Maternal Cigarette Smoking and Congenital Upper and Lower Limb Differences: A Systematic Review and Meta-Analysis

Maternal smoking during pregnancy has been associated with adverse effects on foetal development, including congenital limb anomalies. This systematic review aimed to provide an updated assessment of the association between maternal smoking during pregnancy and the risk of congenital limb anomalies. A systematic search was conducted to identify relevant studies published up to February 2023. Studies reporting on the relationship between maternal smoking during pregnancy and congenital digital anomalies or congenital limb reduction defects were included. Two independent reviewers screened the studies, extracted data, and assessed the quality of the included studies. Meta-analyses were performed to estimate the pooled odds ratios with 95% confidence intervals using fixed and random-effects models. In total, 37 publications comprising 11 cohort and 26 case-control studies were included in the systematic review. The meta-analysis demonstrated a significant increased risk of congenital limb reduction defects (pooled OR: 1.27, 95% CI: 1.18-1.38) in infants born to mothers who smoked during pregnancy. Similarly, a significant relationship was observed for the development of polydactyly/syndactyly/adactyly when considered as a single group (pooled OR: 1.32, 95% CI: 1.25-1.40). Yet, in contrast, no significant association was observed when polydactyly (pooled OR: 1.06, 95% CI: 0.88-1.27) or syndactyly (pooled OR: 0.91, 95% CI: 0.77-1.08) were considered individually. This systematic review provides updated evidence of a significant relationship between maternal smoking during pregnancy and increased risk of congenital limb anomalies. These findings highlight the potential detrimental effects of smoking on foetal limb development and underscore the importance of smoking cessation interventions for pregnant women to mitigate these risks.

Fracture Risk and Use of Angiotensin-Converting Enzyme Inhibitors or Angiotensin II Receptor Blockers

Medications used to treat hypertension may affect fracture risk. This study investigated fracture risk for users of angiotensin converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB). Participants (899 men, median age 70.3 yr (59.9-79.1), range 50.0-96.6 yr; 574 women, median age 65.5 yr (58.1-75.4), range 50.1-94.6 yr) were from the Geelong Osteoporosis Study. Medication use was self-reported and incident fractures were ascertained using radiological reports. Bone mineral density (BMD) was measured at the femoral neck. Participants were divided into four groups: (1) non-users without hypertension, (2) non-users with hypertension, (3) ACEI users and (4) ARB users. Dosage was calculated using the defined daily dose (DDD) criteria. Participants were followed from date of visit to first fracture, death or 31 December 2016, whichever occurred first. Cox proportional hazards models were used for analyses. At least one incident fracture was sustained by 156 men and 135 women over a median(IQR) of 11.5(6.2-13.2) and 10.9(6.3-11.6) years of follow-up, respectively. In unadjusted analyses, compared to non-users without hypertension, men in all three other groups had a higher risk of fracture (Hazard Ratio (HR, 95%CI) 1.54, 1.00-2.37; 1.90, 1.18-3.05; 2.15, 1.26-3.66), for non-users with hypertension, ACEI and ARB users, respectively). Following adjustment for age, prior fracture and BMD, these associations became non-significant. A dose effect for ARB use was observed; men using lower doses had a higher risk of fracture than non-users without hypertension, in both unadjusted (2.66, 1.34-5.29) and adjusted (2.03, 1.01-4.08) analyses, but this association was not observed at higher doses. For women, unadjusted analyses showed a higher risk for ACEI users compared to non-users without hypertension (1.74, 1.07-2.83). This was explained after adjustment for age, alcohol consumption, prior fracture and BMD (1.28, 0.74-2.22). No other differences were observed. In men, lower dose (0 < DDD ≤ 1) ARB use was associated with an increased risk of fracture. ACEI or ARB use was not associated with increased risk of incident fracture in women. These findings may be important for antihypertensive treatment decisions in individuals with a high risk of fracture.

The Added Burden of Personality Disorder on Subsidized Australian Health Service Utilization Among Women With Mental State Disorder

This study aimed to investigate health service utilization among women with mental state disorder only (MSD-PD), mental state disorder plus personality disorder (MSD+PD), and controls in a population-based sample. Women (n = 635) from the Geelong Osteoporosis Study completed mental health assessments and were categorized into groups (MSD-PD, MSD+PD, controls). General practitioner (mental and non-mental health encounters) and specialized mental health service utilization was ascertained from data linkage to the Medicare Benefits Schedule, Australia (01/09/2008-31/12/2012). Negative binomial and binary logistic regression models were employed to assess health service utilization differences between groups. Results indicated that women with MSD+PD had more encounters of non-mental health service utilization than women with MSD-PD and controls. Age significantly modified these relationships: women with MSD+PD and MSD-PD had more encounters of health service utilization at midlife and in the seventh decade of life. No significant differences were found in the frequency of general practitioner mental health service utilization or specialized mental health service utilization between groups. These data suggest that the presence of co-occurring PD is associated with increased health service utilization among women with other common mental health problems. Healthcare providers should be vigilant to the presence of PD when establishing management plans with patients presenting with common mental health problems.

The contribution of musculoskeletal factors to physical frailty: a cross-sectional study

Background

Musculoskeletal conditions and physical frailty have overlapping constructs. We aimed to quantify individual contributions of musculoskeletal factors to frailty.

Methods

Participants included 347 men and 360 women aged ≥60 yr (median ages; 70.8 (66.1–78.6) and 71.0 (65.2–77.5), respectively) from the Geelong Osteoporosis Study. Frailty was defined as ≥3, pre-frail 1–2, and robust 0, of the following; unintentional weight loss, weakness, low physical activity, exhaustion, and slowness. Measures were made of femoral neck BMD, appendicular lean mass index (ALMI, kg/m²) and whole-body fat mass index (FMI, kg/m²) by DXA (Lunar), SOS, BUA and SI at the calcaneus (Lunar Achilles Insight) and handgrip strength by dynamometers. Binary and ordinal logistic regression models and AUROC curves were used to quantify the contribution of musculoskeletal parameters to frailty. Potential confounders included anthropometry, smoking, alcohol, prior fracture, FMI, SES and comorbidities.

Results

Overall, 54(15.6%) men and 62(17.2%) women were frail. In adjusted-binary logistic models, SI, ALMI and HGS were associated with frailty in men (OR = 0.73, 95%CI 0.53–1.01; OR=0.48, 0.34–0.68; and OR = 0.11, 0.06–0.22; respectively). Muscle measures (ALMI and HGS) contributed more to this association than did bone (SI) (AUROCs 0.77, 0.85 vs 0.71, respectively). In women, only HGS was associated with frailty in adjusted models (OR = 0.30 95%CI 0.20–0.45, AUROC = 0.83). In adjusted ordinal models, similar results were observed in men; for women, HGS and ALMI were associated with frailty (ordered OR = 0.30 95%CI 0.20–0.45; OR = 0.56, 0.40–0.80, respectively).

Conclusion

Muscle deficits appeared to contribute more than bone deficits to frailty. This may have implications for identifying potential musculoskeletal targets for preventing or managing the progression of frailty.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04795-4.

The Predictability of Frailty Associated with Musculoskeletal Deficits: A Longitudinal Study

We investigated and quantified the predictability of frailty associated with musculoskeletal parameters. This longitudinal study included 287 men aged ≥ 50 yr at baseline (2001-2006) from the Geelong Osteoporosis Study. Baseline musculoskeletal measures included femoral neck bone mineral density (BMD), appendicular lean mass index (ALMI, kg/m²) and whole-body fat mass index (FMI, kg/m²) and lower-limb strength. Frailty at the 15 yr-follow-up (2016-2019) was defined as ≥ 3 and non-frail as < 3, of the following: unintentional weight loss, weakness, low physical activity, exhaustion, and slowness. Binary regression models and AUROC curves quantified the attributable risk of musculoskeletal factors to frailty and their predictive ability. Potential confounders included anthropometry, smoking, alcohol, FMI, socioeconomic status and comorbidities. Forty-eight (16.7%) men were frail at 15 yr-follow-up. Musculoskeletal models were better predictors of frailty compared to the referent (confounders only) model (AUROC for musculoskeletal factors 0.74 vs 0.67 for the referent model). The model with the highest AUROC (0.74; 95% CI 0.66-0.82) included BMD, ALMI and muscle strength (hip abductors) and was better than the referent model that included only lifestyle factors (p = 0.046). Musculoskeletal parameters improved the predictability model as measured by AUROC for frailty after 15 years. In general, muscle models performed better compared to bone models. Musculoskeletal parameters improved the predictability of frailty of the referent model that included lifestyle factors. Muscle deficits accounted for a greater proportion of the risk for frailty than did bone deficits. Targeting musculoskeletal health could be a possible avenue of intervention in regards to frailty.

Association between bone measures and use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers

Angiotensin-converting enzyme inhibitor use in women was associated with lower femoral neck and lumbar spine bone mineral density as well as trabecular bone score compared to non-users. No differences were identified for men or for those who used ARB medications.

PURPOSE

Many individuals at high fracture risk use medications such as angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB) that could affect bone; thus, this study aimed to investigate whether there are any differences in bone mineral density (BMD) and trabecular bone score (TBS) between ACEI users, ARB users, and non-users.

METHODS

Participants (685 men, 573 women) were from the Geelong Osteoporosis Study. Current medication use was self-reported. BMD at the femoral neck (FNBMD) and lumbar spine (LSBMD) were measured using DXA. TBS was calculated using TBS iNsight software. Linear regression models were used to investigate associations between ACEI or ARB use and bone measures, adjusting for other potential confounders. Due to interaction terms, data were stratified by age.

RESULTS

There were 88 (12.8%) men and 41 (7.2%) women taking an ACEI medication, and 71 (10.4%) men and 76 (13.3%) women taking an ARB medication. Compared to non-users, ACEI use was associated with lower FNBMD (- 7.2%), LSBMD (- 12.2%), and TBS (- 9.0%) for women aged < 65 years. Lower TBS was also observed for women aged ≥ 65 years (- 17.3%). No differences were identified for ARB use.

CONCLUSIONS

Women who used an ACEI medication had lower values for FNBMD, LSBMD and TBS compared to non-users. No differences were identified for men or for those who used ARB medications.

Impact microindentation in men with impaired fasting glucose and type 2 diabetes

BACKGROUND

Individuals with type 2 diabetes (T2DM) are at increased fracture risk, with bone mineral density (BMD) measurements underestimating risk. Impact microindentation (IMI), a technique that measures bone microindentation distances, expressed as bone material strength index (BMSi), may improve fracture risk estimation in individuals with T2DM. This study describes the relationship between BMSi and glycaemia status in men and makes a comparison with bone measures from dual energy X-ray absorptiometry (DXA).

MATERIAL AND METHODS

Participants were 340 men aged 33-96 yr from the Geelong Osteoporosis Study. Impaired fasting glucose (IFG) was defined using fasting plasma glucose (FPG) between 5.5 and 6.9 mmol/L. Diabetes was defined as FPG ≥ 7.0 mmol/L, use of antihyperglycemic medication and/or self-report. Two participants with type 1 diabetes were excluded. BMSi was measured using an OsteoProbe. Femoral neck (FNBMD) and lumbar spine (LSBMD) were measured using DXA (Lunar Prodigy) and trabecular bone score (TBS) was calculated (TBS iNsight Version 2.2). Using linear regression techniques, the relationship between glycaemia status and BMSi was evaluated, adjusting for other potential confounders (including lifestyle factors, clinical measurements and FNBMD). Glycaemia status was also considered as a binary variable (T2DM vs normoglycaemia and IFG).

RESULTS

There were 234 (68.8%) men with normoglycaemia, 59 (17.4%) with IFG and 47 (13.8%) with diabetes. When considering glycaemia status as a binary variable, men with T2DM had lower mean BMSi compared to those without T2DM (normoglycaemia and IFG combined) (79.8; 95%CI 77.0-82.6 vs 83.0; 82.2-83.8 p = 0.043) and this difference in BMSi was independent of FNBMD. No differences were observed for either FNBMD or LSBMD; however, TBS was lower (1.177; 1.121-1.233 vs 1.256; 1.240-1.272, p = 0.015, independent of FNBMD). For glycaemia status considered in three groups, there were no differences in mean BMSi values between men with normoglycaemia, IFG and T2DM (82.9 (95%CI 82.0-83.8), 83.5 (81.8-85.2) and 79.8 (77.0-82.6), respectively; ANCOVA, p = 0.104).

CONCLUSIONS

Measures reflecting bone material properties and microarchitecture (BMSi and TBS) might be better than measures of bone mass (BMD) in identifying individuals with T2DM at risk of fracture.

Burnout and compassion fatigue among Exercise Physiologists in mental healthcare

BACKGROUND

Burnout and compassion fatigue (CF) are common among mental health practitioners. Accredited Exercise Physiologists (AEPs) provide clinical services to individuals experiencing mental illness, increasing their likelihood of experiencing burnout and CF.

AIMS

To examine the prevalence of burnout and CF among AEPs working with people experiencing mental illness.

METHODS

An anonymous online cross-sectional survey of AEPs working with people experiencing mental illness was distributed via the Exercise and Sports Science Australia Mental Health Special Interest Group Facebook page between July and November 2019. In addition to demographics and caseload data, respondents completed the Professional Quality of Life scale and Oldenburg Burnout Inventory (OLBI). Results are reported using descriptive statistics.

RESULTS

Sixty-two AEPs (68%, n = 42 female) completed the survey. Most (n = 53, 86%) reported delivering services to consumers with severe mental health conditions. Less than half (n = 27, 44%) reported working in a dedicated mental health facility. Moderate levels of burnout and CF were experienced by 60% and 30% of respondents, respectively.

CONCLUSIONS

The prevalence of moderate burnout and CF symptoms in AEPs is comparable with other mental health professionals. Strategies to preserve psychological well-being such as enhancing mental health training for undergraduates and formalized supervision structures discussed.

Bone material strength index is associated with prior fracture in men with and without moderate chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) are at high risk for fracture. The ability of bone mineral density (BMD) to predict fractures in CKD patients has been inconsistent. Other measures such as trabecular bone score (TBS) and impact microindentation (IMI) may be more useful in this group. This study aimed to determine if TBS or IMI values differed between men with and without CKD and examine associations between prior fracture, TBS and IMI values.

METHODS

Men (n = 343, age 33-96 yr) from the Geelong Osteoporosis Study were included. Femoral neck (FNBMD) and lumbar spine BMD (LSBMD) were measured using DXA (Lunar ProdigyPro). TBS was determined from lumbar spine scans (TBS iNsight software Version 2.2). IMI values (bone material strength index; BMSi) were measured using an OsteoProbe. CKD was defined as an eGFR<60 mL/min/1.73m² (n = 53). Prior low trauma fractures (n = 37) were ascertained from radiological reports. Associations were examined using binary logistic regression, adjusting for potential confounders. Interaction terms were tested in all models.

RESULTS

Men with CKD tended to have a higher likelihood of prior fracture (adjusted OR 2.27, 95%CI 1.02-5.01). Higher BMSi was associated with a lower likelihood of prior fracture (adjusted OR for 1SD increase: 0.70; 95%CI 0.51-0.97). This association was sustained after adjustment for FNBMD (OR 0.68; 95%CI 0.49-0.96) or LSBMD (OR 0.69; 95%CI 0.49-0.95). No interaction was detected between BMSi and CKD (p = 0.898). No associations were detected between FNBMD, LSBMD or TBS and prior fracture in either population and there were no interactions with CKD for FNBMD, LSBMD or TBS.

CONCLUSIONS

BMSi was associated with prior fracture in men with and without CKD, however, FNBMD, LSBMD and TBS were not. Lack of an interaction term suggests that BMSi performed similarly in identifying the likelihood of prior fracture, regardless of CKD status. IMI may have clinical utility for assessing fracture risk in patients with CKD.

Phylogenetic Variation of Chelonid Alphaherpesvirus 5 (ChHV5) in Populations of Green Turtles Chelonia mydas along the Queensland Coast, Australia

Sea turtle fibropapillomatosis (FP) is a disease marked by the proliferation of benign but debilitating cutaneous and occasional visceral tumors, likely to be caused by chelonid alphaherpesvirus 5 (ChHV5). This study presents a phylogeny of ChHV5 strains found on the east coast of Queensland, Australia, and a validation for previously unused primers. Two different primer sets (gB-1534 and gB-813) were designed to target a region including part of the UL27 glycoprotein B (gB) gene and part of UL28 of ChHV5. Sequences obtained from FP tumors found on juvenile green turtles Chelonia mydas (<65 cm curved carapace length) had substantial homology with published ChHV5 sequences, while a skin biopsy from a turtle without FP failed to react in the PCRs used in this study. The resulting sequences were used to generate a neighbor-joining tree from which three clusters of ChHV5 from Australian waters were identified: north Australian, north Queensland, and Queensland clusters. The clusters reflect the collection sites on the east coast of Queensland with a definitive north-south trend. Received October 22, 2016; accepted May 7, 2017.

Identification of p53 peptides recognized by CD8(+) T lymphocytes from patients with bladder cancer

In many types of cancer, p53 frequently accumulates in tumor cells and anti-p53 antibodies can be detected. However, only four CD8(+) T-cell epitopes from p53 have been identified in humans so far. To further analyze the development of a T-cell response against p53, peptides having binding motifs specific for HLA-A1, -A2, -A3, -A24, -B7, -B35, -B44, and -B51 molecules have been defined. The HLA-binding capacity of those peptides was tested, and the stability of formed complexes was defined. Thirteen peptides that bound to HLA-A24 and -B44 molecules are presented. The positive peptides were then used to detect the anti-p53 response of CD8(+) T lymphocytes from patients with bladder cancer. Six peptides, presented by HLA-A2, -B51, or -A24, were able to stimulate T cells from two patients (among 16) with tumor cells that strongly accumulated p53. On the contrary, p53 peptides systematically failed to stimulate T cells from healthy donors or patients with low or undetectable levels of p53 in their tumor cells. These results have led to the identification of four new potential T CD8(+) epitopes from p53: 194-203 associating with HLA-B51 and 204-212, 211-218, and 235-243 associating with HLA-A24.

Cervical headache

Headache presents a diagnostic challenge for the physical therapist due to similarities of signs and symptoms among the many types of headache. Effective treatment depends upon accurate diagnosis and identifying the factors that may precipitate or perpetuate the symptoms. This commentary overviews some common forms of headache and specifically addresses cervical headache as a possible beneficiary of physical therapy intervention. Details of the history and physical examination, which is designed to diagnose cervical headache and rule out potential serious pathologies, are presented. Guidelines for treatment of articular and myofascial dysfunction are presented. A case report illustrating principles of examination, inherent ambiguities in diagnosis, and successful treatment is also presented.

Multiple outbreaks of Norwalk-like virus gastro-enteritis associated with a Mediterranean-style restaurant

The role of diverse infectious agents, particularly Norwalk-like viruses (NLV), in three successive gastro-enteritis outbreaks in one setting (a restaurant) was evaluated. Methods included standard bacteriological tests, specific tests for Escherichia coli, tests for verocytotoxins, electron microscopy (EM) for viruses and reverse transcription-PCR (RT-PCR) methodology for NLV. No pathogenic bacteria were detected. Verocytotoxin genes, although detected by PCR in the first outbreak, could not be confirmed in the E. coli isolated, so they did not appear to be of significance. NLV was the main agent detected in each of the three outbreaks. DNA sequencing and phylogenetic analysis of the amplified products obtained from the RT-PCR positive specimens indicated that only one NLV strain was involved in each outbreak, but the NLV strains responsible for the three outbreaks were different from each other. PCR technology for detection of NLV proved highly sensitive, but failed to detect one specimen which was positive by EM. The restaurant associated with the outbreaks is a Mediterranean-style restaurant where food from a common platter is typically eaten with fingers. The findings indicate that NLV was introduced by guests or staff and was not due to a long-term reservoir within the setting.

beta2-adrenergic receptor-selective agonist clenbuterol prevents Fas-induced liver apoptosis and death in mice

Stimulation of the cAMP-signaling pathway modulates apoptosis in several cell types and inhibits Jo2-mediated apoptosis in cultured rat hepatocytes. No information is yet available as to whether the hepatic beta2-adrenergic receptor (AR) expression level, including beta2-AR-dependent adenylyl cyclase activation, modulates hepatocyte sensitivity to apoptosis in vivo or whether this sensitivity can be modified by beta2-AR ligands. We have examined this using C57BL/6 mice, in which hepatic beta2-AR densities are low, and transgenic F28 mice, which overexpress beta2-ARs and have elevated basal liver adenylyl cyclase activity. The F28 mice were resistant to Jo2-induced liver apoptosis and death. The beta-AR antagonist propranolol sensitized the F28 livers to Jo2. In normal mice clenbuterol, a beta2-AR-specific agonist, considerably reduced Jo2-induced liver apoptosis and death; salbutamol, another beta2-AR-selective agonist, also reduced Jo2-induced apoptosis and retarded death but with less efficacy than clenbuterol; and propranolol blocked the protective effect of clenbuterol. This indicates that the expression level of functional beta2-ARs modulates Fas-regulated liver apoptosis and that this apoptosis can be inhibited in vivo by giving beta2-AR agonists. This may well form the basis for a new therapeutic approach to diseases involving abnormal apoptosis.

Immune response to recombinant capsid proteins of adenovirus in humans: antifiber and anti-penton base antibodies have a synergistic effect on neutralizing activity

Replication-deficient adenovirus used in humans for gene therapy induces a strong immune response to the vector, resulting in transient recombinant protein expression and the blocking of gene transfer upon a second administration. Therefore, in this study we examined in detail the capsid-specific humoral immune response in sera of patients with lung cancer who had been given one dose of a replication-defective adenovirus. We analyzed the immune response to the three major components of the viral capsid, hexon (Hx), penton base (Pb), and fiber (Fi). A longitudinal study of the humoral response assayed on adenovirus particle-coated enzyme-linked immunosorbent assay plates showed that patients had preexisting immunity to adenovirus prior to the administration of adenovirus-beta-gal. The level of the response increased in three patients after adenovirus administration and remained at a maximum after three months. One patient had a strong immune response to adenovirus prior to treatment, and this response was unaffected by adenovirus administration. Sera collected from the patients were assayed for recognition of each individual viral capsid protein to determine more precisely the molecular basis of the humoral immune response. Clear differences existed in the humoral response to the three major components of the viral capsid in serum from humans. Sequential appearance of these antibodies was observed: anti-Fi antibodies appeared first, followed by anti-Pb antibodies and then by anti-Hx antibodies. Moreover, anti-Fi antibodies preferentially recognized the native trimeric form of Fi protein, suggesting that they recognized conformational epitopes. Our results showed that sera with no neutralizing activity contained only anti-Fi antibodies. In contrast, neutralizing activity was only obtained with sera containing anti-Fi and anti-Pb antibodies. More importantly, we showed that anti-native Fi and anti-Pb antibodies had a synergistic effect on neutralization. The application of these conclusions to human gene therapy with recombinant adenovirus should lead to the development of strategies to overcome the formation of such neutralization antibodies, which have been shown to limit the efficacy of gene transfer in humans.

Humoral immune response to the capsid components of recombinant adenoviruses: routes of immunization modulate virus-induced Ig subclass shifts

This study examines in detail the capsid-specific humoral immune response of BALB/c mice after one single injection of a replication-defective adenovirus. Two routes of immunization, intravenous (i.v.) and intraperitoneal (i.p.), were compared for the response induced against the adenovirus particle and the three major components of the viral capsid, hexon, penton base, and fiber. A single immunization with the replication-defective adenovirus induces a long and persistent humoral response specific for the virus. However, the molecular components of the viral capsid are differentially recognized depending on the route of immunization. The sera from mice immunized i.p. recognized only the hexon protein and a preferential switch to the IgG2a subclass was obtained which remained stable 100 days post-immunization. The sera obtained from mice immunized i.v. gave a more complex response. At the beginning of the response, an isotype bias toward the IgG2a subclass was observed, but the isotype distribution changed during the whole period of the response. Neutralizing activity was maximum 45 days after immunization by both routes, and no activity was detectable after 3 months. However, the i.v. serum displayed a higher neutralizing activity than the i.p. serum. The IgM antiviral antibodies appeared to be an important component of the neutralizing activity, and the two routes of immunization do not induce the same IgG isotypes to neutralize viral infectivity. Extension of these findings to human gene therapy using recombinant adenoviruses may help to characterize the precise viral protein targets of neutralizing antibodies.

Transgenic mice carrying the human beta 2-adrenergic receptor gene with its own promoter overexpress beta 2-adrenergic receptors in liver

Up to now, transgenic mice models created to study the physiological impact of alterations in the human beta-adrenoceptor system have only focused on cardiac tissues and carried hybrid transgenes with strong cardiac promoters. We have developed a transgenic mouse strain (F28) carrying the human beta 2-adrenoceptor gene with its natural promoter region with the aim of producing a model that more closely reproduces the natural human beta 2-adrenoceptor tissue expression pattern. By means of northern blot analyses, using the appropriate probes, we have obtained evidence that (a) the human beta 2-adrenoceptor's structural gene is transcribed in several tissues of F28 mice; (b) the tissue distribution pattern of human beta 2-adrenoceptor mRNA in F28 mice completely differs from that of mouse beta 2-adrenoceptor mRNA; and (c) the tissue distribution pattern of mouse beta 2-adrenoceptor mRNA in F28 mice is very similar to that observed in their non-transgenic littermates. Like humans, F28 mice express human beta 2-adrenoceptor mRNA in liver, lung, brain, heart, and muscle. However, unlike humans, F28 mice do not accumulate human beta 2-adrenoceptor mRNA in kidney and spleen. By using [125I]iodocyanopindolol to label all beta-adrenoceptors and ICI 118,551 to discriminate between the binding to beta 2- and beta 1-adrenoceptors we have demonstrated that the beta 2-adrenoceptor binding activity increases over control values in F28 mouse tissues that accumulate transgenic mRNA. Accordingly, the number of beta 2-adrenoceptors increased slightly over the control values in muscle, heart, brain, and lung of F28 mice, while in liver these receptors were strongly overexpressed. We further showed that transgene beta 2-adrenoceptors couple to GTP-binding proteins, mediate beta-adrenoceptor agonist-stimulated adenylyl cyclase activation, and cause a strong enhancement of this response in liver membranes of F28 versus control mice. Finally, F28 mice show a phenotype of depressed ponderal development and perturbed hindquarter movements. This unique model should be useful to further investigate beta 2-adrenoceptor causal relationships with human pathologies.

Automated device for preparing agar media

An automated device which facilitates safe and effective agar media preparation without constant supervision is described.