Digital pure shear-strain moiré patterns

A method of constructing digital shear-strain moiré patterns with pure shear-strain fringes is proposed here with the help of digital image processing techniques and moiré carrier patterns of rotation. This method is developed from a digital pure secondary moiré pattern method. The pure shear-strain moiré patterns do not require a high fringe density of primary moiré patterns. It can give the shear-strain values at every point over the whole field and give the visible distribution of the shear-strain field.

The role of hyaluronan-binding protein in assembly of pericellular matrices

Hyaluronan-dependent pericellular matrices or "coats" are expressed by a variety of cell types in culture and modulation of their expression may be important in regulation of cell interactions in vivo during development. Monoclonal antibody IVd4, which recognizes hyaluronan-binding protein with the properties of a hyaluronan receptor, was shown to block formation of these coats by a variety of cells. Using rat fibrosarcoma cells, it was found that the antibody not only blocked initial formation of the coats but also caused their loss when added subsequent to formation. The loss of preformed coats in the presence of antibody occurred at 4 degrees and 37 degrees, implying that the function of hyaluronan-binding protein in coat formation is not in mediating metabolic processes. The antibody also had no significant effect on hyaluronan production by the fibrosarcoma cells. In addition, hyaluronan hexasaccharide, a competitive inhibitor of the interaction between polymeric hyaluronan and its cell surface receptor, was found to inhibit coat formation. Thus it is concluded that a hyaluronan-binding protein with the properties of a hyaluronan receptor is required for pericellular matrix formation.

Cloning and sequencing of the matrix protein (M) gene of turkey rhinotracheitis virus reveal a gene order different from that of respiratory syncytial virus

Several biochemical properties and the sequence of the fusion glycoprotein (F) have indicated that turkey rhinotracheitis virus (TRTV) is a pneumovirus, subfamily Pneumovirinae of the Paramyxoviridae family. As TRTV was known to generate polycistronic mRNAs, cDNA was generated from TRTV strain UK/3BV/85-infected Vero cell mRNAs using an oligonucleotide primer corresponding to a region of the F gene. Sequencing of four cDNAs revealed that the gene adjacent to the beginning (3' end) of the F gene was that for the matrix (M) protein, i.e., that TRTV had the partial gene order 3'-M-F-5'. This was unexpected as human respiratory syncytial (RS) virus, the type species of the genus Pneumovirus, has the partial gene order 3'-M-SH-G-F-5', where SH and G are the small hydrophobic protein and attachment glycoprotein, respectively. Instead TRTV resembled the Morbillivirus and Paramyxovirus genera of the Paramyxoviridae (subfamily Paramyxovirinae) which have the partial gene order 3'-M-F-5'. Two further oligonucleotides, one corresponding to a sequence near the end of the M gene and the other (oligo B) to a sequence near the beginning of the F gene, with their 5' ends spaced 300 nucleotides apart on the basis of the cDNA sequence, were used in a polymerase chain reaction (PCR) using genomic RNA as template. Only a PCR product of 0.3 kb was obtained. The same sized product was also obtained using these oligonucleotides and genomic RNA from three other TRTV strains (SA/91/78, UK/8544/85, and SA/2381/88) which had been grown in chicken tracheal organ cultures. In addition PCR was performed using genomic RNA from TRTV-3BV and SA/2381/88 with oligo B and another oligonucleotide near the 5' end of the gene upstream from M, spaced 1141 nucleotides apart on the basis of the sequence data. Only a 1.14-kb PCR product was obtained. Larger products would have been expected if another gene had been situated between M and F. The absence of such larger products, plus the demonstration that infected cells contained M-F dicistronic mRNAs, supported the conclusion that in the TRTV genome the M gene is adjacent to the F gene in the order 3'-M-F-5'. The 5' termini of the M and F mRNAs were confirmed by mRNA mapping. The TRTV M gene encoded a protein of 254 amino acids, very similar to that of RS virus (256 residues; 37% amino acid identity) but very different from that of the morbilliviruses and paramyxoviruses (approximately 350 residues).(ABSTRACT TRUNCATED AT 400 WORDS)

Genomic mapping by single copy landmark detection: a predictive model with a discrete mathematical approach

One of the goals of the Human Genome Project is to produce libraries of largely contiguous, ordered sets of molecular clones for use in sequencing and gene mapping projects. This is planned to be done for human and many model organisms. Theory and practice have shown that long-range contiguity and the degree to which the entire genome is covered by ordered clones can be affected by many biological variables. Many laboratories are currently experimenting with different experimental strategies and theoretical models to help plan strategies for accomplishing long-range molecular mapping of genomes. Here we describe a new mathematical model and formulas for helping to plan genome mapping projects, using various single-copy landmark (SCL) detection, or "anchoring", strategies. We derive formulas that allow us to examine the effects of interactions among the following variables: average insert size of the cloning vector, average size of SCL, the number of SCL, and the redundancy in coverage of the clone library. We also examine and compare three different ways in which anchoring can be implemented: (1) anchors are selected independently of the library to be ordered (random anchoring); (2) anchors are made from end probes from both ends of clones in the library to be ordered (nonrandom anchoring); and (3) anchors are made from one end or the other, randomly, from clones in the library to be ordered (nonrandom anchoring). Our results show that, for biologically realistic conditions, nonrandom anchoring is always more effective than random anchoring for contig building, and there is little to be gained from making SCL from both ends of clones vs. only one end of clones.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular analysis of neurofibromatosis type 1 mutations

We have examined a panel of 115 unrelated NF1 individuals for mutation in the 3' region of the NF1 gene, using Southern blotting and polymerase chain reaction amplification of exons followed by single-strand conformation polymorphism (SSCP) analysis. We found only 2 unequivocal mutations: a 571 bp deletion which removed exon 6 and resulted in a frameshift in exon 7, and a 2 bp deletion in exon 1. A third sequence variation detected by SSCP was predicted to cause a lysine-arginine substitution in exon 6. This is a conservative change, and since the affected individual is a new mutation whose parents are not available, we cannot be sure of its biological significance. We detected mutations in at most 3% of individuals, from an analysis which covered 17% of the coding sequence by SSCP and a larger region by Southern blotting. This relative failure to detect mutations accords with the experience of others. Even allowing for the incomplete sensitivity of the methods used, the results suggest that the majority of NF1 mutations lie elsewhere in the coding sequence or outside it.

Titrating luteinizing hormone surge requirements for ovulatory changes in primate follicles. II. Progesterone receptor expression in luteinizing granulosa cells

The events in granulosa cells that are initiated by the midcycle LH surge during luteinization of the primate follicle are poorly defined. This study was designed 1) to determine whether an ovulatory dose of hCG can induce progesterone receptors (PR) in macaque granulosa cells, and if so, 2) to begin titrating gonadotropin requirements for PR expression and progesterone production by luteinizing granulosa cells. Rhesus monkeys were treated with human FSH and LH for up to 9 days to stimulate the growth of multiple follicles. The next day, animals (n = 4-5/group) received: 1) no ovulatory stimulus; 2) 1000 IU hCG, im; 3) one injection of 100 micrograms GnRH, sc (GnRH-1); 4) three injections of GnRH (GnRH-3) at 3-h intervals (0800, 1100, and 1400 h); or 5) two injections of 50 micrograms GnRH agonist (GnRHa), sc, 8 h apart (0800 and 1700 h). Granulosa cells obtained by follicle aspiration 27 h after the hCG or initial GnRH/GnRHa injection or on days 8 or 10 from animals receiving no ovulatory stimulus were processed for indirect immunocytochemistry using a monoclonal antibody to human PR (JZB39). Specific staining for PR, determined by comparing cells incubated with PR antibody vs. a nonspecific antibody, was undetectable in granulosa cells from monkeys without an ovulatory stimulus. In contrast, the majority (64 +/- 5%) of cells from hCG-treated animals stained intensely for PR. In the GnRH/GnRHa groups, granulosa cells from only one animal (i.e. one GnRH-3 monkey) showed positive staining for PR. During 24-h culture in Ham's F-10 medium containing 10% monkey serum, basal progesterone production by cells from the hCG-treated group (2163 nmol/L.8 x 10(4) cells) was higher than that by cells from the no ovulatory stimulus/GnRH-1/GnRH-3/GnRHa groups (60, 111, 194, and 332 nmol/L, respectively). However, granulosa cells from the hCG-treated group were less responsive to hCG in vitro in terms of enhanced progesterone production (2 times control levels) than cells from the other four groups (up to 30 times control levels). This study provides direct evidence that an ovulatory dose of hCG induces PR expression in granulosa cells of luteinizing follicles during stimulated cycles in rhesus monkeys. However, repeated injections of GnRH/GnRHa that produced surge levels (greater than 100 ng/mL) of endogenous LH for up to 14 h failed to induce PR expression or progesterone production by granulosa cells. Thus, an extended LH surge more typical of that in the normal menstrual cycle (48-50 h) may be necessary for PR expression and luteinization of granulosa cells in primate follicles.

Intravenous recombinant tissue-type plasminogen activator in acute myocardial infarction

The efficacy and safety of intravenously administered recombinant tissue-type plasminogen activator (rt-PA, Boehringer Ingelheim Corp.) was investigated in 10 patients with acute myocardial infarction (AMI). rt-PA was given as a 10 mg bolus dose followed by infusions of 50 mg, 20 mg and 20 mg in three successive hours. All patients underwent baseline coronary angiography before thrombolytic therapy. Ninety minutes after the initiation of rt-PA infusion, recanalization of infarct-related coronary arteries as confirmed by angiography was achieved in 7 patients. The largest reduction in circulating fibrinogen was observed 4 to 6 h after the start of rt-PA infusion--14.3%. Moderate hemorrhage at the sites of arterial puncture occurred in 2 cases, probably as a result of heparin anticoagulation. No other side effects occurred. So rt-PA is an effective and safe thrombolytic agent.

Secondary prevention of myocardial reinfarction with low dose aspirin

A clinical trial of secondary prevention of reinfarction with low dose aspirin is reported. 50 mg aspirin per day was administered in 216 case. 211 cases did not take aspirin or any other antiplatelet agents as a control group. The follow-up periods in the two groups were 19.4 +/- 12.6 mon and 20.7 +/- 13.0 mon, respectively. There were 175 males in the aspirin group and 137 males in the control group. The incidence of reinfarction was reduced by 65% and platelet aggregation was inhibited obviously in the aspirin group as compared to the control group in men, whereas no significant trends were observed in women.

Evaluation of a lens opacities classification system II (LOCS II) in the survey population-based sample

In the field work of population-based research, 3 groups of eyes were graded by 2 observers in LOCS II. The reproducibility of LOCS II was evaluated by agreements (85%-100%) and k values (0.661-1) obtained in our study. The satisfying results show that LOCS II is not only easy to be learned and to be applied consistently by different observers, but also good reproducibility in the field work. The longitudinal cataract study is going to be performed in our plan.

[CA125 and radioimmunoimaging in monitoring of epithelial ovarian carcinoma]

Serum CA125 was measured by monoclonal antibody-OC125 in 50 primary and 29 suspected recurrent ovarian cancer patients. Among the later, RII examination by using 131I labelled polyclonal antibody-OCOV3 was carried out in 16 cases at the same time. For the suspected recurrent cases, the results, as checked by surgico-pathological findings, revealed a corroborative rate of 79.3% for CA125 assay and 87.5% for RII technique. The positive predictive value of both CA125 assay and RII were 100%, while the negative predictive value was only 25% for CA125 assay and 50% for RII technique. However, for each individual case if the results of the two tests were combined, the negative predictive value was also 100%. Preoperative CA125 level had no significant relationship with the prognosis in primary cases. But the two year survival rate for recurrent cases with a preoperative CA125 less than or equal to 35,000 U/L was much higher than those with CA125 greater than 35,000 U/L.

Cytogenetics of beavers: a case of speciation by monobrachial centric fusions

A comparison of G-banded chromosomes of four North American beavers, Castor canadensis (two males, two females), and four Eurasian beavers, Castor fiber (two males, two females), revealed that extensive monobrachial centric fusions distinguished the karyotypes of the two species. The complex multivalent formations that would occur in meiosis of a hypothetical hybrid would be expected to produce unbalanced gametes and postmating reproductive isolation. Thus, neither species was derived from the other; rather, they likely were derived from isolated populations in which some of the acrocentrics fused independently to produce monobrachial homology.Key words: beaver, chromosomes, karyotype evolution, monobrachial rearrangements, reproductive isolation.

HLA antigens and Vogt-Koyanagi-Harada's disease

Thirty patients with Vogt-Koyanagi-Harada's disease were typed for HLA-A and HLA-B antigenic determinants by a microlymphocytotoxicity technique. HLA-B22 antigen showed an increased frequency of 43.3% in the patient group (relative risk = 8.69; exact P < 0.0001; corrected P < 0.0025) compared with normal control group (frequency = 7.69%). This association suggests that immunogenetic factor may play an important role in the pathogenesis of Vogt-Koyanagi-Harada's disease.

Molecular transfer of a species-specific behavior from Drosophila simulans to Drosophila melanogaster

Drosophila males modulate the interpulse intervals produced during their courtship songs. These song cycles, which are altered by mutations in the clock gene period, exhibit a species-specific variation that facilitates mating. We have used chimeric period gene constructs from Drosophila melanogaster and Drosophila simulans in germline transformation experiments to map the genetic control of their song rhythm difference to a small segment of the amino acid encoding information within this gene.

Deduced amino acid sequence of the fusion glycoprotein of turkey rhinotracheitis virus has greater identity with that of human respiratory syncytial virus, a pneumovirus, than that of paramyxoviruses and morbilliviruses

The sequence of the fusion (F) glycoprotein of turkey rhinotracheitis virus (TRTV) has been deduced from cDNA clones derived from oligo(dT)-selected infected cell RNA. The protein consists of 538 amino acids, the F2 and F1 subunits containing 102 (including the F2-F1 connecting peptide RRRR) and 436 residues, respectively. Each subunit has one potential N-linked glycosylation site. The protein has 38 to 39% amino acid identity with the F protein of respiratory syncytial virus (Pneumovirus genus) but only about half that with members of the other two genera (Paramyxovirus and Morbillivirus) in the Paramyxoviridae family. This is the first sequence evidence to support the view that TRTV is a pneumovirus, the first avian member of the genus to be described.

Basal cell carcinoma syndrome: report of 10 cases

Ten cases of basal cell carcinoma syndrome are presented. The jaw cysts were proved histopathologically to be odontogenic keratocysts. The multiple naevoid lesions on the skin were identified as basal cell carcinoma in two cases. Skeletal anomalies and intracranial calcification were present in all cases. A positive family history with others affected by the syndrome was traced in two cases.

[Effect of acupuncture on exercise ability in rabbits]

7 male rabbits were chosen for the experiments. They were tired out on the P20 type table. The blood samples were obtained from the arteria before and after exercise. Blood gas was tested by ABL3 acid-bases balance laboratory made by Denmark's Radiometer Company. The results showed that blood pH and glucose were reduced after exercise, compared with that before exercise (P less than 0.05). The blood was acid. But when they were given acupuncture on Shenshu (U.B. 23) point bilateral, their exercise-duration under the same intensity was prolonged (P less than 0.05), blood glucose restored, and blood acid-base balance was relatively stable. The complexity of this mechanism needs further study.

[The polymorphisms of HTC-defined HLA specificities in the Shanghai Chinese population]

With reference sera and homozygous typing cells (HTCs) of 3rd Asia-Oceania Histocompatibility Workshop Conference, 56 healthy unrelated subjects in Shanghai were typed for HLA-A, B, C, DR, DQ, and Dw. This paper presents the results of HLA-Dw typing, its relationship to serological class II antigens, and the distribution of Dw in the population. The polymorphism patterns of Chinese Dw specificities were quite different from those in Caucasoids and Japanese. The predominant Dw phenotypes detected in Shanghai Chinese were Dw 2, Dw 3, DKT 2, Dw 7 c, (Dw7 + Dw 17) and Dw 23 (DB 5). And significant correlations were observed between Dw 1 and DR 1, Dw 2 and DR 2, Dw 3 and DR 3, Dw 7 c and DR 7, DB 7 and DRw 8, as well as Dw 23 and DR 9. SMY 129, a novel Dw specificity defined by local HTCs and co-studied by the laboratories joined for Dw typing in 3rd AOHWC showed its correlation with DR 5. Nevertheless, more than fifty percent of Dw specificities could not be assigned in the four correspondent designated serological antigens, DR 2, DR 5, DRw 8 and DR 9, respectively, which, together with other blank Dw specificities, gave a total blank Dw gene frequency as high as 43.2% in the population. It was suggested by further analysis that novel Dw specificities might be identified more effectively if efforts would be concentrated on DR 5 and DR 9, two antigen families which, in some way, might represent the characteristics of HLA system in Chinese. Besides, certain HTC-defined antigens, e.g. Dw 3 and the DR 4-related Dw specificities, have been revealed to be in linkage disequilibrium with other DR antigens in addition with the correspondent designated ones, resulting in some unique haplotype combinations in Shanghai Chinese. It seems to us that the particular patterns of polymorphisms of serum- and cell-defined HLA class II antigens would be helpful to elucidate the mechanisms by which certain diseases are in association with HLA in Chinese in a different manner as compared with that in Caucasoids.

[Early stage of gan-zheng in children treated with sheng-zhang-Ling]

The authors report here the results of prospective clinic study on 108 cases of the early stage of Gan-Zheng (infantile malnutrition) in children. It was proved that professor Zhan Qisun's tested recipe Sheng-Zhang-Ling(SZL) had an obvious effect in treating children with early stage of Gan-Zheng. The total effective rate was 90.2%, and the significantly effective rate was 60.79%. Various symptoms of patients using this prescription disappeared or improved. The increase of body weight, height and subcutaneous fat of these patients was faster than those of the blank control group and the group using zinc sulfate. The difference was statistically significant among those three groups. It was indicated that effects of the SZL group were not caused by children's natural growth and development. There was an obvious advantage over the zinc sulfate group with regard to clinical effects, side effects and total synthetic effects. It was concluded SZL is an effective prescription for curing patients with early stage of Gan-Zheng and stimulating children's growth and development. Hemoglobin, D-xylose in urine, serum gastrin, serum zinc ion were detected before and after the treatment. It was suggested that SZL had the effects to stimulate gastrointestinal secretion and absorption, to improve digestive function, to increase serum zinc ion and to cure anemia.

Are human luteinizing granulosa cells a site of action for progesterone and relaxin?

Specific nuclear staining for progesterone receptor (PR) was detected by immunocytochemistry in human granulosa cells (GCs) obtained from in vitro fertilization protocols. The percent of PR-positive cells (60% to 80%) remained unchanged during 7 days of culture in media containing fetal calf serum, in the absence or presence of human chorionic gonadotropin (hCG) or the progesterone antagonist RU486. Progesterone (P) production by GCs cultured on extracellular matrix from bovine corneal endothelial cells was stimulated by hCG and prostaglandin E2 (PGE2). However, addition of RU486 or human relaxin had no effect on control, hCG-, or PGE2-stimulated P production. Thus, the receptor data are consistent with an autocrine action of P in luteinizing GCs, but initial experiments in cell culture did not define a role for P or relaxin in modulating luteal steroidogenesis.

[Purification and identification of human cardiac myosin light chains]

Normal human left ventricular myocardium was obtained within 5 hours after death. Crude cardiac myosin was extracted from the myocardium by the method of Schossler, and cardiac myosin light chains (CMLC) were purified by isoelectric precipitation, fast protein liquid chromatography and preparative SDS-PAGE, respectively. The three methods were compared. The Ca2(+)-activated ATPase activity of cardiac myosin was 101.4 nmole Pi/mg/min. Molecular weights of CMLCI (24500) and CMLC II (20,000) were identified by analytical SDS-PAGE. All of the results mentioned above were consistent with data reported in the literature. An analytical electrophoresis test of the stability of CMLC stored at -20 degrees C demonstrated that liquid CMLC at long storage times or lower concentrations was easily degraded.

Fringe multiplication methods for digital interferometric fringes

Holographic moire fringes can be multiplied by using diffraction interferometry, an approach which is not applicable to some other interferometric techniques such as geometric moire. Three fringe multiplication methods are proposed which use a digital image processing technique to multiply various interferometric fringes. These methods are easy to handle and greatly improve the measurement accuracy. They enlarge the testing range for applying the interferometric techniques.

Diagnostic value of computed tomography in parotid tumours

In 18 cases of parotid tumours, CT demonstrated their primary site, extent and invasion of surrounding tissue precisely. It was valuable in the majority of cases in differentiating benign from malignant tumours and could distinguish accurately intrinsic from extrinsic. CT sialography was superior in equivocal cases when it made the tumour easier to identify and the diagnosis more accurate.

Spin filtering processes and automatic extraction of fringe centerlines in digitial interferometric patterns

Two filtering algorithms-spin filter and binary spin filter-suitable for various digital interferometric images are presented in this paper. Both can filter out the noise in the interferometric patterns without distorting the fringe features, whereas other commonly used filters, such as median filter and FFT passband filter, may blur the patterns. A process for automatically extracting fringe centerlines all over the field is also proposed. This is done by using the spin filters mentioned above together with the derivative binary image. The effectiveness of this technique is illustrated experimentally.

Behaviour modification by in vitro mutagenesis of a variable region within the period gene of Drosophila

The period gene of Drosophila melanogaster, implicated in the control of both the circadian and male courtship song rhythms, is found to be polymorphic. Alleles differ in the length of a region of the gene encoding a series of threonine-glycine repeat units. The phenotypes of transformed fruit flies, in which the only functional period gene lacks the entire perfect threonine-glycine repeat region, show that the effects of the period gene on the circadian and male courtship song rhythms can be dissociated.

A family of unusually spliced biologically active transcripts encoded by a Drosophila clock gene

Complementary DNA cloning of the transcripts of the Drosophila clock gene period reveals three distinct transcripts. These result from unusual splicing pathways, one involving a CG 3' splice site and one resulting in the use of two different reading frames in one exon, and they predict three separate proteins. Two of the cloned cDNAs can restore clock function to mutant arrhythmic flies.

Molecular mapping of point mutations in the period gene that stop or speed up biological clocks in Drosophila melanogaster

The pero1 and the pers mutations in Drosophila melanogaster, which seem to eliminate or speed up, respectively, the clocks underlying biological rhythmicity, were mapped to single nucleotides. Chimeric DNA fragments consisting of well-defined wild-type plus mutant DNA subsegments were constructed, introduced into flies by germ-line transformation, and assayed for biological activity. These experiments localized both pero1 and pers to a 1.7-kilobase DNA fragment that is mostly coding DNA. Sequencing of this subsegment from each mutant showed that pero1 is completely accounted for by a nonsense mutation in the third coding exon of a 4.5-kilobase RNA transcribed from this locus. The pers mutation is also a single nucleotide substitution, in the fourth coding exon, which results in a serine-to-asparagine substitution in the per gene protein product. The functional significance of these changes is discussed with reference to the phenotypes of the two mutations.

Germ-line transformation involving DNA from the period locus in Drosophila melanogaster: overlapping genomic fragments that restore circadian and ultradian rhythmicity to per0 and per- mutants

P-element-mediated transformations involving DNA fragments from the period (per) clock gene of Drosophila melanogaster have shown that several subsegments of the locus restore rhythmicity to per0 or per- mutants. Such fragments overlap in a genomic region complementary to one transcript, a 4.5-kb RNA which is probably the per message, in that it is necessary and (in terms of expression from this X-chromosomal locus) sufficient for the fly's circadian rhythms. It is also at least necessary for the high-frequency oscillations normally produced by courting males as they vibrate their wings. The entirety of the 4.5-kb transcript is not necessary for rather strong rhythmicity; nor does it seem to be sufficient, in transformants, for wild-type behavioral phenotypes. A 0.9-kb RNA, homologous to genomic region immediately adjacent to the source of the 4.5-kb species, oscillates in its abundance over the course of a day; but coverage of this transcript source in several transformants carrying a per0 mutation--which eliminates the 0.9-kb RNA's oscillation--does not restore rhythmicity. All of the independently isolated arrhythmic mutations tested were covered by the same array of overlapping per+-derived DNA fragments, implying that the only portion of the locus which has mutated to arrhythmicity is complementary to the 4.5-kb transcript.

A Drosophila Minute gene encodes a ribosomal protein

Minute genes have long constituted a special problem in Drosophila genetics. For at least 50-60 different genes scattered throughout the genome, dominant mutations and/or deficiencies have been recognized which result in a common phenotype consisting of short thin bristles, slow development, reduced viability, rough eyes, small body size and etched tergites. Schultz proposed that the Minute loci encode similar but separate functions involved in growth and division common to all cells. Atwood and Ritossa suggested that Minute loci encode components of the protein synthetic machinery, specifically the transfer RNA genes; this now seems unlikely on grounds of both mapping and mutability studies. More recently, we and others suggested that the Minute loci are ribosomal protein genes. We report here that transformation with a cloned 3.3-kilobase (kb) region containing the gene encoding the large subunit ribosomal protein 49 (rp49) suppresses the dominant phenotypes of Minute (3)99D, a previously undescribed Minute associated with a chromosomal deficiency of the 99D interval. This activity is specific to the 99D Minute as it does not suppress other Minute loci elsewhere in the genome. This result provides direct evidence that the Minute locus at the 99D interval encodes the ribosomal protein 49.

Unbuffered osmium staining of cell organelles: alterations induced by cell injury

We have studied the localization of osmium reduction products to investigate the functional state of organelles as well as organelle interrelationships during cell injury. In normal hepatocytes osmium deposits of variable intensity are seen in nuclear envelope, endoplasmic reticulum. Golgi cisternae and vesicles and lysosomes. Buffering of osmium with s- collidine (pH 7.4) prevents the deposition of osmium. Reversible (30 min) and irreversible (60 min) ischemia without reflow causes no change in the pattern of osmium deposition. Irreversible ischemia followed by reflow causes decreased staining of endoplasmic reticulum (ER) and redistribution of the osmium deposits through the cytoplasm. Reversibly injured pancreatic acinar cells in cultured explants manifest a similar loss of osmium staining in the endoplasmic reticulum cisternae. The administration of antimicrotubule drugs induces an accentuation of osmium staining in localized cisternal elements of hepatocytes. These heavily stained cisternae appear to give rise to the bounding membranes of drug-induced autophagic vacuoles. Cytoplasmic organelles sequestered inside the autophagic vacuoles acquire intense staining when they begin to undergo degradation. In homogenized liver tissue all the subcellular organelles show osmium deposits. The deposits are preferentially localized along the organelle membranes. In particular the dense deposits in the ER lumen are not seen in the subcellular fractions. Phospholipase A2 (3 units/mg protein) enhances the deposition of osmium in the lumen of microsomal vesicles, whereas the presence of detergent has no such effect. Addition of EDTA to the homogenizing medium enhances the ultrastructural preservation of the subcellular fractions but has little effect on the deposition of osmium. OsO4 deposition occurs at acid pH and the intensity and pattern of the stain can be modified in vivo and in vitro. Osmium tetroxide deposition is induced at sites of membrane transformation (autophagic vacuoles) and degradation (lysosomes). Calcium influx and phospholipase activation (ischemia, tissue homogenization, phospholipase addition) enhance osmium deposition and/or influence the localization of the staining pattern.