Infectious Complications in Bone Marrow Transplant Patients

In 11 patients receiving transplants of allogeneic bone marrow, the graft was successful in six. Nine patients developed infections, and six died—five of septicaemia and one of Pneumocystis carinii pneumonia. Fifty individual infections occurred. Predisposing factors included severe underlying diseases, long-term exposure to resistant hospital organisms, heavy immunosuppressive therapy, and graft-versus-host disease. Gram-negative bacilli and Candida albicans were the most common causative organisms. In every instance of septicaemia identical organisms were isolated from blood cultures and simultaneously obtained stool cultures. Infection with exogenous organisms often occurred in patients occupying conventional isolation rooms. Isolation of one patient for 45 days in a laminar air flow room prevented infection with exogenous organisms.     

Microbiological Evaluation of Protected Environments During Patient Occupancy

Microbiological monitoring has been conducted in two life island (LI) units and two laminar airflow (LAF) rooms while they were occupied by patients undergoing cancer chemotherapy. There were only 5 organisms per 1,000 ft(3) of air sampled in LAF rooms, 31 organisms in LI units, and over 3,000 organisms in regular hospital rooms. None of the floor samples obtained from hospital rooms was sterile, compared to over 70% in LAF rooms. The rate of deposition of organisms onto settling plates was one organism per 4.5 hr in LAF rooms compared to one organism per 0.08 hr in hospital rooms. Potential pathogens were isolated much more frequently from environmental samples obtained from hospital rooms than from LI units or LAF rooms. Two sites of persistent contamination arose in the LAF rooms: the vinyl tile flooring and the water supply system. Over half of the potential pathogens cultured from the protected environment units were cultured initially from the patients who occupied the units.     

Cellular changes in the bone marrow of Plasmodium berghei-infected mice: II. Blast transformation and phagocytosis

The present work is concerned with early cellular changes occurring during a malaria infection. Blast transformation by lymphoid cells and phagocytosis by adherent cells from the bone marrow was performed, using immune and nonimmune Balb/c mice. Nonadherent bone marrow cells from immune mice show an increased specific lymphoblast transformation. This increase was not observed during a lethal infection (PI). Adherent bone marrow cells were assayed for phagocytosis of parasitized (PE) or normal erythrocytes (NE). Cells from immune mice show an increase in phagocytosis of PE and NE. Cells from PI mice showed a decreased phagocytosis throughout the infection, beginning at Day 1 after challenge.     

Different Types of Door-Opening Motions as Contributing Factors to Containment Failures in Hospital Isolation Rooms

Hospital isolation rooms are vital for the containment (when under negative pressure) of patients with, or the protection (when under positive pressure) of patients, from airborne infectious agents. Such facilities were essential for the management of highly contagious patients during the 2003 severe acute respiratory syndrome (SARS) outbreaks and the more recent 2009 A/H1N1 influenza pandemic. Many different types of door designs are used in the construction of such isolation rooms, which may be related to the space available and affordability. Using colored food dye as a tracer, the qualitative effects of door-opening motions on the dissemination of potentially contaminated air into and out of a single isolation room were visualized and filmed using Reynolds-number-equivalent, small-scale, water-tank models fitted with programmable door-opening and moving human figure motions. Careful scaling considerations involved in the design and construction of these water-tank models enabled these results to be accurately extrapolated to the full-scale situation. Four simple types of door design were tested: variable speed single and double, sliding and hinged doors, in combination with the moving human figure. The resulting video footage was edited, synchronized and presented in a series of split-screen formats. From these experiments, it is clear that double-hinged doors pose the greatest risk of leakage into or out of the room, followed by (in order of decreasing risk) single-hinged, double-sliding and single-sliding doors. The relative effect of the moving human figure on spreading any potential contamination was greatest with the sliding doors, as the bulk airflows induced were large relative to those resulting from these door-opening motions. However, with the hinged doors, the airflows induced by these door-opening motions were significantly greater. Further experiments involving a simulated ventilated environment are required, but from these findings alone, it appears that sliding-doors are far more effective for hospital isolation room containment.     

Pineal control of immune status and hematological changes in blood and bone marrow of male squirrels (Funambulus pennanti) during their reproductively active phase

In addition to pineal control of reproduction in seasonal breeders, melatonin is also known to influence various immune parameters. In the present experiment, we assessed the effect of exogenous melatonin treatment on different hematological parameters of peripheral blood and bone marrow cells, together with histological observations of spleen and thymus blastogenic response and stimulation ratio, and hormonal assays (melatonin and testosterone) of Indian palm squirrel (Funambulus pennanti) during their reproductively active phase when endogenous melatonin levels are low. Daily subcutaneous injection of melatonin (25 microg/100 g body mass.) at 17.30-18.00 h to adult male squirrels for 60 consecutive days during May-June significantly increased the lymphocyte count of blood and bone marrow and the blastogenic response/percent stimulation ratio of spleen and thymus. Histological observation showed densely packed thymocytes and splenocytes. During this period, peripheral testosterone level was high and melatonin was low establishing an inverse relationship as noted earlier for this squirrel. In pinealectomized squirrels, decreased total leukocyte count and percent lymphocyte count in peripheral blood and bone marrow, along with a decreased cell density in spleen and thymus was observed histologically. Further, melatonin treatment of pinealectomized squirrels resulted in restoration of the immune parameters in line with a normal control level. We suggest that during the reproductively active period of male Indian palm squirrels the lymphoid organs were sensitive to melatonin; hence, the exogenous melatonin treatment had an immuno-enhancing effect.     

Comparative levels and types of microbial contamination detected in industrial clean rooms

The primary objective of this study was to determine quantitatively and qualitatively the predominant types of microbial contamination occurring in conventional and laminar flow clean rooms. One horizontal laminar flow, three conventional industrial clean rooms, and three open factory areas were selected for microbiological tests. The results showed that as the environment and personnel of a clean room were controlled in a more positive manner with respect to the reduction of particulate contamination, the levels of airborne and surface microbial contaminants were reduced accordingly. The chief sources of microbial contamination were associated with the density and activity of clean room personnel. In addition, the majority of microorganisms isolated from the intramural air by air samplers were those indigenous to humans. Studies on the fallout and accumulation of airborne microorganisms on stainless-steel surfaces showed that, although there were no significant differences in the levels of microbial contamination among the conventional clean rooms, the type of microorganism detected on stainless-steel surfaces was consistently and significantly different. In addition, the "plateau phenomenon" occurred in all environments studied. It was concluded that the stainless-steel strip method for detecting microbial accumulation on surfaces is efficient and sensitive in ultra-clean environments and is the most reliable and practical method for monitoring microbial contamination in future class 100 clean rooms to be used for the assembly of spacecraft which will be sterilized.     

Effects of marrow donor and recipient age on immune responses

This report describes treatments to restore diminished splenic immune responses of old mice. Lethal irradiation, followed by young bone marrow and infant thymus transplants, restored the T cell mitogen response and the antibody-forming cell response against sheep red blood cells in the old mice. Although old bone marrow cells restore these immune responses in young recipients, as well as do young bone marrow cells, old bone marrow in old recipients did not improve their levels of response. Longevities of old recipients with rejuvenated responses were not increased, and aging of tail tendon collagen was not affected. The effect of lethal irradiation before the marrow transplant was shown to be minimal, by the use of unirradiated old W-anemic recipients. Parabiosing young mice with old partners caused impairment of these two immune responses in the young partners without enhancing them in the old partners. The old partners did not have increased longevities. To explain these results, we suggest the following hypothesis: old bone marrow contains precursors that produce suppressive factors or cells when in an old environment but not when in a young environment. However, these factors, if allowed to develop in an old environment, can function in a young parabiosed partner.     

Cellular changes in bone marrow of malaria-infected mice. III. Chemotaxis of granulocytes

The number of bone marrow cells and their chemotactic activity was studied during malaria infection. Two days after infection of Balb/c mice with Plasmodium berghei, an increase in granulocyte number was observed in the blood. A modified Boyden chamber chemotaxis assay was employed to investigate the mechanism of granulocyte accumulation in the blood. Bone marrow cells from normal mice, from mice during a primary lethal infection and from immune mice after challenge were compared. The complement factor C5a showed chemotactic activity for bone marrow cells; a significant decrease of chemotaxis was only observed after 6 days of primary infection. Extracts of spleen, liver and infected erythrocytes lacked chemotactic activity, or caused inhibition of cell migration. Serum from mice with a 2-day primary infection contained chemotactic activity. The active component was heat labile, protease sensitive and had an estimated molecular weight of 250,000.     

The mast cell-committed progenitor. In vitro generation of committed progenitors from bone marrow

Mast cell-committed progenitors are detected in the unique microenvironment of the mesenteric lymph node (MLN) of Nippostrongylus brasiliensis-infected mice but not in naive bone marrow. We have determined that MLN cells, after infection, produce high levels of IL-3, IL-4, and IgE, presumably in the form of immune complexes with antigens produced by the infecting helminth. After N. brasiliensis infection, peak production of these factors occurs several days before the peak appearance of mast cell-committed progenitors in the MLN. To determine if these factors play a role in mast cell commitment, we recreated these conditions, in vitro. Naive bone marrow cells were cultured with combinations of IL-3, IL-4, and IgE immune complexes, or on IgE-coated plates, and then assayed for acquisition of the ability to form mast cell colonies when supplemented with fibroblast-conditioned medium alone. IL-3 and IgE immune complexes, and, unexpectedly, IgE immune complexes alone were found to be capable of producing mast cell-committed progenitors, i.e., cells responsive to fibroblast-conditioned medium alone, from bone marrow, whereas IL-4 did not enhance production of mast cell-committed progenitors from bone marrow. Production of IFN-gamma peaked at the same time point as committed progenitor activity and may be responsible for down regulating the response.     

Plasmodium berghei: influence on granulopoiesis and macrophage production in BALB/c mice

Granulocyte and macrophage progenitor cells forming colonies in vitro (GM-CFC) from bone marrow, spleen, and peripheral blood of BALB/c mice infected with Plasmodium berghei were cultured at various times postinfection in a viscous, 0.8% methylcellulose system. The numbers of GM-CFCs from bone marrow increased gradually during the first week of infection, reaching a maximum around the tenth day of the disease. Subsequently, a rise of GM-CFCs in cultures of nucleated cells from the peripheral blood was observed and, with some delay, in spleen cell cultures also, with a maximum around the end of the second week. After the tenth day of malaria infection a fall of colony frequency in bone marrow-derived cells took place, leading to subnormal values of GM-CFCs during the third week of infection. Subsequently, a decrease in the spleen cell cultures followed, but colony numbers did not fall to normal values. The general increase in GM-CFCs in the different organs was preceded by a rise in serum levels of colony-stimulating activity (CSA), attaining a maximum 1 week after P. berghei inoculation. During the following period the CSA levels fell and reached normal values around the seventeenth day of the disease. Chemotherapy with chloroquine started on the fifteenth day of infection, when GM-CFCs in the bone marrow have dropped to normal values, stopped their further decrease. In the spleen a gradual normalization took more than 2 weeks. A challenge infection evoked an elevation of GM-CFC numbers in the bone marrow and in the spleen during the first 10 days in only about 50% of immune mice. The reaction was immediate in some animals, but generally lower and of shorter duration than during primary infection. The results have indicated that a lethal P. berghei infection in mice caused a transient increase in production of CSA followed by a general recruitment of GM-CFCs in all hemopoietic organs.     

Uncomplicated HL-A Matched Sibling Bone Marrow Graft for Combined Immune Deficiency

When an apparently identical HL-A donor can be found and satisfactorily checked by the mixed lymphocyte reaction, it is worth attempting simple bone marrow grafting in a patient with combined immune deficiency syndrome who otherwise would die. Immunocompetence was given in this way to a baby girl by her 4-year-old brother and was confirmed by the presence of Y-chromosome in most of the transforming lymphocytes. IgA was late to emerge, presumably owing to the immaturity for IgA of the donor''s bone marrow.     

Enhanced differentiation of splenic plasma cells but diminished long-lived high-affinity bone marrow plasma cells in aged mice

In the present work, we have dissected the mechanisms responsible for the impaired humoral responses in aging. We found that there was a substantially higher level of Ab-forming cells in the spleens of aged mice than that of young controls. However, the number of high-affinity, class-switched Ab-forming cells was severely decreased in the spleen of aged mice. The accumulation of low-affinity IgM Ab-forming cells in the spleens of aged animals was not due to a deficiency in isotype switching because the number of total IgG1 splenic plasma cells was not significantly reduced. Remarkably, plasma cells of both low and high affinity were significantly diminished in the bone marrow of aged mice compared with that of young mice. The results from reconstitution experiments showed that aged bone marrow was less supportive for plasma cells derived from young splenic B cells. These findings suggest that humoral immune deficiency in aging results from at least two mechanisms: the inability to generate sufficient numbers of high-affinity Ab-forming cells, which is a result of diminished germinal center reaction, and the defective bone marrow environment that has diminished ability to support the selection and survival of long-term Ab-forming cells.     

烧伤病房不动杆菌属无硝生物型感染流行病学调查

本文通过对烧伤病室隔离区不动杆菌无硝生物型感染流行病学调查,发现烧伤病人创面本菌的定植或感染高达４２．５９％,均为耐药菌株;对氨苄青霉素,头孢唑啉耐花分别达１００％、９５．７％。通过质粒图谱及限制性内切酶指纹图分析确定流行株菌质粒为２２Ｋ、ｂ２６ｋｂ两种、是通过手接触与空气传播的。     

Architectural design influences the diversity and structure of the built environment microbiome

Buildings are complex ecosystems that house trillions of microorganisms interacting with each other, with humans and with their environment. Understanding the ecological and evolutionary processes that determine the diversity and composition of the built environment microbiome—the community of microorganisms that live indoors—is important for understanding the relationship between building design, biodiversity and human health. In this study, we used high-throughput sequencing of the bacterial 16S rRNA gene to quantify relationships between building attributes and airborne bacterial communities at a health-care facility. We quantified airborne bacterial community structure and environmental conditions in patient rooms exposed to mechanical or window ventilation and in outdoor air. The phylogenetic diversity of airborne bacterial communities was lower indoors than outdoors, and mechanically ventilated rooms contained less diverse microbial communities than did window-ventilated rooms. Bacterial communities in indoor environments contained many taxa that are absent or rare outdoors, including taxa closely related to potential human pathogens. Building attributes, specifically the source of ventilation air, airflow rates, relative humidity and temperature, were correlated with the diversity and composition of indoor bacterial communities. The relative abundance of bacteria closely related to human pathogens was higher indoors than outdoors, and higher in rooms with lower airflow rates and lower relative humidity. The observed relationship between building design and airborne bacterial diversity suggests that we can manage indoor environments, altering through building design and operation the community of microbial species that potentially colonize the human microbiome during our time indoors.     

Long-term follow-up of bone marrow transplant patients

Preparation for discharge begins prior to the admission for bone marrow transplant. Assessment of the home environment and the effect of prolonged isolation on the life style of the patient and family are important factors. Once the transplant process has been accomplished and the patient meets the criteria for discharge, physical preparation of the home environment can begin. In the immediate post-transplant period, treatment or prophylaxis of graft-versus-host disease (GVHD) is monitored. Immune globulins may be replaced every three to four weeks. Long-term follow-up often continues for many years, especially when chronic GVHD is present. Continued psychosocial support is needed throughout this process to prepare the patient for re-entry into the community.     

Comparative study of antibody formation in ontogenetically determined and experimentally shaped populations of cooperating mouse cells

When studying the levels of immune response to the sheep erythrocytes in the adoptive transfer system in a population of cooperating bone marrow and spleen cells of the intact mice formed under the effect of hydrocortisone, differences have been found in their capacity to produce antibody-forming cells. Unlike the population of spleen cells formed during ontogenesis, the population of cooperating bone marrow cells acquires the capacity to develop an intensive enough immune response only after twofold immunization of the recipient and remains insensitive to the priming treatment of the donors with the sheep erythrocytes. These behavioral peculiarities of the population of cooperating bone marrow cells are due to relative deficiency of mature T-B helpers; the primed spleen T-lymphocytes are not involved in the formation of the pool of the latter.     

Airborne Microorganisms in Broiler Processing Plants

Concentrations of total aerobic bacteria, molds, yeasts, coliforms, enterococci, and psychrophiles were determined in the air of two poultry processing plants with Andersen samplers and a mobile power supply. Total aerobic bacterial counts were highest in the dressing room, with diminishing numbers in the shackling, eviscerating, and holding rooms, when sampling was carried out during plant operation. The average counts per ft³ of air in these four rooms were 2,200; 560; 230; and 62, respectively. (Each value is the average of 36 observations.) The number of organisms increased in the shackling and dressing rooms once processing was begun. Average total aerobic bacterial counts increased from 70 to 870 to 3,000 in the shackling room and from 310 to 4,900 to 7,000 in the dressing room when sampling was carried out at 5:00 am (before plant operations), 9:00 am, and 2:00 pm, respectively. (Each value is the mean of 12 observations.) Airborne molds might originate from a source other than the poultry being processed.     

Effect of Foot-and-Mouth Disease Virus Infection on the Frequency,Phenotype and Function of Circulating Dendritic Cells in Cattle

Foot-and-mouth disease virus (FMDV) is a highly contagious virus that causes one of the most devastating diseases in cloven-hoofed animals. Disease symptoms develop within 2 to 3 days of exposure and include fever and vesicular lesions on the tongue and hooves. Dendritic cells (DC) play an essential role in protective immune responses against pathogens. Therefore, investigating their role during FMDV infection would lead to a better understanding of host-pathogen interactions. In this study, following infection of cattle with FMDV, we investigated the frequency and function of conventional (cDC) and plasmacytoid DC (pDC) in blood by using multi-color flow cytometry. We show that the frequency of cDC and pDC increased following FMDV infection and peaked 3 to 4 days post-infection. During peak viremia, the cattle became lymphopenic, the expression of MHC class II molecules on cDC and pDC was dramatically down-regulated, the processing of exogenous antigen by cDC and pDC was impaired, and there was an increase in IL-10 production by DC and monocytes. Notably, after clearance of FMDV from the blood, MHC class II expression returned to pre-infection levels. Altogether, our study demonstrates that in cattle, FMDV inhibits the function of DC, thereby retarding the initiation of adaptive immune responses, potentially enhancing virus shedding during the acute phase of infection.     

Viral abrogation of stem cell transplantation tolerance causes graft rejection and host death by different mechanisms

Tolerance-based stem cell transplantation using sublethal conditioning is being considered for the treatment of human disease, but safety and efficacy remain to be established. We have shown that mouse bone marrow recipients treated with sublethal irradiation plus transient blockade of the CD40-CD154 costimulatory pathway develop permanent hematopoietic chimerism across allogeneic barriers. We now report that infection with lymphocytic choriomeningitis virus at the time of transplantation prevented engraftment of allogeneic, but not syngeneic, bone marrow in similarly treated mice. Infected allograft recipients also failed to clear the virus and died. Postmortem study revealed hypoplastic bone marrow and spleens. The cause of death was virus-induced IFN-alphabeta. The rejection of allogeneic bone marrow was mediated by a radioresistant CD8(+)TCR-alphabeta(+)NK1.1(-) T cell population. We conclude that a noncytopathic viral infection at the time of transplantation can prevent engraftment of allogeneic bone marrow and result in the death of sublethally irradiated mice treated with costimulation blockade. Clinical application of stem cell transplantation protocols based on costimulation blockade and tolerance induction may require patient isolation to facilitate the procedure and to protect recipients.     

Cell-mediated immunity in Cryptococcosis

Cell-mediated immune responses in patients who had recovered from cryptococcosis were compared to those of healthy subjects. Cryptococcal patients were mildly lymphopenic but showed no defect in percentage of thymus-derived lymphocytes. One-third had positive delayed skin test reactions to cryptococcal antigen. Their skin test reactivity to two commonly used noncryptococcal antigens was less intense than healthy control subjects. Strongly positive and specific lymphocyte transformation occurred in the presence of an extract of Cryptococcus neoformans (cryptococcin) in half of the patients. In contrast, few healthy subjects had positive transformation responses to cryptococcin. One patient who was followed sequentially through treatment of cryptococcal meningitis acquired strong cryptococcin reactivity during the course of treatment. Cellular immunologic response to cryptococcin identifies many subjects who have had C. neoformans exposure, and may be of value for assessing immunologic status of patients undergoing therapy. These studies also indicate that most patients with cryptococcosis have a degree of deficiency in cell-mediated response to fungal antigens even when a specific underlying disease process cannot be identified.