Predictors of Hospital-related Outcomes of COVID-19 Infection in Patients With Inflammatory Bowel Disease in the Early Pandemic Phase: A Nationwide Inpatient Database Survey

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at higher risk for severe COVID-19 infection. However, most studies are single-center, and nationwide data in the United States are lacking. This study aimed to investigate hospital-related outcomes and predictors of these outcomes in patients with IBD and COVID-19 infection.

METHODS

The National Inpatient Sample and National Readmission database were queried for all the patient hospitalizations with IBD with concurrent COVID-19 in the study group and non-COVID-19 related hospitalizations in the control group. For patients under 18 years, elective and trauma-related hospitalizations were excluded. Primary outcomes included mortality, septic shock, mechanical ventilation, and intensive care utilization. Secondary outcomes included length of stay and total hospitalization costs.

RESULTS

From this query, 8865 adult patients with IBD and COVID-19 were identified. These patients were relatively older (62.8 vs 57.7 years, P < .01), and the majority were females (52.1% with COVID-19 vs 55.2% without COVID-19). Patients with IBD and COVID-19 had higher mortality (12.24% vs 2.55%; P < .01), increased incidence of septic shock (7.9% vs 4.4%; P < .01), mechanical ventilation (11.5% vs 3.7%; P < .01), and intensive care utilization (12% vs 4.6%; P < .01). These patients also had higher mean length of stay (8.28 days vs 5.47 days; P < .01) and total hospitalization costs ($21 390 vs $16 468; P < .01) than those without COVID-19 infection.

CONCLUSIONS

Patients with IBD and COVID-19 have worse outcomes, with a higher incidence of severe COVID-19 disease, leading to higher mortality rates, longer lengths of stay, and increased total hospitalization costs. Encouraging preventive health measures and treating promptly with advanced COVID-19 therapies may improve outcomes and decrease the healthcare burden.

Bach Mai Procedure for complete mesocolic excision, central vascular ligation, and D3 lymphadenectomy in total laparoscopic right hemicolectomy: a prospective study

PURPOSE

Total laparoscopic right hemicolectomy with complete mesocolic excision (CME), central vascular ligation (CVL), and D3 lymphadenectomy is still the most challenging colon procedures for gastrointestinal surgeons. We herein report the technical details and our preliminary experience of Bach Mai Procedure - a novel-combining (cranial, medial to lateral, and caudal) approach with early resection of the terminal ileum.

METHODS

The dissection stage was central vascular isolation and ligation by a combined multiple approaches in the following four steps: cranial approach, dissecting along the inferior aspect of pancreatic isthmus to reveal the middle colic vessels and the anterior aspect of the superior mesentery vein and then exposed the right gastroepiploic vein and the trunk of Henle; medial-to-lateral approach, exposing the surgical axis - the superior mesenteric vascular axis and then early resection of the terminal ileum to open the dissection from the bottom up; and caudal approach, radical ligation of the ileocecal artery and right colic artery (central vascular ligation), lymph node dissection (D3 lymphadenectomy), and resecting the Toldt fascia of the colon to release the entire right colon from the abdominal wall.

RESULTS

In 12 months, there were 32 cases of primary right-sided colon malignancies that have undergone tLRH_{D3, CME/CVL} based on the Bach Mai Procedure. In 3 cases (9.4%), the tumor site was hepatic flexure. The median of lymph node number (LNN) was 38, with the maximum number which was 101. No serious postoperative complications (grade 3 or higher) neither inhospital mortality was detected.

CONCLUSION

This Bach Mai procedure, a novel-combining approach with early resection of the terminal ileum, is technically feasible and safe for tLRH_{D3, CME/CVL}. Further investigations and follow-up must be proceeded to evaluate the long-term outcomes of our technique.

Isolated complete caudate lobectomy with Glissonean pedicle isolation using Takasaki's technique and right-left approach: preliminary experience from two case reports

Background

Tumors located in the caudate lobe may be primary tumor or metastases from other sites. Isolated caudate lobectomy (ICL) is a challenging procedure due to its complex structure and location. The access route to the caudate lobe has an important role in the success of the operation.

Methods

Based on the characteristics of the segment I location, which is the part of the liver located in front of the vena cava, below the hepatic veins, and cranial to the hilar plate, our approach aims to isolate the entire caudate lobe from these anatomical structures with the following steps: dissecting the caudate lobe from the hilar plate and isolating the caudate lobe from the IVC and from the hepatic veins along with parenchymal resection.

Results

We report two successful cases with the Glissonean pedicle transection method described by Takasaki and the combined right- and left-side approach: a 63-year-old female patient with a 46-mm-in-diameter HCC tumor and a 39-year-old female patient with a 45-mm lesion and the pathological result was focal nodular hyperplasia.

Conclusions

We found this to be a safe and effective approach, which can be applied to all cases of benign tumors or in the case of malignant tumors located entirely in the caudate lobe when extended hepatic resection is not possible due to poor liver function or small remnant liver volume.

Perpetration of Intimate Partner Violence Among Men Living with HIV in Northern Vietnam

We examined the prevalence of intimate partner violence (IPV) perpetration and characteristics of HIV-infected male perpetrators. The cross-sectional study was conducted in Vietnam with male antiretroviral treatment clients (N = 1099; mean age = 40.2 years). Bivariable associations were tested between psychological or physical/sexual IPV perpetration in the last 12 months and sociodemographic, psychosocial, and sexual behavioral factors using prevalence ratios. Factors significant at p < 0.10 were entered in multivariable models for each IPV outcome using a modified Poisson approach. Results showed 15.6% (N = 171/1099) reported perpetrating psychological IPV and 7.6% (N = 84/1099) perpetrating physical/sexual IPV in the last 12 months. HIV risk behaviors, including hazardous drinking and multiple sexual partners, having witnessed interparental violence as a child, and depressive symptoms were associated with perpetrating IPV. HIV interventions targeting HIV-infected men in Vietnam should intervene on IPV perpetration by addressing the co-occurring factors of sexual risk, depression, alcohol use, and child maltreatment that are correlated with IPV.

Low-temperature deposition of BaCuSF, a visible through mid-infrared p-type transparent conductor

Barium copper sulfur fluoride (BaCuSF) is a p-type transparent conductor (p-TC) that, when doped with potassium, exhibits exceptionally high conductivity. The results of a detailed optical and electronic characterization of BaCuSF thin films deposited at a substrate temperature of 100 °C are presented. X-ray diffractometry shows the presence of a cubic BaCuSF phase. Spectroscopic measurements demonstrate that the films transmit from the visible through the mid-infrared with a band gap of 1.8 eV. Hall measurements indicate that the material is a degenerate semiconductor. As deposited, the films exhibit conductivity at room temperature of approximately 260 S/cm - among the highest reported room temperature conductivities for p-TCs. After post-deposition treatment in water, their conductivity increases to as high as 800 S/cm, and their band gap is reduced to 1.5 eV. The potential for low temperature deposition of p-type films with high conductivity and optical transmittance makes BaCuSF promising for several applications including flexible electronics and photovoltaics.

Characterization of mid-infrared single mode fibers as modal filters

We present a technique for measuring the modal filtering ability of single mode fibers. The ideal modal filter rejects all input field components that have no overlap with the fundamental mode of the filter and does not attenuate the fundamental mode. We define the quality of a nonideal modal filter Q(f) as the ratio of transmittance for the fundamental mode to the transmittance for an input field that has no overlap with the fundamental mode. We demonstrate the technique on a 20 cm long mid-infrared fiber that was produced by the U.S. Naval Research Laboratory. The filter quality Q(f) for this fiber at 10.5 microm wavelength is 1000+/-300. The absorption and scattering losses in the fundamental mode are approximately 8 dB/m. The total transmittance for the fundamental mode, including Fresnel reflections, is 0.428+/-0.002. The application of interest is the search for extrasolar Earthlike planets using nulling interferometry. It requires high rejection ratios to suppress the light of a bright star, so that the faint planet becomes visible. The use of modal filters increases the rejection ratio (or, equivalently, relaxes requirements on the wavefront quality) by reducing the sensitivity to small wavefront errors. We show theoretically that, exclusive of coupling losses, the use of a modal filter leads to the improvement of the rejection ratio in a two-beam interferometer by a factor of Q(f).

Small-core As-Se fiber for Raman amplification

We have demonstrated Raman small-core As-Se fiber. More than 20-dB of gain was observed in a 1.1-m length of fiber pumped by a nanosecond pulse of approximately 10.8-W peak power at 1.50 microm. The peak of the Raman gain occurred at a shift of approximately 240 cm(-1). The Raman gain coefficient is estimated to be approximately 2.3 x 10(-11) m/W, which is more than 300 times greater than that of silica. The large Raman gain coefficient coupled with the large IR transparency window of these fibers shows promise for development of As-Se Raman fiber lasers and amplifiers in the near-, mid-, and long-IR spectral regions.

Highly nonlinear As-S-Se glasses for all-optical switching

We have synthesized a series of chalcogenide glasses from the As-S-Se system that is designed to have strong nonlinearities. Measurements reveal that many of these glasses offer optical Kerr nonlinearities greater than 400 times that of fused silica at 1.25 and 1.55mum and figures of merit for all-optical switching greater than 5 at 1.55mum .

Cyclin-dependent kinases prevent DNA re-replication through multiple mechanisms

The stable propagation of genetic information requires that the entire genome of an organism be faithfully replicated once and only once each cell cycle. In eukaryotes, this replication is initiated at hundreds to thousands of replication origins distributed over the genome, each of which must be prohibited from re-initiating DNA replication within every cell cycle. How cells prevent re-initiation has been a long-standing question in cell biology. In several eukaryotes, cyclin-dependent kinases (CDKs) have been implicated in promoting the block to re-initiation, but exactly how they perform this function is unclear. Here we show that B-type CDKs in Saccharomyces cerevisiae prevent re-initiation through multiple overlapping mechanisms, including phosphorylation of the origin recognition complex (ORC), downregulation of Cdc6 activity, and nuclear exclusion of the Mcm2-7 complex. Only when all three inhibitory pathways are disrupted do origins re-initiate DNA replication in G2/M cells. These studies show that each of these three independent mechanisms of regulation is functionally important.

A sperm cytoskeletal protein that signals oocyte meiotic maturation and ovulation

Caenorhabditis elegans oocytes, like those of most animals, arrest during meiotic prophase. Sperm promote the resumption of meiosis (maturation) and contraction of smooth muscle-like gonadal sheath cells, which are required for ovulation. We show that the major sperm cytoskeletal protein (MSP) is a bipartite signal for oocyte maturation and sheath contraction. MSP also functions in sperm locomotion, playing a role analogous to actin. Thus, during evolution, MSP has acquired extracellular signaling and intracellular cytoskeletal functions for reproduction. Proteins with MSP-like domains are found in plants, fungi, and other animals, suggesting that related signaling functions may exist in other phyla.

Carboxy-terminal proteolytic processing of Helicobacter pylori vacuolating toxin

The vacA gene of Helicobacter pylori strain 60190 encodes a 1, 287-amino-acid protoxin, which undergoes cleavage of a 33-amino-acid amino-terminal signal sequence and carboxy-terminal proteolytic processing to yield a mature secreted toxin. Several features of VacA suggest that it belongs to the autotransporter family of gram-negative bacterial secreted proteins. Based on matrix-assisted laser desorption ionization-time of flight mass spectrometric analysis, we calculate that the mature toxin has a mass of 88.2+/-0.2 kDa and consists of approximately 821 amino acids.

Scanning by DOVAM-S detects all unique sequence changes in blinded analyses: evidence that the scanning conditions are generic

The [detection of virtually all mutations]-SSCP (DOVAM-S) is a highly sensitive variant of single strand conformation polymorphism (SSCP). Mutations in the factor IX gene were used to find a set of five SSCP conditions that detects virtually all mutations. A blinded analysis of the factor IX gene in patients with hemophilia B detected 82 of 82 unique mutations. Since the method was developed and tested on the factor IX gene, it is possible that the conditions selected work more efficiently in the factor IX gene than in other genes. To test the general applicability of the conditions under which DOVAM-S detected all mutations in this gene, blinded analyses were performed in the human factor VIII and ataxia-telangiectasia (ATM) genes. Segments were amplified individually, combined into groups of 16 to 18 amplified segments and electrophoresed in five different nondenaturing conditions of varying matrices, buffers, temperatures and additives. Blinded analyses were performed in 92 samples from patients with hemophilia A (factor VIII gene) and 19 samples from A-T patients (ATM gene). Combined with an earlier blinded analysis in the factor IX gene, all of the 250 mutations and polymorphisms (180 of which are unique) were detected in both analyses. For two, three and four joint conditions, the average detection frequency ranged from 77%-97%, 91%-100% and 95%-100%, respectively. For each of the genes, one mutation may have been missed if only four conditions were used. With DOVAM-S, approximately 500 kb of autosomal sequence can be scanned in five gels with virtually 100% detection of mutations within the scanned region. The detection of 180 out of 180 unique sequence changes implies that DOVAM-S detects at least 96.5% (P = 0.03) of mutations. Blinded analyses that detect 400 unique sequence changes are required to determine that a scanning method detects at least 98.5% of mutations.

Clb/Cdc28 kinases promote nuclear export of the replication initiator proteins Mcm2-7

BACKGROUND

In the budding yeast Saccharomyces cerevisiae, the cyclin-dependent kinases of the Clb/Cdc28 family restrict the initiation of DNA replication to once per cell cycle by preventing the re-assembly of pre-replicative complexes (pre-RCs) at replication origins that have already initiated replication. This assembly involves the Cdc6-dependent loading of six minichromosome maintenance (Mcm) proteins, Mcm2-7, onto origins. How Clb/Cdc28 kinases prevent pre-RC assembly is not understood.

RESULTS

In living cells, the Mcm proteins were found to colocalize in a cell-cycle-regulated manner. Mcm2-4, 6 and 7 were concentrated in the nucleus in G1 phase, gradually exported to the cytoplasm during S phase, and excluded from the nucleus by G2 and M phase. Tagging any single Mcm protein with the SV40 nuclear localization signal made all Mcm proteins constitutively nuclear. In the absence of functional Cdc6, Clb/Cdc28 kinases were necessary and sufficient for efficient net nuclear export of a fusion protein between Mcm7 and the green fluorescent protein (Mcm7-GFP), whereas inactivation of these kinases at the end of mitosis coincided with the net nuclear import of Mcm7-GFP. In contrast, in the presence of functional Cdc6, which loads Mcm proteins onto chromatin, S-phase progression as well as Clb/Cdc28 kinases was required for Mcm-GFP export.

CONCLUSIONS

We propose that Clb/Cdc28 kinases prevent pre-RC reassembly in part by promoting the net nuclear export of Mcm proteins. We further propose that Mcm proteins become refractory to this regulation when they load onto chromatin and must be dislodged by DNA replication before they can be exported. Such an arrangement could ensure that Mcm proteins complete their replication function before they are removed from the nucleus.

High-pressure liquid chromatography quantitation of cytochrome c using 393 nm detection

The release of cytochrome c from the mitochondrial intermembrane space can induce apoptotic cell death. Previous methods to detect cytochrome c release from mitochondria have relied upon immunoblotting, a procedure that can be limited by nonlinearity of signal, epitope masking, and impracticality for large numbers of samples. In order to circumvent these limitations, we have developed a reverse-phase high-pressure liquid chromatography method for cytochrome c detection and quantitation by taking advantage of a novel acid-induced absorbance maximum at 393 nm for cytochrome c in buffer containing 0.1% trifluoroacetic acid. Using a C4 reverse-phase analytical column, this assay had a quantitation limit of 10 ng (0.8 pmol) of cytochrome c. We demonstrated the detection and quantitation of cytochrome c from isolated mitochondria. This method of cytochrome c analysis may be useful for the study of agents that cause mitochondrial dysfunction and apoptotic cell death.

Effect of temperature on the absorption loss of chalcogenide glass fibers

The change in the absorption loss of IR-transmitting chalcogenide glass fibers in the temperature range of -90 degrees C <or= T <or= 70 degrees C was investigated. For sulfur-based glass fibers the change in loss relative to room temperature was slightly affected by the temperature in the wavelength region of 1-5 microm. For lambda >or= 6 microm the change in loss was mainly due to multiphonon absorption. The change in loss for tellurium-based glass fibers increased significantly at T = 60 degrees C. The increase in the loss at short wavelengths (lambda <or= 4.1 microm) was due to electronic excitations in the tail states. Between 5 and 9 microm there was noticeable free-carrier absorption. Beyond lambda >or= 9 microm, multiphonon absorption dominated the loss spectrum.

Mass spectrometric analysis of the electroeluates of fluorescent proteins after preparative electrophoresis in the automated HPGE-1000 apparatus

Bands of green fluorescent protein (GFP) and R-phycoerythrin (PHYCO) in gel electrophoresis on the automated apparatus for gel electrophoresis with periodic fluorescence scanning (HPGE), the HPGE-1000 apparatus, were retrieved from the gel by electroelution. While PHYCO was recovered in a single volume of electroeluate buffer after the predicted migration time, GFP fluorescence was lost under the same conditions and could only be recovered using multiple changes of electroeluate buffer. The multiple volumes of buffer necessitated pooling, concentration, and storage, conditions under which a minor GFP component, GFP-II, formed artifactually. PHYCO after electroelution also exhibits a minor component present in the original preparation. The electroeluate of GFP, transferred into a mass spectrometer after pooling, concentration and storage, is indistinguishable in mass from the original preparation.

Simultaneous assessment of conformation and aggregation of beta-amyloid peptide using electrospray ionization mass spectrometry

Electrospray ionization mass spectrometry was used to study conformation and aggregation of the synthetic beta-amyloid peptide, residues 1-40 (betaA4), as a function of concentration and sample aging. All mass spectra showed a major envelope of peaks corresponding to charge states of 7-3 of the monomeric form of betaA4. In addition, weaker envelopes of peaks corresponding to charge states of dimeric, trimeric, and tetrameric betaA4 species were seen under gentle ionization conditions. The average charge state of the envelope associated with the monomeric form decreased by ca. 0.5 z as samples were aged, indicating that the relatively open form (likely random coil) of the peptide was modified into the more compact form (likely beta-sheet) as a function of sample aging. The aggregate forms became weaker and ultimately were absent both in the more dilute solutions and in aged aliquots of the concentrated sample. These aggregates were interpreted as assemblies of the random coil form. We interpret our inability to see an ion envelope that can be associated with aggregates of the beta-sheet form to be a consequence of the presumed very compact nature of this form. A model for the formation of betaA4 fibrils is proposed and discussed.

Gas-phase protonation of pyridine. A variable-time neutralization-reionization and Ab initio study of pyridinium radicals

Gas-phase protonation of pyridine with CH3NH3+, NH4+, t-C4H9+, H3O+ and CH5+ under thermal conditions was studied by variable-time neutralization-reionization mass spectrometry and ab initio calculations. N-Protonation was found to occur exclusively for CH3NH3+ through H3O+ and predominantly for CH5+. The calculated MP2/6-311G(2d,p) energies gave the proton affinities of N, C-2, C-3 and C-4 in pyridine as 924, 658, 686 and 637 kJ mol-1, respectively, which were in good agreement with previous experimental and theoretical results. Vertical neutralization of the N-protonated isomer (1H+) was accompanied by moderate Franck-Condon effects that deposited 20-21 kJ mol-1 in the 1H-pyridinium radicals (1H) formed. 1H was calculated by UMP2/6-311G(2d,p) and B3LYP/6-311G(2d,p) to be a bound species in its ground electronic state. A substantial fraction of stable 1H was detected in the spectra, which depended on the precursor ion internal energy. Deuterium labeling showed a specific loss of the N-bound hydrogen or deuterium in the radicals. The specificity increased with increasing internal energy in the radicals and decreasing contribution of ion dissociations following reionization. Variable-time measurements established specific loss of the N-bound deuterium also in dissociating low-energy 1D. Loss of hydrogen from 1H+ cations following reionization was highly endothermic and was accompanied by rearrangements that partially scrambled the ring hydrogens.

Protonation sites in gaseous pyrrole and imidazole: a neutralization-reionization and ab initio study

Mild gas-phase acids C4H9+ and NH4+ protonate pyrrole at C-2 and C-3 but not at the nitrogen atom, as determined by deuterium labeling and neutralization-reionization mass spectrometry. Proton affinities in pyrrole are calculated by MP2/6-311G(2d,p) as 866, 845 and 786 kJ mol-1 for protonation at C-2, C-3 and N, respectively. Vertical neutralization of protonated pyrrole generates bound radicals that in part dissociate by loss of hydrogen atoms. Unimolecular loss of hydrogen atom from C-2- and C-3-protonated pyrrole cations is preceded by proton migration in the ring. Protonation of gaseous imidazole is predicted to occur exclusively at the N-3 imine nitrogen to yield a stable aromatic cation. Proton affinities in imidazole are calculated as 941, 804, 791, 791 and 724 for the N-3, C-4, C-2, C-5 and N-1 positions, respectively. Radicals derived from protonated imidazole are only weakly bound. Vertical neutralization of N-3-protonated imidazole is accompanied by large Franck-Condon effects which deposit on average 183 kJ mol-1 vibrational energy in the radicals formed. The radicals dissociate unimolecularly by loss of hydrogen atom, which involves both direct N-H bond cleavage and isomerization to the more stable C-2 H-isomer. Potential energy barriers to isomerizations and dissociations in protonated pyrrole and imidazole isomers and their radicals were investigated by ab initio calculations.

Energy effects in collisional neutralization with organic molecules

Neutralization-reionization of CH3OH+., CH3NH2+. and (CH3)2NH+. ions was studied under conditions of exothermic and endothermic electron transfer and distributions of internal energy in the reionized ions were determined. The internal energy deposited on neutralization at kiloelectronvolt collision energies is governed by Franck-Condon effects for the systems under study, whereas the endothermic or exothermic energy balance in electron transfer from molecular targets has only a small effect on the high-energy fraction of the molecules formed. Electron transfer from low-lying molecular orbitals of the organic donor is suggested to occur during random orientations of the ion-molecule collision pair. The internal energy of the precursor ions to be neutralized has a large effect on the relative abundances of survivor ions in the spectra. Vertical recombination energies of CH3OH+. and CH3NH2+. are found by Gaussian-2 level calculations to differ substantially from vertical ionization energies of the corresponding neutral molecules. Franck-Condon effects are analyzed for the vibrational modes that are affected most by vertical electron transfer.

Infrared evanescent-absorption spectroscopy with chalcogenide glass fibers

We have used telluride glass fibers fabricated in house to measure the evanescent-absorption spectra of water, methanol, ethanol, isopropanol, acetone, ethanoic acid, hexane, and chloroform. Furthermore, detection limits of less than 2 vol. % solute were obtained for mixtures of water and methanol, ethanol, isopropanol, acetone, and ethanoic acid. Techniques to reduce the detection limits are discussed.

Anti-TAPA-1 antibodies induce protein tyrosine phosphorylation that is prevented by increasing intracellular thiol levels

We studied the signal induced by the anti-TAPA-1 antibody and compared it to the signal induced by anti-IgM antibodies in a human B cell line, OCl-LY8. We found that exposure of these cells to either antibody resulted in a rapid increase in protein tyrosine phosphorylation which was prevented by inhibitors of tyrosine kinases. Tyrosine phosphorylation was an early event in the cascase leading to the antiproliferative effect of the anti-TAPA-1 antibody. However, 2-ME, a reducing agent that is not an inhibitor of tyrosine kinases, prevented both tyrosine phosphorylation and the antiproliferative effect of the antibody. Cells grown in low concentrations of 2-ME did not exhibit an increase in tyrosine phosphorylation in response to the anti-TAPA-1 antibody and were insensitive to the antiproliferative effect of the antibody. In contrast, the same cells maintained in 2-ME were able to induce tyrosine phosphorylation in response to anti-IgM. The use of 2-ME resulted in an increase in intracellular thiols, mostly glutathione. Moreover, compounds that block glutathione synthesis rendered cells susceptible to the antibody, even in the presence of 2-ME. These experiments demonstrate that tyrosine kinases are involved in propagating the antiproliferative signal initiated by the anti-TAPA-1 antibody and suggest that this signal is dependent upon the level of intracellular thiols.

Anti-TAPA-1 antibodies induce protein tyrosine phosphorylation that is prevented by increasing intracellular thiol levels

We studied the signal induced by the anti-TAPA-1 antibody and compared it to the signal induced by anti-IgM antibodies in a human B cell line, OCl-LY8. We found that exposure of these cells to either antibody resulted in a rapid increase in protein tyrosine phosphorylation which was prevented by inhibitors of tyrosine kinases. Tyrosine phosphorylation was an early event in the cascase leading to the antiproliferative effect of the anti-TAPA-1 antibody. However, 2-ME, a reducing agent that is not an inhibitor of tyrosine kinases, prevented both tyrosine phosphorylation and the antiproliferative effect of the antibody. Cells grown in low concentrations of 2-ME did not exhibit an increase in tyrosine phosphorylation in response to the anti-TAPA-1 antibody and were insensitive to the antiproliferative effect of the antibody. In contrast, the same cells maintained in 2-ME were able to induce tyrosine phosphorylation in response to anti-IgM. The use of 2-ME resulted in an increase in intracellular thiols, mostly glutathione. Moreover, compounds that block glutathione synthesis rendered cells susceptible to the antibody, even in the presence of 2-ME. These experiments demonstrate that tyrosine kinases are involved in propagating the antiproliferative signal initiated by the anti-TAPA-1 antibody and suggest that this signal is dependent upon the level of intracellular thiols.

DaCosta's syndrome: chronic symptomatic hyperventilation

In 1871, DaCosta published his observation of somatic symptoms preceded by significant hyperventilation. More than a century later, the hyperventilation syndrome remains a poorly defined but common clinical condition. Although familiar to most practitioners of medicine when it presents as an acute phenomenon, the diagnosis may go unrecognized in its chronic form. The ability of a chronic hyperventilatory state to mimic a life-threatening cardiopulmonary disease is not always appreciated.

Unilateral diaphragmatic paralysis: a matter for concern

A dilemma often faces the clinician who is asked to evaluate unilateral elevation of a hemidiaphragm that is identified on routine chest roentgenogram. The possibilities include neoplasm, infection, neuromuscular disease, trauma, or benign etiologies. We present an asymptomatic patient with this finding to provide some guidelines for the nature and extent of further investigation of unilateral diaphragmatic paralysis.

Interleukin-2 enhances the translocation of Escherichia coli from the intestines to other organs

To determine if interleukin-2 (IL-2) would inhibit gastrointestinal bacterial translocation, mice were gut-decontaminated and recolonized with Escherichia coli C25; some groups were pretreated with 200 mg/kg cyclophosphamide. IL-2 (1.68 mg/kg) or sterile diluent was injected twice daily for 3 or 5 days, and mice were sacrificed the next day. High cecal levels of E. coli C25 were present in all mice. The overall incidence of E. coli C25 translocation to mesenteric lymph nodes was not reduced by IL-2. The median numbers of translocated E. coli C25/g of mesenteric lymph node were significantly (P less than .005) higher after both 3 days (659 vs. 117) and 5 days (550 vs. 50) of treatment with IL-2 with cyclophosphamide and after 5 days (1784 vs. 225) of IL-2 without cyclophosphamide. IL-2 prevented neutropenia and exacerbated lymphopenia caused by cyclophosphamide. The in vitro growth of E. coli C25 was not affected by up to 10(5) units/ml IL-2. Ileal and cecal structures assessed by light and electron microscopy were not altered by IL-2. Thus, IL-2 unexpectedly enhanced the translocation of E. coli C25 from the gastrointestinal tracts of both cyclophosphamide-pretreated and normal mice.

Structure and membrane topology of TAPA-1

TAPA-1 (the target of an antiproliferative antibody) is a 26-kDa cell surface protein expressed on most human cell lines. TAPA-1 is a member of an evolutionarily related family of cell surface proteins all of which contain four transmembrane domains. A model is proposed for topology of TAPA-1 based on proteolysis studies in the in vitro translated protein embedded into microsomal membranes. This analysis predicts that the amino and the carboxyl termini of the molecule are cytoplasmic and that the two hydrophilic regions of the molecule are extracellular. The antigenic epitope of the human TAPA-1 is contained within a subregion of the second extracellular domain of the protein. This is the only region in the protein that has not been tightly conserved in mammalian evolution.

Bronchogenic carcinoma and the acquired immunodeficiency syndrome

The majority of patients with the acquired immunodeficiency syndrome will develop clinical and radiographic pulmonary involvement during the course of their disease. Although opportunistic pathogens account for the majority of these intrathoracic abnormalities, pulmonary neoplasms are being encountered more often than would be expected for the age group under consideration. Clinicians need to be vigilant for the possibility of the early appearance of bronchogenic carcinoma in this subset of patients.

Evaluation of Fsub(1) hybrids incorporating the rin (ripening inhibitor) gene to improve the storage life and fruit quality of fresh market tomatoes (Lycopersicon esculentum Mill.)

Four new F1 hybrids which incorporate the ripening inhibitor (rin) tomato mutation were compared with standard commercial tomato cultivars, including Flora-Dade, for the fresh market in New South Wales and Victoria. The rin gene, in the heterozygous condition, delayed the start of ripening by a few days, increased the interval between breaker and full ripe from 5 to 7 days compared with commercial cultivars, and increased the storage life of ripe fruits from 28 to 40 days at 20�C. There were no significant differences between the level of red colour developed by the rin hybrids and reference tomatoes; however, the rin hybrid fruits took 4 days longer to reach full red colour. The fruits of rin hybrid were as firm as the reference tomatoes when picked at breaker and stored at 20�C for 6 days. However, rin hybrid fruits were significantly (P<0.05) firmer than those of reference tomatoes when harvested at a full ripe stage. Of the 4 rin hybrids tested, HRAS 87-70, which showed the most promise, was released in February 1990 as 'Red Centre'.

Use of high soil solution electrical conductivity to improve the quality of fresh market tomatoes from coastal New South Wales

High electrical conductivity (EC) in the soil solution or hydroponic medium is thought to increase the concentration of total soluble solids (TSS) and thereby improve the flavour of tomato fruit. We used trickle irrigation in 2 field experiments (1988, 1989) to apply KC1 at rates up to 4.4 t/ha to tomatoes to raise soil solution EC and examine the effects on TSS and other components of fruit quality, as well as yield. The KCl was subject to leaching in both years and EC varied widely despite regular additions of KCl. Where a high EC was achieved in 1988 (3.9 mS/cm) there was no effect on fruit firmness or TSS, but titratable acids (TA) increased from 7.25 to 8.0 m.e./100 mL. In 1989, high EC (>7mS/cm) resulted in a small increase in TSS (0.3%) in 1 of 6 harvests but significant (P<0.05) increases in TA in 4 harvests. Yield was unaffected (P>0.05). We conclude that irrigation with salinised water is unlikely to be an effective means of raising the TSS of tomatoes grown on freely draining soils in the high rainfall environment of coastal New South Wales.

Effect of photodynamic therapy on blood flow in normal and tumor vessels

The aim of this series of experiments was to determine the dynamic blood flow changes that occur in normal and neoplastic tissues during photodynamic therapy. Mice bearing SMT-F tumors and rats with transplanted chondrosarcomas were injected with graded doses of dihematoporphyrin ether. Studies of changes in single-vessel and whole-tumor blood flow were carried out with 630 nm light activation. A helium neon laser Doppler velocimeter was used to stimulate dihematoporphyrin ether, as well as to measure changes in flow velocity in both single-vessel and whole-tumor models. There was a reduction of flow velocity in all vessels and tumors in animals injected with 1 to 40 mg/kg dihematoporphyrin ether intraperitoneally. The extent of flow reduction was related to drug dose administered. Decreases in blood flow began within 10 seconds of light stimulation and were maximal within 5 minutes. Both normal and tumor vessels responded similarly. We conclude that photodynamic therapy leads to significant microcirculatory changes that may be pertinent to the mechanism of tumor necrosis.

Pneumococcosuria in adults

Pneumococcal bacteriuria is usually felt to indicate systemic pneumococcal infection, especially in children. To determine the frequency and significance of pneumococcosuria in adults, we reviewed the Shreveport Veterans Administration Medical Center microbiology laboratory log books for 1982 through 1985. During these 4 years, more patients had pneumococcal bacteriuria than bacteremia (38 versus 33), but only 2 patients had both. The medical records from 31 bacteriuric patients with 35 positive urine specimens were available for review. The collection technique was reliable for 23 (66%) urine specimens; the type of collection technique used was unknown for 12 (34%). The urine pH was less than or equal to 6 in 24 (68%) specimens, and the specific gravity was greater than 1.020 in 12 specimens (34%). A total of 24 specimens grew only Streptococcus pneumoniae, and 11 yielded mixed growth. All 31 patients were men, 25 (81%) were 60 years or older, and 13 (42%) had underlying genitourinary disorders. A total of 7 patients had genitourinary symptoms, 7 had fever, 5 had leukocytosis, and 12 had pyuria; however, these symptoms and signs were frequently accounted for by factors other than pneumococcosuria. Pneumococcosuria was an unexpected finding in all but two (6%) bacteremic patients. These were the only patients with systemic pneumococcal infections, and both died despite appropriate antibiotics. Among the 20 surviving patients with follow-up urine samples, pneumococcosuria resolved whether or not they had received antibiotics. Thus, pneumococcosuria in our patient population was frequently not accompanied by systemic pneumococcal infection and by itself did not require antibiotic therapy.

Results of a prospective statewide reporting system for infective endocarditis

To better understand the microbiology, anatomy, and demography of infectious endocarditis, we devised a prospective statewide reporting system to study these infections. Because our study design required accurate diagnosis, reliable case reporting, and a high probability of physician-to-case exposure, we enlisted the help of cardiologists, cardiovascular surgeons, and infectious disease specialists throughout Louisiana. All Louisiana members of the American College of Cardiology and the Infectious Diseases Society of America were invited to participate. Participants were supplied with a brief endocarditis report form and asked to complete the form as they saw patients with infective endocarditis. Seventy-five patients with infective endocarditis were reported for a case rate of 1.7 per 100,000 persons per year. This report analyzes the results from this one-year study.

Candida krusei infectious arthritis. A rare complication of neutropenia

Candida krusei infections are increasing in neutropenic patients. This is the first report of a case of C. krusei arthritis in a neutropenic leukemic patient. The organism colonized the patient's respiratory tract and most likely seeded the right knee by hematogenous spread. Knee swelling and tenderness were minimal. Joint fluid Gram stain and fungal smears did not show the organism despite positive results on cultures. With therapy, the joint fluid converted from neutrophilic predominance to lymphocytic predominance. Despite sterilization of knee fluid, clinical relapse occurred after therapy with 256 mg of systemic amphotericin B; the infection was cured after a total dose of 456 mg.