HIV prevalence, risk behaviors, health care use, and mental health status of transgender persons: implications for public health intervention

OBJECTIVES

This study described HIV prevalence, risk behaviors, health care use, and mental health status of male-to-female and female-to-male transgender persons and determined factors associated with HIV.

METHODS

We recruited transgender persons through targeted sampling, respondent-driven sampling, and agency referrals; 392 male-to-female and 123 female-to-male transgender persons were interviewed and tested for HIV.

RESULTS

HIV prevalence among male-to-female transgender persons was 35%. African American race (adjusted odds ratio [OR] = 5.81; 95% confidence interval [CI] = 2.82, 11.96), a history of injection drug use (OR = 2.69; 95% CI = 1.56, 4.62), multiple sex partners (adjusted OR = 2.64; 95% CI = 1.50, 4.62), and low education (adjusted OR = 2.08; 95% CI = 1.17, 3.68) were independently associated with HIV. Among female-to-male transgender persons, HIV prevalence (2%) and risk behaviors were much lower. Most male-to-female (78%) and female-to-male (83%) transgender persons had seen a medical provider in the past 6 months. Sixty-two percent of the male-to-female and 55% of the female-to-male transgender persons were depressed; 32% of each population had attempted suicide.

CONCLUSIONS

High HIV prevalence suggests an urgent need for risk reduction interventions for male-to-female transgender persons. Recent contact with medical providers was observed, suggesting that medical providers could provide an important link to needed prevention, health, and social services.

The Circuit Party Men's Health Survey: findings and implications for gay and bisexual men

OBJECTIVES

This study examined characteristics of gay and bisexual men who attend circuit parties, frequency of and motivations for attending parties, drug use and sexual behavior during circuit party weekends, and use of risk reduction materials available at parties.

METHODS

A cross-sectional survey was conducted among 295 gay and bisexual men from the San Francisco Bay Area who had attended a circuit party in the previous year.

RESULTS

One fourth of the men reported a drug "overuse" incident in the previous year. Nearly all respondents reported use of drugs during circuit party weekends, including ecstasy (75%), ketamine (58%), crystal methamphetamine (36%), gamma hydroxybutyrate or gamma butyrolactone (25%), and Viagra (12%). Two thirds of the men reported having sex (oral or anal), 49% reported having anal sex, and 28% reported having unprotected anal sex during the 3-day period. An association was found between use of drugs and sexual risk behavior. Prevention materials were observed at party events by some men; however, relatively few men used the materials. Common motivations for attending the parties were "to listen to music and dance" and "to be with friends."

CONCLUSIONS

Intensive, targeted health promotion efforts are needed for gay and bisexual men who attend circuit parties.

Drug use and sexual risk behavior among gay and bisexual men who attend circuit parties: a venue-based comparison

CONTEXT

HIV risk behavior among urban gay/bisexual men has recently increased. High-risk sexual activity and drug use may be particularly high during circuit party (CP) weekends, during which gay/bisexual men congregate for social activities and dancing.

OBJECTIVES

To compare prevalence of risk behaviors during CP weekends with those during non-CP weekends.

DESIGN

Cross-sectional study.

PARTICIPANTS

295 gay/bisexual men from the San Francisco Bay Area.

MAIN OUTCOME MEASURES

Drug use and sexual risk behavior during a San Francisco CP weekend, a CP weekend held in another geographic area (distant weekends), and two non-CP weekends.

RESULTS

During their most recent distant CP weekend, 80% of participants used methylenedioxymethamphetamine (ecstasy), 66% ketamine, 43% crystal methamphetamines, 29% gamma-hydroxybutyrate or gamma-butyrolactone (GHB/GBL), 14% sildenafil (Viagra), and 12% amyl nitrites (poppers); 53% used four or more drugs. Drug use prevalence was greater during CP than non-CP weekends ( p <.001). Unprotected anal sex with partners of unknown or opposite HIV serostatus was most prevalent during distant CP weekends, reported by 21% of HIV-positive and 9% of HIV-negative participants. In multivariate analysis, predictors of unprotected anal sex with opposite or unknown HIV serostatus partners included being HIV-positive (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4-7.5), and weekend use of crystal methamphetamines (OR 2.4; 95% CI, 1.1-4.9), sildenafil (OR, 3.8; 95% CI, 2.0-7.3), and amyl nitrites (OR, 2.2; 95% CI, 1.3-4.0).

CONCLUSIONS

Prevalence of high-risk activity during these weekends suggests significant potential for HIV transmission in this population. Public health programs in communities hosting CPs should aim to reduce rates of drug use and sexual risk behavior among CP participants, especially HIV-positive men.

Tuberculous mycotic aneurysm of the aorta: review of published medical and surgical experience

To define the epidemiology, pathogenesis, pathology, presentation, and management of tuberculous mycotic aneurysm of the aorta (TBAA) in the therapeutic era, we reviewed all of the cases reported in the English language literature from 1945 to the present. To the 39 cases in the published literature, we add two cases of our own. Although it is exceedingly rare, the prevalence of this lesion has remained relatively constant. In 75% of the cases, TBAA appeared to result from erosion of the aortic wall by a contiguous focus; 25% from direct seeding of the aortic intima or of the adventitia or media (via the vasa vasorum). Most of the aneurysms were saccular (90%) and false (88%). The thoracic and abdominal aortas were affected with equal frequency. The mean (+/- SD) age of the patients was 50+/-16 years. Twenty-two were men, and 19 were women. In 63% of the cases, tuberculosis (TB) was diagnosed at presentation. Disseminated TB was present in 46% of the cases. One or more of three clinical scenarios suggested TBAA: persistent pain, major bleeding, and a palpable or radiographically visible para-aortic mass, especially if it is expanding or pulsatile. In turn, each of these findings suggested a complication of TBAA that may be an indication for surgical intervention. Among the patients who were offered both medical and surgical treatment, 20 of 23 (87%) survived. Among those who were offered only one form of treatment or were offered no treatment at all there were no survivors. Both in situ reconstruction with a prosthetic graft, and extra-anatomic bypass appeared to offer excellent results, provided that an effective regimen of antituberculous drugs was delivered postoperatively. We offer our conclusions: (1) symptomatic TBAA is a rare but uniformly fatal lesion if not diagnosed promptly, (2) in the context of active TB, and especially miliary TB, TBAA should be suspected whenever one or more of the three clinical scenarios are present, and (3) combined medical and surgical therapy appears to offer the best chance of a cure.

Sustained growth and three-dimensional organization of primary mammary tumor epithelial cells embedded in collagen gels

We have developed a method for embedding cells within a collagen matrix which allows sustained growth of mouse mammary tumor epithelial cells in primary culture. A characteristic and reproducible pattern of organization and growth occurs: the cells rearrange themselves and produce duct-like structures extending into the matrix, resulting in a three-dimensional outgrowth. Autoradiography showed continuous [3H]thymidine incorporation during 8 weeks in culture. An increase in DNA content of the cultured cells as a function of time was observed. Mouse mammary tumor cells cultured in the conventional monolayer system failed to show any significant increase in cell number during a culture period of 6 weeks. In addition, in such monolayer systems, cells progressively became detached from the dishes in long-term culture. The mammary epithelial cell origin of the collagen gel cell outgrowths was shown by electron microscopic demonstration of polarized cells containing tight junctions and budding mammary tumor virus particles. In addition, in vivo transplantation of collagen gel outgrowths resulted in the development of mammary adenocarcinoma histologically similar to the donor tumor. Cellular outgrowth patterns resembling those from tumor cells were also seen in similar collagen gel cultures of normal mammary cells from mouse and human and of hyperplastic alveolar nodule cells from mouse. The significance and usefulness of this system in comparison to the conventional monolayer system are discussed.

Can communities and academia work together on public health research? Evaluation results from a community-based participatory research partnership in Detroit

This article reports the results of a formative evaluation of the first 4 years of the Detroit Community-Academic Urban Research Center (URC), a community-based participatory research partnership that was founded in 1995 with core funding from the Centers for Disease Control and Prevention (CDC). Several organizations are members of this partnership, including a university, six community-based organizations, a city health department, a health care system, and CDC. The Detroit URC is a strong partnership that has accomplished many of its goals, including the receipt of over $11 million in funding for 12 community-based participatory research projects during its initial 4 years. Detroit URC Board members identified a number of facilitating factors for their growth and achievements, such as (1) developing a sound infrastructure and set of processes for making decisions and working together, (2) building trust among partners, (3) garnering committed and active leadership from community partners, and (4) receiving support from CDC. Board members also identified a number of ongoing challenges, including organizational constraints, time pressures, and balancing community interests in interventions and academic research needs. Overall, the Detroit URC represents a partnership approach to identifying community health concerns and implementing potential solutions.

Methamphetamine and sildenafil (Viagra) use are linked to unprotected receptive and insertive anal sex, respectively, in a sample of men who have sex with men

OBJECTIVES

There is evidence that methamphetamine and sildenafil (Viagra) use are associated with sexual risk behaviour among men who have sex with men (MSM). We investigated the association of methamphetamine, sildenafil, and other substance use with unprotected receptive and insertive anal sex among MSM by conducting an encounter specific analysis.

METHODS

Data were from a cross sectional, community based survey of MSM in San Francisco regarding behaviour during their most recent anal sex encounter. Mulitvariate regression analysed independent associations of specific substance use and demographic variables with unprotected anal sex behaviours.

RESULTS

The sample (n = 388) was diverse in race/ethnicity, age, income, education, HIV status, and homosexual/bisexual identification. More than half (53%) reported unprotected anal sex, including insertive (29%) and receptive (37%) during their most recent anal sex encounter; 12% reported unprotected insertive and 17% reported unprotected receptive anal sex with an HIV discordant or unknown partner. Methamphetamine was used by 15% and sildenafil was used by 6% of the men before or during the encounter; 2% used both drugs. In multivariate analysis controlling for demographic factors and other substance use, methamphetamine use was associated with unprotected receptive (odds ratio (OR), 2.03; 95% confidence interval (CI), 1.09 to 3.76) and sildenafil use was associated with unprotected insertive (OR, 6.51; CI, 2.46 to 17.24) anal sex. Effects were stronger with HIV discordant or unknown sex partners specifically.

CONCLUSION

Encounter specific associations of methamphetamine and sildenafil use with unprotected receptive and insertive anal sex, respectively, indicate the importance of assessment specificity and tailoring risk reduction efforts to address certain drugs and sexual behavioural roles among MSM.

Sustained growth in primary culture of normal mammary epithelial cells embedded in collagen gels

Normal mammary epithelial cells from BALB/cfC3H midpregnant mice were freed from stromal cell types by Percoll density gradient centrifugation after collagenase digestion and were then embedded within collagen gels. Sustained growth leading to an increase in cell number was accomplished in response to cholera toxin and high concentrations of horse serum. The extent of growth was found to be dependent on the horse serum concentration, the maximum growth being attained at 50%. A serum concentration of 12.5% horse serum and 2.5% fetal calf serum, along with cholera toxin at 0.01 mug/ml, allowed maintenance but failed to cause any significant increase in cell number during the experimental period of 2 weeks. This same maintenance medium was used to determine the effects of various exogenously added steroids, protein hormones, and organ extracts on the proliferation of mammary epithelial cells in culture. Hormones failed to elicit any proliferative response, but extracts of kidney, brain, uterus, and spleen produced proliferative responses equal to or greater than the response obtained with 50% horse serum and cholera toxin. Kidney extracts prepared from midpregnant mice, virgin mice, and virgin mice given pituitary isografts all showed comparable activities, suggesting that the concentration of stimulatory factor(s) was not influenced by the hormonal status of the donor. Normal mammary epithelial cells that had undergone a 10- to 15-fold increase in cell number over initial values during 2-3 weeks in culture were passaged to secondary gel cultures. Outgrowth similar to those seen in primary culture were seen again in secondary culture. The present system provides a method for sustaining growth in culture of primary mammary epithelial cells from normal tissues.

Growth factor- and cyclic nucleotide-induced proliferation of normal and malignant mammary epithelial cells in primary culture

Sustained growth of normal mouse mammary epithelial cells in primary culture, leading to an increase in cell number, in response to growth factors [epidermal growth factor (EGF) and fibroblast growth factor (FGF)] or cholera toxin has been achieved by embedding the cells inside collagen cells. Inclusion of agents known to increase the level of cellular cAMP have been found to be favorable for mammary epithelial cell proliferation. Cholera toxin is by far the best of all of the agents tested (prostaglandins E1 and E2, isoproterenol, theophylline, and dibutyryl cAMP). When growth factors (EGF or FGF) are added with cholera toxin, a synergistic effect resulting in a response much greater than with either of them alone is seen. This synergism was best seen in normal mammary epithelial cells from nonpregnant mice. The extent of this synergistic effect was found to be less in normal cells from pregnant mice, suggesting that these cells may be less responsive to EGF during pregnancy. Tumor cells were found to be rather inconsistent in their responses to EGF and cholera toxin, ranging from a minimal response, similar to that of normal cells from pregnant animals, to a maximal response, similar to that of normal cells from nonpregnant animals.

Diffusion-weighted mr in cerebral venous thrombosis

The diagnosis of cerebral venous thrombosis is often difficult both clinically and radiologically and until now there is no method available to predict if brain lesions, detected clinically and using conventional brain imaging methods, may lead to full recovery, as expected in vasogenic edema or ischemic infarcts and even a hematoma. New fast neuroimaging techniques such as diffusion-weighted imaging (DWI) are sensitive to different reasons of changes in local tissular water concentration thus giving further insight into the pathophysiological mechanism as well as prognosis of cerebral venous thrombosis. We report the cases of 18 consecutive patients with a diagnosis of cerebral venous thrombosis based on clinical and imaging criteria. All patients underwent magnetic resonance imaging (MRI) of the brain, which comprised isotropic diffusion-weighted MR. Diffusion-weighted MRI showed positive findings in 17/18 cases. In 7 cases the clot could be directly visualized as an area of hyperintensity in the affected vein on DWI. In 7 cases DWI showed areas of signal loss corresponding to hematomas. In 6 cases DWI showed changes in signal intensity that were more subtle. In 4 cases of superficial venous thrombosis, there were areas of decreased ADC values (0.65-0.79 x 10(-3) mm(2)/s) whereas in 2 cases of deep venous thrombosis, increased DWI intensities could be found that corresponded to both an increase and a decrease in ADC, corresponding to a coexistence of cytotoxic and vasogenic edemas. Diffusion-weighted MRI can demonstrate directly the presence of an intravenous clot in a select number of patients. It can also demonstrate early ischemic changes, and can differentiate conventional T2-weighted MR areas of cytotoxic from vasogenic edema.

Relation between directly detected patent foramen ovale and ischemic brain lesions in sport divers

BACKGROUND

In divers, the significance of a patent foramen ovale and its potential relation to paradoxical gas emboli remain uncertain.

OBJECTIVE

To assess the prevalence of symptoms of decompression illness and ischemic brain lesions in divers with regard to the presence of a patent foramen ovale.

DESIGN

Retrospective cohort study.

SETTING

University hospital and three diving clubs in Switzerland.

PARTICIPANTS

52 sport divers and 52 nondiving controls.

MEASUREMENTS

Prevalence of self-reported decompression events, patent foramen ovale on contrast transesophageal echocardiography, and ischemic brain lesions on magnetic resonance imaging.

RESULTS

The risk for decompression illness events was 4.5-fold greater in divers with patent foramen ovale than in divers without patent foramen ovale (risk ratio, 4.5 [95% CI, 1.2 to 18.0]; P = 0.03). Among divers, 1.23 +/- 2.0 and 0.64 +/- 1.22 ischemic brain lesions per person (mean +/- SD) were detected in those with and those without patent foramen ovale, respectively. Among controls, 0.22 +/- 0.44 and 0.12 +/- 0.63 lesion per person were detected (P < 0.001 for all groups).

CONCLUSIONS

Regardless of whether a diver has a patent foramen ovale, diving is associated with ischemic brain lesions.

Mammary phenotypic expression induced in epidermal cells by embryonic mammary mesenchyme

The goal of this research was to establish methods for inducing mammary epithelial differentiation from nonmammary epithelium. For this purpose, mid-ventral or dorsal epidermis (skin epithelium; SKE) from 13-day rat or mouse embryos was associated with 13-day embryonic mouse mammary mesenchyme (mammary gland mesenchyme; MGM) (mouse MGM+rat or mouse SKE). The resultant MGM+SKE recombinants as well as controls (homotypic mouse mammary recombinants, homotypic mouse skin recombinants and mouse mammary mesenchyme by itself) were grafted under the renal capsule of syngeneic or athymic female nude mouse hosts. Most female hosts were induced to undergo lactogenesis by grafting an adult pituitary which elicited a state of hyperprolactinemia. Tissue recombinants of mouse MGM+rat or mouse SKE grown for 1 month in vivo formed a hair-bearing keratinized skin from which mammary ductal structures extended into the mesenchyme. The ducts were composed of columnar luminal epithelial cells as well as basal, actin-positive myoepithelial cells. When grown in pituitary-grafted hosts, the ductal epithelial cells expressed casein and alpha-lactalbumin as judged by immunocytochemistry. The expression of caseins in MGM+SKE recombinants was confirmed by Western blot. The epithelial cells in mouse MGM+rat SKE recombinants expressing milk proteins were shown to be rat cells while the surrounding connective tissue was composed of mouse cells based upon staining with Hoechst dye 33258. Using mammary-specific markers, these studies confirmed the earlier morphological studies of Propper and unequivocally demonstrated for the first time that embryonic mammary mesenchyme can induce morphological and functional mammary differentiation from nonmammary epithelium.

Treatment of non-Hodgkin's lymphoma of Waldeyer's ring: radiotherapy versus chemotherapy versus combined therapy

Treatment of stage IA non-Hodgkin's lymphoma (NHL) of Waldeyer's ring remains controversial, probably because of the small number of patients and the scarcity of controlled studies. Between 1981 and 1991, 316 patients with stage I NHL of Waldeyer's ring were randomised for treatment with radiotherapy alone (extended fields), 101 patients; combined chemotherapy with a regimen of CHOP (cyclophosphamide, vincristine, doxorubicin, and prednisone) or CHOP-like (epirubicin instead of doxorubicin), 106 patients; and combined therapy (radiotherapy followed by the same combination chemotherapy), 109 patients. Median follow-up was 6.8 years. Complete response was achieved in 93, 87 and 97%, respectively. Relapses were least frequent in patients treated with combination therapy. The 5-year rate for failure-free survival was 48% for radiation therapy, 45% for the patients who were treated with chemotherapy, which was statistically significantly less than the 83% for patients treated with combined therapy (P < 0.001). Overall survival was also better in the combined therapy arm: 90%, statistically different to 58% for the patients treated with chemotherapy alone and 56% for patients treated with radiation therapy (P < 0.001). Toxicity was mild and late side-effects were not observed in any patients. From these results combined therapy should be considered as the best therapeutic approach in patients with localised NHL of Waldeyer's ring.

Prehabilitation in thoracic surgery

Surgical resection remains the best treatment option for patients with early stage of non-small cell lung cancer (NSCLC). However, it may be responsible of postoperative complication and mortality, especially in patients with impaired pulmonary function. Enhanced recovery after surgery (ERAS) programs have been focused mainly in minimal invasive surgery approach during lung resection and respiratory rehabilitation after surgery. Preoperative exercise-based intervention (prehabilitation) has demonstrated reduction of morbi-mortality in other surgeries but in thoracic surgery continues to be under discussion. Cardio-pulmonary exercise test (CPET) is the gold standard technique to predict postoperative morbi-mortality. The implementation of a preoperative respiratory rehabilitation could optimize patient's physical capacity before surgery and improve outcomes and enhance recovery. The aim of this systematic review of the literature is to identify the effectiveness and safety of prehabilitation programs in thoracic surgery, the type of exercise and its duration, and the group of patients with best benefit. Prehabilitation is a safe intervention without side effects in patients. High-intensity interval training (HIT) with duration of 2 to 6 weeks seems to be the best exercise programme in a prehabilitation intervention but it exists heterogeneity in terms of intensity and duration. Prehabilitation increase exercise capacity and significantly enhances pulmonary function. But the reduction of postoperative complication and mortality has not been clearly demonstrated. Different criteria selection, type of intervention and small sample size, in addition to no randomization, could justify disparate results. It seems that not all patients can benefit from prehabilitation and it could be indicated only in patients with impaired lung function. Further randomized clinical trials with enough patients, correct duration of HIT (2 to 6 weeks) and focused in COPD patients are needed to clarify the suitability of prehabilitation. Meanwhile, safety of prehabilitation and good results of some studies support this intervention in high-risk patients.

Cytomegalovirus infection of rats increases the neointimal response to vascular injury without consistent evidence of direct infection of the vascular wall

BACKGROUND

Previous studies suggest that infection may play a role in restenosis and atherogenesis; cytomegalovirus (CMV) is one of the implicated pathogens. To determine a potential causal role of CMV in these disease processes, we assessed whether CMV infection increases the neointimal response to injury of the rat carotid artery.

METHODS AND RESULTS

Carotid injury was performed on 60 rats; immediately thereafter, 30 rats were infected with rat CMV, and the other 30 were mock-infected. Six weeks later, rats were euthanized, and the salivary glands, spleen, and carotid arteries were harvested. CMV infection was associated with significant exacerbation of the neointimal response to injury (neointimal to medial ratio 0.81+/-0. 59 versus 0.31+/-0.38 in CMV-infected versus control rats; P<0.0001). This occurred despite absence of infectious virus from vascular tissues and detection of CMV DNA by polymerase chain reaction in the injured artery only at day 3 after infection. Persistent distant infection, associated with systemic cytokine response, was evidenced by isolation of infectious virus from homogenates of both salivary glands and spleen and by higher serum levels of interleukin (IL)-2 and IL-4 (but not interferon-gamma and tumor necrosis factor-alpha) in infected versus noninfected rats.

CONCLUSIONS

CMV infection of immunocompetent adult rats increases the neointimal response to vascular injury, suggesting that CMV may play a causal role in atherosclerosis/restenosis. Importantly, this CMV-induced response occurs even without the presence of virus in the vascular wall, suggesting that inflammatory and immune responses to infection of nonvascular tissues may contribute to the vascular response to injury.

Comparison of the growth of normal and neoplastic mouse mammary cells on plastic, on collagen gels and in collagen gels

The growth of normal and neoplastic mouse mammary cells was compared in primary cultures on plastic, on rat tail collagen gels and in rat tail collagen gels. Cells on plastic grew for the first few days, then stopped with only a 1- to 3-fold increase in cell number after 2 weeks in culture. Cells grown on or in collagen gels grew continuously over the 2-week culture period with up to 10-fold increase in cell number for cultures on collagen gels and a 20-fold increase for cells embedded in collagen gels. The difference in growth rates between cells grown in collagen gel and those grown on collagen gels was due, in part, to the three-dimensional growth of the colonies in collagen gel their two-dimensional growth on collagen gel. Cells grown on and in collagen gel can produce an electron-dense basal lamina-like structure which is associated with collagen IV and laminin as judged by immunofluorescence. Cells grown on plastic do not form this structure. Cis-OH-proline blocks the production of collagen and inhibits the growth of the cultured cells indicating collagen production to be involved in growth. Rat tail collagen gels are a superior substratum for the growth of mouse mammary cells and this may be related to the cells' ability to form a collagen IV-containing basal lamina-like structure.

Transgenes expressing the Wnt-1 and int-2 proto-oncogenes cooperate during mammary carcinogenesis in doubly transgenic mice

The Wnt-1 and int-2 proto-oncogenes are transcriptionally activated by mouse mammary tumor virus insertion mutations in virus-induced tumors and encode secretory glycoproteins. To determine whether these two genes can cooperate during carcinogenesis, we have crossed two previously characterized lines of transgenic mice to obtain bitransgenic animals carrying both Wnt-1 and int-2 transgenes under the control of the mouse mammary tumor virus long terminal repeat. Mammary carcinomas appear earlier and with higher frequency in the bitransgenic animals, especially the males, than in either parental line. Nearly all bitransgenic males develop mammary neoplasms within 8 months of birth, whereas only 15% of Wnt-1 transgenic males and none of the int-2 transgenic males have tumors. In virgin bitransgenic females, tumors occur approximately 2 months earlier than in their Wnt-1 transgenic siblings; int-2 transgenic females rarely exhibit tumors. Preneoplastic glands from the bitransgenic animals of either sex demonstrate pronounced epithelial hyperplasia similar to that seen in Wnt-1 transgenic virgin females and males, and both transgenes are expressed in the hyperplastic glands and mammary tumors. RNA from the int-2 transgene is more abundant in mammary glands from bitransgenic animals than from int-2 transgenic animals; the increase is associated with high levels of RNA specific for keratin genes 14 and 18, suggesting that Wnt-1-induced epithelial hyperplasia is responsible for the observed increase in expression of the int-2 transgene.

Stem cells for brain repair in neonatal hypoxia-ischemia

Neonatal hypoxic-ischemic insults are a significant cause of pediatric encephalopathy, developmental delays, and spastic cerebral palsy. Although the developing brain's plasticity allows for remarkable self-repair, severe disruption of normal myelination and cortical development upon neonatal brain injury are likely to generate life-persisting sensory-motor and cognitive deficits in the growing child. Currently, no treatments are available that can address the long-term consequences. Thus, regenerative medicine appears as a promising avenue to help restore normal developmental processes in affected infants. Stem cell therapy has proven effective in promoting functional recovery in animal models of neonatal hypoxic-ischemic injury and therefore represents a hopeful therapy for this unmet medical condition. Neural stem cells derived from pluripotent stem cells or fetal tissues as well as umbilical cord blood and mesenchymal stem cells have all shown initial success in improving functional outcomes. However, much still remains to be understood about how those stem cells can safely be administered to infants and what their repair mechanisms in the brain are. In this review, we discuss updated research into pathophysiological mechanisms of neonatal brain injury, the types of stem cell therapies currently being tested in this context, and the potential mechanisms through which exogenous stem cells might interact with and influence the developing brain.

Decreased hepatic ALT synthesis is an outcome of subchronic microcystin-LR toxicity

Alanine aminotransferase (ALT; EC 2.6.1.2) is important for the transamination of amino acids and is also an important serum marker of hepatic damage. However, we had previously shown that hepatic ALT activity decreases with subchronic exposure to the hepatotoxin, microcystin-LR (MCLR), a potent inhibitor of serine/threonine protein phosphatases types 1 and 2A. These previous findings suggest that one outcome of subchronic MCLR toxicosis is decreased ALT synthesis by hepatocytes. This could affect the diagnostic sensitivity of serum ALT activity and metabolic processes within the cell. This study was done to investigate the mechanism by which ALT activity decreases following prolonged MCLR exposure. Immunoblots were first performed on liver tissue from 12 Harlan-Sprague-Dawley rats that had been treated with 0, 16, 32, or 48 microg/kg of microcystin-LR per day by continuous intraperitoneal infusion for 28 days. These revealed a dose-dependent decrease in ALT protein concentrations that correlated directly with hepatic ALT activity (r = 0.8132; P = 0.0013). Sixteen additional rats, treated with the same doses of MCLR showed a dose-dependent decrease in hepatic ALT activity to approximately 19% of values in saline-treated controls. Northern blot analysis revealed a decrease in hepatic ALT mRNA that correlated directly to hepatic ALT activity (r = 0.7909; P = 0.0004). It was concluded that subchronic MCLR exposure causes decreased hepatic ALT protein and mRNA concentrations. These findings suggest that one sequela of MCLR toxicosis is decreased hepatic ALT synthesis.

Effect of adenosine and inosine on ureagenesis in hepatocytes

Adenosine and inosine produced a dose-dependent stimulation of ureagenesis in isolated rat hepatocytes. Hypoxanthine, xanthine and uric acid were without effect. Half-maximally effective concentrations were 0.08 microM for adenosine and 5 microM for inosine. Activation of ureagenesis by both nucleosides had the following characteristics: (a) it was observed with either glutamine or (NH4)2CO3, provided that glucose was present; (b) it was not detected when glucose was replaced by lactate plus oleate; (c) it was mutually antagonized by glucagon, but not by adrenaline; and (d) it was dependent on Ca2+. We suggest that the action of adenosine and inosine on ureagenesis might be of physiological significance.

Interferon alpha 2b as maintenance therapy in low grade malignant lymphoma improves duration of remission and survival

We assessed the efficacy and toxicity of interferon alpha 2b (IFN) as maintenance therapy in patients with low grade malignant lymphoma. Between March 1986 and December 1989, 98 patients with low-grade malignant lymphoma in complete remission after conventional chemotherapy were randomly assigned to received IFN, 5.0 MU three times a week for one year, as maintenance therapy (n = 48), or to receive no treatment (control group, n = 50). In March 1994, the median duration of response had not yet been reached in the patients treated with IFN compared to 46 months in the control group. At 9-years 62% of the patients in the IFN arm remain in first complete remission compared to only 25% in the control group (p <.001). In addition, the median duration of survival has not yet been reached in either the IFN arm compared to 74 months in the control group (p <.001). Quality of life was excellent in both groups and severe side effects secondary to IFN treatment were not observed. All patients completed the planned dose of IFN. We conclude that IFN as maintenance therapy in low-grade malignant lymphoma is an excellent therapeutic option because it improves the duration of remission and survival without producing severe side effects or reducing the quality of life.

Imaging the rat brain on a 1.5 T clinical MR-scanner

Magnetic resonance imaging (MRI) offers a noninvasive technique for studying neurodegenerative events in the rat brain, however, most of the studies are performed on small bore purpose dedicated MR scanners of limited availability and at high cost. The present study explored the feasibility of using a clinical whole body MR-scanner to perform imaging in rat brain and specifically in models of Parkinson's (PD) and Huntington's disease (HD). For that purpose rats were placed into a specially designed PVC device equipped with a flexible surface coil-and T2-weighted spin echo sequences were acquired on a Siemens Magnetom Vision at 1.5 T. In the experimental protocols of PD and HD, animals underwent 6-hydroxydopamine (6-OHDA) and quinolinic acid (QA) injections, respectively and were subsequently grafted with fetal tissue. T2-weighted images showed a small hyperintense area at the 6-OHDA lesion site and a diffuse hyperintensity in the striata with QA lesions. Transplants were seen as a hypointense area surrounded by a hyperintense rim on T1-weighted images. Moreover, disturbances of the blood-brain-barrier and its time of restoration could be monitored. In conclusion, high-resolution in vivo imaging of small animals is feasible with clinical MR-scanners and hence allows the study of various experimental protocols.