Production and characterization of monoclonal antibodies to bovine brain succinic semialdehyde reductase

Monoclonal antibodies against bovine brain succinic semialdehyde reductase were produced and characterized. A total of nine monoclonal antibodies recognizing different epitopes of the enzyme were obtained, of which two inhibited the enzyme activity and three stained cytosol of rat spinal cord neurons as observed by indirect immunofluorescence microscopy. When unfractionated total proteins of bovine brain homogenate were separated by gel electrophoresis and immunoblotted, the antibodies specifically recognized a single protein band of 34 kDa, which comigrates with purified bovine succinic semialdehyde reductase. Using the antisuccinic semialdehyde reductase antibodies as probes, we investigated the cross-reactivities of brain succinic semialdehyde reductases from some mammalian and an avian species. The immunoreactive bands on western blots appeared to be the same in molecular mass--34 kDa--in all animal species tested, including humans. The result indicates that brain succinic semialdehyde reductase is distinct from other aldehyde reductases and that mammalian brains contain only one succinic semialdehyde reductase. Moreover, the enzymes among the species are immunologically very similar, although some properties of the enzymes reported previously were different from one another.

Loss of heterozygosity on the short arm of chromosome 17 in uterine cervical carcinomas

DNA samples from 26 cervical carcinoma and normal tissue pairs were studied by restriction fragment length polymorphism (RFLP) analysis to determine the frequency of loss of heterozygosity (LOH) on 17p. Allelic loss in the p13.1 region of chromosome 17, known to contain the TP53 locus, was not detected in any of 10 informative cases. Instead, LOH was detected on 17p13.3 in eight (40%) of 20 informative cases with at least one of two 17p13.3 markers. Examination of the intragenic region of p53 in the same samples using polymerase chain reaction (PCR)-RFLP analysis showed no LOH in the gene (none of 16 informative individuals).

Stage IIb cervical carcinoma: MR evaluation of effect of intraarterial chemotherapy

PURPOSE

To evaluate magnetic resonance (MR) imaging in assessment of tumor response after intraarterial chemotherapy (IAC) in cervical carcinoma.

MATERIALS AND METHODS

MR images of 19 patients who underwent IAC because of stage IIb cervical carcinoma were prospectively analyzed and compared with pathologic findings. Three courses of IAC were administered, and MR images were obtained before and after treatment. Extent of reduction of tumor volume determined eligibility for surgery. MR images of 17 patients who were candidates for surgery were correlated with pathologic specimens.

RESULTS

Average reduction in tumor volume was 88.5%. Response to IAC was complete in seven patients, partial in 11, and minor in one. MR imaging findings after IAC correlated well with pathologic findings.

CONCLUSION

MR imaging is useful in assessment of tumor response to IAC and provides criteria for decision making with regard to further radiation or surgical therapy.

Static circumferential tangential modulus of human atherosclerotic tissue

The mechanical properties of atherosclerotic plaque may be of critical importance to the processes of plaque rupture, the most common antecedent of myocardial infarction. To investigate the effects of plaque structure and applied tensile stress on the static circumferential tangential modulus of atherosclerotic plaque, the stress-strain behavior of 26 human aortic intimal plaques was studied. Intimal plaques were collected during routine autopsies of 21 patients from the abdominal (n = 19) and thoracic (n = 2) aorta and were classified by histological analysis as cellular (n = 12), hypocellular (n = 9), and calcified (n = 5). At a physiologic applied circumferential tensile stress of 25 kPa, the tangential moduli of cellular, hypocellular, and calcified specimens were 927 +/- 468 kPa, 2312 +/- 2180 kPa, and 1466 +/- 1284 kPa, respectively. There was a nonsignificant difference in tangential modulus at 25 kPa stress between specimens classified as cellular and hypocellular (p = 0.098), cellular and calcified (p = 0.410), and hypocellular and calcified (p = 0.380). This is in marked contrast to the previously measured radial compressive behavior of plaque tissue, which showed that cellular, hypocellular, and calcified plaques were significantly different in their modulus. In tension, all 26 plaques tested demonstrated a statistically significant increase in tangential modulus with increasing applied circumferential stress. We conclude that the static circumferential tangential modulus of atherosclerotic plaque, unlike its radial compressive modulus, is not significantly affected by the degree of cellularity and calcification determined by histological characterization.(ABSTRACT TRUNCATED AT 250 WORDS)

The deactivation of hCG by nicking and dissociation

Human chorionic gonadotropin (hCG) is composed of an alpha- and a beta-subunit, joined noncovalently. A proportion of hCG molecules in pregnancy serum and urine samples have nicks or a missing peptide linkage between either beta-subunit residues 44 and 45 or beta-subunit residues 47 and 48. These nicks ablate the steroidogenic activity of hCG. We examined the source of nicking, and the occurrence and stability of nicked hCG molecules produced during pregnancy. We investigated the source of nicking. Standard hCG was added to three samples of whole blood, and incubated 18 h at 37 C. No change in extent of nicking was detected. However, nicking of hCG beta-subunit was detected by gel electrophoresis (bands at M(r) = 17,000 and M(r) = 22,000, corresponding to the peptides beta 1-47(44) and beta 48(45)-145, respectively) in culture fluids from first trimester placental explants and from JAr malignant trophoblast cells. We inferred that nicking occurs before or immediately upon secretion by trophoblast tissue. We examined the occurrence of nicking. Levels of total hCG (nicked+nonnicked) and intact hCG (nonnicked) were determined in 233 serum and 168 urine samples from 4-40 weeks of pregnancy. From the two measurements the extent of nicking was estimated. A linear relationship was indicated between advancing weeks of gestation and increasing extent of nicking (regression analysis, months vs. percent nicked, 95% correlation). Minimum nicking was observed in serum from the first 2 months of pregnancy (mean = 9% of hCG molecules), increased nicking in the months after, and maximum nicking in samples from the last 2 months of pregnancy (mean = 21% of hCG molecules, t test first 2 months vs. last 2 months, P < 0.00005). Similar results were observed with urine samples (first 2 months mean = 9%, last 2 months = 27%, t test P < 0.00005). We concluded that nicking is more prevalent after the hCG peak (after 2 months of pregnancy). Finally, we examined the stabilities of nicked and intact hCG molecules. Standard hCG (batch CR127, 20% nicked) and hCG preparation C5 (100% nicked) were incubated for varying times in whole blood. C5 hCG dissociated rapidly into free alpha- and beta-subunits (dissociation half-life 22 +/- 5.2 h), over 30 times faster than standard hCG (dissociation half-life 700 h).(ABSTRACT TRUNCATED AT 400 WORDS)

Vertical banded gastroplasty: is obesity worth it?

Obesity is a public health issue of major concern for the United States and other developed nations. In the last several decades, bariatric surgery has developed as a means of treating morbid obesity. Vertical banded gastroplasty (VBG) is an attractive procedure because it has fewer side effects than other forms of bariatric surgery and maintains physiological continuity of the gut. VBG was performed in 36 patients at a rural community hospital from 1982-1990. There was only one intraoperative complication necessitating splenectomy and two early postoperative complications--gastric leak and marginal stress ulcer--necessitating reexploration. Twenty-five patients were available for follow-up, at which time they were an average of 6.4 years out of surgery. Two of these patients had died, both from cardiac arrest months or years after VBG. The remainder had gone from a preoperative average of 86.7% over ideal weight according to 1983 Metropolitan Life insurance Tables to 54.5% over ideal weight. Mean BMI for this group had changed from 41.2 preoperatively to 34.7 at follow-up. Success was defined as weight loss to < 60% over ideal or BMI < 35, removing the individual from the morbidly obese category. According to this criteria, VBG provided successful weight loss in 72% of subjects in the follow-up group. Weight loss results may have been biased as a significant number of patients were lost to follow-up and may have constituted failures. In general, most individuals did not make concomitant changes in diet or sedentary life-style which would have supported weight loss effected by VBG. Moreover, regain of weight was progressive and possibly inexorable. Nearly all individuals nonetheless reported great satisfaction with their surgery. VBG is a viable option in the treatment of morbid obesity, but criteria for success needs to be better defined in order to determine whether the procedure is "worth it."

Effective blocking of natural cytotoxicity of young rabbit serum on murine thymocytes by high concentration of glucose in complement-dependent cytotoxicity method

By an accidental observation, the natural cytotoxicity of 21-day-old rabbit sera to murine thymocytes was found to be almost completely inhibitable by 4.5 mg/ml glucose. This enabled us to use unabsorbed young rabbit serum as a source of complement for antibody-mediated cytotoxic treatment of murine thymocytes. This glucose-sensitive natural cytotoxic activity was recovered in the immunoglobulin fraction purified on an affinity column, and was dependent on complement activity. The unabsorbed 21-day-old rabbit sera had much higher complement activity than those from 14-day-old rabbits and commercially available low background complement. Indeed, complete depletion of CD4+ cells from murine thymocytes and splenocytes was achieved using unabsorbed 21-day rabbit serum as a source of complement and a monoclonal antibody GK1.5 which has been claimed to be inefficient in complement-dependent killing. Owing to the increase in complement titer and circulating blood volume 14-21 days after birth, the use of 21-day-old rabbit sera assures a much more abundant supply of complement for the treatment of murine lymphocytes.

[The effects of antibodies and complement in macrophage-mediated cytotoxicity on metacercariae of the lung fluke, Paragonimus westermani]

Paragonimus westermani is a tissue migrating parasite in the early stage until arriving at lung, and most of the parasites spend their life spans there. Considerable immune responses including activation of macrophages are taken place during the residence of parasites in the host. However, concerning the immunologic defense mechanisms of the host against this parasite, only a few document is available so far. In this study, the cytotoxic effect of peritoneal macrophages under the presence of antibody and/or complement against metacercariae of P. westermani was investigated in vitro. Metacercariae were collected from the crayfish, Cambaroides similis and hatched out in Tyrode solution (pH 7.4). Plastic adherent cells from normal or infected rat (Wistar) peritoneal exudates were used as experimental macrophages. Polyclonal antibodies were obtained from infected rats and a cat. Cat IgG was fractioned with ion exchange chromatography. Fresh rabbit complement was used according to experimental scheme. Various combinations of peritoneal macrophages, normal or infected rat serum, complement and cat IgG were incubated at 36 degrees C in 5% CO2 incubator for 6, 14, 24 and 48 hours. The results obtained were as follows: 1. P. westermani infection activated peritoneal macrophages non-specifically and this activation induced increases of cell adherence and cytotoxicity on metacercariae. 2. In the presence of infected rat serum the antibody-dependent cell-mediated cytotoxicity of peritoneal macrophages on metacercariae was significantly increased and showed a peak at 6-hour incubation. But the cytotoxic effect was markedly reduced after inactivation of complement and heat-labile IgE antibody by the heating of infected serum at 56 degrees C for 30 minutes. 3. The highest cytotoxic effect (100%) of concomitant incubation with IgG and complement showed 24 hours after incubation, although cell adherence was relatively low at 6-hour incubation and 0% at 24-hour incubation. 4. Coordinative functions of complement with serum and IgG were effective in cell adherence and in cytotoxicity, but it is not clear the independent role of complement on the macrophage-mediated cytotoxicity in this study. With these results it is assumed that P. westermani infection can induce the non-specific activation of peritoneal macrophages, and serum antibodies including IgE antibody might enhance the cytotoxicity by macrophages.

Scanning electron microscopic observations of Thelazia callipaeda from human

Four females and a male nematode isolated from 2 patients who visited eye clinics in Seoul were identified as Thelazia callipaeda and their ultrastructures were observed by scanning electron microscopy (SEM). General features of the worms were slender and attenuated at both ends. Vaginal opening was located at 0.27 mm from the anterior end, and in front of the esophago-intestinal junction. In the body cuticle transverse striations varied characteristically through the body. The number of cuticular transverse striations was 400-650/mm at head portion, 250/mm at middle portion and 300-350/mm at tail portion. The SEM observation of the mouth part of the females showed 6 cord-like cuticular thickenings in hexagonal arrangement and an amphid was observed. A lateral line, a vaginal opening, a pair of phasmids, and an anus were identified in the body portion. A pair of papillae and 6 cord-like cuticular thickenings were on the mouth part of the male. It was difficult to observe structures at the tail of the male except wrinkle-like structures. Most of the larvae isolated from the uterus of a female worm were sheathed and thus cuticular striations were not seen. Others were un-sheathed and revealed cuticular striations. The oval membrane which encysted sheathed larvae was also observed. These are the 18th and 19th record of human thelaziasis in Korea as the literature are concerned.

Review of the 4-quinolones

Improvements in antimicrobial activity and pharmacokinetics have moved the 4-quinolones into the forefront of antibiotic research. The 4-quinolones are analogues of nalidixic acid, and there are presently at least six agents in this group under investigation in the United States. It is difficult to generalize their clinical usefulness, since these agents exhibit different pharmacokinetic profiles, antimicrobial activity (with varied minimum inhibitory concentrations among similar organisms), and dosage regimens. The 4-quinolones are potential therapeutic alternatives for infections caused by a variety of organisms. They include: Neisseria gonorrhoeae; Pseudomonas aeruginosa; Haemophilus influenzae; Staphylococcus aureus; common enteric pathogens (salmonella, shigella, campylobacter, etc); and intracellular bacteria (legionella, chlamydia, mycobacteria, etc). Clinical efficacy has been demonstrated in urinary tract infections, respiratory tract infections, and sexually transmitted diseases. Future studies will undoubtedly demonstrate effectiveness in numerous additional infectious processes. The purpose of this article is to compare the 4-quinolones in regards to pharmacokinetics and spectrum of activity and review the clinical studies involving these agents.

Multiple myeloma in Korea--clinical analysis and treatment results in 61 cases

A clinical analysis was made of 61 cases of multiple myeloma diagnosed between January 1976 and June 1984 at Seoul National University Hospital using the criteria of the Southwest Oncology Group.

The following observations were made. 1) The major clinical problems at Initial presentation were bone pain(52%), anemia(20 %), renal impairment(11%), and infection(10%). 2) Clinical stages at presentation were stage I, 11%; stage II, 8%; and stage III, 81% of patients. Three(5%) of the patients in stage II and 18(31%) in stage III showed renal impairment with a serum creatinine ≥2.0 mg/dl. 3) Combination chemotherapy produced a response rate of 29% with melphalan and prednisone, and 40% with M2 protocol(among 14 and 20 evaluable patients respectively). Both regimens showed statistically significant survival difference between responders and non-responders(p <0.01). 4) The median survival of all patients was 13 months. 5)Age, calcium level, creatinine level, and performance status were important prognostic factors on survival.

Review of imipenem

Imipenem, a new carbapenem beta-lactam broad-spectrum antibiotic, is highly active in vitro against most aerobic and anaerobic gram-positive and gram-negative bacteria isolated from infectious diseases of human beings. Except for enterococci and methicillin-resistant staphylococci most gram-positive cocci are inhibited by less than 2 micrograms/ml. Although the MIC-90 of methicillin-resistant staphylococci may be less than 4 micrograms/ml, these bacteria are usually resistant to imipenem by modified testing methods. The enterococcus, S. faecalis, has an MIC-90 of less than 8 micrograms/ml but bactericidal concentration may be much higher. Most Enterobacteriaceae are highly susceptible to imipenem with MIC-90 of 0.5 to 2.0 micrograms/ml. Proteus species are less susceptible with MICs of 4 to 8 micrograms/ml. Isolates of P. aeruginosa have variable susceptibility with MICs ranging from 0.25 to 16 micrograms/ml. Pseudomonas maltophilia and P. cepacia are usually resistant to imipenem. Except for Clostridium species, most strict anaerobes are susceptible to less than 1.0 micrograms/ml of imipenem. When combined with cilastatin (1:1 ratio), the renal elimination of the active form is increased. The serum halflife in normal renal function is about 1 hour and increases to 3.4 hours in anuria. Major adverse effects are similar to those of cephalosporins except for seizures in some patients. Colonization with fungi and drug-resistant bacteria occurs in about 5% of imipenem-treated patients. Clinical studies have demonstrated efficacy in 79% to 96% of patients treated.

Naloxone in septic shock: report of two cases

Two cases are reported describing the use of intravenous naloxone in surgical patients with prolonged hypotension unresponsive to conventional intensive care, including dopamine, intravenous fluids, diuretics, and steroids.The findings were in agreement with those of previous reports suggesting that endorphins may contribute to the hypotension of sepsis and that naloxone's antagonistic effect on endorphin may have therapeutic value in the treatment of septic shock.