Genetic-epidemiologic study of omphalocele and gastroschisis: evidence for heterogeneity

On the basis of clinical manifestations, epidemiologic characteristics, and the presence of additional malformations, omphalocele (OM) and gastroschisis (GA) are considered casually and pathogenetically distinct abdominal wall defects. More than 50% of infants with OM have additional defects, but only about 15% of those with GA do. To evaluate whether there is heterogeneity between isolated and multiply affected cases of OM and GA, we analyzed epidemiologic characteristics and familial risks of major defects for 82 OM and 81 GA cases drawn from a population-based study in the Maryland-Washington, DC-Northern Virginia area and born from 1980 through June 1987. We examined year of birth, sex, race, and maternal age distributions after stratifying the infants into isolated and multiple defect groups. We found significant differences in maternal age between cases with isolated OM and GA, but not between cases with GA or OM who had other defects. Using regressive logistic models, we analyzed familial aggregation of birth defects among relatives of infants with OM and GA. An autosomal recessive model of inheritance was found to be the most parsimonious explanation for the families of infants with isolated OM or GA. However, for families of infants with multiple defects, a sporadic or nongenetic model fit best. These findings are not only useful for estimating familial risk of major birth defects, but they also suggest further heterogeneity of infants with OM and GA according to the presence of other malformations.

Palate teratogenicity and embryotoxicity of cyclosporin A in mice

Mice of the A/J and B10.A/SgSnJ strains were treated with 50 mg of cyclosporin A (CsA) per kg of body weight on day 12 of gestation. There were significantly more fetal resorptions in both the A/J and B10.A strain when treated with CsA than in controls treated with olive oil. A low frequency (7.6%) of isolated cleft palates were induced in the A/J strain, which was significantly greater than that observed in A/J mice treated with olive oil alone. No cleft palates were induced in B10.A, which suggests that any increase in susceptibility that was observed could not be attributed to H-2 linked genes.

Gastrointestinal involvement in L-tryptophan (L-Trp) associated eosinophilia-myalgia syndrome (EMS)

We report a 45-year-old female who had symptomatic gastrointestinal involvement, eosinophils in the cellular infiltrate, and who proved to have L-tryptophan-associated eosinophilia-myalgia syndrome. This case illustrates that gastrointestinal disease can be a major, seemingly primary clinical presentation in this syndrome, and that a drug history, specifically L-tryptophan, needs to be included in the differential diagnosis of "eosinophilic gastroenteritis."

Highly conserved hexamer, octamer and nonamer motifs are positive cis-regulatory elements of the wheat histone H3 gene

Base substitution mutations were introduced into the promoter region of the wheat histone H3 gene, and promoter activity was assayed in stably transformed sunflower calli or in wheat protoplasts transfected transiently. At least four positive regulatory elements, a hexamer motif (ACGTCA), two octamer(-like) motifs of a direct (CcCGGATC) and a reverse (aATCCGCG) form, and a nonamer motif (CATCCAACG) were identified within the -185 region of the H3 promoter. Analyses of the type I element (CCACGTCACCaATCCGCG) consisting of the hexamer and reverse-oriented octamer motifs, and which is conserved in other plant histone genes as well, predicted the presence of an octamer-binding protein(s).

Intercellular space is affected by the polysialic acid content of NCAM

We have previously proposed that polysialic acid (PSA), which is attached to NCAM on the cell surface, can serve to regulate a variety of cell-cell interactions. The present study provides evidence that hydrated PSA influences a sufficiently large volume at the cell surface to exert broad steric effects, and that the removal of PSA in fact causes a detectable change in intercellular space. Using F11 neuron/neuroblastoma hybrid cells as a model system, the measured density and size of PSA suggests that a substantial fraction of the space between two apposed cell surface membranes could be sterically influenced by the presence of PSA. Specific enzymatic removal of PSA, which is similar in magnitude to changes that occur in many tissues during normal development, caused about a 25% decrease in the distance between two apposed cells. By contrast, removal of both heparan sulfate and chondroitin sulfate from the cells had no effect on this parameter. It is proposed that such changes in membrane-membrane distance could serve to alter selectively the efficiency of encounter between complementary receptors on apposing cells, and explain at least in part the broad biological influences of PSA.

Purification of bovine interphotoreceptor retinoid-binding protein and its uveitogenicity in Lewis rats

Interphotoreceptor retinoid-binding protein, IRBP, not only functioning as a shuttle to carry the retinoid between photoreceptor cells and pigment epithelium, but also inducing experimental autoimmune uveoretinitis (EAU), was purified by ConA Sepharose affinity chromatography from the fractions containing IRBP obtained in the course of ion-exchange chromatography by which the bovine retinal S-antigen was purified. This much simplified method allows more rapid purification of the two kinds of protein. EAU was successfully induced with injecting 50 micrograms of IRBP emulsified with Freund's complete adjuvant into the right hind footpads of Lewis rats. It was characterized by panophthalmia or endophthalmia with the severest damage in the posterior retina. Lymphocytes, mononuclear and polymorphonuclear cells were found to be the inflammatory cells of infiltration, with lymphocytes being predominant.

Complex segregation analysis of nonsyndromic cleft lip and palate

This study was undertaken to examine the inheritance pattern of nonsyndromic cleft lip with or without cleft palate (CL/P). Complex segregation analysis using the unified model as in POINTER and the regressive model as in REGD programs were applied to analyze a midwestern U.S. Caucasian population of 79 families ascertained through a proband with CL/F. In REGD, the dominant or codominant Mendelian major locus models of inheritance were the most parsimonious fit. In POINTER, besides the Mendelian major locus model, the multifactorial threshold (MF/T) model and the mixed model were also consistent with the observed data. However, the high heritability parameter of .93 (SD .063) in the MF/T model suggests that any random exogenous factors are unlikely to be the underlying mechanisms, and the mixed model indicates that this high heritability is accounted for by a major dominant locus component. These findings indicate that the best explanation for the etiology of CL/P in this study population is a putative major locus associated with markedly decreased penetrance. Molecular studies may provide further insight into the genetic mechanism underlying CL/P.

Using log-linear models to test for associations among congenital malformations

Log-linear models can be used to test for pairwise associations and higher order interactions among anatomically distinct birth defects or congenital malformations. A log-linear model, including terms for every possible pairwise association among seven severe and easily detectable congenital malformations, was examined using data on 16,217 infants registered in the Metropolitan Atlanta Congenital Defects Program between 1968 and 1986. The resulting model showed clear patterns of strong association between some congenital malformations and not others, and the presence of 3-way interaction terms where the association between two malformations depended on the presence of a third. Examining a more parsimonious log-linear model showed overlapping patterns of pairwise association involving anal-rectal atresia and omphalocele, anal-rectal atresia and limb deficiency, and anal-rectal atresia and tracheaesophageal fistula. A second common pattern involved a triangular cluster with a hierarchical relationship among the three malformations (where there was a strong association between the first and second malformations and between the first and third malformations, but the association between the second and third was only seen in the absence of the first). Three such overlapping triangular clusters were identified from these data: neural tube defects, oral clefts, and omphalocele; neural tube defects, oral clefts, and limb deficiency; and limb deficiency, diaphragmatic hernia, and neural tube defects.(ABSTRACT TRUNCATED AT 250 WORDS)

[Longitudinal changes of serum specific antibodies in Lewis rats immunized with IRBP]

The serum antibodies specific to either interphotoreceptor retinoid-binding protein (IRBP) or retinal S-antigen were longitudinally determined in Lewis rats immunized with 50 x 10(-6)g of IRBP emulsified with complete Freund's adjuvant. To our knowledge, it is the first time to purify IRBP and to address the experiment with IRBP in China. It was shown that the antibody specific to IRBP appeared on the 7th day, followed by a gradual increase, and reached its peak on the 26th day after immunization. No antibody specific to S-antigen was found. The relation between anti-IRBP antibody and experimental autoimmune uveoretinitis (EAU) which occurred in the increasing phase of the antibody suggests that the humoral immunity may be implicated in the pathogenesis of EAU.

A detailed multipoint map of human chromosome 4 provides evidence for linkage heterogeneity and position-specific recombination rates

Utilizing the CEPH reference panel and genotypic data for 53 markers, we have constructed a 20-locus multipoint genetic map of human chromosome 4. New RFLPs are reported for four loci. The map integrates a high-resolution genetic map of 4p16 into a continuous map extending to 4q31 and an unlinked cluster of three loci at 4q35. The 20 linked markers form a continuous linkage group of 152 cM in males and 202 cM in females. Likely genetic locations are provided for 25 polymorphic anonymous sequences and 28 gene-specific RFLPs. The map was constructed employing the LINKAGE and CRIMAP computational methodologies to build the multipoint map via a stepwise algorithm. A detailed 10-point map of the 4p16 region constructed from the CEPH panel provides evidence for heterogeneity in the linkage maps constructed from families segregating for Huntington disease (HD). It additionally provides evidence for position-specific recombination frequencies in the telomeric region of 4p.

Ferritin in astrocytomas

Ferritin in 119 astrocytoma cases was studied by immunocytochemical PAP and immunogold silver staining (IGSS) methods. In 57% of the cases, ferritin was found in the cytoplasm of the tumor cells. The higher the differentiation of the tumor cells, the less ferritin they contained. Contrary to the reaction of glial fibrillary acidic protein (GFAP), the positive rate of ferritin in various types and grades of astrocytomas was inversely proportional to their degree of differentiation. Electron microscopic observation in 30 cases showed ferritin in the cell sap, cytocavity network, endoplasmic reticulum, Golgi apparatus and also in lysosomes. Some of the cases had extraordinary high level of ferritin in their blood serum.

[Anti-arrhythmia and vegetative nervous system effects of anisodamine]

Anisodamine (Ani) is an alkaloid first isolated in China from the root of Anisodus tanguticus. Ani 10, 15 mg.kg-1 i.v. markedly shortened the duration of arrhythmias induced by aconitine (10 micrograms.kg-1 i.v.) or by BaCl2 (2 mg.kg-1 i.v.) in anesthetized rats. Ani significantly effected on arrhythmias induced by early coronary artery ligation in rats by reducing total numbers of ectopic beats and shortening the duration of ventricular tachycardia and ventricular fibrillation 30 min after coronary ligation. The incidence of ventricular fibrillation of mice induced by chloroform were reduced from 100% to 20% and 10% by i.v. Ani 1 and 10 mg.kg-1 respectively. Ani 0.05, 0.25 mumol.L-1 prolonged the duration of neurologic refractory period of isolated guinea pig left atria and 10 mg.kg-1 i.v. had no effect on tachycardia induced by i.v. isoproterenol (0.01 mg.kg-1) but blocked the stimulation of nervi vagus. After i.v. Ani 15 mg.kg-1 P-P, P-R and QT-c intervals on the ECG were prolonged. Mean arterial pressure and diastolic pressure were reduced but systolic pressure was not effected.

Gastritis associated with infection by Helicobacter pylori in humans: geographical differences

Previous studies have indicated that infection rates of Helicobacter pylori are influenced by geographical factors. The present studies evaluate the characteristics of gastritis, associated with infection by H. pyrlori, and demonstrate relationships between different geographical locations and the extent of inflammatory cell accumulation in the gastric mucosa. Gastric biopsy specimens were obtained from patients infected with H. pylori at three clinical sites (two from North America and one from South America). Gastric inflammation was evaluated by quantitative histomorphometric techniques. Patients from South America had a more severe gastritis than did those from North America. Additionally, in South American patients the neutrophil was the predominant inflammatory cell type in the gastric mucosa. In contrast, the lymphocyte was the primary cell composing the mucosal infiltrate of infected North American subjects. Eosinophil infiltration into the mucosa correlated with the extent of mucosal atrophy; however, there were no differences between the North and South American patient populations in the extent of mucosal atrophy present in the specimens. We conclude that the characteristics (severity and cell type) of gastritis associated with infection by H. pylori are influenced by geographical factors that may be similar to those that modify infection rates for different geographical locations.

Transmucosal endoscopic needle aspiration: utility in the diagnosis of extrinsic malignant masses of the gastrointestinal tract

Transmucosal endoscopic needle aspiration established the diagnosis in three patients with extrinsic malignant compression of the GI tract. The technique had not been applied previously to the diagnosis of such lesions. Our initial experience shows it to be a safe and effective method.

Relationship between gastric inflammatory response and symptoms in patients infected with Helicobacter pylori

The relationship between the histologic severity of gastritis and associated symptoms was examined in 19 adult patients infected with Helicobacter pylori. At the time of gastrointestinal endoscopy, symptoms of dyspepsia were assessed by means of a linear analog scale. Gastric inflammation was quantitated with histomorphometric techniques. Symptoms such as epigastric pain, burping/belching, and nausea correlated with the degree of inflammation. These positive correlations suggest that the severity of the histologic gastritis contributes to the severity of symptoms. Therefore, utilization of a linear analog scale to assess symptoms may be a useful technique in evaluating the outcome of therapeutic trials of patients with symptomatic H. pylori infection.

[Serum antibodies to bovine retinal S antigen in the patients with uveitis and healthy subjects]

The antibodies to bovine S-Ag in sera were determined by ELISA in 43 patients with acute or chronic, anterior or panuveitis and in 32 healthy persons as controls. The results showed that the antibodies titers to bovine S-Ag in the patients with panuveitis were not different from those in the controls (P greater than 0.05). However the antibody titers to bovine S-Ag in the patients with anterior uveitis were significantly lower than those in the controls (0.01 less than P less than 0.05). It is suggested that there are naturally occurring antibodies to S-Ag in health persons. The relationship between antibodies to S-Ag and uveitis is discussed. It is indicated that natural antibodies to S-Ag may play a protective role in the healthy subjects.

[Effect of histamine on the action potential of the maxillary nerve in rabbits]

The significant enhancement of action potential as recorded from rabbit maxillary nerve with topically applied 1.0 mmol/L histamine on the nasal mucosa was completely blocked by pretreatment with diphenhydramine (H1 antagonist) but not with cimetidine (H2 antagonist). This fact gives new support to the concept that histamine exerts its pathological effect on nasal mucosa at least partly via an afferent nervous pathway of the trigeminal nerve.

Colonic lipomas: outcome of endoscopic removal

Colonic lipomas are benign adipose tumors which are usually submucosal. With the increase in the number of endoscopic procedures being performed, these tumors are often detected incidentally at colonoscopy. Although the risks of removing these tumors have been recognized, numerous reports have documented safe removal by snare electrocautery. We have reviewed the clinical outcome and the endoscopic and histopathologic features of seven lipomas that were endoscopically removed over a 5-year period. Four patients recovered uneventfully, while three patients (42.8%) developed colonic perforation after the polypectomy. In the latter group, the lipomas were significantly larger than they were in the patients who did not develop colonic perforation (1.9 +/- 0.4 and 4.2 +/- 0.7 cm, respectively; p = 0.048). Furthermore, the polypectomy specimens from those patients who developed perforation all contained significant muscularis propria. Lipomatous polyps that are identified at endoscopy to be greater than or equal to 2 cm in diameter and to have a limited pedicle are at the greatest risk for endoscopic perforation.

Role of nucleolar organiser regions in differentiating malignant from benign tumours of the colon

An argyrophilic technique (AgNOR) was applied to paraffin wax sections of 12 tubular adenomas, 17 villous adenomas with moderate and severe atypia, and 21 colonic adenocarcinomas. The range of the mean number of nucleolar organiser regions (NORS) per nucleus was 1.54-3.28 (99% CI 2.29-3.04) for tubular adenomas 3.07-4.36 (2.98-4.43), and 3.60-5.02 (3.74-4.69) for villous adenomas with moderate and severe atypia, respectively, and 5.53-9.33 (6.15-8.54) for highly differentiated adenocarcinomas. The number of AgNORs permitted differentiation among the three groups. The differences observed were significant. Malignant tumour cells were characterised by a large number of AgNORs which were small in size and showed a scattered distribution. Nuclei of tubular adenoma and villous adenoma with moderate atypia had only a small number of large sized AgNORs in a clustered distribution. It is suggested that this method distinguishes malignant epithelial cells from benign cells of colon, even those with severe atypia, and that it is a useful adjunct to diagnostic histopathology.

[Ultrastructural localization of ferritin in glioma]

In this study, we localized ferritin in 30 cases of glioma under electron microscope by using immunogold staining technique, and detected serum ferritin concentration in 25 patients with gliomas by the ELISA method. The results were as follows: Ferritin positives were mainly diffused in the cell sap, and the strongest immunostain was in the secondary lysosomes, while the endothelial reticulum and Golgi apparatus were rarely found to contain ferritin. Mitochondria and nucleus never had ferritin. Elevated level of serum ferritin was seen in glioma of grade II, III and IV, but the serum ferritin level of grade I remained normal. After resection of the tumor, serum ferritin decreased. These results suggested that the neoplastic cells of glioma could synthesize ferritin and release it to the exterior of the cells resulting in elevated serum ferritin, which may be helpful for clinical diagnosis, treatment and prognosis of glioma.

Cytotoxic triterpenes from a Chinese medicine, Goreishi

Bioactivity-guided fractionation of the methanol extract of Goreishi (the feces of Trogopterus xanthipes Milne-Edwards) afforded one new and three known cytotoxic triterpenes, namely, 3-O-cis-p-coumaroyltormentic acid, pomolic acid, 2 alpha-hydroxyursolic acid, and jacoumaric acid. In the course of this investigation, six additional compounds having no cytotoxic activity were isolated, namely, maslinic acid, 3-O-trans-p-coumaroylmaslinic acid, ursolic acid, tormentic acid, euscaphic acid, and a new triterpene, 3-O-trans-p-coumaroyltormentic acid. The structures of the new compounds were established on the basis of X-nucleus-proton correlation with fixed evolution time (XCORFE) and other spectroscopic evidence.

Predicting intrauterine growth retardation in sibships while considering maternal and infant covariates

Data on 6,210 full-term sibships (gestational age greater than 36 weeks) reconstructed from birth certificates registered in Maryland between 1980 and 1984 were used to study sibship aggregation and recurrence risk of intrauterine growth retardation (IUGR) while considering maternal and infant covariates. In this study, IUGR was defined as being below the 10th percentile for race-, sex-, and gestational-age-specific birth weight based on all births registered in Maryland during 1984. Maternal factors (race, age at delivery, marital status, amount of prenatal care, concurrent illnesses, and complications during pregnancy) and infant factors (congenital malformations and first born child or not) were used as covariates in a modified logistic regression model which allowed correlation among sibs. First-time mothers who were under age 30 years, unmarried, received too little prenatal care, or had any reported pregnancy complications were at high risk of delivering an infant with IUGR. Even given the effects of these risk factors, however, there was a significant correlation in risk among full sibs (r = .237 +/- .028), which, combined with information on risk factors, can be used to estimate sibling recurrence risk for IUGR.

Separation of Cucurbitacins by Overpressure Layer Chromatography from Hemsleya gigantha1

Mixtures of cucurbitacins were obtained from an ethanol extract of H. GIGANTHA tubers. Purification was achieved by using the over-pressure layer chromatographic (OPLC) technique to yield cucurbitacin-F, 23,24-dihydrocucurbitacin-F, cucurbitacin-F-25- O-acetate, and 23,24-dihydrocucurbitacin-F-25- O-acetate.

Problems of genetic model testing in early onset periodontitis

Familial aggregation of early onset or juvenile periodontitis (JP), a disorder that varies in expression and age of onset, has been recognized for some time. Autosomal recessive and X-linked inheritance patterns have been suggested, and one large pedigree has demonstrated autosomal dominant inheritance. The variability and age limitations in clinical phenotypic diagnosis present several problems to genetic analysis, because information on members of the youngest and older generations may be lost to the analysis. The purpose of the present study was to elucidate the genetic basis of JP by formal pedigree analysis and comparison of competing genetic models. Twenty-eight families were included, with general and specific autosomal models, and an X-linked model being compared. The autosomal recessive model provided the most parsimonious explanation of the data, and its likelihood was not significantly different from the more general model. Likelihoods for the sporadic (nongenetic) and X-linked models were considerably lower than the autosomal models. While comparison of genetic models suggests recessive inheritance of JP, the serious complications to pedigree analysis posed by limitations warns against acceptance of this conclusion, without more exhaustive evaluation of: (1) a more extensive collection of family data, (2) more complete investigation of the effects of age limitations on comparisons among competing models, and (3) elucidation of the importance of diagnosis and phenotype assignment of adults through past dental records.

Preoperative balloon occlusion of arteriovenous malformations

Many materials have been utilized to embolize cerebral arteriovenous malformations (AVMs) preoperatively. Specific vascular anatomy with large feeding vessels deep to the nidus or aneurysms within feeding arteries favor the use of detachable balloons over other embolic agents. Detachable balloons allow test occlusion of a vascular pedicle before permanent occlusion and can obliterate aneurysms in feeding arteries. We describe 36 feeder arterial balloon occlusions performed in 31 patients. Twenty-nine patients subsequently had surgical resection. None of the patients developed normal perfusion pressure breakthrough or required blood transfusions. The preoperative balloon occlusion was judged by the neurosurgeon to decrease significantly the difficulty in surgical resection of the malformation. The remaining 2 patients underwent embolization before radiosurgery. One patient had aneurysms in the feeding artery, which was balloon-occluded to diminish the risk of hemorrhage. There were two neurological deficits and three asymptomatic arterial dissections related to the balloon procedure. Balloon occlusion of feeding arterial pedicles in selected cerebral AVMs may be a valuable surgical adjunct.

Distribution of polyamines and their biosynthetic enzymes in intestinal adaptation

Ornithine decarboxylase (ODC) and the polyamines have been shown to be important for growth processes in the intestinal mucosa. The highest activity of ODC is found in the differentiated, nonproliferating villus-tip cells rather than in the rapidly proliferating undifferentiated crypt cells. During poststarvation refeeding and lactation, we now show that increases in ODC activity paralleled the time course of mucosal hyperplasia and thymidine incorporation. Increases in ODC (threefold) were similar in villus and crypt cells, and the villus-crypt gradient of decreasing ODC activity (40:1) was maintained. The activity of the other polyamine biosynthetic enzyme, S-adenosylmethionine decarboxylase (SDC), was highest in the crypt cells in the basal state and increased throughout the entire villus-crypt axis during refeeding and lactation, preserving a villus-crypt gradient opposite to that of ODC. During hyperplasia, all three polyamines increased. Putrescine was highest in the villus-tip cells, paralleling ODC activity, whereas spermidine and spermine were highest in the crypt cells and paralleled the distribution of SDC activity. Thus SDC activity and spermidine and spermine content may play a more important role than ODC and putrescine in regulation of intestinal mucosal proliferation. It is also possible that the threefold increases in the low levels of ODC in the crypt cells are adequate to trigger cell proliferation, whereas the higher ODC levels in villus cells may represent an association with the differentiation of the enterocytes.

Effect of maternal and infant covariates on sibship correlation in birth weight

Birth weight on 12,644 singleton infants from 6,196 sibships born in Maryland between 1980 and 1984 were used to estimate the effects of nine maternal and infant covariates on the sibship correlation in birth weight. Assuming a homogeneous correlation across all families, the estimated intraclass correlation was 0.4664 (+/- 0.0099). This high sibship correlation makes it possible to predict, with reasonable accuracy, the birth weight of a child given information on previous sibs, as well as covariates on the mother and/or infant pertinent to a given pregnancy. The reduction in variance associated with incorporating information on the nine covariates used here was approximately equal to that obtained by conditioning on a single previous sib. Testing for heterogeneity in correlation among different groups of families showed that a crude measure of parity (first live birth vs. other), time between births, mother's marital status, and maternal age at the birth of the last child significantly influenced the sibship correlation in birth weight.

Differential protective effects of varying degrees of hypoxia on the cytotoxicities of etoposide and bleomycin

Oxygen is thought to be involved both directly and indirectly in the mechanisms of action of several anti-cancer agents. We studied the effects of various oxygen concentrations on the cytotoxicities of the following drugs: bleomycin (BLM), etoposide (VP-16), doxorubicin (DOX), and mitomycin C (MMC). Human sarcoma cells, MESSA, were exposed to drug for 1 h at one of several oxygen concentrations: less than 1%, 2.5%, 5%, 21%, and 95%. Cytotoxicity was assessed by cellular incorporation of 3H-thymidine into DNA 5 days after drug exposure. Control experiments varying oxygen concentration without drugs demonstrated toxicity only at the highest concentration (95%). Three different responses of drug sensitivity to varying oxygen tensions were observed. BLM, which has been shown to utilize oxygen as a substrate in generating free radicals and producing DNA scission, demonstrated a progressive increase in cytotoxicity over the entire range of increasing oxygen concentrations. This is consistent with the model of a BLM-cation-oxygen complex and catalytic reduction of oxygen. VP-16, which also produces DNA strand breakage but by interaction with topoisomerase II, exhibited a threshold response. VP-16 toxicity was ameliorated by anoxic conditions (less than 1% O2), but not by oxygen concentrations of 2.5%-95%. The reason for this protective effect of anoxia with VP-16 is not clear. In contrast, acute anoxia had no effect on the cytotoxicities of DOX and MMC. We conclude that acute hypoxia protects cells from both BLM and VP-16 but that the nature of that protection is different. VP-16 toxicity is blunted only by severe anoxia, whereas BLM exhibits a dose response effect over the entire range of oxygen concentrations.

Genetic analysis of juvenile periodontitis in families ascertained through an affected proband

Data from 28 families ascertained through a proband with juvenile periodontitis were used to test a series of Mendelian models of inheritance that included both autosomal and X-linked transmission. There was strong evidence of familial aggregation of this progressive dental disease, and the best-fitting model was an autosomal recessive model. Because of the rather limited age range for expression of the disease in this situation, simulations were done, in a model-choice analysis using samples of this size, to assess the chance of mistaking an autosomal dominant disease (with masking of the affected phenotype outside a specified age range) for an autosomal recessive disease. While the rate of Type II error was fairly high (40%) when competing models in these simulations were compared, these data suggest that it is reasonable to infer that juvenile periodontitis is an autosomal recessive disorder.

Polyamines in intestinal and pancreatic adaptation

The intestinal mucosa is a rapidly proliferative tissue, with a highly dynamic cell population. Its total cellular mass is well controlled and can adapt, with hypo- or hyperplasia, to a wide variety of stimuli. Luminal nutrients, hormonal factors, and pancreatic and biliary secretions have all been implicated in the regulation of intestinal mucosal adaptation. Similarly, the same factors appear essential for the maintenance of exocrine pancreatic structure and function. The polyamines (putrescine, spermidine, and spermine) and the key enzyme controlling their synthesis (ornithine decarboxylase, ODC) are important for many cell growth processes, and may play important roles in intestinal and pancreatic adaptation. During intestinal adaptation in response to jejunectomy, lactation and pancreatico-biliary diversion (PBD), intestinal contents of ODC and polyamines are increased, paralleling increases in mucosal proliferative indices and DNA synthesis. With administration of the specific inhibitor of ODC (difluoromethylornithine, DFMO) the increases in ODC and polyamines are suppressed, and intestinal adaptation is abrogated. In pancreatic hyperplasia induced by caerulein, pancreatic polyamines are increased. With DFMO administration, caerulein-induced increases in pancreatic DNA synthesis were inhibited and pancreatic hypertrophy was partially suppressed. PBD-induced pancreatic hypertrophy, however, was not affected by DFMO. Thus, the role of polyamines in the adaptation of the pancreas, with a relatively quiescent proliferative status, is as yet undefined. It seems clear, however, that the induction of ODC and the resultant increase in polyamine biosynthesis are critical for the normal growth and especially for adaptive hyperplasia of the intestinal mucosa.

Kinetic changes in mucosal ornithine decarboxylase activity during azoxymethane-induced colonic carcinogenesis in the rat

In the azoxymethane (AOM)-treated rat model of colonic carcinogenesis, serial injections of the carcinogen lead to the eventual development of colonic tumors. However, the precise nature of carcinogenesis events in this commonly used model is not well defined, and the occurrence of classic initiation and promotion phases after serial injections is uncertain. Since increases in ornithine decarboxylase (ODC) activity have been associated with promotion in other tumor models, we measured mucosal ODC during AOM carcinogenesis in the rat. We gave male Fischer 344 rats ten weekly injections of AOM at a dose of 3 mg/kg (Wk 1-10) and measured colonic mucosal ODC activity during the entire 25-wk course. Colonic tumor incidence at Wk 25 was 0% in controls and 48% in AOM animals (15 of 31). Mucosal ODC in AOM animals was significantly increased over controls. The time course of changes in mucosal ODC was similar throughout the entire colon and differed generally in magnitude only. Distinct and prolonged increases in ODC activity occurred within 4 h of a single injection of carcinogen and persisted for at least 14 days. With a second AOM injection on Day 7, there was another distinct and prolonged increase in ODC over the persistently elevated activity. Over the entire 25 wk, the increase in ODC was distinctly biphasic, higher at Wk 2, 11, and 13 than at Wk 6, 17, 21, and 25. The findings indicate that AOM induces an increase in mucosal ODC during colonic carcinogenesis, and they suggest that this carcinogenesis model, with ten weekly injections of carcinogen, has the properties of a multistep process. The early peak in ODC might be associated with the early carcinogenesis (initiation) phase(s), and a subsequent second increase in ODC might be associated with late carcinogenesis (post-initiation or promotion) phase (s). These results strengthen the utility of the rat AOM colonic carcinogenesis model for further studies of the role of ODC and polyamine metabolism in neoplastic transformation.

The Vibrational-Spectrum of Sodium Propionate CH3CH2CO2Na, CH3CD2CO2Na, CD3CH2CO2Na and CD3CD2CO2Na in Aqueous-Solution and in the Solid-State

Infrared absorption spectra of aqueous solutions and KBr discs, reflection spectra of the diluted powders and of an oriented thin film, and Raman spectra of the powdered solids have been measured for CH3CH2CO2Na, CH3CD2CO2Na, CD3CH2CO2Na and CD3CD2CO2Na. Selective deuteration makes possible complete vibrational assignments in the CH and CD stretching regions where band overlap is extensive, but produces complicated changes in 1200- 800 cm-1 range. Average methyl CH stretching frequencies are higher in propionate ion than in paraffins in spite of the interposed methylene group. In the solids the CO stretching vibrations show more frequency splittings than expected for the number of molecules per unit cell (2), and some orientational disorder is indicated. The shape of the anions was not established; there is no evidence indicating the presence of more than one conformation in solution.

Polyamines and intestinal growth: absolute requirement for ODC activity in adaptation during lactation

Ornithine decarboxylase (ODC), through the regulation of polyamine biosynthesis, is important in cell proliferation and differentiation. We followed intestinal mucosal ODC activity in lactating Lewis rats and correlated the ODC levels with the characteristic small intestinal adaptive changes accompanying lactation. During the first 14 days of lactation, mucosal ODC activity increased, with the maximal increase on day 5 corresponding to the time of maximal morphological intestinal adaptation. In animals given the specific inhibitor of ODC, alpha-difluoromethylornithine (DFMO), intestinal mucosal ODC activity was inhibited, and intestinal adaptation was suppressed, with marked diminution of the adaptive increase in mucosal weight and thickness especially in crypt depth. Our results suggest that ODC activity plays an essential role in mucosal hyperplasia during the intestinal adaptation accompanying lactation, possibly through the stimulation of crypt cell proliferation.