Predicting survival after treatment for fracture of the proximal femur and the effect of delays to surgery

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate the prognosis after treatment for femoral neck fracture, to assess the impact of delay to surgery, and to devise a clinical prediction rule and score.

METHODS

A prospective observational study was conducted in which 1780 patients treated surgically in two teaching hospitals between 1 November 1997 and 31 October 1999 were followed over 12 months. Logistic regression was used to distinguish the effects of predictor variables on survival. Using a probit transformation of the predicted posterior probabilities of death, a prognostic score was devised with scores constrained so that a nominal score of approximately 90 represented a 50:50 chance of survival over 12 months.

RESULTS

Mortality was 30.1% in men and 19.5% in women. Increasing age, male gender, longer pre-operative delay, a higher American Society of Anesthesiology score, a lower Mental Test score, and a lower activities of daily living (Barthel) score were associated with increased risks of death. Of those waiting between 1 and 5 days for surgery, approximately 8 medium-risk and 17 high-risk patients (with prognostic scores of 90 and 120, respectively) would have to have their delay reduced to < 24 hours to yield one additional survivor.

CONCLUSION

The application of prediction rules must be guided by ethical, social, and scientific concerns.

CD44 expression in papillary serous endometrial carcinoma

The objective of this paper is to evaluate the relationship between CD44 expression and the clinicopathologic features of papillary serous endometrial cancer. CD44 expression was assessed in 32 cases of papillary serous endometrial carcinoma by standard immunohistochemical staining techniques. Clinicopathologic features including myometrial invasion, nodal metastases, tumor spread, stage, and the shedding of malignant cells on cervical cytology were reviewed. The Chi-square test was used for statistical analysis. CD44 was not expressed in 81% of patients with papillary serous endometrial carcinoma. Malignant cells were seen on cervical cytology in 68% of all cases with significantly more in the CD44-negative group (78% vs. 33%, P 0.05). CD44 expression was not related to stage, myometrial invasion, nodal involvement, or intraperitoneal spread. We conclude that the cell adhesion molecule CD44 is expressed infrequently in papillary serous endometrial carcinoma. Shedding of malignant cells on cervical cytology is common in papillary serous endometrial cancer and occurs more frequently in CD44-negative cases. CD44 expression doesn't appear to be related to known prognostic features such as nodal metastases or stage. The biologic aggressiveness of this tumor type may, in part, be related to its lack of CD44 expression.

Acid-base balance of cats with chronic renal failure: effect of deterioration in renal function

In a previous cross-sectional study of feline chronic renal failure (CRF), metabolic acidosis was identified in 52.6 per cent of animals with severe renal failure (plasma creatinine concentration >400 micromol/litre). The aim of this longitudinal study was to determine whether metabolic acidosis preceded or accompanied a deterioration in renal function in cats with CRF. Data were analysed from 55 cats with CRF that had been followed longitudinally for at least four months. Twenty-one cases showed deterioration in renal function over the period of the study, as evidenced by significant rises in their plasma creatinine concentrations and decreases in bodyweight. In five of the 21 cases, acidaemia accompanied the deterioration in renal function. Only one of these cats had evidence of metabolic acidosis before renal function deterioration. One other case developed metabolic acidosis without a rise in plasma creatinine concentration. These data suggest that biochemical evidence of metabolic acidosis does not generally occur until late in the course of feline CRF.

CD44 expression in papillary serous endometrial carcinoma

The objective of this paper is to evaluate the relationship between CD44 expression and the clinicopathologic features of papillary serous endometrial cancer. CD44 expression was assessed in 32 cases of papillary serous endometrial carcinoma by standard immunohistochemical staining techniques. Clinicopathologic features including myometrial invasion, nodal metastases, tumor spread, stage, and the shedding of malignant cells on cervical cytology were reviewed. The Chi-square test was used for statistical analysis.

CD44 was not expressed in 81% of patients with papillary serous endometrial carcinoma. Malignant cells were seen on cervical cytology in 68% of all cases with significantly more in the CD44-negative group (78% vs. 33%, P 0.05). CD44 expression was not related to stage, myometrial invasion, nodal involvement, or intraperitoneal spread. We conclude that the cell adhesion molecule CD44 is expressed infrequently in papillary serous endometrial carcinoma. Shedding of malignant cells on cervical cytology is common in papillary serous endometrial cancer and occurs more frequently in CD44-negative cases. CD44 expression doesn't appear to be related to known prognostic features such as nodal metastases or stage. The biologic aggressiveness of this tumor type may, in part, be related to its lack of CD44 expression.

Identification of equine cecal bacteria producing amines in an in vitro model of carbohydrate overload

Acute laminitis has been associated with the overgrowth of gram-positive bacteria within the equine hindgut, causing the release of factor(s) leading to ischemia-reperfusion of the digits. The products of fermentation which trigger acute laminitis are, as yet, unknown; however, vasoactive amines are possible candidates. The objectives of this study were to use an in vitro model of carbohydrate overload to study the change in populations of cecal streptococci and lactobacilli and to establish whether certain species of these bacteria were capable of producing vasoactive amines from amino acids. Cecal contents from 10 horses were divided into aliquots and incubated anaerobically with either corn starch or inulin (fructan; both at 1 g/100 ml). Samples were taken at 6-h intervals over a 24-h period for enumeration of streptococci, lactobacilli, and gram-negative anaerobes by a dilution method onto standard selective growth media. The effects of the antibiotic virginiamycin (1 mg/100 ml) and calcium hydrogen phosphate (CaHPO(4); 0.3 g/100 ml) were also examined. Fermentation of excess carbohydrate was associated with increases in numbers of streptococci and lactobacilli (2- to 3.5-log unit increases; inhibited by virginiamycin) but numbers of gram-negative anaerobes were not significantly affected. A screening agar technique followed by 16S rRNA gene sequence analysis enabled the identification of 26 different bacterial strains capable of producing one or more vasoactive amines. These included members of the species Streptococcus bovis and five different Lactobacillus spp. These data suggest that certain bacteria, whose overgrowth is associated with carbohydrate fermentation, are capable of producing vasoactive amines which may play a role in the pathogenesis of acute laminitis.

Identification and quantification of amines in the equine caecum

Acute laminitis has been associated with the release of compounds, as yet unidentified, produced by hindgut fermentation which affect blood flow to the digit. The objectives of this study were to identify amine compounds in equine caecal and colonic contents, some of which are known to have vasoactive properties. In addition, the concentrations of amines in caecal contents of horses fed either grass or hay diets were compared. Fifteen amines were identified in equine hindgut contents in concentrations greater than 1 microM. The caecal concentrations of phenylethylamine, isoamylamine, cadaverine, diaminoheptane and spermidine were significantly higher in horses on spring/summer grass compared with those on winter grass or hay. These data show that many amines are present in the equine hindgut, some of which may have the potential to cause peripheral vasoconstriction if released into the circulation from the gastrointestinal tract.

The morphological and spectral phenotype of apoptosis in HeLa cells varies following exposure to UV-C and the addition of inhibitors of ICE and CPP32

Numerous extra- and intracellular factors, including UV radiation, can initiate a programme of cell death by apoptosis. While apoptosis is commonly defined morphologically, the relationships between morphology and molecular events are not well established. To investigate these relationships in HeLa cells, eight morphometric criteria for cell proliferation and damage and 10 criteria for apoptotic phenotype were examined using light microscopy, and corroborated by ultrastructure and spectral imaging. They were identified (1) during a time course after irradiation with 0, 10 or 30 J/m2 UV-C; (2) after separation of apoptotic from normal cells on a Percoll gradient; and (3) after irradiation with UV-C plus perturbation of the apoptotic pathway by treatment with inhibitors of two caspases, ICE and CPP32. The number of cells in apoptosis increased in a dose-dependent manner after UV-C treatment. Centrifugation of irradiated cells on a Percoll gradient increased the collection of apoptotic cells tenfold. The stereotypical apoptotic phenotype, in which cells have deep cytoplasmic blebbing and highly condensed DNA, comprised only a few percent of all apoptosis, and was rarely seen in groups receiving caspase inhibitors. The most common apoptotic phenotype was a rounded cell with large spherical nucleolus and associated DNA. After treatment with UV-C plus inhibitors the apoptotic index was decreased by about 30% compared to UV-C radiation alone. These apoptotic cells had dark spherical cytoplasm with small blebs, greatly increased numbers of cytoplasmic ribosomes, abundant nucleolar material with a large separate granular component, and chromatin condensed at the nuclear membrane. Using the technique of spectral imaging, it was found that the spectrum obtained from the granular component of the nucleolus, which was elevated in apoptotic cells treated with UV-C plus inhibitors, was similar to the dense accumulation of ribosomes in the apoptotic cytoplasm. The data indicate that spectral imaging may be a useful tool for identifying and characterizing variations in the apoptotic process, and that the caspase inhibitors used here do not completely abolish UV-C induced apoptosis, but rather alter its incidence and progression.

Uptake of 5-hydroxytryptamine by equine digital vein endothelial cells: inhibition by amines found in the equine caecum

REASONS FOR PERFORMING STUDY

5-hydroxytryptamine (5-HT; serotonin) is a potent vasoconstrictor of equine digital blood vessels and has been implicated in the pathogenesis of acute laminitis.

OBJECTIVES

The aims of this study were firstly to examine whether cells of the digital blood vessel wall exhibited an active uptake mechanism for 5-HT and to characterise its efficiency; and secondly, to study the potential inhibitory effect on this process of other amines, produced in the equine caecum.

METHODS

Confluent monolayers of equine digital vein endothelial cells (EDVEC) and equine digital vein smooth muscle cells (EDVSMC) were incubated with [3H]5-HT (0.1-250 micromol/l) and the total and active uptake calculated. Equine pulmonary vein endothelial cells (EPVEC) were used as a positive control.

RESULTS

Both EDVEC and EDVSMC showed uptake of [3H]5-HT by nonfaci litated diffusion; however, only EDVEC showed evidence of saturable facilitated uptake mechanism, with a Km of 41.6 +/- 9.3 micromol/l, which was significantly higher than that of EPVEC (9.9 +/- 2.1 micromol/l). All 6 caecally-derived amines examined (tyramine, spermine, isoamylamine, tryptamine, phenylethylamine and isobutylamine) inhibited the total uptake of [3H]5-HT in a concentration-dependent manner, tyramine having the lowest IC50 (3.7 x 10(-6) mol/l).

CONCLUSIONS

These data suggest that facilitated uptake into the endothelium could play a role in moderating the vasoconstrictor response to 5-HT in the equine digital circulation.

POTENTIAL CLINICAL RELEVANCE

The vasoconstrictor action of 5-HT could be potentiated by gut-derived amines, providing a feasible link between GI disturbances and the pathophysiology of laminits.

Assessment of acid-base status of cats with naturally occurring chronic renal failure

Metabolic acidosis is reported to be a common complication of feline chronic renal failure (CRF) but acid-base status of feline patients with this disease is rarely assessed by general practitioners. A cross-sectional study involving 59 cases of naturally occurring feline CRF was conducted to determine the prevalence of acid-base disturbances. Cases were categorised on the basis of their plasma creatinine concentrations as mild, moderate or severe. A group of 27 clinically healthy, age-matched cats was assessed for comparison. A low venous blood pH (<7.270) was found in 10 of the 19 severe cases (52.6 per cent), three of the 20 moderate cases (15 per cent) and none of the 20 mild cases. Acidaemia was associated with an increased anion gap contributed to by both low plasma bicarbonate and low chloride ion concentrations. Biochemical analysis of urine samples showed urine pH to decrease with increasing severity of renal failure. Urinary loss of bicarbonate was not associated with the occurrence of acidaemia and there was a tendency for urinary ammonium ion excretion to decrease as the severity of renal failure increased. Cats with naturally occurring CRF do not show plasma biochemical evidence of acid-base disturbances until the disease is advanced.

Production of amines in equine cecal contents in an in vitro model of carbohydrate overload

Acute laminitis can be induced experimentally in horses by the administration of carbohydrate, resulting in fermentation within the cecum and ischemia-reperfusion of the digits. The products of fermentation that trigger acute laminitis are as yet unknown; however, compounds such as amines might play a role due to their potential vasoactive properties. The objectives of this study were to quantify the amines present in equine cecal contents and to use a model of carbohydrate overload in vitro to test the hypothesis that carbohydrate fermentation is associated with increased amine production. Cecal contents from each horse were divided into aliquots and incubated anaerobically with either cornstarch or inulin (a form of fructan carbohydrate; both 1 g/100 mL). The pH was measured and samples were taken at the same time for amine measurement by HPLC at 2-h intervals over a 24-h period. In a second set of experiments, the effects of the antibiotic virginiamycin (1 mg/100 mL), calcium (CaPO4; 0.3 g/100 mL), and plant steroidal saponin (Yucca schidigera extract; 0.1 g/100 mL) were examined on pH and amine concentrations in cecal contents incubated with starch or inulin. Both starch and inulin caused significant time-dependent falls in pH, from 6.7 +/- 0.1 at 0 h to 5.2 +/- 0.1 (starch) and 5.0 +/- 0.1 (inulin) at 24 h. Fermentation of carbohydrate was also associated with increased production of phenylethylamine and isoamylamine (two- to threefold increases) as well as putrescine and cadaverine (1.5- to twofold increases). Virginiamycin inhibited the fall in pH and increases in production of phenylethylamine and isoamylamine, while calcium phosphate moderated the changes in pH only. Yucca schidigera extract was without effect. These data show that fermentation of carbohydrate by equine cecal microbiota may lead to increased production of amines.

Adverse and beneficial secondary effects of mass treatment with azithromycin to eliminate blindness due to trachoma in Nepal

Mass administration of azithromycin to eliminate blindness due to trachoma has raised concerns regarding the emergence of antimicrobial resistance. During 2000, we compared the antimicrobial resistance of nasopharyngeal pneumococcal isolates recovered from and the prevalence of impetigo, respiratory symptoms, and diarrhea among 458 children in Nepal before and after mass administration of azithromycin. No azithromycin-resistant pneumococci were isolated except from 4.3% of children who had received azithromycin during 2 previous mass treatments (P<.001). There were decreases in the prevalence of impetigo (from 14% to 6% of subjects; adjusted odds ratio [OR], 0.41; 95% confidence interval [CI], 0.21-0.80) and diarrhea (from 32% to 11%; adjusted OR, 0.26; 95% CI, 0.14-0.43) 10 days after azithromycin treatment. The absence of macrolide-resistant isolates after 1 mass treatment with azithromycin is encouraging, although the recovery of azithromycin-resistant isolates after 2 mass treatments suggests the need for resistance monitoring when multiple rounds of antimicrobial treatment are given.

Density and binding characteristics of beta-adrenoceptors in the normal and failing equine myocardium

Beta-adrenoceptors are important regulators of cardiac function and their characteristics are known to change in human and canine diseased myocardium. This study aimed to determine the density and subtypes of beta-adrenoceptors in the normal and failing equine ventricular myocardium. Membrane preparations of the left papillary muscles were incubated with increasing concentrations of the nonselective beta-adrenoceptor antagonist [3H]-CGP12177. Saturable and reversible binding of [3H]-CGP12177 to myocardial membranes was demonstrated with Kd values (+/- s.d.) of 0.49 +/- 0.40 and 0.43 +/- 0.22 nmol/l and Bmax values of 93.4 +/- 20.5 and 110.0 +/- 21.2 and fmol/mg protein for normal (n = 19) and heart failure (n = 10) tissues, respectively. Heart failure had no significant effect on the density of ventricular beta-adrenoceptors. The cardiac beta-adrenoceptors were further characterised by studying displacement of [3H]-CGP12177 (0.6 nmol/l) with the beta1-selective antagonists CGP20712A and the beta2-selective antagonist ICI118.551. In normal ventricular muscle, CGP20712A was 26 times more potent than ICI118.551 (Ki values 30.4 +/- 24.8 and 814.1 +/- 485.2 nmol/l, respectively). In heart failure cases, CGP 20712A curves were monophasic with a Ki value of 45.6 +/- 39.7 nmol/l. ICI 118.551 curves were biphasic in 5 horses where 11-31% of the cardiac beta-adrenoceptors had a high affinity for ICI 118.551. These data suggest that the normal equine ventricular myocardium possesses predominately beta1-adrenoceptors, with no evidence for co-existence of a significant population of beta2-adrenoceptors. The density of beta-adrenoceptors did not appear to change in heart failure, but the appearance of receptors with a high affinity for ICI118.551 may suggest that, in some cases, heart failure increases the expression of beta2-adrenoceptors in equine ventricular myocardium. This study provides an insight into the role of the adrenergic system in heart disease in the horse. Further studies in this area are warranted.

Differential effects of genistein on apoptosis induced by fluoride and pertussis toxin in human and rat pancreatic islets and RINm5F cells

Clonal pancreatic beta-cell lines have been used widely for the study of the factors involved in the regulation of apoptosis but it has not been firmly established that the response of normal islets mirrors that found in transformed beta-cells. In the present work, the role of pertussis toxin (Ptx)-sensitive G-proteins in the control of beta-cell apoptosis was studied in isolated rat and human islets of Langerhans and compared with the clonal beta-cell line, RINm5F. Annexin-V and deoxycarboxyfluoroscein diacetate staining was used to identify viable, apoptotic and necrotic cells directly, under fluorescence illumination. Treatment of human and rat islet cells with the G-protein activator fluoride (NaF; 5 mM) caused a marked increase in apoptosis that was further potentiated in islets pretreated with Ptx. The tyrosine kinase inhibitor genistein (100 microM) also increased islet cell apoptosis and the combination of 100 microM genistein and 5 mM NaF did not lead to any diminution of the apoptotic response. This latter effect was quite different from that seen in RINm5F cells where the combination of 100 microM genistein and 5 mM NaF resulted in much less apoptosis than was observed with either agent alone. In islets treated with a lower concentration of genistein (25 microM; that did not, itself, increase cell death), the drug attenuated NaF-induced apoptosis and also blocked the enhancement mediated by Ptx. These results revealed that human (and rat) islets are equipped with a Ptx-sensitive pathway that may be regulated by tyrosine phosphorylation and is anti-apoptotic. However, they also define conditions under which marked differences in response between RINm5F cells and normal islets were observed and they suggest that care should be taken when extrapolating data obtained with clonal cell lines to the situation in normal islet cells.

The psychological assessment of learning potential

BACKGROUND

The paper considers the construct of learning potential (or dynamic assessment) and its use in the psychoeducational assessment of children with learning difficulties.

AIMS

The principal research aim was to examine the extent to which learning potential (dynamic) assessment can predict which children with severe learning difficulties will gain most from a structured programme of cognitive intervention.

SAMPLE

The sample consisted of 30 children (mean age 9 years) based in a school for children with moderate/severe learning difficulties.

METHODS

Half of the children were assessed both before and after the delivery of a 15-month cognitive intervention programme undertaken by the first author. The other half took part in the assessments but continued with their usual classroom programme. Assessments included the use of both dynamic and static measures. On the basis of the assessments, students were divided into high and low potential groups and comparison of gains after the intervention was undertaken.

RESULTS

The measurement of learning potential appeared to predict subsequent performance in some, but not all, areas. Those who were most likely to make gains were those children deemed as 'high potential' who also received the cognitive intervention.

CONCLUSIONS

The value of learning potential assessment was not clearly demonstrated. The implications of the results are explored and, in particular, the authors warn of the dangers of drawing upon the results of learning potential measures in an inappropriate fashion. (school) psychologists, the complexity of the measures, ongoing debates validity and applicability and the pressures from resource managers for clearcut psychometric results have tended to deter all but the practitioner.

A case of a methadone-induced movement disorder

OBJECTIVE

To increase awareness of the possibility of opioid induced movement disorders.

SETTING

A university-affiliated Veterans Affairs Hospital.

PATIENT

A patient with upper extremity pain due to complex regional pain syndrome type I (reflex sympathetic dystrophy).

INTERVENTIONS

Attempted pain control with methadone.

RESULTS AND CONCLUSIONS

After failing many attempts at control, the authors were able to provide their patient significant pain relief from her complex regional pain syndrome type I using methadone. Unfortunately, the patient eventually developed a movement disorder, characterized by tremor, choreiform movements, and a gait abnormality, probably related to this opioid. The authors conclude that, while this type of movement disorder is uncommon, clinicians need to be aware of opioid-induced movement disorders, because they are disturbing to patients and often easily treated.

Alpha2 receptors and agonists in pain management

Alpha(2) agonists have been in clinical use for decades, primarily in the treatment of hypertension. In recent years, alpha(2) agonists have found wider application, particularly in the fields of anesthesia and pain management. It has been noted that these agents can enhance analgesia provided by traditional analgesics, such as opiates, and may result in opiate-sparing effects. This has important implications for the management of acute postoperative pain and chronic pain states, including disorders involving spasticity or myofascial pain, neuropathic pain, and chronic daily headaches. The clinical utility of these agents is ever expanding, as they are gaining broader use in neuraxial analgesia, and new applications are continuously under investigation. The alpha(2) agonists that are currently employed in anesthesia and pain management include clonidine, tizanidine, and dexmedetomidine. Moxonidine and radolmidine, which are not currently in clinical use in humans, may offer favorable side-effect profiles when compared with traditional alpha(2) agonists, and may thereby allow for more widespread pain management applications.

A preponderance of CCR5(+) CXCR4(+) mononuclear cells enhances gastrointestinal mucosal susceptibility to human immunodeficiency virus type 1 infection

The gastrointestinal mucosa harbors the majority of the body's CD4(+) cells and appears to be uniquely susceptible to human immunodeficiency virus type 1 (HIV-1) infection. We undertook this study to examine the role of differences in chemokine receptor expression on infection of mucosal mononuclear cells (MMCs) and peripheral blood mononuclear cells (PBMCs) by R5- and X4-tropic HIV-1. We performed in vitro infections of MMCs and PBMCs with R5- and X4-tropic HIV-1, engineered to express murine CD24 on the infected cell's surface, allowing for quantification of HIV-infected cells and their phenotypic characterization. A greater percentage of MMCs than PBMCs are infected by both R5- and X4-tropic HIV-1. Significant differences exist in terms of chemokine receptor expression in the blood and gastrointestinal mucosa; mucosal cells are predominantly CCR5(+) CXCR4(+), while these cells make up less than 20% of the peripheral blood cells. It is this cell population that is most susceptible to infection with both R5- and X4-tropic HIV-1 in both compartments. Regardless of whether viral isolates were derived from the blood or mucosa of HIV-1-infected patients, HIV-1 p24 production was greater in MMCs than in PBMCs. Further, the chemokine receptor tropism of these patient-derived viral isolates did not differ between compartments. We conclude that, based on these findings, the gastrointestinal mucosa represents a favored target for HIV-1, in part due to its large population of CXCR4(+) CCR5(+) target cells and not to differences in the virus that it contains.

Sensitive and reproducible quantitation of mucosal HIV-1 RNA and DNA viral burden in patients with detectable and undetectable plasma viral HIV-1 RNA using endoscopic biopsies

Mucosal tissue is the main portal of entry for HIV-1 infection and, in macaques, has been demonstrated to be a significant compartment for viral replication and CD4+ T lymphocyte depletion. Quantitating tissue viral burden in addition to plasma viral load provides insights into HIV-1 pathogenesis and an additional means to gauge antiretroviral response. The aim of this study was to develop reliable, reproducible, and sensitive assays to quantitate tissue viral burden of HIV-1 RNA and DNA using 1-3 endoscopically acquired, rectosigmoid biopsies. Total DNA and RNA were simultaneously extracted following homogenization from the same tissue samples. Quantitative polymerase chain reaction (PCR) assay in the HIV-1 LTR region was used to detect viral DNA and RT-PCR for viral RNA. It was determined that HIV-1 RNA and DNA can be reproducibly quantified from a single rectosigmoid biopsy with minimal intra-assay or intra-patient variability. These results reflect high recovery of extracted nucleic acids with calculated results accurately reflecting in vivo levels. The techniques outlined differ from currently available approaches by incorporating control standards to identify loss or degradation of RNA and DNA from acquisition through the in vitro assay and permit extraction with high yields of RNA and DNA from the same tissue sample.