Antimicrobial efficacy of in vitro and ex vivo photodynamic therapy using porphyrins against Moraxella spp. isolated from bovine keratoconjunctivitis.

Infectious bovine keratoconjunctivitis (IBK) is an ocular disease affecting bovine herds worldwide, and it causes significant economic loss. The etiologic agent of IBK is considered to be Moraxella bovis, but M. ovis and M. bovoculi are frequently recovered of animals presenting clinical signs of IBK. The therapeutic measures available for its control have limited efficacy. Antimicrobial photodynamic therapy (aPDT) using porphyrins as photosensitizing molecules is an alternative method that can be used to reduce microbial growth. We evaluated the antibacterial activity of aPDT using two water-soluble tetra-cationic porphyrins (H2TMeP and ZnTMeP) against 22 clinical isolates and standard strains of Moraxella spp. in vitro and in an ex vivo model. For the in vitro assay, 4.0 µM of porphyrin was incubated with approximately 1.0 × 104 CFU/mL of each Moraxella sp. isolate and exposed to artificial light for 0, 2.5, 5, and 7.5 min. Next, 50 µL of this solution was plated and incubated for 24 h until CFU measurement. For the ex vivo assay, corneas excised from the eyeballs of slaughtered cattle were irrigated with Moraxella spp. culture, followed by the addition of zinc(II) porphyrin ZnTMeP (4.0 µM). The corneal samples were irradiated for 0, 7.5, and 30 min, followed by swab collection, plating, and CFU count. The results demonstrated the in vitro inactivation of the strains and clinical isolates of Moraxella spp. after 2.5 min of irradiation using ZnTMeP, reaching complete inactivation until 7.5 min. In the ex vivo experiment, the use of ZnTMeP resulted in the most significant reduction in bacterial concentration after 30 min of irradiation. These results encourage future in vivo experiments to investigate the role of metalloporphyrin ZnTMeP in the inactivation of Moraxella spp. isolates causing IBK.

A search for RNA insertions and NS3 gene duplication in the genome of cytopathic isolates of bovine viral diarrhea virus.

Calves born persistently infected with non-cytopathic bovine viral diarrhea virus (ncpBVDV) frequently develop a fatal gastroenteric illness called mucosal disease. Both the original virus (ncpBVDV) and an antigenically identical but cytopathic virus (cpBVDV) can be isolated from animals affected by mucosal disease. Cytopathic BVDVs originate from their ncp counterparts by diverse genetic mechanisms, all leading to the expression of the non-structural polypeptide NS3 as a discrete protein. In contrast, ncpBVDVs express only the large precursor polypeptide, NS2-3, which contains the NS3 sequence within its carboxy-terminal half. We report here the investigation of the mechanism leading to NS3 expression in 41 cpBVDV isolates. An RT-PCR strategy was employed to detect RNA insertions within the NS2-3 gene and/or duplication of the NS3 gene, two common mechanisms of NS3 expression. RT-PCR amplification revealed insertions in the NS2-3 gene of three cp isolates, with the inserts being similar in size to that present in the cpBVDV NADL strain. Sequencing of one such insert revealed a 296-nucleotide sequence with a central core of 270 nucleotides coding for an amino acid sequence highly homologous (98%) to the NADL insert, a sequence corresponding to part of the cellular J-Domain gene. One cpBVDV isolate contained a duplication of the NS3 gene downstream from the original locus. In contrast, no detectable NS2-3 insertions or NS3 gene duplications were observed in the genome of 37 cp isolates. These results demonstrate that processing of NS2-3 without bulk mRNA insertions or NS3 gene duplications seems to be a frequent mechanism leading to NS3 expression and BVDV cytopathology.

Dexamethasone-induced reactivation of bovine herpesvirus type 5 latent infection in experimentally infected rabbits results in a broader distribution of latent viral DNA in the brain.

Bovine herpesvirus type 5 (BHV-5) is a major agent of meningoencephalitis in cattle and establishes latent infections mainly in sensory nerve ganglia. The distribution of latent BHV-5 DNA in the brain of rabbits prior to and after virus reactivation was studied using a nested PCR. Fifteen rabbits inoculated intranasally with BHV-5 were euthanized 60 days post-inoculation (group A, N = 8) or submitted to dexamethasone treatment (2.6 mg kg(-1) day(-1), im, for 5 days) and euthanized 60 days later (group B, N = 7) for tissue examination. Two groups of BHV-1-infected rabbits (C, N = 3 and D, N = 3) submitted to each treatment were used as controls. Viral DNA of group A rabbits was consistently detected in trigeminal ganglia (8/8), frequently in cerebellum (5/8), anterior cerebral cortex and pons-medulla (3/8) and occasionally in dorsolateral (2/8), ventrolateral and posterior cerebral cortices, midbrain and thalamus (1/8). Viral DNA of group B rabbits showed a broader distribution, being detected at higher frequency in ventrolateral (6/7) and posterior cerebral cortices (5/7), pons-medulla (6/7), thalamus (4/7), and midbrain (3/7). In contrast, rabbits inoculated with BHV-1 harbored viral DNA almost completely restricted to trigeminal ganglia and the distribution did not change post-reactivation. These results demonstrate that latency by BHV-5 is established in several areas of the rabbit's brain and that virus reactivation leads to a broader distribution of latent viral DNA. Spread of virus from trigeminal ganglia and other areas of the brain likely contributes to this dissemination and may contribute to the recrudescence of neurological disease frequently observed upon BHV-5 reactivation.

The cytotoxicity of gamma-L-glutaminyl-4-hydroxybenzene for cells that contain tyrosinase, a study of melanocytes in the hair follicle of the mouse.

The s.c. administration of gamma-L-glutaminyl-4-hydroxybenzene (GHB) to neonatal black mice produced a prompt, generalized, and selective swelling and lysis of the melanocytes of the hair follicles. The findings indicate that this cytotoxic effect was dependent upon the intracellular activation of GHB by tyrosinase. Supportive of this conclusion were: (a) an absence of comparable cytological alterations in adjacent keratinocytes; (b) a lack of response by melanocytes of albino mice; and (c) patterns of deficient pigmentation produced by GHB in juvenile black mice, suggesting that susceptible follicles were those in the tyrosinase-producing growth phase. The administration of GHB also induced condensation, or "apoptosis," of individual follicular keratinocytes of both black and albino mice and in the melanocytes in the latter. This response was apparently independent of tyrosinase. It was transitory and without appreciable effect on hair growth. The findings further characterize the selective cytolytic properties of GHB for mammalian cells that possess tyrosinase and suggest a potential for this natural compound as a chemotherapeutic agent against melanocarcinoma.

Inhibition of DNA polymerase from L1210 murine leukemia by a sulfhydryl reagent from agaricus bisporus.

The 490 quinone, a natural sulfhydryl-arylating reagent from the mushroom, Agaricus bisporus, markedly inhibited L1210 murine leukemia DNA polymerase alpha while resulting in little inhibition of DNA polymerase beta from this source. This quinone was more strongly inhibitory than p-chloromercuri-benzoate or N-ethylmaleimide and was less readily neutralized by sulfhydryl-containing molecules such as dithioerythritol. Preliminary experiments indicate that DNA protects DNA polymerase alpha from inhibition by the 490 quinone. The inhibition of DNA synthesis by quinone 490 may contribute significantly to the cytotoxicity of this compound and to the potential of gamma-L-glutaminyl-4-hydroxybenzene as an antitumor agent.

gamma-L-Glutaminyl-4-hydroxybenzene, an inducer of cryptobiosis in Agaricus bisporus and a source of specific metabolic inhibitors for melanogenic cells.

A stable phenol, gamma-L-glutaminyl-4-hydroxybenzene (GHB), is oxidized by tyrosinase in the gill tissues of the mushroom Agaricus bisporus to a quinone and a second oxidation product which together suppress mitochondrial energy production and the synthesis of proteins and nucleic acids in the zygote, thus establishing dormancy in the spores. Brief incubation of cultured murine L1210 leukemia and B-16 melanoma cells with muM concentrations of the purified quinone notably prolonged survival times or blocked tumor growth in histocompatible mice inoculated i.p. with high concentrations of the exposed cells. The instability of the quinone precluded in vivo administration. The short incubation of cultured B-16 melanoma cells with mM concentrations of GHB markedly prolonged survival times or abolished tumor growth in histocompatible C57BL/6J mice inoculated i.p. with 5 X 10(6) exposed cells. This response did not occur with L1210 leukemia cells, which lack the enzyme tyrosinase. The survival times of mice bearing B-16 melanoma, but not of those with L1210 leukemia, were slightly prolonged by a single injection and were significantly extended by daily i.p. injections of GHB. Normal C57BL/6J mice, given GHB i.p. as single or multiple 400-mg/kg doses, manifested no systemic toxicity but showed depigmentation of the hair after 2 to 3 weeks. These studies provide evidence that GHB exerts cytotoxicity specifically for cells that by their content of tyrosinase convert the phenol to the quinone. This targeted response minimizes systemic toxocity and underscores the potential therapeutic application of this agent to melanocarcinoma.

Neospora caninum DNA distribution in tissues of gerbils as experimental models of chronic neosporosis / [Distribuição do DNA de Neospora caninum em tecidos de gerbilos como modelos experimentais de neosporose crônica]

Neospora caninum is the main etiologic agent of neosporosis in domestic animals and its pathogenesis comprises two characteristic phases: acute and chronic. Rodents are used as experimental models to mimic acute and chronic bovine neosporosis. In this study, we inoculated a total of 27 female gerbils, with different doses of N. caninum tachyzoites aiming to induce chronic disease. DNA was extracted from different organs of each animal after spontaneous death or euthanasia. Encephalic tissues were submitted to a highly sensitive real time PCR aiming to detect chronically infected animals. All the other samples were submitted to standard PCR. A total of 11 gerbils died due to acute neosporosis, as confirmed by N. caninum DNA detection in organs. 5x103 tachyzoites/mL of N. caninum was the dosage of antigen that can induce chronic infection in gerbils. In the encephalon sections of some animals that showed clinical signs of persistent infection, we found 70% positive for the anterior encephalon section, suggesting this area as preferential for cyst formation. Therefore, we determined the doses of tachyzoites that cause acute or chronic infection and detection of positive tissues, preferably, systemic organs during acute and encephalon in chronic phases.(AU)

Neospora caninum é o principal agente etiológico da neosporose em animais domésticos, e sua patogênese compreende duas fases características: aguda e crônica. Roedores são usados como modelos experimentais para simular neosporose bovina aguda e crônica. Neste estudo, foi inoculado um total de 27 gerbilos, fêmeas, com diferentes doses de taquizoítos de N. caninum, visando induzir doença crônica. O DNA foi extraído de diferentes órgãos de cada animal após a morte espontânea ou a eutanásia. Os tecidos encefálicos foram submetidos à PCR em tempo real de alta sensibilidade para detecção de animais com infecção crônica. Todas as outras amostras foram submetidas à PCR padrão. Um total de 11 gerbilos morreu devido à neosporose aguda, como confirmado pela detecção de DNA de N. caninum nos órgãos. A dosagem de antígeno que pode induzir infecção crônica foi de 5x103 taquizoítos/mL de N. caninum. Em seções do encéfalo de alguns animais, que apresentaram sinais clínicos de infecção persistente, encontraram-se 70% de positividade para a seção do encéfalo anterior, sugerindo essa área como preferencial para a formação de cisto. Assim, foram determinadas,, em gerbilos, as dosagens de taquizoítos capazes de induzir infecção crônica ou aguda, bem como foram detectados tecidos positivos, preferencialmente, em órgãos sistêmicos, na fase aguda, e no encéfalo, na crônica.(AU)

Toxoplasma gondii genotyping from free-range chickens (Gallus gallus domesticus) in a rural area of Rio Grande do Sul, Brazil / [Genotipagem de Toxoplasma gondii em galinhas domésticas em uma área rural do Rio Grande do Sul, Brasil]

Free-range chickens may ingest oocysts of T. gondii present in the environment and consequently harbor virulent strains of this parasite in different tissues, without any clinical signs. Isolation of T. gondii through bioassays on mice and cats from naturally infected chicken tissues has been described in several countries, demonstrating the importance of free-range chickens in the transmission of this parasite. The aim of this study was the genotypic characterization of T. gondii isolates obtained from naturally infected free-range chickens in a rural area of the state of Rio Grande do Sul, Brazil. Brain and heart tissue from 12 chickens seropositive for T. gondii were processed using peptic digestion technique for parasite isolation. From 12 samples subjected to mouse bioassay, nine isolates were obtained. RFLP-PCR genotypic characterization was performed using 11 genetic markers: SAG1, 5'-3'SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico. Genetic characterization of the isolates revealed the presence of five atypical genotypes according to ToxoDB (# 11, # 55, # 64, # 140 and # 163). Our results showed a wide genetic diversity of T. gondii in free-range chickens in this region.(AU)

Galinhas criadas ao ar livre podem ingerir oocistos de T. gondii presentes no ambiente e, com isso, albergar cepas virulentas desse parasita em diferentes tecidos, sem sinais clínicos. O isolamento de T. gondii por meio de bioensaios em camundongos e gatos, a partir de tecidos de galinhas naturalmente infectadas, tem sido descrito em vários países. Isso demonstra a importância das galinhas caipiras na epidemiologia desse parasita. O objetivo deste trabalho foi caracterizar genotipicamente isolados de T. gondii obtidos de galinhas caipiras naturalmente infectadas em uma área rural do município de Santa Maria, estado do Rio Grande do Sul, Brasil. Fragmentos de cérebro e de coração, de 12 galinhas soropositivas para T. gondii, foram processados pela técnica de digestão péptica para isolamento do parasita. Das 12 amostras submetidas a bioensaio com camundongos, nove isolados foram obtidos. A caracterização genotípica por RFLP-PCR foi realizada utilizando-se 11 marcadores genéticos: SAG1, 5'-3'SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 e Apico e revelou a presença de cinco genótipos atípicos de acordo com o ToxoDB (# 11, # 55, # 64, # 140 e # 163). Os resultados mostraram uma ampla diversidade genética de T. gondii em galinhas caipiras nessa região.(AU)

The toxicity of melanin precursors.

The quinone intermediates resulting from tyrosinase-mediated oxidation of tyrosine were evaluated as sulfhydryl reagent inhibitors of purified calf thymus DNA polymerase alpha in order to determine which of these might be cytotoxic. Dopachrome and an oxidation product of 2,4,5-trihydroxyphenylalanine were relatively ineffective as inhibitors of DNA polymerase alpha. On the other hand, a dopaquinone analogue, 4-(2-N-acetylaminoethyl)-1,2-benzoquinone, synthesized from N-acetyl dopamine, was demonstrated to have marked affinity for this sulfhydryl enzyme. This property was shared by 1,2-benzoquinone. These studies point to dopaquinone as a significant toxic metabolite in melanin biosynthesis.

The induction of intractranial neoplasms by the inoculation of avian sarcoma virus in perinatal and adult rats.

The induction of intracranial neoplasms following the intracerebral inoculation of avian sarcoma virus (ASV) in neonatal mammals is well established. The present study demonstrates the susceptibility of adult rats and compares the incidence and morphology of tumors induced by a uniform inoculum of the Bratislava-77 strain of ASV in adult, neonatal, and fetal Fischer 344 rats. Post-inoculation mortality varied significantly between groups inoculated at 1, 10 and 100 days and was most precipitous in perinatally inoculated rats. Percentage of tumor induction declined from 100% among rats inoculated at 1 day of age to 50% among rats inoculated at 100 days of age. The mean number of tumors/animal was inversely proportional to the logarithm of the age at inoculation. A large majority of tumors in each group were glial; the remainder were mesenchymal and mixed glial and mesenchymal. Neuroglial tumors included: mixed gliomas with oligodendroglial and astrocytic elements; and gemistocytic, pilocytic, fibrillary, anaplastic and protoplasmic astrocytomas. Tumors induced in perinates were more heterogeneous in histological pattern while tumors induced in perinates were more heterogeneous in histological pattern while tumors induced in older animals tended to be purely astrocytic and of uniform cell type. Mesenchymal tumors occurred primarily in the meninges and were common among animals inoculated perinatally but were rare among animals inoculated as adults. No neuronal tumors were encountered even among rats inoculated as early as 16 days of gestation.

Ataxia, chorea, seizures, and dementia. Pathologic features of a newly defined familial disorder.

Five generations of a family exhibit a unique autosomal dominant neurologic disorder characterized by the development (usually between 15 and 30 years of age) of ataxia, seizures, choreiform movements, progressive dementia, and death after 15 to 25 years of illness. Neuropathologic findings in two deceased family members revealed remarkably similar findings, including marked neuronal loss of the dentate nucleus, microcalcification of the globus pallidus, neuroaxonal dystrophy of the nucleus gracilis, and demyelination of the centrum semiovale. The clinical and pathologic findings are closely correlated. Ataxia and chorea are related to severe neuronal loss in the dentate nucleus with calcification in the globus pallidus. Dementia occurs with progressive demyelination of the centrum semiovale, and loss of posterior column function occurs with neuroaxonal dystrophy of the nucleus gracilis and nucleus cuneatus.

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part II. Standardization of the neuropathologic assessment of Alzheimer's disease.

The Neuropathology Task Force of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) has developed a practical and standardized neuropathology protocol for the postmortem assessment of dementia and control subjects. The protocol provides neuropathologic definitions of such terms as "definite Alzheimer's disease" (AD), "probable AD," "possible AD," and "normal brain" to indicate levels of diagnostic certainty, reduce subjective interpretation, and assure common language. To pretest the protocol, neuropathologists from 15 participating centers entered information on autopsy brains from 142 demented patients clinically diagnosed as probable AD and on eight nondemented patients. Eighty-four percent of the dementia cases fulfilled CERAD neuropathologic criteria for definite AD. As increasingly large numbers of prospectively studied dementia and control subjects are autopsied, the CERAD neuropathology protocol will help to refine diagnostic criteria, assess overlapping pathology, and lead to a better understanding of early subclinical changes of AD and normal aging.

Hemorrhagic white matter infarction in three critically ill patients.

Extensive areas of hemorrhagic softening developed in the cerebral white matter in three critically ill patients. The anatomic peculiarities of the vasculature of this region, as well as the possible roles of edema and vasospasm, are weighed as factors in the pathogenesis of these unusual lesions.

Subacute diencephalic angioencephalopathy--report of an additional case.

The following report presents an additional example of subactue diencephalic angioencephalopathy. The patient, a 68-year-old man, unexplicably withdrawn and asocial throughout his life, presented with an altered mental status of relatively recent onset. His illness was marked by progressive dementia and ended in death within 7 weeks. The neuropathologic findings were essentially identical to those described in the previous case in both their histology and topographic localization within the thalamus. The etiology, pathogenesis, and reason for the localization of this entity are unknown. Nevertheless, the lesion underscores the major role of the thalamus in cognitive function, emotional behavior, and awareness.

Intrapreputial infection of young bulls with bovine herpesvirus type 1.2 (BHV-1.2): acute balanoposthitis, latent infection and detection of viral DNA in regional neural and non-neural tissues 50 days after experimental reactivation.

Venereal infection of bulls with bovine herpesvirus type 1.2 (BHV-1.2) may result in acute balanoposthitis followed by the establishment of latent infection, presumably in dorsal root nerve ganglia. We herein report the characterization of the acute and latent infection of young bulls with a Brazilian BHV-1.2 isolate and the investigation of neural and non-neural sites in which viral DNA persists during latent infection, i.e. 110 days after inoculation and 50 days after experimental reactivation. Intrapreputial inoculation of BHV-1.2 isolate SV-56/90 (10(6.5)pfu per animal) resulted in severe balanoposthitis, characterized by redness of the penis and preputial mucosa, coalescent vesicles and fibrinous exsudate in all four infected bulls. Virus shedding was detected in preputial secretions and semen up to days 14 and 13 pi, respectively. Dexamethasone administration at day 60 pi led to reactivation of the infection in all animals, resulting in virus shedding in preputial secretions and/or in semen. At day 50 post-reactivation (pr), the animals were euthanized and regional tissues were collected for PCR and virus isolation. Viral DNA was consistently detected in the dorsal root ganglia of nerves genito-femoral (4/4) and obturator (4/4); frequently in the pudendal (3/4), sciatic (3/4) and rectal caudal nerve ganglia (2/3). In addition, viral DNA was detected in the pelvic sympathetic plexus of one bull and in regional lymph nodes (deep inguinal (2/4); sacral (1/4); medial iliac (1/4)) of two bulls. No infectious virus could be recovered from homogenates of DNA positive tissues, indicating the absence of actively replicating virus. These results demonstrate that BHV-1.2 DNA may persist in several sacral nerve ganglia and in regional lymph nodes as well during latent infection, i.e. 50 days after experimental reactivation. These findings may help in understanding the pathogenesis of acute and latent genital infection by BHV-1.2.

Topographic relationship between neurofibrillary change and acetylcholinesterase rich neurons in the upper brain stem of patients with senile dementia of the Alzheimer's type and Down's syndrome.

In order to establish the topographical relationship between neurofibrillary change and the distribution of cholinergic neurons, the upper brain stems were studied from nine cases of senile dementia of the Alzheimer's type (SDAT). For each case, the distribution of the neurofibrillary changes was recorded and compared with the distribution in five control patients of acetylcholinesterase-rich neurons as determined by enzyme histochemistry. The numbers and distribution of neurons with neurofibrillary change were also studied in five age-matched controls and in three individuals with Down's syndrome. The results indicate that, in contrast to that in control patients, the upper brain stem is heavily involved by neurofibrillary change in SDAT. Correlation of the distribution of neurofibrillary tangles in SDAT patients with the localization of acetylcholinesterase-rich neurons suggests that most of the cholinergic nuclei in the upper brain stem are affected in SDAT, but are not exclusively or predominantly involved. Most neurofibrillary tangles were found in noncholinergic nuclei such as the raphe nuclei and the locus ceruleus. The individuals with Down's syndrome showed a heavy involvement in the older cases, thus reinforcing the significance of Down's syndrome in defining the evolution of pathologic changes in Alzheimer's disease or SDAT.

Alpers' syndrome presenting with seizures and multiple stroke-like episodes in a 17-year-old male.

Alpers' syndrome is a progressive neurodegenerative disorder with liver disease that usually presents in the first few years of life. Only rarely have patients presented later in life with delayed onset of Alpers' syndrome. Herein we present a case of a 17-year-old male with a progressive 8-month course of severe headaches, multiple stroke-like episodes with visual deficits, and seizures that concluded with acute hemorrhagic pancreatitis. Neuropathological findings were characteristic for Alpers' syndrome: neurodegeneration and astrogliosis of the occipital cortices including the striate cortices, similar but less advanced changes in the parietal cortices, right Ammons horn sclerosis, degeneration of the posterior columns, and mild cerebellar Purkinje cell loss. Examination of the liver revealed extensive centrilobular hepatocyte necrosis. Skeletal muscle did not contain ragged red fibers, nor were there mitochondrial DNA point mutations characteristic for mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS).

The effects of cosmic particle radiation on pocket mice aboard Apollo XVIII: VII: results of scalp examination.

The scalps of the four pocket mice that were recovered alive from the Apollo XVII flight contained acute focal lesions in the epidermis and an inflammatory reaction in the subjacent dermis and subcutaneous tissue. Hair follicles were focally damaged in three of the four mice. There were 13 scalp lesions singled out in the four flight mice because of histological features that distinguished them from changes observed in the scalps of the control mice. There was only one possible coincidence between a lesion and the trajectory of a cosmic ray particle registered in a subscalp dosimeter. There is, however, a possibility that at least some lesions were produced by unregistered particles.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: XII. Results of examination of the calvarium, brain, and meninges.

Tissue reactions were found around the monitor (dosimeter) assemblies that had been implanted beneath the scalp of the five pocket mice that flew on Apollo XVII. Mitosis in the dentate gyrus of the hippocampal formation was considerably reduced in comparison with that in control animals. Otherwise the brain tissue as well as the menings in the flight animals appeared unaltered. Since the animals were exposed primarily to high Z-high energy (HZE) cosmic ray particles at the lower end of the high LET spectrum, the lack of changes in the brain cannot be taken as evidence that the brain will suffer no damage from the heavier HZE particles on prolonged manned missions.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: VI. launch, flight, and recovery.

The final phase to fly five pocket mice in the Apollo XVII command module was carried out at the NASA Kennedy Space Center. Upon completion of the 13-d space flight, the package was removed from the spacecraft and, after having been purged with an oxygen-helium gas mixture, was flown to American Samo. Four of the five mice were recovered alive from the package. Analysis of the mouse that died during the flight revealed several factors that could have contributed to its death, the chief of which was massive hemorrhage in its middle ear cavities.