DNA damage evaluation of hydroxyapatite on fibroblast cell L929 using the single cell gel electrophoresis assay

Hydroxyapatite is the main component of the bone which is a potential biomaterial substance that can be applied in orthopaedics. In this study, the biocompatibility of this biomaterial was assessed using an in vitro technique. The cytotoxicity and genotoxicity effect of HA2 and HA3 against L929 fibroblast cell was evaluated using the MTT Assay and Alkaline Comet Assay respectively. Both HA2 and HA3 compound showed low cytotoxicity effect as determined using MTT Assay. Cells viability following 72 hours incubation at maximum concentration of both HA2 and HA3 (200 mg/ml) were 75.3 +/- 8.8% and 86.7 +/- 13.1% respectively. However, the cytotoxicity effect of ZnSO4.7H2O as a positive control showed an IC50 values of 46 mg/ml (160 microM). On the other hand, both HA2 and HA3 compound showed a slight genotoxicity effect as determined using the Alkaline Comet Assay following incubation at the concentration 200 mg/ml for 72 hours. This assay has been widely used in genetic toxicology to detect DNA strand breaks and alkali-labile site. The percentage of the cells with DNA damage for both substance was 27.7 +/- 1.3% and 15.6 +/- 1.0% for HA2 and HA3 respectively. Incubation of the cells for 24 hours with 38 microg/ml (IC25) of positive control showed an increase in percentage of cells with DNA damage (67.5 +/- 0.7%). In conclusion, our study indicated that both hydroxyapatite compounds showed a good biocompatibility in fibroblast cells.

Cell death induced by hydroxyapatite on L929 fibroblast cells

Biomaterials intended for end-use application as bone-graft substitutes have to undergo safety evaluation. In this study, we investigated the in vitro cytotoxic effects especially to determine the mode of death of two hydroxyapatite compounds (HA2, HA3) which were synthesized locally. The methods used for cytotoxicity was the standard MTT assay whereas AO/PI staining was performed to determine the mode of cell death in HA treated L929 fibroblasts. Our results demonstrated that both HA2 and HA3 were not significantly cytotoxic as more than 75% cells after 72 hours treatment were viable. Furthermore, we found that the major mode of cell death in HA treated cells was apoptosis. In conclusion, our results demonstrated that these hydroxyapatite compounds are not cytotoxic where the mode of death was primarily via apoptosis.

Frequency of extended spectrum beta lactamase producing gram negative bacilli among clinical isolates at clinical laboratories of Army Medical College, Rawalpindi

BACKGROUND

This study was carried out in Microbiology department of Army Medical College, Rawalpindi to find out the frequency of extended spectrum beta lactamase producing gram negative bacilli among clinical isolates recovered from clinical specimens received from Military Hospital, Rawalpindi.

METHODS

This study was carried out from 1st Jan 2002 to 30th Dec 2002. A total of 812 consecutive Gram-negative bacilli were recovered during the study period from various samples including urine, blood, pus, sputum, high vaginal swab (HVS), aspirates, i/v canula/Central venous lines (CVP), chest tubes and catheter tips. Extended spectrum beta lactamase detection in these isolates was carried out by Kirby Bauer disc diffusion method on Mueller Hinton agar. A susceptibility disk containing amoxicillin-clavulanate was placed as the inhibitor of beta lactamase in the center of the plate, and cefotaxime, ceftazidime, ceftriaxone and aztreonam disks were placed 30 mm (center to center) from the amoxicillin-clavulanate disk. Enhancement of the zone of inhibition of the oxyimino-beta-lactam caused by the synergy of the clavulanate in the amoxicillin-clavulanate disk was considered as evidence of ESBL production. Escherichia coli ATCC 25922 and K. pneumoniae ATCC 700603 were used as control strains.

RESULTS

The frequency of ESBL producing gram negative bacilli among the clinical isolates was 45%.

Frequency of Campylobacter jejuni in diarrhoea/dysentery in children in Rawalpindi and Islamabad

OBJECTIVE

To determine the frequency of Campylobacter jejuni infection in children suffering from diarrhoea/dysentery in the Department of Microbiology, Army Medical College and Military Hospital, Rawalpindi, from 29 August 2002 to 29 November 2002.

METHODS

The study was carried out on one hundred stool samples of children up to the age of twelve years admitted with diarrhoea/dysentery in Military hospital, Rawalpindi. The samples were collected in clean polypropylene containers containing Cary Blair medium. These were transported to the Microbiology Department, Army Medical College, Rawalpindi within 1-2 hours. The samples were inoculated on Modified Preston (Oxoid) and Karmali media (Oxoid) beside other routine stool culture media. The cultures were incubated at 42 degrees C under microaerophilic conditions. The growth after 48 hours was provisionally identified by colonial morphology, oxidase test, Gram staining and motility. The organisms were identified to species level by hippurate hydrolysis, urease test, nitrate reduction, catalase test, H2S production and resistance to cephalothin.

RESULTS

Eighteen percent of samples yielded the growth of Campylobacter jejuni. Mean age of children with Campylobacter jejuni infection was 18 months with peak incidence from 12 to 21 months. Male female ratio was 1.7:1. All the children had loose motions. Seven out 18 (39%) had a combination of symptoms of loose motions, vomiting and pain abdomen. Those having fever with or without other complaints constituted 11 out of 18 (61.11%) i.e. more than 50% of all the children yielding C. jejuni had fever. About 90% of diarrhoeal stools had blood and fifty percent also had mucous. There was either history of chicken meat consumption or contact with cattle and pets in most of the cases and both in some of them.

CONCLUSION

Campylobacter jejuni is a frequent cause of diarrhoea/dysentery in children in our set up. In children it is often related to pets keeping and chicken meat consumption. In the remaining, untreated drinking water may be the source. Campylobacter jejuni frequently presents with blood and mucous in stools with sporadic cases presenting with watery diarrhoea.

Loss of mitochondrial transmembrane potential and caspase-9 activation during apoptosis induced by the novel styryl-lactone goniothalamin in HL-60 leukemia cells

Styryl-lactones such as goniothalamin represent a new class of compounds with potential anti-cancer properties. In this study, we investigated the mechanisms of goniothalamin (GTN), a plant styryl-lactone induced apoptosis in human promyelocytic leukemia HL-60 cells. This plant extract resulted in apoptosis in HL-60 cells as assessed by the externalisation of phosphatidylserine. Using the mitochondrial membrane dye (DIOC(6)) in conjunction with flow cytometry, we found that GTN treated HL-60 cells demonstrated a loss of mitochondrial transmembrane potential (Deltapsi(m)). Further immunoblotting on these cells showed activation of initiator caspase-9 and the executioner caspases-3 and -7. Pretreatment with the pharmacological caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone (Z-VAD.FMK) abrogated apoptosis as assessed by all of the apoptotic features in this study. In summary, our results demonstrate that goniothalamin-induced apoptosis occurs via the mitochondrial pathway in a caspase dependent manner.

Bicondylar tibial plateau fractures managed with the Sheffield Hybrid Fixator. Biomechanical study and operative technique

The two main challenges in the management of bicondylar tibial plateau fractures are: Firstly, the compromised skin and soft tissue envelope which invite a high rate of complications following attempted open reduction and dual plating. Secondly, poor bone quality and comminuted fracture patterns, which create difficulty in achieving stable fixation. Although dual plating is considered to be the best mechanical method of stabilizing these complex fractures, there remains concern regarding the high rate of complications associated with extensive soft tissue dissection, required for the insertion of these plates in an already compromised knee. The Sheffield Hybrid fixator (SHF) technique offers a solution to the two main problems of these difficult fractures by minimizing soft tissue dissection, since bone fragments are reduced and fixed percutaneously, and providing superior cancellous bone purchase with beam loading stabilization for comminuted fractures. Our biomechanical testing showed the SHF with four tensioned wires to be as strong as dual plating and able to provide adequate mechanical stability in the fixation of bicondylar tibial plateau fractures. This was confirmed clinically by a prospective review of the use of the SHF at our centre, for managing complex and high-energy tibial plateau fractures with a good final outcome and no cases of deep infection or septic arthritis.

Induction of stress response renders human tumor cell lines resistant to curcumin-mediated apoptosis: role of reactive oxygen intermediates

Curcumin, a well-known dietary pigment derived from Curcuma longa, has been shown to be a potent antiinflammatory, antioxidant, and anticarcinogenic compound. The present study was designed to investigate the cytotoxic potential of curcumin against a range of human tumor cell lines in an attempt to understand its mechanism of action, which may lead to its possible therapeutic applications. We have shown that different cancer cell lines differ in their sensitivity to curcumin. Cell lines established from malignancies like leukemia, breast, colon, hepatocellular, and ovarian carcinomas underwent apoptosis in the presence of curcumin, whereas cell lines from lung, kidney, prostate, cervix, CNS malignancies, and melanomas showed resistance to the cytotoxic effects of curcumin. Sensitivity of the cancer cell lines to curcumin correlated with the generation of superoxide radicals as determined by the reduction of ferricytochrome C. Curcumin-resistant tumor cell lines showed significantly higher production of Hsp70, thus mounting a stress response and protecting the cells from the apoptotic cell death. These observations yield clues toward understanding the regulation of the cell death machinery by the stress proteins. Interestingly, curcumin had no effect on nontransformed cell lines, which showed neither superoxide generation nor the induction of a stress response. These observations demonstrate that curcumin is an interesting molecule with varied actions, depending on the cell type.

Reliability of the Severin classification in the assessment of developmental dysplasia of the hip

This study was undertaken to investigate the reliability of Severin's classification at various ages, and to determine whether the reliability is improved by careful measurement rather than subjective assessment. The radiographs taken at ages 6, 10 and 16 years of 20 randomly selected patients treated for developmental dysplasia of the hip were graded by six observers on two separate occasions using parameters measured according to Severin's criteria. In addition, four of these observers regraded the same radiographs using subjective assessment without measurements being made on two other separate occasions. Agreements between and within observers were evaluated using the weighted Cohen's kappa statistic for each age group. Intraobserver reliability was good, there being a close association between the measured and the subjectively observed ratings. This accords with the subjective nature of this classification. The interobserver reliability was found to be poor although it improved when direct measurements were made. Overall agreement between observers improves as patient age increases. It is concluded that comparisons between different observers using the Severin classification system are not reliable. However, a single investigator comparing treatment modalities in the same study allowing for individual bias in assessing deformity and subluxation would produce reliable results.

Isolation and bioactivities of constitutents of the roots of Garcinia atroviridis

Two new prenylated compounds, the benzoquinone atrovirinone (1) and the depsidone atrovirisidone (2), were isolated from the roots of Garcinia atroviridis. Their structures were determined on the basis of the analysis of spectroscopic data. While compound 2 showed some cytotoxicity against HeLa cells, both compounds 1 and 2 were only mildly inhibitory toward Bacillus cereus and Staphylococcus aureus.

Adsorptive stripping voltammetric determination of antihypertensive agent: diltiazem

Adsorptive stripping voltammetry was used to determine the antihypertensive agent diltiazem in phosphate buffer (pH 7.0). The adsorptive cathodic peak was observed at -1.72 V vs. Ag/AgCl. The peak response was characterized with respect to pH, preconcentration time, possible interferences, accumulation potential and supporting electrolytes. The obtained results were analyzed and the statistical parameters were calculated. The proposed method was applied to determine the mentioned drug in pharmaceutical formulation (capsule) and urine. The detection limit is 1x10(-8) M (4.5 ng ml(-1)) using 180 s preconcentration time, whereas the lower limit of detection is 6x10(-9) M (2.7 ng ml(-1)).

Is breech presentation in nulliparous women at term an absolute indication for cesarean section?

BACKGROUND

The aim of this report was to study the perinatal outcome of singleton breech presentation in nulliparous women who delivered after 37 weeks, either vaginally or by cesarean section, and whether by elective surgery or emergency, and to identify the indications for cesarean sections.

SUBJECTS AND METHODS

This is a retrospective study conducted at King Fahd Hospital of the University, AlKhobar, Saudi Arabia, to compare perinatal mortality and morbidity of singleton term breech infants delivered vaginally and by cesarean section in nulliparous women.

RESULTS

There were 112 singleton term breech presentations, of which 96 (85.7%) were allowed to have a trial of labor. Of these, 67 (69.8%) had a successful vaginal delivery. Women who delivered by elective cesarean section were significantly older than those who delivered vaginally (P<0.0001), and those who delivered by emergency cesarean section (P<0.004). The infants delivered by cesarean section were heavier in weight than those delivered vaginally (P<0.0001). There were no significant differences in 5 minute Apgar scores and perinatal mortality between the groups.

CONCLUSION

With proper selection of nulliparous women with breech presentation for vaginal delivery, cesarean section can be avoided in the majority of cases without compromising the perinatal outcome.

Acoustic-phonetic features for the automatic classification of fricatives

In this article, the acoustic-phonetic characteristics of the American English fricative consonants are investigated from the automatic classification standpoint. The features studied in the literature are evaluated and new features are proposed. To test the value of the extracted features, a statistically guided, knowledge-based, acoustic-phonetic system for the automatic classification of fricatives in speaker-independent continuous speech is proposed. The system uses an auditory-based front-end processing system and incorporates new algorithms for the extraction and manipulation of the acoustic-phonetic features that proved to be rich in their information content. Classification experiments are performed using hard-decision algorithms on fricatives extracted from the TIMIT database continuous speech of 60 speakers (not used in the design/training process) from seven different dialects of American English. An accuracy of 93% is obtained for voicing detection, 91% for place of articulation detection, and 87% for the overall classification of fricatives.

Cathodic adsorptive stripping voltammetric determination of muscle relaxant: gallamine triethiodide (flaxedil)

A sensitive and simple voltammetric method of analysis is developed for the determination of trace amounts of gallamine triethiode in phosphate media. This method is based on controlled adsorptive preconcentration of the relaxant onto a Hanging Mercury Drop Electrode (HMDE) whereby mercurous iodide salt(s) are formed. The technique used is Cathodic Linear Sweep Stripping Voltammetry (CLSSV). The adsorptive response was evaluated with respect to preconcentration time and potential. As little as 3 x 10(-9) mol dm(-3) i.e. 2.7 ppb flaxedil (proconcentration time 300 seconds) can be determined successfully. The application of this method was tested in the determination of flaxedil in pharmaceutical preparation (ampoules).

Lipoid proteinosis: report of four siblings and brief review of the literature

Lipoid proteinosis (Urbach-Wiethe disease) is a rare autosomal recessive disorder associated with deposition of periodic acid-Schiff (PAS)-positive hyaline material in various tissues including skin, mucous membranes, and internal organs. A family is reported in which four siblings (two boys and two girls) born to nonconsanguineous parents had lipoid proteinosis. All had the characteristic hoarseness of voice and three had skin lesions. The diagnosis was confirmed by the presence of typical features on light and electron microscopy.

Antimicrobial, antioxidant, antitumour-promoting and cytotoxic activities of different plant part extracts of Garcinia atroviridis griff. ex T. anders

Crude extracts (methanol) of various parts, viz. the leaves, fruits, roots, stem and trunk bark, of Garcinia atroviridis were screened for antimicrobial, cytotoxic, brine shrimp toxic, antitumour-promoting and antioxidant activities. The crude extracts exhibited predominantly antibacterial activity with the root extract showing the strongest inhibition against the test bacteria at a minimum inhibitory dose (MID) of 15.6 microg/disc. Although all the extracts failed to inhibit the growth of most of the test fungi, significant antifungal activity against Cladosporium herbarum was exhibited by most notably the fruit (MID: 100 microg), and the leaf (MID: 400 microg) extracts. None of the extracts were significantly cytotoxic, and lethal towards brine shrimps. The root, leaf, trunk and stem bark extracts (except for the fruits) showed strong antioxidant activity exceeding that of the standard antioxidant, alpha-tocopherol. Antitumour-promoting activity (>95% inhibition) was shown by the fruit, leaf, stem and trunk bark extracts.

Screening of Zingiberaceae extracts for antimicrobial and antioxidant activities

Dichloromethane and methanol extracts of 13 Zingiberaceae species from the Alpinia, Costus and Zingiber genera were screened for antimicrobial and antioxidant activities. The antimicrobial activity of most of the extracts was antibacterial with only the methanol extract of Costus discolor showing very potent antifungal activity against only Aspergillus ochraceous (MID, 15.6 microg per disc). All the extracts showed strong antioxidant activity comparable with or higher that of alpha-tocopherol.

Ultrastructural characterization of the rabbit mandibular condyle following experimental induction of anterior disk displacement

Previous studies in our laboratory have shown that surgical induction of anterior disk displacement (ADD) in the rabbit craniomandibular joint (CMJ) leads to cellular and extracellular alterations consistent with osteoarthritis. Similar findings were also reported in human ADD as well as osteoarthritis of other joints. The purpose of this study was to further characterize these histopathological findings at the ultrastructural level. The right joint of 15 rabbits was exposed surgically and all discal attachments were severed except for the posterior attachment. The disk was then repositioned anteriorly and sutured to the zygomatic arch. The left joint served as a sham-operated control. Ten additional joints were used as nonoperated controls. Mandibular condyles were excised 2 weeks following surgery and processed for transmission electron microscopy. Experimental condyles showed neovascularization, fibrillation and vacuolation of the extracellular matrix and an increase in the number of apoptotic cells compared to controls. In addition, chondrocytes in osteoarthritic cartilage showed an increase in the amounts of rough endoplasmic reticulum and Golgi complex suggesting an increase in protein synthesis. The presence of thick collagen fibers in osteoarthritic cartilage supports our previous immunohistochemical results of the presence of type I collagen instead of normally existing type II collagen. It was concluded that surgical induction of ADD in the rabbit CMJ leads to ultrastructural changes in the mandibular condylar cartilage consistent with degenerative alterations known to occur in osteoarthritis.

Growth and anthraquinone production of Morinda elliptica cell suspension cultures in a stirred-tank bioreactor

The effects of medium strategy, number of impellers, aeration mode, and mode of operation on Morinda elliptica cell suspension cultures in a stirred-tank bioreactor are described. A lower number of impellers and continuous aeration contributed toward high cell growth rate, whereas a higher number of impellers reduced cell growth rate, although not anthraquinone yield. The semicontinuous mode could indirectly imitate the larger scale version of production medium strategy and improved anthraquinone production even with 0. 012% (v/v) antifoam addition. Production medium promoted both growth (maximum dry cell weight of 24.6 g/L) and anthraquinone formation (maximum content of 19.5 mg/g of dry cell weight), without any necessity for antifoam addition. Cultures in production medium or with higher growth rate and anthraquinone production were less acidic than cultures in growth medium or with lower growth rate and anthraquinone production. Using the best operating variables, growth of M. elliptica cells (24.6 g/L) and anthraquinone yield (0.25 g/L) were 45% and 140%, respectively, lower than those using a shake flask culture after 12 days of cultivation.

Development of an improved technique for the perfusion of the isolated caudal lobe of sheep liver

The study was designed to develop an improved technique for perfusing the isolated caudal lobe of sheep liver. Twenty caudal lobes were perfused for 3-4 h, in a non-recirculating mode, with Krebs-Henseleit bicarbonate buffer. The perfusion system was designed to give a constant flow. The hepatic viability and functional normality of the perfused lobe were assessed by measuring the perfusion flow rate, pH, K+ efflux, O2 uptake, substrate uptake, gluconeogenesis from propionate and amino acids, and ureagenesis from ammonia and amino acids. Liver tissue was sampled for histological examination, as well as for the determination of liver glycogen and wet : dry weight ratio. The perfusion flow rate and pH were both stable throughout the perfusion. The potassium concentration in the effluent perfusate did not increase during the perfusion, suggesting that there was no loss of viability or hypoxia. The perfused lobe extracted more than 50% of the O2 supply. The rate of oxygen consumption was comparable to the rate reported in vivo. The initial glycogen content was reduced by about 40% after 4 h perfusion. The wet : dry weight ratio was 3.6, consistent with the absence of tissue oedema. Urea production was stimulated when NH4Cl (0.3 mM) was added to the medium but there was no significant increase in urea release when alanine (0.15 mM), glutamine (0.2 mM) or lysine (0.2 mM) was added. Urea production, however, increased by about 171% when a physiological mixture of amino acids was added. Propionate (0.5 mM), alanine and glutamine stimulated glucose production but not lysine or the complete amino acid mixture. Glutamine release was lower than that reported in the rat liver. Changing the direction of flow also revealed an apparent difference between livers from sheep and rats in their metabolism of ammonia. The improved technique offers a simple practical and inexpensive approach to many problems in ruminant physiology and nutritional biochemistry.

Antimicrobial susceptibility of bifidobacteria

Eighteen Bifidobacterium strains were tested for their susceptibility to a range of antimicrobial agents. All the strains tested, including the reference culture Lactobacillus acidophilus CH2, were susceptible to several groups of antimicrobial agents, they were cephalosporin (cefamandole, cefazolin, cefaperazone, cefoxitin), polypeptide (bacitracin), macrolide (erythromycin), penicillin (amoxicillin), phenicol (chloramphenicol) and beta-lactam (imipenem). Fourteen strains were resistant to more than 10 antibiotics. The reference culture was resistant to only three antibiotics. The results showed that bifidobacteria are resistant to a wide range of antimicrobial agents.

Some evidences for the involvement of plasmid in diuron herbicide degradation

Pseudomonas sp. strain Bk8 was isolated from field soil contaminated with different urea-herbicides. This strain is a plasmid (pBkB)-harbouring organism capable of complete degradation of diuron herbicide. Plasmid-cured strain Bk8M was obtained by treatment of Pseudomonas sp. Bk8 with Mitomycin C. This cured strain is capable of only partial degradation of diuron side chain and accumulated a phenolic compound in the medium during growing on diuron as a sole source of carbon and energy. Conjugation experiment was carried out using Bk8M as a recipient and Bk8 as a donor of pBk8 plasmid. The transconjugant was able to degrade a diuron without accumulation of phenolic compound. It was proposed that plasmid pBk8 is self-transmissible and involved in the degradation of diuron aromatic ring but it is not connected with the transformation of diuron into diuron phenol compound.

Detoxication of the herbicide diuron by Pseudomonas sp

A strain of bacteria able to detoxicate the herbicide diuron in pure culture was isolated from sites contaminated with different urea herbicides. Diuron was used as a sole source of carbon and energy by this isolate which is a Gram-negative, aerobic, rod-shaped bacterium with a single polar flagellum, and grows at 40 degrees C. The strain has been identified as Pseudomonas sp.

Screening for the in vitro anti-tumor-promoting activities of edible plants from Malaysia

A total of 114 methanol extracts from 42 plant families of edible Malaysian plants were screened for their inhibitory activities toward tumor promoter 12-O-hexadecanoylphorbol-13-acetate (HPA)-induced Epstein-Barr virus (EBV) activation in Raji cells. By testing at a concentration of 200 micrograms/ml, 74% of the 114 extracts inhibited EBV activation by 30% or more. This rate is comparable to those observed in the previous tests on edible Thai (60%) and Indonesian (71%) plants, and, importantly, much higher than that (26%) observed for Japanese edible plants. Approximately half of the Malaysian plants did not taxonomically overlap those from the other three countries, suggesting that Malaysian plants, as well as Thai and Indonesian plants, are an exclusive source of effective chemopreventive agents. Further dilution experiments indicated an extract from the leaves of Piper betle L. (Piperaceae) to be one of the most promising species. The high potential of edible Southeast Asian plants for cancer chemoprevention is collectively discussed.

Antiviral, cyototoxic and antimicrobial activities of anthraquinones isolated from the roots of morinda elliptica

2-Formyl-1-hydroxyanthraquinone, along with ten other known anthraquinones (1-hydroxy-2-methylanthraquinone, nordamnacanthal, damnacanthal, lucidin-?-methyl ether, rubiadin, rubiadin-1-methyl ether, soranjidiol, morindone, morindone-5-methyl ether and alizarin-1-methyl ether), isolated from the roots of Morinda elliptica , were assayed for anti-HIV, cytotoxic and antimicrobial activites. Only damnacanthal showed moderate activity against HIV. It was cytotoxic towards the MCF-7 (breast carcinoma) and CEM-SS (T-lymphoblastic leukaemia) cell line. Nordamnacanthal was very cytotoxic against the CEM-SS cell lines. Other anthraquinones that showed strong cytotoxicity towards the cell lines tested were lucidin-?-methyl ether (CEM-SS and MCF-7) and rubiadin (CEM-SS). Three anthraquinones viz., nordamnacanthal, damnacanthal and morindone, were found to have strong antimicrobial activity.

Determination of trace metal ions in common salt by stripping voltammetry

Sensitive voltammetric methods using cathodic and anodic differential pulse stripping techniques were applied for determination of trace ions cadmium(II), cobalt(II), copper(II), lead(II), manganese(II), nickel(II), and zinc(II), which are usually found in different grades of common salt as contaminants. The optimal conditions, i.e., deposition time, preconcentration potential, supporting electrolyte, and ionic strength, were investigated for each metal ion. Concentration of the metal ion was determined by the standard addition method. Metal content varied according to the quality of the table salt.

Anthraquinones from hedyotis herbacea

A new anthraquinone, 2-hydroxymethyl-10-hydroxy-1,4-anthraquinone (1), was isolated from Hedyotis herbacea along with three other known derivatives: 1,4-dihydroxy-2-hydroxymethylanthraquinone (2); 2, 3-dimethoxy-9-hydroxy-1,4-anthraquinone; and 1,4-dihydroxy-2, 3-dimethoxyanthraquinone. The structure of 1 was determined based on analysis of its spectroscopic data.

Caspases-3 and -7 are activated in goniothalamin-induced apoptosis in human Jurkat T-cells

Goniothalamin, a plant styrylpyrone derivative isolated from Goniothalamus andersonii, induced apoptosis in Jurkat T-cells as assessed by the externalisation of phosphatidylserine. Immunoblotting showed processing of caspases-3 and -7 with the appearance of their catalytically active large subunits of 17 and 19 kDa, respectively. Activation of these caspases was further evidenced by detection of poly(ADP-ribose) polymerase cleavage (PARP). Pre-treatment with the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone (Z-VAD.FMK) blocked apoptosis and the resultant cleavage of these caspases and PARP. Our results demonstrate that activation of at least two effector caspases is a key feature of goniothalamin-induced apoptosis in Jurkat T-cells.

Induction of apoptosis in AK-5 cells by rotenone involves participation of caspases

AK-5 tumour cells undergo apoptosis after treatment with rotenone an electron transport inhibitor and oligomycin which inhibits mitochondrial ATPases. Apoptotic process involves the induction of caspases 2 and 3, whereas caspase 1 does not seem to be participating in rotenone/oligomycin induced apoptosis. DEVD which is a specific inhibitor of caspase 3, inhibited apoptosis in AK-5 cells. We have also observed a significant lowering of intracellular pH in AK-5 cells which are induced into the apoptotic process by rotenone. These results suggest an important role for mitochondrial electron transport in the induction of apoptosis in AK-5 tumour cells.

Continuous antibody production by phytohemagglutinin-L-aggregated hybridoma cells

Phytohemagglutinin-L (PHA-L) induced aggregation of SP2 myeloma and antibody-producing hybridoma cells. The aggregates were of diverse shapes, and major-axis length of the hybridoma aggregates was mostly 50-80 microm at 1 microg/ml PHA-L and 100-150 microm at 5 microg/ml. PHA-L did not suppress growth rate at these concentrations. The aggregated cells had almost the same antibody productivity as that of non-aggregated cells in a static culture. Essentially, identical results were obtained with soybean agglutinin (SBA). On the other hand, pokeweed mitogen (PWM) did not induce apparent aggregation at a concentration of 10 microg/ml. These results suggest that lectin binding to particular carbohydrate moiety on the cell surface is necessary for cell agglutination. Using PHA-L, a 200-ml suspension culture of aggregated hybridoma cells was successfully performed in a spinner flask over 10 days. The aggregates were mainly globular with a diameter of 50-100 microm at 1-2 microg/ml PHA-L. The aggregation greatly enhanced settlement of hybridoma cells by gravity, and medium exchanges were thereby easily performed in a short period. During a course of the semi-continuous culture, antibody concentrations of culture medium were maintained at approximately 10 microg/ml which was comparable to that of static culture of the aggregated hybridoma cells. Thus, the lectin aggregation is applicable to the separation of culture medium from anchorage-independent cells like hybridomas, and can be employed in a large-scale commercial production of biologically active proteins.

Antitumor activity of curcumin is mediated through the induction of apoptosis in AK-5 tumor cells

Curcumin, the yellow pigment of turmeric (Curcuma longa), used commonly as a spice, has been shown to possess anticarcinogenic activity. Curcumin inhibited AK-5 tumor growth and induced apoptosis in AK-5 cells. Curcumin induced apoptosis is mediated through the activation of caspase-3, which is specifically inhibited by the tetrapeptide Ac-DEVD-CHO. In addition, curcumin induced tumor cell death is caused through the generation of reactive oxygen intermediates which is inhibited by N-acetyl-L-cysteine. Our studies suggest that the apoptotic process induced by curcumin is the mechanism mediating AK-5 tumor cell death.

Emergency cervical cerclage: A review of 15 cases

BACKGROUND

This report describes our experience with 15 consecutive emergency cervical cerclages performed at Al Yamamah Hospital.

PATIENTS AND METHODS

Between February 1994 and February 1997, 15 women with singleton pregnancies between 18 and 26 weeksâ gestation, with a cervical dilatation between 3 and 10 cm and with membrane prolapse, underwent emergency cerclage after excluding labor, placental abruption and intrauterine infection. The membranes were replaced using the technique of overfilling the urinary bladder and then performing McDonaldâs cerclage. All the patients received prophylactic antibiotics and tocolytics.

RESULTS

Of the 15 pregnancies, two aborted and 13 ended in live births. Nine of the live births survived, giving a survival rate of 60%. The mean extension of pregnancy in the survivors was 11.5 weeks (range 7.6-15.2 weeks), and the gestational age at delivery ranged from 30-38+ weeks. In six of the patients, suture failed to prolong the pregnancy long enough to produce a âtake-home baby.â All the failures were due to subclinical intrauterine infection. There was no maternal morbidity.

CONCLUSION

Emergency cerclage should be considered as a management option in women with painless cervical dilatation and membrane prolapse in the midtrimester.

Cathodic adsorptive stripping voltammetric determination of the anti-inflammatory drug indomethacin

Sensitive voltammetric methods have been developed for the determination of the anti-inflammatory, anti-pyretic and analgesic drug indomethacin sodium. The methods are based on the controlled adsorptive preconcentration of the drug on a hanging mercury drop electrode (HMDE), followed by tracing the voltammogram in a cathodic potential scan. The modes used are cyclic voltammetry (CV), cathodic stripping voltammetry (CSV) and differential pulse stripping voltammetry (DPSV). Amounts as low as 10 nM (10 ng x ml(-1)) (60 s preconcentration) by CSV and 0.5 microM (190 ng x ml(-1)) (300 s) by DPSV can be determined accurately. The R.S.D. at the 1 x 10(-6) M level is 1.4%. The interference of some metal ions and the application of the method to analysis of urine, plasma and pharmaceutical formulations are described.

Selective involvement of caspase-3 in ceramide induced apoptosis in AK-5 tumor cells

Ceramide, a product of sphingomyelin metabolism, is a novel lipid second messenger that mediates diverse cellular functions. The present study demonstrates the activation of caspase-3/CPP-32beta, during apoptosis induced by cell permeable exogenous ceramides, in AK-5 tumor, a spontaneously regressing rat histiocytoma. The apoptotic events were suppressed by the caspase-3 specific tetrapeptide inhibitor DEVD-CHO but not by the caspase-1 inhibitor YVAD-CMK. In cells overexpressing Bcl-2, a significant decrease in cell death was observed after exogenous addition of ceramides. Furthermore the processing of caspase-3 to its active form upon apoptotic stimulus, and the subsequent cleavage of the substrate PARP, suggested a central role for caspase-3 in the ceramide mediated apoptosis in AK-5 tumor cells.

Administration of anti-IL-12 antibody in vivo inhibits rejection of a rat histiocytoma and suppresses cytokine response in a tumour-bearing host

Activated macrophages are the major producers of heterodimeric cytokine interleukin-12 (IL-12). Earlier evidence suggested that early rejection of AK-5 tumours is mediated by IL-12 through interferon-gamma (IFN-gamma) production, involving activation of natural killer (NK) cells and upregulation of T-helper 1 (Th1)-type cytokine response. Injection of anti-IL-12 antibody into AK-5 tumour-bearing animals resulted in a large number of changes in the host immune response towards the tumour. These animals showed diminished NK-mediated antibody-dependent cell-mediated cellular cytotoxicity (ADCC) activity, down-regulation of Th1-type cytokine response, decreased anti-tumour antibody response ultimately leading to either delay or inhibition of the tumour-regression process. There was also increased production of IL-10 in the animals that had received anti-IL-12 antibody thereby resulting in the down-regulation of IL-2 and IFN-gamma production. IL-12 plays a major role in the activation of the different immune parameters responsible for early rejection of AK-5 tumour. We also studied the activation status of macrophages from tumour-transplanted animals and their ability to produce IL-12. Monocytes/macrophages from antibody-injected animals were less active and produced lower quantities of IL-12, IL-1 beta and tumour necrosis factor-alpha (TNF-alpha) as compared with the macrophages from AK-5 tumour-bearing animals.

Participation of CED-3/ICE and YAMA proteinases in the execution of apoptosis in AK-5 tumor cells leading to spontaneous tumor regression

AK-5, which is a spontaneously regressing rat histiocytoma, is killed by necrosis (perforin mediated) and apoptosis. We have studied the induction of apoptosis in AK-5 tumor cells by each of the following: a factor from anti-AK-5 antiserum, dexamethasone, and natural killer cells. Partial inhibition in apoptosis was observed when AK-5 cells were transfected with Crm A gene, a specific inhibitor of ICE protease. Similarly peptide inhibitors Ac-YVAD-cmk and Ac-DEVD-CHO inhibited partially the formation of nuclear bodies and DNA fragmentation induced by each of the above-mentioned apoptotic inducers. Although NK cells were able to kill Crm A and bcl-2 transfected clones by cytotoxic action, they failed to induce DNA fragmentation in these clones, suggesting a dual mode of action by NK cells in the induction of target cell death. We were unable to detect ICE and YAMA/CPP32 transcripts in control AK-5 cells, but upon induction of the apoptotic process, there was significant expression of these transcripts in AK-5 cells. When bcl-2 gene was introduced into AK-5 cells there was complete inhibition of apoptosis, suggesting its affect to be upstream of ICE and YAMA proteases. These results suggest an important role for cysteine proteases in the execution of apoptosis, leading to tumor cell death and the regression of AK-5 tumor in syngeneic hosts.

Uptake and metabolism of propionate in the liver isolated from sheep treated with glucagon

The uptake and metabolism of propionate in the isolated perfused caudal lobe of the liver and in isolated hepatocytes were examined following treatment of sheep with glucagon or saline. Glucagon or sterile saline was infused at 9.8 micrograms/min for 3 h into the jugular vein and then the caudal lobe of the liver was removed surgically under anaesthesia. The caudal lobe was used either to prepare hepatocytes or in a non-recirculating perfusion experiment. Uptake and metabolism of propionate were studied using [2-14C]propionate. In studies using the non-recirculation perfusion of the caudal lobe of the sheep liver it was shown that the treatment of sheep with glucagon resulted in an increased rate of gluconeogenesis from propionate and in an increased net uptake of propionate by the caudal lobe. The uptake of propionate into the hepatocytes was saturable, concentrative and exhibited a K(m) for propionate of 0.24 (SE 0.07) mM and a maximal rate of uptake (Vmax) of 6.7 (SE 0.6) nmol/mg dry cells per min and was unaffected by glucagon treatment of sheep. After incubation of cells in medium containing 0.5 mM-[2-14C]propionate for 10 min, the rate of gluconeogenesis from propionate was 22% higher in the hepatocytes isolated from glucagon-treated sheep. Concentrations in the medium of 1.35 mM butyrate and 1 mM-caproate inhibited propionate uptake by about 50% and abolished the glucagon-induced stimulation of gluconeogenesis from propionate. The results are consistent with a regulatory role for glucagon in the gluconeogenesis from propionate in the sheep liver.

Natural killer cell as the effector which mediates in vivo apoptosis in AK-5 tumor cells

AK-5 tumor cell death is mediated by natural killer cells through necrosis (perforin mediated) and apoptosis. Apoptosis is the mechanism which operates in immune animals in vivo. We have identified natural killer (NK) cell as the effector cell which induces apoptosis leading to tumor cell death in vivo. Naive NK cell which is unable to kill the AK-5 tumor cell can be activated with IL-2/IL-12 to make it capable of inducing apoptosis in tumor cells. NK cells from tumor-rejected animals show higher expression of Fas ligand and serine esterase granzyme B. In addition, NK cell-mediated apoptosis in AK-5 cells is totally abolished when effector cells are treated with anti-NKR-P1 mAb 3.2.3 and complement. NK cell-mediated apoptotic activity is inhibited in bcl-2 transfected tumor cells; however, the cytotoxic activity (perforin-mediated) remains unaffected. These observations suggest an important role for activated NK cells in inducing tumor cell death through necrosis (ADCC) and apoptosis leading to spontaneous regression of the AK-5 tumor in syngeneic animals.

Cytotoxicity and electron microscopy of cell death induced by goniothalamin

The cytotoxicity of goniothalamin was found to be strong towards both cancerous (HGC-27, MCF-7, PANC-1, HeLa), and non-cancerous (3T3) cell lines, especially in cases of dividing cells. Drug exposure studies indicated that the cytotoxic action of goniothalamin was time- and dose-dependent. At the ultrastructural level, goniothalamin-induced cytotoxicity revealed a necrotic mode of cell death towards MCF-7 cells.

Caspase-2/NEDD-2 protease mediates execution of apoptosis in AK-5 tumor cells

AK-5 tumour cells have been shown to undergo apoptosis in vitro and in vivo. The efficient killing of tumour cells by necrosis and apoptosis leads to spontaneous regression of the tumour. To investigate a possible involvement of caspase-2/Nedd-2 protease in AK-5 apoptosis, we introduced Nedd-2 gene in antisense orientation and showed inhibition of tumour cell apoptosis. Similarly introduction of the bcl-2 gene in tumour cells also inhibited the apoptotic programme. NK cells which have previously been shown to be the effector cells also fail to induce apoptosis in Nedd-2 antisense and bcl-2 transfected clones whereas NK mediated cytotoxic activity is not altered in the transfectants. These results suggest participation of Nedd-2 protease in the induction of apoptosis in AK-5 cells leading to tumour regression.

Induced intensification: agricultural change in Bangladesh with implications for Malthus and Boserup

Bangladesh is dominated by a small-holder agrarian economy under extreme stress. Production shortfalls, increasing economic polarization, and chronic malnutrition are persistent, but major famine has been diverted in part by significant growth in agriculture. This recent history is open to both Malthusian and Boserupian interpretations-a history we explore here through a test of the induced intensification thesis of agricultural change. This thesis, framed by variations in the behavior of small-holders, has grown from a simple demand-production relationship to a consideration of the mediating influences on that relationship. The induced intensification thesis is reviewed and tested for 265 households in 6 villages in Bangladesh from 1950-1986. A time-series analysis of an induced intensification model provides relatively high levels of explained variance in cropping intensity (frequency and land productivity) and also indicates the relative impacts of household class, environment, and cropping strategies. On average, the small-holders in question kept pace with the demands on production, although important class and village variations were evident and the proportion of landless households increased. These results, coupled with evidence that agricultural growth involved intensification thresholds, provide clues about Malthusian and Boserupian interpretations of Bangladesh, and suggest that small-holder agriculture there is likely to continue on a "muted" path of growth.

Histochemical and immunohistochemical studies of the effects of experimental anterior disc displacement on sulfated glycosaminoglycans, hyaluronic acid, and link protein of the rabbit craniomandibular joint

PURPOSE

The purpose of this study was to determine the effects of surgically induced anterior disc displacement (ADD) on sulfated glycosaminoglycans (GAGs) such as keratan sulfate (KS), chondroitin-4-sulfate (C4S), and chondroitin-6-sulfate (C6S), hyaluronic acid (HA), and link protein (LP) of the rabbit craniomandibular joint (CMJ) using histochemical and immunohistochemical techniques.

MATERIALS AND METHODS

The right joint of 20 rabbits was exposed surgically, and all discal attachments were severed except for the posterior attachment. The disc was then repositioned anteriorly and sutured to the zygomatic arch. The left joint served as a sham-operated control. Ten additional joints were used as nonoperated controls. Deeply anesthetized rabbits were perfused with 2% buffered formalin 2 weeks (10 rabbits) or 6 weeks (10 rabbits) after surgery. Discs, bilaminar zones, condyles, and articular eminences were excised. Condyles and articular eminences were decalcified in ethylenediaminetetraacetic acid (EDTA). All tissues were sectioned at 10 microns in a cryostat. Sections were incubated with alcian blue and monoclonal antibodies directed against KS, C4S, C6S, HA, or LP. After incubation in the appropriate fluorescein isothiocyanate (FITC)-labeled secondary antibodies, tissue sections were studied under the fluorescence microscope.

RESULTS

The results showed a reduction in alcian blue staining and KS, C4S, C6S, HA, and LP immunostaining in the disc and articular surfaces at 2 weeks after induction of ADD. This reduction was followed by an increase in their immunostaining at 6 weeks. Also, there was a progressive increase in alcian blue staining, and KS, C4S, C6S, and HA immunostaining in the bilaminar zone at 2 and 6 weeks.

CONCLUSION

It was concluded that surgical induction of ADD in the rabbit CMJ leads to alterations in KS, C4S, C6S, HA, and LP content, consistent with similar changes accompanying osteoarthritis of other synovial joints.

An immunohistochemical study of collagen types III, VI and IX in rabbit craniomandibular joint tissues following surgical induction of anterior disk displacement

The purpose of this study was to determine the effect of surgical induction of anterior disk displacement (ADD) on type-III, VI and IX collagens of the rabbit craniomandibular joint (CMJ) tissues using an immunohistochemical technique. The right joint was exposed surgically, all discal attachments were severed except for the posterior discal attachment (bilaminar zone). The disk was then repositioned anteriorly and sutured to the zygomatic arch. The left joint served as a sham-operated control. Ten additional joints were used as non-operated controls. Deeply anesthetized rabbits were perfused with 2% buffered formalin 2 weeks (10 rabbits) or 6 weeks (10 rabbits) following surgery. The articular disk, bilaminar zone, mandibular condyle and articular eminence were excised. The last two were decalcified in EDTA. All tissues were then sectioned at 10 microns in a cryostat. Sections were incubated with monoclonal antibodies directed against type-III, VI or IX collagens. Following incubation in the appropriate FITC-labelled secondary antibodies, all sections were studied under the fluorescence microscope. The results showed a reduction in immunostaining for type-VI and IX collagens in the condylar cartilage, disk and articular eminence at 2 weeks, followed by an increase in their immunostaining at 6 weeks and the appearance of a de novo type-III collagen in the condylar cartilage and the articular eminence. It is concluded that surgical induction of ADD in the rabbit CMJ leads to alterations in its type-III, VI and IX collagens.

Metabolism of goniothalamin in animal and microbial system

Of the twenty microorganisms screened for metabolism of goniothalamin only Streptomyces aurofaciens ATCC 10762 and Nocardia species NRRL 5646 produced two metabolites, 3,4-dihydrogoniothalamin and 3,4,7,8 tetrahydrogoniothalamin. The identity of the isolated metabolites were established using TLC, HPLC, MS, IR, and 1H- and 13C-NMR spectroscopy. In addition, the substrate had been transformed into two unknown metabolites by Aspergillus niger ATCC 11394 and Septomyxa affinis ATCC 6737 in low yield. Three of the metabolites were also detected and identified in the urine and blood samples of the goniothalamin-treated Sprague-Dawley rats. The obtained results are in agreement with and support the principle of microbial models of mammalian metabolism.

The influence of cultured Schwann cells on regeneration through acellular basal lamina grafts

Acellular basal lamina grafts have been shown to be less immunogenic in comparison to cellular grafts, but possess a limited potential for supporting axonal regeneration through them. The present study describes the effect of cultured Schwann cells on enhancing regeneration through acellular grafts. 2 cm long acellular grafts, and in vitro Schwann cell populated acellular grafts were used to repair a surgically created gap in the host peroneal nerve. The transplants were analyzed at 1, 2, 4 and 8 weeks to determine their ability to support axonal regeneration. Host axonal regeneration through Schwann cell cocultured acellular grafts occurred rapidly and was significantly better as compared to non-cultured acellular grafts. The results demonstrate a beneficial effect of Schwann cell culture pretreatment on regeneration through acellular grafts and an improved recovery of the target muscle. The procedure of first preparing acellular grafts with subsequent coculture with Schwann cells offers a novel approach for the repair of injured nervous tissue.

An immunohistochemical study of the effects of surgical induction of anterior disc displacement in the rabbit craniomandibular joint on type I and type II collagens

The right craniomandibular joint (CMJ) was exposed surgically and all the discal attachments severed except for the posterior one. The disc was then repositioned anteriorly and sutured to the zygomatic arch. The left joint served as a sham-operated control; 10 other joints were used as non-operated controls. Deeply anaesthetized rabbits were perfused with 2% buffered formalin 2 weeks (10 rabbits) or 6 weeks (10 rabbits) after the induction of the anterior disc displacement (ADD). The articular disc, bilaminar zone, mandibular condyle and articular eminence were excised. The condyles and the articular eminences were demineralized in EDTA. All tissues were then sectioned at 10 microns in a cryostat. Sections were incubated with polyclonal antibodies directed against type I or type II collagens. Following incubation in the appropriate fluorescein isothiocyanate-labelled secondary antibodies, these specimens were studied under the fluorescence microscope. At 2 weeks there was a reduction in type II collagen immunostaining; some areas of the experimental condylar cartilage showed a switch from type II to type I collagen. However, at 6 weeks there was an increase in type II collagen immunostaining and a decrease in type I compared to the 2-week group. It is concluded that surgical induction of ADD in the rabbit CMJ leads to alteration in the condylar cartilage collagen phenotype similar to that reported for osteoarthritic cartilage of other synovial joints.

Fine needle aspiration biopsy of hydatid cysts

Fine needle aspiration biopsy (FNAB) was performed in 31 patients with hydatid disease by 15 operators in 41 biopsy events during the period 1983-93. The FNABs were unintentionally done without prior clinical suspicion of hydatid cysts (HCs) in 18 patients and intentionally (with prior clinical suspicion of HC) in 13 patients for pathologic confirmation required for specific therapy. The FNABs were performed with the guidance of fluoroscopy (n = 7), CT (n = 14) or ultrasonography (n = 10). The material included both closed, open and ruptured HCs from different locations such as abdomen, thorax, spine and bone. Pathologic confirmation of HC was achieved by recovering and demonstrating parasitic material in the specimen. In only 7 of 31 patients were the specimens diagnostic at the initial interpretation. This emphasizes the importance of alerting the pathologist about the possibility of hydatid disease. In 25 of 31 patients (81%) no biopsy reactions occurred. In 5 patients minor allergic reactions occurred and 3 had filling of air into intrathoracic cysts not requiring therapy. One patient, with a FNAB of a liver HC, had a sudden severe drop in blood pressure, which required anti-shock therapy with subsequent recovery without sequelae. All complications occurred with non-intentional biopsy of HC. Suggestions for diagnostic and therapeutic management of patients with HC and advice to avoid or limit potential complications or spread of disease are given where a planned biopsy is necessary for appropriate and effective therapy.