Availability of discographic computed tomography in automated percutaneous lumbar discectomy

Automated percutaneous lumbar discectomy (APLD) has been developed since 1984 when Gary Onik first attempted it. This procedure has many advantages and has been used widely in the treatment of protruded disc diseases. The success rate of APLD by authors from March 1988 to February 1993 when the discographic computed tomography (CT) had not been performed was 74%. In evaluating lumbar disc diseases, we have used discographic CT. According to the patterns of dye distribution in the disc, two different types of protrusion can be distinguished: broad dye base protrusion and narrow dye base protrusion. From April 1993 to July 1994, 52 patients with protruded disc diseases were performed discographic CT. 23 Patients had narrow dye base protrusion and 29 patients had broad dye base protrusion. 29 patients with a broad dye base on discographic CT were treated with APLD and evaluated. The success rate in these patients was 93% by Macnab's criteria. Thus, we suggest that it is mandatory to apply discographic CT to increase the success rate of APLD in patients with protruded disc diseases.

Percutaneous absorption of topical parathion through porcine skin: in vitro studies on the effect of environmental perturbations

Topical use of pesticides in domestic animals such as swine is a common practice; however, the effect of environmental factors on the extent of absorption has not received attention. Since no single factor can exert its effects alone in the natural environment, the interaction of environmental factors on the percutaneous absorption of pesticides must be understood before potential toxicity of dermal absorption of pesticides can be effectively estimated. In the present studies, the effects of air temperature (Ta), perfusate temperature (Tp), perfusate flow (F) and relative humidity (%RH) on absorption of parathion were studied in vitro in porcine skin. Parathion absorption was determined by measuring radiolabel appearing in the perfusate over time. Three main environmental parameters were found to have a significant effect on parathion penetration. Increasing Ta from 37 degrees C to 42 degrees C, %RH from 60% to 90% or F from 4 ml/h to 8 ml/h each produced a significant increase in penetration. The following significantly positive two-way interactions among test parameters were seen: Ta x F and %RH x F at the 4 micrograms dose, %RH x F at the 40 micrograms dose and Ta x %RH, Ta x F and %RH x F at the 400 micrograms dose. There were no three-way interactions at any of the three doses tested. These results suggest that the factors tested are not independent variables and must be considered interactive when used in assessing pesticide percutaneous absorption.

Percutaneous absorption, dermatopharmacokinetics and related bio-transformation studies of carbaryl, lindane, malathion, and parathion in isolated perfused porcine skin

The percutaneous absorption of topically applied pesticides is a primary route for systemic exposure and potential toxicity. The isolated perfused porcine skin flap (IPPSF) is an in vitro model for studying percutaneous absorption of xenobiotics as well as cutaneous metabolism and toxicity in an anatomically intact viable skin preparation. In the present studies, percutaneous absorption of four different pesticides, carbaryl (C), lindane (L), malathion (M), and parathion (P), was assessed topically in an ethanol vehicle. A 4-compartment pharmacokinetic model was utilized to model their absorption profile. The order of absorption was C > P > L > M for the 8-h experimental period, but C > L > P > M for a model-extrapolated 6-day prediction. Metabolism of C and P was also assessed by high performance liquid chromatography (HPLC). The HPLC results indicate a significant first-pass effect for both pesticides after topical application, with parathion being metabolized to paraoxon and para-nitrophenol and carbaryl to naphthol. In addition, comparison of the metabolic data of P with previous results underscores the difference between non-recirculating and recirculating IPPSF systems in xenobiotic metabolism studies.

Localization of mucin (MUC2 and MUC3) messenger RNA and peptide expression in human normal intestine and colon cancer

BACKGROUND/AIMS

Several studies have reported Northern blot data showing that mucin is expressed in a tissue-specific manner. To determine whether expression is limited to specific cell types within these tissues requires histological analysis.

METHODS

Both immunocytochemistry and in situ hybridization were used to identify cell types expressing the MUC2 and MUC3 mucins in the human small intestine, colon, and colon carcinoma.

RESULTS

In the normal small intestine and colon, an antibody recognizing the MUC2 apomucin stained goblet cells. In contrast, an antibody recognizing the MUC3 apomucin stained both goblet and absorptive cells. Consistent with this, in situ hybridization showed MUC2 messenger RNA (mRNA) only in goblet cells and MUC3 mRNA in both goblet and absorptive cells. In several samples of moderately well-differentiated colon cancer, MUC2 and MUC3 showed distinct patterns of expression, but the expression level of each was reduced compared with levels in normal tissue; there was considerable tumor-to-tumor and cell-to-cell variability using both mucin antibodies and complementary DNA probes.

CONCLUSIONS

Individual mucin genes have distinct patterns of expression within mucin-producing tissues, suggesting that the various mucin gene products play distinct functional roles.

Electric-field-induced volume and membrane ionic permeability changes of red blood cells

When an external electric field (EF) is applied to red blood cells (RBC's), the RBC's are observed to undergo a swelling action. The swelling may or may not lead to hemolysis, depending on the EF strength. An objective verification of this swelling is by measuring the RBC mean corpuscular volume (MCV). In this study, the RBC's were exposed to the appropriate EF strength to induce swelling, but caused minimal hemolysis. The MCV was measured. The change in the erythrocyte membrane ionic permeability as a result of the EF exposure was also determined, as an objective verification of presumed membrane conductance change concomitant with the swelling. The fluxes of cations K+, Na+, and Ca++ and anion Cl- were measured. The results showed that red cell MCV was indeed increased after EF application. The EF also altered the membrane ionic conductance to allow ions to flow down their respective concentration gradient across the membrane. Without a counterbalancing ionic pressure gradient, hemoglobin colloidal pressure inevitably drew H2O in, thus producing the observed swelling.

Effects of anatomical site and occlusion on the percutaneous absorption and residue pattern of 2,6-[ring-14C]parathion in vivo in pigs

The effects of anatomical site and occlusion on the percutaneous absorption and residue pattern of total 14C were investigated following topical application of 2,6-[ring-14C]parathion onto four skin sites (300 micrograms/10 microCi; 40 micrograms/cm2) in weanling swine using occluded and nonoccluded dosing systems. The excretion profile was examined after iv administration. After dosing onto the abdomen, buttocks, back, and shoulder (N = 4/site), total urinary and fecal excretion (%dose) by 168 hr were, for the occluded system, 43.94 +/- 2.24, 48.47 +/- 7.85, 48.82 +/- 4.49, and 29.28 +/- 5.70%, and for the nonoccluded system, 7.47 +/- 2.16, 15.60 +/- 3.71, 25.00 +/- 8.75, and 17.41 +/- 1.76%, respectively. After iv dosing, 98.44 +/- 2.83% of the applied dose was excreted primarily via urine. The total recoveries for different sites ranged from 90.09 +/- 7.10 to 94.62 +/- 1.98% in the occluded system, 77.84 +/- 5.75 to 88.18 +/- 3.34% in the nonoccluded system, and 99.03 +/- 2.89% in the iv experiments. Time of maximal excretion rate was determined in the occluded system as abdomen (7.9 +/- 3.6 hr) < buttocks (9.4 +/- 2.6 hr) < shoulder (10.5 +/- 3.8 hr) < back (13.3 +/- 7.7 hr), but in the nonoccluded system as buttocks (11.9 +/- 3.6 hr) < shoulder (12.6 +/- 4.1 hr) < back (14.3 +/- 6.4 hr) < abdomen (16.9 +/- 7.1 hr). The percutaneous absorption from the shoulder was much lower than that from the other three sites under occluded conditions. However, if nonoccluded dosing was employed, absorption from the abdomen became the lowest, with shoulder and buttocks being similar, and the back the highest. Occlusion conceals the site difference and enhances both the extent and the rate of parathion percutaneous absorption in vivo. 14C residue pattern in tissues and dosing materials was site and dosing method dependent, all of which are factors which must be considered when assessing the risk of exposure to topically applied compounds.

Molecular typing of hepatitis C virus genome from sera and liver tissues of patients with anti-HCV positive chronic liver disease

The authors investigated the distribution of HCV genotypes in patients with various chronic liver diseases in Korea. Study population was 70 individuals, positive for second generation anti-HCV EIA, consisting of 37 cases with sporadic non-A, non-B (NANB) chronic hepatitis (CH), 12 NANB hepatocellular carcinoma, 16 post-transfusion NANB hepatitis, 4 non-B blood donors and 1 healthy family member of a patient with sporadic CH. Molecular typing was performed by RT-nested PCR with type-specific primer sets deduced from the NS-5 region of HCV. The prevalence of type II was 75.0% and type III was 25.0% in sera. In liver tissues, type II HCV was shown in 63.0%, type III HCV in 3.7% and co-infections with type II and III HCV were observed in 18.5% of 27 samples biopsied. In the sera of patients with chronic hepatitis, typing results were relatively well correlated with those in tissues (75%), but type III could not be observed. Among 12 HCC patients, type III HCV appeared only in tissues, not in sera. These results suggest that type II HCV may be the major HCV type in Korea, and co-infections with type II and-III HCV may not be rare in chronic liver diseases with HCV.

Dietary regulation of rat intestinal angiotensin-converting enzyme and dipeptidyl peptidase IV

The small intestinal brush-border membrane contains several peptidases that are involved in the hydrolysis of dietary peptides containing proline. A high-proline (gelatin) diet was administered to one of several groups of rats to study its possible regulatory effect on levels of two prolyl peptidases, namely angiotensin-converting enzyme (ACE) and dipeptidyl peptidase IV (DPP IV). Groups of rats were maintained on isocaloric diets containing either low (4%), normal (17%), or high (50%) protein (casein) or high (50%) gelatin. After 7 days, brush-border membranes and total RNA were prepared from the small intestine. ACE activity was 3- to 10-fold higher in brush-border membranes from the gelatin group compared with the low-protein group. DPP IV exhibited a three- to sixfold increase. Immunoblot analysis of brush-border membrane-associated ACE protein indicated a six- to eightfold increase in the high-gelatin group. There was also a 1.5- to 3-fold increase in steady-state levels of ACE and DPP IV mRNA. These results suggest that a diet high in proline (gelatin) is particularly effective in increasing intestinal levels of these two enzymes.

Transdermal iontophoretic peptide delivery: in vitro and in vivo studies with luteinizing hormone releasing hormone

Protein and peptide drugs are not orally active. Their large molecular size and charged character make them poor candidates for passive transdermal delivery. With an applied electromotive force, these drugs can be forced through the skin to be absorbed by the systemic circulation. The present study investigates the transdermal iontophoretic delivery of a peptide hormone in an in vitro model system, the isolated perfused porcine skin flap, as well as in vivo. It is shown that with knowledge of the systemic disposition of the drug, transdermal fluxes can be utilized to accurately predict in vivo serum concentrations. It is also shown that the iontophoretically delivered hormone retains both its immunologic and biologic activity.

Percutaneous absorption of parathion in vitro in porcine skin: effects of dose, temperature, humidity, and perfusate composition on absorptive flux

The effect of environmental factors on the percutaneous absorption of parathion in excised porcine skin was assessed in a flow-through diffusion cell system by varying the temperature (T), relative humidity (%RH), perfusate flow rate (F), and composition (porcine serum) at three parathion doses (4, 40, and 400 micrograms/cm2) compared to standard conditions (air temperature = 37 degrees C, perfusate temperature = 37 degrees C, %RH = 60, flow rate = 4 ml/hr, and standard bovine serum albumin medium). Parathion absorption was assessed by monitoring total radiolabeled activity appearing in the perfusate over time. High relative humidity significantly increased parathion penetration, as did two elevated temperature conditions. The effects of flow rate and perfusate composition were variable and dose dependent. In the present studies, lower applied doses appeared to be more sensitive to changes in the environmental conditions studied. These results suggest that these parameters have independent and different degrees of effect on parathion percutaneous absorption. Experimental conditions should be strictly controlled and dose-response studies need to be conducted when evaluating transdermal studies. Finally, if similar effects occur in vivo, the risk assessment calculations on percutaneous absorption should take these parameters into consideration.

Nonuniform alteration of cis-diamminedichloroplatinum(II) tissue distribution in dogs with whole body hyperthermia

The purpose of this study was to investigate the pharmacokinetics and tissue disposition of cisplatin (CDDP) in euthermic and hyperthermic dogs to determine if hyperthermic alteration of tissue CDDP concentration is uniform. Eighteen female beagle dogs received 20, 50, or 80 mg/m2 CDDP by constant infusion for 60 min under normothermic or hyperthermic conditions (n = 3/subgroup). Blood, plasma, and ultrafiltered plasma samples were collected during the infusion. At termination of infusion, animals were immediately sacrificed, all major tissues were collected, and platinum levels were determined by atomic absorption spectroscopy. Platinum concentrations in all blood fractions of hyperthermic dogs tended to be lower than those of normothermic dogs. The correlation between dose and blood area under the concentration-time curve was linear at both temperatures. Each tissue concentration was normalized for that individual dog's blood area under the curve. The ratio of relative extraction at 42 degrees C to that at 37 degrees C were compared for each tissue. Values of 1.0 were interpreted as indicating uniform relative tissue extraction at each temperature. Values of greater than 2.0 were obtained in lung and ileum, while values of greater than 1.5 were obtained in liver, adrenal, stomach, colon, duodenum, spleen, and pancreas. Values of less than 1.0 were obtained in skin and superficial lymph nodes. These results indicate that hyperthermia significantly alters the pattern of CDDP tissue disposition in a nonuniform manner and that pharmacokinetic data obtained at one temperature, e.g., areas under the curve, cannot be used to directly predict tissue concentrations at another temperature.

A case of urethral replacement with polytetrafluoro-ethylene graft for multiple anterior urethral strictures

Recently, the authors had an opportunity to treat a 73-year-old male patient who was transferred to our institution with problematic multiple strictures of the anterior urethra subsequent to a suprapubic cystostomy. A proximal urethra was reconstructed with scrotal skin, but due to the shortage of distal skin, as a last resort we reconstructed a distal urethra using a polytetrafluoroethylene graft in place of 10 cm long urethral strictures. About 5 months after surgery, we had to reexplore the polytetrafluoroethylene graft area because of pain and found, much to our surprise, that the urethra had been completely regenerated around the length of polytetrafluoroethylene graft which now remained freely detached in the urethral canal. Following removal of the polytetrafluoroethylene graft, the patient could urinate normally and was subsequently discharged without further problems. We concluded that this case was incidentally successful with good regeneration of urethral mucosa of the anterior urethra by grafting a polytetrafluoroethylene tube.

Modulation of cellular transglutaminase: protease-induced activation

Multiple molecular forms of transglutaminase are found in cells and each form is widely distributed. We find a 95 K dalton enzyme associated with membrane fractions. A 50 K dalton enzyme occurs primarily in epidermis and hair follicles. Cells after treatment with proteases show greater transglutaminase activity. The activated enzyme in rat chondrosarcoma cells is one of 95 K daltons, whereas mouse epidermal cells and rabbit endometrium cells after protease activation display enzymes of both 95 K daltons and 50 K daltons. The 95 K dalton enzyme, but not that of 80 K daltons, can be activated by proteases or sulfhydryl compounds after cell lysis. In cells that undergo terminal differentiation, e.g., reticulocytes, megakaryocytes, monocytes, chondrocytes, and epidermal cells, the forms of transglutaminase are modulated. Our findings suggest that these modulations in differentiating cells are the results of transglutaminase post-translational modifications that cause pronounced changes in catalytic activity.

A case report: carcinoma of the gastric stump after Billroth II resection

Carcinoma of the gastric stump as a late complication for resection of benign disease is a well recognized clinical entity.

The risk of stump carcinoma, at least in Western Europe, is estimated to be increased twofold compared with the normal population.

But in Korea there has been one report. Recently we experienced a case of carcinoma of the stump which developed about 20 years after a gastro-jejunostomy for a duodenal ulcer.

Iconic indexing by 2-d strings

In this paper, we describe a new way of representing a symbolic picture by a two-dimensional string. A picture query can also be specified as a 2-D string. The problem of pictorial information retrieval then becomes a problem of 2-D subsequence matching. We present algorithms for encoding a symbolic picture into its 2-D string representation, reconstructing a picture from its 2-D string representation, and matching a 2-D string with another 2-D string. We also prove the necessary and sufficient conditions to characterize ambiguous pictures for reduced 2-D strings as well as normal 2-D strings. This approach thus allows an efficient and natural way to construct iconic indexes for pictures.

Cellular transglutaminase. The particulate-associated transglutaminase from chondrosarcoma and liver: partial purification and characterization

A transglutaminase from the malignant chondrocytes, rat swarm chondrosarcoma cells, was partially purified and characterized in an effort to understand transformation-induced changes in its activity. This enzyme separated by DE52 column chromatography after extraction from the particulate fraction of cell lysate was found to be distinct from previously characterized transglutaminases in its electrophoretic mobility, molecular size, substrate specificity, and immunologic reactivity. This enzyme was identified as a transglutaminase by its catalysis of amine (putrescine, spermine) incorporation at the carboxamide group of protein-bound gamma-glutamyl residues, and accordance of its kinetic data with the modified double displacement mechanism described for other transglutaminases. Limited proteolysis of the isolated enzyme resulted in a 3-4-fold increase of catalytic activity and a concomitant reduction of molecular size by approximately one-half. Incubation of labeled amine with chondrosarcoma cell lysate resulted in labeling of only a few proteins that appeared to be extensively cross-linked and that were located mostly in the particulate fraction of the cells. Transglutaminase extracted from the rat liver particulate fraction displayed enzymatic and structural properties closely resembling those of the enzyme from chondrosarcoma cells.

Analysis of complete responders after initial treatment with chemotherapy in head and neck cancer

We treated 60 patients with cisplatin-based combination chemotherapy before definitive surgery and/or radiation. All had squamous cell tumors of the head and neck, stages II to IV, M0. Twelve patients (20%) achieved a complete remission after chemotherapy. Eight of these patients showed no histologic evidence of residual disease after biopsy or surgery. Definitive local therapy with surgery and/or radiation was carried out on almost all patients regardless of the extent of the response to preceding chemotherapy. Chemotherapy-induced complete responders have had an improved survival rate in comparison with patients achieving a partial response or less. The extent of primary tumor correlates inversely with a complete response to chemotherapy.

Picture indexing and abstraction techniques for pictorial databases

We present an approach for picture indexing and abstraction. Picture indexing facilitates information retrieval from a pictorial database consisting of picture objects and picture relations. To construct picture indexes, abstraction operations to perform picture object clustering and classification are formulated. To substantiate the abstraction operations, we also formalize syntactic abstraction rules and semantic abstraction rules. We then illustrate by examples how to apply these abstraction operations to obtain various picture indexes, and how to construct icons to facilitate accessing of pictorial data.

Myringoplasty (A review of 365 operations)

A series of 365 cases of tympanic membrane repair by the same surgeon is analysed, comparing the results of different techniques and grafting materials. A detailed study of 206 of these cases employing the underlay technique with temporal fascia is reported. In this group a graft take rate of 91.4 per cent in dry ears, and of 89.3 per cent in all cases, was achieved. Various factors liable to influence the success rate are analysed and discussed. No cases of conductive or sensori-neural hearing loss resulting from the operation were encountered.

Accelerating effect of ascorbic acid on N-nitrosamine formation and nitrosation by oxyhyponitrite

The reaction of nitrite ion with ascorbic acid and its effect on the rate of nitrosation of secondary amines have been investigated by differential pulse polarography in aqueous acidic solution. Ascorbic acid shows nonuniform behavior: it accelerates the nitrosation of N-methylaniline between pH 1.00 and 1.95, allows the nitrosation of diphenylamine and iminodiacetonitrile, but inhibits the nitrosation of secondary amines, such as dimethylamine, diethylamine, proline, hydroxyproline, N-methylaminoacetonitrile, N-methylaminopropionitrile, and sarcosine. The nitrosating agent generated by the reaction between ascorbic acid and nitrite ion appears to be oxyhyponitrite ion (N2O3-2).

Translation of fuzzy queries for relational database system

The concept of a database skeleton which reflects both the user's conception of the real world and the system's understanding of the interrelationships among database entities is described. It consists of a conceptual schema (conceptual graphs) and a relational schema (information graph). With the aid of the database skeleton, fuzzy queries can be translated and disambiguated by analyzing the queries using the conceptual graphs of a database skeleton. The query language XQL is introduced, and the XQL translator is described in some detail.

Platelet adhesion to solid surfaces. The effects of plasma proteins and substrate wettability

Platelet adhesion tests were performed using protein-free washed pig platelet suspensions in conjunction with a simple open-static method on smooth, well-defined protein-coated glass and polymer surfaces and bare glass and polymer surfaces. A normalization technique was introduced in an attempt to correct day-to-day variations in platelet reactivity. Protein coatings reduced platelet adhesion (to glass as well as polymer surfaces) to such a low level that the platelet density on one protein/substrate combination could not be distinguished from that on any other protein/substrate combination. Specifically, albumin and fibrinogen behaved identically regardless of the substrate on which they were coated. The addition of albumin and gamma-globulin to the platelet-suspension also significantly reduced platelet adhesion to glass surfaces. Whereas the extent of platelet adhesion from protein-free suspensions to bare glass and polymer surfaces depended on their wettability, the presence of specific chemical groups in the proteins, such as (-CONH-), may have an overriding effect on platelet adhesion to solid surfaces.

Inhibition of dimethylnitrosamine-induced strand breaks in liver DNA and liver cell necrosis by diethyldithiocarbamate

Diethyldithiocarbamate (DEDTC) prevented dimethylnitrosamine (DMN)-induced strand breaks in liver DNA and liver cell necrosis in male Wistar rats. In contrast, DEDTC did not inhibit the fragmentation of liver DNA caused by several other chemical carcinogens (N-hydroxy-2-acetylaminofluorene, 3-hydroxyxanthine, aflatoxin B1, N-acetoxy-2-acetylaminofluorene, methyl methanesulfonate, methylnitrosourea, and methylazoxy-methanol acetate), whether or not they required metabolic activation. Aminoacetonitrile exerted an action similar to that of DEDTC. The inhibitory effect was transitory, lasting at least for 4 hours, and protection for longer than 4 hours required multiple administrations of DEDTC. DEDTC also inhibited the serum clearance of DMN, methylation of liver DNA, and oxidative demethylation of DMN in the in vitro hepatic microsomal system prepared from either male Wistar rats or from hamsters. Interference of the metabolism of DMN appeared to be the mechanism by which DEDTC arrested DMN-induced biochemical and biologic effects.