Robustness of cancer microbiome signals over a broad range of methodological variation

In 2020, we identified cancer-specific microbial signals in The Cancer Genome Atlas (TCGA) [1]. Multiple peer-reviewed papers independently verified or extended our findings [2-12]. Given this impact, we carefully considered concerns by Gihawi et al. [13] that batch correction and database contamination with host sequences artificially created the appearance of cancer type-specific microbiomes. (1) We tested batch correction by comparing raw and Voom-SNM-corrected data per-batch, finding predictive equivalence and significantly similar features. We found consistent results with a modern microbiome-specific method (ConQuR [14]), and when restricting to taxa found in an independent, highly-decontaminated cohort. (2) Using Conterminator [15], we found low levels of human contamination in our original databases (~1% of genomes). We demonstrated that the increased detection of human reads in Gihawi et al. [13] was due to using a newer human genome reference. (3) We developed Exhaustive, a method twice as sensitive as Conterminator, to clean RefSeq. We comprehensively host-deplete TCGA with many human (pan)genome references. We repeated all analyses with this and the Gihawi et al. [13] pipeline, and found cancer type-specific microbiomes. These extensive re-analyses and updated methods validate our original conclusion that cancer type-specific microbial signatures exist in TCGA, and show they are robust to methodology.

Patterns of colorectal cancer screening and adherence rates among an average-risk population enrolled in a national health insurance provider during 2009-2018 in the United States

While colorectal cancer (CRC) is the second leading cause of cancer-related mortality in the United States (US), outcomes can be improved through timely screening. Despite the benefits and widespread availability of screening tests, adherence to recommended screening strategies is low. The study aimed to provide recent evidence regarding screening rates and adherence to screening recommendations among adults at average risk for CRC in a commercially insured and Medicare Advantage population. De-identified administrative data from a large US research database were examined to determine screening rates for the years 2009 through 2018. The study population included adults aged 50-75 years and annual study population counts ranged from 1,390,594 in 2009 to 1,654,544 in 2018. Incident screening rates were found to be relatively stable across the study years (approximately 15 %) with adherence lowest in the youngest age group (ages 50-54 years). Colonoscopies accounted for approximately 50 % of all screening tests performed, while there was a substantial increase in the use of home-based screening tests over the study timeframe. The use of the fecal immunochemical test increased from 17.2 % in 2009 to 28.9 % in 2018 and the multi-target stool DNA test increased from 0.4 % in 2015 to 9.0 % in 2018. Overall though, CRC screening and adherence rates remain relatively low among adults at average risk for CRC in the US. Improving adherence rates with CRC screening recommendations among individuals at average risk for CRC is required to improve health outcomes.

Comparative effectiveness of safety planning intervention with instrumental support calls (ISC) versus safety planning intervention with two-way text message caring contacts (CC) in adolescents and adults screening positive for suicide risk in emergency departments and primary care clinics: Protocol for a pragmatic randomized controlled trial

BACKGROUND

Suicide is a leading cause of death in adolescents and adults in the US. Follow-up support delivered when patients return home after an emergency department (ED) or primary care encounter can significantly reduce suicidal ideation and attempts. Two follow-up models to augment usual care including the Safety Planning Intervention have high efficacy: Instrumental Support Calls (ISC) and Caring Contacts (CC) two-way text messages, but they have never been compared to assess which works best. This protocol for the Suicide Prevention Among Recipients of Care (SPARC) Trial aims to determine which model is most effective for adolescents and adults with suicide risk.

METHODS

The SPARC Trial is a pragmatic randomized controlled trial comparing the effectiveness of ISC versus CC. The sample includes 720 adolescents (12-17 years) and 790 adults (18+ years) who screen positive for suicide risk during an ED or primary care encounter. All participants receive usual care and are randomized 1:1 to ISC or CC. The state suicide hotline delivers both follow-up interventions. The trial is single-masked, with participants unaware of the alternative treatment, and is stratified by adolescents/adults. The primary outcome is suicidal ideation and behavior, measured using the Columbia Suicide Severity Rating Scale (C-SSRS) screener at 6 months. Secondary outcomes include C-SSRS at 12 months, and loneliness, return to crisis care for suicidality, and utilization of outpatient mental health services at 6 and 12 months.

DISCUSSION

Directly comparing ISC and CC will determine which follow-up intervention is most effective for suicide prevention in adolescents and adults.

Comparative effectiveness of two versions of a caring contacts intervention in healthcare providers, staff, and patients for reducing loneliness and mental distress: A randomized controlled trial

BACKGROUND

Caring Contacts can effectively reduce suicide ideation, attempts, and death. In published clinical trials, Caring Contacts were sent by someone who knew the recipient. At scale, Caring Contacts programs rarely introduce the recipient and sender. It is not known whether receiving Caring Contacts from someone unknown is as effective as messages from someone the recipient has met.

METHODS

Pragmatic randomized controlled trial comparing Caring Contacts with (CC+) versus without an introductory phone call (CC). Recruitment occurred January-July 2021, with outcomes assessed at 6 months. Participants were primary care patients or healthcare providers/staff reporting adverse mental health outcomes on a qualifying survey. Participants were sent 11 standardized caring text messages over 6 months; when participants replied, they received personalized unscripted responses. CC+ calls were semi-structured. The primary outcome was loneliness (NIH Toolkit).

RESULTS

Participants included 331 patients (mean [SD] age: 45.5 [16.4], 78.9 % female) and 335 healthcare providers/staff (mean [SD] age: 40.9 [11.8], 86.6 % female). There were no significant differences in loneliness at 6 months by treatment arm in either stratum. In patients, mean (SD) loneliness was 61.9 (10.7) in CC, and 60.8 (10.3) in CC+, adjusted mean difference of -1.0 (95 % CI: -3.0, 1.0); p-value = 0.31. In providers/staff, mean (SD) loneliness was 61.2 (11) in CC, and 61.3 (11.1) in CC+, adjusted mean difference of 0.2 (95 % CI: -1.8, 2.2); p-value = 0.83.

LIMITATIONS

Study population was 93 % white which may limit generalizability.

CONCLUSIONS

Including an initial phone call added operational complexity without significantly improving the effectiveness of a Caring Contacts program.

Patterns of initial colorectal cancer screenings after turning 50 years old and follow-up rates of colonoscopy after positive stool-based testing among the average-risk population

OBJECTIVES

Effective colorectal cancer (CRC) screening requires proper adherence beginning at the recommended screening age. For those with positive results on stool-based tests (SBTs), a follow-up colonoscopy is warranted. The objectives of this study were to 1) examine initial screening rates after turning 50 years old; and 2) assess rates of follow-up colonoscopy after a positive SBT.

METHODS

This retrospective study used de-identified administrative claims data from 01/01/2006 to 06/30/2020 for commercially insured and Medicare Advantage enrollees. For objective 1, the index year was the year enrollees turned 50. Rates of CRC screening during and after the index year were captured. For objective 2, the index date was the claim date of a fecal immunochemical test (FIT) or multitarget stool DNA test (mt-sDNA) where linked lab data indicated a positive test result. Rates and time to follow-up colonoscopy after a positive SBT were assessed.

RESULTS

Approximately 53% of enrollees initiated CRC screening within five years after turning 50 (50+ cohort N = 718,562). Among enrollees with an available lab result indicating a positive SBT (N = 7329; 2110 FIT and 5219 mt-sDNA), overall follow-up colonoscopy within 6 months of the positive result was less than optimal (65%) and varied by modality; 72% vs 46% (p < .001) among enrollees with a positive mt-sDNA test compared to FIT test, respectively.

CONCLUSION

There is potential for improving CRC screening among the eligible average-risk population, both to start screening once they reach the screening-eligible age, and to complete the CRC screening paradigm after a positive stool-based screen.

Introduction of a standardised maternity early warning system: indicative data from a before-and-after study at a large pilot site before national rollout in Aotearoa New Zealand

Strong evidence now demonstrates that recognition and response systems using standardised early warning scores can help prevent harm associated with in-hospital clinical deterioration in non-pregnant adult patients. However, a standardised maternity-specific early warning system has not yet been agreed in the UK. In Aotearoa New Zealand, following the nationwide implementation of the standardised New Zealand Early Warning Score (NZEWS) for adult inpatients, a modified maternity-specific variation (NZMEWS) was piloted in a major tertiary hospital in Auckland, before national rollout. Following implementation in July 2018, we observed a significant and sustained reduction in severe maternal morbidity as measured by emergency response calls to women who were very unwell (emergency response team call), and a non-significant reduction in cardiorespiratory arrest team calls. Emergency response team calls to maternity wards fell from a median of 0.8 per 100 births at baseline (January 2017-May 2018) to 0.6 per 100 births monthly (from March 2019 to December 2020) (p < 0.0001). Cardiorespiratory arrest team calls to maternity wards fell from 0.14 per 100 births per quarter (quarter 1 2017-quarter 2 2018) to 0.09 calls per 100 births per quarter after NZMEWS was introduced (quarter 3 2018-quarter 4 2020) (p = 0.2593). These early results provide evidence that NZMEWS can detect and prevent deterioration of pregnant women, although there are multiple factors that may have contributed to the reduction in emergency response calls noted.

Quantitative middle cerebral artery flow in normal and vasospastic arteries

To determine the degree of MCA vasospasm necessary to exceed the ischaemic threshold of blood flow reduction to less than 1/3 normal flow, we developed a computer model of blood flow in the middle cerebral artery distribution. When solved for a 3 mm trunk diameter, it showed a normal flow of 179 ml/min. It was necessary to decrease trunk diameter by 75%, or branch diameter by 50%, or increase peripheral resistance by a factor of 3, in order to decrease blood flow to less than 1/3 normal.

Dual glutathione-S-transferase-θ1 and -μ1 gene deletions determine imatinib failure in chronic myeloid leukemia

Approximately 40% of patients with chronic myeloid leukemia (CML) receiving imatinib fail treatment. There is an increased risk of CML in subjects with (i) deletions of genes encoding glutathione-S-transferase (GST)-θ1 (GSTT1) and -μ1, (GSTM1) and (ii) the GST-π1 (GSTP1) single-nucleotide polymorphism (SNP) Ile105Val (GSTP1*B; rs1695); however, their effects on imatinib treatment outcome are not known. Here, we assess the role of these GSTs in relation to imatinib treatment outcome in 193 CML patients. Deletion of GSTT1 alone, or in combination with deletion of the GSTM1 gene, significantly increased the likelihood of imatinib failure (P = 0.021 and P < 0.001, respectively). The GSTP1*B SNP was not associated with time to imatinib failure. Losses of the GSTT1 and GSTM1 genes are therefore important determinants of imatinib failure in CML. Screening for GSTT1 and GSTM1 gene deletions during diagnosis may identify patients who may be better treated using an alternative therapy.

Outpatient-Based Pulmonary Rehabilitation for COPD: A Cost of Illness Study

Pulmonary rehabilitation (PR) as recommended by COPD guidelines is a multimodality educational, self-management, supervised exercise program, resulting in improved symptom control, quality of life, and reduction of exacerbations, but there is a need to establish the affordability of PR for healthcare providers. We designed a cost-of-illness study of PR in advanced COPD, with an 8-week hospital-based program, measuring direct healthcare costs for 12 months before and after PR. In 31 patients (female = 16), aged 68 (±8) years, and FEV1% predicted to be 40 (±16.6), there was a reduction in inpatient hospital stay by net 2.35 days (78%; ) and routine primary care visits. Costs were reduced by £1835 per person (base year 2008), with a saving of £791 to 1313 GBP per person, per year. Therefore, PR provision in COPD is likely to be affordable due to reduced direct healthcare costs, even without considering the individual and societal benefits.

The impact of bird populations on the microbiological quality of bathing waters

To ensure optimum quality at Bathing Waters, the control of diffuse sources of bacterial contamination is receiving increasing attention. As part of an initiative to improve the quality of the EU designated bathing waters on the Fylde Coast (North West England), a project was undertaken to quantify the faecal indicator load from birds and assess the significance on water quality. High bird counts are encountered on the Fylde Coast with gulls, feral pigeons and starlings being prominent. The piers at Blackpool make an attractive roost for starlings with numbers peaking at over 30,000 in late summer. Systematic recording of bird numbers and locations was undertaken during 2001/2. Estimates were also made of the daily faecal organism production by the different species. The spatial distribution of faecal organisms from the bird population was statistically linked to synoptic water quality data. This allowed estimates to be made of the contribution from birds to the faecal pollution load at the bathing waters. The work confirmed a statistically significant link between bird populations and water quality with a marked seasonal bias.

Interhemispheric asymmetry of regional cerebral blood flow in prepubescent boys with attention deficit hyperactivity disorder

The prefrontal cortex is asymmetric in both structure and function. In normal subjects, the right prefrontal cortex is activated more than the left during response inhibition. Patients with attention deficit hyperactivity disorder (ADHD) have impaired response inhibition and altered structural interhemispheric asymmetry. This study was conducted to examine the functional interhemispheric asymmetry during response inhibition in children with ADHD. Subjects were divided into three groups according to the level of motor hyperactivity. Blood flow tracer (99m)Tc-ethyl cysteinate dimer was injected while subjects were performing a response inhibition task (RIT), followed by single photon emission computerized tomography (SPECT). After three-dimensional reconstruction, filtering and smoothing, individual scans were morphed to a template. Three average group images were created from individual scans. Each average group image was subtracted voxel-by-voxel from its mirror image to compare the regional cerebral blood flow (rCBF) in the right and left cerebral hemispheres, yielding images of significant interhemispheric rCBF asymmetry. The severe hyperactivity group exhibited most prefrontal left>right rCBF asymmetry and left>right occipitoparietal asymmetry. Reversal of functional prefrontal asymmetry in boys with severe motor hyperactivity supports the hypothesis of right prefrontal cortex dysfunction in ADHD.

Safety and immunogenicity of varying dosages of trivalent inactivated influenza vaccine administered by needle-free jet injectors

To evaluate the perceived pain, other adverse events, and immunogenicity of influenza virus vaccine administered by needle-free jet injector (JI) compared with that of vaccine administered by needle and syringe (N&S), we randomly assigned 304 healthy young adults to receive one of three dosages (0.5, 0.3, or 0.2 ml) of the 1998-1999 season vaccine administered by either of two JI devices or by N&S. In multivariate analysis, female gender and JI administration were associated with higher levels of pain reported at the time of vaccination as well as with the occurrence of local injection site reactions following vaccination. Immune response did not vary significantly by dosage but administration by one JI device was associated with higher post-vaccination H1N1 antibody titers.

Neuropeptide abnormalities in patients with early Alzheimer disease

BACKGROUND

Deficits in somatostatin-like immunoreactivity (SLI) and corticotropin-releasing factor immunoreactivity (CRF-IR) are well recognized as prominent neurochemical deficits in Alzheimer disease (AD). The question of whether these profound neuropeptidergic deficits found in patients with end-stage disease extend into those with much earlier disease is relatively unanswered. To determine the relation between level of SLI and CRF-IR in different cerebrocortical regions to the earliest signs of cognitive deterioration in AD.

METHODS

We examined SLI and CRF-IR levels in 9 neocortical brain regions of 66 elderly patients in a postmortem study of nursing home residents who had either no significant neuropathologic lesions or lesions associated only with AD. Patients were assessed by the Clinical Dementia Rating scale (CDR) to have no dementia or questionable, mild, or moderate dementia, and were compared with 15 patients with severe dementia.

RESULTS

Both CRF-IR and SLI were significantly reduced in the cortices of patients with the most severe dementia, but only the levels of CRF-IR were reduced in those with mild (CDR = 1.0) and moderate dementia (CDR = 2.0). Levels of CRF-IR and SLI correlated significantly with CDR, but this correlation was more robust for CRF-IR and persisted even when severely cognitively impaired patients were eliminated from analysis.

CONCLUSIONS

Although SLI and CRF-IR levels are significantly reduced in patients with severe dementia, only CRF-IR is reduced significantly in the cortices of those with mild dementia. Thus, CRF-IR can serve as a potential neurochemical marker of early dementia and possibly early AD.

A biomechanical comparison of different wrist external fixators with and without K-wire augmentation

To compare stability of wrist external fixation, simulated unstable extra-articular distal radius fractures were created in 7 fresh-frozen cadaveric upper extremities and stabilized using 4 different external fixators. Physiologic muscle tension across the wrist was simulated by application of 40-N load distributed among the wrist tendons. Alternating loads of up to 100 N in flexion and extension of the wrist were applied during stability testing and 3-dimensional kinematics of the proximal and distal fracture fragments were determined using attached infrared light-emitting diodes and a 3-dimensional motion tracking system. Fracture stability was reassessed for each of the constructs after augmentation of the fracture fragments with a single dorsal transfixion K-wire. K-wire augmentation demonstrated a significant reduction in motion of the distal radial fragment of at least 40% in all 3 rotational planes. For flexion/extension, the reduction in motion was from 4.5 degrees to 2.6 degrees. For radial/ulnar deviation, the range of motion decreased from 3.0 degrees to 1.5 degrees. Rotational motion declined from an average of 3.2 degrees to 1.2 degrees. The addition of the single dorsal transfixion K-wire significantly improved stability of each of the 4 fixators in at least 1 of the 3 planes in which motion was measured. While we compared the most rigid with some of the least rigid external fixators, the data do not support an important difference in fracture fragment stability among the 4 fixators. The data much more strongly support the concept of K-wire augmentation for increasing stability of an unstable extra-articular distal radius fracture regardless of the type of external fixator that is used.

Impact of plasmapheresis on disopyramide elimination

The impact of plasmapheresis on the disposition of disopyramide was investigated in a 16-year-old female with systemic lupus erythematosus. Determination of total disopyramide plasma concentrations immediately prior to and following a 4-h plasmapheresis treatment revealed a significant reduction (i.e., 1.77 to 0.7 mg/l or approximately 60%). However, reassessment of the total serum concentration after 1.5 h (i.e., post equilibrium) revealed a rebounding of the value to 1.64 mg/l. Associated with this reduction in total serum levels was a decrease in the protein-bound fraction of disopyramide from 69.5% (pre treatment) to 48.6% (post treatment) that corresponded to a commensurate reduction in the concentration of alpha1-acid glycoprotein (i.e., 119 mg/dl pre treatment to 48.9 mg/dl post treatment). Despite these alterations in disopyramide concentrations, the procedure removed only 2.7% of the disopyramide dose and was not associated with the appearance of a cardiac dysrhythmia.

Cholinergic markers in elderly patients with early signs of Alzheimer disease

CONTEXT

A central tenet of Alzheimer disease (AD) is the loss of cortical cholinergic function and cholinergic markers in postmortem brain specimens. Whether these profound deficits in cholinergic markers found in end-stage patients are also found in patients with much earlier disease is not known.

OBJECTIVE

To determine whether cholinergic deficits in AD precede, follow, or occur in synchrony with the earliest signs of cognitive deterioration.

DESIGN, SETTING, AND PATIENTS

Postmortem study of nursing home residents with Clinical Dementia Rating (CDR) Scale scores of 0.0 to 2.0 and 4.0 to 5.0 who underwent autopsy between 1986 and 1997, comparing the activity of the cholinergic marker enzymes in the cortices of 66 elderly subjects with no (CDR score = 0.0; n = 18), questionable (CDR score = 0.5; n = 11), mild (CDR score = 1.0; n = 22), or moderate (CDR score = 2.0; n = 15) dementia vs subjects with severe dementia (CDR score = 4.0-5.0; n = 15).

MAIN OUTCOME MEASURES

Activity of the cholinergic marker enzymes choline acetyltransferase and acetylcholinesterase in 9 neocortical brain regions.

RESULTS

The activity of choline acetyltransferase and acetylcholinesterase in 9 neocortical brain regions did not differ significantly in subjects with CDR scores of 0.0 to 2.0, but was significantly lower in subjects with severe dementia (CDR score = 4.0-5.0). Choline acetyltransferase levels were significantly correlated with severity of neuropathological lesions of AD, as measured by density of neuritic plaques and neurofibrillary tangles.

CONCLUSIONS

Although neocortical cholinergic deficits are characteristic of severely demented AD patients, in this study, cholinergic deficits were not apparent in individuals with mild AD and were not present until relatively late in the course of the disease. These results suggest that patients with more severe disease should be a target for cholinergic treatment.

Load-displacement behavior in a distal radial fracture model. The effect of simulated healing on motion

External fixation of fractures of the distal end of the radius neutralizes external forces and maintains axial alignment during healing. As far as we know, there have been no biomechanical studies of the effects of early removal of the fixator in a partially healed fracture model. The purpose of the present study was to observe the load-displacement behavior of a distal radial fracture model in which we had simulated partial healing by injection of butyl-rubber caulk and augmented this simulated healing with Kirschner-wire fixation. Sixteen fresh-frozen hand-wrist-forearm specimens from cadavera were mounted in mid-rotation in resin pots, and a load was applied. An osteotomy was used to simulate the fracture. Relative motion at the site of the osteotomy was compared, with use of a three-dimensional Optotrak kinematic device, during physiological loading of six constructs with Kirschner-wire transfixion or outrigger fixation. In the experimental group, partial healing was simulated by injection of butyl-rubber caulk into the site of the osteotomy and testing with simulated muscle-loading was performed through a full range of motion of the wrist. No difference could be detected between the relative motion at the osteotomy sites that had been treated with standard fully augmented external fixation and that in the experimental group (p > 0.05). T test analysis revealed that motion was equivalent regardless of whether Kirschner-wire transfixion or outrigger fixation had been used (p = 0.62) and that all of the augmented constructs had significantly less relative motion than all of the nonaugmented constructs (p < 0.001).

Selective effects of methylphenidate in attention deficit hyperactivity disorder: a functional magnetic resonance study

Functional MRI revealed differences between children with Attention Deficit Hyperactivity Disorder (ADHD) and healthy controls in their frontal-striatal function and its modulation by methylphenidate during response inhibition. Children performed two go/no-go tasks with and without drug. ADHD children had impaired inhibitory control on both tasks. Off-drug frontal-striatal activation during response inhibition differed between ADHD and healthy children: ADHD children had greater frontal activation on one task and reduced striatal activation on the other task. Drug effects differed between ADHD and healthy children: The drug improved response inhibition in both groups on one task and only in ADHD children on the other task. The drug modulated brain activation during response inhibition on only one task: It increased frontal activation to an equal extent in both groups. In contrast, it increased striatal activation in ADHD children but reduced it in healthy children. These results suggest that ADHD is characterized by atypical frontal-striatal function and that methylphenidate affects striatal activation differently in ADHD than in healthy children.

Spatial and physical frames of reference in positioning a limb

Splints attached to the right forearm were used to rotate the forearm's physical reference frame, as defined by the eigenvectors of its inertia tensor, relative to its spatial reference frame. In two experiments, when subjects were required to orient the forearm parallel to, or at 45 degrees to, the environmental horizontal, they produced limb orientations that were systematically deflected from the forearm's longitudinal spatial axis in the direction of the forearm's physical axes. The position sense seems to be based on inertial eigenvectors rather than on joint angles or gravitational torques.

The significance of the extracellular matrix in intracranial aneurysms

To what extent might change sin the extracellular matrix proteins in intracranial aneurysms (IA) or parent artery (PA) wall contribute to enlargement? Using IA specimens obtained from the coroner's office, the wall structure by light (Trichrome and Actin stains) and immunofluorescent microscopy (IF) (collagen I and fibronectin) have been studied in 18 specimens. It is well known that IA only arise when there is a deficiency in the internal elastic membrane and some breakdown in the media. The results show a normal three layer structure of intima, media, (muscularis), and adventitia in the PA extending out into the neck of the aneurysm. Immunofluorescent stains (IS) show collagen I and fibronectin limited to the adventitia and muscularis, respectively, of the PA and control arteries. The enlarging IA wall shows almost complete loss of this architecture. By IF stain, collagen I and fibronectin are intermingled throughout the IA wall. It is postulated that loss of structure and the confining muscularis layer permit easier elastic enlargement from a more or less homogeneous wall structure.

A unique mental health network for Victorian aboriginal people

The Victorian Aboriginal Mental Health Network (VAMHN) is a unique mental health programme for Aboriginal people in Australia. The network was set up in 1987. The services and programmes developed include a community consultation service, a psychiatric inpatient unit; and educational, evaluative and research programmes. Utilisation of the network has steadily increased and the demand for both primary and secondary consultations continues to grow.

The Keyes technique and self-inflicted injuries. Three case reports

Three cases of self-inflicted gingival injuries resulting from the improper use of the Keyes technique are presented. The profession must assume responsibility for studies to determine the safety of the methods of application of the hydrogen peroxide, salt and baking soda mixtures and disseminate this information for the public interest.

Comparison of regional cerebral blood flow in TIA patients with and without occlusion or stenosis of major vessels

The purpose of this study is to compare the background regional cerebral blood flow (rCBF) in TIA patients with and without angiographically demonstrable lesions. 147 TIA patients with severe stenosis or occlusion of major vessels supplying the brain (A group) were compared with a similar group without any arterial lesion demonstrable by angiography (B group). Their rCBFs were measured by the intravenous Xe133 technique. The average of mean rCBF (MrCBF) in (A) group (119 cases) with a mean age of 59.9 yrs was 50.1 +/- 12.3 ml/100g/m and the average of MrCBF in (B) group (31 cases) with a mean age of 59.3 years was 47.6 +/- 11.8 ml/100g/m. In spite of no angiographic lesion in (B) group, the MrCBF was lower in value than that in (A) group. The average of hemispheric rCBF (HrCBF) was approximately the same bilaterally in a control group (55.4 ml/100g/m), and even in (B) group there was no significant difference between the symptomatic side and the non-symptomatic side. In (A) group, HrCBF on the symptomatic side (48.1 ml/100g/m) was significantly lower on the average than that on the opposite side (51.5 ml/100g/m). Comparing probe by probe in TIA patients, the average rCBF of the symptomatic site was 44.1 +/- 11.9 ml/100g/m and that of the symmetrically opposite site was 47.6 +/- 13.0 ml/100g/m in (A) group. In (B) group, the average rCBF of the symptomatic site was 46.2 +/- 10.8 ml/100g/m, and 47.7 +/- 10.8 ml/100g/m for the non-symptomatic site. These values in both group (A) and (B), have a significant difference between symptomatic probes and non-symptomatic probes (p less than 8.0 X 10(-7) and p less than 6.5 X 10(-3)).

Microelectrode for measuring local cortical oxygen tension and blood flow in the same microareas of cat cortex

The purpose of this study is to investigate the relationship between changes in cortical Po2 (bPo2) and cortical blood flow when inhalating different oxygen mixtures. Experiments were performed on 31 cats anaesthetized with N2O/O2 plus supplemental drugs for immobilization and analgesia. Cortical Po2 was measured by the polarographic method using 25 microns Pt electrode (coated) and a 250 micron Ag-AgCl2 indifferent electrode, especially designed to rest lightly on the cortex by means of coiled spring support. Using the same electrode but with opposite tip polarization; local cortical blood flow (lCoBF) was measured at the same site by the H2-clearance method. The change of bPo2 in going from FiO2 25% to FiO2 75% was measured at 58 different sites. (Table 2). At 25% FiO2 the mean bPo2 was 24 +/- 16 mm Hg, with a range from 4 to 92 mm Hg. With increased FiO2 to 75% local bPo2 responded quite differently at adjacent sites. At 75% FiO2 the mean bPo2 was 42.7 +/- 32 mm Hg with a range from 10 mm Hg to 198 mm Hg. The bPo2 and lCoBF were both measured at 44 of the 58 different sites. Cortical sites with a resting bPo2 greater than 30 mm Hg at 25% FiO2 had a lCBF = 57 +/- 12 ml/100g m; whereas sites with resting normoxic bPO2 less than 20 mm Hg had a mean ICoBF = 56 +/- 14 ml/100g min.(ABSTRACT TRUNCATED AT 250 WORDS)

The ultrasound macroscope: initial studies of breast tissue

A system called the ultrasound macroscope has been developed to measure the ultrasonic properties of tissues. Based on the concept of the scanning acoustic microscope, it is capable of generating quantitative images of ultrasound velocity, attenuation and backscatter for macroscopic slices of tissue. By maintaining high resolution (approximately 120 microns at 13 MHz) the morphology of complex tissues is well delineated. Data from regions of interest in the tissue are transformed into three dimensional probability distributions representative of the tissue's ultrasonic characteristics. Sets of two dimensional projections of these distributions are used to display the information. As an initial study, the properties of breast tissues are analyzed. Examples of both normal and abnormal pathology are presented and the relevance of the results to clinical imaging are discussed.

Cortical oxidative metabolism under conditions of ischemia, hypoxia, and asphyxia in the rabbit

The purpose of this investigation was to compare the effects of hypoxia, asphyxia, and ischemia on brain cortical oxidative metabolism. This study was carried out using 14 New Zealand White rabbits. The effects of episodic stress were measured simultaneously on brain functional metabolism by monitoring cortical oxygen tension (brain pO2), cortical cerebral blood flow (cCBF), cortical blood volume, and mitochondrial oxidative metabolism. During hypoxia (when the fraction of inspired O2 (FiO2) was reduced to 10%) and asphyxia (induced by turning the respirator off), there was a decrease of brain pO2 but an increase of cCBF and blood volume. Similarly, there was a reduction of cortical oxidative metabolism. In post-asphyxic conditions, an overshoot of brain pO2 and post-asphyxic oxidation of cytochrome (Cyt.) aa3 were usually shown. Under ischemic conditions (induced by sudden severe hypotension plus bilateral common carotid occlusion), cCBF and blood volume were decreased. There was also a decrease of brain pO2 and a reduction of Cyt. aa3 following ischemia. These techniques are applicable in intraoperative monitoring of patients.

Regional cerebral blood flow in patients with vertebrobasilar disease

We have investigated the changes in regional cerebral blood flow (rCBF) in patients with occlusive vertebrobasilar disease. Fifty patients who showed severe stenosis or occlusion of the vertebrobasilar artery territory were studied by angiography. Lesions in 13 of these patients were limited to the vertebrobasilar artery (limited VB group), and 37 patients showed combined vertebrobasilar/carotid artery lesions (combined VB-C group). Measurements of rCBF in the group of 50 patients using the intravenous xenon 133 technique showed that there was a significant decrease in the mean rCBF (47.5 +/- 1.4 ml/100 gm/min) as compared with 19 age-matched normal subjects (54.9 +/- 1.8 ml/100 gm/min. There was also a significant difference in mean rCBF between the combined VB-C group (45.6 +/- 1.5 ml/100 gm/min) and a group of 153 patients with limited carotid artery lesions (C group, 49.8 +/- 1.0 ml/100 gm/min). However, no significant difference in mean rCBF was found between the limited VB group and normal subjects. There were no differences in rCBF when evaluated according to the presence or absence of angiographic collateral circulation via the posterior communicating artery (Pcom). Good correlation was found between mean rCBF and direction of collateral flow via the Pcom (p less than 0.05). The value of hemispheric rCBF of patients with carotid system transient ischemic attacks (TIAs) was significantly lower than that of patients with vertebrobasilar system TIAs (p less than 0.02). In cerebral autoregulation tests of 24 patients with occlusive vertebrobasilar disease (7 patients from the limited VB group and 17 patients from the combined VB-C group), 13 of these 24 patients (54%) showed an impairment of autoregulation.

Long-term evaluation of cerebral blood flow, transient ischemic attacks, and stroke after STA-MCA anastomosis

A group of 107 consecutive patients with patent extracranial-intracranial bypasses were followed an average of 25.2 months to determine the long-term results on regional cerebral blood flow (rCBF), transient ischemic attacks (TIAs), and stroke incidence. Average mean rCBF initially rose to 110% at 1 week, then gradually fell to 105% at 6 months, and 85% at 2 years. Maximum increase in cerebral blood flow occurred in patients with middle cerebral artery stenosis or those in the preoperative low flow group, i.e., less than 50 ml/100 gm/min. In the group with TIAs plus mild stroke, the mean rCBF rose to 122% at 1 week, compared to the group with TIAs only who showed a mean increase to 107% at one week. Clinical improvement was excellent or good in 82% of those with TIAs only; in those with TIAs plus mild stroke, 77% had excellent or good relief of TIAs; and in those with mild stroke only, 70% recovered from their neurological deficits. In the 25.2 months of average follow-up, stroke occurred in only 1 patient on the side of the anastomosis, and in 2 patients on the side opposite the anastomosis, giving an average stroke incidence of 1.5% per year.

Hemodynamics, oxygen consumption and serum catecholamine changes in progressive, lethal peritonitis in the dog

A progressive, lethal canine peritonitis model was developed using the intraperitoneal injection of previously processed, frozen human stool. Of 15 dogs with fecal contamination, seven died within 24 hours and eight died over two to nine days, with a mean of five days. The model was associated with an initial hyperdynamic state which became quite variable as sepsis progressed. The cardiac index in the septic dogs correlated directly with the arteriovenous oxygen content difference. Evidence of multiple system organ failure and a significant increase in norepinephrine levels was noted in the septic dogs. The serum catecholamine levels were inversely correlated with the systemic blood pressure but did not correlate with the systemic vascular resistance or the cardiac index. This implies a lack of responsiveness of resistance vessels or the heart to catecholamines in this severely septic dog model.

Ethnic and cultural determinants of the perceptions of female dental students

A survey of women dental students enrolled in all American and Canadian dental schools during the 1977-78 academic year was conducted to determine their backgrounds, current status, motivation regarding dentistry as a career, perception of the dental school environment, preferences in dental education, and future plans. The data were analyzed on the basis of ethnic or racial derivation to delineate differences in the perceptions of female dental students of various ethnic groups. Recognizing the nature of such differences may prove beneficial to dental educators, who must determine the specific problems faced by female students of various ethnic groups.

Acute lymphoblastic leukemia with giant intracytoplasmic inclusions

Leukemic cells of bone marrow and peripheral blood showing clusters of distinctive, large, uniform, rounded intracytoplasmic inclusions were found in a patient who had acute lymphoblastic leukemia. These membrane-bound inclusions ranged from 0.8 to 1.4 microgram in diameter and were clearly demonstrated on routinely stained preparations. Electron microscopy disclosed transitions between well-developed mitochondria and the electron-dense structures. The functional significance of these presumably altered mitochondria is uncertain. Whorled lamellar internal structures, in occasional fingerprintlike arrangements, may represent duplication of mitochondrial cristae and, functionally, may reflect increased metabolic rate or otherwise abnormal metabolism. Cytochemical studies demonstrated the presence of both periodic acid-Schiff positivity and nonspecific esterase activity in these inclusions, but no peroxidase or acid phosphatase was found. These findings support the lymphoid nature of the disorder. Immunologic surface membrane markers are consistent with this case being, as with the majority of acute lymphoblastic leukemias, of non-B, non-T cell type. Cytogenetic studies on cultured leukemic cells from bone marrow and peripheral blood showed a consistently abnormal karyotype associated with the presence of an XXY chromosomal constitution. Since no other tissues (e.g., dermal fibroblasts) were examined, the diagnosis of Klinefelter's syndrome cannot be confirmed. A causal relationship between the coexistence of the abnormal karyotype and the acute leukemia was not proven but was suspected.

Women dental students: preferences in support services

Female dental students in 68 American and Canadian dental schools were surveyed to determine their attitudes and concerns about women in dental school, and their preferences in support services. Almost 80 percent of the women reported that their sex did not not hinder them in achieving peak academic success. They believe that qualifications, rather than sex, should be the primary consideration in admitting students and hiring faculty. The majority of respondents indicated that the most beneficial support service for women would be a seminar series specific to their concerns. They also believe that to have women dentists used as role models in lectures and textbooks would be both appropriate and supportive.