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Biomedical subjects

J Stoddard

Publications and source records attributed to J Stoddard.

13 recordsLinked to original sources
PubMed2005

Dissection efficiency during laparoscopic oesophageal dissection.

Advanced techniques in laparoscopic surgery have led to an increased need for appropriate training in instrument handling and dissection. Recent developments in computer video technology have facilitated critical analysis of surgical technique. Video deconstruction of oesophageal hiatal dissection during six laparoscopic fundoplication procedures was undertaken. The procedures were performed by surgeons with a wide range of surgical experience, and the investigators analysing performance were blinded to their level of training. Sequential five-second video segments were analysed in detail by 3 investigators. A taxonomy list was developed to describe individual types of movement. The number and time per movement was assessed and a degree of efficiency was assigned. An efficient movement was defined as one that advances the dissection towards a recognised goal. The total oesophageal dissection time varied from 10 minutes (min) to 25 min (mean 16 min). The mean number of actions performed was 173 (range 120-272). A mean of 7 min was spent separating tissues (range 5-13), with 6 min spent grasping and positioning tissue (range 3-8). The amount of time spent in inefficient movement varied from 3 to 14 min (mean 7 min). The greatest variation between operators was seen in the efficiency of tissue separation when using dissecting instruments. Inexperienced operators spent a lot more time performing additional movements such as scope cleaning, observation and instrument exchange. This technique of video deconstruction can identify key areas for improvement. This could be used for trainee assessment and to provide constructive feedback. Future development in this area could enhance training in advanced laparoscopic techniques.

Journal Article↗
PubMed2001

Synthesis and analysis of ethylated tetracycline, an antibiotic derivative that inhibits the growth of tetracycline-resistant XL1-Blue bacteria.

Bacterial resistance to antibiotics is a significant problem in medical care facilities, causing increased fatalities due to infection. The present study demonstrates that antibiotic structures can be selectively altered in a manner that revives their ability to inhibit bacterial growth. The antibiotic tetracycline was ethylated at the position of the phenolic hydroxy group with the use of diazoethane, forming an ethyl ether functional group. This derivative was dissolved in Luria-Bertani (LB) agar medium, then placed in tissue culture for screening against a tetracycline-resistant bacterial strain. The growth of this bacterial strain, designated XL1-Blue, was inhibited by the ethylated form of tetracycline. The procedure for synthesizing ethylated tetracycline utilizes diazoethane and is presented with the molecular structures and IR spectra. The ethylated form of tetracycline was stable at -20 degrees C for many weeks, and was soluble in LB agar plate medium. Ethylated tetracycline induced growth inhibition of XL1-Blue bacteria within the first 24 h of incubation. The level of bacterial growth inhibition was greater than 30%. Calculation of the partition coefficient, log P, was accomplished and indicates that ethylated tetracycline has an increased lipophilic tendency relative to unmodified tetracycline, and therefore has greater solubility in lipid bilayers.

Acetates↗
PubMed2000

Modified antibiotics-methylated ampicillin and ethylated ampicillin-inhibit growth of ampicillin-resistant strain of bacteria.

Bacterial resistance to antibiotics is a significant problem in health facilities and results in higher costs for health care and increased fatalities due to infection. The work presented here suggests that antibiotic molecular structure can be altered in a selected manner, which will revive the bacterial growth inhibiting capability. A bacterial strain PKK3535(DH1), which is resistant to the antibiotic ampicillin, was found to be highly growth inhibited by these altered forms of ampicillin when tested in tissue culture. The level of growth inhibition of bacterial strain PKK3535(DHI) was greater than 50%, for both molecular variants of ampicillin that were investigated. The bacteria strain used for testing was a clinical isolate obtained from the University Hospital of the University of Nebraska, Omaha. These two antibiotic variants were methylated ampicillin and ethylated ampicillin. The synthetic procedure for generating these variants is presented as well as the molecular structure. The methylated and ethylated ampicillin were found to be stable at 0 degrees C for many weeks, were somewhat less soluble than normal ampicillin, but dissolved in LB plate media. The resistant bacteria strain was plated onto LB media with altered ampicillin and profound inhibition of bacteria growth was seen within the first 24 hours of incubation. These molecular variants of ampicillin provide evidence of a means to combat the proliferation of resistant bacterial strains. The molecular alteration of antibiotics may provide a suitable means to study and combat the appearance of antibiotic-resistant bacteria.

Ampicillin↗
PubMed1999

American Academy of Pediatrics. Pediatric Practice Action Group and Task Force on Medical Informatics. Privacy protection and health information: patient rights and pediatrician responsibilities.

Pediatricians and pediatric medical and surgical subspecialists should know their legal responsibilities to protect the privacy of identifiable patient health information. Although paper and electronic medical records have the same privacy standards, health data that are stored or transmitted electronically are vulnerable to unique security breaches. This statement describes the privacy and confidentiality needs and rights of pediatric patients and suggests appropriate security strategies to deter unauthorized access and inappropriate use of patient data. Limitations to physician liability are discussed for transferred data. Any new standards for patient privacy and confidentiality must balance the health needs of the community and the rights of the patient without compromising the ability of pediatricians to provide quality care.

Computer Security↗
PubMed1998

Reduced prefrontal and increased subcortical brain functioning assessed using positron emission tomography in predatory and affective murderers.

There appear to be no brain imaging studies investigating which brain mechanisms subserve affective, impulsive violence versus planned, predatory violence. It was hypothesized that affectively violent offenders would have lower prefrontal activity, higher subcortical activity, and reduced prefrontal/subcortical ratios relative to controls, while predatory violent offenders would show relatively normal brain functioning. Glucose metabolism was assessed using positron emission tomography in 41 comparisons, 15 predatory murderers, and nine affective murderers in left and right hemisphere prefrontal (medial and lateral) and subcortical (amygdala, midbrain, hippocampus, and thalamus) regions. Affective murderers relative to comparisons had lower left and right prefrontal functioning, higher right hemisphere subcortical functioning, and lower right hemisphere prefrontal/subcortical ratios. In contrast, predatory murderers had prefrontal functioning that was more equivalent to comparisons, while also having excessively high right subcortical activity. Results support the hypothesis that emotional, unplanned impulsive murderers are less able to regulate and control aggressive impulses generated from subcortical structures due to deficient prefrontal regulation. It is hypothesized that excessive subcortical activity predisposes to aggressive behaviour, but that while predatory murderers have sufficiently good prefrontal functioning to regulate these aggressive impulses, the affective murderers lack such prefrontal control over emotion regulation.

Affect↗
PubMed1998

Prefrontal glucose deficits in murderers lacking psychosocial deprivation.

Previous research has suggested that links between autonomic nervous system functioning and violence are strongest in those who come from benign home backgrounds, but there appears to be no similar research using brain-imaging measures of central nervous system functioning. It was hypothesized that murderers who had no early psychosocial deprivation (e.g., no childhood abuse, family neglect) would demonstrate lower prefrontal glucose metabolism than murderers with early psychosocial deprivation and a group of normal controls. Murderers from a previous study, which showed prefrontal deficits in murderers, were assessed for psychosocial deprivation and divided into those with and without deprivation. Murderers without any clear psychosocial deficits were significantly lower on prefrontal glucose metabolism than murderers with psychosocial deficits and controls. These results suggest that murderers lacking psychosocial deficits are characterized by prefrontal deficits. It is argued that among violent offenders without deprived home backgrounds, the "social push" to violence is minimized, and consequently, brain abnormalities provide a relatively stronger predisposition to violence in this group.

Adult↗
PubMed1996

Asymmetries in intermanual transfer of maze learning in right- and left-handed adults.

This study examined asymmetries in transfer learning on a finger maze as a function of handedness, hand at acquisition and maze orientation at transfer. In both handedness groups, right-hand acquisition enhanced opposite hand performance on an identical and a vertically reversed maze at transfer, relative to a mirror-reversed maze; left-hand acquisition, in turn, enhanced opposite hand transfer on the spatially reversed mazes relative to the identical maze. The findings suggest that different strategies (i.e. verbal versus spatial/motoric) come into play in maze learning depending on the hand used at acquisition (right versus left, respectively) rather than on overall hand dominance.

Adult↗
PubMed1994

Selective reductions in prefrontal glucose metabolism in murderers.

This study tests the hypothesis that seriously violent offenders pleading not guilty by reason of insanity or incompetent to stand trial are characterized by prefrontal dysfunction. This hypothesis was tested in a group of 22 subjects accused of murder and 22 age-matched and gender-matched controls by measuring local cerebral uptake of glucose using positron emission tomography during the continuous performance task. Murderers had significantly lower glucose metabolism in both lateral and medial prefrontal cortex relative to controls. No group differences were observed for posterior frontal, temporal, and parietal glucose metabolism, indicating regional specificity for the prefrontal deficit. Group differences were not found to be a function of raised levels of left-handedness, schizophrenia, ethnic minority status, head injury, or motivation deficits in the murder group. These preliminary results suggest that deficits localized to the prefrontal cortex may be related to violence in a selected group of offenders, although further studies are needed to establish the generalizability of these findings to violent offenders in the community.

Adult↗
PubMedDate not supplied

Trauma-induced immune dysfunction: a challenge for critical care.

Multiply injured trauma patients present a major challenge for the critical care nurse. Should the patient survive the initial injuries, the third phase of mortality (five to seven days following injury) is sepsis. Research findings document a strong link between trauma and immune dysfunction. This article highlights the main immunological defects and underlying mechanisms for trauma-induced immune dysfunction. It provides the theoretical foundation that underlies the rationale for current and future immune-based therapy for trauma patients. Because of the complexity of caring for and preventing septic complications in the trauma patient, advanced practice nurses and nurse educators can use this material to update the knowledge and skills of critical care nurses.

Adult↗