Medroxyprogesterone attenuates estrogen-mediated inhibition of neointima formation after balloon injury of the rat carotid artery

BACKGROUND

Estrogen blunts the neointimal proliferative response to balloon injury of the carotid artery in intact female rats and gonadectomized rats of both sexes. This study tested whether, in gonadectomized rats of both sexes. (1) progestin (medroxyprogesterone acetate, MPA) alters neointima formation in injured carotid arteries, (2) addition of MPA alters the antiproliferative effects of estrogen, and (3) an interaction between MPA and estrogen can be accounted for by MPA-induced alterations in serum 17 beta-estradiol levels.

METHODS AND RESULTS

Male and female Sprague-Dawley rats were subjected to gonadectomy, then were randomly divided into four subgroups and treated with either (1) 17 beta-estradiol, (2) MPA, (3) 17 beta-estradiol + MPA, or (4) vehicle, and balloon injury of the right common carotid artery was carried out. Two weeks later, rats were killed by overdose of pentobarbital, and the carotid arteries were subjected to morphometric analysis for evaluation of myointimal thickening. Estradiol inhibited myointimal proliferation after vascular injury in gonadectomized rats of both sexes (P < .05). MPA alone did not alter neointima formation, but addition of MPA to estradiol completely blocked the antiproliferative effects of estrogen without altering serum 17 beta-estradiol levels.

CONCLUSIONS

These data indicate that exogenous progestin given alone does not alter the vascular injury response in the rat carotid injury model but that addition of a progestin blocks the antiproliferative effects of estrogen in this model. These effects are seen in gonadectomized rats of both sexes. These findings have direct implications for postmenopausal hormone replacement therapy in humans.

Nonspecific esterase activity in astrocytes of the goldfish brain

We examined the distribution of nonspecific esterase (NSE) activity in the brain of the goldfish, Carassius auritus, and found that the enzyme is expressed at high levels in cells that appeared to be radial astrocytes. Several instances in which neurons expressed NSE activity were also seen. To confirm the identity of the radial profiles as astrocytes, similar sections were labeled with antiserum against goldfish glial fibrillary acidic protein (GFAP). The concordance between the NSE and the anti-GFAP data in both the visual system and the telencephalon was essentially complete, confirming that the NSE reaction was labeling astrocytes in these structures. The two methods also gave similar results in both the cerebellum and the vagal lobes, although the concordance between them in these instances was somewhat less complete. Both the NSE reaction and immunohistochemistry with anti-GFAP serum revealed labeled nonradial cells lying free in the cerebellar molecular layer. We suggest that these cells may represent free astrocytes, a cell type that has not previously been reported in morphological studies of the teleostean brain. On the basis of our observations, we suggest that the NSE reaction may be a useful adjunct in morphological studies of teleost astroglia. Finally, we propose that the expression of NSE activity in goldfish astrocytes may he related to their ability to internalize neural debris during Wallerian degeneration.

Age-related decline of rat liver multicatalytic proteinase activity and protection from oxidative inactivation by heat-shock protein 90

To test whether an observed age-related increase in the level of oxidized protein in rat liver is due to a decrease in the activity of the multicatalytic proteinase (MCP), this protease was isolated from liver of young (8-month-old) and old (24-month-old) male Fischer 344 rats. Three peptidase activities of the MCP were assayed using fluorogenic peptides: trypsin-like, chymotrypsin-like, and peptidylglutamyl-peptide hydrolase. Only peptidylglutamyl-peptide hydrolase activity declined with age, with protease from old animals exhibiting approximately 50% of the activity of that from young animals. Bidimensional gel electrophoresis and thermostability studies did not reveal age-related structural modifications of the MCP subunits. Peptidylglutamyl-peptide hydrolase activity and trypsin-like activity were sensitive to metal-catalyzed oxidation. In some preparations, a 95-kDa protein that has been identified as the heat shock protein 90 copurified with the MCP. In the presence of HSP 90, trypsin-like activity is protected from oxidative inactivation and chymotrypsin-like activity is slightly activated. Peptidylglutamyl-peptide hydrolase activity remained sensitive to oxidation in protease isolated from young rats, but that from old rats was resistant to oxidative inactivation. Furthermore, addition of rat HSP 90 to rat liver MCP (purified from 8-month-old animals and free of contaminating HSP 90) was found to protect trypsin-like activity from oxidative inactivation.

The phosphatase activity of carbonic anhydrase III is reversibly regulated by glutathiolation

Carbonic anhydrase isozyme III (CAIII) is unique among the carbonic anhydrases because it demonstrates phosphatase activity. CAIII forms a disulfide link between glutathione and two of its five cysteine residues, a process termed S-glutathiolation. Glutathiolation of CAIII occurs in vivo and is increased during aging and under acute oxidative stress. We show that glutathiolation serves to reversibly regulate the phosphatase activity of CAIII. Glutathiolation of Cys-186 is required for phosphatase activity, while glutathiolation of Cys-181 blocks activity. Phosphotyrosine is the preferred substrate, although phosphoserine and phosphothreonine can also be cleaved. Thus, glutathiolation is a reversible covalent modification that can regulate CAIII, a phosphatase that may function in the cellular response to oxidative stress.

Specific uptake of intracranial horseradish peroxidase (HRP) by microglial cells in the goldfish

Intracranial injections of horseradish peroxidase (HRP) in the goldfish labeled a population of cells with many similarities to microglia. The fact that neither macroglia nor neurons appeared to be labeled by these injections supports this identification. The labeled cells responded to Wallerian degeneration of the optic paths by accumulating in the optic terminal zones, a cellular behavior which strongly supports their identification as microglia.

Extracranial intravascular vasodilatory response to acetazolamide and magnetic resonance angiography

Cerebral vasodilatory testing provides an important measure of both the hemodynamic significance of arterial occlusive disease and the adequacy of collateral pathways. This study measured the extracranial intravascular volume flow rate response to acetazolamide using phase-contrast magnetic resonance angiography. From 10 patients with unilateral carotid transient ischemic attacks (TIAs), a total of 18 extracranial carotid arteries (10 symptomatic, 8 asymptomatic, 2 occluded) and 19 extracranial vertebral arteries were studied. Patients were free of large-vessel intracranial stenoses, evident areas of ischemic infarction, evident areas of nonspecific white matter change, and hemodynamic or low-flow induction of TIA symptomatology. Asymptomatic carotid volume flow rates rose from 151 +/- 19 (standard error of mean) to 220 +/- 26 ml/min while symptomatic flow rates rose from 106 +/- 22 to 145 +/- 25 ml/min. Dominant vertebral volume flow rates rose from 128 +/- 23 to 160 +/- 22 ml/min while nondominant rates rose from 40 +/- 12 to 61 +/- 15 ml/min. Carotid volume flow rates were inversely proportional to percent stenosis for both baseline (r = 0.51, p < 0.02) and acetazolamide (r = 0.81, p < 0.001) data. Baseline-plus-acetazolamide volume flow rate techniques safely measure intravascular vasodilatory responses. Intracranial measurement techniques are being developed to further study cerebrovascular reserve using phase-contrast magnetic resonance angiography.

Comparison of the effects of ozone on the modification of amino acid residues in glutamine synthetase and bovine serum albumin

During exposure to ozone, the methionine and aromatic amino acid residues of Escherichia coli glutamine synthetase (GS) and bovine serum albumin (BSA) are oxidized rapidly in the order Met > Trp > Tyr approximately His > Phe. The loss of His is matched by a nearly equivalent formation of aspartate or of a derivative that is converted to aspartic acid upon acid hydrolysis. Conversion of His to aspartate was confirmed by showing that the oxidation of E. coli protein in which all His residues were uniformly labeled with 14C gave rise to 14C-labeled aspartic acid in 80% yield and also by the demonstration that His residues in the tripeptides Ala-His-Ala or Ala-Ala-His gave rise to nearly stoichiometric amounts of aspartic acid whereas oxidation of His-Ala-Ala yielded only 36% aspartate. The oxidation of BSA and GS led to formation, respectively, of 11 and 3.3 eq of carbonyl groups and 0.5 and 0.3 eq of quinoprotein per subunit. Although BSA and GS contain nearly identical amounts of each kind of aromatic amino acid residues, oxidation of these residues in BSA was about 1.5-2.0 times faster than in GS indicating that the susceptibility to oxidation is dependent on the primary, secondary, tertiary, and quaternary structure of the protein.

Regulation of HIV-1 protease activity through cysteine modification

The homodimeric protease of the human immunodeficiency virus 1 contains two cysteine residues per monomer which are highly conserved among viral isolates. However, these cysteine residues are not essential for catalytic activity which raises the question of why they are conserved. We have found previously that these cysteine residues are unusually susceptible to oxidation by metal ions, and this results in inhibition of protease activity. Recombinant protease mutants (C67A, C95A, and the double mutant C67A,C95A) were prepared to assess the possible role of these cysteines in redox regulation of the enzyme. Mixed disulfides were formed between the cysteine residues of the enzymes and low molecular weight thiols. Enzyme activity was lost when a mixed disulfide was formed between 5,5'-dithiobis(2-nitrobenzoic acid) and cysteine 95, while the same mixed disulfide at cysteine 67 reduced activity by 50%. This effect was reversible as normal activity could be restored when the enzyme was treated with dithiothreitol. The cysteines could also be modified with the common cellular thiol glutathione. Modification with glutathione was verified by mass spectrometry of the protein peaks obtained from HPLC separation. Glutathiolation of cysteine 95 abolished activity whereas modification at cysteine 67 increased the k(cat) by more than 2-fold with no effect on K(m). In addition, glutathiolation at cysteine 67 markedly stabilized the enzyme activity presumably by reducing autoproteolysis. These results demonstrate one possible mechanism for regulation of the HIV-1 protease through cysteine modification and identify additional targets for affecting protease activity other than the active site.

Determination of 2-oxohistidine by amino acid analysis

Oxidative modification of proteins has been implicated in aging, ischemia reperfusion, carcinogenesis, and other phenomena. Oxidation of the C-2 position of the imidazole ring of histidine converts the residue to 2-oxohistidine, a novel amino acid which may serve as a marker of oxidative modification of proteins (K. Uchida and S. Kawakishi, J. Biol. Chem. 269, 2405-2410, 1994). It has been identified in oxidatively modified proteins by electrochemical detection during reverse-phase high-pressure liquid chromatography, by mass spectrometry, and as the phenylthiohydantoin after Edman degradation, but not by amino acid analysis of protein hydrolysates. We now describe procedures for stabilizing 2-oxohistidine which allow its quantification by routine methods of amino acid analysis. These include classical ion exchange chromatography with postcolumn derivatization by o-phthaldialdehyde, reverse-phase chromatography with precolumn derivatization by o-phthaldialdehyde, and reverse-phase chromatography with precolumn derivatization by 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate. Using these techniques, a previously unidentified amino acid which appears during the oxidative inactivation of glutamine synthetase was shown to be 2-oxohistidine. One picomole of 2-oxohistidine was readily detected in a protein hydrolysate containing 1700 pmol total amino acids.

Laparoscopic suturing and ligation techniques

The laparoscopic literature addressing operative techniques and use of suturing and knot tying is reviewed. Many operations that have traditionally been performed by laparotomy, may now be primarily accomplished by laparoscopy. Increasing improvements in laparoscopic instruments and techniques permit more surgical procedures to be performed on an ambulatory basis, therefore setting a new trend in gynecologic surgery. The evolution of endoscopic procedures will require laparoscopic surgeons to master suturing techniques which will improve their level of comfort and performance. This review of suturing and knot tying procedures may be helpful to both the established surgeons and the beginners as it gives a comprehensive review of laparoscopic suturing and knot tying techniques.

Inhibition of the human immunodeficiency virus-1 protease and human immunodeficiency virus-1 replication by bathocuproine disulfonic acid Cu1+

The protease encoded by the human immunodeficiency virus-1 (HIV-1) is essential for processing viral polyproteins which contain the enzymes and structural proteins required for the infectious virus. It was previously found that cupric chloride, in the presence of dithiothreitol or ascorbic acid, could inhibit the HIV-1 protease. It was suggested that a Cu1+ chelate was the moiety responsible for inhibition of the protease. This hypothesis has now been investigated directly by utilizing the stable Cu1+ chelate, bathocuproine disulfonic acid Cu1+ (BCDS-Cu1+). BCDS-Cu1+ inhibited the HIV-1 wild type protease as well as a mutant HIV-1 protease lacking cysteines. BCDS-Cu1+ was a competitive inhibitor of the mutant HIV-1 protease with an apparent Ki of 1 microM. Replication of HIV-1 in human lymphocytes and the cytotoxic effect of HIV-1 in CEM cells was inhibited by micromolar BCDS-Cu1+. Inhibition of the protease and of HIV replication by BCDS-Cu1+ was dependent on the presence of Cu1+ as BCDS alone was ineffective. EDTA blocked the inhibition of the protease by Cu1+ but was unable to block inhibition of the protease by BCDS-Cu1+, indicating that the Cu1+ complex was the inhibitory agent. The apparent IC50 for BCDS-Cu1+ on the inhibition of replication by primary isolates of HIV-1 was 5 microM. However, BCDS-Cu1+ did not affect polyprotein processing in an H9 cell line chronically infected with HIV-1, indicating that BCDS-Cu1+ acts by yet another mechanism to block HIV infection. Other possible targets for BCDS-Cu1+ include inhibition of viral adsorption and/or inhibition of the HIV-1 integrase.

Magnetic field effects on spatial discrimination and melatonin levels in mice

Previous research has demonstrated a decrement in spatial discrimination learning following exposure to a .30 Tesla magnetic field. It had been suggested that those findings might be the result of an interaction between the magnetic field and physiological ferromagnetic material (magnetite). In the present study, mice were exposed for 100 min to a 2.0 Tesla field and both their left-right discrimination learning ability and serum melatonin levels were compared with a control group. Results indicated a significant interference with spatial discrimination learning following exposure, but no significant differences in serum melatonin levels. These findings appeared to rule out magnetically induced melatonin fatigue as an explanation of the decrement in spatial learning, as opposed to other possibilities such as magnetic effects on brain magnetite. However, additional controls are suggested for future research.

Basilar artery dolichoectasia. Review of the literature and six patients studied with magnetic resonance angiography

Six patients for whom computed tomography revealed a curvilinear calcific mass anterior to their brainstem were evaluated and magnetic resonance imaging and magnetic resonance angiography were performed on each. Magnetic resonance studies confirmed the suspicion of basilar artery dolichoectasia, and demonstrated a partial thrombus in the basilar artery in 1 patient. The patients' clinical features were combined with those of basilar artery dolichoectasia patients reported in the literature (n = 122) who had case histories sufficiently detailed enough to determine each person's mode of clinical presentation. Basilar artery dolichoectasia patients were more often men (95/128, 74%) and had a mean age of 59 +/- 11 years. Of the 128 patients studied, there were cranial nerve compressive signs in 74 (58%), especially facial spasm (29/74, 39%) and trigeminal neuralgia (20/74, 27%); vertebral basilar insufficiency or vertebral basilar stroke or both in 61 (48%); hydrocephalus in 40 (31%); compressive brainstem symptoms and signs that progressed clinically in 31 (24%); and arterial hypertension in 31 (24%). Magnetic resonance imaging and magnetic resonance angiography safely diagnose this interesting arterial abnormality. The modes of clinical presentation of this disorder are reviewed.

Carbonic anhydrase III. Oxidative modification in vivo and loss of phosphatase activity during aging

Oxidative modification of DNA, lipids, and proteins occurs as a consequence of reaction with free radicals and activated oxygen. Oxidative modification of total cellular proteins has been described under many pathologic and experimental conditions, but no specific proteins have been identified as in vivo targets for oxidative modification. Utilizing an immunochemical method for detection of oxidatively modified proteins, we identified a protein in rat liver that was highly oxidized. It was purified to homogeneity and identified as carbonic anhydrase, isozyme III. Its characteristics match those previously described for a protein that was lost during aging of the rat, senescence marker protein-1. Carbonic anhydrase III was purified from rats aged 2, 10, and 18 months, and the proteins were characterized. All three preparations were highly oxidatively modified as assessed by their carbonyl content. The enzyme has three known catalytic activities, and the specific activities for carbon dioxide hydration and for ester hydrolysis decreased during aging by approximately 30%. However, the third activity, that of a phosphatase, was virtually lost during aging. While the physiologic role of carbonic anhydrase III is unknown, we suggest that it functions in an oxidizing environment, which leads to its own oxidative modification.

Use of end-tidal carbon dioxide to predict outcome in prehospital cardiac arrest

STUDY OBJECTIVE

End-tidal CO2 (ETCO2) measurement can be used to predict death in prehospital cardiac arrest patients with pulseless electrical activity (PEA).

DESIGN

A prospective, observational study.

SETTING

An urban and rural emergency medical services system in northwestern Washington state.

PARTICIPANTS

Ninety consecutive victims of prehospital cardiac arrest with PEA.

INTERVENTIONS

Patients were intubated in the field and treated using standard advanced cardiac life support protocols with online medical control. In addition, all patients were evaluated using mainstream ETCO2 monitoring. In this study, a hypothetical decision was made to cease resuscitative efforts based on an ETCO2 level of 10 mm Hg or less after 20 minutes of advanced cardiac life support.

RESULTS

The study included 90 patients (61 were men) with a mean age of 67.6 +/- 13.6 years (range, 27 to 95 years). The initial ETCO2 averaged 11.7 +/- 6.6 mm Hg in nonsurvivors (range, 5 to 50 mm Hg) and 10.9 +/- 4.9 mm Hg in survivors (range, 5 to 24 mm Hg) (P > .672 [NS]). After 20 minutes of advanced cardiac life support, ETCO2 averaged 3.9 +/- 2.8 mm Hg (range, 0 to 12 mm Hg) in patients in whom the theoretical decision was made to cease field resuscitation. In contrast, survivors' ETCO2, just before restoration of circulation, averaged 31 +/- 5.3 mm Hg (range, 16 to 35 mm Hg) (P < .0001). Using an ETCO2 of 10 mm Hg or less as a theoretical threshold to predict death in the field successfully discriminated between the 16 survivors to hospital admission (those that achieved return of spontaneous circulation) and 75 prehospital deaths. Of the 16 survivors to hospital admission, 9 died in the hospital, and 7 were discharged from the hospital alive. In 13 of the 16 survivors, the first evidence of return of spontaneous circulation, before a palpable pulse or blood pressure, was a rising ETCO2. The logistic-regression parameters for the model are 4.4391 + ETCO2*-0.3624 (P < .0001). Sensitivity was 97.3%; specificity 100%; positive predictive value 100%; and negative predictive value 88.9%.

CONCLUSION

This study suggests that a low ETCO2 (10 mm Hg or less) can be used to predict irreversible death in patients with pulseless electrical activity undergoing prehospital advanced cardiac life support. If future studies validate this model, use of ETCO2 may allow for triage decisions in the field.

Recognition, assessment, and treatment of anxiety in the critical care patient

A multidisciplinary group of experts involved in the treatment of critically ill patients participated in a workshop conference designed to develop practice recommendations for the recognition, assessment, and treatment of anxiety in the critical care environment. Anxiety was identified as a ubiquitous problem in critical care that may interfere with healing and recovery. The faculty agreed that clinicians should be familiar with the signs and symptoms of anxiety and should be able to determine when interventions are necessary. Whenever possible, nonpharmacologic methods for anxiolysis should be incorporated into intensive care protocols. Intensive care personnel should be trained in those interventions that require specialized expertise, and they should become familiar with the drugs available for the treatment of anxiety. Protocols for determining the best agents to be used in a given setting and their most appropriate method of administration should be established. Pharmacologic and nonpharmacologic treatments are not mutually exclusive but should be complementary. Finally, procedures for obtaining psychiatric consultation, when necessary, should be in place.

Aging of the liver: proteolysis of oxidatively modified glutamine synthetase

During aging cells accumulate altered forms of proteins, notably oxidatively modified proteins. The multicatalytic protease selectively degrades oxidized proteins, suggesting that the age-related accumulation of oxidized proteins might be a consequence of decreased activity of this protease. The protease activity of liver homogenates was assayed with an improved fluorimetric method, using oxidatively modified glutamine synthetase as substrate. Application of this assay to extracts from liver of Fischer 344 rats from both Japan and the United States demonstrated a marked preference for the oxidized substrates, as expected. Extracts from animals ages 8 to 26 months maintain both total proteolytic activity and the ability to distinguish between native and oxidized substrates. Oxidatively modified hepatocyte extracts were also employed as substrate, and older animals again maintained proteolytic activity. The multicatalytic protease was purified from liver of young and old rats, and the specific activity of the preparations were comparable when assayed with oxidatively modified glutamine synthetase. We conclude that the intrinsic neutral or alkaline proteolytic activity of rat liver is maintained during aging.

Comparison of the effect of intermittent administration and continuous infusion of famotidine on gastric pH in critically ill patients: results of a prospective, randomized, crossover study

OBJECTIVES

To compare the effects of intermittent intravenous administration and continuous intravenous infusion of famotidine on gastric pH in critically ill patients.

DESIGN

A prospective, randomized, crossover study of continuous infusion and bolus administration of famotidine in critically ill patients.

SETTING

A 14-bed medical intensive care unit (ICU) of a 500-bed county hospital.

PATIENTS

Medical ICU patients requiring stress ulcer prophylaxis.

INTERVENTIONS

Patients were randomized to receive an equivalent dose of famotidine by continuous infusion or intravenous bolus for 24 hrs, and then were crossed over to the other arm of the study.

MEASUREMENTS AND MAIN RESULTS

Critically ill patients who met the inclusion criteria were randomly assigned to receive famotidine 20 mg i.v. over 10 mins, every 12 hrs or a continuous infusion of 1.7 mg/hr for 24 hrs. After a 16-hr washout period, patients crossed over to the other arm of the study. Gastric pH was monitored continuously for 24 hrs. A total of 710 gastric pH measurements were obtained for each phase of the study. The mean area under the pH-time curve for a 24-hr period was higher for continuous infusion than bolus administration (p = .05). Continuous infusion of famotidine maintained a gastric pH of > or = 4 over a longer time period than bolus administration (20.8 hrs vs. 12.6 hrs, respectively; p < .01). Onset of therapeutic gastric pH for continuous infusion was slightly delayed as compared with bolus administration.

CONCLUSIONS

Continuous infusion of famotidine is more effective than an equivalent dose given by intermittent bolus in maintaining the appropriate gastric pH necessary for prevention of stress ulceration. Delayed onset of effect may warrant a priming dose when famotidine is given by continuous infusion.

Oxidative modification of fibrinogen inhibits thrombin-catalyzed clot formation

Plasma fibrinogen plays a central role in controlling hemostasis. In an earlier report, we found that fibrinogen is oxidized when whole plasma is treated with a metal-catalyzed oxidation system. These studies show that oxidative modification of purified human fibrinogen leads to an exposure-dependent loss of thrombin-induced clot formation. Inhibition of clotting occurred when either metal-catalyzed oxidation or gamma-irradiation was employed to generate oxidizing radicals. Both systems caused covalent modification of fibrinogen, assessed by measuring incorporation of protein carbonyls. Thrombin-catalyzed fibrinopeptide release was normal in irradiated fibrinogen and was only slightly diminished in protein exposed to metal-catalyzed oxidation, indicating that the inhibition of clotting activity was due to impaired fibrin monomer polymerization. Thus, oxidative modification of normal fibrinogen causes dysfibrinogenemia and constitutes a novel mechanism for inhibition of thrombosis.

Anticardiolipin antibodies in a university hospital population

We have retrospectively reviewed data on our university hospital patients who had had at least one anticardiolipin antibody (aCL) titer performed (n = 781) during a 32-month study period between January 1991 and September 1993. We were able to locate clinical data on 95% (741 of 781) of these patients. Women (W) predominated at 70% (513 of 741), with men (M) at 30% (228 of 741). Reasons for ordering this test included brain infarct (M, 16%; W, 9%), multiple brain infarcts (M, 5%; W, 5%), migraine (M, 5%; W, 19%), and excessive clotting tendencies (M, 19%; W, 10%). Overall, aCL positivity was found in 10% of patients (73 of 741), with second-titer-confirmed positivity at 82% (60 of 73), men positive at 8% (18 of 228), and women positive at 11% (55 of 513; M versus W NS). For men, brain infarct (16% of aCL-positive in M versus 5% in W, p = 0.02), and for women, multiple brain infarcts (32% versus 0%, p = 0.01), migraine (10% versus 0%, p = 0.01), and systemic lupus erythematosus (30% versus 14%, p = 0.07) were the evident men-versus-women differences. We further studied stroke risk factors, associated conditions, family history, and laboratory findings relative to both sexes. aCL positivity continues to present differently, based on sex, at our university hospital.

A multicenter study of laparoscopic management of selected cystic adnexal masses in postmenopausal women

BACKGROUND

The objective of this study was to determine the ability to predict benign adnexal masses in postmenopausal women and to evaluate the effectiveness of laparoscopic management in selected patients.

STUDY DESIGN

Postmenopausal women found to have an adnexal mass were prospectively evaluated with clinical examination, sonography, and serum CA-125 levels. Women with cystic masses greater than 3 cm but less than 10 cm, with distinct borders, without solid parts or septations greater than 2 mm, without ascites or matted bowel, and with serum CA-125 levels less than 35 IU per mL were operated upon by laparoscopy.

RESULTS

Sixty-one women gave consent for the study. Cyst size ranged from 3 to 10 cm. All masses were accurately predicted to be benign. Fifty-eight (95 percent) women were successfully managed by operative laparoscopy and three required laparotomy. For the patients managed by laparoscopy, the mean operative time was 63 minutes, the mean postoperative hospitalization period was 12 hours, and the mean return to normal activity was 5.6 days.

CONCLUSIONS

The combination of clinical examination, sonographic appearance and serum CA-125 levels can accurately predict benign masses in postmenopausal women. Operative laparoscopy is acceptable for these patients and provides for a short period of hospitalization and a rapid recovery.

Differential susceptibility of plasma proteins to oxidative modification: examination by western blot immunoassay

Plasma proteins are exposed to oxidants in a variety of circumstances in vivo, such as during tissue injury and inflammation. In this report, the relative susceptibility of each of the major plasma proteins to oxidative modification was assessed by exposing whole plasma to a metal-catalyzed radical generating system and detecting oxidation (protein carbonyl groups) using a novel Western blot immunoassay. Proteins were derivitized with dinitrophenylhydrazine, separated by SDS-gel electrophoresis, and screened with antibodies against dinitrophenyl groups. As little as 1 pmol of protein-associated carbonyls could be detected (100 ng of a 50 kD protein containing 0.5 mol carbonyl/mol protein). Individual plasma proteins were identified by their comigration with standards, crossreactivity with specific antibodies, and by comparison of plasma to serum. Using this approach, we found that plasma fibrinogen was much more susceptible to oxidative modification compared to the other major plasma proteins, albumin, immunoglobulins, and transferrin. The results emphasize the utility of this method for studying oxidation of proteins in cell extracts and tissues and indicate that experiments on the effects of oxidation on fibrinogen function are merited.

Pharmacology of intravenous sedatives and opioids in critically ill patients

Many agents are available for sedation of agitated, delirious patients. In general, they should be administered intravenously to achieve a painless, more rapid, and more reliable onset of action. Proper selection of an agent requires understanding the basic principles discussed in this article, including the T-1/2 alpha and T-1/2 beta and the side-effect profile associated with each class of drugs, as well as for each agent. As a group, BNZs tend to be the safest and most predictable, and can be titrated easily when administered intravenously. Neuroleptic agents such as haloperidol may act synergistically with BNZs, resulting in control of agitation without significantly depressing the patient's level of consciousness or respiratory drive. Barbiturates, highly effective sedatives, more profoundly depress the respiratory and cardiovascular systems, and probably should be reserved for the severely agitated patient who cannot be controlled otherwise. Etomidate and propofol, useful for short-term procedures, probably should be avoided for long-term use in the agitated patient because of potentially serious side effects. Opioids should be used to provide adequate pain relief and to supplement other sedatives. Inadequate doses or dosing regimens should be avoided. Once sedation has been achieved, control usually can be maintained with continuous intravenous infusions of BNZs, perhaps in combination with a continuous infusion of an opioid or intermittent administration of a neuroleptic agent. With goal-oriented titration of the pharmacologic therapy, patients can be maintained safely in a sedate, calm state; intermittent periods of agitation, alternating with periods of severely depressed level of consciousness, can be avoided. Finally, when pharmacologic suppression of agitation and delirium is needed, the patient must be evaluated fully to determine the underlying cause of the confusional state.