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Biomedical subjects

C C Lu

Publications and source records attributed to C C Lu.

At least 145 records · Page 8Linked to original sources

Psoas abscess resulting from perforating carcinoma of the sigmoid colon. Report of a case.

We report a case of a left psoas abscess resulting from a perforating carcinoma of the sigmoid colon. The chief complaints were edema of the left leg and pain in the left thigh. Single and double contrast barium-enema film demonstrated an extrinsic inflammatory mass distorting the sigmoid colon. A preoperative diagnosis of sigmoid carcinoma was not made on these examinations, nor on flexible colonoscopy. Carcinoma of the colon should be considered as a cause of an unexplained psoas abscess.

Abscess↗

Basal-lateral and intracellular membrane populations of rat exorbital lacrimal gland.

With the goal of isolating and identifying plasma membrane vesicle populations from epithelial cells of the rat exorbital lacrimal gland, we have designed an analytical fractionation of homogenates of the gland parenchyma. This fractionation utilizes separation procedures based on three independent physical properties of subcellular particles: sedimentation coefficient, density, and density after interaction of membrane cholesterol with digitonin. A commonly accepted marker for basal-lateral membranes, Na-K-ATPase, is associated with at least two physically distinct membrane populations. One population can be identified as basal-lateral membrane fragments on the basis of its fractional and specific contents of Na-K-ATPase; it accounts for 50% of the total Na-K-ATPase activity, enriched 29-fold with respect to the initial homogenate. With these values we calculate that the sample of basal membranes has been purified 60-fold with respect to the initial homogenate. The remaining Na-K-ATPase activity appears to be associated, at three- to fivefold lower specific activities, with intracellular membrane populations. We speculate that these populations have been derived from the Golgi complex.

Alkaline Phosphatase↗

Resolution of apical and basal-lateral membrane populations from rat exorbital gland.

We performed analytical fractionation studies with the goal of isolating basal-lateral and apical membrane vesicles from epithelial cells of rat exorbital lacrimal gland. A density region designated window II contained elements of three physically and biochemically distinct membrane populations. These were resolved by countercurrent distribution in an aqueous polymer two-phase system. One population contained 50% of the NADPH-cytochrome c reductase activity recovered from window II and appeared to be of intracellular origin. A second population contained 70% of the recovered Na-K-ATPase, maximally enriched 42-fold with respect to the initial homogenate. This population was the major locus of alanine transport activity, roughly 85% of which was mediated by systems believed to be characteristic of epithelial cell basal-lateral membranes. It also contained portions of the alkaline phosphatase, galactosyltransferase, acid phosphatase, and NADPH-cytochrome c reductase activities. A third population accounted for 33% of the recovered alkaline phosphatase and was a secondary locus of Na-alanine transport activity, 45% of which could be attributed to systems believed to be characteristic of epithelial cell apical membranes.

Alanine↗

Esophagotracheal fistula from a pharyngoesophageal diverticulum.

Pharyngo-esophageal (Zenker's) diverticula are rarely associated with tracheal fistulas; however, the diagnosis should be suspected in the diverticulum patient who presents with spasms of coughing while eating since, if found, it changes the surgical management. The roentgenographic findings, diagnostic modalities, and surgical management of such a patient are herein presented.

Aged↗

Teratogenic effects of nickel chloride on embryonic mice and its transfer to embryonic mice.

Administration of nickel chloride to the pregnant mice on the seventh to eleventh day of their gestational period, resulted in significant embryotoxic effects in terms of an increased resorption rate, a decreased fetal weight, delay in skeletal ossification and high incidence of malformation. Among the cases of fetal malformation, the following malformations were observed to occur at a higher rate of incidence: acephalia, exencephaly, cerebral hernia, open eyelid, cleft palate, micromelia, ankylosis of the extremity, club foot and skeletal anomalies. Most skeletal anomalies were in the form of vertebral and/or rib fusions and were found mostly at thoracic and lumbar levels. The concentration of nickel retained in embryonic tissues was 800 times higher in the exposed compared to control groups and indicated that increased tissue levels of nickel chloride had a toxic influence on the developing embryo.

Abnormalities, Drug-Induced↗

The role of central 5-hydroxytryptamine in acupuncture analgesia.

The role played by central 5-hydroxytryptamine (5-HT) in acupuncture analgesia (AA) has been studied in rats with the tail-flick response as the antinociceptive test. The analgesic effect of acupuncture can be enhanced or lowered by the increment or the decrement of the 5-HT level in the CNS. Furthermore, the turnover rate of 5-HT in the CNS has been found to be greatly facilitated during the period of acupuncture. The results imply that 5-HT in the CNS may be one of the most important neurochemical agents mediating AA.

5,6-Dihydroxytryptamine↗

Cytotoxic effects of chemotherapeutic drugs on mouse testis cells.

Studies of testicular cell killing in mice by several chemotherapeutic drugs have been performed to EVALUATE THE HARMFUL EFFECTS OF ONCOLYTIC AGENTS ON REPRODUCTION. Seven drugs, Adriamycin, 1-beta-D-arabinofuranosylcytosine, bleomycin, cyclophosphamide, hydroxyurea, vinblastine, and vincristine, given as single injections, were cytotoxic to differentiated spermatogonia. Adriamycin was also highly effective in killing stem cells. The other drugs produced little or no stem cell loss even at doses toxic to the animals. Negligible killing of spermatocytes and spermatids was noted at any dose level. The results demonstrated that oncolytic agents preferntially killed cells at specific stages of the spermatogenic pathway in mice at doses within the clinical range for humans.

Animals↗

Effects of estrogen on human seminiferous tubules: light and electron microscopic analysis.

Morphological features of testes from four subjects after long-term treatment with ethinyl-estradiol (1--2 mg daily) and from five non-treated patients with prostatic carcinoma were studied by means of light and electron microscopy. The non-treated seminiferous tubules contained spermatagonia, spermatocytes, spermatids, spermatozoa, and Sertoli cells and showed no apparent morphologic abnormalities. On the other hand, the estrogen-treated testicular tissue contained only Sertoli cells and very few spermatogonia within the seminiferous tubules. The nuclei of Sertoli cells occasionally contained two nucleoli. The nucleolar complex was composed of a fine granular spherical body surrounded by a large granular, reticular network. The cytoplasm of the Sertoli cell contained osmiophilic lipid-like bodies. These lipid-like bodies appeared more pronounced in patients treated with higher doses of estrogen, suggesting a diminution of secretion of Sertoli cell hormone. Blebbing from the outer nuclear membrane appeared to have formed numerous vesicles in the cytoplasm. These vesicles usually contained several membrane-bound granular bodies. In the estrogen-treated testes, there was a marked increase in thickness and infolding of the basement membrane. Two unusual patterns of the basement membrane were observed: one appeared to be a reticular anastomosis, the other, an electron-dense trilayer. The morphological picture of seminiferous tubules from the estrogen-treated subjects appeared to correlate well with the suppressed plasma and testicular levels of testesterone, the undetectable circulating gonadotrophins, and the elevated plasma and testicular levels of estradiol-17 beta reported by Rodriguez-Rigau et al. ('77).

Adult↗

Does a normal small-bowel enteroclysis exclude small-bowel disease? A long-term follow-up of consecutive normal studies.

The purpose of our study was to determine if a normal small-bowel enteroclysis excludes small-bowel disease in adult patients, using long-term follow-up as the major reference standard. We reviewed 193 consecutive small-bowel enteroclysis (SBE) studies completed during a period from January 1987 to February 1989, of which 83 were judged to be normal at the time of the study. Eight of these latter patients were excluded due to inadequate follow-up. The indications included detection of gastrointestinal bleeding, small-bowel obstruction, Crohn's disease, nonspecific abdominal pain, chronic diarrhea, and a miscellaneous group. Each patient was followed for at least 3 years by chart review or until a definite diagnosis was established. Six of the 75 patients whose SBE was originally interpreted as normal were eventually judged to have small-bowel disease. The remaining 69 patients were judged to be free of small-bowel disease by autopsy, surgical laparotomy, endoscopic observation or biopsy, or long-term follow-up for at least 3 years. Therefore, a normal SBE correctly excluded small-bowel disease in 69 of our 75 patients (true negatives) and failed to diagnose disease in six patients (false negatives), for a specificity of .92 +/- .03 (SE). In this experience, SBE was sufficiently specific in most patients to exclude small-bowel disease.

Adolescent↗

Parathyroid hormone and parathyroid hormone related protein assays in the investigation of hypercalcemic patients in hospital in a Chinese population.

There are many pathological causes and potential mechanisms for hypercalcemia. We measured intact parathyroid hormone (PTH) and parathyroid hormone related protein (PTHrP) in the hypercalcemic in-patients and attempted to evaluate the roles of PTH and PTHrP in hypercalcemia due to malignancy. We performed a prospective study of 178 patients with corrected serum calcium concentrations greater than 2.74 mmol/l in a hospital over a 3-year period. We measured calcium and albumin using a Hitachi 747 autoanalyzer, and we measured PTH and PTHrP by two-site immunoradiometric assays (IRMA). Hypercalcemia was attributed to malignancy alone in 93 patients (52.3%), primary hyperparathyroidism (HPT) alone in 28 patients (15.7%), uremia with hemodialysis in 23 patients (12.9%), unknown in 16 patients (9%), primary HPT coexisting with malignancy in 7 patients (3.9%) and other rare causes (6.2%). Plasma PTHrP levels were elevated in 71/93 (76.3%) patients with hypercalcemia due to malignancy, but the elevated PTHrP percentage differed for each kind of tumor. PTHrP levels were elevated in 100% of patients with squamous carcinomas (CA) in the lung, esophagus, skin, cholangiocarcinoma of liver, and breast CA. The positive bony metastatic rate was 44.1% (41/93). There was no correlation between high PTHrP and bony metastasis. There was a good correlation between the corrected serum calcium and PTHrP levels (r = 0.476, p < 0.001), but no correlation between survival time and serum calcium level or PTHrP level. There was no significant difference in life expectancy after cancer diagnosis between the high PTHrP group and normal PTHrP group, and there was no significant difference in life expectancy after the first occurrence of hypercalcemia between the two groups. Measurement of both PTH and PTHrP levels led to a change in the initial diagnosis in 7 patients. In routine practice, measurement of serum PTH alone is not enough. This study suggests that the appropriate combination of PTH and PTHrP assays results in a more accurate diagnosis of the hypercalcemic causes. In addition, especially high PTHrP levels should be screened for malignancy. However, the prognosis in cancer patients after hypercalcemia with high PTHrP group, as compared to those with the normal PTHrP group is not significantly different.

Adult↗

Transfer of chromic chloride to embryonic mice and changes in the embryonic mouse neuroepithelium.

Transfer of CrCl3 to embryonic mice and changes in the embryonic mouse neuroepithelium associated with Cr-induced neural tube defects were studied. A single intraperitoneal injection of 51CrCl3 was administered on the 8th day of gestation and animals were killed at various intervals for measurements of radioactivity in the maternal blood and embryos. Radioactivity per gram of fetal tissues increased during the observed period, while those of maternal blood decreased. Pregnant mice were injected intraperitoneally with a single dose of CrCl3 (non-radioactive) on the 8th day of gestation. Animals were killed at specified times after injection and embryos were removed and examined histologically. At 4, 8 and 12 h after injection many pyknotic cells were observed on the neural plate, especially at 8 h after injection. These data suggest that CrCl3 may affect embryos directly and cause neural tube defects and that pyknotic cells on the neural plate may be an early pathological finding in cases of developing exencephaly.

Animals↗