Immunosuppression with cyclosporine during the incubation period of experimental woodchuck hepatitis virus infection increases the frequency of chronic infection in adult woodchucks

The immunosuppressive agent cyclosporine was given to adult woodchucks during acute experimental infection with woodchuck hepatitis virus (WHV). All 17 woodchucks given WHV alone or with a vehicle resolved the infection (i.e., zero chronicity), but when cyclosporine was given throughout the incubation and acute phases of infection (0-12 or 14 weeks; n = 12), the rate of chronic infection increased to 92%. When cyclosporine was given only during the incubation period (0-4 weeks; n = 10) or only during the acute phase of infection (2-12 weeks; n = 9), the rates increased to 50% and 55%, respectively. However, when the drug was given after the acute phase (8-18 weeks; n = 9), the chronic infection rate (11%) did not differ from that in untreated and vehicle controls. Immune responses inhibited by cyclosporine are important in resolution of acute WHV infection and occur mainly during the first 8 weeks. Immunosuppression of these responses for even short intervals during incubation (e.g., 0-4 weeks) increases the risk of chronicity.

The human fibroblast receptor for gp86 of human cytomegalovirus is a phosphorylated glycoprotein

A human embryonic lung (HEL) cell receptor for gp86 of human cytomegalovirus that functions in virus-cell fusion was further characterized. Anti-idiotype antibodies that mimic gp86 were used to immunoprecipitate the 92.5-kDa fibroblast membrane receptor for gp86, which was preincubated with various endoglycosidases. The receptor, which has a pI ranging from 5.3 to 5.6, appears to be a glycoprotein with primarily N-linked sugar residues, some of which have high concentrations of mannose and some of which are complex oligosaccharides. Western blots (immunoblots) of electrophoretically transferred receptor incubated with various biotinylated lectins confirmed the presence of sugar moieties, including N-acetylglucosamine, glucose or mannose, and galactose, but not fucose or N-acetylgalactosamine. This gp86 receptor from uninfected HEL cells also incorporated radiolabeled phosphate from orthophosphoric acid, indicating that it is a constitutively phosphorylated receptor.

Clinically relevant optimization of 3-D conformal treatments

In this paper a method of computer-aided optimization of 3-D conformal treatment plans is presented which incorporates models to predict the clinical consequences of resulting dose distributions. Even though these models are simplistic, it is submitted that their intelligent use leads to treatment plans which indicate lower normal tissue complications and higher tumor control. Dose distribution data, biological models, and observed normal tissue and tumor response data are used to compute tumor control and normal tissue complication probabilities for each of the critical normal structures encountered in a treatment plan. These quantities are combined into a single score using an objective function which incorporates the importance of each end point as assessed by the physician. Using the "simulated annealing" method of optimization, the beam weights are adjusted to maximize the score. Additional constraints are applied to ensure consistency of the results of optimization with the judgment of the physician. These optimization methods have been applied to conformal treatment plans consisting of multiple fixed fields with conformal field shaping. The results indicate that the methods presented have considerable potential.

AHCA (American Health Care Association) leaders look to the year ahead

During the past 15 months, long term care providers have worked diligently to implement the nursing facility reform provisions of the Omnibus Budget Reconciliation Act of 1987 (OBRA). Other significant events, such as the release of final rules clarifying OBRA and state funding shortfalls, promise to keep the industry busy in the coming years. Provider interviewed leaders of the American Health Care Association (AHCA) to assess the present state of the industry and talk about the Association's goals.

Improving documentation of aggressive behavior in nursing home residents

1. Although 66% of the 1.3 million elderly nursing home residents in the US exhibit aggressive tendencies, research indicates that caregivers underdocument aggressive incidents. As a result, the extent of aggression is unknown. 2. This study found that LPNs reported the largest percentage (41%) of the 51 documented aggressive incidents, which reportedly occurred most frequently in the bathroom (49% of the time) between 5 AM and noon (86% of the time). Most aggressive residents (55.1%) never had visitors. 3. This study concludes that nursing practice would benefit from a consistent definition of aggression, an easy-to-use clinical instrument to collect data on aggression, and caregiver education programs on assessing aggression.

Workers Compensation cases with traumatic brain injury: an insurance carrier's analysis of care, costs, and outcomes

The purpose of this survey was to review the medical care, medical costs, and outcomes of 86 Workers Compensation cases involving traumatic brain injury. An analysis of ICD-9 diagnoses, Rancho Los Amigos Cognitive Levels, age, sex, accident description, management techniques, costs, outcomes, and many other factors was conducted. The total indemnity (wage loss) and medical payments amounted to $27.1 million. For example, one case with temporal lobe hematoma, due to a fall in 1972, has had $1.1 million in medical payments since the injury occurred. The current average age is 40 years with 71% still residing at home. Only 10% are currently employed and 40% are known to be receiving other benefits. The increasing frequency and severity of these cases, as well as the extension of survival due to improved care and technology, highlight the need to address the question, "Who will be the caretakers, and what will be the associated costs?" Actuarial projections into the 21st century are given. It is concluded that, while further long-term studies are needed, Workers Compensation carrier representatives and health care providers must continue to work together on the interdisciplinary rehabilitation team.

Correlates of disruptive behavior in cognitively impaired elderly nursing home residents

Disruptive behavior, resulting in negative consequences for both residents and caregivers, occurs in a large proportion of the nursing home population. This review of literature surveys studies that describe disruptive behavior and the correlates of this behavior in the cognitively impaired elderly. In the studies reviewed, the average prevalence of reported disruptive behavior among a total of 5,650 subjects was 42.8%. Correlates most frequently linked with disruptive behavior include cognitive status, functional ability, age, and premorbid personality. Suggestions for future research are discussed.

Anti-idiotype antibodies that mimic gp86 of human cytomegalovirus inhibit viral fusion but not attachment

Human cytomegalovirus (CMV) infects cells by sequential processes involving attachment, fusion with the cell membrane, and penetration of the capsid. We used two monoclonal anti-idiotype that mimic one of the CMV envelope glycoproteins, gp86, to study its role in the early phases of CMV infection. Neither of two such antibodies inhibited virus binding to human embryonic lung (HEL) fibroblasts; however, both antibodies inhibited the fusion of CMV with HEL cells, as measured by an assay in which viral envelope is labeled with a fluorescent amphiphile (octadecyl rhodamine B chloride, or R18), resulting in increased fluorescence during fusion of virus with the cell membrane. Because these anti-idiotype antibodies were shown previously to bind to specific receptors on HEL cell membranes, these findings suggest that both gp86 and its cell membrane receptor may function in the fusion of human CMV with HEL cells.

The trauma of suction-assisted lipectomy cannula on flap circulation in rats

The effect of suction-assisted lipectomy on cutaneous blood vessels of inguinal skin flaps was studied and compared in 191 rats. Different types of cannula tips were used; the number of passes was standardized. In one experiment, following suctioning, 3 X 2 cm groin island flaps based on inferior epigastric pedicles were raised and then reattached. Fluorescein dye study and microangiography were performed to evaluate flap viability. Flap survival was determined clinically and by histologic examination on the fifth postoperative day. Three-sided inguinal random-pattern flaps were raised in a second experiment and reattached following suctioning. On the fifth postoperative day, surviving flap areas were measured using standard photographs and an imaging computer and were compared with controls. Results showed that cannula passes accompanied by vacuum are harmful to vessels, while those unaccompanied by vacuum are not. The greater the number of suctioning passes, the more trauma there is to vessels and the greater is the likelihood of flap necrosis. Conical and spatula tips were more harmful to vessels than spherical, cobra, keel cobra, or Fournier tips. These results support the conclusion that suction-assisted lipectomy enhances the possibility of skin necrosis by traumatizing the vascular pedicle of a flap, especially when it is used as an adjunct to flap elevation.

Elevated formation of nitrate and N-nitrosodimethylamine in woodchucks (Marmota monax) associated with chronic woodchuck hepatitis virus infection

Nitrate balance and N-nitrosodimethylamine (NDMA) excretion were studied in woodchucks chronically infected with woodchuck hepatitis virus (WHV). Twenty-four-h urinary recovery of a bolus dose of [15N]nitrate was 54 +/- 12% in woodchucks. WHV-infected animals formed 3-fold more nitrate endogenously than did control animals (P less than 0.01). Treatment of WHV-infected animals with Escherichia coli lipopolysaccharide increased nitrate excretion 15-fold, while uninfected animals increased nitrate excretion 4-fold. The endogenous formation of NDMA was higher in WHV-infected woodchucks than in uninfected controls. After administration of L-[15N2]arginine, [15N]nitrate, and [15N]NDMA were detected in urine indicating that arginine is a precursor of biosynthesized nitrate and the hepatocarcinogen NDMA. NDMA probably results from the formation of nitrosating agents during the oxidation of arginine to oxides of nitrogen and citrulline. Woodchucks chronically infected with WHV develop hepatocellular carcinomas with high frequency. Our observations suggest an additional mechanism that may be involved in the pathogenesis of hepatocellular carcinoma associated with chronic WHV infection.

The effect of hypothermic cardiopulmonary bypass and total circulatory arrest on cerebral metabolism in neonates, infants, and children

Cardiopulmonary bypass management in neonates, infants, and children often requires the use of deep hypothermia at 18 degrees C with occasional periods of circulatory arrest and represents marked physiologic extremes of temperature and perfusion. The safety of these techniques is largely dependent on the reduction of metabolism, particularly cerebral metabolism. We studied the effect of hypothermia on cerebral metabolism during cardiac surgery and quantified the changes. Cerebral metabolism was measured before, during, and after hypothermic cardiopulmonary bypass in 46 pediatric patients, aged 1 day to 14 years. Patients were grouped on the basis of the different bypass techniques commonly used in children: group A--moderate hypothermic bypass at 28 degrees C; group B--deep hypothermic bypass at 18 degrees to 20 degrees C with maintenance of continuous flow; and group C--deep hypothermic circulatory arrest at 18 degrees C. Cerebral metabolism significantly decreased under hypothermic conditions in all groups compared with control levels at normothermia, the data demonstrating an exponential relationship between temperature and cerebral metabolism and an average temperature coefficient of 3.65. There was no significant difference in the rate of metabolism reduction (temperature coefficient) in patients cooled to 28 degrees and 18 degrees C. From these data we were able to derive an equation that numerically expresses a hypothermic metabolic index, which quantitates duration of brain protection provided by reduction of cerebral metabolism owing to hypothermic bypass over any temperature range. Based on this index, patients cooled to 28 degrees C have a predicted ischemic tolerance of 11 to 19 minutes. The predicted duration that the brain can tolerate ischemia ("safe" period of deep hypothermic circulatory arrest) in patients cooled to 18 degrees C, based on our metabolic index, is 39 to 65 minutes, similar to the safe period of deep hypothermic circulatory arrest known to be tolerated clinically. In groups A and B (no circulatory arrest), cerebral metabolism returned to control in the rewarming phase of bypass and after bypass. In group C (circulatory arrest), cerebral metabolism and oxygen extraction remained significantly reduced during rewarming and after bypass, suggesting disordered cerebral metabolism and oxygen utilization after deep hypothermic circulatory arrest. The results of this study suggest that cerebral metabolism is exponentially related to temperature during hypothermic bypass with a temperature coefficient of 3.65 in neonates infants and children. Deep hypothermic circulatory arrest changes cerebral metabolism and blood flow after the arrest period despite adequate hypothermic suppression of metabolism.

Cyclosporin A modulates the course of woodchuck hepatitis virus infection and induces chronicity

Immunosuppression is known to influence the state of chronic hepatitis B virus infection, and is thought to increase the risk of developing chronic infection in newly exposed individuals. Cyclosporin A (CsA), an immunosuppressive agent that inhibits Th cell function, was administered to woodchucks chronically infected with woodchuck hepatitis virus (WHV), and resulted in a decreased severity of chronic hepatitis and an increased viremia during the treatment. Adult woodchucks inoculated with WHV and given CsA for 14 wk had increased viremias, decreased acute phase liver injury, and developed chronic infections at a higher rate compared with immunocompetent woodchucks given virus alone (chronicity in seven of seven WHV + CsA + vs zero of nine WHV + CsA-; p less than 0.001). These results in a relevant animal model of hepatitis B virus infection indicate: 1) that liver injury in acute hepadnavirus infections is immune-mediated and not a direct cytopathic effect of virus replication; 2) that Th cells function in the inflammatory response and in the immunologic control of hepadnavirus infection; and 3) that suppression of Th cell function in acute hepadnavirus infection decreases liver injury but alters the outcome of infection in favor of chronicity. These results also suggest continued challenges in the application of CsA in liver transplantation for hepatitis B virus-induced diseases.

Cyclosporin A modulates the course of woodchuck hepatitis virus infection and induces chronicity

Immunosuppression is known to influence the state of chronic hepatitis B virus infection, and is thought to increase the risk of developing chronic infection in newly exposed individuals. Cyclosporin A (CsA), an immunosuppressive agent that inhibits Th cell function, was administered to woodchucks chronically infected with woodchuck hepatitis virus (WHV), and resulted in a decreased severity of chronic hepatitis and an increased viremia during the treatment. Adult woodchucks inoculated with WHV and given CsA for 14 wk had increased viremias, decreased acute phase liver injury, and developed chronic infections at a higher rate compared with immunocompetent woodchucks given virus alone (chronicity in seven of seven WHV + CsA + vs zero of nine WHV + CsA-; p less than 0.001). These results in a relevant animal model of hepatitis B virus infection indicate: 1) that liver injury in acute hepadnavirus infections is immune-mediated and not a direct cytopathic effect of virus replication; 2) that Th cells function in the inflammatory response and in the immunologic control of hepadnavirus infection; and 3) that suppression of Th cell function in acute hepadnavirus infection decreases liver injury but alters the outcome of infection in favor of chronicity. These results also suggest continued challenges in the application of CsA in liver transplantation for hepatitis B virus-induced diseases.

Cerebral blood flow response to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in children

We examined the relationship of changes in partial pressure of carbon dioxide on cerebral blood flow responsiveness in 20 pediatric patients undergoing hypothermic cardiopulmonary bypass. Cerebral blood flow was measured during steady-state hypothermic cardiopulmonary bypass with the use of xenon 133 clearance methodology at two different arterial carbon dioxide tensions. During these measurements there was no significant change in mean arterial pressure, nasopharyngeal temperature, pump flow rate, or hematocrit value. Cerebral blood flow was found to be significantly greater at higher arterial carbon dioxide tensions (p less than 0.01), so that for every millimeter of mercury rise in arterial carbon dioxide tension there was a 1.2 ml.100 gm-1.min-1 increase in cerebral blood flow. Two factors, deep hypothermia (18 degrees to 22 degrees C) and reduced age (less than 1 year), diminished the effect carbon dioxide had on cerebral blood flow responsiveness but did not eliminate it. We conclude that cerebral blood flow remains responsive to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in infants and children; that is, increasing arterial carbon dioxide tension will independently increase cerebral blood flow.

Stiff-man syndrome: a GABAergic autoimmune disorder with autoantigenic heterogeneity

Autoantibodies that reacted with cell bodies and axon terminals of gamma-aminobutyric acid (GABA)ergic neurons were present in the serum and cerebrospinal fluid in a patient with stiff-man syndrome with type I diabetes. Immunoblot experiments using this patient's serum and cerebrospinal fluid did not corroborate an earlier observation that these autoantibodies are directed against the GABAergic cytosolic enzyme, L-glutamic acid decarboxylase. While L-glutamic acid decarboxylase autoantibodies may be associated with this syndrome, they do not appear to be easily demonstrated.

Natural history of experimental woodchuck hepatitis virus infection: molecular virologic features of the pancreas, kidney, ovary, and testis

The kinetic patterns of woodchuck hepatitis virus (WHV) infection were monitored in the pancreas, kidneys, ovaries, and testes. Groups of woodchucks experimentally infected with a standardized inoculum of WHV were sacrificed at different times over a 65-week period beginning in the preacute phase of viral infection and continuing to the period of serologic recovery or the establishment of chronic infections and subsequent hepatocellular carcinoma (B. E. Korba, P. J. Cote, F. V. Wells, B. Baldwin, H. Popper, R. H. Purcell, B. C. Tennant, and J. L. Gerin, J. Virol. 63:1360-1370, 1989). Tissues from an additional group of long-term (2 to 3 years) chronic WHV carriers which had been infected with the same WHV inocula were also examined. Viral DNA replication intermediates were found in all four tissues during the acute phase of WHV infection. However, WHV DNA replication intermediates were observed only in the kidneys of a small proportion of the chronically infected animals. Following the acute phase of infection, WHV DNA was present only in the pancreas, kidneys, and ovaries of the chronically infected woodchucks. A progressive evolution of different WHV genomic forms related to the replicative state of WHV was observed in these tissues. Histologic evaluation of these four tissues revealed only minimal, localized lesions which were not correlated with the state of WHV activity. The observations compiled in this study further extend the tissue tropism of WHV.

Caregivers' perception of aggressive behavior in cognitively impaired nursing home residents

Aggressive behaviors of nursing home residents represent a significant problem for caregivers and families. A guided interview format was used to collect data from 21 nurses and 20 nursing assistants in order to gather information on the characteristics of aggressive behavior and how it is managed in cognitively impaired nursing home residents. Sixty-eight percent of the caregivers stated the residents were physically aggressive, while 95% cited verbal aggression. Aggression occurred most commonly in the mornings while the caregiver was dressing the resident. Inadequate staffing and new staff were both seen as problems by the caregivers. Talking soothingly and assuring the resident were techniques initially used to comfort the residents. Reasoning with the resident was the most common follow-up procedure used by the caregivers.

Endocrine correlates of hibernation-independent gonadal recrudescence and the limited late-winter breeding season in woodchucks, Marmota monax

Woodchucks (Marmota monax) normally experience gonadal recrudescence towards the end of a 4-5 month hibernation, emerge in late winter, immediately breed in a short 3-week breeding season, and have regressed gonads before the next hibernation. Our studies of wild and captive animals show that fertile females give birth to single litters after a 32-day gestation and their breeding season is terminated by a reactivation of the corpora lutea of pregnancy for 1-3 months immediately postpartum. In nonbred females the breeding season is likewise terminated by spontaneous luteinization of the ovaries for 1-3 months shortly after the vernal equinox. Tests regress and testosterone declines during and after the breeding season. Circannual reproductive cycles persist in the absence of hibernation and are shortened to 9-10 months after 3-5 years of a 12L:12D photoperiod. Unique aspects of this species that merit endocrine investigation include descent/retraction of testes, transient luteolysis at parturition, superactivation of postpartum corpora lutea, regulation of the pituitary-gonadal axis by an annual endogenous metabolic cycle entrained to the annual change in photoperiod, and the hormonal basis of hibernation.

Expression of infectious woodchuck hepatitis virus in murine and avian fibroblasts

The liver is the primary site for replication of the hepadnavirus genome. We asked whether the posttranscriptional phase of the viral replication cycle would depend on hepatocyte-specific functions. For this purpose, we assayed a previously constructed chimera between sequences of the cytomegalovirus immediate-early promoter-enhancer region and woodchuck hepatitis virus (WHV) (C. Seeger and J. Maragos, J. Virol. 63:1907-1915, 1989) for its ability to direct the synthesis of infectious WHV in hepatoma cells and in murine and avian fibroblast cells. Viruslike particles containing WHV DNA were produced transiently in transfected hepatoma cells and in fibroblasts. Inoculation of woodchucks with culture medium from hepatoma cells or fibroblasts transfected with viral DNA led to productive WHV infection, as observed following infection of woodchucks with serum from WHV-infected animals. These results demonstrate that posttranscriptional events of the hepadnavirus replication cycle are not dependent on hepatocyte-specific functions.

Hepatocellular carcinoma in woodchuck hepatitis virus-infected woodchucks: presence of viral DNA in tumor tissue from chronic carriers and animals serologically recovered from acute infections

During long-term studies of the natural history of woodchuck hepatitis virus infection, five cases of histologically confirmed, primary hepatocellular carcinoma were observed in a total of 92 woodchucks which had recovered, by analysis of viral serologic markers (WHsAg-, anti-WHc+, anti-WHs+), from experimental acute woodchuck hepatitis virus infections 20 to 30 months prior to the detection of hepatocellular carcinoma. No hepatocellular carcinoma was observed in 167 uninfected controls at least 3 years of age and held in the same laboratory environment. Southern blot hybridization analysis of liver tissue taken from four of these recovered woodchucks revealed the presence of low levels (0.1 to 0.3 copies per cell) of integrated woodchuck hepatitis virus DNA in hepatocellular carcinoma (four of four animals) and nonneoplastic tissue (three of four animals). Similarly, hepatocellular carcinoma tissue obtained from two wild-caught, naturally infected and serologically recovered woodchucks also contained low levels of integrated woodchuck hepatitis virus DNA. Liver tissues from another 27 of these 92 recovered woodchucks (without hepatocellular carcinoma) were examined for woodchuck hepatitis virus nucleic acids 13 to 31 months following experimental woodchuck hepatitis virus infection. Nonreplicating woodchuck hepatitis virus DNA was present in the liver of eight (30%) and in the peripheral blood lymphocytes from eight (30%) of these 27 animals. These results were in marked contrast to the analysis of woodchuck hepatitis virus DNA in the liver tissue of chronic woodchuck hepatitis virus carriers (20 experimentally infected and nine naturally infected). In these animals, high levels of replicating woodchuck hepatitis virus DNA (up to 2,000 copies per cell) were observed in all hepatocellular carcinoma and nonneoplastic liver tissue. Integrated woodchuck hepatitis virus DNA was found in eight of 60 individual hepatocellular carcinomas detected in 29 chronic carriers, 15 to 40 months postinfection. Integrated woodchuck hepatitis virus DNA was present in the nonneoplastic tissue from four of these 29 chronic woodchuck hepatitis virus carriers.

Natural history of woodchuck hepatitis virus infections during the course of experimental viral infection: molecular virologic features of the liver and lymphoid tissues

In this study, the kinetic patterns of woodchuck hepatitis virus (WHV) infection were monitored in the liver and the five primary components of the lymphoid system (peripheral blood lymphocytes, lymph nodes, bone marrow, spleen, and thymus). Groups of woodchucks experimentally infected with a standardized inoculum of WHV were sacrificed at different times over a 65-week period beginning in the preacute phase of viral infection and continuing to the period of serologic recovery or the establishment of chronic infections and subsequent hepatocellular carcinoma. Infection by WHV was not limited to the liver but involved the major components of the lymphoid system during all stages of virus infection. A complex series of kinetic patterns was observed for the appearance of WHV DNA in the different lymphoid compartments and the liver during the entire course of viral infection. A progressive evolution of different WHV genomic forms related to the replicative state of WHV was also observed. Lymphoid cells of the bone marrow were the first cells in which WHV DNA was detected, followed in order by the liver, the spleen, peripheral blood lymphocytes, lymph nodes, and finally the thymus. Several differences were observed in the cellular WHV DNA patterns between woodchucks that developed chronic WHV infections and those that serologically recovered from acute WHV infections. The observations compiled in this study indicate that the host lymphoid system is intimately involved in the natural history of hepadnavirus infections from the earliest stages of virus entry.