Clinical genetic studies of Alzheimer's disease

In this article, the authors review the genetic investigations in Alzheimer's disease employing epidemiologic study techniques--mainly case-control, twin, and cumulative risk studies--as well as pedigree and genetic linkage studies and discuss the implications these studies have for identifying and characterizing a possible genetic etiology of Alzheimer's disease. Some of the methodologic issues associated with each of these techniques and the more general problems associated with identifying genetic factors in Alzheimer's disease are discussed, and some directions and prospects for future research in this area are indicated.

Retinoblastoma protein and simian virus 40-dependent immortalization of human fibroblasts

Transformation and immortalization of human diploid fibroblasts by simian virus 40 (SV40) is at least a two-stage process, since transformants have a limited lifespan in culture. We have isolated immortalized derivatives (AR5 and HAL) from transformants generated with an origin-defective SV40 genome encoding a heat-labile large T protein (T antigen) and reported that both preimmortal and immortal transformants are continuously dependent on T antigen function for growth as determined by temperature shift experiments. In this study, we demonstrate complex formation between T antigen and the retinoblastoma susceptibility gene product (Rb) at 35 degrees C and observed a reduction in complexes under conditions of loss of T antigen function and growth inhibition at 39 degrees C. Viral oncogenes (polyomavirus large T protein and adenovirus E1A 12S protein) known to bind Rb were introduced into AR5 and HAL cells, both stably by gene transfer and transiently by virus vectors. Such double transformants are still unable to proliferate at 39 degrees C, although complex formation with the newly introduced oncogenes was demonstrated. We suggest that T antigen interacts with other cellular processes in addition to Rb to transform and immortalize human cells in culture. Our finding that p53-T antigen complexes are also temperature dependent in AR5 and HAL cells could provide such an additional mechanism.

[Preliminary infection source of downy mildew of Corydalis yanhusuo W. T. Wang]

The downy mildew of Corydalis yanhusuo caused by Peronospora corydalis usually brings about devastating harm in Anhui Province. In the past, it was generally held that the spores in diseased remains buried in soil were the main source of preliminary infection. But, according to our test, it is the mycelia in tubers that are mainly the preliminary infections source.

[Isolation of bilirubin oxidase from Myrothecium verrucaria and the optimum conditions of enzyme production]

A bilirubin oxidase (EC 1.3.3.5) producing strain, Mv 2.1089, was isolated from several strains of Myrothecium verrucaria by dilution method. The optimum conditions of enzyme production were investigated and the results were as follows: the suitable medium was cultured at 25 degrees C on a rotating shaker glucose and peptone, at pH 6.0. The strain was cultured at 25 degrees C on a rotating shaker (150 r/min) for 96 h. Bilirubin oxidase with 0.5-1.5 u/ml was obtained in the culture medium.

A three-year follow-up study of age-related dementia in an urban area of Beijing

A 3-year follow-up study of 1090 people aged 60 years or over in an urban area of Beijing, China, was conducted to determine the incidence of dementia and its characteristics of distribution. This cohort has been studied first in a cross-sectional survey of dementia in 1986. The follow-up examination employed the same interviewers, psychiatrists, instruments (Mini-Mental State Examination and the Crichton Royal Behavior Rating Scale) and diagnostic criteria for dementia (modified DSM-III) in 1989. The respondent rate in this study was 75.7%. The average annual incidence rate of moderate and severe dementia for greater than or equal to 60 years was 0.3% (95% confidence interval 0.08-0.52%). As expected, the rate increased sharply with aging. No sex difference was found. The prevalence rate of moderate and severe dementia was 1.10% among those aged greater than or equal to 65 years, similar to that (1.82%) in the first survey. Our results showed that the multi-infarct dementia was somewhat more common than primary degenerative dementia (ratio 3:2), both among incident cases and current prevalent ones. The average duration of dementia in the community was 8.0 years (SD 3.4). The risk for death in demented patients was 3 times higher than in the whole cohort (standardized mortality ratio = 2.95), and no specific cause of death was observed. In addition, our study showed that elderly people with less education, a history of consistent unemployment, limited physical activity and stroke history had a higher risk for developing dementia.

Contribution of multiple rounds of viral entry and reverse transcription to expression of human immunodeficiency virus type 1. A quantitative kinetic study

Human immunodeficiency virus 1 (HIV-1) infection in vitro has been analyzed by the kinetics of expression of HIV-1 RNA and antigens during treatment with antiviral agents. Intracellular HIV-1 RNA rose from input values of 15 molecules per cell to 28 molecules per cell within 3 h after infection and reached a peak of 13,125 in 5 days. The first detectable increase in levels of HIV-1 capsid protein production was 1 day after infection. Virus infection was interrupted at different time points by the introduction of either 2',3'-dideoxycytidine, 3'-azido-3'-deoxythymidine, or suramin to block reverse transcription, or recombinant soluble CD4 to block binding and re-entry of progeny virus. Two results are noteworthy. First, the three inhibitors of reverse transcription blocked viral expression when added up to 48 h after infection. Second, the extent of infection, although postponed, is not greatly altered by culture of infected cells in recombinant soluble CD4. These data imply that reinfection with progeny virus, while necessary for rapid virus expression, is not required for the establishment of productive HIV-1 infection.

[Selection of optimum technological conditions for vinegar-processing of fresh rhizoma Corydalis]

The Total alkaloid contents of chloroform extracts and aqueous decoctions of different vinegar-processed samples of fresh Rhizoma Corydalis were determined and compared using orthogonal experimental design. Two optimum schemes suggested by the results are 1. If aqueous decoction is wanted, the fresh tuber Corydalis should be scalded by hot edible vinegar till the liquid has permeated to its center; 2. If total alkaloid extract is required for making Chinese traditional patent medicine, the fresh Rhizoma should be slightly scalded with edible vinegar which has been diluted with an equal volume of water.

Refractive index measurement using a standard compensating method

The first three significant digits of a sample's refractive index are compensated by a standard, therefore a precise measurement, which is the same as the refractive index of the standard, can be obtained. The method only needs a thin sample.

[Comparison of analgesic effect between locally vinegar-processed preparation of fresh rhizoma Corydalis and traditionally vinegar-processed rhizoma Corydalis]

Hot plate and writhing methods were used in the comparison of the analgesic effect of vinegar-processed fresh tuber corydalis and the traditionally vinegar-processed Rhizoma Corydalis. The result shows that the effect of the former is stronger than that of the latter.

Lipid-protein interactions in thylakoid membranes of chilling-resistant and -sensitive plants studied by spin label electron spin resonance spectroscopy

Lipid-protein interactions in thylakoid membranes from lettuce, pea, tomato, and cucumber have been studied using spin-labeled analogues of the thylakoid membrane lipid components, monogalactosyl diglyceride and phosphatidylglycerol. The electron spin resonance spectra of the spin-labeled lipids all consist of two components, one corresponding to the fluid lipid environment in the membranes and the other to the motionally restricted lipids interacting with the integral membrane proteins. Comparison of the spectra from the same spin label in thylakoid membranes from different plants shows that the overall lipid fluidity in the membranes decreases with chilling sensitivity. Spectral subtraction has been used to quantitate the fraction of the membrane lipids in contact with integral membrane proteins. Thylakoid membranes of cucumber, a typical chilling-sensitive plant, have been found to have a higher proportion of motionally restricted lipids and a different lipid selectivity for lipid-protein interaction, as compared with those of pea, a typical chilling-resistant plant. This correlation with chilling sensitivity holds generally for the different plants studied. It seems likely that the chilling sensitivity in thylakoid membranes is not determined by lipid fluidity alone, but also by the lipid-protein interactions which could affect protein function in a more direct manner.

The development of the lamprey pattern generator for locomotion

The life cycle of the lamprey includes a larval stage that can last for several years. The motor behavior of the larval lamprey, the ammocoete, has been only minimally studied and little is known of the neural correlates of that behavior. Comparison of known larval behavior to that of adults leaves unclear whether there are large or small changes in the spinal nervous system during transformation. The motor output of isolated larval and transforming spinal cords when stimulated to "swim" with D-glutamate has some differences from that of comparable adult preparations, but shares many important features with adults. Primarily, the fictive swimming is less well regulated and less stable than adults of the same species. We propose that a major difference in the structure and organization of the central pattern generator for locomotion between adults and ammocoetes is a relative lack or immaturity of some cell types that participate in the coordination of the segments and the generation of the rhythm of the periodic bursting.

Inhibitory effect of omeprazole on the metabolism of midazolam in vitro

To examine the effect of omeprazole on the hepatic drug metabolizing enzyme system microsomes from rat and human liver samples were incubated with midazolam (CAS 59467-70-8) in the absence and presence of various concentrations of omeprazole (CAS 73590-58-6), its sulfone metabolite and for comparison also with cimetidine. In the extracted incubation mixtures unchanged midazolam, a-OH-midazolam, 4-OH-midazolam and di-OH-midazolam were analyzed by HPLC. In both species omeprazole (and its sulfone) inhibited the formation of all three oxidized metabolites of midazolam and the corresponding IC50-values (range 0.2-1.3 mmol/l for rat microsomes and 0.2-1.5 mmol/l for human microsomes) were comparable to cimetidine (range 0.05 to 3.8 mmol/l). These results indicate that the oxidative metabolism of midazolam can be inhibited in vitro by omeprazole (and/or its sulfone metabolite) and this interaction should be considered if both drugs are administered concomitantly in man.

[Chemical evaluation of vinegar-processing method for fresh rhizoma Corydalis]

Qualitative and quantitative analysis were carried out on the samples of Rhizoma Corydalis in both the locally vinegar-processed (fresh) and traditionally vinegar-processed forms. No difference was found in the main chemical constituents. However, both the total alkaloids and the corydalis B content of the former are higher than those of the latter.

Tuning sensitivity of dye laser birefringent filters

An analysis of the angle between the optical axis and the optical surface of a birefringent filter used in the cw dye laserhas been made. It shows that the tuning sensitivity of the filter reaches its maximum when the angle is ~30-35 degrees .

[Effects of fu-mai mixture on oxygen consumption, PaO2 and pulmonary artery pressure of animals under hypoxia]

10% Fu-mai mixture has been used in anoxia mice per os 0.5 ml one time. The experimental results indicate that the tolerance to anoxia under low or normal pressures is increased and the oxygen consumption at 5th, 10th, 15th, 20th and 25th minute is reduced. Moreover, the decrease of PaO2 and increase of pulmonic pressure in acute anoxia rabbits can be inhibited by transfusing 2.5 ml of the mixture. The virulence is very slight.

Is cyclosporin A an inhibitor of drug metabolism?

1. The potential for a drug interaction between cyclosporin A and midazolam was investigated since both compounds appear to be metabolized by the same cytochrome P-450 isoenzyme. 2. In vitro evaluation of the binding of cyclosporin A to rat microsomal cytochrome P-450 indicated a Ks-value of 0.4 microM. In further studies with rat liver microsomes IC50-values of 6, 8 and 70 microM cyclosporin A were determined for the inhibition of the metabolism of midazolam to its alpha-OH-,4-OH- and di-OH-metabolites, respectively. 3. Comparative studies with human liver microsomes indicated IC50-values of approximately 300 microM for the formation of alpha-OH-midazolam and of 65 microM for the formation of 4-OH-midazolam. 4. The pharmacokinetics of a single intravenous dose of midazolam (0.075 mg kg-1) was studied in nine patients receiving cyclosporin A to prevent rejection of their transplanted kidneys. The average steady state blood concentrations of cyclosporin A, measured by r.i.a. using a specific monoclonal antibody, varied during a dosing interval between 175 and 600 ng ml-1. 5. In these patients the hepatic elimination of midazolam was characterized by a mean t1/2 (+/- s.d.) of 2.3 +/- 1.2 h and a plasma clearance (CL) of 414 +/- 95 ml min-1. These values were not different from those of normal human subjects (t1/2 = 1.5 to 4 h, CL = 350 to 700 ml min-1). 6. From the results of the in vitro experiments it is concluded that cyclosporin A may potentially inhibit drug metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary lymphomas of the lung: morphological, immunohistochemical and clinical features

Sixty-two cases of primary malignant lymphoma of the lung were investigated. Fifty-eight lymphomas were of B- and two of T-cell type. Two cases of high-grade lymphoma could not be further classified. The largest group (43 cases) consisted of low-grade B-cell lymphoma of the bronchus-associated lymphoid tissue. These showed features similar to low-grade B-cell lymphomas of the mucosa-associated lymphoid tissue of the stomach. The low-grade lymphomas showed a peak occurrence in the sixth decade, the high-grade lymphomas in the seventh decade. Males predominated slightly. Three-quarters of the patients with low-grade B-cell lymphoma of the bronchus-associated lymphoid tissue showed solitary or multiple sharply defined nodules of the lung. The prognosis of the B-cell-derived lung lymphomas without constitutional symptoms was relatively favourable, regardless of whether they were of low- or high-grade malignancy, whereas patients with constitutional symptoms and the two patients with T-cell lymphomas showed a bad prognosis. However, recurrences and metastases in the lung, stomach, lymph nodes and salivary glands were seen in about 46% of the cases of low-grade B-cell lymphoma of the bronchus-associated lymphoid tissue.

Titration of human immunodeficiency virus type 1 (HIV-1) and quantitative analysis of virus expression in vitro using liquid RNA-RNA hybridization

An assay is described for titration of human immunodeficiency virus type 1 (HIV-1) and for quantitative analysis of virus expression in vitro. The assay utilizes a liquid RNA-RNA hybridization method coupled with reversible target capture (RTC) on oligo(dT) derivatized magnetic particles. The assay provides a rapid, specific, and sensitive method for quantitation of HIV-1 RNA molecules present either in cells or in viral particles from cell-free culture media. Chronically infected monocytoid U1.1 cells were found to carry 52 pg HIV-1 RNA per 200,000 cells (160 HIV-1 RNA molecules per cell). In contrast, acutely infected CEM and H9 cells carried 3010 and 4370 pg HIV-1 RNA per 200,000 cells (9040 and 13,110 HIV-1 RNA molecules per cell, respectively). No hybridization was observed with uninfected cells or cells infected with HIV-2, HTLV-I, HTLV-II, or EBV. Use of liquid HIV-1 RNA hybridization in association with HIV-1 protein detection methods permits more complete characterization of HIV-1 expression in host cells than either method alone, and also provides a method for standardizing preparations of virus.

Lipid-protein interactions in stacked and destacked thylakoid membranes and the influence of phosphorylation and illumination. Spin label ESR studies

The effects of membrane destacking, protein phosphorylation, and continuous illumination have been studied in pea thylakoid membranes using ESR spectroscopy of an incorporated spin-labelled phosphatidylglycerol. This spin-labelled analogue of an endogenous thylakoid lipid has previously been shown to exhibit a selectivity of interaction with thylakoid proteins. Neither destacking, phosphorylation nor illumination was found to change the ESR spectra appreciably, suggesting that for phosphatidylglycerol at least, neither the number of protein-associated membrane lipids nor their pattern of selectivity was altered. The redistribution of the thylakoid protein complexes in the membrane, under these various conditions, therefore takes place with conservation of the properties of the lipid/protein interface.

Determination of the fast axis with an infrared spectrometer for quartz and mica waveplates

The variation of dichroism with wavelength is used in an infrared spectrometer to find the fast and slow axes of quartz and mica waveplates.

[Observations on neuronal activity in frontal cortex and EMGs in monkeys during performing noxious and innocuous heat discrimination GO/NO-GO task]

To study the functional implication of neuronal responses in frontal cortex to noxious and innocuous heat stimuli, experiments were carried out on two monkeys (Macaca mulatta) during performing a delayed discrimination GO/NO-GO task. The animals were trained to hold a lever for at least 3 s in the response period when an innocuous heat stimulus had been applied to the forearm in the cue period, or release it within 1 s with a noxious one. After a criterion of 90% of correct responses in 3 successive days was reached, single neuronal activity was recorded from the frontal cortex along with EMGs from six muscles in both arms. Of 142 task-related neurons recorded, 87 (66.4%) were related to heat, 34 to visual, and 21 to both visual and heat stimuli. Among the heat-related neurons, 22 were responsive to noxious heat, 18 to innocuous heat, and 47 to both. Of the neurons responding to both noxious and innocuous heat stimuli, 4 neurons showed changes in discharge rates, depending on the type of stimuli. In most cases, muscular activities just appeared at the moment of lever pressing and/or releasing in m. extensor digitorium communis, m. flexor carpi ulnaris and m. flexor carpi radialis of the performing arm. No regular muscular activities appeared in other muscles and in other periods of the task. The result showed that the neuronal responses in frontal cortex elicited by heat stimuli in the cue period were not related directly to the initiation and modulation of behaviours.(ABSTRACT TRUNCATED AT 250 WORDS)

[Relation of serum growth hormone and estradiol levels and osteoporosis in postmenopausal women]

Serum GH, E2, FSH, LH levels, bone mass, serum alkaline phosphatase (AKP), calcium levels and urinary calcium/creatine ratio in 42 postmenopausal women were compared with those in 30 women of fertile age. In thirteen out of the postmenopausal women we also observed these parameters before and after treatment with diethylstilbestrol (DES). The postmenopausal women had significantly reduced serum GH (P less than 0.01) and E2 levels (P less than 0.001) and increased serum FSH(P less than 0.001), LH levels (P less than 0.001), and had lower bone mass (P less than 0.01). They also had increased serum AKP levels (P less than 0.05) and urinary calcium/creatine ratio(P less than 0.01). There were positive correlations between serum E2 and GH levels, between postmenopausal bone loss and serum E2, GH decline. The postmenopausal bone loss began early as menopause commenced. After treatment with DES in 13 postmenopausal women, we observed that GH significantly increased (P less than 0.01) and FSH, LH decreased (P less than 0.001), AKP decreased by 27.58% and urinary calcium/creatine ratio decreased by 43.94% (compared with that before treatment). Our results indicate that bone turnover increased after menopause and resorption exceeded formation. There is bone loss in early postmenopause. The postmenopausal bone loss is related to serum GH, E2 levels. Estrogen replacement therapy is necessary in postmenopausal women and it should be given as early as possible. After treatment with DES, increased serum GH levels, decreased AKP values (27.58%) and urinary calcium/creatine ratio (43.94%) suggest that estrogen may play a definite role in bone metabolism through increased GH.

Spin-label ESR studies of lipid-protein interactions in thylakoid membranes

Lipid-protein interactions in thylakoid membranes, and in the subthylakoid membrane fractions containing either photosystem 1 or photosystem 2, have been studied by using spin-labeled analogues of the thylakoid membrane lipid components, monogalactosyldiacylglycerol, phosphatidylglycerol, and phosphatidylcholine. The electron spin resonance spectra of the spin-labeled lipids all consist of two components, one corresponding to the fluid lipid environment in the membranes and the other to the motionally restricted membrane lipids interacting directly with the integral membrane proteins. Spectral subtraction has been used to quantitate the fraction of the membrane lipids in contact with the membrane proteins and to determine the selectivity between the different lipid classes for the lipid-protein interaction. The fractions of motionally restricted lipid in the thylakoid membrane are 0.36, 0.39, and 0.53, for the spin-labeled monogalactosyldiacylglycerol, phosphatidylcholine, the phosphatidylglycerol, respectively. Spin-labeled monogalactosyldiacylglycerol exhibits very little preferential interaction over phosphatidylchline, which suggests that part of the role of monogalactosyldiacylglycerol in thylakoid membranes is structural, as is the case for phosphatidylcholine in mammalian membranes. Spin-labeled phosphatidylglycerol shows a preferential interaction over the corresponding monogalactosyldiacylglycerol and phosphatidylcholine analogues, in contrast to the common behavior of this lipid in mammalian systems. This pattern of lipid selectivity is preserved in both the photosystem 1 and photosystem 2 enriched subthylakoid membrane fractions.

Growth of immortal simian virus 40 tsA-transformed human fibroblasts is temperature dependent

Simian virus 40 (SV40)-mediated transformation of human fibroblasts offers an experimental system for studying both carcinogenesis and cellular aging, since such transformants show the typical features of altered cellular growth but still have a limited life span in culture and undergo senescence. We have previously demonstrated (D. S. Neufeld, S. Ripley, A. Henderson, and H. L. Ozer, Mol. Cell. Biol. 7:2794-2802, 1987) that transformants generated with origin-defective mutants of SV40 show an increased frequency of overcoming senescence and becoming immortal. To clarify further the role of large T antigen, we have generated immortalized transformants by using origin-defective mutants of SV40 encoding a heat-labile large T antigen (tsA58 transformants). At a temperature permissive for large-T-antigen function (35 degrees C), the cell line AR5 had properties resembling those of cell lines transformed with wild-type SV40. However, the AR5 cells were unable to proliferate or form colonies at temperatures restrictive for large-T-antigen function (39 degrees C), demonstrating a continuous need for large T antigen even in immortalized human fibroblasts. Such immortal temperature-dependent transformants should be useful cell lines for the identification of other cellular or viral gene products that induce cell proliferation in human cells.

Different requirements for protein kinase C activation and Ca2+-independent insulin secretion in response to guanine nucleotides. Endogenously generated diacylglycerol requires elevated Ca2+ for kinase C insertion into membranes

Electrically permeabilized RINm5F cells were used to assess the factors required for activation of protein kinase C (PKC) and insulin secretion. PKC was activated either by phorbol 12-myristate 13-acetate (PMA) or by the generation of endogenous diacylglycerol in response to the nonhydrolyzable guanine nucleotide analog guanosine 5'-O-(thiotriphosphate) (GTP gamma S). As shown previously, both PMA and GTP gamma S elicit Ca2+-independent insulin secretion. This effect was mimicked by guanyl-5'-yl imidodiphosphate (Gpp(NH)p) but not by guanosine 5'-O-(3-fluorotriphosphate) and guanosine 5'-O-(3-phenyltriphosphate) possessing only one negative charge in the gamma-phosphate group. The action of PMA was mediated by PKC, since the agent caused both phosphorylation of specific protein substrates and association of the enzyme with cellular membranes. This translocation was independent of the Ca2+ concentration employed. In contrast, GTP gamma S only promoted association of PKC with membranes at 10(-6) and 10(-5) M Ca2+ and failed to alter significantly protein phosphorylation in the absence of Ca2+. Neither Gpp(NH)p, which stimulates insulin release, nor the other two GTP analogs, increased the proportion of PKC associated with membranes. To verify that the Ca2+-dependent effect of GTP gamma S on PKC is due to activation of phospholipase C, we measured the generation of diacylglycerol. GTP gamma S indeed stimulated diacylglycerol production in the leaky cells by about 50% at Ca2+ concentrations between 10(-7) and 10(-5) M, an effect which was almost abolished in the absence of Ca2+. Thus, at 10(-7) M Ca2+, the concentration found in resting intact cells, the generated diacylglycerol was not sufficient to cause PKC insertion into the membrane, demonstrating that both elevated Ca2+ and diacylglycerol are necessary for translocation to occur. It is concluded that while PKC activation by PMA elicits Ca2+-independent insulin secretion, the kinase seems not to mediate the stimulatory action of GTP analogs in the absence of Ca2+.

Mode of activation of bovine brain inositol 1,4,5-trisphosphate 3-kinase by calmodulin and calcium

The effect of Ca2+ and calmodulin (CaM) on the activation of purified bovine brain Ins(1,4,5)P3 kinase was quantified and interpreted according to the model of sequential equilibria generally used for other calmodulin-stimulated systems. Two main conclusions can be drawn. (i) CaM.Ca3 and CaM.Ca4 together are the biologically active species in vitro, as is the case for the great majority of other calmodulin targets. (ii) These species bind in a non-co-operative way to the enzyme with an affinity constant of 8.23 x 10(9) M-1, i.e. approx 10-fold higher than for most calmodulin-activated target enzymes. The dose-response curve of the activation of Ins(1,4,5)P3 kinase by calmodulin is not significantly impaired by melittin and trifluoperazine, whereas under very similar assay conditions the half-maximal activation of bovine brain cyclic AMP phosphodiesterase requires over 30-50-fold higher concentrations of CaM when 1 microM melittin or 20 microM-trifluoperazine is present in the assay medium. Similarly, 1 microM of the anti-calmodulin peptides seminalplasmin and gramicidin S, as well as 20 microM of N-(6-aminohexyl)-5-chloro-1-naphthalene-sulphonamide (W7), do not inhibit the activation process. These data suggest that binding and activation of Ins(1,4,5)P3 kinase require surface sites of calmodulin which are different from those involved in the binding of most other target enzymes or of model peptides.

An epidemiological survey of age-related dementia in an urban area of Beijing

An epidemiological survey of age-related dementia among community residents of an urban of Beijing was conducted in 1986. Initial screening of 1331 subjects aged 60 and above was made using the Mini-Mental State Examination (MMSE) with a cutoff point of 17. All suspected cases of dementia and 5.5% of all others were then given a full clinical examination, with subjects being diagnosed and classified according to DSM-III criteria. The MMSE was found to have satisfactory sensitivity, although scores were significantly correlated with education. Prevalence rates of moderate and severe dementia were 1.28% for those aged 60 and above and 1.82% for those aged 65 and above. Rates for multi-infarct dementia were higher than those for primary degenerative dementia; females had higher rates than males and rates increased sharply with age. All the dementia cases were cared for in their own homes, by relatives. There is a need for increased knowledge and services for elderly people in the community.

Methionine-enkephalin alteration of mitogenic and mixed lymphocyte culture responses in zinc-deficient mice

The effects of methionine-enkephalin (Met-Enk) on mitogenic and mixed lymphocyte culture (MLC) proliferation of splenocytes from Zn-deficient, restricted and control mice were evaluated. The data from this experiment show that Met-Enk can suppress the responses of splenocyte from the 3 groups to concanavalin A (Con A), but less inhibition was observed in the Zn-deficient group. Met-Enk can also enhance the responses to pokeweed mitogen (PWM) and decrease the response to lipopolysaccharide (LPS) in all groups. Alteration of proliferative responses to Con A and PWM were reversible in the presence of naloxone 10 mumol/L indicating that the effect of Met-Enk on cellular proliferation was mediated by the opioid receptor. In the proliferation of MLC, the response of lymphocytes from Zn-deficient mice was increased in the absence of Met-Enk and Met-Enk can suppress this increased response. It is therefore concluded that Met-Enk can modify the pattern of mitogenic responses and the alteration in Con A and MLC responses can be influenced by zinc deficiency.

Neurological and electroneuromyographic assessment of the adverse effects of acrylamide on occupationally exposed workers

Seventy-one acrylamide workers and fifty-one unexposed referents were studied. Weak legs and numb hands and feet, preceded by skin peeling from the hands, were the early symptoms of the acrylamide workers; their early signs were impairment of vibration sensation in their toes and loss of ankle reflexes. Three cases had cerebellar involvement followed by polyneuropathy due to heavy exposure. Electroneuromyographic changes, including a decrease in the sensory action potential amplitude, neurogenic abnormalities in electromyography, and prolongation of the ankle tendon reflex latency, are of greater importance in the early detection of acrylamide neurotoxicity since they can precede the neuropathic symptoms and signs. The diagnostic criteria for occupational acrylamide intoxication of this study revealed three severe poisonings, six moderate poisonings, and 43 mild poisonings. The total prevalence of acrylamide poisoning was 73.2%. The prevention of dermal exposure to acrylamide should be emphasized.

Canine bone blood flow estimated with microspheres

Blood flow rate in the periosteal and endosteal cortices of the diaphysis of long bones was determined in eight anesthetized adult dogs using the radioactively labeled microsphere method. The flow rate in endosteal and periosteal cortices is not significantly different unless the endosteal cortex contains cancellous bone from the medullary cavity. The highest flow rate is in the ulna, with 6.50 ml/min/100 g for the endosteal cortex and 5.15 ml/min/100 g for the periosteal cortex. The lowest flow rate is in the femur, with 2.89 ml/min/100 g for the endosteal cortex and 2.29 ml/min/100 g for the periosteal cortex. The results of this study indicate that variation of blood flow does exist between bones of dogs. However, the flow rates of individual bone on the left and right sides in the same dog are not significantly different. This indicates that the data are reproducible and reliable, and differences are not an inaccuracy of the radioactively labeled microsphere method. The results also demonstrate that there are no significant differences in bone blood flow as measured with small numbers (fewer than 400 microspheres per sample) and large numbers (more than 400 microspheres per sample) of microspheres. The adequate number of microspheres in each bone sample is 150-250. Therefore, a dose of 0.5 x 10(6) spheres/kg body weight can be sufficient.

Lymphocyte predominant Hodgkin's disease of nodular subtype combined with pulmonary lymphoid infiltration and hypogammaglobulinaemia

Two cases of lymphocyte predominant Hodgkin's disease of nodular subtype (HDNP) are reported. In contrast to classic cases of HDNP which often involve only one lymph node region and show no further symptoms, these two patients exhibited lymphoid infiltrates of the lung and hypogammaglobulinaemia. In patient 2 a monotypic immunoglobulin pattern (light chain kappa) was demonstrated in the L & H-, Hodgkin- and Sternberg-Reed cells. Both cases represent an uncommon variant of lymphocyte predominant Hodgkin's disease.

Changes in DNA copy numbers of bovine papillomavirus type 1 after termination of retinoic acid treatment

The number of bovine papillomavirus type 1 (BPV) DNA copies [plasmid pdBPV-1 (142-6)] was examined in transformed C127 cells of an RIII mouse during exposure to all-trans-retinoic acid (RA) and after its withdrawal. RA treatment of a transformed cell line reduced the number from approximately 60 copies to an average of less than one copy per cell within 5 weeks. The composition of the RA-treated cell population was heterogeneous with respect to BPV DNA copies: 89.7% of the cells had no detectable copies, 8.6% had one copy, 1.7% had fewer than five copies, and one in 13,000 cells carried more than 10 copies. The low number of BPV DNA copies in the RA-treated cell population did not increase when the cells were subcultured before reaching confluence. RA-treated cell populations that contained less than one BPV DNA copy lost the transformed phenotype. However, a small fraction of cells (1 in 13,000) with greater than or equal to 10 BPV DNA copies retained the capacity to develop into transformed colonies. The relevance of these results to the regression of papillomavirus, DNA-carrying human lesions after exposure to retinoids and the redevelopment of these lesions after withdrawal of retinoids is discussed.

An electroneurographic assessment of subclinical lead neurotoxicity

While heavy exposure to inorganic lead is capable of inducing symptomatic neuropathy in man, the subclinical neuropathy due to low levels of occupational lead exposure remains to be proved. The reported results of electroneurographic studies on lead workers, however, have been controversial. In this study, 40 lead smeltery workers and 50 non-exposed referents were investigated. The air concentrations of lead at worksites were 0.25 to 42.5 mg/m3. The geometric means of PbB, PbU and delta-ALAU in lead exposed group were 40.03 micrograms/dl, 71 micrograms/l and 4.68 mg/l respectively, which were significantly higher (P less than 0.001) than those (7.01 micrograms/dl, 6.0 micrograms/l and 1.81 mg/l respectively) in the reference group. There were no clinical symptoms or signs of nerve damage in either group. Alcoholism and diabetes were excluded in both groups. Nerve conduction velocity was measured by a DISA 1500 electromyograph in both groups. Eleven electroneurographic parameters, including motor nerve conduction velocity (MCV) and distal latency (DML) of median, ulnar and peroneal nerves as well as sensory nerve conduction velocity (SCV) and distal latency (DSL) of median, ulnar and sural nerves, showed statistically significant differences between the two groups. However, the results of electroneurographic measurements of each individual in the lead-exposed group were all within the normal range. There was no correlation between the blood-lead levels and the neurophysiological measurements except for the median MCV. No correlation was seen between the median MCV and the exposure duration.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved plaque production for short-term bone marrow and fetal liver cultures

The addition of 0.5% globulin-free (GF-BSA) or 0.5% delipidated BSA (D-BSA) to short-term murine bone marrow (BM) (cultures) increased the number of plaque-forming cells (PFC) responding to trinitrophenylated lipopolysaccharide (TNP-LPS) 2-5-fold (1.1 X 10(4)-2.7 X 10(4) PFC per 10 X 10(6) nucleated BM cells). Although it was necessary to continue to supplement these cultures with 5% fetal calf serum (FCS), the inclusion of the aforementioned BSA preparations provided enhanced PFC production for all lots of FCS tested. Similarly, these preparations of BSA made it feasible to also culture BM in autologous mouse sera (MS) or in medium without 2-mercaptoethanol (2-ME) if in the latter case the D-BSA was pretreated with 2-ME. Thus, the inclusion of GF-BSA or D-BSA in short term cultures of BM not only substantially increased the number of Ig-secreting B cells produced in response to TNP-LPS but seemed to eliminate the need to screen for supportive batches of FCS or MS. These preparations of BSA also facilitated hapten specific PFC responses of fetal liver cultures.

Effect of retinoic acid on bovine papillomavirus (BPV) DNA-induced transformation and number of BPV DNA copies

The effect of all-trans-retinoic acid (RA) was examined on (1) transformation induced in C127 cells by transfection with plasmid pdBPV-1 (142-6), which contains DNA of bovine papillomavirus (BPV), (2) the capacity of transformed BPV DNA-containing clones to form colonies with transformed properties (e.g., piling up into multilayered colonies), and (3) the number of BPV DNA copies in transformed cells. At nontoxic doses ranging from 10(-7) to 10(-5) M, RA reduced the frequency of transformed foci in a dose-dependent manner. The extent of inhibition depended on the length of RA treatment and on the time that elapsed between DNA transfection and RA treatment. RA exerted only a slight inhibitory effect during the first days after transfection. Complete inhibition was observed when the cells were continuously exposed after transfection to RA at doses ranging from 0.5 to 1 X 10(-5) M. The inhibitory effect of RA on transformation was reversible. Transformed foci started to form after withdrawal of RA treatment. In the presence of RA (5 X 10(-6) M), cells from transformed colonies were no longer able to form foci displaying transformed properties. The number of BPV DNA copies gradually decreased when the cells were grown over several generations in the presence of RA (5 X 10(-6) M). After approximately 30 cell generations, the cell cultures appeared to have less than one copy of BPV DNA.

Effects of irradiation on cortical bone and their time-related changes. A biomechanical and histomorphological study

The effects of high-dose irradiation on the biomechanical and morphological properties of cortical bone and their time-related changes were studied in male Sprague-Dawley rats. A single fraction of 3500 rads was applied to the middle part of the right thigh. Age and sex-matched control rats that did not receive radiation were used for comparison. Two weeks after irradiation, the animals had lost weight and disappearance of bone cells, shrunken osteocytes, and significantly decreased bone-turnover activities were noted. The bone marrow showed reduced hematopoietic elements and sinusoids with increased fat. No change in the torsional strength and geometric properties of bone was noted at this time. Six to ten weeks after irradiation, histopathological abnormalities of the bone persisted, and there was an accelerated resorption process. However, significant increases in the strength and cortical area of bone appeared only in the non-irradiated, contralateral femur. On the irradiated side, decreased cortical area and increased porosity of bone were found at fourteen to eighteen weeks when compared with the control rats. Other histomorphological properties, such as bone porosity, osteocyte count, and periosteal new-bone formation, appeared to recover eighteen weeks after irradiation, as they became similar to the values for the age-matched normal control rats.