Showing papers by "University of Texas Health Science Center at Houston published in 1976"

Menkes disease: a biochemical abnormality in cultured human fibroblasts

Abstract: Cultured skin fibroblasts from patients with Menkes disease, an X-linked disorder involving a defect in copper metabolism, were analyzed for copper concentration by means of atomic absorption spectrophotometry. These cultures consistently exhibited elevated copper concentrations (mean = 335.5 ng of copper per mg of protein) when compared to control fibroblast cultures (mean = 59.2 ng of copper per mg of protein). External factors that could influence the copper content of cultures were found not to affect the differences in copper concentration between control and Menkes cells. Furthermore, Menkes cells could be differentiated from cultured fibroblasts of controls, of presumed heterozygotes, and of Wilson's disease patients by copper concentration. These observations led to the conclusion that the increased copper content of cultured Menkes cells was characteristic of Menkes disease, resulting from the expression of the genetic abnormality. This provides a genetic marker, a defect in metal metabolism demonstrated in human fibroblasts, that should prove valuable in both the diagnosis of Menkes disease and in the study of the fundamental defect of this genetic disorder.

Effect of intravenous hyperalimentation on established delayed hypersensitivity in the cancer patient.

Abstract: Forty-seven cancer patients were selected for study based on their candidacy for hyperalimentation. Each patient received selected skin test antigens intradermally in the forearm prior to the initiation of hyperalimentation, and at 7-day intervals throughout treatment with either chemotherapy, radiation therapy or surgery. Of 23 patients who received chemotherapy, 17 initially had negative skin tests. Thirteen of these patients had positive skin tests after an average of 11.4 +/- 5.5 days of hyperalimentation. Response to chemotherapy occurred only in hyperalimentation. Response to chemotherapy occurred only in those patients whose skin tests were positive, and conversion of skin test reactivity to positive occurred before clinical regression of metastatic disease. No patient who received radiation therapy developed or retained positive skin test reactivity, although nutritional repletion was considered satisfactory in each patient. Surgical patients whose skin tests converted to positive or remained positive preoperatively had an uncomplicated postoperative recovery, whereas 2 of 4 patients whose skin tests remained negative expired postoperatively. Absence of established delayed hypersensitivity in the cancer patient who is treated with chemotherapy or surgery is probably secondary to generalized malnutrition, and established cell-mediated immunity can be restored by proper nutritional repletion.

Hepatic adenomata with type 1 glycogen storage disease.

Abstract: In older patients with glucose-6-phosphatase deficiency, adenomatous nodules develop within the liver parenchyma. Investigation of eight such patients, age 3 to 28 years, using radioisotopic scans, has demonstrated areas of depressed isotope uptake in the liver in all except the one preteenaged child. Three patients were further studied with hepatic angiograms and liver biopsy specimens. A diffuse nodularity, more widespread than apparent on isotopic scans, was demonstrated on angiograms. Although initial histologic study in each case showed adenomatous tissue without evidence of neoplasm, the development of hepatocellular carcinoma in one of our patients and in others from the literature suggests that the nodules may be premalignant. ( JAMA 236:1481-1484, 1976)

Effects of Irradiation on the Eye

Abstract: From 1954 through 1971, 47 patients with malignant tumors of the nasal cavity and paranasal sinuses were treated with an entire eye included in the tumor dose volume. All patients were treated with megavoltage radiation and received approximately 6,000 rads in 30 fractions in six weeks. Two thirds of the patients treated by irradiation alone had no problems with vision or difficulties related to treatment of the eye. When 5-fluorouracil (5-FU) was used in conjunction with high-dose radiotherapy, loss of vision was much more frequent and all patients had either visual loss or major clinical difficulties.

Comparative susceptibility of latin american and united states students to enteric pathogens.

Abstract: This study was designed to verify the importance of toxigenic Escherichia coli and other etiologic agents in diarrhea of travelers. In particular, we sought data to compare the relative importance ...

Infinite allele model with varying mutation rate

Abstract: Available data suggest that the variation in mutation rate among protein loci follows the gamma distribution. Thus, taking into account this variation, formulae are developed for the distribution of allele frequencies, mean and variance of heterozygosity, expected number of alleles, proportion of polymorphic loci, and genetic distance. These formulae should be more appropriate for the analysis of gene frequency data for protein loci than equivalent formulae with constant mutation rate.

Ribosomal-associated phosphatidylserine synthetase from Escherichia coli: purification by substrate-specific elution from phosphocellulose using cytidine 5'-diphospho-1,2-diacyl-sn-glycerol

Abstract: Cytidine 5'-diphospho-1,2-diacyl-sn-glycerol (CDPdiglyceride):L-serine O-phosphatidyltransferase (EC 2.7.8.8, phosphatidylserine synthetase) is bound tightly to the ribosomes in crude extracts of Escherichia coli. After separation of the enzyme from the ribosomes by the method of Raetz and Kennedy (Raetz, C.R.H., and Kennedy, E.P. (1974), J. Biol. Chem. 249, 5038), we have purified the enzyme to 97% of homogenekty. The major portion of the overall 5500-fold purification was attained by substrate-specific elution from phosphocellulose using CDP-diglyceride in the presence of detergent. The purified enzyme migrated as a single band with an apparent minimum molecular weight of 54 000 when subjected to electrophoresis on polyacrylamide disc gels containing sodium dodecyl sulfate. The purified enzyme catalyzed exchange reactions between cytidine 5'- monophosphate (CMP) and CDP-diglyceride and between serine and phosphatidylserine. The enzyme also catalyzed the hydrolysis of CDP-diglyceride to form CMP and phosphatidic acid. dCDP-diglyceride was equivalent to CDP-diglyceride in all reactions catalyzed by the enzyme. In addition, the purified enzyme catalyzed the formation of phosphatidylglycerol or phosphatidylglycerophosphate at a very slow rate when serine was replaced as substrate by glycerol or sn-glycero-3-phosphate, respectively. These results suggest catalysis occurs via a ping-pong mechanism through the formation of a phosphatidyl-enzyme intermediate.

Membrane-associated phosphatidylglycerophosphate synthetase from Escherichia coli: purification by substrate affinity chromatography on cytidine 5'-diphospho-1,2-diacyl-sn-glycerol sepharose.

Abstract: The membrane-associated cytidine 5'-diphospho-1,2-diacyl-sn-glycerol (CDP-diglyceride):sn-glycerol-3-phosphate phosphatidyltransferase (EC 2.7.8.5) from Escherichia coli has been solubilized wiTriton X-100 and purified 6000-fold to 85% of homogeneity. The major purification was attained using several modifications of the the CDP-diglyceride Sepharose affinity chromatography system described by Larson et al. (Larson, T.J., Hirabayashi, T., and Dowhan, W. (1976), Biochemistry 15, 974). The native enzyme in Triton X-100 had an apparent molecular weight of over 200 000, as judged by Sepharose 6B gel filtration. The apparent size of the native enzyme appeared to be due to its association with Triton X-100, as judged by sucrose gradient centrifugation, polyacrylamide gel electrophoresis, and the lack of affinity for ion-exchange resins. The minimum subunit molecular weight of the enzyme, determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis, was 24 000. This low molecular weight is consistent with the stability of enzyme to heat, urea, or sodium dodecyl sulfate denaturation. The purified enzyme had an absolute requirement for magnesium ion (KM = 50 mM) and Triton X-100 (0.5-6%) for activity when either CDP-diglyceride or dCDP-diglyceride was used as substrate. Kinetic analysis of the enzymatic reaction indicated an ordered sequential Bi-Bi reaction with the liponucleotide forming a dead-end complex at high concentration, which inhibited both the forward and reverse reactions. The enzyme would not hydrolyze the pyrophosphate bond of its lipid substrate or the phosphate esters of its lipid product but would catalyze a cytidine 5'-monophosphate dependent exchange reaction between glycero-3-phosphate and phosphatidylglycerophosphate.

Color receptor identities of goldfish cones

Abstract: Goldfish retinas were exposed to spectral lights, then incubated with nitroblue tetrazolium chloride. Diformazan deposits revealed that five morphologically distinct cone types were segregated into three color classes: red long double and long single cones, green short double and long single cones, and blue short single and miniature short single cones.

Genetics and the etiology of childhood cancer.

Abstract: A consideration of the world-wide incidences of childhood cancer and of hereditary subgroups leads to the conclusion that two successive mutations can initiate cancer cells and that such cells usually proceed to develop into detectable cancers in a period of time which is short compared with the time required for most adult cancers. Environmental carcinogens could hypothetically increase the rates at which these mutations occur, but they probably, in fact, contribute little to the incidences. Certain exceptions, notably leukemia and lymphoma, are noteworthy, and a viral origin for them has been widely hypothesized. If most solid tumors of childhood are indeed correctly attributable to mutations in germ and/or somatic cells, then the prospect for the prevention of childhood cancer becomes very dim. In fact, the incidence of the germinal forms may increase as treatment improves (18). In theory, one might be able to identify individuals harboring cancer genes germinally and even to identify them prenatally. But even if the burden of cancer attributable to the hereditary subgroups were elimanted, there would still remain the larger nonhereditary group resulting from somatic mutations. If this hypothesis is correct, then childhood cancer cannot be prevented. With this conclusion goes the admonition, however, that environmental mutagens might significantly increase the burden of childhood cancer. One such mutagen, therapeutic radiation, is known to increase the prospect that second tumors will occur in patients who carry a germinal cancer mutation. The major effort to reduce the incidence of childhood cancer by prevention should be spent in examining the possibility that leukemia and lymphoma are viral in origin. If the arguments presented are correct, then the main effort against childhood cancer must be that of early diagnosis and treatment. I realize that many have already argued for that strategy in the approach to cancer generally, but I now believe that it is particularly relevant to any program against cancer in children.

Enteropathogenic Escherichia coli: lack of correlation of serotype with pathogenicity.

Abstract: Forty-eight strains of Escherichia coli isolated from children with diarrhea were classified according to nine enteropathogenic serotypes. The strains were examined for production of enterotoxin and for invasiveness by study of bacteria or bacteria-free filtrates in conventional animal and tissue culture models. Filtrates of only three strains (6%) consistently dilated rabbit ileal loops, while all 48 strains yielded negative results in suckling mice, adrenal cells, and guinea pig eyes. When filtrates of the three strains that dilated the rabbit ileum were heated at 60 C for 30 min, the reaction in rabbit ileal loops was negative; this finding indicated the production of a heat-labile enterotoxin. This study shows the lack of correlation between classical enteropathogenic serotypes of E. coli and presently known virulence properties in animal models. The results raise doubts about the value of serotyping E. coli isolates from sporadic cases of diarrhea. When it is suspected that an E. coli isolate is enteropathogenic, it may be important to perform more than one laboratory assay.

Antidiarrheal Agents in the Treatment of Acute Diarrhea in Children

Abstract: To evaluate the efficacy of antidiarrheal agents in the treatment of diarrheal illnesses, a study was conducted with children in Guatemala who had an acute diarrheal illness. Eighty patients, aged 3 to 11 years, were hospitalized and treated for two days with one of five agents: kaolin-pectin suspension concentrate (Kao-Con), kaolin suspension, pectin suspension, diphenoxylate-atropine liquid (Lomotil), or placebo. Although the patients receiving kaolin-pectin produced stools that tended to be more formed than those of the placebo-treated group patients, the study did not demonstrate any effect by any of the agents tested in influencing the frequency of bowel movement, the water content of the stools, or the weight of stools. Kaolinpectin suspension and diphenoxylate-atropine liquid do not appear to be useful in the relief of acute nonspecific diarrhea in children. (JAMA236:844-846, 1976)

Testing the neutral mutation hypothesis by distribution of single locus heterozygosity.

Abstract: ONE of the most controversial issues in population genetics at present is whether the widespread protein variation in natural populations is maintained by some form of balancing selection1–3 or merely represents the drifting polymorphism of neutral or nearly neutral mutations4–6. By the neutral mutation hypothesis the level of genetic variability in an equilibrium population is determined by mutation rate, v, and effective population size, Ne. If we use the infinite allele model, in which new mutations are assumed to be always different from the pre-existing alleles in the population, the average heterozygosity per locus is given bywhereM = 4Nev (ref. 7).

Responses of mosquitofish (Gambusia affinis) to ash effluent and thermal stress

Abstract: Mosquitofish, the only fish species inhabiting a drainage system that received high coal ash concentration at one end and thermal discharges at the other, appeared to successfully function in this environment with no apparent detrimental effects. Temperature conditions (44.5 C) were more limiting to the species' functional capacity than was coal ash turbidity (275 JTU) with high metal concentrations. Laboratory preference, avoidance, and lethal temperature trials supported the field observations. Mosquitofish had a final temperature preferendum at 34.7–35.1 C (both individual and group response), an upper temperature avoidance at 39 C when acclimated at 30 and 36 C, and an upper lethal temperature limit at 38 C. The species survived in this aquatic system in which elemental concentrations, determined by neutron activation analysis, were sufficiently high to be lethal to other fish species according to values from the literature and by in situ toxicity tests. Of the 40 elements measured, five (cal...

Improved Chemotherapy for Small-Cell Undifferentiated Lung Cancer

Abstract: Bleomycin sulfate, doxorubicin hydrochloride, cyclophosphamide, and vincristine sulfate combination chemotherapy was given to 29 patients with small-cell undifferentiated lung cancer. Only four of these patients had limited disease, and in these patients there was 100% complete remission; two of these four patients remain in complete remission at more than 52 and 60 weeks. Of the 25 patients with generalized disease, 18 (72%) had neoplasm regression (>50%), including two with complete remission (8%). The median duration of remission was 25 weeks. The median survival time from diagnosis was 39 weeks and that from initiation of therapy, 35 weeks. The drug regimen was well tolerated, and although substantial leukopenia was produced, there were only three patients in whom granulocytopenic infections developed. There was only one drug-related death. ( JAMA 235:1225-1229, 1976)

Posterior accessory foramina of the human mandible.

Abstract: A study was performed on 150 dry, adult, human mandibles from cadavers of unspecified sex and unknown ethnic background, which had been imported from India. These mandibles were placed in the “standard basal position” and topographically divided into 11 bilateral areas posterior to the second bicuspid teeth. The accessory foramina in these areas were studied to determine their mean diameter, incidence of occurrence, and the areas in which they occurred. The medial surfaces of the mandibles exhibited foramina more frequently and in greater numbers than did the lateral surfaces. The right and left halves of the mandibles showed remarkable similarity. Much of the data obtained correlated with previous investigations, indicating that neurovascular components enter and leave the body on the mandible in the posterior region. Foramina 0.4 mm. or larger in diameter were evaluated separately. These larger foramina occur most often in the superior and middle thirds on the medial surface of the ramus (areas 6 and 7). They also occur fairly frequently in the retromolar area (area 11). This information can be usefully applied to future dissection studies concerning the soft-tissue components of these foramina. The data obtained reveal that these foramina occur frequently and in approximately the same locations. This suggests that these foramina are functionally important in supplying neural and/or vascular components to the mandible.

Phosphatidylglycerol biosynthesis in Bacillus licheniformis Resolution of membrane-bound enzymes by affinity chromatography on cytidinediphospho-sn-1,2-diacylglycerol Sepharose.

Abstract: Cytidinediphospho-sn-1,2-diaclglycerol (CDP-diglyceride) has been covalently linked to Sephrose 4B via adipic acid dihydrazide spacer arm forming an effective affinity chromatography column. This liponucleo-tide ligand and sn-glycero-3-phosphate are subtracts for the formation of 3-sn-phoshatidyl-1'-sn-glycero-3'-phosphate (PGP) catalyzed in both eukaryotic and prokaryotic organisms by sn-glycero-3-phosphate: CMP phosphatidlytranferase (PGP synthetase). Using this CDP-diglyceride Sephrose affinity column we were able to resolve the membrane associated 3-sn-phosphatidyl'1-sn-glycerol (PG) synthesizing system present in Bacillus licheniformis into two activities. A PGP synthetase activity was adsorbed to the affinity column and was eluted using buffer containg CDP-diglyceride; a PGP phosphatease acactivity had no affinity for the column. Both PGP synthase and PGP phosphatase of B. licheniformis were associated with a membrane component of the cell as evidenced by sucrose gradient centrifugation, differential centrifugation, and solubilization by buffers containing detergent...

The transient distribution of allele frequencies under mutation pressure.

Abstract: The transient distribution of allele frequencies in a finite population is derived under the assumption that there are k possible alleic states at a locus and mutation occurs in all directions. At steady state this distribution becomes identical with the distribution obtained by Wright, Kimura and Crow when k = ∞. The rate of approach to the steady state distribution is generally very slow, the asymptotic rate being 2v + 1/(2N), where v and N are the mutation rate and effective population size, respectively. Using this distribution it is shown that when population size is suddenly increased, the expected number of alleles increases more rapidly than the expected heterozygosity. Implications of the present study on testing hypotheses for the maintenance of genetic variability in populations are discussed.

Archeology, population genetics and studies of human racial ancestry.

Abstract: Using traditional classification, many people have tried to determine the place and time of origin of the major human races. Two basically conflicting views have prevailed, one asserting that races developed as local variations in a species evolving phyletically over much of the Old World for up to one million years, and the other view holding that present races are local variations on populations recently expanding into most areas and replacing the previous hominid inhabitants, this occuring since the time of the Neanderthals. Both views are based on the same archeological data. Gene frequency data and time-calibrated genetic distance measures have recently been applied to this problem. Here we show that the probable demographic nature of Pleistocene populations has obscured genetic distances to such an extent that they cannot be used to discriminate between the two viewpoints of racial origins. The racial classifications themselves are probably not useful in this context and obscure the question, so that we presently do not have a scientifically valid understanding of racial origins.

Estrogen receptors in the rat uterus. Retention of hormone-receptor complexes.

Abstract: The retention pattern and biochemical characteristics of estrogen receptors in the nuclei of uterine cells were studied as a function of time after the in vivo injection of estradiol (E2) to immature female rats. One hour after the injection of 0.1 mug of tritiated E2, approximately 0.20 pmol per uterus of receptor bound hormone is retained in uterine nuclei. This dose of E2 produces a maximal uterotrophic response. Six hours after E2 administration, uterine nuclei retain 0.04-0.08 pmol of hormone per uterus. Hormone receptor complexes extracted from uterine nuclei 1, 3, and 6 h after in vivo injection of hormone have similar structural and binding characteristics. Receptors extracted at all three times sediment at 5S in high salt gradients and have a dissociation binding constant of approximately 3 nM for E2. The wash-out curves of receptors as a function of salt concentration are identical for uterine nuclei from animals treated for 1 or 6 h with estradiol, suggesting that the nature of the nuclear binding of receptors is not altered during this time interval. Experiments utilizing the injection of unlabeled estradiol, followed by an in vitro exchange procedure with tritiated estradiol, indicated that the total nuclear estrogen receptor sites, i.e., filled and vacant, decreased similarly.

Non-histone protein synthesis during G1 phase and its relation to DNA replication.

Abstract: The kinetics of non-histone chromosomal protein (NHCP) synthesis were studied in Chinese hamster ovary (CHO) plateau phase cells stimulated to proliferate and were compared to NHCP synthesis kinetics in two populations of synchronous G1 traversing cells. In all cases, NHCP synthesis rates increase 3- to 5-fold as cells traversed G1 and attained maximum values one hour before semi-conservative DNA replication began. Similar to results in synchronous G1 cells, the molecular weight distributions of the NHCP fraction from stimulated plateau phase cells underwent only minor changes, measured by sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis, as these cells moved toward S phase. Yet, during this progression after plateau phase and in the transition from early G1 to late G1 in synchronous cells, the total NHCP fraction increased significantly (1.5–2-fold) in amount per cell. These data indicate that plateau phase cells are similar to early G1 cells, both in terms of their amounts of non-histone per cell and in their subsequent NHCP synthesis kinetics as they move toward S phase. These results extend previous findings which suggested that NHCP synthesis was coupled to DNA replication and demonstrate that the increased NHCP synthesis and accumulation in chromatin may be a biochemical marker for G1 progression.

The effect of hypophysectomy on the uterine response to estradiol

Abstract: Following estradiol (E2) administration early increases (within 4 h) in uterine wet weight and the synthesis of 2-deoxyglucose-6-phosphate (2-DGP) from 2-deoxyglucose (2-DG) are similar in ovariectomized (OVX) and ovariectomizedhypophysectomized (OVX-HX) rats. Most late uterine responses occurring 24 h after hormone treatment, however, are greatly diminished in OVXHX animals relative to OVX animals. The diminished responses include increases in uterine wet weight, dry weight, RNA content, protein content and the incorporation of thymidine into uterine DNA. These late uterine responses are not diminished in OVXSham HX rats relative to OVX rats. The diminished responses observed in OVX-HX rats are not due to a shift in the dose-response curve for E2, but result from a decrease in the magnitude of the maximum uterine response. These diminished responses are not due to alterations in the content, structure or binding affinity of uterine E2 receptors in OVX-HX rats relative to OVX rats. One late response, the synthesis of 2-DGP from 2-DG 24 h after E2 treatment, is not significantly diminished in OVX-HX rats. These results suggest that a pituitary factor(s) is directly or indirectly required for the complete uterine response to E2 to occur normally in OVX rats. (Endocrinology 101: 403, 1977) T HE OVERALL response of the rat uterus to estrogens is a complex process which seems to involve at least two major temporal phases, an early phase and a late phase (1-5). Specific responses occurring in the early phase are increases in uterine wet weight (3,6,7), glucose metabolism (7-9) and RNA polymerase activities (10-12) while late responses include increases in uterine dry weight (4-6), DNA synthesis (9,13), protein (10,14) and RNA content (10,14). It has been suggested that these late uterine responses represent true growth of the organ, while the early responses represent a preparation for this growth. The overall uterine response appears to be mediated by a series of interacReceived January 3, 1977. Supported by NIH Grant HD-08615. A preliminary' report of this investigation was presented at the Fall Meeting of the American Society for Pharmacology and Experimental Therapeutics, New Orleans, Louisiana, August 15-19, 1976 (The Pharmacologist 18: 250, 1976, Abstract 749). * Recipient of NIH Research Fellowship Award (Am 05246). t Recipient of NIH Research Career Development Award (I KO4 HD00099). tions in which hormonal regulation may exist at multiple sites within uterine nuclei and at various times after hormone treatment (see 5 and 15 for recent reviews). In this investigation we have sought to determine if the overall endocrine status of the animal could differentially affect these early and late uterine responses to estrogens, since these responses are qualitatively distinct. As an initial approach to this question, we have compared various estrogenic responses of the uterus in ovariectomized (OVX) and ovariectomized-hypophysectomized (OVX-HX) rats. These studies indicate that early uterine responses are comparable in both.groups of animals, but that most late uterine responses are dramatically decreased in the OVX-HX animals. Materials and Methods Animals used in this study were purchased from Zivic-Miller Laboratories, Allison Park, Pennsylvania, which also performed all surgical procedures. Immature Sprague Dawley rats (50 g body weight) were either ovariectomized (OVX), ovariectomized-hypophysectomized (OVX-HX) or ovariectomized-sham hypophysectomized

Immunotherapy of breast cancer, malignant melanoma, and acute leukemia with BCG: Prolongation of disease free interval and survival

Abstract: Results of immunotherapy with BCG in patients with malignant melanoma, breast cancer, and acute leukemia are described. The first study demonstrated that high doses of living BCG organisms (6×108 viable units) delivered by scarification in the upper arms and legs prolonged the disease-free interval and survival of 52 malignant melanoma patients with regional lymph node metastases compared to 218 comparable surgical control patients. Patients with trunk and extremity, but not head and neck melanoma, benefited from BCG, suggesting the importance of the delivery of BCG into the tumor-involved lymphatics.