Harnessing tumor immunity with cytotoxics: T cells monitoring in mice bearing lung tumors treated with anti-VEGF and pemetrexed-cisplatin doublet

BACKGROUND

Successful immunotherapy is restricted to some cancers only, and combinatorial strategies with other drugs could help to improve their efficacy. Here, we monitor T cells in NSCLC model after treatment with cytotoxics (CT) and anti-VEGF drugs, to understand when immune checkpoint inhibitors should be best associated next.

METHODS

In vivo study was performed on BALB/c mice grafted with KLN205 cells. Eight treatments were tested including control, cisplatin and pemetrexed as low (LD CT) and full (MTD CT) dose as single agents, flat dose anti-VEGF and the association anti-VEGF + CT. Full immunomonitoring was performed by flow cytometry on tumor, spleen and blood over 3 weeks.

RESULTS

Immunomodulatory effect was dependent upon both treatments and time. In tumors, combination groups shown numerical lower Treg cells on Day 21. In spleen, anti-VEGF and LD CT group shown higher CD8/Treg ratio on Day 7; on Day 14, higher T CD4 were observed in both combination groups. Finally, in blood, Tregs were lower and CD8/Treg ratio higher, on Day 14 in both combination groups. On Day 21, CD4 and CD8 T cells were higher in the anti-VEGF + MTD CT group.

CONCLUSIONS

Anti-VEGF associated to CT triggers notable increase in CD8/Tregs ratio. Regarding the scheduling, a two-week delay after using anti-VEGF and CT could be the best sequence to optimize antitumor efficacy.

Unravelling direct and indirect contact patterns between duck farms in France and their association with the 2016-2017 epidemic of Highly Pathogenic Avian Influenza (H5N8)

Live animal movements generate direct contacts (via the exchange of live animals) and indirect contacts (via the transit of transport vehicles) between farms, which can contribute to the spread of pathogens. However, most analyses focus solely on direct contacts and can therefore underestimate the contribution of live animal movements in the spread of infectious diseases. Here, we used French live duck movement data (2016-2018) from one of the largest transport companies to compare direct and indirect contact patterns between duck farms and evaluate how these patterns were associated with the French 2016-2017 epidemic of highly pathogenic avian influenza H5N8. A total number of 614 farms were included in the study, and two directed networks were generated: the animal introduction network (exchange of live ducks) and the transit network (transit of transport vehicles). Following descriptive analyses, these two networks were scrutinized in relation to farm infection status during the epidemic. Results showed that farms were substantially more connected in the transit network than in the animal introduction network and that the transit of transport vehicles generated more opportunities for transmission than the exchange of live animals. We also showed that animal introduction and transit networks' statistics decreased substantially during the epidemic (January-March 2017) compared to non-epidemic periods (January-March 2016 and January-March 2018). We estimated a probability of 33.3 % that a farm exposed to the infection through either of the two live duck movement networks (i.e. that was in direct or indirect contact with a farm that was reported as infected in the following seven days) becomes infected within seven days after the contact. However, we also demonstrated that the level of exposure of farms by these two contact patterns was low, leading only to a handful of transmission events through these routes. As a consequence, we showed that live animal movement patterns are efficient transmission routes for HPAI but have been efficiently reduced to limit the spread during the French 2020-2021 epidemic. These results underpin the relevance of studying indirect contacts resulting from the movement of animals to understand their transmission potential and the importance of accounting for both routes when designing disease control strategies.

Prototyping Trastuzumab Docetaxel Immunoliposomes with a New FCM-Based Method to Quantify Optimal Antibody Density on Nanoparticles

Developing targeted nanoparticles is a rising strategy to improve drug delivery in oncology. Antibodies are the most commonly used targeting agents. However, determination of their optimal number at the surface remains a challenging issue, mainly due to the difficulties in measuring precisely surface coating levels when prototyping nanoparticles. We developed an original quantitative assay to measure the exact number of coated antibodies per nanoparticle. Using flow cytometry optimized for submicron particle analysis and beads covered with known amounts of human IgG-kappa mimicking various amounts of antibodies, this new method was tested as part of the prototyping of docetaxel liposomes coated with trastuzumab against Her2+ breast cancer. This quantification method allowed to discriminate various batches of immunoliposomes depending on their trastuzumab density on nanoparticle surface (i.e., 330 (Immunoliposome-1), 480 (Immunoliposome-2) and 690 (Immunoliposome-3), p = 0.004, One-way ANOVA). Here we showed that optimal number of grafted antibodies on nanoparticles should be finely tuned and highest density of targeting agent is not necessarily associated with highest efficacy. Overall, this new method should help to better prototype third generation nanoparticles.

Initial 200 cases of carotid artery stenting using a reversal-of-flow cerebral protection device

AIM

Because embolic complications can occur during carotid angioplasty and stenting (CAS), a new device, the Parodi Anti-Emboli System (PAES) was developed to protect the brain from embolization. We describe our initial experience with this device.

METHODS

Between September 1999 and December 2003, CAS was performed in 200 consecutive patients (146 men; mean age, 70.4 years) with symptomatic (52%) or asymptomatic (48%) severe carotid artery stenosis (>70%). De novo lesions were present in 169 patients, restenosis in 18, and radiation-induced stenosis in 13. Wallstents were inserted in all cases, with selective predilatation, and the PAES was employed during all CAS procedures. Patients were evaluated by a neurologist before and after CAS. Minor strokes, major or fatal strokes, and myocardial infarctions that occurred within 30 days of the procedure were recorded.

RESULTS

The overall technical success rate for CAS using the PAES (with the PAES placed in position percutaneously) was 99%. The overall perioperative stroke and death rate was 1.5%. There were four transient neurologic events after CAS, three of which were related to hemodynamic instability and one to postoperative embolization.

CONCLUSIONS

Our experience indicates that CAS using the PAES is safe and effective. The protection device may prevent the debris released by angioplasty from entering the cerebral circulation. Additional studies of this device are warranted.

Factors increasing the mortality rate for patients with ruptured abdominal aortic aneurysms

The objective of this report was to analyze the current surgical results of operative treatment in patients suffering ruptured AAA (abdominal aortic aneurysms) and to define those independent predictive factors for mortality. During a period of 2 years, from January 1996 to December 1997, 144 patients operated on for ruptured AAA in 10 hospitals were included in a multicenter retrospective study. Among the collected variables concerning each patient, those with potential relation to surgical mortality were studied: gender, age, diabetes, hypertension, cardiopathy, pulmonary obstructive disease, preoperative renal dysfunction, symptomatic cerebrovascular disease, peripheral vascular disease, hematocrit on admission, preoperative hypotension < 80 mmHg, loss of consciousness, cardiac arrest, aortic aneurysm location (infrarenal versus non-infrarenal), iliac involvement, aneurysm size, type of rupture, left renal vein ligature, ligature of a patent inferior mesenteric artery, place of aortic cross-clamping, type of grafting, exclusion of both hypogastric arteries, venous technical complications, associated surgery, use of cell saver, intraoperative blood loss, and postoperative complications (renal failure, sepsis, coagulopathy, cardiac complications, pulmonary complications, colon ischemia, prosthetic graft complications, and need for reoperation). Those variables with statistical significance in the univariate analysis were introduced into a multivariate logistic regression model to determine the independent predictors of death. From our results we concluded that surgery for ruptured abdominal aortic aneurysms continues to have an excessively high mortality rate. Even though some preoperative variables could be identified as predictors of mortality, an absolute mortality risk has not yet been determined and the decision to negate surgery should be individualized rather than taken on that basis only. Early diagnosis and treatment of symptomatic aneurysms would improve mortality figures and selective screening should be contemplated.

A novel mechanism for skeletal resistance in uremia

BACKGROUND

In treating secondary hyperparathyroidism, the target level of serum intact parathyroid hormone (I-PTH) should be three to five times normal to prevent adynamic bone disease. In circulation, there is a non-(1-84) PTH-truncated fragment, likely 7-84, which, in addition to PTH 1-84, is measured by most I-PTH immunoradiometric (IRMA) assays, giving erroneously high I-PTH values. We have developed a new IRMA assay in which the labeled antibody recognizes only the first six amino acids of the PTH molecule. Thus, this new IRMA assay (Whole PTH) measures only the biologically active 1-84 PTH molecule.

METHODS

Using this new IRMA assay (Whole PTH) and the Nichols "intact" PTH assay, we compared the ability of each assay to recognize human PTH (hPTH) 1-84 and hPTH 7-84 and examined the percentage of non-1-84 PTH in circulation and in parathyroid glands. Possible antagonistic effects of the 7-84 PTH fragment on the biological activity of 1-84 PTH in rats were also tested.

RESULTS

In 28 uremic patients, PTH values measured with the Nichols assay, representing a combined measurement of both hPTH 1-84 and hPTH 7-84, were 34% higher than with the Whole assay (hPTH 1-84 only); the median PTH was 523 versus 318 pg/mL (P < 0.001). Similar results were found in 14 renal transplant patients. In osteoblast-like cells, ROS 17.2, 1-84 PTH (10-8 mol/L) increased cAMP from 18.1 +/- 1.25 to 738 +/- 4.13 mmol/well. Conversely, the same concentration of 7-84 PTH had no effect. In parathyroidectomized rats fed a calcium-deficient diet, 7-84 PTH was not only biologically inactive, but had antagonistic effects on 1-84 PTH in bone. Plasma calcium was increased (0.65 mg/dL) two hours after 1-84 PTH treatment, while 7-84 PTH had no effect. When 1-84 PTH and 7-84 PTH were given simultaneously in a 1:1 molar ratio, the calcemic response to 1-84 PTH was decreased by 94%. In normal rats, the administration of 1-84 PTH increased renal fractional excretion of phosphate (11.9 to 27.7%, P < 0.001). However, when 1-84 PTH and 7-84 PTH were given simultaneously, the 7-84 PTH decreased the phosphaturic response by 50.2% (P < 0.005). Finally, in surgically excised parathyroid glands from six uremic patients, we found that 44.1% of the total intracellular PTH was the non-PTH (1-84), most likely PTH 7-84.

CONCLUSION

In patients with chronic renal failure, the presence of high circulating levels of non-1-84 PTH fragments (most likely 7-84 PTH) detected by the "intact" assay and the antagonistic effects of 7-84 PTH on the biological activity of 1-84 PTH explain the need of higher levels of "intact" PTH to prevent adynamic bone disease.

Functional anatomy of perceptual and semantic processing for odors

The functional anatomy of perceptual and semantic processings for odors was studied using positron emission tomography (PET). The first experiment was a pretest in which 71 normal subjects were asked to rate 185 odorants in terms of intensity, familiarity, hedonicity, and comestibility and to name the odorants. This pretest was necessary to select the most appropriate stimuli for the different cognitive tasks of the second experiment. The second one was a PET experiment in which 15 normal subjects were scanned using the water bolus method to measure regional cerebral blood flow (rCBF) during the performance in three conditions. In the first (perceptual) condition, subjects were asked to judge whether an odor was familiar or not. In the second (semantic) condition, subjects had to decide whether an odor corresponded to a comestible item or not. In the third (detection) condition, subjects had to judge whether the perceived stimulus was made of an odor or was just air. It was hypothetized that the three tasks were hierarchically organized from a superficial detection level to a deep semantic level. Odorants were presented with an air-flow olfactometer, which allowed the stimulations to be synchronized with breathing. Subtraction of activation images obtained between familiarity and control judgments revealed that familiarity judgments were mainly associated with the activity of the right orbito-frontal area, the subcallosal gyrus, the left inferior frontal gyrus, the left superior frontal gyrus, and the anterior cingulate (Brodmann's areas 11, 25, 47, 9, and 32, respectively). The comestibility minus familiarity comparison showed that comestibility judgments selectively activated the primary visual areas. In contrast, a decrease in rCBF was observed in these same visual areas for familiarity judgments and in the orbito-frontal area for comestibility judgments. These results suggest that orbito-frontal and visual regions interact in odor processing in a complementary way, depending on the task requirements.

Stress induces neurogenesis in non-neuronal cell cultures of adult olfactory epithelium

Among the basal cells of the olfactory epithelium is a stem cell which divides and whose progeny differentiate into new sensory neurons throughout adult life. Olfactory neurogenesis is highly regulated, for example it is stimulated by epithelial damage. Previous reports implicate several growth factors in progenitor cell proliferation and neuronal differentiation in vitro but these studies differ in growth conditions and age of donors making it difficult to determine precisely the roles of neurogenic stimuli and their sites of action. The aims of the present study were to develop purified basal cell cultures from adult olfactory epithelium and to stimulate neurogenesis in defined growth conditions in order to elucidate the cellular mechanisms by which neurogenesis is stimulated after epithelial damage. We show here that differentiated olfactory sensory neurons arise after biochemical or mechanical stress of rat and mouse olfactory epithelial cell cultures in the absence of growth factors, complex media (e.g., serum, conditioned media, pituitary and hypothalamic extracts), or other cells (e.g., explants, feeder layers of glia, or other non-epithelial cells). Prior to the stress, these cultures contained basal cells and supporting cells but not neurons. After the stress, some cells differentiated into bipolar neurons expressing a number of neuronal proteins including olfactory marker protein. Bromodeoxyuridine experiments show that the differentiated neurons arose from recently divided cells which did not divide again before differentiating. We conclude that stress disrupts cell surface contacts to induce the immediate neuronal precursors to undergo final differentiation into olfactory sensory neurons. This may be a mechanism for enhanced neurogenesis after epithelial damage.

Generation of neurons from a nonneuronal precursor in adult olfactory epithelium in vitro

Within the olfactory epithelium is a stem cell which can divide and differentiate to produce new sensory neurons. The identity of the neuronal stem cell is unknown but one candidate is the horizontal basal cell which lies adjacent to the basement membrane and expresses keratin. Previous attempts to generate mature sensory neurons from purified horizontal basal cells in vitro were unsuccessful. We show here for the first time that olfactory neurogenesis can be reproduced in vitro from partially-purified cultures of adult rat precursor cells cultivated in a serum-free medium. Rat olfactory epithelium was dissected from the nasal septum and separated from the underlying lamina propria, and its cells were dissociated and grown in a medium containing epidermal growth factor for 5 days. Immunochemistry showed that only supporting cells (SUS1-positive) and horizontal basal cells (keratin-positive) survived for this period. At day 6, the cells were stressed either by passaging them or by a simple mechanical stress. In each case, a morphological and immunological differentiation was observed within 24-48 hr. Newly formed bipolar cells were found to be S100-, glial fibrillary acidic protein (GFAP-), neural cell adhesion molecule (N-CAM+), and/or microtubule-associated protein 5 (MAP-5+). After passaging 14% of the surviving cells were immature neurons (MAP-5+) and 4% were mature olfactory neurons (MAP-5+) and olfactory marker protein (OMP+)). In addition the same experiment was conducted on transgenic mice in which the lacZ gene was linked to the OMP promoter. Using 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) staining we showed that OMP+ cells disappeared before day 5 in culture but reappeared after passaging. These results suggest that olfactory sensory neurons can arise from a non-neuronal precursor, probably the keratin-positive horizontal basal cell.

In vitro induction of apoptosis or differentiation by dopamine in an immortalized olfactory neuronal cell line

A new neuronal cell line was generated by transfection of rat olfactory epithelium with immortalizing recombinant oncogene E1A of adenovirus-2. The resulting 13.S.1.24 line of transformed cells expressed an antigenic phenotype of olfactory neuronal progenitors. Addition of dopamine to 13.S.1.24 cultures induced reduction of cell number within 2 days. Two hallmarks of apoptosis were detected in dopamine-treated cultures: internucleosomal DNA fragmentation and nuclear condensation. Dopamine did not alter the cell proliferation rate, as assessed by [3H]thymidine incorporation. Dopamine also stimulated differentiation of surviving 13.S.1.24 cells into bipolar olfactory marker protein-immunoreactive neurons. Time-dependency assessments over 1 week of treatment indicated that apoptosis and differentiation induced by dopamine were concomitant. Both apoptosis and differentiation triggered by dopamine were dose-dependent, half-maximal effects being obtained with approximately 10 microM dopamine. Mediation of both effects by dopaminergic D2 receptors was supported by several observations: active dopamine doses in micromolar ranges, quinpirole agonism and eticlopride antagonism, D2-characteristic rank order of potency among the three agonists tested, and specific binding of a selective D2-like radioligand to 13.S.1.24 cells. The present data altogether indicated that dopamine commits immortalized olfactory neuronal cells in vitro either to apoptosis or to olfactory-like differentiation via D2 dopaminergic receptors.

Is short-term odour recognition predictable from odour profile?

Smelling an odour induces a pattern of sensations, images and memories which participate in identification. It was proposed that perceptual memory performances for odours could be inferred from the description of these olfactory representations. The subject was asked to elaborate an odour descriptor profile, and a short-term odour recognition memory task was chosen to test the individual perceptual memory performance. Two pattern-recognition methods based on artificial neural networks and discriminant analysis were carried out and allowed odour profile and perceptual memory performance to be related. Insofar as the subjects gave dichotomic responses in the recognition memory task, each response could be evaluated in terms of correct or incorrect responses. Simulations indicated that the olfactory recognition memory performance can be predicted in man from odour-elicited semantic profiles by using artificial neural networks. It was also shown that all semantic descriptors do not participate in olfactory recognition to the same degree. Low-level information, such as intensity, familiarity and hedonic judgements, did not allow the artificial neural network to predict the olfactory performance. By contrast, high-level information, such as gustatory, olfactory and visual evocations, allowed artificial networks to make such predictions.

Intraoperative salvage in patients undergoing elective abdominal aortic aneurysm repair: an analysis of cost and benefit

PURPOSE

Although autologous blood procurement has become a standard of care in elective surgery, recent studies have questioned its cost-effectiveness. We therefore reviewed our 3-year experience with intraoperative cell salvage in patients who underwent elective abdominal aortic aneurysm repair.

METHODS

A 3-year retrospective chart review of elective abdominal aortic aneurysm (infrarenal and suprarenal) repair was performed. Transthoracic repairs were excluded.

RESULTS

Estimated blood lost was 1748 +/- 1236 ml, or 35% of baseline blood volume (5012 +/- 689 ml). Overall, 164 (89%) received red blood cell (RBC) transfusions (3.5 +/- 2.0 U/patient). The cost per patient for cell salvage was $315 +/- $97, representing 31% of all RBC costs and 24% of total blood component costs. Mean salvage volume infused was 578 +/- 600 ml; at a mean hematocrit level of 55.7% the RBC volume infused from salvage during surgery was 313 +/- 328 ml (representing 27% of total RBC volume lost during the hospital stay). This mean RBC volume salvaged represented the equivalent of 1.6 blood bank RBC units. The mean blood bank costs saved by using cell salvage was $248, or 79% of the $315 actually spent for salvage. We found no decrease in percentage of patients undergoing transfusion until salvage volumes that were infused exceeded 750 ml, or the equivalent of two blood bank units; all of these patients who benefitted had estimated blood lost > or = 1000 ml.

CONCLUSIONS

We conclude that use of intraoperative cell salvage was most beneficial for patients who had estimated blood loss greater than or equal to 1000 ml and cell salvage volumes infused greater than or equal to 750 ml. Patients who are estimated to lose less than 1000 ml receive little benefit yet incur substantial costs from intraoperative cell salvage.

Physiological and histological recovery of the olfactory mucosa of the frog after a dichlobenil injection

Four days after a single systemic injection of 50 mg/kg of dichlobenil (2,6-dichlorobenzonitrile), the olfactory neuroepithelium of the frog is extensively damaged. At the same time, electrophysiological responses to odorant stimulations (2-heptanone, D-limonene, amyl acetate, camphor) are largely reduced. Pretreatment of the animals with metyrapone, an inhibitor of cytochrome P-450 enzymatic systems, inhibits the histological and physiological toxic effects of the dichlobenil injection. The olfactory tissue recovered 3 months after the dichlobenil injections and responses to odorant stimulations returned. The same dichlobenil injections did not induce lesions in the vomeronasal neuroepithelium.

Isolation of mature olfactory neurones using retrograde labelling and flow cytometry

Currently we can observe an increasing interest for epithelial olfactory neurones. Several laboratories are involved in elucidation of the odorant-molecule recognition process and transduction cascade which brings information to the olfactory bulb. Others use this model, unique in mammals, to accumulate new knowledge on the neurogenesis phenomenon. Here we describe a simple and efficient method to purify mature olfactory neurone populations extracted from the nasal cavity. The approach relies on retrograde axonal tracing followed by flow cytometry sorting. For this purpose we inject a fluorescent dye (Fast Blue or diI C18(3)) in the olfactory bulb of adult rats. Seven days later, we extract the nasal turbinates and separate the mucosa from the subjacent lamina propria. The tissue is enzymatically dissociated and the labelled cells are sorted with a flow cytometer. Purification of the mature olfactory neurones varies from 80 to 99%.

Beneficial effects of donor-specific transfusions on long-term renal allograft function

The induction of immunologic unresponsiveness to improve renal allograft survival was attempted in 163 patients by the pretransplant administration of donor-specific whole blood or buffy coat in conjunction with continuous Aza immunosuppression. All donor-recipient combinations were at least one-haplotype disparate, and 21 were two-haplotype disparate. Transient sensitization occurred in 2% and permanent sensitization in 7%. Over a 10-year period, the DST+Aza allograft survival rate is similar to the HLA-identical sibling transplants. The CMV sepsis rate was only 2%, and there were no lymphoproliferative neoplasms. The low rate of sensitization (7%) has permitted almost all patients to undergo eventual renal transplantation from the specific blood donor. This and the low rate of early rejection (3%) argues for a modification of the immunologic response.

The role of cholesterol accumulation in prosthetic vascular graft anastomotic intimal hyperplasia

PURPOSE

To demonstrate that modulation of plasma cholesterol concentrations affects prosthetic vascular graft anastomotic intimal hyperplasia (AIH), aortic grafts were examined histologically and biochemically in 41 rabbits.

METHODS

Twenty-seven rabbits were fed standard rabbit diet, whereas 14 were fed cholesterol-supplemented diet to induce hypercholesterolemia.

RESULTS

A smooth muscle cell proliferative response, similar to AIH in humans, was seen equally at the proximal and distal anastomoses. However, surface area and thickness of AIH were significantly greater in rabbits with hypercholesterolemia. Anastomotic tissue cholesterol concentrations were fifteenfold higher in rabbits with hypercholesterolemia than in rabbits with normal cholesterol concentrations and anastomotic cholesterol concentrations were fivefold higher than in the aorta away from the graft in rabbits with hypercholesterolemia. Preferential deposition of radioiodinated dilactitol tyramine coupled to low-density lipoproteins, but not albumin, was demonstrated in anastomotic areas and grafts of rabbits with normal cholesterol concentrations as well. Surface area and thickness of AIH correlated closely with plasma and tissue cholesterol concentrations.

CONCLUSIONS

Oxidized products of lipoproteins have been shown to stimulate production of growth factors that cause smooth muscle cell proliferation, migration, and synthetic function. It is likely they play an important part in prosthetic vascular graft AIH, similar to their role in atherogenesis.

Renal autotransplantation in the management of a ureteroarterial fistula: a case report and review of the literature

A 57-year-old woman who had been treated with an indwelling ureteral stent for over a year was admitted with massive gross hematuria caused by a fistula between the left ureter and hypogastric artery. Despite intensive radiographic evaluation, the definitive diagnosis was made only at the time of surgical exploration. Because of radiation-induced retroperitoneal fibrosis, midureteral obstruction, and prior pelvic and abdominal surgery, primary ureteral repair was not possible, and renal autotransplantation was performed. This case illustrates the need to consider the diagnosis of ureteroarterial fistula in patients with massive hematuria who have chronic indwelling stents, and the feasibility of autotransplantation when primary ureteral repair is not feasible.

Tolerance of gastric mucosal flap to postoperative irradiation

When malignant lesions of the oral cavity, base of tongue, and oropharynx are treated with radical resection, adequate reconstruction is required. The free gastric mucosal flap with microvascular transfer is being used with increasing frequency at Washington University Medical Center. Because of the advanced nature of the primary lesions, most patients also require postoperative radiation therapy. In this paper the tolerance of the gastric mucosal flap to postoperative radiation therapy is reviewed. The changes resulting from radiation therapy in the mucosal flap were found to be acceptable, and no major complications were encountered.

A canine model of paired graft thrombosis

A novel canine model for reliably producing graft thrombosis is described. Two unilateral aortoiliac bypasses are performed while preserving the integrity of the native vascular tree. These grafts are briefly mechanically occluded at the time of the initial operation, and they remain occluded postoperatively because flow is preferentially directed through the larger-caliber, thrombo-resistant native circulation. Percutaneous temporary intra-arterial balloon occlusion of the native vessels redirects flow into the occluded graft segments, which can be used in experimental protocols. This new model for studying graft thrombosis requires only a single, simple operative procedure, and easily allows secondary percutaneous graft manipulation.

Results from six autonomic nervous system responses confirm "autonomic response specificity" hypothesis

The Autonomic Nervous System (ANS) specificity concept corresponds, according to Lacey, to the preferential reaction on the part of the same subject along a determined ANS channel. Six channels: skin potential, resistance, blood flow, temperature, and instantaneous heart and respiratory frequencies were recorded simultaneously in 33 subjects submitted to a verbal association test likely to arouse different kinds of emotions, and to mental arithmetic. Studies of these six parameters in relation to mean response, and principal component analysis made it possible to bring the individual response to the fore via ANS preferential channels, and thus to confirm Lacey's hypothesis, while adding further evidence as corollaries.

Comparison of the sensitivity of C57BL/6J and AKR/J mice to airborne molecules of isovaleric acid and amyl acetate

Wysocki et al. (1977) have previously compared the abilities of several inbred strains of mice to avoid odorized drinks after odor-aversion conditioning and have proposed C57BL/6 mice as an animal model to study the specific anosmia to isovaleric acid. We have compared the olfactory performances of C57BL/6J mice and AKR/J mice using one-bottle and two-bottle tests to study the latencies of contacts with odorized or control drinks after odor-aversion conditioning. In both inbred strains, sensitivities to airborne molecules of amyl acetate (control odor) or isovaleric acid are demonstrated. Differences in behavioral strategies are suggested but the results are consistent with the hypothesis of a selective hyposmia to isovaleric acid in C57BL/6J mice.

Olfactory discrimination over a wide concentration range. Comparison of receptor cell and bulb neuron abilities

Until now, olfactory discrimination had never been investigated using stimuli delivered over a wide concentration range. However, the fact that intensity variations might influence qualitative discrimination has been suggested in numerous physiological and psychophysical studies. The aim of the present work was to investigate qualitative coding mechanisms when stimulus intensity varies. For this purpose, receptor cell and olfactory bulb neuron unit activities were recorded in response to 2-s pulse delivery of 4 odorants available at 20 discrete concentration values over a range from 1 x 10(-6) to 5.62 x 10(-2) of saturation. Two types of mathematical analyses, Pearson's r correlation coefficient calculation and principal component factor analysis, were applied to odor-evoked discharge frequencies. In both receptor cells and bulb neurons, qualitative discrimination abilities were found to increase with stimulus concentration. Furthermore, the results suggest that the olfactory bulb can send a discriminant and specific message at lower concentrations than the olfactory mucosa. The amplifying role of convergence of primary afferences onto olfactory glomeruli could account for this ability of the bulb neurons.

A comparative study of 2-deoxyglucose patterns of glomerular activation in the olfactory bulbs of C57 BL/6J and AKR/J mice

We have studied the patterns of glomerular activation evoked in the olfactory bulbs of C57BL/6J and AKR/J mice by olfactory stimulations with amyl acetate or isovaleric acid. Patterns of glomerular activation were obtained with the 2-deoxyglucose method and subsequently compared using a computer-assisted image analysis. The mice of both inbred strains stimulated with amyl acetate or isovaleric acid were characterized by areas of high 2-deoxyglucose uptake in their glomerular layer. Statistical comparisons of the patterns demonstrated that they were odor-specific. Although C57BL/6J mice have been found to be specifically anosmic to isovaleric acid, our findings indicate that their olfactory system is topographically activated by olfactory stimulations with this odorant. However, patterns of glomerular activity evoked by isovaleric acid stimulations are not similar in the two studied strains.

Thromboxane synthesis inhibition and renal allograft function

These data indicate that chronic administration of CGS-12970 to renal allograft recipients maintains renal allograft function. These effects are probably due to selective inhibition of local tissue TXA2 production. These data also suggest that elevations in renal allograft tissue prostacyclin production may be secondary to ischemia since improving renal blood flow and GFR with selective thromboxane synthesis inhibitors leads to normalization of renal prostacyclin synthesis. The possible utility of using CGS-12970 as an adjunct therapy in human renal allotransplantation should be strongly considered.

Specificity of spatial patterns of glomerular activation in the mouse olfactory bulb: computer-assisted image analysis of 2-deoxyglucose autoradiograms

We have developed a computer-assisted method for analyzing the 2-deoxyglucose (2-DG) autoradiograms of mice olfactory bulbs. The purpose of the study was to numerize the maps of glomerular activation in order to achieve a statistical comparison of the glomerular patterns evoked by different stimuli. The spatial distribution of glomerular activation was displayed on unfolded representations of the glomerular layer which were built up using glomerular optical densities (OD) measured systematically within 13 sections per bulb. Each bulbar sample was converted into an 'OD profile'. A matrix composed of 18 OD profiles was submitted to a principal component analysis. The first factor which accounted for 28% of the variance separated unambiguously two clusters corresponding to the bulbs issued from animals stimulated with amylacetate and isovaleric acid, respectively. The second and third factors which accounted for 14% and 12% of the variance segregated the control group (animals exposed to pure air) from the odor-stimulated ones. It was demonstrated that the cluster separation was actually due to the specific spatial distribution of the most-labelled glomeruli. A particular attention was paid to the well-delineated glomerular activation evoked by isovaleric acid. The results demonstrate the specificity and reliability of the glomerular 2-DG patterns. The method should be useful for further comparisons of patterns elicited by larger sets of odorant compounds.

Electrophysiological recordings from olfactory receptor cells in adult mice

A new preparation for in vivo electrophysiological recording of olfactory receptor cell activity in the mouse is described. Receptor cells were characterized by their spontaneous activity and responses to odorants. These preliminary observations suggest that the olfactory receptor cells in mouse are more selective than receptor cells of the frog olfactory epithelium.

Olfactory discrimination of structurally related molecules: receptor cell responses to camphoraceous odorants

Electrophysiological investigations of the selective sensitivity of receptor cells have shown that odorants could be distributed into groups according to the profiles of responses that they elicited from a population of receptor cells. As the concept of odorant group plays an important role in the understanding of olfactory coding, an attempt was made to investigate in detail the group properties of a number of structurally and qualitatively related molecules: 1,8 cineole, DL-camphor, borneol, iso-borneol, adamantane, fenchone, fenchyl alcohol, 3,3,5-tri-methyl cyclohexanone, camphene, 1,1,2,2-tetra-bromoethane. These odorants, along with several other representatives of other odorant groups, were utilized to stimulate a set of 71 individually recorded receptor cells. Factor analysis of electrophysiological data demonstrated that the grouping of odorants with camphor could be predicted on the basis of the shape and size of the molecules. The analysis also showed that even a clearly defined odorant group such as the camphor group is not likely to be determined by a single type of receptor site.

Receptor cell responses to odorants: similarities and differences among odorants

An extensive exploration of the discriminating properties of olfactory receptors cells has been conducted in our laboratory through the statistical processing of single cell responses recorded in the frog's olfactory epithelium. Similarities between odorant stimulating properties could be demonstrated by comparing the complex response profiles of receptor cells, resulting in the concept of odorant groups which depicts consistent relationships found between some odorous compounds. The recording technique limits the number of odorants which can be tested and compared within the same series of experiments. Thus, based upon previous studies we have chosen a specific set of 20 odorants whose characteristics are known but, up to this time, have not been compared in the same experimental system. These odorants were: acetophenone, anisole, n-butanol, DL-camphor, cyclodecanone, 1,8-cineole, p-cymene, D-citronellol, n-heptanol, isoamyl acetate, isovaleric acid, D-limonene, methyl amylketone, L-menthol, phenol, thiophenol, pyridine, thymol, cyclohexanol, cyclohexanone. The pattern of similarities between these odorants, as delineated with the aid of correlation coefficient computation, factor analysis and non-hierarchical taxonomy, confirms the reality of several odorant groups previously suggested and describes their cross-relationships. The receptor mechanisms underlying these odorant groups are discussed. Because reliable prominent features of the olfactory stimulus space can be established on an objective basis, the findings are proposed as a reference for future studies on other aspects of olfactory discrimination.

Discrete colon ulcers as a cause of lower gastrointestinal bleeding and perforation in end-stage renal disease

Since 1975 at our institution six cases of discrete colon ulcers have been noted in patients with end-stage renal disease. Five patients were on long-term hemodialysis, and one patient had received a cadaver kidney transplant. Four patients presented with lower gastrointestinal hemorrhage-two acute and two subacute. Two patients presented with diffuse abdominal pain and peritoneal signs. Two colon ulcers were diagnosed by colonoscopy, two were diagnosed in laparotomy, one was diagnosed by arteriography, and one ulcer was diagnosed only on pathologic examination of the resected colon. Pathologic examination disclosed idiopathic ulcers in all six cases. All patients were managed surgically. The mortality rate was 50%. Discrete colon ulcers should be considered in the differential diagnosis when the hemodialysis or kidney transplant patient presents with lower gastrointestinal bleeding or abdominal pain and peritoneal signs.

Altered adenylate cyclase kinetics in hyperfunctioning human parathyroid glands

Current evidence suggests that parathyroid gland adenylate cyclase is involved in the control of parathyroid hormone (PTH) secretion. Thus, the altered control of PTH release in hyperparathyroidism may relate to altered adenylate cyclase activation. Therefore, we examined adenylate cyclase kinetics in membrane preparations from hyperfunctioning human parathyroid glands and normal human and bovine parathyroid tissues. There were no differences in the affinity for ATP between enzymes of normal and pathological tissue. However, the enzyme in 10 hyperfunctioning glands showed increased affinity for Mg++. The activation constant for Mg++ (KaMg) of adenylate cyclase in normal human glands was 10.6 +/- 2 mM, a value not different from that of normal bovine parathyroid tissue (9.5 +/- 1 mM). In contrast, the adenylate cyclase in membrane preparations from three of four hyperplastic and six of seven adenomatous human glands showed a markedly reduced KaMg, ranging from 0.85-1.64 mM and from 1.58-6.46 mM, respectively. In one adenoma and one hyperplastic gland, the Ka of the enzyme for Mg++ was close to normal. The addition of guanylylimidodiphosphate or GTP to the incubation mixture increased, in a dose-dependent manner, the apparent KaMg of the enzyme in the abnormal tissue toward normal, suggesting a defective nucleotide regulatory site in the adenylate cyclase of hyperparathyroid glands. In addition, the hyperparathyroid gland enzyme was less susceptible to inhibition by calcium, requiring 0.7-1 mM Ca++ for 50% inhibition, whereas comparable inhibition of the normal adenylate cyclase was seen at 0.22-0.28 mM Ca++. We conclude that the abnormal control of PTH secretion in hyperparathyroidism may be related, at least in part, to alterations in the characteristics of parathyroid gland adenylate cyclase.

Cryptococcal pyelonephritis and disseminated cryptococcosis in a renal transplant recipient

Symptomatic cryptococcal pyelonephritis, meningitis, and disseminated cryptococcosis are described in a renal cadaver transplant recipient who subsequently died of Klebsiella pneumoniae sepsis. The presence of cryptococcuria and a subsequent positive CSF India ink stain led to the initial diagnosis of disseminated cryptococcosis. Therapy with 0.511 g of amphotericin B and 112.5 g of flucytosine for four weeks did not eradicate Cryptococcus from the kidney and was associated with hepatotoxicity. The importance of urinary examination and culture for C neoformans is emphasized. Cryptococcal pyelonephritis should be considered in the differential diagnosis of allograft rejection in the renal transplant patient.