First Report of Leaf Curl on Celery Caused by Colletotrichum acutatum in the United States.

In June 2010 and July 2011, celery (Apium graveolens) samples cv. Tango were submitted to the Penn State Plant Disease Clinic from Franklin and Dauphin Counties, PA, respectively. Plants exhibited curling and twisting of leaves and petioles and dark, brownish-black necrotic lesions at the base of the plant, extending up the petioles. A fungal organism with morphology consistent to Colletotrichum acutatum J.H. Simmonds was isolated from plant lesion tissue excised from the Dauphin Co. sample. Grown on half strength potato dextrose agar (PDA), the colony had gray aerial mycelium and a pink reverse. Conidia were 5.1 to 14.5 × 2.6 to 5.1 µm, aseptate, hyaline, elliptical, with one or both ends slightly pointed, and formed from the mycelium or in dense orange masses of acervuli on the aerial surface of the culture. Setae were not present. To test pathogenicity, five 23-week-old plants of the cv. Sonora and five 11-week-old plants each of the cvs. Tango and Tall Utah were sprayed until runoff with a conidial suspension (1.3 × 106 conidia/ml and 1.4 × 106 conidia/ml, respectively) and 0.025% Tween. One plant of each cv. was sprayed with milliQ water and 0.025% Tween as a control. Plastic bags were sprayed with the conidial suspension (milliQ water for the control), and secured over the individual plants for 24 h to create a humidity chamber. Plants were incubated in a growth chamber with a 16-h photoperiod, 25°C day/18°C night temperatures, and 70% humidity. Post-inoculation, all of the cv. Tango plants exhibited leaf cupping and curling after 7 days and most plants had dark stem lesions after 3 weeks, consistent with celery leaf curl symptoms. Plants of cvs. Tall Utah and Sonora developed malformed leaves and leaf curl symptoms 16 days and 10 days post-inoculation, respectively. None of the control plants developed symptoms. Infected tissue was excised from diseased plants, surface disinfested in 0.5% sodium hypochlorite for 45 s and plated on half strength PDA. Fungal colonies consistent with C. acutatum were recovered from all inoculated celery tissues (except two of the five inoculated cv. Tall Utah plants and the negative controls). To verify morphological identification, the internal transcribed spacer (ITS) rDNA region was amplified and sequenced for our original isolate and those recovered from the inoculated plants using ITS1 and ITS4 primers (2) (GenBank Accession No. JQ794875). Sequence homology revealed 99 to 100% similarity to accessioned isolates of C. acutatum, which included the holotype and a paratype of C. acutatum (Accession Nos. AF411700 and AF411701, respectively). Celery leaf curl has been reported to have caused devastating crop losses on celery in Australia (1, 3) and to our knowledge, C. acutatum causing leaf curl of celery has not been officially reported in the United States. Infected celery plants are unmarketable because of the leaf malformation and eventual plant necrosis caused by C. acutatum. As such, this disease could have serious negative implications for celery growers in the United States. References: (1) J. B. Heaton and S. R. Dullahide. Australas. Plant Pathol. 22:152, 1993. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (3) D. G Wright and J. B. Heaton. Australas. Plant Pathol. 20:155, 1991.

The organizer factors Chordin and Noggin are required for mouse forebrain development.

In mice, there is evidence suggesting that the development of head and trunk structures is organized by distinctly separated cell populations. The head organizer is located in the anterior visceral endoderm (AVE) and the trunk organizer in the node and anterior primitive streak. In amphibians, Spemann's organizer, which is homologous to the node, partially overlaps with anterior endoderm cells expressing homologues of the AVE markers cerberus, Hex and Hesx1. For mice, this raises the question of whether the AVE and node are independent of each other, as suggested by their anatomical separation, or functionally interdependent as is the case in amphibians. Chordin and Noggin are secreted bone morphogenetic protein (BMP) antagonists expressed in the mouse node, but not in the AVE. Here we show that mice double-homozygous mutants that are for chordin and noggin display severe defects in the development of the prosencephalon. The results show that BMP antagonists in the node and its derivatives are required for head development.

Postburn psychologic adaptation of family members of patients with burns.

Although long-term followup studies have shown that the quality of family support is the most important factor influencing a patient's postburn adjustment, little has been published regarding the process of postburn adaptation of family members. This article describes a model of postburn adaptation that delineates the most common sequence of cognitive and emotional issues faced by autonomous, adult family members of burn survivors from the time of the patient's acute injury through completion of the patient's recovery and rehabilitation. In addition to focusing burn team attention on the needs of family members, this model includes descriptions of specific interventions burn staff can make with family members to resolve the issues faced and thus facilitate appropriate postburn adjustment.

The role of the psychiatrist in the team treatment of the adult patient with burns.

Improved survival rates for patients with major burn injuries and the consistent finding of significant long-term psychologic disability among survivors of burn trauma call for a redefinition of the role of the psychiatric consultant in the care of patients with burns. In addition to the traditional functions of diagnosis and treatment of discrete psychiatric disorders in patients with burns, this expanded role includes assisting the patient's normal process of psychologic adaptation after injury, assessing and managing burn pain, and facilitating communication among all members of the burn team. The functions of the psychiatrist are most effectively carried out when the psychiatrist is able to participate on a regular basis in the care of every patient as a member of the burn team.

Reduced bacteria on transplantable allograft skin after preparation with chlorhexidine gluconate, povidone-iodine, and isopropanol.

A comparison was made of the residual microbiologic contamination on transplantable allograft skin for burn wound coverage taken from cadaver donors prepared by two different protocols. One group was prepared with povidone-iodine, detergent, and 70% isopropanol; the other was prepared with these agents and 4% chlorhexidine gluconate (CG). The skin from each of the donor bodies was removed from independently prepared body areas. Without CG, 13.7% of donor body areas were contaminated; with CG, only 5.6% were contaminated. The number of gram-positive bacterial species isolated from skin after CG preparation was dramatically reduced. The gram-positive bacterial contamination rate dropped from 12.1% to 2.2% of donor body areas, a drop of 82%. With CG, 12 of the 15 contaminant species were eliminated; and we saw a general reduction in the total number of contaminated body areas, a specific and pronounced reduction in gram-positive bacteria, and an increase from 86.3% to 94.4% in the amount of skin obtained from donor cadavers that tested negative for bacterial contamination.

The effects of biological wound dressings on the healing process.

Three major biological dressings are available for the temporary closure of wounds: partial-thickness cadaveric human allograft skin, several forms of partial-thickness antibiotic-treated porcine xenograft skin, and human amnion. Generally, biological dressings reduce pain, close the wound to contamination and fluid loss, and prepare the wound bed for permanent closure, usually with autografts. The three types of biological dressings differ in their performance, with allograft skin being clearly superior in its wound maintenance and preparation characteristics, while porcine xenograft presents serious difficulties in incorporation into the wound bed and antigenic challenge to the recipient, and amnion is excessively fragile and tends to allow wound desiccation. The most serious potential liability of biological wound dressings is transmission of infection; however, the actual incidence of such transmission is extremely low. The advantages of physiological coverage provided by biological wound dressings greatly outweighs the chance for harm in the case of human allograft.

The benefits of percutaneous cholecystostomy for decompression of selected cases of obstructive jaundice.

Eleven selected patients with obstructive jaundice underwent percutaneous cholecystostomy (PC) for decompression. Ten of these patients had the constellation of distal common duct obstruction, nondilated or minimally dilated intrahepatic ducts, and a distended gallbladder; one patient with a bleeding dyscrasia had moderately dilated intrahepatic bile ducts. All procedures were successful and effective, and 10 of 11 cholecystostomies were performed within 5-15 minutes. No specific complications occurred. The success, ease, and safety of the procedure indicate primary use of PC for biliary decompression when the intrahepatic bile ducts are minimally dilated or nondilated, because standard transhepatic biliary drainage may be difficult in these cases. Because cannulation of the cystic duct and hence internalization through the tumor may be difficult, PC may be most valuable preoperatively, or before standard percutaneous biliary drainage, or as an alternative to endoscopic drainage. This is a rapid and safe method with which to achieve biliary decompression, especially with minimally dilated or nondilated intrahepatic bile ducts.

A model for evaluating tissue donation seminars: implications for skin banks.

Educational seminars on tissue donation are costly in terms of time, effort, and resources, for both the planners and the participants. Although long-term outcomes from these projects cannot always be practically assessed, specific short-term conclusions can be drawn and degrees of success measured. An ideal evaluation technique needs to address issues such as identification of participant interests, levels of existing participant knowledge, and participant reaction to presented materials. Assessment in these areas allows for subsequent modifications intended to produce more effective and interesting seminars. Such an evaluation technique has been developed, and it is presented here in the context of its application to an educational seminar on the topic of organ and tissue procurement with special reference to skin banking.

Psychological stages in adaptation following burn injury: a method for facilitating psychological recovery of burn victims.

As a result of clinical observation of 444 patients hospitalized for treatment of acute burn injury at Humana Burn Center between July 1983 and October 1986, we have developed a seven-stage method of assessing and assisting the burn victim's psychological recovery. This method delineates the stages in the normal psychological healing process in burn victims and offers specific suggestions for staff interventions to assist the patient at each stage. This method can be utilized in an integrated fashion by all members of the multi-disciplinary burn team to expedite the patient's psychological recovery and to maximize his compliance with necessary treatment modalities.

Development of a passive device for freezing large amounts of transplantable skin at one time in a -70 degrees C mechanical refrigerator.

A simple device has been developed for the simultaneous cooling of up to 9120 cm2 of allograft skin in a flat package format. The device, named an insulated alternating-offset heat sink device, is composed of a stack of interleaved layers of 2.0-mm-thick packets of skin and 3.18-mm-thick aluminum heat sinks (each 33.0 cm long by 22.9 cm wide). Four skin packets are placed in a single layer on each heat sink plate, and the number of plates can be varied to accommodate different numbers of skin packets. Every heat sink protrudes 6.3 cm of its 33.0-cm length beyond the skin packets to make a fin for heat convection, but adjacent plates alternate the direction of their fin protrusion so that the layers of plates alternate in their 6.3-cm offset. Insulation layers of 2.54-cm-thick expanded polystyrene are placed on the exposed surfaces of the top and bottom heat sinks in the stack, and the stack is held together by rubber bands. The device is cooled in a -70 degrees C mechanical refrigerator. Maximal cooling rates of -1.8 degrees C min-1 are obtained for both 6- and 11-plate devices, and -3.0 degrees C min-1 for a 2-plate device. The exothermic temperature plateaus associated with skin cooled in these devices are 1.5-1.8 min in duration. Skin cooled by this technique maintains levels of glucose oxidation similar to those associated with skin cooled by liquid nitrogen vapor at a controlled rate of -1 degree C min-1, provided rapid warming is employed after -70 degrees C storage. The development of this device provides a method for the simple, low-cost cryopreservation of the large amounts of allograft skin obtained from a cadaveric donor.

Pain associated with an adherent polyurethane wound dressing.

Patient ratings of pain associated with autograft skin donor sites covered by an adherent polyurethane film dressing (Op-Site, Smith & Nephew) were collected using a modified Visual Analogue Scale. Analyses were undertaken to examine differences between pain levels under conditions of rest and activity, and with variations in application technique. It was found that with proper application and with at-rest patients, Op-Site-covered donor sites could be maintained relatively pain free. However, both specific conditions of application and increases in patient ambulation could result in the patient experiencing donor-site pain of an intensity comparable to concurrent burn-wound pain. To utilize fully their potential for pain control, the polyurethane film dressings must be appropriately applied and maintained, and their use coupled with an adequate analgesic regimen.

The role of sampling in the detection of microbial contamination on cadaveric allograft skin used as a biological wound dressing.

The availability of cryopreservation and low temperature storage techniques for cadaveric allograft skin allows it to be preserved while microbial assessments are made before its use as a temporary biological dressing on burn wounds. In a 300-donor, 5-year prospective study, we tested ten skin samples from defined areas on each donor for microbiological contamination. Although the skin from 52.3 per cent of the donors possessed some detectable residual microbial contamination after surgical body preparation and skin removal, such contamination was limited to an average of 1.4 areas per body, leaving 86 per cent of all skin obtained free from detectable contamination and suitable for use as biological wound dressings. The number of skin samples tested per donor body determined the accuracy of detection of the presence of contamination. Testing one skin sample per donor body yielded a correct skin assessment 92 per cent of the time, while testing five skin samples increased the accuracy to 96 per cent, and testing ten skin samples yielded a 99.9 per cent accuracy in detection of skin contamination. Thus, it is within the ability of a skin bank to set the limits of microbiological risk to patients receiving processed cadaveric allograft skin.

Cryopreservation of skin using an insulated heat sink box stored at -70 degrees C.

The cooling of skin to a temperature of -70 degrees C was carried out by two methods: programmed controlled-rate (PCR) cooling at -1 degree C min-1 to -70 degrees C, and variable-rate cooling to -70 degrees C in an insulated heat sink box (IHSB). The IHSB was constructed of polystyrene and contained two aluminum heat sinks placed one on each side of flat packets of skin. The IHSB containing skin was cooled in a -70 degrees C constant-temperature refrigerator. When using the IHSB, the insulation provides a slow cooling rate while the paired heat sinks provide even heat flow across the top and bottom surfaces of the flat skin packets, minimizing the duration and potential damaging effects of the exothermic temperature plateau which occurs at the freezing point. When followed by 24-hr storage at -70 degrees C and warming at about 316 degrees C min-1, the IHSB cooling method was equivalent to the PCR method in generating a suitably slow cooling rate of -1 to -2 degrees C min-1, and maintaining about 80% of normal skin cell glucose metabolism. The development of the IHSB cooling system provides a method for the simple, cost-efficient cryopreservation of small amounts of autograft skin, such as those remaining from surgical procedures, and can also provide an allograft skin banking capability to any facility possessing a -70 degrees C refrigerator.

Variables determining the amount of microbial contamination on cadaveric allograft skin used as a biological wound dressing.

The increased availability and use of cadaveric allograft skin as a temporary burn wound dressing has emphasized the need for a complete understanding of the parameters affecting the contamination level of this material. We undertook a prospective evaluation of the allograft skin obtained from 300 cadaveric donors over 5 years. We evaluated the contribution to skin contamination of eight parameters: sex, age, race, cause of death, elapsed time postmortem before skin removal, total refrigerated storage time of the skin prior to cryopreservation, donor body area from which the skin was removed, and choice of surgical operators or teams. The only parameters significantly related to skin contamination level were the choice of surgical operator or team which prepared the body and removed the skin (P = 0.0001) and the acceptance of skin from donors when the cause of death was unknown but presumed to be from natural causes (PNC) such as myocardial infarction or cerebral vascular accident (P = 0.006). In the case of the PNC deaths, there was only a small 3.4 per cent increase in bacterial contamination and no increase in fungi or yeast, while some surgical operators were associated with five-fold more bacterial contamination and nearly 13-fold more fungal contamination than other surgical operators. We conclude that the performance of surgical operators appears to be the major determinant of the microbiological cleanliness of skin from cadaveric allograft donors.

Optimum warming rates to maintain glucose metabolism in porcine skin cryopreserved by slow cooling.

The optimum warming rate for cryopreserved skin (dimensions: 7.6 cm X 20 cm X 0.38 mm thick) folded double in a flat package format was tested using a recently developed quantitative assay of skin cell metabolism. The assay measured the metabolic conversion of glucose to carbon dioxide by intact partial-thickness skin. Skin cooled at a constant, controlled rate of -1 degree C min-1 to a temperature of -100 degrees C, and then rapidly transferred to -196 degrees C for overnight storage, could be optimally warmed at rates of 95-260 degrees C min-1 by immersion in 10-20 degrees C water. The amount of metabolic activity remaining in skin warmed at rates within this optimal range was 76-78% of normal. Slightly less than maximal metabolic activity, 71-75% of normal, resulted from warming rates of 292-458 degrees C min-1, obtained by immersion in 25-37 degrees C water. Skin metabolism remaining after warming rates of 30-53 degrees C min-1 (3-5 degrees C water) was 52-70% of normal, while that remaining after rates of 501-882 degrees C (40-65 degrees C water) was 0-47% of normal. These experiments establish practical upper and lower limits for post-cryopreservation warming rates employed to maintain skin cell metabolism, and the cellular viability which depends upon that metabolism.

Integrated study of the structural and metabolic degeneration of skin during 4 degrees C storage in nutrient medium.

Integrated studies of the structural and metabolic degradation of skin during 4 degrees C refrigerated storage in Eagle's minimal essential medium were undertaken. Skin degeneration occurred in three phases during the first 7 weeks of refrigeration. Phase I (Days 1-10) was characterized by the release of cellular debris and leakage of intracellular enzymes into the storage medium, shrinkage of the epithelium, and vacuolization and cell loss in the vascular bundles of the papillary dermis. The release of debris was accelerated by a 2-hr incubation of the skin at 25 and 37 degrees C prior to 4 degrees C storage. The ability of dermal cells to metabolize glucose, aspartic acid, glutamic acid, ornithine, and orotic acid to carbon dioxide dropped to low levels during Phase I. Phase II (Days 11-30) was characterized by a period of less intense physical decay, but with continued cellular and vascular degeneration. By the third week, there was nearly total loss of recognizable vascular bundles in the papillary dermis. Phase III (Days 31-58) was characterized by the exfoliation of large amounts of cellular debris and significant loss of structural integrity. By the fifth week, nearly all of the nuclei in the epidermis became pyknotic, and the vascular bundles of the reticular dermis were lost. Previous reports of the maximum allowable duration of skin storage at 0-8 degrees C have ranged from 0.3 to 185 days; however, our findings suggest that the useful limit of refrigerated skin storage in nutrient medium is 1 week if physiological function and structural integrity are desired for optimum postgraft performance.

Delirium in burn patients isolated in a plenum laminar air flow ventilation unit.

The incidence of psychological morbidity associated with delirium was compared between burn patients isolated in a bed-size plenum laminar air flow ventilation unit (PLAFVU) and matched control burn patients treated in standard open cubicles. In patients with burn sizes of less than 60 per cent of body surface area, delirium developed in 40 per cent of the patients treated in the PLAFVU, but only in 7 per cent of the matched control patients (P = 0.04). Most of the patients with burn sizes of 60 per cent or greater exhibited delirium regardless of the method of treatment. The development of psychological morbidity was more strongly associated with treatment in the PLAFVU than with common causes such as hyponatraemia or septicaemia. The present study suggests that in the majority of burn patients, i.e. those with less than 60 per cent burns, the development of psychological morbidity may in fact be influenced by types of treatment which affect patient psychology, rather than being solely the result of physiological derangements.