Ubiquitous Presence in Mammalian Cells of Enzymatic Activity Specifically Cleaving 8-Hydroxyguanine-containing DNA

Here we report the finding of enzymatic activity that specifically cleaves DNA containing 8-hydroxyguanine (oh⁸Gua) residues in various mammalian cells. To detect this activity, we used a synthetic double-stranded DNA containing a single oh⁸Gua at a defined position as the substrate, and analyzed the products of enzymatic digestion by polyacrylamide gel electrophoresis. Two cleavage sites near the oh⁸Gua residue were detected with partially purified fractions from cow brain and rat liver, and also with preparations from all mammalian tissues examined. These results suggest that enzymatic activity for the removal of oh⁸Gua from DNA is widely distributed in mammalian cells.     

Prostatic carcinoma in a young adult: a case report]

We report a case of carcinoma of the prostate in a 30-year-old man. Serum acid phosphatase was normal. A transrectal biopsy of the prostate demonstrated an undifferentiated carcinoma. Total prostatocystectomy was performed and subsequent pathologic report stated that the mass was an undifferentiated carcinoma of the prostate gland. Metastases to the intrapelvic lymph node were present. Although immunohistochemical prostatic acid phosphatase (PAP) activity was not demonstrated, prostatic specific antigen (PSA) staining revealed a positive reaction within the tumor cells, confirming prostatic carcinoma. The patient's course has been uneventful without any recurrence by the intermittent adjuvant chemotherapy 8 months postoperatively. Review of the literature in Japan disclosed 16 cases (including our case) of carcinoma of the prostate in patients under 40 years of age.     

Comparative pharmacokinetics of pipecuronium bromide, pancuronium bromide and vecuronium bromide in anesthetized man

The pharmacokinetics of pipecuronium bromide was studied in 9 male patients (ASA class 1-2, 20-65 years of age). Following a single intravenous dose of pipecuronium 0.08 mg.kg-1, plasma levels were measured by capillary gas chromatography. Plasma concentration-time curves were evaluated by fitting the data to a bi-exponential equation. The pharmacokinetic parameters of pipecuronium were compared with those of pancuronium (0.08 mg.kg-1) and vecuronium (0.08 mg.kg-1) previously obtained under the same anesthesia (66% N2O, 33% O2 and 1% halothane). With pipecuronium, following pharmacokinetic parameters were obtained; distribution half-life; T1/2 alpha = 3.9 +/- 0.7 min (mean +/- SEM), elimination half-life; T1/2 beta = 102 +/- 12 min, volume of the central compartment; V1 = 95 +/- 13 ml.kg-1, volume of distribution at steady state; Vdss = 264 +/- 41 ml.kg-1, clearance; Cl = 1.8 +/- 0.2 ml.min-1.kg-1. Microconstants of two-compartment open models (k12, k21, k10) were also calculated. Using Mann-Whitney's U-test, these parameters of pipecuronium were compared with those of pancuronium (n = 3) and vecuronium (n = 4). V1 and Vdss of pipecuronium were significantly larger than those of pancuronium (V1; 38 +/- 12 ml.kg-1 and Vdss; 120 +/- 4 ml.kg-1) (both P less than 0.10). Reflecting the larger central volume of pipecuronium, pipecuronium tended to have a larger clearance than that of pancuroniumu (Cl; 1.1 +/- 0.2 ml.min-1.kg-1).(ABSTRACT TRUNCATED AT 250 WORDS)     

Transepithelial movement of non-polar and polar compounds in male rat reproductive tubule examined by in vivo microperifusion and in vivo micropuncture

Proluminal movement of 3H-testosterone and 3H-sucrose from peritubular to intratubular fluids of the adult rat testis and epididymis was investigated by using in vivo microperifusion and subsequent micropuncture of seminiferous tubules and caput, corpus, and cauda epididymal tubules. Tubules were perifused with Minimum Essential Medium containing 3H-testosterone or 3H-sucrose. 14C-polyethyleneglycol was included in the perifusion fluid as a marker for contamination of intraluminal fluid by interstitial fluid. Radioactivity of isotopes in perifusion and intraluminal fluids was determined at one and two hours after perifusion and the percentage of peritubular isotopes appearing in intraluminal fluid was determined. Net entry of 3H-sucrose into the seminiferous and epididymal tubules was significantly reduced. Proluminal movement of 3H-androgen across the seminiferous epithelium was also restricted. In contrast, intraluminal 3H-androgen concentrations in caput epididymal fluid were 200 to 300% of those in peritubular fluid at both one and two hours after perifusion. Similar results were found in the corpus epididymidis. 3H-androgen concentrations in cauda epididymal fluid were approximately 125% of peritubular isotope concentrations. The exact mechanism underlying this uphill proluminal movement of 3H-androgen into the rat epididymal lumen remains to be elucidated.     

Determination of the exposure concentration of propylene oxide to produce neuropathy in rats

Although propylene oxide, which is similar in chemical structure to ethylene oxide, is expected to produce neuropathy, there is no convincing evidence of the degeneration of the peripheral nervous system. To determine the exposure concentration of propylene oxide necessary to produce neuropathy in male Wistar rats, we subjected them to repeated exposures of propylene oxide at concentrations of 500, 750, 1000, 1500 and 2000 ppm. The test rats were subjected to a single 6 hour exposure of propylene oxide at a concentration of 1500 parts per million 5 times a week for 3 weeks. They developed a significant decrease in body weight, abnormal posture of the hindlegs and axonal degeneration of myelinated fibers in the peroneal and sural nerves, the nerves to the soleus muscle, and in the fasciculus gracilis of the spinal cord. Therefore, it was concluded that propylene oxide induces neuropathy in rats characterized by axonal degeneration, similar to that produced by ethylene oxide, and that the exposure to the higher concentration of propylene oxide is more necessary to produce neuropathy than in the case of ethylene oxide neuropathy in rats.     

Herpes zoster ophthalmicus complicated by hyphema and hemorrhagic glaucoma

We treated two patients with herpes zoster ophthalmicus in whom hyphema and hemorrhagic glaucoma occurred. Case 1 complained of facial skin eruption, and was given intravenous acyclovir for 7 days. Hyphema and high intraocular pressure occurred in the left eye 10 days after the onset of the skin eruption. Case 2 had severe pain and blisters on her face, and was given intravenous acyclovir for 7 days. An intracameral hemorrhage and glaucoma developed in the right eye 15 days after the onset of the skin lesion. Intravenous acyclovir may be necessary for longer than 7-day periods if the iridocyclitis remains.     

Pseudopodia of capillary endothelium in ocular tissues

The frequencies of pseudopodia projecting from capillaries of various parts of the eye were observed in 16 human eyes with a transmission electron microscope. The pseudopodia were found mainly projecting from the choriocapillaris and rarely seen in the retina, iris or ciliary body. The frequencies of pseudopodia from the choriocapillaris were not correlated with the localization in the fundus (macular area or peripheral fundus), age, sex, time elapsed between death or enucleation and fixation. The significance of pseudopodia from the choriocapillaris is unknown. However, there is the possibility that pseudopodia are related to choroidal neovascularization or have other physiological functions.     

High human IgG levels in severe combined immunodeficient mouse reconstituted with human splenic tissues from patients with gastric cancer.

We implanted normal peripheral blood lymphocytes (PBL) from healthy donors and splenic tissues from patients with gastric cancers into the severe combined immunodeficient (SCID) mouse, demonstrating that SCID mouse with splenic tissue can produce a high level of human immunoglobulin G (IgG). The normal PBLs at 10(7) and 10(8)/mouse were implanted intraperitoneally, and three splenic tissues with a size of 3 x 3 x 3 mm from gastric cancer patients were inoculated subcutaneously into the bilateral backs of the mice. At 2, 4, 6 and 8 weeks after inoculation, mice were killed, and the human IgG was assessed by an ELISA method. SCID mice with splenic tissue revealed high human IgG levels from 2 weeks after inoculation and approximately 2 mg of IgG per ml was observed at 8 weeks post-implantation, while the IgG levels in mice treated with PBLs were limited. Since the half life of the extrinsic human IgG was 10.2 days, the high level of human IgG in the SCID mice was supposed to be produced by human plasma cells in the splenic tissue from gastric cancer patients. This model was thought to be adequate for evaluating human immunological functions in vivo.     

Effects of intrahippocampal injections of N-methyl-D-aspartate receptor antagonists and scopolamine on working and reference memory assessed in rats by a three-panel runway task.

In order to elucidate the roles of hippocampal N-methyl-D-aspartate-type excitatory amino acid receptors in working and reference memory in rats, the effects of intrahippocampal injections of selective and competitive N-methyl-D-aspartate receptor antagonists such as CGS 19755 (cis-4-phosphonomethyl-2-piperidine carboxylic acid), 3-[(+-)-2-carboxypiperazin-4-yl]propyl-1-phosphonic acid and 2-amino-5-phosphonovaleric acid on this behavior were examined with a three-panel runway task. The results were compared with the effect of the muscarinic receptor antagonist scopolamine. In the working memory task, CGS 19755 and 3-[(+-)-2-carboxypiperazin-4-yl]propyl-1-phosphonic acid at 10 and 32 ng/side, injected bilaterally into the dorsal hippocampus before testing, produced a significant increase in the number of errors (attempts to pass through two incorrect panels of the three panel-gates at four choice points). This also occurred after the rats were given systemic injection of these drugs at 3.2 and 10 mg/kg. In the reference memory task, neither CGS 19755 nor 3-[(+-)-2-carboxypiperazin-4-yl]propyl-1-phosphonic acid affected the number of errors, whether given at doses up to 32 ng/side intrahippocampally or up to 10 mg/kg systemically. Working memory errors also increased significantly after intrahippocampal injections of d-2-amino-5-phosphonovaleric acid at 100 and 320 ng/side, but were not affected by I-2-amino-5-phosphonovaleric acid at doses up to 1 microgram/side. On the other hand, intrahippocampal scopolamine at 1.0 and 3.2 micrograms/side increased significantly working memory errors, without affecting reference memory errors.(ABSTRACT TRUNCATED AT 250 WORDS)     

Middle-ear paraganglioma masquerading as traumatic facial nerve palsy.

We report the case of a 52-year-old female with middle-ear paraganglioma masquerading as a traumatic facial palsy, and describe the diagnostic steps and surgical treatment by the tympanomastoid approach.