Robot-assisted pancreaticoduodenectomy. Safety and feasibility

Background: The availability of robotic assistance could make laparoscopic pancreaticoduo- denectomy safely feasible. We herein provide a systematic review on laparoscopic robot-assisted pancreaticoduodenectomy (RAPD). Methods: Literature search was conducted on multiple databases considering articles published in English up to October 31, 2014, reporting on ten or more patients. Results: A total of 262 articles were identified. Excluding duplicates (n=172), studies not matching inclusion criteria (n=77), and studies not suitable for other reasons (n=6), a total of seven studies reporting on 312 RAPDs were eventually reviewed. These studies were either retrospective cohort studies (n=4) or case-matched studies (n=3). No randomized controlled trial was identified. Most patients undergoing RAPD were diagnosed with malignant tumors (224/312; 71.8%). RAPD was feasible in most patients. Conversion to open surgery was reported in 9.2% of the patients. A hybrid RAPD technique, employing standard laparoscopy or open surgery through a mini-incision, was adopted in most patients (178/312; 57.0%). Overall, there were six postoperative deaths at 30 days (6/312; 1.9%), including one intraoperative death caused by portal vein injury, while 137 out of 260 patients with complete information developed postoperative complications (52.7%). The mean length of hospital stay ranged from 10–29 days. Postoperative pancreatic fistula (POPF) occurred in 66 patients (66/312; 21.1%). Grade C POPF was reported in eight patients (8/312; 2.5%). The costs of RAPD were assessed in two studies, demonstrating additional costs ranging from 4,000–5,000 US dollars to 6,193 Euro. The mean number of examined lymph nodes and the rate of positive surgical margins indicate that RAPD could be an appropriate oncologic operation. Conclusion: RAPD is safely feasible. These results were obtained in selected patients and in specialized centers. RAPD should not be implemented in the occasional patient by surgeons without advanced laparoscopic skills and formal training in robotic surgery

Fecal non-aureus Staphylococci are a potential cause of bovine intramammary infection

The presence of non-aureus staphylococci (NAS) in bovine rectal feces has recently been described. Similar to other mastitis causing pathogens, shedding of NAS in the environment could result in intramammary infection. The objective of this study was to investigate whether NAS strains present in feces can cause intramammary infection, likely via teat apex colonization. During a cross-sectional study in 5 dairy herds, samples were collected from the habitats quarter milk, teat apices, and rectal feces from 25%, 10%, and 25% of the lactating cows, respectively, with a cow serving as the source of one type of sample only. Samples from clinical mastitis cases were continuously collected during the 1-year study period as well. The 6 most prevalent NAS species, Staphylococcus (S.) chromogenes, S. cohnii, S. devriesei, S. equorum, S. haemolyticus, and S. hominis, were further subtyped by random amplification of polymorphic deoxyribonucleic acid polymerase chain reaction (RAPD-PCR), when the same NAS species was present in the same herd in the three habitats. For S. chromogenes, S. cohnii, S. devriesei, and S. haemolyticus, the same RAPD type was found in rectal feces, teat apices, and quarter milk, indicating that fecal NAS can infect the mammary gland. For S. hominis and S. equorum, we were unable to confirm the presence of the same RAPD types in the three habitats

Detection of genetic diversity among Indian strains of _Xanthomonas campestris_ pv. _mangiferaeindicae_ using PCR-RAPD

The randomly amplified polymorphic DNA (RAPD) technique was used to investigate the genetic diversity in 6 strains of _Xanthomonas campestris_ pv. _mangiferaeindicae_ (_Xcmi_), the causal pathogen of mango bacterial canker disease (MBCD). The RAPD analysis was also intended to identify molecular markers, specific to the species to develop PCR-based markers for detection of _Xcmi_ in mango field and planting materials. Twenty RAPD primers (CP 1-CP 20) were evaluated to establish molecular characters and genetic variability in the genome of _Xcmi_. Among these, only 4 were found efficient for development of reproducible banding pattern. It has been observed that the largest and smallest amplified RAPD products were of 2.036 and 0.201 kbp. A total of 136 bands were scored against 6 strains of _Xcmi_. There was 7.66 per cent polymorphism in individual isolates which indicates significant polymorphism among the evaluated strains, with mean difference of 0.33 (_Xcmi_ 2 vs. _Xcmi_ 8) and 0.29 (_Xcmi_ 10 vs. _Xcmi_ 12). However, the single linkage euclidean distances were statistically significant (P>0.05), i.e., 0.58. The markers CP 5, 10, 16 and 19 were amplified in all the strains with polymorphic alleles, which indicates that these markers could be used for rapid detection of genetic variability in _Xcmi_ strains

Genotyping of human and animal isolates of Giardia intestinalis : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Microbiology at Massey University

Giardia intestinalis is an important protozoan parasite that infects humans and animals. It has been suggested that cattle may be a major source of human Giardia infection so a dairy farming region of New Zealand was investigated. This thesis uses three molecular methods to genotype G. intestinalis isolates obtained from human and animal faecal specimens collected in the Waikato region of New Zealand, to determine if giardiasis is a zoonotic disease. Random amplification of polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) fingerprinting techniques were initially assessed for their ability to genotype G. intestinalis isolates. "Clear cut" evidence of zoonosis could not be established by either method, due to a low sample number. To determine the stability of the G. intestinalis genome an axenic culture of G. intestinalis trophozoites was stressed with toxic levels of metronidazole and the survivors, following a number of passages, were examined using AFLP and RAPD analysis. The DNA fingerprints were compared to those of the original wild-type with the results being indicative of an unstable G. intestinalis genome. A third molecular method was employed, which amplifies a portion of the tandemly repeated ribosomal DNA (rDNA). Each cyst contains 512 head to tail tandem repeat copies of the rRNA gene made up of both conserved and variable regions. The use of nested primers increased the sensitivity and specificity of the PCR reaction allowing the amplification of a 505bp rDNA fragment. DNA sequence analysis and alignment of the amplified products facilitated the comparison of G. intestinalis isolates. The relationship of the sequence data was generated and displayed using Splitstree software indicating that zoonosis did occur

Efficient DNA isolation from moroccan arar tree [Tetraclinis articulata (Vahl) Masters] leaves and optimization of the rapd-pcr molecular technique

Efficient DNA isolation from Moroccan Arar tree [Tetraclinis articulata (Vahl) Masters] leaves and optimization of the RAPD-PCR molecular technique. Molecular genetic analysis of Arar tree [Tetraclinis articulata (Vahl) Masters] is often limited by the availability of fresh tissue and an efficient and reliable protocol for high quality genomic DNA extraction. In this study, two DNA extraction protocols were specifically developed for extracting high quality genomic DNA from Arar tree leaves: modified QIAgen DNA Kit and protocol developed by Ouenzar et al. (1998). DNA yield and purity were monitored by gel electrophoresis and by determining absorbance at UV (A260/A280 and A260/A230). Both ratios were between 1.7 and 2.0, indicating that the presence of contaminating metabolites was minimal. The DNA yield obtained ranged between 20 to 40 μg/g of plant materiel. The Ouenzar and collaborators protocol gave higher yield but was more time consuming compared to QIAgen Kit. However, both techniques gave DNA of good quality that is amenable to RAPD-PCR reactions. Additionally, restriction digestion and PCR analyses of the obtained DNA showed its compatibility with downstream applications. Randomly Amplified Polymorphic DNA profiling from the isolated DNA was optimized to produce scorable and clear amplicons. The presented protocols allow easy and high quality DNA isolation for genetic diversity studies within Arar tree

The development of techniques to distinguish species and strains of giardia : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Microbiology at Massey University

Water supplies, in some rural areas of New Zealand, contain Giardia cysts. This is assumed to make the water unsuitable for human consumption. G. intestinalis and/or G. muris cysts may be present but are not distinguished by the standard test. G. muris infects rodents only so it is not infectious for humans. However G. intestinalis infects humans and a wide range of animals, but it is unclear if the strains which infect animals also infect humans. If G. intestinalis strains are host-specific, then since water in rural areas may contain cysts derived only from animal species it would follow that the water (even if G. muris and/or G. Intestinalis cysts were found) may not be infectious for humans. Investigation of host-specificity of G. intestinalis would be facilitated by a reliable test to distinguish strains of the organism and this thesis investigates the use of PCR for this purpose. A series of random primers were investigated for their ability to distinguish strains of G. intestinalis when used with a variety of PCR protocols. We found that several of these primers (especially GC50 at an annealing temperature of 35°C, and GC80 at an annealing temperature of 35°C) had the potential to distinguish strains. The differences seen were not large but this may be because some of the isolates were clonally related. Consequently we concluded that further modifications and extensions of PCR when applied to human and animal strains should distinguish strains and may have the potential to address the question of host-specificity. The major aim of the thesis however was to produce primers which when used in the PCR are capable of distinguishing G. muris from G. intestinalis. The same approach,ie the use of a random primer, was used to distinguish G. muris from G. intestinalis. Clear differences were seen but the non-specificity of the random primer would allow the organisms to be reliably distinguished only in the absence of other organisms. To avoid this lack of specificity an amplified band produced with G. muris DNA but not with G. intestinalis DNA was sequenced and a primer pair was selected. These primers were, in principle, long enough (21-mer and 23-mer) to be specific for the target DNA and were chosen so as to have matched melting temperatures. The selected primer pair amplified a sequence 307bp long, and the primer sequences were specific for the target species, namely G. muris. Thus in our hands using PCR this primer pair amplified DNA from the available strains of G. muris but failed to amplify DNA from any of seven G. intestinalis strains. Further work is required to establish both an optimal method for lysing cysts and to estimate the minimum number of cysts required to ensure that DNA is available for amplification. However, the availability of the G. muris -specific primers, along with the recently developed genus and G. intestinalis -specific primers should allow us to undertake investigations of water supplies to see if G. muris, G. intestinalis or both species are present. In the case of a small rural supply it would seem reasonable to accept the potability of water supplies containing G. muris only, as long as assurance could be given that G. intestinalis was not present

Survival of thermophilic spore-forming bacteria in a 90+ year old milk powder from Ernest Shackelton's Cape Royds Hut in Antarctica

Milk powder taken to Antarctica on Shackelton's British Antarctic Expedition in 1907 was produced in New Zealand by a roller drying process in the first factory in the world dedicated to this process. Thermophilic bacilli are the dominant contaminants of modern spray-dried milk powders and the 1907 milk powder allows a comparison to be made of contaminating strains in roller-dried and spray-dried powders. Samples of milk powder obtained from Shackelton's Hut at Cape Royds had low levels of thermophilic contamination (<500 cfu ml−1) but the two dominant strains (Bacillus licheniformis strain F and Bacillus subtilis) were typical of those found in spray-dried powders. Soil samples from the floor of the hut also contained these strains, whereas soils distant from the hut did not. Differences in the RAPD profiles of isolates from the milk powder and the soils suggest that contamination of the milk from the soil was unlikely. It is significant that the most commonly encountered contaminant strain in modern spray-dried milk (Anoxybacillus flavithermus strain C) was not detected in the 1907 sample

RAPD PCR Confirms Absence of Genetic Variation Between Insecticide Resistant Variants of the Green Peach Aphid, \u3ci\u3eMyzus Persicae\u3c/i\u3e (Homoptera: Aphididae)

Previous allozyme analysis has revealed an apparent absence of enzyme variability in the green peach aphid, Myzus persicae (Sulzer). We are interested in determining the genetic relatedness of individual M persicae clones carrying different numbers of esterase 4 (E4) gene copies conferring resistance to insecticides, in order to determine how many times and in what geographic locations resistance via gene duplication may have evolved. We have therefore extended the analysis of genetic variability in M. persicae to the DNA level using random amplification of polymorphic DNA (RAPD) with single 10 mer oligonucleotide primers. Here we report a lack of variability be- tween resistant clones in Wisconsin populations even at the DNA level Further, \u27fast\u27 E4 (FE4) variants appear to be absent from Wisconsin populations, despite FE4 variants of moderate resistance (Rl) being the most common clones in the United Kingdom. These results suggest that resistance in M. persicae may have evolved a very few times and that North American populations may differ from those in Europe by founder effects

Survival of thermophilic spore-forming bacteria in a 90+ year old milk powder from Ernest Shackelton's Cape Royds Hut in Antarctica

Milk powder taken to Antarctica on Shackelton's British Antarctic Expedition in 1907 was produced in New Zealand by a roller drying process in the first factory in the world dedicated to this process. Thermophilic bacilli are the dominant contaminants of modern spray-dried milk powders and the 1907 milk powder allows a comparison to be made of contaminating strains in roller-dried and spray-dried powders. Samples of milk powder obtained from Shackelton's Hut at Cape Royds had low levels of thermophilic contamination (<500 cfu ml−1) but the two dominant strains (Bacillus licheniformis strain F and Bacillus subtilis) were typical of those found in spray-dried powders. Soil samples from the floor of the hut also contained these strains, whereas soils distant from the hut did not. Differences in the RAPD profiles of isolates from the milk powder and the soils suggest that contamination of the milk from the soil was unlikely. It is significant that the most commonly encountered contaminant strain in modern spray-dried milk (Anoxybacillus flavithermus strain C) was not detected in the 1907 sample