Isolation of Toxigenic Hafnia alvei from a Probable Case of Hemolytic Uremic Syndrome

An 11-year-old girl presented to a central California children's hospital with a 3-day history of erythematous lesions on her forehead, neck, and trunk, abdominal pain, persistent emesis, and decreased urinary output. One day prior to admission she had a mild bout of diarrhea with a small amount of blood in her stool. Upon admission her condition rapidly worsened with acute renal failure, anemia, and thrombocytopenia. One of the possible causes of this condition included hemolytic uremic syndrome. Stool cultures of this patient tested at the children's hospital and at a state reference laboratory were repeatedly negative for Escherichia coli O157:H7. However, the state reference laboratory detected a toxigenic strain of Hafnia alvei active on Vero cells from two consecutive stool cultures during the acute phase of her illness.

Cross-sectional association between markers of inflammation and serum sex steroid levels in the postmenopausal estrogen/progestin interventions trial

BACKGROUND

Standard risk factors do not adequately capture cardiovascular risk in postmenopausal women. We sought to determine the associations between levels of sex steroids and levels of inflammatory markers in postmenopausal women.

METHODS

We analyzed baseline data from a subset of postmenopausal women aged 45-64 years who had stored samples during a randomized controlled trial. We measured levels of C-reactive protein (CRP), interleukin-6 (IL-6), matrix metalloproteinase-9 (MMP-9), soluble intercellular adhesion molecule (sICAM), and circulating sex steroids. Multiple linear regression models were created with each of the following hormone levels as the primary exposure variable: estrone, total estradiol, bioavailable estradiol, total testosterone, bioavailable testosterone, progesterone, and sex hormone-binding globulin (SHBG). Sociodemographic and lifestyle covariates were derived from standardized self-report questionnaires and direct measurement (weight, height).

RESULTS

Mean age of the 623 women was 56 years. After adjustment for age, body mass index (BMI), physical activity, alcohol consumption, and smoking, the bioavailable testosterone level (p = 0.03) was positively and the SHBG level (p < 0.001) was negatively associated with the logCRP level. The increment in CRP level between the highest and lowest quartile of bioavailable testosterone was 1.28 microg/mL. The increment in CRP level between the lowest and highest quartile of SHBG was 2.62 microg/mL. Compared with SHBG or bioavailable testosterone as predictors of logCRP in separate regression models, when both SHBG and bioavailable testosterone were included in the same multivariate linear regression model, only SHBG remained a statistically significant predictor of logCRP. Progesterone level was positively associated with the logMMP-9 level (p < 0.001); no other sex steroid level was associated with the logMMP-9 level. In multiply adjusted models, no association was found between levels of any sex steroid and IL-6 or sICAM level.

Antenatal psychiatric illness and adequacy of prenatal care in an ethnically diverse inner-city obstetric population

OBJECTIVE

This study assessed the prevalence of antenatal psychiatric illness in low-income, ethnically diverse patients in an urban obstetric clinic and examined associations between positive psychiatric screens and inadequate utilization of prenatal care.

METHODS

Bilingual research assistants administered the Primary Care Evaluation of Mental Disorders Patient Health Questionnaire and the Mood Disorder Questionnaire to 154 English- and Spanish-speaking pregnant patients attending routine prenatal visits. We assessed associations between patient characteristics, current and past psychiatric diagnoses, and utilization of prenatal care.

RESULTS

Forty-five (29%) women screened positive for criteria for current psychiatric disorders with the highest rates for major or minor depression (26%) and anxiety disorders (10%). Inadequate prenatal care utilization was significantly associated with past psychiatric history and domestic abuse in the last year, but not with current psychiatric diagnosis, alcohol abuse, age, primiparity, marital status, receipt of government assistance, or unplanned pregnancy. Even after adjustment for possible confounding risk factors (e.g. past substance abuse, single marital status, unstable housing, education less than high school, and having other children), past psychiatric history was still significantly associated with inadequate prenatal care utilization and delayed initiation of care.

CONCLUSIONS

A high percentage of disadvantaged pregnant women meet screening criteria for psychiatric disorders when screened during routine prenatal visits. Screening for past psychiatric history in routine prenatal visits could identify patients at risk for inadequate utilization of prenatal care.

Bone mineral density and adjuvant therapy in breast cancer survivors

Compared to mean values from a US database, premenopausal breast cancer survivors (BCS) had significantly higher whole body bone mineral density (BMD) compared to age and ethnicity matched referents; higher whole body BMD was present in all premenopausal BCS, including those who received chemotherapy, tamoxifen+chemotherapy, or no adjuvant therapy. Postmenopausal BCS who had received no adjuvant therapy also had higher whole body BMD compared to similarly aged women. In contrast, hip and lumbar spine BMD values in BCS were similar to those of the population-based database.

The role of serial bone mineral density testing for osteoporosis

As a whole, groups of women who gain more bone mineral density (BMD) on antiresorptive medications experience greater fracture protection, although the relationship is not clear on the individual level. A literature search (Medline 1966 to present) for randomized, controlled trials was performed with keywords serial bone density, osteoporosis, dual-energy x-ray absorptiometry, fracture, alendronate, risedronate, calcitonin, estrogen replacement therapy, and raloxifene. Also, reference lists and tables of contents from journals were searched manually for additional relevant randomized controlled trials. Trials were 2-3 years in duration, and the number of subjects ranged from 670 to 3954. Medications analyzed include alendronate, either 5 mg/day or 5 mg/day, followed by 10 mg/day; raloxifene, 60 or 120 mg/day; and combination hormone replacement therapy (HRT) of four different regimen types. There have been no controlled studies showing that change in treatment based on serial bone density measurement results in improved patient outcomes. Whereas studies have shown changes in BMD during antiresorptive therapy to be predictive of fracture reduction in groups of patients, their utility in individual patients remains inconclusive. Osteoporotic women who lose BMD in the first year of alendronate or raloxifene use will likely gain BMD in the second year of treatment, illustrating regression to the mean. Effective medication for osteoporosis should not be changed solely because of BMD loss occurring after the first year of treatment. Young, healthy, postmenopausal women taking commonly prescribed doses of estrogen or estrogen/progestin (HRT) rarely lose BMD. Bone loss over the first 12 months of HRT is independent of bone loss in the next 24 months. If bone is not lost in the first 12 months of HRT, there is a significant chance that bone density will be lost later in treatment. Half of placebo-treated women do not lose BMD over 3 years. Treatment should be continued in patients who initially lose bone density on therapy because most will gain density with continued treatment and end in gaining bone overall. Also, patients who gain large amounts of bone in the first year and lose in the second year are not necessarily failing therapy but rather may be showing that a random error in the earlier bone density change corrects itself later. Loss of BMD with alendronate, raloxifene, or combination conjugated equine estrogen/ medroxyprogesterone acetate is likely to convert to gain in BMD. More research is needed to confirm that this regression to the mean may apply to all densitometry techniques, antiresorptives, age groups, and genders.

Tolterodine: a clinical review

This analysis reviews clinical trials of the efficacy and safety of tolterodine for use in overactive bladder. It also compares the safety and efficacy of tolterodine and previously available pharmacotherapy. The MEDLINE database (1966 to present) was searched for all English language randomized controlled trials with keyword tolterodine. The search retrieved 10 randomized controlled trials involving tolterodine. Studies ranged from 2 to 12 weeks in duration. Nine trials studied tolterodine vs. placebo, 6 compared tolterodine vs. oxybutynin, 6 compared different doses of tolterodine, and 1 compared immediate-release and extended-release tolterodine. Doses of tolterodine were 0.5-4 mg bid or 4 mg extended-release daily, and doses of oxybutynin were 5 mg bid or tid. All studies found a benefit of tolterodine over placebo in decreasing symptoms of overactive bladder. Parameters significantly improved by tolterodine include number of voids per day, urine volume per void, number of incontinent episodes per day, pad use, maximal cystometric capacity, residual volume, volume at first detrusor contraction, and volume at normal desire to void. Tolterodine 2 mg bid was consistently of equal efficacy as oxybutynin 5 mg tid. Adverse events with both medications were mostly dose-related autonomic nervous system events. The most common adverse event was dry mouth, which was both more frequent and more severe with oxybutynin 5 mg tid than with tolterodine 2 mg bid. Dry mouth did not generally result in discontinuation of medication with either drug. Most drug withdrawal was because of blurred vision or headache. Tolterodine 2 mg bid caused less dose reduction, patient withdrawal, and adverse events, especially dry mouth, compared with oxybutynin 5 mg tid. A single trial found tolterodine extended-release 4 mg/day to have improved efficacy for decreasing urge incontinence episodes along with lower frequency of dry mouth vs. immediate-release tolterodine 2 mg bid. At 4 mg bid, tolterodine caused urinary retention. Neither drug significantly altered any laboratory tests, nor was there clear evidence of electrocardiographic abnormalities induced by either drug. In all randomized controlled trials to date, tolterodine 2 mg bid is an equally effective alternative to oxybutynin 5 mg tid, while causing less intense and less frequent dry mouth or need for treatment withdrawal.

Risedronate: a clinical review

BACKGROUND

Risedronate sodium has recently been approved for the prevention and treatment of postmenopausal and corticosteroid-induced osteoporosis.

METHODS

Studies of risedronate were obtained from the MEDLINE database (1966 to the present) of references using risedronate, risedronic acid, osteoporosis, and human subject as keywords. Additional references were sought from the reference lists of the articles obtained.

RESULTS

Nine randomized controlled trials and 7 other clinical trials were obtained. In postmenopausal women with normal bone density, risedronate increases lumbar spine bone density and preserves femoral neck density. In postmenopausal women with prior vertebral fracture, risedronate decreases new vertebral and nonvertebral fracture incidence. In patients who experienced breast cancer and who have chemotherapy-induced menopause, risedronate preserves bone. Risedronate prevents vertebral bone loss in patients beginning long-term corticosteroid therapy. Risedronate decreases pagetic bone pain and induces radiological improvement in pagetic lesions. Risedronate induces normalization of biochemical abnormalities and may be more effective than etidronate disodium for Paget disease. Only one study, a trial in patients with postmenopausal osteoporosis using a low dose (2.5 mg) of risedronate, did not have a positive result. Adverse effects in patients with postmenopausal osteoporosis, breast cancer, and Paget disease and in those taking corticosteroids are similar to those of patients taking placebo, and do not include notable upper gastrointestinal tract adverse event rates or serious adverse events.

CONCLUSIONS

Risedronate prevents postmenopausal bone loss, decreases fracture in those with established postmenopausal osteoporosis, effectively treats Paget disease, and prevents corticosteroid-induced bone loss. Long-term toxic effects and efficacy, particularly fracture end point data, are unknown. Also undefined are optimal duration of therapy, potential for use in combination with other agents, and direct comparison with other bisphosphonates used for osteoporosis.

Information technology and the National Centers of Excellence in Women's Health

Women are increasingly turning to the Internet for health information. The National Centers of Excellence in Women's Health (U.S. Dept. of Health and Human Services) have as one goal the use of information technology to improve care of women. Telemedicine, the Internet, and Resource Centers were used for patient consultation, patient support, support of women in academics, and clinician education regarding women's health. Access of the lay public to high-quality health information was achieved using the Internet as well as Resource Centers employing Internet educational modalities. Telemedicine, distance learning for clinicians and patient consultations for those far from medical care, has been used successfully. For clinicians, continuing medical education regarding women's health and calendars of opportunities for education in women's health were made available on-line. Creative new uses of information technology have been developed by the Centers of Excellence in Women's Health. These modalities may be adopted, tested, and adapted by others seeking to improve the care and health of women.

Gender differences in osteoporosis treatment: a review of clinical research

Morbidity from osteoporosis in the aging population is substantial in both men and women; however, therapeutic options approved by the Food and Drug Administration are open only for use in women. A literature search was performed to define gender differences in pharmacologic osteoporosis treatments in published research. Only two studies on the efficacy of pharmacologic osteoporosis interventions in both genders were found, both of which involved glucocorticoid-treated patients. There is clearly a lack of information on osteoporosis treatment approaches in men compared to women, despite the increasingly recognized risk of osteoporosis in men. Although there are no approved therapies for osteoporosis in men in the United States, the scant but promising evidence suggests potential benefit from alendronate and risedronate in men as well as women. Further gender-comparative research regarding nonestrogenic approaches to osteoporosis is warranted.

Relationships between ambulance transports for alcohol intoxication and assault

OBJECTIVE

To evaluate the association between ambulance transports for assault and those for alcohol intoxication.

METHODS

A retrospective analysis of emergency medical services (EMS) calls was performed. The authors used logistic regression models to compare patients transported for alcohol intoxication with a control group of patients transported for respiratory distress (asthma or shortness of breath) with respect to whether they had been transported on a separate occasion for a chief complaint of assault.

RESULTS

Patients transported for alcohol intoxication had 9 times the risk of transport for assault as compared with the control group (OR = 9.3; 95% CI = 6.4, 13.6). The odds of transport for assault among the alcohol patients increased 17.1% with each alcohol transport (OR = 1.17; 95% CI = 1.14, 1.20) but decreased for the control group (OR = 0.34; 95% CI = 0.26, 0.44). Repeat transports for assault were more common among the alcohol patients than among the control group (OR = 3.3; 95% CI = 1.1, 11.3). The mean number of assault transports was higher among the alcohol patients than among the patients never transported for alcohol intoxication (p < 0.0001).

CONCLUSIONS

Patients transported on multiple occasions for acute alcohol intoxication are at relatively high risk for assault. This risk group should be targeted for focused assault prevention interventions that include components designed to reduce incidents of repeat alcohol intoxication.

Guns and knives in New Mexico: patterns of penetrating trauma, 1978-1993

OBJECTIVE

To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.

METHODS

The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978-1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.

RESULTS

Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.

CONCLUSIONS

Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.

Occupational injury mortality in New Mexico

STUDY OBJECTIVE

To examine specific risks for occupational injury deaths in New Mexico.

DESIGN

Retrospective review of state medical investigator reports from 1980 through 1991 with regard to industry, agent of death, gender, ethnicity, location, and alcohol and other drug involvement.

PARTICIPANTS

New Mexico residents who were fatally injured while on the job.

RESULTS

We identified 613 deaths: 87.1% unintentional, 10.6% homicides, and 2.3% suicides. Industries with the most fatalities were construction (11.8%), oil/gas (10.6%), and farming (8.6%). The primary agents of death were motor vehicles (41.7%), firearms (10.1%), and falling objects (10.0%). Almost all (95.6%) of the decedents were male. However, females were overrepresented among homicide deaths (P < .0001). Most unintentional injuries occurred in rural areas (69.1%), whereas most homicides (73.4%) and suicides (71.4%) occurred in urban areas. Drug or alcohol use was evident in 19.4% of cases.

CONCLUSION

New Mexico has a high rate of occupational injury death, which appears to be associated with rural location and use of motor vehicles and alcohol.

Resistance and disease in Brugia malayi infection of ferrets following prior infection, injection of attenuated infective larvae and injections of larval extracts

A partial resistance expressed by a 53% to 78% reduction in lymphatic filariae from a challenge infection was induced in ferrets (Mustela putorius furo) by a prior infection and by injection of radiation attenuated infective larvae (L3) but not by injections of lyophilized microfilariae (mf) or L3. Equivalent acquired resistance was demonstrated with and without overt filarial disease. A prior infection resulted in peripheral lymphoedema in approximately one-third of the amicrofilaraemic resistant ferrets following challenge infection and injection of attenuated larvae resulted in inflammatory responses characteristic of a hyper-responsive syndrome in one-half of the amicrofilaraemic ferrets. Injections of lyophilized mf inhibited microfilaraemia and promoted development of lymphostatic disease. A limited examination of immune responses and histopathology suggested that disease in partially resistant ferrets was associated with high TH2 dependent responses directed, at least in part, to mature filariae and to mf. Mechanisms of resistance were not identified.

Coronary collateral circulation in the transplanted heart

BACKGROUND

The concept that coronary collateral (CC) circulation can develop in cardiac transplant recipients (CTR) is controversial. Indeed, a decreased occurrence of CC in CTR has been previously reported.

METHODS AND RESULTS

We reviewed 102 coronary angiograms in 73 CTR to evaluate the presence and significance of CC in denervated human hearts. These angiograms were compared with angiograms of 70 nontransplanted patients. Twenty-six CTR who had undergone at least two coronary angiograms, thus allowing comparative evaluations, form the basis for this study. Angiograms were analyzed using a modification of CC classification (Rentrop et al) from grade 0 for complete absence to grade 4 representing mature collateral with clear filling of epicardial vessels. Coronary artery disease was classified according to the scheme reported by Gao et al. For the purpose of this study, all type A lesions were grouped as large vessel disease (LVD), and types B1, B2, and C were collectively grouped as small vessel (epicardial) disease (SVD). The presence of CC circulation in all 73 CTR was grade 0, 7 (10%); grade 1, 41 (56%); grade 2, 33 (45%); grade 3, 30 (41%); and grade 4, 5 (7%). However, in control nontransplanted subjects grades 0, 1, 2, 3, and 4 were found in 47 (67%), 22 (31%), 4 (6%), 11 (15%), and 16 (20%) patients, respectively. The presence of mature collaterals (grade 4) in both groups were associated with type A lesions and was frequent in nontransplanted hearts. In contrast, grade 2 and grade 3 vascular channels probably representing CC with "myocardial blush" was more frequent in CTR and was mostly associated with small vessel coronary arteriopathy.

CONCLUSIONS

These results suggest the presence of atypical CC in patients with cardiac allograft arteriopathy. It is speculated that this atypical form of CC with "blush pattern" may represent an angiogenic response to microvascular ischemia due to allograft coronary arteriopathy.

Immune responses and chronic lymphedema in experimental filariasis

Chronic lymphedema is a clinically important manifestation of lymphatic filariasis but the factors which govern the development and progression of lymphedema remain unclear. Because immune responses are major determinants of disease expression in filariasis, we compared immune responses in ferrets reinfected with B. malayi in which disease expression varied from virtually no overt disease to severe chronic lymphedema of the infected limbs. No immune correlates specific for development of chronic lymphedema were identified by antigen recognition profiles (Western-blots), magnitude of the antibody (IgG) responses (ELISA) or blastogenic responses of lymphocytes to filarial extracts. Prausnitz-Kustner (PK) tests for filarial specific IgE indicated that the initial period of a severe lymphedema, which became chronic, often was associated with relatively high IgE titers. The results suggest that a high level of immediate hypersensitivity to filarial antigens is a significant factor in initiating persistent lymphedema on reinfections of partially resistant hosts. Histologic study of persistent edema of up to 2 years duration demonstrated dermal changes consistent with chronic lymphedema, but not the dermal proliferation characteristic of elephantiasis.

Lymphatic imaging in experimental filariasis using magnetic resonance

RATIONALE AND OBJECTIVES

To evaluate acquired lymphatic abnormalities caused by filariasis, the authors examined the peripheral lymphatic system in normal ferrets and those chronically infected with Brugia malayi using magnetic resonance imaging (MRI). The findings were compared with previously obtained lymphangioscintigraphic (LAS) images in ferrets both with and without experimental filariasis.

METHODS

Fifteen ferrets (11 infected with B. malayi and four noninfected controls) underwent whole body coronal MRI using a quadrature transmission-receive head coil at 0.5 Tesla operating at a resonant frequency of 21.5 mHz for protons with a 25-cm field of view.

RESULTS

In contrast to normal animals, infected ferrets showed dilated hindlimb dermal lymphatic collaterals, enlarged high-signal intensity groin lymph nodes with punctate low-signal intensity centers and separate low-signal intensity spots with irregular thin channels, suggestive of nests of viable adult nematodes within tortuous lymphatics and nodes. MRI correlated with the LAS findings, and the interpretations were supported by light, scanning electron, and video microscopy.

CONCLUSIONS

T2-weighted MRI in conjunction with LAS accurately depicts the peripheral lymphatic system in filarial-infected ferrets. These two modalities are useful complementary techniques to examine disorders characterized by lymphatic insufficiency.

Relation of level of exercise, age, and weight-cycling history to weight and eating concerns in male and female runners

We examined the association between level of exercise and degree of weight preoccupation in a large sample of male and female runners, as well as risk factors posited to influence weight and eating concerns in the general population. Subjects were 2,459 males and 1,786 females who had completed a questionnaire on weight and eating concerns in a national running magazine. Eight percent of the males and 24% of the females had symptomatic scores on the Eating Attitudes Test (EAT). Exercise level, defined as weekly running mileage, was positively associated with excessive weight and eating concerns in males but not in females. Both sexes with a history of weight cycling were more likely to have symptomatic EAT scores than those with no such history. These results highlight the importance of studying these concerns in males as well as females and of examining the role of exercise level and weight-cycling history in the development of serious weight preoccupations.

Vascular abnormalities in experimental and human lymphatic filariasis

Whereas clinical descriptions of grotesque lymphedema and standard light microscopy in human filariasis have elucidated the natural progression of this disease, the link between the nematode and vascular abnormalities including elephantiasis remains poorly understood. Accordingly, we examined the nature and distribution of lymphatic and blood vascular derangements in a variety of tissues and organs from 37 ferrets acutely and chronically infected with Brugia malayi and in 15 patients with Wuchereria bancrofti or Brugia malayi infestation (resected skin, subcutaneous tissue, and lymph nodes) using light and transmission electron microscopy, immunohistochemistry, and in vivo microscopy. In ferrets, eosinophilic abscesses and epithelioid and giant cell granulomas with fragmented worms in various stages of disintegration were found in multiple organs. Blood microvasculopathy consisted of endothelial hyperplasia, focal thickening and stenosis, vessel obliteration with marked perivascular infiltration of lymphocytes, plasma cells, eosinophils, and numerous large macrophages laden with a coarse golden-brown pigment. Endothelial ballooning and swelling, pavementing, denuding, scarring, and sludge formation were seen along with high endothelium in atypical locations. Dilated lymphatics were most prominent near adult worms and showed plump endothelium, thickened walls and valves, thrombus formation, and often perilymphangitis and adjacent tissue fibrosis. In vivo microscopy showed wriggling live adult worms in dilated incompetent sludge-filled groin lymphatics even when microfilaremia and peripheral edema were absent. In human tissues, in addition to "pachyderm" skin changes (keratosis, papillomatosis, acanthosis and collagen deposition), there was blood vessel and lymphatic vasculopathy similar to ferrets (angiocentric inflammation, congestion, vasculitis, thrombosis, thickened vessel walls, dilated lymphatics, lymphangitis, reactive lymph nodal hyperplasia and nodal fibrosis). These changes reflect generalized endothelial damage due to worm products, physical injury to valves and vessel walls from lymphatic-dwelling live worms, and host immune reactivity. Whereas adult worms target the lymphatic apparatus, their offspring and the host immune response primarily affects the blood microvasculature.

Identification of interleukin 6 as a synergistic factor for the differentiation-inducing effect of TNF on leukemic ML-1 cells

Recombinant TNF was capable of inducing differentiation of human leukemic ML-1 cells in the monocytic pathway. Recombinant interleukin 6 did not have the activity but it could significantly increase the activity of recombinant TNF. Both of these molecules were found to play a similar role in PWM-induced conditioned medium from human lymphocytes (LCM). The differentiation inducing effect of LCM could be partially neutralized by antibody to interleukin 6. Fractionation of LCM also identified interleukin 6 as the factor that synergizes with TNF.

Whole body lymphangioscintigraphy in ferrets chronically infected with Brugia malayi

Whole body lymphangioscintigraphy was performed after intradermal injection of 99mtechnetium human serum albumin or antimony colloid in the distal hindlimbs and forelimbs of ferrets chronically infected with Brugia malayi. The findings were compared with control ferrets and those with surgical interruption of the iliac lymphatics. While only one infected ferret manifested chronic hindlimb lymphedema, all exhibited delayed transport of radioisotope from the hindpaw with obstruction in the groin, poor or absent visualization of central lymphatic channels and regional lymph nodes, a picture similar to that following surgically induced lymphatic obstruction. In control ferrets, there was prompt visualization of peripheral lymphatic channels and regional lymph nodes with sharper and more extensive channel visualization after radiolabeled albumin and more intense sustained nodal visualization after radiolabeled antimony colloid. This noninvasive technique provides a readily repeatable investigative tool adaptable to small animals to study the evolution of lymphatic filariasis and other conditions associated with lymphatic obstruction.

Growth characteristics of the murine trisomy 19 thymus

Development of the trisomy 19 mouse thymus was studied by (1) evaluation of cell and nuclear counts and volume distributions and (2) examination of the in vivo cell cycle characteristics using flow cytometry. Direct preparations of thymuses from affected animals and their normal littermates at 17, 18, 19 gestational days, and at term were used. Cell numbers in aliquots from the trisomic thymus suspensions were always significantly less than those in the normal animals. There were no differences in cellular or nuclear volumes between the two groups. However, the populations of cells in the trisomic suspensions showed a lag in the normally occurring transition from a larger to a smaller size. DNA distribution histograms from these suspensions were generated using a TPS-1 Cell Sorter, and percentages of cells in different phases of the cell cycle were estimated using computer analysis. The resulting graphs and numerical data from the trisomic mice, when compared with the normals, showed consistent increases in the relative numbers of cells in the S and G2 + M phases of the cell cycle. Because growth retardation is a major feature of trisomy 19, as well as in other murine trisomies, these results suggest that cell cycle alterations may, in part, contribute to the reduced cell number, delayed development, and smaller size of the trisomic animals.

Cytogenetic studies of familial and sporadic Alzheimer disease

We present cytogenetic findings in 7 familial and 5 sporadic Alzheimer disease (AD) patients and 34 unaffected relatives, spouses, and normal controls. Our study was prompted by reports of increased chromosome abnormalities in patients and family members at risk for AD. Coded peripheral blood chromosome preparations were evaluated for aneuploidy, aberration rates, and banding patterns. Statistical analyses of our results showed no increase in aneuploidy or aberrations in AD patients, their relatives, or normals. Chromosome loss or gain in aneuploid cells was not specific except in two individuals. These two older persons studied, one with AD and one unaffected, were observed to have increased sex chromosome aneuploidy. This finding was attributed to aging and was not considered to be an effect of AD.

Conditioned taste preferences based on caloric density

Conditioning involved adding one flavor (e.g., vanilla) to an artificial diet of high caloric density and a second flavor (e.g., anise) to a similar low-calorie diet. When the rats were tested with identical foods to which the flavors were added, they showed a strong preference for the high-calorie flavor. The parameters of conditioning were varied in four experiments, which showed that the conditioning of taste preferences is rapid and powerful and has generality over a range of conditioned stimulus parameters. The last experiment indicated that the unconditioned stimulus for this conditioning is probably some oral cue, such as the taste of starch, which is correlated with caloric benefit, rather than caloric benefit per se.

Cytogenetic studies of a male with sporadic intestinal lymphangiectasia: 45,X/46,XY mosaicism with pseudo- and hyperdiploid subpopulations in cultured tissues

45,X/46,XY mosaicism was found in peripheral blood, bone marrow, and tissue cultures of an adult male with intestinal lymphangiectasia (IL). Turner phenotype was not present; his meiotic metaphase analysis was normak, and his dermatoglyphics resembled those of his family. Ten separate tissue culture lines from three biopsies of skin and thyroid gland contained 45,X cells (14.8 to 78.3%). Autosomal aneuploidy, resulting in pseudo- or hyperdiploidy, was also present in 4.3 to 41.6% of the cells. A hyperdiploid clone with a 47,X,+10,+18 karyotype was found in 22.6% of cells in one line. A second hyperdiploid clone with a 48,X,+2,+18,+18 karyotype occurred in 7.6% of cells from another line containing a total of 41.6% pseudo- and hyperdiploid cells. Such clonal abnormalities were not typical of tissue cultures from other patients done in our laboratory. Growth of our patient's tissue cultures was subnormal, and none proliferated beyond the fourth subculture. The significance of this observation remains to be determined. Our results do not allow us to conclude whether our patient's mosaicism of somatic tissues arose during embryogenesis, or whether it originated post-natally. The secondary immunodeficiency which occurs in IL may explain persistence of cells with unusual combinations of autosomal aneuploidy in our patient's tissues.

Laboratory mice carrying three pairs of Robertsonian translocations: establishment of a strain and analysis of meiotic segregation

The evolution of a 2n = 34 combined Robertsonian translocation strain Rb(5.19)1Wh/(6.15)1Ald/(8.17)HEM is described. Homozygotes had three large ring translocation bivalents at M I and regular meiotic disjunction at M II. Male and female F_1· heterozygotes had similar frequencies of abnormal meiotic disjunction at M II, but aneuploid embryos were more frequent in (F₁<i>♂ </i>X NIH GP ♀) crosses (25.6%) than (F₁ ♀ X GP <i>♂</i>) crosses (13.5%) at 10 days’ gestation. It could not be determined whether this discrepancy was genetic in origin or due to limitations in the techniques of M II analysis. Rb(5.19), as well as Rb(6.15) or (8.17), contributed to the aneuploidy, although previous M II analysis of singly heterozygous Rb(5.19)/+ males demonstrated comparatively regular meiotic disjunction. Trisomic embryos were not detected beyond 10 days in five (F₁ ♀ X GP <i>♂</i>) crosses, suggesting that their survival in F₁ females is limited. The ratios of the different types of balanced embryos from the (F₁ X GP) crosses indicated random meiotic segregation of the three translocation chromosomes in triple heterozygotes. Analysis of complementary groups of balanced embryos from the same crosses also demonstrated lack of preferential segregation of the translocations; embryos with translocations and those with their corresponding homologous acrocentrics were equally frequent. Triploid embryos (3.3 %) were also detected in (F₁<i>♂ </i>X NIH GP ♀) crosses. The translocations and Y chromosome served as paternal markers, permitting its origin to be determined in two of three cases (dispermy). One growth-retarded triploid had a distinctive anomaly: failure of lens induction and lack of optic cup development. The combined strain provided a complex of markers for determining polyploidy mechanisms, as well as a common genetic background for comparing behavior of the three translocations at M I.

Trisomy 19 in the laboratory mouse. II. Intra-uterine growth and histological studies of trisomics and their normal littermates

Weights of viable trisomic mouse fetuses and placentas were compared with those of normal littermates between 12½ and 19½ days’ gestation. Mean trisomic fetal and placental weights were below normal weights at all stages. Differences in mean body weight were consistently significant, whereas those in placental weight varied. Trisomic fetuses of a specific karyotype predisposing to cleft palate were not smaller than trisomics of two other karyotypes, suggesting that a greater generalized growth lag was not responsible for the cleft palate. At each developmental stage, ratios of placental to body weights of normal and trisomic mice were similar. Sections of trisomic organs showed only one specific change: excessive degeneration of oocytes in some trisomic ovaries. All of these findings are discussed in relation to other studies of fetal and placental weight in mice and to studies of the effects of trisomy upon human development in utero.

Trisomy 19 in the laboratory mouse. I. Frequency in different crosses at specific developmental stages and relationship of trisomy to cleft palate

<i>T(5;19)1Wh × T(9;19)163H</i> F₁ hybrids were used in four types of crosses to produce fetuses with trisomy 19. Trisomy was more frequent early in gestation (7.9–23.0 %) than after 16½ days (4.5–16.9 %) and was associated with many non-viable implantations. Male hybrids produced significantly more trisomics than female hybrids in crosses with NIH GP mice terminated early in gestation. In fetuses beyond 16 V2 days, isolated cleft palate was consistently associated with trisomy 19. It was found only in trisomics carrying one <i>T1Wh </i>and two <i>T163H </i>translocations, although trisomics with one <i>T163H </i>and two <i>T1Wh </i>or with single <i>T163H </i>and <i>T1Wh </i>translocations were also produced. These and other observations demonstrate the effects of genetic background upon frequency of trisomy, survival of conceptuses, and phenotype of trisomic fetuses. These effects, as well as trans-location-specific meiotic mechanisms, must be considered when mouse translocation trisomy is compared with that of humans.

Studies of mice with a balanced complement of 36 chromosomes derived from F 1 hybrids of T1Wh and T1Ald translocation homozygotes

F(1) hybrids with 38 chromosomes, including single T1Wh and T1Ald translocations, resulted when mice homozygous for the Robertsonian translocations T1Wh and T1Ald were crossed. Meiotic studies of the hybrids showed two trivalents, indicating nonhomology of the T1Wh and T1Ald chromosomes. The hybrids had frequent (25%) unbalanced meiotic metaphase II complements; one trisomic mouse resulted from six F(1) crosses. The F(1) crosses also produced one mouse with 36 chromosomes homozygous for both T1Wh and T1Ald, as well as mice with balanced polymorphic complements of 37, 38, 39, and 40 chromosomes. By crossing the F(2), a homogeneous line with 36 chromosomes was established. The line is phenotypically normal, fertile, and has balanced meiotic metaphase II complements. Analysis of the chromosomes of these mice with quinacrine mustard and the Giemsa-banding technique confirmed that T1Wh and T1Ald consisted of chromosomes 5;19 and 6;15, respectively. Crosses between this line and other existing translocation stocks may produce new strains of mice with even further reduction in chromosome number. Accumulation of Robertsonian translocations, a possible evolutionary mechanism in the wild, can be studied in the laboratory. F(1) hybrids from certain crosses are also an important model for human translocation carriers; both have similar meiotic abnormalities and often have aneuploid offspring.

Trisomy for the smallest autosome of the mouse and identification of the T1Wh translocation chromosome

Quinacrine-mustard staining and Giemsa-banding identified the large chromosome of the T1Wh translocations as No. 5; the small autosome of the translocation had previously been found to be No. 19. Others have demonstrated that translocation T163H involved autosomes 9 and 19; these findings were confirmed in our study. Meiotic studies of (T1Wh × T163H) F₁ hybrids showed a chain quadrivalent at metaphase I, confirming that both translocations shared in common only chromosome 19. Metaphase II analysis of F₁ hybrids demonstrated frequent nondisjunction of the T1Wh and T163H translocation chromosomes, and 12 % of 75 F₂ offspring from 16 F₁ crosses were trisomic for chromosome 19. Trisomics had three translocation chromosomes and a chromosome number of 38. All newborn trisomics were smaller than their normal littermates and died during the first day of life. The only specific malformation found so far has been cleft palate.

Relation of level of exercise, age, and weight-cycling history to weight and eating concerns in male and female runners

We examined the association between level of exercise and degree of weight preoccupation in a large sample of male and female runners, as well as risk factors posited to influence weight and eating concerns in the general population. Subjects were 2,459 males and 1,786 females who had completed a questionnaire on weight and eating concerns in a national running magazine. Eight percent of the males and 24% of the females had symptomatic scores on the Eating Attitudes Test (EAT). Exercise level, defined as weekly running mileage, was positively associated with excessive weight and eating concerns in males but not in females. Both sexes with a history of weight cycling were more likely to have symptomatic EAT scores than those with no such history. These results highlight the importance of studying these concerns in males as well as females and of examining the role of exercise level and weight-cycling history in the development of serious weight preoccupations.