Toxicity and human health assessment of an alcohol-to-jet (ATJ) synthetic kerosene developed under an international agreement with Sweden

Alcohol-to-jet (ATJ) Synthetic Kerosene with Aromatics (SKA) fuels are produced by dehydration and refining of alcohol feed stocks. ATJ SKA fuel known as SB-8 was developed by Swedish Biofuels as a cooperative agreement between Sweden and AFRL/RQTF. SB-8 including standard additives was tested in a 90-day toxicity study with male and female Fischer 344 rats exposed to 0, 200, 700, or 2000 mg/m³ fuel in an aerosol/vapor mixture for 6 hr/day, 5 days/week. Aerosols represented 0.04 and 0.84% average fuel concentration in 700 or 2000 mg/m³ exposure groups. Examination of vaginal cytology and sperm parameters found no marked changes in reproductive health. Neurobehavioral effects were increased rearing activity (motor activity) and significantly decreased grooming (functional observational battery) in 2000 mg/m³ female rats. Hematological changes were limited to elevated platelet counts in 2000 mg/m³ exposed males. Minimal focal alveolar epithelial hyperplasia with increased number of alveolar macrophages was noted in some 2000 mg/m³ males and one female rat. Additional rats tested for genotoxicity by micronucleus (MN) formation did not detect bone marrow cell toxicity or alterations in number of MN; SB-8 was not clastogenic. Inhalation results were similar to effects reported for JP-8. Both JP-8 and SB fuels were moderately irritating under occlusive wrapped conditions but slightly irritating under semi-occlusion. Exposure to SB-8, alone or as 50:50 blend with petroleum-derived JP-8, is not likely to enhance adverse human health risks in the military workplace.

Exclusive enteral nutrition in the management of Crohn's disease: a qualitative exploration of experiences, challenges and enablers in adult patients

BACKGROUND

Exclusive enteral nutrition (EEN) is a first-line treatment for Crohn's disease in paediatrics with similar efficiency to corticosteroids. Benefits in adults have not been consistently observed with non-adherence cited as a limiting factor. This study aimed to gain an in depth understanding of the adult patient experience with EEN, identifying challenges and enablers to inform clinicians in the development of strategies to help increase patient adherence.

METHODS

This exploratory, qualitative study utilised individual semi-structured interviews with 17 adult patients who had completed EEN. Participants were purposively recruited across a range of ages, social backgrounds and clinical experience. Interviews were audio recorded, transcribed and independently thematically analysed by two researchers to provide consensus in identifying key themes.

RESULTS

Three major themes were identified. (i) Personal experience of EEN evolved over time, with the first few weeks the most challenging, becoming easier as symptoms improved, and participants became used to the EEN regimen. (ii) Participants developed coping strategies to manage challenges, including the impact on meal-based social participation and dietary restriction and monotony. (iii) Enabling factors for adherence to EEN included patient self-efficacy, health system support, supplement characteristics and access, and social support.

CONCLUSIONS

This study explored the evolving experiences of patients who completed a prescribed course of EEN. Patients described the challenges they faced, how they overcame them identifying enablers for adherence. This provides useful strategies for clinicians to integrate in their assessments and share with patients starting EEN.

Effects of energy, mineral supplementation, or both, in combination with monensin on performance of steers grazing winter wheat pasture

A 2-yr study was conducted during the 2004 to 2005 (YR1) and 2005 to 2006 (YR2) winter wheat grazing seasons to determine the effects of supplementation strategies and delivery methods on supplement intake and growth performance of grazing steers (YR1, n = 253, initial BW 255 +/- 25 kg; YR2, n = 116, initial BW 287 +/- 14 kg). The 5 treatments were as follows: 1) negative control (NC), no supplemental nutrients; 2) free-choice, nonmedicated mineral (MIN); 3) free-choice, medicated mineral with 1,785 mg of monensin/kg of mineral mixture (RMIN); 4) RMIN and soybean hulls (SH-RMIN); and 5) a soybean hull-based energy supplement containing 165 mg of monensin/kg (GRNGOLD). Energy supplements were hand-fed on alternate days (average daily intake = 0.91 kg/steer). Inclusion of monensin in the free-choice mineral mixture decreased intake of the mineral mixture by 63% in YR1 and 55% in YR2 when no other supplement was offered. Consumption of RMIN provided from 129 to 161 mg of monensin/steer on average, whereas GRNGOLD provided 150 mg of monensin/d. Compared with NC, MIN did not affect ADG in YR1 (P = 0.38) but increased (P = 0.01) ADG by 0.22 kg/steer in YR2. Conversely, ADG of RMIN steers was greater (P = 0.03) than that of MIN steers during YR1 (0.72 vs. 0.55 kg/steer) but not different (P = 0.35) in YR2. Providing supplemental energy increased ADG by 0.13 kg/steer (0.85 vs. 0.72 +/- 0.053) in YR1 compared with RMIN, but no increase in ADG was observed in YR2. No difference (P > 0.24) was observed in ADG between SH-RMIN and GRNGOLD in either year. Conversion of the energy supplements (kg of as-fed supplement divided by kg of additional ADG) was excellent in YR1, resulting in 1 kg of BW gain for each 3.1 kg of supplement consumed. However, due to smaller increases in ADG with the energy and monensin supplements in YR2, supplement conversion for YR2 averaged 17.6. The absence of a difference (P > 0.24) in ADG between steers that received SH-RMIN and GRNGOLD suggests that the method of delivery (separate packages vs. a single package) for energy, monensin, and mineral supplementation is not important.

Randomized single blind trial of two low-volume bowel preparations for screening computed tomographic colonography

BACKGROUND

Bowel preparation is an important part of computed tomographic colonography (CTC); we evaluated two small-volume preparations for screening CTC with regard to quality of preparation and patient acceptability.

METHODS

Asymptomatic subjects at average risk for colorectal cancer from a community-based CTC screening program were randomized to bowel preparation comprising magnesium/bisacodyl/picolax or polyethylene glycol (PEG)/picolax. CTC images were evaluated by a blinded investigator for residual feces and fluid; subjects completed a questionnaire regarding acceptability of the preparation.

RESULTS

In 176 subjects randomized to magnesium/bisacodyl/picolax (n = 82) or PEG/picolax (n = 94), the former preparation was discontinued because of syncope or presyncope in four (5%) subjects. Another 137 subjects received PEG/picolax without a significant adverse event. There were no other major differences in acceptability of the preparations as reported by subjects. The quality of bowel preparations for reporting CTC was similar.

CONCLUSION

For subjects having screening CTC, both small-volume bowel preparations are generally well tolerated and result in minimal fluid and fecal residue; however, the magnesium/bisacodyl/picolax preparation was accompanied by an unacceptable incidence of syncope and is no longer used by us.

Chronic narcotic use in inflammatory bowel disease patients: prevalence and clinical characteristics

BACKGROUND

Narcotic addiction can be a significant problem in inflammatory bowel disease (IBD). However, there are few published reports about this problem.

METHODS

All patients prescribed narcotics chronically in the absence of demonstrable organic pathology were identified on the computerized Brisbane IBD Research Group database (n=332 patients with informative data as of 1 January 1999). Individual case records were reviewed with regard to clinical, psychiatric and social characteristics of these patients, and the prevalence of psychiatric disorders were compared with a control group of IBD patients.

RESULTS

Eleven patients were identified. Nine had complete datasets, eight with Crohn's disease (CD), of which six had previous stricturing ileal disease, and one patient had ulcerative colitis, making a prevalence of 2.7% of IBD patients and 5.1% of CD patients. A 67% prevalence of a psychiatric disorder in narcotic users was significantly greater than the 8% prevalence in the control group of IBD patients (odds ratio 22, 95% CI 3.24-177).

CONCLUSIONS

A significant proportion of IBD patients without demonstrable organic pathology were chronic narcotic users. Psychiatric disorders are common in this subgroup, as with chronic functional abdominal pain syndromes. It is suggested that inappropriate narcotic use in IBD patients can be reduced by appreciating that narcotics are a temporary therapy only for IBD patients, and awareness of pre-existing social and psychiatric disorders, which not only impact on clinical presentation of pain, but also help define the subgroup of patients who are at risk of narcotic misuse.

Extracolonic findings at virtual colonoscopy: implications for screening programs

OBJECTIVE

Virtual colonoscopy (VC) is an evolving technology proposed as a possible screening tool for colorectal cancer. In contrast to conventional colonoscopy, VC may detect extracolonic abdominal pathology. This may lead to unnecessary investigation of benign lesions, or may benefit the patient by identifying serious pathology at an early stage. The aim of this study was to assess the prevalence and characteristics of extracolonic pathology found in patients undergoing VC.

METHODS

A total of 100 patients aged > or = 55 yr, referred for colonoscopy for bowel symptoms or family history of bowel cancer, underwent VC. Axial views of the abdomen were reviewed prospectively by a single radiologist for extracolonic pathology. Patients with extracolonic abnormalities were referred to their local doctor or to a specialist clinic when appropriate. Case records were reviewed and treating doctors contacted to document subsequent investigations and procedures generated.

RESULTS

Fifteen patients (15%) had extracolonic abnormalities detected. In four patients, the pathology had been diagnosed previously (umbilical hernia, gallbladder and renal calculi, 3.5-cm aortic aneurysm, ovarian cyst). Eleven patients had new abnormalities detected: ovarian cysts (three), liver cysts (two), uterine fibroids (two), gallstones (one), splenic calcifications (one), aortic aneurysm (one), and renal tumor (one). Two patients with ovarian cysts underwent surgery, and histology showed benign cysts.

CONCLUSIONS

Extracolonic abnormalities are common at VC. Most are benign, but may lead to investigative and procedural costs. These data should be carefully evaluated in feasibility and cost-effectiveness studies on colorectal cancer screening using VC.

Virtual colonoscopy compared with conventional colonoscopy: a developing technology

AIM

To determine the accuracy of computed tomography colography (virtual colonoscopy) in detecting colorectal polyps and colorectal cancer.

DESIGN

Blinded comparison of virtual colonoscopy (initially supine-only scans and later supine plus prone scans) with the criterion standard of conventional colonoscopy.

SUBJECTS AND SETTING

100 patients aged 55 years or over referred to a public teaching hospital for colonoscopy, July 1997 to January 2000, because of colonic symptoms or a family history of bowel cancer.

MAIN OUTCOME MEASURES

Presence and size of polyps and other lesions; certainty of polyp identification on virtual colonoscopy (on 100-point visual analogue scale); sensitivity and predictive values of virtual colonoscopy.

RESULTS

Conventional colonoscopy identifed 121 polyps in 47 patients; 28 of these polyps, in 19 patients, were identified by virtual colonoscopy. Sensitivity of virtual colonoscopy for detecting polyps (using supine plus prone scans) was 73% for polyps with diameter > or = 10 mm (95% CI, 39%-94%) and 19% for smaller polyps (95% CI, 10%-31%) (P < 0.001); corresponding figures for supine-only scans were 57% (95% CI, 18%-90%) and 11% (95% CI, 4%-24%), respectively. Ten polyps identified at virtual colonoscopy were considered false-positive findings (8%). The value of finding a polyp on virtual colonoscopy (with thresholds of 5 mm for diameter and 30 points for certainty score) was assessed as a predictor of finding a polyp (diameter > 5 mm) on conventional colonoscopy. Positive and negative predictive values were 88% and 89%, respectively, for supine plus prone scans.

CONCLUSION

Although virtual colonoscopy shows potential as a diagnostic tool for colorectal neoplasia, it is currently not sufficiently sensitive for widespread use.

Blood group A and B antigens are strongly expressed on platelets of some individuals

It is widely thought that expression of ABH antigens on platelets is insufficient to materially affect the survival of ABH-incompatible platelets in transfusion recipients, but anecdotal reports of poor survival of A and B mismatched platelets suggest that this is not always the case. The A and B antigen expression on platelets of 100 group A(1) and group B blood donors was measured, and 7% and 4%, respectively, had platelets whose A and B antigen levels consistently exceeded the mean plus 2 SD. On the basis of flow cytometric and statistical analysis, donors whose platelets contained higher than normal levels of A antigen were subdivided into 2 groups, designated Type I and Type II ("high expressers"). Serum A(1)- and B-glycosyltransferase levels of A and B high expressers were significantly higher than those of group A(1) and B individuals with normal expression. H antigen levels were low on the red cells of high expressers, indicating that the anomaly affects other cell lineages. Immunochemical studies demonstrated high levels of A antigen on various glycoproteins (GPs) from high-expresser platelets, especially GPIIb and PECAM (CD31). The A(1) Type II high-expresser phenotype was inherited as an autosomal dominant trait in one family. The sequences of exons 5, 6, and 7 of the A(1)-transferase gene of one Type II A(1) high expresser and exon 7 from 3 other genes were identical to the reported normal sequences. Further studies are needed to define the molecular basis for the high-expresser trait and to characterize its clinical implications. (Blood. 2000;96:1574-1581)

Hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) appears to be declining in Taiwan and potentially in other high-prevalence areas as a consequence of vaccination for hepatitis B virus (HBV). However, there is evidence that the incidence of HCC is increasing in North America and Europe. This appears to be related to the increasing prevalence and duration of hepatitis C virus (HCV) infection in these countries. There is also growing evidence to support an increase in the risk of HCC in patients with HCV who are coinfected with occult HBV (patients who have lost HBV surface antigen but still have detectable HBV DNA either in blood or liver). Occult HBV infection in patients with HCV may be more common than previously thought, and HCC that occurs in this setting appears to have a worse prognosis. There is continuing interest in the effect of interferon therapy on the incidence of HCC in patients with HCV. Several studies from Japan have shown a benefit in patients without cirrhosis, although there are a number of potentially confounding variables that may partly explain these results. Prospective randomized studies are needed to investigate this important question. The molecular biology of HCC and the events of malignant transformation in the liver continue to be areas of intense study. Recently, there has been considerable interest in telomeres, the repeat units on the ends of chromosomes, and the enzyme that maintains these, telomerase. Telomeres shorten with each cell division and can be used to determine the number of divisions a cell has undergone. Eventually they reach a critical length, with further loss resulting in cellular senescence. Telomerase restores telomere length and may help malignant cells escape senescence. Nearly all HCCs have telomerase activity and assessments of telomeres and telomerase may be clinically useful.

Cash budgeting: an underutilized resource management tool in not-for-profit health care entities

Cash budgeting is generally considered to be an important part of resource management in all businesses. However, respondents to a survey of not-for-profit health care entities revealed that some 40 percent of the participants do not currently prepare cash budgets. Where budgeting occurred, the cash forecasts covered various time frames, and distribution of the document was inconsistent. Most budgets presented cash receipts and disbursements according to operating, investing, and financing activities--a format consistent with the year-end cash flow statement. By routinely preparing monthly cash budgets, the not-for-profit health care entity can project cash inflow/outflow or position with anticipated cash insufficiencies and surpluses. The budget should be compared each month to actual results to evaluate performance. The magnitude and timing of cash flows is much too critical to be left to chance.

Osteoinduction of human demineralized bone: characterization in a rat model

The increasing clinical use of human demineralized bone matrix has brought about the desire to understand better the osteoinductivity of these graft materials. The rat heterotopic model has been used successfully to show the sequence of events involved in the endochondral ossification process resulting in osteoinduction. In this study, the osteoinductive potential of human demineralized bone powder was assessed, using immune compromised rats (athymic rnu/rnu) to avoid problems associated with cross species incompatibilities. Implants were placed in subcutaneous or intermuscular sites. This model is characterized to provide a basis for routinely determining the performance of human demineralized bone powder. Demineralized bone powder was prepared from rat and human cortical bone according to a strict protocol. The lack of response to guanidine HCl extracted (noninductive) demineralized bone showed the selectivity of the assay. The same lots of human and rat demineralized bone were tested in sequential experiments during a 1-year period. These results showed reproducible induction of the demineralized bone powder between experiments. Combining demineralized bone with the guanidine HCl extracted demineralized bone in varying ratios tested the sensitivity of the assay. These results showed an increase in bone formation with increasing quantities of active demineralized bone and established the ability of the bioassay to differentiate between the various levels of active (osteoinductive) demineralized bone powder. With this model, consistent performance of demineralized bone powder processed by well controlled methods was seen.

Mechanical and morphologic investigation of the tensile strength of a bone-hydroxyapatite interface

For load-bearing calcium-phosphate biomaterials, it is important to understand the relative contributions of direct physical-chemical bonding vs. mechanical interlocking to interfacial strength. In the limit of a perfectly smooth hydroxyapatite (HA) surface, a tensile test of the bone-HA interface affords an opportunity to isolate the bonding contribution related to HA surface chemistry alone. This study measured the bone-HA interfacial tensile strength for highly polished (approximately 0.05 micron alumina) dense HA disks (5.25 mm in diameter, 1.3 in mm thickness) in rabbit tibiae. Each of five rabbits received four HA disks, two per proximal tibia. Pull-off loads ranged from 3.14 +/- 2.38N at 55 days after implantation to 18.35 +/- 11.9N at 88 days; nominal interfacial tensile strengths were 0.15 +/- 0.11 MPa and 0.85 +/- 0.55 MPa, respectively. SEM of failed interfaces revealed failures between HA and bone, within the HA itself and within adjacent bone. Tissue remnants on HA were identified as mineralized bone with either a lamellar or trabecular structure. Oriented collagen fibers in the bone intricately interdigitated with the HA surface, which frequently showed breakdown at material grain boundaries and a rougher surface than originally implanted. Mechanical interlocking could not be eliminated as a mode of tissue attachment and contribution to bone-HA bonding, even after implanting an extremely smooth HA surface.

Carbon dioxide laser surgery for cervical intra-epithelial neoplasia. A report on 300 cases

The CO2 laser was used to treat 300 patients with cervical intra-epithelial neoplasia (CIN). The patient characteristics, histological features, complications and follow-up are described and our experience is discussed. The CO2 laser appears to be safe and efficient for outpatient treatment of CIN, with a cure rate of 94%.

Comparison of effects of prolactin and growth hormone on adrenal 5alpha-reductase in hypophysectomized rats

Adrenal 5alpha-reductase activity was measured in female rats 0, 2, 5, and 6 days after hypophysectomy. Enzyme activity increased progressively exhibing a 35-fold elevation at 6 days. The effects of high (250 mug/100 g of body wt), intermediate (25 mug/100 g of body wt), and low (2.5 mug/100 of body wt) daily doses of bovine prolactin and bovine growth hormone were compared at 2 and 5 days posthypophysectomy. At 2 days, enzyme activity was partially inhibited by the high and intermediate doses of prolactin and not affected by growth hormone. At 5 days all doses of prolactin were inhibitory, whereas enzyme activity was suppressed only by the high dose of growth hormone. With a given dose of hormone, the amount of suppression of enzyme activity is greater at 5 days than at 2 days posthypophysectomy. In 5-day hypophysectomized rats the inhibitory effects of prolactin and growth hormone were additive. It is concluded that: (i) hormonal sensitivity and responsiveness of the adrenal reductase pathway increases with duration of pituitary ablation; (ii) the reductive pathway is more sensitive to the effects of prolactin than growth hormone; and (iii) the effects of growth hormone and prolactin on reductase activity are mediated via different mechanisms, as suggested by the additive effects of individual hormones.

Experiments on the Transmission of Human Cold to Hedgehogs: A Preliminary Note: (Section of Comparative Medicine)

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