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Biomedical subjects

K C Ho

Publications and source records attributed to K C Ho.

At least 109 records · Page 6Linked to original sources
PubMed1980

Chromatin-negative Klinefelter's syndrome with focal megalencephaly.

At autopsy, 72-year-old white male with chromatin-negative Klinefelter's syndrome, mental retardation, psychotic behavior, and carcinoma of the lung was noted to have right unilateral focal cerebral and cerebellar megalencephaly with broad gyri, a cytoarchitectually abnormal cortex, and thickened cerebral vessels. Literature about the neuropathology of Klinefelter's syndrome and several cases of other chromosome aberrations (XYY and XO syndromes) are reviewed. These neuropathological changes are thought to be related to clinical manifestation.

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PubMed1980

The risk of arachnoiditis from experimental nonionic contrast media.

Aqueous myelographic contrast media are needed that are less expensive and better tolerated than metrizamide. This study compares two new, nonionic aqueous contrast media, ioglunide and iopamidol, with two previously developed contrast media, metrizamide and iocarmate. Myelography was performed with one of the contrast media in monkeys; four weeks later the degree of arachnoid fibrosis was determined in each animal by myelographic and histologic studies of the dural sac. Iopamidol, ioglunide, and metrizamide produced no more arachnoid changes than were found in the control animals. Iocarmate produced moderate to severe arachnoiditis.

Animals↗
PubMed1980

Analysis of brain weight. I. Adult brain weight in relation to sex, race, and age.

The weights of fresh brains obtained at consecutive autopsies over a period of five years were reviewed. Brains with lesions, such as large tumor, hemorrhage, infarct, or edema, were excluded. Analysis of the brain weight of 1,261 subjects, aged 25 to 80 years, show that the mean brain weight decreases in order from white men to black men to white women to black women. These differences are statistically significant and become apparent at age 6 years. The rate of decrease for the brain weight after age 25 years is highest for white men, followed by black women, white women, and black men, and, except that between white men and white women, the differences are statistically insignificant. Contrary to earlier reports, the mass decreases rapidly after age 80 years. In evaluating an individual brain weight, it is important to compare it with the norm for each subgroup of a given age.

Adult↗
PubMed1980

Analysis of brain weight. II. Adult brain weight in relation to body height, weight, and surface area.

Analysis of 1,261 adult subjects, ages 25 to 80 years, showed that there is a positive relationship between the brain weight and the body dimensions. The brain weight, however, increases at a slower rate than the body dimensions. There is indication that only a small portion of the brain varies with variation in the body dimensions. Among parameters, the brain weight correlates best with the body surface area, followed by the body height and body weight. The brain weight is related to the body weight partly because it increases with increasing height. When adjusted to body dimensions, the brain weight is greater for white men than for black men and for white women than for black men. Our study also shows that the loss of brain mass proceeds at a slightly faster rate than loss of body mass.

Adult↗
PubMed1979

The contracting cord sign of multiple sclerosis.

A new sign of multiple sclerosis, the contracting cord sign, is described. The myelographic demonstration of a large cord that subsequently decreases in size may suggest multiple sclerosis. Multiple sclerosis must be considered in the differential diagnosis of an enlarged spinal cord. Distinguishing between the collapsing cord and the contracting cord is discussed.

Adult↗
PubMed1979

CT detection of demyelinated plaques in multiple sclerosis.

CT images and anatomic slices of two brains containing numerous demyelinated plaques were correlated. Demyelinated plaques smaller than 0.7 cm were not detected by CT. Some larger plaques were misinterpreted as normal structures. These and other considerations suggest that chronic cerebral demyelination cannot be excluded by negative nonenhanced CT scan.

Brain↗
PubMed1978

Computed tomography of anatomic specimens.

To obtain high quality computed tomographic (CT) images of specimens, the specimens must be submerged in water and immobilized. We describe a simple, effective technique for imaging brain specimens in various CT scanners. Anatomic sections that correspond exactly to the plane of the CT image may be obtained

Brain↗
PubMed1978

Arachnoiditis from experimental myelography with aqueous contrast media.

Myelography was performed on 80 monkeys to study postmyelographic arachnoiditis. Metrizamide myelography caused arachnoiditis when high concentrations were used, but not with the usual clinical concentrations. Arachnoiditis resulted after myelography with meglumine iocarmate; however, the risk of arachnoiditis was reduced by diluting the contrast medium. Prophylactic intrathecal methylprednisolone was not effective in preventing arachnoiditis. Blood in the cerebrospinal fluid did not affect the degree of arachnoiditis.

Animals↗
PubMed1978

Ineffectiveness of prophylactic intrathecal methylprednisolone in myelography with aqueous media.

The effectiveness of prophylactic intrathecal methylprednisone (MP) in preventing arachnoiditis from iocarmate myelography was studied. Monkeys were injected intrathecally with locarmate, MP, or a combination of the two. Twelve weeks later the severity of arachnoiditis was determined in each animal. There was no significant prophylactic effect of intrathecal MP on arachnoiditis from locarmate. Some arachnoiditis was found in control animals treated with MP alone.

Animals↗
PubMed1978

Comparison of arachnoiditis produced by meglumine iocarmate and metrizamide myelography in an animal model.

Myelography in monkeys was performed with either meglumine iocarmate or metrizamide. The severity of resultant arachnoiditis in each animal 12 weeks later was evaluated by repeat myelography and by histologic study of the arachnoid. Three of the four animals examined with meglumine iocarmate had severe arachnoiditis; none of the four animals examined with metrizamide had as severe changes. The difference between the two groups was statistically significant (P less than .05).

Animals↗
PubMed1977

The relation of axonal transport of mitochondria with microtubules and other axoplasmic organelles.

Axonal transport of mitochondria was studied in frog sciatic nerves incubated in agents selected for their known or alleged effect on microtubules or axonal flow. Quantitative data on mitochondria, microtubules, neurofilaments, endoplasmic reticulum, and cross-sectional area of the axon indicate that axonal transport of mitochondria is dependent on microtubules. When more than half of the microtubules are destroyed, the axonal transport of mitochondria is diminished in proportion to the destruction of microtubules. Axonal transport of mitochondria is not related to neurofilaments and endoplasmic reticulum. Changes in the cross-sectional area of axons, even upon reduction to half the normal size, do not noticeably affect mitochondrial transport. Cyanide which blocks oxidative metabolism also blocks axonal transport of mitochondria, but analysis of fine structure indicates that cyanide is destructive to microtubules as well.

Animals↗
PubMed1977

Experimental production of arachnoiditis with water-soluble myelographic media.

After myelography with either metrizamide (300mg l/ml) or meglumine iocarmate (280 mg l/ml), mild to severe arachnoid fibrosis was demonstrated radiographically and histologically in primates. Intrathecal injections of metrizamide (170 mg l/ml) or autologous cerebrospinal fluid produced less arachnoiditis. The risk of arachnoiditis is probably minimized by the use of reduced volumes and concentrations of water-soluble media. Controlled studies of arachnoiditis following myelography are probably more reliable in the primate model than in other experimental animals.

Animals↗
PubMed1977

Arachnoiditis following myelography with water-soluble agents. The role of contrast medium osmolality.

The role of contrast medium osmolality in postmyelographic arachnoiditis was studied. Monkeys were injected intrathecally with isotonic saline (290 mOs/kg), hypertonic saline (1,449 mOs/kg), metrizamide (456 or 300 mOs/kg), or methylglucamine iocarnate (1,049 mOs/kg). After 12 weeks the animals were examined for evidence of arachnoiditis, with myelography just prior to sacrifice and microscopic examination of the excised dural sac and its contents. Intrathecal injections of methyglucamine iocarmate or metrizamide caused arachnoiditis while saline did not. Only one animal given 170 mg l/ml (300 mOs/kg) exhibited a more severe reaction than the controls. An increase in the cerebrospinal fluid osmolality alone does not cause arachnoiditis.

Animals↗
PubMed1977

Arachnoiditis following myelography with metrizamide in monkeys. Effect of blood in the cerebrospinal fluid.

Monkeys were injected intrathecally with blood, metrizamide (Amipaque) or a mixture of blood and metrizamide. Twelve weeks later the animals were examined for evidence of arachnoiditis. Either blood or metrizamide alone in sufficient amounts resulted in arachnoiditis. The addition of blood to metrizamide did not alter the severity or risk of arachnoiditis from experimental myelography with metrizamide.

Animals↗
PubMedDate not supplied

Normal and degenerating articular cartilage: in vitro correlation of MR imaging and histologic findings.

Histologic correlation of the different magnetic resonance (MR) appearances of articular cartilage has not been studied extensively. Therefore, the authors correlated thin (high-resolution) MR sections of articular cartilage with histologic sections. Human cadaver lumbar facet joints were imaged with a 1-mm section thickness and a 4-cm field of view, then sectioned and stained for histologic comparison. MR imaging patterns were identified that correlated with normal cartilage and three histologically different patterns of degeneration.

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