Comparative Study on Calretinin Immunoreactivity in Gerbil and Rat Retina

Expression of calretinin in retina has been ascribed to multiple biological and functional aspects in the visual system. In this study, we examined the distribution patterns of calretinin immunoreactivity in gerbil and rat retina. In the gerbil, calretinin immunoreactivity was present in bipolar and amacrine cells of the inner nuclear layer and in neurones of the ganglion cell layer. In the rat, amacrine and ganglion cells showed calretinin immunoreactivity, but bipolar cells did not contain calretinin immunoreactivity. In both species, calretinin immunoreactivity was absent in cones, cone bipolars, and horizontal cells. In conclusion, gerbil as well as rat has a rod-dominant retina. The differences in calretinin expression between rat and gerbil require further investigations under various functional and developmental conditions.

Hydroxyurea (HU)-induced apoptosis in the mouse fetal tissues

Hydroxyurea (HU), a ribonucleotide reductase inhibitor, induces morphological anomalies in the central nervous system (CNS), craniofacial tissues and limb buds in animals, and neonatal respiratory distress in humans. In the present study, pregnant mice were treated with 400 mg/kg of HU at day 13 of gestation, and their fetuses were examined from 1 to 48 hours after treatment (HAT) to find a clue to clarify the mechanisms of HU-induced fetotoxicity and teratogenecity. At 6 and 12 HAT, a moderate to marked increase in the number of pyknotic cells was detected in the CNS and lung. A mild increase in the number of pyknotic cells was also found in the craniofacial mesenchymal tissues, limb buds and so on. These pyknotic cells had nuclei positively stained by the TUNEL method, which is widely used for the detection of apoptotic nuclei, and they also showed electron microscopic characteristics identical to those of apoptotic cells. The present results suggest that the HU-induced fetotoxicity is characterized by excess apoptotic cell death in the fetal tissues, and that such excess cell death in the fetal CNS, lung, craniofacial tissue and limb bud may have a certain relation to the later occurrence of morphological or functional anomalies reported in these tissues following HU-administration.

Nutrient removal processes for low strength wastewater

For nutrient removal from low strength wastewater, biological nutrient removal (BNR) processes available at present are not efficient due to the shortage of organic carbon. By using the carbon source obtained from the degradation of return sludge, it was attempted to enhance the efficiency of denitrification and phosphorus release. Based on its degradation mechanism, the ENR (Endogenous Nitrate Respiration) process was developed and compared with the conventional A2/O (Anaerobic/Anoxic/Aerobic), MUCT (Modified University of Cape Town) processes. In the experiment, the specific phosphorus release rates of A2/O, MUCT, and ENR processes were 0.8, 2.3, and 2.6 mg PO1-P g1 MLVSS-h. As the nitrate concentration decreased below 3.0 mg NO1-N l1 due to the endogenous nitrate respiration, the effluent nitrate of the ENR process was lower than the A2/O process and the MUCT process by 25% and 10% while the phosphorus removal efficiencies increased by 15% and 6%, respectively. It was found that the ENR process was an effective and economical alternative for removing nutrient from low strength wastewater

Novel method for enhancing permeate flux of submerged membrane system in two-phase anaerobic reactor

A two-phase anaerobic reactor system with a submerged membrane in the acidogenic reactor was designed for the enhancement of organic acid conversion and methane recovery. A submerged membrane system in a two-phase anaerobic reactor was tested to increase the sludge retention time (SRT) of acidogen and to enhance the solid separation. The pilot plant experiment was performed for piggery wastewater treatment for a year. The membrane material used was mixed esters of cellulose of 0.5 micron pore size. COD removal efficiency was 80% and the methane production showed 0.32 m3/kg COD removed for the submerged membrane system in the anaerobic digester. As the cake resistance of the membrane caused a serious problem, a stainless-steel prefilter and air backwashing methods were applied to minimize the cake resistance effectively. Among the tested prefilters, the 63 microns pore prefilter showed the best performance for reducing cake resistance and a successful long-term operation. By cleaning with alkali first and acidic solutions later, the permeate flux decreased by long-term operation was recovered to 89% of that with a new membrane.

Identification of rice varieties with high tolerance or sensitivity to lead and characterization of the mechanism of tolerance

Pb inhibits plant growth. To study Pb tolerance in rice (Oryza sativa), we screened 229 varieties for Pb tolerance or sensitivity. Three-day-old seedlings were treated for 12 d with 20 microM Pb solution. Based on the dry weight of the root, three Pb-tolerant (var CH-55, var KH-2J, var Kumnung) and three Pb-sensitive (var Aixueru, var C-9491, var Milyang23) rice varieties were selected. The root biomasses of the tolerant varieties were approximately 10-fold higher than those of the sensitive ones. The greatest morphological difference between the two groups was in the growth of the adventitious roots, as tolerant lines were able to develop adventitious roots after 6 d of Pb treatment, whereas sensitive ones did not develop any even after 15 d. The growth of adventitious roots in the tolerant varieties was dependent on a mechanism, whereby Pb was altered to a form that cannot be taken up by the tissue, because (a) the solution in which the tolerant varieties of rice had grown still contained Pb but nevertheless did not affect the root growth of new rice seedlings, and (b) the adventitious roots of tolerant seedlings developed in Pb solution contained little Pb. The oxalate content in the root and root exudate increased upon Pb treatment in the tolerant varieties, whereas the opposite was observed for the sensitive ones. Oxalate added to the growth solution ameliorated the inhibition of root growth by Pb. These results suggest that compounds such as oxalate secreted from the root may reduce the bio-availability of Pb, and that this may constitute an important Pb tolerance mechanism in the tolerant rice varieties studied here.

Apoptosis in rabbit haemorrhagic disease

Rabbit haemorrhagic disease virus (RHDV) causes an acute hepatitis and disseminated intravascular coagulation. Six rabbits were inoculated experimentally with RHDV to investigate any potential relationship between infection and apoptosis in the liver. Two rabbits were killed at 12 h post-inoculation (PI) and two at 24 h PI. The remaining two rabbits died at 30 h and 31 h PI. Immunohistochemical labelling for RHDV antigen-positive cells, TUNEL assay for apoptotic cells, and DNA analysis were performed on samples of liver. The four rabbits that died or were killed 24-31 h PI had acute hepatitis with infiltration of heterophils and necrotic hepatocytes. RHDV antigen-positive cells and apoptotic cells appeared in the centriacinar areas at 12 h PI; subsequently they spread to periacinar areas and increased in number, but the viral antigen-positive cells outnumbered apoptotic cells. At 24-31 h PI, few apoptotic cells were recognized in the areas infiltrated with lymphocytes and heterophils. The results suggested an association between RHDV infection and apoptosis of hepatocytes.

Diagnostic accuracy in sinus fungus balls: CT scan and operative findings

A fungus ball may be characterized by its radiologic and operative gross findings. Computed tomography (CT) revealed a rim of soft tissue attenuation of variable thickening along the bony walls of the isolated paranasal sinus, or mottled hyperdense foci of variable size. A small amount of friable muddy mass surrounded by purulent secretions or dirty brown clay-like materials provide highly pathognomonic findings. However, these characteristics may induce clinical misdiagnosis. During the last four years we experienced 11 cases of chronic paranasal sinusitis in which pathologic examination failed to confirm fungal hyphae, despite clinical suspicion of a fungus ball based on operative or CT findings. During the same period, we also experienced another 52 patients who were diagnosed with fungus ball at pathologic examination. To evaluate the diagnostic accuracy of CT scans and operative gross findings in sinus fungus balls, we reviewed the medical records of these 63 patients and also reviewed CT scans and operative records of another 1127 patients who received endoscopic sinus surgery for chronic rhinosinusitis. The sensitivity of CT evaluation was 62%, and specificity was 99%. The false-positive and false-negative rate were 22% and 2%, respectively. With regard to operative findings, such as clay-like inspissated mucus, the sensitivity, specificity, and predictive value positive rate were 100%, 99%, and 83%, respectively. To make a diagnosis of fungus ball, a high index of suspicion is necessary and a pathologic confirmation is mandatory.

Identification of p53 gene mutations in breast cancers and their effects on transcriptional activation function

Somatic mutations in the p53 tumor suppressor gene are the most common genetic alterations found in human malignancies. In the present study, we studied 36 primary human breast carcinomas, using a polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and sequencing analysis of exons 2 through 9 for the presence of p53 gene mutations. Six of 36 (17%) breast cancers contained mutations within the core domain of the p53 protein responsible for sequence-specific DNA binding (codons 102-292); all 5 missense mutations clustered between codons 240 and 291 (codons 240, 243, 250, 285, and 291), whereas one nonsense mutation occurred at codon 199. By using recombinant PCR in vitro mutagenesis, we introduced point mutations at codons 199 from Gly to stop (gly199stop), 240 from Ser to Ile (ser240Ile), 250 from Pro to Ala (pro250ala), 285 from Glu to Lys (glu285lys), and 291 from Lys to Asn (lys291asn), and all the p53 sequences were subcloned into the CMVneoBam vector under the control of the cytomegalovirus (CMV) promoter. To test whether the mutants p53 were functionally wild-type (wt) or mutant, we transfected them to p53-null Saos-2 cells with a reporter plasmid containing a p53-responsive element, and performed chloramphenicol acetyltransferase (CAT) assay. Transient CAT assay for transcriptional activation revealed that one group, including gly199stop, ser240ile, glu285lys, and lys291asn, abolished the transcriptional activity, whereas the other group, including pro250ala, retained stronger transcriptional transactivation activity than that of wt p53.

Narrow internal auditory canal syndrome: parasaggital reconstruction

Narrow internal auditory canal (IAC) syndrome is a malformation of the temporal bone, that is defined as an IAC diameter of only 1-2 mm on high-resolution computed tomographic scans (HRCT). This syndrome is known to be caused by the absence (aplasia or hypoplasia) of the vestibulocochlear nerve. We present a case of unilateral narrow IAC syndrome which was diagnosed by HRCT. The aplasia of the vestibulocochlear nerve was confirmed using parasigittal reconstruction magnetic resonance image (MRI). The IAC was composed of two separate canals, one of which contained a facial nerve and the other was empty with aplasia of the vestibulocochlear nerve.

US in the diagnosis of pediatric chest diseases

Most pediatric chest diseases are adequately evaluated with chest radiography. However, when chest radiography does not allow identification of the location and nature of an area of increased opacity, ultrasonography (US) can help establish the diagnosis. US may be helpful in evaluation of persistent or unusual areas of increased opacity in the peripheral lung, pleural abnormalities, and mediastinal widening; US is particularly useful in patients with complete opacification of a hemithorax at radiography. In cases of pulmonary parenchymal lesions, identification of air or fluid bronchograms at US and of pulmonary vessels at color flow imaging is useful for differentiating pulmonary consolidation or atelectasis from lung masses and pleural lesions. US allows characterization of pleural fluid collections as simple, complicated, or fibroadhesive, which is important information for planning thoracentesis or thoracotomy. Computed tomography and magnetic resonance imaging are superior to US in evaluation of the mediastinum, but US is a reasonable alternative in certain situations (eg, to avoid unnecessary investigation of a normal thymus simulating a mediastinal mass). In cases of chest wall lesions, US may enable localization of the site of origin to soft tissues or an extrapleural intrathoracic location. Osseous involvement, particularly rib involvement, is easily evaluated with US.

Decreased osteopontin expression in the rat kidney on a sodium deficient diet

Osteopontin (OPN) is a secreted phosphoprotein that is constitutively expressed in the normal kidney and is induced by various experimental and pathologic conditions. Several possible functions of OPN have been suggested, however the mechanism and significance of OPN expression are still uncertain. Since high salt concentration or salt crystal have been known to enhance OPN expression in intact kidney or cultured renal cells, in the present study we examined whether or not a low salt condition had an effect on OPN expression in the kidney. Adult male Sprague-Dawley rats were fed either a normal sodium or a sodium deficient diet for 1 week. Kidneys were processed for in situ hybridization using a digoxigenin-labeled riboprobe and for immunohistochemistry using antibodies to OPN, renin, and Na-K-ATPase. In rats fed a normal sodium diet, OPN mRNA and protein were expressed only in the descending thin limbs of Henle's loop (DTL) and in the papillary and pelvic surface epithelium (PSE). In rats fed a sodium deficient diet, there was a marked decrease in OPN immunoreactivity in the DTL, but no changes in PSE. In contrast, no changes were observed in OPN mRNA expression in the DTL by in situ hybridization, indicating that decreased OPN protein expression was a result of translational regulation. As expected, rats fed a sodium deficient diet were associated with increased immunoreactivity for Na-K-ATPase and renin compatible with activation of the renin-angiotensin system. These results suggest that dietary sodium may be involved in the regulation of OPN expression in the DTL of the rat kidney.

Bioavailability of itraconazole in rats and rabbits after administration of tablets containing solid dispersion particles

A tablet dosage form containing solid dispersions of itraconazole (Asd tablets) was prepared by using the spray-drying and wet granulation methods. The dissolution rate of itraconazole from Asd tablets was fast, with more than 90% released within 10 min, compared to less than 20% for a marketed product, Sporanox capsules. The oral absorption of itraconazole from Asd tablets was determined in rats and rabbits and was compared with that for Sporanox capsules. In the rat, there was no difference between the Asd tablets and Sporanox capsules in the mean area under the curve (AUC) (3089.5 +/- 4332.8 ng.hr/ml and 3653.9 +/- 2348.9 ng.hr/ml, respectively) and Cmax (295.0 +/- 344.5 and 390.5 +/- 169.4 ng/ml, respectively). Also, in the rabbit, no difference was found between the two products in the mean AUC (AUMC; 19357.9 +/- 5117.5 ng.hr/ml and 23382.2 +/- 6236.5 ng.hr/ml, respectively) and Cmax (766.4 +/- 276.5 and 1127.5 +/- 577.9 ng/ml, respectively). Despite the rapid in vitro release characteristics of itraconazole from the Asd tablets, the in vivo absorption of itraconazole was comparable to that of Sporanox capsules, with no difference in Tmax in both animal species. Serum levels of the major active metabolite hydroxyitraconazole were also measured. Itraconazole was rapidly converted to hydroxyitraconazole in both rats and rabbits, but there were species-specific differences in their pharmacokinetics. It is concluded that, in addition to drug solubility and dissolution characteristics, other formulation factors such as the physical state of the drug and the granulation process, may also need to be considered in the prediction of the in vivo absorption of itraconazole based on in vitro data.

Enhanced solubility and dissolution rate of itraconazole by a solid dispersion technique

The aim of the present study was to improve the solubility and dissolution rate of a poorly water-soluble drug, itraconazole, by a solid dispersion technique. Solid dispersion particles of itraconazole were prepared with various pH-independent and -dependent hydrophilic polymers and were characterized by differential scanning calorimetry, powder X-ray diffraction and scanning electron microscopy. Of the polymers tested, pH-dependent hydrophilic polymers, AEA and Eudragit E 100, resulted in highest increases in drug solubility (range, 141.4-146.9-fold increases). The shape of the solid dispersion particles was spherical, with their internal diameter ranging from 1-10 microm. The dissolution rate of itraconazole from the tablets prepared by spray drying (SD-T) was fast, with > 90% released within 5 min.SD-T prepared with AEA or Eudragit E 100 at a 1:1 drug hydrophilic polymer ratio (w/w) showed approximately 70-fold increases in the dissolution rate over a marketed product.

Determination of the motif responsible for interaction between the rice APETALA1/AGAMOUS-LIKE9 family proteins using a yeast two-hybrid system

A MADS family gene, OsMADS6, was isolated from a rice (Oryza sativa L.) young flower cDNA library using OsAMDS1 as a probe. With this clone, various MADS box genes that encode for protein-to-protein interaction partners of the OsMADS6 protein were isolated by the yeast two-hybrid screening method. On the basis of sequence homology, OsMADS6 and the selected partners can be classified in the APETALA1/AGAMOUS-LIKE9 (AP1/AGL9) family. One of the interaction partners, OsMADS14, was selected for further study. Both genes began expression at early stages of flower development, and their expression was extended into the later stages. In mature flowers the OsMADS6 transcript was detectable in lodicules and also weakly in sterile lemmas and carpels, whereas the OsMADS14 transcript was detectable in sterile lemmas, paleas/lemmas, stamens, and carpels. Using the yeast two-hybrid system, we demonstrated that the region containing of the 109th to 137th amino acid residues of OsMADS6 is indispensable in the interaction with OsMADS14. Site-directed mutation analysis revealed that the four periodical leucine residues within the region are essential for this interaction. Furthermore, it was shown that the 14 amino acid residues located immediately downstream of the K domain enhance the interaction, and that the two leucine residues within this region play an important role in that enhancement.

Identification of a rice APETALA3 homologue by yeast two-hybrid screening

A cDNA clone OsMADS16 was isolated from the rice young inflorescence cDNA expression library by the yeast two-hybrid screening method with OsMADS4 as bait. We have previously shown that the OsMADS4 gene is a member of the PI family and that the MADS-box gene is involved in controlling development of the second and third whorls of rice flowers. The sequence comparison indicated that OsMADS16 belongs to the AP3 family. The OsMADS16 protein contains a PI-derived motif, FAFRVVPSQPNLH, that is a conserved sequence in AP3 family genes at the C-terminal region. In addition, OsMADS16 contains a paleoAP3 motif, YGGNHDLRLG, downstream of the PI-derived motif. The paleoAP3 motif is a consensus sequence in the C-terminal region of the AP3 family genes of lower eudicot and magnolid dicot species. RNA blot analysis showed that the OsMADS16 gene was expressed in the second and third whorls, whereas the OsMADS4 transcripts were present in the second, third, and fourth whorls. These expression patterns of the OsMADS16 and OsMADS4 genes are very similar to those of AP3 and PI, respectively. In the yeast two-hybrid system, OsMADS4 interacted only with OsMADS16 among several rice MADS genes investigated, suggesting that OsMADS4 and OsMADS16 function as a heterodimer in specifying sepal and petal identities. The OsMADS16 protein displayed transcription activation ability in yeast, whereas AP3 did not. It was also shown in yeast that OsMADS16 interacted with PI whereas OsMADS4 did not interact with AP3. These differences between OsMADS16 and AP3 indicate that the functions of the AP3 family genes of monocots and dicots diverged during molecular evolution processes of the B function genes. Deletion analysis showed that the 155-200 amino acid region of the OsMADS16 protein plays an important role in the transcription activation ability.

Korean dental hygienists' knowledge and opinions about etiology and prevention of dental caries

OBJECTIVES

Because of their formal education Korean dental hygienists have the potential to be the primary source of information on caries prevention for patients and the general public, and influence the use and adoption of caries preventive procedures. The purposes of this study were to determine the knowledge and opinions about caries etiology and prevention among Korean dental hygienists, and to describe associated factors.

METHODS

A pre-tested, 20-item questionnaire was mailed to 1120 dental hygienists selected by stratified random sampling and allocated proportionately. A postcard reminder was sent to all dental hygienists after 1 week. Non-respondents were sent additional complete mailings after 3 and 7 weeks. The response rate was 77% (n=863).

RESULTS

Analysis of six factors thought to be related to knowledge about caries etiology and prevention showed that dental hygienists who were taught to provide oral health education and believe that it is desirable to practice oral health education during dental hygiene school and those employed in health centers were likely to be more knowledgeable about caries etiology and prevention than other hygienists (P<0.05). In regression analysis of the perceived effectiveness of caries preventive procedures, hygienists who provided oral health education during their formal training tended to rate caries preventive procedures as being more effective than other dental hygienists (P<0.05).

CONCLUSIONS

Overall, the results of this study suggest that most dental hygienists do not have up-to-date information on the etiology and prevention of dental caries, mechanisms of action of fluoride and effectiveness of preventive procedures. Efforts to increase the level of knowledge of Korean dental hygienists about caries prevention should focus on strategies to educate dental hygienists who have not been taught to provide oral health education, who do not have favorable opinions about the desirability of oral health education, and who had no experience with providing oral health education as part of their work, especially hygienists working in private clinics. Further, these efforts should include the revision of dental hygiene curricula and continuing education courses.

A capsaicin-receptor antagonist, capsazepine, reduces inflammation-induced hyperalgesic responses in the rat: evidence for an endogenous capsaicin-like substance

In the present study, the presence of an endogenous capsaicin-like substance and the role of capsaicin receptors in nociception during inflammation were assessed using Fos immunohistochemistry and the paw-withdrawal test in rats. Intradermal injection of carrageenan in the hind-paw produced inflammation in the foot pad, increased the number of cells exhibiting Fos-like immunoreactivity in the dorsal horn of the spinal cord, and decreased the paw-withdrawal latency. Intradermal injection of capsazepine, a capsaicin-receptor antagonist, significantly reduced the number of cells exhibiting Fos-like immunoreactivity, significantly increased the paw-withdrawal latency, but did not decrease inflammation induced by carrageenan injection. Intradermal injection of capsaicin or formalin also increased Fos-positive neurons. Capsaicin- or formalin-induced Fos expression was reduced in both cases by pretreatment of capsazepine, but to a much lesser extent for formalin. The capsazepine inhibition of carrageenan inflammation-induced hyperalgesic responses strongly suggests that an endogenous capsaicin-like substance is released in inflamed tissues and produces nociceptive neural impulses by acting on capsaicin receptors present on sensory neurons. Furthermore, our results indicate that capsaicin receptors take part only in generating nociceptive signals in sensory neurons, but not in activating the inflammation-promoting cells.

Expressed sequence tags of radish flower buds and characterization of a CONSTANS LIKE 1 gene

Expressed sequence tag (EST) analysis was conducted for young flower buds of radish plants. Among a total of 66 ESTs examined, 40 showed a significant similarity to previously identified genes. Twenty-eight ESTs were similar to proteins identified in other plants, 11 were similar to eukaryotic proteins other than plants, and one was similar to a prokaryotic protein. Four clones were selected for further studies. EST clone 81, which showed a homology to germin-like proteins was expressed more abundantly in leaves and roots as compared to flower buds. Clone 105 was highly homologous to the translation inhibitor protein and was expressed in all three organs, but the expression level was higher in flower buds and roots. Another EST clone, 133, which shared a significant similarity with the Ran-binding protein, hybridized to two different size transcripts that were detectable only in flower buds. Clone 39 was a homolog of CONSTANS, which is a gene involved in controlling the flowering time in Arabidopsis. The cDNA clone of EST clone 39 containing the entire open reading frame was obtained and designated as RsCOL1 (Raphanus sativus CONSTANS LIKE 1). It was 1049 bp long and contained an open reading frame of 307 amino acid residues (calculated molecular mass = 33.1 kDa). The RsCOL1 protein contained two putative zinc finger motifs in the amino terminal region which were 59% identical to the corresponding region of the Arabidopsis CO protein. The radish protein also contained a predicted nuclear localization domain in the carboxyl terminal region which was 87% identical to the corresponding region of CO. DNA blot analysis revealed that the radish genome contained several genes similar to RsCOL1. RNA blot analysis showed that RsCOL1 was strongly expressed in flower buds at the early bolting stage, and the expression level declined as the flower bud matured. The transcript was also detectable in leaves and roots. In mature flowers, the RsCOL1 transcript was present primarily in carpels.

Inhibition by noncompetitive NMDA receptor antagonists of apomorphine-induced climbing behavior in mice

The N-methyl-D-aspartate (NMDA) subtype of glutamate receptors is an important mediator of several forms of neural and behavioral plasticity. In the present study, we examined the potential role of NMDA receptors in the glutamatergic modulation of dopaminergic function at the postsynaptic dopamine receptor by determining the effects of NMDA antagonists on apomorphine-induced climbing behavior in mice. The noncompetitive NMDA receptor antagonists, MK-801, ketamine, dextrorphan, and dextromethorphan attenuated the apomorphine-induced climbing behavior at does well below those that produce untoward side effects. These results suggest that the NMDA receptors play important roles in the glutamatergic modulation of dopaminergic function at the postsynaptic dopamine receptors that mediate the apomorphine-induced climbing behavior in mice.

Subpectoral implantation of ICD generators: long-term follow-up

A nonthoracotomy surgical approach using an endocardial electrode and combined implantation of a subcutaneous patch and the implantable cardioverter defibrillator (ICD) generator in a subpectoral pocket has been described. We report the long-term follow-up results in patients undergoing implantation using this approach. The patient population consisted of 28 patients (22 men and 6 women) with a mean age of 59 +/- 12 years. The underlying heart disease consisted of coronary artery disease in 20 patients and dilated cardiomyopathy in 8 patients. Sustained ventricular tachycardia was the mode of presentation in 16 patients and sudden cardiac death in 12 patients. The mean left ventricular ejection fraction was 31% +/- 6%. The lead system consisted of an 8 French bipolar passive fixation rate sensing lead positioned at the right ventricular apex, an 11 French spring coil electrode positioned at the superior vena cava-right atrial junction (surface area 700 mm2), and submuscular placement of a large patch (surface area 28 cm2) on the anterolateral chest wall near the cardiac apex via a submammary incision. A defibrillation threshold of < or = 15 joules (J) was required for implantation. This criterion was not satisfied in five patients; thus, a limited thoracotomy was performed via the submammary incision, and the large patch was placed epicardially. The mean R wave amplitude was 12 +/- 3 mV, the mean pacing threshold was 1.0 +/- 0.5 V at 0.5 msec, and the mean defibrillation threshold was 12.6 +/- 3 J. ICD generators implanted were the Ventak-P in 17, PCD-7217 in 5, and the Cadence V-100 in 6 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful treatment of right ventricular failure with atrial septostomy

In the case reported, a patient with severe right ventricular failure following coronary revascularization was successfully weaned from cardiopulmonary bypass following creation of an atrial septal defect. This technique facilitated rapid decompression of the failing right ventricle by shunting blood to the more compliant left ventricle, thus augmenting left ventricular preload and enhancing cardiac output. Recovery of right ventricular function was demonstrated by progressive hemodynamic improvement, as well as reduction of right-to-left intracardiac shunting and resolution of arterial hypoxemia.

Five-year experience with the Ionescu-Shiley bovine pericardial valve in the aortic position

Between February, 1977, and April, 1982, 168 patients underwent aortic valve replacement (AVR) with an Ionescu-Shiley bovine pericardial valve. Concomitant procedures were performed in 71 patients. There were 12 hospital deaths (7.1%). Among patients having AVR only, there were 5 deaths (5.2%). Assessment included valve durability, incidence of thromboembolism, clinical improvement, and patient survival. There was 100% follow-up. Actuarial freedom from intrinsic valve failure at 5 years was 96.3 +/- 3.6%. Intrinsic valve failure occurred only once, 0.3 episodes per 100 patient-years. Four patients had thromboembolic complications. As for clinical status, 99.3% of surviving patients are in New York Heart Association Functional Class I or II, including 79 patients with valve sizes 17, 19, or 21 mm (56%). Among 13 late deaths, 9 were related to the cardiovascular system. Overall patient survival is 84.9 +/- 4.7%. Among the 92 patients with isolated AVR, 87.8 +/- 5.9% are alive at the 5-year follow-up. If the incidence of valve failure is not altered in years to come, the durability of the Ionescu-Shiley bovine pericardial valve will surpass that of previous bioprostheses.

Corrected transposition of the great vessels associated with an obscured ventricular septal defect due to an abnormal systemic atrioventricular valve (report of a case and surgical considerations)

A case of corrected transposition associated with atrial septal defect, obscured ventricular septal defect, mild pulmonary valvar stenosis, severe systemic atrioventricular valve regurgitation and complete heart block is described. Closure of an atrial septal defect and a ventricular septal defect was carried out through a left atriotomy. Systemic atrioventricular valve replacement with a 27 mm. Hancock porcine valve was performed through the same approach. A permanent Demand rechargeable pulse generator unit with myocardial unipolar electrode lead was implanted. In the presence of complete heart block, a beating heart was not mandatory while repairing the ventricular septal defect. This enabled us to employ the hypothermic cardioplegic technique which greatly facilitated the surgical repair. Despite the multiplicity and magnitude of the anomalies, gratifying results were obtained. The surgical approach and technical precautions are discussed.

Role of surgery in the management of pulmonary sporotrichosis

Management of four patients with sporotrichosis is summarized; one was treated medically and three were treated surgically. Thirty-seven cases from the literature are reviewed. The role of surgery in the management of pulmonary sporotrichosis is outlined as follows: (1) diagnosis of pulmonary infiltrates and/or pulmonary cavities of undetermined origin, (2) surgical intervention in patients with persistent infiltrates with cavitary lesions resulting from sporotrichosis, following failed medical treatment, and (3) resection of associated pulmonary cavitary lesions in patients in spite of adequte medical control of sporotrichosis. Surgical principles that must be observed in the management of pulmonary sporotrichosis follows:(1) Resection is the procedure of choice. The magnitude ranges from segmental resection to pneumonectomy. Clean resection is necessary. (2) Antifungal drug therapy--preferably with amphotericin B--is advisable preoperatively and postoperatively, since the major cause of late death is progression of the disease when clean resection has not been feasible. (3) Resection combined with drug therapy can be curative without increased risk in physiologically operable and anatomically resectable disease. (4) Thoracoplasty can be a lifesaving procedure for bilateral cavitary lesions with severe hemoptysis in patients with impaired pulmonary functions.

Cyanosis in a patient with combined ostium primum and secundum atial septal defects and anomalous inferior vena cava with azygos continuation. Case report and surgical considerations

A case is described of combined ostium primum and ostium secundum atrial septal defects and azygos connection of the inferior vena cava plus cyanosis. Emphasis is made to recognize the functional mechanism of cyanosis and to demonstrate the anatomic site of hepatic venous drainage so that an appropriate corrective operative procedure can be planned. A gratifying result was achieved in this case after closure of the atrial septal defects.

Surgical repair of right aortic arch with aberrant left subclavian artery and left ligamentum arteriosum

Five cases of right aortic arch with aberrant left subclavian artery and left ligamentum arteriosum, with or without Kommerell's diverticulum, are presented. Either right or left thoracotomy with divesion of the aberrant retroesophageal left subclavian artery can be accomplished with good results. However, a right thoracotomy is recommended in the presence of a large Kommerell diverticulum because such a diverticulum should be excised. The development of a subclavian steal syndrome later in life may be prevented by reimplantation of the divided left subclavian artery into the aorta or the left common carotid artery.

Retention of pacemaker electrode complicated by Serratia marcescens septicemia. Removal with total cardiopulmonary bypass

A case in which Serratia marcescens septicemia complicated the insertion of a transvernous pacemaker unit is reported. Appropriate antibiotic therapy and removal of the pacemaker electrode are two essential steps to achieve a complete cure in this stimulation. Open cardiotomy with total cardiopulmonary bypass provides a safe approach for withdrawal of an incarcerated electrode and is justified because of the lethal potential of systemic Serratia infections, particularly those superimposed on intracardiac prostheses.

The role of surgery in the management of pulmonary monosporosis. A collective review

Nine cases of pulmonary monosporosis treated in the Missouri State Chest Hospital over a period of 19 years (1956 to 1975) were reviewed. Nine other cases from the literature are summarized. Ten of these 18 patients underwent resectional operations with two operative deaths, one from respiratory insufficiency and the other from a bronchopleural fistula and massive hemorrhage. The rest of the patients had an uneventful recovery. The indications for resectional surgery are re-established for suitable cases. The underlying disease is the major determinant of the outcome of the surgery. Other modes of treatment are also discussed. Based on the analysis of these 18 cases, a guideline for the management of pulmonary monosporosis is proposed.

Total correction of double-outlet ventricle with concordant atrioventricular relation, dextrocardia, pulmonary stenosis, and situs inversus

A case of successful surgical correction of double-outlet right ventricle with concordant atrioventricular relation, pulmonic stenosis, and situs inversus is described. Transposition of the great vessels was not present. Intracardiac repair with a Teflon tunnel conduit gave an excellent result. Proper resection of the subpulmonic obstructing fibromuscular band required no patch reconstruction of the outflow tract.

The case for early surgical treatment of left-sided primary infective endocarditis. A collective review

Sixteen cases of infective endocarditis requiring valve replacement with a prosthesis are described. The indication for surgery was intractable congestive heart failure in all. Fourteen patients underwent aortic valve replacement, with five hospital deaths secondary to cardiac decompensation and one late death related to recurrent periprosthetic insufficiency. Two patients who required mitral valve replacement did well, with no early or late deaths. A collected review of 293 cases of left-sided primary infective endocarditis reported in the English literature confirms the feasibility, advisability, and life-saving potential of urgent surgical intervention in patients with persistent or progressive congestive heart failure, irrespective of the activity of the infective process or the duration of antibiotic therapy. All infected tissue should be resected, and Teflon bolsters should be used to minimize the incidence of periprosthetic leaks. The incidence of prosthetic infection is minimal, contrasted with the fatal potential of procrastination to achieve microbial cure.