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Single-stranded DNA or RNA sequences rich in guanine (G) can adopt non-canonical structures known as G-quadruplexes (G4). Mitochondrial DNA (mtDNA) sequences that are predicted to form G4 are enriched on the heavy-strand and have been associated with formation of deletion breakpoints. Increasing evidence supports the ability of mtDNA to form G4 in cancer cells; however, the functional roles of G4 structures in regulating mitochondrial nucleic acid homeostasis in non-cancerous cells remain unclear. Here, we demonstrate by live cell imaging that the G4-ligand RHPS4 localizes primarily to mitochondria at low doses. We find that low doses of RHPS4 do not induce a nuclear DNA damage response but do cause an acute inhibition of mitochondrial transcript elongation, leading to respiratory complex depletion. We also observe that RHPS4 interferes with mtDNA levels or synthesis both in cells and isolated mitochondria. Importantly, a mtDNA variant that increases G4 stability and anti-parallel G4-forming character shows a stronger respiratory defect in response to RHPS4, supporting the conclusion that mitochondrial sensitivity to RHPS4 is G4-mediated. Taken together, our results indicate a direct role for G4 perturbation in mitochondrial genome replication, transcription processivity, and respiratory function in normal cells.

Single-stranded DNA or RNA sequences rich in guanine (G) can adopt non-canonical structures known as G-quadruplexes (G4). Predicted G4-forming sequences in the mitochondrial genome are enriched on the heavy-strand and have been associated with formation of deletion breakpoints that cause mitochondrial disorders. However, the functional roles of G4 structures in regulating mitochondrial respiration in non-cancerous cells remain unclear. Here, we demonstrate that RHPS4, previously thought to be a nuclear G4-ligand, localizes primarily to mitochondria in live cells by mechanisms involving mitochondrial membrane potential. We find that RHPS4 exposure causes an acute inhibition of mitochondrial transcript elongation, leading to respiratory complex depletion. At higher ligand doses, RHPS4 causes mitochondrial DNA (mtDNA) replication pausing and genome depletion. Using these different levels of RHPS4 exposure, we describe discrete nuclear gene expression responses associated with mitochondrial transcription inhibition or with mtDNA depletion. Importantly, a mtDNA variant with increased anti-parallel G4-forming characteristic shows a stronger respiratory defect in response to RHPS4, supporting the conclusion that mitochondrial sensitivity to RHPS4 is G4-structure mediated. Thus, we demonstrate a direct role for G4 perturbation in mitochondrial genome replication, transcription processivity, and respiratory function in normal cells and describe the first molecule that differentially recognizes G4 structures in mtDNA.

The MHC is recognized for its importance in human health and disease. However, many disease-associated variants throughout the region remain of unknown significance, residing predominantly within non-coding regions of the MHC. The characterization of non-coding RNA transcripts throughout the MHC is thus central to understanding the genetic contribution of these variants. Therefore, we characterize novel miRNA transcripts throughout the MHC by performing deep RNA sequencing of two B lymphoblastoid cell lines with completely characterized MHC haplotypes. Our analysis identifies 89 novel miRNA transcripts, 48 of which undergo Dicer-dependent biogenesis and are loaded onto the Argonaute silencing complex. Several of the identified mature miRNA and pre-miRNA transcripts are unique to specific MHC haplotypes and overlap common SNPs. Furthermore, 43 of the 89 identified novel miRNA transcripts lie within linkage disequilibrium blocks that contain a disease-associated SNP. These disease associated SNPs are associated with 65 unique disease phenotypes, suggesting that these transcripts may play a role in the etiology of numerous diseases associated with the MHC. Additional in silico analysis reveals the potential for thousands of putative pre-miRNA encoding loci within the MHC that may be expressed by different cell types and at different developmental stages.

Heparan sulfate proteoglycan is thought to act as primary receptor for adeno-associated virus type 2 (AAV-2). Reported coreceptors include alphaVbeta5 integrin, fibroblast growth factor receptor 1 (FGFR-1), and hepatocyte growth factor (c-Met). The interaction of AAV type 3 (AAV-3) with possible cell membrane receptors is incompletely defined. In this study, using assays detecting competition with viral infection, virus binding inhibition assays and dot blotting, we show attachment of AAV-3 strain H to heparin, heparan sulfate, and FGFR-1. These findings provide new information on the possible receptor array used by AAV-3.

The bovine parvovirus (BPV) hemagglutinates human erythrocytes by binding to glycophorin A (GPA). The purpose of this study was to determine which carbohydrate on GPA binds BPV. Treatment of GPA with alpha2,3,-6,-8 neuraminidase eliminated binding of BPV to GPA. Beta-elimination of O-linked sialic acids on GPA eliminated binding, while removal of N-linked carbohydrates using the N-glycosidase PNGase F failed to eliminate binding. Treatment of GPA with a neuraminidase which specifically cleaved alpha2,3 glycosidic bonds eliminated BPV binding and, following this treatment, virus binding to GPA was restored by reconstitution of alpha2,3-linked neuraminic acids. These results indicated the O-linked alpha2,3 neuraminic acids of GPA bind BPV.

The Drosophila homeotic selector (HOM) genes encode a family of DNA binding transcription factors that specify developmental fates of different body segments by differentially regulating the activity of downstream target genes. A central question is how the HOM proteins achieve their developmental specificity despite the very similar DNA binding specificities of isolated HOM proteins in vitro. Specificity could be achieved by differential interactions with protein cofactors. The extradenticle gene might encode such a cofactor since it interacts genetically in parallel with Ultrabithorax, abdominal-A, and perhaps other HOM genes. By using a yeast two-hybrid system, we demonstrate selective interaction of the extradenticle homeodomain protein with certain Ultrabithorax and abdominal-A proteins but not with an Antennapedia protein or a more distant homeodomain protein. Strong interaction with Ultrabithorax proteins requires only the Ultrabithorax homeodomain and a 15-residue N-terminal extension that includes Tyr-Pro-Trp-Met (YPWM), a tetrapeptide motif found near the homeodomain in most HOM proteins and their mammalian Hox counterparts. The size and sequence of the region between the YPWM element and the homeodomain differ among Ultrabithorax isoforms, and this variable region appears to affect the interaction detected in the assay.

Entry events of bovine parvovirus (BPV) were studied. Transmission electron micrographs of infected cells showed virus particles in cytoplasmic vesicles. Chemical inhibitors that block certain aspects of the cellular machinery were employed to assess viral dependency upon those cellular processes. Chlorpromazine, ammonium chloride, chloroquine and bafilamicin A1 were used to inhibit acidification of endosomes and clathrin-associated endocytosis. Nystatin was used as an inhibitor of the caveolae pathway. Cytochalasin D and ML-7 were used to inhibit actin and myosin functions, respectively. Nocodazole and colchicine were employed to inhibit microtubule activity. Virus entry was assessed by measuring viral transcription using real-time PCR, synthesis of capsid protein and assembly of infectious progeny virus in the presence of inhibitor blockage. The results indicated that BPV entry into embryonic bovine trachael cells utilizes endocytosis in clathrin-coated vesicles, is dependent upon acidification, and appears to be associated with actin and microtubule dependency. Evidence for viral entry through caveolae was not obtained. These findings provide a fuller understanding of the early cell-entry events of the replication cycle for members of the genus Bocavirus.

Different eukaryotic transcription factors can act through the same upstream binding site to differentially regulate target gene expression, but little is known of the underlying mechanisms. Here, we show that Ultrabithorax and even-skipped homeo domain proteins (UBX and EVE) of Drosophila melanogaster exert active and opposite effects on in vitro transcription when bound to a common site upstream of a core promoter. Both the activator UBX and the repressor EVE affect the extent but not the rate constant of preinitiation complex (preIC) formation. Both regulators act early in preIC assembly and are dispensable later. Assembling complexes become resistant to regulation by the bound proteins, but activation by UBX is restored upon ATP or dATP addition, and regulation by both proteins is restored after the addition of all four nucleoside triphosphates and transcription initiation. The results establish that upstream activators and repressors can function by fundamentally similar mechanisms, by differentially regulating an early step in preIC assembly, leading to formation of functionally distinct transcription complexes. A subsequent step renders mature complexes transiently refractory to activation and repression. Implications for the mechanism of transcription complex assembly and turnover and its regulation are discussed, including a new role for ATP in turnover.

Detection of herpes simplex virus in clinical specimens by the suspension-infection technique was compared with detection by conventional cell culture. The sensitivity and specificity of the suspension-infection technique compared with those of conventional culture were 95.9 to 98.2% and 97.5 to 100%, respectively, depending on the cell line used in the tests. The mean time to diagnosis by the suspension-infection technique was 1 day, compared with 4.8 days by conventional culture. Comparable detection of low-level positive specimens was observed with the methods. In a clinical setting, the isolation rates obtained by suspension-infection and conventional culture were indistinguishable. These results indicate that the suspension-infection method can be used for the detection of herpes simplex virus and can yield rapid diagnostic results without a time-consuming centrifugation step.

The composition of cosmetic tattoos might prove relevant to their treatment by high-powered lasers.To test the accuracy and completeness of information supplied by the tattoo ink manufacturers and to perform an elemental assay of tattoo pigments using scanning electron microscopy with energy-dispersive x-ray analysis.Samples of 30 tattoo inks were examined using "standardless" energy-dispersive spectrometry. This technique uses quantitative electron x-ray microanalysis. The technique reliably identifies all elements with the exception of those elements with atomic numbers less than 11.A major national referral laboratory for microscopic examination and biochemical analysis of tissue. These results were compared with ink compositions compiled from manufacturer-supplied material safety data sheets.(1) The percentage of any given element in whole tattoo pigments. (2) The presence or absence of elements and/or compounds as recorded in material safety data sheets supplied by the tattoo ink manufacturers.Of the 30 tattoo inks studied, the most commonly identified elements were aluminum (87% of the pigments), oxygen (73% of the pigments), titanium (67% of the pigments), and carbon (67% of the pigments). The relative contribution of elements to the tattoo ink compositions was highly variable between different compounds. Overall, the manufacturer-supplied data sheets were consistent with the elemental analysis, but there were important exceptions.The composition of elements in tattoo inks varies greatly, even among like-colored pigments. Knowledge of the chemical composition of popular tattoo inks might aid the clinician in effective laser removal.

Bloom syndrome (BS) is characterized by genomic instability and cancer susceptibility caused by defects in BLM, a DNA helicase of the RecQ-family (J. German and N. A. Ellis, The Genetic Basis of Human Cancer, pp. 301-316, 1998). RecQ helicases and topoisomerase III proteins interact physically and functionally in yeast (S. Gangloff et al., Mol. Cell. Biol., 14: 8391-8398, 1994) and in Escherichia coli can function together to enable passage of double-stranded DNA (F. G. Harmon et al., Mol. Cell, 3: 611-620, 1999). We demonstrate in somatic and meiotic human cells an association between BLM and topoisomerase IIIalpha. These proteins colocalize in promyelocytic leukemia protein nuclear bodies, and this localization is disrupted in BS cells. Thus, mechanisms by which RecQ helicases and topoisomerase III proteins cooperate to maintain genomic stability in model organisms likely apply to humans.

Bovine parvovirus (BPV), an autonomous parvovirus, haemagglutinates human type O erythrocytes and infects certain bovine cells in culture. Little is known about the receptor to which it attaches, either on nucleated host cells or on erythrocytes. Haemagglutination assays and radiolabelled virus-binding tests measuring the effects of trypsin, chymotrypsin, neuraminidase, phospholipase C and sodium periodate on attachment of BPV to receptors indicated that BPV interacted with N-acetylneuraminic acid-containing (sialyl) glycoproteins. SDS-polyacrylamide gel separation of erythrocyte ghost proteins and virus overlay protein-binding revealed BPV binding to glycophorin A. Confirmation testing showed BPV binding to purified glycophorin A on dot blots and on gels containing membrane glycophorin A and purified glycophorin A. Further, in competition assays, purified glycophorin A completely inhibited the BPV haemagglutination reaction. The results of this study indicate that BPV binds to sialated membrane glycoproteins, one of which is the major erythrocyte membrane glycoprotein, glycophorin A.

Fourier transform infrared and Raman (FT-IR and FT-Raman) microspectroscopy were used to study materials found in human tissue. Individual cases involving cholesterol, calcium stearate, and a polystyrenesulfonate ion exchange resin demonstrate the utility of the spectroscopic data. Characteristic spectral bands for these materials were compared with those of authentic chemical species to confirm their identities. The role of vibrational spectroscopy in pathologic diagnoses is discussed.

Fourier transform infrared (FT-IR) spectral mapping was used to study polymers in human tissue associated with silicone breast implants. Biomaterials such as polyesters, polyurethanes and silicone were identified by FT-IR spectroscopy, and their relative locations and distributions within tissue specimens were characterized by three-dimensional (3D) spectral maps.

To determine the clinical features and outcome of patients with pulmonary alveolar microlithiasis and to determine the chemical composition of the microliths.We studied seven cases of pulmonary alveolar microlithiasis. The patients were six women and one man, aged 19 to 70 years (mean age 44.5 years). Clinically, five patients were known to have suffered from this condition for 5 to 41 years. One patient presented with shortness of breath, and another had a gradual decrease in exercise tolerance. None of the patients had a previous history of disturbances in metabolism or any other relevant medical condition. Reports on radiographic studies were available in six cases, and chest radiographs were available for review in the seventh case. They all showed diffuse bilateral pulmonary infiltrates. Open lung biopsies were performed in two patients, and autopsy lung material was reviewed in five patients.Histologically, the lung showed the typical features of pulmonary alveolar microlithiasis, that is, presence of numerous microliths filling the alveolar spaces with either a normal or thickened fibrotic interstitium. Chemical analysis performed on the lung tissue of six of these patients revealed that the microliths consisted principally of calcium and phosphorus salts. Five of these patients died of respiratory failure; however, their deaths occurred from 5 to 41 years following the initial diagnosis. No follow-up information was obtained in two patients.The findings of this study confirm that pulmonary alveolar microlithiasis can be seen in any age group and that the microliths are composed principally of salts of calcium and phosphorus. Additionally, these cases confirm that the disease typically follows a protracted course.

Sodium polystyrene sulfonate (kayexalate) is a cation-exchange resin given enterally for the treatment of hyperkalemia. Aspiration of this material is a rare occurrence, but when visualized in the alveolus, it has a characteristic microscopic appearance that is virtually diagnostic. In two cases, recognition of the characteristic morphology of the foreign material raised the question of sodium polystyrene sulfonate.We used infrared spectroscopy to demonstrate the presence of this material in lung biopsies of two patients by identifying foreign body particles. Histories of the patients were reviewed for exposure to sodium polystyrene sulfonate.Two lung specimens were referred to the Armed Forces Institute of Pathology with an unknown foreign material identified within the air spaces.The lung biopsies were from two children, one postterm female infant who died at 3 days of life and a 4-year-old girl who underwent lung biopsy during surgical repair for tetralogy of Fallot. Both patients had received sodium polystyrene sulfonate previously for control of hyperkalemia.The lung specimens showed characteristic basophilic, amorphous foreign material in airspaces on histologic sections. The identity of this material was confirmed by Fourier transform infrared microspectrophotometry.To our knowledge, we report the first two cases of sodium polystyrene sulfonate aspiration in children. This material has a distinctive morphologic appearance on histologic sections, and its identity can be confirmed by Fourier transform infrared microspectrophotometry.

Calcium oxalate crystals in pathologic specimens were examined by the laser Raman microprobe, a nondestructive spectroscopic technique. Although research focused on the identification of calcium oxalate deposits in tissue sections, kidney stones were also studied to determine the in situ structural specificity of the technique.Paraffin-embedded tissue specimens were cut into sections of 2 to 6 microns. The unstained sections were placed on metal (aluminum)-plated slides and excited with the 514.5-nm line of an argon-ion laser, which was focused to a 1-micron spot size using a high-resolution optical microscope.The laser Raman microprobe technique generates spectra that differentiate the monohydrate (CaC2O4.H2O, whewellite) and the dihydrate (CaC2O4.2H2O, weddellite) forms of calcium oxalate inclusions in tissue sections.Characteristic spectra were generated and provided unequivocal evidence for the identification of the dihydrate oxalate form of calcium oxalate crystals in cases of oxalosis of the myocardium and for the monohydrate oxalate structure in a case of oxalosis of the pituitary. Finally, the combined occurrence of both oxalate structures was confirmed in kidney stone specimens.The results obtained in this investigation demonstrate the efficacy of the laser Raman microprobe as a useful adjunct in diagnostic pathology.

The topography of the Aleutian mink disease parvovirus (ADV) G virion was analyzed with monoclonal antibodies and polyclonal antiserum. There was homology between the two major structural proteins as others have previously reported. Trypsin treatment of the virion with subsequent immunoblotting revealed that VP2 represents the main peptide on the exterior of virion and that VP1 is probably embedded within the capsid. Additional analyses of the trypsin-treated virions showed that VP2 is responsible for binding complement and that it also represents the structural part of the virion that binds to cellular receptors. A third protein, p34, was detected that might represent a third structural polypeptide because of its many unique epitopes relative to the other peptides detected.

Fourier-transform infrared microspectroscopy was used to identify polymeric microparticles, such as polyethylene, polysulfone, polytetrafluoroethylene, polyurethane, silicon-based, and nylon-based plastics, in tissue sections. Foreign particles as small as 30 microns in diameter were identified. In addition to being a nondestructive technique, infrared microscopy allows for more precise structural identification of polymeric materials than do X-ray or scanning electron microscopy.

The Ultrabithorax (Ubx) gene of Drosophila melanogaster encodes a family of UBX proteins that are thought to specify the developmental fates of segments in the posterior thorax and anterior abdomen by controlling the expression of a set of target genes. UBX proteins bind DNA in vitro, and they activate or repress different natural and synthetic target promoters in cultured cells. Here it is shown that a purified UBX protein can stimulate transcription of a synthetic target gene in extracts of cultured D. melanogaster cells. Stimulation is dependent on the presence of upstream, promoter-region binding sites but is independent of binding site orientation. A naturally occurring binding site cluster and a binding site consensus sequence consisting of TAA trinucleotide repeats can mediate this activation. A minimal promoter fused to such sites is activated by UBX, suggesting that transcriptional stimulation could result from an interaction between the promoter-bound protein and the general transcriptional machinery.

The diagnosis of viral infections by culture relies on the collection of proper specimens, proper care to protect the virus in the specimens from environmental damage, and use of an adequate transport system to maintain virus activity. Collection of specimens with swabs that are toxic to either virus or cell culture should be avoided. A variety of transport media have been formulated, beginning with early bacteriological transport media. Certain swab-tube combinations have proven to be both effective and convenient. Of the liquid transport media, sucrose-based and broth-based media appear to be the most widely accepted and used. Studies on virus stability show that most viruses tested are sufficiently stable in transport media to withstand a transport time of 1 to 3 days. Some viruses may withstand longer transport times. In many cases, it is not necessary to store virus specimens in a refrigerator or send them to the laboratory on wet ice or frozen on dry ice. However, the specimen should not be exposed to environmental extremes. Modern viral transport media allow for more effective use of viral culture and culture enhancement techniques for the diagnosis of human viral infections.

Editor,—Abnormal pigmentation of the conjunctiva has been associated with various pathological conditions including melanosis, melanocytic tumours, foreign bodies, systemic disease, topical and systemic use of medications, and industrial exposure to various chemicals.1 2 ### CASE REPORTS In this report, abnormal pigmentation of the conjunctiva and lacrimal sac was noted in 10 patients using kohl (eyeliner, surma) that was made in India.3-5 This eyeliner is used by millions in the Middle East, Asia, and Africa. The median age of nine women and one man was 52 years (range 40–64 years). All patients had used kohl for many years. The two patients with conjunctival pigmentation had bilateral, diffuse pigmentation of the fornicial and tarsal conjunctiva of the upper and lower eyelids in the form of discrete, punctate black deposits (Fig 1). The other eight patients presented with epiphora and had chronic dacryocystitis associated …

A new chlamydia transport medium (ChlamydiaPort; Scott Laboratories, Inc., Fiskeville, R.I.) was evaluated for its suitability as a transport medium for herpes simplex virus (HSV). Two laboratory HSV strains (McIntyre and 333) and two clinical isolates (AO218 and AO301) were suspended in ChlamydiaPort, ViraPort (Scott Laboratories), and cell culture medium and maintained at 2 and 22 degrees C. Samples were tested at various time intervals to determine surviving virus. The range of half-lives of the HSV strains held at 2 degrees C in ChlamydiaPort medium was from 3.5 to 10 days, while virus stability was greater in ViraPort and less in cell culture medium. These HSV strains held at 22 degrees C in ChlamydiaPort had half-lives from 1.5 to 6 days, which were significantly greater than the half-lives of the viruses held in either tissue culture medium or ViraPort. Clinical specimens were tested for virus by using the Selecticult-HSV (Scott Laboratories) system to determine the performance of the transport medium under field conditions. Clinical specimens maintained up to 5 days at ambient temperatures in ChlamydiaPort medium appeared suitable for diagnostic testing without detectable loss of positive specimens. In addition, there was a significant decrease in the average time required for diagnosis when compared with a standard transport system, Virocult (Microdiagnostics, Cleveland, Ohio). These results show that HSV infections can be successfully diagnosed in distant virology laboratories by shipping specimens in ChlamydiaPort transport medium at ambient temperatures.

Summary Adenovirus-associated virus (AAV) structural proteins (VP1, VP2, and VP3) have been examined to determine if areas of sequence homology exist between these three virion proteins. Tryptic and chymotryptic maps have been produced which demonstrate extensive areas of sequence homology common to all three proteins. The amino acid compositions of the proteins were also determined and were found to be very similar. These data are consistent with the hypothesis that all three virion proteins arise either from a common precursor or similar transcripts.

An avidin-biotin complex system was compared with three commercially available immunofluorescence kits for serotyping herpes simplex virus isolates from clinical specimens. Sensitivity values showed that the Electro-Nucleonics and Immulok reagents were useful in detecting the presence of virus, whereas the predictive values showed that the Syva and Immulok reagents possessed adequate discrimination between the herpes simplex virus serotypes. The avidin-biotin complex system was equal or superior to the immunofluorescence reagents tested both in detecting herpes simplex virus antigens in cell culture and in serotyping herpes simplex virus isolates.

The influence of environmental pH on AAV was studied in infectious virus titrations, induction of CF antigens production of infectious virus, induction of immunofluorescent stainable antigen, and aggregation of the viral particles. The pH of the medium was found to influence the titer of virus stocks in that less virus was registered at acid pH's, giving differences of up to 105 TCID50 in HEK and HEp-2 cells. Less infectious virus was produced in KB cells, and decreased amounts of CF antigen appeared at acid pH's. However, increased levels of detectable intracellular FA antigen appeared at acid pH's. Electron microscopic examination of AAV particles negatively stained at various pH's showed increasingly large aggregates of particles as the pH was lowered. Under the acid conditions studied, the adenovirus helper and cell activities were only slightly suppressed, with the greatest effect due to aggregation of the virus particles.

1,4-Cyclohexanedione has been converted into compounds 8 and 9. Treatment of 8 and 9 with base produces compound 10, which has been converted into 3-(1,1-ethylenedioxyoctyl)-cyclopentanone.

The cryogenic system of the Fermilab Magnet Test Facility has been used to provide cooling for the testting of approximately 1200 Energy Saver superconducting magnets. The system provides liquid helium, liquid nitrogen, gas purification, and vacuum support for six magnet test stands. It provides for simultaneous high current testing of two superconducting magnets and non-high current cold testing of two additional magnets. The cryogenic system has been in operation for about 32000 hours. The 1200 magnets have taken slightly more than three years to test.

In a series of electron microscopic studies of human urinary stones, a stone composed of sodium orthophosphate hydrate was identified. The stone was recovered from a patient who succumbed to advanced renal failure. A massive failure of the sodium pump, which cotransports phosphate across the brush border membrane of the proximal tubules is thought to be responsible for such an exceptional stone. This appears to be the first description of sodium phosphate crystal in a human urinary stone. Electron microscopy is a useful tool for stone analysis.

Fifty-four patients (47 of whom were evaluable) with non-small cell lung cancer were treated with a five-drug regimen consisting of cyclophosphamide, vincristine, lomustine, cisplatin, and doxorubicin. Six complete and 16 partial responses were achieved, for an overall response rate of 47% (22 of 47 patients). Response by cell type was as follows: epidermoid carcinoma, 41% (seven of 17 patients); adenocarcinoma, 42% (eight of 19); and large cell carcinoma, 64% (seven of 11). Response in patients with limited disease was 48% (11 of 23 patients) and in patients with extensive disease, 46% (11 of 24). Previously untreated patients had response rates of 53%, versus 22% in those with prior therapy.

In 1950 the term "sclerosing lipogranuloma" was introduced to designate a praticular subcutaneous granulomatous reaction that was believed to be a "local reactive process following injury to adipose tissue." Subsequent reports have shown that exogenous lipid injections probably are responsible for this lesion. We have studied 23 cases involving penis, scrotum, spermatic cord, and perineum, nine of which had been previously reported. We have been able to identify paraffin hydrocarbons by means of infrared-absorption spectrophotometry in 21 of these cases. We belive this entity should be redefined as a "local reactive process following injection of exogenous lipids into the subcutaneous tissues." In conventional microscopical sections, the lesion must be differentiated from adenomatoid tumor, sclerosing liposarcoma, and lymphangioma.

The development of aortic and coronary atherosclerotic plaques were investigated in roosters fed an atherogenic diet with and without the addition of Valium (0.2 mg/kg twice daily) over a period of 5 months, as a step toward understanding the role of emotional factors in atherogenesis. Plasma levels of cholesterol and triglycerides, hemodynamic parameters, and body weight were measured. There was a progressive, and quantitatively similar, body weight gain in all birds. In addition, there were no significant differences in values for blood pressure, cardiac output, and heart rate between the various experimental groups. Conversely, birds receiving the atherogenic diet, as well as those receiving the atherogenic diet along with Valium, exhibited a marked hypercholesterolemia which reached a peak of 600 mg/dl in 4-6 weeks, before decreasing to between 200 and 300 mg/dl by the 10th week. Plasma triglyceride levels followed a qualitatively similar pattern as plasma cholesterol. Those birds fed an atherogenic diet alone developed atherosclerotic lesions on the aortic surface which was more pronounced on the abdominal than the thoracic aorta. Aortas from birds given Valium along with the atherogenic diet were completely free of lesions despite the fact that plasma cholesterol and triglyceride levels were not significantly different in the two groups. Histological sections of coronary arteries showed severe lesions in 4 out of 7 birds which were fed the atherogenic diet alone, whereas the birds given Valium along with the atherogenic diet had only an occasional slight lipid deposit. It was concluded that Valium provides some protection against the development of atherosclerosis in roosters fed an atherogenic diet.

Calcium oxalate stones are very common and increasing. Crystal growth is no less important than the crystal nucleation in the pathogenesis of stone formation. The crystal growth was studied in human calcium oxalate stones by a combined electron microscopy and x-ray diffraction. The main mode of weddellite growth was interpenetration twinning of tetrahedral bipyramids. Bipyramids may form as initial crystal seeds, develop from anhedral crystals (crystals which lack flat symmetric faces) of spherular or mulberry shape, develop on the surface of preformed bipyramids by spiral dislocation mechanisms, or develop on whewellite crystal by heterogeneous nucleation and epitaxy. Heterogeneous nucleations of whewellite on weddellite, and calcium apatite on whewellite were also observed. Whewellite grew mainly by parallel twinning. Interpenetration twinning was exceptional. Transformation of anhedral to euhedral (completely bounded by flat faces that are set ar fixed angles to one another) whewellite occurred by parallel fissurations followed by brick wall like stacking of the crystals, while euhedral transformation of weddellite occurred by protrusion of bipyramids frm anhedral crystal surface. Occasionally, an evidence of crystal dissolution was noted. Although an aggregation of crystals is believed to play a pivotal role in stone nidus formation, growth in size of the formed crystals, and twinning and epitactic crystal intergrowth apparently play a significant role in the obstructive urinary stone formation.

A previous study of urinary stones by a combined electron microscopy demonstrated the potential of scanning electron microscopy and X-ray analysis as an analytic tool for urinary stones. Electron diffraction was chosen for the final confirmation of crystals in the study. Although electron diffraction is highly accurate for this purpose, it is desirable to establish the sensitivity of X-ray analysis for the identification of stone components relative to the more commonly used methods. Eighty six consecutive urinary stones were analyzed by X-ray analysis and the findings were compared with those of X-ray diffraction, infrared spectrometry and chemical analysis. The results indicate that X-ray analysis exceeds X-ray diffraction and infrared spectroscopy in its sensitivity for the identification of stone components several fold. This was largely due to the inability of the latter methods to detect apatite in more than half of the apatite containing stones. The findings in X-ray analysis had the best correlation with chemical analysis, which was applied mainly to the detection of apatite. X-ray analysis is particularly suited for the detection of rare and minor inorganic components of urinary stones such as silica and gypsum, and is obviously one of the most powerful tools for the analysis of urinary stones. Further application of X-ray analysis to urinary stone is likely to discern rare inorganic components of urinary stones overlooked by other methods.

An unusual foreign body reaction to silica (quartz), resembling fibrous histiocytoma, is described in 7 patients (age range 22 to 71 years). These lesions occurred in the inguinal region (4 cases) or the abdominal wall (3 cases), and in 5 instances were associated with a history of injection at the same site 10 to 41 years previously. Most commonly the injection consisted of the administration of a sclerosing agent for the repair of a hernia. Microscopically these lesions contained broad sheets of histiocytes separated by bands or concentrically lamellated nodules of collagen. Intra- and extra-cellular birefringent crystals, identified by x-ray diffraction as silica (quartz), were present in all cases and served to distinguish this process from a true neoplasm. Although the injection therapy for hernia is now obsolete, it was formerly practiced in the United States with a variety of sclerosing agents including silica (quartz). Since these lesions are often confused with a benign or malignant fibrous histiocytoma it is recommended that fibro-histiocytic lesions associated with a previous hernia or injection at the same site be examined for the presence of silica.

Bovine parvovirus has been found to infect two cell strains: buffalo lung fibroblasts and embryonic bovine tracheal cells. Infectivity titers were best determined by plaque assays. Immunofluorescence studies revealed intranuclear staining, whereas complement fixation tests confirmed bovine parvovirus antigen production. These cell strains represent economical and convenient cell types which can be used in studies on bovine parvovirus.

Graphite can be identified in tissue sections by its birefringence, in spite of its black color, and by its resistance to conventional incineration, but it is removed by exposure to radiofrequency-excited oxygen plasma. Amorphous carbon is removed by conventional or radiofrequency incineration.

The 1500 W helium refrigerator system utilizes two oil-injected screw compressors staged to feed a liquid nitrogen pre-cooled cold box. Refrigeration is provided by two Sulzer TGL-22 magnetic/gas bearing turbines. The refrigerator feeds six magnet test stands via a 10,000 L dewar and subcooler equipped distribution box. The design of the controls has permitted the system to be routinely operated 24 hours a day, seven days a week with only five operators. It operated approximately 90% of the 4 1/2 years prior to a one-year shutdown in 1984, during which the compressor skid was moved. Scheduled maintenance, failures, repairs and holidays are about equal to the 10$ off time. The equipment described was used to test approximately 1200 superconducting magnets for the Fermilab accelerator ring.1 The seven year operating experience is presented as an equipment and technique review. Compressor hours currently exceed 42,000 and turbine hours exceed 39,000 each. Failure rates, causes, preventive maintenance, monitoring practices and equipment, and modifications are examined along with notes on some of the more successful applications of technique and equipment.

The main purpose of this work was to isolate the components in acetone soluble lipids of lepromas of the nine-banded armadillo by high performance liquid chromatography (HPLC), and then to examine the mass spectrometric characteristics of the two peaks (molecular weights 2000 and 1600) found by HPLC. The armadillo had been inoculated with Mycobacterium leprae isolated from a mangabey monkey with naturally acquired leprosy. According to the results of HPLC, gas liquid chromatographic and mass spectral analyses, the GPC peak I lipid at 2000 D was identified as phenolic glycolipid and the GPC peak II lipid at 1600 D, as phthiocerol dimycocerosate. It was thought that the GPC peak I lipid and the GPC peak II lipid were included in the spherical droplets (peribacillary substance) around M. leprae. It was concluded that the microorganisms causing leprosy-like changes in the mangabey monkey were either M. leprae or a very closely related bacillus.

A nonfamilial case of agiomatosis retinae (retinal hemangioblastoma) was studied by electron microscopy. In addition to the three major types of cells previously identified within the tumor (endothelial cells, pericytes, heavily lipidized stromal cells), fibrous astrocytes in different stages of lipidization were also found. The endothelial cells were fenestrated, providing the basis for the extravasated exudate that is characteristic of the tumor. The pericytes were completely surrounded by casement membranes and displayed no significant lipidization; in a cellular plaque of vasular tissue at the base of the lesion, however, some of the multilaminar pericytes showed evidence of early smooth muscle differentiation. The stromal cells contained abundant lipid vacuoles and a few organelles, and exhibited granular degeneration of cytoplasmic filaments between the lipid vacuoles. There was spotty basement membrane formation where the stromal cells abutted on the vascular elements. No interconversion could be demonstrated among the endothelial cells, pericytes, and stromal cells. A source for the stromal cells was discovered in the early lipisization of fibrous astrocytes. Analysis of the extracted lipid from the tumor by means of infrared spectroscopy, lipid chromatography, and x-ray diffraction disclosed that the lipid was mostly cholestrol stearate, a plasma lipid. It is suggested that in the retinal lesions the leaky (fenestrated) capillaries of the tumor allowed the passive imbibition of plasma lipid by the fibrous astrocytes, leading to their gradual transformation into the fully lipidized stromal cells.