Mammographic changes in postmenopausal women undergoing hormonal replacement therapy

Increasing numbers of postmenopausal women are undergoing hormonal replacement therapy. In this pictorial essay, we present the spectrum of mammographic changes seen in these women. These changes include symmetric and asymmetric increase in breast density, increase in size of fibroadenomas, and development or increase in size of cysts. Our examples illustrate that differentiation of hormonal therapy changes from neoplasm can occasionally be problematic when a focal density or mass is seen on mammograms. Furthermore, reexamination of published reports and our cases suggests that treatment with estrogen alone promotes enlargement of cysts and fibroadenomas, whereas treatment with a combination of estrogen and progesterone is more likely to be associated with diffuse increase in density.

Diagnosis of appendicitis: imaging findings in patients with atypical clinical features

Acute appendicitis is usually diagnosed on the basis of signs, symptoms, and results of simple laboratory tests. However, in patients with atypical clinical features, imaging studies play a significant role in preoperative diagnosis and determination of proper treatment. In this pictorial essay, we present a spectrum of imaging findings in patients whose clinical features were unusual because of the abnormal position of the appendix, the presence of other illnesses, or the presence of complications in children. Appendicitis was not initially considered on clinical presentation in any of our cases. In most cases, the correct diagnosis of appendicitis was made or, at least in retrospect, could have been made on the basis of imaging findings.

Lumbar extradural morphine and caudal extradural morphine for postoperative analgesia and their adverse effects

The efficacy of morphine by either lumbar extradural route or caudal extradural route and their adverse effects for postoperative analgesia were studied by comparing with the control group without morphine administration. 105 patients, 79 males and 26 females, aged 18 to 70 years, scheduled for hemorrhoidectomy surgery were selected. They were randomly assigned into three groups, i.e group I: without morphine use as control group (n = 35), group II: lumbar extradural morphine group (n = 35) and group III: caudal extradural morphine group (n = 35). Patients in group I received general anesthesia by face mask after induction by intravenous anesthetics and maintained with potent halogenated inhalation agents (isoflurane) through face mask. Patients in group II received lumbar extradural blockade through the L4-L5 intervertebral space, and those in group III received caudal extradural blockade through the sacrococcygeal junction (sacral hiatus) for intraoperative anesthesia and analgesia. Drugs included 0.5% bupivacaine 10ml + 2% xylocaine 10ml + 2mg morphine HCl + 0.1mg epinephrine were given either into the lumbar extradural space or into the caudal extradural space. No more narcotic has been given throughout the whole intraoperative course. All of these patients were followed up 24 hours later after the end of anesthesia. There were 11 patients (31.4%) in the control group, 26 patients (74.3%) in the lumbar extradural morphine group, and 25 patients (71.4%) in the caudal extradural morphine group who did not need additional narcotic for pain relief for more than 24 hours postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of selective tight-binding inhibitors of leukotriene A4 hydrolase

Leukotriene A4 hydrolase is a zinc-containing enzyme which exhibits both epoxide hydrolase and aminopeptidase activities. Since the enzyme product leukotriene B4 is an inflammatory mediator, it is of interest to develop selective inhibitors of leukotriene A4 hydrolase as potential antiinflammatory agents and as mechanistic probes. A systematic study on the enzyme specificity and the inhibition of its amidase activity with more than 30 synthetic inhibitors has led to the development of an alpha-keto-beta-amino ester (26) and a thioamine (27) as tight-binding, competitive type transition-state analog inhibitors of the aminopeptidase activity, with Ki values of 46 and 18 nM, respectively. Both compounds also inhibit the epoxide hydrolase activity, with the IC50 values of 1 microM and 0.1 microM for 26 and 27, respectively.

An antinociceptive effect of the intraperitoneal injection of nifedipine in rats, measured by tail-flick test

The tail-flick (TF) technique was used to assess the antinociceptive properties of nifedipine (NIF) given intraperitoneally (i.p.). First, the most suitable intensity of the noxious stimulus (temperature of the bulb) has been ascertained and used in the main study. Male Sprague-Dawley rats received NIF, dissolved in dimethyl sulfoxide (DMSO) at the doses of 0.0, 0.5, 2, 5, 10 and 15 mg/kg, or control with no injection. For the main study, the noxious stimulus was limited to 15 sec (cut-off time) and TF latencies were recorded up to 120 min. The antinociceptive response was expressed as the area under the curve for each rat and analyzed by one-way ANOVA. The antinociceptive response to the lower doses of NIF (0.5 and 2 mg/kg) did not differ from control (no injection) and DMSO alone. Significance was found at 5, 10 and 15 mg NIF with no difference among the doses. However, there was an increasing tendency of the mean values from 0.5 to 15 mg NIF resulting in a positive correlation. The correlation coefficient was 0.32483 (p = 0.015) and regression equation Y = (19.37) x dose + 1320. Our data suggest that spinal mechanisms are involved in NIF-induced antinociception.

Enzyme-catalyzed oligosaccharide synthesis

Cell-surface carbohydrates and their conjugates are involved in many types of molecular recognition. This review describes recent developments in enzyme-catalyzed oligosaccharide synthesis, with particular focus on glycosyltransferase and glycosidase reactions. With the increasing availability of glycosyltransferases via recombinant DNA technology, glycosyltransferase-catalyzed glycosylation with in situ regeneration of sugar nucleotides appears to be the most effective method for large-scale stereocontrolled oligosaccharide synthesis.

Enzymatic synthesis of (R) and (S) 1-deuterohexanol

This paper describes practical enzymatic procedures for the synthesis of (R) and (S) 1-deuterohexanol, a useful building block for chiral poly isocyanated liquid crystals. Alcohol dehydrogenases from horse liver and Pseudomonas catalyzed the reduction of hexanal with deuterated NAD (NADD) resulting in 50% and 89% yields of (R) and (S) 1-deuterohexanol, respectively. The deuterated cofactor was regenerated in situ by alcohol dehydrogenase catalyzed oxidation of ethanol-d6 or 2-propanol-d8. The (S) alcohol was also synthesized by the horse liver alcohol dehydrogenase reduction of 1-deuterohexanal, which was prepared chemically from hexanal. The yields of the reaction were greatly increased by the use of a biphasic system or with the immobilized enzyme in anhydrous organic solvents. Horse liver alcohol dehydrogenase was stabilized by immobilization on PAN or noncovalent entrapment on XAD resin.

New developments in enzymatic peptide synthesis

This review article describes new enzymatic methods developed for the efficient and irreversible synthesis of peptides based on native and modified proteases, and for the synthesis of polypeptides containing D- and/or unnatural amino acids. Potential opportunities for future developments in the field based on new enzymes, tailor-made catalytic antibodies, and on the technique of in vitro mutagenesis are also described.

[Prolongation of hyperbaric bupivacaine spinal anesthesia with clonidine]

Recent reports showed that spinal clonidine might provide satisfactory analgesia via a nonopioid mechanism. In this study we tried to evaluate the prolongation of analgesic effect of the hyperbaric bupivacaine spinal anesthesia with clonidine. 40 ASA class I-II patients scheduled for TURP were randomly classified into two groups of 20 each. In saline group, 3 ml 0.5% hyperbaric bupivacaine plus 1 ml normal saline was given. In clonidine group, 1 ml (0.15 mg) clonidine in addition to 3 ml 0.5% bupivacaine was given. All the patients were placed in lateral position and dural puncture was made at the L3-4 interspace using a 25G spinal needle. Assessment of the sensory blockade by "pinprick" and motor blockade by Bromage scale and measurement of blood pressure and heart rate were performed after injection. All data were analyzed by Student's t-test. A p value less than 0.05 was considered statistically significant. Our results showed that the highest sensory blockade level and the time required for maximal spread of the sensory blockade were of no significant difference between groups. The mean time for two segments regression and mean time for regression to L2 were significantly greater in the clonidine group than in the saline group (p less than 0.001). Motor blockade was also prolonged in the clonidine group than the clonidine group. Side effects such as hypotension (10 in clonidine gp vs 4 in saline gp) and bradycardia (4 clonidine gp vs 2 in saline gp) commonly occurred in the clonidine group, but all patients could be effectively treated with ephedrine and atropine respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequence and analysis of the rpoN sigma factor gene of rhizobium sp. strain NGR234, a primary coregulator of symbiosis

We report the nucleotide sequence of the rpoN gene from broad-host-range Rhizobium sp. strain NGR234 and analyze the encoded RPON protein, a sigma factor. Comparative analysis of the deduced amino acid sequence of RPON from NGR234 with sequences from other gram-negative bacteria identified a perfectly conserved RPON box unique to RPON sigma factors. Symbiotic regulatory phenotypes were defined for a site-directed internal deletion within the coding sequence of the rpoN gene of Rhizobium strain NGR234: they included quantitative nodulation kinetics on Vigna unguiculata and microscopic analysis of the Fix- determinate nodules of V. unguiculata and Macroptilium atropurpureum. RPON was a primary coregulator of nodulation and was implicated in establishment or maintenance of the plant-synthesized peribacteroid membrane. Phenotypes of rpoN in Rhizobium strain NGR234 could be grouped as symbiosis related, rather than simply pleiotropically physiological as in free-living bacteria such as Klebsiella pneumoniae and Pseudomonas putida.

Intrathecal morphine's effect on somatosensory impulses transmission-studied with posterior tibial nerve SSEP

In order to investigate neurotoxic potential of spinally injected morphine solution, somatosensory evoked potential (SSEP) was utilized to detect the change of electrophysiologic activity of spinal neurons after long term application of intrathecal morphine. Eight patients received intrathecal morphine injection regularly after CHEMO-PORT implantation were studied with posterior tibial nerve SSEP. Patients received SSEP examination just before and right after first episode of morphine injection and were followed up at 30 minutes, 60 minutes, 2 hours, 8 hours, and the 7th day and the third month of regularly injection. The results showed that there were no definite change of latencies and amplitudes of impulses generated by lumbar spinal cord (N22) and cortex (P40). We therefore suggest that electrophysiologic activities of spinal cord and cortex are not affected by chronic intrathecal morphine injection. Possible mechanism and proposed pathway of morphine's action were also discussed.

The depth to the epidural space

Two hundred and ten patients, 145 males and 65 females, aged 20 to 72 years old, ready to receive extracorporeal shock wave lithotripsy under epidural anesthesia were studied to evaluate if any correlation existed between body weight, body surface area, body mass index and body height and the depth to the epidural space. The mean value for the depth to the epidural space was 4.77 +/- 0.55 cm for males, 4.25 +/- 0.55 cm for females and the overall average was 4.61 +/- 0.60 cm. The range of the depth to the epidural space was 3.0-7.0 cm. Linear regression analysis revealed significant correlation between body weight, body surface area, body mass index, body height an the depth to the epidural space, in the order of BW greater than BSA greater than BMI greater than BH. It is concluded that body weight, body surface area, body mass index and body height affect the depth to the epidural space and play an important role in predicting the depth to the epidural space.

Molecular cloning, nucleotide sequence and fine-structural analysis of the Corynebacterium glutamicum fda gene: structural comparison of C. glutamicum fructose-1,6-biphosphate aldolase to class I and class II aldolases

The Corynebacterium glutamicum fda gene encoding fructose-1,6-biphosphate (FBP) aldolase has been isolated by complementation of an Escherichia coli mutant. The nucleotide sequence of a 3371 bp chromosomal fragment containing the C. glutamicum fda gene was determined. The N-terminal amino acid sequence of C. glutamicum FBP aldolase identified the correct initiation site for the fda gene, and a molecular weight of 37,092 was predicted for the fda polypeptide. S1 nuclease mapping identified the transcriptional start site, and Northern hybridization analysis indicated that the fda gene encodes a single 1.3 kb transcript. The primary structure of C. glutamicum FBP aldolase shows strong homology to class II FBP aldolases. Conservation of primary structure was observed between class I and class II aldolases, but several residues essential for catalytic activity in class I aldolases were absent from class II aldolases.

Enzymatic catalysts in organic synthesis

The synthetic value of enzymes is being increasingly recognized. With an understanding of enzyme-catalyzed reactions and the techniques now available for the low-cost production and rational alteration of enzymes and for the design of new enzymatic activities, biocatalytic synthesis should become one of the most valuable synthetic methods. The fundamental as well as the practical issues of this rapidly growing area are described and its impact on the technology pertaining to synthesis is considered.

Multiple host-specificity loci of the broad host-range Rhizobium sp. NGR234 selected using the widely compatible legume Vigna unguiculata

Specificity in legume-Rhizobium symbiosis depends on plant and rhizobial genes. As our objective was to study broad host-range determinants of rhizobia, we sought a legume and a Rhizobium with the lowest possible specificity. By inoculating 12 different legumes with a heterogenous collection of 35 fast-growing rhizobia, we found Rhizobium sp. NGR234 to be the Rhizobium and Vigna unguiculata to be the plant with the lowest specificities. Transfer of cloned fragments of the Sym-plasmid pNGR234a into heterologous rhizobia, screening for extension of host-range of the transconjugants to include V. unguiculata, and restriction mapping of the Hsn- and overlapping clones, proved that there were at least three distinct Hsn-regions (HsnI, II, and III) on pNGR234a. HsnI is located next to nodD, HsnII is linked to nifKDH and HsnIII to nodC. In addition to nodulation of Vigna, HsnI conferred upon the transconjugants the ability to nodulate Glycine max, Macroptilium atropurpureum and Psophocarpus tetragonolobus. All three Hsn-regions, when transferred to the appropriate recipients, induced root-hair-curling on M. atropurpureum. Hsn-region III was able to complement a mutation in the host-range gene nodH of R. meliloti strain 2011. Homology to "nod-box"-sequences could be shown only for the sub-clones containing HsnII and HsnIII, thus suggesting different regulation mechanisms for HsnI and HsnII/III.

S-adenosylmethionine: studies on chemical and enzymatic synthesis

Several methods for the chemical and enzymatic synthesis of (-)-S-adenosylmethionine (AdoMet) are described and compared. Studies on the effects of solvents, pH, methylating reagents, and KI on the coupling of sodium homocysteine thiolate and 5'-chloro-5'-deoxyadenosine led to an improved procedure for the synthesis of (+/-)-AdoMet. The use of trimethylsulfonium iodide as a methylating agent under acidic conditions results in a higher content of the desired (-)-epimer than does the use of CH3I. The enzymatic synthesis of (-)-AdoMet using AdoMet synthetase from an over-producing strain of Escherichia coli is demonstrated and the effect of product inhibition on preparative-scale synthesis is illustrated. A new HPLC technique for separation of the epimeric mixture of AdoMet, which allows small-scale preparation of optically pure AdoMet from the enzyme product, has been developed. With this HPLC technique, evidence that (-)-AdoMet is the sole epimer formed by the enzyme has been shown.

Identification of Rhizobium plasmid sequences involved in recognition of Psophocarpus, Vigna, and other legumes

Symbiotic DNA sequences involved in nodulation by Rhizobium must include genes responsible for recognizing homologous hosts. We sought these genes by mobilizing the symbiotic plasmid of a broad host-range Rhizobium MPIK3030 (= NGR234) that can nodulate Glycine max, Psophocarpus tetragonolobus, Vigna unguiculata, etc., into two Nod- Rhizobium mutants as well as into Agrobacterium tumefaciens. Subsequently, cosmid clones of pMPIK3030a were mobilized into Nod+ Rhizobium that cannot nodulate the chosen hosts. Nodule development was monitored by examining the ultrastructure of nodules formed by the transconjugants. pMPIK3030a could complement Nod- and Nif- deletions in R. leguminosarum and R. meliloti as well as enable A. tumefaciens to nodulate. Three non-overlapping sets of cosmids were found that conferred upon a slow-growing Rhizobium species, as well as on R. loti and R. meliloti, the ability to nodulate Psophocarpus and Vigna, thus pointing to the existence of three sets of host-specificity genes. Recipients harboring these hsn regions had truly broadened host-range since they could nodulate both their original hosts as well as MPIK3030 hosts.

A comparative study of effectiveness in plaque removal by Super Floss and waxed dental floss

The effectiveness of Super Floss and waxed dental floss as proximal surface cleansing agents was compared in 34 subjects. Each subject used 1 agent twice daily for 2 weeks followed by the other agent used with the same frequency and for the same period. The order in which the agents were used was selected at random. Plaque was stained by erythrosin, and a plaque index of Wolffe used. Super Floss was found to be superior to waxed dental floss in removing proximal plaque, but neither was 100% effective. Some plaque was present in 49.9% of the proximal surfaces when Super Floss had been used and on 54.7% when the waxed dental floss had been used. Both agents cleaned distal surfaces better than mesial surfaces, proximal surfaces of anterior teeth more effectively than those of posterior teeth, the coronal half of the proximal surfaces better than the apical half and the facial half more efficiently than the lingual half. No differences were found between maxillary teeth and mandibular teeth. Subjects used more lengths of Super Floss than of waxed dental floss, indicating its relative 'brittleness'. However, the majority of subjects preferred Super Floss, mainly because it was thicker and felt more abrasive.

Morphology of root nodules and nodule-like structures formed by Rhizobium and Agrobacterium strains containing a Rhizobium meliloti megaplasmid

We examined expression of the megaplasmid pRme41b of Rhizobium meliloti in two different Rhizobium sp. Strains and in Agrobacterium tumefaciens. Transfer of pRme41b into these bacteria was facilitated by insertion of a recombinant plasmid coding for mobilization functions of RP4 into the nif region (Kondorosi, A., E. Kondorosi, C.E. Pankhurst, W. J. Broughton, and Z. Banfalvi, 1982, Mol. Gen. Genet., 188:433-439). In all cases, transconjugants formed nodule-like structures on the roots of Medicago sativa. These structures were largely composed of meristematic cells but they were not invaded by bacteria. Bacteria were found only within infection threads in root hairs, and within intercellular spaces of the outermost cells of the structures. The donor strain of R. meliloti containing pAK11 or pAK12 in pRme41b initially produced nodules on M. sativa that did not fix nitrogen (Fix-). In these nodules, bacteria were released from infection threads into the host cells but they did not multiply appreciably. Any bacteroids formed degenerated prematurely. In some cases, however, reversion to a Fix+ phenotype occurred after 4 to 6 wk. Bacteria released into newly infected cells in these nodules showed normal development into bacteriods.

Carbamazepine therapy complicated by nodal bradycardia and water intoxication

A case is reported of water intoxication and cardiac conduction disturbances occurring as a late complication of carbamazepine therapy for trigeminal neuralgia. These uncommon but potentially hazardous complications of therapy are reported because of the wide use of carbamazepine as the agent of choice for trigeminal neuralgia and as an anticonvulsant.

Structure of acid protease from Endothia parasitica in cross-linked form at 2.45-A resolution

The structure of acid protease from Endothia parasitica in strongly cross-linked form is compared with that of the untreated protein at 2.45-a resolution. The only observed conformation change introduced by the cross-linking reaction is at the N terminal. Otherwise the two main chain structures are essentially identical. Approximately 2 molecules of the inhibitor, 1,2-epoxy-3-(p-nitrophenoxy)propane, are found to be incorporated into each protein molecule. They are covalently bound to the two aspartic residues at the active center.

Enzymic synthesis of opioid peptides

Protected opioid pentapeptides were synthesized by the papain-catalyzed condensation of small synthetic fragments. These peptides, free as well as protected, were identical with those prepared by the dicyclohexylcarbodiimide-1-hydroxybenzotriazole method.

Synthesis of a fully active snake venom cardiotoxin by fragment condensation on solid polymer

A polypeptide cardiotoxin containing 60 amino acids with 4 disulfide bonds has been synthesized by the "fragment solid-phase" method. The identity of the synthetic product with native cardiotoxin was established by chromatography on Sephadex G-50, carboxymethyl-cellulose column chromatography, thin layer chromatography, disc gel electrophoresis, amino acid analysis, end group analysis, peptide mapping, circular dichroism spectra, and four biological tests.

Purfication of synthetic cardiotoxin by affinity chromatography

A polypeptide containing 60 amino acids with 4 disulphide bonds, synthesized by the solid-phase method, was highly purifed by anticardiotoxin-Sepharose affinity chromatography following gel filtration and CM-cellulose chromatography. The identification of the final product as cardiotoxin was confirmed by thin-layer chromatography on silica gel, polyacrylamide gel electrophoresis, amino acid analysis, circular dichroism spectra, N-terminal analysis and four biological tests.

Renaturation of a reduced Taiwan cobra cardiotoxin

Refolding of a denatured protein obtained by reducing cardiotoxin from the Taiwan cobra with mercaptoethanol has been carried out in aqueous and non-aqueous solutions. Oxidation of the reduced protein in 0.05 M phosphate buffer (pH 7.2) resulted in isolating an active protein which showed, as compared to native cardiotoxin, identical conformation and biological activities such as lethality, antigenicity and muscle contracture inducing activity. On the other hand, the reduced protein was undergoing incorrect SS-pairing and several inactive products were formed in a mixture of 1,2-ethanediol and 1-propanol (1 : 1; v/v).