Plasminogen activation activity of urokinase determined via a cascade enzymatic reaction system

A method for determining the plasminogen activation rate by urokinase via a cascade enzymatic reaction system is presented. A procedure of parameter estimation has been proposed for the determination of the activity of urokinase and the kinetic constants. Urokinase from urine has been successfully assayed through use of a plasminogen concentration lower than its saturating level. The methodology presented in this work may be adopted for the analysis of other cascade enzymatic reaction systems.

Enhanced phosphorylation of a 65 kDa protein is associated with rapid induction of stress proteins in 9L rat brain tumor cells

Induction of heat-shock proteins and glucose-regulated proteins in 9L rat brain tumor cells can be differentially elicited by sodium arsenite, cadmium chloride, zinc chloride, copper sulfate, sodium fluoride, and L-azetidine-2-carboxylic acid. The kinds of stress protein induced by the above chemicals varied considerably, mainly determined by the nature and the concentration of the chemicals, as well as the treatment protocols. In addition, at the concentrations where stress proteins can be induced, the above chemicals were able to suppress general protein synthesis and were cytotoxic. Enhanced phosphorylation of a protein with an apparent molecular weight of 65 kDa was detected during the induction of stress proteins except in azetidine treatments during which uptake of phosphate by the cells was impaired after prolonged incubation. The phosphate moiety on the 65 kDa phosphoprotein appeared to be alkaline-stable and two-dimensional gel electrophoresis revealed that the phosphoprotein resolved into four isoforms with isoelectric points ranging from 5.1 to 5.6. Enhanced phosphorylation of the same protein was also detected in heat-shocked and withangulatin A-treated 9L cells in which stress proteins were induced. It is suggested that this phosphoprotein may be a common target for heat stress response-stimulated phosphorylation and important in the further metabolic responses of the cell to stress.

Dietary risk factors for the incidence and recurrence of colorectal adenomatous polyps. A case-control study

OBJECTIVE

To investigate the association of dietary factors with the incidence and recurrence of colorectal adenomatous polyps.

DESIGN

Two case-control studies.

SETTING

Three university-based colonoscopy practices in New York City.

PATIENTS

For the incidence study, 286 patients with pathologically confirmed incident adenomatous polyps (162 men and 124 women) were compared with 480 controls (210 men and 270 women) with no current or previous neoplasia. For the recurrence study, 186 patients with recurrent polyps (130 men and 56 women) were compared with 330 controls (187 men and 143 women). These patients had a history of polyps but no current neoplasia.

MEASUREMENTS

Structured interviews using the Block food frequency questionnaire were conducted on all participants and were compared over quartiles of crude nutrient intake of total and saturated fat; fiber; protein; carbohydrates; carotene; vitamins A, C, and E; and various food groups. Data were adjusted for age, Quetelet index, and caloric intake by multiple logistic regression for men and women separately.

RESULTS

For incident polyps, elevated adjusted odds ratios (high to low quartile) for women were found for saturated fat (odds ratio, 2.3; 95% CI, 0.9 to 5.8) and the ratio of red meat to chicken and fish intake (odds ratio, 1.9; CI, 1.0 to 3.6). Protective associations were observed for fish and chicken (odds ratio, 0.6; CI, 0.3 to 1.2) and vitamin A intake (odds ratio, 0.4; CI, 0.2 to 0.9). Among women, recurrent polyps showed an association with total dietary fat (odds ratio, 4.4; CI, 1.0 to 19.5), saturated fat (odds ratio, 3.8; CI, 1.0 to 14.9; P = 0.15 for the trend), and total fiber (odds ratio, 0.2; CI, 0.1 to 0.5; P = 0.01) and a borderline association with carbohydrates (odds ratio, 0.3; CI, 0.1 to 1.3; P = 0.10). No consistent relations were observed for men, although increased caloric intake increased the risk for incidence and recurrence in both men and women.

CONCLUSIONS

These findings are consistent with previously described relations between diet and the incidence of colon cancer and suggest that, at least in women, dietary modification may be warranted in patients diagnosed with polyps.

Okadaic acid as an inducer of the 78-kDa glucose-regulated protein in 9L rat brain tumor cells

Okadaic acid (OA), a potent inhibitor of protein phosphatases 1 and 2A, has been widely used as a tool for unravelling the regulation of cellular metabolic processes involving protein phosphorylation/dephosphorylation. It has recently been found that OA can induce reversible hyperphosphorylation of vimentin and reorganization of intermediate filaments [Lee et al., J. Cell. Biochem. 49: 378-393, 1992]. We report here that OA specifically induced the synthesis of a 78-kDa protein, which was identified as the 78-kDa glucose-regulated protein (GRP78) by two-dimensional sodium dodecylsulfate-polyacrylamide gel electrophoresis and peptide mapping. The induction of GRP78 by OA was dose-dependent and reversible. For 7 h treatments, GRP78 synthesis was initially enhanced under 50 nM OA and became the highest (about 6-fold) under 200 nM OA. Meanwhile, under 200 nM OA, GRP78 synthesis was initially enhanced after 4 h and reached its maximal level (about 8-fold) after 15 h of treatment. Subsequently, upon removal of OA, the level of OA-induced GRP78 was reduced to basal level after 12 h of recovery. Induction of GRP78 synthesis by OA was abolished in cells pretreated with actinomycin D and cycloheximide, indicating that it was regulated at the transcriptional level and its induction required de novo protein synthesis. Furthermore, OA suppressed protein glycosylation, and the result lent support to the hypothesis that suppression of protein glycosylation may correlate with induction of GRP78 synthesis.

Mortality trends of pancreatic cancer: an affluent type of cancer in Taiwan

Interest in the increasing trends in pancreatic cancer mortality in Taiwan has recently emerged. The mortality data for pancreatic cancer in Taiwan from 1971 to 1988 for both sexes are presented to cast some light on the etiology of this ominous and yet little-known disease. A steeply increasing trend was found between 1975 and 1984 for both sexes; it dropped in 1985-86 and climbed again in 1987-88. The urban excess risks persisted in our study period of 18 years. Further study is mandatory to elucidate the etiological implications of dietary and other lifestyle changes on the magnitude of these rising secular trends and urban-rural gradients, particularly in the elderly, as well as the puzzling finding of cross-sectional drops in mortalities between 1985 and 1986. It is speculated that the drop may be associated with an economic recession that occurred in Taiwan between 1980 and 1981.

Hepatitis C and B viruses in hepatitis B surface antigen-negative hepatocellular carcinoma

The relative role of hepatitis C virus and hepatitis B virus in hepatitis B surface antigen-negative hepatocellular carcinoma was evaluated by polymerase chain reaction in 31 patients from Taiwan. Twenty-one were positive for antibody to hepatitis C virus (group 1) and 10 were negative (group 2). Of the group 1 patients, hepatitis C viral RNA was detected in the serum by polymerase chain reaction in 16 and in the liver tissue in 17, whereas hepatitis B viral DNA was found in the liver tissue in only 4, and none were found in the serum. In group 2 patients, hepatitis C viral RNA was detected in the serum of 1 and in the liver tissue of another. In contrast, hepatitis B viral DNA was found in the serum of 4 patients and in the liver tissues of 5. It was concluded that hepatitis C virus plays an important role in hepatocarcinogenesis in hepatitis B surface antigen-negative patients in Taiwan, especially in those who had antibody to hepatitis C virus; in those without antibody to hepatitis C virus, hepatitis B virus might still be associated with the development of hepatocellular carcinoma in a significant proportion of such patients.

Trends in mortality from diabetes mellitus in Taiwan, 1960-1988

The increasing trends of mortality from diabetes mellitus in Taiwan are becoming a public health concern. The age-adjusted death rate for diabetes was 3.7 per 100,000 population in 1960, which increased to 23.2 per 100,000 in 1988, a 6.3-fold increase over the past 30 years. The mortality data for diabetes in Taiwan from 1960 to 1988 for both sexes are presented and analysed using an age-period-cohort model in order to gain a better understanding of the possible determinants of the time trends of this disease. Steeply increasing trends which are particularly prominent in the elderly are found in the periods studied. Females and urban dwellers demonstrated greater risks for developing the disease. Significant cohort effects were found which peaked in the birth-cohort 1910-1917. This declined thereafter for females but has levelled since then for males. Further study is necessary to assess the aetiological implications of diet and urbanization on time trends of diabetes.

Induction of HSP70 is associated with vincristine resistance in heat-shocked 9L rat brain tumour cells

The most prominent cellular changes in heat-shock response are induction of HSPs synthesis and reorganisation of cytoskeleton. Vincristine was used as a tool to evaluate the integrity of microtubules in 9L rat brain tumour cells recovering from heat-shock treatment. Cells treated at 45 degrees C for 15 min and recovered under normal growing condition became resistant to vincristine-inflicted cytotoxicity and microtubule destruction. Among all HSPs, the level of HSP70 and the degree of vincristine resistance are best correlated. HSP70 and tubulin were found to be associated with each other as they were co-immunoprecipitated by either anti-HSP70 or anti-beta-tubulin monoclonal antibody. The current studies establish for the first time that HSP70 can complex with tubulin in cells and this association may stabilise the organisation of microtubules thus protect the heat-treated cells from vincristine damage. These findings are noteworthy in combining hyperthermia and chemotherapy in the management of malignant diseases.

NSR1 is required for pre-rRNA processing and for the proper maintenance of steady-state levels of ribosomal subunits

NSR1 is a yeast nuclear localization sequence-binding protein showing striking similarity in its domain structure to nucleolin. Cells lacking NSR1 are viable but have a severe growth defect. We show here that NSR1, like nucleolin, is involved in ribosome biogenesis. The nsr1 mutant is deficient in pre-rRNA processing such that the initial 35S pre-rRNA processing is blocked and 20S pre-rRNA is nearly absent. The reduced amount of 20S pre-rRNA leads to a shortage of 18S rRNA and is reflected in a change in the distribution of 60S and 40S ribosomal subunits; there is no free pool of 40S subunits, and the free pool of 60S subunits is greatly increased in size. The lack of free 40S subunits or the improper assembly of these subunits causes the nsr1 mutant to show sensitivity to the antibiotic paromomycin, which affects protein translation, at concentrations that do not affect the growth of the wild-type strain. Our data support the idea that NSR1 is involved in the proper assembly of pre-rRNA particles, possibly by bringing rRNA and ribosomal proteins together by virtue of its nuclear localization sequence-binding domain and multiple RNA recognition motifs. Alternatively, NSR1 may also act to regulate the nuclear entry of ribosomal proteins required for proper assembly of pre-rRNA particles.

Herpes simplex virus type 1 entry through a cascade of virus-cell interactions requires different roles of gD and gH in penetration

We examined the entry process of herpes simplex virus type 1 (HSV-1) by using infectious virus and previously characterized noninfectious viruses that can bind to cells but cannot penetrate as a result of inactivation of essential viral glycoprotein D (gD) or H (gH). After contact of infectious virus with the cell plasma membrane, discernible changes of the envelope and tegument could be seen by electron microscopy. Noninfectious virions were arrested at distinct steps in interactions with cells. Viruses inactivated by anti-gD neutralizing antibodies attached to cells but were arrested prior to initiation of a visible fusion bridge between the virus and cell. As judged from its increased sensitivity to elution, virus lacking gD was less stably bound to cells than was virus containing gD. Moreover, soluble gD could substantially reduce virus attachment when added to cells prior to or with the addition of virus. Virus inactivated by anti-gH neutralizing antibodies attached and could form a fusion bridge but did not show expansion of the fusion bridge or extensive rearrangement of the envelope and tegument. We propose a model for infectious entry of HSV-1 by a series of interactions between the virion envelope and the cell plasma membrane that trigger virion disassembly, membrane fusion, and capsid penetration. In this entry process, gD mediates a stable attachment that is likely required for penetration, and gH seems to participate in fusion initiation or expansion.

Reversible hyperphosphorylation and reorganization of vimentin intermediate filaments by okadaic acid in 9L rat brain tumor cells

Okadaic acid (OA), a protein phosphatase inhibitor, was found to induce hyperphosphorylation and reorganization of vimentin intermediate filaments in 9L rat brain tumor cells. The process was dose dependent. Vimentin phosphorylation was initially enhanced by 400 nM OA in 30 min and reached maximal level (about 26-fold) when cells were treated with 400 nM OA for 90 min. Upon removal of OA, dephosphorylation of the hyperphosphorylated vimentin was observed and the levels of phosphorylation returned to that of the controls after the cells recovered under normal growing conditions for 11 h. The phosphorylation and dephosphorylation of vimentin induced by OA concomitantly resulted in reversible reorganization of vimentin filaments and alteration of cell morphology. Cells rounded up as they were entering mitosis in the presence of OA and returned to normal appearance after 11 h of recovery. Immuno-staining with anti-vimentin antibody revealed that vimentin filaments were disassembled and clustered around the nucleus when the cells were treated with OA but subsequently returned to the filamentous states when OA was removed. Two-dimensional electrophoresis analysis further revealed that hyperphosphorylation of vimentin generated at least seven isoforms having different isoelectric points. Furthermore, the enhanced vimentin phosphorylation was accompanied by changes in the detergent-solubility of the protein. In untreated cells, the detergent-soluble and -insoluble vimentins were of equal amounts but the solubility could be increased when vimentins were hyperphosphorylated in the presence of OA. Taken together, the results indicated that OA could be involved in reversible hyperphosphorylation and reorganization of vimentin intermediate filaments, which may play an important role in the structure-function regulation of cytoskeleton in the cell.

Structure of a protected C3-C10 subunit of erythromycin and its C8 epimer

(1) (2S,3R,4R,6R)-3,4-O-Carbonyl-7,7-dimethylenedithio-2,4,6-trimet hylnonane-1,3,4-triol, C15H26O4S2, M(r) = 334.49, triclinic, P1, a = 6.460 (2), b = 8.917 (3), c = 15.616 (5) A, alpha = 83.60 (3), beta = 83.41 (2), gamma = 89.52 (2) degrees, V = 888.0 (5) A3, Z = 2, Dx = 1.25 g cm-3, mu = 2.980 cm-1, lambda (Mo K alpha) = 0.7107 A, F(000) = 360, T = 298 K, R = 0.0465 for 1832 reflections [Fo greater than or equal to 4 sigma (Fo)]. (2) (2S,3R,4R,6S)-3,4-O-Carbonyl-7,7-dimethylenedithio-2,4,6-trimet hylnonane-1,3,4-triol, C15H26O4S2, M(r) = 334.49, monoclinic, P21, a = 8.1849 (8), b = 8.9456 (14), c = 12.0258 (14) A, beta = 100.878 (8) degrees, V = 864.7 (2) A3, Z = 2, Dx = 1.28 g cm-3, mu = 3.060 cm-1, lambda (Mo K alpha) = 0.7107 A, F(000) = 360, T = 298 K, R = 0.0569 for 2001 reflections [Fo greater than or equal to 4 sigma (Fo)]. The two diastereomers differ in configuration at C6. For (1) there are two unique molecules in the unit cell. These two molecules differ in conformation by a rotation about the bond C7-C8. The molecules are hydrogen bonded into infinite chains along b. The hydroxyl O atom of molecule (2), O10', acts as both a donor and an acceptor in hydrogen-bonding interactions with the carbonyl O atom, O14, and the hydroxyl H atom, H10, of molecule (1).(ABSTRACT TRUNCATED AT 250 WORDS)

Acupuncture in the treatment of renal colic

A prospective randomized study was performed to compare the effect of acupuncture and intramuscular Avafortan injection in the treatment of renal colic. Our results showed that acupuncture is as effective in relieving renal colic as Avafortan but it had a more rapid analgesic onset (3.14 +/- 2.88 minutes versus 15.44 +/- 7.55 minutes, p less than 0.05). Of the patients in the Avafortan group 7 (43.8%) had side effects, including skin rash in 3, tachycardia in 2, drowsiness in 1 and facial flush in 1. No side effects were noted in the acupuncture group. During 2 hours of observation acupuncture and Avafortan seemed to be ineffective in promoting stone passage. However, patients receiving Avafortan treatment were more likely to have paralytic ileus. In summary, acupuncture can be a good alternative for the treatment of renal colic.

The association of breast cancer and colorectal cancer in men. An analysis of surveillance, epidemiology, and end results program data

There is a known increased risk for the co-occurrence of both breast cancer and colorectal cancer in the same women, presumably as a result of either shared reproductive hormonal or environmental risk factors. Using data from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute, the authors investigated whether there is a similar relationship between breast cancer, colorectal cancer, and prostate cancer in men. The observed-expected ratio was not significantly elevated for either colorectal cancer after breast cancer or for breast cancer after colorectal cancer in men. There was an increased incidence of prostate cancer after colorectal cancer, but this relationship was not present in the opposite direction and is believed to result from detection bias. There was an increased incidence of breast and colorectal cancer in women. These results suggest that the observed breast and colorectal cancer relationship in women may be a result of shared reproductive hormonal factors.

Induction of heat-shock response and alterations of protein phosphorylation by a novel topoisomerase II inhibitor, withangulatin A, in 9L rat brain tumor cells

Withangulatin A is a newly identified in vitro topoisomerase II inhibitor isolated from the Chinese antitumor herb Physalis angulata. In vivo, it was found to be cytotoxic, capable of suppressing general protein synthesis and of inducing the synthesis of a small set of proteins including those generated by heat-shock treatment. The 70 kDa protein generated by withangulatin A was unequivocally identified as the heat-shock protein 70 (HSP70) since both proteins migrated to the same position on two-dimensional polyacrylamide gels, could be recognized by a monoclonal antibody to human HSP70, and exhibited identical peptide maps. The induction of protein synthesis by withangulatin A was regulated at the transcriptional level since it was aborted in cells pre-treated with actinomycin D. However, the initiation of this process did not require de novo protein synthesis since it was not affected by cycloheximide. Other cellular effect of withangulatin A was alterations of protein phosphorylation including an enhancement of phosphorylation of a 65 kDa protein which was also detected in the heat-shocked cells. Moreover, this process was observed within 7.5 min after the initial heat treatment which is much faster than the onset of HSP synthesis. Therefore, increased phosphorylation of the 65 kDa protein may represent one of the earliest signals generated by both heat-shock and withangluatin A and may be involved in the upstream regulation of heat-shock response in cells.

Fluorescent tetradecanoylphorbol acetate: a novel probe of phorbol ester binding domains

Protein kinase C (PKC) has a prominent role in signal transduction of many bioactive substances. We synthesized the fluorescent derivative, phorbol-13-acetate-12-N-methyl-N-4-(N,N'-di(2-hydroxyethyl)amino)-7-n itr obenz-2-oxa-1,3-diazole-aminododecanoate (N-C12-Ac(13)) of 12-O-tetradecanoylphorbol-13-acetate (TPA) to monitor the location of phorbol ester binding sites and evaluate its potential use as a probe of PKC in viable cells. The excitation maximum wavelength of N-C12-Ac(13) is close to 488 nm, facilitating its use in argon-ion laser flow and imaging cytometry. When incubated with 100 nM N-C12-Ac(13) at 25 degrees C, P3HR-1 Burkitt lymphoma cells accumulated the dye rapidly, reaching maximum fluorescence within 25 min, 20-fold above autofluorescence. Addition of unlabeled TPA significantly decreased the fluorescence of N-C12-Ac(13) stained cells in a dose-dependent manner indicating specific displacement of the bound fluoroprobe. Competitive displacement of [3H]-phorbol-12,13-dibutyrate ([3H]-PBu2) from rat brain cytosol with N-C12-Ac(13) gave an apparent dissociation constant (Kd) of 11 nM. N-C12-Ac(13) possessed biological activity similar to TPA. Like TPA (final concentration 65 nM) N-C12-Ac(13), at a lower concentration (51 nM), induced expression of Epstein-Barr viral glycoprotein in P3HR-1 cells, differentiation of promyelocytic HL60 cells, and caused predicted changes in the mitotic cycle of histiocytic DD cells. Microspectrofluorometric images of single cells labeled with N-C12-Ac(13) showed bright fluorescence localized intracellularly and dim fluorescence in the nuclear region, consistent with dye binding mainly to cytoplasmic structures and/or organelles and being mostly excluded from the nucleus. Because of the high level of non-specific binding of N-C12-Ac(13), this probe is not ideal for visualizing PKC in intact cells, but would be a valuable fluoroprobe to investigate the kinetic properties of purified PKC. Also, knowledge gained from these studies allows us to predict structures of fluorescent phorbols likely to have less non-specific binding and, consequently, be potentially useful for monitoring PKC in viable cells.

Structure of a fully protected seco-erythronolide B acid derivative

(3S,4R,5S,6R,7R,9R,10S,11S,12S,13S,- 14R)-14-Benzyloxymethoxy-10,12-O-carbonyl-4-N- imidazolylcarbonyl-6,7-O-isopropylidene-3,5,7,9,11,- 13-hexamethylhexadec-1-ene-4,6,7,10,12,14-hexol, C38H56N2O9, Mr = 684.87, monoclinic, P2(1), a = 8.7302 (12), b = 15.597 (2), c = 14.463 (2) A, beta = 104.797 (10) degrees, V = 1904.1 (4) A3, Z = 2, Dx (198 K) = 1.19 g cm-3, mu = 0.7893 cm-1, Mo K alpha radiation, lambda = 0.7107 A, F(000) = 740, T = 198 K, R = 0.0301 for 3141 reflections [Fo greater than or equal to 4 sigma (Fo)]. The crystal structure was undertaken to determine the stereochemistry of the title compound. The molecule is folded on itself in such a way that the portion of the molecule from the phenyl ring at C44 and extending to C28 forms nearly a single turn of a right-handed screw. Large deviations from ideality for several Csp3-Csp3 bond angles are observed that are presumably due to intramolecular steric effects. The largest deviations are: C3-C4-C5 117.8 (2), C5-C6-C7 121.2 (2), C7-C8-C9 115.3 (2), C9-C10-C11 116.2 (2), C11-C12-C13 117.2 (2), C14-C15-C16 115.5 (3) degrees.

The NSR1 gene encodes a protein that specifically binds nuclear localization sequences and has two RNA recognition motifs

We previously identified a protein (p67) in the yeast, Saccharomyces cerevisiae, that specifically recognizes nuclear localization sequences. We report here the partial purification of p67, and the isolation, sequencing, and disruption of the gene (NSR1) encoding this protein. p67 was purified using an affinity column conjugated with a peptide containing the histone H2B nuclear localization sequence from yeast. Using antibodies against p67 we have cloned the gene for this protein. The protein encoded by the NSR1 gene recognizes the wild-type H2B nuclear localization sequence, but does not recognize a mutant H2B sequence that is incompetent for nuclear localization in vivo. Interestingly, the NSR1 protein has two RNA recognition motifs, as well as an acidic NH2 terminus containing a series of serine clusters, and a basic COOH terminus containing arg-gly repeats. We have confirmed the nuclear localization of p67 by immunofluorescence and found that a restricted portion of the nucleus is highlighted. We have also shown that NSR1 (p67) is required for normal cell growth.

Obesity and colorectal adenomatous polyps

Obesity has been investigated as a risk factor for various malignancies, including colon cancer. A case-control study was conducted on patients in three colonoscopy practices in New York City to determine possible risk factors for colorectal adenomatous polyps, a known precursor lesion for most cases of colorectal cancer. Among 301 case subjects with incidence adenomatous polyps (174 men and 127 women) and 506 control subjects (223 men and 283 women), an increased risk was observed with increasing body mass index in women (odds ratio 2.1, 95% confidence interval 1.1-4.0; for highest versus lowest quartile, linear trend P = .02). A nonsignificant trend was observed for men. The increased risk seen in women is consistent with prior observations regarding reproductive hormonal and dietary risk factors for colorectal cancer.

Age-period-cohort analysis of pancreatic cancer mortality in Taiwan, 1971-1986

Interest has recently emerged about the increasing trend of pancreatic cancer mortality in Taiwan, particularly in the elderly. The mortality data of pancreatic cancer over the period 1971-1986 for males and females aged 40-84 in Taiwan were analysed using a log-linear Poisson model to examine the effects of age, calendar period of death, and birth cohort. This age-period-cohort model provides a summary guide for the reading and interpretation of cancer mortality trends. Age is the strongest factor in predicting pancreatic cancer mortality according to the models; the oldest age group 80-84 years old has 14.5 times the risk of the youngest age group 40-44. The cohort effect is also of particular interest because the generation at greatest risk for pancreatic cancer in both sexes, is the one born between 1917 and 1926, and a declining trend is observed thereafter for more recent cohorts. Parameters of the period factor show no observable trend before 1975, followed by a significantly increasing risk in the subsequent time period. However, the drop of pancreatic cancer mortality over all age groups between 1985-86 is puzzling and a further study to monitor the secular trends in the following years is warranted.

Experimental study of the effect of prostaglandin administration on tooth movement--with particular emphasis on the relationship to the method of PGE1 administration

Recently, the mechanism of action of prostaglandins in promoting bone resorption has received wide attention. Prostaglandins are used in orthodontics to shorten the period of tooth movement. PGE1 was administered locally (5 micrograms/kg every 12 hours) and systemically (7.5 ng/kg/min) to rats to study the difference in the efficacy of the two methods of administration in accelerating bone resorption. The Waldo method was used on 72 Wistar rats (8 weeks old) for 5 days to induce mesial movement of the first molar. The body weight of the rats was measured every 12 hours from the start of the experiment. Tissues were examined in the mesial surface of the mesial root and in the interradicular septum between the linguomesial root and the linguodistal root of the upper first molar. The pressure side of the mesial surface of the mesial root was studied, as well as the pressure side of the interradicular septum. The results showed that decrease in body weight during the experiment was more prominent in the local administration group than in the systemic administration group. In both the group receiving PGE1 through local administration and the group receiving PGE1 through systemic administration, the numbers of osteoclasts and Howship's lacunae were markedly increased over those in the control groups. Moreover, compared with local administration, systemic administration of PGE1 had a more marked effect on bone resorption.

Identification and characterization of a nuclear localization sequence-binding protein in yeast

Nuclear proteins contain specific regions that are required for entry into the nucleus. Using ligand blotting, we have shown that a 67-kDa yeast nuclear envelope protein (p67) recognizes synthetic peptides containing the yeast histone H2B or simian virus 40 large tumor antigen nuclear localization sequence. Both free peptide and peptide conjugated to human serum albumin are recognized. The interaction between p67 and the nuclear localization sequences is specific; neither a mutant peptide that is incompetent for nuclear transport in vivo nor HSA can interact with p67 on blots. Moreover, although the wild-type peptide competes for binding to p67, the mutant peptides do not. p67 appears to be located at the nuclear envelope and is not present in other subcellular fractions. The nuclear localization sequence-binding protein is not extracted from the nuclear envelope with nonionic detergents and only partially extracted with high-salt buffer or 8 M urea, suggestive of a tight association with the nuclear envelope. Together our results are consistent with a role for p67 in nuclear transport.

Surgical treatment of salivary gland tumors

Two hundred fifteen patients (74.14%) with benign tumors and 75 patients (25.86%) with malignant tumors of the salivary glands were analyzed. One hundred eighty-five of these patients were followed for 1 to 20 years postoperatively. Of 150 benign tumors, recurrence was noted in 15 cases (9.75%). The 5-year recurrence rate was 7.82%. With the malignant tumors, recurrence was noted in 16 patients (51.6%). The 5-year recurrence rate was 27.75%.

The need for definitive therapy in the management of perforated gastric ulcers. Review of 202 cases

A retrospective study of 202 patients who presented to three Louisiana hospitals with perforated gastric ulcers was performed. Patients were treated surgically, medically, or were not treated. Only those patients with gastric ulcers were included in the study, not those with "channel ulcers" or peptic ulcers. The mortality rate of the 185 patients who were treated with operation was 18%. Of those patients treated nonoperatively, the mortality was 95% (one survivor). There was a definite difference in mortality among those patients treated with definitive operative procedures (11.3%) versus those patients treated with nondefinitive surgery (22.9%). This difference was consistent even in the presence of purulent exudate in the abdominal cavity and among those patients presenting in shock. The mortality among those patients who presented with a initial blood pressure of 90 mmHg or less were defined as being in shock, and the mortality in this subgroup was 52.8%. The mortality among those patients who had purulent fluid within the abdominal cavity was about the same, regardless of type of surgical procedure. The patients who underwent nondefinitive procedures required subsequent operative treatment in 25.7% of cases. Also noted was the lack of correlation between symptoms of ulcer disease and perforation. Those patients treated with definitive surgery (57%) and those treated with nondefinitive surgery (41%) reported no symptoms consistent with ulcer disease before operation.

Weight-bearing exercise training and lumbar bone mineral content in postmenopausal women

STUDY OBJECTIVE

To assess the effect of weight-bearing exercise training and subsequent detraining on lumbar bone mineral content in postmenopausal women.

DESIGN

Non-randomized, controlled, short-term (9 months) trial and long-term (22 months) exercise training and detraining (13 months).

SETTING

Section of applied physiology at a university school of medicine.

PATIENTS

Thirty-five healthy, sedentary postmenopausal women, 55 to 70 years old. All women completed the study. There was 90% compliance with exercise training.

INTERVENTIONS

All women were given calcium, 1500 mg daily. The exercise group did weight-bearing exercise (walking, jogging, stair climbing) at 70% to 90% of maximal oxygen uptake capacity for 50 to 60 min, 3 times weekly.

MEASUREMENTS AND MAIN RESULTS

Bone mineral content increased 5.2% (95% confidence interval [CI], 2.0% to 8.4%; P = 0.0037) above baseline after short-term training whereas there was no change (-1.4%) in the control group. After 22 months of exercise, bone mineral content was 6.1% (95% CI, 3.9% to 8.3% above baseline; P = 0.0001) in the long-term training group. After 13 months of decreased activity, bone mass was 1.1% above baseline in the detraining group.

CONCLUSIONS

Weight-bearing exercise led to significant increases above baseline in bone mineral content which were maintained with continued training in older, postmenopausal women. With reduced weight-bearing exercise, bone mass reverted to baseline levels. Further studies are needed to determine the threshold exercise prescription that will produce significant increases in bone mass.

Cecal diverticulitis: changing trends in management

Diagnosis of cecal diverticulitis remains a dilemma. Preoperatively it can mimic appendicitis, and intraoperatively the surgeon is confronted with an inflammatory mass that may masquerade as a neoplasm. We reviewed 18 cases of pathologically documented cecal diverticulitis and one case of solitary diverticulitis of the ascending colon. Ileocolonic resection was done in 16 patients, and three patients had local resection. Patients having local resection had greater morbidity and a significantly longer hospital stay. There were no deaths. We have found ileocolonic resection to be safe and effective, and we recommend it as the procedure of choice for cecal diverticulitis.

The effect of preoperative total parenteral nutrition on surgery outcomes

The effect of preoperative total parenteral nutrition (TPN) on morbidity and mortality was studied in medical records of discharged surgical patients. Patients were classified into two groups on the basis of their ability to meet established criteria for malnutrition and the use of preoperative or postoperative TPN. The control group consisted of 44 patients who received TPN only after surgery or for less than 5 days preoperatively. The experimental group consisted of 26 patients who received treatment for at least 5 days before surgery and/or after surgery. Nutrition parameters measured included serum albumin, total lymphocyte count, hemoglobin, weight, and percent weight loss. Major septic complications (MSC) considered were intra-abdominal sepsis, wound dehiscence, septicemia, and pneumonia. Other complications included respiratory failure, congestive heart failure, fistulas, urinary tract infection, shock, and death. The experimental group showed improvements after surgery in the nutritional parameters listed and had a lower incidence of morbidity and mortality. Deficits in serum albumin, total lymphocyte count, and weight losses greater than or equal to 10% have been significantly (p less than .01) linked to the incidence of MSC. MSC also has been more frequently noted among patients who did not have TPN prior to surgery and who died following surgery. Therefore, preoperative TPN does appear to make a difference in the outcome of surgery.

Surgical treatment of pleomorphic adenoma of the parotid gland: report of 110 cases

One hundred benign and ten malignant pleomorphic adenomas of the parotid gland were analyzed. Follow up ranged from two to 20 years. Of 54 cases of benign pleomorphic adenoma of the parotid gland, recurrence was noted in five cases (9.2%). The five-year recurrence rate was 17.2%. Of the six malignant pleomorphic adenoma, recurrence within the first ten years took place in four patients (66.6%).

Ileosigmoid knot

A 30-year-old black man had emergency surgery for an acute abdominal condition. Intraoperative diagnosis of an ileosigmoid knot was made and gangrenous bowel was resected, with ilioileostomy, reanastomosis, end colostomy, and Hartmann pouch.

Possible role of tensile stress in the etiology of cervical erosive lesions of teeth

A tensile stress hypothesis for the etiology of idiopathic cervical erosions of human teeth is presented. It is proposed that when occlusion is not ideal, lateral forces cause the teeth to bend. The tensile stresses created during bending disrupt the chemical bonds of the crystalline structures of enamel and dentin. Small molecules may enter between the crystals and prevent the reestablishment of the chemical bonds. As a result, the disrupted tooth structure is more susceptible to loss through dissolution and abrasion and results in the development of the typically wedge-shaped lesions. Patients with lesions typical of hundreds examined by the authors were presented to illustrate the concept. The possible consequences of the proposed hypothesis were discussed. The hypothetical conclusions made in this article will be tested by experimentation.

Surgical judgment in the management of abdominal stab wounds. Utilizing clinical criteria from a 10-year experience

A 10-year retrospective study of patients with stab wounds to the abdomen managed under a protocol of selective management has been performed. Patients were assessed on the basis of clinical presentation and physical examination, with minimal diagnostic studies. Peritoneal lavage was not utilized in the evaluation of the patients. Two hundred and nineteen such patients were identified. One hundred and eleven of these patients were treated nonoperatively. Ninety patients were treated by immediate laparotomy. Eighteen patients, initially observed, underwent delayed laparotomy. One patient, not explored despite clear-cut indications for laparotomy, died of sepsis, emphasizing the need for strict adherence to the stated protocol. The negative or unnecessary laparotomy rate was 7.8%. The false-negative examination rate was 5.5%. Overall mortality rate was 2.3%. The accuracy of careful clinical evaluation and observation is comparable to, or better than, any other method currently available to identify intra-abdominal injuries in patients with abdominal stab wounds. The study suggests that selective management of stab wounds of the abdomen may be safely practiced in a smaller community hospital.