Trial of labor after cesarean: Maternal and neonatal outcomes from the Consortium on Safe Labor

BACKGROUND

The aim of our study is to describe maternal and neonatal morbidity and mortality in patients undergoing trial of labor after cesarean from the Consortium on Safe Labor.

METHODS

This was a secondary analysis of the Consortium on Safe Labor database, a retrospective cohort study over a 7 year study period. Maternal and neonatal outcomes were evaluated based on desired delivery mode: planned elective repeat cesarean delivery or trial of labor after cesarean.

RESULTS

Of 9858 patients in our analysis, our study population had 4400 patients (45%) who desired trial of labor after cesarean and 5458 patients (55%) who desired elective repeat cesarean delivery. Women who attempted trial of labor after cesarean compared to those who had an elective repeat cesarean delivery were more likely to have an obstetric hemorrhage (adjusted odds ratio 1.6; 95% CI 1.3 -2.0) and blood transfusion (adjusted odds ratio 2.3; 95% CI 1.6 -3.2).

CONCLUSION

Maternal morbidity in women undergoing trial of labor after cesarean was predominantly hemorrhage-related.

A survey evaluating practice pattern in management of obstetric hemorrhage

BACKGROUND

Hemorrhage anticipation and management has shifted significantly over the past decade due to evolution of data surrounding management of obstetric hemorrhage. Limited data exists which describe the practical use and clinical application of hemorrhage management. Our goal was to identify obstetric hemorrhage management patterns in a cohort of practicing Maternal Fetal Medicine physicians.

METHODS

We administered a survey to Maternal Fetal Medicine (MFM) fellows and faculty that addressed the management of hemorrhage including risk assessment, uterotonic use, antifibrinolytic use, cell saver use, and abnormal placentation management. An email was sent out regarding the survey to a listserv of all Maternal Fetal Medicine fellow program coordinators to disseminate to their faculty and fellows. Eighty responses were obtained.

RESULTS

A total of 78 surveys were analyzed. Participants preferred methylergonovine as a first line agent (n = 57; 73%, n = 62; 80%). Most participants would consider using cell salvage when also activating MTP (28, 48%) or during scheduled deliveries who are high risk of hemorrhage (40, 69%). Approximately a third of providers would use TXA (tranexamic acid) prophylactically (n = 21; 28%). Only 26% of MFM fellows felt comfortable performing cesarean hysterectomy without Gynecologic Oncology.

CONCLUSION

In comparison to prior reports, TXA use has increased substantially. Further, when looking at the management of abnormal placentation, the use of magnetic resonance imaging and embolization have both increased. Possibly due to the rise in centers of excellence for treatment of accreta spectrum disorders, Maternal Fetal Medicine fellows still feel largely unprepared to perform a cesarean hysterectomy without Gynecologic Oncology.

Mitigation of SARS-CoV-2 transmission at a large public university

In Fall 2020, universities saw extensive transmission of SARS-CoV-2 among their populations, threatening health of the university and surrounding communities, and viability of in-person instruction. Here we report a case study at the University of Illinois at Urbana-Champaign, where a multimodal “SHIELD: Target, Test, and Tell” program, with other non-pharmaceutical interventions, was employed to keep classrooms and laboratories open. The program included epidemiological modeling and surveillance, fast/frequent testing using a novel low-cost and scalable saliva-based RT-qPCR assay for SARS-CoV-2 that bypasses RNA extraction, called covidSHIELD, and digital tools for communication and compliance. In Fall 2020, we performed >1,000,000 covidSHIELD tests, positivity rates remained low, we had zero COVID-19-related hospitalizations or deaths amongst our university community, and mortality in the surrounding Champaign County was reduced more than 4-fold relative to expected. This case study shows that fast/frequent testing and other interventions mitigated transmission of SARS-CoV-2 at a large public university.

Mitigation of SARS-CoV-2 transmission at a large public university

In Fall 2020, universities saw extensive transmission of SARS-CoV-2 among their populations, threatening health of the university and surrounding communities, and viability of in-person instruction. Here we report a case study at the University of Illinois at Urbana-Champaign, where a multimodal “SHIELD: Target, Test, and Tell” program, with other non-pharmaceutical interventions, was employed to keep classrooms and laboratories open. The program included epidemiological modeling and surveillance, fast/frequent testing using a novel low-cost and scalable saliva-based RT-qPCR assay for SARS-CoV-2 that bypasses RNA extraction, called covidSHIELD, and digital tools for communication and compliance. In Fall 2020, we performed >1,000,000 covidSHIELD tests, positivity rates remained low, we had zero COVID-19-related hospitalizations or deaths amongst our university community, and mortality in the surrounding Champaign County was reduced more than 4-fold relative to expected. This case study shows that fast/frequent testing and other interventions mitigated transmission of SARS-CoV-2 at a large public university.

Safely opening university campuses has been a major challenge during the COVID-19 pandemic. Here, the authors describe a program of public health measures employed at a university in the United States which, combined with other non-pharmaceutical interventions, allowed the university to stay open in fall 2020 with limited evidence of transmission.

Diffusion tensor imaging properties and neurobehavioral outcomes in children with hydrocephalus

BACKGROUND AND PURPOSE

White matter structural alterations and the correlation with neuropsychological deficits in children with hydrocephalus have not been well investigated. In this prospective study, the objectives were the following: 1) to apply DTI to detect in vivo white matter alterations based on diffusion properties in children with acute hydrocephalus, 2) to quantify early neuropsychological deficits, and 3) to explore the correlation between potential neuropsychological deficits and abnormalities in functionally related white matter.

MATERIALS AND METHODS

A total of 44 children, 24 with hydrocephalus and 20 controls, were enrolled in the study. DTI indices, FA, MD, AD, and RD, were evaluated in the gCC, sCC, PLIC, and ALIC. The ABAS-II was used as a broad screener of development, including conceptual, social, practical, and motor skills. The correlation between the Motor Scale and DTI indices in the PLIC was analyzed.

RESULTS

DTI analyses showed that the gCC and sCC in children with hydrocephalus had lower FA and higher MD, driven by the increased RD with statistical significance (P < .05) or trend-level significance (P = .06). The PLIC and ALIC had significantly higher AD in children with hydrocephalus (P < .05). On the ABAS-II, parent ratings of general adaptive skills, conceptual skills, and motor skills were significantly lower in children with hydrocephalus (all at P < .05). The MD and RD values in the PLIC were found to have trend-level or significant correlation with the Motor Scale (P = .057, .041, respectively).

CONCLUSIONS

DTI reveals alterations in the white matter structure in children with hydrocephalus with preliminary findings suggesting correlation with clinical motor deficits.

Effects of stocking and nitrogen fertilization rates on steers grazing dallisgrass-dominated pasture

To compare the performance of steer calves managed under different stocking rates (SR; 3.7, 6.2, 8.6, and 11.1 steers/ha for 140 d; chi(I1)) and N fertilization rates (112, 224, and 336 kg of N/ha; chi(I2)) in May 1996, 1997, and 1998, 72 steer calves (BW = 231 +/- 2.5 kg) were assigned randomly to one of 12 0.81-ha dallisgrass (51%)/common bermudagrass (32%) pastures. One-third of the fertilizer was applied in the form of ammonium nitrate in May, June, and August to achieve the prescribed totals. Treatments were separated using a polynomial regression equation: gammai = beta0 + beta1chi(I1) + beta2chi(I2) + beta(11)chi2(I1) + beta(12)chi2(I2) + beta(12)chi(i1)chi(i2) + epsilonI, with years as replicates. Within the range of the data, ADG and BW gain per steer were greatest at a stocking rate of 3.7 steers/ha and 336 kg/ha of N. Body weight gain per hectare peaked at 701 kg when cattle were stocked at 8.9 steers/ha and the pasture was fertilized with 336 kg/ha of N. The least cost of production was at a stocking rate of 3.7 steers/ha, with 112 kg/ha of fertilizer N applied, and the greatest cost of production was at a stocking rate of 11.1 steers/ha with 336 kg/ha of fertilizer N applied. Fertilization at 336 kg/ha of N produced the most profitable stocking rate at 7.3 steers/ha and returned 355.64 dollars. The optimal stocking rate for net return was 79, 81, and 82% of that for maximum BW gain per hectare for 112, 224, and 336 kg/ha of N, respectively. Under the assumptions made in the financial analysis, these data show that the economically optimal carrying capacity of similar pastures can be increased with N fertilizer up to at least 336 kg/ha annually.

Effect of species of cool-season annual grass interseeded into Bermudagrass sod on the performance of growing calves

Two experiments were conducted to evaluate the effect of species of cool-season annual grass on the growth of stocker cattle over 3 yr. In Exp. 1, the small grains (SG) oat (O), rye (R), and wheat (W), or combinations of SG and annual ryegrass (RG), were interseeded into Bermudagrass sod in a completely randomized design with a 3 x 2 factorial arrangement of treatments. In Exp. 2, RG was planted alone or with O, R, triticale (T), or W in a completely randomized design. Pastures were planted in late October of each year, and seeding rates were 134.4 and 22.4 kg/ha for SG and RG, respectively. In Exp. 1, grazing was initiated on December 18. In Exp. 2, grazing was initiated on December 23 for SG pastures and January 21 or February 16 for RG pastures in yr 1 and on December 8 for all pastures in yr 2. Grazing was managed using the put-and-take method, in which additional calves were added as needed to maintain equal grazing pressure among pastures. In Exp. 1, no interactions (P > or = 0.28) were detected, so the main effects of SG species and RG addition are discussed. From December 18 to March 12, there were no differences in ADG (P > or = 0.17), whereas during the spring (from March 12 to May 7), addition of RG increased (P = 0.05) ADG. Using RG increased (P < or = 0.01) animal grazing-days/hectare and BW gain/hectare. Wheat tended (P = 0.08) to increase BW gain/hectare compared with the other SG, and O tended (P = 0.09) to produce less BW gain/hectare than the other SG. The treatment x year interaction was significant (P < or = 0.05) in Exp. 2. In yr 1, no differences (P = 0.25) were observed for ADG from December 23 to March 8, but during the spring grazing period (from March 8 to May 5), ADG of calves grazing TRG was less (P < or = 0.04) than that of those grazing RG, RRG, or WRG. The RRG combination produced more (P < or = 0.03) BW gain/hectare than ORG, RG, or TRG and tended (P = 0.06) to produce more BW gain/hectare than WRG. The WRG combination produced more (P < or = 0.05) BW gain/hectare than TRG and RG, and ORG tended (P = 0.09) to produce more BW gain/hectare than RG alone. Pastures planted to R or W produced more (P < or = 0.05) BW gain/hectare than RG alone or T. During yr 2, there were no differences (P > or = 0.44) in ADG, BW gain/hectare, or grazing-days/hectare. In conclusion, the choice of cool-season annual to establish is highly weather-dependent, but R and W are generally superior to other small grains, and RG is a necessary complement to SG when interseeding cool-season annuals into Bermudagrass sod.

Chemical composition and in situ dry matter and fiber disappearance of sorghum x Sudangrass hybrids

Three sorghum x Sudangrass hybrids were planted in twelve 0.2-ha plots to test the effect of date of harvest and hybrid on plant maturity, DM yield, chemical composition, and in situ DM and fiber disappearance. Sweet Sunny Sue (a non-brown midrib (BMR) hybrid; nonBMR), NutriPlus BMR (a BMR hybrid; NP-BMR), and Dry Stalk BMR (a BMR hybrid; DS-BMR) were planted on 26 June 2003 at 22.4 kg of seed/ha. Beginning 34 d after planting, plant height and phenological growth stage were assessed weekly in 10 random, 0.5-m(2) quadrats per plot. Plants were clipped to 2.5 cm in height and analyzed for CP, NDF, and ADF using near-infrared spectroscopy. Composite samples harvested from each plot on d 34, 48, and 63 were incubated in the rumen of 3 steers to determine the in situ disappearance of DM and NDF in a 3 x 3 Latin square. Forage yield was greater (P < or =0.02) for nonBMR than NP-BMR on d 41 and 55 and tended (P = 0.08) to be greater on d 48. The DS-BMR hybrid produced more (P = 0.04) forage DM than the NP-BMR on d 48. When DM yield was regressed on growth stage at harvest, BMR hybrids were predicted to produce 265 kg/ha more DM (P < 0.01) than nonBMR, at the late-boot stage. At all harvest dates, NDF concentrations were less (P < or =0.02) for BMR than nonBMR. The DS-BMR had greater (P < or =0.02) NDF concentrations than NP-BMR on d 41, 48, 55, and 63. Detergent fiber concentrations were predicted to be greater (P < 0.01) in nonBMR than BMR when regressed on growth stage at harvest, but the magnitude of the differences in fiber concentration diminished with growth stage. The A fractions of DM and NDF were greater (P < 0.01) and the C fraction was less (P < 0.01) for BMR hybrids than nonBMR. The B fraction of DM was not affected (P = 0.15) by hybrid type. The B fraction of NDF was not different (P = 0.28) on d 34 but was greater (P < 0.01) on d 48 and 63 for BMR than nonBMR. Effective degradability of NDF and DM was greater (P < 0.02) for BMR than nonBMR on all harvest dates. The A fraction of DM was less for DS-BMR than NP-BMR (P < 0.01), but the B and C fractions of NDF and DM did not differ (P > 0.13) between BMR hybrids. This research indicates that forage chemical composition and ruminal in situ disappearance are improved in the BMR sorghum x Sudangrass hybrids tested compared with the nonBMR. Yield reductions are commonly reported for BMR hybrids, but predicted DM yields in the current study were not reduced if harvested at a similar phenological growth stage.

Mecamylamine blocks nicotine-induced enhancement of the P20 auditory event-related potential and evoked gamma

Cigarette smoking is significantly more prevalent in individuals with schizophrenia than in non-affected populations. Certain neurocognitive deficits and disruptions common in schizophrenia may be altered by smoking, leading to the hypothesis that schizophrenics engage in smoking behavior to alleviate specific neurocognitive symptoms of the disorder. Additionally, research suggests that individuals with schizophrenia have altered auditory event-related potentials (ERPs) and abnormalities in evoked gamma oscillations which are both indices of sensory information processing. This study was conducted to examine the effect of acute administration of nicotine and the non-specific nicotinic antagonist mecamylamine on the P20 and N40 components of the ERP and evoked gamma oscillations in mice. Acute nicotine (1 mg/kg) significantly increased P20 amplitude, an effect that was blocked by pretreatment with mecamylamine (2 mg/kg). Additionally, acute nicotine increased the normal burst of evoked gamma following an auditory stimulus. The increase in evoked gamma was also blocked by mecamylamine pretreatment. Although acute nicotine decreased amplitude of the N40 component, this decrease was not attenuated by mecamylamine. These results replicate findings that nicotine may enhance early sensory information processing through the nicotinic acetylcholinergic receptor system in an established model (ERPs) and extend these findings in an emerging, novel model (evoked gamma oscillations) of sensory information processing. The results also support the hypothesis that nicotine may be beneficial to individuals with deficits in neurocognitive functions, such as those suffering from schizophrenia.

Parasitic worms and inflammatory diseases

The debate on whether infection precipitates or prevents autoimmunity remains a contentious one. Recently the suggestion that some unknown microbe can be at the origin of some chronic inflammatory diseases has been countered by accumulating evidence that decreasing infection rates might have an important role to play in the rising prevalence of autoimmune disorders. The 'Hygiene Hypothesis' was initially postulated to explain the inverse correlation between the incidence of infections and the rise of allergic diseases, particularly in the developed world. Latterly, the Hygiene Hypothesis has been extended to also incorporate autoimmune diseases in general. Amongst the various infectious agents, a particular emphasis has been put on the interaction between parasitic worms and humans. Worm parasites have co-evolved with the mammalian immune system for many millions of years and during this time, they have developed extremely effective strategies to modulate and evade host defences and so maintain their evolutionary fitness. It is therefore reasonable to conclude that the human immune system has been shaped by its relationship with parasitic worms and this may be a necessary requirement for maintaining our immunological health. Fully understanding this relationship may lead to novel and effective treatments for a host of deleterious inflammatory reactions.

Gene expression profiling of hypoxia signaling in human hepatocellular carcinoma cells

Cellular, local, and organismal responses to low O2 availability occur during processes such as anaerobic metabolism and wound healing and pathological conditions such as stroke and cancer. These responses include increases in glycolytic activity, vascularization, breathing, and red blood cell production. These responses are mediated in part by the hypoxia-inducible factors (HIFs), which receive information on O2 levels from a group of iron- and O2-dependent hydroxylases. Hypoxia mimics, such as cobalt chloride, nickel chloride, and deferoxamine, act to simulate hypoxia by altering the iron status of these hydroxylases. To determine whether these mimics are appropriate substitutes for the lower O2 tension evoked naturally, we compared transcriptional responses of a Hep3B cell line using high-density oligonucleotide arrays. A battery of core genes was identified that was shared by all four treatments (hypoxia, cobalt, nickel, and deferoxamine) including glycolytic enzymes, cell cycle regulators, and apoptotic genes. Importantly, cobalt, nickel, and deferoxamine influenced transcription of distinct sets of genes that were not affected by cellular hypoxia. These global responses to hypoxia indicate a balancing act between adaptation and programmed cell death and suggest caution in the use of hypoxia mimics as substitutes for the low O2 tension that occurs in vivo.

Evaluation of alternative tactics for management of insecticide-resistant horn flies (Diptera: Muscidae)

A 3-yr study was conducted to determine the efficacy of tactics that could be used to manage populations of insecticide-resistant horn flies, Hematobia irritans irritans (L.). Insecticide spray, spot-on or pour-on formulations and two IGRs in bolus formulation, 1.3- and 3.2-ha pasture rotations on different rotation schedules, 0-50% Brahman breeding, selected fly-resistant cows, and a mechanical trap were evaluated singly and in combination. Concentration-mortality tests indicated that horn flies collected from cows used in the current study were significantly less susceptible to diazinon, coumaphos, and methoxychlor than horn flies from cows at the same locations previously used to determine baseline susceptibility. During the 3-yr study at the Southeast Research and Extension Center (SEREC), the IGR-bolus significantly reduced (P < 0.05) horn fly numbers on both the continuous and rotational graze regimens, resulting in significantly (P < 0.05) greater calf weaning weights (average of 24 kg). Horn fly numbers were significantly greater on untreated cows during the 3-yr study at the Southwest Research and Extension Center (SWREC) compared with the mean fly numbers on cows that received fly-management treatments. All tactics and tactic-combinations used at SWREC on cattle having no Brahman breeding failed to significantly reduce insecticide-resistant horn fly numbers. However, the combination of Brahman breeding with the IGR-Bolus and mechanical trap significantly reduced horn fly numbers and resulted in significant increases in calf weaning weight. In addition, mean horn fly numbers decreased significantly as the percentage Brahman breeding increased with 50% Brahman breeding reducing horn fly numbers by 140 flies per cow. No significant difference was found between the mean fly numbers on the fly-resistant purebred group and the cows that had no Brahman breeding but received the IGR-Bolus or used the mechanical trap. The use of synergized zeta-cypermethrin pour-on treatment successfully complimented the use of IGR-bolus and mechanical traps in reducing insecticide-resistant horn fly numbers. Neither 1.3- nor 3.2-ha size paddocks and stocking rates used in the rotation graze regimens at SEREC and SWREC, respectively, significantly reduced horn fly numbers when compared with continuously grazed paddocks. Data indicated the importance of using tactics that reduce horn fly numbers to approximately 150 horn flies per cow. These data demonstrated the efficacy of using tactic combinations to manage insecticide-resistant horn fly populations.

Winter-annual pasture as a supplement for beef cows

In each of two experiments, 120 pregnant beef cows were stratified by body condition score, BW, breed, and age, randomly divided into six groups of 20, and assigned to one of six 5.1-ha bermudagrass (Cynodon dactylon [L.] Pers.) pastures (two replicates/ treatment) in early January to evaluate the use of winter-annual pasture as a supplement. All cows in Exp. 1 and 2 had ad libitum access to bermudagrass/dallisgrass (Paspalum dilatatum Poir.) hay plus three treatments: 1) a concentrate-based supplement fed 3 d/wk, 2) limit grazing on winter-annual pasture 2 d/wk (7 hr/ d; 0.04 ha x cow(-1) x grazing d(-1)), or 3) limit grazing on winter-annual pasture 3 d/wk (7 hr/d; 0.04 ha x cow(-1) x grazing d(-1)) sod-seeded into a portion of the pasture until mid-May. The seeded portion of pastures in Exp. 1 was planted with a mixture of wheat (Triticum aestivum L.) and rye (Secale cereale L.), but annual ryegrass (Lolium multiflorum Lam.) was added to the seed mixture in Exp. 2. In mid-May, cows were blocked by treatment and the previous sorting factors, randomly assigned to six new groups of 20, and placed on the six perennial pastures until calves were weaned. Groups of cows were exposed to a bull for 60 d beginning in mid-May. In Exp. 1 and 2, limit-grazing winter-annual pasture compared to the concentrate-based supplement or limit grazing 2 vs 3 d/wk did not affect (P > 0.15) cow BW. In Exp. 1, cows limit grazed on winter-annual pasture had a lower (P = 0.05) body condition score than cows fed the concentrate-based supplement in the early spring. However, in Exp. 2, cows limit grazed on winter-annual pasture had higher (P < or = 0.07) body condition score than cows fed the concentrate-based supplement. The conception rate of cows in Exp. 1 and 2 did not differ (P > 0.22) between cows fed concentrate-based supplements and cows limit grazed on winter-annual pasture. In Exp. 2, cows limit grazed 2 d/wk tended to have a greater (P = 0.10) conception rate than cows limit grazed 3 d/wk. In Exp. 1 and 2, birth weight, total gain, BW, and ADG of calves were not affected (P > 0.15) by treatment. We conclude that wheat and rye pasture is a marginal supplement for lactating beef cows. However, cows limit grazed 2 d/wk on winter-annual pasture of wheat, rye, and annual ryegrass as a supplement maintained BW and body condition score as well as cows fed the concentrate-based supplement. But, grazing pasture 3 vs 2 d/wk did not seem to affect performance of cows.

Cutting edge: interactions through the IL-10 receptor regulate autoimmune diabetes

BDC2.5/nonobese diabetic (NOD) transgenic mice express a TCR from a diabetogenic T cell clone yet do not spontaneously develop diabetes at high incidence. Evidence exists showing that in the absence of endogenous TCR alpha-chain rearrangements this transgenic mouse spontaneously develops diabetes and that CTLA-4 negatively regulates diabetes onset. This strongly suggests that onset of diabetes in BDC2.5/NOD mice is governed by T cell regulation. We addressed the mechanism of immune regulation in BDC2.5/NOD mice. We find that activated spleen cells from young, but not old, BDC2.5/NOD mice are able to transfer diabetes to NOD-scid recipients. We have used anti-IL-10R to show that the failure of splenocytes from older mice to transfer diabetes is due to dominant regulation. We furthermore found that diabetes developed following anti-IL-10R treatment of 6-wk old BDC2.5/NOD mice indicating that endogenous IL-10 plays a key role in the regulation of diabetes onset in this transgenic mouse.

Tolerogenic strategies to halt or prevent type 1 diabetes

A variety of therapeutic strategies have been developed to tolerize autoreactive T cells and prevent autoimmune pathology. In terms of type 1 diabetes, prevention strategies can inhibit the priming and expansion of autoreactive T cells; however, a cure for diabetes would require tolerance to be established in the presence of primed effector cells together with replacement of the destroyed beta cell mass. Replacement of beta cells could be accomplished by transplantation of islets or stem cells or through islet regeneration. We will focus here on tolerogenic strategies that have been used to prevent onset of type 1 diabetes and discuss the potential for a cure.

Screening and early detection among racial and ethnic minority women

OBJECTIVES

To highlight sociocultural factors reported to influence and strategies to promote breast and cervical cancer screening and early detection behaviors of racial and ethnic minority women.

DATA SOURCES

Published articles, book chapters, and reports.

CONCLUSIONS

The most successful strategies for promoting screening and early detection among racial and ethnic minority women are collaborative and include approaches that are culturally sensitive and appropriate.

NURSING IMPLICATIONS

Intercultural and intracultural differences in racial and ethnic minority women challenge nurses to explore strategies that focus on the health care provider, the health care delivery system, and the individual woman within the context of the woman's culture.

Qualitative research with diverse populations

OBJECTIVES

To describe the benefits of conducting qualitative research with members of diverse cultures.

DATA SOURCES

Research studies, articles and books on philosophy of science.

CONCLUSIONS

Qualitative research with diverse populations is useful when little research exists on a topic, when there are no reliable and valid instruments for the groups, and when the appropriate language to use or the appropriate concepts and questions to ask are unclear. Participating in research that includes discussing your experiences has also been found to be valuable to those participating.

IMPLICATIONS FOR NURSING PRACTICE

Qualitative studies with diverse groups are needed to understand the concepts that are important to members of these groups, and to guide us in asking the correct questions using correct language.

African American women's experiences with breast cancer screening

PURPOSE

To describe the experience and meaning of breast cancer screening for African American women. Breast cancer screening offers the greatest hope of reducing breast cancer mortality and improving breast cancer outcomes. Despite the proliferation of initiatives targeting African American women, they continue to be first diagnosed only when they have late-stage disease.

DESIGN AND METHODS

Using hermeneutic phenomenological research methods, 23 low- and middle-income African American women were interviewed to gain an understanding of their experiences with breast cancer screening.

FINDINGS

Participants varied in their experiences with breast cancer screening. Women spoke of a desire for a holistic approach to health that did not separate the breast from the rest of the body. This desire is indicated in the theme of minding the body, self, and spirit, along with themes of relationships and spreading the word about breast health issues.

CONCLUSIONS

Interventions for African American women should include a focus on minding the body, self, and spirit to promote breast cancer screening, and should indicate the importance of relationships and spreading the word about breast cancer screening.

Evaluation and management of headache in the emergency department

In the ED, correct diagnosis is the necessary foundation on which specific therapy is based. There is no substitute for obtaining a thorough history and examining the patient competently. Patients with a past history of primary headaches, such as migraine, also may be afflicted with (new) secondary headaches. Although efficiency is desirable from the perspective of ED management, a thoughtful approach complemented by the judicious selection of tests is compatible with that goal as well as achieving the desired outcome of accurate diagnosis and relief of pain. Arrangements for long-term follow-up are important.

The role of justice in team member satisfaction with the leader and attachment to the team

This study examined the effects of team decision accuracy, team member decision influence, leader consideration behaviors, and justice perceptions on staff members' satisfaction with the leader and attachment to the team in hierarchical decision-making teams. The authors proposed that staff members' justice perceptions would mediate the relationship between (a) team decision accuracy, (b) the amount of influence a staff member has in the team leader's decision, and (c) the leader's consideration behaviors and staff attachment to the team and satisfaction with the leader. The results of an experiment involving 128 participants in a total of 64 teams, who made recommendations to a confederate acting as the team leader, generally support the proposed model.

Clinical implications of sex in acute temporomandibular disorders

BACKGROUND

Previous research on temporomandibular disorders, or TMDs, has been somewhat limited, with studies having low numbers of subjects, restricting the focus to women or looking at patients already diagnosed with chronic TMD. Because early intervention is beneficial, it is important to understand the symptoms that men and women have in the acute stage of TMD.

METHODS

A total of 233 patients (161 women, 72 men) with acute TMD symptoms were assessed with a battery of biopsychosocial measures. Patients were diagnosed as having TMD on the basis of research diagnostic criteria, or RDC, or RDC, for TMD. After six months, patients were reassessed to determine whether they continued to have pain, thus classifying them as having chronic TMD. The authors found that 153 patients (47 men, 106 women) had developed a chronic condition, while 80 patients (25 men, 55 women) no longer reported pain (nonchronic).

RESULTS

Female and male patients who developed chronic TMD differed significantly from patients who had acute symptoms that subsided. Women who developed chronic TMD exhibited significantly more psychosocial distress and impairment than women who did not develop chronic TMD, in terms of Diagnostic and Statistical Manual, Fourth Edition, or DSM-IV, diagnoses; Beck Depression Inventory, or BDI, scores; Minnesota Multiphasic Personality Inventory scores; Multidimensional Pain Inventory, or MPI, scores; and physical and psychological measures assessed with the RDC for TMD. Men who developed chronic TMD differed significantly from men who did not develop chronic TMD, in that they exhibited more impairment in terms of DSM-IV diagnoses and BDI and RDC measures.

CONCLUSIONS

These findings provide evidence that significant differences exist between men and women in regard to acute TMD symptoms.

CLINICAL IMPLICATIONS

The biopsychosocial differences between men and women suggest that some treatments may be more beneficial for women than for men.

The role of decision influence and team performance in member self-efficacy, withdrawal, satisfaction with the leader, and willingness to return

This study examines team performance as a moderator of the relationship between decision influence and outcomes relevant to team effectiveness in hierarchical teams with distributed ex pertise. In this type of team staff members have unique roles and make recommendations to the team leader, who ultimately makes the team's final decisions. It is suggested that the positive rela tionship between decision influence and favorable outcomes (e.g., satisfaction) consistently described in the literature is dependent on team performance in this type of team. Specifically, team effec tiveness outcomes are proposed to be consistently more favorable in higher performing than in lower performing teams. Decision influence is proposed to relate positively to member satisfaction with the leader, willingness to return, and self-efficacy and to relate negatively to withdrawal in higher performing teams. The opposite pattern of relationships is expected in lower performing teams. A laboratory study was conducted with 228 undergradu ates performing a computer task as subordinates in 76 four-person teams with a confederate leader. The results generally support the hypotheses and illustrate a dilemma for leaders attempting to manage team effectiveness.

Nondepleting anti-CD4 has an immediate action on diabetogenic effector cells, halting their destruction of pancreatic beta cells

The induction of tolerance in a primed immune system is a major aim for therapy in autoimmunity and transplant rejection. In this paper, we investigate the action of the nondepleting anti-CD4 Ab, YTS 177. Although this Ab is nondepleting, we have demonstrated a direct action in vivo on activated effector cells. We show that the Ab inhibits transfer of insulin-dependent diabetes mellitus by the CD4+ Th1 clone BDC2.5 to nonobese diabetic mice. Furthermore, we show that this Ab acts directly on diabetogenic effector cells because it prevented BDC2.5-induced insulin-dependent diabetes mellitus in nonobese diabetic-scid recipients in the absence of other T cells. The Ab halts the diabetic process even when it is administered after the BDC2.5 cells have infiltrated the pancreas and destruction of islets is already underway. This is accompanied by an immediate decrease in proinflammatory cytokine production with cessation of beta cell destruction and disappearance of infiltrating cells from the pancreas, leaving any remaining beta cells intact. These data suggest that Abs such as this may be effective not only because they induce regulatory T cells but also because they are able to directly prevent effector cell function.

Metallic normal state of Y1Ba2Cu3O(7-delta)

Flux flow was studied over an entire temperature range down to T approximately 2% of T(c) by using intense pulsed current densities to overcome flux-vortex pinning. The resistivity at high vortex velocities is proportional to B and roughly follows rho approximately rho(n)B/H(c2), with a prefactor of order unity. Contrary to some speculation, rho(n) saturates to a finite residual value as T-->0, indicating a metallic (rho-->finite) rather than insulating (rho-->infinity) normal state, and the vortex dissipation continues to be conventional as T-->0.

Cholinergic neurotransmission influences covert orientation of visuospatial attention in the rat

RATIONALE

Both monkey and human studies have suggested that attentional orienting may be mediated by the cholinergic neurotransmitter system.

OBJECTIVES

The purpose of the present study was to examine whether the cholinergic agonist (nicotine) and/or antagonist (scopolamine) influence covert orientation in the rat.

METHODS

Rats carried out a visual reaction time task to measure covert orienting of attention following systemic administration of nicotine or scopolamine.

RESULTS

Nicotine reduced reaction times, abolishing the validity effect by differentially speeding the reaction times for invalidly cued targets. Conversely, scopolamine increased the validity effect by disproportionately lengthening reaction times to invalidly cued targets.

CONCLUSIONS

Taken together, these data indicate that cholinergic transmission represents an important neurochemical substrate of visuospatial attention, specifically influencing disengagement or movement of attention.

Anticipatory errors after unilateral lesions of the subthalamic nucleus in the rat: evidence for a failure of response inhibition

The nature of anticipatory responding in rats with unilateral subthalamic nucleus lesions was examined. Rats were trained to respond toward visual targets that were preceded by 1 of 4 different cues. For normal rats, a cue invokes an involuntary attentional orienting that enhances processing of the target at the location of attention. The cue is also a salient stimulus to which a response must be suppressed. Therefore, this task was used to investigate possible attentional impairments, as well as the ability of a lesioned rat to suppress competing motor programs. Responding under target control was not affected by the lesion. There was an increase in anticipatory responses before target onset, which could be accounted for by a failure to inhibit contralateral responses.

Anticipatory errors after unilateral lesions of the subthalamic nucleus in the rat: evidence for a failure of response inhibition

The nature of anticipatory responding in rats with unilateral subthalamic nucleus lesions was examined. Rats were trained to respond toward visual targets that were preceded by 1 of 4 different cues. For normal rats, a cue invokes an involuntary attentional orienting that enhances processing of the target at the location of attention. The cue is also a salient stimulus to which a response must be suppressed. Therefore, this task was used to investigate possible attentional impairments, as well as the ability of a lesioned rat to suppress competing motor programs. Responding under target control was not affected by the lesion. There was an increase in anticipatory responses before target onset, which could be accounted for by a failure to inhibit contralateral responses.

Shaping a research agenda for the African-American community: issues and opportunities

Building on a previously published NBNA article, this article emphasizes the continuing need for African-American nurses to be actively involved in shaping a research agenda for improving the health and well-being of the African-American community. Thus, this article briefly highlights implications for research targeting African-Americans and summarizes selected information on the National Institute of Nursing Research (NINR). As the National Black Nurses Association and its members continue to develop, implement, and evaluate a research agenda targeting African-Americans, they are encouraged to explore opportunities for research training and career development provided through the National Institute of Nursing Research (NINR).

Phase I study of an engineered aglycosylated humanized CD3 antibody in renal transplant rejection

BACKGROUND

The potential therapeutic benefits of CD3 monoclonal antibodies, such as OKT3, have been limited by their immunogenicity and their propensity to activate a severe cytokine release syndrome. This has constrained the clinical use of OKT3 to the treatment of acute rejection episodes of organ allografts.

METHODS

We have humanized a rat CD3 antibody and created a single amino acid substitution in position 297 of the IgG1 heavy chain to prevent glycosylation and, consequently, binding of the therapeutic antibody to Fc receptors and to complement. This antibody has been given as first line antirejection therapy in nine kidney transplant recipients with biopsy-proven acute rejection episodes.

RESULTS

None of the patients demonstrated any antiglobulin response nor any significant cytokine release syndrome. Seven of the nine showed evidence of resolution of their rejection, although some patients experienced re-rejection.

CONCLUSIONS

These findings suggest that CD3 antibodies can be engineered to lose their toxicity while retaining their potency as immunosuppressants. Nonactivating humanized CD3 monoclonal antibodies now merit further investigation in the management of transplant patients and in therapy of autoimmune diseases.

Attentional orienting is impaired by unilateral lesions of the thalamic reticular nucleus in the rat

The thalamic reticular nucleus (TRN) has been implicated in attentional processes based on its anatomical, electrophysiological, and neurochemical relationships with the sensory nuclei of the thalamus and corresponding sensory areas of cortex. This study examined the possibility that the TRN is involved in covert orienting of attention. Attention can be summoned to a spatial location in the absence of an overt orienting response. The reaction time to a visual target is faster when attention has been drawn to the location of the target by a preceding cue in that location (valid cue) compared with when the cue misdirects attention (invalid cue) away from the location of the subsequent target. This reaction time difference is referred to as the "validity effect." Rats were trained to perform such a reaction time task with visual cues and targets presented in poke holes to either side of the rat's head, which had to be maintained centrally and still. If the rat made an overt orienting response to the cue, the trial was aborted. Unilateral lesions were made by injection of ibotenic acid in the TRN. After surgery, there was no bias apparent in their responding; they were as likely to initiate responses and were equally accurate to either side. There was, however, a complete abolition of the validity effect for responses to contralateral targets. The data are discussed in terms of a role for the TRN in attentional processing.

Pregnancy loss rates following second trimester genetic amniocentesis

Data from 3,953 consecutive second trimester genetic amniocenteses were analysed to determine pregnancy loss rates up to 6 weeks after the procedure. Information was prospectively collected on a cohort of 3,685 women in 3,896 singleton and 50 twin pregnancies, from 2 operating sites in Perth, Western Australia, using 9 operators over the 6-year period, 1989 to 1995. Complete information regarding pregnancy outcome was obtained for 3,643 of the 3,685 women (98.9%). There were 27 identified singletons and 1 set of twins lost within 6 weeks following amniocentesis. The overall pregnancy loss rate in this cohort was 29 of 3,911 (0.74%). The pregnancy loss rate associated with genetic amniocentesis is not excessive in comparison to the calculated background pregnancy loss rate of 1%, and it is suggested that each prenatal diagnostic team should determine their own complication rates for the purpose of counselling prior to amniocentesis.

Breast cancer screening and African American women: fear, fatalism, and silence

PURPOSE/OBJECTIVES

To explore the beliefs, attitudes, and practices related to breast cancer and breast cancer screening among low- and middle-income African American women.

DESIGN

Qualitative study using focus group methodology.

SAMPLE/SETTING

26 African American women, age 40-65, selected from three employment groups, recruited from a community-based center and a local teacher's union in a moderate-sized urban area.

METHODS

Three 90-minute focus group discussions exploring breast cancer beliefs, attitudes, and practices were audiotaped, transcribed verbatim, and analyzed using thematic context analysis techniques.

FINDINGS

When breast cancer was discussed, fear was the predominant feeling expressed in all groups. This fear was a primary reason not to engage in breast cancer screening. Unemployed women and service workers emphasized the role of violence in causing breast cancer, whereas teachers discussed injury and sex as causing breast cancer. All participants stressed that breast cancer is seldom discussed within the African American community. Teachers added that this secrecy within the African American community leads to breast cancer being viewed as a white woman's disease.

CONCLUSIONS

Despite initiatives promoting breast cancer awareness. African American women still hold misconceptions regarding the etiology of breast cancer and fatalistic perspectives regarding breast cancer outcomes, perhaps because breast cancer is discussed infrequently. Because pain, fear, and fatalism were discussed in all groups, future research should address the influence of these factors to increase screening behaviors.

IMPLICATIONS FOR NURSING PRACTICE

Because unemployed women, service workers, and teachers differed in their beliefs about breast cancer and breast cancer screening, nurses must be mindful of the need to tailor Interventions to address the needs of both low- and middle-income African American women.

Both CD4(+) T cells and CD8(+) T cells are required for iodine accelerated thyroiditis in NOD mice

The nonobese diabetic (NOD) mouse, a spontaneous animal model for insulin-dependent diabetes mellitus, displays a tendency in common with human diabetic populations to develop autoimmune thyroiditis although incidence and severity of thyroid lesions vary widely among different colonies around the world. A congenic strain of NOD mice bearing I-Ak on a NOD background (NOD-H2(h4)) has recently been derived and displays a much greater tendency to develop thyroiditis and autoantibodies to mouse thyroglobulin (MTg) although it is free of diabetes. Both thyroid infiltrates and autoantibody formation are accelerated and enhanced in NOD-H2(h4) mice by increased iodine intake. The effect of increased iodine intake on NOD mice themselves has not been directly investigated although a recent study of these animals given high or low doses of iodine showed no follicular destruction unless the mice were first rendered goitrous by iodine deprivation. We found that dietary iodine increased both the incidence and the severity of thyroid lesions in our NOD mice although autoantibodies to MTg were absent. NOD background genes appear to be essential for the development of these lesions, which were maximal after 4 weeks of iodine administration and showed no significant regression when the iodine was stopped. Furthermore, our studies show for the first time that both CD4(+) and CD8(+) T cells are necessary for the development of this accelerated but essentially spontaneous murine thyroid disease.

Antecedents of Leader Utilization of Staff Input in Decision-Making Teams

The purpose of this experiment was to explore the possibility that the inconsistent findings of Brehmer and Hagafors (1986, Organizational Behavior and Human Decision Processes, 38, 181-195), Sniezek and Buckley (1995, Organizational Behavior and Human Decision Processes, 62, 159-174), and leader-member exchange research regarding leaders' propensity to differentially and accurately weight staff input can be explained as a result of experience, the availability to the leader of staff member judgment confidence, and the cumulative past accuracy of each staff member. The availability to the team leader of staff member past judgment accuracy and staff member judgment confidence was provided in an environment in which differential staff weighting was the appropriate staff utilization strategy. Eighty-four leaders of four-person decision-making teams performed 63 decisions on a computerized decision-making task. Both experience and providing leaders with cumulative staff past accuracy information were related to greater staff weighting variability and greater staff weighting accuracy. Although positively related to staff weighting, staff confidence information did not improve leader weighting variability nor actual staff weighting accuracy. Copyright 1999 Academic Press.

Influence of arm positioning on rest/stress technetium-99m labeled sestamibi tomographic myocardial perfusion imaging

BACKGROUND

Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is routinely performed with patients' arms positioned above their heads to avoid potential attenuation artifact and reduced image quality. Currently no data are available to support the use of this practice using 99mTc SPECT MPI:

METHODS AND RESULTS

Forty-one patients referred for routine rest/stress MPI were imaged using the standard protocol with arms positioned above their heads and again with their arms at their sides. The patients were injected with 10 to 45 mCi (370 to 1665 MBq) of 99mTc-labeled sestamibi (99mTc-sestamibi), and SPECT images were acquired 30 to 90 minutes later. Thirty patients were imaged on an ADAC Vertex dual-head camera and 11 patients on an ADAC Cirrus single-head camera. Images were interpreted by 3 nuclear cardiologists without knowledge of patient identity, arm position, or camera type using a 17-segment scoring model. No significant differences were noted in the percentage of abnormal study results, reversibility extent, or location of MPI defects between the 2 arm positions in the same patients. Image quality was also similar.

CONCLUSION

Arm positioning does not influence the interpretation of 99mTc-sestamibi SPECT myocardial perfusion imaging with regard to image quality or defect location and extent.

Reaction time performance following unilateral striatal dopamine depletion and lesions of the subthalamic nucleus in the rat

The akinesia resulting from Parkinson's disease or striatal dopamine depletion in experimental animals can be ameliorated or reversed by inactivation of the subthalamic nucleus. This inactivation might be effective by restoring balance to the basal ganglia motor circuits. Alternatively, new movement-related deficits might be introduced which mask the original impairments (e.g. hyperkinesia might replace hypokinesia). In the present study, striatal dopamine depletion was effected unilaterally, in order to dissociate generalized effects, e.g. hyperkinesia, from response-specific initiation effects. Rats were trained in a lateralized visual reaction time task and then assigned to one of four groups: striatal dopamine depletion; cell body lesion of the subthalamic nucleus; combined striatal dopamine depletion and subthalamic nucleus lesion; or control. As expected, rats with striatal dopamine depletion exhibited slower reaction time and a bias to respond to the ipsilateral side. The subthalamic nucleus lesion resulted in no reaction time change (in particular, there was no evidence of faster reaction times), but there was an increase in anticipatory responding. The group with the combined striatal dopamine depletion and subthalamic nucleus lesion had no reaction time impairment. This group showed an increase in anticipatory errors and a contralateral response bias. These data demonstrate that lesions of the subthalamic nucleus do not merely cancel the akinesia which follows striatal dopamine depletion by the addition of a hyperkinetic impairment. Rather, there appears to be a change in the balance of the motor system.

Prenatal diagnosis of hepatic mesenchymal hamartoma

A case of hepatic mesenchymal hamartoma diagnosed prenatally with ultrasound and confirmed histologically post-delivery is presented. Although histologically benign, this lesion resulted in fetal demise secondary to congestive cardiac failure in the third trimester. The development of non-immune hydrops in association with a fetal hepatic mesenchymal hamartoma is a poor prognostic sign for perinatal survival.

Effect of subcutaneous granulocyte colony-stimulating factor injectate volume on drug efficacy, site complications, and client comfort

PURPOSE/OBJECTIVES

To determine the effect of administering 1.6 ml (480 mcg) of granulocyte colony-stimulating factor (G-CSF) in one subcutaneous injection or two injections of 0.8 ml each.

DESIGN

Experimental.

SETTING

27-bed bone marrow transplant intensive care unit of a metropolitan, university medical center in the southwestern United States.

SAMPLE

Nonprobability; 76 women who received high-dose chemotherapy for breast cancer followed by hemopoietic rescue.

METHODS

Subjects were randomized into an experimental group that received one injection per 480 mcg dose and a control group that received two injections per 480 mcg dose administered by research associates using a standardized injection technique.

MAIN RESEARCH VARIABLES

Injectate volume. The number of days post-transplant until the absolute neutrophil count (ANC) returned to 1,000/mm3, the incidence and surface area in mm2 of site complications, and scores on Tursky's Quantified Pain Descriptor immediately following the injection(s).

FINDINGS

No significant difference existed between the two groups in ANC recovery time, frequency or size of site complications, or intensity, reaction, or sensation of discomfort reported.

CONCLUSIONS

Administering 1.6 ml doses of G-CSF in one injection instead of two does not result in slower ANC recovery, induration, more frequent or larger bruises or areas of erythema, or greater client discomfort.

IMPLICATIONS FOR NURSING PRACTICE

Administering one injection instead of two may decrease patients' anxiety, the nursing time needed for preparation and administration of injections, patient instruction for self-administration, the potential for contamination of vials or loss of dose, and the cost of supplies.

Integrating cancer risk assessment into a community health nursing course

BACKGROUND

Because the state of Maryland has the fourth highest cancer death rate among the states and the District of Columbia, a community-based hospital identified the need to develop a cancer prevention, screening, and education program for the community at large and the employees. Subsequently, as a prerequisite for graduation, Community Health Nursing Students (CHN) conducted a project with the goal of assessing hospital employee cancer risk status and presenting a hospital-based cancer education program.

METHOD

Data regarding employee cancer risk status were gathered using a modified 31-item cancer-risk-assessment guide; risk factors for cancers of the lung, colon-rectum, skin, prostate, breast, and cervix were identified.

RESULTS

Overall, the employees were at a high to moderate risk of developing cancers of the cervix, followed by cancers of the skin and breast, and at lowest risk of developing cancer of the lung, followed by cancers of the prostate and colon-rectum.

CONCLUSION

The findings provided baseline data for the development of employee-focused cancer education and screening programs.

Thymus-dependent monoclonal antibody-induced protection from transferred diabetes

It is well established that long-term protection from insulin-dependent diabetes mellitus (IDDM) can be afforded to non-obese diabetic (NOD) mice by a short course of non-depleting (nd) anti-CD4 monoclonal antibodies (mAb). Since it is increasingly apparent that the CD8+ T cell plays a prominent role in the development of IDDM, we have investigated the effect of an anti-CD8 mAb (YTS 105) of the same isotype in both spontaneous and induced IDDM in NOD mice. Treatment with YTS 105 for 3 weeks was able to prevent the transfer of IDDM for a long period, and also substantially reduced spontaneous IDDM in female NOD mice. The role of the thymus in tolerance induction by these antibodies was studied. In the adult transfer model, thymectomized NOD mice, unlike their euthymic counterparts, were not protected long-term by treatment with YTS 105, and began to become overtly diabetic shortly after treatment. This was also true when the nd anti-CD4 mAb was used. Protection from spontaneous disease was not affected in the same way by thymectomy. The reasons for the observed effect of the thymus in the transfer model, and the differences between the two models that may explain the contrasting results are discussed.

Clinical assessment of asymptomatic knees: comparison of men and women

Two hundred ten adults, 100 women and 110 men, were recruited on the condition of always having asymptomatic knee joints. These recruits were initially solicited by newspaper advertisement. The women were recruited in 3 weeks, but additional efforts and 3 months were necessary to assemble the group of men. The volunteers underwent a uniform comprehensive medical history questionnaire, physical examination, and plain film radiographs. The data collected were subjected to computerization and statistical analysis. Although these subjects were always asymptomatic, only 4.5% of 200 women's knees and 21% of 220 men's knees had no "positive" physical findings. The findings of hypermobile patella, patellar crepitus, and lateral patellar position on Merchant x-ray view were common. Findings not present or infrequent in these asymptomatic subjects and potentially pathological were patellar J-sign, decreased range of motion, asymmetrical ligamentous laxity, McMurray's sign, compartmental crepitus, and severe degenerative arthritis or loose bodies on radiograph. The findings in women were different from those observed in men. This gender-specific information should be helpful in patient management but also useful and timely for establishing practice guidelines, treatment algorithms, and outcome study instruments.

Chromosomal instability is correlated with telomere erosion and inactivation of G2 checkpoint function in human fibroblasts expressing human papillomavirus type 16 E6 oncoprotein

Cell cycle checkpoints and tumor suppressor gene functions appear to be required for the maintenance of a stable genome in proliferating cells. In this study chromosomal destabilization was monitored in relation to telomere structure, lifespan control and G2 checkpoint function. Replicative senescence was inactivated in secondary cultures of human skin fibroblasts by expressing the human papillomavirus type 16 (HPV-16) E6 oncoprotein to inactivate p53. Chromosome aberrations were enumerated during in vitro aging of isogenic control (F5neo) and HPV-16E6-expressing (F5E6) fibroblasts. We found that structural and numerical aberrations in chromosomes were significantly increased in F5E6 cells during aging in vitro and fluorescence in situ hybridization (FISH) analysis using chromosome-specific probes demonstrated the occurrence of rearrangements involving chromosome 4 and 6 in genetically unstable F5E6 cells. Flow cytometry and karyotypic analyses revealed increased polyploidy and aneuploidy in F5E6 cells only at passages > 16, although these cells displayed defective mitotic spindle checkpoint function associated with inactivation of p53 at passages 5 and 16. G2 checkpoint function was confirmed to be gradually but progressively inactivated during in vitro aging of E6-expressing cells. Aging of F5neo fibroblasts was documented during in vitro passaging by induction of a senescence-associated marker, pH 6.0 lysosomal beta-galactosidase. F5E6 cells displayed extension of in vitro lifespan and did not induce beta-galactosidase at high passage. Erosion of telomeres during in vitro aging of telomerase-negative F5neo cells was demonstrated by Southern hybridization and by quantitative FISH analysis on an individual cell level. Telomeric signals diminished continuously as F5neo cells aged in vitro being reduced by 80% near the time of replicative senescence. Telomeric signals detected by FISH also decreased continuously during aging of telomerase-negative F5E6 cells, but telomeres appeared to be stabilized at passage 34 when telomerase was expressed. Chromosomal instability in E6-expressing cells was correlated (P < 0.05) with both loss of telomeric signals and inactivation of G2 checkpoint function. The results suggest that chromosomal stability depends upon a complex interaction among the systems of telomere length maintenance and cell cycle checkpoints.

Excitotoxic lesions of the subthalamic nucleus ameliorate asymmetry induced by striatal dopamine depletion in the rat

We investigated the effect of unilateral dorsal striatal dopamine depletion (by intrastriatal infusion of 6-OHDA), ibotenic acid lesions of the subthalamic nucleus (STN) and combined dopamine depletion and STN lesions on sensorimotor asymmetry using a test of somatosensory asymmetry [T. Schallert et al., Pharmacol. Biochem. Behav. 16 (1982) 455-462]. The unilateral striatal dopamine depletion resulted in a somatosensory asymmetry. This asymmetry was ameliorated in the rats with combined dopamine depletion and STN lesion. indicating the potential beneficial nature of STN inactivation in rats with striatal dopamine depletion.

alpha-Cell neogenesis in an animal model of IDDM

Currently there is debate regarding the capacity of pancreatic islets to regenerate in adult animals. Because pancreatic endocrine cells are thought to arise from duct cells, we examined the pancreatic ductal epithelium of the diabetic NOD mouse for evidence of islet neogenesis. We have evidence of duct proliferation as well as ductal cell differentiation, as suggested by bromodeoxyuridine-labeling and the presence of glucagon-containing cells within these ducts. In addition, the ductal epithelia in diabetic NOD mice expressed the neuroendocrine markers neuropeptide Y and tyrosine hydroxylase. These ducts also expressed the homeobox gene product, insulin promoter factor 1. Ductal cell proliferation and expression of these markers was not observed in transgenic NOD mice (NOD-E), which do not develop clinical or histopathological symptoms of IDDM. This suggests that the observed ductal cell proliferation and differentiation was a direct result of beta-cell destruction and insulin insufficiency in these adult diabetic mice, which further suggests that these events are recapitulating islet ontogeny observed during embryogenesis. It is possible that comparable processes occur in the human diabetic pancreas.