Species difference in susceptibility to phorbol myristate acetate-induced leukopenia and lung injury: rat vs. dog

Phorbol myristate acetate (PMA) was administered intravenously in a single dose to rats (400 micrograms/kg) and in a single and repeated doses to dogs (40 micrograms/kg). Severe leukopenia was observed in both species. The leukopenia in rats was due to a decreased number of both lymphocytes and neutrophils while the leukopenia in dogs was mainly due to a decreased number of neutrophils. The rats recovered from leukopenia much faster than the dogs. The dog which received a single injection developed focal fibrosis in the lungs. Rats showed only slight localized hemorrhage in the lungs, although the rats received a ten-fold larger dose of PMA than the dogs. Lungs of dogs which received multiple injections revealed severe hemorrhagic lesions in most alveoli. Lung lesions induced by PMA are thought to be mediated by activated leukocytes. This suggests that the severity of lung lesion correlates with the degree and duration of neutropenia. In conclusion, intravenous administration of PMA caused lung damage in rats and dogs. However, rats show much less sensitivity to PMA than dogs, resulting from the different response of leukocytes to PMA.

HCV RNA and antibody to HCV core protein in Japanese patients with chronic liver disease

We evaluated the prevalence of hepatitis C virus (HCV) RNA and antibody (anti-HCVcore) to the putative HCV core protein in Japanese patients with chronic liver disease. Sera were screened by solid-phase enzyme immunoassay with a recombinant HCV core protein and by the reverse transcription-polymerase chain reaction (RT-PCR) test which directly detects the HCV genome. Anti-HCV core was detected with high titers in 95% (69/73) of chronic non-A, non-B hepatitis, and 94% (65/69) of anti-HCVcore-positive patients had the genome. Anti-HCVcore was also found with lower titers in 24% (10/41) of chronic hepatitis B virus carriers, and three of them had the genome. Only one (3%) of the 35 patients negative for anti-HCVcore tested positive to RT-PCR. These findings indicate the overwhelming prevalence of HCV infection in Japanese patients with chronic non-A, non-B hepatitis and a close relationship between the presence of anti-HCVcore and chronic hepatitis C in this population.

Formation of PhIP in a mixture of creatinine, phenylalanine and sugar or aldehyde by aqueous heating

A mixture of 100 mM creatinine and 100 mM L-phenylalanine was heated at 60 or 37 degrees C in the presence of sugar or aldehyde. A mutagen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) formed in the model system was determined by reversed-phase HPLC. Any sugars tested induced the formation of PhIP when heated at 60 degrees C, though PhIP was not detected in a mixture without sugar. Among the sugars tested, D-erythrose and D-glyceraldehyde were more productive than pentose (D-arabinose and D-ribose) and hexose (D-glucose and D-galactose) in the yield of PhIP. Moreover, PhIP was formed even when a mixture of creatinine, L-phenylalanine and D-glucose or D-ribose was incubated at 37 degrees C for a long time. Both formaldehyde and acetaldehyde also induced the formation of PhIP, though PhIP was not detected in a mixture without sugar or aldehyde even when heated at 100 degrees C. These results indicate that PhIP can be formed at low-temperature heating and that either sugar or aldehyde is essential for PhIP formation in the model system. Our data also suggest that aldehydes may be a key reactant in the formation of PhIP in aqueous heating of the mixture of creatinine and L-phenylalanine.

Predictions of energy intake and energy allowance of patients with Duchenne muscular dystrophy and their validity

Patients with Duchenne muscular dystrophy are so malnourished that energy supplementation is crucial. Their degree of energy deficiency was assessed as difference between their energy intake and their energy allowance, which were deduced from easily measured parameters. A significant, negative relationship was found between the basal metabolic rate (BMR) (Y, %, BMR/standard BMR) and body weight (X, %, body weight/standard body weight) in the patients, from which the formula for the BMR was deduced to be Y = -1.116X + 174.5 (n = 202, r = -0.72, p less than 0.001). Thus, it is possible to estimate the energy allowance for individual patients by a factorial procedure from the presumed BMR and a factor for physical activity. In addition, their energy intake was calculated from a constant protein-energy % (14.6%) in their diet and nitrogen intake which was deduced from a significant positive correlation between their nitrogen intake (Y, mg/kg/day) and their nitrogen excretion in 24 h urine samples (X, mg/kg/day). This correlation conformed to the equation Y = 1.053X + 32.4 (n = 267, r = +0.76, p less than 0.001). The validities of the above predictions for energy intake and allowance were examined by plotting the degree of energy deficiency (% ratio of presumed intake/presumed allowance) against the concentrations of retinal binding protein, prealbumin and transferrin in the serum, because rapid turnover proteins are sensitive to energy deficiency. Significant positive correlations were obtained with both variables, suggesting that these predictions were valid.

Protein and energy metabolism in patients with progressive muscular dystrophy

Studies were made on whether body weight loss in patients with muscular dystrophy is due to reduced intake and/or abnormal expenditure of energy. For this, food intakes and various physiological variables were surveyed in totals of 310 patients with Duchenne muscular dystrophy (DMD) of 11 to 29 years old and 28 patients with limb-girdle muscular dystrophy (LGMD) of 30 to 47 years old. Energy and protein intakes, expressed on a unit body weight basis, in DMD patients were comparable to, or higher than the allowances for age-matched healthy controls, whereas those in LGMD patients were 92 and 94% respectively of these allowances. The basal metabolic rate (BMR), expressed as kcal/kg/day, of DMD patients of all ages was higher than that of controls, the difference increasing with age, and being about 20 to 30% higher than that of controls in older patients with DMD. The BMR of LGMD patients was nearly normal. The maintenance requirements of conventional dietary protein in DMD and LGMD patients were 1.26 and 0.84 g/kg/day, respectively. These values were about 68 and 12% higher than the normal adult value (0.75 g/kg/day), indicating decreased protein utilization and increased protein catabolism. Daily excretion of urinary 3-methylhistidine (3MH) per unit muscle mass (micrograms/mg creatinine) by MD patients was significantly higher than that by controls, indicating increased degradation of muscle protein. The BMR, maintenance protein requirement and 3MH excretion of DMD patients suggest that DMD is a hypercatabolic disease. Comparison of the energy and protein intakes with the allowances estimated in consideration of increased requirements showed deficiencies of energy and protein in DMD patients. Thus, we conclude that the underweight of the DMD patients resulted from nutrient deficiencies due to hypercatabolism, despite their considerably high intakes of energy and protein, expressed as per kg body weight. These deficiencies were confirmed by demonstrating decreased concentrations of free essential amino acids, particularly branched chain amino acids, in their serum. The values of variables of LGMD patients were intermediate between those of DMD patients and control subjects.

Elevation of levels of carcinogenic tryptophan pyrolysis products in plasma and red blood cells of patients with uremia

The carcinogenic tryptophan pyrolysis products, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), have been measured in plasma and red blood cells (RBC) of patients with uremia and normal subjects by using a high-performance liquid chromatography (HPLC) method. In both uremic patients and normal subjects, these carcinogens have been detected in RBC as well as plasma. Trp-P-1 and Trp-P-2 levels in plasma of uremic patients were significantly higher than those of normal subjects. Moreover, these carcinogen levels in RBC (per hemoglobin) were significantly elevated in uremic patients in spite of the presence of severe anemia. These results suggest that patients with uremia are continuously exposed to higher levels of these carcinogens as compared with normal subjects. Our data also support the idea that these carcinogens in plasma and RBC are suitable for monitoring exposure levels in humans.

Occurrence of carcinogenic amino-alpha-carbolines in some environmental samples

The carcinogenic amino-alpha-carbolines, 2-amino-9H-pyrido[2,3-b]indole and AalphaC, have been measured in airborne particles, rain water, soil and cigarette-smoke-polluted indoor air by high-performance liquid chromatography. These carcinogens were found in all kinds of environmental samples examined, although MeAalphaC was not detected in soil. Considering the present results, together with the previous findings that these carcinogens were present in foodstuffs, cigarette smoke and diesel-exhaust particles, amino-alpha-carbolines are likely to be ubiquitous environmental pollutants. Our data also support the hypothesis that amino-alpha-carbolines are formed through combustion of various materials such as food, grass and petroleum.

Detection of a carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), in cigarette smoke condensate

A carcinogenic heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), was measured in condensate of cigarette mainstream smoke by HPLC. PhIP was detected in all brands of filter-tipped cigarettes analyzed. The mean level of PhIP in the cigarette mainstream smoke was 16.4 ng/cig.

[Carcinogenic heterocyclic amines in the environment]

The purpose of this report is to summarize data on carcinogenic heterocyclic amines mainly from the aspect of environmental medicine. Since 1977, a new series of heterocyclic amines has been isolated as potent mutagens and they have been shown to be carcinogenic to experimental animals. Among these carcinogens, carcinogenic amino-alpha-carbolines and amino-gamma-carbolines are widely distributed in such components of the environment as airborne particles, rain water, cigarette smoke, diesel exhaust particles and cooked foods. Moreover, most carcinogenic heterocyclic amines are reported to be present in cigarette smoke. These facts suggest that carcinogenic heterocyclic amines are likely to be ubiquitous environmental pollutants. These results also support the hypothesis that carcinogenic heterocyclic amines may be formed through combustion of various materials such as food, grass and petroleum.

Urinary excretion levels of carcinogenic glutamic acid pyrolysis products and their N-acetyl derivatives in humans

The carcinogenic glutamic acid pyrolysis products 2-amino-6-methyldipyrido [1, 2-a: 3', 2'-d]imidazole (Glu-P-1) and 2-amino-dipyrido [1, 2-a: 3', 2'-d] imidazole (Glu-P-2), and their N-acetyl derivatives were measured in 24-h urine of individual subjects by high-performance liquid chromatography. These compounds were detected in all urine samples analyzed, although the contents varied widely among subjects. The mean levels of Glu-P-1, N-acetyl-Glu-P-1, Glu-P-2 and N-acetyl-Glu-P-2 in 24-h urine were 0.53, 0.41, 2.12 and 4.60 pmol, respectively. In vitro experiments revealed N-acetyltransferase activity with Glu-P-1 and Glu-P-2 in the cytosolic fractions from rat kidneys and human autopsy kidney specimens as well as those from liver specimens, suggesting that extrahepatic tissues may also play significant roles in the N-acetylation of these carcinogens. These results show that Glu-P-1 and Glu-P-2, after being partially N-acetylated in metabolic organs such as liver and kidney, are excreted into urine together with their N-acetyl derivatives. It is suggested that daily excretion of carcinogenic glutamic acid pyrolysis products and their N-acetyl derivatives into urine can be a suitable biological monitor for exposure to these carcinogens.

ABBREVIATIONS

Glu-P-1, 2-amino-6-methyldipyrido [1, 2-a: 3', 2'-d] imidazole; Glu-P-2, 2-aminodipyrido [1, 2-a: 3', 2'-d] imidazole; N-acetyl-Glu-P-1, 2-acetylamino-6-methyldipyrido [1, 2-a: 3', 2'-d] imidazole; N-acetyl-Glu-P-2, 2-acetylaminodipyrido[1,2- a:3', 2'-d]imidazole; HPLC, high-performance liquid chromatography.

[Antero-lateral uncoforaminectomy in treatment of cervical spondylotic monoradiculopathy]

Thirty seven patients with cervical spondylotic monoradiculopathy treated with antero-lateral uncoforaminectomy were analysed. Spondylotic spur of the level associated with radiculopathy was revealed to be continuous from the uncovertebral joint to the posterior ridge of the vertebral body in 35 patients. Antero-lateral uncoforaminectomy was found to safely remove the continuous type of spur, resulting in decompression of the cord-root-complex, which shifted anteriorly after surgery. As a result, no neurological symptoms were observed in 36 of 37 radiculopathy patients. It could be concluded that the most important factor in relieving neurological manifestations of this disorder is decompression of the cord-root-complex.

The particle size of hepatitis C virus estimated by filtration through microporous regenerated cellulose fibre

To estimate the particle size of hepatitis C virus (HCV), a major causative agent of post-transfusion non-A, non-B hepatitis, we filtered plasma or serum samples through microporous cellulose fibres with different pore sizes. The amount of HCV particles in samples before and after filtration was determined by a quantitative reverse transcriptase polymerase chain reaction (PCR) method. Since there is no quantitative biological assay for HCV, except for that in chimpanzees, the HCV titre obtained from the PCR method was used in an equation constructed previously for application to filtration experiments with a flavivirus which is distantly related to HCV. The particle was estimated to be between 30 and 38 nm in diameter, although the possibility remained that larger HCV particles or HCV aggregates with a diameter of more than 39 nm might exist. Double-step filtration through microporous cellulose fibres with a pore size of 35 nm reduced the HCV content to below levels detectable by our PCR method, indicating that it is possible to eliminate HCV particles by simple filtration techniques.

[Dumbbell type tumor of a nerve root treated surgically by vertical curvilinear approach]

A 42-year-old man was admitted for further examination of an abnormal shadow on the posterior mediastinum which was incidentally detected by a routine chest X-ray. Myelography followed by computerized tomographic scanning (CT) revealed that a dumbbell shaped tumor had developed in the paravertebral area adjacent to the vertebral canal through an intervertebral foramen. A vertical curvilinear incision centered at T-6 was made with the patient in a prone position. Total laminectomy or T-5 and T-6 and resection of the left 6th rib provided sufficiently wide exposure for a one-stage resection of the tumor. The dumbbell shaped tumor originated from the root of 6th spinal nerve but did not extend to the spinal cord. The extirpated tumor was diagnosed histologically as schwannoma. Because tumor location had been determined preoperatively by CT scanning after myelography, it was possible to perform complete extirpation of the tumor while avoiding the complications of laminectomy and unnecessary thoracotomy.

Structure and organization of the hepatitis C virus genome isolated from human carriers

Hepatitis C virus (HCV) is a major causative agent of posttransfusion non-A, non-B hepatitis, which often develops into malignant chronic diseases, including liver cirrhosis and hepatocellular carcinoma. We have cloned from human carriers overlapping cDNAs (9,416 bp) covering the entire coding region of the HCV genome. The latter encodes a 3,010-amino-acid polyprotein. In addition, there are 332 and 54 bases of 5' and 3' noncoding sequences, respectively. Our HCV strain has a 77% nucleic acid identity to the HCV strain cloned by workers at Chiron Corporation. The hydrophobicity profile of the putative polyprotein is similar to those of flaviviruses, but it has limited amino acid homology to polyproteins of flaviviruses and other viruses, indicating that HCV is at most distantly related to flaviviruses.

Carcinogenic tryptophan pyrolysis products in the environment

The purpose of this study is to evaluate the risk of carcinogenic tryptophan pyrolysis products to human health. During the last decade, a new series of heterocyclic amines has been isolated as potent mutagens and later shown to be potent carcinogens in experimental animals. Among them, 3-amino-1, 4-dimethyl-5H-pyrido [4, 3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido [4, 3-b]indole (Trp-P-2), carcinogenic tryptophan pyrolysis products, have been investigated from various points of view and useful pieces of information about them have been collected. These carcinogens are widely distributed in the environment such as airborne particles, rain water, cigarette smoke and cooked foods, and they possess various pharmacotoxicological activities such as convulsant activities and potent inhibitory effects on platelet function and dopamine metabolism. Recent investigations revealed that these compounds are present in human samples such as plasma, urine and bile, indicating that humans are actually exposed to these compound. It is a matter of urgency to establish a suitable method for monitoring the exposure levels of these compounds to humans.

Expression of the hepatitis B surface antigen gene containing the preS2 region in Saccharomyces cerevisiae

We constructed a plasmid, pBH103-ME5, in which the region encoding the 10 preS2 amino acid residues and the S domain of the hepatitis B surface antigen (HBsAg) were regulated by the promoter of the yeast repressible acid phosphatase gene. Saccharomyces cerevisiae carrying pBH103-ME5 produced the HBs antigen (yHBsAg), when it was cultured in a medium containing a low concentration of phosphate. The antigen was purified to homogeneity. Its molecular weight was determined by Western blotting to be 24,000, and its amino acid composition agreed well with that deduced from the nucleotide sequence. The C-terminal amino acid sequence of yHBsAg was exactly the same as that predicted from the nucleotide sequence, while the N-terminal amino acid acetylserine, which was followed by 8 amino acid residues coded by the preS2 region. These results indicate that the recombinant yeast produced a single polypeptide consisting of the preS2 region and the subsequent S domain after being processed at the N-terminus.

Detection of carcinogenic amino-alpha-carbolines and amino-gamma-carbolines in diesel-exhaust particles

Diesel-exhaust particles are known to contain mutagenic and carcinogenic chemicals. The aim of this study was to determine whether carcinogenic amino-alpha-carbolines and amino-gamma-carbolines are present in diesel-exhaust particles. These carcinogens which were originally isolated from pyrolysates of proteins and amino acids have been detected in diesel-exhaust particles obtained from two test vehicles as well as in standard materials of automobile-exhaust particles obtained from National Institute for Environmental studies. The levels of these carcinogens were far less than those of polycyclic aromatic hydrocarbons such as benzo[a]pyrene. However, the presence of these amino-alpha-carbolines and amino-gamma-carbolines in diesel-exhaust particles suggests that these compounds are environmental pollutants and also that diesel-exhaust is one of the sources of these carcinogens in the outdoor environment.

Zone-specific hepatotoxicity of gossypol in perfused rat liver

Gossypol selectively damages the periportal region of lobules in perfused rat liver, while retrograde perfusion caused pericentral liver damage. Moreover, the addition of 0.4% bovine serum albumin(BSA) to the perfusate completely prevented the toxic effect of gossypol on hepatocytes, decreasing the absorption of gossypol by the liver. This study indicates that the damage caused by gossypol depends upon the direction of exposure and can be protected against by its binding to BSA.

Simultaneous determination of amino-alpha-carbolines and amino-gamma-carbolines in cigarette smoke condensate by high-performance liquid chromatography

A method for the simultaneous detection of amino-alpha-carbolines (2-amino-alpha-carboline and 2-amino-3-methyl-alpha-carboline) and amino-gamma-carbolines (3-amino-1,4-dimethyl-5H-pyrido [4,3-b]indole and 3-amino-1-methyl-5H-pyrido [4,3-b]indole) by high-performance liquid chromatography has been developed. It consists of a three-step purification using three different columns with fluorometric detection. With this method, we have demonstrated that both amino-alpha-carbolines and amino-gamma-carbolines are present in cigarette smoke condensate. The method may be useful for detecting these carcinogens in various materials.

Detection of carcinogenic glutamic acid pyrolysis products in cigarette smoke condensate

Carcinogenic glutamic acid pyrolysis products were measured in condensate of cigarette mainstream smoke by HPLC. These carcinogens were found to be present in all brands of filter-tipped cigarette analyzed. The mean levels of 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole and 2-aminodipyridol[1,2-a:3',2'-d]imidazole in the cigarette mainstream smoke were 0.66 and 0.63 ng/cig respectively.

[Surgical treatment of metastatic spinal malignancies]

The goal of surgical treatment of metastatic tumors of the spine is maintaining the relief of pain and/or neurologic symptoms for as long as possible after surgery. For the quality of life, thirty-five patients were surgically treated. By preoperative analyses, tumor invasion was divided into 3 types as follows; Type 1: involvement of vertebral body, Type 2: involvement of posterior column, Type 3: involvement of anterior and posterior column. Of 35 patients, 31 were in Type 1 or 3, who underwent anterior and/or posterior direct decompression by removal of the tumor, followed by vertebral reconstruction. Posterior surgery was performed on the remaining 4 patients in Type 2, resulting in complete decompression. A combined anterior or posterior instrumentation with anterior reconstruction for the involved vertebral body in Type 1 and 3 provided rigid spinal stability immediately after surgery. Neurologic improvement was evaluated by Frankel's classification. As a result, 4 patients who are alive have been ambulatory for an average duration of 26.3 months. Thirty-one, who survived for an average duration of 10 months, had no neurologic deterioration in an average duration of 8.4 months. Removal of the tumor and reconstructive surgery combined with rigid spinal instrumentation may provide satisfactory results.

Antagonism of gamma-aminobutyric acidA receptor-mediated responses by amino-gamma-carbolines

The amino-gamma-carbolines 3-amino-1-methyl-5H-pyrido[4,3-b]indole and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole were demonstrated to be potent convulsants. Administered i.p. in rats, these compounds penetrated the blood-brain barrier rapidly and appeared in the cerebrospinal fluid. When administered i.c.v., they induced convulsions with short onset latencies, suggesting that these compounds themselves have convulsant activities. In in vitro experiments using the whole cell clamp method, they suppressed gamma-aminobutyric acid (GABA)-induced Cl- current isolated on the dissociated mouse sensory neurons in dose-dependent manners through their actions as antagonists at GABAA receptors. The relative potency of the suppressive effects on GABA-induced Cl- current was compatible with that of the convulsant activities in mice. Furthermore, Ro15-1788 did not affect their convulsant activities. These results suggested that the amino-gamma-carbolines induced convulsions through their actions as antagonists at GABAA receptors and not through their actions as inverse agonists or antagonists at benzodiazepine receptors. Structure-activity relationships indicated that the 3-amino-group is important for the activities of amino-gamma-carbolines as GABAA receptor antagonists.

Mountains and Arid Climates of Middle Latitudes

Simulations from a global climate model with and without orography have been used to investigate the role of mountains in maintaining extensive arid climates in middle latitudes of the Northern Hemisphere. Dry climates similar to those observed were simulated over central Asia and western interior North America in the experiment with mountains, whereas relatively moist climates were simulated in these areas in the absence of orography. The experiments suggest that these interior regions are dry because general subsidence and relatively infrequent storm development occur upstream of orographically induced stationary wave troughs. Downstream of these troughs, precipitation-bearing storms develop frequently in association with strong jet streams. In contrast, both atmospheric circulation and precipitation were more zonally symmetric in the experiment without mountains. In addition, orography reduces the moisture transport into the continental interiors from nearby oceanic sources. The relative soil wetness of these regions in the experiment without mountains is consistent with paleoclimatic evidence of less aridity during the late Tertiary, before substantial uplift of the Rocky Mountains and Tibetan Plateau is believed to have occurred.

Carcinogenic tryptophan pyrolysis products in cigarette smoke condensate and cigarette smoke-polluted indoor air

The carcinogenic tryptophan pyrolysis products, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido-[4,3-b]indole (Trp-P-2), have been measured in condensate of cigarette mainstream smoke by high-performance liquid chromatography. These carcinogens have been detected in indoor air as well as in the air of the outdoor environment. Levels of these carcinogens in indoor air were much higher than those in outdoor air. The source of these carcinogens in indoor air was determined to be cigarette smoke by the application of smoking machine studies. Concentrations of these carcinogens in indoor air increased markedly with an increase in cigarettes smoked. The results in this investigation suggest that cigarette smoking is a source of carcinogenic tryptophan pyrolysis products in the indoor environment. Our data also suggest that smokers are persistently exposed to the carcinogenic heterocyclic amines together with potent carcinogens such as polynuclear aromatic hydrocarbons and N-nitroso compounds.