Influence of chest background on pulmonary 99mTc-DTPA clearance in interstitial lung disease.

We examined the effect of chest extracellular 99mTc-diethylenetriamine pentaacetate (DTPA) as a background in the measurement of pulmonary 99mTc-DTPA clearance in patients with interstitial lung disease (ILD). Eight healthy nonsmokers (HN) and eight patients with ILD were studied. We monitored changes in gamma counts after the inhalation of 99mTc-DTPA aerosol by using a gamma camera placed over the anterior chest. The rate constant of pulmonary 99mTc-DTPA clearance (k; %/min) was assessed by calculating the slope of the decrease in the gamma counts. The chest background, estimated by 99mTc-DTPA intravenous injection, was subtracted from the original data to obtain the corrected DTPA clearance (kc; %/min). In patients with ILD, k was significantly greater [2.19 +/- 1.03 (SD) %/min; n = 8] compared with HN (0.86 +/- 0.17%/min; n = 8; P < 0.01). In patients with ILD, kc was also greater (2.80 +/- 1.15%/min; n = 8; P < 0.01) compared with HN (1.20 +/- 0.12%/min; n = 8). There was no difference in percent underestimation of k between the two groups (29.1 +/- 8.8% for HN, 22.5 +/- 7.9% for patients with ILD). There was a significant correlation between k and kc among all subjects (r = 0.987, P < 0.01). We conclude that background causes significant underestimation of pulmonary 99mTc-DTPA clearance.     

The role of nicotianamine synthase in response to Fe nutrition status in Gramineae

Nicotianamine is an intermediate for the biosynthesis of mugineic acid-family phytosiderophores (MAs) in the Gramineae and a key substance for iron metabolism in dicots. Nicotianamine synthase catalyzes the formation of nicotianamine from S-adenosylmethionine. Nicotianamine synthase activity was induced in barley roots at the 3rd day after withholding Fe supply and declined within one day followmg the supply of Fe³⁺-epihydroxymugineic acid. The induction of nicotianamine synthase activity by Fe-deficiency was observed also in sorghum, maize, and rye, and the level of nicotianamine synthase activity was highly associated with the MAs secreted among graminaceous plant tested. Therefore, the nicotianamine synthase gene may be a suitable candidate for making a transgenic plant tolerant to Fe-deficiency.Abbreviations p-APMSF (p-amidinophenyl) methanesulfonylfluoride hydrochloride - NA nicotianamine - DMA 2-deoxymugineic acid - E-64 trans-epoxysuccinyl-leucylamido-(4-guanidino) butane - epiHMA 3-epihydroxymugineic acid - MAs mugineic acid-family phytosiderophores which include deoxymugineic acid, mugineic acid, hydroxymugineic acid, epihydroxymugineic acid and avenic acid - PVP polyvinylpyrrolidone - SAM S-adenosylmethionine     

Recognition of facial expressions in a Japanese monkey (Macaca fuscata) and humans (Homo sapiens)

Recognition of facial expressions by a Japanese monkey and two humans was studied. The monkey subject matched 20 photographs of monkey facial expressions and 20 photographs of human facial expressions. Humans sorted the same pictures. Matching accuracy by the monkey was about 80% correct for both human and monkey facial expressions. The confusion matrices of those facial expressions were analyzed by a multi-dimensional scaling procedure (MDSCAL). The resulting MDS plots suggested that the important cues in recognizing facial expressions of monkeys were “thrusting the mouth” and ‘raising the eyebrows.” Comparison of the MDS plots by the monkey subject with those by human subjects suggested that the monkey categorized the human “happiness” faces. This may suggest that the monkey has an ability to recognize human smile face even though it is learned. However, the monkey did not differentiate the human “anger/disgust” faces from the human “sad” faces, while human subjects clearly did. This may correlate with the lack of eyebrow movement in monkeys.     

Interspecific allometry of the mandible,dental arch,and molar area in anthropoid primates: Functional morphology of masticatory components

Allometric equations relating the lengths and widths of the mandible and dental arch, and of molar area, were obtained in a wide range of anthropoid primates grouped into four subsets, pongids, cercopithecids, nonmarmoset platyrrhines, and marmosets. Mandibular width is negatively allometric against length across anthropoids but cercopithecids had relatively wider mandibles than nonmarmosets of the same size class. Mandibular length relative to dental arch length was isometric within and between the four groups but dental arch width scaled negatively against all the other dimensions examined in this study, indicating a functional dissociation between the dental arcade and the bony mandible. Molar area showed various scaling patterns relative to mandibular length (isometry) and width (positive). There were no parameters that scaled positively against body weight across groups, except for molar area in cercopithecids (strongly) and nonmarmoset (moderately). Notable functional specializations include relatively long dental arches in cercopithecoids, related to large, elongate bilophodont molars, and the tendency to increase relative jaw length across the range of anthropoid sizes, reflecting negative allometry of the brain (cranial bicondylar width). We caution that various allometry and functional patterns may be masked by generalizing from broad taxonomic comparison involving a large sweep of adaptative patterns.     

MORPHOLOGICAL AND BIOCHEMICAL STUDIES OF B CELLS OF FETAL RAT ENDOCRINE PANCREAS IN ORGAN CULTURE : Evidence for (Pro)Insulin Biosynthesis

Fetal rat pancreases explanted on the 18th day of gestation and maintained in organ culture for 1–10 days were utilized for this series of studies. Ultrastructurally, at the time of explantation, the majority of fetal B cells was sparsely granulated and characterized by numerous free ribosomes and undeveloped rough endoplasmic reticulum (RER) and Golgi complexes. During the culture period, extensive development of the RER and Golgi complexes preceded an increasing accumulation of β-granules. This later increase in the number of β-granules and in the concentration of immunoreactive insulin was paralleled by a reduction of RER and Golgi complex activity. High resolution radioautographic studies of pulse-chase experiment over a 1 hr period demonstrated the shift of silver grains from the elements of the RER, through the Golgi region, and finally to the β-granules. Incubation with ¹⁴C-labeled leucine demonstrated the incorporation of radioactivity into molecules possessing the immunological and electrophoretic properties of insulin. These studies indicate that de novo synthesis of (pro)insulin occurs also during culture of fetal rat pancreas explanted relatively late in gestation.     

Mutagens formed from butylated hydroxyanisole treated with nitrite under acidic conditions

The reaction products from butylated hydroxyanisole treated with nitrite under acidic conditions were investigated for mutagenic activity in Salmonella typhimurium his reversion assay and for DNA-damaging activity using H17 Rec+ (wild) and M45 Rec- (recombinationless) of Bacillus subtilis. The chloroform extract of the reaction mixture showed 9 spots on thin-layer chromatography (TLC). Compounds from 2 spots on the TLC had high mutagenic activity in TA100 without S9 mix, with DNA-damaging activity. The 2 mutagens were then crystallized from the reaction mixture and identified to be 2-tert.-butyl-p-quinone (t-BQ) and the dimer of t-BQ; 3,3'-di-tert.-butyl-biphenyldiquinone-(2,5,2',5') (BBDQ), from their instrumental analysis. The mutagenic activities of t-BQ and BBDQ were determined by Ames test, and the induced mutation frequencies were about 1.9 X 10(-4) (t-BQ) and 8.3 X 10(-5) (BBDQ).     

Effects of trichloroethylene,tetrachloroethylene and dichloromethane on enzymatic activities in soil

Summary Enzyme assays for -glucosidase, -acetylglucosaminidase, phosphatase, phosphodiesterase, and proteinase were made in soil samples incubated for two months after contamination with trichloroethylene, tetrachloroethylene, and dichloromethane. These volatile chlorinated hydrocarbons were added at doses of 10, 100, and 1000 g per 100 g dry soil, respectively. Almost no effect was observed in soil sample contaminated with 10 g of the chemicals when compared with control soil. When 100 g of the volatile chlorinated hydrocarbons was added, the activity of -glucosidase, -acetylglucosaminidase and, in part, also of proteinase, was reduced during the first 28 days of incubation but returned to the same or slightly higher level than in the control soil after 2 months. Trichloroethylene, tetrachloroethylene, and dichloromethane at a concentration of 1000 g per 100 g soil primarily inhibited activity of all enzymes under test. However, after two months, the enzymatic activities especially in soil samples contaminated with tetrachloroethylene and dichloromethane were found to be at the same or higher level than in the control soil.     

Escherichia coli H+-ATPase: loss of the carboxyl terminal region of the gamma subunit causes defective assembly of the F1 portion

Mutant genes for the gamma subunit of H+-translocating ATPase (H+-ATPase) were cloned from eight different strains of Escherichia coli isolated in this laboratory. Determination of their nucleotide sequences revealed that they are amber nonsense mutations: a Gln codon at position 15, 158, 227, 262, and 270, respectively, was replaced by a termination codon in these strains. As terminal Met is missing in the gamma subunit, these results indicate that these strains are capable of synthesizing fragments of gamma subunits of 13, 156, 225, 260, and 268 amino acid residues, respectively. Studies on the properties of membranes of these strains suggested the importance of the region between Gln 269 and the carboxyl terminus (residue 286) for forming a stable F1 complex with ATPase activity and the region between Gln 226 and Gln 261 for normal interaction of F1 with F0. The sequence from Gln 261 to Gln 269 also seemed to be important for stability of F1 assembly on the membranes. The high frequency of the nonsense mutations suggested that the number of essential residues is limited in this subunit. Comparison of the homologies of the amino acid sequences of the gamma subunits from four different sources confirmed this notion: 19% of amino acid residues are identically conserved in these four strains, and the conserved regions are the amino terminal and carboxyl terminal regions.     

Selective inhibition by ionophore A23187 of the enzyme isomerization in the catalytic cycle of sarcoplasmic reticulum Ca2+-ATPase

The effect of a lipophilic antibiotic, ionophore A23187, on the purified Ca2+-ATPase from sarcoplasmic reticulum was investigated. When the enzyme was pretreated with A23187 in the presence and absence of Ca2+, the Ca2+-dependent ATPase activity was inhibited almost completely, but the activity of the contaminating Mg2+-ATPase was unaffected. The steady state level of the phosphoenzyme (EP) from ATP or Pi was not substantially altered. When the pretreatment was performed in the presence of Ca2+, EP formation from ATP was only slightly retarded, but EP decomposition was strongly inhibited. Under these conditions, the accumulated EP was ADP-sensitive. EP formation from Pi after chelating of Ca2+ was quite slow, whereas EP once formed was in rapid equilibrium with Pi of the medium. On the other hand, when the pretreatment was performed in the absence of Ca2+, EP formation from ATP was extremely slow, but EP once formed was in rapid dynamic equilibrium with ATP of the medium. EP formation from Pi was very fast, and this EP was in rapid equilibrium with Pi of the medium. These results demonstrate that A23187 selectively inhibits isomerization of the enzyme between the high Ca2+-affinity form and the low Ca2+-affinity form in the catalytic cycle, whether or not the enzyme is phosphorylated. This suggests that interactions between the enzyme protein and the surrounding lipids could play a crucial role in this isomerization.