Quantitative structure-metabolism relationship analyses of MAO-mediated toxication of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and analogues.

The 1-octanol/water partition coefficients of a number of toxic and nontoxic analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were determined using centrifugal partition chromatography (CPC), a novel and effective technique for measuring lipophilicity, and found to be highly correlated with values calculated by a fragmental method. Some conformational properties of these compounds were also assessed by molecular mechanics calculations and 1H-NMR spectroscopy. A quantitative structure-metabolism relationship (QSMR) study of MPTP and analogues based on literature data was undertaken in order to determine the key features eliciting MAO-A and MAO-B reactivity and selectivity and influencing toxication. Multiple regression analysis (MRA) and comparative molecular field analysis (CoMFA) showed that MAO-B activity is nonlinearly (parabolically or bilinearly) correlated to the lipophilicity of MPTP analogues and influenced negatively by steric effects exerted by bulky substituents in the ortho position. With regard to MAO-A activity, while lipophilicity was shown to play no relevant role, electrostatic and steric fields led to a 3D-QSAR model with an acceptable predictive value (cross-validated r2 = 0.571). The results of this study bring evidence at a quantitative level that the MAO-B and MAO-A catalytic sites differ in their hydrophobic, steric, and stereoelectronic requirements.


Utilization of glutathione during 1,2-dihaloethane metabolism in rat hepatocytes.

The metabolism of 1,2-dihaloethanes (DHEs) to glutathione-containing metabolites by freshly isolated rat hepatocytes was investigated. 1,2-Dichloroethane (DCE), 1,2-dibromoethane (DBE), and 1-bromo-2-chloroethane (BCE) were metabolized to S-(2-hydroxyethyl)glutathione (HEG), S-(carboxymethyl)glutathione (CMG), and S,S'-(1,2-ethanediyl)bis(glutathione) (GEG). The formation of these glutathione-containing metabolites was concomitant with the depletion of intracellular glutathione (GSH) and accounted for 58%, 84%, and 71% of the DCE-, BCE-, and DBE-induced loss of intracellular GSH, respectively. The covalent binding of [14C]DBE to hepatocyte protein reached 18.7 nmol/mL of cell suspension (7.8 nmol/mg of protein) within 2.0 h of incubation. Half of this covalent binding occurred within 0.5 h of incubation (4.0 nmol/mg of protein) in the presence of high levels of intracellular GSH (30% of initial GSH level at 0.5 h). Hepatocyte metabolism of 2-chloroacetic acid produced only CMG. 2-Chloroethanol metabolism gave rise to CMG and HEG in a 11.5:1.0 ratio; 2-chloroacetaldehyde produced almost equal amounts of CMG and HEG. GEG formation was increased significantly for DBE and BCE when GSH was added to the medium during treatment, suggesting that the GSH conjugates S-(2-haloethyl)glutathione are exported from the hepatocytes. These results indicate that the glutathione S-transferase-catalyzed conjugation of GSH with the DHEs is responsible for the majority of the DHE-induced GSH depletion. The S-(2-haloethyl)glutathione conjugates appear responsible for the extensive covalent binding to protein observed during [14C]DBE metabolism.


Update on oral contraceptive pills and postcoital contraception.

Modern oral contraceptive pills are safe for the majority of American women. The most important contraindications to oral contraceptive pill use are a history of thrombophlebitis or thromboembolism while on the pill or during pregnancy, smoking over 15 cigarettes daily if over 35 years of age, active liver disease, hypertension, diabetes, a lipid disorder, or breast cancer. A history of gestational diabetes is not an absolute contraindication to oral contraceptive pill use, but women with such a history must be encouraged to exercise and eat properly to reduce the high risk of developing overt diabetes. Couples should be encouraged to use condoms to reduce the risk of sexually transmitted diseases. Most antibiotics do not decrease the effectiveness of the pill. Nonuse of contraception among adolescents and older couples is the most common reason for failure. Postcoital contraceptive pills are available but are not completely effective. The use of modern contraceptives is almost always safer than nonuse.


The calcium-binding protein calreticulin is covalently modified in rat liver by a reactive metabolite of the inhalation anesthetic halothane.

A general procedure is presented for the isolation of several liver microsomal target proteins of the reactive trifluoroacetyl halide metabolite of halothane. It was found that most of these proteins could be selectively extracted from microsomes with 0.1% sodium deoxycholate and separated into partially purified fractions by DEAE-Sepharose anion-exchange chromatography. Using this method, we describe the isolation and identification of a 63-kDa target protein of halothane in rat liver. Amino acid sequences of the N-terminal and of several internal peptides of the protein, as well as the deduced amino acid sequence of a nearly full-length rat liver cDNA clone of the protein, showed 98% identity with a reported murine cDNA that encodes for calreticulin, a major calcium-binding protein of the lumen of endoplasmic reticulum. Although it remains to be determined what role calreticulin has in the development of halothane hepatitis, this study has shown that calreticulin can be a target of reactive metabolites of xenobiotics.


Identification of cyclophosphamide-DNA adducts in rat embryos exposed in vitro to 4-hydroperoxycyclophosphamide.

Cyclophosphamide and other bifunctional alkylating agents are potent animal teratogens inducing a variety of malformations. Although cyclophosphamide-induced DNA damage is implicated as a primary mechanism underlying the teratogenesis initiated by cyclophosphamide, additional insights into the complex nature of the teratogenic process have been hampered by the inability to analyze the primary teratogenic lesions, i.e., cyclophosphamide-DNA adducts. Using tandem mass spectrometry, we show that the monofunctional adduct N-(2-chloroethyl)-N-[2-(7-guaninyl)ethyl]amine (NOR-G) and bifunctional adduct N,N-bis[2-(7-guaninyl)ethyl]amine (G-NOR-G) can be detected in the DNA of organogenesis-stage rat embryos after an in vitro exposure to an embryotoxic concentration of activated cyclophosphamide, i.e., 4-hydroperoxycyclophosphamide.


Abortion: epidemiology, safety, and technique.

In 1991, the abortion literature was characterized by articles relating to 1) epidemiologic issues in abortion care, 2) advances in knowledge and experience with medical abortifacients such as mifepristone (RU 486), and 3) cervical ripening prior to abortion with the use of both mifepristone and prostaglandins. Technical methods of achieving termination of pregnancy continue to be similar in the United States, the United Kingdom, and Europe, although induction-abortion times are generally slower in Europe than in the United States. Surgically, dilatation and evacuation procedures continue to be more common in the United States than in other countries. The effectiveness of mifepristone is undisputed, and the recommended dose for early first-trimester termination is being compared with lower dose alternative regimens. There is additional evidence that at least in the short term, the negative psychological sequelae of abortion are infrequent and are inconsequential as a public health issue.


Inhibition of acetylcholinesterase by hemicholiniums, conformationally constrained choline analogues. Evaluation of aryl and alkyl substituents. Comparisons with choline and (3-hydroxyphenyl)trimethylammonium.

2-Substituted-2-hydroxy-4,4-dimethylmorpholiniums (hemicholiniums) inhibit acetylcholinesterase (EC 3.1.1.7)-catalyzed hydrolysis of acetylthiocholine (ATCh). The 4-substituted arenes [NH2, NHC(O)CH3, Cl, CN, and NO2] have values of inhibition constants (Ki) that range from 220 to 3690 microM, which correlate with Hammett sigma, rho approximately 0.8. The alkyl compounds, hydrogen, methyl, tert-butyl, and trifluoromethyl, have values of Ki of 550, 560, 1200, and 1200 microM, respectively. These values compare favorably with Ki = 960 microM for choline. The conformation of AChE-bound choline must be gauche to support our suggestion that hemicholiniums are conformationally constrained analogues of choline. (3-Hydroxyphenyl)trimethylammonium (5) inhibits most strongly, Ki = 0.21 microM, of the compounds examined in this study. The solvent isotope effect (H2OKi/D2OKi = 0.83 +/- 0.04) suggests that inhibition by 5 involves hydrogen bonding. The binding by AChE of the hemicholiniums of various sizes and the strong binding of 5 support an earlier proposal [Schowen, K. B., Smissman, E. E., and Stephen, W. F., Jr. (1975) J. Med. Chem. 18, 292-300] that the active site of AChE has ample space for rotation about the C-C bond in choline. Compound 5, which has one more carbon between the hydroxy and trimethylammonium than does choline, inhibits much more potently than either choline or the hemicholiniums. Compound 5 provides a correct spacer to span the trimethylammonium recognition site and the esteratic site of AChE. This aromatic spacer interacts favorably with the hydrophobic active site, and the phenolic hydroxyl probably hydrogen bonds to the histidine in the esteratic site. Choline in any conformation and the hemicholiniums are too short to make a strong hydrogen bond.


Associations of the bacterial mutagenicity of halogenated 2(5H)-furanones with their MNDO-PM3 computed properties and mode of reactivity with sodium borohydride.

Electrophilicity as a general basis for both the mutagenicity and nucleophile inactivation of halogen-substituted 2(5H)-furanones was tested. Lowest unoccupied molecular orbital (LUMO) energy levels and stabilities of 2(5H)-furanone radical anions and C-2, C-3, and C-4 anionic hydride adducts were computed with MNDO-PM3 for each of 10 compounds. These three computed sets of values were considered electrophilicity indicators. Each individual value from a given indicator set was plotted against the logarithm of the Salmonella typhimurium (TA100) mutagenicities (log Mm) for each of the corresponding compounds. Highest occupied molecular orbital (HOMO) energy levels for the 10 compounds were also computed. Strong negative correlations were obtained from the plots of LUMO and radical anion stability against log Mm of the 10 compounds. Also, a negative correlation was observed for the plot of the stability of the C-4 anionic hydride adduct for a smaller set of six compounds possessing a 4-(chloromethyl)-2(5H)-furanone structure and having the same HOMO characteristics. HOMO energies failed to correlate with mutagenicity. Neither computed atomic charge nor 13C chemical shift values for the larger compound group of 10 correlated well with mutagenicity or with each other. Sodium borohydride and borodeuteride reductions of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone demonstrated experimentally that hydride became attached to C-4.


Inactivation of alpha 1-proteinase inhibitor by peroxynitrite.

We here report the reactions of peroxynitrite (O=NOO-) with alpha 1-proteinase inhibitor (alpha 1PI) and with a synthetic decapeptide (MER10) containing the sequence of amino acids found in the active site of alpha 1PI (Pro-Met-Ser-Ile-Pro-Pro-Glu-Val-Lys-Phe). Peroxynitrite inactivates alpha 1PI at both pH 7.4 and 12.0. Thiourea and methionine protect alpha 1PI against inactivation by peroxynitrite, while mannitol and benzoate fail to afford effective protection. The major product isolated from the reaction between peroxynitrite and MER10 was analyzed by NMR, mass spectrometry, and amino acid analysis. These analyses indicate that peroxynitrite primarily oxidizes the methionine residue in the peptide. We detect neither smaller molecular weight peptides, which would indicate cleavage of MER10, nor hydroxylation or nitration of the phenylalanine residue. Our results suggest that peroxynitrite is capable of oxidizing methionine residues in proteins without the involvement of the hydroxyl radical or nitrogen dioxide. The implications of these observations on lung diseases attributed to cigarette smoke are discussed.


New condoms for men and women, diaphragms, cervical caps, and spermicides: overcoming barriers to barriers and spermicides.

Barriers and spermicides are being developed for the prevention of unwanted pregnancy and sexually transmitted infection. The inconvenience of current methods limits their acceptability and leads to higher user failure rates. New methods, such as female condoms, nonlatex male condoms, and new cervical caps are being developed: the Reality (Wisconsin Pharmacal, Jackson, WI) polyurethane vaginal pouch has already received conditional Food and Drug Administration approval for use in the United States. The material used in a Food and Drug Administration-approved nonallergenic glove is being tested for its effectiveness as a condom. In addition, the Fem Cap, a cervical cap that had a life table probability of failure within 1 year of 4.8%, is expected to be available within the next 2 years. It is important for clinicians to be informed of new options becoming available for those patients who may be good candidates for these barrier methods.


Future directions in contraception.

Although contraceptive research has markedly decreased in the United States, it has continued in other countries. The emphasis has been on the development of long-acting, noncoitally related contraceptives, including the progestogen-only and progestogen-estrogen vaginal rings. The levonorgestrel-releasing intrauterine device is highly effective and, like other contraceptives, may contribute to a decrease in the incidence of pelvic inflammatory disease. There is a great need for more effective, acceptable barrier contraceptives. The vaginal condom does not appear to be acceptable to many couples. Studies continue to demonstrate couples' lack of adherence to plans for abstinence and poor utilization of the present barrier contraceptives. The potential for the development of a male contraceptive utilizing gonadotrophin hormone-releasing hormone agonists or antagonists in conjunction with testosterone may hold promise in the future.


Investigative techniques, assessment of incontinence, and urodynamics.

The past year's literature reflects a continued interest in studying and refining standard investigative techniques, both urodynamic and radiographic, that have long been used to evaluate patients with lower urinary tract dysfunction. In addition, new, simple, and inexpensive technologies that allow relatively accurate diagnosis and that minimize medical costs have been introduced. These continued efforts to understand the pathophysiology of the lower urinary tract better bring both the practicing physician and the urogynecologist closer to making correct diagnoses and appropriate therapeutic decisions.


Surgical treatment and complications of urinary incontinence.

Numerous surgical approaches to the management of incontinence, particularly genuine stress incontinence, have been reported. No single operation is a panacea for the condition, and many factors must be taken into account before deciding which procedure is best tailored to an individual's needs. The procedures vary in their results, morbidity, and associated complications. Awareness of these previous complications encourages their avoidance and permits better management should they occur.


Toxicology of drinking water disinfection byproducts from nutrients. Rate studies of destruction of polyunsaturated fatty acids in vitro by chlorine-based disinfectants.

As model reactions between unsaturated fats and water disinfectants in the GI tract, relative rates of destruction of seven polyunsaturated fatty acids (L, alpha Ln, gamma Ln, Ara, EPA, DH, and DT) by OCl- and NH2Cl were investigated in vitro. Using millimolar solutions of seven PUFAs combined with various OCl- mole ratios, disappearance of PUFAs was followed by UV spectrophotometry at pH = 9.5 and at 35 degrees C via conjugated hydroperoxydienes at 234 nm. While OCl- rapidly destroyed all PUFAs, NH2Cl was inert. Overall second-order rate constants computed for L at increasing times disclosed that the attack on the cis-CH=CHCH2CH=CH moiety by OCl- does not follow simple second-order kinetics. Using a logit-log transform and second-order polynomial regression analysis of L's disappearance in a stoichiometric ([L] = 1.2 mM; [ClO-] = 2.4 mM) mix, data were analyzed by the time ratio method of Schwemer and Frost. These agreed with a sequential system of at least two irreversible second-order reactions having k1 = 15.6 L.mol-1.s-1 and k2 = 2.6 L.mol-1.s-1. Preliminary GC/MS analysis indicated that the initial product is a mix of chlorohydrin isomers. These undergo second addition of HOCl and/or lose halogens and polymerize. Additional minor products were also C5-C9 mono- and bifunctional carboxylates and mixed acid aldehydes. Studies with mol equiv of Cl- - free 36ClO- allowed estimation of covalent binding of Cl by L at various times, supporting the kinetic findings. For other PUFAs of higher degree unsaturation, the complexity of feasible reactions precluded an analogous approach.(ABSTRACT TRUNCATED AT 250 WORDS)


Mutagenic activation of benzidine requires prior bacterial acetylation and subsequent conversion by prostaglandin H synthase to 4-nitro-4'-(acetylamino)biphenyl.

We have used the Ames test in combination with prostaglandin H synthase (PHS) to study the bioactivation of benzidine as well as other aromatic amines. Previous investigations established that the formation of benzidine mutagens by PHS is dramatically enhanced in Salmonella typhimurium strains with high levels of acetyl CoA-dependent arylamine N-acetyltransferase/arylhydroxylamine O-acetyltransferase activity despite the fact that acetylation of aromatic amines decreases their susceptibility to oxidation by peroxidases. In this study, we used a new strain (YG1012) that has very high acetylation capability to investigate the metabolism and mutagenicity of benzidine and N-acetylbenzidine catalyzed by PHS (from ram seminal vesicle microsomes) and horseradish peroxidase (HRP). YG1012 bacteria rapidly acetylated benzidine to N-acetylbenzidine and N,N'-diacetylbenzidine. Preincubation of the bacteria with benzidine before addition of PHS increased the mutagenicity. Under conditions identical to those used to assess mutagenicity, PHS metabolized benzidine rapidly, but the substrate was not totally consumed, with about 40% of the original concentration remaining intact. These data suggest that conversion to N-acetylbenzidine may be the initial step in the bioactivation of benzidine in the PHS-mediated Ames assay. N-Acetylbenzidine is a cosubstrate for PHS peroxidase activity as measured by 5-phenyl-4-pentenyl hydroperoxide reduction, spectral changes, and formation of protein adducts. N-Acetylbenzidine was converted to mutagens by PHS but not HRP, with enhanced mutagenicity observed in bacteria with high acetylation activity. We used reverse- phase HPLC to characterize the metabolites of N-acetylbenzidine formed by PHS and HRP.(ABSTRACT TRUNCATED AT 250 WORDS)


Idiopathic fecal incontinence.

Pelvic floor dysfunction is related to neuropathic injury to the pelvic floor musculature. Clinically, the patient may present with genital prolapse or urinary or fecal incontinence. For a successful outcome, the physician must consider all pelvic compartments in the evaluation and treatment of patients with these disorders. Disorders of the posterior compartment are the least familiar to the gynecologist. Idiopathic fecal incontinence, a posterior compartment defect, is defined as a progressive deterioration of anal sphincter function in patients with no history of sphincter damage. This review discusses the latest findings about idiopathic fecal incontinence within the context of pelvic floor dysfunction and neuropathy.


Lower urinary tract infection in women.

Infections of the lower urinary tract affect 10% to 20% of all women, among whom a substantial proportion go on to experience recurrent infections. Bacterial virulence factors, particularly those enhancing mucosal adherence, are important in the pathogenesis of urinary tract infection. The use of a diaphragm with spermicides predisposes to urinary tract infection, most likely through alterations of the normal vaginal flora. Urine microscopy is the most accurate rapid office test for urinary tract infection. Automated and dipstick techniques yield slightly lower sensitivity and specificity. Recent treatment trials indicate that 3-day therapy for uncomplicated lower urinary tract infection provides an optimal balance between efficacy and adverse effects when compared with single-dose therapy or treatment for 7 to 10 days. Antibiotic prophylaxis is an important strategy in treating recurrent infections and is effective for periods as long as 5 years without undue emergence of resistant bacterial strains. Interstitial cystitis remains an elusive entity without definite diagnostic criteria or clearly effective therapy.


Malignant endometrial pathology.

This review discusses recent papers on endometrial carcinoma variants, immunohistochemical studies, and prognostic indicators. The aggressive nature of uterine papillary serous carcinoma is confirmed, even in the absence of myometrial or vascular invasion, with a comprehensive review of the histology, clinical presentation, and proposed treatment protocols. The possible etiologic role of radiation in the development of uterine papillary serous carcinoma is alluded to. The virulence of endometrial carcinomas with trophoblastic differentiation, endometrial carcinomas with a malignant giant cell component, and clear cell carcinomas of the endometrium is documented. A series of immunohistochemical studies is presented suggesting that uterine carcinosarcomas are metaplastic carcinomas derived from a common stem cell and that a shared histogenesis of endometrial stromal tumors and uterine mesoderm exists. Immunohistochemical techniques may clarify diagnostic problems of uterine tumors and their metastases and differentiate mucinous tumors of endometrium from endocervical origin. Staining of both carcinoembryonic antigen and ferritin in neoplastic endometria may be helpful in their differentiation from hyperplasias in curettage specimens. Significant prognosticators in endometrial carcinoma are depth of myometrial invasion and lymphovascular space involvement with greatest prognostic information provided by the depth of myometrial invasion above DNA index.


Benign and malignant breast pathology.

Research is focused on defining high-risk factors associated with the development of breast cancer and occult metastatic disease in node-negative patients. The interaction between hormones and growth factors is being diligently investigated, both in the genesis of breast cancer and in metastases. The effect of oral contraceptives on breast pathology remains under close scrutiny. Screening mammography for young women is proving to be of doubtful value.


Ovarian pathology.

During the period under review (December 1990 through January 1992), the revised World Health Organization Histological Classification of Ovarian Neoplasms and Tumor-like Lesions was completed, and it is presented herein. This system of classification incorporates recent advances and includes newly recognized entities and subtypes. A number of significant reviews covering the whole field of ovarian tumor pathology have been published, including reviews of clinical syndromes associated with ovarian neoplasia, metastatic tumors of the ovary, and the interrelationships between ovarian and appendiceal mucinous tumors and pseudomyxoma peritonei.


Measurement in psychogeriatrics.

Stake's concept of Responsive Evaluation is applied in evaluating the chain of psychogeriatric services of a general psychiatric hospital. Central to the approach presented are methodological considerations in describing individual treatment courses in their objective and subjective features. This can only be accomplished by establishing multidimensional strategies, incorporating biological, mental, psychological, and sociocultural aspects.


Treatment of behavioral symptomatology of Alzheimer's disease, with emphasis on aggression: current clinical approaches.

A scientific information base is developing which focuses on understanding and managing behavior problems in geriatric populations, especially those with dementing illnesses such as Alzheimer's disease. Many of these behavior problems occur in long-term care settings, which have a high prevalence of residents exhibiting emotional and behavioral disorders, often secondary to psychiatric illness. Prior to beginning treatment, behavior disorders must be systematically evaluated and understood to insure optimum care planning. One approach to effectively treating these disorders is to first separate them into two categories: those not amenable to psychotherapeutic medication treatment (nonpsychiatric disorders) and those that are amenable (psychiatric disorders). Specific nonpharmacological treatments may benefit those nonpsychiatric behavioral disorders and include behavioral and environmental paradigms. The psychiatric disorders, especially aggression and assaultive behavior, may be treated beneficially using a variety of psychopharmacological agents, including antianxiety agents, neuroleptics, carbamazepine, beta-blockers, and lithium. The most effective approach toward treating the psychiatric behavior disorders often combines both medication and nonmedication strategies.


Psychiatric phenomena in dementia of the Alzheimer type.

Psychiatric symptoms and behavioral disturbances are of importance in dementia of the Alzheimer type (DAT) but have been relatively neglected by researchers. The main psychiatric symptoms are disorders of thought content (delusions and paranoid ideation), disorders of perception (hallucinations and misidentifications) and disorders of affect (depressed and elevated mood). They occur commonly in DAT, and there is evidence that they may indicate subtypes of the disorder in view of their demographic, structural, and prognostic correlates. Personality changes are very common, and these may be the earliest manifestation of dementia. Behavioral disturbances tend to be associated with advanced dementia and are particularly disruptive to caregivers. Structural correlates suggest that some behaviors are a direct result of brain damage. Psychiatric and behavioral features in DAT are important, as they may serve as a model for symptomatology in functional psychiatric disorders.


Functional assessment staging (FAST) in Alzheimer's disease: reliability, validity, and ordinality.

Evaluation of changes in functional performance and activities of daily living skills is an essential aspect of the assessment of elderly individuals with chronic illness. Although functional decrement is a central aspect of Alzheimer's disease (AD), many measures currently utilized to assess these changes have limitations. Empirical and systematic examination of the functional changes occurring in patients with AD has resulted in the development of an assessment measure termed Functional Assessment Staging (FAST) that allows for the specific evaluation of these changes throughout the entire course of AD. In this paper the results of three separate investigations regarding the reliability, validity, and progressive ordinality of FAST are described. The results indicate that FAST is a reliable and valid assessment technique for evaluating functional deterioration in AD patients throughout the entire course of the illness. Moreover, the results suggest that the FAST elucidates a characteristic pattern of progressive, ordinal, and functional decline in AD. Because the elements of functional capacity incorporated in FAST are relatively universal and readily ascertainable, as well as characteristic of the course of AD, FAST can serve as a strong diagnostic and differential diagnostic aid for clinicians. The sensitivity of FAST to the entire course of AD, even in its most severe stages, may be indicative of the potential value of this instrument for further investigation of the temporal longitudinal course of AD, and of the relationships between clinical pathology and neuropathology throughout the entire longitudinal course of AD.


Functional rating scales and psychometric assessment in Alzheimer's disease: applications in pharmacological trials.

New findings on cognitive aging show that decline in brain functions is not part of a general decline of functioning in old age. We know now that with increasing age there is a differentiation of cognitive functions into two independent dimensions (fluid and crystallized functions). This two-dimensional model allows a more precise description of the cognitive aging process and of pathological changes. While crystallized cognitive abilities can be improved by training till late in life, fluid cognitive functions are subject to a progressive decrease starting as early as age 30, becoming most evident in cases of organic mental disorders. Thus, pathological aging is not necessarily accompanied by global loss of functions. Different abilities undergo changes in different ways, a fact taken into consideration by modern methods of psychometric evaluation. Beyond the aging processes mentioned previously, cognitive and behavioral changes in the elderly may be considered to be early indicators of organic mental disorders. The Nuremberg Self-Evaluation List seems to be a promising approach to diagnosis.


Global rating, symptoms, behavior, and cognitive performance as indicators of efficacy in clinical studies with nimodipine in elderly patients with cognitive impairment syndromes.

Nimodipine is a calcium antagonist which improves learning and memory in brain-lesioned or aged animals (LeVere & Sandin, 1989; Schuurman & Traber, 1989). It also accelerates the recovery of experimentally damaged sciatic nerves (van der Zee et al., 1987) and reduces age-associated gait abnormalities in aging rats (Schuurman et al., 1987). Selective action on cerebral vessels has also been proven. Vasoconstriction was prevented or reduced with nimodipine under experimental conditions (Toward, 1981) and cerebral blood flow could be increased (Kazda et al., 1982). The drug has been tested in subarachnoid hemorrhage, stroke, severe head injury, cerebral resuscitation after cardiac arrest, impaired brain function in old age, and dementia. Methodological aspects of clinical studies with this agent are examined in this paper.


Pharmacologic treatment of Alzheimer's disease: a methodologic critique based upon current knowledge of symptomatology and relevance for drug trials.

Research on the nature of clinical symptomatology in AD indicates that two fundamentally different types of symptoms are identifiable. Symptoms within each of these two domains have common characteristics. The first symptomatic domain has been termed the "cognitive domain" and the second the "noncognitive behavioral domain." Symptoms and losses in the cognitive domain occur invariably and progressively with the advance of AD over time. Symptoms in the behavioral domain do not invariably occur in AD and do not progress monotonically with the advance in AD over time. However, characteristic behavioral domain symptoms can be described over the course of AD. The two symptomatic domains are likely to differ not only in nature and progression in AD, but also in underlying pathophysiology and in terms of possible treatment modalities. They also pose fundamentally different issues of assessment in AD. These distinct factors necessitate the separate assessment of the two symptomatic domains in AD treatment trials. Judgments of efficacy and utility in remediating either symptomatic domain in AD should take into consideration the effects of treatment on both cognitive domain and behavioral domain symptoms separately and interactively. Appropriate assessment procedures are discussed.


A comparative study of the maximum oxygen uptake of regularly exercising and non-exercising health adult men in sedentary occupations.

This study aims to assess and compare the aerobic fitness (max VO2) of 210 healthy adult men in sedentary occupations in Singapore. All the subjects studied were in codes 0 to 2 of the Singapore Standard Occupational Classification, comprising professional, technical, administrative and related workers. Their max VO2 were determined from direct analyses of their expired respiratory gases during an all-out run on a treadmill. Of these 210 men, 71 (33.8 per cent) were recreation-related regular exercisers and their mean max VO2 of 40.9 ml/kg per min STPD (at standard temperature and pressure, dry) and 95 per cent confidence interval of 39.2-42.6 ml/kg per min was significantly higher (p less than 0.001) than that of the remaining 139 men (34.3 ml/kg per min STPD) with 95 per cent confidence intervals of 33.2-35.4 ml/kg per min who were not regular exercisers. The regular exercisers also met the max VO2 requirements for heavy physical work capacity and compared favourably with the recommended standards for aerobic fitness in the National Physical Fitness Award of Singapore as well as Cooper's Standards based on North American men while the non-regular exercisers did not. The study has shown that the recreation-related regular exercise of the study-defined type, intensity, duration and frequency can significantly improve the physical work capacity of healthy adult men in sedentary occupations in Singapore.


Mortality of urban transit workers: indications of an excess of deaths by suicide using gas.

Urban bus drivers are exposed to a variety of discomforts and physical hazards associated with their occupation. We obtained death certificates for 99 per cent of 219 decreased members of the Amalgamated Transit Union Local 596 of Edmonton, Alberta, and conducted a proportionate mortality study against the distribution of all deaths among men in the province of Alberta, standardized by age and year of death. We found a highly significant excess from undetermined accidents due to gas (proportionate mortality ratio (PMR) 3761, based on 3 cases; p less than 0.003), which may bear a relationship to an elevation observed for suicide due to gas, which failed to achieve statistical significance (PMR 242, based on 2 cases). Collateral evidence suggests that this excess may include misclassification of some suicides. Gas inhalation as an instrument of suicide may be suggested by familiarity with vehicle exhaust. No other excess achieved statistical significance. Several causes of death showed elevated PMRs of relatively modest magnitude; elevations in PMR for lung cancer (PMR 154) and chronic obstructive pulmonary disease (PMR 176) suggest a mutual association with smoking.


Workplace upper limb disorders: a prospective study with intervention.

A prospective longitudinal study was carried out to investigate the occurrence of upper limb disorders in an electromechanical plant between 1980 and 1988. It included clinical and epidemiological studies, measurement of vibration produced by the power tools used, ergonomic assessment of the works and time and motion studies. Simultaneously during the same period remedial actions were taken through multidisciplinary interventions when the specific causal factors were known. The study shows the clinical entities of the disorder, identifies the risk factors and evaluates the results of the interventions. It assists in establishing a cause and effect relationship for the condition and demonstrates the way a preventive strategy could be developed.


Epilepsy and employability: a comparative evaluation of epileptic employees working in the steel plants of India.

Information on seizures and provoking factors, occupational status, shift work, overtime, home and work place adjustment was obtained from 176 epileptic employees working in hazardous, less and non-hazardous areas of steel plants in India. Accidents at work and sickness absence were also assessed in 44 epileptics. An overall comparison was made between Group A hazardous (63) and Group B less/non-hazardous (76) of the total of 139 epileptic employees over a three year period. Group A performed better than Group B. When compared with 77 employees with occupational dermatoses, 139 epileptics did more fixed shifts and had less promotion.


Causes of hypersensitivity reactions in flour mill workers in Sudan.

A study of 237 male workers at two flour mills and 71 controls was carried out in Sudan in order to investigate the main possible causes of hypersensitivity reactions to flour dust. Statistical analysis was carried out for the skin test results of wheat, mixed moulds (A13), grain dust, and mixed moulds (group MH) allergen extracts. The results showed that there was no statistical significance between the two exposed groups namely allergy complaining vs. allergy non-complaining except for wheat results in one of the two flour mills which was very slightly significant. But there were highly significant differences between the exposed compared with the control group in all allergens tested. There was no significant correlation, between allergic symptoms and precipitins to wheat or grain dust, nor between precipitins and positive skin tests. The results of respirable flour dust concentrations at different work locations had exceeded the threshold limit values which were taken as 10 mg/m3. Aspergillus supp. and Rhizopus niger were the predominant fungi in the wheat grains and products which were collected from the two mills.


Management of post-incident trauma: a fire service perspective.

Post-incident trauma relates to the results of exposure to death and destruction. It has specific features relating both to the incident and symptoms it produces. Reactive symptoms occur in most people in the immediate after-period but rising or persisting anxiety towards the end of the first week indicates a risk of a serious disorder developing. Management should start immediately after the event and is a three stage process. Immediate management involves de-briefing and peer group support of the participants in the incident. For those who continue to experience rising or persisting anxiety after the first week, referral to occupational health advisers, welfare/counsellors or general practitioners is necessary and, if symptoms persist or recur, tertiary referral to specialist advisers such as psychologists or psychiatrists may be required. The most important factor in the treatment of post-incident trauma is to acknowledge its existence. Whilst the coping mechanisms are well established in theory, they require widespread implementation in practice.


An evaluation of several laboratory tests and test combinations in the detection of lupus anticoagulant.

The laboratory assessment of the lupus anticoagulant, a factor frequently associated with venous and arterial thrombosis, recurrent miscarriages and abortions, is not straightforward, as indicated by the variety of tests proposed and the different results obtained. On account of the marked variability and heterogeneity of lupus anticoagulant among patients, no single test or reagent will identify all patients with lupus anticoagulant, and a panel of several tests has to be used. This is time consuming and increases the workload of the laboratory. The aim of this study was to assess the minimum number of tests necessary for the satisfactory identification of the patient with lupus anticoagulant. Our study confirms that lupus anticoagulant may be present in a significant number of patients with normal routine activated partial thromboplastin time, a test which therefore cannot be used as the sole criterion for identifying patients suspected of having lupus anticoagulant. In contrast all patients who had positive results in at least one test could be detected (100% sensitivity) with two combinations of tests: (1) dilute activated partial thromboplastin time and Kaolin clotting time and (2) dilute activated partial thromboplastin time and tissue thromboplastin inhibition test. Since the latter inhibition test has been reported to give a high number of false-positive or negative results, we suggest the combination of dilute activated partial thromboplastin time and Kaolin clotting time as the standard pair of tests for the screening of suspected lupus anticoagulant patients.


Evidence that factor VII levels correlate strongly with fibrinopeptide A release: evaluation by an ex vivo method.

The generation of thrombin was estimated by an assay for fibrinopeptide A which was developed and employed to evaluate the relationship between factor VII and thrombin release. The amount of fibrinopeptide A released correlated strongly, when assayed in the early stages of the reaction, with factor VII coagulant activity levels in the range 50-2,000 units/dl. The method was then applied to study the relationship between factor VII and fibrinopeptide A in plasma from blood donors, women on the pill and patients on oral anticoagulants (with a range of factor VII coagulant activity from 8.5 to 600 units/dl). The overall evaluation of the relationship between factor VII and fibrinopeptide A showed a strong correlation which was higher for factor VII coagulant activity (r = 0.90) than for factor VII antigen levels (r = 0.817). The regression analysis which best fitted the data was the multiplicative one, indicating that thrombin formation increases faster when factor VII coagulant activity is in the upper part of the normal range or higher. In patients on oral anticoagulants, the correlation between factor VII and fibrinopeptide A was very poor. Our data fit well with the findings of the epidemiological studies in which high levels of factor VII coagulant activity were shown to be associated with an increased incidence of fatal coronary artery disease.


The effects of lipoproteins on the tissue factor-dependent activation of factor X.

We examined the effect of the lipoproteins on the activation of human factor X in an in vitro system containing purified human factor VII, low levels of tissue factor and calcium ions. In the absence of the lipoproteins the maximum activation was achieved within 10 min of the start of incubation; after this period the formation of factor Xa ceases. When very low-density lipoproteins, low-density lipoproteins or high-density lipoproteins were present at normal or subnormal plasma concentrations, the factor Xa generated was almost doubled after 10 min. This increase could be abolished by treating each lipoprotein subfraction with the phospholipase A2; hence, the treated lipoproteins lowered the factor Xa activity. We conclude that the phospholipids favor factor Xa formation and protect the tissue factor/factor VIIa/factor Xa complex from a potent inhibitor contained in the lipoprotein subfractions.


Molecular characterization of the P and I variants of alpha 1-antitrypsin.

Two rare alpha 1-antitrypsin variants, Pi I and Plowell, originally defined at the protein level through isoelectric focusing, were characterized at the DNA level by the polymerase chain reaction and direct sequencing. The I variant was confirmed in one individual and three independent families to result from a CGC(Arg) to TGC(Cys) transition at codon 39, within exon II. In our population, the Pi I variant might be more common than expected. The Plowell allele was shown in one M3P heterozygous individual to be due to a GAT(Asp) to GTT(Val) change at codon 256, in agreement with a previous study based on hybridization with allele-specific oligonucleotides.


Molecular economy and antibody function: the evolution of a Protecton.

The humoral immune response protects against a very large array of pathogens which attempt to escape immune recognition by changing the antigens they display. When looked at from the point of two competing sets of DNA (i.e., the pathogens vs. the host), there is a vastly larger pool of mutating pathogen DNA than in, say, a mouse. The stratagems that allow a tiny fraction of the mouse's genome to effectively compete with a hugely diverse array of pathogens is analyzed in terms of how antibody functions and how the immune system avoids such pitfalls as self-recognition and destruction. This review is a more general description of a lengthy series of papers which detailed the evolution of the Protecton. Starting from the obvious, that is the concentration-dependence of antibody function, it is apparent that the functional antibody repertoire must be relatively small if a sufficient concentration of specific antibody is to be produced in time to arrest the growth of pathogens and eventually eliminate them. Thus, commonly quoted estimates of antibody repertoires in the range from greater than 10(10) to "complete" (infinite?) must be seriously in error. Other well known "facts", such as D-diversity, and B cell signaling by receptor aggregation are also shown to be lacking in biological commonsense.


Cell adhesion molecules in neoplastic disease.

In a variety of human malignancies, tumorigenesis and the development of metastatic disease are accompanied by changes in the expression of cell adhesion molecules. In carcinomas, normally expressed cell adhesion molecules are lost, or expressed in a functionally altered form, events which may help tumor cells to escape from contact-mediated controls and leave the primary tumor. The development of metastatic potential is, in a number of solid tumors, associated with the expression of new cell adhesion molecules by the tumor cells. These newly expressed cell adhesion molecules appear to mediate tumor cell interaction with leukocytes and endothelium, and may direct dissemination of the tumor cells throughout the body.


CD38: a multi-lineage cell activation molecule with a split personality.

This review reports the characteristics of the human surface molecule CD38, a structure not linked to a definite line and predominantly expressed in early and activated phenotypes. The CD38 molecule consists of a single chain of 46 kDa, spanning the membrane and with the carboxyl terminus located in the extracellular compartment. The CD38 molecule is also involved in the transduction of activation and proliferation signals, which are line unrestricted. The gene coding for the CD38 antigen has been cloned and used for the construction of simian and mouse transfectants expressing the human molecule. These cell models are used for the analysis of several unanswered issues, mainly concerning the in vivo function of CD38, the existence of a natural ligand and of polymorphism in the population.


Update on tumor vaccines.

Vaccination against tumor has always been an attractive idea for the treatment of patients bearing tumor. By harnessing the host's own immune response the attack on tumor cells would act on a continuing basis, with emerging tumor cells stimulating their own destruction. However, the approach has been hampered by our poor understanding of the nature of tumor antigens and of the pathways by which immune cells might operate against tumor growth. Recent developments in molecular biology and immunology are remedying this deficiency and bringing vaccination to the forefront of new approaches to treatment of a range of tumors. Results obtained in B-cell tumors, where the idiotypic immunoglobulin at the cell surface provides a well-defined tumor antigen, are already indicating exciting possibilities as well as delineating problems. There is considerable clinical evidence that patients have some intrinsic ability to control tumor growth and that certain tumors remain dormant for long periods. Attempts to understand and perhaps stimulate the mechanisms involved are being made through the use of biological modifiers and by manipulating potential effector cells in vitro. Ideally this approach, which may include non-specific and specific elements, could be combined with specific vaccination in order to combat the apparent ability of many tumor cells to evade host defences.


Are heat shock proteins involved in autoimmunity?

Heat shock proteins (HSPs) have been postulated to be critical antigens in both autoimmune disease and experimental models of autoimmunity. This postulate has been largely based on the remarkable conservation of aminoacid sequence between human and bacterial HSPs, so that it has been argued that immune responses initially directed against the HSP of an infectious agent, would have the potential to initiate or maintain autoimmune disease. This would apply especially to T cell recognition of HSPs, since the T cell focuses on short peptide epitopes within a protein antigen rather than on the antigen's secondary structure. This article critically evaluates the available experimental evidence relating to this hypothesis: although research has clearly highlighted the central role of HSPs in the cellular immune response to pathogenic organisms and has shown the potential for T cell responses directed against self HSPs, a role for self HSPs as major target antigens in autoimmune disease has yet to be firmly established.


Nursing's agenda for health care reform: a critique.

This paper discusses the nature of the health care crisis with a focus on the issues of economics, the private insurance industry, race and ethics as they relate to Nursing's Agenda for Health Care Reform. Recommendations are made for assuring the entire population quality, equitable health care.


Predicting nursing student's success on NCLEX-RN.

The purpose of this retrospective pilot study was to evaluate the importance of four predictor variables in predicting success on the NCLEX-RN. The predictor variables included: pre-nursing GPA, ACT scores, comprehensive examination scores and scores on the Basics I, NLN Achievement Test. The subjects were a sample of 35 graduates of a newly developed baccalaureate nursing program. Findings of this study were inconclusive. Basic I test scores were significantly correlated with successful achievement on the NCLEX-RN and were significant predictors of success. The other variables were not significant predictors. Recommendations were to repeat the study with a larger sample.


Storage proteins are present in the hemolymph from larvae and adults of the Colorado potato beetle.

The protein composition of larval and adult hemolymph from the Colorado potato beetle, Leptinotarsa decemlineata, was investigated and some abundant, high molecular weight proteins were identified and characterized. Diapause protein 1, which occurs in the hemolymph of last instar larvae and short-day adults, appeared to be a storage protein. This protein dissociated into two bands due to the high pH used in nondenaturing gels. Its quaternary structure was established by chemical crosslinking. It appeared to be a hexamer. Diapause protein 1 is composed of approximately 82,000 subunits. The amino acid composition and N-terminal sequence of this protein has been determined. Specific antibodies against diapause protein 1 have been developed. Topical application of 1 microgram pyriproxyfen, a juvenile hormone analog, to last instar larvae and short-day adults suppressed the appearance of this protein in the hemolymph. Pyriproxyfen prematurely induced vitellogenin, when applied to last instar larvae. A larval specific protein was also identified in the hemolymph. Its temporary appearance in the hemolymph of last instar larvae, its subunit composition (M(r) approximately 82,000) and its suppression by pyriproxyfen suggests that this protein is a storage protein as well.


Infradian cycles of oxygen consumption in diapausing pupae of the flesh fly, Sarcophaga crassipalpis, monitored by a scanning microrespirographic method.

Fine details of the infradian O2 consumption cycles that characterize pupal diapause in flesh flies have been monitored by a newly designed microrespirographic method coupled with an electronically regulated O2 generator. During the 4-5 days between the peaks of elevated O2 consumption, the diapausing pupae maintained a very low and fairly constant respiratory rate (13 microl O2 x g-1.h-1). During the intercalated peaks of increased respiratory metabolism, which lasted an average of 33.6 h to 24-27 degrees C, the average maximum rate of O2 consumption was 86.9 microl.g-1.h-1, a value of 6.7 times higher than the interpeak values. The respiratory peaks started abruptly in some cases while the decline was consistently gradual. During the periods between the peaks there were no discontinuous bursts of CO2 release, a feature common to diapause in many other insects. Diapause was characteristically terminated during a peak of the O2 consumption cycle. At diapause termination O2 consumption remained at the maximum values of the peak for many hours and then gradually increased to levels characteristic of nondiapause development.


Separation of insect hemolymph proteins by cascade-mode multi-affinity chromatography.

The hemolymph of the adult female Manduca sexta was fractionated by cascade-mode multi-affinity chromatography (CASMAC) on a main-line tandem column chain containing Zn(2+)-TED, T-gel, Ni(2+)-DPA, and phenylsepharose and a side-line column containing Zn(2+)-DPA. The technique separated some of the previously described major hemolymph proteins, and yielded a number of fractions with simple composition. Some of these fractions contained only less abundant proteins of Manduca hemolymph. Thus, it appears that CASMAC would be a very useful fractionation technique for purification and characterization of the minor proteins of insect hemolymph.


Allatostatins in the nerves of the antennal pulsatile organ muscle of the cockroach Diploptera punctata.

The presence of allatostatins in the nerves of the antennal pulsatile organ muscle of the cockroach Diploptera punctata was confirmed by immunocytochemistry, bioassay, and HPLC. Immunocytochemical reactivity with monoclonal antibody against allatostatin I showed strong allatostatin immunoreactivity in the antennal heart nerve which innervates this muscle with varicosities along the muscle fibers and in the insertion of the muscle on the pulsatile ampullae. Bioassay of Sep-Pak purified muscle extract demonstrated inhibition of juvenile hormone synthesis by corpora allata in vitro. A dose-response curve showed maximum inhibition of juvenile hormone synthesis was achieved with 10-20 pulsatile organ muscle eq/corpora allata, and 50% inhibition achieved with an estimated 2.6 pulsatile organ muscle eq. Two successive HPLC separations of the Sep-Pak purified extract yielded bioactive fractions corresponding to the elution times of the five known allatostatins.


Role of phospholipids in the lipophorin particles of Rhodnius prolixus.

The lipophorin of Rhodnius prolixus metabolically labelled with 32P exclusively in the phospholipid moiety was purified on a potassium bromide gradient and treated with phospholipase A2 in the presence of an excess of fatty acid-free albumin. The treatment completely removed the phospholipids from the particles and generated [32P]-lysophosphatidylcholine, [32P]-lysophosphatidylethanolamine, and free fatty acids that remained bound to albumin. The phospholipid-depleted lipophorin particles remained soluble, indicating that phospholipids are not essential in maintaining the stability of the particles in aqueous solution. Complete removal of phospholipids did not affect the association of apolipophorin III with lipophorin particles. Lipophorin density increased slightly from 1.120 to 1.134 g/ml after treatment. The phospholipid-depleted particles also retained their ability to be recognized and loaded in vitro with phospholipids delivered by the fat body, thus supporting the concept of lipophorin's role as a reusable lipid shuttle for phospholipids.


Storage proteins of the larval root weevil Diaprepes abbreviatus (Coleoptera: Curculionidae): riboflavin binding and subunit isolation.

Proteins present at high concentrations in hemolymph of the larval weevil Diaprepes abbreviatus were previously shown to bind a synthetic coumarin, 7-amino-3-phenyl coumarin (coumarin-10). One of the two native proteins previously identified (protein I) is now shown to separate into two distinct bands (proteins Ia and Ib) using native gradient pore-limiting electrophoresis. The high concentration of proteins Ia, Ib, and II in larval hemolymph, their disappearance from hemolymph upon pupation, and an apparent hexameric structure shown by chemical crosslinking identify them as hexameric storage proteins (hexamerins). At least one chromatographic form of Ib isolated by anion exchange HPLC is now shown to bind riboflavin (Rb). Binding was also demonstrated by quenching of Rb fluorescence by a partially isolated mixture of the storage proteins. Lipophorin did not quench Rb fluorescence. Rb was heat-extracted from whole hemolymph and identified by its fluorescence spectra and by reverse phase HPLC with fluorescence detection. The two subunits shared by the three holoproteins have been isolated by sequential density gradient ultracentrifugation, gel permeation HPLC, and reverse phase HPLC. All three holoproteins shared the alpha subunit (M(r) 75,000), while the beta subunit (M(r) 71,000) was lacking from one of the three. Repeated passage through an anion exchange column yielded two of the three proteins (Ib and II) in homogeneous form. Chemical crosslinking with dimethylsuberimidate indicated a hexameric structure for the holoproteins. All subunits and holoproteins stained as high mannose glycoproteins when probed with biotinylated concanavalin A on PVDF membranes. The alpha subunit was high in Met, His, and Thr, and the beta subunit was high in Lys. Both were high in Pro and had approximately 16% Phe+Tyr. Sequences of the 20 N-terminal amino acid residues of each subunit showed 45-60% homology between subunits. These coleopteran proteins also showed some sequential homology but no immunological cross-reactivity with storage proteins from the lepidopterans Galleria mellonella and Heliothis virescens.


[Attributable risk percent under an effect modifier and legal causality].

Among civil trials there are cases which are influenced by evidence derived from epidemiologic studies. In such cases, causality of a factor (X) illegitimately introduced by defendants is considered to be measured with an epidemiologic measure, attributable risk percent (AR%) expressing the level of risk. This paper aims to discuss calculations and interpretations of AR% in complicated cases where plaintiffs themselves introduced an additional risk factor (Y) for the alleged health injury. When X is not an effect modifier, AR% of X adjusted for Y can be simply adopted for arriving at a judgement of causality. Where Y is an effect modifier, and is not an indispensable item in the plaintiffs' daily life (e.g., smoking), the AR% of X for those not exposed to Y and also the AR% for those exposed to Y may both need to exceed a legally determined threshold, in order for X to be legally acknowledged as being causal to the alleged injury. The role of epidemiologists for such trials is to determine the AR% of X for each level of Y, and to advise the court on a realistic range of the AR%s.


[A review of studies on school-based smoking prevention programs].

Research papers on school-based programs designed to prevent adolescent smoking were reviewed to determine trends in the development of smoking prevention programs as well as measures and methods of evaluation. In the USA and Europe, evaluation studies have demonstrated that the most promising smoking prevention approaches are those that focus primary attention on the psychosocial factors promoting smoking initiation. In Japan, however, most programs have shown little success. The following recommendations are made for improving the methods for evaluating program effectiveness and the future of research orientation of educational program on adolescent smoking. 1) Refinement and standardization of evaluation methods to be valid and feasible for use in studies of Japanese adolescents. 2) Improved study designs for evaluation of program effectiveness which include control groups and long term follow-up. 3) Applying smoking prevention programs which were demonstrated to be effective in the USA and Europe. 4) Development of effective cessation programs for adolescent smokers.


[Effect of daily energy intake and amount of walking on body weight reduction and its maintenance].

The relationship of daily energy intake and the amount of walking performed, based on pedometer readings, for effective body weight reduction were studied based on results of a weight reduction program at the Aichi Prefectural Center of Health Care from 1983 to 1990. In addition, a follow-up study based on a mailed questionnaire was performed, to further determine the relationship to maintenance of body weight reduction of energy intake and amount of walking after the conclusion of program. The subjects were two-hundred and forty middle-aged obese women who were placed on a 5-month weight reduction program consisting of diet (1500 kcal/day) and exercise (10000 walk steps/day). At the end of the program, the mean energy intake and the mean number of steps per day had reached target levels and the mean body weight reduction was 4.2 kg. The relationship of energy intake, and the number of steps walked at the end of program to the amount of reduction in body weight during the program was analyzed by multiple regression analysis, and the amount of walking expressed in the number of steps necessary for weight reduction were calculated for various energy intakes. A follow-up study was performed in 1988, with sixty-six women responding to the mailed questionnaire. Since the end of the program, body weight increase of 1.1 kg occurred, but body weight was still lower than initially. Although mean energy intake increased after the program, a level about 200 kcal less than at the beginning of the program was being maintained, so the effect of diet recommendation in the program appeared to be retained.(ABSTRACT TRUNCATED AT 250 WORDS)


[A study of the relationship between job type and/or position to life style and health of male white-collar workers].

The relationship between the type of job and/or position of male white-collar workers to their working life, life style, health behavior, and health condition was examined based on data obtained from a survey of 1129 male workers in a major computer manufacturing company in 1988. The results were as follows: 1. Work, life style, health behavior, and health condition of male white-collar workers are strongly affected by type of job and position when adjusted for education, income, and age. 2. Workers in the sales department and engineering department appeared to have the most problems associated with working life, life style, health behavior, and health condition. Workers in sales, especially, displayed Type A behavior and their job was characterized by a lot of business transactions in a working environment that requires them to work until late at night. This leads to an irregular diet, late bed time, and makes their family relationships worse. Workers in the engineering department had work loads that were heavy because they have the longest working hours, and the content of their jobs is a mixture of both research and sales. Consequently their health is not good. On the other hands, workers in the laboratory had the best situation, and with general workers about average in terms of working life, life style, health behavior, and the state of health. 3. The department heads have the best conditions of life and health over all, except for their diet. The chiefs of sections are generally in the middle between the department heads and ordinary workers in terms of life and health. They drink and smoke heavily and show Type A behavior characteristics. Ordinary workers appear to have the most problems in working life, life style, health behavior, and health condition. From these results it may be concluded that this is associated with the difference in work type and position of these workers compared to managerial class and also with a low level of morale.


[The rupture of cedar pollens in nasal secretions].

Allergic rhinitis caused by pollen of Japanese cedar (Cryptomeria japonica) is found in Japan. These pollens, when inhaled into the nasal cavity, contact the nasal mucus membrane, and the allergens separate from the pollens, and pass through the nasal mucosa to interact with the mast cell-bound IgE. Patients with allergic rhinitis produce a great volume of nasal secretion from the mucosa. The morphological transformation of the cedar pollens when mixed with nasal secretion was studied. Nasal secretion was collected from two patients with allergic rhinitis. Cedar pollen gathered from a Japanese cedar tree was mixed with distilled water, and the cedar pollen suspension was mixed with a drop of nasal secretion on a slide glass at the room temperature (23 degrees C), and examined by phase-contrast microscopy. Of the pollen 20.6% were ruptured after 3 min, and 52.9% after 10 min, 84.9% after 40 min, and 81.3% after 60 min respectively. Further changes in shape of the ruptured pollens were observed with continued incubation. A hole opened in the cytoplasmic membrane through which the nucleus escaped, and crinkling of the residual cytoplasmic membrane was observed. The escaped nucleus separated into many small granules. In order to determine possible causes of the pollen rupture in nasal secretion, the relationship between pH of the nasal secretion and rupture rate was examined. The pH of the nasal secretion from two patients was 8.95 and 9.15 respectively. Salt solutions of 0.1 M NaCl, (NH4) 2SO4, NaNO3, CaCl2, Na2SO4, KCl, MgSO4, had pH range from 5.13 to 6.40.(ABSTRACT TRUNCATED AT 250 WORDS)


[Involuntary smoking in a workplace situation--discomfort of nonsmokers and interpersonal awareness of smokers].

A questionnaire survey was conducted to examine the socio-behavioral interaction between smokers and nonsmokers in a workplace situation. A socio-behavioral interaction is hypothesized to be centered around the subjective discomfort such as 'bothered feelings' towards involuntary smoking among nonsmokers. Study subjects were 1,134 nonsmokers and 1,457 smokers working in 21 small-scale production companies in Japan. Among nonsmokers, a combined 93.3% reported 'perceived exposure to smoking', 'always', 'often', or 'sometimes' compared to 6.6% reporting 'never'. Similarly, 74.6% experienced 'bothered feelings' 'sometimes', 'always', or 'often' compared to 25.3% reporting 'never'. A combined total of 39.4% expressed their discomfort to smokers 'sometimes', 'often', and 'always' compared to 60.6% who 'never' did. In contrast, 59.1% of smokers responded that they smoked with consideration of nonsmokers' presence (interpersonal awareness) 'sometimes', 'often', and 'always' compared to 41.0% for 'never'. 'Bothered feelings' among nonsmokers was significantly lower among those with past smoking history and correlated positively with 'perceived exposure to smoking' (rs = 0.22, p less than 0.001) and with 'expression of discomfort among both male (rs = 0.32, p less than 0.001) and female nonsmokers (rs = 0.34, p less than 0.001). Among male smokers 'interpersonal awareness' was significantly higher for those with less cigarette consumption and with past history of smoking cessation. A regression analysis was performed using mean scores calculated for smokers and nonsmokers of each workplace. Lower 'bothered feelings' of nonsmokers significantly correlated with higher 'interpersonal awareness' of smokers (r = -0.59, p less than 0.005). These finding imply the presence of socio-behavioral interactions between smokers and nonsmokers and thus suggest the significance of workplace education on involuntary smoking.


[Problems associated with mass-screening system for gastric cancer in Japan].

In the mass-screening system for gastric cancer, subjects are primarily examined by contrasted indirect roentgenography and if secondary examination is diagnosed to be necessary, they are examined by contrasted direct roentgenography or gastric fiberscopy. Methods for increasing the efficiency of this system from the standpoint of cost-effectiveness were studied, and the basis for decision of whether or not serological examinations such as of serum pepsinogens and serum anti-Helicobacter-antibodies should be brought in to the system, and in what manner serological examinations should be brought in to the system if proven to be effective were examined. Problems found in the present practiced system and the proposed new system with serological examinations were repetition interval for examinations, selection of high-risk subjects and communication between subjects and the medical staff or among the members of the medical staff. Analysis by receiver operating characteristics curve should be included when serological examinations are indicated. In addition whether the mass-screening system for gastric cancer produces an actual reduction in death by gastric cancer should be confirmed after the system is made more efficient.


[Relationship of smoking to absenteeism due to illness and injury in male workers].

The relationship between smoking and absenteeism due to illness and injury was studied in 21,924 male workers employed in the chemical fiber industry in Japan. Smokers had a significantly higher incidence of absence than non-smokers. The proportion of cases of absence in smokers was 30% higher and the number of days of absence was 28% greater than in non-smokers. Ex-smokers also had a significantly higher incidence of absence than non-smokers. In ex-smokers the proportion of cases of absence was 22% higher and the number of days of absence was 68% greater than in non-smokers. Although there was no significant difference between smokers and non-smokers in the number of days of absence attributed to cardiovascular or respiratory diseases, smokers were absent for about twice as many days as non-smokers for diseases of the digestive system. For ex-smokers the number of days of absence was 4.3 times higher for cardiovascular diseases, 1.5 times higher for respiratory diseases, and 2.9 times higher for digestive system diseases than in non-smokers. After correction for age, type of work, Body Mass Index, exercise, and drinking by multiple logistic analysis significantly elevated relative risks for absence persisted both in smokers and ex-smokers vs. non-smokers at 1.4 and 1.3, respectively. Significant dose-response relationships between incidence of absence and the number of cigarettes smoked per day were observed in respiratory disease, diseases of the digestive system and all disease causes. A significant dose-response relationship between incidence of absence and smoking index was also observed for diseases of the digestive system. These findings clearly indicate that smoking by workers was associated with absence due to illness and injury, and suggest that smoking was a factor contributing to an increase in absenteeism due to illness and injury in workers.


[A cross-sectional study of lipid peroxide levels (plasma TBA levels) in a mass health examination].

Differences in plasma thiobarbituric acid (TBA) levels were studied by sex and age in 1,178 adults (471 males and 707 females) participating in a mass health examination conducted in a town of Kumamoto Prefecture in 1989. The relationships between plasma TBA levels and obesity, the consumption of cigarettes, alcohol, and fish, and various indices for health status derived from the data of physiological examinations were analyzed in age-groups 40-59 and 60-79 for both sexes. The prevalence of abnormal physiological findings by plasma TBA levels were further investigated. The results were as follows; 1. The highest plasma TBA levels for males were observed in the group aged 40-49, with levels gradually decreasing with age thereafter. The plasma TBA levels for females increased with age and the highest levels were obtained at age 60-69. The plasma TBA levels for males were significantly higher than for females at aged 40-49. 2. Plasma TBA levels for both sexes increased with obesity and the amount of fish consumed. 3. Plasma TBA levels in all examined groups had significant and strong positive correlations with serum total cholesterol levels and atherogenic indices, and had significant positive correlations with serum calcium and gamma-GTP levels. 4. A stepwise multiple regression analysis showed that plasma TBA levels for males were associated with serum total cholesterol, gamma-GTP, fish consumption and serum HDL-cholesterol in that order. The levels for female were associated with serum total cholesterol, body mass index, serum HDL-cholesterol and serum calcium in that order. The relationship with serum HDL-cholesterol was a negative correlation. 5. Prevalence of abnormal values of serum total cholesterol, atherogenic index and body mass index were significantly higher in the high-plasma TBA level group than in the group with median-plasma TBA level. These results suggest that plasma TBA levels may be useful as an index of undesirable lipid metabolism. Further studies should be performed to establish the significance of the relation of plasma TBA levels to fish consumption.


[A nested case-control study of risk factors for intracerebral hemorrhage and cerebral infarction classified by computed tomographic findings].

Risk factors for intracerebral hemorrhage (ICH) and cerebral infarction (CI), were studied by a prospective study of 7,390 men and women aged 40-69 without a history of stroke living in three rural populations in Japan. Baseline examinations were done for populations in Akita-Ikawa and Akita-Ishizawa in 1975-1979, and for Ibaraki-Kyowa in 1981-1987, and followed until 1989 for Akita-Ikawa and Ibaraki-Kyowa and 1987 Akita-Ishizawa. There were 246 stroke cases diagnosed by clinical criteria during the follow-up period in which 74 percent (n = 181) had data from computed tomography (CT) performed within three weeks of the onset. According to these CT-findings, 181 stroke were classified as 48 with ICH, 50 with CI in penetrating artery regions (penetrating artery infarction), 33 with CI in cortical artery regions (cortical artery infarction), and 31 with subarachnoid hemorrhage while there were 19 with stroke without any evident CT abnormality. Cortical artery infarction was further classified as embolic type (n = 17) and thrombotic type (n = 9) according to clinical findings of the onset and presence of possible embolic sources such as atrial fibrillation, congenital heart disease, myocardial infarction and heart valve diseases. Using a nested case-control design, risk variables at baseline examination were compared between 131 stroke cases, 48 ICH and 83 CI, with 655 controls matched for sex, age (+/- 3), and the follow-up year. Univariate analysis showed that high blood pressure was associated with all types of stroke. From conditional logistic regression analysis significant risk variables were found to be high blood pressure for ICH and penetrating artery infarction, while atrial fibrillation and ST-T abnormality in electrocardiogram (ECG) were risk variables for cortical artery infarction. Associations with hypertensive or arteriosclerotic changes in ocular fundus were stronger for penetrating artery infarction than ICH and cortical artery infarction. ST-T abnormality in ECG was associated with embolic type cortical artery infarction and high blood pressure was associated with the thrombotic type, although the number of cases were small. Compared to controls, cortical artery infarction showed a higher mean value of serum total cholesterol for thrombotic type cortical infarction, and lower mean values for embolic type and ICH, but none of them reached statistical significance. The present study also suggests that duration of hypertension varied with type of stroke. ICH may develop due to acute effects of hypertension, while penetrating artery infarction and cortical artery infarction develop by chronic effects of hypertension.


[Differences in the prevalences of Raynaud's phenomenon in general populations living in a mountain area and in a plain area].

Raynaud's phenomenon (RP) which is the episodic and reversible vascular spasm of the extremities can be elicited by cold or emotional changes. RP has been classified into two groups. One is primary Raynaud's phenomenon (PRP) with no identifiable underlying disease and/or cause, and the other is the secondary form of RP (Raynaud's syndrome) with underlying disease and/or cause, e.g., collagen disease, trauma, vibration from vibrating tools, etc. In the present study using this definition of RP the prevalences of RP were studied in general populations in a mountain village "T" and in a town "K" located in a plain area in Gifu prefecture, Japan. The prevalences of RP in T Village were 8.0% (25/314) in males and 3.5% (16/454) in females, and in K Town 2.7% (7/259) in males and 3.2% (21/657) in females. In 52% of the male cases in T Village it was estimated that the exposure to vibration from vibrating tools was the cause of RP. In K Town no male cases of RP were induced by vibration. Exposure to vibration may be one of the important factors when prevalences of RP are investigated in various areas. There were no significant differences between the two areas in the prevalences of PRP (T Village: male 2.9%, female 3.1%; K Town: male 2.7%, female 2.9%). The annual mean air temperature was usually 5-6 degrees C lower in T Village than that in K Town. From the results of this study the differences in the mean air temperature did not appear to have a significant influence on the prevalence of PRP in each area.


[Effects of food intake, dietary habits and life style on health status as determined by clinical blood tests of adult men].

A survey of the frequency of various kinds of foods, dietary habits, life style, and health status was performed on 2,049 men aged from 40 to 59 living in an urban area who were participants in a "human dock" medical checkup. The relationships between these factors and health status were studied in order to identify a particular life style associated with good health status. The instrument utilized in this survey was a special form of a structured questionnaire. The results are summarized below. 1. The frequency of various kinds of foods were correlated with the kind of breakfast eaten, dietary habits, physical exercise habits, daily physical activity, smoking, and occupation. The strongest correlation to frequency of various kinds of foods was found to be with the kind of breakfast eaten and dietary habits. 2. Dietary habits were also correlated to various aspects of life style: smoking, drinking, the frequency of various kinds of foods, kind of breakfast eaten, daily physical activity, sleeping hours, habits related to physical exercise, and the frequency of meals eaten away from home. Dietary habits correlated most closely with the frequency of various kinds of foods and daily physical activity. The frequency of various kinds of food and dietary habits were found to correlate with various aspects of life style, and those subjects with good overall life styles were also found to have desirable dietary life styles. The correlation of desirable dietary habits, food intake and a suitable life style with good health status was confirmed by the results of clinical blood tests used as an index of health status.(ABSTRACT TRUNCATED AT 250 WORDS)


Peptide sequencing by matrix-assisted laser-desorption mass spectrometry.

A novel method of peptide sequencing by mass spectrometry is described. Metastable decay of laser-desorbed ions, taking place in the first field-free drift region of a reflection time-of-flight mass spectrometer, has been monitored to get structural information from larger peptides. Fragment ions from metastable decay are mass analysed by adjusting the potentials of the ion reflectron according to the kinetic energies of the ions. The features of the technique and its significance for future applications are outlined.


Determination of the acyl moieties of the antibiotic complex A40926 and their relation with the membrane lipids of the producer strain.

Structures of the fatty acid residues characterizing the various components of A40926 were determined by gas chromatography/mass spectrometry on the methyl esters obtained by methanolysis of the complex. The results confirm the residues previously assigned to Factor A (n-undecanoic acid) and B (10-methyl-undecanoic acid) and establish the residues of Factor A1 (9-methyl-decanoic acid), B1 (n-dodecanoic acid), RS1 (8-methyl-nonanoic acid), RS2 (n-decanoic acid), and RS3 (n-tridecanoic acid). As the Actinomadura species contain in their mycelia large quantities of C15-C17 fatty acid residues as membrane phospholipids, these mycelia were saponified and the fatty acids obtained were analyzed as above. There is a close correlation between the fatty acid content of A40926 complex and that of the longer homologues in the producer mycelia.


Ionspray mass spectrometry of marine toxins. IV. Determination of diarrhetic shellfish poisoning toxins in mussel tissue by liquid chromatography/mass spectrometry.

An improved liquid chromatographic/mass spectrometric (LC/MS) method utilizing gradient elution and ion-spray ionization is described for the sensitive determination of okadaic acid and dinophysistoxin-1, the principal toxins implicated in cases of diarrhetic shellfish poisoning. The method was used to confirm the presence of both toxins, together with a recently identified isomer of okadaic acid, dinophysistoxin-2, in various samples of cultivated blue mussels (Mytilus edulis) from Canadian and European waters. The method provided a mass detection limit of 0.4 ng for each toxin, thus allowing detection of 40 ng per g of whole mussel tissue (or approximately 10 ng/g if only the digestive glands were used in the assay). Quantitative results obtained by LC/MS were in good agreement with those obtained by derivatization and high-performance liquid chromatography with fluorescence detection.


Analysis of saxitoxin in urine by continuous-flow fast-atom bombardment mass spectrometry.

An improved method of saxitoxin analysis in urine using continuous-flow fast-atom bombardment mass spectrometry was developed. Parameters studied were matrix composition, matrix flow, temperature of probe tip, probe-tip design and sample extraction. Optimal detection was obtained using the following matrix composition: 5% glycerol, 0.5% acetic acid, 0.025% sodium dodecylsulfate, 0.1% polyethylene glycol (PEG) 400 and 0.5% PEG 300; probe-tip temperature: (approximately 55 degrees C); flow rate: 5 or 8 microL per min.; probe tip: Olson-Hogge design. The STX standard was detected at 200 pg with signal-to-noise ratio of 11. The percent recovery of saxitoxin from human urine after clean-up on a weak cation exchange column was 75%.


Secondary-ion and electron production from surfaces bombarded by large polyatomic ions.

Heavy molecular ions with energies in the range 10-20 keV and masses from 276 u to 132,000 u, produced by matrix-assisted laser desorption, were used as primary projectiles to produce secondary-ion spectra from a variety of surfaces in a tandem time-of-flight mass spectrometer. In the negative mode the ratio of electron emission to secondary-ion emission was found to decrease rapidly with increasing projectile mass. Ion emission was found to dominate for primary ions larger than approximately 10,000 u. Positive or negative molecular ions and cations were observed from several organic targets of masses up to 1140 u (gramicidin S) for incident projectiles up to mass 132,000 u, i.e., for projectile speeds down to approximately 7000 m/s. Other ions characteristic of the target were also observed for these projectiles. Thus, large polyatomic ions can cause secondary-ion desorption even at very low velocity. The background ions of both polarities are similar to those found in keV particle bombardment by monatomic projectiles. The same ions are observed for all the projectiles; most can be identified with hydrocarbon background. The relative intensities of the background positive ions are largely independent of projectile, and for both polarities the ratio of the ions characterizing the target to those forming the background is approximately constant for all the projectiles. These results strongly suggest that the background ions come from the usual layer of organic impurities attached to the target surface. No direct evidence for surface-induced dissociation was observed in this mass and energy range.


Fragmentation studies of peptides: the formation of y ions.

The mechanism for the formation of y ions in the collision-induced dissociation (CID) spectra of protonated peptides produced by fast-atom bombardment was investigated by tandem mass spectrometry and deuterium labelling studies. The results show that a hydrogen atom attached to nitrogen and not to carbon migrates during cleavage of the amide bond. A mechanism based on these results is presented.


Preservation and visualization of molecular structure in detergent-extracted whole mounts of cultured cells.

Today's electron microscopes have a resolution sufficient to resolve supramolecular structures. However, the methods used to prepare biological samples for electron microscopy often limit our ability to achieve the resolution that is theoretically possible. We use whole mounts of detergent-extracted cells grown on Formvar-coated gold grids as a model system to evaluate various steps in the preparation of biological samples for high resolution scanning electron microscopy (SEM). Factors that are important in determining the structure and composition of detergent-extracted cells include the nature of the detergent and the composition of the extraction vehicle. Chelation of calcium is extremely important to stabilize and preserve the cytoskeletal filaments. We have also demonstrated both morphologically and by gel electrophoresis that treatment of cells with bifunctional protein crosslinkers before or during extraction with detergent can significantly enhance the preservation of both proteins and supramolecular structures. The methods used to dry samples are a major determinant of the quality of structural preservation. For cytoskeletons freeze-drying (FD) is superior to critical point-drying (CPD), one reason being that CPD samples have to be dehydrated, thereby causing more shrinkage as compared to FD samples. The high pressures to which samples are exposed during CPD may also cause increased shrinkage, and water contamination during CPD causes severe structural damage. We have obtained the best structural preservation of detergent-extracted and fixed cells by manually plunging them into liquid propane and drying over night in a freeze-dryer. The factor that most limits achievement of high resolution in SEM is the metal coat, which has to be very thin, uniform, and free of grain in order not to hide structures or to create artifactual ones. We have found that sputter-coating with 1-3 nm of tungsten (W) or niobium (Nb) gives extremely fine-grained films as well as satisfactory emission of secondary electrons. These samples can also be examined at high resolution by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). The best preservation and visualization of supramolecular structures have been obtained using cryosputtering, in which the samples are freeze-dried and then sputter-coated within the freeze-dryer while still frozen.


Sample preparation for electron microscopy of internal cell structure.

Methods are reviewed for examination of internal cell structure by high-resolution scanning electron microscopy and compared with the rapid-freeze deep-etch replica technique used in transmission electron microscopy. Rapid freezing of fresh material, followed by freeze-fracture, provides a theoretically attractive approach in ultrastructure studies, but the high protein and solute content of most cells prevents a deep three-dimensional view for material frozen without some form of extraction. After discussion of other methods it is concluded that the most useful general approach, at least for cultured cells, is to first permeabilize or break open the cells in a medium which preserves the structure under study in a functional state as, for example, the movement of chromosomes along the division spindle, or transport of proteins within the Golgi region. After permeabilization, with attendant partial extraction, the preparation can be fixed, then viewed by either deep-etch replication, or by high-resolution scanning electron microscopy, with structure of interest revealed in deep view.


Ultrastructural imaging of freeze-fractured plant cells in the scanning electron microscope.

The application of the freeze-fracture and cytoplasmic maceration technique in ultrastructural studies of plant cells is described. A major advantage of the technique is, that by extracting mobile cytoplasmic components from the freeze-fractured cells, surface relief is introduced and three-dimensional information is obtainable. The details of specimen preparation are described and the results obtained are reviewed. The use of chitosan embedding for very small or fragile specimens is described.


Freeze-substitution of chemically stabilized samples for biological field emission scanning electron microscopy.

The high resolution imaging capabilities of modern field emission scanning electron microscopes require adequately improved tissue preparation procedures to prevent the collapse of macromolecular structures and the extraction of molecules. A routine cryo-stabilization technique is described which utilizes chemical crosslinking and cryo-dehydration for mechanical and chemical stabilization of protein and lipid structures and increase of electrical conductivity of the sample. Thiocarbohydrazide (TCH) serves as a general mordant for osmium tetroxide crosslinking. However, extensive washing after all impregnation steps is necessary to dissolve unspecific osmium black precipitations at the sample surface. Collagen I aggregates showed increased stability against collapse after TCH osmification alone, whereas pulmonary surfactant liposomes require additional freeze-substitution in methanol and Freon 113 for stabilization during critical point drying. Environmental scanning electron microscopy (at water vapor pressures of 5-10 torr within the specimen chamber) was used to control, in the wet phase, the stabilization procedure at the level of chemical crosslinkage. It could be confirmed that tannic acid, often used to stabilize lipids, leads to artificial rearrangement of bilayered liposomes into compact presumable multilayered bodies, whereas the TCH osmification preserved liposome structures and their aggregates. The increase of electrical conductivity of sliced tissue was demonstrated on kidney. Support technologies for the cryo-stabilization procedures are described in detail, as well as simple routines for first stabilization trials with new samples. On pulmonary tissue, the excellent preservation of alveolar shape and fine structures of intermediate forms of surfactant are described.


Chemical extraction of the cytosol using osmium tetroxide for high resolution scanning electron microscopy.

Detailed examination of subcellular structures in three dimensions (3D) by high resolution scanning electron microscopy (HRSEM) is now possible due to improvements in the design of the scanning electron microscope and the introduction of methods of specimen preparation using chemical removal of the cytosol and cytoskeleton by dilute osmium tetroxide. Cells which have been fixed, frozen, cleaved, thawed, and subjected to cytosol extraction display intact intracellular structures in 3D including nuclear chromatin, endoplasmic reticulum, mitochondria, and the Golgi complex at a resolution close to that of conventional biological transmission electron microscopy (TEM). Small changes in the 3D structure of subcellular components can be conveniently examined in this way in development, in a variety of physiological processes and in disease. Broad areas of the specimen can be quickly surveyed by HRSEM since sectioning is not required and specimens of comparatively large size (up to 5 mm3) can be placed in the microscope. Extraction of the cytosol with dilute osmium tetroxide (OsO4) exposes subcellular structures in relief, permitting their examination in 3D from several aspects. However, the OsO4 extraction technique is limited, since significant intracellular structures, such as the cytoskeleton, vesicles, and antibody binding sites can be removed or inactivated during the cytosol removal steps.


Determination of conditions for optimum resolution of a high angle thin window energy dispersive spectrometer.

The energy resolution of an energy dispersive spectrometer (EDS) equipped with an ultrathin window (UTW) and mounted at a high take-off angle (72 degrees) on a transmission electron microscope has been studied under a variety of operating conditions. The spectrometer resolution is close to that specified by the manufacturer, up to count rates of 400 cps. Above 400 cps the resolution deteriorates rapidly, and the MCA dead time and zero width increase. Above 10 keV, the height of the background is much greater than expected for bremsstrahlung and shows the shape which has previously been attributed to backscattered electron flux into the detector. It is postulated that the deterioration in resolution with count rate is caused by backscattered electrons reaching the detector through the UTW.


Preparation of aqueous standards for low temperature X-ray microanalysis.

A technique, using Nuclepore polycarbonate membrane filters as a containing medium for very small volumes of ionic standard solutions, to produce homogeneous ice standards is described. The standards are suitable for use in a scanning electron microscope. The relationship between elemental X-ray counts and ionic concentration is found to be linear. The method is rapid and simple. Minimum detectable concentrations are given.


Ultrastructural studies on membrane, cytoskeletal, mucous, and protective compartments in olfaction.

There is a great variety in the morphological appearance of olfactory structures across the metazoan animal kingdom. Despite this variety the receptive structures themselves have a strikingly similar architecture, namely some type of elongated cellular extension that is spanned by a membrane and surrounded by mucus. These cellular extensions can either be modified primary or secondary cilia, or microvilli. There are more similarities between membranes of these extensions than between the cytoskeletal elements immediately underneath the membranes. One might infer that the cytoskeletal elements of the cellular extensions merely serve as a scaffold for the membranes, whereas the similarity in membrane ultrastructure provides morphological evidence supporting the concept that these membranes are responsible for the initial olfactory transduction process. The transduced message is transported to the brain, where it is decoded to initiate the cascade of events resulting in the organisms' appropriate behavioral response to the initial odorous stimulus. The varying appearance of olfactory structures across the animal kingdom is probably produced by evolutionary pressure to adapt the olfactory system to the animal's environment. This review deals with the ultrastructural aspects of these facets of olfaction.


Cortical ultrastructure and chemoreception in ciliated protists (Ciliophora).

The ciliated protists (ciliates) offer a unique opportunity to explore the relationship between chemoreception and cell structure. Ciliates resemble chemosensory neurons in their responses to stimuli and presence of cilia. Ciliates have highly patterned surfaces that should permit precise localization of chemoreceptors in relation to effector organelles. Furthermore, ciliates are easy to grow and to manipulate genetically; they can also be readily studied biochemically and by electrophysiological techniques. This review contains a comparative description of the ultrastructural features of the ciliate cell surface relevant to chemoreception, examines the structural features of putative chemoreceptive cilia, and provides a summary of the electron microscopic information available so far bearing on chemoreceptive aspects of swimming, feeding, excretion, endocytosis, and sexual responses of ciliates. The electron microscopic identification and localization of specific chemoreceptive macromolecules and organelles at the molecular level have not yet been achieved in ciliates. These await the development of specific probes for chemoreceptor and transduction macromolecules. Nevertheless, the electron microscope has provided a wealth of information about the surface features of ciliates where chemoreception is believed to take place. Such morphological information will prove essential to a complete understanding of reception and transduction at the molecular level. In the ciliates, major questions to be answered relate to the apportionment of chemoreceptive functions between the cilia and cell soma, the global distribution of receptors in relation to the anterior-posterior, dorsal-ventral, and left-right axes of the cell, and the relationship of receptors to ultrastructural components of the cell coat, cell membrane, and cytoskeleton.