Effect of rate of intracellular transport and diacytosis on cytotoxicity of hybrid toxins. Study with hybrids using hepatic asialoglycoprotein receptor-mediated endocytosis

The effects of diacytosis and intracellular transport rate on cytotoxicity of hybrid toxins were studied with conjugates of diphtheria toxin fragment A (DTA) to asialoorosomucoid (ASOR) and its reduced and carboxymethylated cyanogen bromide fragment I (RC-ASCNBr-I) in cultured rat hepatocytes. In the hepatocytes the kinetics of uptake of the conjugate of asialoorosomucoid (DTA-ASOR) and that of the conjugate of the cyanogen bromide fragment (DTA-RC-ASCNBr-I) were quite similar, but the rate of accumulation of DTA moiety into the lysosomes, as determined by Percoll density gradient centrifugation, was found to be greater for the latter than the former. However, after internalization, DTA-RC-ASCNBr-I was diacytosed to a lesser extent than that of DTA-ASOR, particularly when colchicine was present during internalization. Analysis of the subunits of DTA-ASOR internalized by the hepatocytes indicated that they were accumulated disproportionately in a time-dependent manner so that the glycoprotein moiety was accumulated progressively more than the toxin moiety. Cytotoxicity of DTA-ASOR toward the hepatocytes was 2-times as much as that of DTA-RC-ASCNBr-I. Colchicine enhanced the toxicity of DTA-RC-ASCNBr-I (33-fold) to a greater extent than that of DTA-ASOR (12-fold). The difference in enhancement by colchicine was also observed in the rate of cell intoxication by the conjugates. Both conjugates were more toxic to the hepatocytes after incubation with the cells at 18 degrees C than at 37 degrees C. In the presence of vanadate (0.2 mM), which enhanced diacytosis, toxicity of DTA-ASOR decreased by 5-fold. After incubation with the hepatocytes, a partial dissociation of DTA-ASOR was found to occur independently of the receptor-mediated endocytosis. Taken together, these results indicate that diacytosis, subunit dissociation and rapid transport of conjugate toward lysosomes affect kinetically the rate of accumulation of the conjugate into a yet unidentified compartment of toxin translocation.

Effects on anti-lipid peroxidation of Cudrania cochinchinensis var. gerontogea

From the root bark of Cudrania cochinchinensis (Lour.) Kudo et Masamune var. gerontogea (Sieb. et Zucc.) Kudo et Masamune, 3 xanthones, cudraxanthone I, 1,3,7-trihydroxy-2-(3-methylbut-2- enyl)-xanthone, and lancerin, were further isolated and characterized. It was found that pretreatment with 600 mg/kg oral dose of the EtOH root extract of Cudrania cochinchinensis var. gerontogea in mice inhibited the lipid peroxidation stimulated by FeCl2-ascorbic acid-adenosine 5'-diphosphate (ADP) mixture. For searching bioactive constituents, the isolated xanthones from this folk medicine were investigated in anti-lipid peroxidative activities in the rat liver homogenate. The results showed that most of the tested xanthones effectively exhibited anti-lipid peroxidation stimulated by (a) FeCl2-ascorbic acid mixture or (b) CCl4-nicotinamide adenine dinucleotide phosphate (NADPH) mixture. As shown by the result, gerontoxanthone C and I were more active than vitamin E.

Class II transactivator (CIITA) is sufficient for the inducible expression of major histocompatibility complex class II genes

The class II transactivator (CIITA) has been shown to be required for major histocompatibility complex (MHC) class II gene expression in B cells and its deficiency is responsible for a hereditary MHC class II deficiency. Here we show that CIITA is also involved in the inducible expression of class II genes upon interferon gamma (IFN-gamma) treatment. The expression of CIITA is also inducible with IFN-gamma before the induction of MHC class II mRNA. In addition, CIITA mRNA expression does not require new protein synthesis, although new protein synthesis is necessary for the transcription of class II. This suggests that synthesis of new CIITA protein may be essential to induce class II gene expression. We also showed that the JAK1 protein tyrosine kinase activity is required to induce the expression of CIITA upon IFN-gamma stimulation. This finding indicates that CIITA is part of the signaling cascade from the IFN-gamma receptor to the activation of class II genes. In addition, the expression of CIITA is sufficient to activate class II genes in the absence of IFN-gamma stimulation suggesting that CIITA is the major regulatory factor for the inducible expression of class II genes. Together, these data suggest that CIITA is the IFN-inducible cycloheximide sensitive factor previously shown to be required for the induction of MHC class II gene expression.

Color Doppler ultrasonography and serum CA 125 in the differentiation of benign and malignant ovarian tumors

Color Doppler ultrasonography and serum CA 125 were used to evaluate 114 adnexal tumors prior to surgery. Six patients were excluded from this study because of ovarian cancer, borderline ovarian malignancy, and tubal gestation. A total of 108 patients were eligible: 83 patients with benign and 25 patients with malignant ovarian tumors. Resistance index (RI) was used to determine the peripheral resistance of intratumoral vessels. The cutoff point for the RI was defined as 0.5. The blood flow was considered to be normal when the RI was greater than 0.5 and abnormal when it was less than 0.5. The blood flow was detected in 100% of malignant tumors and 59% of benign tumors. The initial cutoff value for CA 125 was 35 U/mL. Sensitivity, specificity, positive predictive value, and negative predictive value were compared in terms of RI, serum CA 125, and a combination of the two. Our conclusion is that the combination of RI and CA 125 gives a sensitivity of 100% and negative predictive value of 100%. If the cutoff point of CA 125 was raised from 35 to 65 U/mL, then a specificity of 100% and positive predictive value of 100% were also attained with the use of RI and CA 125 without changes in sensitivity or negative predictive value. We conclude that the combination of color Doppler ultrasonography and serum CA 125 is an effective method to differentiate benign from malignant ovarian tumors.

Acute endothelial reperfusion injury after coronary artery bypass grafting

Coronary artery endothelium exhibits functional impairment after ischemia and reperfusion. Canine left anterior descending coronary arteries were exposed to ischemia (60 minutes) followed by reperfusion (60 minutes) through a left internal mammary artery graft. In organ chamber experiments, control (left circumflex coronary artery) and reperfused (left anterior descending coronary artery) arterial segments were contracted with prostaglandin F2 alpha and exposed to hypoxia (oxygen tension = 35 +/- 5 mm Hg). Reperfused coronary rings with endothelium exhibited contractions to hypoxia that were significantly greater than contractions in control rings with endothelium (+78% +/- 8% and +14% +/- 5%, respectively; p < 0.05). This phenomenon could be blocked by NG-monomethyl-L-arginine. Electron microscopic studies showed platelet adhesion and aggregation, denudation of the endothelium and disruption of the intercellular junctions, edematous subendothelial matrix, and vesiculation of the smooth muscle cells in reperfused LAD. Swelling, vacuole formation, and loss of neurofilament occurred in the nerve fibers accompanying the vessels. These phenomena were not observed in control vessels. This study demonstrates that early after coronary artery bypass grafting, hypoxia can induce coronary vasospasm mediated by an L-arginine-dependent metabolic pathway in the endothelium. The ultrastructural changes in the coronary endothelium include platelet adhesion, aggregation, and platelet-induced contraction of coronary smooth muscle. The endothelium-dependent hypoxic coronary vasospasm and ultrastructural changes in the coronary endothelium may play an important role in the pathogenesis of myocardial ischemia and infarction after coronary artery bypass grafting.

Human dermal papilla cells and outer root sheath cells: no follicular differentiation in nude mice and chicken embryos

Human scalp specimens were incubated in 5 U/ml dispase solution at 4 degrees C overnight before the isolation of dermal papillae and follicle epithelium. This pretreatment not only facilitated the attachment and cell outgrowth of dermal papillae but also made it easier to pluck out hairs with intact follicle epithelium. The outer root sheath cells were released from the follicle epithelium and grown on a feeder layer of mitomycin C-treated human dermal fibroblasts. The subcultured outer root sheath cells were grown in a serum-free medium. When the mixtures of early-passage dermal papilla cells and outer root sheath cells were injected into the subcutis of nude mice, an epidermal cyst surrounded by layers of fibrous tissue was found in three weeks. No hair follicles were found when the mixtures were implanted onto the chorioallantoic membrane of nine-day-old chicken embryos. A keratinized mass lying on the chorionic epithelium with or without smaller similar masses in the chorioallantoic membrane was found in eight days. No hair follicle-like structure could be found. Possible factors contributing to the failure to undergo follicular differentiation in this study are discussed.

Endothelium dysfunction in cardiovascular diseases

During the past 10 years, it has become obvious that endothelium regulates vasomotion, modulates hemostasis, influences vascular permeability, and controls blood vessel growth. The role of endothelium in modulating vasomotor tone is mediated by the releasing of a number of potent vasoactive compounds, including endothelium-derived relaxing factors (one of which is either nitric oxide or a compound that releases nitric oxide), vasoactive prostaglandins, endothelium-derived hyperpolarizing factor, and a number of constricting factors (such as thromboxane A2, endothelin, superoxide anion, L-arginine-dependent products etc.). This role of the endothelium is dramatically changed by several disease processes, including diabetes mellitus, cerebrovascular disease, and so on. Abnormalities of endothelial regulation of vascular tone may contribute to a number of clinical syndromes, including atherosclerosis, hypertension, septic shock syndrome, and many others. Endothelium dysfunction, characterized by altered synthesis or release of these relaxing factors along with maintained or facilitated synthesis or release of contracting factors, can lead to various pathological conditions such as thrombosis, vasospasm, and hypertension. Better understanding of the exact nature of endothelial dysfunction, including the role played by endothelium-derived vasoactive factors, may provide a basis for novel therapies in these vasculopathies.

Surgical treatment of acute type A aortic dissection with an intraluminal sutureless graft

The surgical treatment of acute type A aortic dissection remains a great challenge to all cardiac surgeons. From January 1991 to June 1993, 21 consecutive patients (13 men and eight women, aged 34 to 74 years) underwent emergency operations to repair acute type A aortic dissection, with the aid of hypothermic circulatory arrest. The intima tear was located in the ascending aorta in 13 patients, in the aortic arch in five patients, and in the descending aorta in three patients. The dissected ascending aorta was replaced with sutureless, intraluminal vascular grafts in all 21 patients. The intima tears in the aortic arch of five patients were primarily repaired. Modified Cabrol's shunts were created in seven patients for hemostasis, and Dacron grafts were used to wrap the ascending aorta in 18 patients. Retrograde cerebral perfusion during circulatory arrest was performed on 15 patients. The circulatory arrest time was 37 +/- 10 minutes (mean +/- SD). All patients survived the operation and regained consciousness in the early postoperative period without neurologic deficit. Post-treatment follow-ups (mean, 18.2 months) were completed in all patients except one, who died 12 months after the operation as a result of a traffic accident. All of the surviving patients are doing well without any further aortic operations. Our experience suggests that surgical repair of the acute type A aortic dissection can be a simple and safe procedure if sutureless intraluminal grafts are used and hypothermic circulatory arrest and retrograde cerebral perfusion are utilized.

Reversal of refractory hypotension in septic shock by inhibitor of nitric oxide synthase

Septic shock is a life-threatening condition that results from exposure to bacterial endotoxin. It is mediated by the release of cytokines. Some of these cytokines cause the release of vasoactive substances. We report the case of a 62-year-old male patient who received redo operation for replacement of the degenerative porcine aortic and mitral prostheses. High cardiac output shock developed on the seventh postoperative day with severe metabolic acidosis and oliguria. Systemic vascular resistance and mean arterial pressure elevated within 5 min and stabilized 60 min after the start of a single dose of intravenous administration of NG-monomethyl-L-arginine (50 mg), a potent and selective inhibitor of nitric oxide synthesis. These findings indicate that nitric oxide overproduction is an important contributor to refractory hypotension in high cardiac output septic shock. Our findings suggested the utilization of nitric oxide synthase inhibitor in the treatment of septic shock in humans.

Immunosuppressive effects of azelastine hydrochloride on contact hypersensitivity and T-cell proliferative response: a comparative study with FK-506

Azelastine hydrochloride (AZE) is an anti-allergic drug that inhibits the release of various chemical mediators from mast cells. We compared the immunosuppressive effects of AZE and FK-506 in vivo and in vitro. Topical application of AZE strongly inhibited the efferent phase of contact hypersensitivity, as did application of FK-506. In in vitro experiments, we found that 1) the suppression by AZE on interleukin (IL)-2 production from splenic T cells was partial and considerably large amounts of IL-2 were still produced, even in the presence of 10(-5) M of AZE, which was in sharp contrast to the observed marked inhibition of [3H]-TdR incorporation; 2) AZE significantly inhibited the phorbol myristate acetate-induced IL-2 responsiveness; 3) AZE did not inhibit the IL-2 receptor alpha expression of activated T cells; and 4) the significant inhibitory action was still observed even when AZE was added at 48 h after the initiation of culture. In regard to FK-506, we found that 1) FK-506 completely blocked the production of IL-2; 2) exogeneous IL-2 consistently restored the FK-506-induced inhibition; 3) FK-506 affected the phorbol myristate acetate-induced IL-2 responsiveness very little, if any; and 4) the significant suppression was observed only when FK-506 was added within 24 h after the initiation of culture. Thus, AZE exerts its in vitro immunosuppressive activity preferentially by interfering with the IL-2 responsiveness, with partial inhibition of IL-2 production. Conversely, FK-506 acts as a strong inhibitor of IL-2 production without a prominent effect on IL-2 responsiveness. The immunosuppressive activity of AZE shown in vitro may also be operative in vivo and may be applicable for topical use.

Gastric arteriolar and venular responses to nitrogenous and nonnitrogenous vasodilating agents in the rat

We made in vivo microvascular observations to simultaneously compare the actions of various direct vasodilators on the resistance and capacitance vessels without confounding systemic hemodynamic effects. The responses of gastric submucosal arteriolar and venular diameters to the topical application of 10(-7) 10(-5), and 10(-3) M of the vasodilators nitroglycerin (NTG), sodium nitroprusside (SNP), hydralazine (HYD), and adenosine (ADN), and acetylcholine (ACh) were studied in 6 rats for each agent using in vivo microscopy. The basal diameters of arterioles, 37 +/- 2 microns (mean +/- SE), were maximally dilated to 86 +/- 2 microns by 10(-3) M ADN, NTG, SNP or ACh, while with 10(-3) M HYD dilation was just 55%. The basal diameters of venules, 36 +/- 2 microns, were maximally dilated only to 51 +/- 1 micron by 10(-3) M ADN, NTG or SNP, while those by 10(-3) M HYD and ACh were 60 and 71%, respectively. We observed that: (1) NTG and SNP were the strongest arteriolar and venular dilators, but at low dose (10(-7) M), NTG was more effective than SNP. (2) Gastric submucosal venules had considerably less dilating capacity than arterioles. (3) ADN was as effective as NTG and SNP for both arteriolar and venular dilation at 10(-3) M. It was less potent at lower concentrations. (4) ACh was as potent as ADN, NTG and SNP in dilating arterioles, but it was notably less potent in dilating venules. (5) HYD was the weakest arteriolar and venular dilator among all agents studied, and its action on venules was slightly greater than that on arterioles.

Why are children hospitalized? The role of non-clinical factors in pediatric hospitalizations

OBJECTIVE

Pediatric medical discharge rates vary widely across hospital service areas, beyond differences explained by chance or disease incidence alone. This study examines the relationship between the characteristics of local medical services and the likelihood of hospitalization.

DESIGN

Small area and population-based regression analysis.

SETTING

The 72 hospital service areas of Maine, New Hampshire, and Vermont.

STUDY POPULATION

The 589,290 (1989) children of Maine, New Hampshire, and Vermont < 15 years of age with 120,806 discharges during 1985 through 1989.

MEASUREMENT AND MAIN RESULTS

Using logistic regression and controlling for community income, we found that children residing in zip codes with high per capita bed supply (4.0/1000) had 9% more discharges (odds ratio: 1.09; 99% confidence interval: 1.07, 1.11) compared with children in areas with low per capita bed supply (1.9/1000). Children living 30 minutes from the nearest hospital had 15% fewer medical discharges (odds ratio: 0.849; confidence interval: 0.830, 0.867) than those living in a zip code with a hospital. Residence in one of the three academic medical center hospital service areas resulted in 32% fewer discharges (odds ratio: 0.68; confidence interval: 0.66, 0.70). Similar and statistically significant (P < .01) results were noted for the most common nonperinatal diagnostic categories: asthma/bronchitis (diagnostic related group = 98) and gastroenteritis (diagnostic related group = 184). No effect was noted for femur fracture, a condition for which admission rates equal disease incidence.

CONCLUSIONS

The supply and character of medical care are important influences on the likelihood of hospitalization for pediatric medical conditions for which outpatient alternatives are available.

RNA transcription in porcine skeletal muscle nuclei during postnatal development

Postnatal developmental pretranslational regulation of skeletal muscle alpha-actin gene expression was investigated. Northern blot analysis of skeletal muscle alpha-actin and beta-tubulin mRNA from 1- and 28-day-old pigs indicated that there are developmental increases in alpha-actin mRNA abundance (P < 0.03) and no significant changes in beta-tubulin mRNA (P > 0.1). A system for isolation of nuclei from porcine skeletal muscle and for transcriptional "run-on" analysis was established in order to investigate the regulatory mechanism of developmental changes in porcine skeletal muscle protein. Skeletal muscle nuclei were isolated from longissimus dorsi (LD) muscle of 1- and 28-day-old pigs by adapting a method to isolate nuclei from cardiac muscle. Results from a [3H]-UTP incorporation assay indicate that these nuclei preparations have the capacity to synthesize RNA and attain maximum incorporation after 40-45 min at 26 degrees C. Messenger RNA syntheses from skeletal muscle nuclei from 1- and 28-day-old pigs were not significantly different (P > 0.25). All nascent tRNA, rRNA, and mRNA in the nuclei were elongated since [3H]-UTP incorporation was reduced after addition of 0.05 micrograms/ml alpha-amanitin to the transcription mixture. Transcription "run-on" assay results indicated that more (P < 0.02) skeletal muscle alpha-actin pre-mRNA was synthesized in the 28-day-old pig skeletal muscle nuclei than in the 1-day-old pig skeletal muscle nuclei. These results indicate that the relative increase in skeletal muscle alpha-actin mRNA observed in the older animals was due, at least in part, to an increase in the transcriptional activity of the skeletal muscle alpha-actin gene.

Host recognition by the VirA, VirG two-component regulatory proteins of agrobacterium tumefaciens

Agrobacterium tumefaciens contains about 25 vir genes localized on a 200-kb tumour-inducing (Ti) plasmid that direct a conjugation-like transfer of tumorigenic DNA from the bacterium to the nuclei of infected plant cells. These genes are strongly and coordinately induced during infection in response to three different classes of stimuli which are thought to be key chemical features of a typical wound site. These stimuli are (i) guaiacol and syringol derivatives such as acetosyringone, (ii) sugars such as glucose and glucuronic acid, and (iii) acidic pH. The sensing of these compounds is carried out by the VirA, VirG and ChvE proteins. VirA is a four-domain histidine protein kinase, while VirG is a transcriptional activator which is activated by VirA-mediated phosphorylation. ChvE is a chromosomally encoded periplasmic sugar binding protein which is required for sensing sugars but dispensable for sensing the other two stimuli. Here we will review the nature of these chemical stimuli, the structure and function of the three regulatory proteins, their similarity to sensors found in human and animal pathogens, the factors influencing their pool size, and their role in the host range of different strains of A. tumefaciens.

Characterization of the release of cholecystokinin from a murine neuroendocrine tumor cell line, STC-1

The murine neuroendocrine cell line, STC-1, was found to contain 296.8 +/- 1.8 fmol of cholecystokinin-like immunoreactivity (CCK-LI) per mg cell protein. Immunocytochemical stain of STC-1 cells maintained in monolayer culture indicated that CCK-LI activity was present in 93% of the cells. Analysis by reverse-phase high-performance liquid chromatography indicated that STC-1 cells contained CCK-8 and an unidentified form as the predominant storage form. form. However, only CCK-8 was released into the culture medium upon stimulation by various secretagogues. The release of CCK-LI from STC-1 cells was stimulated by dibutyryl cAMP, forskolin, KCl, A23187, 4 beta-phorbol 12-myristate 13-acetate and luminal stimulants, e.g., sodium oleate, L-tryptophan, camostat and plaunotol. The release of CCK-LI from STC-1 cells was also stimulated by a neuropeptide, bombesin. The stimulatory effects of most of these agents were dose dependent. The stimulatory effects of dibutyryl cAMP, forskolin, and plaunotol were potentiated by 3-isobutyl-1-methyl xanthine, while that of camostat was not. The results obtained in this study indicate that the release of CCK from STC-1 cells shares the same characteristics of CCK release as from the CCK-secreting cells of the intestinal mucosa observed both in the dog and the rat in vitro and in vivo. Thus, the cellular mechanism of CCK release which appears to be cAMP- and Ca(2+)-dependent may be modulated by cellular protein kinase C activity. The STC-1 cell appears to be a suitable model for studying the mechanism of CCK release.

Treatment of acute type A aortic dissection with intraluminal sutureless prosthesis

Sutureless intraluminal aortic graft has been used for substitution of aorta, with the advantages of decreasing the aortic cross-clamp time and decreased blood loss. From January 1991 to December 1992, 10 consecutive patients underwent emergency operations to repair acute type A aortic dissection in which sutureless intraluminal grafts were used for replacement of ascending aorta. There were 5 men and 5 women, with ages that ranged from 40 to 74 years (mean, 51 years). The inclusion method was used in all patients. Modified Cabrol shunts were created in 7 patients. Dacron graft (Meadox Medicals, Inc, Oakland, NJ) was used to wrap the ascending aorta in 7 patients. The circulatory arrest time was 33 +/- 13 (mean +/- standard deviation) minutes, and the cardiac ischemic time was 64 +/- 17 minutes. Retrograde superior vena cava cerebral perfusion during circulatory arrest was performed on 4 patients. All patients survived. One patient had a minor stroke and pneumonia with complete recovery. There was no evidence of pseudoaneurysm formation, graft erosion, graft migration, or aortic bleeding in the postoperative period. No patients had permanent renal deficit. Follow-up (1 to 22 months; mean, 9.6 months) of all patients revealed satisfactory graft function, with no device-related deaths and no known complications attributable to the prosthesis, such as thrombosis, erosion, pseudoaneurysm formation, or hemorrhage. Our experience suggests that grafting of the ascending aorta is less hazardous with the sutureless grafts than with the conventional sutured anastomosis technique. We are now using this method whenever possible in all substitutions of the aorta.

Primary malignant lymphoma of the uterine cervix shows favorable response to neoadjuvant chemotherapy

Primary malignant lymphoma localized in the uterine cervix is a rare condition for which radiation therapy, surgery, or chemotherapy either alone or in combination have been the mainstay of treatment. The effectiveness of neoadjuvant chemotherapy for this condition, however, has not been evaluated. We experienced one case of primary malignant lymphoma of the uterine cervix, stage IIa according to FIGO, and IEA according to the Ann Arbor staging system for extranodal lymphomas, which was treated with neoadjuvant chemotherapy and surgery. The patient first underwent neoadjuvant chemotherapy consisting of cyclophosphamide, vinblastine, epirubicin, bleomycin, procarbazin, and oncovin (COP-BLAM) to reduce the size of the tumor. This was followed by an extended total hysterectomy, left salpingo-oophorectomy, and bilateral pelvic lymph node dissection. Neoadjuvant chemotherapy given before surgery resulted in a remarkable reduction in the tumor size which made the subsequent surgery technically easy. In addition, it is possible that intraoperative micrometastasis of the tumor cells could be better prevented. The patient received additional chemotherapy with COP-BLAM schedules postoperatively. No evidence of recurrent lymphoma has been observed in 2 years after the treatment. Neoadjuvant chemotherapy may be an effective treatment modality for primary malignant lymphoma of the uterine cervix.

Use of Gore-Tex sling in brow suspension procedure

A variety of materials have been employed for brow suspension surgery for ptosis. Gore-Tex (expanded polytetrafluoroethylene ePTFE) has been used as vascular prosthesis. We have used cylinder Gore-Tex in brow suspension surgery for 15 ptotic eyelids (11 patients), including 10 eyes (8 patients) of congenital ptosis, 1 eye of traumatic ptosis in a young male, and 4 eyes (2 patients) of myogenic ptosis in elderly patients. All of the eyelids had minimal or absent levator muscle function, and drooped to cover the visual axes. The surgical technique for the 10 congenital ptotic eyelids was a modified Fox's method. The remaining 5 adult eyelids were operated by a modified Crawford's method, with interlocking of the two suspension bands at the lower apex of each triangle and direct suturing of the bands to the tarsal plate. The use of Gore-Tex in brow suspension makes it easy to adjust the height and contour of the operated eyelids. Patients were followed-up from 2 to 16 months (average 9.1 months) postoperatively. The only complication was granuloma formation at the most upper knot area in 5 patients (6 eyelids), one of which also had granuloma at the ipsilateral fornix with the Gore-Tex band cutting through the conjunctiva. One eyelid drooped due to knot granuloma and infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term results of polytetrafluoroethylene mitral annuloplasty

Prosthetic rings are customarily used for mitral annuloplasty to plicate and reinforce the annulus and keep the annulus from further dilating. From July 1984 to March 1992, mitral annular plication using polytetrafluoroethylene (PTFE) graft material was performed on 73 patients (age range, 15 to 69 years; mean, 35.7 years) with mitral regurgitation. The cause of the mitral regurgitation was rheumatic in 50.7% and degenerative in 36.9% of the patients. After other repair procedures on the mitral valve apparatus had been performed, a PTFE graft (3 mm) was tailored to the length of the free edge of the anterior leaflet and then inserted at the posterior part of the mitral annulus between the commissures. The operative mortality was 2.7%. Follow-up ranged from 0.7 to 8.5 years (mean, 5.6 years). Postoperative echocardiography confirmed that 94.2% of the survivors had either no or only mild mitral regurgitation with a large mitral valve area (2.7 +/- 0.3 cm2) and almost no pressure gradient across the mitral valve or left ventricular outflow tract. Two patients successfully underwent redo PTFE mitral annuloplasty. Two patients died, one 15 and the other 20 months later, due to myocardial failure, with no mitral regurgitation. The event-free survival rate was 90% +/- 4% at 8 years. We conclude that PTFE mitral annuloplasty is an effective procedure that yields good long-term results.

The changes of ocular axial length and corneal curvatures after scleral buckling for retinal detachment

As myopia plays an important role in the pathogenesis of retinal detachment, alterations of refractive components after scleral buckling procedures for retinal detachment may be an important factor for retinal redetachment. To find out the refractive change following retinal detachment surgery, we prospectively followed up the alterations of corneal curvature, and axial components (axial length, anterior chamber depth, lens thickness, and vitreous length) of 44 eyes of rhegmatogenous retinal detachment before and after operations. The procedures consisted of encircling scleral buckling (12 eyes) and segmental scleral buckling (32 eyes). All patients were followed for 6 months postoperatively. The corneal curvatures were measured with a keratometer, the axial length and axial components were measured with an A-scan ultrasonography. The methods and materials used in operation were recorded in detail to correlate with the refractive changes. The corneal curvature showed a trend to flatten early after operation (the 1st week), and gradually reversed to steepening. But, the difference was statistically significant only at the K2 (vertical meridian) in the 1st postoperative week and the K1 (horizontal meridian) in the 4th postoperative week. Lengthening of eyeballs were noted in the encircling group (12 eyes), but only the elongation in the 1st postoperative week was statistically significant. While in segmental buckling group, the axial length of the eyeballs was transiently shortened. The shortening was significant in the 2nd, 4th, and 6th week after operation. The reduction of eyeball's axial length was related to the shortening of vitreous length and shallowing of anterior chamber.(ABSTRACT TRUNCATED AT 250 WORDS)

Intractable nontuberculous mycobacterial keratitis successfully treated by penetrating keratoplasty--3 cases report

Since the first diagnosis of nontuberculous mycobacterial keratitis in Taiwan on 1983 by Chen et al., we have collected another 70 cases. Although most of the cases were difficult to treat medically, almost all cases healed before optical penetrating keratoplasties were performed. But, three of these cases responded poorly to medical treatment with sporadical relapse. Finally, penetrating keratoplasties (PKP) were performed on these three cases. These three cases were all males, aged 48, 27, and 35 respectively. The durations from the onset to receiving PK were 10, 4, and 6 months. All had histories of corneal trauma and all cases responded poorly or inconsistently to topical amikacin, erythromycin and antituberculous drugs. Histopathological examination of the diseased corneas in the first chronic case showed granuloma formation in the area of ulcer base. The second case presented lymphocyte clustering in the subepithelial region. The third case, which was operated in a relatively inflamed stage, had lymphocytes infiltrating the whole layer of the cornea. The results of PKP in the three eyes were therapeutically and optically successful, though the second case failed in the first penetrating keratoplasty due to acute tissue failure without recurrent infection. The best corrected visual acuities in the three eyes, postoperatively, were 20/25, 20/40, and 20/100 respectively. With the successful experience of these three cases, we suggest that performing PKP for intractable nontuberculous mycobacterial keratitis at an early stage may reduce the duration of the patients' suffering.

Comparison of five modalities in localization of primary aldosteronism

BACKGROUND

The best response to surgical treatment of primary aldosteronism occurs in patients with an aldosterone-producing adenoma (APA), so pre-operative localization of the lesion is necessary.

METHODS

A comparison was made of five localizing modalities-computed tomography (CT) of the adrenal gland, magnetic resonance imaging (MRI), dexamethasone suppression-131I-19-cholesterol adrenal scintiscan (DS, NP-59 adrenal scan), adrenal venography (venography) and adrenal venous sampling for aldosterone content (AVS) in 22 patients (12 women, 10 men) with primary aldosteronism; all had undergone operative confirmation within the past 9 years. The age at diagnosis ranged from 27 to 67 years (mean: 39.7).

RESULTS

Unilateral adrenalectomy resulted in normal blood pressure without medication in 63.6% (14/22), and in improvement in 36.4% (8/22). Correct localization of the lesion was obtained in 95% (20/21) by CT, 100% (7/7) by MRI, 80% (12/15) by DS,NP-59 adrenal scan, 100% (6/6) by AVS and 78% (7/9) by venography.

CONCLUSIONS

This experience would advocate CT of the adrenals as the initial means of localizing an APA on an outpatient basis because it is comfortable, safe, inexpensive and gives immediate results. The major role of MRI in the evaluation of adrenal adenoma should be complementary to CT. DS, NP-59 adrenal scan can be an adjuvant method for localization if CT scan results are not definitive. Adrenal venous catheterization with blood sampling for aldosterone content could be reserved for patients whose biochemical finging suggests the presence of an APA, and for whom CT or MRI of the adrenals and DS, NP-59 adrenal scan are inconclusive.