Invited article: millimeter-wave bolometer array receiver for the Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument

The Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument is a millimeter-wave cryogenic receiver designed to observe galaxy clusters via the Sunyaev-Zel'dovich effect from the 12 m APEX telescope on the Atacama plateau in Chile. The receiver contains a focal plane of 280 superconducting transition-edge sensor (TES) bolometers instrumented with a frequency-domain multiplexed readout system. The bolometers are cooled to 280 mK via a three-stage helium sorption refrigerator and a mechanical pulse-tube cooler. Three warm mirrors, two 4 K lenses, and a horn array couple the TES bolometers to the telescope. APEX-SZ observes in a single frequency band at 150 GHz with 1' angular resolution and a 22' field-of-view, all well suited for cluster mapping. The APEX-SZ receiver has played a key role in the introduction of several new technologies including TES bolometers, the frequency-domain multiplexed readout, and the use of a pulse-tube cooler with bolometers. As a result of these new technologies, the instrument has a higher instantaneous sensitivity and covers a larger field-of-view than earlier generations of Sunyaev-Zel'dovich instruments. The TES bolometers have a median sensitivity of 890 μK(CMB)√s (NEy of 3.5 × 10(-4) √s). We have also demonstrated upgraded detectors with improved sensitivity of 530 μK(CMB)√s (NEy of 2.2 × 10(-4) √s). Since its commissioning in April 2007, APEX-SZ has been used to map 48 clusters. We describe the design of the receiver and its performance when installed on the APEX telescope.

CT-guided biopsies: quality, complications and impact on treatment: a retrospective initial quality control

PURPOSE

To retrospectively evaluate the quality and complications of CT-guided biopsies and their impact on treatment.

MATERIALS AND METHODS

A total of 265 CT-guided interventions performed during a 6-month period were extracted by digital database query. These included 127 CT-guided biopsies, which were classified by patient age, organ/body area, histopathological biopsy diagnosis, complications, and performing physician.

RESULTS

In 51 % of cases (65 / 127), CT-guided biopsies led to a malignant diagnosis and a change in the patient's treatment. Retrospectively, complications were to be expected in a range of 12 - 26 %, given a 95 % confidence interval. In terms of organ/body area, most complications occurred in lung biopsies (23 / 56; 41 %). 80 % of CT-guided biopsies were performed without complications. 2 of the 11 physicians performed 66 % of all biopsies (84 / 127) and had significantly fewer complications than the others. Patient age was a statistically significant factor for complications (p < 0.018) as well as for a malignant biopsy diagnosis (p < 0.009).

CONCLUSION

Our initial quality control assessment suggests that frequent use of CT-guided biopsy by the performing physician rather than the general level of experience is associated with fewer complications for patients. Age is a significant factor for complications of CT-guided biopsies, thus leading to an increased risk/benefit ratio. As expected, age also significantly increases the risk of a malignant biopsy result. Complications and malignant biopsy results were not significantly associated. CT-guided biopsies triggered a change in treatment in over 50 % of cases.

Relationship between active inflammatory lesions in the spine and sacroiliac joints and new development of chronic lesions on whole-body MRI in early axial spondyloarthritis: results of the ESTHER trial at week 48

AIM

To investigate the relationship between active inflammatory lesions on whole-body MRI (wb-MRI) and new development of chronic lesions on T1 MRI in patients with early axial spondyloarthritis (SpA) treated either with etanercept (ETA) or sulfasalazine (SSZ).

METHODS

Wb-MRIs of 65 patients treated either with ETA (n=35) or SSZ (n=30) over 1 year were scored for active inflammation, fatty lesions, erosions and ankylosis in the 23 vertebral units (VUs) of the spine and in the sacroiliac joints (SI joints). Scoring was performed by two blinded radiologists.

RESULTS

If there was no previous inflammation in the bone no new fatty lesions occurred in SI joint quadrants and only a few (0.6%) in spine VUs. There was a significant relationship between disappearance of inflammation and the appearance of fatty lesions: if baseline inflammation resolved fatty lesions occurred in 10.5% of SI joint quadrants and 17.9% of VUs. If inflammation did not resolve over 1 year, fatty lesions occurred less frequently: 2.4% (SI joint quadrants) and 7.2% (VUs). There was a significantly higher increase of the mean fatty lesion score between baseline and week 48 in the ETA (4.0 vs 4.8 for the SI joints and 1.9 vs 2.7 for the spine) compared to the SSZ (3.0 vs 3.2 for the SI joints and 1.1 vs 1.2 for the spine, respectively) group (p=0.001 and p=0.020 for the differences). No significant changes in the erosion or ankylosis score were observed in any of the two groups during this time.

CONCLUSIONS

These data indicate that there is a close interaction between inflammation, tumour necrosis factor blockade and the development of fatty lesions in subchondral bone marrow of patients with axial SpA.

Hepatic artery pseudoaneurysms arising from within a hepatocellular carcinoma

We report a case of a 70-year-old man with a large hepatocellular carcinoma (HCC) containing two pseudoaneurysms measuring up to 2 cm in diameter. The pseudoaneurysms and part of the HCC were supplied by branches from the middle colic artery, which arises from the superior mesenteric artery. This complex arterial vasculature was visualised on CT and confirmed with conventional angiography.

Attitudes and knowledge of medical and nursing staff toward elder abuse

Although physicians and nurses are best positioned to recognize and diagnose cases of elder abuse, the level of reporting these cases is much lower than its true incidence. Our aim was to assess and compare knowledge and attitudes of physicians and nurses toward this phenomenon. Two hundred and thirty-five nurses and physicians were asked to participate in the study. One hundred nurses and 57 physicians ultimately completed the questionnaires. The main finding was that participants had a low level of knowledge of elder abuse issues and the relevant laws and regulations (mean correct answers 5.36+/-1.45 of 10 and 4.67+/-1.34 of 8, respectively). No significant differences were found in the physicians' knowledge according to medical specialty, hospital type, years in the profession and geriatric experience. Licensed practical nurses knew less than registered and academic nurses relating to the abuse issue and state reporting laws (p=0.003 and 0.02, respectively). No significant differences relating to the knowledge of elder abuse were found between nurses and physicians nor between general and geriatric hospital employees. Both physicians and nurses tended to have neutral attitudes regarding this issue. However, employees of geriatric hospitals had better attitudes than general hospital workers (p=0.008). Most responders believed that the unwillingness to get legally involved had been the main reason of not reporting suspected cases. This study emphasizes the need to take more efficient measures to improve the knowledge of the medical and nursing staff concerning elder abuse and to encourage medical personnel to be more concerned and involved in the safeguarding of the elderly.

Circadian activity associated with spatial learning and memory in aging rhesus monkeys

In rodents, spatial learning and memory tests require navigation, whereas in nonhuman primates these tests generally do not involve a navigational component, thus assessing nonhomologous neural systems. To allow closer parallels between rodent and primate studies, we developed a navigational spatial learning and memory task for nonhuman primates and assessed the performance of elderly (19-25 years) female rhesus monkeys (Macaca mulatta). The animals were allowed to navigate in a room containing a series of food ports. After they learned to retrieve food from the ports, a single port was repeatedly baited and the animals were tested until they learned the correct location. The location of the baited port was then changed (shift position). We also determined whether test performance was associated with circadian activity measured with accelerometers. Performance measures included trials to criterion, search strategies, and several indices of circadian activity. Animals learned the task as reflected in their search strategies. Correlations were found between the number of initial or shift trials and circadian activity parameters including day activity, dark:light activity ratio, sleep latency, and wake bouts. Thus, disruptions in circadian rhythms in nonhuman primates are associated with poorer performance on this novel test. These data support the usefulness of this spatial navigational test to assess spatial learning and memory in rhesus monkeys and the importance of circadian activity in performance.

Body mass index and risk of all-cause and cardiovascular mortality in hospitalized elderly patients with diabetes mellitus

AIMS

Obesity is linked to increased morbidity and mortality risk in both the general population and in patients with diabetes mellitus; however, recent reports suggest that, in hospitalized elderly individuals, the association between body mass index (BMI) and mortality may be inverse. The present study sought to investigate the association between BMI and survival in hospitalized elderly individuals with diabetes mellitus.

METHODS

The medical records of 470 patients (226 males, mean age of 81.5 +/- 7.0 years) admitted to an acute geriatric ward between 1999 and 2000 were reviewed. Of the 140 patients with diabetes mellitus, 122 had more than 6 months of follow-up and were included in this analysis. Patients were followed up until 31 August 2004. Mortality data were extracted from death certificates.

RESULTS

During a mean follow-up of 3.7 +/- 1.6 years, 69 (56.6%) subjects died, 31 (25.4%) from cardiovascular causes. Those who died from any cause had lower baseline BMI than those who survived (24.0 +/- 4.0 vs. 27.1 +/- 4.3 kg/m(2); P < 0.0001). Similarly, those who died of cardiovascular causes had lower baseline BMI than those who did not (23.7 +/- 3.6 vs. 25.9 +/- 4.5, P = 0.01). BMI was inversely associated with all-cause [relative risk (RR) 0.89, 95% confidence interval (CI) 0.83-0.96, P = 0.002] and cardiovascular death (RR 0.83, 95% CI 0.74-0.93, P = 0.002) even after controlling for age, sex, smoking, dyslipidaemia and reason for hospital admission.

CONCLUSIONS

In very elderly subjects with diabetes mellitus, increased BMI was associated with reduced mortality risk.

Multiple granulomas in three squirrel monkeys (Saimiri sciureus) caused by Mycobacterium microti

Mycobacterium microti, a member of the Mycobacterium tuberculosis complex, causes tuberculosis in small rodents and occasionally in other mammals including man. Three adult male squirrel monkeys, two with a history of lethargy, weakness and stridor and one with paralysis of the hind legs, were presented for necropsy. One of the two lethargic animals showed multiple granulomas in the mesentery, mesenteric lymph nodes, lung, liver, kidneys and spleen, while the other showed granulomas only in the lung. The animal with paralysis of the legs had an abscess-like lesion in the skeletal muscle of the neck, granulomas in the mesenteric and mediastinal lymph nodes, and a fracture of the thirteenth thoracic vertebra with severe lesions of the spinal cord. Histologically the granulomas showed typical features of tuberculous granulomas, i.e., central necrosis surrounded by epithelioid cells, multinucleated giant cells, inflammatory cells and a border of connective tissue. Ziehl-Neelsen stain demonstrated sporadic acid-fast bacilli within the granulomas, these organisms being identified as M. microti by microbiological and molecular methods.

The trans-neptunian object UB313 is larger than Pluto

The most distant known object in the Solar System, 2003 UB313 (97 au from the Sun), was recently discovered near its aphelion. Its high eccentricity and inclination to the ecliptic plane, along with its perihelion near the orbit of Neptune, identify it as a member of the 'scattered disk'. This disk of bodies probably originates in the Kuiper belt objects, which orbit near the ecliptic plane in circular orbits between 30 and 50 au, and may include Pluto as a member. The optical brightness of 2003 UB313, if adjusted to Pluto's distance, is greater than that of Pluto, which suggested that it might be larger than Pluto. The actual size, however, could not be determined from the optical measurements because the surface reflectivity (albedo) was unknown. Here we report observations of the thermal emission of 2003 UB313 at a wavelength of 1.2 mm, which in combination with the measured optical brightness leads to a diameter of 3,000 +/- 300 +/- 100 km. Here the first error reflects measurement uncertainties, while the second derives from the unknown object orientation. This makes 2003 UB313 the largest known trans-neptunian object, even larger than Pluto (2,300 km). The albedo is 0.60 +/- 0.10 +/- 0.05, which is strikingly similar to that of Pluto, suggesting that the methane seen in the optical spectrum causes a highly reflective icy surface.

Hysteroscopy may be justified after two miscarriages

BACKGROUND

Recurrent pregnancy loss is traditionally investigated after three or more consecutive pregnancy losses. Although there is a trend to start investigation after two miscarriages, data are not available to date to justify this approach. We sought to compare the frequency of uterine anomalies between women referred to hysteroscopy for repeated miscarriages after two, and three or more, miscarriages respectively.

METHODS

A retrospective analysis of acquired and congenital uterine anomalies in all patients undergoing hysteroscopy for repeated pregnancy loss at an academic and referral medical centre.

RESULTS

Hysteroscopy was performed on 165 women referred for recurrent pregnancy loss: 67 after two and 98 after three or more consecutive miscarriages. The rate of uterine anomalies did not differ significantly and was 32 versus 28% respectively.

CONCLUSIONS

Hysteroscopy may be justified following two spontaneous pregnancy losses.