Long-Term Outcome of Immediate Versus Postponed Intervention in Patients With Infected Necrotizing Pancreatitis (POINTER): Multicenter Randomized Trial

OBJECTIVE

To compare the long-term outcomes of immediate drainage versus the postponed-drainage approach in patients with infected necrotizing pancreatitis.

BACKGROUND

In the randomized POINTER trial, patients assigned to the postponed-drainage approach using antibiotic treatment required fewer interventions, as compared with immediate drainage, and over a third were treated without any intervention.

METHODS

Clinical data of those patients alive after the initial 6-month follow-up were re-evaluated. The primary outcome was a composite of death and major complications.

RESULTS

Out of 104 patients, 88 were re-evaluated with a median follow-up of 51 months. After the initial 6-month follow-up, the primary outcome occurred in 7 of 47 patients (15%) in the immediate-drainage group and 7 of 41 patients (17%) in the postponed-drainage group (RR 0.87, 95% CI 0.33-2.28; P =0.78). Additional drainage procedures were performed in 7 patients (15%) versus 3 patients (7%) (RR 2.03; 95% CI 0.56-7.37; P =0.34). The median number of additional interventions was 0 (IQR 0-0) in both groups ( P =0.028). In the total follow-up, the median number of interventions was higher in the immediate-drainage group than in the postponed-drainage group (4 vs. 1, P =0.001). Eventually, 14 of 15 patients (93%) in the postponed-drainage group who were successfully treated in the initial 6-month follow-up with antibiotics and without any intervention remained without intervention. At the end of follow-up, pancreatic function and quality of life were similar.

CONCLUSIONS

Also, during long-term follow-up, a postponed-drainage approach using antibiotics in patients with infected necrotizing pancreatitis results in fewer interventions as compared with immediate drainage and should therefore be the preferred approach.

TRIAL REGISTRATION

ISRCTN33682933.

Barriers to transition in young adults with neurogenic bladder

INTRODUCTION

'Transition' not only involves finding an adult healthcare provider, but also includes the process of developing the patient's ability to care for him/herself. Recent literature states that 40% of young adults with special healthcare needs are receiving the tools needed for transition. Pediatric urologists treating patients with complex anomalies, such as spina bifida, often anticipate poor outcomes for patients who are ill equipped for transition to adult care. The goal of this study was to identify potential barriers for young adults with neurogenic bladder when transitioning to independent care.

STUDY DESIGN

A prospective IRB-approved study was performed on all patients with neurogenic bladder referred to the transitional urology clinic. Reasons for missed appointments were tracked, and all patients were asked to complete the Transition Readiness Assessment Questionnaire (TRAQ) in private prior to an appointment. The TRAQ responses are scaled 1-5, with higher numbers corresponding to higher transition readiness of each individual skill. The mean score for each question was calculated across all patients, and the mean TRAQ score was calculated across all questions for each patient. To assess if certain subgroups were more prepared for transition, mean scores were compared between sexes, patients aged <19 and ≥19 years old, and between ambulatory and full-time wheelchair users with unpaired t-tests.

RESULTS

A total of 73% (58/79) of patients referred to the transitional clinic came to their appointment. The most common reason for missed clinic appointments was related to health insurance coverage (47%). A total of 42 patients completed the TRAQ at a mean age of 19.5 years old; 90% (38/42) had spina bifida. Females, ambulatory patients, and those ≥19 years old had higher overall mean TRAQ scores, but these differences were not statistically significant. The highest TRAQ scores were related to taking and ordering medications, utilization of medical supplies, communication with healthcare providers, and assisting with household duties. The majority of the patients indicated 'I am learning to do this'. The lowest scores were in response to questions about health insurance coverage, payments for medications or medical equipment, financial help, and utilization of community services. Most patients responded 'I do not know how but I want to learn'.

CONCLUSIONS

Young adults with neurogenic bladder needed the most guidance during transition to independent care, with management of health insurance and finances. Based on these findings, dedicated social work and nurse visits have been included into the transition process.

Non-absorbable sutures are associated with lower recurrence rates in laparoscopic percutaneous inguinal hernia ligation

INTRODUCTION

Laparoscopic hernia repair with percutaneous ligation of the patent processes vaginalis is a minimally invasive alternative to open inguinal herniorrhaphy in children. With the camera port concealed at the umbilicus, this technique offers an excellent cosmetic result. It is also faster than the traditional laparoscopic repair with no differences in complication rates or hospital stay. The goal of this study was to describe a series of consecutive patients, emphasizing the impact of suture materials (absorbable vs. non-absorbable) on hernia recurrences.

METHODS

A retrospective review was performed of consecutive transperitoneal laparoscopic subcutaneous ligations of a symptomatic hernia and/or communicating hydrocele by 4 surgeons. Patients > Tanner 2 or with prior hernia repair were excluded. The success of the procedure and number of sutures used was compared between cases performed with absorbable vs. non-absorbable suture. Risk factors for surgical failure (age, weight, number of sutures used, suture type) were assessed with logistic regression.

RESULTS

94 patients underwent laparoscopic percutaneous hernia ligation at a mean age of 4.9 years. Outcomes in 85 (90%) patients with 97 hernia repairs at a mean of 8 months after surgery revealed 26% polyglactin vs 4% polyester recurrences (p = 0.004) which occurred at mean of 3.6 months after surgery, Table 1. Repairs performed with non-absorbable suture required only 1 suture more often than those performed with absorbable suture (76% vs 60%, p = 0.163). Logistic regression revealed suture type was an independent predictor for failure (p = 0.017). Weight (p = 0.249), age (p = 0.055), and number of sutures (p = 0.469) were not significantly associated with recurrent hernia.

DISCUSSION

Our review of consecutive hernia repairs using the single port percutaneous ligation revealed a significantly higher recurrent hernia rate with absorbable (26%) versus non-absorbable (4%) suture. This finding remained significant in a logistic regression model irregardless of number of sutures placed, age, and weight. Though the authors acknowledge the drawback of the potential for learning curve to confound our data, we still feel these findings are clinically important as this analysis of outcomes has changed our surgical practice as now all providers involved perform this procedure with exclusively non-absorbable suture. We thus suggest that surgeons who perform this technique, especially those newly adopting it, use non-absorbable suture for optimal patient outcomes.

CONCLUSIONS

Recurrent hernia after laparoscopic percutaneous hernia ligation was significantly lower in repairs performed with non-absorbable suture. Based on this data, we recommend the use of non-absorbable suture during laparoscopic ligation of inguinal hernias in children.

Incidental biliary adenofibroma with dysplastic features

We present a case of an incidentally detected cystic liver mass on CT scan, with histology showing biliary epithelium embedded in fibrous stroma and dysplastic features, consistent with an adenofibroma. This is only the third case described in the literature with malignant histology and the first case with angiographic imaging and subsequent management with preoperative embolization prior to surgical resection. We discuss the differential of the imaging findings and the features of this rare entity. Because of the risk of malignant transformation, consideration of this tumour is important to ensure early detection and ultimately resection for improved survival.

Reconstruction of the symphysis pubis to repair a complex midline hernia in the setting of congenital bladder exstrophy

PURPOSE

A 40-year-old man with congenital midline defect and wide pubic symphysis diastasis secondary to bladder exstrophy presented with a massive incisional hernia resulting from complications of multiple prior abdominal repairs. Using a multi-disciplinary team of general, plastic, and urologic surgeons, we performed a complex hernia repair including creation of a pubic symphysis with rib graft for inferior fixation of mesh.

METHODS

The skin graft overlying the peritoneum was excised, and the posterior rectus sheath mobilized, then re-approximated. The previously augmented bladder and urethra were mobilized into the pelvis, after which a rib graft was constructed from the 7th rib and used to create a symphysis pubis using a mortise joint. This rib graft was used to fix the inferior portion of a 20 × 25 cm porcine xenograft mesh in a retro-rectus position. With the defect closed, prior skin scars were excised and the wound closed over multiple drains.

RESULTS

The patient tolerated the procedure well. His post-operative course was complicated by a vesico-cutaneous fistula and associated urinary tract and wound infections. This resolved by drainage with a urethral catheter and bilateral percutaneous nephrostomies. The patient has subsequently healed well with an intact hernia repair. The increased intra-abdominal pressure from his intact abdominal wall has been associated with increased stress urinary incontinence.

CONCLUSIONS

Although a difficult operation prone to serious complications, reconstruction of the symphysis pubis is an effective means for creating an inferior border to affix mesh in complex hernia repairs associated with bladder exstrophy.

Characterization of peripheral nerve sheath tumors with 3T proton MR spectroscopy

BACKGROUND AND PURPOSE

The characterization of peripheral nerve sheath tumors is challenging. The purpose here was to investigate the diagnostic value of quantitative proton MR spectroscopy at 3T for the characterization of peripheral nerve sheath tumors as benign or malignant, compared with PET.

MATERIALS AND METHODS

Twenty participants with 24 peripheral nerve sheath tumors underwent MR spectroscopy by use of a point-resolved sequence (TE, 135 ms). Six voxels were placed in 4 histologically proven malignant peripheral nerve sheath tumors and 22 voxels in 20 benign peripheral nerve sheath tumors (9 histologically proven, 11 with documented stability). The presence or absence of a trimethylamine signal was evaluated, the trimethylamine concentration estimated by use of phantom replacement methodology, and the trimethylamine fraction relative to Cr measured. MR spectroscopy results for benign and malignant peripheral nerve sheath tumors were compared by use of a Mann-Whitney test, and concordance or discordance with PET findings was recorded.

RESULTS

In all malignant tumors and in 9 of 18 benign peripheral nerve sheath tumors, a trimethylamine peak was detected, offering the presence of trimethylamine as a sensitive (100%), but not specific (50%), marker of malignant disease. Trimethylamine concentrations (2.2 ± 2.8 vs 6.6 ± 5.8 institutional units; P < .049) and the trimethylamine fraction (27 ± 42 vs 88 ± 22%; P < .012) were lower in benign than malignant peripheral nerve sheath tumors. A trimethylamine fraction threshold of 50% resulted in 100% sensitivity (95% CI, 58.0%-100%) and 72.2% (95% CI, 59.5%-75%) specificity for distinguishing benign from malignant disease. MR spectroscopy and PET results were concordant in 12 of 16 cases, (2 false-positive results for MR spectroscopy and PET each).

CONCLUSIONS

Quantitative measurement of trimethylamine concentration by use of MR spectroscopy is feasible in peripheral nerve sheath tumors and shows promise as a method for the differentiation of benign and malignant lesions. Trimethylamine presence within a peripheral nerve sheath tumor is a sensitive marker of malignant disease, but quantitative measurement of trimethylamine content is required to improve specificity.

SU-E-I-24: Determining the Optimal B-Values to Use in Diffusion Weighted Imaging for Differentiating Benign and Malignant Breast Lesions

PURPOSE

To investigate and determine the optimal b-values for Diffusion Weighted Imaging(DWI) for Apparent Diffusion Coefficient(ADC) maps in differentiating normal, benign and malignant breast tissue.

METHODS

Twenty-five patients underwent diffusion-weighted magnetic resonance imaging (DWI-MRI) and conventional breast MRI with suspicious breast fmdings(BIRADS >4). Breast lesions were defined by pathology. The DWI was acquired with different b-values ranging from 0,500, 600,750 and 1000s/mm² . Apparent Diffusion Coefficient(ADC) maps of breast tissue were constructed using different b-values, e.g., using either 2 b-values(0- 1000) or combinations of 3 or more (0,500,1000 or 0,600,750,1000). Quantitative analyses of the ADC maps of glandular, fatty and lesion tissue were obtained. Ratios of lesion to glandular tissue(L/GT) and signal to noise(SNR) were assessed. Paired t-tests were performed for statistical significance.

RESULTS

Eighteen patients had invasive ductal carcinoma and 7 had benign breast lesions. The mean ADC value for malignant lesions using all b values was 1.17±0.16×10-3mm² /s with a lesion to glandular(L/GT) ratio=0.65. The benign lesions, ADC map value was 1.86±0.03×10-3mm² /s with L/GT=0.98. There was a significant difference(P<0.05) between benign and malignant lesions ADC map value.The lowest SNR(12±6) was with single b-values. There was a significant difference(P<0.05) in SNR with multiple b-values(34±6) compared to single b-values. The highest SNR was given by using two b values greater than 500. Finally, the background noise for all combinations was surprising stable and ranged between 60±20%.

CONCLUSIONS

This is the first study to investigate the effect of changing different b values in DWI breast imaging. There were significant differences in the SNR between single and multiple b values. Our data show suggest that the recommended b-values for DWI in breast are 0, and two that are 500 or greater. Therefore use of at least 3 b-values in DWI/ADC mapping of breast lesions are needed for better characterization of benign and malignant breast tissue. P50CA88843, Avon Foundation for Women:01-2008-012, U01CA070095, andU01CA140204.

PGAT: a multistrain analysis resource for microbial genomes

Motivation: The Prokaryotic-genome Analysis Tool (PGAT) is a web-based database application for comparing gene content and sequence across multiple microbial genomes facilitating the discovery of genetic differences that may explain observed phenotypes. PGAT supports database queries to identify genes that are present or absent in user-selected genomes, comparison of sequence polymorphisms in sets of orthologous genes, multigenome display of regions surrounding a query gene, comparison of the distribution of genes in metabolic pathways and manual community annotation.

Availability and Implementation:The PGAT website may be accessed at http://nwrce.org/pgat.

Contact:mbrittna@uw.edu

Molecular and functional imaging of breast cancer

Despite several major advances in breast cancer diagnosis and treatment, the American Cancer Society has estimated that in the US alone 43300 women and 400 men will die from breast cancer in 2007. Breast cancer typically is a multi-focal, multi-faceted disease, with the major cause of mortality being complications due to metastasis. Whereas a decade ago genetic alterations were the primary focus in cancer research, it is now apparent that the physiological tumor microenvironment, interactions between cancer cells and stromal cells such as endothelial cells, fibroblasts and macrophages, the extracellular matrix, and a multitude of secreted factors and cytokines influence progression, aggressiveness, and response of the disease to treatment. Prevention, early diagnosis, and treatment are the three broad challenges for MR molecular and functional imaging in reducing mortality from this disease. Multi-parametric molecular and functional MRI provides unprecedented opportunities for identifying novel targets for imaging and therapy at the bench, as well as for accurate diagnosis and monitoring response to therapy at the bedside. Here we provide an overview of the current status of molecular and functional MRI of breast cancer, outlining some key developments, as well as identifying some of the important challenges facing this field in the future.

Double-balloon enteroscopy: indications, diagnostic yield, and complications in a series of 275 patients with suspected small-bowel disease

BACKGROUND AND STUDY AIMS

Until recently, only the proximal small bowel was accessible for diagnostic and therapeutic endoscopy. This paper describes experience in the first 275 patients examined and treated with the new method of double-balloon enteroscopy (DBE), which is expected to make full-length enteroscopy possible.

PATIENTS AND METHODS

Between November 2003 and May 2005, double-balloon enteroscopy was conducted in 275 consecutive patients presenting at two tertiary referral hospitals. The characteristics of the patients, indications for the procedures, procedural parameters, and diagnostic yield are described here. All conventional treatment options were available. The tolerability of the procedure was assessed in a small subset of the patients. After the procedure, the patients were monitored in a recovery room for at least 2h. They were discharged afterwards, provided there were no signs of complications or complaints.

RESULTS

The main indication for DBE was suspected small-bowel bleeding (n=168), and the lesions responsible for the bleeding were found in 123 patients (73 %) and treated in 61 (55 %). In patients with refractory celiac disease (n=25), DBE revealed a high proportion (six patients, 23 %) of enteropathy-associated T-cell lymphomas that had not been suspected on other tests. Further DBE indications were surveillance and treatment of hereditary polyposis syndromes (n=20); and suspected Crohn's disease, which was diagnosed with DBE in four of 13 patients (30 %). No relevant pathology was found in 24 % of the patients. Panenteroscopy was successfully performed in 26 of 62 patients (42 %) in whom it was attempted, in either one or two sessions. The average duration of the procedures was 90 min (range 30 - 180 min, SD 42), and the average insertion length was 270 cm (range 60 - 600 cm, SD 104). Patients' tolerance of the procedure was excellent. Severe complications were recognized in three cases (1 %), all involving pancreatitis.

CONCLUSIONS

This large pilot series shows that DBE is a well-tolerated and safe new endoscopic technique with a high diagnostic yield in selected patients.

Perfusion-weighted MRI as a marker of response to treatment in acute and subacute stroke

We carried out baseline and short-term follow-up MRI, including perfusion-weighted imaging (PWI) and tests of neurologic and cognitive function on 15 consecutive patients with large-vessel ischemic stroke who showed a persistent large perfusion-diffusion mismatch at enrollment up to seven days after the onset of symptoms. Of these, ten underwent induced blood pressure elevation with phenylephrine and oral medications (in eight) or intravenous fluids (in two) with the goal of improving perfusion; five had no such treatment. Significant functional improvement was defined by a reduction of 3 or more points on the NIH stroke scale (NIHSS). Significant improvement in perfusion was defined by a reduction in the volume of hypoperfused brain by 30 cc on PWI using time-to-peak (TTP) maps, without enlargement of the infarct. There was a strong, statistically significant association between improved function and improved perfusion: six (75%) of eight patients who improved in function, but none of the seven who did not, showed a reduction in volume of hypoperfused brain. All six patients who met the perfusion goal, and only two (22%) of nine who did not showed significant functional improvement (Fisher's exact: P < 0.01). There were no differences between patients who improved functionally and those who did not with respect to age, initial volume of abnormality on DWI or PWI, initial NIHSS, or changes on DWI. These findings indicate that reduction in volume of hypoperfused brain on PWI is a marker of response to treatment to improve perfusion even in subacute stroke and that partial reperfusion of regions of salvageable but dysfunctional tissue is a mechanism of improved function associated with induced blood pressure elevation.

Childhood invasive pneumococcal disease in Tasmania, 1994-2000

OBJECTIVE

To describe the burden of invasive pneumococcal disease in Tasmanian children, including age-specific incidence and antibiotic-resistance pattern.

METHODS

A population-based retrospective study was carried out, examining cases of childhood disease associated with isolates of Streptococcus pneumoniae from normally sterile sites, identified via scrutiny of laboratory records at all major Tasmanian laboratories during a 7-year period between January 1994 and December 2000. Medical records were sub-sequently examined for information describing the clinical syndrome and course of disease.

RESULTS

Invasive pneumococcal disease was identified in 76 children during the 7-year period. The incidence per 100 000 children was 28.5 (95% CI 22.0-36.3) in children under 5 years and 54.3 (95% CI 40.2-71.8) in children under 2 years. The incidence of meningitis in children younger than 2 years was 12.2 (95% CI 6.1-21.8). Penicillin resistance was observed in 2.6% of cases, with no high level resistance. Predisposing conditions were identified in 34% of children with invasive disease.

CONCLUSIONS

The incidence of invasive pneumococcal disease was comparable to many urban populations in Australia. The high rate of predisposing conditions supports the recommendations of the Australian Technical Advisory Group on Immunisation for targeted immunization in this group. The paucity of data describing Indigenous status is an argument for improved data collection in this area. The low level of penicillin resistance necessitates ongoing surveillance, and the lack of serotype information requires prospective data collection.

Hypoperfusion of Wernicke's area predicts severity of semantic deficit in acute stroke

Based on earlier findings that the presence of word comprehension impairment (a deficit in the meaning of words, or lexical semantics) in acute stroke was strongly associated with the presence of hypoperfusion or infarct in Wernicke's area, we tested the hypothesis that the severity of word comprehension impairment was correlated with the magnitude of delay in perfusion of Wernicke's area on magnetic resonance perfusion-weighted imaging. Eighty patients were prospectively studied within 24 hours of onset or progression of acute left hemisphere stroke symptoms, with diffusion-weighted imaging, perfusion-weighted imaging, and detailed language tests. For 50 patients without infarct in Wernicke's area, we found a strong Pearson correlation between the rate of errors on a word comprehension test and the mean number of seconds of delay in time-to-peak concentration of contrast in Wernicke's area, relative to the homologous region on the right. These results add further evidence for the crucial role of Wernicke's area (Brodmann's area 22) in word comprehension and indicate that the magnitude of delay on PWI may be a gross indicator of tissue dysfunction.

Quantitative proton MR spectroscopic imaging of normal human cerebellum and brain stem

Quantitative, multislice proton MR spectroscopic imaging (MRSI) was used to investigate regional metabolite levels and ratios in the normal adult human posterior fossa. Six normal volunteers (36 +/- 3 years, five male, one female) were scanned on a 1.5 T scanner using multislice MRSI at long echo time (TE 280 msec). The entire cerebellum was covered using three oblique-axial slice locations, which also included the pons, mid-brain, insular cortex, and parieto-occipital lobe. Concentrations of N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) were estimated using the phantom replacement technique. Regional variations of the concentrations were assessed using ANOVA (P < 0.05). High-resolution MRSI data was obtained in all subjects and brain regions examined. Metabolite concentrations (mM) (mean +/- SD) were as follows: cerebellar vermis: 2.3 +/- 0.4, 8.8 +/- 1.7 and 7.6 +/- 1.0 for Cho, Cr, and NAA respectively; cerebellar hemisphere: 2.2 +/- 0.6, 8.9 +/- 2.1, 7.5 +/- 0.8; pons 2.2 +/- 0.5, 4.3 +/- 1.1, 8.3 +/- 0.9; insular cortex, 1.8 +/- 0.5, 7.8 +/- 2, 8.0 +/- 1.1, parieto-occipital gray matter, 1.3 +/- 0.3, 5.7 +/- 1.1, 7.2 +/- 0.9, and occipital white matter, 1.4 +/- 0.3, 5.3 +/- 1.3, 7.5 +/- 0.8. Consistent with previous reports, significantly higher levels of Cr were found in the cerebellum compared to parieto-occipital gray and occipital white matter, and pons (P < 0.0001). NAA was essentially uniformly distributed within the regions chosen for analysis, with the highest level in the pons (P < 0.04). Cho was significantly higher in the cerebellum and pons than parieto-occipital gray and occipital white matter (P < 0.002) and was also higher in the pons than in the insular cortex (P < 0.05). Quantitative multislice MRSI of the posterior fossa is feasible and significant regional differences in metabolite concentrations were found.

A model for multiparametric mri tissue characterization in experimental cerebral ischemia with histological validation in rat: part 1

BACKGROUND AND PURPOSE

After stroke, brain tissue undergoes time-dependent heterogeneous histopathological change. These tissue alterations have MRI characteristics that allow segmentation of ischemic from nonischemic tissue. Moreover, MRI segmentation generates different zones within the lesion that may reflect heterogeneity of tissue damage.

METHODS

A vector tissue signature model is presented that uses multiparametric MRI for segmentation and characterization of tissue. An objective (unsupervised) computer segmentation algorithm was incorporated into this model with the use of a modified version of the Iterative Self-Organizing Data Analysis Technique (ISODATA). The ability of the model to characterize ischemic tissue after permanent middle cerebral ischemia occlusion in the rat was tested. Multiparametric ISODATA measurements of the ischemic tissue were compared with quantitative histological characterization of the tissue from 4 hours to 1 week after stroke.

RESULTS

The ISODATA segmentation of tissue identified a gradation of cerebral tissue damage at all time points after stroke. The histological scoring of ischemic tissue from 4 hours to 1 week after stroke on all the animals was significantly correlated with ISODATA segmentation (r=0.78, P<0.001; n=20) when a multiparametric (T2-, T1-, diffusion-weighted imaging) data set was used, less correlated (r=0.70, P<0.01; n=20) when a T2- and T1-weighted data set was used, and not correlated (r=-0.12, P>0.47; n=20) when only a diffusion-weighted imaging data set was used.

CONCLUSIONS

Our data indicate that an integrated set of MRI parameters can distinguish and stage ischemic tissue damage in an objective manner.

Multiparametric MRI tissue characterization in clinical stroke with correlation to clinical outcome: part 2

BACKGROUND AND PURPOSE

Multiparametric MRI generates different zones within the lesion that may reflect heterogeneity of tissue damage in cerebral ischemia. This study presents the application of a novel model of tissue characterization based on an angular separation between tissues obtained with the use of an objective (unsupervised) computer segmentation algorithm implementing a modified version of the Iterative Self-Organizing Data Analysis Technique (ISODATA). We test the utility of this model to identify ischemic tissue in clinical stroke.

METHODS

MR parameters diffusion-, T2-, and T1-weighted imaging (DWI, T2WI, and T1WI, respectively) were obtained from 10 patients at 3 time points (30 studies) after stroke: acute (</=12 hours), subacute (3 to 5 days), and chronic (3 months). The National Institutes of Health Stroke Scale (NIHSS) was measured, and volumes were obtained from the ISODATA, DWI, and T2WI maps on patients at each time point.

RESULTS

The acute (</=12 hours) multiparametric ISODATA volume was significantly correlated with the acute (</=12 hours) DWI (r=0.96, P<0.05; n=10) and chronic (3 months) T2WI volume (r=0.69, P<0.05; n=10). The ISODATA-defined tissue regions exhibited MR indices consistent with ischemic and/or infarcted tissue at each time point. The acute (</=12 hours) multiparametric ISODATA volumes were significantly correlated (r=0.82, P<0.009; n=10) with the final NIHSS score. In comparison, the acute (</=12 hours) DWI volumes were less correlated (r=0.77, P<0.05; n=10) and T2WI volume (</=12h) exhibited a marginal correlation (r=0.66, P<0.05; n=10) with the final NIHSS score.

CONCLUSIONS

The integrated ISODATA approach to tissue segmentation and classification discriminated abnormal from normal tissue at each time point. The ISODATA volume was significantly correlated with the current MR standards used in the clinical setting and the 3-month clinical status of the patient.

Disruption of the developmentally regulated Rev3l gene causes embryonic lethality

The REV3 gene encodes the catalytic subunit of DNA polymerase (pol) zeta, which can replicate past certain types of DNA lesions [1]. Saccharomyces cerevisiae rev3 mutants are viable and have lower rates of spontaneous and DNA-damage-induced mutagenesis [2]. Reduction in the level of Rev31, the presumed catalytic subunit of mammalian pol zeta, decreased damage-induced mutagenesis in human cell lines [3]. To study the function of mammalian Rev31, we inactivated the gene in mice. Two exons containing conserved DNA polymerase motifs were replaced by a cassette encoding G418 resistance and beta-galactosidase, under the control of the Rev3l promoter. Surprisingly, disruption of Rev3l caused mid-gestation embryonic lethality, with the frequency of Rev3l(-/-) embryos declining markedly between 9.5 and 12.5 days post coitum (dpc). Rev3l(-/-) embryos were smaller than their heterozygous littermates and showed retarded development. Tissues in many areas were disorganised, with significantly reduced cell density. Rev3l expression, traced by beta-galactosidase staining, was first detected during early somitogenesis and gradually expanded to other tissues of mesodermal origin, including extraembryonic membranes. Embryonic death coincided with the period of more widely distributed Rev3l expression. The data demonstrate an essential function for murine Rev31 and suggest that bypass of specific types of DNAlesions by pol zeta is essential for cell viability during embryonic development in mammals.

Boundary-based warping of brain MR images

The goal of this work was to develop a warping technique for mapping a brain image to another image or atlas data, with minimum user interaction and independent of gray level information. We have developed and tested three different methods for warping magnetic resonance (MR) brain images. We utilize a deformable contour to extract and warp the boundaries of the two images. A mesh-grid coordinate system is constructed for each brain, by applying a distance transformation to the resulting contours, and scaling. In the first method (MGC), the first image is mapped to the second image based on a one-to-one mapping between different layers defined by the mesh-grid. In the second method (IDW), the corresponding pixels in the two images are found using the above mesh-grid system and a local inverse-distance weights interpolation. In the third proposed method (TSB), a subset of grid points is used for finding the parameters of a spline transformation, which defines the global warping. The warping methods were applied to clinical MR consisting of diffusion-weighted and T2-weighted images of the human brain. The IDW and TSB methods were superior in ranking of diagnostic quality of the warped MR images to the MGC (P < 0.01) as defined by a neuroradiologist. The deformable contour warping produced excellent diagnostic quality for the diffusion-weighted images coregistered and warped to T2 weighted images. J. Magn. Reson. Imaging 2000;12:417-429.

Unsupervised segmentation of multiparameter MRI in experimental cerebral ischemia with comparison to T2, diffusion, and ADC MRI parameters and histopathological validation

This study presents histological validation of an objective (unsupervised) computer segmentation algorithm, the iterative self-organizing data analysis technique (ISODATA), for analysis of multiparameter magnetic resonance imaging (MRI) data in experimental focal cerebral ischemia. T2-, T1-, and diffusion (DWI) weighted coronal images were acquired from 4 to 168 hours after stroke on separate groups of animals. Animals were killed immediately after MRI for histological analysis. MR images were coregistered/warped to histology. MRI lesion areas were defined using DWI, apparent diffusion coefficient (ADC) maps, T2-weighted images, and ISODATA. The last techniques clearly discriminated between ischemia-altered and morphologically intact tissue. ISODATA areas were congruent and significantly correlated (r = 0.99, P < 0.05) with histologically defined lesions. In contrast, DWI, ADC, and T2 lesion areas showed no significant correlation with histologically evaluated lesions until subacute time points. These data indicate that multiparameter ISODATA methodology can accurately detect and identify ischemic cell damage early and late after ischemia, with ISODATA outperforming ADC, DWI, and T2-weighted images in identification of ischemic lesions from 4 to 168 hours after stroke.

A conserved His-Asp signal response regulator-like gene in Heterosigma akashiwo chloroplasts

Regulation of gene expression in plastids may involve molecular components conserved from cyanobacteria-like ancestors. Among prokaryotes, genes are commonly regulated at the transcriptional level by 'two-component' or 'His-Asp' signal transducers, consisting of a 'sensor kinase', which autophosphorylates at a conserved histidine residue, and a cognate response regulator, which is phosphorylated by the sensor kinase at a conserved aspartate residue. A putative His-Asp response regulator gene (trg1: transcriptional regulatory gene 1) has been identified in the estuarine raphidophytic alga Heterosigma akashiwo. The chloroplast-encoded trg1 is 693 bp in length, contains no introns, and yields a conceptual translation product of 231 amino acids, with a predicted mass of 27 kDa. Homology searches suggest that Heterosigma trgl has an omnpR-like identity within the DNA-binding His-Asp family of response regulators. trg1 contains both the phosphorylation and DNA-binding domains which are present in prokaryote response regulators. Quantitative competitive RT-PCR showed that Heterosigma trg1 is expressed at low levels (5 microg per g total RNA). In contrast, psbA (a photosystem II component) transcript is abundant (60 mg per g total RNA). Cell cycle analysis showed that psbA abundance oscillates in response to light but trg1 mRNA levels are invariant. We hypothesize that a His-Asp phosphorelay mechanism may affect chloroplast genome transcription in a manner similar to bacterial signal transduction pathways in which 'sensor kinase' and cognate 'response regulator' proteins interact.

Identification of cerebral ischemic lesions in rat using Eigenimage filtered magnetic resonance imaging

An accurate noninvasive time-independent identification of an ischemic cerebral lesion is an important objective of magnetic resonance imaging (MRI). This study describes a novel application of a multiparameter MRI analysis algorithm, the Eigenimage (EI) filter, to experimental stroke. The EI is a linear filter that maximizes the projection of a desired tissue (ischemic tissue) while it minimizes the projection of undesired tissues (nonischemic tissue) onto a composite image called an eigenimage. Rats (n=26) were subjected to permanent middle cerebral artery occlusion. T2- and T1-weighted coronal MRI were acquired on separate groups of animals. The animals were immediately sacrificed after each imaging session for histopathological analysis of tissue at 4-8 h, 16-24 h, and 48-168 h after stroke onset. Lesion areas from MRI were defined using EI. The EI defined lesion areas were coregistered and warped to the corresponding histopathological sections. The ischemic lesion as defined by EI exhibited ischemic cell damage ranging from scattered acute cell damage to pan necrosis. Ischemic cellular damage was not detected in homologous contralateral hemisphere regions. EI lesion areas overlaid on histopathological sections were significantly correlated (r=0.92, p<0.05) acutely, (r=0.98, p<0.05) subacutely, and (r=0.99, p<0.05) chronically. These data indicate that EI methodology can accurately segment ischemic damage after MCA occlusion from 4-168 h after stroke.

Registration and warping of magnetic resonance images to histological sections

We present a method for coregistration and warping of magnetic resonance images (MRI) to histological sections for comparison purposes. This methodology consists of a modified head and hat surface-based registration algorithm followed by a new automated warping approach using nonlinear thin plate splines to compensate for distortions between the data sets. To test the methodology, 15 male Wistar rats were subjected to focal cerebral ischemia via permanent occlusion of the middle cerebral artery. The MRI images were acquired in separate groups of animals at 16-24 h (n = 9) and 48-168 h (n = 6) postocclusion. After imaging, animals were immediately sacrificed and hematoxylin- and eosin-stained brain sections were obtained for histological analysis. The MRI was coregistered and warped to histological sections. The MRI lesion areas were defined using the Eigenimage (EI) filter technique. The EI is a linear filter that maximizes the projection of a desired tissue (ischemic tissue) while it minimizes the projection of undesired tissues (nonischemic tissue) onto a composite image called an EI. When using coregistration without warping the MRI lesion area demonstrated poor correlation (r = 0.55, p > 0.01) with a percent difference between the two lesion areas of 22.5% +/- 10.8%. After warping, the MRI and histology had significant correlation (r = 0.97, p < 0.01) and a decreased percent difference of 5.56% +/- 4.31%. This methodology is simple and robust for coregistration and warping of MRI to histological sections and can be utilized in many applications for comparison of MRI to histological data.

The incidence of retinopathy of prematurity and steroid therapy for broncho-pulmonary dysplasia

To determine whether prolonged dexamethasone therapy, used in the treatment of bronchopulmonary dysplasia (BPD), affects the incidence of retinopathy of prematurity (ROP), premature born infants (Gestational age < 33 weeks) treated or not with dexamethasone for BPD were retrospectively studied over a 5 year period. Although the dexamethasone treated group had a significant lower gestational age and a longer period of total ventilatory support there was no significant difference in incidence of ROP between the groups.

Cyclin B2-null mice develop normally and are fertile whereas cyclin B1-null mice die in utero

Two B-type cyclins, B1 and B2, have been identified in mammals. Proliferating cells express both cyclins, which bind to and activate p34(cdc2). To test whether the two B-type cyclins have distinct roles, we generated lines of transgenic mice, one lacking cyclin B1 and the other lacking cyclin B2. Cyclin B1 proved to be an essential gene; no homozygous B1-null pups were born. In contrast, nullizygous B2 mice developed normally and did not display any obvious abnormalities. Both male and female cyclin B2-null mice were fertile, which was unexpected in view of the high levels and distinct patterns of expression of cyclin B2 during spermatogenesis. We show that the expression of cyclin B1 overlaps the expression of cyclin B2 in the mature testis, but not vice versa. Cyclin B1 can be found both on intracellular membranes and free in the cytoplasm, in contrast to cyclin B2, which is membrane-associated. These observations suggest that cyclin B1 may compensate for the loss of cyclin B2 in the mutant mice, and implies that cyclin B1 is capable of targeting the p34(cdc2) kinase to the essential substrates of cyclin B2.

Is malnutrition overdiagnosed in older hospitalized patients? Association between the soluble interleukin-2 receptor and serum markers of malnutrition

BACKGROUND

Many researchers have speculated that markers of malnutrition such as albumin, prealbumin, cholesterol, and transferrin are influenced by inflammation. The mechanism of this interaction has not been well understood.

METHODS

This was a prospective cross-sectional study. We evaluated 72 male patients older than 60 years admitted to a geriatric rehabilitation unit. Subjects with severe hepatic or renal diseases were excluded. We measured body mass index, caloric intake, serum albumin, prealbumin, cholesterol, transferrin, hemoglobin, and total lymphocyte count. To detect inflammation, we measured C-reactive protein, Westergren sedimentation rate, fibrinogen, and cytokines including tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), IL-6, IL-2, and the soluble IL-2 receptor.

RESULTS

Soluble IL-2 receptor was negatively associated with albumin (r = -.479, p < .0001), prealbumin (r = -.520, p = < .0001), cholesterol (r = -.487, p = .0001), transferrin (r = -.455, p = .0002), and hemoglobin (r = -.371, p = .002). TNF-alpha, IL-1 beta, IL-6, and IL-2 were not associated with these measures.

CONCLUSIONS

Inflammation increases the incidence of hypoalbuminemia and hypocholesterolemia, potentially leading to overdiagnosis of malnutrition. We suggest that albumin, cholesterol, prealbumin, and transferrin be used with caution when assessing the nutritional status of older hospitalized patients. In the future, soluble IL-2 receptor levels might be used to correct for the impact of inflammation on these markers of malnutrition.

Substitution of night-time continuous subcutaneous insulin infusion therapy for bedtime NPH insulin in a multiple injection regimen improves counterregulatory hormonal responses and warning symptoms of hypoglycaemia in IDDM

In patients with insulin-dependent diabetes mellitus (IDDM) good glycaemic control confers an enhanced risk of hypoglycaemia. Nocturnal hypoglycaemia occurs frequently and contributes to the syndrome of hypoglycaemia unawareness. In order to avoid nocturnal hypoglycaemia we substituted night-time continuous subcutaneous insulin infusion (CSII) therapy in 14 patients with well-controlled IDDM using a multiple injection regimen for the more variable bedtime NPH insulin. During a stepwise hypoglycaemic clamp we studied the effect of this regimen on counterregulatory hormonal responses, warning symptoms and cognitive function. In addition, we investigated the incidence of daytime hypoglycaemia and the acceptability of night-time CSII treatment. CSII was associated with a lower frequency of hypoglycaemia (mean+/-SEM): 16.1+/-3.1 vs 23.6+/-3.3) episodes during the last 6 weeks of treatment, p=0.03 (CSII vs NPH)) with maintenance of good glycaemic control (HbA1c 7.2+/-0.2 vs 7.1+/-0.2 %, p=0.2). Hypoglycaemic thresholds for the growth hormone response and for autonomic symptoms were lower for CSII treatment than for NPH treatment. Of 14 patients 6 decided to continue with the nocturnal CSII treatment. In conclusion, nocturnal CSII improves warning symptoms and counterregulatory hormonal responses to hypoglycaemia and is an acceptable treatment strategy for patients suffering from hypoglycaemia unawareness, as demonstrated in this acute feasibility study.

Prediction of impending hemorrhagic transformation in ischemic stroke using magnetic resonance imaging in rats

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) of ischemic brain tissue may occur in stroke patients either spontaneously or after thrombolysis. A method to assess the risk of HT in ischemic tissue after stroke would improve the safety of thrombolytic therapy. As a means of predicting HT, we investigated the role of contrast-enhanced MRI at acute time points in a rat middle cerebral artery occlusion model with reperfusion.

METHODS

Intraluminal suture occlusion of the middle cerebral artery was used to produce transient ischemia in male Wistar rats (n=11). Reperfusion was performed by withdrawal of the occluding filament after 2 (n=4), 3 (n=6), or 4 (n=1) hours. MRI studies were performed before and after reperfusion with the use of conventional T1-weighted imaging, with and without gadolinium (Gd-DTPA) contrast agent, and T2-weighted imaging. Follow-up MRI and histological studies were obtained at 24 hours.

RESULTS

Petechial hemorrhage occurred by 24 hours in 9 of 11 animals. All animals showed brain swelling and cellular death throughout the ischemic region at 24 hours. A hyperintense region in the preoptic area became visible after Gd-DTPA injection within minutes after reperfusion in animals with subsequent HT. All animals showing acute Gd-DTPA enhancement subsequently developed petechial hemorrhage (or died) by 24 hours. In these animals, statistically significant differences in signal intensity (P=.0005) between the ipsilateral enhancing region and a homologous contralateral region were detected on post-Gd-DTPA T1-weighted imaging. There was also a statistically significant correlation (P=.01) between the rate of Gd-DTPA uptake and the size of the enhancing area. Two animals did not enhance with Gd-DTPA and did not exhibit hemorrhage on histological examination or MRI at 24 hours. No abnormalities were seen on precontrast T1-weighted images before and shortly after reperfusion or postcontrast T1-weighted images before reperfusion.

CONCLUSIONS

The primary finding of this study was the detection of early Gd-DTPA parenchymal enhancement in 82% of the animals after reperfusion. Enhancement was seen before any detectable hemorrhage, suggesting that early endothelial ischemic damage occurs before gross brain infarction and hemorrhage. Thus, we suggest that acute Gd-DTPA enhancement may provide an early prediction of petechial hemorrhage.

Metabolic efficacy of preprandial administration of Lys(B28), Pro(B29) human insulin analog in IDDM patients. A comparison with human regular insulin during a three-meal test period

OBJECTIVE

The objective of this study was to compare the efficacy of the rapid-acting Lys(B28), Pro(B29) human insulin analog, insulin lispro, with currently available short-acting human insulin in a multiple injection therapy (MIT) regimen with respect to blood glucose and plasma insulin profiles and to serum metabolites (lactate, free fatty acids, glycerol, and beta-hydroxybutyrate) in 12 well-controlled type 1 diabetic subjects (8 male, HbA1c 6.8 +/- 0.9% [mean +/- SD]).

RESEARCH DESIGN AND METHODS

After a run-in period of 4 weeks, patients were treated with either lispro at mealtime or human insulin 30 min before the meal for two periods of 4 weeks in a randomized open-label crossover study. Intermediate-acting insulin (NPH insulin) was given at bedtime. At the end of both study periods, metabolic profiles were assessed from 10:00 P.M. to 7:00 P.M. the next day.

RESULTS

During the treatment periods, glycemic control was stable during lispro but improved during human insulin (delta HbA1c lispro 0.1 +/- 0.48, NS; human insulin -0.41 +/- 0.34%, P < 0.05). Glucose excursions, as measured by the incremental AUC, during the day and for the 2-h postprandial periods, were lower, although not significantly, for lispro. Insulin profiles demonstrated a faster rise after administration of lispro as compared with human insulin, peaking at 61 +/- 11.9 and 111 +/- 48.1 min (P < 0.01). Glycerol levels showed a slight increase before lunch and dinner, suggestive of enhanced lipolytic activity and compatible with the lower insulin levels.

CONCLUSIONS

Lispro insulin applied in an MIT regimen creates more physiologic insulin profiles and tends to lower the glycemic excursions during the day compared with short-acting insulin. The analog can be applied safely in an MIT regimen, with mealtime intervals up to 5 h.

Counterregulatory hormone responses and symptoms during hypoglycaemia induced by porcine, human regular insulin, and Lys(B28), Pro(B29) human insulin analogue (insulin Lispro) in healthy male volunteers

Lys(B28)Pro(B29) human insulin analogue (Lispro) is a newly developed monomeric insulin analogue with a rapid onset and short duration of action. The aim of the study was to compare the thresholds for the counterregulatory responses during a stepwise euglycaemic/hypoglycaemic clamp for insulin lispro (LP), human (H), and porcine (P) insulin in a randomized order in 12 healthy male volunteers (age 22.4 +/- 1.7 years, BMI 21.9 +/- 1.7 kg m-2). A euglycaemic period of 2 h was followed by three hypoglycaemic levels of 60 min each; from 150-210 min at 3.5 mmol l-1, 240-300 min at 3.0 mmol l-1 and 330-390 min at 2.5 mmol l-1. Plasma insulin levels during the 50 mU kg-1 h-1 infusions and blood glucose levels were not significantly different. The glucose requirements (mean +/- SD) during the last part of the euglycaemic period (90-120 min) tended to be higher during LP compared to those during H and P; 2239 +/- 702 and 1929 +/- 769, 1957 +/- 725 mg kg-1, P = 0.067, respectively. The thresholds (blood glucose level at which a sustained elevation of the counterregulatory hormones as compared to the mean at normoglycaemia level 4.0 mmol l-1, occurs) for the various hormones were very similar during LP, H, and P insulin infusions and occurred at 253.8 +/- 56.7, 256.3 +/- 55.3 and 257.5 +/- 70.0 min for adrenaline; 241.4 +/- 80.3, 260.5 +/- 82.5 and 225.0 +/- 75.9 min for noradrenaline; 307.5 +/- 65.5, 304.1 +/- 74.1 and 322.5 +/- 40.4 min for cortisol; 263.8 +/- 50.3, 255.0 +/- 63.6 and 249.6 +/- 50.9 min for growth hormone; 236.3 +/- 78.2, 200.0 +/- 73.1 and 226.3 +/- 65.5 for pancreatic polypeptide. The autonomic and neuroglycopenic symptoms were elicited at 240 and 300 min, respectively. In conclusion, our data indicate a tendency to a higher biological activity of approximately 10% for Lispro insulin. During a stepwise euglycaemic/hypoglycaemic clamp, the counterregulatory hormone responses to insulin lispro, human insulin, and porcine insulin were similar.

HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets) pathophysiology and anesthetic considerations

HELLP syndrome in the parturient (hemolysis, elevated liver enzymes, and low platelet count) is associated with poor maternal and fetal outcomes. Maternal mortality has been estimated to be as high as 24%. Patients with HELLP syndrome are also at greater risk of pulmonary edema, adult respiratory distress syndrome, abruptio placentae, disseminated intravascular coagulation, ruptured liver hematomas, and acute renal failure. Perinatal mortality is equally high, ranging from 79 to 367 per 1,000 live births, and neonatal complications correlate with the severity of maternal disease. Many clinicians view HELLP syndrome as an entity of preeclampsia, and because of varied symptomatology, the initial diagnosis may be obscured. Prodromal signs include: (1) weakness and fatigue, (2) nausea and vomiting, (3) right upper quadrant and/or epigastric pain, (4) headache, (5) changes in vision, (6) increased tendency to bleed from minor trauma, (7) jaundice, (8) diarrhea, and (9) shoulder or neck pain. Before delivery, aggressive obstetric management is directed toward stabilization of the affected organ systems, if possible, and timely interruption of the pregnancy in the early phase of the accelerated disease progression. Definitive therapy is delivery. Parturients with HELLP syndrome are often critically ill; their infants are frequently premature and their conditions are compromised. Management criteria should include a multidisciplinary approach in a tertiary care center. Obstetric anesthesia personnel should perform a thorough preanesthetic evaluation and be familiar with the pathophysiologic changes of this syndrome. Determining the anesthetic of choice depends on the patient's condition, fetal well-being, and the urgency of the situation. In the presence of severe coagulopathy, regional anesthesia is contraindicated.

Biosynthesis of prothrombin: intracellular localization of the vitamin K-dependent carboxylase and the sites of gamma-carboxylation

Prothrombin is a vitamin K-dependent blood coagulation protein that undergoes posttranslational gamma-carboxylation and propeptide cleavage during biosynthesis. The propeptide contains the gamma-carboxylation recognition site that directs gamma-carboxylation. To identify the intracellular sites of carboxylation and propeptide cleavage, we monitored the synthesis of prothrombin in Chinese hamster ovary cells stably transfected with the prothrombin cDNA by immunofluorescent staining. The vitamin K-dependent carboxylase was located in the endoplasmic reticulum and Golgi complex. Antibodies specific to prothrombin processing intermediates were used for immunocytolocalization. Anti-des-gamma-carboxyprothrombin antibodies stained only the endoplasmic reticulum whereas antiproprothrombin antibodies (specific for the propeptide) and antiprothrombin:Mg(II) antibodies (which bind the carboxylated forms of proprothrombin and prothrombin) stained both the endoplasmic reticulum and the Golgi complex. Antiprothrombin:Ca(II)-specific antibodies (which bind only to the carboxylated form of prothrombin lacking the propeptide) stained only the Golgi complex and secretory vesicles, and colocalized with antimannosidase II and anti-p200 in the juxtanuclear Golgi complex. These results indicate that uncarboxylated proprothrombin undergoes complete gamma-carboxylation in the endoplasmic reticulum and that gamma-carboxylation precedes propeptide cleavage during prothrombin biosynthesis.

Moving pictures and pulsed-field gel electrophoresis show only linear mitochondrial DNA molecules from yeasts with linear-mapping and circular-mapping mitochondrial genomes

The mobility of mitochondrial DNA (mtDNA) in pulsed-field gel electrophoresis (PFGE) and its appearance in moving pictures from fluorescence microscopy were used to investigate the mitochondrial genome structure for five Pichia and Williopsis strains of yeast. An apocytochrome b-gene hybridization probe identified only linear mtDNA molecules for each strain when total cellular DNA was fractionated by PFGE. Most of the mass of DNA isolated from mitochondria for one linear-mapping and one circular-mapping mitochondrial genome was found in linear molecules much larger than the genome size of 50 kb; some molecules were as long as 1500 kb, but only a trace amount of apparently circular mtDNA was found for the strain with the circular-mapping genome. Probes for both the apocytochrome-b and mitochondrial small rRNA subunit genes hybridized strongly to mtDNA of approximately 50-100 kb, but weakly to the larger DNA from mitochondria of these two strains. For the four linear-mapping strains, PFGE revealed two or three distinct bands of linear mtDNA, larger than the genome size, within a smear of approximately 50-100 kb, but a smear without bands was found for the circular-mapping strain.

The treatment of osteoarthritis of the knee with pulsed electrical stimulation

OBJECTIVE

The safety and effectiveness of pulsed electrical stimulation was evaluated for the treatment of osteoarthritis (OA) of the knee.

METHODS

A multicenter, double blind, randomized, placebo controlled trial that enrolled 78 patients with OA of the knee incorporated 3 primary efficacy variables of patients' pain, patients' function, and physician global evaluation of patients' condition, and 6 secondary variables that included duration of morning stiffness, range of motion, knee tenderness, joint swelling, joint circumference, and walking time. Measurements were recorded at baseline and during the 4 week treatment period.

RESULTS

Patients treated with the active devices showed significantly greater improvement than the placebo group for all primary efficacy variables in comparisons of mean change from baseline to the end of treatment (p < 0.05). Improvement of > or = 50% from baseline was demonstrated in at least one primary efficacy variable in 50% of the active device group, in 2 variables in 32%, and in all 3 variables in 24%. In the placebo group improvement of > or = 50% occurred in 36% for one, 6% for 2, and 6% for 3 variables. Mean morning stiffness decreased 20 min in the active device group and increased 2 min in the placebo group (p < 0.05). No statistically significant differences were observed for tenderness, swelling, or walking time.

CONCLUSION

The improvements in clinical measures for pain and function found in this study suggest that pulsed electrical stimulation is effective for treating OA of the knee. Studies for longterm effects are warranted.

Influences on weight loss in type 2 diabetic patients: little long-term benefit from group behaviour therapy and exercise training

The aim of our study was to assess the long-term (24 months) efficacy of a comprehensive weight reduction programme as compared to that of a conventional programme. The Comprehensive Programme comprised, besides the Conventional Programme (diet counselling), behavioural modification and exercise training. The 2-year follow-up period was completed by 53 patients (19M/34F; 88.3%). The differences (95% confidence intervals; CI) between the change in body weight of patients in the Comprehensive Programme compared to the Conventional Programme after 6 and 24 months of treatment were -2.2 (-4.0, -0.3) kg, p = 0.03 and -1.3 (-3.3, 0.7) kg, p = 0.21, respectively. In comparison to the Conventional Programme, the Comprehensive Programme resulted in a greater decrease (95% CI) of HbA1c after 6 months: -0.8 (-1.2, -0.2)%, p = 0.01, but not after 2 years: -0.4 (-1.0, 0.1)%, p = 0.12. The effects on blood pressure and serum lipids of the Comprehensive Programme and the Conventional Programme were comparable. Changes in body weight at 6 months correlated well with changes in HbA1c, fasting plasma insulin, and blood pressure, whereas at 24 months no such correlation was found with HbA1c. Pretreatment variates that were associated with the greatest 2-year weight loss were a high HbA1c value, a low energy per cent carbohydrate intake and a low percentage of obese subjects within the family. In conclusion, the long-term outcome of the Comprehensive Programme was not different from that of the Conventional Programme. The achieved body weight reduction was associated with a sustained fall in blood pressure, but with only a transient beneficial effect on the glycaemic control in the Type 2 diabetic patient.

Determinants of insulin sensitivity and consequences for lipoproteins and blood pressure in subjects with non-insulin-dependent diabetes mellitus

The aim of the present study was to investigate the possible determinants of insulin sensitivity and the relationships of these determinants and insulin sensitivity to lipoprotein levels and blood pressure in patients with non-insulin-dependent diabetes mellitus (NIDDM). We studied 46 patients with NIDDM (26 women, 20 men) treated either with diet alone or in combination with sulfonylureas. Insulin sensitivity was assessed as the insulin-mediated glucose uptake rate (M value) with the hyperinsulinemic euglycemic clamp technique. In a multiple regression model, only percent body fat, waist to hip ratio (WHR), and resting energy expenditure (REE) emerged as significant independent determinants of the M value, with a multiple R2 for the model of 44%, whereas age, hemoglobin A1c (HbA1c) level, thyroid function, fitness level, smoking status, alcohol consumption, and dietary habits did not contribute significantly. The M value was independently and negatively associated with the concentrations of triglyceride (TG) and very-low-density lipoprotein (VLDL) cholesterol and positively associated with high-density lipoprotein (HDL) cholesterol subfractions and apolipoprotein A1. In our predominantly normotensive subjects, we found no association between the M value and blood pressure. Moreover, fasting insulin contributed directly, ie, independent of the M value, to the variation of TG, but not to the other lipoproteins and not to blood pressure. The results suggest that in NIDDM (1) insulin sensitivity is determined mainly by percentage body fat and REE, (2) the insulin level determines the TG level directly, whereas the lipoproteins are influenced indirectly as a reflection of the degree of insulin resistance, and (3) insulin sensitivity is not related to blood pressure in a normotensive population.

The pharmacodynamics and activity of intranasally administered insulin in healthy male volunteers

The objective of the study was to assess the bioavailability and absorption dynamics of intranasal insulin (with di-decanoyl-alpha-phosphatidylcholine, DDPC, as absorption enhancer) in two potencies (U200 and U500). Toward this aim, the euglycemic clamp technique combined with somatostatin (100 micrograms/h) was used. Insulin was administered to 12 healthy males: 5 IU intravenously (20-min infusion); 10 IU subcutaneously; 50 IU (U200) and 50 IU, 100 IU, and 150 IU (U500) intranasally. Peak insulin levels (mean +/- SD) were reached at 17.9 +/- 2.6, 77.9 +/- 38.3, 23.3 +/- 5.4, 25.4 +/- 8.4, 26.2 +/- 8.3, and 27.5 +/- 5.8 min, respectively. For the 50 IU dose, peak glucose requirements during the clamp and time to peak were not significantly different for U200 and U500: 548.8 +/- 279.5 vs. 452.4 +/- 232.9 mg/min and 41.3 +/- 16.2 vs. 51.5 +/- 29.9 min, respectively. Compared with intravenous insulin, the bioavailability calculated from the total area under the insulin curve was 13.2% (95% confidence interval 7.9, 21.9) and 8.8% (95% confidence interval 5.6, 13.8), and compared with subcutaneous insulin, the bioavailability was 14.8% (95% confidence interval 8.7, 25.2) and 9.9% (95% confidence interval 6.4, 15.4) for the U200 and U500 preparations, respectively. An apparent nonlinear dose-dependent relation was found for the U500 potency. The within-subject variability of the areas under the curves of plasma insulin after the administration of 100 IU was 43.6% (range 20.7-85.7). In conclusion, this nasal insulin preparation has promising absorption and action profiles in both potencies, which makes it suitable for further exploration of clinical applications.

Total hip replacement without cement for non-inflammatory osteoarthrosis in patients who are less than forty-five years old

Forty-two patients (forty-four hips) who, at an age of less than forty-five years, had a total hip replacement without cement for the treatment of non-inflammatory osteoarthrosis, were followed for three to seven years (average, four and one-half years). At the latest follow-up evaluation, thirty-seven hips (84 per cent) had an excellent Harris rating; three (7 per cent), good; one (2 per cent), fair; and three (7 per cent), poor. The mean Harris hip score was 92 points, compared with 43 points before the operation. Two hips (5 per cent) had a revision due to complications. In another hip, there was a progressive radiolucent line around the femoral component, increased shedding of beads, and a low score for fixation and stability, according to the criteria of Engh et al. We concluded that total hip arthroplasty without cement, at least for the time-period studied, has a high rate of success for the management of patients less than forty-five years old who have non-inflammatory osteoarthrosis of the hip.

Quantitative effects of cerebral infarction on spatial learning in rats

Outcome following stroke is difficult to measure because the behavioral response to infarction is variable. We hypothesized that cognitive function, such as spatial learning, may be a reproducible and sensitive outcome variable. We developed an animal model of multifocal cerebral ischemia in order to study the effects of infarction on learning. To cause ischemia, several hundred microspheres were injected into the internal carotid arteries of rats. After ischemia, behavior was measured using a global rating and a Morris water maze. Postmortem serial brain sections were stained and the size of the infarctions was measured. We found that intracerebral microspheres caused cortical infarction and an impairment of spatial learning. This impairment was not due to occlusion of the internal carotid artery and was not found in animals who received a sham injection of saline. The degree of learning impairment was not correlated with the volume density of the infarctions or with the volume density of the remaining cerebral hemisphere. The learning impairment clearly differentiated normal from lesioned animals, and the impairment was probably due to a delay in acquisition of spatial information rather than a defect in retention or retrieval. Measurement of learning deficit after cerebral ischemia is an efficient and sensitive method for evaluating new stroke treatments and possibly for exploring structure function relationships.

Osteotomy of the tibial tubercle during total knee replacement. A report of twenty-six cases

The cases of twenty-four patients who had twenty-six osteotomies of the tibial tubercle in conjunction with total knee replacement were analyzed with regard to complications and technical considerations. The patients were followed for a minimum of two years (average, three years and six months). Major complications related to the surgical technique occurred in 23 per cent of the knees and complications not related to the technique, in an additional 8 per cent. Rheumatoid arthritis and a history of at least one previous operation about the knee were predisposing factors for these complications.

Core decompression of the distal femur for avascular necrosis of the knee

From 1974 to 1981, we performed 28 core decompressions of the distal femur for pathologically confirmed avascular necrosis. At a mean follow-up of 54 months (range 20 to 140 months) and using the Ficat stages, all seven cases in stage I and stage II had good results. Of 21 cases in stage III, 11 cases had good results, four had poor results, and six needed total knee replacement. There were no significant orthopaedic complications. The procedure is worthwhile and will be more accurate with new methods of imaging.

Bladder leiomyoma

We herein present a case of leiomyoma of the urinary bladder discovered during evaluation for stress urinary incontinence. The histologic findings of this benign tumor and its urologic implications are reviewed.

Intertrochanteric osteotomy for avascular necrosis of the femoral head

Of 24 intertrochanteric osteotomies for avascular necrosis of the femoral head, 22 were followed up for an average of 63 months. Sixteen of the 22 cases had good or excellent results, including 5 of the 6 cases with Stage II disease and 11 of the 16 with Stage III changes. Success seemed to be inversely related to the size of the lesion. There were six major orthopaedic complications, but despite these we feel that the operation has a definite role in the treatment of the young active patient.

Revision of septic total knee arthroplasty

Nine patients with septic total knee arthroplasties (TKA) were treated between 1980 and 1984; six were gram-positive infections and three were gram-negative. Initial treatment included the maintenance of all solidly fixed components. Patients with loose components were treated with removal of all prosthetic material and subsequent reimplantation after a six-week course of antibiotics. At follow-up examination six of nine patients had satisfactory results. One patient maintained his original femoral and tibial components and one patient required a knee fusion to treat his recurrent gram-negative infection. Overall, complications were associated with chronic infection, gram-negative infection, and abnormalities of the extensor mechanism.