Prospective Nonrandomized Comparison Between Open and Robot-Assisted Kidney Transplantation: Analysis of Midterm Functional Outcomes

Introduction: To compare short- and midterm outcomes of the first 55 patients undergoing robot-assisted kidney transplant (RAKT) with patients undergoing open kidney transplant (OKT) during the same period in a tertiary care hospital. Materials and Methods: Data of all end-stage renal disease patients undergoing renal transplant were prospectively maintained. All graft kidneys were harvested laparoscopically. Both RAKT and OKT were performed using standardized techniques, and all RAKTs were performed by a single experienced robotic surgeon. Chi-square test/Fisher exact test was done for categorical data, and Mann-Whitney U test was done for continuous data. Discrete variables were expressed in absolute numbers and percentages. For all tests, p < 0.05 was considered significant. All results were expressed as mean ± standard deviation or median with range. Results: Between April 2016 and September 2018, 55 patients underwent RAKT. The same was compared with 152 patients who underwent OKT. The two groups were comparable in terms of age, gender, and body mass index. Duration on hemodialysis was significantly higher in the RAKT group, and hemoglobin and donor kidney glomerular filtration rate was significantly better in the RAKT group. Requirement of perioperative analgesia was significantly less in the RAKT group. Rewarm ischemia time was significantly longer in the RAKT group. The fall in serum creatinine was slower in RAKT group till 3 months. The serum creatinine levels were statistically similar in the two cohorts at 3 months (p = 0.082), which was maintained at median 29 months of follow-up (p = 0.067). Tacrolimus levels on postoperative day 2 were found to be significantly higher in RAKT cohort (17.98 ± 14.41) vs OKT cohort (11.38 ± 6.93). Surgical-site infections were rare in the RAKT group. Conclusions: RAKT confers advantage of decreased wound morbidity with similar functional outcomes compared with OKT in midterm. It looks promising; however, long-term follow-up of larger numbers of patients is needed.

Myg1 exonuclease couples the nuclear and mitochondrial translational programs through RNA processing

Semi-autonomous functioning of mitochondria in eukaryotic cell necessitates coordination with nucleus. Several RNA species fine-tune mitochondrial processes by synchronizing with the nuclear program, however the involved components remain enigmatic. In this study, we identify a widely conserved dually localized protein Myg1, and establish its role as a 3′-5′ RNA exonuclease. We employ mouse melanoma cells, and knockout of the Myg1 ortholog in Saccharomyces cerevisiae with complementation using human Myg1 to decipher the conserved role of Myg1 in selective RNA processing. Localization of Myg1 to nucleolus and mitochondrial matrix was studied through imaging and confirmed by sub-cellular fractionation studies. We developed Silexoseqencing, a methodology to map the RNAse trail at single-nucleotide resolution, and identified in situ cleavage by Myg1 on specific transcripts in the two organelles. In nucleolus, Myg1 processes pre-ribosomal RNA involved in ribosome assembly and alters cytoplasmic translation. In mitochondrial matrix, Myg1 processes 3′-termini of the mito-ribosomal and messenger RNAs and controls translation of mitochondrial proteins. We provide a molecular link to the possible involvement of Myg1 in chronic depigmenting disorder vitiligo. Our study identifies a key component involved in regulating spatially segregated organellar RNA processing and establishes the evolutionarily conserved ribonuclease as a coordinator of nucleo-mitochondrial crosstalk.

Adrenocortical Suppression in Children with Nephrotic Syndrome Treated with Low-Dose Alternate Day Corticosteroids

Corticosteroids form the mainstay of therapy for all forms of nephrotic syndrome. The long-term use of this medication is associated with serious side effects including adrenocortical suppression. The primary objective of this study was to identify adrenocortical suppression (assessed by single morning serum cortisol levels) in children with nephrotic syndrome on treatment with low-dose alternate day steroids. This cross-sectional study was conducted in the Department of Pediatrics in a tertiary care hospital from January 2014 to January 2015. Seventy children (1–18 years) with nephrotic syndrome (steroid sensitive and resistant) who were in remission and on low-dose alternate day steroids for at least 8 weeks or had received steroids of 2 mg/kg/d for at least 2 weeks in the last 1 year (infrequent relapsers) were enrolled. Relevant history was taken, clinical examination was done and blood samples were drawn for serum cortisol, lipid profile, kidney function tests, fasting blood sugar, glycated hemoglobin (HbA_1c), and serum albumin. Forty percent (28/70) children had adrenocortical suppression as assessed by low morning serum cortisol levels. The mean serum cortisol levels were 188 nmol/L and were significantly lower in frequently relapsing individuals (85.9 nmol/L) as compared to other types of nephrotic syndrome (P = 0.05). The prevalence of adrenocortical suppression was higher in steroid-resistant patients (57%) as compared to 28% in frequently relapsing and 11% in steroid-dependent patients. Fifty-seven percent of patients with adrenocortical suppression had short stature while 50% had obesity. All individuals had normal serum HbA_1c levels. The cumulative steroid doses and total duration of corticosteroid therapy were significantly higher in patients with adrenocortical suppression. Children with nephrotic syndrome treated with low-dose alternate day steroids have a high prevalence of adrenocortical suppression on screening with single morning cortisol sample. Those with frequently relapsing or steroid-resistant diseases are at a higher risk of suppression.

Enhancement of coral calcification via the interplay of nickel and urease

Corals are the main reef builders through the formation of calcium carbonate skeletons. In recent decades, coral calcification has however been impacted by many global (climate change) and local stressors (such as destructive fishing practices and changes in water quality). In this particular context, it is crucial to identify and characterize the various factors that promote coral calcification. We thus performed the first investigation of the effect of nickel and urea enrichment on the calcification rates of three coral species. These two factors may indeed interact with calcification through the activity of urease, which catalyzes the hydrolysis of urea to produce inorganic carbon and ammonia that are involved in the calcification process. Experiments were performed with the asymbiotic coral Dendrophyllia arbuscula and, to further assess if urea and/or nickel has an indirect link with calcification through photosynthesis, results were compared with those obtained with two symbiotic corals, Acropora muricata and Pocillopora damicornis, for which we also measured photosynthetic rates. Ambient and enriched nickel (0.12 and 3.50 μg L^-1) combined with ambient and enriched urea concentrations (0.26 and 5.52 μmol L^-1) were tested during 4 weeks in aquaria. We demonstrate in the study that a nickel enrichment alone or combined with a urea enrichment strongly stimulated urea uptake rates of the three tested species. In addition, this enhancement of urea uptake and hydrolysis significantly increased the long-term calcification rates (i.e. growth) of the three coral species investigated, inducing a 1.49-fold to 1.64-fold increase, respectively for D. arbuscula and P. damicornis. Since calcification was greatly enhanced by nickel in the asymbiotic coral species - i.e. in absence of photosynthesis - we concluded that the effect of increased urease activity on calcification was mainly direct. According to our results, it can be assumed that corals in some fringing reefs, benefiting from seawater enriched in nickel may have advantages and might be able to use urea more effectively as a carbon and nitrogen source. It can also be suggested that urea, for which hotspots are regularly measured in reef waters may alleviate the negative consequences of thermal stress on corals.

Collapsing glomerulopathy associated with hepatitis B infection: A case report

Collapsing glomerulopathy has been classified as a variant of focal segmental glomerulosclerosis. It is associated with infections, inflammations, and certain medications. While its association with human immunodeficiency virus has been well established its occurrence with hepatitis B has not been reported. We present here a case of collapsing glomerulopathy in a child with hepatitis B infection.

Efficient quasi-solid state dye sensitized solar cell using succinonitrile : thiourea based electrolyte composition

SEM micrograph of the optimized electrolyte with SCN : TU. Inset shows the current density–voltage characteristics of the DSSCs with reference and optimized electrolytes, A1 and A2, respectively.

Population diversity and adaptive evolution in keratinization genes: impact of environment in shaping skin phenotypes

Several studies have demonstrated the role of climatic factors in shaping skin phenotypes, particularly pigmentation. Keratinization is another well-designed feature of human skin, which is involved in modulating transepidermal water loss (TEWL). Although this physiological process is closely linked to climate, presently it is not clear whether genetic diversity is observed in keratinization and whether this process also responds to the environmental pressure. To address this, we adopted a multipronged approach, which involved analysis of 1) copy number variations in diverse Indian and HapMap populations from varied geographical regions; 2) genetic association with geoclimatic parameters in 61 populations of dbCLINE database in a set of 549 genes from four processes namely keratinization, pigmentation, epidermal differentiation, and housekeeping functions; 3) sequence divergence in 4,316 orthologous promoters and corresponding exonic regions of human and chimpanzee with macaque as outgroup, and 4) protein sequence divergence (Ka/Ks) across nine vertebrate classes, which differ in their extent of TEWL. Our analyses demonstrate that keratinization and epidermal differentiation genes are under accelerated evolution in the human lineage, relative to pigmentation and housekeeping genes. We show that this entire pathway may have been driven by environmental selection pressure through concordant functional polymorphisms across several genes involved in skin keratinization. Remarkably, this underappreciated function of skin may be a crucial determinant of adaptation to diverse environmental pressures across world populations.

Clinical efficacy of various root canal obturating methods in primary teeth: a comparative study

AIM

The purpose of this in vivo study was to evaluate and compare the efficacy of different obturating methods used in primary teeth, when obturated using a combination of zinc oxide and iodoform paste (Endoflas F.S.).

MATERIALS AND METHODS

A group of 29 patients aged 3-9 years and a total of 64 teeth were selected. These 64 teeth (32 anterior teeth=32 canals, and 32 posterior teeth=80 canals) were randomly divided into 4 groups. Teeth were obturated with Lentulo spiral, pressure syringe, bi-directional spiral and Pastinject. Post-operative evaluation was done for: quality of canal obturation, (underfilled, optimally filled, overfilled) and presence of voids.

RESULTS

Pastinject exhibited the highest number of optimally filled canals, while the highest number of underfilled canals were observed with bi-directional spiral, and the highest number of overfilled canals were observed with pressure syringe. A minimum number of voids was present in canals filled with the Pastinject technique and pressure syringe.

CONCLUSION

These results suggest that Pastinject was the most effective technique for obturation of primary teeth.

Relationship of leukocyte CR1 transcript and protein with the pathophysiology and prognosis of systemic lupus erythematosus: a follow-up study

Complement Receptor 1 (CR1) is a key complement regulatory protein (CRP) involved in the clearance of immune complexes. Earlier, we reported a marked decline of leukocyte CR1 (L-CR1) transcript and protein in patients with active systemic lupus erythematosus (SLE) and suggested L-CR1 transcript as a putative non-invasive disease marker for SLE. This follow-up study involving 18 patients with active SLE was conducted for further confirmation of the relationship between L-CR1 and SLE. Blood samples from the patients were collected on day 1 of the diagnosis (0 month) and at different time intervals (3 and 6 months) for analysis of L-CR1 transcript and L-CR1 protein by semi-quantitative reverse-transcriptase-polymerase chain reaction (RT-PCR) and western blotting respectively. Within 6 months, 15 patients entered remission. On day 1, the mean values of L-CR1 transcript (8.42 ± 3.53) and L-CR1 protein (4683 ± 1094) in the SLE patients were 6 times and 12 times lower than the normal controls (n = 103). At the end of month 6, these values increased by 4.5 and 6.5 times respectively for CR1 transcript (37.86 ± 8.52) and protein (30,265 ± 8614). Simultaneously, the SLE Disease Activity Index (SLEDAI) scores decreased by 4.8 times (4.47 ± 3.32) as compared with the scores obtained on day 1 (21.45 ± 5.67). Moreover, CR1 values correlated negatively with the SLEDAI scores. Levels of L-CR1 protein and transcript remained low in the three patients who did not enter remission. All of the above results suggested that an increase in the levels of L-CR1 related to good prognosis. Since the levels of L-CR1 protein is influenced by variables like proteolytic cleavage and secretion from leukocytes, the values of L-CR1 transcript on day 1 and subsequent follow-up points may bring a better insight into the state of the disease activity. An extended follow-up study is needed to confirm the significance of L-CR1 as a prognostic marker for SLE.

The UK Government two-week rule and its impact on melanoma prognosis: an evidence-based study

INTRODUCTION

In order to tackle increasing waiting lists the UK Government's 'two-week rule' was introduced for a number of cancers, including melanoma, in 2000. Whilst there is evidence that secondary prevention (i. e. early diagnosis) improves patient outcome, particularly in melanoma where early surgical excision is the only intervention to improve survival, there is as yet no evidence base for a 2-week limit. Any survival benefit from this Government target will not be demonstrable until long-term follow-up is available, realistically 10-year mortality figures in 2010.

PATIENTS AND METHODS

To investigate an evidence base for the two-week rule in melanoma, we performed a retrospective study on patients with suspected skin cancers referred to a rapid access Pigmented Lesion Clinic (PLC) over a 4-year period with long-term survival data, and compared them to a historical control group.

RESULTS

A total of 4399 patients attended the PLC from January 1993 to December 1996 and all were seen within 2 weeks. Ninety-six melanomas were diagnosed during this period with 96% treated within 2 weeks of GP referral, the majority (74%) excised on the day of PLC attendance. Melanoma patients (n = 78) diagnosed in the 2 years prior to the inception of the PLC waited 3-34 days for consultation and 4-74 days for treatment. Melanoma patients diagnosed in the PLC had significantly thinner tumours (Mann Whitney test, P < 0.001) and improved overall survival (chi(2) 18.1924; P < 0.001) compared with melanoma patients diagnosed before the inception of the clinic.

CONCLUSIONS

This is, to our knowledge, the first example that consultation within a 2-week time-frame of GP referral impacts patient survival and the first evidence base behind Government guidelines for this particular cancer.

Familial prevalence among first-degree relatives of celiac disease in North India

BACKGROUND AND OBJECTIVES

Prevalence of celiac disease is increased in first-degree relatives with reported prevalence rates in the west between 2.8 and 10%. Paucity of similar data from Asia and the Indian subcontinent prompted us to determine the familial prevalence of celiac disease in first-degree relatives of patients diagnosed with this disorder in Northern India.

METHODS

One hundred sixty-nine first-degree relatives (66 parents, 71 siblings and 32 children) of 53 probands were screened by using anti tissue transglutaminase antibodies. Duodenal biopsy was performed in all seropositive relatives and graded as per Marsh classification. Patients with both positive serology and biopsy suggestive of celiac disease were classified as typical celiac disease whereas those with only positive serology were classified as potential celiacs.

RESULTS

The prevalence of celiac disease among first-degree relatives was 8.2% (14/169). The prevalence of celiac disease among siblings (15.6%) was much higher as compared to that in parents (3.5%) and offspring (3%). More than one family member was affected in 23% (12/53) of families. Of 14 new cases detected by targeted screening, 11 (78%) were overtly symptomatic with either chronic diarrhoea (8) or easy fatiguability (3). Growth retardation was seen in all six newly diagnosed children, three of whom (22%) were otherwise asymptomatic. Eight members detected to be seropositive had minimal changes on duodenal biopsy (Marsh I and II) suggesting that they have potential celiac disease.

CONCLUSION

Familial prevalence of celiac disease in North India is similar to the data from the West. However unlike the situation in the West, the overwhelming majority of first-degree relatives in India are overtly symptomatic with majority having chronic diarrhoea. Since gluten restriction is a highly effective treatment modality, early detection of these patients would result in significant improvement in quality of life as manifested by cessation of diarrhoea and improvement in growth and lab parameters. Our data strongly supports the targeted screening of all first-degree relatives of celiac disease patients in north India.

A comparative study on characterization of textile wastewaters (untreated and treated) toxicity by chemical and biological tests

Toxicity of textile wastewaters (untreated and treated) and their ingredient chemicals was quantified in terms of their chemical characteristics, fish (Gambusia affinis) mortality and end point growth responses of duckweed (Lemna aequinoctialis) in short-term bioassays. Other parameters of fish bioassay were erythrocyte morphology and its counts. Despite of a definite correlation between data of biological tests (LC/EC(50) values) with that of chemical tests, biological tests were found to be relatively more sensitive to both wastewaters and ingredient chemicals. Amongst all the examined parameters of test organisms, fish RBCs (morphology and counts) sensitivity to pollutants in the wastewaters was usually maximum and therefore, their study should be included in the routine fish bioassay. Other advantage of biological test such as on Lemna is even detection of eutrophic potential of wastewaters, as noted at their higher dilutions. The ingredient chemicals (major) contributing maximum toxicity to textile dye wastewater were, acids (HCl and H(2)SO(4)), alkali (Na(2)O SiO(2)), salt (NaNO(2)) and heavy metal (Cu), whereas dyes (4) were relatively less toxic.

Profiling cytochrome P450 CYP1 enzyme expression in primary melanoma and disseminated disease utilizing spectral imaging microscopy (SIM)

8556

Background: The aim of this study was to profile cytochrome CYP1 family (CYP1A1/1A2, and CYP1B1) mono-oxygenase enzymes during the malignant progression of primary melanoma and metastatic disease. Methods: Tissue microarrays of primary (n = 75), and metastatic (n = 104) melanoma were constructed with the patient demographics: (1) primary melanoma; age 22 to 93 (median 59); sex M/F 36/44; Breslow thickness 0.4 to 15 mm (median 2.5 mm); ulceration 25/80, and (2) metastatic melanoma; age 26 to 92 (median 60 mm); sex M/F 54/49; ulceration 30/104; number of nodes 1 to 15 (median 2); extra-capsular spread 20/95. CYP1 protein was detected by IHC using validated selective poly- and monoclonal antibodies. Vector SG (grey) stain for CYP1 was used with nuclear fast red counterstain to aid spectral resolution from background melanin. Staining intensity was scored visually (negative 0, weak 1, moderate 2, strong 3) and using SIM at every pixel of a captured image of each melanoma core. Reference spectra of individual chromophores were used to spectrally ‘un-mix’ CYP1 staining before the mean normalised absorbance intensity was determined. Grading was by the 2002 AJCC classification system: primary stage I n = 27 (1A 8, 1B 19), and stage II n = 48 (2A 22, 2B 16, 2C 10), lymph node metastasis stage III n = 98 (3B 53, 3C 45), visceral metastasis stage IV n = 6. Normal skin (n = 27), benign naevi (n = 14), and dysplastic naevi (n = 21) were also included. Results: CYP1B1 was not in normal skin but was over-expressed in both primary and metastatic melanoma (visual: 71% & 65%, SIM: 91% & 83%). Primary melanoma (stage I & II) was significantly greater (p = 0.004) than metastasis (stage III & IV). CYP1B1 did not correlate with ulceration or Breslow thickness but did correlate with N stage lymph node metastasis (p = 0.005). CYP1B1 expression in dysplastic naevi indicated up-regulation at an early stage of melanoma progression. CYP1A1/1A2 was not expressed in normal skin nor primary/metastatic melanoma. Conclusions: CYP1B1 protein expression is maintained with advancing AJCC stage from primary through to visceral metastasis. Future work will seek to correlate protein expression with functionality with a view to exploiting CYP1B1 in the enzyme/prodrug therapy of malignant melanoma.

No significant financial relationships to disclose.

Stratification of patients by melanoma cell adhesion molecule (MCAM) expression on the basis of risk: implications for sentinel lymph node biopsy

BACKGROUND

The usual indication for sentinel lymph node biopsy (SLNB) in melanoma is a primary tumour >1mm thickness but under these criteria less than 20% of SLNBs are positive. Of those patients with a negative sentinel node (SN) over 10% will have disease recurrence within 3 years. A more accurate delineation of candidate patients for SLNB and risk profile for negative SN patients is therefore desirable. Melanoma cell adhesion molecule (MCAM) is a predominant cell adhesion molecule of melanomas and its expression has been implicated in tumour progression and metastasis.

AIMS

To compare MCAM expression in primary and metastatic melanoma and to investigate if MCAM expression in patients meeting the criteria for SLNB correlated with patient outcome.

METHODS

Tissue arrays of primary (n=78) and metastatic (n=92) melanomas were constructed from archived paraffin embedded tissue and MCAM expression detected by immunohistochemistry. Staining positivity and intensity were assessed by visual scoring and correlated with clinical outcome.

RESULTS

In patients meeting the current criteria for SLNB, Cox multivariate analysis showed both MCAM expression positivity and intensity were independently predictive of survival (P=0.007) and development of lymph node disease (P=0.01) in primary melanoma over and above established markers of prognosis, such as Breslow thickness. MCAM-negative patients had a 5-year survival of 92% compared with 40% for MCAM positive.

CONCLUSIONS

Measurement of MCAM expression represents a potential method to stratify SLNB patients on the basis of risk. This would have considerable benefits in terms of both cost and patient morbidity.

A prospective analysis of c-myc oncoprotein levels as a prognostic marker in malignant melanoma

BACKGROUND

Previous studies from our group had identified c-myc oncoprotein expression as an important prognostic parameter in a series of retrospective studies of primary and metastatic melanoma and other variants of this disease. This study set out to prospectively evaluate the prognostic significance of c-myc positivity in a consecutive series of primary melanomas presenting at Mount Vernon Hospital Regional Plastic Surgery and Burns Centre.

METHODS

A consecutive series of 117 primary melanomas underwent flow cytometric analysis for c-myc expression at diagnosis. Routine clinical and histological parameters were collected from each patient's clinical records and survival assessed. The mean follow up was 45 months.

RESULTS

Kaplan-Meier survival analysis demonstrated that Breslow depth, histogenic subtype, ulceration, age and sex had prognostic significance. Survival analysis revealed high c-myc positivity to be significantly associated with poorer outcome (P<0.043). Each of the main prognostic parameters were assessed for their independent significance using Cox Proportional Hazards; only c-myc retained independent significance (P<0.039).

CONCLUSIONS

The strength of this study is that it was performed in a consecutive series of patients followed up in a longitudinal prospective study. c-myc was not the strongest predictor of survival in univariate analysis, but was the only parameter that retained significance in multivariate analysis.

Role of anti cyclic citrullinated peptide antibodies in erosive disease in patients with rheumatoid arthritis

BACKGROUND & OBJECTIVES

Antibodies to cyclic citrullinated peptide (CCP) are a recently described marker in rheumatoid arthritis (RA), which are said to connote aggressive disease. No data on these antibodies are available from India. We undertook this study to evaluate the role of second generation anti CCP antibodies (anti CCP-2) in predicting erosive disease in Indian patients with rheumatoid arthritis and to define their role in seronegative RA.

METHODS

A total of 211 patients with established RA were evaluated in this cross-sectional study for radiographic erosions. A high percentage of seronegative RA patients (40%) were included to assess the role of anti CCP-2 antibodies in this subgroup. Radiographic damage was quantified using modified Sharp score. Apart from anti CCP-2 antibodies, other factors evaluated for their ability to predict erosions included rheumatoid factor (RF) positivity, disease duration, and disease modifying anti rheumatic drugs (DMARD) naïve period.

RESULTS

Anti CCP-2 antibodies were seen in 80 per cent patients with RA. Predictors of erosive disease included anti CCP-2 antibody positivity and DMARD naïve period. Patients positive for both RF and anti CCP-2 antibodies had a higher prevalence of erosions as compared to patients positive for only one antibody or negative for both. In seronegative RA (RF absent), anti CCP-2 antibodies were seen in over 50 per cent patients and were associated with a higher incidence of erosive disease.

INTERPRETATION & CONCLUSION

Our finding showed that anti CCP-2 antibodies were present in 80 per cent patients with established RA. These have an independent role in predicting erosive disease, especially in the seronegative subgroup.

The relation between c-myc expression and interferon sensitivity in uveal melanoma

BACKGROUND/AIM

Interferons (IFN) are currently being used to treat melanoma, including some patients with uveal melanoma. IFN is thought to inhibit tumour growth through downregulation of the c-myc oncogene; the overexpression of which has been shown to be associated with resistance in cell lines. The aim of this study was to investigate the relation between c-myc gene expression and IFN sensitivity in a series of uveal melanomas in a short term chemosensitivity assay.

METHODS

Tumours from 45 patients with uveal melanoma who had undergone enucleation were studied. The ATP chemosensitivity assay was used to study sensitivity to IFN-alpha-2b in freshly isolated cells from each tumour. Flow cytometry was used to assess c-myc expression in formalin fixed material from the primary specimens.

RESULTS

There was a wide range of IFN sensitivity between the specimens whereas c-myc expression was universal and present in 80% of the tumour cells in 80% of the specimens. Higher c-myc expression was associated with IFN-alpha resistance as measured by the maximum percentage of inhibition (p = 0.05) and there was a trend with the IFN sensitivity index (p = 0.07).

CONCLUSIONS

These results demonstrate that tumours with high c-myc expression are also associated with IFN resistance. Future research is required to explore the potential of c-myc gene manipulation combined with IFN therapy.

Photonic logic NOR gate based on two symmetric microring resonators

We demonstrate an all-optical NOR logic gate based on symmetric GaAs-AlGaAs microring resonators whose resonances are closely matched. Two input pump data streams are tuned close to one resonance of the symmetric microrings to switch a probe beam tuned to another resonance by two-photon absorption. The switching energy of the gate is 20 pJ/pulse, and the switching window is 40 ps, limited by the carrier lifetime. The use of two rings provides for better cascading in photonic logic circuits because of the higher number of available ports.

Environmental concentrations of agricultural herbicides in Saskatchewan, Canada: bromoxynil, dicamba, diclofop, MCPA, and trifluralin

Herbicides are the most commonly used group of agricultural pesticides on the Canadian Prairies and, in 1990, more than 20000 Mg of herbicides were applied in the provinces of Alberta, Saskatchewan, and Manitoba. The present paper reports on environmental concentrations of five herbicides currently used in the prairie region. The herbicides bromoxynil [3,5-dibromo-4-hydroxy-benzonitrile], dicamba [3,6-dichloro-o-anisic acid], diclofop [(RS)-2-[4-(2,4-dichlorophenoxy)-phenoxy]propanoic acid], MCPA [(4-chloro-2-methylphenoxy)acetic acid], and trifluralin [alpha,alpha,alpha-trifluoro-2,6-dinitro-N,N-isopropyl-p-toluidine] were measured in the atmosphere, bulk atmospheric deposits, surface film, and dugout (pond) water at two sites near Regina, Saskatchewan, during 1989 and 1990. All five herbicides were detected in air and surface film and all but trifluralin were detected in the bulk atmospheric deposits and dugout water. Trifluralin was most frequently detected in air (79% of samples) whereas bromoxynil was present in maximum concentration (4.2 ng m(-3)). MCPA was present in maximum levels in bulk atmospheric (wet plus dry) deposits (2350 ng m(-2) d(-1)), surface film (390 ng m(-2)), and dugout water (330 ng L(-1)), whereas dicamba was most frequently detected in surface film (47%) and dugout water (97%). The highest quantities of the herbicides tended to be present during or immediately after the time of regional application.

Use of an early-detection strategy to improve disease control in melanoma patients

In order to assess whether early detection might lead to improvement in disease control for patients with melanoma, a rapid access pigmented lesion clinic (PLC) was set up at Mount Vernon Hospital, UK in 1993. Previously we have shown that thinner melanomas were detected via the PLC compared with those presenting prior to its establishment and with those referred via existing routes of referral. The aim of this study was to investigate whether both rates of disease recurrence and disease-free interval were improved via a rapid access PLC. A retrospective case notes audit was performed on three patient groups: those diagnosed with melanoma 1991-1992, those diagnosed via the PLC (1993-1996) and those diagnosed with melanoma through existing routes of referral after establishment of the PLC (1993-1996). There was a significantly improved disease-free interval for patients with regional recurrences diagnosed via the pigmented lesion clinic (PLC) when compared with pre-PLC, non-PLC groups (chi2=13.8487, p=0.0002; chi2=17.0164, p<0.0001, respectively), and when compared with all melanoma patients diagnosed after the establishment of the PLC, irrespective of route of referral (chi2=5.2773, p=0.0216). Local recurrences developed later in patients in the PLC group compared with the pre-PLC group (chi2=6.4883, p=0.0109), and the non-PLC group (chi2=18.49, p<0.0001). In addition there was a reduction in the proportion of regional and local recurrences in the PLC group when compared with the pre-PLC group (chi2=13.92, P<0.001; chi2=2.85, P=0.09 respectively) and non-PLC group (chi2=17.15, P<0.001; chi2=7.73, P=0.005, respectively). These results support the use of rapid access PLCs as a means of improving disease control for melanoma patients.

Protein kinase Calpha mediates the effect of antiarrhythmic peptide on gap junction conductance

We investigated the effects of the antiarrhythmic peptide AAP10 (GAG-4Hyp-PY-CONH2, 50 nM) on pairs of adult guinea pig cardiomyocytes and on pairs of HeLa-cells transfected with rat connexin43 (Cx43). Using double cell voltage clamp technique in cardiomyocytes under control conditions, gap junction conductance (Gj) steadily decreased (by -0.3 to -0.4 nS/min). In contrast, 50 nM AAP10 significantly enhanced Gj (by +0.22 to +0.29 nS/min). This effect of AAP10 could be significantly antagonized by bisindolylmaleimide I (BIM), and by the protein kinase C (PKC) subtype-specific inhibitors HBDDE (PKCgamma and -alpha) and CGP 54345 (PKCalpha). In HeLa-Cx43 cells we found similar electrophysiological effects of AAP10. For further analysis, we incubated HeLa-Cx43 cells with [32P]orthophosphate (0.05 mCi/ml) for 4 h at 37 degrees C followed by addition of 50 nM AAP10 for 15 min. We found that incorporation of 32P into Cx43 was significantly enhanced in the presence of AAP10, which was completely inhibited in presence of BIM. PKC enzyme-linked immunosorbent assay (ELISA) revealed significant activation of PKC by AAP10 in HeLa-Cx43 cells, which could be inhibited by HBDDE and CGP 54345. Finally, a binding study using [14C]-AAP10 as radioligand was performed. We found a saturable binding of [14C]-AAP10 with a KD of 0.88 nM to cardiac membrane preparations. For assessment of the antiarrhythmic activity in anesthetized rats, we infused aconitine until the occurrence of ventricular fibrillation (VF). The aconitine dose required for initiation of VF was significantly enhanced in the presence of AAP10. In conclusion; AAP10 increases Gj in both adult cardiomyocytes and transfected HeLa-Cx43 cells. AAP10 leads to enhanced phosphorylation of Cx43 via activation of PKCalpha. A membrane receptor exists for antiarrhythmic peptides.

Transfusion associated infections: a threat to life

Blood transfusion is indispensable in the management of many haematological diseases and has become the mainstay in major surgical procedures. Transfusion-transmitted infections have been a major threat to life since the dawn of transfusion therapy. The authors have highlighted the different viral, parasitic and bacterial infections associated with transfusion and have focussed on the precautionary measures that can be implemented for prevention of the infections along with a brief review of the literature.

The c-myc oncogene: use of a biological prognostic marker as a potential target for gene therapy in melanoma

The c-myc oncogene has been shown to be overexpressed in a number of malignancies, and may play an important role in the pathogenesis of malignant melanoma. Previous prognostic studies have demonstrated c-myc overexpression in a range of cutaneous melanomas, and levels of c-myc oncoprotein expression have been shown to correlate with clinical outcome in both primary and secondary disease. The purpose of this study was to investigate the in vitro manipulation of c-myc expression using antisense oligonucleotides. The human melanoma cell lines A375M, Be11 and WM115 were treated with c-myc antisense oligonucleotides, and the cellular growth was compared with controls. Antisense oligonucleotides reduced the growth rate of all three cell lines, and produced a reduction in c-myc gene expression as measured by flow cytometry. The growth inhibitions in the A375M, Be11 and WM115 cell lines at 72 h were 36.6%, 35.8% and 29.3%, respectively. Each of these was significantly different from control cultures (P<0.01). The c-myc antisense produced a mean 75% reduction in c-myc oncoprotein expression when compared with controls in the A375M cells (P<0.001), a 49% reduction in the Be11 cells (P<0.001) and a 28% reduction in the WM115 cells (P=0.005). This study demonstrates the importance of the c-myc oncogene in controlling melanoma growth. It suggests that blocking the expression of this gene, using an antisense approach, reduces melanoma cell growth, and may potentially provide a novel gene-therapy strategy for the treatment of advanced melanoma.

Long-term results of facial rejuvenation by carbon dioxide laser resurfacing using a quantitative method of assessment

Carbon dioxide laser resurfacing has been widely reported as an effective method for treating facial rhytides. Few published series, however, have assessed the long-term results of this procedure. We prospectively reviewed our long-term results of perioral CO(2) laser resurfacing using an accurate, reproducible and quantitative method of evaluation. Wrinkle depth was measured using a silicone elastomer to provide an exact negative-replica mask of the perioral region. Simple light microscopy was then used to measure the depth of rhytides. This was carried out preoperatively, 6 weeks postoperatively and 2 years postoperatively, and the results were compared for 31 patients. CO(2) laser resurfacing achieved a highly significant mean reduction in wrinkle depth at 6 weeks of 91% (paired t -test:P <0.00001), and this was well maintained at 2 years, when the mean reduction in wrinkle depth was 87% (paired t-test: P<0.00001). During the long follow-up, complications were few, with transient erythema being the most common; there were no cases of scarring. As in other series that have reported longer follow-up, we encountered three cases of minor hypopigmentation. We have used light microscopy on silicone moulds as an accurate method of assessing outcome after laser resurfacing of perioral rhytides. The early highly significant reduction in wrinkle depth was maintained at 2 years with minimal associated short-term or long-term morbidity.

Exposure of ground-rig applicators to the herbicide bromoxynil applied as a 1:1 mixture of butyrate and octanoate

Bromoxynil is a herbicide used extensively on the Canadian prairies for weed control in cereal production. This is a report on exposure to and absorption of bromoxynil by farmers during handling, transferring, mixing, and then applying the herbicide to cereal crops using tractor-drawn ground-rigs. The 14 individual spray operations, in which farmers applied 9 kg of bromoxynil (phenol equivalent, p.e.) to 32 ha, lasted from 113 to 549 min and involved one to five tank fills. In five of the spray operations, the farmers wore neoprene gauntlet-style protective gloves. Tractors, equipped with cabs, were used in nine spray operations.Air sampling, hand washes, and dermal patch dosimeters served as the basis to calculate the amount of bromoxynil (p.e.) available for inhalation, deposition on the hands, and deposition under a standardized set of protective clothing. Tractors, equipped with cabs, decreased inhalation exposure by a factor of approximately 10. Use of gauntlet-style neoprene protective gloves decreased dermal exposure to the hands region of the body by 25 times, whereas two layers of laundered cotton provided a protective effect of > 15 in the chest region. The median value for the amount of bromoxynil (p.e.) inhaled was 0.018 microg x kg BW(-1)x kg (p.e.)(-1) for the 14 spray operations. The hands region of the body was the area most exposed to bromoxynil (p.e.), the median value of dermal deposition to the hands being 808 microg (p.e.) compared to 1,600 microg (p.e.) for the whole body, when protective gloves were not worn. The urinary excretion pattern of bromoxynil (p.e.) did not demonstrate an obvious maximum followed by a continuous decline to background concentrations. Instead, the amounts excreted increased over the first few days after application and then tended to remain relatively constant during the remainder of the 10-day sampling period. The median value for urinary excretion was 2.22 ng x g creat(-1) x kg BW(-1) x kg (p.e.)(-1).