Investigating the Impact of Isolation During COVID-19 on Family Functioning - An Australian Snapshot

This study explored possible changes in family functioning from the perspective of parents during the COVID-19 pandemic. Thirty-four parents/guardians of children under 18 years completed a semi-structured interview, average length 47 min. Interviews focussed on changes in different aspects of family functioning including family roles, routines, and rules; parenting practices; communication and relationships; and strengths, challenges, and tensions. Data were analysed using reflexive thematic analysis applied in an idiographic and inductive manner to reduce the loss of individual experiences and perspectives. Four superordinate themes were identified: shifting family roles and boundaries throughout the pandemic; impacts on routines and relationships; opportunities and resourcing; and, experiences of support and unity. Gender differences were evident across some themes, particularly changing roles, workload and work-home boundaries. Challenges and tensions were frequently highlighted, particularly by “vulnerable” family groups such as those with children with disabilities. Parents also described a renewed sense of family and community that underpinned adaptive coping responses. The results highlight the importance of family connectedness in times of need.

Adverse health events associated with clinical placement: A systematic review

OBJECTIVE

Clinical placement is a fundamental aspect of student learning and skill development across healthcare disciplines. However, participation in clinical placements can also present significant risk to students. This systematic literature review sought to examine the range of risks and hazards encountered by students across healthcare disciplines during their clinical placements.

DESIGN

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis reporting guidelines were utilised in conducting this exploratory systematic review.

DATA SOURCES

The CINAHL Complete, Medline Complete, and PsycINFO databases were searched. Reference lists of eligible records obtained via database searching were screened, and a supplementary key author search was conducted. Research published between 2013 and 2018 and conducted in the context of comparative international healthcare systems was the focus of this study.

REVIEW METHODS

Study titles and abstracts were screened, and the full text of potentially relevant records was perused. Records meeting key eligibility criteria by addressing risk posed to students in healthcare disciplines within a clinical placement context were included in the final synthesis.

RESULTS

The search identified 46 eligible records. The literature highlighted the worrying trend that students, most notably in the nursing discipline, can be exposed to a wide range of risks and adverse health events during clinical placement.

CONCLUSIONS

As risks in unpredictable clinical environments cannot be eradicated, this review demonstrated a critical need for educative action to enable students to competently and confidently manage risks, and to reduce occurrence of adverse health events.

Characterization of high-dimensional entangled systems via mutually unbiased measurements

Mutually unbiased bases (MUBs) play a key role in many protocols in quantum science, such as quantum key distribution. However, defining MUBs for arbitrary high-dimensional systems is theoretically difficult, and measurements in such bases can be hard to implement. We show experimentally that efficient quantum state reconstruction of a high-dimensional multipartite quantum system can be performed by considering only the MUBs of the individual parts. The state spaces of the individual subsystems are always smaller than the state space of the composite system. Thus, the benefit of this method is that MUBs need to be defined for the small Hilbert spaces of the subsystems rather than for the large space of the overall system. This becomes especially relevant where the definition or measurement of MUBs for the overall system is challenging. We illustrate this approach by implementing measurements for a high-dimensional system consisting of two photons entangled in the orbital angular momentum degree of freedom, and we reconstruct the state of this system for dimensions of the individual photons from d = 2 to 5.

Cyclooxygenase expression and platelet function in healthy dogs receiving low-dose aspirin

BACKGROUND

Low-dose aspirin is used to prevent thromboembolic complications in dogs, but some animals are nonresponsive to the antiplatelet effects of aspirin ("aspirin resistance").

HYPOTHESIS/OBJECTIVES

That low-dose aspirin would inhibit platelet function, decrease thromboxane synthesis, and alter platelet cyclooxygenase (COX) expression.

ANIMALS

Twenty-four healthy dogs.

METHODS

A repeated measures study. Platelet function (PFA-100 closure time, collagen/epinephrine), platelet COX-1 and COX-2 expression, and urine 11-dehydro-thromboxane B(2) (11-dTXB(2)) were evaluated before and during aspirin administration (1 mg/kg Q24 hours PO, 10 days). Based on prolongation of closure times after aspirin administration, dogs were divided into categories according to aspirin responsiveness: responders, nonresponders, and inconsistent responders.

RESULTS

Low-dose aspirin increased closure times significantly (62% by Day 10, P < .001), with an equal distribution among aspirin responsiveness categories, 8 dogs per group. Platelet COX-1 mean fluorescent intensity (MFI) increased significantly during treatment, 13% on Day 3 (range, -29.7-136.1%) (P = .047) and 72% on Day 10 (range, -0.37-210%) (P < .001). Platelet COX-2 MFI increased significantly by 34% (range, -29.2-270%) on Day 3 (P = .003) and 74% (range, -19.7-226%) on Day 10 (P < .001). Urinary 11-dTXB(2) concentrations significantly (P = .005, P < .001) decreased at both time points. There was no difference between aspirin responsiveness and either platelet COX expression or thromboxane production.

CONCLUSIONS AND CLINICAL IMPORTANCE

Low-dose aspirin consistently inhibits platelet function in approximately one-third of healthy dogs, despite decreased thromboxane synthesis and increased platelet COX expression in most dogs. COX isoform expression before treatment did not predict aspirin resistance.

Perceived discrimination and hypertension among African Americans in the Jackson Heart Study

OBJECTIVES

Using Jackson Heart Study data, we examined whether perceived discrimination was associated with prevalent hypertension in African Americans.

METHODS

Everyday discrimination, lifetime discrimination, burden of discrimination, and stress from discrimination were examined among 4939 participants aged 35 to 84 years (women = 3123; men = 1816). We estimated prevalence ratios of hypertension by discrimination, and adjusted for age, gender, socioeconomic status, and risk factors.

RESULTS

The prevalence of hypertension was 64.0% in women and 59.7% in men. After adjustment for age, gender, and socioeconomic status, lifetime discrimination and burden of discrimination were associated with greater hypertension prevalence (prevalence ratios for highest vs lowest quartile were 1.08 [95% confidence interval (CI) = 1.02, 1.15] and 1.09 [95% CI = 1.02,1.16] for lifetime discrimination and burden of discrimination, respectively). Associations were slightly weakened after adjustment for body mass index and behavioral factors. No associations were observed for everyday discrimination.

CONCLUSIONS

Further understanding the role of perceived discrimination in the etiology of hypertension may be beneficial in eliminating hypertension disparities.

Influence of albuminuria and glomerular filtration rate on blood pressure response to antihypertensive drug therapy

BACKGROUND

Albuminuria and glomerular filtration rate (GFR), two factors linked to kidney and vascular function, may influence longitudinal blood pressure (BP) responses to complex antihypertensive drug regimens.

METHODS

We reviewed the clinic records of 459 patients with hypertension in an urban, academic practice.

RESULTS

Mean patient age was 57-years, 89% of patients were African American, and 69% were women. Mean patient systolic/diastolic BP (SBP/DBP) at baseline was 171/98 mmHg while taking an average of 3.3 antihypertensive medications. At baseline, 27% of patients had estimated (e)GFR <60 ml/min/1.73(2), 28% had micro-albuminuria (30-300 mg/g) and 16% had macro-albuminuria (>300 mg/g). The average longitudinal BP decline over the observation period (mean 7.2 visits) was 25/12 mmHg. In adjusted regression models, macro-albuminuria predicted a 10.3 mmHg lesser longitudinal SBP reduction (p < 0.001) and a 7.9 mmHg lesser longitudinal DBP reduction (p < 0.001); similarly eGFR <60 ml/min/1.73(2) predicted an 8.4 mmHg lesser longitudinal SBP reduction (p < 0.001) and a 4.5 lesser longitudinal DBP reduction (p < 0.001). Presence of either micro- or macro-albuminuria, or lower eGFR, also significantly delayed the time to attainment of goal BP.

CONCLUSIONS

These data suggest that an attenuated decline in BP in drug-treated hypertensives, resulting in higher average BP levels over the long-term, may mediate a portion of the increased risk of cardiovascular-renal disease linked to elevated urinary albumin excretion and reduced eGFR.

Use of trifluoroacetic acid to quantify small, polar compounds in rat plasma during discovery-phase pharmacokinetic evaluation

Although it is accepted that trifluoroacetic acid (TFA) can cause suppression of an analyte during LC/MS analysis, this paper presents a relatively sensitive gradient method that uses a TFA mobile phase for the improved quantification of small, polar drug-like compounds. The described method was developed in a discovery drug metabolism and pharmacokinetics (DMPK) laboratory for the screening measurement of compound concentrations to calculate PK parameters and CNS exposure of compounds from a chemical series that had poor chromatography under generic methods using formic acid mobile phase. The samples were collected by a Culex automated sampling unit, and the plasma proteins were precipitated by a Tecan robot in 96-well plates. After centrifugation, the supernatant was removed, dried down using a SPE-Dry unit, and the samples were reconstituted in aqueous buffer on the robot. The samples were analyzed on an Agilent LC/MSD using a 5-min gradient on a 5 cm phenyl column. No additional steps, such as the "TFA-fix", were necessary. Although sample batches were analyzed over 6h, no drift or degradation of signal was observed. The improved chromatography resulted in a method that was selective, rugged, and had a dynamic range from 5 to 20,000 nM, which was sufficient to quantitate low volume, serial plasma samples collected out to 8 h postdose.

Immunological and hematological effects observed in B6C3F1 mice exposed to JP-8 jet fuel for 14 days

JP-8 is the primary jet fuel used by the U.S. Air Force and NATO allies. Exposure is likely to be widespread and to include both military and aviation industry personnel as well as residents living near fuel contaminated sites. This study examines the effects of JP-8 on humoral and cell-mediated and hematological parameters. A suite of immunotoxicological endpoints was evaluated in adult female B6C3F1 mice gavaged with JP-8 (in an olive oil carrier) ranging from 250-2500 mg/kg/d for 14 d. One day following the last exposure, significant increases in liver mass were detected beginning at exposure levels of 1000 mg/kg/d, while thymic mass was decreased at exposure levels of 1500 mg/kg/d and above. Decreases in thymic cellularity, however, were only observed at exposure levels of 2000 mg/kg/d and above. Mean corpuscular volume was increased (1500-2500 mg/kg/d), while the hematocrit, hemoglobin concentration, and red blood cell count were decreased only at the 2500 mg/kg/d exposure level. Natural killer cell (NK) activity and T- and B-cell proliferation were not altered. Decreases in the plaque-forming cell (PFC) response were dose responsive at levels of 500 mg/kg/d and greater, while unexpectedly, serum levels of anti-SRBC immunoglobulin M (IgM) were not altered. Alterations were detected in thymic and splenic CD4/8 subpopulations, and proliferative responses of bone marrow progenitor cells were enhanced in mice exposed to 2000 mg/kg/d of JP-8. This study establishes that humoral immune function is impaired with lower exposure levels of JP-8 than are required to affect primary and secondary immune organ weights and cellularities, CD4/8 subpopulations, and hematological endpoints.

Determinants of blood pressure response to quinapril in black and white hypertensive patients: the Quinapril Titration Interval Management Evaluation trial

Race has been considered an important factor in determining blood pressure response to treatment and selection of antihypertensive drug therapy. Data collected during a clinical trial that evaluated rapidity of medication up-titration with blood pressure response to monotherapy with the angiotensin-converting enzyme (ACE) inhibitor quinapril were used to characterize response in 533 black and 2046 white participants. Our objectives were to examine the influence of race and other factors on blood pressure response and to assess the degree to which nonrace factors account for apparent racial differences in response. Average systolic and diastolic blood pressure responses (baseline minus follow-up) to treatment were assessed with treatment groups combined. Crude systolic and diastolic blood pressure responses averaged 4.7 and 2.4 mm Hg less, respectively, in black compared with white participants; however, the response distributions largely overlapped. In multivariate linear regression models adjusted for study design variables and measured participant characteristics, the racial difference in systolic response was reduced by 51% to 2.3 mm Hg, and diastolic response by 21% to 1.9 mm Hg. In these models, participant characteristics, including age, gender, body size, and pretreatment blood pressure severity, significantly predicted either attenuated or enhanced blood pressure response to treatment. Our findings demonstrate that a large source of variability of blood pressure response to treatment is within, not between, racial groups, and that factors that vary at the level of the individual contribute to apparent racial differences in response to treatment.

Kallikrein-binding protein inhibits retinal neovascularization and decreases vascular leakage

AIMS/HYPOTHESIS

Kallikrein-binding protein (KBP) is a serine proteinase inhibitor (serpin). It specifically binds to tissue kallikrein and inhibits kallikrein activity. Our study was designed to test its effects on retinal neovascularization and vascular permeability.

METHODS

Endothelial cell proliferation was determined by [(3)H] thymidine incorporation assay and apoptosis quantified by Annexin V staining and flow cytometry. Effect on retinal neovascularization was determined by fluorescein angiography and count of pre-retinal vascular cells in an oxygen-induced retinopathy (OIR) model. Vascular permeability was assayed by the Evans blue method. Vascular endothelial growth factor (VEGF) was measured by Western blot analysis and ELISA.

RESULTS

Kallikrein-binding protein specifically inhibited proliferation and induced apoptosis in retinal capillary endothelial cells. Intravitreal injection of KBP inhibited retinal neovascularization in an OIR model. Moreover, KBP decreased vascular leakage in the retina, iris and choroid in rats with OIR. Blockade of kinin receptors by specific antagonists showed significantly weaker inhibition of endothelial cells, when compared to that of KBP, suggesting that the anti-angiogenic activity of KBP is not through inhibiting kallikrein activity or kinin production. KBP competed with (125)I-VEGF for binding to endothelial cells and down-regulated VEGF production in endothelial cells and in the retina of the OIR rat model.

CONCLUSION/INTERPRETATION

Kallikrein-binding protein is a multi-functional serpin, and its vascular activities are independent of its interactions with the kallikrein-kinin system. Inhibition of VEGF binding to its receptors and down-regulation of VEGF expression could represent a mechanism for the vascular activities of KBP.

Effects of telmisartan on arterial stiffness in Type 2 diabetes patients with essential hypertension

Arterial wall stiffness, an important independent risk factor for cardiovascular disease in patients with hypertension, is worsened by the coexistence of diabetes mellitus. This randomised, prospective, double-blind, crossover trial assessed the effects of telmisartan on arterial stiffness in patients with Type 2 diabetes with essential hypertension. After a two-week placebo wash out period, 28 ambulatory patients received telmisartan (40 mg) or placebo for three weeks. Following a second two-week placebo wash out period, patients received the alternate treatment for a further three weeks. Augmentation index and central blood pressure (BP) were determined using the SphygmoCor device and pulse wave velocity (PWV) was measured using an automatic device, the Complior trade mark, at the beginning and the end of each period. Telmisartan significantly reduced the carotid femoral PWV compared with placebo (mean adjusted treatment difference 0.95 m/s; 95% CI: 1.67, 0.23 m/s; p=0.013). Peripheral and central diastolic, systolic and pulse pressures were also significantly reduced with telmisartan compared with placebo. In conclusion, telmisartan reduces arterial stiffness and peripheral and central BPs as assessed by PWV and pulse contour analysis in hypertensive patients with Type 2 diabetes. These properties of telmisartan suggest that it may improve cardiovascular outcome in this patient population.

New salt-sensitivity metrics: variability-adjusted blood pressure change and the urinary sodium-to-creatinine ratio

DESIGN

We report the results of a 24-week, placebo-controlled, two-period, crossover trial of sodium supplementation in 112 normotensive African Americans, aged 25 to 64 years, with average blood pressure (BP) of 105/70 mm Hg. Estimated 24-hour urinary sodium excretion was 133.6 mmol; the average urinary sodium-to-creatinine ratio was 0.74.

METHODS

Variability-adjusted BP change was the difference in BP level after the respective treatment periods, divided by the intra-person standard deviation of the average BP obtained at 3 consecutive screening visits during a 4-week period.

RESULTS

The urinary sodium-to-creatinine ratio and the total urine sodium content were 37.8% and 26.5% higher, respectively, at the end of the sodium treatment period. Twenty-four hour ambulatory BP change (mm Hg) (95% CI) was systolic 1.2 (0, 2.4), and diastolic 0.7 (-0.3, 1.8); cuff BP change was systolic 0.9 (-1, 2.9), and diastolic 1.4 (0.1, 2.7). Variability-adjusted BP change was systolic 0.2 (-0.4, 0.8) and diastolic 0.4 (-0.1, 0.9). Though variability-adjusted and unadjusted SBP change correlated highly (r = 0.941, P<.001), only the former correlated with body mass index (r = 0.224, P<.05), a known correlate of salt sensitivity. While total urinary sodium content in timed urine collections and urinary sodium-to-creatinine ratio correlated (r = 0.727, P<.001), neither correlated with cuff BP changes. Change in urinary sodium-to-creatinine ratios of 3 consecutive pooled overnight 8-hour urine collections correlated with changes in 24-hour ambulatory SBP (r = 0.294, P<.001) and DBP (r = 0.193, P<.05); however, change in total urinary sodium content was uncorrelated. Total urinary sodium content of these pooled collections (P = .001), but not the urinary sodium-to-creatinine ratio, was positively related to urinary creatinine excretion per kilogram of body weight, the latter being an indicator of urine collection duration.

CONCLUSIONS

The lack of effect of the duration of urine collection on the urinary sodium-to-creatinine ratio is advantageous in individuals who may report inaccurately the duration of their urine collection. Sequential regression analyses demonstrated that the urinary sodium-to-creatinine ratio conveyed all of the changes in urinary sodium excretion information contained in aggregate urinary sodium excretion-and more. Variability-adjusted BP change was the more sensitive metric of BP response to dietary sodium manipulations, than unadjusted BP change. Thus, variability-adjusted BP change and the urinary sodium-to-creatinine ratio appear to be incrementally better metrics of salt sensitivity than those traditionally used.

Disease-free survival difference between African Americans and whites after radical prostatectomy for local prostate cancer: a multivariable analysis

OBJECTIVES

Age-adjusted mortality rates (per 100,000) for men with prostate cancer from 1991 through 1997 reported by the Surveillance, Epidemiology, and End Results national registry have consistently demonstrated that African-American men (AAM) have twice the death rate of white men (WM). However, there has been considerable controversy as to how this relates to progression-free survival among these men. In an attempt to address this controversy of localized prostate cancer, we report on a multivariable analysis of survival data of a large number of AAM and WM who underwent radical prostatectomy.

METHODS

The study cohort was composed of 791 men whose only prostate cancer treatment was radical prostatectomy performed between July 1990 and December 1999. The variables analyzed were age, preoperative prostate-specific antigen level, pathologic grade and stage, and race/ethnicity. Pathologic examination of all specimens was performed in a uniform manner according to an established protocol. Multivariable analysis based on Cox's proportional hazards regression model was performed to assess whether a significant difference in progression-free survival time between AAM and WM persisted after controlling for the main effects of other prognostic factors.

RESULTS

The study cohort consisted of 229 AAM and 562 WM. Our results indicated that all variables, except age, had highly significant effects on progression-free survival, even in the presence of other predictors.

CONCLUSIONS

The effects of age, preoperative serum prostate-specific antigen level, and pathologic grade and stage did not account for the racial disparity in progression-free survival among men diagnosed with clinically localized prostate cancer and treated with radical prostatectomy.

Evaluation of immunotoxicity induced by single or concurrent exposure to N,N-diethyl-m-toluamide (DEET), pyridostigmine bromide (PYR), and JP-8 jet fuel

Approximately 5,000 to 80,000 of the US service personnel involved in the Persian Gulf War have complained of a variety of nonspecific symptoms since their return in 1991. These symptoms have been collectively labeled Gulf War Illness and include muscle fatigue, general malaise, myalgia, impaired cognition, ataxia, headaches, fever, joint pain, skin rash, gastrointestinal disturbances, sleep disturbances, and respiratory difficulties. Exposures of military and service personnel were diverse and included the prescribed anti-nerve gas agent pyridostigmine bromide (PYR), N.N-diethyl-m-toluamide (DEET) insect repellent, and environmental exposures to jet fuel. Thus, studies in our laboratory were undertaken to determine if concurrent exposure to these agents, singly or in combination, would contribute to significant alterations in immunological function and disease susceptibility. To assess immune status, eight-week old B6C3F1 female mice were exposed for 14 days to single compounds or tertiary mixtures of 15.5 mg/kg DEET, 2 mg/kg PYR, and 500 mg/kg JP-8 (termed low dose), or 31 mg/kg DEET, 5 mg/kg PYR, and 1,000 mg/kg JP-8 (termed high dose). Immunosuppression was assessed 24 h after the last exposure. No remarkable alterations were evident in hematological parameters, spleen and thymus organ weight and total cellularity, natural killer (NK) cell activity, cytotoxic T-cell activity, or mitogen-induced lymphocyte proliferation after exposure to either single or tertiary mixtures at low or high doses. A few changes in CD4/CD8 flow cytometric lymphocyte subpopulations were detected after exposure to the tertiary mixture at the high dose. Delayed type hypersensitivity (DTH) was decreased by 88% after exposure to the high-dose mixture, and suppression of antibody-specific IgM immune responses (plaque-forming cell, PFC) occurred after exposure to all single and tertiary mixtures at both dose levels. In the PFC response, antagonism was apparent in the mixture, while coexposure to these agents resulted in a synergistic effect in the DTH response. Susceptibility to B16F10 tumor or Listeria monocytogenes challenge was not affected after single or tertiary exposures. These data suggest that combined exposure to DEET, PYR, and JP-8 does not profoundly alter many immunological endpoints, but does selectively target functional endpoints such as the PFC and DTH response. This should be considered when assessing human health risks in the military environment.

Fish oil supplementation does not impair the gut immune response to Trichinella spiralis infection in rats

BACKGROUND

Fish oil has been recommended as a source of omega-3 fatty acids for preterm infants and for therapy of some inflammatory diseases.

METHODS

Because fish oil supplementation could downregulate the host's immune response, we studied the gut inflammatory response to an enteric infection in 72 rats assigned to three dietary groups with differing fatty acid profile: 1) fish oil, rich in eicosapentaenoic and docosahexaenoic acid; 2) olive oil, containing 71% monounsaturated fat; and 3) rat chow, containing 57% saturated fat. One half (n = 36) of the rats were infected with Trichinella spiralis larvae; the other half served as controls. The inflammatory response to initial infection (study 1), and type I hypersensitivity response to a subsequent parasite-derived antigenic challenge (study 2) were assessed. Jejunal inflammatory cell infiltrate, mean villus height, disaccharidase levels, changes in short-circuit current in response to glucose absorption, and chloride secretagogues (study 1) were measured 9 days after infection. Short-circuit current changes induced by chloride secretion were measured when the proximal jejunum was challenged with T. spiralis-derived antigen 40 days after infection (study 2).

RESULTS

In study 1, jejunal tissue from infected animals had more eosinophilic infiltrate, lower disaccharidase levels, and less glucose absorptive and chloride secretory capacity than tissue from noninfected animals. In study 2, the jejunum of infected animals showed an antigen-induced chloride secretory response, whereas no response was obtained from jejunal tissue from noninfected animals. Type of diet did not affect the response in either study.

CONCLUSION

Under the conditions of this experiment, fish oil supplementation did not interfere with the local intestinal inflammatory response after T. spiralis infection.

Induction of uncoupling protein expression in brown and white adipose tissue by leptin

Deposition of excess body fat occurs when energy intake chronically exceeds energy expenditure. In ob/ob mice, the absence of leptin affects both components of the energy balance equation, and the mice become morbidly obese after weaning. Treatment of ob/ob mice with exogenous leptin reduces body weight by decreasing food intake and stimulating energy utilization, but even when saline- and leptin-injected ob/ob mice are pair-fed, mice receiving leptin lose significantly more weight. Therefore, the purpose of the present study was to test the hypotheses that uncoupling protein-1 (UCP1) expression is reduced in adipose tissue from ob/ob mice and is restored by treatment with exogenous leptin. Lean and ob/ob mice (5-6 weeks old) were housed at 23 C and treated with leptin (20 microg/g BW x day) for 3 days before they were killed. Compared with levels in lean littermates, UCP1 messenger RNA (mRNA) and protein levels were lower in brown adipose tissue (BAT) and retroperitoneal white adipose tissue (WAT) from ob/ob mice. Treatment of ob/ob mice with leptin reduced body weight and produced a 4- to 5-fold increase in UCP1 mRNA levels in both interscapular BAT and retroperitoneal WAT. The increases in UCP1 mRNA were accompanied by comparable increases in UCP1 protein in mitochondrial preparations from each tissue. Given that the sole known function of UCP1 is to uncouple oxidative phosphorylation, the present results are consistent with the conclusion that leptin stimulates energy utilization in ob/ob mice by increasing thermogenic activity and capacity (UCP1). In addition, the present results suggest that decreased UCP1 expression in BAT and WAT of ob/ob mice is in part responsible for their increased metabolic efficiency and propensity to become obese.

Inconclusive clinical and ultrasound evaluation of the scrotum: impact of magnetic resonance imaging on patient management and cost

OBJECTIVES

To determine the diagnostic utility and net cost of magnetic resonance imaging (MRI) in the management of clinically and sonographically inconclusive scrotal lesions.

METHODS

A multicenter retrospective review identified 34 patients diagnosed with scrotal MRI following inconclusive clinical and ultrasound (US) evaluation. Final diagnoses were based on surgery (n = 18) or clinical and US follow-up (n = 16). Final diagnoses of 29 testicular lesions were as follows: orchitis (n = 11), infarct (n = 6), neoplasm (n = 6), rupture (n = 3), torsion (n = 2), and radiation fibrosis (n = 1). Final diagnoses of five extratesticular lesions were as follows: epididymitis (n = 2), epididymal abscess (n = 2), and neoplasm (n = 1). Management plans prior to and following MRI findings were formulated by a general urologist and a urologic oncologist. The costs of the pre-MRI and post-MRI management plans were estimated using the Medicare reimbursement schedule.

RESULTS

The leading US diagnosis was correct for 10 of 34 patients (29%) and the leading MRI diagnosis was correct for 31 of 34 patients (91%). MRI improved the management plan of the general urologist and urologic oncologist in 19 patients (56%) and 17 patients (50%), respectively. MRI worsened the management plan of both clinicians in 1 patient. Management was unchanged in all other patients. The overall net cost savings were $543 to $730 per patient for the urologic oncologist and the general urologist, respectively, and $3833 per patient originally scheduled for surgery.

CONCLUSIONS

Use of MRI after inconclusive clinical and US evaluation of scrotal lesions may improve management, decrease the number of surgical procedures, and result in net cost savings.

Vertebral artery injury during anterior decompression of the cervical spine. A retrospective review of ten patients

Ten patients who suffered iatrogenic injury to a vertebral artery during anterior cervical decompression were reviewed to assess the mechanisms of injury, their operative management, and the subsequent outcome. All had been undergoing a partial vertebral body resection for spondylitic radiculopathy or myelopathy (4), tumour (2), ossification of the posterior longitudinal ligament (1), nonunion of a fracture (2), or osteomyelitis (1). The use of an air drill had been responsible for most injuries. The final control of haemorrhage had been by tamponade (3), direct exposure and electrocoagulation (1), transosseous suture (2), open suture (1), or open placement of a haemostatic clip (3). Five patients had postoperative neurological deficits, but most of them resolved. We found direct arterial exposure and control to be safe, quick and reliable. Careful use of the air drill, particularly in pathologically weakened bone, as in infection or tumour, is essential. Arterial injury is best avoided by a thorough knowledge of the anatomical relationships of the artery, the spinal canal, and the vertebral body.

Acute childbirth morbidity: its measurement using hospital charges

OBJECTIVES

An analytic descriptive analysis of acute childbirth morbidity was carried out at Duke University Medical Center, comparing patients delivered by primary cesarean section with those delivered vaginally.

STUDY DESIGN

All primary cesarean deliveries and vaginal deliveries from July 1, 1981, through June 30, 1986, were combined with maternal and infant charge data. A total of 7256 patients were analyzed. A description of the charges for the associated diagnoses was carried out. A morbidity index was used to identify differences in predicted median hospital charges with 95% confidence intervals.

RESULTS

The ratio of mean primary cesarean delivery to mean vaginal delivery total charges was 2.5:1. The magnitude of the mean hospital charges was inversely related to the frequency of the indication with the lowest charges associated with dystocia and the highest with multiple pregnancy. Antepartum risk factors (increased maternal age, patient referral) were associated with increases in maternal and infant morbidity as measured by the morbidity index. Chronic maternal hypertension resulted in decreased maternal morbidity but increased infant morbidity when primary cesarean delivery was used. Although preterm delivery was associated with large increases in charges, it was not significantly altered by using primary cesarean delivery. Risk factors associated with the management of abnormalities of labor were associated with decreases in maternal and infant morbidity when primary cesarean delivery was used.

CONCLUSION

Analysis of acute childbirth morbidity, as measured by hospital charges, showed marked variation of diagnosis and risk-specific charges for patients delivered by primary cesarean section.

Bone morphogenetic protein-2b stimulation of growth and osteogenic phenotypes in rat osteoblast-like cells: comparison with TGF-beta 1

The biologic effects of recombinant human bone morphogenetic protein-2b (BMP-2b = BMP-4) were studied and compared with transforming growth factor-beta 1 (TGF-beta 1) in fetal rat osteoblast-like (ROB) cells. Similar to the effects of TGF-beta 1, BMP-2b stimulated DNA and collagen synthesis as well as protein accumulation. Unlike TGF-beta 1, which inhibited alkaline phosphatase activity, BMP-2b enhanced enzyme activity eight-to ninefold over the control level. The present study demonstrates direct actions of BMP-2b on bone-associated cells to stimulate osteogenic phenotypes in vitro and provides a cellular mechanism for the induction of bone formation by BMP-2b in vivo.

Bone-inducing activity of mature BMP-2b produced from a hybrid BMP-2a/2b precursor

The human osteoinductive proteins BMP-2a and BMP-2b have been cloned and expressed in mammalian cells. In order to improve expression levels we examined the role of the proregion in assembly and export. Use of the BMP-2a proregion combined with the mature region of BMP-2b leads to dramatically improved expression of mature BMP-2b. Mature BMP-2b has been purified to near homogeneity from the BMP-2a/2b hybrid, and its structural properties and biological activity determined. Recombinant mature BMP-2b homodimer elicits bone formation in vivo.