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PubMedDate not supplied

Dietary supplementation with antioxidants improves functions and decreases oxidative stress of leukocytes from prematurely aging mice.

OBJECTIVES: Aging is accompanied by chronic inflammation and oxidative stress, which lead to a marked impairment of immune function and therefore increased mortality. This study assessed the effect of dietary supplementation, for 15 wk, with 5% and 20% (w/w) of biscuits enriched with nutritional doses of vitamins C and E, zinc, selenium, and beta-carotenes on function and oxidative stress parameters of peritoneal leukocytes from middle-aged, prematurely aging mice (PAM) and non-prematurely aging mice (NPAM). METHODS: After supplementation we measured leukocyte functions (adherence, chemotaxis, phagocytosis, intracellular reactive oxygen species levels, lymphoproliferation, natural killer activity, and interleukin-2 release), antioxidant defenses (superoxide dismutase, glutathione peroxidase, and reduced glutathione), oxidant compounds (extracellular O(2)(-), glutathione disulfide, glutathione disulfide/reduced glutathione ratio, tumor necrosis factor-alpha, nitric oxide, and prostaglandin E(2)), and lipid and DNA oxidative damage, measured by malondialdehyde and 8-oxo,7,8-dihydro-2'-deoxyguanosine levels, respectively. RESULTS: In general, leukocyte functions were improved and redox homeostasis was restored after intake of antioxidants. In consequence, malondialdehyde and 8-oxo,7,8-dihydro-2'-deoxyguanosine in PAM and NPAM were strikingly decreased after 5% and 20% supplementation (malondialdehyde, P < 0.001 in PAM; P < 0.01 in NPAM after both treatments; 8-oxo,7,8-dihydro-2'-deoxyguanosine, P < 0.01 after 5% supplementation and P < 0.001 after 20% supplementation in PAM and NPAM). Moreover, the effect of the antioxidants was stronger in PAM than in NPAM, and 20% supplementation was more effective than 5%. CONCLUSION: Our data suggest that improvement of leukocyte function and restoration of redox balance after consumption of adequate levels of antioxidants from adulthood may be useful to attain healthy aging, especially in animals with premature aging.

Aging↗

PubMed2006

Primary acquired melanosis of the conjunctiva.

BACKGROUND: Primary acquired melanosis (PAM) presents as a unilateral patchy area of conjunctival pigmentation mostly found in middle-aged or elderly white patients. Because PAM has the potential of becoming malignant, it is important to recognize PAM and to rule out other causes of pigmented lesions. The presence or absence of atypia is helpful in determining the potential for malignancy, because PAM without atypia is usually benign, whereas PAM with atypia may convert into a conjunctival melanoma. If atypia is present, the presence or absence of epithelioid cells and the pattern of intraepithelial growth are the main factors in determining the likelihood of neoplastic transformation. However, atypia can only be determined with histopathologic examination. Therefore, a biopsy is usually recommended. CASE REPORT: A 72-year-old white man presented for his annual examination with no visual complaints. His ocular history was remarkable for early cataracts and for a choroidal nevus. Slit lamp examination found a large dark area of elevated conjunctival pigmentation at the medial canthus that extended onto the superior bulbar conjunctiva and superior palpebral conjunctiva in the left eye. No conjunctival pigmentation had been noted previously. Results of a biopsy indicated primary acquired melanosis with atypia. The lesion was surgically excised, and the conjunctiva was reconstructed with an amniotic membrane graft. The patient was subsequently treated with topical 5-fluorouracil chemotherapy. There have been no signs of recurrence to date after his treatment. CONCLUSION: Because of the potential for malignancy, biopsies of all cases of primary acquired melanosis are indicated. If atypia is present, treatment options include local excision, cryotherapy, and topical chemotherapy.

Aged↗

PubMed2006

Quantitative digital histochemistry with methenamine silver staining in renal allograft biopsies excluding pure chronic allograft nephropathy cases.

Deterioration of renal function is correlated with irreversible damage in chronic diseases. Recently we described a digital quantitative histochemistry method, relying on periodic acid methenamine silver (PAMS) staining to determine the chronic renal lesions. This index was strongly correlated with progressive deterioration of renal function in grafts with chronic allograft nephropathy (CAN). Herein the method has been applied to a cohort of renal allografts which were biopsied for various reasons, we sought to highlight its value to quantify chronic graft damage. Forty-four renal allograft biopsies from 37 patients with elevated serum creatinine values (SCr) underwent light microscopic image analysis (Mediscope, Dokuz Eylül University, Clinical Engineering Department, Izmir, Turkey) of the PAMS-stained area percentage (SAP). SCr was recorded at four intervals to overcome acute effects: the under SCr value before (SCr1) and after a biopsy within 3 months (SCr3), SCr at the time of the biopsy (SCr2), and the latest value (SCr4). The PAMS-SAP scores were strongly associated with increased interstitial fibrosis and tubular atrophy Banff scores (Kruskal-Wallis test, P = .006 and P = .003, respectively). There was a moderate positive correlation between PAMS and SCr3 (Pearson correlation test, P = .04, r = .312), and a strong positive correlation between time from transplantation to biopsy (Pearson correlation test, P << .000, r = .532). The present results show that PAMS-SAP seems to be of value to quantify renal scarring in allograft biopsies, reflecting four compartments. The strong correlation with time is noteworthy especially as a probable reflection of aging of the renal allograft.

Anti-Infective Agents, Urinary↗

PubMed1989

Pre-arrest morbidity and other correlates of survival after in-hospital cardiopulmonary arrest.

PURPOSE: Recent reports on the use of in-hospital cardiopulmonary resuscitation (CPR) have failed to provide an applicable method to identify patients who have little chance of surviving CPR. We prospectively evaluated the clinical characteristics and outcome of 140 consecutive hospitalized patients who had cardiopulmonary arrest and received CPR, and we propose a method for predicting survival in this setting. PATIENTS AND METHODS: The study period was July 1 through December 31, 1985, and the patient population consisted of 91 men and 49 women (age range, 18 to 92 years). We devised a multifactorial scoring system, the Pre-Arrest Morbidity (PAM) Index, to evaluate pre-arrest morbidity in individual patients. RESULTS: Seventy-seven (55%) of these patients were successfully resuscitated, 34 (24.3%) were discharged from the hospital alive, and 29 (20.7%) were long-term survivors (alive three months after discharge). Multivariate analysis of pre-arrest clinical variables demonstrated a significant association with mortality for hypotension, azotemia, and age 65 years or older, although none of these factors was absolutely predictive of a fatal outcome. The PAM Index was found to correlate inversely with the frequency of successful resuscitation, and the probability of short-term and long-term survival after CPR. Patients with PAM scores of 7 or greater had an extremely low likelihood of long-term survival (less than 15%), and no patient with a score of more than 8 survived to discharge. When the PAM score was considered in multivariate analysis of pre-arrest variables, it became the only significant independent predictor of mortality. CONCLUSION: The PAM Index may be useful in identifying patients in whom CPR may be ineffective.

Adult↗

PubMed1979

Application of a simple high-performance liquid chromatographic method for the determination of melphalan in the presence of its hydrolysis products.

A procedure for the separation and quantitation of melphalan (L-PAM) and its hydrolysis products by high-performance liquid chromatography is described. The hydrolysis of L-PAM at 25 +/- 0.1 degrees and 41 +/- 0.1 degrees was studied between pH 3.0 and 9.0. The pattern of hydrolysis suggested that L-PAM decomposes via two consecutive pseudo first-order reactions. Pseudo first-order rate constants (k1) were determined for the disappearance of L-PAM at various pH values in buffered solutions and in a formulated product. At both temperatures L-PAM solutions were found to be most stable at low pH. Chloride ion was found to reduce the rate of hydrolysis.

Chromatography, High Pressure Liquid↗

PubMed1998

Ultrastructural study of porcine alveolar macrophages infected in vitro with porcine reproductive and respiratory syndrome (PRRS) virus, with and without Haemophilus parasuis.

Two experiments were designed to study ultrastructural changes in porcine alveolar macrophages (PAM) inoculated with porcine reproductive and respiratory syndrome (PRRS) virus (experiment 1) and with PRRS virus and Haemophilus parasuis (experiment 2). In both experiments, the viral infectious dose represented a "multiplicity of infection" of 1. Viral infection alone induced minimal ultrastructural changes at this dose, consisting only of an increase in lysosome numbers. Mixed viral and bacterial infection induced the production of greatly increased numbers of phagosomes and phagolysosomes. The PAM were of low efficacy in phagocytizing H. parasuis. PRRS virus infection had only a minimal effect on the phagocytosis of H. parasuis by PAM. It is suggested that the virus induces PAM activation rather than PAM destruction.

Age Factors↗

PubMed1998

Simulated postaggression metabolism in healthy subjects: metabolic changes and insulin resistance.

Postaggression metabolism (PAM) is difficult to study in critically ill patients. The objective of this study was to simulate PAM in healthy subjects to quantify insulin sensitivity under these conditions. Six healthy men (age, 24 +/- 1 years; body mass index, 22.0 +/- 0.7 kg/m2 [mean +/- SE]) received an intravenous (i.v.) infusion of insulin-counteracting hormones (epinephrine 100 ng/kg/min, glucagon 16 ng/kg/min, hydrocortisone 5 microg/kg/min, and growth hormone [GH]-releasing hormone 50 microg/h) for 4 hours in addition to glucose (270 mg/kg/h). Control experiments used glucose only. In additional experiments, insulin sensitivity was measured by a two-step hyperinsulinemic glucose clamp with and without concomitant hormone infusion (insulin infusion rate, 2.5 and 5.0 mU/kg/min for hormone infusion or 1.0 and 2.5 mU/kg/min for control experiments). Plasma stress hormones reached levels comparable to severe PAM (epinephrine, 1,085 +/- 89 pg/mL; glucagon, 1,100 +/- 114 pg/mL; cortisone, 1,004 +/- 32 ng/mL; and GH, 20.6 +/- 6.1 pg/mL) in the hormone infusion experiment. This resulted in hyperglycemia and hyperinsulinemia (steady-state blood glucose, 19.7 +/- 0.4 mmol/L; serum insulin, 352 +/-8 pmol/L) in comparison to the control experiments with glucose infusion only (maximal blood glucose 7.2 +/- 0.8 mmol/L; serum insulin, 110 +/- 16 pmol/L). The insulin sensitivity index (S(I)) was 88% +/- 6% lower during hormone infusion (0.6 +/- 0.4 mL/min/m2/microU/min) compared with the control experiments (4.5 +/- 1.3 mL/min/m2/microU/min). Infusion of insulin-counteracting hormones at high doses allows simulation of the changes in carbohydrate metabolism observed in PAM in healthy subjects. The observed profound decrease in insulin sensitivity explains the hyperglycemia observed in nondiabetic critically ill patients. With this experimental setup, standardized investigations of therapeutic interventions in PAM should be possible.

Adult↗

PubMed1991

The role of carboxylesterase in species variation of oxime protection against soman.

Oxime protection against soman, a highly toxic anticholinesterase agent, was examined in mice and guinea pigs. The maximal protection produced by the oximes PAM and HI-6 varied as much as 6-fold between these species. Since endogenous carboxylesterase (CaE) is known to be an important determinant of species variation in soman toxicity, the protection of PAM and HI-6 against soman was also measured in animals whose endogenous CaE was inhibited with cresylbenzodioxaphosphorin oxide. In CaE-inhibited animals the soman LD50 values were similar in unprotected mice and guinea pigs (10.2 vs. 12.2 micrograms/kg) and oxime-protected mice and guinea pigs (38.1 vs. 40.3 micrograms/kg for PAM; 159 vs. 151 micrograms/kg for HI-6). The levels of oxime protection observed in CaE-inhibited animals agreed with previous experiments in other species that have no endogenous plasma CaE. The 4-5 times greater in vivo protection against soman of HI-6 vs. PAM in CaE-inhibited animals correlated with in vitro experiments in which HI-6 produced 3-5 times more oxime reactivation of soman-inhibited AChE than PAM.

Animals↗

PubMed1986

Potential acuity meter for predicting visual acuity after Nd:YAG posterior capsulotomy.

We studied 30 patients with opacifications of the posterior capsule to determine if the potential acuity meter (PAM) could accurately predict final visual outcome after Nd:YAG discussion. The final visual acuity was within one line of the PAM prediction in 22 of 30 patients (73%), better by two or more lines in seven patients (23%), and worse in one patient (4%) by two lines. Although in thicker capsules the final acuity was occasionally better than the PAM prediction, the rates of false negative and false positive predictions were very low. Mild cystoid macular edema (3 patients), age-related macular degeneration (3 patients), intraocular lens status, and level of initial acuity did not diminish PAM accuracy. The PAM effectively predicts final visual acuity after YAG posterior capsulotomy, when used in a patient, unhurried manner.

Adult↗

PubMed1987

Potential acuity meter for predicting postoperative visual acuity in penetrating keratoplasty. A new method using a hard contact lens.

An irregular corneal surface degrades the optical transmission and limits the effectiveness of the potential acuity meter (PAM) in predicting post-keratoplasty visual acuity. The authors investigated the efficacy of using a temporarily placed hard contact lens to neutralize surface irregularities in conjunction with the PAM in predicting post-keratoplasty visual acuity. A prospective evaluation was performed on 40 keratoplasty patients with a mean follow-up of 10.4 months. Of 27 patients with corneas clear enough to permit them to read letters on the PAM chart, 17 (63%) had very accurately predicted visual acuities by this new method, compared to only eight patients (30%) with the PAM alone. Three patients had predicted visions better than final vision, but this was due to a concurrent cataract in two cases and chronic cystoid macular edema (CME) in the third case. This study indicates that temporarily placing a hard contact lens for use with the PAM can increase its accuracy in predicting final visual acuity after penetrating keratoplasty.

Adult↗

PubMed1999

Potential acuity pinhole: a simple method to measure potential visual acuity in patients with cataracts, comparison to potential acuity meter.

OBJECTIVE: To describe the potential acuity pinhole (PAP) test and compare its accuracy to the potential acuity meter (PAM) in predicting visual outcome after cataract surgery. STUDY DESIGN: Prospective case series. PARTICIPANTS: A total of 56 preoperative patients with cataracts participated. MAIN OUTCOME MEASURES: Accuracy of predicting postoperative distance visual acuity was measured. METHODS: Lines of inaccuracy were calculated by subtracting actual postoperative best-corrected distance visual acuity (BCVA) from predicted values. Variables analyzed were method of prediction, preoperative BCVA, and preoperative spherical equivalent. RESULTS: The PAP test predicted visual outcomes within 2 lines in 100%, 100%, and 56% of eyes with preoperative BCVA of 20/50 and better (group 1), 20/60 to 20/100 (group II), and 20/200 and worse (group III), respectively. The PAM predictions within 2 lines for the same groups were 42%, 47%, and 0%, respectively. Mean lines of inaccuracy of PAP predictions were 0.83, 1.11, and 3.50 lines for groups I, II, and III, respectively. Mean lines of inaccuracy for PAM predictions were 2.50, 2.68, and 6.22 lines for the same groups. Differences in lines of prediction between PAM and PAP were 1.67 (P = 0.004), 1.58 (P = 0.0002), and 2.72 lines (P = 0.0001) for groups I, II, and III, respectively. There was no statistically significant correlation between PAP predictions and preoperative myopic spherical equivalent. CONCLUSIONS: The PAP test is a simple, inexpensive, and relatively reliable method to estimate visual outcome after uncomplicated cataract surgery in eyes with no coexisting disease. It is less accurate in patients with preoperative BCVA worse than 20/200. It appears to be more predictive than PAM.

Adult↗

PubMed1999

Autocrine growth loops dependent on peptidyl alpha-amidating enzyme as targets for novel tumor cell growth inhibitors.

Many small cell lung tumors are dependent in vitro and in vivo on autocrine growth loops. The prototypical small cell lung cancer autocrine growth factor, gastrin-releasing peptide (GRP), is one of many peptide hormones which require post-translational carboxy-terminal alpha-amidation for bioactivity. We have reported that neuroendocrine human lung tumor cell lines express the bifunctional enzyme PAM which catalyzes the biosynthesis of alpha-amidated peptides in a two-step process, and have recently shown that non-small cell lung cancer cell lines and tumors, generally considered to be non-endocrine in nature, also express PAM. We have also shown that two chemical classes of PAM inhibitors, substrate analogues and specific copper chelators, inhibit amidating enzyme activity in cell-free extracts. Here we demonstrate in vitro growth inhibition of lung cancer tumor cell lines by both these classes of PAM inhibitors using the MTT assay and the clonogenic assay. Growth inhibition in a small cell lung cancer cell line can be overcome by exogenous addition of synthetic alpha-amidated GRP. Similar growth-suppressive effects are seen in cell lines stably transfected with a vector expressing antisense PAM RNA. These data support the mechanism of inhibition for a new type of chemotherapeutic/intervention agent, directed at synthesis and activation of peptide growth factors, and support our postulate that alpha-amidated peptide hormones are a common component in lung tumor autocrine growth biology which can be inhibited by targeting the biochemical mechanisms necessary for growth factor synthesis.

Anti-Bacterial Agents↗

PubMed1977

Induction of aryl hydrocarbon hydroxylase in human pulmonary alveolar macrophages and peripheral lymphocytes by cigarette tars.

Cigarette smoking is associated with alterations in pulmonary alveolar macrophages (PAMs), including increased cytoplasmic inclusions and induction of the aryl hydrocarbon hydroxylase (AHH) system. Nonpigmented PAMs from nonsmokers were able to ingest and accumulate pigment from lysed PAMs of smokers, however, this pigment did not induce AHH activity in either PAMs or peripheral lymphocytes. In contrast, the cigarette tars significantly induced AHH levels in PAMs and in peripheral lymphocytes from either nonsmokers or smokers. This provides further evidence that components in cigarette smoke can explain the in vivo induction of AHH documented in cells from smokers.

Aryl Hydrocarbon Hydroxylases↗

PubMed1979

Phagocytosis of asbestos fibers by human pulmonary alveolar macrophages.

Human pulmonary alveolar macrophages (PAMs) were cultured for 24--72 h with varying concentrations (0--300 microgram/ml) of amosite asbestos (AS). At lower AS concentrations, (less than 100 microgram/ml) no decrease in cell viability occurred during the first 24 h of culture. Significant cytotoxicity (P less than 0.005 in all instances) was observed, however, following incubation for 24 h with higher AS concentrations (greater than 100 microgram/ml). Even following incubation with lower concentrations of AS, significant cytotoxicity (P less than 0.006 in all instances) was observed after 48 or 72 h of culture. Scanning electron microscopy (SEM) clearly illustrates the various stages of AS phagocytosis by PAMs. SEM also documented morphological changes in PAMs following AS exposure. These included increased zeiosis and the appearance of a fibrous-like material on the surface of AS fibers following initial contact with the PAM cytoplasmic membrane. Further study of the biological interactions between AS and human cells, such as PAMs, might provide valuable information regarding the etiology of AS-related lung disorders.

Adult↗

PubMed1998

Peptidylglycine alpha-amidating mono-oxygenase: neuropeptide amidation as a target for drug design.

1. Peptidylglycine alpha-amidating mono-oxygenase (PAM) is a bifunctional key enzyme in the bioactivation of neuropeptides. Its biosynthesis, distribution, functional role, and pharmacological manipulation are discussed. 2. PAM biosynthesis from a single gene precursor is characterized by alternative splicing and endoproteolytic events, which control intracellular transport, targeting, and enzyme activity. 3. The enzyme is mainly stored in secretory vesicles of many neuronal and endocrine cells with high abundance in the pituitary gland. Its functional role has been studied using enzyme inhibitors. Thus selective, peripheral PAM inhibition reduces substance P along with an anti-inflammatory action. 4. PAM-related pathologies are characterized by an increased relative abundance of alpha-amidated neuropeptides. To attenuate such hormone overproduction, novel, specific, and disease-targeted PAM inhibitors may be developed based on enzyme polymorphism.

Animals↗

PubMed1981

Quantitative analysis of melphalan and its major hydrolysate in patients and animals by reversed-phase high-performance liquid chromatography.

The detection of 4-bis-(2-hydroxyethyl)amino-1-phenylalanine (L-DOH) in blood samples taken from patients after treatment with melphalan [4-bis-(2-chloroethyl)amino-1-phenylalanine, L-PAM] suggests that the quantification of this major hydrolysate of L-PAM can be of considerable importance in L-PAM chemotherapy. A reversed-phase high-performance liquid chromatographic procedure has been developed for the quantitative analysis of both L-PAM and L-DOH in biological samples, with a detection sensitivity of 0.1 ppm. This method provides a distinct separation of L-PAM (retention time 12 min) and L-DOH (retention time 6.5 min), with no interference from the biological background (retention time 1.4--3 min).

Animals↗

PubMed1999

A correlation method for detecting the sound-evoked post-auricular muscle response (PAMR).

We have made detailed measurements of the sound-evoked post-auricular muscle response (PAMR) in four adults and two infants, in an attempt to understand the inter-relationships between sound level, potentiation of the PAMR with voluntary PAM contraction or eye rotation, electromyographic (EMG) noise, amplitude of the PAMR, and a correlation measure of the presence of the PAMR. We have found that the amplitude of the PAMR is a simple linear function of the decibel level of a monophasic click (0.1 ms duration), and that the PAMR amplitude is also a saturating power function of the level of tonic EMG. As a result, PAMR=PAM(o).SL. (EMG-EMG(noise))(2)/[(EMG-EMG(noise))(2)+beta(2)], where SL is the decibel level of a click above subjective threshold, PAM(o) is a parameter accounting for the differing PAMR amplitude across individuals or with altered electrode placement, EMG(noise) is the component of EMG not associated with PAMR potentiation, and beta determines the initial rate of growth of PAMR at low levels of PAM activation. We have also found that the correlation measure (C) of the PAMR follows a saturating power function of the signal-to-noise ratio (SNR=PAMR/EMG), with C=SNR(2)/(SNR(2)+delta(2)), where delta determines the onset of saturation in the correlation as a function of SNR. The combination of these two relationships means that correlation is a non-monotonic function of the EMG (PAM activation): it can be large for moderate levels of EMG, but small for high levels of EMG, because the PAMR amplitude saturates but the EMG does not. The correlation is a fast, convenient means of detecting the PAMR, whether using clicks or tone-bursts, and can be used effectively in adults or infants, as long as the reflex is moderately activated. This moderate activation is most effectively produced by eye rotation towards the recording electrodes.

Acoustic Stimulation↗

PubMed1986

The influence of cataract types on potential acuity meter results.

The records of 100 patients who had cataract surgery were reviewed to compare preoperative potential acuity meter (PAM) results with postoperative visual acuity. A PAM acuity was obtainable in 95 patients. In 82 of the 95 patients (86%), the PAM levels were within three lines of the outcome. Potential acuity meter results substantially lower (less than or equal to four Snellen lines) than outcome generally occurred when posterior subcapsular (PSC) or PSC plus diffuse cortical or nuclear changes were present. We believe that the PAM projection can usually go around or through the nuclear sclerosis to give an accurate prediction. However, with PSC or mixed type, one may not always find a window in the cataract. Also, PSC or diffuse cortical cataracts may be particularly disruptive to the paracentral diffracted light that is an important factor in PAM acuity.

Cataract Extraction↗