wise F(ST) values ranged from 0.003 (between FDTNR and FDANR) to 0.112 (between FMTNR and FDTNR). Phylogenetic analysis and multi-dimensional scaling revealed clustering of FDTNR and FDANR together while FMTNR and FMANR clustered separately with Murrah in between farm and field Nili-Ravi buffaloes. Based on the results, the paper also proposes three pronged strategy for conservation and sustainable genetic improvement of Nili-Ravi buffalo in India.

Comparison of the Effects of Zonisamide, Ethosuximide and Pregabalin in the Chronic Constriction Injury Induced Neuropathic Pain in Rats

Background:

Evidence has been generated that various anticonvulsant agents provide relief of several chronic pain syndromes and therefore as an alternative to opioids, nonsteroidal anti-inflammatory, and tricyclic antidepressant drugs in the treatment of neuropathic pain. The results of these studies thus raise the question of whether all anticonvulsant drugs or particular mechanistic classes may be efficacious in the treatment of neuropathic pain syndromes.

Aim:

The aim was to compare the clinically used anticonvulsant drugs which are differ in their mechanism of action in a chronic pain model, the chronic constriction injury, in order to determine if all anticonvulsants or only particular mechanistic classes of anticonvulsants are analgesic.

Materials and Methods:

The study included zonisamide, ethosuximide and pregabalin. All compounds were anticonvulsant with diverse mechanism of actions. The peripheral neuropathic pain was induced by chronic constriction injury of the sciatic nerve in male Sprague-Dawley rats. Zonisamide (80 and 40 mg/kg), ethosuximide (300 and 100 mg/kg), pregabalin (50 and 20 mg/kg), and saline was administered intraperitoneally in respective groups in a blinded, randomized manner from postoperative day (POD) 7-13. Paw withdrawal duration to spontaneous pain, chemical allodynia and mechanical hyperalgesia and paw withdrawal latency to mechanical allodynia and thermal hyperalgesia were tested before drug administration on POD7 and after administration on POD 7, 9, 11 and 13.

Results:

The present study suggests that these drugs could provide an effective alternative in the treatment of neuropathic pain. However, zonisamide and pregabalin appears to have suitable efficacy to treat a wide spectrum of neuropathic pain condition.

Conclusion:

The present findings suggest that the inhibition of N-type calcium channels or voltage-gated sodium and T-type calcium channels provides better analgesic potential instead of inhibition of T-type calcium channels alone.

Magnetic sentinel node and occult lesion localization in breast cancer (MagSNOLL Trial)

BACKGROUND

Non-palpable breast cancers require localization-guided surgery and axillary staging using sentinel lymph node biopsy (SLNB). This study investigated the novel technique of magnetic-guided lesion localization and concurrent SLNB, which avoids the need for wire-guided localization and radioisotopes.

METHODS

An ultrasound-guided intratumoral injection of magnetic tracer (0·5 ml) was performed in a protocol-driven predefined minimum of ten patients with palpable breast cancer to assess the ability of the magnetic tracer safely to localize the tumour at the site of injection and concurrently drain to the lymphatics. Once successful lesion localization had been confirmed (peak magnetometer count retained at the centre of the tumour), the technique was undertaken in a further 20 patients with non-palpable breast cancers awaiting wide local excision and SLNB. All patients underwent SLNB with both the magnetic and standard dual (radioisotope and Patent Blue V dye) techniques.

RESULTS

Thirty-two patients were recruited, of whom 12 (1 with bilateral disease) presented with palpable and 20 with non-palpable breast cancer. Peak magnetometer counts were retained at the tumour centre in all palpable (13) and non-palpable (20) breast cancers. Re-excisions for involved margins were necessary in two patients with non-palpable breast cancers. The sentinel lymph node identification rates were 28 of 33 procedures for the magnetic technique alone, 32 of 33 for the magnetic technique combined with blue dye, and 32 of 33 for the standard dual technique.

CONCLUSION

Magnetic lesion localization is feasible, with intratumoral magnetic tracer injection combined with a periareolar injection of blue dye for subsequent SNLB.

Genetic analysis of river, swamp and hybrid buffaloes of north-east India throw new light on phylogeography of water buffalo (Bubalus bubalis)

This study analysed buffaloes from north-east India and compared their nuclear and mitochondrial DNA variations with buffaloes of mainland India, China, Mediterranean and South-East Asia. Microsatellite genotypes of 338 buffaloes including 210 from six north-east Indian buffalo populations and three mainland Indian breeds were analysed to evaluate their genetic structure and evolutionary relationships. Phylogenetic analysis and multidimensional scaling plot of pairwise FST revealed the clustering of all swamp-type buffaloes of north-east India with Lower Assamese (significantly hybrid type) buffaloes in one plane and all the mainland river buffaloes in another plane while the upper Assamese buffaloes being distinct from both these clusters. Analysis of mtDNA D-loop region of 530-bp length was performed on 345 sequences belonging to 23 buffalo populations from various geographical regions to establish the phylogeography of Indian water buffalo. The swamp buffaloes of north-east India clustered with both the lineages of Chinese swamp buffalo. Multidimensional scaling display of pairwise FST derived from mitochondrial DNA data showed clustering of upper Assamese, Chilika and Mediterranean buffaloes distinctly from all the other Indian buffalo populations. Median-joining network analysis further confirmed the distinctness and ancestral nature of these buffaloes. The study revealed north-east region of India forming part of the wider hybrid zone of water buffalo that may probably extend from north-east India to South-East Asia.

Presence of diabetes mellitus in the 'Dawoodi Bohra youth community' in Udaipur, Rajasthan

BACKGROUND & OBJECTIVES

Diabetes mellitus is a major public health problem worldwide. With the rising incidence of diabetes in India, it becomes particularly relevant to ascertain its prevalence in various ethnic groups. The objective of this study was to find out the presence of diabetes mellitus in the 'Dawoodi Bohra Youth Community' and also to assess the factors responsible for it.

METHODS

A house-to-house study was conducted and 2179 subjects were questioned randomly; children below 18 yr of age were excluded. A questionnaire was given to each member and questions were also asked to test their level of awareness regarding diabetes which was graded on a 5-pointer scale where 1 meant 'very poor' and 5-'excellent'. Diabetes was diagnosed using GOD-POD (oxidase-peroxidase) method according to the WHO criteria.

RESULTS

Total number of diabetic subjects found was 246 (11.29%) with a mean age of 60.21±10.91 years. The condition was more common in males (58.94%). The highest prevalence was recorded in the age group of 65-69 yr (22.01%) and none had diabetes in the age group 11-24 yr. Pedigree analysis showed that 109 (44.30%) subjects had at least one affected relative and 23 (9.34%) had at least two diabetic family members; 52 were found to have parents with diabetes. On the 5-pointer scale, the overall care in diabetic subjects was 3.76±0.56 as compared to 2.86±0.60 in non-diabetic subjects (p<0.001).

INTERPRETATION & CONCLUSIONS

Our results indicated that the marital alliances, familial aggregation and lifestyle could be the major factors which enhanced the chances of diabetes in this community. This research work also reflected poor awareness among these people regarding their health and diseases.

Subcutaneous mycoses caused by Rhytidhysteron species in an immunocompetent patient

Subcutaneous mycoses are chronic fungal infections of the skin and subcutaneous tissues caused by variety of fungal agents and usually occur following trauma with vegetative matter. We report a case of subcutaneous mycoses caused by rare fungus belonging to the genus Rhytidhysteron, in an immunocompetent male who presented with a subcutaneous nodule on left foot. This unusual species was identified and confirmed by molecular methods.

Uncommon locations and presentations of hydatid cyst

Background:

Hydatid disease (HD) is an ancient disease and even was known to Hippocrates. This disease involves all human parts and most common affected organs are liver and lungs. Incidence of unusual site is about 8-10%. The clinical picture depends upon the involved organs, its effects on adjacent structures, complications due to secondary infection, rupture, and anaphylaxis caused by hydatid cysts.

Aim:

The aim of this study was to find out incidence of unusual location of hydatid cyst in the human body.

Materials and Methods:

A retrospective study of HD was carried in a medical college between July 2007 and June 2012. A total 79 cases of HD were treated during this period. Information on clinical presentation and management were reviewed, and results presented as summary statistics.

Results:

Sixty one cases were of liver HD, and 11 were with hydatid lung disease. Fifty cases were with right lobe involvement, and rest 11 were with both lobe involvement. Out of 11 lung hydatid only one case was with bilateral lung involvement. Only eight cases of HD of uncommon locations and presentations were encountered during this period. First case presented with left hypochondriac mass as splenic HD, second with pelvic HD along with obstructive uropathy, third with non-functioning right kidney with bilateral psoas muscles HD, fourth with HD involving mesentery, fifth with pelvic pain due to right ovary HD, sixth with simultaneous involvement of the liver and right subdiaphragmatic region, seventh with HD of right inguinal region, and eighth with hydatid cyst of the left kidney. Even though, there was no mortality found in these patients, there was high morbidity.

Conclusion:

We conclude that Echinococcus granulosus can affect any organ in the body from head to toe, and a high suspicion of this disease is justified in endemic regions. Moreover, medical treatment should be given in the pre-operative period as well as in the post-operative period for 4-6 weeks.

A Clinical Trial of Nitrosense patch for the treatment of patients with painful diabetic neuropathy

AIMS

Impaired nitric oxide synthesis has been implicated as one of the underlying causes of diabetic painful neuropathy (DPN). Hence, effects of a cutaneous, nitric oxide releasing patch (NitroSense Derma Protect) were evaluated in subjects with DPN.

METHODS

Fifty diabetics were randomised to active/placebo arms after a 2 wk wash-out period. Patients received 24 mg patches (each patch releases around 9 nmol/cm2/min of nitric oxide) for 3 hrs, every other day during a 3 wks period, or indistinguishable placebo patches. The extent of pain was recorded at start, at each visit and following completion of the study. Changes in pain from baseline were measured using the 11 point lickert scale (PLS), visual analogue scale (VAS), short form mcgill, pain questionnaire (SF-MPQ), present pain intensity (PPI) scale.

RESULTS

Subjects treated with patch experienced a statistically significant reduction in pain from baseline when compared to placebo (PLS scale; p = 0.05). Defining responders as subjects with a > 50% reduction in PLS score from baseline, the number needed to treat (NNT) was calculated as 3.0. A significant post-treatment decrease (p = 0.009) in vibration perception threshold (VPT) for left foot after active treatment was observed.

CONCLUSIONS

Present results highlight utility of NitroSense Derma Protect as controllable nitric oxide source for patients with DPN.

Adaptive radiotherapy in lung cancer: dosimetric benefits and clinical outcome

OBJECTIVE

Anatomical changes during radiotherapy (RT) might introduce discrepancies between planned and delivered doses. This study evaluates the need for adaptive treatment in lung cancer RT.

METHODS

15 patients with non-small-cell lung cancer, undergoing radical RT with or without concurrent chemotherapy, consecutively underwent planning CT scans at baseline and after 44-46 Gy. Target volumes were delineated on both scans. Phase I delivered 44-46 Gy to the initial planning target volume (PTV). Two Phase II plans for 16-20 Gy were developed on initial and mid-treatment scans, the treatment being delivered with the mid-treatment plan. The second CT structure set was fused with the initial scan data set using dose wash. Volumetric and dosimetric changes in target volumes and critical structures were assessed.

RESULTS

There was significant reduction in primary gross tumour volume (34.00%; p = 0.02) and PTV (34.70%; p < 0.01) in the second scan. In Plan 2, delivering the same dose to the initial PTV would have resulted in a significantly higher dose to the lung PTV (V20, 52.18%; V5, 21.76%; mean, 23.93%), contralateral lung (mean, 29.43%), heart (V10, 81.47%; V5, 56.62%; mean, 35.21%) and spinal cord (maximum dose, 37.53%).

CONCLUSION

Treatment replanning can account for anatomical changes during RT and thereby enable better normal tissue sparing, while allowing radical target doses with the possibility of maximizing local control.

ADVANCES IN KNOWLEDGE

This study supports the sparse dosimetric data regarding the quantitative tumour volume reduction, re-emphasizing the need for adaptive replanning for minimizing normal tissue toxicity without compromising local control, and adds to the existing body of literature.

Basal subtype, as approximated by triple-negative phenotype, is associated with locoregional recurrence in a case-control study of women with 0-3 positive lymph nodes after mastectomy

PURPOSE

Basal subtype, as approximated by the triple-negative phenotype (ER-PR-Her2-), has correlated with higher LRR in recent studies. Indications for postmastectomy RT (PMRT) in women with 0-3 positive lymph nodes remain unclear. We evaluated the importance of biologic subtype in a cohort of women with LRR after mastectomy.

METHODS

We identified 22 women with 0-3 positive lymph nodes at our institution who were initially treated with mastectomy (without post-mastectomy radiation), suffered LRRs, and had paraffin-embedded tissue blocks from the primary mastectomy specimen available for staining. None of these women received PMRT. We case-control matched these to 29 women with 0-3 positive nodes who had mastectomy (no PMRT) and remained without evidence of disease at last follow-up and had available primary specimens for processing. We matched controls for age (±3 years) and follow-up duration (<5 year vs. more). Paraffin-embedded specimens were used to construct a triple-redundant tissue microarray. We used conditional logistic regressions to study the association between each predictor and LRR. Results were summarized based on odds ratio (OR).

RESULTS

On univariate analysis, ER+, PR+, or the combination was strongly associated with lower odds of LRR. Basal subtype, as approximated by ER-PR-Her2- (TN), was associated with higher LRR (OR 8.5, p = 0.048). Use of chemotherapy also was associated with lower LRR (OR 0.126, p = 0.0073).

CONCLUSIONS

Our data are concordant with reports from others demonstrating that TN phenotype is associated with higher LRR and can be considered along with other predictors of LRR when selecting women for PMRT.

Management of incidentally detected gallbladder carcinomas in a high prevalence area of gallbladder cancer

BACKGROUND

There is an increasing incidence of advanced unresectable gallbladder cancer even in patients who undergo re-exploration and these cases are marked by poor survival even after undergoing curative resection and adjuvant chemotherapy. Lack of suspicion during primary surgery, unavailability of frozen section facilities and delayed referrals are believed to contribute to this high incidence.

AIM

Our aim was to evaluate the results of re-surgery in incidental gallbladder cancers detected after open or laparoscopic cholecystectomy and to assess the outcome in patients who underwent complete radical cholecystectomy and adjuvant therapy.

METHOD

We retrospectively analyzed the data from a prospectively maintained computerized database of all patients with incidentally detected gallbladder cancers operated in the Department of Surgical Oncology, from June 2006 to January 2013.

RESULTS

Forty-two patients with incidental gallbladder cancer were re-explored. The median time of re-exploration after initial surgery was 65 days. Eighteen (43%) patients were found inoperable due to locally advanced unresectable or metastatic disease. Among the 24 (57%) patients who underwent completion radical cholecystectomy, 11 developed recurrence over a median time of 11 months.

CONCLUSION

Despite the dismal prognosis, more than half of the incidentally detected gallbladder carcinoma patients could receive curative treatment. Identification of patients with incidentally discovered gallbladder cancer and early referral to an oncology center may ensure these patients receive curative resection thereby increasing their chances for long-term disease free survival.

Mobile phone health apps for diabetes management: current evidence and future developments

Can an app help manage diabetes? We discuss how the advent of mobile health apps in connecting patients to providers is creating new opportunities for the management of diabetes. Although there are promising outcomes, there is still much to be learned about how such technology could be fully exploited.

Genetic diversity within 5'upstream region of Toll-like receptor 8 gene reveals differentiation of riverine and swamp buffaloes

In this study the nucleotide diversity in the 5'untranslated region (UTR) of TLR8 gene in riverine as well as swamp buffaloes has been described. Analysis of the 5'UTR of TLR8 gene showed presence of two SNPs in this region, g.-139G>T and g.-128A>G. A PCR-RFLP assay designed for genotyping of g.-139G>T SNP across 667 samples from 2 buffalo populations revealed a striking difference in allele frequency distribution across the swamp and riverine buffaloes. The frequency of T allele was higher in swamp buffalo as compared to riverine buffalo, ranging from 0.71 to 1. The G allele on the other hand exhibited a higher frequency across all the Indian riverine buffalo breeds/populations. The principal component analysis revealed separate clusters for the riverine and swamp buffaloes, as expected; however, the riverine type Assamese buffalo population of eastern India formed a distinct cluster. Since most of the buffalo populations in the eastern region are swamp type, this demarcation may be related to the difference in immune response in riverine and swamp buffaloes. These preliminary results indicate that the genetic variation observed in 5'upstream region of TLR8 gene, which differentiates swamp and riverine buffalo, needs to be further explored for association with disease susceptibility in buffalo, an important dairy and meat animal of Southeast Asia.

Caprine Toll-like receptor 8 gene sequence characterization reveals close relationships among ruminant species

TLR8 mediates antiviral immunity by recognizing ssRNA viruses and triggers potent antiviral and antitumor immune responses. In this study, approximately 3.5 Kb nucleotide sequence data of caprine TLR8 gene were generated from one sample each of twelve different Indian goat breeds belonging to different geographical regions. Cloning and characterization of cDNA synthesized from RNA purified from goat spleen revealed TLR8 ORF to be of 3102 nucleotides long coding for 1033 amino acids similar to other ruminant species, that is sheep, buffalo and cattle. The sequence analysis at nucleotide level revealed goat TLR8 to be closer to buffalo sharing 99.6% homology, followed by cattle and sheep. Simple Modular Architecture Research Tool (SMART) used for the structural analysis of goat TLR8 showed the presence of 16 leucine-rich repeats (LRRs) along with single Toll/interleukin-1 receptor (TIR) domain. TIR domain when compared with other livestock species was found to be conserved in ruminant species goat, sheep, cattle and buffalo. The phylogenetic analysis also revealed grouping of all ruminant species together, goat being closer to buffalo followed by cattle and sheep. Total 4 polymorphic sites were observed in TLR8 gene of one specimen goat representing each of 12 different breeds studied, all of which were synonymous and present within the coding region. Of these 4 SNPs, two were in ectodomains, one in TIR domain and one was found to be present in transmembrane domain. PCR-RFLP genotyping of two of the SNPs indicated variations in allele frequencies among different goat breeds. The expression profiling in 13 tissues of goat showed maximum expression of TLR8 gene in kidney followed by spleen, lung and lymph node. Overall, our results indicate conservation of TLR8 gene among the ruminant species and low variation within Indian goat breeds.

Primary breast tuberculosis presenting as a lump: a rare modern disease

Breast tuberculosis is an uncommon form of entity especially in the infra-mammary area. A 25- year-old female, presented with a lump in the breast and infra-mammary area. She was having off and on fever without any other complaints. There was no positive family history. Primary breast tuberculosis was diagnosed on fine needle aspiration cytology wherein ZN stain for acid fast bacilli was positive. The patient received antitubercular drugs and at 3 month follow up the swelling had resolved and the patient was asymptomatic. Breast tuberculosis is a rare disease with non-specific clinical, radiological, and histological findings. Misdiagnosis is common as biopsy specimens are pauci-bacillary and investigations such as microscopy and culture are frequently negative.

Cardioprotective effect of lycopene against isoproterenol-induced myocardial infarction in rats

The present study was designed to evaluate the cardioprotective potential of lycopene (LCP) against isoproterenol (ISP)-induced myocardial infarction (MI), by assessing hemodynamic, biochemical and histopathological parameters. Wistar male albino rats were orally administered with LCP (0.5, 1.0 and 1.5 mg/kg) or with vehicle for 30 days, with concurrent subcutaneous injections of ISP (85 mg/kg) on days 28 and 29. ISP significantly (p < 0.05) decreased systolic, diastolic and mean arterial blood pressure (SAP, DAP and MAP, respectively) and heart rate (HR). ISP also decreased contractility (+LVdP/dt), relaxation (-LVdP/dt) and increased left ventricular end-diastolic pressure (LVEDP). In addition to functional impairment, ISP also caused a significant (p < 0.05) decrease in antioxidants, namely, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx), glutathione (GSH), cardiac injury marker enzymes, creatine phosphokinase-MB (CK-MB) and lactate dehydrogenase (LDH), as well as induced lipid peroxidation, malonaldialdehyde (MDA) and histopathological alterations in heart. However, pretreatment with LCP significantly (p < 0.05) attenuated ISP-induced cardiac dysfunction as evidenced by improved SAP, DAP, MAP, HR, (±)LVdP/dt and reduced LVEDP. Pretreatment with LCP also significantly (p < 0.05) prevented the depletion of antioxidants (SOD, CAT, GSHPx and GSH), myocyte injury marker enzymes (CK-MB and LDH) and inhibited lipid peroxidation and MDA formation in the heart. Furthermore, reduced necrosis, edema and infiltration of inflammatory cells on histopathological examination also depicted the protective effect of LCP against the deleterious effect of ISP. Based on the results, it is suggested that LCP possesses significant cardioprotective potential and may serve as an adjunct in treatment and prophylaxis of MI.

Sequential therapy (triple drug-based induction chemotherapy followed by concurrent chemoradiotherapy) in locally advanced inoperable head and neck cancer patients - Single institute experience

Context:

India has a high incidence of head and neck squamous cell carcinoma (HNSCC) mostly presenting in advanced stage. In the majority of inoperable patients a combination of chemotherapy and radiotherapy (CRT) is considered as the treatment of choice. Adding induction chemotherapy (ICT) before CRT has shown to decrease systemic relapse. Incorporation of taxanes to the cisplatin and 5-FU-based ICT has shown increase in response rates.

Aims:

To evaluate the efficacy and toxicity of triple drug-based ICT followed by CCRT in locally advanced, inoperable HNSCC in the Indian context.

Settings and Design:

Prospective, non-controlled, observational study, a single-institute experience.

Materials and Methods:

Consecutive, locally advanced inoperable HNSCC patients were put on sequential therapy consisting of docetaxel, 5-FU and cisplatin for three cycles followed by concurrent weekly cisplatin and radiotherapy for responding or stable disease patients.

Results:

Forty-four patients were enrolled with male,female ratio of 33/44(75%) and 11/44(25%). Hypopharynx 16/44(36.36%) was the most common site followed by oral cavity 12/44(27.27%) and oropharynx 12/44(27.27%); 38/44(86.36%) patients could complete the planned treatment. Seven patients required dose reduction in ICT. As per the RECIST criteria, 16 patients had Complete Response (CR) and 15 had partial response (PR), 10 had stable disease (SD) and three had progressive disease (PD) after ICT. Thirty-eight patients received concomitant chemo radiotherapy (CCRT); 28/44 (66.63%) patients achieved CR, 10/44 (22.72 %) had PR. The main toxicity was mucositis 18/44 (40.90%) secondary to ICT. Grade III and IV hematological toxicity was seen in 16/44(36.36%), of which 6/44 (13.63%) had febrile neutropenia.

Conclusions:

Triple drug-based sequential therapy is tolerable in our context. In this trial from a single institute the results are very encouraging.

Formulation development and evaluation of alginate microspheres of Ibuprofen

The present study was designed to investigate the effects of different variables on the release profile of ibuprofen microspheres formulated using modified emulsification method. Eight batches of microspheres (F1-F8) were prepared by applying 2³ factorial design. The amount of sodium alginate, amount of calcium chloride, and amount of magnesium stearate were selected as formulation variables. All the batches were evaluated in terms of percentage yield, percentage encapsulation efficiency and in vitro release characteristics. The batch F7 was found to be optimum batch and was further characterized via scanning electron microscopy (SEM) and particle size analysis. Multiple linear regression was applied to confirm significant effect of each variable on release characteristics. The model developed in the present study can be effectively utilized to achieve the formulation with desired release characteristics.

Dynamic mutation-selection balance as an evolutionary attractor

The vast majority of mutations are deleterious and are eliminated by purifying selection. Yet in finite asexual populations, purifying selection cannot completely prevent the accumulation of deleterious mutations due to Muller's ratchet: once lost by stochastic drift, the most-fit class of genotypes is lost forever. If deleterious mutations are weakly selected, Muller's ratchet can lead to a rapid degradation of population fitness. Evidently, the long-term stability of an asexual population requires an influx of beneficial mutations that continuously compensate for the accumulation of the weakly deleterious ones. Hence any stable evolutionary state of a population in a static environment must involve a dynamic mutation-selection balance, where accumulation of deleterious mutations is on average offset by the influx of beneficial mutations. We argue that such a state can exist for any population size N and mutation rate U and calculate the fraction of beneficial mutations, ε, that maintains the balanced state. We find that a surprisingly low ε suffices to achieve stability, even in small populations in the face of high mutation rates and weak selection, maintaining a well-adapted population in spite of Muller's ratchet. This may explain the maintenance of mitochondria and other asexual genomes.