Fertility preservation in pediatric solid tumors: A report from the Children's Oncology Group

Treatment for childhood solid tumors may lead to an increased risk for gonadal dysfunction/infertility. Discussion of risk should occur at diagnosis, any changes in therapy, and during survivorship. Gonadotoxic therapies were abstracted from 32 Children's Oncology Group (COG) phase III, frontline solid tumor protocols, in use from 2000 to 2022. Risk for gonadal dysfunction/infertility was assessed based on gonadotoxic therapies, sex, and pubertal status and assigned as minimal, significant, and high following the Oncofertility Consortium Pediatric Initiative Network (PIN) risk stratification. Most protocols (65.6%, 21/32) contained at least one therapeutic arm with a high level of increased risk. Solid tumor therapies present challenges in risk stratification due to response-adjusted therapy and the need to account for radiation field in the risk assessment. This guide hopes to serve as a tool to assist in standardizing gonadotoxic risk assessments across disciplines and improve referral for fertility services and reproductive health counseling for patients receiving COG-based solid tumor therapy. Internationally, many solid tumor therapies follow similar paradigms to COG studies, and risk stratifications may be generalizable to similar styles of therapy. In addition, this model may be applied to other international groups with the goal of standardizing fertility assessments.

Pre- versus Post-synaptic Forms of LTP in Two Branches of the Same Hippocampal Afferent

There has been considerable controversy about pre- versus postsynaptic expression of memory-related long-term potentiation (LTP), with corresponding disputes about underlying mechanisms. We report here an instance in male mice, in which both types of potentiation are expressed but in separate branches of the same hippocampal afferent. Induction of LTP in the dentate gyrus (DG) branch of the lateral perforant path (LPP) reduces paired-pulse facilitation, is blocked by antagonism of cannabinoid receptor type 1, and is not affected by suppression of postsynaptic actin polymerization. These observations are consistent with presynaptic expression. The opposite pattern of results was obtained in the LPP branch that innervates the distal dendrites of CA3: LTP did not reduce paired-pulse facilitation, was unaffected by the cannabinoid receptor blocker, and required postsynaptic actin filament assembly. Differences in the two LPP termination sites were also noted for frequency facilitation of synaptic responses, an effect that was reproduced in a two-step simulation by small adjustments to vesicle release dynamics. These results indicate that different types of glutamatergic neurons impose different forms of filtering and synaptic plasticity on their afferents. They also suggest that inputs are routed to, and encoded by, different sites within the hippocampus depending upon the pattern of activity arriving over the parent axon.

Fertility preservation in pediatric leukemia and lymphoma: A report from the Children's Oncology Group

Certain chemotherapy agents, radiation, and surgery can all negatively impact future fertility. Consults regarding treatment-related risk for infertility and gonadal late effects of these agents should occur at the time of diagnosis as well as during survivorship. Counseling on fertility risk has traditionally varied significantly across providers and institutions. We aim to provide a guide to standardize the assignment of gonadotoxic risk, which can be used in counseling patients both at the time of diagnosis and in survivorship. Gonadotoxic therapies were abstracted from 26 frontline Children's Oncology Group (COG) phase III protocols for leukemia/lymphoma, in use from 2000-2022. A stratification system based on gonadotoxic therapies, sex, and pubertal status was used to assign treatments into minimal, significant, and high level of increased risk for gonadal dysfunction/infertility. Risk levels were assigned to protocols and different treatment arms to aid oncologists and survivor care providers in counseling patients regarding treatment-related gonadotoxicity. Males were most commonly at high risk, with at least one high-risk arm in 14/26 protocols (54%), followed by pubertal females (23% of protocols) and prepubertal females (15% of protocols). All patients who received direct gonadal radiation or hematopoietic stem cell transplant (HSCT) were considered at high risk. Partnering with patients and their oncology/survivorship team is imperative for effective fertility counseling both prior to and post treatment, and this comprehensive guide can be used as a tool to standardize and improve reproductive health counseling in patients undergoing COG-based leukemia/lymphoma care.

Photophysical properties of 2-Phenylindole in poly (vinyl alcohol) film at room temperature. Enhanced phosphorescence anisotropy with direct triplet state excitation

We report the spectral properties of 2-Phenylindole (2PI) embedded in rigid poly (vinyl alcohol) (PVA) film. The 2PI in PVA film shows relatively strong and structured fluorescence with a maximum at 370 nm and surprisingly strong room temperature phosphorescence with an emission maximum of about 500 nm. The dye is highly immobilized in the polymer matrix, thus presenting high fluorescence anisotropy in an isotropic film of about 0.3 at room temperature. The 2-Phenylindole phosphorescence excited in the usual way through the electronic singlet state excitation (S₀ → S₁ absorption) results in a very low, near zero anisotropy. We now report that we can directly excite the dye to the triplet state T₁ and observe high phosphorescence anisotropy similar to the fluorescence anisotropy. The extinction coefficient for S₀ → T₁ absorption in the PVA matrix is unusually high- only about 3 orders of magnitude lower than S₀ → S₁ absorption. We consider this direct excitation to indole's triplet state a very significant finding that may lead to many practical applications. The unusually long-wavelength of excitation around 400 nm, much above typical UV absorption, results in a high phosphorescence anisotropy. This provides a new way to study rotational motion of larger biological objects in the microsecond time scale not accessible through typical fluorescence studies.

Correlation of surface expression of CD11b or CD32 in polymorphonuclear cells (PMNs) and CD69 in natural killer cells (NK) with progression-free survival (PFS) following chemoimmunotherapy with rituximab and liposomal doxorubicin (LD) in patients (pts) with relapsed or refractory B-cell lymphoma

8583

Antibody dependent cellular citotoxicity (ADCC) play a significant role in rituximab's anti-tumor activity. FcγRIIIa polymorphisms have been associated with clinical responses to rituximab. The predictive value of FcγRIIIa polymorphisms is lost when rituximab is combined with chemotherapy. Alternative assays to assess the immune system had not been studied in patients treated with rituximab plus chemotherapy. To this end, we prospectively studied the pre-treatment quality and function of PMNs and NK cells from pts with refractory/relapsed B-cell lymphomas in a Phase I/II trial. Forty-two B-cell lymphoma patients pts completed treatment. Demographics: 22M:20F; Median age = 61.8 (range 35–83); Patients received R (375 mg/m2/dose) on day 1 and LD (30 mg/m2/dose) on day 3 q21 day × 6 cycles. Pre-treatment flow cytometry was performed to assess surface expression of CD11b, CD62, CD69, CD16, CD32 and CD64 in PMNs or NKcells was performed. Serum or PBMC's were isolated from each patient and used 51Cr release assays to study rituximab-associated complement mediated cytotoxicity (CMC) or ADCC. To correlate laboratory parameters with response rate, and PFS patients were divided in tertiles. Overall, R+LD was very well-tolerated. Overall response rate (ORR) = 68% (39% CR, 19% PR); median time-to-progression (TTP) = 12 m. Surface expression of CD32 in PMNs, and CD69 in NKcells correlated with better response rates. Surface expression of CD11b and CD32 in the PMN's correlated with a longer PFS (P = 0.040 and P = 0.015, respectively).There was a non-statistically significant trend towards an improved in PFS in those patients whom their PBMC's exhibited a higher degree of ex-vivo rituximab ADCC. Our data suggest that R+LD is a safe and effective regimen and that the quality of the immune system prior to a chemo-immunotherapy regimen may play a role in clinical outcomes, specifically the expression of CD11b and CD32 in PMNs or CD69 in NKcells. Our data supports further research in seeking ways to enhance the quality of the immune system to improve responses to rituximab ± chemotherapy.

[Table: see text]

Blood flow through axially symmetric sections of compliant vessels: new effective closed models

Due to a tremendous complexity of the human cardiovascular system it remains unfeasible to numerically simulate larger sections of the circulatory system using the full three-dimensional (viscous, incompressible Navier-Stokes) equations for blood flow in compliant vessels. Several "effective" one-dimensional models have been used to simplify the calculation in the axially symmetric sections. All of the one-dimensional models assume an ad hoc axial velocity profile to obtain a closed system of equations, and the Law of Laplace (the independent ring model) to model the vessel wall behavior. In this work we obtain an effective system of equations with the following two novel features: (1) the effective equations do not require an ad hoc closure assumption (the closure follows from the analysis of the original three-dimensional equations) and (2) the vessel wall is modeled as a nonlinearly elastic shell using the Koiter model or the nonlinear membrane model. The first novelty provides a higher-order accurate solution to the original three-dimensional problem, and the second allows deformations of the vessel wall that are not necessarily small.

Structure and growth mechanism study of Wurtzite CdSe nanorods grown by solvothermal techniques

Hexagonal cadmium selenide nanorods 32-170 nm in length and 12-28 nm in diameter were grown by a solvothermal technique by reacting cadmium chloride and selenium powders in ethylenediamine at 140 degrees C. Using electron microscopy, the shape, size, and crystal structure of the nanorods were determined. A detailed microscopy analysis revealed that the nanorods grow through the coalescence of very small particles or fiberlike structures of the compound. The size, shape and strain structures in the nanorods are defined by their growth mechanism.

Joint acceleration during gait in relation to age

Forty-four male and female subjects with no history of falling and whose ages ranged from 10 to 68 years participated in a series of experiments to assess movement at the joints during gait while walking in a straight line, in pivot turns and in turns of 0.33 and 0.66 m diameter. Acceleration at the joints in the forward and side-to-side direction was measured by dual-axis accelerometers placed at the ankles, knees, hips, shoulders, and on the head. Eye movement was assessed from electrodes placed on the sides of the eyes. The results of the experiments showed that for people whose age was above 40 years, significant increases in the forward-back and side-to-side movements occurred at all joints and progressively increased with age. By age 60, adverse movement of the joints as much as quadrupled in many subjects when compared to people whose age was 20-30 years. The increase in joint acceleration occurred equally in the front-back and side-to-side planes. The mechanism of the increased joint movement may be due to tendon laxness, peripheral neuropathy or loss of central control of gait due to age. Accelerometry may be a much more sensitive technique to analyze abnormalities in gait than standard video or observational gait analysis. Results are given as mean (SD) unless otherwise stated.

Determination of IgG subclasses and avidity of antithyroid peroxidase antibodies in patients with subclinical hypothyroidism - a comparison with patients with overt hypothyroidism

OBJECTIVE

To evaluate the immunoglobulin G subclasses of anti-TPO and antibody avidity in patients with subclinical hypothyroidism (sH), overt hypothyroidism (H) and a control group (C).

METHODS

According to the TSH, fT4 and anti-TPO antibody levels, appraised by immunometric assays, 95 female patients were divided into three groups (sH, H and C). IgG subclass levels and avidity were measured by a homemade ELISA. Results were analyzed by nonparametric tests and Spearman's rank correlation.

RESULTS

The predominant IgG subclasses detected in both case groups were IgG1 and IgG4 with a significantly higher level of IgG4 in the sH group. Consequently, the IgG1/IgG4 ratio was significantly lower in sH patients.

CONCLUSION

The higher levels of IgG4 anti-TPO reduced significantly the IgG1/IgG4 ratio in sH patients. These results permit to envisage that increasing this ratio could be useful as a positive predictive factor for the development of overt disease in such patients.

Differences between inhaled and intravenous bronchial challenge to detect O(3)-induced hyperresponsiveness

Ozone (O(3))-induced airway hyperresponsiveness in laboratory animals is usually demonstrated through dose-response curves with inhaled or intravenous bronchoconstrictor agonists. However, comparability of these two routes has not been well documented. Thus guinea pig airway responsiveness to ACh and histamine was evaluated 16-18 h after O(3) (3 parts/million, 1 h) or air exposure by two plethysmographic methods (spontaneously breathing and mechanically ventilated) and by two administration routes (inhalatory or intravenous). We found that O(3) caused airway hyperresponsiveness to intravenous, but not to inhaled, agonists, independent of the plethysmographic method used. Suitability of the inhalatory route to detect airway hyperresponsiveness was corroborated with inhaled ACh after an antigen challenge or extending O(3) exposure to 3 h. Acetylcholinesterase activity was not modified after O(3) exposure in lung homogenates and blood samples. Thus inhaled agonists were less effective to reveal the airway hyperresponsiveness after an acute O(3) exposure than intravenous ones, at least for the 1-h exposure to 3 parts/million, and this difference seems not to be related to an O(3)-induced inhibition of the acetylcholinesterase activity.

Ex vivo purging by adenoviral p53 gene therapy does not affect NOD-SCID repopulating activity of human CD34+ cells

Co-incubation of a replication-deficient, recombinant adenovirus carrying the wild-type p53 gene (rAd-p53) and hematopoietic stem cell (HSC) products from patients with breast cancer can significantly reduce tumor cell contamination. Whereas this approach provides a powerful tumor cell purging strategy, potential detrimental effects on the HSC population have not been investigated. The ability of human HSC to reconstitute hematopoiesis in severe combined immunodeficient (SCID) mice and to undergo secondary transplantation provides the only nonclinical measure of self-renewing, stem cell function. The objective of this study was to investigate whether co-incubation with rAd-p53 compromised the SCID repopulating activity (SRA) of HSC. Granulocyte colony-stimulating factor-mobilized human CD34+ cells were co-cultured with rAd-p53 at our targeted clinical dose, and the ability of these cells to establish multilineage hematopoiesis in sublethally irradiated, nonobese diabetic (NOD)-SCID mice was investigated. The persistence of human cells in the mice was investigated by flow cytometry, granulocyte-macrophage colony-forming unit assay, and polymerase chain reaction of human Alu sequences. Further, limiting dilution analysis provided a quantitative comparison between the SRA of CD34+ cells co-incubated with rAd-p53 and control CD34+ cells (no rAd-p53 co-incubation). We conclude that co-incubation with rAd-p53 has little effect on the SRA of HSC.

Flt3 ligand: a novel cytokine prevents allergic asthma in a mouse model

Flt-3 ligand (FL), a recently described growth factor affecting early hematopoietic progenitor cells, can also support the expansion of dendritic cells secreting IL-12. Since type 2 T cells predominate in asthma and IL-12 prevents the differentiation of naive T lymphocytes to a type 2 phenotype, we hypothesized that FL could prevent the development of asthma-like conditions in the ovalbumin mouse model. We found that co-administration of FL during ovalbumin sensitization abrogated late allergic responses, but had no effect on early allergic responses. Airway hyperresponsiveness to methacholine was also blocked by FL treatment. Analysis of bronchoalveolar lavage (BAL) fluid demonstrated a significant reduction in eosinophils, with concomitant decreases in IL-5 and increases in IFN-gamma levels. However, there was no change in BAL fluid IL-4 and serum IgE levels. These data suggest that FL treatment prevents ovalbumin-induced asthma in the mouse and may provide a useful adjuvant in the treatment of human asthma.

Flt3 ligand and granulocyte-macrophage colony-stimulating factor preferentially expand and stimulate different dendritic and T-cell subsets

OBJECTIVE

Mechanisms of T-cell stimulation by Flt3 ligand (Flt3L) and granulocyte-macrophage colony-stimulating factor (GM-CSF) remain unclear. Herein, we compared the effects of Flt3L and GM-CSF on the expansion of dendritic cells (DC) and T-cell subsets and cytokine expression.

METHODS

Naïve and effector/memory T cells were analyzed by flow cytometry (FC). CD4(+) and CD8(+) T cells and CD11c(+)CD11b(dull/-)(DC1) and CD11c(+)CD11b(+) (DC2) subsets were isolated and the frequency of IFN-gamma-, IL-12- (type 1) and IL-4-, IL-10 (type 2)-producing cells and cytokine mRNA expression evaluated.

RESULTS

Flt3L expanded both DC1 and DC2 subsets with a significantly higher percentage and number of DC1 than DC2, while GM-CSF preferentially expanded the DC2 subset. Isolated DC1 from Flt3L-injected mice had significantly higher levels of IL-12 (p40) than IL-10, while the converse occurred with DC2. The numbers of naïve and memory T cells were elevated in mice that received Flt3L or GM-CSF. However, the number of memory CD4(+) and CD8(+) T cells was significantly increased in Flt3L as compared to GM-CSF cohorts. While GM-CSF increased the frequency of both type 1 and type 2 cytokine-producing cells, Flt3L significantly augmented the frequency of type 1 T cells.

CONCLUSIONS

In contrast to GM-CSF, Flt3L preferentially induces the expansion of type 1 T cells. The mechanism of Flt3L-induced T-cell stimulation is associated with the expansion of the IL-12 (p40)-producing DC1 and memory T cells.

Breakthrough cancer pain: a randomized trial comparing oral transmucosal fentanyl citrate (OTFC) and morphine sulfate immediate release (MSIR)

Oral transmucosal fentanyl citrate (OTFC); Actiq) is a drug delivery formulation used for management of breakthrough cancer pain. Previous studies with open-label comparisons indicated OTFC was more effective than patients' usual opioid for breakthrough pain. The objective of this study was to compare OTFC and morphine sulfate immediate release (MSIR) for management of breakthrough pain in patients receiving a fixed scheduled opioid regimen. This double-blind, double-dummy, randomized, multiple crossover study was conducted at 19 US university- and community-based hospitals and clinics and comprised 134 adult ambulatory cancer patients. Patients were receiving a fixed scheduled opioid regimen equivalent to 60-1000 mg/day oral morphine or 50-300 microg/h transdermal fentanyl, were using a 'successful' MSIR dose (15-60 mg) as defined by entry criteria, and were experiencing 1-4 episodes of breakthrough pain per day. In open-label fashion, OTFC was titrated such that a single unit (200-1600 microg) provided adequate pain relief with acceptable side effects. Successfully titrated patients entered the double-blind phase of the study and received ten prenumbered sets of randomized capsules and oral transmucosal units. Five sets were the successful OTFC dose paired with placebo capsules, and five sets were placebo OTFC paired with capsules containing the successful MSIR dose. Patients took one set of study medication for each episode of target breakthrough pain. Pain intensity (PI), pain relief (PR) and global performance of medication (GP) scores were recorded. Pain intensity differences (PID) were calculated and 15-min PID was the primary efficacy variable. Adverse events were recorded. Sixty-nine percent of patients (93/134) found a successful dose of OTFC. OTFC yielded outcomes (PI, PID, and PR) at all time points that were significantly better than MSIR. GP also favored OTFC and more patients opted to continue with OTFC than MSIR following the study. Somnolence, nausea, constipation, and dizziness were the most common drug-associated side effects. In conclusion, OTFC was more effective than MSIR in treating breakthrough cancer pain.

Testing for HIV: current practices in the academic ED

The objective of this study was to determine common practices for testing for Human Immunodeficiency Virus (HIV), particularly in patients with other sexually transmitted diseases (STD) in emergency departments (ED) with residency training in Emergency Medicine. Via mail, 112 directors of academic emergency medicine programs in the United States were surveyed. Surveys from 95 academic institutions were completed, returned, and included in the analysis. Three EDs (3%) routinely tested for HIV in patients with suspected STD. HIV testing was performed in the ED in 54% of responding institutions under special circumstances such as employee testing after occupational exposures (54%), cases of rape (46%), and suspicion of HIV infection by clinical manifestations other than suspected STD (36%). Based on the results it was determined that academic EDs do not routinely test for HIV in patients suspected of having a STD and have variable testing practices and policies regarding other possible HIV exposures.

Aortic root disease and valve disease associated with ankylosing spondylitis

OBJECTIVES

This study sought to determine the prevalence, characteristics, relation to clinical features and evolution of aortic root disease and valve disease associated with ankylosing spondylitis (AKS).

BACKGROUND

Aortic root disease and valve disease are common in patients with AKS, but their clinical and prognostic implications have not been well defined.

METHODS

Forty-four outpatients with AKS and 30 age- and gender-matched healthy volunteers underwent initial transesophageal echocardiography and rheumatologic evaluations. Twenty-five patients underwent clinical and echocardiographic follow-up 39+/-10 months later.

RESULTS

Aortic root disease and valve disease were common in patients (82%) as compared with controls (27%; p < 0.001). Aortic root thickening, increased stiffness and dilatation were seen in 61%, 61% and 25% of patients, respectively. Valve thickening (41% for the aortic and 34% for the mitral valve) manifested predominantly (74%) as nodularities of the aortic cusps and basal thickening of the anterior mitral leaflet, forming the characteristic subaortic bump. Valve regurgitation was seen in almost half of patients, and 40% had moderate lesions. Except for the duration of AKS, aortic root disease and valve disease were unrelated to the activity, severity or therapy of AKS. During follow-up of 25 patients, in up to 24% new aortic root or valve abnormalities developed, in 12% existing valve regurgitation worsened significantly and in 20% abnormalities resolved. Twenty percent of patients developed heart failure, underwent valve replacement, had a stroke or died, as compared with 3% of control subjects.

CONCLUSIONS

Aortic root disease and valve disease are common in patients with AKS, are unrelated to clinical features of AKS, can resolve or progress over time and are associated with clinically important cardiovascular morbidity.

[Current aspects of surgical management of patellar dislocation in the growth period with special reference to Goldthwait surgery]

RESEARCH QUESTION

The Goldthwait procedure is an operative treatment method for patellar dislocation in children which respects the growth plate. The aim of the study was to analyse the long term results of this procedure.

METHODS

The results of 36 knees (26 children) operated on because of patellar dislocation according to the Goldthwait technique alone or in combination with other procedures (Krogius, patellar fixation) between 1941-1991 at Balgrist Clinic were analysed. Therefore, we used an own score.

RESULTS

After a mean follow-up of 16 years (1.5 to 51 years) we found in 77.8% of the cases good and very good subjective results, and in 63.9% good and very good objective results. A recurrence of dislocation occurred in 36.1% of the cases. In 76.9% of these cases a reoperation was performed, of which only one case led to an acceptable final result. The operation results were unsatisfactory in the presence of condylar dysplasia with an angle of more than 160 degrees. The age at the time of surgery and the degree of patellar dysplasia had no effect on the outcome. The success was increased through the use of the Goldthwait procedure in conjunction with other techniques. Pathologic leg axis or severe arthrosis did not occur.

CONCLUSION

In absence of significant condylar dysplasia the Goldthwait procedure combined with other techniques provides acceptable results. The technique alone is less efficient.

Discovering asymptomatic biochemical abnormalities on a Baltimore internal medicine service

To assess the frequency of abnormalities that could be discovered through biochemical profile screening on patients admitted to a city hospital internal medicine ward service, we conducted a prospective cross-sectional chart and laboratory review. All unassigned patients admitted to the general medicine service during 1- to 2-month period in late 1993 and the spring of 1994 were eligible. The main outcome measures were frequency of abnormal test results and identification of significance. Admitted patients (N = 222) were evaluated with a 24-panel biochemical profile. Of 5,328 tests, 29% were outside the standard reference range. Of 3,851 tests classified as screening, 1,049 (27%) were outside the reference range. Of overall screening tests, 741 (19%) were judged potentially important by the predetermined criteria. The prevalence did not differ significantly when analyzed by age, race, gender, or history of substance abuse. Our experience indicates that asymptomatic biochemical abnormalities are common in patients admitted to a city hospital medical service and that admission biochemical screening is an effective method of identifying potential comorbidity. Further studies are needed to assess the impact of this approach.

Anomalous origin of left internal mammary artery from the lateral junction of the left subclavian artery and aorta

We describe the first reported case of an internal mammary artery originating from the junction of the left subclavian artery and aorta. Noting this, along with other reported anomalies and various pathologic conditions, it appears warranted to perform routine preoperative internal mammary artery angiography before coronary artery bypass surgery.

[Drug residues in untreated swine]

The concentration of sulfadimidine was measured in the urine of pigs which were housed (over five days) in boxes where other pigs have been treated orally with sulfadimidine before. Sulfadimidine was measured in the urine of the unmedicated pigs in a concentration of up to 4 micrograms/ml. Considering these urine concentrations, violative sulfadimidine tissue residues would be expectable in the carcass after slaughter. The practice of fixing withdrawal times must be considered again to ensure that drug residues in tissues are below the MRL before slaughter also in unmedicated animals.

Characterization of a cell line derived from a human giant cell tumor that stimulates osteoclastic bone resorption

Giant cell tumors of bone are common but unusual tumors that are comprised of multiple cell types. Most attention has been focused on the giant cells, which resemble osteoclasts morphologically and functionally. This study examines the properties of a cell line derived from mononuclear cells from one of these tumors, since it appears likely that these cells may be able to influence the activities of cells with the osteoclast phenotype. This cell line, C433, has the following characteristics: (1) it represents undifferentiated cells, not recognized by any known antigenic markers for leukocytes; (2) it contains tartrate-resistant acid phosphatase; (3) it responds to the osteotropic factors 1,25 dihydroxyvitamin D3, insulin-like growth factor I and II, but not to parathyroid hormone; (4) it forms sarcomas in nude mice; and (5) it produces an activity that stimulates isolated avian and rat osteoclasts to resorb bone. This cell line may be useful in examining interactions between osteoclasts and accessory cells involved in bone resorption.

Uterine and placental alterations in pregnant sows associated with the porcine epidemic abortion and respiratory syndrome (PEARS)

In the winter of 1990/91 a new, economically devastating disease occurred in european pig breeding herds, characterized by late-term abortion, stillbirth and a high morbidity and mortality of suckling piglets. Because of the clinical picture the disease was named porcine epidemic and respiratory syndrome (PEARS). In this study investigations were carried out in tissues of uterus and placentae of late gestational sows (107 to 112 days of gestation) in three different groups of animals: group I = control animals (n = 2) group II = naturally infected sows (n = 12) from farms, where PEARS recently had been introduced; group III = sows (n = 2), experimentally inoculated with placental homogenates from animals of group II. Both in naturally infected as well as in experimentally infected sows a multifocal, lymphohistiocytic vasculitis and perivascular cell infiltration was observed in the endometrium and maternal part of the placenta, but not in the fetal one. In the fetomaternal unit there were multifocal microseparations of the epithelial layers present. Transmission electron microscopically spherical or oval virus-like particles of 45 to 75 mm in diameter were frequently found on the surface of endothelial cells of blood vessels in the maternal placenta, in a few cases in the intercellular channel system between uterine epithelial cells or on endothelial cells of capillaries in the fetal placenta. Serological results indicate, that an infection with Lelystad virus had occurred in naturally and experimentally infected sows and that transplacental infection was present.

Increased production of tumor necrosis factor by normal immune cells in a model of the humoral hypercalcemia of malignancy

The rat Leydig cell tumor is a well characterized model of the humoral hypercalcemia of malignancy. The studies reported here were provoked by the observation that tumor-bearing rats become extremely cachectic and develop hypertriglyceridemia as they become hypercalcemic. Since the bone resorbing cytokine tumor necrosis factor (TNF)/cachectin is associated with cachexia and hypertriglyceridemia, we examined hypercalcemic tumor-bearing rats for evidence of increased TNF production using a TNF radioimmunoassay. We found that immunoreactive TNF was increased in the plasma of tumor-bearing rats. The increase in plasma TNF was comparable to that previously shown in hypercalcemic nude mice bearing Chinese hamster ovarian cell tumors transfected with the human TNF gene. There was no detectable TNF activity in tumor culture media which suggested that the tumor itself was not the source of excess TNF production. However, we found that tumor cell conditioned media enhanced the production of TNF activity by normal macrophages in vitro, indicating that increased TNF production in vivo may result from a tumor factor(s) which stimulates TNF production by normal immune cells. When TNF was added together with tumor products to organ cultures of fetal rat long bones, osteoclastic bone resorption was potentiated. These data are consistent with the concept that in this model of the humoral hypercalcemia of malignancy, increased TNF production by normal immune cells is increased, has systemic effects as suggested by cachexia and hypertriglyceridemia, and may work in concert with factors produced directly by tumor cells to overwhelm normal calcium homeostasis.

Stimulation of tumor necrosis factor release from monocytic cells by the A375 human melanoma via granulocyte-macrophage colony-stimulating factor

It has long been known that complex interactions occur between tumors and normal host immune cells. The human melanoma cell line A375 has been used previously as an indicator cell for tumor cell cytotoxicity mediated by monocytes. During other studies on this tumor cell line, we noted that the conditioned media harvested from A375 cultures induced both the human monocytoid cell line U937 and human blood monocytes to release the cytokine tumor necrosis factor (TNF). We characterized this tumor factor which induced TNF release by monocytic cells. Purification was performed using ammonium sulfate precipitation, ion exchange (DEAE) chromatography, gel filtration, and reversed-phase high performance liquid chromatography. The factor copurified with granulocyte-macrophage colony-stimulating factor (GM-CSF). The purified material caused the release of TNF by U937 cells and stimulated formation of granulocyte-macrophage colonies in methyl cellulose. TNF release by U937 cells in response to A375-conditioned medium was inhibited by neutralizing antibodies to GM-CSF. The TNF-inducing activity in A375-conditioned medium was completely removed by an anti-GM-CSF affinity column. Western blotting using antibodies to GM-CSF confirmed a single Mr27,000 band in A375-conditioned medium. We found that recombinant human GM-CSF stimulated TNF production by the same cells as the tumor-conditioned medium. These data show that A375 human melanoma cells produce GM-CSF, which in turn causes TNF production by cells in the monocyte lineage. The combination of GM-CSF production by the tumor and TNF production by immune cells may influence not only tumor growth but also some of the paraneoplastic syndromes associated with malignancy such as hypercalcemia, cachexia and leukocytosis.

Antibiotic susceptibility of clinical isolates of Pseudomonas aeruginosa

Three hundred and twenty two clinical isolates of Pseudomonas aeruginosa collected in Morelia, México, were analyzed for in vitro susceptibility to five antibiotics by agar dilution tests. Antibiotic resistance was shown by 50% of total isolates. Frequencies of resistance were: streptomycin, 47%; gentamicin, 13%; tobramycin, 8%; and carbenicillin, 7%; no amikacin resistance was found. The more common resistance patterns were streptomycin, gentamicin-streptomycin, and tobramycin-gentamicin-streptomycin. Resistance to either tobramycin, gentamicin or carbenicillin was found mainly in pyocin type 10 isolates. The proportion of antibiotic resistant isolates ranged from 37 to 75% in four hospitals, and amounted 24% in three clinical laboratories.

Mycotic flora in the lower digestive tract of feral pigeons (Columba livia) in the El Paso, Texas area

Fourteen species of fungus were isolated from the lower digestive tract of 39 of 80 pigeons. Sixteen pigeons had concurrent isolations while two harbored three species. Fungi isolated were Allescheria boydii, Aspergillus spp., Candida krusei, Chrysosporium spp., Geotrichum candidum, Mucor spp., Paeciliomyces spp., Penicillium spp., Rhizopus spp., Rhodotorula spp., Scopulariopsis spp., Streptomyces spp., and Trichosporon cutaneum. There was no apparent evidence that these fungi were associated with clinical disease in any of the pigeons.