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Biomedical subjects

R E Weller

Publications and source records attributed to R E Weller.

At least 73 records · Page 4Linked to original sources
PubMed1984

Myeloproliferative disease in a cat.

Myeloproliferative disorders, a complex of cytologic abnormalities arising in the bone marrow, are among domestic animals most frequently recognized in cats but are relatively uncommon. A 4-year-old female Siamese, with splenomegaly and weight loss, was listless, anorectic, pale and dehydrated. A hemogram showed severe, macrocytic normochromic anemia, leukocytosis and reticulocytosis, with abnormally high numbers of nucleated RBC and undifferentiated blast cells. Bone marrow smears contained predominantly undifferentiated blast cells, RBC precursors and myeloblasts. The fluorescent antibody test for FeLV was positive. The cat died 66 days later despite a blood transfusion and chemotherapy. Necropsy confirmed a diagnosis of myeloproliferative disease, with hepatic and splenic invasion.

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PubMed1983

Retinotopic patterns of connections of area 17 with visual areas V-II and MT in macaque monkeys.

Patterns of connections of Area 17 with extrastriate visual areas V-II and MT were studied in macaque monkeys by using 3H-proline and HRP as anatomical tracers. The results support previous conclusions that V-II is a split representation of the visual hemifield with most of the outer border formed by the zero horizontal meridian, and that MT is a topological representation of the visual hemifield. V-II was estimated to be about 10-12 mm wide, 110 mm long along its shared border with V-I, and 920 mm2 in surface area, thereby almost equaling Area 17 in size. MT was judged to be 7 mm wide and 12 mm long, with a surface area of 68 mm2, or roughly 7% of the area of Area 17. In some cases, there was evidence for projections from Area 17 to a third area (or areas) of cortex of about 2 mm wide and of uncertain length on the outer boundary of V-II. Terminations in V-II and MT were concentrated in layer IV and extended into inner layer III. Cells projecting back to Area 17 were largely in layers III and V in V-II and in layers III and VI in MT.

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PubMed1982

Chemotherapeutic responses in dogs with lymphosarcoma and hypercalcemia.

Twelve dogs with lymphosarcoma and hypercalcemia were treated over a period of 36 months. Signs and laboratory findings were referable to hypercalcemia and azotemia. All dogs were staged, classified histologically, and given cytoreductive chemotherapy, using 5 drugs (vincristine sulfate, cytosine arabinoside, cyclophosphamide, L-asparaginase and prednisone). For azotemia, symptomatic therapy (0.9% NaCl solution and furosemide) was given. Seven dogs responded completely, with marked reduction of lymphadenopathy and return of serum calcium concentration to normal. Median duration of remission in this group was 48 days (range, 14 to 93), and median survival time was 112 days (range, 85 to 153). Five nonresponding dogs had less than 50% reduction in measurable tumor mass, although serum calcium concentration returned to normal. The median survival time for this group was 34 days (range, 23 to 68). Two of the nonresponders died from sepsis and another from disseminated intravascular coagulation. Response to therapy did not appear to be influenced by age, breed, sex, initial calcium concentration, degree of azotemia, or histologic classification.

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PubMed1982

Cortical connections of striate cortex in the owl monkey.

Injections of tritiated proline and horseradish peroxidase were used to study cortical connections of striate cortex in owl monkeys. All cases resulted in label in area 18 (V-II) and the middle temporal visual area (MT). In most, but not all cases, label was also present in the dorsomedial visual area (DM). The connections between striate cortex and each of these three visual areas were retinotopic and reciprocal. Projections to V-II, MT, and DM were concentrated in layers IV and III, while pyramidal cells in layers III, V, and VI of these areas projected back to striate cortex.

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PubMed1981

The organization of somatosensory area II in tree shrews.

Microelectrode multiunit recording methods were used to determine the somatotopic organization of the second somatosensory area, S-II, in tree shrews. Neurons were activated by light tactile stimuli, and receptive fields were located on the contralateral body surface only. The orientation of S-II was such that the top of the head adjoined S-I and the distal limbs pointed away from S-I so that the representation could be characterized as "erect". In general, the distortions of the body surface in S-II were similar to those found in S-I of the tree shrew (Sur et al., '80), with the exception that proportionately less cortex was devoted to the glabrous nose. The representation in S-II was more continuous than that in S-I. Finally, cortex bordering S-II caudally was found to be responsive to generally more intense somatosensory stimuli such as taps to the body surface.

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PubMed1981

Physiological and anatomical evidence for a discontinuous representation of the trunk in S-I of tree shrews.

Microelectrode mapping methods revealed that the representation of the body surface in the first somatosensory area of cortex, S-I, of the tree shrew is unique in that only the ventral trunk was found in the usual location of the trunk representation in cortex of the dorsolateral surface of the cerebral hemisphere. Instead, the dorsal trunk was found as an extension of the representation of the posterior leg in cortex on the medial wall. The separation of the representation of the trunk occurs along a line that is counter to the orientation of the dorsal root dermatomes, so that S-I of the tree shrew clearly cannot be characterized as a serial representation of dermatomes. Anatomical studies of connections support the conclusion that the representation of the trunk is split in S-I. Both the representation of the dorsal trunk on the medial wall of the cerebral hemisphere and S-I of the dorsolateral surface were found to project to S-II when horseradish peroxidase was injected into S-II.

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PubMed1981

Preservation of retinal ganglion cells and normal patterns of retinogeniculate projections in prosimian primates with long-term ablations of striate cortex.

Retinal ganglion cell distributions and laminar patterns of retinogeniculate projections were studied in prosimian galagos after partial lesions of striate cortex in adults and survivals of 3 months to 3 years. In contrast to lesions in monkeys, where similar procedures led to a loss of ganglion cells and of projections to the parvocellular layers of the lateral geniculate nucleus, the striate cortex lesions in galagos produced no detectable loss of ganglion cells and no change in the laminar pattern of retinogeniculate terminations.

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PubMed1980

Representation of the body surface in somatosensory area I of tree shrews, Tupaia glis.

Microelectrode mapping methods were used to determine the organization of the first somatosensory area, S-I, of tree shrews. Tree shrews were chosen for study because of their generalized body form, phylogenetic relationship to primates, and smooth, easily mapped cortex. A systematic representation of the contralateral body surface was found in an architectonically distinct zone identified as somatic koniocortex. Overall features of somatotopic organization were similar to S-I of other mammals, S-I of prosimian primates, and the Area 3b "S-I proper" representation of monkeys. Like Area 3b in monkeys and the somatic koniocortex in galagos, S-I in tree shrews is bordered caudally by cortex also responsive to somatosensory stimuli. Several aspects of S-I organization in tree shrews appear to be primitive and generalized. These include the representation of the trunk with the ventrum at the caudal margin of S-I, the restriction of the glabrous digits of the hand and foot to the rostral half of the representation and pointed rostralward, the representation of an anterior strip of the forelimb lateral to the hand, and a posterior strip of hindlimb medial to the foot representation. As in a number of other mammals, a large portion of S-I in tree shrews is devoted to the head. However, the proportion of S-I activated from the glabrous nose is greater in tree shrews than iun any previously studied mammal. We conclude that S-I of tree shrews has both specialized and generalized features, and that the generalized features importantly relate to an understanding of the evolution of the primate somatosensory system.

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PubMed1980

Chemoimmunotherapy for canine lymphosarcoma: a prospective evaluation of specific and nonspecific immunomodulation.

Fifty-six dogs were given chemoimmunotherapy for spontaneous lymphosarcoma. The dogs had been given identical combination chemotherapy (8 weeks) for induction of remission, and after achieving complete clinical remission, they were randomly assigned to one of three treatment groups to evaluate immunotherapy as a method ancillary to chemotherapy to maintain or extend the remission. For immunostimulation, one-third of the dogs were given chemically modified autochthonous tumor cell extract in Freund's complete adjuvant (FCA), one-third were given nonmodified tumor cell extract in FCA, and one-third were given FCA alone. A historical control population of dogs given the same chemotherapy was used for comparison. Of the 56 dogs, 50 (89.3%) achieved initial remission, but 18 of the latter relapsed clinically during the initial 8-week-chemotherapy regimen. The remaining 32 dogs (or 57.1% of the original 56 dogs) were subsequently given immunotherapy. Duration of remission and survival time were recorded. The median remission duration and survival time for all dogs given immunotherapy following cytoreductive chemotherapy were significantly longer than the historical control population given chemotherapy alone. However, there was no significant difference in remission duration or survival among the three immunotherapy groups.

Animals↗
PubMed1980

Histologic classification as a prognostic criterion for canine lymphosarcoma.

Neoplastic tissues from 72 dogs with lymphosarcoma were histologically classified according to the Rappaport schema to determine if the histologic features of the disease had any clinical or prognostic importance. Of 72 dogs, lymphosarcomas in 7 were classified as nodular (9.7%) and 65 were classified as diffuse (90.3%). The two principal cytologic types were lymphocytic, poorly differentiated, and histiocytic, which composed 39% and 56% of the lymphosarcomas, respectively; whereas lymphocytic, well differentiated, mixed, and undifferentiated composed 6%. Clinically, all of the dogs were stage III or IV, according to the accepted criteria for canine lymphosarcoma. The overall complete remission rate was 64% and was defined as no clinical evidence of disease after 9 weeks of chemotherapy. Median remission among nodular histiocytic, diffuse lymphocytic, poorly differentiated, and diffuse histiocytic (DH) groups of dogs was 42 days, 29 days, and 42 days (range, 0 to 1,095), respectively. Median survival for the same groups was 235 days, 190 days, and 173 days (range, 1 to 1,261), respectively. A logarithmic analysis of variance revealed no significant differences among nodular histiocytic, diffuse lymphocytic, poorly differentiated, and DH groups relative to days remission, as well as to days survival. It was observed that those dogs with neoplasms classified as DH had longer remission durations. It would appear that for any one animal, histologic classification according to the Rappaport schema cannot be used as a prognostic criterion in predicting therapeutic response, remission, or survival.

Animals↗
PubMed1979

Multiple skeletal metastases of osteogenic sarcoma in a dog.

A 9-year-old male German Shepherd Dog with osteogenic sarcoma involving the right humerus was treated by scapulohumeral disarticulation and adjuvant chemotherapy. Doxorubicin was used, at a dosage of 30 mg/m2 of body surface. Chemotherapy was unsuccessful, and 4 months after surgery, the dog developed multiple metastases of osteogenic sarcoma in the appendicular skeleton, a metastatic pattern rarely observed with primary bone tumors.

Animals↗
PubMed1979

Hematologic abnormalities preceding myeloid leukemia in three cats.

Cytopenia were recognized in three cats infected with feline leukemia virus. In one cat, marrow blast cells were increased in number, and a diagnosis of aleukemic leukemia was made. The disease progressed slowly for 3 1/2 months before terminating in acute myelomonocytic leukemia, recognized as a blast crisis in blood. In the other two cats, neutropenia and altered granulopoiesis in bone marrow preceded development of myeloid leukemia.

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