Multi-omic assessment shows dysregulation of pulmonary and systemic immunity to e-cigarette exposure

Electronic cigarette (Ecig) use has become more common, gaining increasing acceptance as a safer alternative to tobacco smoking. However, the 2019 outbreak of Ecig and Vaping-Associated Lung Injury (EVALI) alerted the community to the potential for incorporation of deleterious ingredients such as vitamin E acetate into products without adequate safety testing. Understanding Ecig induced molecular changes in the lung and systemically can provide a path to safety assessment and protect consumers from unsafe formulations. While vitamin E acetate has been largely removed from commercial and illicit products, many Ecig products contain additives that remain largely uncharacterized. In this study, we determined the lung-specific effects as well as systemic immune effects in response to exposure to a common Ecig base, propylene glycol and vegetable glycerin (PGVG), with and without a 1% addition of phytol, a diterpene alcohol that has been found in commercial products. We exposed animals to PGVG with and without phytol and assessed metabolite, lipid, and transcriptional markers in the lung. We found both lung-specific as well as systemic effects in immune parameters, metabolites, and lipids. Phytol drove modest changes in lung function and increased splenic CD4 T cell populations. We also conducted multi-omic data integration to better understand early complex pulmonary responses, highlighting a central enhancement of acetylcholine responses and downregulation of palmitic acid connected with conventional flow cytometric assessments of lung, systemic inflammation, and pulmonary function. Our results demonstrate that Ecig exposure not only leads to changes in pulmonary function but also affects systemic immune and metabolic parameters.

Effect of E-cigarette use on lung immunity to influenza infection

Use of E-cigarettes, also called vaping, has been significantly increasing, with over 10 million adults and 3 million adolescents reported to actively vape. Of particular concern recently is the association of vaping with increased risk of respiratory infection, including influenza and COVID-19. Despite the claims of safety, lung immunological development appears to be impacted by vaping, with associated pulmonary toxicity and potential to impair immunity against respiratory infections.

Immunity against respiratory pathogens, particularly viral pathogens is dependent on a robust CD4 and CD8 T cell responses responsible for viral clearance. CD4 and CD8 T cells then develop memory responses to protect against reinfection. T cell memory also provides protection against infection after vaccination. We asked whether vaping exposure affects T cell responses to influenza infection. We exposed animals for 8 weeks to base components of vape devices, including propylene glycol (PG), vegetable glycerin (VG), and a novel cutting agent, phytol, then assessed immune responses to influenza. We find that PGVG and phytol exposure alters pulmonary function, promotes proteomic changes to the lung, and modify immune cell subsets in the lung. We also find that PGVG and phytol exposure alters T cell responses to influenza infection, particularly T cell memory protection against heterologous infection. These results suggest that vaping affects immune responses to respiratory influenza infection, including T cell memory responses. Effects of vaping on T cell memory may have wide ranging consequences for T cell mediated protection against other respiratory disease including SARS-CoV-2 and protection after vaccination.

Supported by NIH (P20 GM121176; P20GM130422)

Adapting Mindfulness-Based Interventions for Residents of Long-Term Care Facilities

Mindfulness-based interventions (MBIs) have received increased clinical attention in recent years. While some MBI research has focused on healthy older adults, research with more emotionally and physically vulnerable populations, such as residents of long-term care facilities (LTCFs), is lacking. The current paper presents quantitative and qualitative results from a pilot study of an individual MBI designed for residents of LTCFs. Participants included 8 residents from two skilled nursing facilities in the southeastern United States. Data were collected between October 2016 through June 2017. A modified MBI is proposed with specific adaptations for LTCF residents. Recommended adaptations for LTCFs include a shift from a group to an individual format, individual weekly instructor–participant meetings, removal of the yoga and full-day silent retreat and shortening the duration of the formal practices. The current study found that these adaptations result in an individual MBI that is accessible to most LTCF residents while still providing the associated benefits of traditional group MBIs.

A 3-month, randomized, double-blind, placebo-controlled study to evaluate the safety and efficacy of a highly optimized, capacitively coupled, pulsed electrical stimulator in patients with osteoarthritis of the knee

OBJECTIVE

To investigate the efficacy and safety of a capacitively coupled, pulsed electrical stimulation device in treating knee osteoarthritis (OA).

DESIGN

Fifty-eight outpatients with moderate to severe OA of the knee entered a 3-month, double-blind, placebo-controlled trial, using either an active or placebo device at home for 6 to 14 h/day. Outcome measures included a patient global evaluation, a patient report of knee pain severity, and the Western Ontario and McMaster Universities (WOMAC) questionnaire.

RESULTS

Active treatment provided superior outcomes between baseline and 3-month follow-up measurements: 50.6% greater improvement than placebo in patient global (P=0.03), 31.2% in patient pain (P=0.04), 25.1% in WOMAC stiffness (P=0.03), 29.5% in WOMAC function (P=0.01), 19.9% in WOMAC pain (P=0.11), and 27% in total WOMAC (P=0.01). The percent of patients who improved by more than 50% was 38.5 active vs 5.3 placebo in patient global (P=0.01), 43.6 vs 15.8 in patient pain (P=0.04), 38.5 vs 10.5 in WOMAC pain (P=0.03), 28.2 vs 5.3 in WOMAC stiffness (P=0.08), 23.1 vs 5.3 in WOMAC function (P=0.14), and 23.1 vs 5.3 in total WOMAC (P=0.14). Twenty-one percent of placebo and 18% of actively treated patients developed a transient rash at the electrode sites. No other adverse device effects were reported.

CONCLUSION

A highly optimized, capacitively coupled, pulsed electrical stimulus device significantly improved symptoms and function in knee OA without causing any serious side effects.

In vitro dephosphorylation of alpha-crystallin is dependent on the state of oligomerization

alphaA- and alphaB-crystallin, members of the small heat shock protein family, are present in lens cell extracts as large aggregates. Both alpha-crystallins are found partially phosphorylated. This study tests the ability of five phosphatases (protein phosphatase PP1, PP2A, PP2B, alkaline and acid phosphatases) to dephosphorylate alphaA- and alphaB-crystallin in vitro. Activity of a phosphatase was dependent on the size of the aggregate. Each of the phosphatases tested showed different specificity and efficiency towards alphaA- and alphaB-crystallins, which depended on the oligomeric state of the alpha-crystallin aggregate. Alkaline phosphatase dephosphorylated both alphaA- and alphaB-crystallin. The reaction was faster when alpha-crystallin was in a tetrameric form. PP2A dephosphorylated primarily alphaA-crystallin but only after the conversion of alpha-crystallin to tetramers. PP1 and PP2B did not dephosphorylate either alphaA- or alphaB-crystallins present as large aggregates but could not be tested on the lower molecular weight form of alphaA-crystallin. Acid phosphatase dephosphorylated both alphaA- and alphaB-crystallin. The results suggest that an important relationship exists between the structure of alpha-crystallin and its level of phosphorylation in the cell.

A lens glutathione S-transferase, class mu, with thiol-specific antioxidant activity

A protein that protected against the thiol-mediated metal-catalysed oxidative inactivation of enzymes but did not protect against the ascorbate-dependent oxidation system was extensively purified from bovine lens. The protein was a homodimer (pI 7) of 26 kDa subunits. Sixty per cent of the protein sequence was obtained by Edman sequencing and by sequence comparison was determined to be a class mu glutathione S-transferase (GST). The sequence of the enzyme is homologous to, but not identical to, that of any other class mu GST in the databanks. The complete protein sequence was derived from sequencing the cDNA and is the first complete sequence of a class mu GST from a bovine tissue. The enzyme was cloned and expressed in E. coli. The recombinant GST also protected against the thiol-mediated oxidative inactivation of enzymes but with lower activity than the native enzyme did and the recombinant GST had a comparable higher K(m)for GSH. The native and recombinant enzymes possessed similar low level peroxidase activity utilizing alkyl and cumene peroxides as substrates, but exhibited little activity against hydrogen peroxide.

An atypical form of alphaB-crystallin is present in high concentration in some human cataractous lenses. Identification and characterization of aberrant N- and C-terminal processing

Two unique polypeptides, 22.4 and 16.4 kDa, were prominent in some human cataracts. Both proteins were identified as modified forms of the small heat shock protein, alphaB-crystallin. The concentration of total alphaB-crystallin in most of these cataracts was significantly increased. The 22.4-kDa protein was subsequently designated as alphaB(g). Mass spectrometric analyses of tryptic and Asp-N digests showed alphaB(g) is alphaB-crystallin minus the C-terminal lysine. alphaB(g) constituted 10-90% of the total alphaB-crystallin in these cataracts and was preferentially phosphorylated over the typical form of alphaB-crystallin. Human alphaB(g) and alphaB-crystallin were cloned and expressed in Escherichia coli. The differences in electrophoretic mobility and the large difference in native pI values suggest some structural differences exist. The chaperone-like activity of recombinant human alphaB(g) was comparable to that of recombinant human alphaB-crystallin in preventing the aggregation of lactalbumin induced by dithiothreitol. The mechanism involved in generating alphaB(g) is not known, but a premature termination of the alphaB-crystallin gene was ruled out by sequencing the polymerase chain reaction products of the last exon for the alphaB-crystallin gene from lenses containing alphaB(g). The 16.4-kDa protein was an N-terminally truncated fragment of alphaB(g). The high concentration of alphaB-crystallin in these cataracts is the first observation of this kind in human lenses.

Betaine-homocysteine methyltransferase is a developmentally regulated enzyme crystallin in rhesus monkey lens

We describe herein the characterization of a major 45-kDa protein from the soluble betaH-crystallin fraction of rhesus monkey (Macaca mulatta) lens. Based on partial peptide sequence, immunoreactivity, and enzymatic activity, this protein has been identified as betaine-homocysteine S-methyltransferase (BHMT: EC 2.1.1.5), an enzyme that catalyzes the methylation of homocysteine using either betaine or thetins as methyl donors. This protein was found to be expressed abundantly in the nuclear region of the monkey lens, reaching approximately 10% of the total nuclear protein, but was barely detectable in the epithelium and cortex regions of the lens. Because the nucleus represents the early embryonic and fetal stages of lens development, we infer that BHMT expression in the lens of the eye is developmentally regulated. By virtue of its high abundance, BHMT can be considered an enzyme crystallin (psi-crystallin). This is the first enzyme crystallin to be found in primate lenses.

Oxidative modification of aldose reductase induced by copper ion. Factors and conditions affecting the process

Bovine lens aldose reductase (ALR2) is inactivated by copper ion [Cu(II)] through an oxygen-independent oxidative modification process. A stoichiometry of 2 equiv of Cu(II)/enzyme mol is required to induce inactivation. While metal chelators such as EDTA or o-phenantroline prevent but do not reverse the ALR2 inactivation, DTT allows the enzyme activity to be rescued by inducing the recovery of the native enzyme form. The inactive enzyme form is characterized by the presence of 2 equiv of bound copper, at least one of which present as Cu(I), and by the presence of two lesser equivalents, with respect to the native enzyme, of reduced thiol residues. Data are presented which indicate that the Cu-induced protein modification responsible for the inactivation of ALR2 is the generation on the enzyme of an intramolecular disulfide bond. GSH significantly interferes with the Cu-dependent inactivation of ALR2 and induces, through its oxidation to GSSG, the generation of an enzyme form linked to a glutathionyl residue by a disulfide bond.

Caught in the cross fire of change: nurses' experience with unlicensed assistive personnel

Under tremendous pressure to contain costs, most U.S. hospitals are radically altering the composition and skill mix of their staff, thinning their skilled registered nurse (RN) ranks, and often substituting them with minimally trained, lower paid, unlicensed assistive personnel (UAP). Twelve staff nurses were interviewed to illuminate the experience of working with UAP, who function largely in untested, expanded roles. Only two nurses viewed this experience positively; the rest were either opposed to or had strong reservations about UAP use. Confusion and emotional turmoil predominated as these nurses struggled to maintain safe, comprehensive care with the assistance of UAP who were often ambivalent and sometimes dangerously inept.

Guinea pig and bovine zeta-crystallins have distinct functional characteristics highlighting replacements in otherwise similar structures

zeta-Crystallin, a major cytosolic protein of guinea pig lens, has been characterized as an NADPH:quinone oxidoreductase (EC 1.6.5.5) [Rao et al. (1992) J. Biol. Chem. 267, 97-103]. A bovine lens homolog with 83% sequence identity was found to have very different functional characteristics. While the bovine lens zeta-crystallin exhibits similar physicochemical properties, such as molecular weight, hydropathy profile, and predicted secondary structure, and exhibits strong immunological cross-reactivity with the guinea pig and human lens zeta-crystallins, it shows minimal quinone oxidoreductase activity. On the other hand, bovine lens zeta-crystallin, but not guinea pig zeta-crystallin, showed a strong binding affinity to single-stranded DNA (ssDNA) that could be competed with NADPH, the specific cofactor of zeta-crystallin. NADH and dextran sulfate did not affect this characteristic of bovine zeta-crystallin and the enzyme showed no binding affinity for the heparin-Ultragel A4R. Two-dimensional electrophoresis of bovine lens zeta-crystallin showed a distinct pattern of posttranslational charge modification as compared to the guinea pig protein. Alignment of eight zeta-crystallin sequences, and computer modelling of the bovine and human forms based on the crystallographically analyzed Escherichia coli form, suggest that if loss of a functional residue accounts for the lowered catalytic activity of the bovine protein, Tyr 52 of the E. coli enzyme, and the equivalent Tyr present in all known mammalian forms except the bovine, is the likely candidate. In the bovine form this tyrosine is replaced by histidine.

Calcium ATPase activity and membrane structure in clear and cataractous human lenses

PURPOSE

Maintenance of calcium homeostasis is imperative for the clarity of the lens. Ca(2+)-ATPase is essential for the removal of cytosolic calcium, either across the plasma membrane or through intracellular organelles such as the endoplasmic reticulum. In this study, membranes prepared from clear lens epithelium were compared to membranes prepared from cataractous lens epithelium.

METHODS

Human lens membranes were prepared by a protocol utilizing homogenization and centrifugation. Ca(2+)-ATPase activity was measured biochemically using Gamma-32P labeled ATP. Lipid order was measured using infrared and Raman spectroscopy.

RESULTS

Ca(2+)-ATPase activity was similar in membranes prepared from cataractous lenses that were classified as nuclear subcapsular, nuclear and brunescent cataracts. Ca(2+)-ATPase activity was approximately 50% less in membranes prepared from cataractous lenses in comparison to clear lenses. Because clear lenses from Indian donors was unavailable, clear human lenses were used as a qualitative control for the measurement for Ca(2+)-ATPase activity. Lipid order was measured in lens fibers from cataractous and clear lenses from the United States donors. Lipid order increased from 55% in the hydrocarbon chains from clear lens fibers to 84% in cataractous lens fibers.

CONCLUSIONS

These findings support the hypothesis that membranes are deranged in cataractous tissue, which should lead to altered levels of calcium.

Targeted disruption of the mouse alpha A-crystallin gene induces cataract and cytoplasmic inclusion bodies containing the small heat shock protein alpha B-crystallin

alpha A-crystallin (alpha A) and alpha B-crystallin (alpha B) are among the predominant proteins of the vertebrate eye lens. In vitro, the alpha-crystallins, which are isolated together as a high molecular mass aggregate, exhibit a number of properties, the most interesting of which is their ability to function as molecular chaperones for other proteins. Here we begin to examine the in vivo functions of alpha-crystallin by generating mice with a targeted disruption of the alpha A gene. Mice that are homozygous for the disrupted allele produce no detectable alpha A in their lenses, based on protein gel electrophoresis and immunoblot analysis. Initially, the alpha A-deficient lenses appear structurally normal, but they are smaller than the lenses of wild-type littermates. alpha A-/- lenses develop an opacification that starts in the nucleus and progresses to a general opacification with age. Light and transmission electron microscopy reveal the presence of dense inclusion bodies in the central lens fiber cells. The inclusions react strongly with antibodies to alpha B but not significantly with antibodies to beta- or gamma-crystallins. In addition, immunoblot analyses demonstrate that a significant portion of the alpha B in alpha A-/- lenses shifts into the insoluble fraction. These studies suggest that alpha A is essential for maintaining lens transparency, possibly by ensuring that alpha B or proteins closely associated with this small heat shock protein remain soluble.

Analysis of small GTP-binding proteins of the lens by GTP overlay assay reveals the presence of unique GTP-binding proteins associated with fiber cells

Low molecular weight GTP-binding proteins are molecular switches which are thought to play pivotal roles in cell growth, differentiation, cytoskeletal organization and vesicular trafficking. In this study, members of this family of proteins have been identified and characterized in the eye lens, for the first time. [alpha 33P]GTP blot overlay assays of monkey and human lens water soluble and membranous insoluble fractions revealed the presence of specific GTP-binding proteins in the range of 20-30 kDa (small GTPases) in both fractions, with much higher amounts in the membranous insoluble fraction. In the insoluble fraction, in addition to 20-30 kDa GTPases, there are three distinct GTP-binding proteins, ranging from 33-45 kDa. The small GTPases (20-30 kDa) were present throughout the lens in epithelium, cortex and nucleus, while the 33-45 kDa GTP-binding protein bands were exclusively associated with the cortex and nucleus (fiber cells). Analysis of lens fractions by two-dimensional electrophoresis, immunoprecipitation using monoclonal and sequence specific polyclonal antibodies and C3 exoenzyme mediated ADP-ribosylation demonstrated the presence of Ras, Rap, Rho, Rac, Rab and several other small GTPases. The 33-45 kDa GTP-binding proteins that are associated with lens fiber cells appear to be distinct from the small GTPases and from heterotrimeric GTPases, and were not detected in brain or heart tissue. The presence of different complements of GTP-binding proteins in lens fibers and epithelial, cells suggests their involvement in important regulatory functions, possibly related to cell growth, differentiation and organization of the cytoskeleton.

Oxidative stress increases production of beta-amyloid precursor protein and beta-amyloid (Abeta) in mammalian lenses, and Abeta has toxic effects on lens epithelial cells

Many amyloid diseases are characterized by protein aggregations linked to oxidative stress. Such diseases including those of the brain, muscle, and blood vessels exhibit plaques containing beta-amyloid (Abeta). Here we demonstrate that Alzheimer's precursor protein (betaAPP) and A beta are present at low levels in normal lenses and increase in intact cultured monkey lenses treated with H2O2 or UV radiation (known cataractogenic agents), and with phorbol 12-myristate 13-acetate. AP-1 factor binding, shown by others to up-regulate betaAPP expression, increased in the monkey lenses treated with H2O2, UV radiation, or phorbol 12-myristate 13-acetate and paralleled the increase in betaAPP expression. Rat lenses exposed to oxidative stress showed increased betaAPP in the anterior epithelium and cortex. Incubation of cultured rabbit lens N/N1003A epithelial cells with Abeta induced inclusions and vacuoles and was cytotoxic. Abeta cross-reacting protein was readily detected in the cortex of a cataractous human lens. Our data show that betaAPP and Abeta increase in mammalian lenses as part of a response to H2O2 or UV radiation and suggest that they may contribute to the mechanism by which oxidative damage leads to lens opacification.

Mixed-lineage acute myeloid leukemia associated with a suprasellar dysgerminoma

An association between primary mediastinal germ cell tumors and hematologic malignancies has been recognized since 1985. We present a patient with a suprasellar germ cell tumor and an associated leukemia. A 20-year-old black female presented in December 1987 with a 6-month history of headaches and weight loss, confusion, polyuria, and polydipsia. Evaluation revealed hypernatremia, normal neurologic examination except poor recall, and an enhancing inhomogeneous suprasellar mass on cranial computed tomography. Biopsy of the mass diagnosed a dysgerminoma, which was treated with craniospinal radiation. In February 1988, the patient developed pancytopenia, which resolved with discontinuation of cimetidine and phenytoin. She did well until June 1988 when she presented with skin lesions over the trunk and extremities. Skin biopsy revealed a leukemic infiltration. She was admitted with a WBC 1,500/microliter (without blasts), Hb 11.6 g/dl, PLT 210,000 microliter. Bone marrow biopsy revealed hypercellularity with 50% blasts, demonstrating mixed-lineage acute myeloblastic leukemia (myelomonocytic-M4; megakaryoblastic-M7). The patient was induced with a standard Ara-C/daunorubicin regimen. Two weeks postinduction, she became septic and expired. An autopsy demonstrated leukemic involvement of the spleen, liver, bone marrow, and skin, without residual dysgerminoma. This represents the first reported case of suprasellar dysgerminoma associated with a mixed-lineage leukemia not related to chemotherapy.

Gunshot wounds to the spine

Gunshot wounds to the spine are becoming more prevalent, especially in urban areas. Neurologic injury can occur even if the projectile does not penetrate the spinal canal. Initial treatment should consist of stabilizing the patient's medical condition followed by a careful neurologic examination. Spinal stability can be determined from plain radiographs and CT scan, with the overwhelming majority of injuries being stable. Retained bullets rarely cause problems of delayed infection, late neurologic decline, or lead toxicity, eliminating the need for prophylactic bullet removal; however, in the thoracolumbar spine, removal of bullet fragments lodged within the spinal canal has been shown to significantly improve neurologic recovery.

Hydration of gamma-crystallins

Four fractions of gamma-crystallins, B(II), C(IIIb), D(IIIa) and E(IVa), were isolated from bovine lenses. The hydration properties of each fraction were measured as a function of protein concentration. The freezable water content was obtained by differential scanning calorimetry and the total water content by thermogravimetric analysis. The difference yields the non-freezable (bound) water content of the crystallins. At physiological protein concentrations the order of the bound water content was C(IIIb) > D(IIIa) >> E(IVa) > B(II). This order was reversed between C and D and between B and E at low protein concentrations. This trend was evident whether the bound water was calculated as a percentage of the total water or as quantity per gram of gamma-crystallin.

Thiol-dependent metal-catalyzed oxidation of bovine lens aldose reductase. I. Studies on the modification process

Bovine lens aldose reductase (alditol: NADP+ oxido-reductase, EC 1.1.1.21) undergoes a thiol-dependent oxidative modification catalyzed by the Fe(II)/Fe(III) redox system. The enzyme is inactivated by various oxygen radical generating systems. However, addition of 2-mercaptoethanol to the oxygen radical generating systems resulted in an initial increase followed by a decrease in the activity of aldose reductase. The net maximal increase in the enzyme activity was observed with 3 mM 2-mercaptoethanol, 0.3 mM FeSO4, and 0.9 mM EDTA, either with or without 1 mM hypoxanthine and 37 mU/ml of xanthine oxidase. The formation of the stable, activated intermediate, ARa, appears to proceed through the reaction between the enzyme and the oxidized form of 2-mercaptoethanol which in the presence of iron, forms a mixed disulfide with a cysteine residue. Reduction of ARa with dithiothreitol released 0.7 mol of 2-mercaptoethanol per mole of enzyme and converted it to a form that resembled the native aldose reductase.

On the stability of bovine gamma II crystallin

Bovine gamma II crystallin, undergoes structural changes when lyophilized. The lyophylized powder does not readily dissolve in buffer, although it can be taken up in distilled water. The lyophylized sample, as opposed to a sample concentrated by vacuum distillation at 30 degrees C, does exhibit different migration on isoelectric focusing gels. The hydration and denaturation properties of the two preparations are different. The lyophylized sample possesses a higher non-freezable water content as a function of concentration than its counterpart. The lyophylized sample also shows less denaturation in differential scanning calorimetry scans, up to 110 degrees C, than its counterpart. This indicates that lyophylization may induce a slight denaturation, due to structural-conformational change. On the other hand, the CD spectra of lyophylized and non-lyophylized gamma II crystallins do not differ significantly. This implies that the conformational changes upon lyophylization do not involve the secondary structure of gamma II crystallin.

Two-dimensional gel electrophoretic analysis of human lens proteins

Human lens proteins from clear lenses were separated and identified using two-dimensional polyacrylamide electrophoresis. Isoelectric focusing, both equilibrium and non-equilibrium, was performed in the first dimension and SDS electrophoresis in the second dimension. Proteins were identified by Western blotting and sequencing techniques and by comparison with patterns obtained with purified crystallin fractions. Analyses were performed on total urea soluble proteins of lenses varying in age from fetal to 73 yr. Several hundred protein spots representing crystallins, cytoskeletal proteins and enzymes were resolved in the fetal lens. In the older lenses there was a dramatic increase in the number of protein species in the molecular weight range of the crystallins and a reduced number of discrete protein species visible at molecular weights greater than 50,000. Conversely, a number of proteins below approximately 15 kDa were visible even in the fetal lens. The number and amount of polypeptides in this molecular weight range were increased in the older lenses. Many of these low molecular weight species could be assigned to either the alpha-, beta- or gamma-crystallin fractions. An age dependent increase in the number of acidic species of both crystallins and other proteins, such as, glyceraldehyde 3-phosphate dehydrogenase was observed as well as the loss or mobility change of gamma-crystallin. Two-dimensional gel electrophoresis provides a sensitive and practical technique for characterizing all of the proteins of the human lens.

Proximal femoral resection and myocutaneous flap for treatment of pressure ulcers in spinal injury patients

A radical proximal femoral resection and flap procedure were used to treat infected trochanteric ulcers communicating with the hip joint in patients with spinal cord injuries. Postoperatively, femoral motion and pistoning were prevented by an abduction pillow and antispasmodic medication. The results of 25 patients and 26 hips with an average follow-up of 14.5 months are presented. Wound closure was achieved in 24 of 26 hips while patients were in the hospital. All wounds eventually healed, and all infections were eradicated. Seven patients had associated clinically significant heterotopic ossification. All of these patients had elimination of infection and postoperative restoration of wheelchair sitting. It is concluded that this radical procedure is extremely effective in treating deep, recalcitrant trochanteric ulcers around the hip. The procedure may potentially be used to treat heterotopic ossification about the hip and restore sitting capability in patients with spinal cord injuries.

zeta-Crystallin is a major protein in the lens of Camelus dromedarius

Camel (Camelus dromedarius) lenses contain a protein with an apparent subunit Mr 38,000 that constitutes approximately 8-13% of the total protein. The protein has been purified and has a native Mr 140,000 as determined by gel filtration. This is consistent with its being a tetramer. The protein reacts with antibodies raised against both guinea pig zeta-crystallin and peptides corresponding to amino acids 1-10 and 295-308, but not to antibodies raised against amino acids 320-328 of zeta-crystallin. Based on these criteria it is concluded that this protein, which is a major constituent of camel lens, is zeta-crystallin. This may be the first example of a protein (enzyme) being independently utilized as a crystallin in the lens of species from two mammalian orders.

Effects of naphthalene metabolites on cultured cells from eye lens

Naphthalene is toxic to the eye and results in opacification of the lens. To investigate the metabolic events that may be occurring in the lens epithelial cells, a cell line of lens from a transgenic mouse was incubated with various metabolites of naphthalene. Naphthoquinone at 50 microM was toxic to most cells with a depletion of glutathione levels noted within 6 h of incubation. At 10 microM, naphthoquinone caused an increase in specific activity of the enzyme DT-diaphorase. This enzyme is thought to be a defense against quinones since semiquinone formation is thought to be lessened. Naphthalene-1,2-dihydrodiol at 50 microM also caused an increase in the specific activity of the DT-diaphorase, while at 10 microM no apparent change occurred in the cells. Although there was evidence of metabolic alterations in the cells with the metabolites of naphthalene, the protein profile by two-dimensional gel electrophoresis did not change and there was no indication of an increase in carbonyl formation in the soluble proteins of the cells. These experiments indicate that the metabolites of naphthalene can cause alteration in the metabolism of the lens cells but may not cause apparent changes in the major proteins within the lens epithelium.

Role of site-specific, metal-catalyzed oxidation in lens aging and cataract: a hypothesis

The evidence reviewed here supports the hypothesis that metal catalyzed oxidation reactions occur in the lens and may make a significant contribution to the changes seen in the lens with age and in cataract formation. The major support for this hypothesis is as follows. (1) All of the components of the non-enzymic metal catalyzed oxidation systems are present in the lens normally. Ascorbate, glutathione and oxygen are present in much lower concentrations. Although, even at low concentrations, the reactions could occur over many years with significant consequences. Components of some of the enzymic systems are also present, although primarily in the epithelial layer and outer cortical region. Copper and iron levels may be increased in some cataracts. (2) Protein carbonyl derivatives are increased in both aging and cataractous lenses. Amino acid-derived protein carbonyl derivatives have only been demonstrated in oxidative reactions derived from oxygen radical generation, particularly those catalyzed by metal-catalyzed oxidation systems. (3) Treatment of isolated bovine crystallins with metal catalyzed oxidation systems generates modifications similar to those found in vivo. The proposed mechanism of site-specific metal catalyzed oxidation appears to be a feasible mechanism of oxidation in the lens, and verification of the mechanism requires further study. Although the focus of this manuscript has been on the oxidative modification induced in proteins,m oxidative damage to DNA or membrane resulting from similar mechanisms may also play an important role in alteration of lens function during aging and cataractogenesis.

Bovine lens aldose reductase: identification of two enzyme forms

Two structurally different forms of bovine lens aldose reductase have been identified. Freshly prepared lens extracts contain an unactivated "b form" (ARb) which is sensitive to inhibition by Sorbinil. Upon incubation of the extracts with oxygen radical generating systems, ARb is converted to a more active "a form" (ARa), which is not inhibited by Sorbinil. ARa and ARb were purified to electrophoretic homogeneity.

Analysis of the proteins of calf and cow trabecular meshwork: development of a model system to study aging effects and glaucoma

The proteins from the trabecular meshwork (TM) of calf and cow eyes were analysed to determine if differences in composition were present and to examine whether this tissue could be used as a framework for the study of glaucoma. Differences in polypeptide composition or amount of protein could be detected with extractions using either acetic acid, neutral buffers and urea, or guanidine hydrochloride. In general, the results suggest that an aggregation of proteins may be occurring with aging. The acid-soluble fraction of both calf and cow TM resembled older human TM specimens with the most prominent protein around 68 kD. To test the utility of the bovine TM system, a mixed function oxidation system was used to determine how the proteins of the TM would react to oxidative stress. Aggregation of the proteins in calf TM as well as actin could be demonstrated, consistent with the idea that the aggregation seen in the cow TM might be the result of oxidation of this tissue. The present study lays a foundation for future work on bovine TM and is consistent with the hypothesis that aging changes in this tissue might be a result of oxidative processes.

The oxidative modification of lens proteins

In summary, in vitro oxidation of lens crystallins mimics many of the post-translational modifications observed with age and in cataracts These results lend further support to earlier proposals that oxidation is a key factor in cataract formation. The extent to which ascorbate contributes to the oxidation reactions in vivo is not known. In addition to the data presented here that ascorbate can produce these effects in vitro, other observations support the possibility that under certain conditions ascorbate may be involved in the generation of reactive oxygen species in the lens. Using electron spin resonance the ascorbyl radical can be detected early in nuclear cataract formation, and there appears to be a decrease in total ascorbic acid (reduced and oxidized), suggesting further oxidation of ascorbate. Iron and copper are both present in mammalian lenses, and there are reports of increased copper levels in the lens with age and in cataracts. Increased metal ion concentrations would facilitate these oxidative processes.

Aging effects of vitamin C on a human lens protein produced in vitro

Human lens gamma-crystallin obtained from the expression of a gene construct stably integrated into mouse L cells was incubated with ascorbate in the presence of iron and oxygen. The resulting oxidation of the gamma-crystallin led to more acidic species of this protein. These alterations were similar to the changes seen with aging in the human lens. The results suggest that oxidation of lens crystallins may be responsible for the changes seen on aging and cataract development and that ascorbate may contribute to these alterations.

Structural changes in bovine lens crystallins induced by ascorbate, metal, and oxygen

Ascorbate, Fe3+, or Cu2+ and oxygen induced the oxidation of bovine lens crystallins. The modifications mimicked those that occur in the lens with aging. The modifications included the formation of nondisulfide crosslinks in alpha- and beta H-crystallin and the cleavage of alpha-, beta H-, and the low molecular weight crystallin fractions. In all three fractions, there was a loss of the more basic protein species and an increase in the more acidic species. Nontryptophan fluorescence with emission spectra between 400 and 500 nm was produced in beta H-crystallin. Cu2+ was less effective than Fe3+ in catalyzing the modification of beta H- and gamma-crystallin. Both metal ions were equally effective in catalyzing the modification of alpha-crystallin.

Phosphorylation of lens fiber cell membrane proteins

Two intrinsic membrane proteins of calf lens fiber cells can be phosphorylated by a soluble bovine lens cAMP-dependent protein kinase and rabbit muscle cAMP-dependent protein kinase. After electrophoresis of the phosphorylated membranes, 32P comigrates with the lens main intrinsic protein at 26-27 kDa and with a minor band of protein that migrates at 19-20 kDa. 32P is also found with proteins that, based on the molecular sizes, are likely multimers of the 19-kDa and 26-kDa proteins. Upon boiling in NaDodSO4, all the radioactivity is found at the top of the gel, suggesting that both phosphoproteins are intrinsic membrane proteins. Serine is the only phospho amino acid detected in both proteins regardless of the source of protein kinase. The phosphorylation sites of both proteins are lost upon cleavage with trypsin and chymotrypsin. The smaller phosphoprotein is likely not a crystallin, because antibodies directed against alpha-, beta-, or gamma-crystallins do not cross-react with the 19-kDa protein. The 19-kDa 32P-labeled protein does not migrate coincident with calf alpha-crystallin.

A comparison of the phosphorylated and unphosphorylated forms of isocitrate dehydrogenase from Escherichia coli ML308

NADP+ can protect active isocitrate dehydrogenase against attack by several proteases. Inactive phosphorylated isocitrate dehydrogenase is much less susceptible to proteolysis than the active enzyme, and it is not protected by NADP+. The results suggest that binding of NADP+ to, or phosphorylation of, active isocitrate dehydrogenase induces similar conformational states. Fluorescence titration experiments show that NADPH can bind to active but not to inactive isocitrate dehydrogenase. It is suggested that the phosphorylation of isocitrate dehydrogenase may occur close to its coenzyme binding site.

Microbiology of superficial and deep tissues in infected diabetic gangrene

In the current study, it is shown that, in the lesions of diabetic gangrene, there are usually mixed flora of two or more organisms. The organisms isolated from the presenting lesion may only partially reflect the organisms found in the deep tissues. Of the 58 cultures from the deep tissues, 11 of the isolates were anaerobes, but those anaerobes were never isolated as a pure culture. Bacterial synergism probably plays a role in infected diabetic gangrene. Maximizing the reduction of systemic infection and local cellulitis by elevation and appropriate antibiotic therapy results in improved wound healing in amputations of the lower extremities in patients with diabetic gangrene. However, apparent from this study, antibiotic therapy does not eradicate the organisms in the deep tissue, and surgical procedures are usually required for definitive treatment. Material from the surgically removed infected tissue should always be cultured for identification of existing organisms. When indicated, appropriate adjustment of antibiotic therapy, based upon these findings, should be prescribed.

Microbiology of deep tissue in diabetic gangrene

Information on the incidence and nature of the causative organisms in the infected tissues of patients with diabetic gangrene is scanty. Studies in which material for culture was obtained from the presenting lesion reveal multiple organisms in host isolates. No data are available regarding the bacterial flora of the deep infected tissue itself, uncontaminated by surface organisms. In this investigation 58 specimens from 52 patients were obtained utilizing aerobic and anaerobic culture techniques. In the surgical theater, material was obtained from the infected deep tissues using careful aseptic dissection techniques. All patients had been on antibiotic therapy from 2 to 10 days before the study. An average of 2.3 organisms per specimen was found. The predominant organisms were Proteus sp., Enterococcus, Staphylococcus aureus, and other enterobacteriacae in that order. Anaerobes were isolated in 27 per cent of cases, but never as the only organism. Prior antibiotic therapy did not eradicate infection in infected diabetic gangrene.

Surgical correction of gait abnormalities following stroke

Lower extremity abnormalities in stroke patients can be reliably improved by surgery. Surgical treatment is most frequently recommended for patients with: equinovarus; toe curling; excessive hip and knee flexion; limb scissoring. Unless the patient's disability is so severe he cannot walk, the operation is performed not before 6 and preferably not until 9 months after sroke.

Fluorescein colchicine. Synthesis, purification, and biological activity

The synthesis of a fluorescent colchicine derivative permits the localization of colchicine-binding receptors in cells. Fluorescein colchicine (FC) was prepared by the addition of fluorescein isothiocyanate to deacetyl colchicine. The product, FC, was separated from the reactants by thin-layer chromatography (TLC). The purity of FC was demonstrated by TLC, UV spectral analysis, and analysis of the kinetics of photodecomposition. FC inhibited [3H] colchicine binding to purified brain tubulin. The biological activity of FC was compared to the activity of unlabeled colchicine on mitosis, motility, secretion, and myogenesis. The effects of FC were identical to those of unlabeled colchicine in all biological systems tested. The results demonstrate that FC may be substituted for colchicine in biological experiments without significant loss in specificity or effectiveness.

A reexamination of the reaction between colchicine and tubulin

The rate of reversible dissociation of the colchicine-tubulin complex has been determined for purified porcine brain tubulin and for sea urchin tubulin from 100,000 times g supernatant. The rate constant, which is essentially the same for both species, is extremely slow; it corresponds to a half-life of approximately 36 hours for the reaction. This rate was the same whether or not sucrose was present, and was not influenced by low concentrations of vinblastine or by millimolar concentrations of colchicine. The association rate constant was determined for porcine brain tubulin with and without CaCl2. The sample without CaCl2 had been maximally polymerized prior to the addition of colchicine. A 4.7-fold difference was observed between the association rate constants under these two conditions. Equilibrium constants calculated from the measured rate constants are 5 to 20 times greater than directly measured values; this suggests that the interaction of microtubules and colchicine is more complex than was previously thought.