Host range of a parasitoid wasp is linked to host susceptibility to its mutualistic viral symbiont.

Parasitoid wasps are one of the most species-rich groups of animals on Earth, due to their ability to successfully develop as parasites of nearly all types of insects. Unlike most known parasitoid wasps that specialize towards one or a few host species, Diachasmimorpha longicaudata is a generalist that can survive within multiple genera of tephritid fruit fly hosts, including many globally important pest species. Diachasmimorpha longicaudata has therefore been widely released to suppress pest populations as part of biological control efforts in tropical and subtropical agricultural ecosystems. In this study, we investigated the role of a mutualistic poxvirus in shaping the host range of D. longicaudata across three genera of agricultural pest species: two of which are permissive hosts for D. longicaudata parasitism and one that is a nonpermissive host. We found that permissive hosts Ceratitis capitata and Bactrocera dorsalis were highly susceptible to manual virus injection, displaying rapid virus replication and abundant fly mortality. However, the nonpermissive host Zeugodacus cucurbitae largely overcame virus infection, exhibiting substantially lower mortality and no virus replication. Investigation of transcriptional dynamics during virus infection demonstrated hindered viral gene expression and limited changes in fly gene expression within the nonpermissive host compared with the permissive species, indicating that the host range of the viral symbiont may influence the host range of D. longicaudata wasps. These findings also reveal that viral symbiont activity may be a major contributor to the success of D. longicaudata as a generalist parasitoid species and a globally successful biological control agent.

MSTO1 mutations cause mtDNA depletion, manifesting as muscular dystrophy with cerebellar involvement.

MSTO1 encodes a cytosolic mitochondrial fusion protein, misato homolog 1 or MSTO1. While the full genotype-phenotype spectrum remains to be explored, pathogenic variants in MSTO1 have recently been reported in a small number of patients presenting with a phenotype of cerebellar ataxia, congenital muscle involvement with histologic findings ranging from myopathic to dystrophic and pigmentary retinopathy. The proposed underlying pathogenic mechanism of MSTO1-related disease is suggestive of impaired mitochondrial fusion secondary to a loss of function of MSTO1. Disorders of mitochondrial fusion and fission have been shown to also lead to mitochondrial DNA (mtDNA) depletion, linking them to the mtDNA depletion syndromes, a clinically and genetically diverse class of mitochondrial diseases characterized by a reduction of cellular mtDNA content. However, the consequences of pathogenic variants in MSTO1 on mtDNA maintenance remain poorly understood. We present extensive phenotypic and genetic data from 12 independent families, including 15 new patients harbouring a broad array of bi-allelic MSTO1 pathogenic variants, and we provide functional characterization from seven MSTO1-related disease patient fibroblasts. Bi-allelic loss-of-function variants in MSTO1 manifest clinically with a remarkably consistent phenotype of childhood-onset muscular dystrophy, corticospinal tract dysfunction and early-onset non-progressive cerebellar atrophy. MSTO1 protein was not detectable in the cultured fibroblasts of all seven patients evaluated, suggesting that pathogenic variants result in a loss of protein expression and/or affect protein stability. Consistent with impaired mitochondrial fusion, mitochondrial networks in fibroblasts were found to be fragmented. Furthermore, all fibroblasts were found to have depletion of mtDNA ranging from 30 to 70% along with alterations to mtDNA nucleoids. Our data corroborate the role of MSTO1 as a mitochondrial fusion protein and highlight a previously unrecognized link to mtDNA regulation. As impaired mitochondrial fusion is a recognized cause of mtDNA depletion syndromes, this novel link to mtDNA depletion in patient fibroblasts suggests that MSTO1-deficiency should also be considered a mtDNA depletion syndrome. Thus, we provide mechanistic insight into the disease pathogenesis associated with MSTO1 mutations and further define the clinical spectrum and the natural history of MSTO1-related disease.

Single amino-acid changes that confer constitutive activation of mTOR are discovered in human cancer.

Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates a variety of cellular functions such as growth, proliferation and autophagy. In a variety of cancer cells, overactivation of mTOR has been reported. In addition, mTOR inhibitors, such as rapamycin and its derivatives, are being evaluated in clinical trials as anticancer drugs. However, no active mutants of mTOR have been identified in human cancer. Here, we report that two different point mutations, S2215Y and R2505P, identified in human cancer genome database confer constitutive activation of mTOR signaling even under nutrient starvation conditions. S2215Y was identified in large intestine adenocarcinoma whereas R2505P was identified in renal cell carcinoma. mTOR complex 1 prepared from cells expressing the mutant mTOR after nutrient starvation still retains the activity to phosphorylate 4E-BP1 in vitro. The cells expressing the mTOR mutant show increased percentage of S-phase cells and exhibit resistance to cell size decrease by amino-acid starvation. The activated mutants are still sensitive to rapamycin. However, they show increased resistance to 1-butanol. Our study points to the idea that mTOR activating mutations can be identified in a wide range of human cancer.

The role of angiostatin in the spontaneous bone and prostate cancers of pet dogs.

Angiostatin is a potent inhibitor of angiogenesis generated in cancer-bearing hosts by tumor-derived proteases. Because the naturally occurring bone and prostate cancers of pet dogs provide unique model systems to study factors that regulate cancer progression and tumor dormancy, we investigated the capacity of these tumors to generate angiostatin. We determined that angiostatin fragments are present in urine of dogs with bone cancer. The identity of these fragments was confirmed by comparison of the experimentally determined protein sequence to that of a clone of canine angiostatin. Importantly, these fragments were absent in urine collected from the same dogs after complete surgical removal of the primary tumor. We also demonstrate that canine prostate cancer cells are capable of processing plasminogen to angiostatin in vitro. These findings provide rationale for using spontaneous canine tumor models to isolate endogenous angiogenesis inhibitors and to investigate their therapeutic use against cancer.

Prostaglandin E2 concentrations in naturally occurring canine cancer.

The purpose of this study was to determine the PGE2 concentration in naturally-occurring cancer in pet dogs and in canine cancer cell lines in order to identify specific types of canine cancer with high PGE2 production which could serve as preclinical models to evaluate anticancer strategies targeting PGE2. PGE2 concentrations were measured by enzyme immunoassay in canine melanoma, soft tissue sarcoma, transitional cell carcinoma, osteosarcoma, and prostatic carcinoma cell lines; in 80 canine tumor tissue samples including oral melanoma (MEL), oral squamous cell carcinoma (SCC), transitional cell carcinoma of the urinary bladder (TCC), lymphoma (LSA), mammary carcinoma (MCA), osteosarcoma (OSA), prostatic carcinoma (PCA); and in corresponding normal organ tissues. High concentrations of PGE(2)(range 400-3300 pg/10(4)cells) were present in cell culture medium from the transitional cell carcinoma, prostatic carcinoma, and osteosarcoma cell lines. PGE2 concentrations in tumor tissues were elevated (tumor PGE2 concentration>mean+2X sd PGE(2)concentration of normal organ tissue) in 21/22 TCC, 5/6 PCA, 7/10 SCC, 5/10 MEL, 3/8 MCA, 4/15 OSA, and 0/9 LSA. Results of this study will help guide future investigations of anticancer therapies that target cyclooxygenase and PGE2.

Development of a System to Provide Full, Real-time Remote Control of a Scanning Electron Microscope across the Second Generation Internet: The Teaching SEM.

The development and makeup of a real-time full remote control system for the University of Michigan, Department of Materials Science and Engineering Teaching SEM is described. The instrument was initially controlled via the campus local area Ethernet network and cable TV network. The latest implementation employs Fast Ethernet, Asynchronous Transfer Mode (ATM) networks, and moving picture experts group (MPEG) video encoding to effect the remote control via the computer network alone. Remote control demonstrations from Washington, DC, Dearborn, MI, and Emerson School, Ann Arbor, MI are described.

Overexpression of the EphA2 tyrosine kinase in prostate cancer.

BACKGROUND: Molecules that are highly expressed by human prostate cancers may serve as therapeutically relevant targets or tumor markers. Tyrosine kinases are frequently overexpressed in metastatic tumor cells and this prompted us to screen for tyrosine kinases that are overexpressed in prostate cancer cells. METHODS: Expression levels of the EphA2 receptor tyrosine kinase were determined by Western blot analysis in canine and human prostate cancer cell lines and in immortalized and transformed variants of 267B1 prostatic epithelial cells. EphA2 levels in benign human prostate and prostate cancers were also determined in formalin-fixed, paraffin-embedded tissues using immunohistochemical staining. RESULTS: Metastatic prostate cancer cells overexpressed EphA2 by 10-100 fold as compared with non-invasive prostatic epithelial cells. EphA2 immunoreactivity in vivo was also significantly greater in human prostate cancers as compared with benign prostate epithelium. CONCLUSIONS: The EphA2 receptor tyrosine kinase is differentially expressed in human and canine prostate cancer cell lines and overexpressed in human prostate cancers as compared with benign prostate tissues. Metastasis-derived canine prostate carcinoma cell lines overexpress EphA2 and may provide pre-clinical models to further evaluate the role of EphA2 in prostate carcinogenesis. Further investigations are needed to determine the utility of EphA2 as a tumor marker and a novel target in human prostate cancer.

The Millon Behavioral Health Inventory Life Threat Reactivity Scale as a predictor of mortality in patients awaiting heart transplantation.

This study examined the Millon Behavioral Health Inventory Life Threat Reactivity Scale (LTRS) as a predictor of mortality in patients awaiting heart transplantation. The one-year mortality while awaiting cardiac transplantation was more than double for the high-risk group based on the LTRS scores. The high-risk group had a 42% mortality rate versus an 18% mortality rate in the low-risk group. Mortality for those patients that received transplants was similar for both groups. A review of the medical literature regarding the role of personality traits in cardiac mortality and the findings of this study are discussed.

Survey results of transplant patients' attitudes on xenografting.

For centuries, many cultures have described mythical creatures with bodies that combined human and animal features, often the result of violating taboos. This study attempted to investigate the beliefs of transplant patients about xenografting. A survey was given to 100 patients ranging in age from 17 to 74 years old, with 65 men and 35 women, including 72 whites, 18 Hispanics, 5 African Americans, and 4 Asian Americans. The subjects included liver, heart, kidney, lung, and multi-organ transplant patients. The patients were not aware of plans for xenografting at the center under study. Eighty patients agreed with xenografting in an emergency situation. Ten subjects replied, "under no circumstances." Ninety percent believed animal research has advanced medical science. In descending order, the patients preferred human (96%), monkey (44%), mechanical (43%), pig (42%), or dog (34%) organs. Twenty-four patients thought a xenograft would change their appearance, personality, or eating or sexual habits. Twenty patients believed animals have souls. The patients also documented any ethical concerns about xenografting.

Synthesis and structure-activity relationships of CP-122,721, a second-generation NK-1 receptor antagonist.

The synthesis and SAR of benzylamine side chain analogs of the NK-1 receptor antagonist CP-99,994 are described. The 5-trifluoromethoxy analog, CP-122,721, shows superior in vivo blockade of NK-1 receptor mediated responses.

An update on transplantation in the geriatric heart transplant patient.

Discussions of the ethics involved in allocating scarce resources often proceed without a grounding in factual experience. This study explored whether there was statistical evidence to support the use of set age limits in patient selection criteria for heart transplantation. Many transplant teams have selection criteria that include age limits, excluding patients more than 60 or 65 years of age from being considered as transplant candidates. The hypothesis was made that patients in the age bracket of 60-69 should have a comparable success rate with transplantation to that of younger recipients when selected by using the same medical and psychiatric criteria. Based on their clinical observations, the authors postulated that the elderly would report better quality of life postoperatively than younger control subjects.

Neurological and psychological sequelae in transplant recipients after bridging with the bioartificial liver.

Prior to the advent of the bioartificial liver there was little hope to offer the families of comatose patients unless an organ could be found immediately, or xenografting was attempted. The elevated intracranial pressure that develops is more life-threatening than prolonged bleeding times. Over a 2-year period, nine patients were bridged to transplantation using the BAL to keep them neurologically intact prior to surgery. The goal is to maintain the ICP less than 20 mmHg in adults and between 10 and 15 mmHg in children, so that the cerebral perfusion pressure remains above 50 mmHg. The first patients, a 35-year-old woman, arrived in stage II coma. The second patient, a 10-year-old boy in stage IV coma, had decerebrate posturing and anisocoria. The third patient, an 18-year-old girl, had an ICP of 28 mmHg with decerebrate posturing and disconjugate gaze. The fourth patient, a 34-year-old male, had an ICP of > 38 mmHg. The fifth patient, a 24-year-old male, had fixed dilated pupils. The sixth patient, a 50-year-old woman, had readings to 52 mmHg. The seventh patient, a 48-year-old male, had postoperative numbness in his fingertips that remitted. The eighth patient, a 31-year-old female, had decerebrate posturing and an ICP of 64 mmHg transiently. The ninth patient, a 52-year-old woman, had decerebrate posturing with a peak ICP of 50 mmHg. All nine patients survived.

Avidity of IgA antibody to Escherichia coli polysaccharide and diphtheria toxin in breast milk from Swedish and Pakistani mothers.

The avidity of breast milk IgA antibody was studied with the aid of thiocyanate elution of antibody from solid-phase bound E.coli polysaccharides and diphtheria toxoid. The relative avidity index for each sample was determined by the molarity of thiocyanate required to elute 50% of the bound IgA antibody under conditions of antigen excess. Milk samples collected from Pakistani mothers during early lactation (2-4 weeks after delivery; n = 12) had a significantly lower median relative avidity index of IgA antibody to E.coli antigens than did early lactation samples from Swedish mothers (n = 11; avidity indices 1.78 M and 2.65 M; P less than 0.02). Samples collected from Pakistani mothers in mid-lactation showed a significant rise in the relative avidity index to a median of 2.50 M (P less than 0.01), with a subsequent fall in late lactation (28-36 weeks after delivery) to 1.75 M (P less than 0.01). Milk samples from Pakistani mothers in mid-lactation (n = 12) also had a lower median relative avidity index of IgA antibody to diphtheria toxoid than did samples from Swedish mothers (n = 14; avidity indices 2.35 M and 4.30 M; P less than 0.002). The lower avidity of breast milk IgA in Pakistani mothers in comparison with Swedish mothers may arise from differences in antigen exposure or nutritional status or could possibly be genetically determined.

Phytophotodermatitis simulating child abuse.

We explored the history in two children who had bizarre, hyperpigmented skin lesions suggestive of child abuse. A final diagnosis of phytophotodermatitis was established. The lesions resulted from inadvertent application of squeezed lime juice to the children's skin by their parents during the routine preparation of drinks, followed by sun exposure, which activated the applied plant psoralens (furocoumarins). Phytophotodermatitis can be induced by a number of plants, and, when unrecognized, may lead to inappropriate investigation of child abuse.

Myalgia and elevation in muscle creatine phosphokinase during zimelidine treatment.

The authors report a case involving a 65-year-old woman with DSM-III criteria for major unipolar depression in whom the administration of zimelidine, a potent and selective 5-hydroxytryptamine reuptake inhibitor, led to the development of a hypersensitivity reaction characterized by a severe headache, low grade fever, abnormal liver enzymes, and generalized myalgia 10 days after initiation of treatment. The most novel aspect of this hypersensitivity reaction to zimelidine was the development of abnormalities in muscle creatine phosphokinase in conjunction with the myalgia.