Upregulation of phospholipase D in astrocytes in response to transient forebrain ischemia

Previous in vitro studies using cell cultures or brain slices have demonstrated that phospholipase D (PLD) in the nervous system is involved in the signaling mechanism in response to a variety of agonists. However, little is known about the pathophysiological role of PLD-mediated signaling in the adult brain. We examined the changes in the expression of a PLD isozyme, PLD1, in the adult rat hippocampus, using immunological approaches and an assay for PLD activity after transient forebrain ischemia (four-vessel occlusion model) that results in the selective delayed death of CA1 pyramidal cells and induces reactive astrocytes in the CA1 subfield. In the control hippocampus, PLD1 the level of immunoreactivity was very low. After ischemia, in parallel with the results of Western blot analysis and the PLD activity assay, immunohistochemical analysis of PLD1 demonstrated that the immunoreactive proteins peaked at 7-14 days and were most prominent in the CA1 and the dentate hilar region. The temporal and spatial patterns of immunoreactivity of both PLD1 and glial fibrillary acidic protein (GFAP) were very similar, indicating that reactive astrocytes express PLD1, confirmed by double staining for PLD1 and GFAP. These results demonstrate that reactive astrocytes upregulate PLD in vivo after injury in the adult rat hippocampus.

The bursal and articular sides of the supraspinatus tendon have a different compressive stiffness

OBJECTIVE

To measure the compressive stiffness of the supraspinatus tendon and to determine whether regional difference exists in the bursal and articular side of the tendon.

DESIGN

Indentation testing was performed on both the bursal and articular sides of the supraspinatus tendon, focused on the 'critical area', where rotator cuff tears often occur.

BACKGROUND

When the supraspinatus tendon wraps around the humeral head or is under impingement condition, compressive force on the tendon surface is expected. Therefore, compressive stress has been recently considered to be one of the important factors associated with the cuff tear. The mechanical properties would be essential for analytic modeling of stress distribution.

METHODS

Indentation tests were performed at 15 locations on the bursal and articular surfaces of the supraspinatus tendon. A mathematical model with exponential relationship was used to describe the measured force-deformation relationship and to calculate the compressive stiffness of the supraspinatus tendon.

RESULTS

The over-all initial stiffness on the bursal and articular sides of the tendon was significantly different. On the bursal side, the anterior third had a significantly higher initial stiffness than the other thirds on average. On the articular side, initial stiffness at location 10 mm proximal to the greater tuberosity was significantly higher than the rest on average.

CONCLUSIONS

The compressive stiffness of the supraspinatus tendon was found to be non-homogenous throughout the structure.RelevanceNon-homogenous compressive stiffness of the supraspinatus tendon would affect the load transmission within the tendon, which might be associated with the potential mechanism of tear. Such characteristics needs to be considered when performing finite element modeling of stress fields in the tendon.

Cloning of a sesquiterpene cyclase and its functional expression by domain swapping strategy

Sesquiterpene cyclase, the first committed step enzyme from the general isoprenoid building block farnesyl pyrophosphate (FPP) for the synthesis of phytoalexin capsidiol, was isolated from the UV-C treated leaves of Capsicum annuum. This sesquiterpene cyclase, termed as CASC2 showing 77% amino acid identity with the previously cloned sesquiterpene cyclase CASC1, was composed of 560 amino acids with a calculated molecular mass of 64,907. The mRNA expression pattern of CASC2 was very similar to that of CASC1 during the time course of UV-C irradiated leaves of pepper on RNA blot analysis by using each specific probe. The heterologous expression in Escherichia coli using the CASC2 full length failed; however the chimeric construct of CASC2 in which the amino terminal 164 amino acid substituted by the equivalent portion of either CASC1 or tobacco sesquiterpene cyclase was capable of expressing the functional sesquiterpene cyclase activities. The radio-labeled enzymatic products catalyzed by the partially purified chimeric CASC2 were comigrated with authentic radio-labeled sesquiterpene on thin layer chromatography.

Suppression of TGF-beta signaling in both normal conjunctival fibroblasts and pterygial body fibroblasts by amniotic membrane

PURPOSE

When used as an alternative substrate following bare sclera removal of pterygium and other ocular surface diseases, amniotic membrane transplantation can reduce scarring on the reconstructed conjunctival surface. This study was carried out to determine if the amniotic membrane (AM) suppresses the expression of the TGFb signaling system in cultured normal conjunctival (HCF) and pterygial body fibroblasts (PBF).

METHODS

HCF and PBF were cultured on AM and plastic wells in serum-containing and serum-free DMEM with or without TGF-beta1. Total RNA was extracted and subjected to Northern hybridization with probes of TGF-beta1, b2 and b3; TGF-beta receptors (TGF- beta R) type I, II and III; a-smooth muscle actin (alpha-SM), b1-integrin, CD44, fibroblast growth factor receptor 1 (FGF-R1/ flg) and platelet-derived growth factor receptor b (PDGFR-beta); and GAPDH as a loading control. MTT assay was used for cell proliferation.

RESULTS

Amniotic membrane markedly suppressed the transcript expression of TGF-beta2, b3 and all three types of TGF-beta receptors by both fibroblasts as compared to their cultures on plastic surface. In addition, expression of CD44 transcript was also markedly suppressed while that of b1 integrin, a-SM actin, and FGFR1/flg was mildly suppressed. In contrast, expression of TGF-beta1 and PDGFR-beta remained largely unchanged. The cell proliferation of HCF and PBF grown on AM was also significantly suppressed.

CONCLUSIONS

Amniotic membrane matrix uniquely suppresses TGF- beta signaling in both types of fibroblasts. It may also suppress signaling via CD44, b1 integrin and FGFR1/flg. As a result, the phenotype may become less mitogenic, contractile and fibrogenic. These data support in part why amniotic membrane transplantation has an anti-scarring effect for conjunctival surface reconstruction.

Synthesis and biological activity of aspirin derivatives

Aspirin has been widely used as analgesic and anti-inflammatory drug. Recently, it was elucidated that aspirin have anti-coaggregatory effect in low dose. This study was carried out to investigate the synthesis of aspirin derivatives from aspirin and aromatic compound of antioxidant and its biological activities. Synthesis of aspirin derivatives was prepared by esterification in the presence of 1,1-carbonyldiimidazole. Biological activities was examined using effect of anti-coagulant on bleeding time, effect of antioxidant and effect of anti-platelet aggregation. As a result, SJ-101 showed strong antioxidative activity and anti-coagulant activity among four compounds. Anti-platelet aggregation of SJ-101 was examined by collagen, ADP, PAF method. SJ-101 exhibited more stronger activity to aspirin at collagen aggregation reaction. These finding demonstrates that SJ-101 is useful as care drug of aging and old-disease because of its has antioxidant activity, anti-coagulant activity and anti-platelet activity.

Analysis of growth rate effects on productivity of recombinant Escherichia coli populations using molecular mechanism models. Reprinted from Biotechnology and Bioengineering, Vol. 26, Issue 1, Pages 66-73 (1984)

The influence of growth rate on Escherichia coli plasmid content and expression of a cloned-gene product has been described by a mathematical model based upon the molecular mechanism of lambdadv plasmid replication and known relationships between growth rate and transcription and translation activities of the host cell. The model simulates correctly decreases in plasmid content with increasing growth rate as observed experimentally for pBR322, NR1, R1, and Col E1 plasmids. A maximum with respect to growth rate in intracellular product accumulation is indicated by the model, as is a transient overshoot in product concentration following a shift from smaller to larger growth rate. Available data, although very limited, show the same trends. These results, obtained without parameter or kinetic form adjustments or manipulation, clearly illustrate the advantages of kinetic descriptions of recombinant systems based upon the pertinent molecular mechanisms.

Incidence and survival characteristics of retinoblastoma in Singapore from 1968-1995

PURPOSE

To describe the incidence and survival of 69 Singapore residents with retinoblastoma in all Singapore hospitals from 1968-1995.

METHODS

Data of all Singapore residents diagnosed with retinoblastoma from 1968-1995 were collected by the Singapore Cancer Registry based on notifications from physicians, pathology records, hospital discharge records, and death certificates. The medical records of 46 patients were traced, and information on laterality of tumor, spread of tumor, mode of treatment, and family history of retinoblastoma was obtained. Time trends and survival characteristics of the cohort were described.

RESULTS

The incidence rate of retinoblastoma was 2.4 per 1 million for children <9 years and 11.1 per 1 million for children <5 years. The incidence of retinoblastoma has been almost uniform over time from 1968-1995, except for an apparent increase in 1988-1992. The 3-year survival rate for retinoblastoma was 83%. Survival rates were higher in children <2 years because children who present at a younger age may have tumors diagnosed at earlier stages of the disease. There was no difference in survival rates for sex, race, laterality, family history of retinoblastoma, treatment, or year of diagnosis.

CONCLUSION

Retinoblastoma is the most common eye cancer in children that may cause blindness or death. The incidence rates of retinoblastoma in Singapore have remained fairly stable over 28 years, and the survival rate is higher in younger children. This study will be helpful in monitoring future disease patterns in Asian populations.

Acidosis induces necrosis and apoptosis of cultured hippocampal neurons

Acidosis, hypoxia, and hypoglycemia rapidly and transiently appear after reduction of cerebral blood flow. Acidosis also accompanies head trauma and subarachnoid hemorrhage. These insults result in necrotic and apoptotic loss of neurons. We previously demonstrated that transient acidification of intracellular pH from 7.3 to 6.5 induces delayed neuronal loss in cultured hippocampal slices (49). We now report that acidosis induced both necrotic and apoptotic loss of neurons. Necrosis and apoptosis were distinguished temporally and pharmacologically. Necrosis appeared rapidly and was dose dependent with the duration of the acidosis treatment. Apoptosis was delayed with maximal number of apoptotic cells seen with a 30-min acidosis treatment. Apoptotic neuronal loss was accompanied by DNA fragmentation and was blocked by inhibitors of protein and RNA synthesis, ectopic expression of the anti-apoptotic gene bcl-2, or an inhibitor of caspases, proteases known to be activated during apoptosis. Necrotic neuronal loss was unaffected by these treatments. Hypothermia, a treatment known to attenuate neuronal loss following a variety of insults, blocked both acidosis-induced necrosis and apoptosis. These results indicate that acidosis is neurotoxic in vitro and suggest that acidosis contributes to both necrotic and apoptotic neuronal loss in vivo.

The effect of a glenoid defect on anteroinferior stability of the shoulder after Bankart repair: a cadaveric study

BACKGROUND

An osseous defect of the glenoid rim is sometimes caused by multiple recurrent dislocations of the shoulder. It is generally thought that a large defect should be treated with bone-grafting, but there is a lack of consensus with regard to how large a defect must be in order to necessitate this procedure. Some investigators have proposed that a defect must involve at least one-third of the glenoid surface in order to necessitate bone-grafting. However, it is difficult to determine (1) whether a defect involves one-third of the glenoid surface and (2) whether a defect of this size is critical to the stability of the shoulder after a Bankart repair. The purposes of the present study were (1) to create and quantify various sizes of osseous defects of the glenoid and (2) to determine the effect of such defects on the stability and motion of the shoulder after Bankart repair.

METHODS

The glenoids from sixteen dried scapulae were photographed, and the images were scanned into a computer. The average shape of the glenoid was determined on the basis of the scans, and this information was used to design custom templates for the purpose of creating various sizes of osseous defects. Ten fresh-frozen cadaveric shoulders then were obtained from individuals who had been an average of seventy-nine years old at the time of death, and all muscles were removed to expose the joint capsule. With use of a custom multiaxis electromechanical testing machine with a six-degrees-of-freedom load-cell, the humeral head was translated ten millimeters in the anteroinferior direction with the arm in abduction and external rotation as well as in abduction and internal rotation. With a fifty-newton axial force constantly applied to the humerus in order to keep the humeral head centered in the glenoid fossa, the peak force that was needed to translate the humeral head a normalized distance was determined under eleven sequential conditions: (1) with the capsule intact, (2) after the creation of a simulated Bankart lesion, (3) after the capsule was repaired, (4) after the creation of an anteroinferior osseous defect with a width that was 9 percent of the glenoid length (average width, 2.8 millimeters), (5) after the capsule was repaired, (6) after the creation of an osseous defect with a width that was 21 percent of the glenoid length (average width, 6.8 millimeters), (7) after the capsule was repaired, (8) after the creation of an osseous defect with a width that was 34 percent of the glenoid length (average width, 10.8 millimeters), (9) after the capsule was repaired, (10) after the creation of an osseous defect with a width that was 46 percent of the glenoid length (average width, 14.8 millimeters), and (11) after the capsule was repaired.

RESULTS

With the arm in abduction and external rotation, the stability of the shoulder after Bankart repair did not change significantly regardless of the size of the osseous defect (p = 0.106). With the arm in abduction and internal rotation, the stability decreased significantly as the size of the osseous defect increased (p<0.0001): the translation force in shoulders in which the width of the osseous defect was at least 21 percent of the glenoid length (average width, 6.8 millimeters) was significantly smaller than the force in shoulders without an osseous defect. The range of external rotation in shoulders in which the width of the osseous defect was at least 21 percent of the glenoid length was significantly less than that in shoulders without a defect (p<0.0001) because of the pretensioning of the capsule caused by closing the gap between the detached capsule and the glenoid rim. The average loss of external rotation was 25 degrees per centimeter of defect.

CONCLUSIONS

An osseous defect with a width that is at least 21 percent of the glenoid length may cause instability and limit the range of motion of the shoulder after Bankart repair.

Effects of hen egg yolk immunoglobulin in passive protection of rainbow trout against Yersinia ruckeri

Anti-Yersinia ruckeri egg yolk immunoglobulin (IgY) was transferred to egg yolk after immunization of White Leghorn hens with formalin-killed whole cells of serovar 1 (RS1154) and serovar 2 (RS1153)Y. ruckeri and its lipopolysaccharide (LPS). The IgY was specific for its homologous LPS in western immunoblot, whereas some protein bands were commonly recognized, even by IgY from eggs of unimmunized hens. Purified LPS from both Y. ruckeri serovar types 1 and 2 had a very poor immunogenicity. The IgY activity was stable when processed into pellet form by a microbial transglutaminase treatment and showed a considerable resistance against acid pepsin for at least 2 h. Feeding specific anti-serovar 1 Y. ruckeri IgY to fish either before or after immersion infection produced marginal reductions in mortalities and in intestine infection. The same IgY did passively protect rainbow trout against infection when administered by intraperitoneal injection 4 h before an immersion challenge.

Effects of exogenous compatible solutes on growth of the hyperthermophilic archaeon Sulfolobus solfataricus

Six known compatible solutes as well as twenty L-amino acids were individually added to a glucose minimal medium and their effects on the growth of Sulfolobus solfataricus (DSM 1617) were examined. Among the compatible solutes tested, putrescine, trehalose, and l-glutamate enhanced the growth of S. solfataricus. On the other hand, glycine betaine, choline, and L-proline showed little or no influence on cell growth. When cells were grown in the glucose medium supplemented with trehalose or L-glutamate, S. solfataricus preferentially utilized the compatible solute over glucose. The growth-enhancement effect of L-glutamate was also observed to be dependent on the glucose concentration in the medium: growth enhancement was higher when the concentration of glucose was low and gradually decreased with increasing glucose concentration. Interestingly, the effects of amino acids on cell growth differed markedly depending on the chemical nature of the amino acid added. While acidic amino acids-L-glutamate and L-aspartate-enhanced the growth rate, almost no growth was observed in the presence of glycine, L-leucine, L-valine, L-phenylalanine, L-threonine, L-methionine, or L-cysteine. Among all the low-molecular-weight solutes tested in this study, the growth-stimulation effect was most profound in the presence of L-glutamate. When S. solfataricus cells were grown in a glucose (1.0 g/l) medium supplemented with 3.0 g/l L-glutamate, the maximal cell density and growth rate were about 3.2- and 2.3-fold higher than those obtained without L-glutamate.

Ablation of P/Q-type Ca(2+) channel currents, altered synaptic transmission, and progressive ataxia in mice lacking the alpha(1A)-subunit

The Ca(2+) channel alpha(1A)-subunit is a voltage-gated, pore-forming membrane protein positioned at the intersection of two important lines of research: one exploring the diversity of Ca(2+) channels and their physiological roles, and the other pursuing mechanisms of ataxia, dystonia, epilepsy, and migraine. alpha(1A)-Subunits are thought to support both P- and Q-type Ca(2+) channel currents, but the most direct test, a null mutant, has not been described, nor is it known which changes in neurotransmission might arise from elimination of the predominant Ca(2+) delivery system at excitatory nerve terminals. We generated alpha(1A)-deficient mice (alpha(1A)(-/-)) and found that they developed a rapidly progressive neurological deficit with specific characteristics of ataxia and dystonia before dying approximately 3-4 weeks after birth. P-type currents in Purkinje neurons and P- and Q-type currents in cerebellar granule cells were eliminated completely whereas other Ca(2+) channel types, including those involved in triggering transmitter release, also underwent concomitant changes in density. Synaptic transmission in alpha(1A)(-/-) hippocampal slices persisted despite the lack of P/Q-type channels but showed enhanced reliance on N-type and R-type Ca(2+) entry. The alpha(1A)(-/-) mice provide a starting point for unraveling neuropathological mechanisms of human diseases generated by mutations in alpha(1A).

Biochemical and pharmacological characteristics of a newly synthesized H+/K+-ATPase inhibitor, YJA20379-8, 3-butyryl-4-[R-1-methylbenzylamino]-8-ethoxy-1,7-naphthyridine, in pigs and rats

We have investigated the effect of the newly synthesized proton-pump inhibitor YJA20379-8, 3-butyryl-4-[R-1-methylbenzylamino]-8-ethoxy-1,7-naphthyridine, on gastric mucosal proton pump (H+/K+-ATPase) activity, gastric acid secretion and gastric lesions in experimental animals. In lyophilized pig gastric microsomes, YJA20379-8 was shown to inhibit H+/K+-ATPase activity; the inhibitory effect was not affected by pH, the IC50 (dose resulting in 50% inhibition) being 28.0 microM and 30.0 microM at pH 6.4 and pH 7.4, respectively. The effect was fully reversed by dilution and subsequent washing of the incubation mixtures of H+/K+-ATPase and YJA20379-8, suggesting the reversible nature of the enzyme inhibition. In pylorus-ligated rats, YJA20379-8 administered by different routes (intraduodenal, subcutaneous, intravenous or oral) resulted in dose-dependent suppression of basal gastric acid secretion. The duration of antisecretory action of 30 mg kg(-1) YJA20379-8 given intraduodenally was very brief (less than 7 h). Pretreatment with YJA20379-8 also dose-dependently prevented gastric lesions induced by absolute ethanol and water-immersion stress in rats. These results suggest that YJA20379-8 might exert its antiulcer activity partly by reversible suppression of acid secretion and partly by protecting the gastric mucosa against ulcerative stimuli.

Comparative study of the inhibition of alpha-glucosidase, alpha-amylase, and cyclomaltodextrin glucanosyltransferase by acarbose, isoacarbose, and acarviosine-glucose

Bacillus stearothermophilus maltogenic amylase hydrolyzes the first glycosidic linkage of acarbose to give acarviosine-glucose. In the presence of carbohydrate acceptors, acarviosine-glucose is primarily transferred to the C-6 position of the acceptor. When d-glucose is the acceptor, isoacarbose is formed. Acarbose, acarviosine-glucose, and isoacarbose were compared as inhibitors of alpha-glucosidase, alpha-amylase, and cyclomaltodextrin glucanosyltransferase. The three inhibitors were found to be competitive inhibitors for alpha-glucosidase and mixed noncompetitive inhibitors for alpha-amylase and cyclomaltodextrin glucanosyltransferase. The K(i) values were dependent on the type of enzyme and their source. Acarviosine-glucose was a potent inhibitor for baker's yeast alpha-glucosidase, inhibiting 430 times more than acarbose, and was an excellent inhibitor for cyclomaltodextrin glucanosyltransferase, inhibiting 6 times more than acarbose. Isoacarbose was the most effective inhibitor of alpha-amylase and cyclomaltodextrin glucanosyltransferase, inhibiting 15.2 and 2.0 times more than acarbose, respectively.

The Wilms tumor suppressor WT1 encodes a transcriptional activator of amphiregulin

WT1 encodes a zinc finger transcription factor implicated in kidney differentiation and tumorigenesis. In reporter assays, WT1 represses transcription from GC- and TC-rich promoters, but its physiological targets remain uncertain. We used hybridization to high-density oligonucleotide arrays to search for native genes whose expression is altered following inducible expression of WT1. The major target of WT1 was amphiregulin, a member of the epidermal growth factor family. The WT1(-KTS) isoform binds directly to the amphiregulin promoter, resulting in potent transcriptional activation. The in vivo expression profile of amphiregulin during fetal kidney development mirrors the highly specific pattern of WT1 itself, and recombinant Amphiregulin stimulates epithelial branching in organ cultures of embryonic mouse kidney. These observations suggest a model for WT1 as a transcriptional regulator during kidney differentiation.

A novel function of IL-12p40 as a chemotactic molecule for macrophages

IL-12p70 plays a pivotal role in regulating the Th1/Th2 balance in the initial stage of immune responses. In contrast, IL-12p40, which is produced excess over IL-12p70, has been known to down-regulate IL-12p70-mediated responses by acting as an antagonist. To investigate in vivo function of IL-12p40, RH7777 rat hepatoma cells were engineered to inducibly express mouse IL-12p40 under the tight control of doxycycline (dox). In the absence of dox, s.c. injection of these cells into syngeneic rat was shown to generate tumors. However, the induction of IL-12p40 by dox was sufficient for inhibiting tumor formation, as well as for tumor regression. Immunohistochemical analysis showed that macrophages, but not CD4+ T, CD8+ T, and NK cells, were predominantly recruited into tumor sites as early as 3 days after IL-12p40 induction. These results were further supported by the observation that IL-12p40, but not C-terminal deletion mutants by more than 5 amino acids, was able to chemoattract peritoneal macrophages in vitro, suggesting that IL-12p40, when produced in a large excess over IL-12p70 in vivo, can initially amplify the immune responses against tumors by directly recruiting macrophages. Our findings indicate that IL-12p40 may function as an effector molecule as well as an antagonist of IL-12p70.

Transient upregulation of osteopontin mRNA in hippocampus and striatum following global forebrain ischemia in rats

We investigated the spatial and temporal expression of osteopontin (OPN) mRNA following transient forebrain ischemia in rats. Experiments were carried out using a four-vessel occlusion model for forebrain ischemia. The transient induction of OPN mRNA after global ischemia occurred earlier in the striatum than in the hippocampus. It was pronounced in the dorsomedial striatum close to the lateral ventricle and in the CA1 subfield and the subiculum of the hippocampus before microglial cells became more reactive. It also could be detected in the dentate hilus and to a marginal extent in the CA3. Our results suggest that the hippocampus and the striatum following global forebrain ischemia upregulate OPN mRNA in different spatiotemporal profiles.

Differential expression and regulation of TGF-beta1, TGF-beta2, TGF-beta3, TGF-betaRI, TGF-betaRII and TGF-betaRIII in cultured human corneal, limbal, and conjunctival fibroblasts

PURPOSE

We have reported that three patterns of cytokine expression are potentially involved between epithelia and fibroblasts of the human ocular surface. The TGF-beta family is a prototypical fibrogenic cytokine responsible for fibroblast activation in wound healing. We investigated how the TGF-beta family is differentially expressed and regulated in cultured human corneal, limbal and conjunctival fibroblasts.

METHODS

Human corneal (HCF), limbal (HLF) and conjunctival fibroblast (HJF) were cultured in DMEM-10% FBS until confluence and switched to serum-free DMEM-ITS for 48 h before adding 10 ng/ml of each of eight cytokines for 4 h in three separate experiments. Total RNA was isolated and subjected to Northern hybridization with GAPDH as a control. ELISA was used to determine TGF-beta1 and TGF-beta2 proteins in the media.

RESULTS

All three isoforms of TGF-beta and three types of TGF-betaR were expressed by HCF, HLF and HJF. Expression of TGF-beta1 mRNA was strongest and upregulated by the three TGF-betas in all three types of fibroblast. PDGF-BB and TGF-alpha slightly increased TGF-beta1 mRNA. TGF-betas also upregulated TGF-beta3 mRNA in HJF. TGF-betaRI mRNA was the only receptor upregulated by TGF-betas. TGF-betaRII and TGF-betaRIII mRNA were not regulated by all cytokines tested.

CONCLUSIONS

TGF-betas auto-induction is the major mechanism upregulating TGF-beta1 expression. Promotion of TGF-beta3 by the TGF-betas may have a special role in HJF. Differential expression and regulation of TGF-betas and TGF-betaRs suggest that each TGF-beta isoform may have specific functions in different ocular surface fibroblasts. No cytokine tested can downregulate TGF-beta1 and the TGF-betaRs.

Incidence of eyelid cancers in Singapore from 1968 to 1995

AIM

To describe the epidemiological characteristics of patients with eyelid malignancies seen in all hospitals in Singapore from 1968 to 1995.

METHOD

The Singapore Cancer Registry has been collecting epidemiological data of all cancers seen in Singapore since 1968. The data of all cases of Singapore residents with eyelid cancers diagnosed from 1968 to 1995 (ICD-9, sites 172.1 and 173.1) were retrieved for analysis.

RESULTS

There were 162 male patients (49.8%) and 163 females (50.2%). The median age at diagnosis was 63 years in males and 66 years in females. The average annual age standardised incidence rate among male Singapore residents was 6.5 per million and 5.5 per million among female Singapore residents. Between 1993 and 1995, the average annual rate for females was 6.8 per million, compared with 3.1 per million between 1968 and 1972. The most common cancer was basal cell carcinoma (84.0%), followed by sebaceous adenocarcinoma (10.2%) and squamous cell carcinoma (3.4%).

CONCLUSION

The annual age standardised incidence for male residents has remained relatively stable. The incidence for female residents has shown a steady increase over the past 28 years. The incidence for males is generally higher than that for females. These expanded epidemiological characteristics may serve to provide a foundation to monitor future disease patterns and to promote further research into the aetiology of these cancers.

Biochemical and pharmacological characteristics of a newly synthesized H+-K+ ATPase inhibitor, YJA20379-1, 2-amino-4,5-dihydro-8-phenylimidazole[2,1-b]thiazolo[5,4-g]benzothiazol e

The biochemical and pharmacological characteristics of a newly synthesized H+-K+ ATPase inhibitor, 2-amino-4,5-dihydro-8-phenylimidazole[2,1-b]thiazolo[5,4-g]benzothiazole (YJA20379-1), were investigated. In the pig gastric microsomes, YJA20379-1 inhibited the gastric H+-K+ ATPase regardless of pH condition, IC50 values being 21 and 24 microM at pH 6.4 and 7.4, respectively. The inhibitory activity of YJA20379-1 was antagonized by dithiothreitol treatment but could not be reversed by dilution and washing of the enzyme preparation. In Sprague-Dawley rats, YJA20379-1, administered i.d., p.o, i.v., or s.c., significantly inhibited basal gastric acid secretion, with ED50 values of 4.7, 20.2, 6.3, and 13.4 mg/kg, respectively. The antisecretory action of YJA20379-1 was short lasting (less than 7 h at an oral dosing of 30 mg/kg). Oral administration of YJA20379-1 also prevented the formation of ethanol, indomethacin, and water immersion stress induced gastric lesions and mepirizole-induced duodenal ulcers in rats. Furthermore, YJA20379-1 accelerated the healing of acetic acid induced chronic gastric ulcers in rats. In conclusion, these results suggest that YJA20379-1 has a potent inhibitory activity on the gastric H+-K+ ATPase but much shorter duration of antisecretory action than omeprazole, thereby exerting its anti-ulcer effects partly with cytoprotective activity.

Management of subluxated crystalline lenses with planned intracapsular cataract extraction and anterior chamber intraocular lens implantation

PURPOSE

To review the visual and surgical outcome of planned intracapsular cataract extraction (ICCE) and anterior chamber intraocular lens (AC IOL) implantation for subluxated crystalline lenses.

METHODS

Eight eyes of 7 patients with subluxated lenses which underwent planned ICCE, AC IOL implantation and peripheral iridectomy by one surgeon between September 1995 and November 1996 were prospectively followed-up to ascertain their visual and surgical outcome.

RESULTS

There were 4 male and 3 female patients. Their mean age was 64.4 years (range, 39-86 years). Seven lenses were removed by cryoextraction while one was removed with the aid of a vectis. The mean post-operative follow-up was 11.6 months, (range, 3-22 months). Excluding 1 eye with pre-existing ocular pathology, all eyes achieved a best corrected visual acuity (BCVA) of 6/12 or better post-operatively. One of these eyes, in a schizophrenia patient, developed subluxation of the AC IOL and retinal detachment 11 months after the cataract surgery due to repeated eye rubbing. The final BCVA became 6/120 after successful repositioning of the AC IOL and retinal re-attachment surgery. One eye achieved a BCVA of 6/36 due to age-related macular degeneration.

CONCLUSION

Our results show that planned ICCE and AC IOL implantation is a useful and safe procedure in the management of subluxated lenses.

Posteroinferior glenoplasty can change glenoid shape and increase the mechanical stability of the shoulder

The treatment of recurrent posterior glenohumeral instability remains an unsolved clinical problem. Although various types of capsulorraphy have been advocated, outcome studies indicate that it is difficult to achieve a balance between stability and mobility. Alterations of the bony glenoid for posterior instability have been proposed, but are not well understood from a mechanical perspective. This investigation had 2 purposes: (1) to determine in a cadaver model if posteroinferior glenoplasty can change the shape of the glenoid, and (2) to determine if altering the shape of the glenoid can increase the mechanical stability of the glenohumeral joint. We determined the effective glenoid shape in 7 normal cadaver glenoids by tracking the path of the center of the humeral head as it was translated across the glenoid face in 8 different directions. These determinations enabled us to calculate the maximum effective slope of the glenoid in each direction. We then determined the mechanical stability of the glenoids in each of the 8 directions by measuring the tangential force required to dislocate the shoulder under a 50-N compressive load. The ratio of the dislocating force to the compressive load was defined as the stability ratio. All measurements were repeated after a standardized posteroinferior glenoplasty was performed. Posteroinferior glenoplasty increased the posteroinferior glenoid depth from 3.8 +/- 0.6 mm to 7.0 +/- 1.8 mm and shifted the center of the humeral head an average of 2.2 mm anteriorly and 1.8 mm superiorly. These changes in dimension could be directly visualized as an immediate mechanical consequence of the glenoplasty procedure, particularly because of the insertion of the bone wedge. Glenoplasty increased the posteroinferior glenoid slope from 0.55 +/- 0.07 to 0.83 +/- 0.12 and increased the posteroinferior stability ratio from 0.47 +/- 0.10 to 0.81 +/- 0.17. This is a more than 70% increase in the tangential force that can be resisted before dislocation. The increase can be quantitatively understood as a direct mechanical consequence of the altered shape of the glenoid concavity. These numbers indicate that, in this cadaveric model, posteroinferior glenoplasty results in defined changes in the effective glenoid shape and in the mechanical stability of the glenohumeral joint. However, this study does not establish the role of this procedure in the clinical management of posterior glenohumeral instability.

Comparison of inferior oblique muscle weakening by anterior transposition or myectomy: a prospective study of 20 cases

BACKGROUND/AIMS

Among the various weakening techniques of inferior oblique muscle overaction, the most commonly used techniques include myectomy, recession, and anterior transposition. Anterior transposition and myectomy were compared to evaluate the surgical results in inferior oblique overaction.

METHODS

20 children with bilateral +3 overacting inferior oblique muscles underwent a prospective randomised study by which the anterior transposition procedure in one eye was compared with the myectomy procedure in the other eye.

RESULTS

Postoperative follow up averaged 2 years. The success rates in two surgical procedures were 85% for the anterior transposition and 25% for the myectomy (standard of success was based on zero inferior oblique overaction). In only one case did the anterior transposition tend to limit the elevation of the eye in the midline, adduction, and abduction. Anterior transposition produced hypotropia at the primary position in only one case. Most eyes that underwent myectomy (75%) showed apparent residual overaction.

CONCLUSION

The anterior transposition appeared to be more effective in eliminating the overaction of inferior oblique muscle than the myectomy.

Disruption of PMR1, encoding a Ca2+-ATPase homolog in Yarrowia lipolytica, affects secretion and processing of homologous and heterologous proteins

The Yarrowia lipolytica PMR1 gene (YlPMR1) is a Saccharomyces cerevisiae PMR1 homolog which encodes a putative secretory pathway Ca2+-ATPase. In this study, we investigated the effects of a YlPMR1 disruption on the processing and secretion of native and foreign proteins in Y. lipolytica and found variable responses by the YlPMR1-disrupted mutant depending on the protein. The secretion of 32-kDa mature alkaline extracellular protease (AEP) was dramatically decreased, and incompletely processed precursors were observed in the YlPMR1-disrupted mutant. A 36- and a 52-kDa premature AEP were secreted, and an intracellular 52-kDa premature AEP was also detected. The acid extracellular protease activity of the YlPMR1-disrupted mutant was increased by 60% compared to that of the wild-type strain. The inhibitory effect of mutations in secretory pathway Ca2+-ATPase genes on the secretion of rice alpha-amylase was also observed in the Y. lipolytica and S. cerevisiae PMR1-disrupted mutants. Unlike rice alpha-amylase, the secretion of Trichoderma reesei endoglucanase I (EGI) was not influenced by the YlPMR1 disruption. However, the secreted EGI from the YlPMR1-disrupted mutant had different characteristics than that of the control. While wild-type cells secreted the hyperglycosylated form of EGI, hyperglycosylation was completely absent in the YlPMR1-disrupted mutant. Our results indicate that the effects of the YlPMR1 disruption as manifested by the phenotypic response depend on the characteristics of the reporter protein in the recombinant yeast strain evaluated.