Biological fate of a single administration of 191Pt in rats following different routes of exposure.

The retention, tissue distribution, and excretion of ¹⁹¹Pt in adult rats was determined following oral, intravenous (IV), and intratracheal administration. The highest retention was obtained following IV dosing, and lowest retention (less than 0.5%) occurred after oral dosing. Tissues containing the highest concentrations of ¹⁹¹Pt following IV administration were the kidney, adrenal, spleen, and liver. Following a single oral dose, almost all of the ¹⁹¹Pt was excreted in the feces due to nonabsorption, whereas after IV dosing, similar quantities were excreted in both the urine and feces. Following IV dosing of pregnant rats, ¹⁹¹Pt was found in all the fetuses; however, the amount was small.     

Assessment of the subchronic oral toxicity of d-limonene in dogs

Several hydrocarbons, including d-limonene, have been shown to produce a male-rat-specific nephrotoxicity that is manifested acutely as exacerbation of hyaline droplet formation. In a study to assess the presence or absence of this response in a non-rodent species, the dog was selected as a relevant model because of an earlier report suggesting that d-limonene may be nephrotoxic in this species. Five male and five female adult beagle dogs per treatment group were gavaged twice daily over a 6-month period with tap-water (control) or d-limonene at 0.12 or 1.2 ml/kg body weight/day (100 or 1000 mg/kg body weight/day). The highest daily dose was determined in a pilot study to be close to the maximum tolerated dose for emesis (ED50 1.6 ml/kg body weight). The test compound was administered in divided doses to minimize the incidence of emesis. Feed consumption and body weight were unaffected by treatment. Linear regression analyses indicated a positive dose-related trend for absolute and relative female kidney weight and relative male kidney weight. There were no histopathological changes in the kidneys, evaluated by both haematoxylin and eosin and Mallory-Heidenhain staining, that could be associated with the organ-weight changes. Furthermore, there was no evidence of hyaline droplet accumulation nor of any other sign of hydrocarbon-induced nephropathy typical of those seen in male rats treated with d-limonene. Thus, dogs are refractory to the hyaline droplet nephropathy observed in male rats, thereby providing additional evidence that the male rat kidney is uniquely sensitive to hydrocarbons like d-limonene, and that this specific male rat nephropathic response may be inappropriate for interspecies extrapolation and human risk assessment.     

The functional asymmetry of auditory cortex is reflected in the organization of local cortical circuits

The primary auditory cortex (A1) is organized tonotopically, with neurons sensitive to high and low frequencies arranged in a rostro-caudal gradient. We used laser scanning photostimulation in acute slices to study the organization of local excitatory connections onto layers 2 and 3 (L2/3) of the mouse A1. Consistent with the organization of other cortical regions, synaptic inputs along the isofrequency axis (orthogonal to the tonotopic axis) arose predominantly within a column. By contrast, we found that local connections along the tonotopic axis differed from those along the isofrequency axis: some input pathways to L3 (but not L2) arose predominantly out-of-column. In vivo cell-attached recordings revealed differences between the sound-responsiveness of neurons in L2 and L3. Our results are consistent with the hypothesis that auditory cortical microcircuitry is specialized to the one-dimensional representation of frequency in the auditory cortex.     

Preventing Infectious Complications of Immunomodulation in COVID-19 in Foreign-Born Patients

Journal of Immigrant and Minority Health - Immunomodulating therapies for COVID-19 may carry risks of reactivating latent infections in foreign-born people. We conducted a rapid review of...     

In vivo and in vitro Activation of T-Antigen Receptors on Leukocytes and Platelets1

Abstract. Serological studies on a patient whose red cells are polyagglutinable due to T activation have demonstrated concomitant T activity of the separated leukocytes and platelets. Normal leukocytes and platelets are not T active, but activation can be induced in vitro by treatment with neuraminidase or with Pneumo-coccus type III filtrate. Such T-active cells absorb anti-T from Arachis hypogea lectin. Tests on different types of separated leukocytes show that both neutrophils and lymphocytes have latent T antigen receptors. Neuraminidase treatment of platelets does not change their ability to promote clot retraction, to aggregate with ADP, or to take up serotonin.     

Oral toxicity of methylcyclopentadienyl manganese tricarbonyl (MMT) in rats

Rats were given a single oral dose of MMT diluted in Wesson Oil. Eight groups of animals were used and the dosages varied from 15 to 150 mg/kg body weight. Necropsies were performed and tissues were taken for histopathological and Mn determinations from animals dying during the study and from a selected number of animals euthanatized at the end of the study. The $\text{LD}{}_{50}\text{14}$ was 58 mg MMT/kg body weight. Histopathological changes were found in the lungs, liver and kidney. The severity of the changes was related to the dose. Concentrations of Mn in selected tissues were elevated in animals dying from exposure. At 14 days post ingestion, the Mn concentrations had fallen to approximately normal values.     

Exposure of laboratory animals to atmospheric maganese from automotive emissions.

Rats and hamsters were exposed eight hours/day for 56 consecutive days to automotive emissions containing increased concentrations of Mn particulate which resulted from the use of a fuel additive, methylcyclopentadienyl manganese tricarbonyl. The exhaust gases were generated by using a 1972 Chevrolet 350 CID engine dynamometer system. The exhaust was diluted and the average concentration of Mn particulate in the irradiated animal exposure chambers was approximately 117 μg/m³.No gross changes in general condition or appearance were observed in any of the animals. Microscopic examination of tissues from the animals showed changes related to the exhaust emissions and no changes were found which could be solely attributed to the presence of Mn or MMT. Mn concentrations in the tissues from exposed animals were generally elevated.     

Thrombocytopenic purpura following iopanoic acid ingestion

A 48-year-old woman had severe symptomatic thrombocytopenia three times in 13 months. Each episode followed ingestion of iopanoic acid. The interval between drug ingestion and onset of symptoms was 40, 12, and 8 hours. Resolution to normal platelet counts occurred in 6, 5, and 8 days. The third thrombocytopenic crisis occurred while the patient was receiving maintenance steroid therapy, given because the initial diagnosis was idiopathic thrombocytopenic purpura. Incubation of platelet-rich plasma with the patient's serum caused platelet lysis if either the patient or the donor serum obtained after ingestion of iopanoic acid was present in the mixture.     

Auto Anti-N—An Additional Example

This report is about an 85-year-old man with carcinoma of the urinary bladder who was type MN and had an antibody with N specificity. Absorption and elution studies proved this example of anti-N to be an autoantibody. Its optimal reactivity at low temperature and 2-mercaptoethanol reduction indicated antibody activity to be associated with an IgM globulin. The antibody failed to react with ficin treated cells. Both direct and indirect antiglobulin tests were negative. There was no clinical evidence of immune hemolysis in this patient. The serologic characteristics of the antibody were constant from discovery until the patient's death due to metastatic neoplasm ten weeks later.