Involvement of CircRNAs in regulating The "New Generation of Cancer Hallmarks": A Special Depiction on Hepatocellular Carcinoma

The concept of 'Hallmarks of Cancer' is an approach of reducing the enormous complexity of cancer to a set of guiding principles. As the underlying mechanism of cancer are portrayed, we find that we gain insight and additional aspects of the disease arise. The understanding of the tumor microenvironment (TME) brought a new dimension and led to the discovery of novel hallmarks such as senescent cells, non-mutational epigenetic reprogramming, polymorphic microbiomes and unlocked phenotypic plasticity. Circular RNAs (circRNAs) are single-stranded, covalently closed RNA molecules that are ubiquitous across all species. Recent studies on the circRNAs have highlighted their crucial function in regulating the formation of human malignancies through a range of biological processes. The primary goal of this review is to clarify the role of circRNAs in the most common form of liver cancer, hepatocellular carcinoma (HCC). This review also addressed the topic of how circRNAs affect HCC hallmarks, including the new generation hallmarks. Finally, the enormous applications that these rapidly expanding ncRNA molecules serve in the functional and molecular development of effective HCC diagnostic biomarkers and therapeutic targets.

Colorectal anticancer activity of a novel class of triazolic triarylmethane derivatives

Triarylmethanes and triazoles constitute privileged structures extensively used in drug discovery programs. In this work, 12 novel triarylmethanes linked to a triazole ring were designed, synthesized, and chemically characterized aiming to target colorectal cancer. The synthetic strategy for triarylmethanes mono- and bi-substituted by a functionalized triazole ring involved a 1,3-dipolar cycloaddition. A preliminary screening in human colorectal cancer cells (HT-29 and HCT116) and murine primary fibroblasts (L929) allowed the selection of the best candidate 9b based on its high inhibition of cancer cell proliferation with an IC50 of 11 μM on HT-29 and 14 μM on HCT116 and its non-cytotoxic effects on murine fibroblasts (<100 μM). A deep mechanistic study on various pathways showed that compound 9b induces caspase-3 cleavage, and its inhibitory effect on PARP activity is correlated with the increase of DNA fragmentation in cancer cells. Moreover, 9b induced apoptosis promoted by the inhibition of anti-apoptotic cell survival signaling pathways demonstrated via the downregulation of phosphorylated Akt and ERK proteins. Finally, the predicted binding modes of compounds 8c and 9b to five potential biological targets (i.e., AKT, ERK-1 and ERK-2, PARP and caspase-3) was evaluated using molecular modeling, and the predictions of the SuperPred webserver identified ERK2 as the most remarkable target. Also predicted in silico, 9b displayed appropriate drug-likeness and good absorption, distribution, metabolism and excretion (ADME) profiles.

Clinical characteristics and short-term outcomes of adult patients with urolithiasis: first report from Somalia

OBJECTIVE

This study aimed to investigate the data of adult patients admitted to the only tertiary care center in Somalia with the diagnosis of urolithiasis and to present the first report from this Sub-Saharan African country.

PATIENTS AND METHODS

This study was designed as a retrospective single-center study conducted in Somalia Turkiye Training and Research Hospital. Adult patients who received the diagnosis of urolithiasis and who were admitted to the urology department constituted the target population. Reviewed data included demographic parameters, stone features, type of surgical procedure, intraoperative and early postoperative complications, and inpatient mortality.

RESULTS

Overall, 3,680 patients were admitted during the study period. Among these, 620 (17%) patients were admitted due to urolithiasis. There was a significant male predominance with a male-to-female ratio of 3.4:1. Urinary bladder was the most common stone location (n=253, 40.8%), followed by the kidney (n=223, 35.9%). The mean stone diameter was 22.41 (5-64); most (39.4%) of the patients had a stone diameter between 20 and 30 mm, while 27.5% had stones with diameters between 10 and 20 mm. Minimally invasive procedures were the primary surgical modality in 52.6% (n=326) of our patients. However, 45.9% (n=285) of the patients underwent open surgery.

CONCLUSIONS

The rate of adults with urolithiasis is relatively high in Somalia, as in many other African countries, with a significant male predominance. Although open surgery is rarely used for treating adult urolithiasis in industrialized countries, this approach is still commonly used in Somalia, similar to other parts of Africa.

Our kidneys and teeth may be closer than we think: relationship between dental calculi and renal stone burden grading in a patient series from Somalia

OBJECTIVE

This study investigated the correlation between dental calculi grading and renal stone burden grading.

PATIENTS AND METHODS

This study was designed as an observational single-center study and included consecutive patients with radiologically confirmed renal stones at our center between January 2022 and July 2022. These patients were referred to the dentistry clinic for a dental examination to assess dental calculi and oral hygiene. Investigated parameters included demographic characteristics, renal stone location and diameter, urine pH, and dental evaluation findings (teeth brushing habits, oral hygiene, and dental calculi). Renal stone burden grade and dental calculi grade were calculated, and Spearman's rank-order correlation analysis was used for correlation analyses.

RESULTS

Overall, 204 patients were included. The mean patient age was 36.3±15.2. Approximately half of the patients (49.2%) had multiple stones. About 36% of the participants had high-grade dental calculi, while 29.4% had intermediate low-grade dental calculi. Oral hygiene was significantly associated with dental calculi grade (p<0.001). The dental calculi grade was positively and moderately correlated with the renal stone diameter (Spearman's rho=0.493, p<0.001). Among patients with a renal stone diameter greater than 20 mm, intermediate to high-grade dental calculi were found in 88.4%. This proportion was 49.1% for those with a renal stone diameter smaller than 20 mm.

CONCLUSIONS

Dentists should consider the presence of undiagnosed kidney stones in patients with especially intermediate or high-grade dental calculi. Urologists should know that patients with large and multiple kidney stones may have dental calculi.

Novel Set of Diarylmethanes to Target Colorectal Cancer: Synthesis, In Vitro and In Silico Studies

Distinctive structural, chemical, and physical properties make the diarylmethane scaffold an essential constituent of many active biomolecules nowadays used in pharmaceutical, agrochemical, and material sciences. In this work, 33 novel diarylmethane molecules aiming to target colorectal cancer were designed. Two series of functionalized olefinic and aryloxy diarylmethanes were synthesized and chemically characterized. The synthetic strategy of olefinic diarylmethanes involved a McMurry cross-coupling reaction as key step and the synthesis of aryloxy diarylmethanes included an O-arylation step. A preliminarily screening in human colorectal cancer cells (HT-29 and HCT116) and murine primary fibroblasts (L929) allowed the selection, for more detailed analyses, of the three best candidates (10a, 10b and 12a) based on their high inhibition of cancer cell proliferation and non-toxic effects on murine fibroblasts (<100 µM). The anticancer potential of these diarylmethane compounds was then assessed using apoptotic (phospho-p38) and anti-apoptotic (phospho-ERK, phospho-Akt) cell survival signaling pathways, by analyzing the DNA fragmentation capacity, and through the caspase-3 and PARP cleavage pro-apoptotic markers. Compound 12a (2-(1-(4-methoxyphenyl)-2-(4-(trifluoromethyl)phenyl) vinyl) pyridine, Z isomer) was found to be the most active molecule. The binding mode to five biological targets (i.e., AKT, ERK-1 and ERK-2, PARP, and caspase-3) was explored using molecular modeling, and AKT was identified as the most interesting target. Finally, compounds 10a, 10b and 12a were predicted to have appropriate drug-likeness and good Absorption, Distribution, Metabolism and Excretion (ADME) profiles.

Association between Vitamin D Deficiency and Vitamin D Receptor Gene Polymorphism (FokI-rs2228570) among Men with Anemia in Babylon Province, Iraq

Vitamin D or calciferol is a fat-soluble vitamin that has a unique feature of synthesizing in the body mainly by exposure to UV from the sunlight and then transformed to 25 (OH) D by the liver and finally to a vital form 1,25-dihydroxyvitamin D by the kidneys. Vitamin D receptor gene polymorphism (FokI-rs2228570) has been proposed as the major cause of anemia. The present study aimed to discover the association between vitamin D deficiency and vitamin D receptor gene polymorphism (FokI-rs2228570) in patients with anemia. A total of 120 men with anemia and no kidney disorders have been compared with 60 healthy controls in the present case-control study. A single nucleotide polymorphism (SNP) FokI-rs2228570 was detected by PCR and PCR-RFLP techniques. Levels of serum vitamin D, erythropoietin, and some biochemical parameters were detected by the ELISA assay technique. The mutant homozygous genotype ff was more frequent in patients with anemia (45%) than in the controls (15%). Also, the frequency of the f allele was associated with a significant decrease in the levels of vitamin D and hemoglobin in patients (0.62%); therefore, the mutant allele is a risk factor for developing anemia compared with genetic patterns FF and Ff. Vitamin D deficiency is common in those with anemia which is often associated with low hemoglobin and high levels of erythropoietin. Additionally, the genetic frequencies also affect the level of vitamin D which is indicated by low levels of mutant patterns (Ff, ff) in which patients suffer from severe anemia.

Physiochemical properties of palm olein

In the last decade, palm oil has ascended to the most advanced and widely used vegetable oil in the world. Triaclglycerol or triglycerides make up the majority of palm oil’s composition. Before being isolated, palm oil undergoes lipase-catalytic hydrolysis, which results in a high fatty acid and glyceride content, as well as a comparatively high fatty acid content.This study is about the physiochemistry of palm olein. This study to characterize palm oil using AOCS method for the determination of physicochemical parameters such as free fatty acids (FFA) is 0.3% to 0.5% is 0.6-1, acid value (AV) is 0.6-1, the result is saponification value (SV) is 210 mg KOH, for this research, 57.10 gI2 is the value of iodine (IV), the specific gravity is 0.9185 and the moisture content is 0.34%.

A possible role for ticks in the transmission of Madurella mycetomatis in a mycetoma-endemic village in Sudan

BACKGROUND

Currently there is a wide knowledge gap in our understanding of mycetoma epidemiological characteristics, including the infection route.

METHODS

A cross-sectional descriptive epidemiological study was carried out to determine the role of exposure to animals and insects such as ticks in the transmission of eumycetoma in two adjacent villages at eastern Sudan.

RESULTS

Significant differences were found between the two villages in the level of contact and exposure to animals and ticks, the percentages of people bitten by ticks, participation in cleaning animal pens and knowledge of the medical importance of ticks. In the village with a high mycetoma prevalence rate, there were high infestation rates of ticks in domestic animals. Hyalomma and Rhipicephalus species were the most prevalent species in houses with mycetoma patients and together they constituted 83% of the total collection. Pool screening of vectors for the detection of Madurella mycetomatis recombinant RNA genes showed one positive pool from Rhipicephalus evertsi following amplification of the universal fungal primer and one positive sample from Hyalomma rufipes following the use of a specific primer.

CONCLUSION

The findings indicate a possible role of ticks in the transmission of eumycetoma causative agents. However, further in-depth studies are needed to verify this.

The anti-inflammatory and analgesic properties of prosopis chilenses in rats

BACKGROUND

Prosopis chilensis is used locally in Sudan for inflammatory conditions of joints; however, literature lacks scientific evidence for anti-inflammatory effect of this plant.

AIMS

To evaluate anti-inflammatory and analgesic effects of prosopis chilenses.

MATERIAL AND METHODS

Edema inhibition percent (EI %) and hot plate method were used to evaluate anti-inflammatory and analgesic effects of Prosopis chilenses in Wistar albino rats. Anti-inflammatory and analgesic effects of Prosopis chilenses were compared to indomethacin and acetylsalicylic acid respectively.

RESULTS

Ethanolic extract of prosopis chilensis at a dose of 200 and 100mg/kg body weight achieved peak EI% (EI% = 96.1%) and (EI% = 94.4%) three and four hours after oral dosing respectively. The maximum EI% for indomethacin was 97.0% and was recorded after 4 hours following oral administration of the drug at a dose of 5 mg/kg body weight. Prosopis chilensis extracts at doses of 100 and 200 mg/kg body weight significantly increased the rats' response time to hot plate compared to acetylsalicylic acid at a dose rate of 100mg/kg body weight (P<0.05).

CONCLUSION

The current results suggest potential anti-inflammatory and analgesic effects of prosopis chilenses. Relevance of these effects to prosopis chilenses phy-to-constituents was discussed.

Using the job characteristics model to compare patient care assignment methods of nurses

The aim of this study was to use Hackman and Oldman's job characteristics model to compare 2 methods of patient care assignment as perceived by nurses in 12 inpatient units of Alexandria Main University Hospital. The job diagnostic survey was used to determine nurses' perceptions toward the components of the model in relation to their performance in utilizing the case and functional methods of patient care assignment. The jobs of intensive care unit nurses who utilized the case method were more enriched than those who utilized the functional method of assignment in the general care units, in terms of their perception scores towards all parts of the model (core job characteristics, critical psychological states, affective and personal outcomes, context satisfaction and individual growth-need strength).

Parvalbumin overexpression alters immune-mediated increases in intracellular calcium, and delays disease onset in a transgenic model of familial amyotrophic lateral sclerosis

Intracellular calcium is increased in vulnerable spinal motoneurons in immune-mediated as well as transgenic models of amyotrophic lateral sclerosis (ALS). To determine whether intracellular calcium levels are influenced by the calcium-binding protein parvalbumin, we developed transgenic mice overexpressing parvalbumin in spinal motoneurons. ALS immunoglobulins increased intracellular calcium and spontaneous transmitter release at motoneuron terminals in control animals, but not in parvalbumin overexpressing transgenic mice. Parvalbumin transgenic mice interbred with mutant SOD1 (mSOD1) transgenic mice, an animal model of familial ALS, had significantly reduced motoneuron loss, and had delayed disease onset (17%) and prolonged survival (11%) when compared with mice with only the mSOD1 transgene. These results affirm the importance of the calcium binding protein parvalbumin in altering calcium homeostasis in motoneurons. The increased motoneuron parvalbumin can significantly attenuate the immune-mediated increases in calcium and to a lesser extent compensate for the mSOD1-mediated 'toxic-gain-of-function' in transgenic mice.

Some pharmacological and toxicological studies on Balanites aegyptiaca bark

The aqueous extract of Balanites aegyptiaca bark, which is used in Sudanese folk medicine in the treatment of jaundice, was without effect when studied on rabbit intestine, rabbit aortic strip, rat stomach strip, rat uterus and rat phrenic nerve-diaphragm in a dose up to 10 mg/mL gut bath. In a larger dose (25 mg) the extract decreased significantly the contractility and the rate of the isolated perfused rabbit heart. Administration of the aqueous extract to biliary duct-ligated rats, showed a dose-dependent significant decrease in serum bilirubin level. The chronic and subchronic toxicity investigations indicate the safety of the aqueous extract at a dose level which showed a significant decrease in serum bilirubin level in experimental obstructive jaundice in rats.

Expression of calbindin-D28K in motoneuron hybrid cells after retroviral infection with calbindin-D28K cDNA prevents amyotrophic lateral sclerosis IgG-mediated cytotoxicity

Calbindin-D28K and/or parvalbumin appear to influence the selective vulnerability of motoneurons in amyotrophic lateral sclerosis (ALS). Their immunoreactivity is undetectable in motoneurons readily damaged in human ALS, and in differentiated motoneuron hybrid cells [ventral spinal cord (VSC 4.1 cells)] that undergo calcium-dependent apoptotic cell death in the presence of ALS immunoglobulins. To provide additional evidence for the role of calcium-binding proteins in motoneuron vulnerability, VSC 4.1 cells were infected with a retrovirus carrying calbindin-D28K cDNA under the control of the promoter of the phosphoglycerate kinase gene. Differentiated calbindin-D28K cDNA-infected cells expressed high calbindin-D28K and demonstrated increased resistance to ALS IgG-mediated toxicity. Treatment with calbindin-D28K antisense oligodeoxynucleotides, which significantly decreased calbindin-D28K expression, rendered these cells vulnerable again to ALS IgG toxicity.

Apoptosis induced by beta-N-oxalylamino-L-alanine on a motoneuron hybrid cell line

It has been suggested that beta-N-oxalylamino-L-alanine, a non-protein amino acid present in the Lathyrus Sativus seeds, may play a role in the etiopathogenesis of neurolathyrism, a toxic form of motor neuron disease clinically characterized by a severe spastic paraparesis. In order to investigate the mechanisms of beta-N-oxalylamino-L-alanine-mediated cell death, we studied the effect of this neurotoxin as well as other excitatory amino acids agonists on the growth and survival of motoneuron hybrid ventral spinal cord 4.1 cells. beta-N-oxalylamino-L-alanine was toxic to ventral spinal cord 4.1 cells in a concentration-dependent fashion (0.5-10 mM). Among the excitatory amino acids tested, only glutamate (1-10 mM), quisqualate (1 mM) and, with less extent, beta-N-methylamino-L-alanine (10 mM) induced a significant reduction of cell survival. The effect of Lathyrus Sativus neurotoxin was a slow process, becoming apparent only after 24-48 h of incubation. Interestingly, a mathematical analysis applied to the time course and dose curve of beta-N-oxalylamino-L-alanine toxicity suggested that even for very low concentrations of the amino acid it is theoretically possible to predict a time-dependent effect. The cell death was not blocked by antagonists of N-methyl-D-aspartate or non-N-methyl-D-aspartate receptors; aurintricarboxylic acid and alpha-tocopherol gave a partial protection; cysteine (1 mM) prevented the toxic effect of both Lathyrus Sativus neurotoxin and glutamate as well as quisqualate. Morphologically, in the presence of either beta-N-oxalylamino-L-alanine, glutamate or quisqualate, ventral spinal cord 4.1 cells showed apoptotic features also confirmed by ISEL technique and agarose gel electrophoresis of genomic DNA. Thus, our results suggest that in ventral spinal cord 4.1 motoneuron hybrid cells, in the absence of functional synaptic excitatory amino acid receptors, beta-N-oxalylamino-L-alanine induces cell degeneration through an apoptotic mechanism, possibly mediated by a block of cystine/glutamate Xc antiporter.

Cost-effectiveness of Helicobacter pylori eradication for the long-term management of duodenal ulcer in Canada

BACKGROUND

A 1994 National Institutes of Health consensus panel recommended that eradication of Helicobacter pylori should be first-line therapy for persons with duodenal ulcer.

OBJECTIVE

To assess the cost-effectiveness of H pylori eradication relative to alternative pharmacologic strategies in the long-term management of persons with confirmed duodenal ulcer.

METHODS

Decision analysis model to estimate expected costs and symptomatic ulcer recurrences during a 12-month period for three general treatment strategies: (1) immediate H pylori eradication; (2) H pylori eradication at first ulcer recurrence; and (3) continuous maintenance therapy with a histamine2 receptor antagonist (ranitidine hydrochloride). Two H pylori eradication therapies were compared: classic triple therapy and omeprazole plus amoxicillin. Probabilities for ulcer recurrence are by meta-analysis of published randomized trials. Health care resources used in the management of duodenal ulcer recurrence were by expert physician panel. All costs are in 1993 Canadian dollars.

RESULTS

Duodenal ulcer recurrence at 6 months (symptomatic and asymptomatic) with placebo was 65.4% and 12.8% with maintenance ranitidine therapy. Where eradication of H pylori was successful (85% of patients), the ulcer recurrence rate to 12 months was 3.7%. Treatment with ranitidine and triple therapy to eradicate H pylori on first presentation has an expected 1-year cost of $253 with 15 symptomatic recurrences per 100 patients; H pylori eradication by omeprazole plus amoxicillin had similar expected costs ($272) and outcomes (15 recurrences per 100 patients). Both of these early H pylori eradication strategies were dominant (less costly with same or better outcomes) over intermittent or continuous maintenance ranitidine therapy or delayed (after first recurrence) H pylori eradication.

CONCLUSION

Our analysis provides economic evidence in support of the recent guidance that for persons with duodenal ulcer, early attempts to eradicate H pylori are recommended.

Apoptotic cell death of a hybrid motoneuron cell line induced by immunoglobulins from patients with amyotrophic lateral sclerosis

Apoptotic cell death has recently been implicated in diseases involving nonproliferating, terminally differentiated cells such as neurons. Previous experiments have documented that immunoglobulins from patients with amyotrophic lateral sclerosis (ALS) can kill motoneuron-neuroblastoma hybrid cells [ventral spinal cord 4.1 (VSC 4.1)] by a calcium-dependent process. Here, we studied the mechanism of ALS IgG-induced cell death. In the presence of ALS IgG the VSC 4.1 cells undergo cell shrinkage and membrane blebbing, which are morphological features of apoptotic cell death. The damaged cells can be identified by in situ end labeling of nicked DNA and biochemically show laddering on agarose gel electrophoresis. This ALS IgG-triggered process is prevented by cycloheximide, aurintricarboxylic acid, and zinc sulfate. These data demonstrate that immunoglobulins from patients with ALS are able to induce apoptosis in motoneuron hybrid cells and provide a potential mechanism for motoneuron degeneration in human ALS.

The role of calcium-binding proteins in selective motoneuron vulnerability in amyotrophic lateral sclerosis

The factors contributing to selective motoneuron loss in amyotrophic lateral sclerosis (ALS) remain undefined. To investigate whether calcium-binding proteins contribute to selective motoneuron vulnerability in ALS, we compared calbindin-D28K and parvalbumin immunoreactivity in motoneuron populations in human ALS, and in a ventral spinal cord hybrid cell line selectively vulnerable to the cytotoxic effects of ALS IgG. In human autopsy specimens, immunoreactive calbindin-D28k and parvalbumin were absent in motoneuron populations lost early in ALS (i.e., cortical and spinal motoneurons, lower cranial nerve motoneurons), while motoneurons damaged late or infrequently in the disease (i.e., Onuf's nucleus motoneurons, oculomotor, trochlear, and abducens nerve neurons) expressed markedly higher levels of immunoreactive calbindin-D28K and/or parvalbumin. Motoneuron-neuroblastoma VSC 4.1 hybrid cells lost immunoreactive calbindin-D28k and parvalbumin following dibutyryl-cyclic AMP-induced differentiation and were killed by IgG from ALS patients. Undifferentiated calbindin/parvalbumin-reactive VSC 4.1 cells were not killed, nor were other cell lines expressing high levels of calbindin-D28K and parvalbumin immunoreactivity (substantia nigra-neuroblastoma hybrid cells and N18TG2 neuroblastoma parent cells). These studies suggest that decreased calbindin-D28K and parvalbumin immunoreactivity may help explain the selective vulnerability of motoneurons in ALS.

Cytogenetic studies of sodium fluoride in mice

The cytogenetic effects of sodium fluoride (NaF) were measured in mice following administration in the drinking water for 6 weeks. Bone fluoride levels were determined and showed a dose-related incorporation of fluoride. Micronuclei were measured in peripheral blood erythrocytes following 1 and 6 weeks of NaF administration. Bone marrow cell preparations were examined for the presence of chromosome aberrations following 6 weeks of treatment; metaphase and anaphase cells were examined. Anaphase cells were scored in three independent laboratories, two of which also scored metaphase cells from the same slides. No increases in micronuclei were seen in peripheral erythrocytes at either time point, and no increases in chromosome aberrations were seen in bone marrow cells when metaphase or anaphase cells were examined. A concurrent positive control, cyclophosphamide, produced significant increases in peripheral blood cell micronuclei and in chromosome aberrations in bone marrow cells in metaphase. No increases in aberrations were seen in the same cyclophosphamide-treated mice when anaphase cells were examined.

NSAID--induced gastroduodenal ulcers: exploring the silent dilemma

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective medications and are very commonly prescribed. They are used by a large proportion of elderly persons who are most prone to adverse events. NSAID gastropathy is the commonest side effect. The relative risk of adverse events is high, but the absolute risk for any individual patient is low. Individualizing the risk/benefit ratio would lead to cost effective care.

Isolation and characterization of a novel acetyl-CoA carboxylase kinase from rat liver

Acetyl-CoA carboxylase is regulated allosterically by citrate and covalently by a phosphorylation/dephosphorylation mechanism. We have isolated and purified from rat livers a novel kinase that phosphorylates and inactivates the carboxylase. This kinase is bound to the carboxylase and can be eluted in salt-rich solution. The native kinase exists as high molecular weight aggregates of a subunit that has a molecular weight of 40,000. The phosphorylation sites of the carboxylase were determined after tryptic and cyanogen bromide digestions of 32P-labeled carboxylase and separation of the peptides by various chromatographic procedures. Amino acid analyses of the phosphopeptides showed that the Ser77 and Ser1200 residues were the sites of phosphorylation. Treating the phosphorylated carboxylase with the Mn(2+)-dependent acetyl-CoA carboxylase phosphatase 2 removed the phosphate and reactivated the carboxylase. These results suggest that both this kinase and the acetyl-CoA carboxylase phosphatase 2 act at the same site(s) in the acetyl-CoA carboxylase molecule. Citrate dramatically inhibits the kinase-mediated phosphorylation of the carboxylase, suggesting that the allosteric modification and activation by citrate render the phosphorylation sites inaccessible to the kinase and therefore maintain high carboxylase activity. This observation indicates that there is a close interplay between the citrate effect on and phosphorylation of the carboxylase in regulating its activity.

The rationale of acid suppression in the treatment of acid-related disease

Acid-related disorders such as gastric and duodenal ulcers and gastro-oesophageal reflux disease have a high prevalence. Traditionally, acid suppression has proved to be the most effective means by which to heal these disorders, but relapse rates are high after cessation of treatment. Recently, Helicobacter pylori infection has been shown to modify several aspects of gastric function. Eradication of H. pylori infection virtually abolishes duodenal ulcer recurrence, implicating this organism in the pathogenesis of peptic ulcers and initiating a whole new strategy in the management of these acid-related disorders. More potent degrees of acid suppression result in faster healing. Moderate acid suppression, as occurs with H2-receptor antagonists, can heal just as many ulcers if treatment is continued for longer. The combination of proton pump inhibitors and antibiotics have successfully eradicated H. pylori in duodenal ulcer patients. Both H2-receptor antagonists and the proton pump inhibitors have satisfactory safety profiles. Due to their superiority in symptom relief, and in the healing of duodenal and gastric ulcers and erosive oesophagitis, and due to their ability to eradicate H. pylori infection in combination with antibiotics, the proton pump inhibitors will probably become accepted as first-line therapy for the treatment of acid-related diseases.

Childhood scleromyositis: an overlap syndrome associated with PM-Scl antibody

Fourteen patients with childhood scleromyositis followed from 1 to more than 10 years experienced concomitant sclerodermoid and dermatomyositis features, variably expressed at one time or another during the course of the disease. The most characteristic features were myalgia-myositis, arthralgia-arthritis, puffy, atrophic, sclerotic fingers, and Raynaud's phenomenon. This overlap syndrome was the most frequent sclerodermoid condition in children, differing from both systemic scleroderma and dermatomyositis. The course of the disease was protracted and rather benign, and PM-Scl antibody was an important diagnostic and prognostic marker. We present criteria for diagnosis of scleromyositis and its differentiation from systemic scleroderma, dermatomyositis, and Sharp overlap syndrome.

The value of routine pancreatic iso-amylase measurements in the diagnosis of pancreatitis

The value of serum pancreatic iso-amylase (Pi) measurements in the clinica diagnosis of pancreatitiss was assessed using a wheat inhibitor kit (Phadebas) and cellulose acetate membrane (CAM) electrophoresis. Wheat inhibition totally suppressed Pi activity in the sera of 3 healthy subjects with substantial Pi bands on electrophoresis. Reference intervals for Pi, salivary iso-amylase (Si) and total alpha-amylase were established from the sera of 61 healthy subjects using CAM electrophoresis. Sera from 47 patients were assayed. Twenty-three had proven acute pancreatitis (AP) and 24 had established chronic pancreatitis (CP). All patients with AP had elevated serum Pi levels. Fifteen of these patients had a low P3 index, which ranged between 55.8% and 82.6% with a mean of 67.1%. An index of less than 100% indicates the presence of P3 isoamylase. P3 iso-amylase only occurred in patients with AP. Thirteen of these 15 patients did not have Si in their serum. In 20 of 24 patients with CP, serum Pi was reduced and in 4 it was at the lower limit of the reference interval. Ten of these patients had raised Si levels. In 13 of these patients the total amylase level was normal; in 4 it was increased and in 7 it was reduced. It is concluded that raised Pi and the P3 index are useful in the diagnosis and monitoring of AP; reduced Pi is highly suggestive of CP, and the use of total alpha-amylase levels alone can be misleading.

Primary structure of the multifunctional alpha subunit protein of yeast fatty acid synthase derived from FAS2 gene sequence

The yeast fatty acid synthase consists of two multifunctional proteins, alpha and beta, arranged in an alpha 6 beta 6 complex with a molecular weight of 2.4 x 10(6). Five of the seven enzymatic activities reside in the beta subunit, while the remaining two activities, beta-ketoacyl synthase and beta-ketoacyl reductase, and the domain of the acyl carrier protein, with its prosthetic group, 4'-phosphopantetheine, are in the alpha subunit. The genes FAS1 and FAS2 coding for beta and alpha subunits, respectively, have been cloned and the sequence of FAS1 has been reported (Chirala, S. S., Kuziora, M. A., Spector, D. M., and Wakil, S. J. (1987) J. Biol. Chem. 262, 4231-4240). In this study, we present the nucleotide sequence of the FAS2 gene. The sequence has an open reading frame, coding for a protein of 1894 amino acids with a calculated molecular weight of 207,863. The location of the serine site of attachment of the prosthetic group of the acyl carrier protein domain and the active cysteine-SH site of beta-ketoacyl synthase have been identified at residues 180 and 1312, respectively, in the deduced amino acid sequence. A putative NADPH binding site of beta-ketoacyl reductase has been suggested at residue 1038 based on the similarities to the consensus amino acid sequences -Gly-Ser-Ala- of the pyridine nucleotide enzymes. We could not find any sequence homology in the 5' flanking sequence of the FAS1 and FAS2 genes that would suggest common regulatory function. However, in the sequence of these two genes there is an identical eight-base pair sequence TCATTATG at the translational initiation site suggesting that the subunit stoichiometry probably results from equal translational efficiency of the mRNAs of both FAS1 and FAS2 genes. The S1 endonuclease mapping suggests that there is a transcriptional initiation site at about 40 nucleotides upstream of the first ATG codon and a transcriptional termination site about 300 nucleotides downstream of the TAG stop codon. The gene does not contain introns as no intron consensus TACTAAC have been found in the sequence.

Protein modulase appears to be a complex of ferredoxin, ferredoxin/thioredoxin reductase, and thioredoxin

Protein modulase and ferredoxin/thioredoxin reductase are soluble proteins that have been suggested to catalyze the light-dependent modulation of enzyme activity in the stromal compartment of the chloroplast. Protein modulase is active in vitro without additional ferredoxin and thioredoxin, whereas ferredoxin/thioredoxin reductase requires additional ferredoxin and thioredoxin. We hypothesize that protein modulase is a complex protein composed of ferredoxin/thioredoxin reductase, ferredoxin, and thioredoxin. In reconstituted chloroplast systems, antiserum directed against ferredoxin, at concentrations sufficient to inhibit the photoreduction of NADP, had no effect on light modulation. Antiserum directed against thioredoxin gave variable results: one batch of polyclonal antibodies inhibited light modulation, another was stimulatory, and another was without effect. These results suggest that the ferredoxin and thioredoxin active in light modulation are not free in solution. Furthermore, molecular sieve chromatography of stromal proteins results in the elution of four species that catalyze light modulation. Based on whether or not ferredoxin and/or thioredoxin must be added for activity, these four species have been tentatively identified as protein modulase, a complex of ferredoxin/thioredoxin reductase and ferredoxin, a complex of ferredoxin/thioredoxin reductase and thioredoxin, and ferredoxin/thioredoxin reductase. That is, the four correspond to all the possible combinations of ferredoxin, ferredoxin/thioredoxin reductase, and thioredoxin. We suggest that buffer ionic strength affects the interactions among these proteins and in part determines the fate of the protein modulase complex in vitro.

Band 3 tyrosine kinase. Association with the human erythrocyte membrane

Band 3, the anion transport protein of the human erythrocyte membrane, is known to be phosphorylated in ghosts at tyrosine 8. The band 3 tyrosine kinase is now shown to be associated with the Triton X-100 insoluble membrane skeleton but not with spectrin or actin. The kinase was reversibly dissociated from membranes and skeletons at elevated ionic strength (50% at mu = 0.15). The binding capacity of the membranes exceeded their native complement of the kinase by at least 60-fold. Prior removal of all peripheral proteins from the cytoplasmic surface of inside-out vesicles did not diminish the rebinding of the kinase, whereas prior removal of band 3 and other accessory proteins from skeletons abolished the rebinding of the kinase. An excess of glyceraldehyde-3-P dehydrogenase, which binds to band 3 in the region of the phosphate acceptor tyrosine 8, both inhibited the phosphorylation of band 3 and released the kinase into solution. Soluble 40/45-kDa chymotryptic fragments from the cytoplasmic pole of band 3 were phosphorylated at least as well as membranous band 3 and caused the release of the kinase from Triton-extracted skeletons. Membrane skeletons lacked most of the membrane band 3, but retained most of the kinase. Nevertheless, the band 3 population solubilized by Triton X-100 from prelabeled ghosts was as well phosphorylated as the population of band 3 retained by the skeletons. Furthermore, the fraction of band 3 not associated with the skeletons following Triton X-100 extraction was a good substrate for the solubilized kinase. We conclude that this tyrosine kinase is reversibly bound to the membrane through electrostatic interactions with the polyacidic sequence surrounding the phosphate accepting tyrosine 8 on band 3. The kinase appears to be preferentially linked to those band 3 molecules associated with the membrane skeleton, but it impartially phosphorylates band 3 species free in the bilayer as well as band 3 fragments in solution. The resemblance of its plasma membrane binding behavior to that of tyrosine kinases of certain viruses causing oncogenic transformation is discussed.

Haematological and biochemical changes in buffalo calves inoculated with Sarcocystis fusiformis from cats

Two groups of buffalo calves were infected with Sarcocystis fusiformis sporocysts. Animals of the first group received each 5 X 10(5) sporocysts, those of the second group 5 million sporocysts. All calves were clinically normal during 6 weeks after infection. Minor changes were observed in the blood cytology, serum alkaline phosphatase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, total proteins, urea and glucose of infected buffalo calves.

Light Activation of Purified Aconitase by Washed Thylakoid Membranes of Pea (Pisum sativum L.)

Purified aconitase, an iron-sulfur protein, from either beef heart mitochondria or pig heart can be activated fully by light when combined with washed thylakoid membranes from pea (Pisum sativum L.) chloroplasts. The light activation of the enzyme does not require any other additive or cofactor and is sensitive to 3-(3,4-dichlorophenyl)-1,1-dimethyl urea, 2,6-dichlorophenol-indophenol, ferricyanide, and methyl viologen, indicating that the photoelectron transport system of the thylakoid membranes, and in particular, photosystem I, is involved in the process of activation. Light activation of the enzyme is also markedly inhibited when the thylakoid membranes are treated with sulfite or arsenite, and abolished totally when the membranes are treated with Zwittergent, suggesting that the light effect mediator involved in the light modulation of chloroplastic enzymes mediates the activation of purified aconitase also.

Proteins, lipids, lipoproteins and some enzyme characterizations of the venom extract from the centipede Scolopendra morsitans

Some components of Scolopendra morsitans venom extract were characterized using disc gel electrophoresis and thin layer chromatography. Its protein component was separated into 13 anodal bands and a slowly moving cathodal band. The extract showed three slowly moving lipoprotein bands and the lipid components included phospholipids, cholesterol, free fatty acids, triglycerides, cholesterol esters and squalene. The enzymes esterase, acid and alkaline phosphatases and amino acid naphthylamidase were present in multiple forms. Acid phosphatase isoenzymes were of low activity.

Cell-free synthesis of active ribulose-1,5-bisphosphate carboxylase in the mesophyll chloroplasts of Sorghum vulgare

Chloroplast and whole leaf cell RNA from Vigna sinensis, a C3 plant were used as exogenous templates for translation in a cell-free light-dependent system of isolated chloroplasts from Sorghum vulgare, a C4-type plant. Analysis of immunoprecipitates of the translated products with the total cellular RNA on sodium dodecyl sulfate polyacrylamide gels revealed the synthesis of both the subunits of ribulose-1,5-bisphosphate carboxylase. Similar analysis of the product translated with the RNA from Vigna chloroplasts, indicated the synthesis of only the large subunit of the carboxylase. Apparently the chloroplast protein synthetic machinery is capable of translating the mRNA for the smaller subunit of this protein as well, which is known to be translated in the cytoplasmic ribosomal system. Sufficient quantities of ribulose-1,5-bisphosphate carboxylase were synthesised in vitro in the preincubated chloroplast system with the whole cell RNA from the C3 plant to assay the ribulose 1,5-bisphosphate-dependent carboxylation. The newly synthesised protein in the cell-free system is identical in many ways to the native enzyme including the Mg2+ concentration-dependent shift in pH optima towards neutral side. It is specifically inhibited by anti-native ribulose-1,5-bisphosphate carboxylase and pyridoxal 5'-phosphate.

A possible mechanism of ammonium ion regulation of photosynthetic carbon flow in higher plants

Addition of NH(4) (+) to the photosynthesizing leaf cells of Dolichos lab lab L. var. Lignosis Prain and leaf discs of Vigna sinensis L. savi ex Hassk caused a significant increase in the flow of photosynthetic carbon toward amino acids with a concomitant decrease toward sugars without affecting the over-all photosynthetic rate. Similar diversion of photosynthetic carbon away from sugars was also observed in the photosynthesizing isolated chloroplasts of V. sinensis, but the latter differed in that they accumulated organic acids rather than amino acids. In an effort to understand the mechanism of NH(4) (+)-mediated regulation, the specific and total activities of NAD(P)-glutamate dehydrogenase, glutamine synthetase, pyruvate kinase, alkaline fructose 1,6-bisphosphatase, and NAD(P)-glyceraldehyde-3-phosphate dehydrogenase of the cells of D. lab lab were checked but none was affected by the added ammonium salts even after prolonged incubation. At certain concentrations, ammonium ions abolished the light activation of NADP-glyceraldehyde-3-phosphate dehydrogenase and alkaline fructose 1,6-bisphosphatase in isolated chloroplasts from dark-adapted Vigna leaves without interfering with the basal dark activity of these enzymes. Based on these observations, a possible mechanism of action of NH(4) (+) in regulating the photosynthetic carbon flow is postulated.

Ultrastructure of glycogen-rich clear cell carcinoma of the palate

Tissues from four local recurrences of a palatal tumor and regional lymph node metastases were studied by light microscopy while ultrastructural observations were made on the most recent tumor. The tumor was composed of solid sheets, clumps, and small nests of polyhedral epithelial cells with well-defined cell boundaries, clear cytoplasm, and cellular pleomorphism. Histochemical stains indicated the presence of abundant intracellular glycogen deposits in all tumor specimens examined. Ultrastructural observations revealed solid sheets of epithelial cells which lacked both surrounding basement lamina and ductal arrangements. The cytoplasm of the tumor cells was filled with beta glycogen deposits and contained scattered bundles of tonofilaments and scant organelles. The transition between the glycogen-rich tumor cells and surface epithelium showed intervening cells which contained diffusely dispersed ribosomes and small amounts of glycogen. The tumor probably originated from surface epithelium.