Neurobehavioral functioning in asymptomatic HIV-1 infected women

Numerous reports have assessed the neuropsychological functioning of medically asymptomatic HIV-1 infected men. However, to date there have been no published studies of the neuropsychological functioning of asymptomatic HIV-1 infected women, even though women represent the fastest-growing demographic group of HIV-1 infected individuals. In this investigation, 31 women (17 asymptomatic HIV-1 seropositive, 14 seronegative) were administered a battery of neurocognitive and neuropsychiatric instruments. Participants in both groups were matched for age, education, months since injection drug use, and substance use. Group comparisons revealed no significant differences in any of the neurocognitive or neuropsychiatric measures. The results of this preliminary study suggest that clinically significant differences in neurobehavioral function are unlikely in medically asymptomatic HIV-1 infected women compared to seronegative controls. However, additional studies are needed with larger sample sizes and with careful attention to possible confounding or masking variables.

Asymptomatic HIV-infected women: preliminary study of quantitative EEG activity and performance on a continuous performance test

Several studies have examined the electrophysiological correlates of human immunodeficiency virus (HIV) infection in medically asymptomatic men. Although the rates of HIV infection are increasing at a greater rate in women than men, there have been no publications to date of electrophysiological functioning in HIV-infected women. In the present study, quantitative electroencephalographic (qEEG) activity was measured in 22 women (11 asymptomatic HIV-seropositive and 11 HIV-seronegative) utilizing a procedure comprised of three auditory continuous performance tests and a set of qEEG components derived from principal components analysis. No significant group differences were found in qEEG or in performance on the continuous performance tests; however, task-related differences were detected across groups between simple and complex language tasks in EEG fast beta power, delta power, and a left-hemisphere principal components analysis-derived EEG component. In examining the electrophysiological correlates of HIV infection, researchers might employ a similar methodology while increasing the sample size and varying the task modality or difficulty.

The clinical significance of focal active colitis

Focal crypt injury by neutrophils (cryptitis/crypt abscesses), or focal active colitis (FAC), is a common isolated finding in endoscopic colorectal biopsies. Focal active colitis is often thought of as a feature of Crohn's disease, but may also be seen in ischemia, infections, partially treated ulcerative colitis, and as an isolated finding in patients undergoing endoscopy to exclude neoplasia. Clinical, endoscopic, and pathological data were retrospectively reviewed from 49 patients with focal active colitis, who had no other diagnostic findings on colorectal biopsy and no history of chronic inflammatory bowel disease. The histological findings were correlated with clinical diagnoses. Follow-up information was available for 42 of 49 focal active colitis patients. None developed inflammatory bowel disease; however, 19 patients had an acute self-limited colitis-like diarrheal illness, 11 had incidental focal active colitis (patients without diarrhea that were endoscoped to exclude colonic neoplasia and found to have asymptomatic FAC), 6 had irritable bowel syndrome, 4 had antibiotic-associated colitis, and 2 had ischemic colitis. Twenty patients were immunosuppressed, and 19 were taking nonsteroidal anti-inflammatory drugs. No histological features predicted final diagnoses. FAC did not predict the development of chronic colitis, even when mild crypt distortion or slight basal plasmacytosis was present. The preponderance of acute self-limited colitis and antibiotic-associated colitis among the FAC patients, along with the high number of immunosuppressed patients, support the conclusion that most FAC cases are infectious. The incidental detection of FAC in patients undergoing endoscopy to exclude colonic neoplasia was not clinically significant. The role of nonsteroidal anti-inflammatory drugs in FAC deserves further study.

Severe life stress as a predictor of early disease progression in HIV infection

OBJECTIVE

Although there is evidence that stress is associated with alterations in immunity, the role of emotional factors in the onset and course of immune-based diseases such as cancer and AIDS has not been established. This prospective study was designed to test the hypothesis that stressful life events accelerate the course of HIV disease.

METHOD

Ninety-three HIV-positive homosexual men who were without clinical symptoms at the time of entry into the study were studied for up to 42 months. Subjects received comprehensive medical, neurological, neuropsychological, and psychiatric assessments every 6 months, including assessment of stressful life events during the preceding 6-month interval. Several statistical approaches were used to assess the relation between stress and disease progression.

RESULTS

The time of the first disease progression was analyzed with a proportional hazard survival method, which demonstrated that the more severe the life stress experienced, the greater the risk of early HIV disease progression. Specifically, for every one severe stress per 6-month study interval, the risk of early disease progression was doubled. Among a subset of 66 subjects who had been in the study for at least 24 months, logistic regression analyses showed that higher severe life stress increased the odds of developing HIV disease progression nearly fourfold. the degree of disease progression was also predicted by severe life stress when a proportional odds logistic regression model was used for analysis.

CONCLUSIONS

This report presents the first evidence from a prospective research study that severe life event stress is associated with an increased rate of early HIV disease progression.

Detection of human papillomavirus DNA in keratoacanthomas by polymerase chain reaction

The etiology of keratoacanthomas is unknown, but human papillomavirus (HPV) has been suspected to be involved in the pathogenesis of this lesion because koilocytic changes may be observed and because HPV has been found in cutaneous squamous-cell carcinomas and premalignant keratoses in immunosuppressed patients. We analyzed DNA extracted from 39 keratoacanthomas from 22 "at-risk" patients (nine patients undergoing UV light and/or anthralin therapy for psoriasis, 10 solid organ transplant recipients, one patient with xeroderma pigmentosa, one patient with acquired immunodeficiency syndrome, and one patient undergoing therapy for non-Hodgkin's lymphoma) for the presence of HPV. The results were compared with analyses of DNA extracted from 30 keratoacanthomas from 28 patients at no known increased risk for these lesions. Using polymerase chain reaction (PCR) primers designed to detect multiple HPV types (including 6, 11, 16, 18, 31, and 33), HPV was detected in seven keratoacanthomas from six of the at-risk patients and in eight sporadic keratoacanthomas from eight patients without risk factors. HPV was also present in one of 26 nonlesional skin controls. Statistical analysis showed a significant difference in the prevalence of HPV DNA sequences found in keratoacanthomas compared to normal control skin (p = 0.038). The presence of virus by PCR could not be predicted by histologic evaluation. Sequence analysis showed the presence of HPV types 11, 13, 24, 33, and 57. Although these results confirm the frequent presence of HPV in keratoacanthomas, the role of this virus in the etiology and pathogenesis of these lesions remains to be elucidated.

Use of thyroid hormone to diminish the cognitive side effects of psychiatric treatment

Electroconvulsive therapy (ECT) and lithium are highly effective treatments for mood disorders. Both treatments, however, are associated with cognitive side effects which reduce patient compliance and treatment satisfaction. Both therapies also have a significant effect on hypothalamic-pituitary-thyroid axis (HPT) activity. Preliminary results from a double-blind, placebo-controlled study of adjunctive thyroid hormone (T3) and ECT showed better memory function in patients receiving T3 compared with placebo. This neuroprotective effect of T3 has been confirmed using electroconvulsive shock (ECS) in rats, and shown to be independent of the number of electrical stimulations. Results of studies in patients with bipolar disorder taking lithium have demonstrated that cognitive deficits are significantly related to diminished thyroid status, but not lithium levels. Preliminary evidence also shows that adjunctive thyroid hormone improves cognitive functioning in patients taking lithium. These findings, if replicated and confirmed, indicate a potential role for adjunctive thyroid hormone in reducing the cognitive side effects of these important psychiatric treatments. This, in turn, may lead to improved treatment compliance, diminished overall morbidity, and reduced healthcare utilization.

Assessment of mood state in patients undergoing electroconvulsive therapy: the utility of visual analog mood scales developed for cognitively impaired patients

Reliable, valid, and brief measures of mood state are essential to the evaluation of electroconvulsive therapy (ECT) efficacy. However, existing measures of mood state may be inappropriate for patients with transient cognitive impairment. Stern and colleagues have recently developed a set of Visual Analog Mood Scales (VAMS) for use in neurologically impaired patients. These brief scales (including measures of sad, confused, afraid, happy, tired, angry, and energetic states) are easily administered and have documented reliability and validity in neurologically impaired patients and in healthy adult and geriatric samples. In the present study, we assessed the validity and sensitivity of the VAMS to detect ECT-related mood change. Twenty-five inpatients who were diagnosed with major depressive episode and referred for ECT were administered the VAMS and the Hamilton Depression Rating Scale (HDRS) both pre- and post-ECT. Results indicate that the VAMS are as sensitive to the therapeutic effects of ECT as is the more lengthy and verbally demanding HDRS. In addition, the VAMS were highly correlated with the clinician's Clinical Global Improvement rating and the patient's self-report using a modified Center for Epidemiological Studies-Depression scale. The VAMS are brief, reliable scales that are sensitive to the treatment effects of ECT and that are appropriate for patients with transient cognitive impairment.

Analysis of chronic endometritis for Chlamydia trachomatis by polymerase chain reaction

Chronic endometritis is characterized histologically by plasma cells infiltrating endometrial stroma. Although it has been speculated that many instances of chronic endometritis are infectious, the origin of most cases is not apparent by routine histopathologic evaluation. Chlamydia trachomatis, an obligate intracellular bacterium, is known to cause chronic endometritis in the setting of pelvic inflammatory disease. The authors analyzed 43 specimens of histopathologically diagnosed chronic endometritis from 38 patients for C trachomatis by PCR using primers for the single-copy major outer membrane protein (MOMP) gene. C trachomatis was detected in only one such case in which dense plasma cell infiltrates were present and concurrent C trachomatis infection of the cervix was documented. Using serially diluted DNA from formalin-fixed, paraffin-embedded McCoy cells, the sensitivity of this method was shown to be equivalent to a single infected cell in a paraffin section. In conjunction with the results of other studies, these data indicate a limited role, if any, of C trachomatis in the origin of mild or moderate chronic endometritis.

A guide for applying principal-components analysis and confirmatory factor analysis to quantitative electroencephalogram data

Principal-components analysis (PCA) has been used in quantitative electroencephalogram (qEEG) research to statistically reduce the dimensionality of the original qEEG measures to a smaller set of theoretically meaningful component variables. However, PCAs involving qEEG have frequently been performed with small sample sizes, producing solutions that are highly unstable. Moreover, solutions have not been independently confirmed using an independent sample and the more rigorous confirmatory factor analysis (CFA) procedure. This paper was intended to illustrate, by way of example, the process of applying PCA and CFA to qEEG data. Explicit decision rules pertaining to the application of PCA and CFA to qEEG are discussed. In the first of two experiments, PCAs were performed on qEEG measures collected from 102 healthy individuals as they performed an auditory continuous performance task. Component solutions were then validated in an independent sample of 106 healthy individuals using the CFA procedure. The results of this experiment confirmed the validity of an oblique, seven component solution. Measures of internal consistency and test-retest reliability for the seven component solution were high. These results support the use of qEEG data as a stable and valid measure of neurophysiological functioning. As measures of these neurophysiological processes are easily derived, they may prove useful in discriminating between and among clinical (neurological) and control populations. Future research directions are highlighted.

Endometrial ablation using a distensible multielectrode balloon

The VestaBlate system uses a multielectrode intrauterine balloon as a device to create effective and safe endometrial ablation (EA). The surface of the distensible balloon is impregnated with thermistors and thin, platelike electrodes. It is designed to deliver low-power electroenergy to the endometrium. Unlike the resectoscope techniques that require nonelectrolytic fluids for uterine distention, moving electrodes at high power outputs, and other variables that are operator dependent, the VestaBlate is computer controlled using a standard type electrosurgical generator. A respiratory enzyme stain, nitroblue tetrazoleum, was used to determine the extent and depth of tissue necrosis to a myometrial depth of 2 to 4 mm with uniform destruction of tissue with power setting at 45 W for a 4-minute application of energy. Sixty-nine patients have been treated, with 45 followed for at least 3 to 9 months. The amenorrhea rate is 40%; the oligomenorhea-hypomenorrhea rate is 49%.

Influence of cognitive reserve on neuropsychological functioning in asymptomatic human immunodeficiency virus-1 infection

OBJECTIVE

To evaluate the influence of cognitive reserve or brain reserve capacity on neuropsychological performance in early human immunodeficiency virus (HIV)-1 infection.

DESIGN

Cross-sectional group comparison study, based on neuropsychological performance, of HIV-1 seropositive and HIV-1 seronegative participants.

SUBJECTS

Seventy-five medically asymptomatic HIV-1-seropositive homosexual or bisexual men and 50 HIV-1-seronegative homosexual or bisexual male controls. Subjects were grouped by HIV-1 status (seropositive vs seronegative) and by cognitive reserve scores (low reserve vs high reserve).

MEASURES

Cognitive reserve scores were based on a combination of years of education, a measure of occupational attainment, and an estimate of premorbid intelligence. Performance on a battery of neuropsychological tests was summarized by empirically derived factor scores and clinical summary ratings.

RESULTS

The HIV-1-seropositive subjects with low cognitive reserve scores exhibited significantly greater deficits on measures of attention and information processing speed, verbal learning and memory, executive functioning, and visuospatial performance than did the HIV-1-seropositive subjects with high cognitive reserve scores. In contrast, there were no significant group differences on these measures between both groups of HIV-1-seronegative subjects.

CONCLUSIONS

Early neuropsychological impairments in HIV-1 infection are most evident in individuals with lower cognitive reserve. As has been found in other neurologic disorders, such as Alzheimer's disease, individuals with greater cognitive reserve may be less sensitive to the initial clinical effects of the underlying neuropathologic process.

Somatic symptoms and HIV infection: relationship to depressive symptoms and indicators of HIV disease

OBJECTIVE

This study examined the relationship of the somatic symptoms fatigue and insomnia with indicators of both psychiatric disturbance and HIV disease severity.

METHOD

Study participants were 98 asymptomatic HIV-infected and 71 uninfected homosexual men; 82 HIV-infected and 64 uninfected men had 6-month follow-up examinations. Scales from the self-reported Profile of Mood States measured fatigue and dysphoric mood. Major depression diagnosis was determined by the Structured Clinical Interview for DSM-III-R. Selected items from the Hamilton depression and anxiety scales measured insomnia and other symptoms of depression. Performance on a battery of standardized tests determined neuropsychological function ratings.

RESULTS

At study entry, complaints of fatigue and insomnia were associated with dysphoric mood, major depression, and other non-HIV-related symptoms of major depression but not with CD4 cell counts or neuropsychological functioning. Increases in levels of fatigue and insomnia over the 6-month follow-up period were associated with increases in non-HIV-related symptoms of depression and in severity of dysphoric mood. Increases in fatigue were also associated with decrements in motor functioning. Otherwise, fatigue or insomnia were not associated with HIV disease progression.

CONCLUSIONS

These findings suggest that complaints of fatigue and insomnia in otherwise asymptomatic HIV-infected patients are likely to be related to psychological disturbances and possibly major depression, which can be treated. HIV-infected patients who complain of fatigue or insomnia should routinely be assessed for major depression.

Stress-associated reductions of cytotoxic T lymphocytes and natural killer cells in asymptomatic HIV infection

OBJECTIVE

Previous research has documented a possible relation of stress and depression to cell-mediated immunity. The authors examined how stressful events and depression may affect key parameters of cellular immunity in subjects with and without HIV infection.

METHOD

Data were collected on 99 asymptomatic HIV-positive and 65 HIV-negative homosexual men as part of an ongoing, longitudinal study. Criticisms of previous studies of psychoimmunity were addressed by 1) using a comprehensive, semistructured interview to measure the objective context of stressful events, 2) double labeling of lymphocytes with monoclonal antibodies to measure subsets of cytotoxic/suppressor T lymphocytes and natural killer (NK) cells, and 3) controlling for circadian effects and methodological factors.

RESULTS

In the HIV-positive men, severe stress was significantly associated with reductions in NK cell populations and a subset of T cells thought to represent cytotoxic T effector cells, particularly the CD8+ T cells expressing the CD57 antigen. In the HIV-negative men, no clear and consistent relation between stress and immune system measures was found. Depression was not correlated with any variables in either of the groups, perhaps due to the low levels of depressive symptoms.

CONCLUSIONS

The findings suggest that stress is associated with reductions in killer lymphocytes (decreased NK cell and cytotoxic T lymphocyte phenotypes). The data provide evidence that stress may alter cell populations that provide cytotoxic defense against infection in HIV-positive men and indicate that the clinical significance of stress-related changes in cytotoxic T lymphocytes and NK cells in HIV infection warrants further study.

Variability of contact transscleral neodymium:YAG cyclophotocoagulation

PURPOSE

To study the variability of ciliary body lesions created by contact Nd:YAG cyclophotocoagulation and to evaluate modifications in probe design to reduce this variability.

METHODS

Contact transscleral Nd:YAG cyclophotocoagulation was performed on fresh, enucleated porcine eyes in three ways: using a standard, handheld fiber-optic probe (98 eyes); using the same probe with an adjunctive contact lens guide to control for probe pressure, angle, and position (69 eyes); and using a spring-loaded handpiece to control for probe pressure (148 eyes). Four laser lesions were created in each eye and were rated for size and severity of tissue response.

RESULTS

For the three groups of eyes, the mean for size differences (largest lesion minus smallest lesion in millimeters for each eye) was 2.53, 1.65, and 2.36, respectively. The mean for severity differences (most severe lesions minus least severe lesion for each eye, based on a four-part subjective rating) was 1.9, 1.1, and 1.7, respectively. These measures of size difference and severity difference were significantly lower with the lens guide than with the other two systems (P = 0.022 and P = 0.020, respectively).

CONCLUSIONS

These findings indicate that contact transscleral cyclophotocoagulation can be associated with considerable variation in the size and severity of the ciliary body reaction. This variation has a significant dependence on probe pressure and orientation against the eye and can be reduced by modification in probe design.

Quantum efficiency measurements and modeling of ion-implanted, laser-annealed charge-coupled devices: x-ray, extreme-ultraviolet, ultraviolet, and optical data

We report quantum efficiency measurements of backilluminated, ion-implanted, laser-annealed CCD's in the wavelength range 13-10,000 Å. The equivalent quantum efficiency (the equivalent photons detected per incident photon) ranges from a minimum of 5% at 1216 Å to a maximum of 87% at 135 Å. Using a simple relationship for the charge-collection efficiency of the CCD pixels as a function of depth, we present a semiempirical model with few parameters that reproduces our measurements with a fair degree of accuracy. The advantage of this model is that it can be used to predict CCD quantum efficiency performance for shallow backside implanted devices without a detailed solution of a system of differential equations, as in conventional approaches, and it yields a simple analytic form for the charge-collection efficiency that is adequate for detector calibration purposes. Making detailed assumptions about the dopant profile, we also solve the current density and continuity equations in order to relate our semiempirical model parameters to surface and bulk device properties. The latter procedure helps to better establish device processing parameters for a given level of CCD quantum efficiency performance.

The health status of women following cosmetic surgery

A retrospective study was performed to determine the frequency of new symptoms and diseases after silicone breast implantation. Questionnaires were mailed to 826 women who made up a breast implant group (n = 516) and a control group who had undergone blepharoplasty (n = 124), liposuction (n = 111), or rhinoplasty (n = 75). Responses were obtained from 370 women (45 percent); however, 68 of these patients (18 percent) were considered ineligible. The overall response rate was 59 percent for the breast implant group and 46 percent for controls. The 302 eligible women included patients with silicone breast implants (n = 222) and controls (n = 80). Women with implants were significantly younger than controls, the median age of women with breast implants being 37 years compared with 46.5 years for controls (p < 0.0001). We compared the incidence of 23 symptoms and 4 connective-tissue diseases after cosmetic surgery in the two groups. The symptoms of swollen glands under arms (p < 0.05) and tender glands under arms (p < 0.01) were statistically more frequent in the breast implant group. The symptom change in skin color was more common in the controls (p < 0.001). The Bonferroni correction for multiple (27) endpoints adjusts the 5 and 1 percent significance cutoff points to 0.00185 and 0.00037, respectively, leaving only change of skin color significant at the 5 percent level on the adjusted data. No cases of scleroderma or lupus were found, and the incidence of arthritis was not significantly different between the implant and control groups.

Mood disorders in HIV infection: prevalence and risk factors in a nonepicenter of the AIDS epidemic

OBJECTIVE

The authors studied the lifetime, initial cross-sectional, and 6-month follow-up prevalence of mood disorders in asymptomatic HIV-infected and uninfected homosexual men who lived in an area with a low prevalence of HIV. They also determined the relationship between current major depression and potential depression risk factors.

METHOD

Subjects included 98 asymptomatic HIV-infected and 71 uninfected homosexual men. Subjects underwent extensive clinical, psychiatric, neuropsychological, and laboratory evaluations.

RESULTS

Similar proportions of HIV-infected and uninfected subjects reported a lifetime (29% and 45%, respectively), an initial current (8% and 3%), and a 6-month follow-up (9% and 11%) history of major depressive disorder. Anxiety disorders were less common, with similar proportions of HIV-infected and uninfected subjects reporting a lifetime (7% and 13%, respectively), an initial current (3% and 7%), and a 6-month follow-up (2% and 5%) history of anxiety disorders. There were no differences in the severity of mood symptoms between HIV-infected and uninfected subjects. Current major depression at initial visit was significantly associated with lifetime history of major depression but not with neuropsychological function or vitamin B12 level.

CONCLUSIONS

These findings are in agreement with previous studies of areas with a high prevalence of HIV. However, the proportion of subjects with mood disorders is high compared with general population studies. Both HIV-infected and uninfected homosexual men may be at high risk for major depression, especially if they have a past history of depression. Moreover, in the asymptomatic stage of HIV infection, major depression does not appear to be secondary to HIV central nervous system effects or low vitamin B12 levels.

Thyroid and adrenal measures during late pregnancy and the puerperium in women who have been major depressed or who become dysphoric postpartum

Prior studies of thyroid, adrenal and mood measures during pregnancy and the puerperium, which we review, have not examined hormone-mood relationships over the full peripartum period during which hormone levels change nor have they compared prior depression history with hormone changes. In a pilot study we measured thyroid and adrenal hormones as well as mood at 38 weeks of pregnancy, and 1, 3, 6, 9 and 12 weeks postpartum in 12 women with major depression history and 14 women with negative psychiatric history. Subjects with prior depressions had significantly higher T3, T4, TSH and cortisol levels during the puerperium. Subjects with higher levels of postpartum dysphoria had lower T4 and free T4 levels as well as higher T3 uptake at 38 weeks of pregnancy and higher cortisol levels during the puerperium. The pathophysiological implications of these findings are discussed.

Vitamin B12 deficiency and nervous system disease in HIV infection

BACKGROUND

Vitamin B12 deficiency may result in a number of neurological and neuropsychiatric disorders. Patients with human immunodeficiency virus type 1 (HIV-1) infection may have a high rate of vitamin B12 deficiency and nervous system disease. Vitamin B12 deficiency may contribute to neurological disease in HIV-1-infected individuals.

OBJECTIVE

To evaluate the possible contribution of vitamin B12 deficiency to neurological disease in HIV-1-infected individuals.

MAIN OUTCOME MEASURES

Comparison of serum vitamin B12 levels with neurological, neuropsychological, and mood state abnormalities in 153 HIV-1-positive subjects and 57 high-risk seronegative controls. A subgroup of 67 subjects underwent additional extensive clinical neurophysiological, cerebrospinal fluid, and magnetic resonance imaging evaluations.

RESULTS

No statistically significant relationships were noted between vitamin B12 levels and abnormalities on any of the measures examined.

CONCLUSIONS

This study does not indicate an important role for vitamin B12 deficiency in the neurological disease of HIV-1 infection.

Menstrual cycle and premenstrual syndrome: modifiers of cardiovascular reactivity in women

Fifteen women prospectively diagnosed with PMS and 15 non-PMS women were each tested twice for cardiovascular stress reactivity and behavioral performance, once during the follicular phase and once during the luteal phase of their cycle. Although blood pressure and heart rate responses to stress did not differ across the menstrual cycle in either group of women, for the non-PMS women, differences in hemodynamic responses were observed across the 2 phases. The luteal phase was associated with greater stroke volume responses and lesser vascular tone. For the PMS women, none of their cardiovascular measures differed across their cycle. Instead, these women showed significantly attenuated blood pressure and heart rate responses compared with non-PMS women, irrespective of cycle phase.

Menstrual cycle and premenstrual syndrome: modifiers of cardiovascular reactivity in women

Fifteen women prospectively diagnosed with PMS and 15 non-PMS women were each tested twice for cardiovascular stress reactivity and behavioral performance, once during the follicular phase and once during the luteal phase of their cycle. Although blood pressure and heart rate responses to stress did not differ across the menstrual cycle in either group of women, for the non-PMS women, differences in hemodynamic responses were observed across the 2 phases. The luteal phase was associated with greater stroke volume responses and lesser vascular tone. For the PMS women, none of their cardiovascular measures differed across their cycle. Instead, these women showed significantly attenuated blood pressure and heart rate responses compared with non-PMS women, irrespective of cycle phase.

Subclinical hypothyroidism: a modifiable risk factor for depression?

The authors assessed the lifetime history of major depression in 16 subjects with subclinical hypothyroidism and 15 subjects whose thyroid function was completely normal. The lifetime frequency of depression was significantly higher in the subjects who met the criteria for subclinical hypothyroidism (56%) than in those who did not (20%), suggesting that subclinical hypothyroidism may lower the threshold for the occurrence of depression.

Prospects for ultrasonic spectroscopy and spectral imaging of abdominal tissues

A system for the digitization and frequency spectral analysis of radiofrequency data for ultrasonic waveforms backscattered from abdominal tissues is described. Studies of phantoms meant to simulate abdominal tissues of differing scattering characteristics indicated that frequency spectral differences due to differences in the frequency dependence of backscattering were seen with 5 MHz probes, but not with a 3.5 MHz probe. Studies of a phantom with a simulated lesion of altered scattering characteristics indicated potential for improved lesion detection and characterization, using custom circuitry developed for variable bandwidth filtering of received ultrasonic beams. The techniques discussed have potential for improved diagnosis of diffuse and focal abdominal abnormalities over that obtained with conventional ultrasonic imaging.