Astrocytes degenerate in frontotemporal dementia: possible relation to hypoperfusion

To understand the extent and specificity of astrocyte pathology in sporadic frontotemporal dementia (FTD), we examined several FTD cases for molecular and morphologic characteristics of astrocyte degeneration. We quantified reactive and degenerating astrocytes in sections of frontal, temporal, parietal, and occipital cortex identified using glial fibrillary acidic protein (GFAP) immunoreactivity, terminal deoxynucleotidyl transferase (TdT) labeling, and morphological characteristics and compared them with nondemented, age-matched control brains. Conventional and confocal microscopy revealed that a subpopulation of GFAP(+) astrocytes exhibited positive TdT labeling and beading of their processes in the frontal, temporal, and parietal cortices in 5 of 7 FTD cases that also exhibited gliosis. This morphology was reproduced in cultured astrocytes using ischemic insults. Degenerating astrocytes in FTD correlated inversely with cerebral blood flow as measured by single photon emission computed tomography (SPECT) analysis of (133)Xe inhalation (r = 0.55, p < 0.05). Furthermore, areas of significant astrogliosis corresponded to areas of SPECT hypoperfusion, suggesting that astrocytes may be affected by or perhaps have a causal role in the disturbances of cerebral perfusion in FTD.

Identification of adult populations at high risk for dental caries using a computerized database and patient records: a pilot project

OBJECTIVES

The purpose of this study is to test the usefulness of dental insurance claims history, supplemented with radiographic caries diagnoses, as a means of identifying caries-active and caries-inactive working adults, as determined by bacterial levels. Computerized identification of at-risk groups may facilitate subject selection for clinical trials designed to test caries-preventive strategies.

METHODS

Two groups of subjects were initially selected from an insurance database based upon their dental service utilization during a one-year period: a "low restorative" group of individuals defined as persons who had received no restorative treatment, and a "high restorative" group comprised of individuals who had received at least three multisurfaced restorations. A chart review confirmed a diagnosis of caries in the high restorative group and an absence of caries in the low restorative group. Subjects were then approached for saliva collection. The low and high restorative groups were compared for salivary mutans streptococci and lactobacilli levels, stimulated flow rate, and buffer capacity (n = 48).

RESULTS

The high and low restorative groups differed in mutans streptococci levels, but not on other measures.

CONCLUSIONS

A group of subjects who had recently received multisurfaced restorations that were placed for reasons of caries had significantly higher levels of mutans streptococci and potential for continued caries activity when compared to a group of subjects who had received no restorations and were caries free.

The prevalence and correlates of psychological distress following physical and sexual assault in a young adult cohort

Among a birth cohort of New Zealand's 21-year-olds, 41% experienced physical or sexual assault in the previous 12 months. The level of psychological distress experienced by the 374 victims was determined in interviews assessing for symptoms indicative of posttraumatic stress disorder and ratings of impairment in activities of daily living. Of the 141 women victims, 32.6% were identified as experiencing psychological distress as were 9.9% of the 233 men. For men, bivariate analyses showed psychological distress was significantly associated with factors indicative of increased assault severity, and for women an increased likelihood of distress was associated with the location of assault and the relationship to the assailant. Positive indicators of social support were not significantly associated with less adverse psychological outcomes. However, for both men and women, resisting the assailant was associated with a reduced likelihood of psychological distress. Multivariate analyses revealed that for both women and men, unemployment uniquely predicted variance in distress, over and above that accounted for by characteristics of the assault.

Paracetamol (acetaminophen) hypersensitivity

BACKGROUND

Acetaminophen (paracetamol) is an analgesic antipyretic drug with no antiinflammatory effects and is widely used worldwide. Earlier clinical studies reported IgE-mediated adverse reactions to acetaminophen, but in vivo and in vitro tests have been inconclusive.

OBJECTIVE

We propose to demonstrate an IgE-mediated mechanism in four patients with adverse reactions to acetaminophen (paracetamol). Tolerance to aspirin and other nonsteroidal antiinflammatory drugs are present in all patients.

METHODS

We studied four patients with anaphylactic reactions to acetaminophen who tolerated aspirin and other nonsteroidal antiinflammatory drugs. Skin tests, oral challenges and immunoassay for allergen-specific IgE antibodies with acetaminophen were performed in all patients.

RESULTS

All patients tolerated the aspirin oral challenge without adverse effects. In contrast, the oral challenge with acetaminophen produced adverse effects in all patients. Skin tests with acetaminophen were positive in two patients (3-mm wheal and flare) and IgE antibodies acetaminophen were detected in serum from two patients.

CONCLUSION

We describe four patients with adverse reactions to acetaminophen but with tolerance to aspirin and other nonsteroidal antiinflammatory drugs. Skin tests, oral challenges, and serum IgE results with acetaminophen suggest that an IgE-mediated mechanism is responsible for these reactions.

An internal histidine residue from the bacterial surface protein, PAM, mediates its binding to the kringle-2 domain of human plasminogen

The determinants of binding of a peptide lacking C-termini-exposed lysine residues to a kringle domain were investigated using an up-regulated lysine binding kringle (K2Pg[C4G/E56D/K72Y]) of plasminogen and a peptide (a1-PAM) with a sequence derived from a surface-exposed M-like streptococcal protein. Significant kringle-induced chemical shifts in a His side-chain of a1-PAM were revealed by two-dimensional NMR. Further studies using isothermal titration calorimetry (ITC) provided support for the involvement of His12 in the peptide/ protein complex. In an effort to screen a1-PAM-derived truncation peptides, a combinatorial mixture, a1deltaa2-PAM[H12X] (where X=Pro, Arg, His, Trp, Lys, Ala, Phe, Asp and Gly), was analyzed using the surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI) platform. The major peptide that remained bound to the surface of the K2Pg[C4G/ E56D/K72Y]-containing chip was that containing His12, corresponding to the wild-type sequence. Minor peaks, representing binding, were obtained for Lys12-, Arg12- and Trp12-containing peptides. Individual peptides containing these amino acids were then examined using ITC and the binding constants obtained correlated with the relative strengths of binding estimated from the SELDI-based screen.

The role of chondrocyte-matrix interactions in maintaining and repairing articular cartilage

Throughout life chondrocytes maintain the articular cartilage matrix by replacing degraded macromolecules and respond to focal cartilage injury or degeneration by increasing local synthesis activity. These observations suggest that mechanisms exist within articular cartilage that stimulate chondrocyte anabolic activity in response to matrix degradation or damage. An important cartilage anabolic factor, insulin-like growth factor I (IGF-I), appears to have a role in stimulating chondrocyte anabolic activity. Although IGF-I is ubiquitous, its bioavailability is controlled by a class of secreted proteins, IGF binding proteins (IGFPBs). Of the six known IGFPBs, IGFBP-3 is the most abundant in human articular cartilage. We recently found that with increasing age, articular chondrocytes increase their expression of IGFBP-3. This observation led us to investigate the potential role of IGFBP-3 in chondrocyte-matrix interactions. Using immunofluorescent staining and confocal microscopy we found that IGFBP-3 accumulates with increasing age in the chondrocyte territorial matrix where it co-localizes with fibronectin, but not with tenascin-C or type VI collagen. Using purified proteins we demonstrated that IGFBP-3 binds to fibronectin in a dose dependent manner, but not to tenascin-C. In vitro studies showed that IGFBP-3 alone inhibited chondrocyte synthetic activity while intact fibronectin alone significantly stimulated activity. When fibronectin and IGFBP-3 were combined we found that the inhibitory activity of low concentrations of IGFPB-3 was enhanced. These observations indicate that in mature articular cartilage IGF-I is stored in the chondrocyte territorial matrix through binding to a complex of IGFPB-3 and intact fibronectin. Storage of IGF-I of the territorial matrix may help maintain a relatively constant level of available IGF-I and the local increase in matrix synthesis following matrix damage may result from release of IGF-I. This mechanism may have an important role in maintaining and repairing articular cartilage and failure of this mechanism may lead to progressive articular cartilage degeneration.

Births: preliminary data for 1999

OBJECTIVES

This report presents preliminary data for 1999 on births in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Data on marital status, prenatal care, cesarean delivery, and low birthweight are also presented.

METHODS

Data in this report are based on more than a 97-percent sample of births for 1999. The records are weighted to independent control counts of births received in State vital statistics offices in 1999. Comparisons are made with 1998 final data.

RESULTS

The crude birth rate in 1999 was 14.5 per 1,000 population, a slight decline from 1998 (14.6), returning to the level observed in 1997. However, the fertility rate, which is limited to women aged 15-44 years, was 65.8 in 1999, a slight increase over the rate for 1998 (65.6). The birth rate for teenagers continued to decline for 1998-99, dropping 3 percent to 49.6 births per 1,000 females aged 15-19 years. The 1999 rate for teenagers is 20 percent lower than the recent high point in 1991. The rate for young teenagers 15-17 years fell 6 percent, and the rate for teenagers 18-19 years declined 2 percent. Since 1991, rates have fallen 26 percent for teenagers 15-17 years, and 15 percent for teenagers 18-19 years. Birth rates for women aged 20-24 years declined slightly between 1998 and 1999 whereas the rate for women aged 25-29 years rose 2 percent. Birth rates for women in their thirties and forties continued their long increase. Rates for women in their thirties increased 2 to 3 percent and were the highest in three decades. The birth rate for women aged 40-44 years was the highest level reported since 1970. The birth rate for unmarried women in 1999 was 43.9 per 1,000, 1 percent lower than in 1998 and 6 percent lower than the peak level reported for 1994 (46.9). However, the number of births to unmarried women was up about 1 percent due to the continued increase in the number of unmarried women of childbearing age. The rate of prenatal care utilization continued to improve. The total cesarean rate increased 4 percent between 1998 and 1999 and continued a 3-year rise. The low birthweight rate remained unchanged at 7.6 percent.

Trends in twin birth outcomes and prenatal care utilization in the United States, 1981-1997

CONTEXT

Multiple births account for an increasing percentage of all low-birth-weight infants, preterm births, and infant mortality in the United States. Since 1981, the percentage of women with multiple births who received intensive prenatal care (defined as a high number of visits, exceeding the recommendation of the American College of Obstetricians and Gynecologists by approximately 1 SD beyond the mean number of visits for women initiating care within each trimester) has increased significantly.

OBJECTIVES

To explore the hypothesis that more aggressive management of twin-birth pregnancies may be associated with changes in birth outcomes in this population.

DESIGN, SETTING, AND SUBJECTS

Cross-sectional and trend analysis of data from the National Center for Health Statistics' birth and infant death records for all twin births occurring in the United States between 1981 and 1997, excluding those with missing or inconsistent data.

MAIN OUTCOME MEASURES

Trends in preterm birth, low birth weight, preterm and term small-for-gestational-age (SGA) births, and infant mortality, by level of prenatal care utilization.

RESULTS

The preterm birth rate for twins increased from 40.9% in 1981 to 55.0% in 1997. The percentage of low-birth-weight infants increased from 51.0% to 54.0%. The preterm SGA rate also increased from 11.9% to 14.1%, while the term SGA rate decreased from 30.7% to 20.5%. For women with intensive prenatal care utilization, the preterm birth rate increased from 35.1% to 55.8%, compared with an increase from 50.6% to 59.2% among women with only adequate use. Twin preterm deliveries involving either induction or first cesarean delivery also increased from 21.9% to 27.3% between 1989-1991 and 1995-1997. The twin infant mortality rate for women with intensive prenatal care use declined between 1983 and 1996 and remained lower than the overall twin infant mortality rate.

CONCLUSIONS

An apparent increase in medical interventions in the management of twins may result in the seeming incongruity of more prenatal care and more preterm births; however, these data suggest that women with intensive prenatal care utilization also have a lower infant mortality rate. JAMA. 2000;283:335-341

Tenascin-C in tendon regions subjected to compression

Tendon regions subjected almost exclusively to tension differ from regions subjected to high levels of compression as well as tension. Regions not exposed to compression consist primarily of spindle-shaped fibroblasts surrounded by densely packed longitudinally oriented collagen fibrils formed principally from type-I collagen. In contrast, regions subjected to compression have a fibrocartilagenous structure and composition: they consist of spherical cells surrounded by a matrix containing hyaline cartilage proteoglycans (aggrecan) and type-II collagen as well as type-I collagen. Reducing their adhesion to the matrix may help cells in the latter regions establish and maintain a spherical shape and minimize their deformation when the tissue is subjected to mechanical stress. We hypothesized that expression of tenascin-C, an anti-adhesive protein, is part of the adaptation of tendon cells to compression that helps establish and maintain fibrocartilagenous regions. To test this hypothesis, we compared segments of bovine flexor tendons subjected to repetitive compression (distal) with segments that are not subjected to compression (proximal) to determine whether they differed in tenascin-C content and expression. RNA and protein analyses showed that tenascin-C expression was elevated in the distal tendon. Tendon cells from the distal segment expressed more tenascin-C mRNA than did cells from the proximal segments for as long as 4 days in cell culture, indicating that increased tenascin-C expression is a relatively stable feature of the distal cells. Moreover, purified tenascin-C inhibited the attachment of cultured tendon cells to fibronectin. These observations support the hypothesis that tenascin-C expression is a cellular adaptation to compression that helps establish and maintain fibrocartilagenous regions of tendons by decreasing cell-matrix adhesion.

Reversible suppression of in vitro biomineralization by activation of protein kinase A

Parathyroid hormone (PTH-(1-34)) potently suppresses apatite deposition in osteoblastic cultures. These inhibitory effects are mediated through signaling events following PTH receptor binding. Using both selective inhibitors and activators of protein kinase A (PKA), this study shows that a transient activation of PKA is sufficient to account for PTH's inhibition of apatite deposition. This inhibition is not a result of reduced cell proliferation, reduced alkaline phosphatase activity, increased collagenase production, or lowering medium pH. Rather, data suggest a functional relationship between matrix assembly and apatite deposition in vitro. Bone sialoprotein (BSP) and apatite co-localize in the extracellular matrix of mineralizing cultures, with matrix deposition of BSP temporally preceding that of apatite. Transient activation of PKA by either PTH-(1-34) or short term cAMP analog treatment blocks the deposition of BSP in the extracellular matrix without a significant reduction in the total amount of BSP synthesized and secreted. This effect is reversible after allowing the cultures to recover in the absence of PKA activators for several days. Thus, a transient activation of PKA may suppress mineral deposition in vitro as a consequence of altering the assembly of an extracellular matrix permissive for apatite formation.

Births: final data for 1998

OBJECTIVES

This report presents 1998 data on U.S. births according to a wide variety of characteristics. Data are presented for maternal demographic characteristics including age, live-birth order, race, Hispanic origin, marital status, and educational attainment; maternal lifestyle and health characteristics (medical risk factors, weight gain, and tobacco and alcohol use); medical care utilization by pregnant women (prenatal care, obstetric procedures, complications of labor and/or delivery, attendant at birth, and method of delivery); and infant health characteristics (period of gestation, birthweight, Apgar score, abnormal conditions, congenital anomalies, and multiple births). Also presented are birth and fertility rates by age, live-birth order, race, Hispanic origin, and marital status. Selected data by mother's State of residence are shown including teenage birth rates and total fertility rates, as well as data on month and day of birth, sex ratio, and age of father. Trends in fertility patterns and maternal and infant characteristics are described and interpreted.

METHODS

Descriptive tabulations of data reported on the birth certificates of the 3.94 million births that occurred in 1998 are presented.

RESULTS

Birth and fertility rates increased in 1998 by about 1 percent, the first increase since 1990. Birth rates for teenagers fell 2-5 percent. Rates for women in their twenties increased 1-2 percent each, whereas rates for women in their thirties rose 2-4 percent. All measures of childbearing by unmarried women increased in 1998; the number of births rose 3 percent, the birth rate increased about 1 percent while the percent of births that were to unmarried women rose to 32.8 percent. Smoking by pregnant women overall dropped again in 1998, but continued to increase among teenagers. Improvements in prenatal care utilization continued. The cesarean delivery rate increased for the second year after declining for 7 consecutive years. The proportion of multiple births continued to rise; higher order multiple births (e.g., triplets, quadruplets) rose by 13 percent in 1998, following a 14 percent rise from 1996 to 1997. Key measures of birth outcome--the percents of low birthweight and preterm births--increased. These changes are in large part the result of increases in multiple births.

Damage control mechanisms in articular cartilage: the role of the insulin-like growth factor I axis

Articular chondrocytes maintain cartilage throughout life by replacing lost or damaged matrix with freshly synthesized material. Synthesis activity is regulated, rapidly increasing to well above basal levels in response to cartilage injury. Such responses suggest that synthesis activity is linked to the rate of matrix loss by endogenous "damage control" mechanisms. As a major stimulator of matrix synthesis in cartilage, insulin-like growth factor I (IGF-I) is likely to play a role in such mechanisms. Although IGF-I is nearly ubiquitous, its bioavailability in cartilage is controlled by IGF-I binding proteins (IGFBPs) secreted by chondrocytes. IGFBPs are part of a complex system, termed the IGF-I axis, that tightly regulates IGF-I activities. For the most part, IGFBPs block IGF-I activity by sequestering IGF-I from its cell surface receptor. We recently found that the expression of one binding protein, IGFBP-3, increases with chondrocyte age, paralleling an age-related decline in synthesis activity. In addition, IGFBP-3 is overexpressed in osteoarthritic cartilage, leading to metabolic disturbances that contribute to cartilage degeneration. These observations indicate that IGFBP-3 plays a crucial role in regulating matrix synthesis in cartilage, and suggest that cartilage damage control mechanisms may fail due to age-related changes in IGFBP-3 expression or distribution. Our investigation of this hypothesis began with immunolocalization studies to determine the tissue distribution of IGFBP-3 in human cartilage. We found that IGFBP-3 accumulated around chondrocytes in the pericellular/territorial matrix, where it co-localized with fibronectin, but not with the other matrix proteins tenascin-C and type VI collagen. This result suggested that the IGFBP-3 distribution is determined by binding to fibronectin. Binding studies using purified proteins demonstrated that IGFBP-3 does in fact bind to fibronectin, but not to tenascin-C or type VI collagen. Finally, we investigated the metabolic effects of fibronectin and IGFBP-3 in a chondrocyte culture system. These experiments showed that fibronectin enhanced the inhibitory effect that low concentrations of IGFBP-3 had on matrix synthesis. Taken together, these observations confirm that IGFBP-3-fibronectin interactions affect the IGF-I axis, and they indicate that IGF-I is stored in the chondrocyte territorial matrix through binding to a complex of IGFBP-3 and intact fibronectin. This arrangement may play an important role in cartilage damage control mechanisms. The local increase in matrix synthesis following injury could result from damage-induced IGF-I release from such pools. An age-related failure to organize this system may contribute to degenerative disease.

Annual summary of vital statistics--1998

Most vital statistics indicators of the health of Americans were stable or showed modest improvements between 1997 and 1998. The preliminary birth rate in 1998 was 14.6 births per 1000 population, up slightly from the record low reported for 1997 (14.5). The fertility rate, births per 1000 women aged 15 to 44 years, increased 1% to 65.6 in 1998, compared with 65.0 in 1997. The 1998 increases, although modest, were the first since 1990, halting the steady decline in the number of births and birth and fertility rates in the 1990s. Fertility rates for total white, non-Hispanic white, and Native American women each increased from 1% to 2% in 1998. The fertility rate for black women declined 19% from 1990 to 1996, but has changed little since 1996. The rate for Hispanic women, which dropped 2%, was lower than in any year for which national data have been available. Birth rates for women 30 years or older continued to increase. The proportion of births to unmarried women remained about the same at one third. The birth rate for teen mothers declined again for the seventh consecutive year, and the use of timely prenatal care (82.8%) improved for the ninth consecutive year, especially for black (73.3%) and Hispanic (74.3%) mothers. The number and rate of multiple births continued their dramatic rise; the number of triplet and higher-order multiple births jumped 16% between 1996 and 1997, accounting, in part, for the slight increase in the percentage of low birth weight (LBW) births. LBW continued to increase from 1997 to 1998 to 7.6%. The infant mortality rate (IMR) was unchanged from 1997 to 1998 (7.2 per 1000 live births). The ratio of the IMR among black infants to that for white infants (2.4) remained the same in 1998 as in 1997. Racial differences in infant mortality remain a major public health concern. In 1997, 65% of all infant deaths occurred to the 7.5% of infants born LBW. Among all of the states, Maine, Massachusetts, and New Hampshire had the lowest IMRs. State-by-state differences in IMR reflect racial composition, the percentage LBW, and birth weight-specific neonatal mortality rate for each state. The United States continues to rank poorly in international comparisons of infant mortality. Expectation of life at birth increased slightly to 76.7 years for all gender and race groups combined. Death rates in the United States continue to decline, including a drop in mortality from human immunodeficiency virus. The age-adjusted death rate for suicide declined 6% in 1998; homicide declined 14%. Death rates for children from all major causes declined again in 1998. A large proportion of childhood deaths, however, continue to occur as a result of preventable injuries.

Births and deaths: preliminary data for 1998

OBJECTIVES

This report presents preliminary data for 1998 on births and deaths in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Natality data on marital status, prenatal care, cesarean delivery, and low birthweight are also presented. Mortality data presented include life expectancy, leading causes of death, and infant mortality.

METHODS

Data in this report are based on more than a 99-percent sample of births and on more than an 85-percent sample of deaths in the United States for 1998. The records are weighted to independent control counts of births, infant deaths, and deaths 1 year and over received in State vital statistics offices in 1998. Comparisons are made with 1997 final data.

RESULTS

The birth rate for teenagers continued to decline, dropping another 2 percent for 1997-98. The rate for young teens aged 15-17 years fell 5 percent, and the rate for teens aged 18-19 years declined 2 percent. Since 1991 rates have fallen 21 percent for teens aged 15-17 years and 13 percent for teens aged 18-19 years. Birth rates for women aged 20-29 years rose slightly. Among women in their thirties, birth rates rose 3 to 4 percent to the highest levels observed in three decades. The birth rate for women aged 40-44 years was the highest level reported since 1970. The birth rate for unmarried women was 44.3 per 1,000, 1 percent higher than 1997, but below the peak level reported for 1994 (46.9). The rate of prenatal care utilization continued to improve. The total cesarean rate increased to 21.2 percent. The low birthweight rate rose from 7.5 to 7.6 percent. In 1998 the age-adjusted death rate reached a record low, 2 percent below the rate for 1997. Human immunodeficiency virus infection (HIV infection) moved off the list of the 15 leading causes of death for the first time since 1987. Declines in age-adjusted rates occurred for Homicide and legal intervention (homicide) (14 percent) and Atherosclerosis (10 percent), while rates for Septicemia and Pneumonia and influenza increased 5 percent. Mortality also decreased for drug-induced deaths, deaths from injury by firearms, and alcohol-induced deaths. The infant mortality rate was unchanged. Life expectancy reached a record high of 76.7 in 1998.

Trends in twin and triplet births: 1980-97

This report presents data from U.S. birth certificates on the numbers and rates of twin and triplet and other higher order multiple births for 1980-97. Over the study period, the number of twin births rose 52 percent (from 68,339 to 104,137) and triplet and other higher order multiple births (heretofore referred to as "triplet/+") climbed 404 percent (from 1,337 to 6,737 births). Comparable but less pronounced rises were observed in twin and triplet/+ birth rates. Growth in twin and triplet/+ birth rates was most marked among women aged 30 years and over. Between 1980-82 and 1995-97, the twin rate rose 63 percent for women aged 40-44 years, and soared nearly 1,000 percent for women 45-49 years. (As one result, there were more twins born to women 45-49 years of age in 1997, than during the entire decade of the 1980's.) The triplet/+ birth rate rose nearly 400 percent for women in their thirties and exploded by more than 1,000 percent for women in their forties. The extraordinary rise in multiple births resulted in a shift in age-specific patterns, and the highest twin and triplet/+ birth rates now are for women 45-49 years of age. Historical differences in twinning rates between non-Hispanic white and black mothers have been largely eliminated (28.8 per 1,000 non-Hispanic white compared with 30.0 for black women). Non-Hispanic white women were more than twice as likely as non-Hispanic black or Hispanic women to have a triplet/+ birth. Rates of low birthweight, very low birthweight, and infant mortality were 4 to 33 times higher for twins and triplet/+ compared with singleton births. The risk for these adverse outcomes was lowest for twins and triplet/+ born to women 35-44 years of age. Twin birth rates for Massachusetts and Connecticut were at least 25 percent higher than the U.S. rate; triplet/+ rates for Nebraska and New Jersey were twice the national level.

Births and deaths: preliminary data for July 1997-June 1998

OBJECTIVES

This report presents preliminary data on births and deaths in the United States from the National Center for Health Statistics (NCHS) for the 12 months ending June 1998. U.S. data on births are shown by age, race, and Hispanic origin of mother. Natality data on marital status, prenatal care, cesarean delivery, and low birthweight are also presented. Mortality data presented include leading causes of death and infant mortality.

METHODS

Data in this report are based on more than a 99-percent sample of births and on more than an 89-percent sample of deaths in the United States for the 12 months ending June 1998. The records are weighted to independent control counts of births, infant deaths, and deaths 1 year and over received in State vital statistics offices from July 1997 to June 1998. Unless otherwise indicated, comparisons are made with final data for the 12-month period ending June 1997.

RESULTS

For the period July 1997-June 1998, the birth rate for teenagers dropped 4 percent to 51.5 births per 1,000 women aged 15-19 years, the lowest level since 1987. Birth rates for teenagers have been declining since 1991. Birth rates for women aged 20-29 years changed very little, whereas rates for women in their thirties and forties rose 2 to 4 percent. The birth rate for unmarried women declined slightly, but the number of births to unmarried women was up about 1 percent because of an increase in the number of unmarried women. The rate of prenatal care utilization continued to improve. The percent of births delivered by cesarean section rose from 20.7 percent to 20.9 percent as the result of a slight increase in the primary cesarean rate and a substantial decline in the rate of vaginal births after previous cesarean (VBAC). The overall low birthweight rate was unchanged at 7.5 percent. Age-adjusted death rates reached a record low, 2 percent below the rate for the previous 12-month period. The largest declines in estimated age-adjusted death rates among the leading causes of death were for Human immunodeficiency virus (HIV) infection (37 percent) and homicide (9 percent). Smaller declines were noted for most of the other leading causes of death, but no increases occurred. Mortality also decreased for firearm injuries and alcohol-induced deaths. The infant mortality rates for all races and white and black infants were about the same as the corresponding rates for the previous 12-month period.

ERCP and stent therapy for progressive jaundice in hepatocellular carcinoma: which patients benefit, which patients don't?

Jaundice in hepatocellular carcinoma (HCC) can be due to biliary obstruction. Endoscopic retrograde cholangiopancreatography (ERCP) can be both diagnostic and therapeutic. Biliary stenting can relieve jaundice and allow further chemotherapy, but at additional expense and potential morbidity. We sought to determine whether CT scan or ultrasound (US) could identify which patients with HCC and jaundice would benefit from endoscopic stenting. We retrospectively analyzed 26 patients with HCC and jaundice who underwent ERCP after CT or US. We compared biliary dilation on CT or US with the dominant biliary stricture seen on ERCP, and with response to biliary stenting. Eleven of 26 patients had dominant biliary stricture on ERCP; 11 underwent stenting. Six of 11 (55%) stented patients had a significant decline in bilirubin; three became eligible for further chemotherapy. All six responders to stenting had biliary dilation on prior CT or US. Procedure-related complications occurred in 1/11 (9%) who underwent stent placement. In conclusion, in selected patients, stenting can safely relieve jaundice and allow subsequent chemotherapy. CT or US accurately predicted lesions that responded to stenting. ERCP and stenting provided no benefit in the absence of biliary dilation on CT or US.

The effect of endoscopic sphincterotomy on acute and chronic complications of biliary endoprostheses

BACKGROUND

Endoscopically placed biliary stents have become routine therapy for bile duct obstruction and bile leaks. Controversy exists regarding the use of biliary sphincterotomy to facilitate placement of 10F plastic stents.

METHODS

We retrospectively studied the effect of sphincterotomy on acute and chronic complications of 10F stent therapy. Data for acute complications, 30-day mortality and stent migration were obtained for 130 patients undergoing placement of a single 10F plastic biliary stent. For 109 patients in whom prolonged stent therapy was undertaken, the occurrence of and time to stent dysfunction were also analyzed. Sphincterotomy was performed in 48 cases (36.9%) based on physician preference.

RESULTS

There were no failures in stent placement. The incidence of acute complications was higher in patients undergoing sphincterotomy (8.3% vs. 1.2%, p = 0.04). Stent migration was more common in the no sphincterotomy group versus the sphincterotomy group (8.5% vs. 0, p = 0.03).

CONCLUSIONS

Sphincterotomy is not necessary for placement of 10F plastic stents and increases acute procedural morbidity. Interestingly, a higher incidence of stent migration was seen in patients who did not undergo biliary sphincterotomy.

Impact of maternal nativity on the prevalence of diabetes during pregnancy among U.S. ethnic groups

OBJECTIVE

This study examines the impact of maternal nativity (birthplace) on the overall prevalence of diabetes during pregnancy and among 15 racial and ethnic groups in the U.S.

RESEARCH DESIGN AND METHODS

Birth certificate data for all resident single live births in the U.S. from 1994 to 1996 were used to calculate reported diabetes prevalence during pregnancy and to assess the impact of maternal birthplace outside of the 50 states and Washington, DC, on the risk of diabetes before and after adjustment for differences in maternal age, other sociodemographic characteristics, and late or no initiation of prenatal care overall and for each racial and ethnic group.

RESULTS

Mothers born outside of the U.S. are significantly more likely to have diabetes during pregnancy. The impact of maternal nativity on diabetes prevalence is largely explained by the older childbearing age of immigrant mothers. However, adjusted diabetes risk remains elevated for Asian-Indian, non-Hispanic black, Filipino, Puerto Rican, and Central and South American mothers who were born outside the U.S. Conversely, birthplace outside the U.S. significantly reduces diabetes risk for Japanese, Mexican, and Native American women.

CONCLUSIONS

Identification, treatment, and follow-up of immigrant mothers with diabetes during pregnancy may require special attention to language and sociocultural barriers to effective care. Systematic surveillance of the prevalence and impact of diabetes during pregnancy for immigrant and nonimmigrant women, particularly in racial and ethnic minority groups, and more detailed studies on the impact of acculturation on diabetes may increase understanding of the epidemiology of diabetes during pregnancy in our increasingly diverse society.

Births: final data for 1997

OBJECTIVES

This report presents 1997 data on U.S. births according to a wide variety of characteristics. Data are presented for maternal demographic characteristics including age, live-birth order, race, Hispanic origin, marital status, and educational attainment; maternal lifestyle and health characteristics (medical risk factors, weight gain, and tobacco and alcohol use); medical care utilization by pregnant women (prenatal care, obstetric procedures, complications of labor and/or delivery, attendant at birth, and method of delivery); and infant health characteristics (period of gestation, birthweight, Apgar score, abnormal conditions, congenital anomalies, and multiple births). Also presented are birth and fertility rates by age, live-birth order, race, Hispanic origin, and marital status. Selected data by mother's State of residence are shown including teenage birth rates and total fertility rates, as well as data on month and day of birth, sex ratio, and age of father. Trends in fertility patterns and maternal and infant characteristics are described and interpreted.

METHODS

Descriptive tabulations of data reported on the birth certificates of the 3.9 million births that occurred in 1997 are presented.

RESULTS

Birth and fertility rates declined very slightly in 1997. Birth rates for teenagers fell 3 to 5 percent. Rates for women in their twenties changed very little, whereas rates for women in their thirties rose 2 percent. The number of births and the birth rate for unmarried women each declined slightly in 1997 while the percent of births that were to unmarried women was unchanged. Smoking by pregnant women overall dropped again in 1997, but continued to increase among teenagers. Improvements in prenatal care utilization continued. The cesarean delivery rate increased slightly after declining for 7 consecutive years. The proportion of multiple birth continued to rise; higher order multiple births (e.g., triplets, quadruplets) rose by 14 percent in 1997, following a 20 percent rise from 1995 to 1996. Key measures of birth outcome--the percents of low birthweight and preterm births--increased, with particularly large increases in the preterm rate. These changes are in large part the result of increases in multiple births.

News & notes: paper digestion by the cellulolytic ruminal bacterium Fibrobacter succinogenes

The objective of this study was to evaluate the ability of the predominant cellulolytic ruminal bacterium Fibrobacter succinogenes S85 to digest filter paper, office paper, newspaper, and magazine paper. When F. succinogenes S85 was incubated with all four paper sources, little digestion of any paper occurred between 0 and 48 h. However, digestion of filter paper increased from 12% at 48 h to 80% at 120 h. No significant digestion of office paper, newspaper, or magazine paper occurred between 48 and 120 h. These results suggest that F. succinogenes S85 is unable to digest office paper, newspaper, or magazine paper.

Annual summary of vital statistics-1997

Many positive trends in the health of Americans continued into 1997. In 1997, the preliminary birth rate declined slightly to 14.6 births per 1000 population, and the fertility rate, births per 1000 women 15 to 44 years of age, was unchanged from the previous year (65.3). These indicators suggest that the downward trend in births observed since the early 1990s may have abated. Fertility rates for white, black, and Native American women were essentially unchanged between 1996 and 1997. Fertility among Hispanic women declined 2% in 1997 to 103.1, the lowest level reported since national data for this group have been available. For the sixth consecutive year, birth rates dropped for teens. Birth rates for women 30 years or older continued to increase. The proportion of births to unmarried women (32.4%) was unchanged in 1997. The trend toward earlier utilization of prenatal care continued for 1997; 82.5% of women began prenatal care in the first trimester. There was no change in the percentage with late (third trimester) or no care in 1997. The cesarean delivery rate rose slightly to 20.8% in 1997, a reversal of the downward trend observed since 1989. The percentage of low birth weight (LBW) infants rose again in 1997 to 7.5%. The percentage of very low birth weight was up only slightly to 1.41%. Among births to white mothers, LBW increased for the fifth consecutive year, to 6.5%, whereas the rate for black mothers remained unchanged at 13%. Much, but not all, of the rise in LBW for white mothers during the 1990s can be attributed to an increase in multiple births. In 1996, the multiple birth rate rose again by 5%, and the higher-order multiple birth rate climbed by 20%. Infant mortality reached an all time low level of 7.1 deaths per 1000 births, based on preliminary 1997 data. Both neonatal and postneonatal mortality rates declined. In 1996, 64% of all infant deaths occurred to the 7.4% of infants born at LBW. Infant mortality rates continue to be more than two times greater for black than for white infants. Among all the states in 1996, Maine, Massachusetts, and New Hampshire had the lowest infant mortality rates. Despite declines in infant mortality, the United States continues to rank poorly in international comparisons of infant mortality. Expectation of life at birth reached a new high in 1997 of 76.5 years for all gender and race groups combined. Age-adjusted death rates declined in 1997 for diseases of the heart, accidents and adverse affects (unintentional injuries), homicide, suicide, malignant neoplasms, cerebrovascular disease, chronic liver disease and cirrhosis, and diabetes. In 1997, mortality due to HIV infection declined by 47%. Death rates for children from all major causes declined again in 1997. Motor vehicle traffic injuries and firearm injuries were the two major causes of traumatic death. A large proportion of childhood deaths continue to occur as a result of preventable injuries.

Effects of fibronectin on articular cartilage chondrocyte proteoglycan synthesis and response to insulin-like growth factor-I

Fibronectin, a ubiquitous glycoprotein of the extracellular matrix, serves as a substrate for cell attachment. Binding to fibronectin through cell-surface receptors promotes a flattened cell shape, stimulates the phosphorylation of intracellular protein, and changes the pattern of gene expression. Although fibronectin is abundant in normal articular cartilage, its effects on chondrocytes are not well understood. Proteolytic fragments of fibronectin stimulate the catabolism of matrix in articular cartilage and may promote the degeneration of cartilage in osteoarthritis; however, intact fibronectin may regulate other aspects of matrix metabolism, including matrix synthesis. To determine whether intact fibronectin affects the synthetic activity of chondrocytes, as well as to determine the responses of chondrocytes to the anabolic growth factor insulin-like growth factor-I, we compared the incorporation of [35S] by articular chondrocytes of the rat cultured in the presence and absence of commercially prepared cellular fibronectin and 0, 10, or 100 ng/ml recombinant human insulin-like growth factor-I. Monolayer and alginate suspension cultures were compared to determine whether responses differed under conditions in which fibronectin promoted a flattened cell shape (monolayer culture) and under those in which cells maintained a spherical shape (alginate culture). In alginate cultures, fibronectin alone stimulated the incorporation of [35S]. Fibronectin with 10 ng/ml insulin-like growth factor-I had additive effects in alginate culture, producing the maximum incorporation of [35S]. In monolayer cultures, fibronectin did not stimulate incorporation and blocked stimulation by 100 ng/ml insulin-like growth factor-I. The cells from the monolayer culture were much less active synthetically (at all doses of the growth factor) than those cultured in alginate. Thus, fibronectin enhanced proteoglycan synthesis and the response to insulin-like growth factor-I in alginate but inhibited the response to the growth factor in monolayers. These observations suggest intact fibronectin may contribute to the maintenance or repair of the matrix of articular cartilage by stimulating proteoglycan synthesis.

Births and deaths: preliminary data for 1997

OBJECTIVES

This report presents preliminary data on births and deaths in the United States from the National Center for Health Statistics (NCHS) for 1997. U.S. data on births are shown by age, race, and Hispanic origin of mother. National and State data on marital status, prenatal care, cesarean delivery, and low birthweight are also presented. Mortality data presented include life expectancy, leading causes of death, and infant mortality.

METHODS

Data in this report are based on a 99 percent sample of births and more than an 85 percent sample of deaths in the United States in 1997. The records are weighted to independent control counts of births, infant deaths, and deaths 1 year and over received in State vital statistics offices in 1997.

RESULTS

According to preliminary data for 1997, the birth rate for teenagers dropped to 52.9 births per 1,000 women aged 15-19 years, 3 percent lower compared with 1996. Birth rates for teenagers have been declining since 1991. Declines for younger teenagers (15-17 years) were greater than for older teenagers. Birth rates for women aged 25-44 years increased 1 to 2 percent; the rate for women aged 20-24 years rose very slightly. The number of births to unmarried women was essentially unchanged and the percent of all births to unmarried women remained at 32.4 percent; the birth rate for unmarried women declined 2 percent. The rate of prenatal care utilization continued to improve. The cesarean delivery rate increased slightly. The overall low birthweight rate increased to 7.5 percent. The largest declines in estimated age-adjusted death rates among the leading causes of death were for Human immunodeficiency virus (HIV) infection (47 percent) and homicide (12 percent). Mortality also decreased for firearm injuries, drug-induced deaths, and alcohol-induced deaths. The age-adjusted death rate increased for Pneumonia and influenza, Chronic obstructive pulmonary diseases, kidney disease, and Septicemia. The preliminary infant mortality rate for 1997 was 7.1 infant deaths per 1,000 live births, down from a rate of 7.3 for 1996. The infant mortality rate for black infants declined 7 percent to 13.7; the white rate was 6.0. Life expectancy reached a record high of 76.5 years in 1997.

Report of final natality statistics, 1996

OBJECTIVES

This report presents 1996 data on U.S. births according to a wide variety of characteristics. Data are presented for maternal demographic characteristics including age, live-birth order, race, Hispanic origin, marital status, and educational attainment; maternal lifestyle and health characteristics (medical risk factors, weight gain, tobacco and alcohol use); medical care utilization by pregnant women (prenatal care, obstetric procedures, complications of labor and/or delivery, attendant at birth, and method of delivery); and infant health characteristics (period of gestation, birthweight, Apgar score, abnormal conditions, congenital anomalies, and multiple births). Also presented are birth and fertility rates by age, live-birth order, race, Hispanic origin, and marital status. Selected data by mother's State of residence are shown including teenage birth rates and total fertility rates, as well as data on month and day of birth, sex ratio, and age of father. Trends in fertility patterns and maternal and infant characteristics are described and interpreted.

METHODS

Descriptive tabulations of data reported on the birth certificates of the 3.9 million births that occurred in 1996 are presented.

RESULTS

Birth and fertility rates declined very slightly in 1996. Birth rates for teenagers fell 3 to 8 percent. Rates for women in their twenties increased slightly in 1996, the first increase since 1990, while rates for women in their thirties rose 2 to 3 percent. The number and percent of births to unmarried women increased slightly in 1996 while the birth rate for unmarried women declined modestly. Smoking by pregnant women overall dropped again in 1996, but increased among teenagers. Improvements in prenatal care utilization continued. The cesarean delivery rate declined. The proportion of multiple births continued to rise; higher order multiple births (e.g., triplets, quadruplets) rose by 19 percent. Key measures of birth outcome--the percents of low birthweight and preterm births--increased slightly, in large part the result of increases in multiple births.

The changing pattern of prenatal care utilization in the United States, 1981-1995, using different prenatal care indices

CONTEXT

Two measures traditionally used to examine adequacy of prenatal care indicate that prenatal care utilization remained unchanged through the 1980s and only began to rise slightly in the 1990s. In recent years, new measures have been developed that include a category for women who receive more than the recommended amount of care (intensive utilization).

OBJECTIVE

To compare the older and newer indices in the monitoring of prenatal care trends in the United States from 1981 to 1995, for the overall population and for selected subpopulations. Second, to examine factors associated with receiving intensive utilization.

DESIGN

Cross-sectional and trend analysis of national birth records.

SETTING

The United States.

SUBJECTS

All live births between 1981 and 1995 (N=54 million).

MAIN OUTCOME MEASURES

Trends in prenatal care utilization, according to 4 indices (the older indices: the Institute of Medicine Index and the trimester that care began, and the newer indices: the R-GINDEX and the Adequacy of Prenatal Care Utilization Index). Multiple logistic regression was used to assess the risk of intensive prenatal care use in 1981 and 1995.

RESULTS

The newer indices showed a steadily increasing trend toward more prenatal care use throughout the study period (R-GINDEX, intensive or adequate use, 32.7% in 1981 to 47.1 % in 1995; the Adequacy of Prenatal Care Utilization Index, intensive use, 18.4% in 1981 to 28.8% in 1995), especially for intensive utilization. Women having a multiple birth were much more likely to have had intensive utilization in 1995 compared with 1981 (R-GINDEX, 22.8% vs 8.5%). Teenagers were more likely to begin care later than adults, but similar proportions of teens and adults had intensive utilization. Intensive use among low-risk women also increased steadily each year. Factors associated with a greater likelihood of receiving intensive use in 1981 and 1995 were having a multiple birth, primiparity, being married, and maternal age of 35 years or older.

CONCLUSIONS

The proportion of women who began care early and received at least the recommended number of visits increased between 1981 and 1995. This change was undetected by more traditional prenatal care indices. These increases have cost and practice implications and suggest a paradox since previous studies have shown that rates of preterm delivery and low birth weight did not improve during this time.

Births of Hispanic origin, 1989-95

OBJECTIVES

This report presents trend data on births in the United States to women of Hispanic and non-Hispanic origin, from 1989 to 1995, for a wide variety of characteristics. Hispanic women data are presented where possible separately for Mexican, Puerto Rican, Cuban, Central and South American, and other Hispanic women while for non-Hispanic women data are shown for white and black women. Maternal demographic characteristics include age, marital status, live-birth order, educational attainment, and mother's place of birth. Health care utilization items include timing of prenatal care, cesarean delivery rate, place of birth and midwife attendance. Infant health characteristics include percents born preterm, low birthweight, very low birthweight, and percent born in multiple births. Trend data for the number of births by State are also presented.

METHODS

Descriptive tabulations of births of Hispanic origin of the mother for births that occurred from 1989 through 1995 are presented.

RESULTS

The number of births born to Hispanic women has risen every year from 1989 to 1995. In addition in 1989 Hispanic women had 14 percent of births in the United States and in 1995 they represented 18 percent. While Hispanic women as a group continue to have higher fertility rates than non-Hispanics, Mexican women in particular have dramatically higher rates. While increases in early prenatal care were observed for all women in the United States, increases were particularly substantial for Hispanic women. The cesarean section rate has been dropping in the United States; yet while rates for Cuban women have also been dropping, the rates are nearly 50 percent higher than those for any other population subgroup.

A Ginkgo biloba extract (EGb 761) prevents mitochondrial aging by protecting against oxidative stress

The effect of aging on indices of oxidative damage in rat mitochondria and the protective effect of the Ginkgo biloba extract EGb 761 was investigated. Mitochondrial DNA from brain and liver of old rats exhibited oxidative damage that is significantly higher than that from young rats. Mitochondrial glutathione is also more oxidized in old than in young rats. Peroxide formation in mitochondria from old animals was higher than in those from young ones. According to morphological parameters (size and complexity), there are two populations of mitochondria. One is composed of large, highly complex mitochondria, and the other population is smaller and less complex. Brain and liver from old animals had a higher proportion of the large, highly complex mitochondria than seen in organs from young animals. Treatment with the Ginkgo biloba extract EGb 761 partially prevented these morphological changes as well as the indices of oxidative damage observed in brain and liver mitochondria from old animals.

Spatial and temporal expression of CD44 isoforms in the developing and growing joints of the rat limb

Hyaluronan is an integral component of proteoglycan-rich extracellular matrices such as hyaline cartilage. Hyaluronan is commonly found in embryonic tissue and is important in the formation of hydrated matrices that allow cellular expansion and migration. Cell surface hyaluronan-binding proteins such as CD44 are presumed to be important in the cellular interactions with hyaluronan in both of these processes. The primary aim of this study was to document the spatial and temporal expressions of CD44 isoforms during the development and growth of the diarthrodial joints of rat limbs. With use of in situ hybridization and immunohistochemistry, the CD44s isoform is selectively identified as localized to a single cell layer on opposing sides of the joint at the first appearance of joint cavitation (on the 18th day of gestation). After joint formation in the neonate, the expression of the CD44s isoform in the cells at the joint surface is lost. These findings suggest that the CD44s isoform has a role in the development of the diarthrodial joint, presumably through interaction with hyaluronan.

The design, synthesis and properties of highly potent and selective inhibitors of herpes simplex virus types 1 and 2 thymidine kinase

The rational design and synthesis of nucleotide analogues as inhibitors of herpes simplex virus (HSV) thymidine kinase is described. Starting from thymidine, product analogues which included phosphates, phosphonates, sulphonates, sulphonamides and carboxamides were prepared. The carboxamide series showed good structure-activity relationships and afforded a lead structure which inhibited the HSV-2 enzyme in the low micromolar range. Replacing the 5-methyl group in thymidine by ethyl enhanced the potency of the lead structure 10-fold. Further optimization of the carboxamide moiety afforded inhibitors active in the sub-nanomolar range and finally the introduction of a 2'-beta-fluoro substituent improved the potency a further twofold. The low water solubility of the most potent inhibitor was overcome by conversion to the 3'-valyl ester, which had good oral bioavailability and showed activity by the oral route in murine models of infection.

Annual summary of vital statistics--1996

Several recent trends in the vital statistics of the United States continued in 1996, including an increase in life expectancy and declines in infant mortality, births to teenage mothers, age-adjusted death rates, and death rates for children and adolescents. In 1996, there were an estimated 3 914 953 births in the United States. The preliminary birth rate remained unchanged at 14.8 births per 1000 population, and the fertility rate, births per 1000 women 15 to 44 years of age, was essentially the same at 65.7. Fertility rates rose slightly for most racial and ethnic groups except black women, for whom the rate hit a historic low of 70.8. Overall, fertility remains particularly high for Hispanic women, although there is considerable variation within this heterogenous group. For the fifth consecutive year, birth rates dropped for teenagers. Birth rates for women >/=30 years of age continued to increase. The birth rate for unmarried women declined 1% in 1996 to 44.6 births per 1000 unmarried women, continuing the decline noted in 1995 for the first time in 2 decades. The percentage of women who began prenatal care in the first trimester rose in 1996 to 81.8%, whereas the percentage with late (third trimester) or no care dropped to 4.1%. The rise in timely prenatal care was greatest for black and Hispanic women. The percentage of low birth weight (LBW) infants reached 7.4% in 1996, its highest level since 1975. The very low birth weight rate remained unchanged at 1.4%. The rise in LBW occurred primarily among white women, whereas the LBW rate for black women dropped to 13.0%, the lowest rate reported since 1987. The rise among white women is only partially a result of increases in multiple births, because LBW rates have also risen among white singleton births. The multiple birth ratio rose again in 1996 by 2%, as it has since 1980. The rise was particularly large for higher-order multiple births. Infant mortality reached an all time low level of 7.2 deaths per 1000 births, based on preliminary 1996 data. Neonatal and postneonatal rates declined, as did rates for both black and white infants. National birth weight specific mortality rates are reported here for the first time. In 1995, 63% of infant deaths occurred to the 7.3% of the population that was born LBW. The four leading cause of infant death were congenital anomalies, disorders relating to short gestation and unspecified birth weight, sudden infant death syndrome, and respiratory distress syndrome, accounting for more than half of infant deaths in 1996. Despite the declines in infant mortality, the United States continues to rank poorly in international comparisons of infant mortality. Expectation of life at birth reached a new high in 1996 of 76.1 years for all gender and race groups combined. Age-adjusted mortality rates declined in 1996 for diseases of the heart, malignant neoplasms, cerebrovascular diseases, accidents and adverse effects, chronic liver disease and cirrhosis, and suicide. They rose, as in the past several years, for chronic obstructive pulmonary diseases, diabetes mellitus, and pneumonia and influenza. For the first time since human immunodeficiency virus infection was created as a special cause-of-death category in 1987, death rates for human immunodeficiency virus infection declined from 15.6 in 1995 to 11.6 in 1996. The homicide rate also declined, as it has since 1991. Death rates for children between 1 and 19 years of age declined in 1996, with an estimated 29 183 deaths to children. Unintentional injury mortality has dropped by approximately 50% among children and adolescents since 1979, although it remains the leading cause of death for all age groups of children from 1 to 19 years. Homicide was the fourth leading cause of death for children 1 to 4 and 5 to 9 years of age, the third leading cause for children 10 to 14, and the second leading cause for 15 to 19 year olds.

Births and deaths: United States, 1996

OBJECTIVES

This report presents preliminary data on births and deaths in the United States from the National Center for Health Statistics for 1996. U.S. data are shown by age, race, and Hispanic origin. National and State data on births by marital status, prenatal care, cesarean delivery, and low birthweight are also presented. Mortality data presented include life expectancy, leading causes of death, and infant mortality.

METHODS

This report, the third in a new statistical series, presents preliminary data for 1996 on births and deaths based on a substantial sample of vital records. The records are weighted to independent control counts of births, infant deaths, and total deaths received in State vital statistics offices during calendar year 1996.

RESULTS

According to preliminary data for 1996, the birth rate for teenagers dropped 4 percent in 1996 to 54.7 births per 1,000 women aged 15-19 years. The teen birth rate has declined 12 percent since 1991 (62.1), with larger reductions for young teenagers 15-17 years and for black teenagers. Birth rates for women aged 20-34 years increased 1-2 percent, while rates for women aged 35-44 years rose 3 percent. The number and percent of births to unmarried women increased about 1 percent, while the birth rate for unmarried women declined 1 percent. The rate of prenatal care utilization improved and the cesarean delivery rate declined. The overall low birthweight rate increased to 7.4 percent. The 1996 preliminary infant mortality rate reached a record low of 7.2 infant deaths per 1,000 live births with all-time lows for white and black infants. Life expectancy reached a record high of 76.1 years with all-time highs for white and black males and black females. The largest declines in age-adjusted death rates among the leading causes of death were for Human immunodeficiency virus (HIV) (26 percent) and Homicide (11 percent), which dropped from the 12th to the 14th leading cause of death.

Age-related decline in chondrocyte response to insulin-like growth factor-I: the role of growth factor binding proteins

The synthetic activity of chondrocytes in articular cartilage declines with age, possibly as a result of decreased sensitivity to anabolic growth factors such as insulin-like growth factor-I. The sensitivity of these cells to insulin-like growth factor-I is regulated, in part, by the synthesis of insulin-like growth factor-I binding proteins. We hypothesized that, as cartilage ages, an increase in the expression of these binding proteins suppresses the synthetic response of chondrocytes to insulin-like growth factor-I. To test this hypothesis, we measured proteoglycan synthesis (incorporation of [35S]sulfate per cell) in alginate cultures of chondrocytes from the articular cartilage of 1, 3, 12, and 24-month-old rats. A dose-response to insulin-like growth factor-I was determined for cells from each age group; incorporation of [35S]sulfate per cell declined with age, regardless of the dose. The sharpest decline was found between cells from the 1 and 3-month-old groups. Using the Western ligand blot technique, we then compared the expression of insulin-like growth factor-I binding protein in chondrocytes from the 1 and 3-month-old rats and found that it was increased in the cells from the older animals. Recombinant insulin-like growth factor-3, when added to the cell cultures of the 1-month-old rats, inhibited incorporation of [35S]sulfate and blocked responses to insulin-like growth factor-I. These findings suggest that the age-related decline in the synthetic response of chondrocytes to insulin-like growth factor-I results, at least in part, from increased expression of insulin-like growth factor binding protein.

"De novo" duplication Xq23-->Xq26 of paternal origin in a girl with a mildly affected phenotype

We report a de novo dup(X)(q23-->q26) in a 3-year-old girl with growth retardation, developmental delay, and minor anomalies. X-inactivation in lymphocytes by BRDU labeling showed the abnormal X was late replicating. The androgen receptor assay (HAR) demonstrated a skewed methylation (88.8%) of the paternal allele and a 11.2% methylation of the maternal allele. These data, which suggest the duplication was paternally inherited, are the first parental-origin identification of a duplication Xq. The mild phenotype of the patient may be related to the size and region of the duplication, the low percentage of a dup(X) active detected by the HAR assay, or a combination of these mechanisms.

Five-year treatment outcomes for teeth with large amalgams and crowns

For 4735 posterior complex amalgams and crowns placed in adults with continuous dental HMO coverage, all additional treatment received over the subsequent 5 years was determined. The restorations were placed under routine clinical conditions by 74 different dentists among a broad spectrum of insured dental patients. Treatment outcomes were described in terms of a hierarchical classification of additional treatments. At the extremes, a successful outcome was defined as no additional treatment or an additional one- or two-surface restoration on the same tooth, and a catastrophic outcome as extraction or endodontic treatment. Due to clinical protocols, teeth with guarded to poor prognosis prior to treatment are overrepresented in the five-surface amalgam cohort. Successful outcomes characterized 72% of four-surface amalgams, 65% of five-surface amalgams, 84% of gold crowns, and 84% of porcelain crowns. Catastrophic outcomes occurred for 10% of four-surface amalgams, 15% of five-surface amalgams, 8% of gold crowns, and 9% of porcelain crowns.

De novo der(X)t(X;10)(q26;q21) with features of distal trisomy 10q: case report of paternal origin identified by late replication with BrdU and the human androgen receptor assay (HAR)

We describe an 11 year old girl with a de novo unbalanced t(X;10) that resulted in a deletion of Xq26-->Xqter and a trisomy of 10q21-->10qter. Her clinical features were of distal trisomy 10q, but she lacked the cardiovascular and renal malformations observed in duplications of 10q24-->10qter and had only moderate mental retardation. X inactivation was assessed on peripheral blood lymphocytes by late replication with BrdU (LR) and the human androgen receptor assay (HAR). By LR the der(X) was inactive without spreading to 10q21-->10qter in all cells. The HAR assay showed skewed methylation of the paternal allele (90%). The correlation of HAR and LR suggests that the der(X) was paternally inherited and is consistent with data from other de novo balanced and unbalanced X;autosome translocations detected in females. This is the first report of parental origin of a de novo trisomy 10q.

Objective structured assessment of technical skill (OSATS) for surgical residents

BACKGROUND

The technical skill of surgical trainees is not well assessed. This study aimed (1) to compare the reliability of three scoring systems, (2) to compare live and bench formats and (3) to assess construct validity of a test of operative skill.

METHODS

Parallel examinations of operative skill, one using live animals and one using simulations, were developed. Performance was graded using operation-specific checklists, detailed global rating forms and pass/fail judgements. Twenty surgical residents each took both formats.

RESULTS

Disattenuated correlations between live and bench scores were high (0.69-0.72). Mean interrater reliability across stations ranged from 0.64 to 0.72. Internal consistency was moderate to high (alpha: 0.61-0.74) for the live format using the checklist and for live and bench formats using global ratings. Global ratings discriminated between resident levels for both formats (bench: F(2,17) = 4.45, P < 0.05; live: F(2,17) = 3.55, P < 0.05), checklists did not.

CONCLUSION

This preliminary study suggests that the Objective Structured Assessment of Technical Skill can reliably and validly assess surgical skills. Global ratings are a better method of assessment than task-specific checklists. Bench model simulation gives equivalent results to use of live animals for this test format.

Triplet births: trends and outcomes, 1971-94

OBJECTIVES

This report describes changes in the number and ratio of live births in triplet and other higher order multiple deliveries from 1971 to 1994 by maternal race, age, education, and marital status. The report also examines the birth outcomes of triplets compared with singletons, including overall gestation specific, and birthweight specific infant mortality rates.

METHODS

Birth data are obtained from the U.S. certificates of live birth. Mortality data were obtained from the Linked Birth and Infant Death Data Sets for the 1983-91 birth cohorts. Most analyses are based on triplet and other higher-order multiple births (quadruplet and quintuplet and greater births) in the aggregate. (Triplet births comprise about 92 percent of all higher order multiple births.) Triplet and other higher order birth ratios for most variables are computed by combining data for years 1982-84 and 1992-94, and for infant mortality by combining birth cohorts for years 1987-91.

FINDINGS

Between 1971 and 1994 the number and ratio of triplet births quadrupled, rising from 1,034 to 4,594, and from 29.1 to 116.2 per 100,000 live births. Most of the increase was among births to white mothers, particularly among married and more educated mothers. Only about one-third of the increase in triplet birthing among white mothers between 1989 and 1994 could be attributed to changes in the maternal age distribution. Massachusetts reported the highest triplet birth ratio (215.9), more than twice the U.S. ratio (105.5). Other States with comparatively high ratios were New Hampshire, New Jersey, and Iowa. Nine of 10 triplets were born preterm compared with 1 of 10 singletons. The average triplet weighed 1,698 grams at birth, one-half that of the average singleton (3,358 grams). Triplets were about 12 times more likely to die during the first year of life as singletons, but had a survival advantage over singletons at lower gestations and birthweights.

Trends and characteristics of births attended by midwives

In 1994 there were 218,466 births attended by midwives in the United States more than seven times the number in 1975 (29,413). The percent of all births attended by midwives rose from 0.9 percent in 1975 to 5.5 percent in 1994. The vast majority of midwife attended births were by certified nurse-midwives (CNMs) and occurred in hospitals. Births attended by other midwives comprised only 6 percent of all midwife-attended births (down 11 percent since-1989) and are becoming increasingly concentrated in out of hospital settings, particularly residences. Due in large part to population characteristics, the proportions of births attended by midwives varies markedly between states. The percentages range from 19 percent in New Mexico to less than 1 percent in Kansas Louisiana Missouri and Nebraska Mothers with midwife attended births in out of hospital settings generally had demographic and lifestyle characteristics that were lower risk for obstetric complications and poor birth outcomes compared with mothers with physician- or midwife attended births in hospitals. That is these mothers were more likely to be married older more educated having higher order births and were less likely to smoke and gain and adequate amount of weight during pregnancy. However women with midwife attended births regardless of type of midwife or birth setting were more likely to initiate prenatal care later in the pregnancy and have fewer overall visits than were women whose births were attended by physicians. Despite less prenatal care a smaller proportion of babies whose births were attended by midwives were preterm or were of low or very low birth weight.

Annual summary of vital statistics--1995

Recent trends in the vital statistics of the United States continued in 1995, including decreases in the number of births, the birth rate, the age-adjusted death rate, and the infant mortality rate; life expectancy at birth increased to a level equal to the record high of 75.8 years in 1992. Marriages and divorces both decreased. An estimated 3,900,089 infants were born during 1995, a decline of 1% from 1994. The preliminary birth rate for 1995 was 14.8 live births per 1000 total population, a 3% decline, and the lowest recorded in nearly two decades. The fertility rate, which relates births to women in the childbearing ages, declined to 65.6 live births per 1000 women 15 to 44 years old, the lowest rate since 1986. According to preliminary data for 1995, fertility rates declined for all racial groups with the gap narrowing between black and white rates. The fertility rate for black women declined 7% to a historic low level (71.7); the preliminary rate for white women (64.5) dropped just 1%. Fertility rates continue to be highest for Hispanic, especially Mexican-American, women. Preliminary data for 1995 suggest a 2% decline in the rate for Hispanic women to 103.7. The birth rate for teenagers has now decreased for four consecutive years, from a high of 62.1 per 1000 women 15 to 19 years old in 1991 to 56.9 in 1995, an overall decline of 8%. The rate of childbearing by unmarried mothers dropped 4% from 1994 to 1995, from 46.9 births per 1000 unmarried women 15 to 44 years old to 44.9, the first decline in the rate in nearly two decades. The proportion of all births occurring to unmarried women dropped as well in 1995, to 32.0% from 32.6% in 1994. Smoking during pregnancy dropped steadily from 1989 (19.5%) to 1994 (14.6%), a decline of about 25%. Prenatal care utilization continued to improve in 1995 with 81.2% of all mothers receiving care in the first trimester compared with 78.9% in 1993. Preliminary data for 1995 suggests continued improvement to 81.2%. The percent of infants delivered by cesarean delivery declined slightly to 20.8% in 1995. The percent of low birth weight (LBW) infants continued to climb in 1994 rising to 7.3%, from 7.2% in 1993. The proportion of LBW improved slightly among black infants, declining from 13.3% to 13.2% between 1993 and 1994. Preliminary figures for 1995 suggest continued decline in LBW for black infants (13.0%). The multiple birth ratio rose to 25.7 per 1000 births for 1994, an increase of 2% over 1993 and 33% since 1980. Age-adjusted death rates in 1995 were lower for heart disease, malignant neoplasms, accidents, and homicide. Although the total number of human immunodeficiency virus (HIV) infection deaths increased slightly from 42,114 in 1994 to an estimated 42,506 in 1995, the age-adjusted death rate for HIV infection did not increase, which may indicate a leveling off of the steep upward trend in mortality from HIV infection since 1987. Nearly 15,000 children between the ages of 1-14 years died in the United States (US) in 1995. The death rate for children 1 to 4 years old in 1995 was 40.4 per 100,000 population aged 1 to 4 years, 6% lower than the rate of 42.9 in 1994. The 1995 death rate for 5- to 14-year-olds was 22.1, 2% lower than the rate of 22.5 in 1994. Since 1979, death rates have declined by 37% for children 1 to 4 years old, and by 30% for children 5 to 14 years old. For children 1 to 4 years old, the leading cause of death was injuries, which accounted for for an estimated 2277 deaths in 1995, 36% of all deaths in this age group. Injuries were the leading cause of death for 5- to 14-year-olds as well, accounting for an ever higher percentage (41%) of all deaths. In 1995, the preliminary infant mortality rate was 7.5 per 1000live births, 6% lower than 1994, and the lowest ever recorded in the US. The decline occurred for neonatal as well as postneonatal mortality rates, and among white and black infants alike.

Three-dimensional structure of the alpha-conotoxin GI at 1.2 A resolution

Predatory marine snails of the genus Conus paralyze their fish prey by injecting a potent toxin. The alpha-conotoxin GI is a 13-residue peptide isolated from venom of Conus geographus. It functions by blocking the postsynaptic nicotinic acetylcholine receptor. After crystallization in deionized water, the three-dimensional structure of the GI neurotoxin was determined to 1.2 A resolution by X-ray crystallography. This structure, which can be described as a triangular slab, shows overall similarities to those derived by NMR, CD, and predictive methods. The principal framework of the molecule is provided by two disulfide bonds, one linking Cys 2 and Cys 7 and the other Cys 3 and Cys 13. Opposite ends of the sequence are drawn together even further by hydrogen bonds between Glu 1 and Cys 13 and between Cys 2 and Ser 12. Since the C-terminus is amidated, only one negative charge is present (carboxylate of Glu 1), and this is not implicated in receptor binding. Two positively charged regions (the alpha-amino group of Glu 1 and the guanido group of Arg 9) are situated 15 A apart at the corners of the triangular face of the molecule. phi, psi angles characteristic of a 3(10) helix were observed for residues 5-7. For residues 8-11, these angles were consistent with either a type I beta-turn or a distorted 3(10) helix.