Modified surgical model of paratopic small bowel transplantation in mice

A murine paratopic model of intestinal transplantation was developed and used to study the immune response to allografts in normal C57BL/6 recipients (H2(b)) and C57BL/6 recipients treated with tacrolimus (1 mg/kg, Days 0-7). B6C3F1 mice (C57BL/6 x C3H/HeJ, H2(bxk)) were used as donors. The paratopic model differed from the standard heterotopic model in that continuity of the intestine graft with the recipient intestine was established by anastomosing the graft ileum to the side of the recipient jejunum. The success rate of this modified procedure was 82% (94/114). Major complications included hypovolemic shock and/or anesthetic-related deaths (8%), infection (8%), and vascular thrombosis (2%). Rejection was assessed using both clinical features (i.e., edema and closure of the stoma, mucous discharge, and a palpable mass) and histologic features (apoptosis of crypt cells, crypt destruction, lymphocytic infiltrate, and mucosal ulceration). Syngeneic grafts appeared clinically and histologically normal throughout the study period. Untreated recipients of allografts developed clinical and histologic evidence of rejection by Day 4 which progressed to severe rejection and graft destruction by Day 18. After initially developing evidence of mild to moderate graft rejection on Day 8, the severity of allograft rejection decreased significantly by Days 10 to 14 in tacrolimus-treated mice. By Day 28 evidence of moderate rejection had recurred in mice treated with an 8-day course of tacrolimus. Consistent with these observations, graft function, as assessed by maltose absorption, was impaired in rejecting allografts when compared with syngeneic grafts. Allografts in mice treated with tacrolimus demonstrated improved maltose absorption relative to allografts from untreated mice. These studies describe a modified technique for intestinal transplantation in mice and provide a detailed analysis of complications as well as an assessment of rejection and its functional consequences. Based on these results, we conclude that the paratopic model of intestinal transplantation in mice is a useful tool for studying the host immune response to intestinal allografts.

Victor Coxon, member, B.J.'s Black Tie Club at Palmer, 1936-1941

The 1930's era was a turbulent time for B.J. Palmer who was proposing radical changes in chiropractic methodologies, i.e., the Hole-in-one upper cervical approach, neurocalometer examinations and heavy reliance on x-ray for vertebral listings. Palmer needed and found an inner circle of loyal supporters at the Fountain Head who were named the "Black Tie Club," identified at important Palmer functions wearing the flowing black tie--the Windsor. One such Black Tie Club member was Victor Coxon--a 1930 Palmer School graduate who passed away recently. The present article explores Coxon's assistant directorship of the B.J. Palmer Chiropractic Clinic, some of his many writings, as well as correspondence Dr. Coxon had with the author.

Disseminated histoplasmosis in an infant with acquired immunodeficiency syndrome

Disseminated histoplasmosis has been recognized as a serious opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS). However, cases reported in the literature have been predominantly in adult patients. Here we report an infant with AIDS who presented with fever, cough, rhinorrhea, hepatosplenomegaly, pancytopenia and coagulopathy, and died of respiratory failure. Autopsy revealed disseminated histoplasmosis involving multiple organs including lungs, intestines, liver, spleen, bone marrow, lymph nodes, kidneys, and meninges. The diagnosis was established based on histomorphology and confirmed by blood culture.

Protein disorder and the evolution of molecular recognition: theory, predictions and observations

Observations going back more than 20 years show that regions in proteins with disordered backbones can play roles in their binding to other molecules; typically, the disordered regions become ordered upon complex formation. Thought-experiments with Schulz Diagrams, which are defined herein, suggest that disorder-to-order transitions are required for natural selection to operate separately on affinity and specificity. Separation of affinity and specificity may be essential for fine-tuning the molecular interaction networks that comprise the living state. For low affinity, high specificity interactions, our analysis suggests that natural selection would parse the amino acids conferring flexibility in the unbound state from those conferring specificity in the bound state. For high affinity, low specificity or for high affinity, multiple specificity interactions, our analysis suggests that the disorder-to-order transitions enable alternative packing interactions between side chains to accommodate the different binding targets. Disorder-to-order transitions upon binding also have significant kinetic implications as well, by having complex effects on both on- and off-rates. Current data are insufficient to decide on these proposals, but sequence and structure analysis on two examples support further investigations of the role of disorder-to-order transitions upon binding.

Right hemisphere speech perception revealed by amobarbital injection and electrical interference

OBJECTIVE

To investigate the right hemispheric speech perception capabilities of an adult right-handed patient with seizures.

METHODS

Consecutive, unilateral, intracarotid sodium amobarbital injections and left hemispheric electrical interference mapping were used to determine lateralization and localization of speech perception, measured as syllable discrimination.

RESULTS

Syllable discrimination remained intact after left and right intracarotid sodium amobarbital injections. Language otherwise strongly lateralized to the left hemisphere. Despite evidence of bilateral speech perception capabilities, electrical interference testing in the left posterior temporal lobe impaired syllable discrimination.

CONCLUSIONS

The results suggest a functionally symmetric, parallel system in the adult brain with preferential use of left hemispheric pathways for speech perception.

Familiar and novel contexts yield different associations between cortisol and behavior among 2-year-old children

We examined 10:30 a.m. salivary cortisol levels in twenty-four 2-year-old children at home, and then at several points during transition into preschool: Week 1, Weeks 6-9, and the 1st week following a month-long holiday break. Cortisol levels did not increase when the children first started school as compared to either home or later school levels. Cortisol levels were correlated across similar, but not across dissimilar, psychosocial contexts. Home levels were correlated wit more shy, anxious, internalizing behavior while the response to starting school was correlated with more assertive, angry, and aggressive behavior. Behavior was assessed using parent temperament reports, teacher reports, and observational measures. We conclude that HPA activity as indexed by salivary cortisol measures is differentially associated with behavior in familiar and novel contexts. Consistent with our prior work, shy/anxious behavior is not significantly associated with elevations in cortisol when young children enter new social situations.

Temporal dynamics of verbal object comprehension

Knowledge of the stage composition and the temporal dynamics of human cognitive operations is critical for building theories of higher mental activity. This information has been difficult to acquire, even with different combinations of techniques such as refined behavioral testing, electrical recording/interference, and metabolic imaging studies. Verbal object comprehension was studied herein in a single individual, by using three tasks (object naming, auditory word comprehension, and visual word comprehension), two languages (English and Farsi), and four techniques (stimulus manipulation, direct cortical electrical interference, electrocorticography, and a variation of the technique of direct cortical electrical interference to produce time-delimited effects, called timeslicing), in a subject in whom indwelling subdural electrode arrays had been placed for clinical purposes. Electrical interference at a pair of electrodes on the left lateral occipitotemporal gyrus interfered with naming in both languages and with comprehension in the language tested (English). The naming and comprehension deficit resulted from interference with processing of verbal object meaning. Electrocorticography indices of cortical activation at this site during naming started 250-300 msec after visual stimulus presentation. By using the timeslicing technique, which varies the onset of electrical interference relative to the behavioral task, we found that completion of processing for verbal object meaning varied from 450 to 750 msec after current onset. This variability was found to be a function of the subject's familiarity with the objects.

Prognostic implications of centrilobular necrosis in pediatric liver transplant recipients

BACKGROUND

We have observed centrilobular necrosis (CLN) in several liver allograft biopsies in our pediatric liver transplant population. The aims of this study were to describe the associated pathologic and clinical features of post-orthotopic liver transplantation CLN and determine its prognostic implications.

METHODS AND RESULTS

CLN was identified and characterized in 44 allografts from 40 patients (17 males and 23 females) among our 443 pediatric recipients. Twenty episodes were associated with cellular rejection, either in the same biopsy (n=15) or within the week prior (n=5), and five were associated with ductopenic rejection. Twelve were associated with vascular thrombosis. No clear etiology was identified in seven episodes, but two also had cholangitis lenta. Of the remaining five biopsies, three showed only centrilobular dropout, suggesting a resolution of some previous insult. The outcome of 40 patients following an initial episode of CLN was poor, with graft failure in 33, chronic poor function in 2, and normal recovery in only 5 patients. The results of retransplantation for graft failure due to CLN were equally poor, with 14 deaths, 3 patients with ductopenic rejection, and only 5 with normal recovery. CLN recurred in four grafts. Overall patient outcome was very poor: 25 deaths; 3 ductopenic rejections; 2 chronic poorly functioning livers; and 10 patients alive and well.

CONCLUSION

We conclude that CLN in pediatric orthotopic liver transplantation recipients is associated with cellular rejection, ductopenic rejection, or acute vessel thrombosis in the majority cases. The prognostic implications of CLN are grave, with high rates of graft failure requiring retransplantation and death.

Decreased PKC-alpha expression increases cellular proliferation, decreases differentiation, and enhances the transformed phenotype of CaCo-2 cells

Previous studies have shown that PKC-alpha protein expression is decreased in sporadic human colon cancers, as well as in colonic tumors of rats induced by chemical carcinogens. To elucidate the potential role of PKC-alpha on several phenotypic characteristics of colon cancer cells, we have transfected cDNAs for PKC-alpha in sense or antisense orientations into CaCo-2 cells, a human colonic adenocarcinoma cell line. Transfected clones were isolated that demonstrated approximately 3-fold increases (sense transfectants) and approximately 95% decreases (antisense transfectants) in PKC-alpha expression with no significant alterations in other PKC isoforms. Transfection of CaCo-2 cells with PKC-alpha in the antisense orientation resulted in enhanced proliferation and decreased differentiation, as well as in a more aggressive transformed phenotype compared with empty vector-transfected control cells. In contrast, cells transfected with PKC-alpha cDNA in the sense orientation demonstrated decreased proliferation, enhanced differentiation, and an attenuated tumor phenotype compared with these control cells. These data show that alterations in the expression of PKC-alpha induce changes in the proliferation, differentiation, and tumorigenicity of CaCo-2 cells. Furthermore, these findings indicate that loss of PKC-alpha expression in sporadic human and chemically induced colonic cancers may confer a relative growth advantage during colonic malignant transformation.

Liver allograft pathology

Complications following orthotopic liver transplantation are often difficult to differentiate from each other. Based on their experience with more than 1,800 transplantations, the authors strive to describe the varied histologic appearances of allograft injuries and how they differ.

The use of ultrasound therapy in wound healing

A review of the evidence for the use of therapeutic ultrasound in the treatment of chronic and acute wounds and a guide to the delivery of appropriate treatment

Quaternion contact ribbons: a new tool for visualizing intra- and intermolecular interactions in proteins

Protein side chain interactions between residues separated by at least one loop or turn or break in the amino acid sequence are called 'nonlocal contacts' in this manuscript, and contiguous sets of such interactions located between segments of secondary structure are called 'contact zones.' A new interactive program, the quaternion contact ribbon tool, has been developed to help protein chemists identify, straighten if twisted, and display contact zones between two neighboring segments of helix.

Treatment with either anti-CD4 or anti-CD8 monoclonal antibodies blocks alphabeta T cell-mediated rejection of intestinal allografts in mice

BACKGROUND

Rejection is the major barrier preventing the more widespread application of intestinal transplantation as treatment for intestinal failure. For this study, a one-way host-versus-graft murine model was used to investigate the contribution of T cell subsets to the rejection of allogeneic intestinal allografts.

METHODS

Intestinal grafts consisting of the donor jejunum and ileum were procured from C57BL/6J (syngeneic group) and B6C3F1/J (C57BL/6 x C3H/HeJ, allogeneic group) mice. These grafts were then transplanted into (1) normal, (2) antibody-treated, or (3) genetically mutated C57BL/6 mice. Mice were killed at predetermined intervals and the grafts assessed for rejection by a blinded pathologist.

RESULTS

No syngeneic mice demonstrated any evidence of rejection. In contrast, the recipients of allografts experienced progressive rejection. Recipient mice treated with tacrolimus developed significantly less severe allograft rejection. None of the alphabeta T cell-deficient recipient mice (T cell receptor beta chain knockout mice) experienced allograft rejection with follow-up ranging from 8 to 28 days. However, mice deficient in gammadelta T cells (T cell receptor delta chain knockout mice) rejected intestinal allografts in a manner indistinguishable from normal recipients. In order to investigate the role of CD4+ and CD8+ T cells, recipient mice were treated 2 days before transplantation with depleting monoclonal antibodies specific for either CD4+ cells or CD8+ cells. Depletion of either population of cells significantly inhibited allograft rejection.

CONCLUSIONS

These data demonstrate that rejection of intestinal allografts in the murine model was absolutely dependent on alphabeta but not gammadelta T cells. Furthermore, both CD4+ and CD8+ T cells were necessary for small bowel allograft rejection. Additional studies will be required to determine whether the effects of monoclonal antibody treatment were due solely to depletion of T cells or were mediated at least in part through an active process that altered the functional properties of the targeted T cell subset.

Do permanent pacemakers need an insulative coating? Results of a prospective randomized double-blind study

During conventional manufacturing of implanted pulse generators (IPGs), an insulative coating is often applied to prevent local muscle stimulation and myopotential sensing in unipolar pacing. This can limit the orientation of the IPG into its pocket, be a potential source of muscle stimulation via coating scratches, and result in an increase in IPG production costs. We hypothesized that advances in the design and construction of current IPGs and leads obviates the need for an insulative coating of the IPG. Using a double-blind prospective randomized design, 39 patients were implanted with either coated or uncoated otherwise identical IPGs (19 dual, 20 single chamber). All testing was done in unipolar and bipolar mode in both channels. A strength-duration curve for muscle stimulation was constructed for all patients with muscle stimulation. Myopotential sensing was established during isometric exercise. At 6-month follow-up when tested in unipolar mode, 3 of 15 (20%) patients with coated IPGs and 3 of 20 (15%) with uncoated IPGs had muscle stimulation at 5.0 V/1.5 ms or lower (P = NS). No patients in either population had muscle stimulation at their normally programmed output. Myopotential sensing occurred in all patients in unipolar mode at a mean of 2.29 +/- 1.3 mV and 2.73 +/- 1.14 mV for coated versus uncoated, respectively (P = NS). The statistical power of these negative observations was 80%. An insulative coating for pacemakers does not appear to alter sensing performance or cause a significant difference in the occurrence or characteristics of muscle stimulation.

Serum vitamin E decreases in HIV-seropositive subjects over time

Vitamin E is an important lipid soluble antioxidant that has a number of crucial functions including protecting lipids from oxidative damage. It also may play an important role in enhancing the immune response in subjects with Human Immunodeficiency Virus (HIV) infection. The current study measured the serum level of vitamin E in 121 HIV seropositive subjects with no prior pulmonary complications. Although the mean level was normal at 9.0 +/- 0.5 microg/ml, 22.3% of the subjects had a deficient level of less than 5 microg/ml. In addition, 42 subjects were studied longitudinally and serum vitamin E levels were determined at baseline and 12 months later. The mean serum vitamin E level in this group significantly decreased after 12 months compared with baseline levels (5.9 +/- 0.5 microg/ml compared with 9.6 +/- 0.9 microg/ml, p = 0.001). The CD4 counts also were significantly decreased after 12 months (460.6 +/- 36.0 cells/mm3 versus 390.5 +/- 37.7 cells/mm3, p = 0.032). No significant correlations were observed between the decrease in serum vitamin E and the change in CD4 count, body mass index (BMI), or serum albumin levels over the 12-month period. In conclusion, a significant portion of HIV-seropositive subjects have a deficiency in serum vitamin E early in the course of their disease. Furthermore, there is a significant decrease in serum vitamin E levels in these subjects over 12 months.

Alveolar fluid glutathione decreases in asymptomatic HIV-seropositive subjects over time

BACKGROUND

Initial investigations demonstrated a deficiency of glutathione (GSH) in the epithelial lining fluid (ELF) of HIV-seropositive patients. In a recent study, our laboratory was unable to document such a deficiency. The current study was performed in an attempt to reconcile those disparate findings.

STUDY OBJECTIVES

To determine if ELF GSH decreases over time in asymptomatic HIV-seropositive subjects.

DESIGN

Prospective, longitudinal study.

SETTING

Major university medical center.

PATIENTS OR PARTICIPANTS

Thirty-three asymptomatic HIV-seropositive volunteers.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

BAL was performed on 33 asymptomatic HIV-seropositive subjects at baseline, 6 months later, and 12 months later. The volume of ELF and the concentration of GSH and oxidized GSH were determined. The concentration of total GSH in ELF was 689.0+/-100.4 microM. This significantly decreased when measured 6 and 12 months later (355.9+/-41.7 microM, and 397.9+/-52.7 microM, respectively, p=0.01, compared with baseline, both comparisons). Significant decreases were also noted in the HIV-seropositive subjects who smoked cigarettes (baseline--762.6+/-142.4 microM; 6 months--373.7+/-45.9 microM; 12 months--459.3+/-73.8 microM, p<0.03, for baseline vs 6 months, and baseline vs 12 months). In nonsmoking HIV-seropositive subjects, there was a decrease in ELF GSH over time, but it did not reach statistical significance (baseline--589.1+/-138.2 microM; 6 months--335.3+/-74.1 microM; 12 months--345.8+/-74.0 microM, p>0.1, all comparisons). The percentage of total GSH in the oxidized form was similar at all three time points (baseline--3.8+/-0.5%; 6 months--3.1+/-0.5%; 12 months--3.9+/-0.9%, p>0.1, all comparisons).

CONCLUSIONS

The current study demonstrates that the GSH level in ELF is significantly decreased in HIV-seropositive subjects 6 and 12 months after the initial determination.

Ultrastructure of human colostral cells

The ultrastructural architecture of colostral cells of mothers of pre- and full-term infants is described. The polymorphonuclears were engaged in vivid phagocytosis of fat droplets. Similar findings were observed on the macrophages. The lymphocytes appeared normal in size and ultrastructure. A small number of eosinophils and basophils were also detected. The number of colostral cells was higher in the colostrum of mothers of preterm newborns. The number of the cells in the colostrum in mothers of both groups decreased with advancement of lactation.

A global perspective: technology in home care. Discussion

Technological advances are changing the way the world shares information and conducts daily business, CARING asked home care colleagues around the world to respond to a question about technology's role in home care delivery. Although the degree of technology's involvement differs from country to country, each country is aware of the possibilities and is looking toward the future.

Hyaluronic acid induces tumour necrosis factor-alpha production by human macrophages in vitro

Foetal wounds heal with minimal or no scar formation. High levels of hyaluronic acid (HA) have been implicated as a contributory factor. Macrophages are essential for normal wound healing, a role facilitated by secretion of an array of cytokines. Of these, tumour necrosis factor alpha (TNF-alpha) has been shown to reduce wound collagen levels and thus scarring. This study examines the ability of HA to stimulate TNF-alpha production by human macrophages. The human U937 myelomonocytic cell line was differentiated into DU937 adherent macrophages. DU937 monolayers were exposed to HA at concentrations of 0.1, 1, 10 and 100 micrograms/ml. Conditioned media from HA-exposed monolayers were assayed for TNF-alpha activity using a standard L929 fibroblast bioassay. TNF-alpha activities of HA-exposed DU937 culture supernatants were compared to those of controls and expressed as % cytotoxicity. Exposure of macrophages to HA at concentrations of 10 micrograms/ml and 100 micrograms/ml significantly stimulated TNF-alpha production, as demonstrated by % cytotoxicities expressed as median (interquartile range) of 33.5 (29-34.5)% (P = 0.03) and 77.5 (67-85)% (P = 0.029) respectively (Mann-Whitney U test). This effect was specifically associated with TNF-alpha generated during HA exposure, as these cytotoxic effects could be abolished by addition of anti-TNF-alpha antibody, reducing cytotoxicity to 9 (6.5-13.5)% and 8.5 (6-12)% respectively. These observations indicate that HA stimulates TNF-alpha production by human macrophages. TNF-alpha is known to downregulate fibroblastic collagen synthesis within experimental wounds. We suggest that the high levels of HA within foetal wounds may play a part in limiting fibroplasia, and thereby limit scarring, via an upregulation of TNF-alpha production from wound macrophages.

Object shape processing in the visual system evaluated using functional MRI

We used functional MRI (fMRI) to determine the cortical regions activated during processing of visual object shape in humans in six men and three women, using a paradigm with a baseline condition of simple shape detection and an activated condition of object/nonobject shape discrimination. Eight of the nine subjects studied showed significant signal changes. Seven of eight showed changes in the occipital lobes (five bilateral, two right only, one left only). All eight subjects with signal changes exhibited changes in the parietal lobes bilaterally. In the occipitotemporal gyri, there were signal changes bilaterally in seven subjects and unilaterally, on the right, in one. Activation-related fMRI signal increases were also present in the posterior superior and middle temporal gyri in seven of the subjects, with four showing bilateral signal changes, two showing signal changes on the left only, and one only on the right. The data strongly suggest that processing of object shape information in humans activates both the ventral and dorsal visual processing pathways ("what" and "where" pathways), described previously both in humans and in nonhuman primates.

Peripheral-type benzodiazepine receptor ligands modulate human natural killer cell activity

Following our earlier work, we evaluated the in vitro effect of ligands active at the peripheral-type benzodiazepine receptors on human natural killer cell activity. Peripheral blood mononuclear cells were incubated with benzodiazepine receptor ligands. After 4 h we observed a nonspecific inhibition of natural killer cell activity induced by both peripheral (Ro5-4864 and PK 11195) and central (clonazepam) benzodiazepine receptor ligands; after 24 h, the suppressive activity was specific to peripheral and mixed (diazepam) ligands, and the central-type ligand had no effect. This significant, specific suppression of NK cell activity was completely reversed by the addition of human recombinant interleukin-2 or human leukocyte interferon. Our research provides additional information on the immunomodulatory effects of peripheral-type benzodiazepine ligands. Further studies are needed to clarify the underlying mechanism of natural killer cell inhibition and to determine the clinical implications of these findings.

Increased living donor volunteer rates with a formal recipient family education program

We have generally encouraged living donation among our kidney recipients. However, an examination of our clinical practice revealed inconsistencies in the depth and content of information transmitted to kidney recipient families regarding living donation. We therefore initiated a structured education program, including an educational video, to ensure that all recipient families would receive a similar exposure to a standard block of information. After the program had been functioning for over a year, we compared the living donor (LD) volunteer rates between the 3-year period before (BEFORE) and the 18 months after (AFTER) initiation of the formal education program. There were 1,363 patients registered on our kidney transplantation waiting list during the 54-month study period (757 white [56%] and 580 black [43%]). We found that 33.4% of the kidney transplant candidates in the period BEFORE the LD education program had at least one potential LD tissue typed, compared with 39.4% in the period AFTER starting the program (P = 0.03). The increase in the proportion of patients with potential donors was greatest among the black (P < 0.05) and elderly (P < 0.01) registrants, which were the groups with the lowest volunteer rates before the program began. Among the registrants with at least one potential donor, the percentage of registrants who ultimately received an LD transplant was highly correlated with the number of donors (R = 0.98). The rate of LD kidney transplantation was significantly higher (P = 0.02) for the patients referred in the period AFTER initiation of the LD education program compared with the period BEFORE the program. The 1- and 3-year graft survival rates for the 170 LD transplants performed in these patients were 96.9% and 93.2%, respectively. These were significantly better than the corresponding 83.9% and 71.4% rates for the 341 kidney transplants from cadaver donors in these registrants (P < 0.001). Black recipients of LD transplants had graft survival rates comparable to whites; the 3-year graft survival rate for LD transplants was 93.9% in whites and 90.6% in blacks (P = NS). We conclude that living kidney donor volunteer rates can be improved by a formal family education program, especially for subgroups of patients with low volunteer rates. A substantial benefit is derived by black patients, who generally experience low graft survival rates with cadaver-donor kidneys. A local formal LD education program is a useful adjunct to national organ donation campaigns.