Biomedical subjects
Publications and source records attributed to K R Lee.
A case in which the uterus from a 44-year-old woman contained an atypical polypoid adenomyoma of the endometrium with adjacent adenomyomatosis in which there were focal areas of adenocarcinoma is described. This unique combination has not been previously reported. Possible histogenesis is discussed.
Intramedullary tuberculoma is rare, and there has been no report of concurrent intramedullary and intracerebral tuberculomas. We report a 30-year-old man with miliary tuberculosis of the lung. He suffered sudden paraplegia due to tuberculomas in the thoracic spinal cord and MRI showed more tuberculomas in the cervical spinal cord, brain stem, and cerebral and cerebellar hemispheres. The tuberculomas were isointense on the T1-weighted images, and hyperintense on the T2-weighted images; there was marked enhancement with intravenous gadolinium-DTPA. All the tuberculomas were very small 1 year after antituberculous chemotherapy.
A 25-year-old woman with acute lymphoblastic leukaemia, while in remission, developed paraparesis, with faecal and urinary incontinence. CT demonstrated increased density of the lumbar theca and enlargement of the nerve roots. Myelography showed complete obstruction below the L3 level. MRI showed increased signal intensity in the lumbar sac on T1 weighting, and the cauda equina enhanced with gadolinium-DTPA. Lymphoblasts were seen in the lumbar spinal fluid. After chemotherapy, these abnormalities resolved, as did the paraparesis and incontinence.
Severe wear of the ultra-high molecular weight polyethylene (UHMWPE) components of total joint replacements limits their long-term success. In previous studies, the infrared spectra obtained on retrieved UHMWPE components were interpreted as evidence that the UHMWPE oxidizes in vivo. In direct contrast, infrared spectroscopy of the retrieved UHMWPE acetabular components examined in this study demonstrated adsorbed esterified fatty acids, readily extractable by hexane, and no substantial evidence of in vivo oxidation. This emphasizes that special care must be taken when using infrared spectroscopy to assess retrieved components.
We have previously shown that the yeast PRP19 protein is associated with the spliceosome during the splicing reaction by immunoprecipitation studies with anti-PRP19 antibody. We have extended such studies by using extracts depleted of specific splicing factors to investigate the step of the spliceosome assembly process that PRP19 is involved in. PRP19 was not associated with the splicing complexes formed in U2- or U6-depleted extracts but was associated with the splicing complex formed in heat-inactivated prp2 extracts. This finding indicates that PRP19 becomes associated with the splicing complexes after or concomitant with binding of the U6 small nuclear ribonucleoprotein particle (snRNP) to the precursor RNA and before formation of the functional spliceosome. We further analyzed whether PRP19 is an integral component of snRNPs. We have constructed a strain in which an epitope of nine amino acid residues recognized by a well-characterized monoclonal antibody, 12CA5, is linked to the carboxyl terminus of the wild-type PRP19 protein. Immunoprecipitation of the splicing extracts with anti-PRP19 antibody or precipitation of the extracts prepared from the epitope-tagged strain with the 12CA5 antibody did not precipitate significant amounts of snRNAs. Addition of micrococcal nuclease-treated extracts to the PRP19-depleted extract restored its splicing activity. These results indicate that PRP19 is not tightly associated with any of the snRNAs required for the splicing reaction. No non-snRNP protein factor has been demonstrated to participate in either step of the spliceosome assembly pathway that PRP19 might be involved in. Thus, PRP19 represents a novel splicing factor.
Twenty-one cases of cerebral hemiatrophy were studied using 1.0 T magnetic resonance imaging (MRI). In addition to showing the generalized decrease in volume of the cerebral hemisphere, three patterns of cerebral hemiatrophy were noted: pattern I, diffuse cortical and subcortical atrophy (six cases):pattern II, diffuse cortical atrophy associated with expanded porencephalic cysts (10 cases); pattern III, old infarction with necrosis in the territory of the middle cerebral artery (five cases). Pattern I and pattern II were believed to have resulted from hypoxic-ischemic encephalopathy with subcortical leukomalacia (SCL). In all 21 cases, MRI also showed Wallerian degeneration, hyperintensive signals in the posterior limb of the internal capsule on the T2-weighted images, and unilateral atrophy of the cerebral peduncle as far as the pyramid of the medulla oblongata. Structural changes such as thickness of the calvarium, dilatation of the ipsilateral side of the frontal and ethmoid sinus, and reduced size of the middle cranial fossa, were found in 13 cases. Thus, MRI is a useful method of examination in the diagnosis of cerebral hemiatrophy as it has the ability to highlight changes in the cerebral hemisphere, basal ganglion, thalamus and brainstem as well as highlighting bony structural changes.
Tissue characterization of different pathologies of the liver can be achieved by differences of relaxation time on changing of pulse sequences in magnetic resonance imaging (MRI). The usefulness of MRI for detection of liver disease is limited when the pathological change is subtle. Chemical shift is a fundamental characteristics in nuclear magnetic resonance (NMR). Chemical shift imaging (CSI) in MRI is based on the different Larmor frequency of proton in water and fat; and therefore it was able to enhance the effectiveness of pathology. For this study, Dixon's method was used to detect liver pathologies and compare its detectability with conventional pulse sequences. Forty cases were enrolled for study; they included 5 health volunteers, 15 hepatomas, 1 cholangiocarcinoma, 5 metastatic hepatic tumors and 14 fatty livers. In hepatic tumors, the lesion number, tumor margination and lesion-to-liver contrast in images were read and analyzed. Signal intensities, signal-to-noise ratio and contrast-to-noise ratio were compared, after measurement, from stored data. In fatty livers, the relative change of signal intensities in different areas of the liver in in-phase and out-phase images were compared with the back muscle and spleen to find where the fatty metamorphosis happened. CSI in spin echo or gradient echo pulse sequences was found to be adequate and valuable for detecting fatty liver, when compared with conventional MRI. CSI not only identified the extension of disease itself but also characterized the fatty change in liver parenchyma. Though CSI affords no further advantages than conventional pulse sequences for detection of hepatic tumors, occasionally, when the image quality of the conventional pulse sequences is not satisfactory or equivocal in lesion detection, the use of CSI might be attempted.
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Using the polymerase chain reaction on paraffin blocks for human papillomavirus (HPV) types 16 and 18, a positive result was seen in three of 20 cases of invasive adenocarcinoma, 15 of 36 cases of adenocarcinoma in-situ, and one of five cases of glandular dysplasia of the uterine cervix. Types 16 and 18 were found with equal frequency. In adenocarcinoma in situ there was no age difference between HPV-positive and or HPV-negative cases. Concomitant squamous dysplasia was slightly more frequent in HPV-positive adenocarcinoma in-situ. HPV positivity rates are lower than most of those previously reported. Possible reasons for this are discussed.
A 4-year-old boy developed acute paraplegia, associated with sensory impairement and bowel and urinary dysfunction after an URI. MRI showed diffuse hyperintensity in T2WI in the spinal cord below the T6 level. Acute transverse myelitis was diagnosed based on the clinical presentations and MRI findings. The patient had poor recovery and two months later, a follow-up MRI disclosed a severe diffuse atrophic change of the spinal cord in the affected segment.
Two hundred forty-eight consecutive patients with clinical Stage I adenocarcinoma of the endometrium were seen between 8/77 and 8/88. Twenty-one were medically not operable and eleven others had papillary serous tumors. The remaining 216 were managed by a consistent operative protocol except that routine preoperative cesium was discontinued after 12/83. Patients received postoperative pelvic radiation on the basis of the depth of invasion, extrauterine pelvic disease, and/or cervix involvement. No patient underwent a pelvic lymphadenectomy. Only palpably suspicious nodes were removed. Twenty-one of these two hundred sixteen patients developed a recurrence. These 21 cases are analyzed for the probability of a staging lymphadenectomy having prevented their recurrence. Median follow-up of all 216 patients is 61 months with a mean time to recurrence of 26.5 months. No patient was lost to follow-up. Patients who recurred are analyzed by grade, depth of invasion, surgical stage, time to recurrence, site of recurrence, survival, protocol breaks, and frozen section discrepancies. No patient recurred on the pelvic side-wall. All patients found to have positive para-aortic nodes have died. No patient who received vaginal and/or pelvic radiation recurred in the pelvis. We conclude that staging lymphadenectomy would not have improved the outcome for these patients.
The clinical and pathologic findings in a 53-year-old woman who developed a uterine adenosarcoma following an adenomyoma are described. During the interval between the diagnosis of adenomyoma and the subsequent diagnosis of adenosarcoma, the patient developed breast carcinoma and received adjuvant chemotherapy that included tamoxifen. The possible stimulatory effects of this drug upon the patient's pre-existing adenomyoma are discussed in view of reports of tamoxifen-associated endometrial carcinoma and uterine sarcomas developing in the setting of estrogen excess.
Survival in 19 patients with papillary serous adenocarcinoma of the endometrium treated at the University of Vermont during the period 1960-1987 was significantly worse than that for 360 patients with other types of endometrial cancer. Deaths were associated with extrauterine spread and deep myometrial invasion detected at the time of surgery. Two patients without myometrial invasion and with extrauterine spread who also died may have developed synchronous peritoneal serous carcinoma.
The cytologic features of fine-needle aspiration specimens from 16 breast carcinomas that closely simulated benign lesions were analyzed and compared to smears from fibroadenomas and fibrocystic change. No combination of features was found that accurately separated all benign and malignant cases. Many nuclei with discernible small nucleoli in smears with many single bipolar nuclei indicated a benign lesion, whereas nuclear hyperchromasia indicated a malignant one.
Most of the primary hepatocellular carcinoma and hemangioma in TIWI are having low signals. Hemangioma is relatively lower in signal intensity than primary hepatocellular carcinoma, but they are really no so easy compare by bare eye. On the contrary, in T2WI, hemangioma is more brighter than primary hepatocellular carcinoma. So, by compare the variety shows from T1WI to T2WI, we can differentiated between primary hepatocellular carcinoma and hemangioma. By measuring the signal intensity in non-tumor area, there are no marked different in T1WI and T2WI, but hemangioma, as compare with primary hepatocellular carcinoma in signal intensity, is lower in T1WI and much higher in T2WI. Such results are all having statistic significant with p value less than 0.05. In measuring the different in signal intensity or ratio between tumor and non-tumor areas, there were mark different in T2WI and whereas there were no different in T1WI. By using two-point method, the T2-relaxation is measured in twenty eight cases of primary hepatocellular carcinoma and thirteen cases (twenty four lesions) of hemangioma. We found that there were nearly equal in nontumor areas, but there were mark different in T2-relaxation. In comparison with intravenous injection of Gd-DTPA in 10 cases of primary hepatocellular carcinoma and six cases of hemangioma, the latter were having similar dynamic CT appearance. Enhancement of signal intensity was found starting from peripheral part to central area. The primary hepatocellular carcinoma were having none of the above phenomenon. The liver MRI study is still expensive and time consuming.(ABSTRACT TRUNCATED AT 250 WORDS)
Within a two and half years period, we collected a total of twenty three cases of adrenal tumors diagnosed by MRI. They included: one cystic case, twelve cases (13 lesions) of adenoma, two cases (3 lesions) of hyperplasia, four cases of pheochromocytoma, three cases of metastases, and one case of adenocarcinoma. Except for the case of adrenal cyst which was followed for one and a half years, all the other twenty two cases were proved by operation and pathology. The benign adenoma and hyperplasia were small in size, and had relative isointensities to the liver in the T1WI and the T2WI. On the contrary, the malignant tumors and pheochromocytoma, all had inhomogeneous signal intensities, showed relatively lower in signal intensities in T1WI and higher in T2WI as compared with the liver. In T2WI, the tumor to liver signal intensity ratio of adenoma and hyperplasia were less than 1.80, whereas the malignant tumors and pheochromocytoma were larger than 1.80. In comparing fifteen cases with Gd-DTPA intravenous injection, all of the benign adenoma did not show an increase in signal intensity, but the malignant tumors and pheochromocytoma showed increase in signal intensity. We concluded that we could primarily differentiate the nature of adrenal tumors by their change in signal intensities between T1WI and T2WI, by measuring the tumor to liver signal intensity ratio or by Gd-DTPA IV injection. Today, although adrenal gland MRI examination is more time consuming and expensive, it is more valuable for highly clinically suspected adrenal lesions with equivocal results after CT or sonogram study.(ABSTRACT TRUNCATED AT 250 WORDS)
We report on 19 cases of intracranial germ cell tumors, including 12 male and 7 female patients; the average age was 16.5 +/- 4.9 years. These tumors included germinoma in 15 cases, yolk sac tumor in 3 cases, embryonal cell carcinoma in 1 case, and mixed tumor in 3 cases. Each of 5 cases had 2 to 3 different kinds of tumor cells, either in one tumor or in different tumors. The locations of tumors were pineal region in 13 cases, suprasellar region in 3 cases, basal ganglion-thalamus in 3 cases, and cerebral hemispheres in 4 cases. Six of them had 2 or more locations. One case had spinal seeding and extraneural metastasis to the liver, retroperitoneum and neck lymph nodes. Eighteen cases received CT scan and 6 cases received MRI examinations, all the tumors had good enhancement by iodium content contrast medium in CT and Gadolinium-DTPA in MRI. Alfa-fetoprotein was elevated in yolk sac tumor, AFT and HCG were elevated only slightly or remained normal in germinoma. Germinomas had good response to radiation therapy and chemotherapy, while nongerminoma had poor response and worse prognosis.
To establish the myelination process of brain of Chinese infants, our study consisted of seventy-five infants ranging in age from 5 days to 2 years old. They were studied with a 1.0 T superconductive MRI. In the new born, myelination could be seen in the brainstem, middle cerebellar peduncle, and posterior limb of the internal capsule in both T1WI and T2WI. Then the myelination process rapidly progressed month by month. Myelination of the centrum semiovale and optic radiation could be seen in T1WI in the newborn up to 3 months old, and in T2WI at 3-5 months old. The myelination of the splenium and the genu of corpus callosum were seen at 3-6 months in T1WI and 5-6 months in T2WI. Myelination of the occipital lobe and frontal lobe were seen at 3-6 months and 5-10 months in T1WI, and 8-14 months, 10-16 months in T2WI respectively. In 7-10 months, the brain appeared as an "early adult pattern" in T1WI; while, in T2WI, the brain appeared as an "early adult pattern" at 14-18 months old. The understanding of the myelination process in infants is important and essential for the judgement of the infantile brain and for the diagnosis of many CNS diseases of infants.