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PubMedDate not supplied

The sexual and reproductive behavior of American women, 1982-1988.

Comparison of 1988 data from the National Survey of Family Growth with 1982 data reveals that the proportion of U.S. women who have had sexual intercourse rose slightly, from 86 percent to 89 percent. Among teenagers, the proportion sexually active rose from 47 percent to 53 percent; most of the change is attributable to increases occurring among white and nonpoor teenagers, thus narrowing racial and income differences. Among women aged 15-44 in 1988 who have ever had intercourse, 67 percent reported that they had had two or more sexual partners in their lifetime. The proportion was highest among women aged 20-34 (about 70 percent), but 58 percent of sexually active teenage women reported having had two or more sexual partners. About 67 percent of women of reproductive age in 1988 were exposed to the risk of unintended pregnancy, up from 63 percent in 1982. Among these women, 35 percent rely on contraceptive sterilization to prevent pregnancy and 55 percent use reversible methods, while 10 percent use no method. Poor women are much more likely than nonpoor women to be using no method of contraception (15 vs. eight percent); among poor teenagers, this proportion reaches 25 percent. The level of contraceptive use at first intercourse among teenage women improved substantially between 1982 and 1988, however, rising from 48 percent to 65 percent. During 1984-1988, almost four in 10 births and almost six in 10 pregnancies among American women were unintended; most of these were mistimed, but 12 percent of births were unwanted ever.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

Thyrotoxic periodic paralysis. Report of 10 cases and review of electromyographic findings.

We reviewed the clinical characteristics of 10 patients with thyrotoxic periodic paralysis. In these patients, a relatively uniform group of young men, the periodic paralysis developed nearly concurrently with the onset of hyperthyroidism. The attacks were precipitated most frequently by rest and by exercise and, occasionally, by ingestion of a large carbohydrate load. In each patient, the paralysis resolved on return of euthyroidism. The approximate incidence rate for thyrotoxic periodic paralysis in our largely white North American patient population (all hyperthyroidism cases) ranged from 0.1% to 0.2%, which is one tenth the rate reported for Oriental populations. In 7 patients, electrodiagnostic testing revealed characteristic changes in compound muscle action potential amplitude in response to exercise of the muscle being tested.

Adult↗

PubMed1989

Purine metabolizing enzyme activities in radiosensitive tissues of mice after sublethal whole-body irradiation.

The activities of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) were determined between days 1-14 in the spleen, thymus and femoral bone marrow of mice subjected to whole-body gama irradiation with a dose of 5.5 Gy. In control animals, the highest activity of ADA (as related to 10(6) cells) was recorded in the thymus (58.9 pmol.s-1), the lowest one in the femur (34.8 pmol.s-1), the PNP activity was the lowest in the thymus (14.5 pmol.s-1) and the highest in the femur (96.0 pmol.s-1). In the spleen, an elevation of ADA activity (up to 379%) was observed during the first postirradiation days; PNP activity was reduced (to 58%) on postirradiation day 3, followed by the return and even elevation on day 14 (265%). In the thymus, a parallel reduction of the activities of both enzymes appeared during the first postirradiation days, with a subsequent increase during the regeneration phase. In the femoral bone marrow, ADA and PNP activities were increased on postirradiation day 1 (275% and 201%, respectively). Reference is made to the possible relationship between the observed characteristic changes in activities and the degree of damage and/or renewal of cell population in the hemopoietic tissues after irradiation.

Adenosine Deaminase↗

PubMed1989

Adult-onset mesangiocapillary glomerulonephritis: a disease with a poor prognosis.

A retrospective analysis of the records of 46 patients with adult-onset mesangiocapillary glomerulonephritis seen over a period of 15 years is reported. There were 28 males and 18 females with a mean age of 34 years. Mean observation period was 60 months. All patients had renal biopsies and characteristic changes, but no dense deposit variant was seen. HBsAg was positive in 20 per cent of the patients tested whereas in the general population it was about 10 per cent. Nephrotic syndrome was the commonest presentation. There was a mean delay of 8.5 months between the onset of symptoms and renal biopsy. Nineteen patients were given steroid/immunosuppressive therapy while 27 received no specific treatment. At the time of review, renal function was stable in 13 patients but progressively deteriorating in 33. In the latter, the slope of the graph of reciprocal of creatinine versus time could be accurately determined. Steroid/immunosuppressive therapy did not influence the rate of progression of renal failure but appeared to hasten and induce more partial remissions of the nephrotic state. There was no difference in cumulative renal survival between treated and untreated patients, and between HBsAg-positive and negative patients. Overall, 23 patients required dialysis/renal transplantation and an additional four had died of end-stage renal failure at the time of this review.

Adolescent↗

PubMed1991

Elderly support and intergenerational transfer in Zimbabwe: an analysis by gender, marital status, and place of residence.

This paper describes elderly support and intergenerational transfer by gender, marital status, and place of residence for 150 elderly persons in Zimbabwe. The survey was conducted in September 1988, and includes information on background characteristics, income, and cash support from all sources, noncash support, and the support of elders to others. Conclusions and implications are discussed.

Aged↗

PubMed1987

Adrenocortical cells of the zona reticularis normally express HLA-DR antigenic determinants.

A distinct population of normal human adrenocortical cells from adult glands spontaneously express HLA-DR, and occasionally also HLA-DQ, antigenic determinants in vivo and in vitro, as detected by immunofluorescence techniques using monoclonal antibodies on frozen tissue sections, primary cultures, and viable cell suspensions. In vivo, these antigenic determinants were found to be confined to the compact-type cells in the zona reticularis. In vitro, the adrenocortical identity of these HLA-DR+ cells was conclusively established by the characteristic change in their morphologic features induced by ACTH1-24 and by the simultaneous detection of tissue-specific adrenal autoantigens in double-label immunofluorescence staining. The cell surface expression of HLA-DR determinants by compact cells persisted in culture for several weeks and was not significantly affected by treatment with ACTH1-24. On the other hand, fetal adrenocortical cells of both transient and definitive zones were invariably negative for the expression of these HLA Class II antigenic determinants. Because normal human adrenocortical cells also express on their surface the molecules which constitute specific autoantigens in autoimmune adrenalitis, these findings argue against the notion that an ectopic HLA-DR expression associated with an otherwise "silent" autoantigen might trigger an organ-specific autoimmune response against endocrine cells. In addition, the expression of HLA-DR determinants by viable normal reticularis cells provides a readily detectable surface marker which may allow the physical separation of this population for studies in vitro.

Adrenal Cortex↗

PubMed1992

Characteristic changes of DNA stemlines during hepatocarcinogenesis in rats.

DNA stemlines of hepatocellular carcinoma (HCC) model of adult Wistar rats established by diethylnitrosamine were quantitatively measured by flow cytometry. The cancer-inducing course was divided into four stages, eg, precirrhosis stage, cirrhosis stage, early cancer stage and cancer progression stage. The advantageous DNA stemline of hepatocytes of normal adult Wistar rats was tetraploid (4C). It was from the cirrhosis stage that atavistic proliferation of hepatocytes with diploid (2C) DNA stemline started and replaced 4C hepatocytes, resulting in a new advantageous population. The features of early cancer stage were formation of HCC with 2C DNA stemline, whereas during the cancer progression stage, HCC cells with aneuploid (AN) DNA stemline presented the advantageous growth. The study clearly shows the change pattern of DNA stemline during the course of hepatocarcinogenesis from 4C-2C-AN, which is believed to be the biokinetic mechanism of the development and progression of HCC.

Aneuploidy↗

PubMed1991

Immunological dysregulation of lymph nodes in AIDS patients.

Changes in immune competent tissues of the HIV-1-infected person reflect to a certain extent the kind and intensity of immunological dysregulations. The diagnostic approach, however, must include immunophenotyping of cells, immunovirological studies of virus distribution in diseased tissues, and functional tests in addition to classical morphology. The latter technique alone just serves as a crude screening method since structural lesions in lymphoid tissues do not permit discrimination from other HIV-independent immune deficiency and autoimmune disorders. Although the overall appearance of lymph nodes in HIV infection and in chronic autoimmune disorders, such as collagen vascular diseases (e.g., rheumatoid arthritis and systemic lupus erythematosus), is similar, immunophenotyping shows a progressive loss of CD4 cells in HIV infection yet a quantitative increase in this cell population in autoimmune disorders (Krueger 1985a). In addition, there are other persistent active infections by lymphotropic viruses (e.g., EBV or HHV-6) which can cause structural and cellular changes in lymphoid tissues closely resembling HIV-induced lesions (Krueger et al. 1988b; Krueger 1985b). The pathological diagnosis therefore nedds to be supplemented by serological studies and--in selected cases--by in situ hybridization for the demonstration of viral genome. Southern blotting for viral DNA can only detect high numbers of viral genome copies in tissue extracts, not in which cell population the virus resides (e.g., malignant cells vs associated "normal" cells), while the polymerase chain amplification reaction, the most sensitive of all (Buchbinder et al. 1988), cannot yet differentiate between latent and (disease-related) active infection. Taking into consideration the above-described precautions in the evaluation of lymphatic lesions, there are a number of characteristic changes which reflect well the sequelae of HIV infection itself and of the ensuing immune dysregulation. Progressive loss of CD4 cells in the paracortex of lymph nodes and in the peripheral blood leads to inversion of the CD4/CD8 ratio. Loss of demonstrable CD4 cells is probably the consequence not only of cell lysis by HIV-1 infection (note: discrepancy between HIV-1 genome positive cell numbers and depletion of CD4 cells) but also of decreased CD4 marker synthesis in infected cells (Stevenson et al. 1987). In this context it is interesting that Fouchard et al. (1986) were able to show HIV expression in CD8 cells and theorized that these developed from infected CD4 cells which subsequently lost the CD4 epitope and expressed CD8.(ABSTRACT TRUNCATED AT 400 WORDS)

Acquired Immunodeficiency Syndrome↗

PubMed1989

Tonometry in question: can visual screening tests play a more decisive role in glaucoma diagnosis and management?

Chronic open-angle glaucoma is a disease in which characteristic changes occur in optic nerve morphology and in ganglion cell function. The utility of intraocular pressure readings in the diagnosis and ongoing management of glaucoma patients is pragmatically considered in the light of the availability of potentially more sensitive means of glaucoma monitoring. Conservative appraisal of the literature suggests that traditional clinical tonometry has low diagnostic sensitivity and specificity. The majority of new cases of glaucomatous visual field loss are most likely to arise from the normotensive population. Clinical studies to determine the correlation between intraocular pressure reduction and the preservation of visual function have repeatedly yielded a much weaker association between these two variables than is perhaps generally assumed. Newer psychophysical methods may have greater potential for rapidly identifying and subsequently monitoring glaucoma patients, but still require refinement and more widespread clinical evaluation. One prerequisite for the eventual adoption of such methods is that clinicians fully appreciate the limitations inherent in tonometry as a glaucoma screening and monitoring technique.

Glaucoma, Open-Angle↗

PubMed1975

Quantitative assessment of the electroencephalogram in renal disease.

EEGs wre recorded from renal patients to determine if there are quantifiable characteristic changes in the EEG was quantified by calculating the percentage of spectral power in the bandwidth 3-7 c/sec referrred to a frequency range of 3-13 c/sec and by computing the mean frequency of the dominant rhythm in the EEG. Blood urea nitrogen and creatinine concentrations, as well as a self-assessment of the patient's clinical condition, were recorded. The general finding of this research is that EEG slowing, as evaluated by power spectral techniques, is correlated with uremia-associated variables. 1. In a non-dialyzed patient population with renal failure, slowing in the EEG was found to be directly corelated with increased creatinine concentrations. 2. Quantitative measures of slow wave activity computed using power spectral techniques were found to be highly corelated with an estimate of slowing made by an electroencephalographer. 3. Compared with undialyzed azotemic patients, malignant hypertensive patients with comparable serum creatinine concentrations typically displayed increased slow wave activity, while slowing was generally reduced in the dialyzed patient population. 4. A series of EEGs recorded from one patient during the first three dialyses of her life revealed that slow wave activity decreased during each successive dialysis. In another patient, all quantified EEG values recorded prior to renal transplantation significantly improved after transplantation...

Adolescent↗

PubMed1989

[Interpretation of mechanograms of the quadriceps femoris muscle twitch from technical, methodologic and physiologic aspects].

It is proved, that the physiological interpretation of the peaks in the quadriceps femoris muscle twitch mechanogramme is possible. The measuring chain (sensor-amplifier-magnetic data recorder-plotter) has a resonance frequency of 170 Hz and is suitable for the true representation of the tension-time-course. In order to compare the tensions with one another, it is necessary to standardize the tensions on the lower leg or body mass. Considering the fact that the twitch mechanogramme is a summation of the contractions of the fast twitch fiber (FTF) and slow twitch fiber population (STF), it has been assumed that both FTF and STF show contraction peaks. Essential methodological influences on the tension-time-course result from the relationship between tension sensor and biological system (lower leg mass). The measuring chain and lower leg mass represent a feather-mass system. The provoked oscillations of the lower leg mass may produce methodological peaks in the twitch mechanogramme. In general, the mechanogramme shows contractions superimposed by mechanical processes. The tonogramme shows that the tension-time-course of the twitch is characterized by several peaks too. In the tonogramme characteristic changes depending on the portion of the quadriceps femoris muscle (rectus femoris, vastus lateralis) can be seen. Following the muscle action potential (MAP) there are frequently reflex-MAP's variable in form and amplitude in the time range between 120-180 ms after the stimulus impulse. They allow to explain the peaks in the mechanogramme with contraction times (CT) of 140-160 ms, or they provoke an extension of the relaxation times. Some reflex-MAP may have a latency of only 80 ms. The analysis of the methodological components influencing the mechanogramme of the muscle twitch shows that the interpretation as FT- or ST-peaks has to be done from the point of view of physiology. The following results indirectly speak for the interpretation as FT- or ST-peaks (CT: 30-50 ms and 75 to 95 ms, respectively). There are the corresponding average CT for groups with clearly different lower leg mass, the relatively higher increase of the peaks with CT between 60-70 ms after a maximal voluntary contraction (MVC) of 10 seconds, the higher average tensions for the ST-peaks by long distance runners and the results for the CT when the lower leg mass is artificially elevated. Furthermore the mechanogrammes of the long distance runners show that the maximum may come to a CT of 100-130 ms.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMedDate not supplied

ABO, MN, Kell, Hp and Gm1 markers in elderly humans.

The prevalence of the markers of blood groups ABO, MN, Kell, Hp, Gm1 was determined in 723 persons belonging to three age groups: from 61 to 91 years, and was compared with a similar study in a population of adults aged 20 to 60 years. It was found that with respect to MN markers the proportion of NN homozygotes was significantly increased, mainly in females aged 71-80 years. In the haptoglobin system a considerable increase was noted in the prevalence of Hp 1-1 phenotype and the appearance of ahaptoglobinaemia. Increased prevalence of the Gm1 marker was observed only in females aged 71-80 years. On the other hand, no significant differences were noted in the frequency of the phenotypes of the ABO and Kell blood groups. These preliminary results confirm the stability of the serological polymorphism in the ABO and Kell blood groups, and in the remaining blood groups studied a natural selection may be supposed to exist. Characteristic changes in the distribution of the frequency of the determined genetic markers encourage the continuation of such studies.

ABO Blood-Group System↗

PubMed1976

Effects of progesterone, prostaglandin F2alpha and its analogue ICI 81008 on the excitability and threshold of the uterus.

Forty-eight uterine strips were excised from 24 New Zealand white rabbits and studied in vitro. Sixteen strips were examined when eight animals were 25 days pregnant, 24 strips when 12 animals were about 12 hours postpartum, and eight strips about 12 hours after four animals received a single dose of 5 mg. progesterone (P) at spontaneous delivery. When after repeated exposures to electric fields (60 cycles per second, alternating current, of optimum strength, four seconds' duration at intervals of 30 seconds) the approximately 0.5 Gm. strips developed approximately 40-50g wall tension (WT) in steady state, the field strength was reduced in graded steps from 12 v per 5 cm. to 10, 8, 6, 4 and 3 v per 5 cm. and WT recorded. By measuring the effect on WT of "decreasing electric field stimulation" (DEFS), myometrical excitably and threshold were characterized and quantitated. The technique is based on the relationship between the fraction of myometrial cells activated in the total cell population and WT. As the stimulus is decreased in graded steps from optimal to increasingly suboptimal, DEFS activates fewer and fewer cells reflected by the decrease in WT. Threshold is defined by the strength of the minimum electric field which provokes WT and subthreshold by the field strength which fails to excite. Thus fractional WT averages the excitability of cells in the tissue and thus DEFS characterizes this important parameter of uterine function and quantitates threshold under a variety of regulatory conditions. The comparative study of excised uteri in three different endocrine states showed that the regulatory conditions of normal pregnancy (P levels 9 ng. per milliliter) suppressed excitability and increased threshold (to 6 v per 5 cm.). Post partum (P levels 1 ng. per milliliter) excitability increased and threshold decreased (to 4 v per 5 cm.), unless P treatment prevented this characteristic change by suppressing excitability and increasing threshold (to 6 v per 5 cm.). Both regulatory agents, prostaglandin F2alpha (PGF2alpha) and its analogue ICI 81008, increased excitability and decreased threshold significantly in picogram per milliliter concentrations. However, this effect was observed only when the P levels were low. These compounds had little effect, even in manogram per milliliter concentrations, when the P levels were high. The studies also revealed a close relationship between threshold and spontaneous uterine activity. Low threshold promoted while high threshold suppressed spontaneous activity. In similar concentrations the oxytocic actions of PGF2alpha and ICI 81008 were similar but the effect of ICI 81008 was prolonged through strong binding at myometrical sites.

Animals↗

PubMed1991

Natural killer (NK) cells in HTLV-I-associated myelopathy/tropical spastic paraparesis-decrease in NK cell subset populations and activity in HTLV-I seropositive individuals.

We examined natural killer (NK) cell activity and NK cell subset populations in 18 patients with HTLV-I associated myelopathy (HAM)/tropical spastic paraparesis (TSP), ten HTLV-I seropositive asymptomatic carriers and 20 seronegative healthy controls. The NK cell activity was significantly decreased in HAM/TSP, compared with that in controls. The percentages of NK cell subsets, such as CD16+, CD11b+, CD56+, CD16+ CD56-, CD16-CD56+, CD16+CD8-, or CD16+CD3+ cells were significantly decreased in HAM/TSP patients. Of particular interest is that the percentage of CD16+CD3+ cells, which have a wide spectrum of cytotoxic properties commonly seen in NK, lymphokine activated killer (LAK) and antibody-dependent cellular-cytotoxic (ADCC) effector cells, was significantly decreased in HAM/TSP as compared to asymptomatic carriers as well as controls. The percentage of CD16+CD3+ cells correlated inversely with the value of spontaneous proliferation of peripheral blood lymphocytes (SPP), which is a characteristic change observed in HAM/TSP.

Adult↗

PubMed1990

[The changes of population and distribution of S-phase cells in precancerous lesions of rat bladder revealed by the method of bromodeoxyuridine labeling].

We studied whether bromodeoxyuridine (BrdU)-labeling method showing the population and/or distribution of S-phase cells in tumor tissues is useful to detect the precancerous lesions of bladder. The bladder lesions were induced by 0.05% N-butyl-N (4-hydroxybutyl) nitrosamine (BBN) in drinking water for ten weeks in five male rats (Wistar-Imamichi). BrdU (50 mg/kg) was injected to intraperitoneal space two hours before the resection of the bladder. The detection of positive cells (S-phase cells taking BrdU) was performed by peroxidase-antiperoxidase method. From five bladder specimens 144 lesions (simple hyperplasia (S)-73, papillary or nodular hyperplasia (PN)-57, papilloma (Pa)-14) were analysed. The labeling index (the ratio of positive cells to all epithelial cells in one lesion) showed no significant difference among the lesions (S, PN, and Pa). For analyses of the distribution patterns of S-phase cells, we investigated whether positive cells aside from basal layers and/or the serial positive cells in basal layers were seen or not in each lesion. The ratios of lesions containing positive cells aside from basal layers were 11% (8/73), 60% (34/57) and 100% (14/14) in S, PN and Pa lesions. The serial positive cells in basal layers were observed in 6% (4/73), 25% (14/57) and 50% (7/14) of S, PN and Pa lesions. Those differences were statistically significant. Above mentioned results suggest that the appearance of S-phase cells aside from basal layers and/or the serial S-phase cells in basal layers is characteristic change in precancerous lesions, which is useful for sooner detection of bladder carcinogenesis.

Animals↗

PubMed1986

Proto-oncogene c-myc is expressed in cerebellar neurons at different developmental stages.

During post-natal cerebellar development the steady-state levels of c-myc transcripts exhibit characteristic changes. As determined by the S1 nuclease protection assay the level of c-myc transcript, which is very high in the late embryonic cerebellum, decreased to low levels shortly after birth. One week later there is a second period of c-myc mRNA accumulation followed by a marked decline to finally reach the low adult value. The second peak of high c-myc mRNA level correlates well with the proliferation of granule cell precursors, and it is characterized by a marked change in the ratio of the two types of transcripts started at the known c-myc promoters 1 and 2. This indicates a change in the cell population involved in the transcription of the c-myc gene. In situ hybridization shows transiently elevated c-myc mRNA levels in neurons of the cerebellar cortex. At post-natal days 3 and 10 (P3 and P10) c-myc transcripts are detectable in the superficial external granular layer composed primarily of mitotically active (neural precursor) cells. Purkinje cell somata show cytoplasmic label at P10. These large postmitotic neurons undergo rapid differentiation at this developmental stage. In the adult cerebellum the low c-myc mRNA level is apparently due to Purkinje cells with barely detectable amounts of c-myc transcripts. The vast majority of mature cerebellar neurons, the internal granule cells, have no specific hybridization signal for c-myc. We conclude that neurons in vivo can accumulate c-myc messenger during proliferation and/or differentiation, perhaps as a cellular response to an external signal.

Aging↗

PubMed1990

Both alpha 1- and beta-adrenoceptor stimulation determine the time course of the inotropic effect of noradrenaline in rabbit heart.

It has been a matter of controversy whether alpha 1-adrenoceptor stimulation contributes to the final inotropic and lusitropic responses in mammalian myocardium to noradrenaline during concomitant and unopposed beta-adrenoceptor stimulation. In the present paper we report studies that compare time courses of the inotropic and lusitropic responses to separate and combined alpha 1- and beta-adrenoceptor stimulation, respectively, in electrically driven rabbit papillary muscles by a submaximal concentration of noradrenaline. Separate alpha 1- or beta-adrenoceptor stimulation (presence of appropriate receptor blocker) showed the characteristic slow and fast development, respectively, of the inotropic responses. Qualitatively, the respective characteristic changes were also observed: alpha 1-adrenoceptor stimulation caused a negative lusitropic effect giving a prolongation of the time to peak tension (TPT), while beta-adrenoceptor stimulation caused a pronounced positive lusitropic effect giving a shortening of TPT. The time course of the inotropic response to combined adrenoceptor stimulation had characteristics that deviated from the respective time courses to separate alpha 1- or beta-adrenoceptor stimulation thus indicating a contribution from both adrenoceptor populations to the final inotropic response. Combined alpha 1- and beta-adrenoceptor stimulation gave a pronounced positive lusitropic response as might be expected due to the obviously dominating role of the beta-adrenergic component. However, the maximal lusitropic effect and the shortening of TPT were both slightly less during combined adrenoceptor stimulation compared to separate beta-stimulation thus indicating an influence of the alpha 1-adrenoceptor mediated negative lusitropic effect. Quantitatively, the separate alpha 1- and the separate beta-adrenoceptor mediated inotropic effects were not additive. In accordance with other recent studies, this indicated an inhibitory interaction between the two adrenergic receptor populations in myocardium.

Animals↗

PubMed1989

Noninvasive determination of age-related changes in the human arterial pulse.

Arterial pressure waves were recorded noninvasively from the carotid, radial, femoral, or all three of these arteries of 1,005 normal subjects, aged 2-91 years, using a new transcutaneous tonometer containing a high fidelity Millar micromanometer. Waves were ensemble-averaged into age-decade groups. Characteristic changes were noted with increasing age. In all sites, pulse amplitude increased with advancing age (carotid, 91.3%; radial 67.5%; femoral, 50.1% from first to eighth decade), diastolic decay steepened, and diastolic waves became less prominent. In the carotid pulse, there was, in youth, a second peak on the downstroke of the waves in late systole. After the third decade, this second peak rose with age to merge with and dominate the initial rise. In the radial pulse, a late systolic wave was also apparent, but this occurred later; with age, this second peak rose but not above the initial rise in early systole, even at the eighth decade. In the femoral artery, there was a single systolic wave at all ages. Aging changes in the arterial pulse are explicable on the basis of both an increase in arterial stiffness with increased pulse-wave velocity and progressively earlier wave reflection. These two factors may be separated and effects of the latter measured from pressure wave-contour analysis using an "augmentation index," determined by a computer algorithm developed from invasive pressure and flow data. Changes in peak pressure in the central (carotid) artery show increasing cardiac afterload with increasing age in a normal population; this can account for the cardiac hypertrophy that occurs with advancing age (even as other organs atrophy) and the predisposition to cardiac failure in the elderly. Identification of mechanisms responsible offers a new approach to reduction of left ventricular afterload.

Aging↗