Incidence of spontaneous abortion among normal women and insulin-dependent diabetic women whose pregnancies were identified within 21 days of conception

Whether pregnant women with insulin-dependent diabetes mellitus have an increased risk of spontaneous abortion is controversial. To address this question, we enrolled 386 women with insulin-dependent diabetes and 432 women without diabetes before or within 21 days after conception and followed both groups prospectively. Sixty-two diabetic women (16.1 percent) and 70 control women (16.2 percent) had pregnancy losses (odds ratio, 0.99; 95 percent confidence interval, 0.67 to 1.46). After adjustment for known risk factors for spontaneous abortion, the rate was still not significantly higher in the diabetic group (odds ratio, 0.91; 95 percent confidence interval, 0.59 to 1.40). Nonetheless, among the diabetic women, most of whom had good metabolic control, those who had spontaneous abortions had higher fasting and postprandial glucose levels in the first trimester than those whose pregnancies continued to delivery (P = 0.01 for fasting glucose levels and P = 0.005 for postprandial levels). In the small subgroup of diabetic women with poor control, who had elevated values for glycosylated hemoglobin in the first trimester, each increase of 1 SD above the normal range was associated with an increase of 3.1 percent in the rate of pregnancy loss (95 percent confidence interval, 0.6 to 5.6). We conclude that diabetic women with good metabolic control are no more likely than nondiabetic women to lose a pregnancy, but that diabetic women with elevated blood glucose and glycosylated hemoglobin levels in the first trimester have a significantly increased risk of having a spontaneous abortion.

Large-area MRI-compatible epidermal electronic interfaces for prosthetic control and cognitive monitoring

Skin-interfaced medical devices are critically important for diagnosing disease, monitoring physiological health and establishing control interfaces with prosthetics, computer systems and wearable robotic devices. Skin-like epidermal electronic technologies can support these use cases in soft and ultrathin materials that conformally interface with the skin in a manner that is mechanically and thermally imperceptible. Nevertheless, schemes so far have limited the overall sizes of these devices to less than a few square centimetres. Here, we present materials, device structures, handling and mounting methods, and manufacturing approaches that enable epidermal electronic interfaces that are orders of magnitude larger than previously realized. As a proof-of-concept, we demonstrate devices for electrophysiological recordings that enable coverage of the full scalp and the full circumference of the forearm. Filamentary conductive architectures in open-network designs minimize radio frequency-induced eddy currents, forming the basis for structural and functional compatibility with magnetic resonance imaging. We demonstrate the use of the large-area interfaces for the multifunctional control of a transhumeral prosthesis by patients who have undergone targeted muscle-reinnervation surgery, in long-term electroencephalography, and in simultaneous electroencephalography and structural and functional magnetic resonance imaging.

Physiological reduction in fasting plasma glucose concentration in the first trimester of normal pregnancy: the diabetes in early pregnancy study

Previous studies indicate that fasting plasma glucose decreases during gestation, but the timing and extent are not consistent from study to study. We had an opportunity to examine this question in the normal pregnancy cohort of women studied in the Diabetes in Early Pregnancy Study. Subjects were monitored to identify pregnancy by human chorionic gonadotropin testing, enrolled within 21 days of conception, and screened to rule out gestational diabetes at the juncture of the second and third trimesters. All subjects were instructed to fast overnight for 10 to 12 hours. Three hundred sixty-one women were studied between 6 and 12 weeks of gestation. A median decrease in plasma glucose of 2 mg/dL was observed between weeks 6 and 10 (P=.007). In a smaller group of subjects evaluated through the third trimester, little further glucose reduction was observed. A reduction in glycosylated hemoglobin levels between 10 and 20 weeks (P=.002) followed the earlier reduction in first trimester glucose levels. Analysis by body mass index (BMI) showed a smaller first trimester reduction with increasing BMI, and none among severely obese women (BMI > 29.9 kg/m2). The decline in fasting plasma glucose in pregnancy begins early in the first trimester, well before fetal glucose requirements can contribute to the decline in the glucose level. Thereafter, plasma glucose levels decrease little. These results suggest that in the setting in which this study was performed (an overnight fast) maternal physiologic adjustments account for a reduction in plasma glucose early in the first trimester of pregnancy, and possibly even later in gestation as well.

Origin of the heavy elements in binary neutron-star mergers from a gravitational-wave event

The cosmic origin of elements heavier than iron has long been uncertain. Theoretical modelling shows that the matter that is expelled in the violent merger of two neutron stars can assemble into heavy elements such as gold and platinum in a process known as rapid neutron capture (r-process) nucleosynthesis. The radioactive decay of isotopes of the heavy elements is predicted to power a distinctive thermal glow (a 'kilonova'). The discovery of an electromagnetic counterpart to the gravitational-wave source GW170817 represents the first opportunity to detect and scrutinize a sample of freshly synthesized r-process elements. Here we report models that predict the electromagnetic emission of kilonovae in detail and enable the mass, velocity and composition of ejecta to be derived from observations. We compare the models to the optical and infrared radiation associated with the GW170817 event to argue that the observed source is a kilonova. We infer the presence of two distinct components of ejecta, one composed primarily of light (atomic mass number less than 140) and one of heavy (atomic mass number greater than 140) r-process elements. The ejected mass and a merger rate inferred from GW170817 imply that such mergers are a dominant mode of r-process production in the Universe.

Deep Brain Stimulation for Depression Informed by Intracranial Recordings

The success of deep brain stimulation (DBS) for treating Parkinson's disease has led to its application to several other disorders, including treatment-resistant depression. Results with DBS for treatment-resistant depression have been heterogeneous, with inconsistencies largely driven by incomplete understanding of the brain networks regulating mood, especially on an individual basis. We report results from the first subject treated with DBS for treatment-resistant depression using an approach that incorporates intracranial recordings to personalize understanding of network behavior and its response to stimulation. These recordings enabled calculation of individually optimized DBS stimulation parameters using a novel inverse solution approach. In the ensuing double-blind, randomized phase incorporating these bespoke parameter sets, DBS led to remission of symptoms and dramatic improvement in quality of life. Results from this initial case demonstrate the feasibility of this personalized platform, which may be used to improve surgical neuromodulation for a vast array of neurologic and psychiatric disorders.

IgM(+) memory B cell expression predicts HIV-associated cryptococcosis status

BACKGROUND

The role of B cells in resistance to Cryptococcus neoformans disease (i.e., cryptococcosis) is unknown. Given evidence that IgM(+) memory B cells are required for immunity to other encapsulated pathogens, we hypothesized that these cells might contribute to resistance to cryptococcosis.

METHODS

We compared levels of IgM expression on memory B cells in 29 HIV-infected individuals who had a history of cryptococcosis (the HIV+CN+ group) with levels in 30 human immunodeficiency virus (HIV)-infected subjects who had no history of cryptococcosis (the HIV+CN- group) and 20 HIV-uninfected subjects who had no history of cryptococcosis (the HIV- group) (cohort 1). We also determined levels of IgM expression on memory B cells in banked samples obtained before cryptococcosis onset from 31 participants in the Multicenter AIDS Cohort Study, of whom 8 had HIV infection and subsequently developed cryptococcosis (the HIV+CN+ group), 8 had HIV infection and did not develop cryptococcosis (the HIV+CN- group), and 15 did not have HIV infection and did not develop cryptococcosis (the HIV- group) (cohort 2).

RESULTS

In cohort 1, the percentage of memory B cells that expressed IgM was lower among HIV+CN+ subjects, compared with HIV+CN- subjects (P < .01) and HIV- subjects (P < .05); expression of IgM on 50% of memory B cells was a significant predictor of C. neoformans disease status (odds ratio, 5.5; P = .03). In cohort 2, the percentage of memory B cells that expressed IgM was lower in HIV+CN+ subjects than in HIV+CN- subjects (P = .02) and HIV- subjects (P < .01); an IgM(+) memory B cell percentage of 38.5% was a significant predictor of future development of cryptococcosis (odds ratio, 14; P = .02).

CONCLUSIONS

These findings suggest that HIV-infected persons in whom the percentage of memory B cells that express IgM is decreased might be at greater risk for the development of cryptococcosis.

Effects of environment on enhancing functional plasticity following cerebral ischemia

Given the brain's capacity to recover from injury, plasticity may be enhanced following cerebral ischemia through environmental manipulation. Thus, the purpose of this study was to (1) determine the effects of early exposure to an enriched environment following ischemia on functional plasticity and (2) examine the relationship between morphological and behavioral plasticity. Adult female rats (n = 38) were divided into ischemia and control groups. Each group was further randomized to either standard (SC) or enriched conditions (EC). After 4 days of environmental exposure, rats were tested for 6 days in the water maze. Control and ischemia rats exposed to EC have increased total dendritic length (P < 0.05) as well as increased number of dendritic segments in the apical (P < 0.05) region of the hippocampal area compared to those housed in SC; furthermore, increased dendritic spine density in the apical (P < 0.05) region was also seen. Behavioral testing showed that ischemia rats exposed to SC have longer swim latencies (P < 0.05) and greater directional heading errors (P < 0.05) than ischemic rats exposed to EC; the latter group performed similar to controls. It is concluded that EC may be a potentially useful therapy in the recovery of spatial memory impairments seen after ischemia.

Plasma C-peptide and diagnosis of factitious hyperinsulinism. Study of an insulin-dependent diabetic patient with "spontaneous" hypoglycemia

Factitious hyperinsulinism was suspected in a patient with an 11-year history of insulin-dependent, ketosis-prone diabetes mellitus who began to experience repetitive episodes of "spontaneous" hypoglycemia. Insulin mediation of the hypoglycemia was confirmed by documenting that urinary insulin and total extractable insulin in plasma increased during periods of hypoglycemia. Failure to detect significant amounts of human C-peptide by radioimmunoassay during periods of hypoglycemia or in response to stimulation with glucagon, leucine, or tolbutamide indicated that the insulin was not endogenous. The diagnosis of factitious hyperinsulinism was ultimately proved by the finding of radioactivity in the patient's urine after 131-I Hippuran was added to a vial of insulin found in the patient's room.

Response acquisition by Siamese fighting fish (Betta splendens) with delayed visual reinforcement

Male Siamese fighting fish, Betta splendens, swam through a ring in an aquarium, breaking a photocell beam and initiating an unsignaled, resetting delay interval. Following delays of 0 s, 10 s, or 25 s, a 15-s mirror presentation released an aggressive display by the fish. Swimming through the ring increased in the absence of either a period of acclimatization to the reinforcer (analogous to magazine training when appetitive reinforcers are used) or explicit training of the response by the experimenters. Response rates were a decreasing function of delay duration. Other fish exposed to a schedule of response-independent mirror presentations failed to acquire and maintain the response. The results demonstrate the robustness and generality of the phenomenon of response acquisition with delayed reinforcement. They further qualify earlier observations about behavioral mechanisms involved in the phenomenon.

Prevalence and molecular characterization of Hepatozoon canis in dogs from urban and rural areas in Southeast Brazil

The objective of this survey was to investigate the prevalence of Hepatozoon infection in dogs in the rural and urban areas of Uberlândia, Brazil by PCR and molecular characterization. DNA was obtained from blood samples collected from 346 local dogs from both genders and various ages. Seventeen PCR products from positive blood samples of urban dogs and 13 from the rural dogs were sequenced. Partial sequences of the 18S rRNA gene indicated that all 30 dogs were infected with Hepatozoon canis similar in sequence to H. canis from southern Europe. Four local dog sequences were submitted to GenBank (accessions JN835188; KF692038; KF692039; KF692040). This study indicates that H. canis is the cause of canine hepatozoonosis in Uberlândia and that infection is similarly widespread in rural and urban dogs.

The visual speech head start improves perception and reduces superior temporal cortex responses to auditory speech

Visual information about speech content from the talker's mouth is often available before auditory information from the talker's voice. Here we examined perceptual and neural responses to words with and without this visual head start. For both types of words, perception was enhanced by viewing the talker's face, but the enhancement was significantly greater for words with a head start. Neural responses were measured from electrodes implanted over auditory association cortex in the posterior superior temporal gyrus (pSTG) of epileptic patients. The presence of visual speech suppressed responses to auditory speech, more so for words with a visual head start. We suggest that the head start inhibits representations of incompatible auditory phonemes, increasing perceptual accuracy and decreasing total neural responses. Together with previous work showing visual cortex modulation (Ozker et al., 2018b) these results from pSTG demonstrate that multisensory interactions are a powerful modulator of activity throughout the speech perception network.

Low-response-rate conditioning history and fixed-interval responding in rats

Bar presses by one group of rats were conditioned under a differential-reinforcement-of-low-rate reinforcement schedule immediately prior to conditioning under a fixed-interval schedule. In a second group of rats, bar presses were conditioned first under a differential-reinforcement-of-low-rate schedule and then under a fixed-ratio schedule prior to conditioning under a fixed-interval schedule. Low response rates occurred under the fixed-interval schedule only when it was immediately preceded by low-rate conditioning. Otherwise, fixed-interval responding was similar to responding under the fixed-ratio schedule. This finding suggests that responses of laboratory animals are sensitive to immediate history, and, unlike human responses, are relatively insensitive to a history of low-rate conditioning when it is followed by high-rate conditioning.

Lack of association between antiphospholipid antibodies and first-trimester spontaneous abortion: prospective study of pregnancies detected within 21 days of conception

OBJECTIVE

To determine the role of antiphospholipid antibodies and anticardiolipin antibodies in first-trimester losses, addressing experimental pitfalls that preclude excluding the possibility that these antibodies reflect merely the selection bias of studying couples only after they have already experienced losses.

DESIGN

Given that retrospective studies cannot exclude the possibility that such antibodies arise as a result of the fetal death, blood samples were obtained either before pregnancy or very early in pregnancy. Sera were obtained within 21 days of conception.

SETTING

Multicenter university-based hospitals (National Institute of Child Health and Human Development collaborative study).

PATIENT(S)

Subjects for the current study were 93 women who later experienced pregnancy loss (48 diabetic; 45 nondiabetic), matched 2:1 with 190 controls (93 diabetic and 97 nondiabetic) who subsequently had normal live-born offspring.

INTERVENTION(S)

Sera from these 283 women were analyzed for antiphospholipid antibodies by enzyme immunoassay. In 260 of the 283 women (87 with pregnancy losses; 173 with live-born infants), sera were also available to perform assays for anticardiolipin antibodies by enzyme immunoassay.

MAIN OUTCOME MEASURE(S)

Pregnancy losses.

RESULT(S)

No association was observed between pregnancy loss and the presence of antiphospholipid antibodies or anticardiolipin antibodies. Levels of antiphospholipid antibodies were 6-19 PL/mL in 62.4% of the pregnancies that ended in losses and > or = 20 PL/mL in 5.4%; among pregnancies resulting in live-born infants, the percentages were 56.8% and 6.8%, respectively. Of the pregnancies that ended in a loss, 5.7% had anticardiolipin antibodies > or = 16 GPL/mL, compared with 5.2% of those ending in a live birth.

CONCLUSION(S)

This prospective study suggests that anticardiolipin antibodies and antiphospholipid antibodies are not associated with an increased risk for first-trimester pregnancy loss.

Spontaneous neuronal oscillations in the human insula are hierarchically organized traveling waves

The insula plays a fundamental role in a wide range of adaptive human behaviors, but its electrophysiological dynamics are poorly understood. Here, we used human intracranial electroencephalographic recordings to investigate the electrophysiological properties and hierarchical organization of spontaneous neuronal oscillations within the insula. We analyzed the neuronal oscillations of the insula directly and found that rhythms in the theta and beta frequency oscillations are widespread and spontaneously present. These oscillations are largely organized along the anterior–posterior (AP) axis of the insula. Both the left and right insula showed anterior-­to-posterior decreasing gradients for the power of oscillations in the beta frequency band. The left insula also showed a posterior-to-anterior decreasing frequency gradient and an anterior-to-posterior decreasing power gradient in the theta frequency band. In addition to measuring the power of these oscillations, we also examined the phase of these signals across simultaneous recording channels and found that the insula oscillations in the theta and beta bands are traveling waves. The strength of the traveling waves in each frequency was positively correlated with the amplitude of each oscillation. However, the theta and beta traveling waves were uncoupled to each other in terms of phase and amplitude, which suggested that insular traveling waves in the theta and beta bands operate independently. Our findings provide new insights into the spatiotemporal dynamics and hierarchical organization of neuronal oscillations within the insula, which, given its rich connectivity with widespread cortical regions, indicates that oscillations and traveling waves have an important role in intrainsular and interinsular communications.

Infectious processes: an infrequent cause of first trimester spontaneous abortions

A systematic assessment of infections beginning early in pregnancy is necessary to determine the true role of infections in pregnancy loss, given that infections could readily arise only after fetal demise. To this end, we have prospectively determined the frequency of infections in pregnant women who were subjects in a multi-centre US study. Insulin-dependent diabetic subjects and controlled subjects were recruited either before conception (86%) or at the latest within 21 days of conception (14%). We collected data prospectively on all important risk factors and potential confounding variables, seeing 386 diabetic subjects weekly and 432 control subjects every other week during the first trimester. At each visit we inquired about untoward events and explicitly about fever or infections. We found no clinical evidence that infection occurred more often in the 116 subjects experiencing pregnancy loss as compared to the 702 having successful pregnancies. This held both for the 2 week interval in which a given loss was recognized clinically as well as in the prior 2 week interval. Similar findings were not only observed for both the control as well as diabetic subjects but also when data were stratified by genital infection only or by systemic infection only. Our prospective data suggest that the attributable risk of infection in first trimester spontaneous abortion is small.

Decoding Depression Severity From Intracranial Neural Activity

BACKGROUND

Disorders of mood and cognition are prevalent, disabling, and notoriously difficult to treat. Fueling this challenge in treatment is a significant gap in our understanding of their neurophysiological basis.

METHODS

We recorded high-density neural activity from intracranial electrodes implanted in depression-relevant prefrontal cortical regions in 3 human subjects with severe depression. Neural recordings were labeled with depression severity scores across a wide dynamic range using an adaptive assessment that allowed sampling with a temporal frequency greater than that possible with typical rating scales. We modeled these data using regularized regression techniques with region selection to decode depression severity from the prefrontal recordings.

RESULTS

Across prefrontal regions, we found that reduced depression severity is associated with decreased low-frequency neural activity and increased high-frequency activity. When constraining our model to decode using a single region, spectral changes in the anterior cingulate cortex best predicted depression severity in all 3 subjects. Relaxing this constraint revealed unique, individual-specific sets of spatiospectral features predictive of symptom severity, reflecting the heterogeneous nature of depression.

CONCLUSIONS

The ability to decode depression severity from neural activity increases our fundamental understanding of how depression manifests in the human brain and provides a target neural signature for personalized neuromodulation therapies.

Imaging versus electrographic connectivity in human mood-related fronto-temporal networks

BACKGROUND

The efficacy of psychiatric DBS is thought to be driven by the connectivity of stimulation targets with mood-relevant fronto-temporal networks, which is typically evaluated using diffusion-weighted tractography.

OBJECTIVE

Leverage intracranial electrophysiology recordings to better predict the circuit-wide effects of neuromodulation to white matter targets. We hypothesize strong convergence between tractography-predicted structural connectivity and stimulation-induced electrophysiological responses.

METHODS

Evoked potentials were elicited by single-pulse stimulation to two common DBS targets for treatment-resistant depression - the subcallosal cingulate (SCC) and ventral capsule/ventral striatum (VCVS) - in two patients undergoing DBS with stereo-electroencephalographic (sEEG) monitoring. Evoked potentials were compared with predicted structural connectivity between DBS leads and sEEG contacts using probabilistic, patient-specific diffusion-weighted tractography.

RESULTS

Evoked potentials and tractography showed strong convergence in both patients in orbitofrontal, ventromedial prefrontal, and lateral prefrontal cortices for both SCC and VCVS stimulation targets. Low convergence was found in anterior cingulate (ACC), where tractography predicted structural connectivity from SCC targets but produced no evoked potentials during SCC stimulation. Further, tractography predicted no connectivity to ACC from VCVS targets, but VCVS stimulation produced robust evoked potentials.

CONCLUSION

The two connectivity methods showed significant convergence, but important differences emerged with respect to the ability of tractography to predict electrophysiological connectivity between SCC and VCVS to regions of the mood-related network. This multimodal approach raises intriguing implications for the use of tractography in surgical targeting and provides new data to enhance our understanding of the network-wide effects of neuromodulation.

Neurofibromatosis and other disorders among children with CNS tumors and their families

We conducted a population-based case-control study with 338 patients, less than 15 years of age, diagnosed with a primary tumor of the central nervous system from January 1968 through December 1977 in 53 New York State counties. The study also included 676 controls selected from the birth certificate files of the New York State Department of Health. We collected information on neurofibromatosis and congenital anomalies in study subjects, their siblings and parents by telephone interview with the mother of each case and control. We obtained supplemental information on neurofibromatosis in the patients and their families from hospital medical records. This study confirmed the strong association of neurofibromatosis with risk of CNS tumors. Thirteen cases and no controls had neurofibromatosis. Two fathers and 3 mothers of cases had neurofibromatosis. Five cases had siblings with neurofibromatosis. None of the first-degree relatives of controls had neurofibromatosis. We observed a relative risk of 4.49 for history of seizures. Seizures are often among the presenting symptoms for CNS tumors. We observed no difference between cases and controls in the occurrence of congenital anomalies. There was a nonsignificant excess of congenital anomalies among siblings of cases compared with controls. This decreased to 1.13 when adjusted for number of siblings.

Understanding longer-term disability outcomes for Māori and non-Māori after hospitalisation for injury: results from a longitudinal cohort study

OBJECTIVES

The objectives are to (1) describe disability outcomes at 24 months after injury and (2) identify factors contributing to disability outcomes at 24 months after injury, for Māori and non-Māori who have been hospitalised for injury.

STUDY DESIGN

This is a prospective cohort study.

METHODS

Prospective Outcomes of Injury Study participants were injured New Zealanders aged 18-64 years and recruited from New Zealand's no-fault injury insurer, the Accident Compensation Corporation's entitlement claims register. Data about a number of pre-injury, injury-related and early post-injury characteristics were collected from interviews held at 3 and 24 months after injury. Disability was measured using the World Health Organization Disability Assessment Schedule (WHODAS). Modified Poisson regression modelling was used to estimate relative risks (RRs) of disability for Māori and non-Māori who were hospitalised for injury.

RESULTS

Analyses were restricted to 375 Māori and 1824 non-Māori participants for whom complete data were available. Of these, 105 (28%) Māori and 446 (24%) non-Māori were hospitalised for their injury. Of these hospitalised groups, 26% of Māori and 10% of non-Māori were experiencing disability (WHODAS ≥10) at 24 months after injury. Māori who were hospitalised for injury and who were not working for pay before their injury (RR = 2.7; 95% confidence interval [CI] 1.4-4.9), who were experiencing disability before their injury (RR = 3.1; 95% CI 1.6-5.8) or who reported trouble accessing healthcare services for their injury (RR = 2.6; 95% CI 1.3-5.2) were independently at increased risk of disability 24 months after injury. Non-Māori who were hospitalised for injury and who had inadequate household income before injury (RR = 2.4; 95% CI 1.4-4.1), less than the secondary school qualifications (RR = 2.0; 95% CI 1.1-3.8), were not working for pay before injury (RR = 2.8; 95% CI 1.5-5.1), were experiencing disability before their injury (RR = 3.0; 95% CI 1.7-5.2), had ≥2 chronic conditions (RR = 3.5; 95% CI 2.0-6.4) or had body mass index ≥30 kg/m2/undisclosed (RR = 2.4; 95% CI 1.3-4.4) were at increased risk of disability 24 months after injury.

CONCLUSIONS

Variables predicting disability 24 months after injury for Māori, also predict disability 24 months after injury for non-Māori, with one notable exception-trouble accessing healthcare services. Our findings show that having access to healthcare services for injury plays an important role after injury and must be focussed on to ensure that the burden of poor injury-related outcomes and injury-related inequities are reduced and ultimately eliminated.

Suppression and enhancement of humoral antibody formation by herpes simplex virus types 1 and 2

Intraperitoneal infection of mice and rats by herpes simplex virus type 2 (HSV-2) but not type 1 (HSV-1) resulted in suppression of antibody formation on subsequent challenge with HSV-1 or HSV-2. Application of silica considerably enhanced antibody formation after primary HSV-1 infection, but only slightly after primary HSV-2 infection. Suppression induced by HSV-2 was, however, reduced significantly by injection of silica 21 days later, on the day of the second injection of HSV-2. Suppression could be detected soon after infection by HSV-2. The degree of this suppression depended on the dose of the injected virus and was abolished by u.v. irradiation of the virus prior to inoculation. Likewise the weak antibody response induced by HSV-2 was abolished for both neutralizing and ELISA antibodies. Infections with HSV-1 evoked considerable numbers of HSV-specific antibody-producing B cells, when assessed by an enzyme-linked immunospot assay. The B cell response to HSV-2, however, was very weak. Silica considerably enhanced the number of specific antibody-producing B cells only during primary HSV-1 infections. The present results in combination with earlier data demonstrate the central role of macrophages, which seem to be the primary target affected by silica, for enhancement and suppression of HSV-induced antibody generation.

Eddy viscosity in dense granular flows

We present a seminal set of experiments on dense granular flows in the stadium shear geometry. The advantage of this geometry is that it produces steady shear flow over large deformations, in which the shear stress is constant. The striking result is that the velocity profiles exhibit an S shape, and are not linear as local constitutive laws would predict. We propose a model that suggests this is a result of wall perturbations which span through the system due to the nonlocal behavior of the material. The model is analogous to that of eddy viscosity in turbulent boundary layers, in which the distance to the wall is introduced to predict velocity profiles. Our findings appear pivotal in a number of experimental and practical situations involving dense granular flows next to a boundary. They could further be adapted to other similar materials such as dense suspensions, foams, or emulsions.

Comparative single- and multiple-dose pharmacokinetics of levodopa and 3-O-methyldopa following a new dual-release and a conventional slow-release formulation of levodopa and benserazide in healthy volunteers

The objective was to assess the single- and multiple-dose pharmacokinetics of levodopa and 3-O-methyldopa following administration of a new dual-release and conventional slow-release formulation of levodopa/benserazide in the dose ratio of 4:1. In an open-label, two-way cross-over study, 20 healthy volunteers were randomized to receive first either Madopar DR or Madopar HBS for 8 days. Then they crossed over to the other formulation. A first dose of 200 mg levodopa and 50 mg benserazide ('250' mg) was given on day 1, '125' mg t.i.d. on the subsequent 6 days (days 2-7), followed by '250' mg on day 8. The two treatment periods of 8 days were separated by a wash-out period of at least 7 days. Blood samples were taken at specific times over a 12-hour period (day 1) or a 36-hour period (day 8). Plasma concentrations of levodopa and 3-O-methyldopa were measured by high-performance liquid chromatography for pharmacokinetic evaluation. The pharmacokinetics of levodopa after a single-dose administration (day 1) of Madopar DR and Madopar HBS were significantly different as reflected by the respective mean values of maximum plasma concentration (C(max) 1.99 vs. 0.82 mg x l-1), time to reach maximum concentration (t(max) 0.7 vs. 2.6 h) and area under the plasma concentration-time curve (AUC(0- infinity ) 4.52 vs. 3.18 mg x h x l-1). The respective values after multiple doses (day 8) were: C(max) 1.98 vs. 0.93 mg x l-1, t(max) 0.7 vs. 2.3 h and AUC(0-infinity ) 4.84 vs. 3.96 mg x h x l-1. The relative bioavailability (Madopar DR vs. Madopar HBS) was 1.73 on day 1 and 1.32 on day 8. Bioequivalence could not be demonstrated for log-transformed data of AUC and C(max) within a predefined range of 80-125 and 70-143%, respectively. In conclusion, the observed differences in C(max), t(max) and AUC are consistent with a faster rate and higher extent of levodopa absorption after administration of Madopar DR. Statistical evaluation of these kinetic data showed that Madopar DR is not bioequivalent to Madopar HBS.

Prospective study showing that antisperm antibodies are not associated with pregnancy losses

OBJECTIVE

To obtain prospective data on the relationship between presence of antisperm antibodies in maternal sera and first trimester pregnancy losses.

DESIGN

First trimester sera obtained from diabetic and nondiabetic women recruited within 21 days of conception were analyzed using the indirect immunobead test for immunoglobulin (Ig)G, IgA, and IgM antisperm antibodies. Regional binding also was considered: sperm head, midpiece, and sperm tail. Results were correlated with pregnancy outcome.

SETTING

Five university centers.

PATIENTS

One hundred eleven women who experienced pregnancy loss (55 diabetic; 56 nondiabetic) were matched 2:1 with 104 diabetic and 116 nondiabetic women (controls) who subsequently had a normal liveborn infant.

INTERVENTION

None.

MAIN OUTCOME MEASURE

Pregnancy outcome (spontaneous abortion, liveborn) correlated with presence or absence of antisperm antibodies.

RESULTS

Analyzing samples without knowledge of clinical status, no differences were observed with respect to IgG, IgA, and IgM binding when a positive test was defined as 50% of sperm showing antibody binding. Likewise, no association was found for IgG and IgM antisperm antibodies at 20% binding. The only positive finding was observed for IgA antisperm antibodies at 20% binding (Fisher's Exact test). This one positive finding merely could reflect multiple comparisons. No significant differences between groups were observed when analysis was stratified according to location of antibody binding (head, midpiece, tail tip, entire sperm). When the sample was stratified into those having and not having a prior loss, a relationship between antisperm antibodies and pregnancy loss still was not evident.

CONCLUSION

Further work is necessary to determine whether IgA antisperm antibodies truly are associated with pregnancy loss or whether antisperm antibodies play any role in repetitive aborters. Findings in this study suggest that antisperm antibodies do not play a major role in pregnancy loss.