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Biomedical subjects

J H Adams

Publications and source records attributed to J H Adams.

At least 109 records · Page 6Linked to original sources
PubMed1986

Neuropathological and clinical correlations in Hurler disease.

We report studies on two patients (1 and 2) with Hurler disease. They both had all of the non-neurological features of Hurler disease to a similar and extreme degree and similar signs of brain damage on computed tomography. However, intellectual function was unusually well-preserved in patient 1, but seriously and typically impaired in patient 2. The reason for this discrepancy has been investigated by reference to the neuropathological findings, the results of alpha-L-iduronidase assays using different substrates and comparisons to other cases (patients 3 and 4). We suggest that patient 1 is an unusual variant of the disease who may have had a very low residual alpha-L-iduronidase activity in neuronal cells only, and that this could not be demonstrated by either enzyme assays on whole brain using the 4-methylumbelliferyliduronide substrate (Crow et al., 1983) or in studies on fibroblast lysates using a radioactive disaccharide substrate.

Brain↗
PubMed1986

Deep intracerebral (basal ganglia) haematomas in fatal non-missile head injury in man.

Deep intracerebral (basal ganglia) haematomas were found post mortem in 63 of 635 fatal non-missile head injuries. In patients with a basal ganglia haematoma, contusions were more severe, there was a reduced incidence of a lucid interval, and there was an increased incidence of road traffic accidents, gliding contusions and diffuse axonal injury than in patients without this type of haematoma. Intracranial haematoma is usually thought to be a secondary event, that is a complication of the original injury, but these results suggest that a deep intracerebral haematoma is a primary event. If a deep intracerebral haematoma is identified on an early CT scan it is likely that the patient has sustained severe diffuse brain damage at the time of injury. In the majority of head injuries damage to blood vessels or axons predominates. In patients with a traumatic deep intracerebral haematoma, it would appear that the deceleration/acceleration forces are such that both axons and blood vessels within the brain are damaged at the time of injury.

Adolescent↗
PubMed1986

Myocardial and pancreatic lesions induced by T-2 toxin, a trichothecene mycotoxin, in swine.

Myocardial and pancreatic lesions induced by sublethal doses of T-2 toxin in swine were characterized by light and electron microscopy. Toxin was given intravenously to six 17- to 18-week-old pigs. Pigs were killed 24 or 48 hours after treatment. Grossly, subendocardial hemorrhages, multifocal pinpoint white foci in myocardium, and pancreatic edema occurred in one treated pig. Histologic changes in myocardium of treated pigs consisted of multifocal edema, mononuclear cell infiltration, myofiber hyalinization, vacuolation, and contraction bands with nuclear pyknosis. Ultrastructurally, there were areas of edema, myofibrillar disorganization, dilation of sarcoplasmic reticulum, and formation of hypercontraction bands. Myocardial mineralization was seen in the pig with gross lesions. Pancreatic changes in treated pigs consisted of multifocal acinar degeneration and necrosis. Ultrastructural changes included irregular dilation of rough endoplasmic reticulum and abnormal zymogen granules. Thus, in addition to radiomimetic lesions of the gastrointestinal tract and lymphoid organs, heart and pancreas are target organs of T-2 toxin in swine.

Animals↗
PubMed1986

Gliding contusions in nonmissile head injury in humans.

"Gliding" contusions, ie, hemorrhagic lesions in the parasagittal white matter, were analyzed in 434 fatal nonmissile head injuries in humans. It is concluded that gliding contusions are a type of diffuse brain damage occurring at the moment of injury. Gliding contusions are significantly associated with road-traffic accidents, with the absence of a skull fracture or a "lucid interval," and with the presence of diffuse axonal injury and deep hemispheric traumatic hematomas.

Accidents, Traffic↗
PubMed1986

Isolate of Anaplasma marginale not transmitted by ticks.

The tick-borne transmissibility of 2 isolates of Anaplasma marginale was compared. Dermacentor variabilis were exposed to A marginale as nymphs by feeding on 1 of 4 splenectomized calves during periods of ascending parasitemia (maximum 49% to 81% parasitized erythrocytes) induced by injection of a stabilate. Tick-borne transmission was attempted, using 26 to 224 adult ticks within 30 to 220 days after molting. Adult D variabilis did not transmit an Illinois isolate of A marginale in 7 tick-borne transmission experiments (P = 0.0047), including 2 experiments in which calves were inoculated IV with homogenates of adult ticks. In contrast, a Virginia isolate of A marginale was readily transmitted by the same tick colony. Thus, previously reported morphologic and immunologic differences among A marginale isolates may extend to tick-borne transmissibility. The Virginia and Illinois A marginale isolates had an inclusion appendage that was not a marker for tick transmissibility.

Anaplasmosis↗
PubMed1986

Identification of antigens of two isolates of Anaplasma marginale, using a western blot technique.

Antigens of the Illinois (IAM) and Florida (FAM) isolates of Anaplasma marginale were analyzed, using the western blot technique and antiserum from A marginale-infected calves. Crude antigens were prepared from the parasitemic blood of each. Antiserum was collected after the primary and recrudescent parasitemias. Antigens were separated, using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Antigens were then transferred onto nitrocellulose membranes and exposed to test sera. Antibodies attached to the membrane-bound antigens were detected, using an avidin/biotin peroxidase assay and biotinylated rabbit anti-goat immunoglobulin G. Antigens detected were of a high molecular weight group (108 to 91 kilodaltons [kd]) or of a low molecular weight group (47 to 27 kd). The IAM antigens were 100 kd, 96 kd, 47 kd, 38 to 43 kd, and 27 kd; these antigens were detected, using anti-IAM and anti-FAM antibodies, but the anti-FAM antibodies had a strong reaction to only the 100-kd and 38- to 43-kd antigens of IAM. The FAM antigens were 108 kd, 91 kd, 47 kd, 38 to 43 kd, and 27 kd; these antigens were detected, using anti-FAM antibodies and, except the 91 kd antigen, anti-IAM antibodies. Because the 91-kd antigen was detected only in the FAM antigen and detected only by sera from FAM-infected calves, this isolate-specific antigen may be associated with the ability of FAM to induce disease in an IAM-immune animal. Sheep anti-A ovis antibodies reacted only to the 38- to 43-kd antigens of each isolate, indicating that these antigens may be genus-specific.(ABSTRACT TRUNCATED AT 250 WORDS)

Anaplasma↗
PubMed1985

Borrelia theileri: isolation from ticks (Boophilus microplus) and tick-borne transmission between splenectomized calves.

The bovine spirochete, Borrelia theileri, was detected in Giemsastained blood smears from a splenectomized calf 17 days after exposure to a laboratory colony of the tropical cattle tick, Boophilus microplus. Spirochetes were detected in the hemolymph and ovary of all engorged female ticks examined, indicating a high infection rate in this tick colony. Spirochetes were detected in a 2nd splenectomized calf 15 days after exposure to the larval offspring of ticks from the 1st calf. The only observable effect of infection in the 2 calves was a maximum rectal temperature increase to 40.2 C, which coincided with the first detectable parasitemia. The tick colony did not have any adverse effects, despite extensive multiplication of spirochetes in their tissues.

Animals↗
PubMed1984

Diffuse axonal injury in head injuries caused by a fall.

82 cases of diffuse axonal injury were found at necropsy in 635 patients with fatal nonmissile head injuries. 13 of these injuries were attributable to falls, and in all the patients fell from a considerable height. Diffuse axonal injury was not found in those with head injuries caused by a simple fall--ie, a fall from not more than the person's own height--but there was a statistically significant association between the presence of diffuse axonal injury and falls from a considerable height. These results indicate that diffuse axonal injury rarely, if ever, occurs as a result of a fall unless the patient has fallen some distance.

Accidents↗
PubMed1984

LET-distributions and doses of HZE radiation components at near-Earth orbits.

Among cosmic rays, the heavy nuclei ranging from carbon to iron provide the principal contribution to the dose equivalent. The LET-distributions and absorbed dose aid dose equivalent have been calculated and are presented as a function of shielding and tissue self-shielding. At solar minimum, outside the magnetosphere, the unshielded dose equivalent of nuclei with atomic number Z > or = 6 is about 47 rem/year. The contribution of the target nuclei adds 7 rem/year. With 4 g/cm2 aluminum shielding, and at a depth of 5 cm in a biological phantom of 30 cm diameter, the respective values are 11 and 10 rem/year. Corresponding dose rates for orbits with various inclinations are presented, as well as the LET distributions of various components of cosmic rays.

Cosmic Radiation↗
PubMed1984

Transmission electron microscopy of meront development of Eimeria vermiformis Ernst, Chobotar and Hammond, 1971 (Apicomplexa, Eucoccidiorida) in the mouse, Mus musculus.

First and second generation meronts of Eimeria vermiformis developed in epithelial cells of the crypts of Lieberkühn. They were usually between the host cell nucleus and the basement membrane. Sporozoite organelles dedifferentiated with the first generation meront's development except for the refractile body and the apical complex, which persisted. After several nuclear divisions, the apical complex dedifferentiated further until only micronemes remained attached by a duct system to the plasmalemma. The form of the apical complex was highly variable. Sometimes the duct system was absent and the micronemes were attached directly to the plasmalemma or a dense material on it. Crescent body-like material was often present in the parasitophorous vacuole next to the microneme structure. The microneme structure was not present in second generation meronts but evaginations of the plasmalemma, cytoplasmic outpocketings, and cytoplasmic vesicles were associated with the round granular bodies in the parasitophorous vacuoles. During first generation merogenesis, invaginations from the parasitophorous vacuole formed channels into the meront along which merozoites budded. Micropores were often at the ends of these invaginations. These and other micropores of the meront had a dense U-shaped band for a collar while those of the merozoites had a collar with a double band of dense material that connected to the inner membrane. First generation merozoites budded randomly from the meront, resulting in a residual body that was usually in the middle of the parasitophorous vacuole. Second generation merozoites budded in one direction, resulting in a peripheral residual body and merozoites that were parallel in an oblong parasitophorous vacuole.

Animals↗
PubMed1984

Radiation doses and LET distributions of cosmic rays.

Among cosmic rays, the heavy nuclei ( HZE particles) like iron provide the dominant contribution to the dose equivalent during exposures in space. The LET distributions and radiation doses of cosmic-ray components have been calculated--with and without the quality factors--for a set of shielding and tissue self-shielding penetration depths. The relative contributions of heavy ions among solar flare particles to the dose equivalent are also explored. The transport calculations of the nuclei in air, shielding materials, and biological tissue-like material were carried out using the partial and total nuclear cross-section equations and nuclear propagation codes of Silberberg and Tsao . Outside the magnetosphere , at solar minimum, the product of the unshielded dose and the quality factors of cosmic-ray protons and heavy nuclei with atomic number Z greater than or equal to 6 are about 5 and 47 rem/year, respectively. With 4 g/cm2 aluminum shielding and at a depth of 5 cm in a biological phantom of 30 cm diameter, the respective values of the dose equivalents are about 4 and 11 rem/year. Due to the hard spectrum of cosmic rays, the attenuation of protons thus is relatively modest, while that of heavy nuclei is larger due to the larger interaction cross section. The dose equivalent of neutrons in the shielded case mentioned above is similar to that of protons. The biological risks are tentatively assessed in terms of the BEIR 1980 report. Uncertainties in risks due to possible large RBE values at low doses of high-LET radiation and due to the microbeam nature of damage by heavy ions are pointed out. Certain experiments and studies by radiobiologists are suggested for reducing the uncertainties in the estimates of the risks.

Cosmic Radiation↗
PubMed1983

Head injury in man and experimental animals: neuropathology.

All of the principal types of brain damage that occur in man as a result of a non-missile head injury, viz. cerebral contusions, intracranial haematoma, raised intracranial pressure, diffuse axonal injury, diffuse hypoxic damage, and diffuse swelling have been produced in subhuman primates subjected to inertial, i.e. non-impact, controlled angular acceleration of the head through 60 degrees in the sagittal, oblique and lateral planes.

Animals↗
PubMed1983

Transmission electron microscopy of intracellular sporozoites of Eimeria vermiformis (Apicomplexa, Eucoccidiida) in the mouse.

Sporozoites of Eimeria vermiformis from the mouse were first seen in the epithelial cells of villus tips and the crypts of Lieberkühn four hours after inoculation (HAI). They were always within a parasitophorous vacuole. By 12 HAI, most were in crypt epithelial cells between the basement membrane and host cell nucleus. The sporozoites in the villus tips had 26 subpellicular microtubules, two polar rings, two preconoidal rings, two refractile bodies surrounded by amylopectin-like granules, a lamellar Golgi apparatus, numerous micronemes, and rhoptries. The sporozoites in the crypt cells had fewer amylopectin-like granules, micronemes, and rhoptries. A nucleolus was visible, as were pieces broken off from the posterior refractile body. Later, the sporozoites folded over to become U-shaped; the infolded membranes fused; and then the inner membranes disappeared so that spherical meronts were formed. Folding sporozoites were first seen 16 HAI and persisted until 52 HAI.

Animals↗
PubMed1982

Diffuse axonal injury due to nonmissile head injury in humans: an analysis of 45 cases.

Forty-five cases of diffuse axonal injury (DAI) brought about by nonmissile head injury in humans are analyzed and compared with 132 cases of fatal head injury without DAI. All cases were subjected to a comprehensive neuropathological study. In the patients with DAI a statistically significant lower incidence of lucid interval, fracture of the skull, cerebral contusions, intracranial hematoma, and evidence of high intracranial pressure were found, with a higher incidence of head injury due to road traffic accident. Brain swelling and hypoxic brain damage were not statistically different in the two groups. The features of DAI in humans are compared with the DAI that has been produced in subhuman primates by pure inertial loading brought about by angular acceleration of the head. The available evidence indicates that DAI in human beings occurs at the time of head injury and is not due to complicating factors such as hypoxia, brain swelling, or raised intracranial pressure.

Adolescent↗