The timecourse of neuronal connections of the rotundoectostriatal pathway in chicks (Gallus gallus) during embryogenesis: a retrograde transport study.

The avian retinotectofugal pathway has been suggested to be homologous to the mammalian retinotectofugal pathway. The projection of the nucleus rotundus upon the ectostriatum is equivalent to that of the pulvinar nucleus upon the extrastriate cortex in mammals. In this system, the optic tectum relays retinal input to the nucleus rotundus, which then ascends to the ectostriatum of the telencephalon. Given the fact that the chick retinotectofugal system becomes mature early during development, the present study attempted to investigate the timecourse of neuronal connections of the embryonic rotundoectostriatal pathway. We used multiple injections of cholera toxin B subunit (CTb) in the ectostriatum of chick embryos to retrogradely trace projections to the nucleus rotundus. We found CTb-labeled neurons in the nucleus rotundus at embryonic day 7.5-8. By embryonic day 8-8.5, increased numbers of CTb-labeled neurons were seen in the nucleus rotundus. It was noted that the time of this initial connection between the nucleus rotundus and the ectostriatum is nearly synchronous with that of the retinotectal and tectorotundal pathways, respectively (Crossland et al., 1975; Thanos & Bonhoeffer, 1987; Wu et al., 2000). These findings, combined with the present study, suggest that the retinotectofugal system becomes established, at least at a structural level, by embryonic day E8.

Living-unrelated kidney donation: a single-center experience.

For 140 consecutive renal transplants performed from January 1995 to October 1997, 25 (18%) were from living-unrelated donors (15 women, 10 men, aged 25-63, mean 43 yr). All donors had pre-transplant imaging evaluation of renal anatomy following renal function assessment (minimal creatinine clearance 75 cm3/min). Admission to the hospital on the day of donation preceded nephrectomy under general anesthesia using an anterior flank, extra-retroperitoneal approach (no rib resection). Post-operative epidural pain control was used for all but 1 donor. The 25 kidney donors were hospitalized for 2 (n = 1), 3 (n = 12), 4 (n = 7), or 5-8 d (n = 5) (average 3.9 d) and had a mean hospitalization charge of $15,501 (range $10,808-$29,579). One intra-operative hemorrhage required transfusion; 1 late neural-related pain syndrome required outpatient wound exploration. Two kidneys were lost: a husband recipient from repetitive acute rejections at 3 months; a friend recipient from chronic rejection at 2.5 yr; both await cadaver transplant. The other 23 kidneys are functioning with a mean serum creatinine of 1.8 (range 1.0-3.3) at 3-36 months (patient survival 100%; graft survival 92%). While most donors were spouses (8 husbands and 10 wives), friends, distant cousins, in-laws, and adoptive relatives did well as donors and recipients. Transplantation may increase by 20% or more at centers which encourage broad application of living donor nephrectomy.

Molecular biology in transplantation medicine.

Serological methods of tissue typing have been used for matching patient-donor pairs for transplantation for several decades. Molecular techniques are rapidly being developed that can provide rapid, accurate tissue typing at the DNA sequence level. These techniques can be used to identify the best match pre-transplant and can also be used for the post-transplant monitoring of engraftment of bone marrow transplant patients.

Current issues in living donor nephrectomy.

Of 96 consecutive renal transplants in 2 years, 50 (52%) were living donor grafts. Donor demographics, treatment plans, length of stay (LOS), charges, and complications were reviewed. Donors included 27 women and 23 men aged 22 to 61 (mean 42.2) years; 33 were living related and 17 living unrelated donors. Racial distribution included 1 Hispanic, 2 Asian, 8 black, and 39 white donors. Pretransplant evaluation defined renal anatomy and function (minimal creatinine clearance 75 cc/min). Hospital admission occurred the morning of donation. Nephrectomy under general anesthesia entailed an anterior flank, extra-retroperitoneal approach (no rib resection); and postoperative epidural pain control was standard. Progressive early ambulation and pulmonary self-care optimized recovery. The 50 donors were hospitalized for 2 (n = 7), 3 (n = 18), 4 (n = 15), 5 (n = 6), and 6-8 (n = 4) days (mean LOS: 3.74 +/- 0.17, range 2-8 days). The mean charge for donor hospitalization was $15,415 +/- $397 (range $10,808-$29,579). One major intraoperative hemorrhage required transfusion; 1 patient was readmitted for wound drainage and pneumonia treated medically. While 40 of 50 patients (80%) were hospitalized for 4 days or less, there was no readmission because of short hospital stay. One early graft loss (3 days) occurred from technical problems; all others gained excellent life sustaining function. Three additional kidneys failed from rejection, noncompliance, and systemic coagulopathy. One recipient died at 8 months (CVA) with normal renal function. Current strategies for successful living kidney donation are thorough patient and family education, ambulatory preoperative testing, morning of surgery admission, and discharge planning beginning before hospitalization. Excellent outcomes may be accompanied by a brief LOS, epidural pain management, and liberal use of willing and healthy related and unrelated living donors.

Kidney transplantation in the older patient.

To determine renal transplant outcome in older patients, 26 consecutive primary kidney allograft recipients aged 50-76 (mean 58) were followed from three to 50 months. Azathioprine, prednisone, and cyclosporine were used in all cases and OKT3 induction in cadaveric grafts. Four patients died at three, 15, 20, and 24 months from infection, hepatic cancer, trauma, and myocardial infarction respectively; each had life-sustaining graft function at final hospital admission or death (one year actuarial patient survival 96.2%). One patient lost a kidney to accelerated acute rejection (one year immunologic graft survival 96.2%) and 11 others (42.3%) experienced acute rejection episodes which were uniformly reversed. Older patients tolerate multidrug immunosuppression, demonstrate acceptable patient survival and good rehabilitation potential, have a low incidence of rejection, and maintain excellent graft function. Renal transplantation is effective and safe renal replacement therapy for patients over age 50 years.

Psychological modulation of the delayed type hypersensitivity skin test.

Considerable data have demonstrated that psychological states can influence the immune system in animals. Whether human immune function can be intentionally modulated by the central nervous system is unknown. This article presents data from two studies that sought to demonstrate intentional modulation of the immune system by psychological interventions. It also discusses the methodological complexities involved with this type of research in humans.

T-lymphocyte subsets in nephrotic syndrome.

T-lymphocyte subsets when measured in steroid responsive nephrotic syndrome (SRNS) have demonstrated significant variance from normal values. T-cell subsets were studied by using two-color flow cytometric analysis in 32 children (9.2 +/- 5 years of age) with SRNS. The children were divided into four groups: a) SRNS in acute relapse, on prednisone; b) SRNS in acute relapse, off prednisone; c) SRNS in long-term remission, off prednisone (nephrotic controls); d) patients in remission on long-term prednisone therapy; and e) 15 age-matched normal controls. Children suffering an acute relapse of SRNS showed an increase in Leu2a+/DR+ (CD8) activated lymphocytes (P less than 0.05), a decrease in Leu4a+ total T-lymphocytes (P = 0.01) and a decrease in Leu3a+ (CD4) helper T-cells (P less than 0.05) when compared to normal controls and nephrotic controls. Though some subset changes may represent a prednisone effect and the functional role of these lymphocytes in the disease process is unknown, this study provides additional evidence to support a role for abnormal T-cell subsets in the etiology of SRNS.

Histocompatibility determinants in childhood postinfectious encephalomyelitis.

Postinfectious encephalomyelitis and multiple sclerosis have clinical, immunologic, and neuroradiographic similarities. We studied HLA determinants in six white children consecutively diagnosed with postinfectious encephalomyelitis. Each of the children had HLA determinants which have been associated with multiple sclerosis. Relative risk (RR) calculations demonstrated that these antigens and genotypes occurred significantly more often in patients with postinfectious encephalomyelitis than in the control population (A3, RR 6.14; B7, RR 6.14; DR2, RR 4.51; A3B7, RR 9.36; A3DR2, RR 5.83; B7DR2, RR 6.13; A3B7DR2, RR 10.90). These data suggest that children with postinfectious encephalomyelitis are genetically predisposed to this demyelinating disease. Although the same HLA determinants were found in these patients as in those with multiple sclerosis, studies of a larger number of postinfectious encephalomyelitis patients will be needed before it can be concluded that the two diseases share a common genetic propensity.

Effects of ribavirin on neutrophil function.

Ribavirin, a broad spectrum antiviral agent, has been shown to exhibit immunosuppressive activity. This property has raised concerns during clinical trials because candidates for antiviral therapy are those who may develop secondary bacterial infection. We therefore investigated a number of parameters of neutrophil function after the in vitro addition of various concentrations of ribavirin. At pharmacologic concentrations (1.25-7.5 micrograms/mL), percent killing of phagocytized bacteria was increased as measured by an acridine orange fluorochrome microassay, significantly higher at a concentration of 5 micrograms/mL (p less than .02). There was no concomitant adverse effect on adherence, random migration, chemotaxis, opsonization or phagocytosis. The present data indicate that ribavirin has no acute suppressive effect on granulocyte function and may even enhance bacterial killing capabilities for treated patients.

Immune modulators as antiviral agents.

Immune modulators have exhibited some limited efficacy in the prevention or treatment of viral infection. Such agents have included transfer factor, thymosin, thymic humoral factors, levamisole, isoprinosine, immune RNA, young lymphocytes, vitamin C, and BCG. This article focuses on data that have examined clinical application of immune adjuvant therapy.

Functional capacity of marginated and bone marrow reserve granulocytes.

Marginated and bone marrow reserve granulocytes were obtained from young healthy volunteers after subcutaneous administration of aqueous epinephrine (0.4 ml/m2) or intravenous administration of hydrocortisone sodium succinate (250 mg), respectively. These leukocytes were compared with circulating granulocytes for the ability to adhere to surfaces, migrate in a random fashion, respond to chemoattractants, interact with autologous serum opsonins, and phagocytize and kill five common bacterial pathogens. As contrasted with circulating neutrophils, marginated cells had enhanced phagocytic and killing capacity for some pathogens, whereas adherence, random migration, chemotaxis, and chemiluminescence for the two cell populations were equivalent. Bone marrow reserve cells demonstrated increased activity for three functional mechanisms; chemotaxis for these cells averaged 21% higher than that for circulating cells, and phagocytosis was 32% higher, with 6 to 17% greater killing of the five bacterial species studied. All of these differences were statistically significant (P less than 0.05). Random migration and interaction with serum opsonins were unchanged in bone marrow granulocytes. These enhanced functional properties of neutrophils which are outside of the circulating pool may represent important host defense mechanisms during episodes of bacterial infection.

A comparison of native and modified intravenous immunoglobulin for the management of hypogammaglobulinemia.

Ten patients with severe hypogammaglobulinemia received 6 monthly infusions of either native or modified intravenous immunoglobulin (IVIG) followed by 6 monthly infusions of the other product in a double-blind, crossover protocol. Clinical parameters were monitored on a daily basis and serum was obtained at 24 hours, 3 weeks, and 4 weeks after each infusion for measurement of total IgG, specific antibodies, and opsonizing antibodies against Streptococcus pneumoniae types 5, 12F, and 14. No differences between the products were seen for total IgG or antibodies against herpes simplex virus types 1 and 2, rubella, toxoplasma cytomegalovirus, diphtheria, or tetanus. Greater opsonizing antibody to the three strains of pneumococci were apparent for native IVIG until the third infusion, after which time products were equal. Clinical parameters (febrile or symptomatic days, missed work/school, time on antibiotics, culture positive infection, and hospitalizations) were equivalent during the treatment period with each preparation. This study showed equivalent efficacy of native IVIG as compared with reduced and alkylated IVIG during maintenance therapy for hypogammaglobulinemia.

In vitro assay of cytotoxicity with cultured liver: accomplishments and possibilities.

Tissue cultures offer potential advantages for assaying the toxicity of chemicals and for evaluating tissue susceptibility to toxic agents. Several properties of cultured cells hinder the immediate, widespread use of tissue cultures to assay toxicity routinely. These points are illustrated by briefly reviewing attempts to utilize different types of hepatic cultures to evaluate the actions of carcinogenic chemicals in vitro. Hepatocytes in vivo apparently can metabolize all known procarcinogenic chemicals, but the process of tissue isolation and the environmental conditions in vitro may modify drastically the responses of hepatocytes and other cultured hepatic cells to toxic chemicals. Before cell cultures can be used routinely as the basis of screening systems to detect chemical toxins, specificity and sensitivity of response to chemicals representing all chemical classes must be validated by laboratory studies.

Ultrastructure of cells cultured on polycarbonate membranes.

A method is described for preparing undisturbed cell cultures for both scanning and transmission electron microscopy. Cells were propagated on polycarbonate membranes with pores of 0.2 micrometer or less. Cultured cells together with their supports were prepared for both scanning electron microscopy and transmission electron microscopy using routine methods. For transmission electron microscopy a rapid schedule of infiltration and polymerization was used. The method described in this report yielded good results and it allowed the fine structure of cultured cells to be viewed in situ by both scanning electron microscopy and transmission electron microscopy.

Soluble HL-A7 antigen: localization in the beta-lipoprotein fraction of human serum.

The HL-A7 antigen of human leukocytes occurs as a soluble, low-density lipoprotein in the serum of HL-A7-positive individuals. Its presence in high concentration may inhibit direct leukocyte grouping, leading to erroneous results. This finding affords an easy method for the preparation of monospecific cytotoxic antiserums by absorption with serum fractions rather than leukocytes.