Sexual risk behaviors of Gay, Lesbian, and bisexual youths in New York City: prevalence and correlates

The lifetime and recent sexual risk behaviors of 156 Gay, Lesbian, and bisexual youths, recruited from Gay-focused organizations in New York City, were examined. The data indicated seven reasons why the youths are at risk for HIV and other STDs: They initiated sex during early adolescence; their first sexual partners were older than they were; HIV barrier methods (e.g., condoms) were initiated subsequent to sexual debut; many lifetime sexual partners and encounters were reported; some youths exchanged sex for goods; many youths reported having had at least one partner at risk for HIV; and the youths engaged in unprotected sexual behaviors during the past 3 months. Significant gender differences emerged (e.g., the male youths reported more lifetime same-sex partners than the female youths; the female youths reported more lifetime other-sex partners than the male youths). Recent sexual risk behaviors (i.e., numbers of same-sex partners, encounters, and unprotected sex during the past 3 months) were related significantly to the youths' average degree of emotional involvement in or average duration of intimate relationships.

Understanding the unprotected sexual behaviors of gay, lesbian, and bisexual youths: an empirical test of the cognitive-environmental model

The cognitive-environmental model (CEM; M. Fishbein et al., 1991) was used to understand the unprotected sexual behaviors of 156 gay, lesbian, and bisexual youths. Unprotected anal sex among the males was associated directly with poor protection skills (e.g., incorrect use of barrier methods, such as condoms), poor intentions to use barrier methods, and poor norms by sexual partners concerning barrier methods. Furthermore, the association between low self-efficacy and increasing unprotected anal sex was attributed to poor intentions. Direct associations of unprotected oral sex with poor intentions and poor partner norms also emerged, as did an indirect relation between unprotected oral sex and low self-efficacy via poor intentions. These last 3 findings were replicated when examining unprotected oral or vaginal-digital sex among the females. Relations among the CEM factors supported some CEM-theoretical propositions.

Life-threatening chickenpox pneumonitis in two previously healthy adults

Images

A new form of access for endo-organ surgery. The initial experience with percutaneous endoscopic gastrostomy

BACKGROUND

Intraluminal gastric surgery provides a new treatment option for various disease processes. This study assesses the safety of a new large-diameter percutaneous endoscopic gastrostomy (PEG) for intraluminal surgery.

METHODS

Investigators at six institutions were asked to complete a standard questionnaire to assess the difficulties associated with the assembly and introduction of the PEG, plus intraoperative and postoperative problems related to placement of the device.

RESULTS

In terms of assembly; 1.9% of respondents reported difficulty obtaining complete vacuum of the balloon tip, and 3.8% had difficulty fitting the graduated dilator to the balloon-tipped cannula. Difficulties associated with introduction of the PEG included disengagement of the dilator from the balloon-tipped cannula (0%), extraction of the dilator-port assembly (0%), difficult PEG pullout (1.9%), abdominal wall bleeding (0%), and difficult PEG dilator separation (7.5%). Intraoperatively, 7.5% of respondents reported inadequate skin bolster fitting, 1.9% had CO(2) leakage into the peritoneal cavity, 0% had inadvertent PEG extraction, and 0% reported injury to the esophagus, colon, or small intestine. Postoperatively, there was a 9.4% rate of wound infection, a 1.9% rate of gastrocutaneous fistula, and a 1.9% rate of esophageal, colon, or small intestine injury.

CONCLUSIONS

The large-diameter PEG is safe and effective for endo-organ surgery. Additional preventive measures for PEG site infection should be investigated.

Rhinovirus identification by BglI digestion of picornavirus RT-PCR amplicons

Rhinoviruses are the main cause of the common cold and precipitate the majority of asthma exacerbations. RT-PCR followed by internal probe hybridisation or Southern blotting, or nested PCRs are currently the most sensitive methods for their identification. However, none of the published techniques can differentiate satisfactorily rhinoviruses from other picornaviruses. Examination of the restriction maps of sequenced rhinoviruses, revealed a highly conserved BglI restriction site (GCCnnnnnGGC), located exactly in the middle of the 380-bp amplicon generated with the OL26-OL27 primer pair, which has been used extensively in the past to identify picornaviruses. Such a site was either not present, or positioned differently in other picornaviruses of known sequence. It was, therefore, considered that digestion of rhinovirus amplicons with this enzyme would result in two equal length fragments, generating a single 190-bp band in gel electrophoresis. In contrast, either one undigested 380-bp band or a double-band pattern would appear in amplicons from other picornaviruses. To test this hypothesis, Bgl digestions of OL26-OL27 amplicons from cultured and wild-type rhinoviruses, whose identity was confirmed by acid lability, as well as from echo, polio and coxsackie viruses were carried out. All rhinovirus samples were digested successfully generating single bands. Among the other picornaviruses, only 6.6% presented a single band pattern, while the rest were as predicted from the model. With a sensitivity of 100% and a specificity over 90%, the method described, which is rapid and remarkably easy to perform, can be used to distinguish rhinoviruses from other picornaviruses to a considerable extent.

Rhinoviruses replicate effectively at lower airway temperatures

Rhinoviruses are epidemiologically connected to the majority of acute asthma exacerbations; however, their ability to infect and replicate in the lower airways is disputed. A frequent argument against this possibility involves the temperature preference for rhinovirus replication, generally accepted to be 33 degrees C, the temperature of the nasal passages. However, this argument is based on studies with a single rhinovirus serotype. In this study, differences in temperature preferences were evaluated between several serotypes and relative titers were determined than can be achieved at upper and lower airway temperatures. Rhinovirus serotypes 1b, 2, 7, 9, 14, 16, 41, and 70 were titrated in Ohio-HeLa cell cultures at either 33 degrees C or 37 degrees C. Possible selection by culture temperature was examined by continuous culture at 33 degrees C and 37 degrees C for 2-4 passages and subsequent titration at both temperatures. Finally, nasal aspirate samples derived from patients with wild-type rhinoviral common colds were cultured at 33 degrees C and 37 degrees C and RT-PCR was used to assess rhinovirus replication at each temperature. The majority of the serotypes and wild-type viruses replicated slightly better at 33 degrees C than at 37 degrees C. However, titers achieved after one or more replicative cycles at 37 degrees C were still high enough to initiate infection. Furthermore, in some instances equal or even better replication was observed at 37 degrees C. It is concluded that temperature preferences may vary between rhinoviruses and are not likely to be a prohibitive factor for infection of the lower airways.

Understanding the unprotected sexual behaviors of gay, lesbian, and bisexual youths: an empirical test of the cognitive-environmental model

The cognitive-environmental model (CEM; M. Fishbein et al., 1991) was used to understand the unprotected sexual behaviors of 156 gay, lesbian, and bisexual youths. Unprotected anal sex among the males was associated directly with poor protection skills (e.g., incorrect use of barrier methods, such as condoms), poor intentions to use barrier methods, and poor norms by sexual partners concerning barrier methods. Furthermore, the association between low self-efficacy and increasing unprotected anal sex was attributed to poor intentions. Direct associations of unprotected oral sex with poor intentions and poor partner norms also emerged, as did an indirect relation between unprotected oral sex and low self-efficacy via poor intentions. These last 3 findings were replicated when examining unprotected oral or vaginal-digital sex among the females. Relations among the CEM factors supported some CEM-theoretical propositions.

Dissociable deficits in the decision-making cognition of chronic amphetamine abusers, opiate abusers, patients with focal damage to prefrontal cortex, and tryptophan-depleted normal volunteers: evidence for monoaminergic mechanisms

We used a novel computerized decision-making task to compare the decision-making behavior of chronic amphetamine abusers, chronic opiate abusers, and patients with focal lesions of orbital prefrontal cortex (PFC) or dorsolateral/medial PFC. We also assessed the effects of reducing central 5-hydroxytryptamine (5-HT) activity using a tryptophan-depleting amino acid drink in normal volunteers. Chronic amphetamine abusers showed suboptimal decisions (correlated with years of abuse), and deliberated for significantly longer before making their choices. The opiate abusers exhibited only the second of these behavioral changes. Importantly, both sub-optimal choices and increased deliberation times were evident in the patients with damage to orbitofrontal PFC but not other sectors of PFC. Qualitatively, the performance of the subjects with lowered plasma tryptophan was similar to that associated with amphetamine abuse, consistent with recent reports of depleted 5-HT in the orbital regions of PFC of methamphetamine abusers. Overall, these data suggest that chronic amphetamine abusers show similar decision-making deficits to those seen after focal damage to orbitofrontal PFC. These deficits may reflect altered neuromodulation of the orbitofrontal PFC and interconnected limbic-striatal systems by both the ascending 5-HT and mesocortical dopamine (DA) projections.

The pharmacokinetics and safety profile of oral ganciclovir in combination with trimethoprim in HIV- and CMV-seropositive patients

AIMS

We investigated the pharmacokinetics and safety profile of oral ganciclovir coadministered with trimethoprim in HIV-and CMV-seropositive patients.

METHODS

In an open-label, randomized, 3-way crossover study, 12 adult males received oral ganciclovir 1000 mg every 8h, oral trimethoprim 200 mg once daily, or both drugs concomitantly in a sequence of three 7-day treatment periods. Pharmacokinetic parameters were determined and adverse events recorded for each treatment.

RESULTS

The presence of trimethoprim significantly decreased CLr (12.9%, P=0.0068) and increased t1/2 (18.1%, P=0.0378) of ganciclovir. However, these changes are unlikely to be clinically meaningful. There were no statistically significant changes in trimethoprim pharmacokinetic parameters in the presence of ganciclovir, with the exception of a 12.7% increase in Cmin. Ganciclovir was well tolerated when administered alone or in combination with trimethoprin.

CONCLUSIONS

There was no clinically significant pharmacokinetic interaction between oral ganciclovir and trimethoprim when coadministered.

Characterization of LMP polymorphism in homozygous typing cells and a random population

Within the class II region of the MHC are several genes whose products are involved in processing antigen for HLA class I presentation. Two such genes, LMP2 and LMP7, encode products that are incorporated into a multicatalytic proteinase complex which serves as the major pathway for protein degradation for class I peptide presentation. Polymorphic residues have been identified in both LMP2 and LMP7. In this report, we describe an ARMS-PCR method to distinguish LMP7 alleles. We applied this method to characterize these alleles in addition to LMP2 alleles in 50 homozygous typing cells (HTC) as well as in a panel of 110 random individuals. Of the four possible combinations of LMP2 and LMP7, we observed three in the HTC population, while all four were observed in the random population. The frequencies at which allele combinations were observed were similar to that predicted by individual allele frequencies. We also analyzed the possibility of linkage disequilibrium of LMP2 and LMP7 alleles with TAP1, TAP2, and specific HLA class I alleles in both populations. From this data, there seems to be no apparent linkage disequilibrium and no indication that particular combinations of LMP2 and LMP7 have been maintained.

The stenosis ratio: a new tool for the diagnosis of degenerative spinal stenosis

CLINICAL RELEVANCE

Low back pain from lumbar spinal stenosis is a significant source of morbidity, especially among the elderly population. Accurate diagnosis is imperative for effective treatment to be initiated. This paper presents a quantitative method for the evaluation of spinal stenosis that, when used in conjunction with CT and MRI, may greatly aid the clinician in the diagnosis of this debilitating condition.

OBJECTIVE

Precise clinical tools for the diagnosis of spinal stenosis are severely lacking. Low back pain and dysfunction derived from lumbar spinal stenosis is a significant source of morbidity, especially among the elderly. Despite its importance, there has been little progress made towards establishing valid, quantitative criteria for the diagnosis of spinal stenosis. We present a new quantitative tool for the diagnosis of lumbar stenosis, the Stenosis Ratio (SR).

METHODS

CT scans and MRI scans of 43 patients presenting with clinico-radiographic evidence of lumbar stenosis were used. The patient group consisted of 13 males and 30 females between the ages 49 and 82 with average age of 67. CT and MRI/scans of 43 patients were digitized and computer analyzed. Measurements of SR, defined as the ratio of the cross-sectional dural area of the motion segment to that of the stable segment, were established for L3-L4, L4-L5 and L5-S1 stenotic levels and compared to SR values for a non-stenotic (internal control) level, L2-L3.

RESULTS

The L4-L5 level had the lowest SR value of 0.71, followed by 0.74 at L3-L4, and 0.87 at L5-S1. Ninety-five percent confidence intervals of (0.66, 0.81), (0.62, 0.81), and (0.73, 1.00) were found for SR values at levels L3-L4, L4-L5 and L5-S1 respectively. The SR at L2-L3 had a mean value of 1.37 with a 95% confidence interval of (0.970, 1.78). At all levels, SRs were significantly lower for the spinal stenotic L3-S1 levels than for the L2-L3 control as confirmed by a student's t-test (p < 0.05).

CONCLUSION

In a select population of patients with spinal stenosis confirmed by neuroradiological assessment, values of SRs were consistently and significantly lower than controls. We believe that measurements of SRs may provide reproducible quantitative measures for the diagnosis of spinal stenosis. SR values below the 95% confidence limit may be indicative of lumbar stenosis. Through the use of ratios, inherent differences in patient size are controlled for, thus allowing comparison of values between patients and treatment groups and effective clinical diagnosis of spinal stenosis.

Propylene glycol toxicosis in a mare

Propylene glycol and mineral oil are commonly used in the veterinary profession for treatment of bovine ketosis and equine impactions, respectively. Accidental administration of 6.0 ml propylene glycol/kg of body weight in horses causes severe depression, ataxia and malodorous breath and feces. However, appropriate medical therapy can result in successful treatment of this toxicosis.

Effects of the novel high-affinity 5-HT(1B/1D)-receptor ligand frovatriptan in human isolated basilar and coronary arteries

The contractile actions of the novel high-affinity 5-hydroxytryptamine (5-HT(1B/1D)) ligand, frovatriptan (formerly VML 251/SB-209509) were investigated in human isolated basilar and coronary arteries in which the endothelium had been removed. Basilar arteries were obtained post mortem, and coronary arteries were obtained from patients undergoing heart transplant (recipient) or from donor hearts that were not suitable for transplant. Frovatriptan was a potent contractile agent in isolated basilar artery with a -log mean effective concentration (EC50) value of 7.86 +/- 0.07 and intrinsic activity of 1.25 +/- 0.10 relative to 5-HT (n = 4). Frovatriptan was 8.5-fold more potent than sumatriptan, which produced a -log EC50 value of 6.93 +/- 0.09 and intrinsic activity 11.1 +/- 0.08 relative to 5-HT (n = 4). In coronary arteries, frovatriptan produced contraction with -log EC50 values of 7.38 +/- 0.12 and 7.81 +/- 0.2 in recipient (n = 7) and donor (n = 3) arteries, respectively. The relative degree of contraction of frovatriptan was lower than that of 5-HT, with relative intrinsic activities of 0.42 +/- 0.06 and 0.40 +/- 0.09, respectively. Sumatriptan produced contraction of human recipient and donor arteries with -log EC50 values (intrinsic activity) of 6.57 +/- 0.13 (0.79 +/- 0.27; n = 6) and 7.35 (1.41; n = 2), respectively. Furthermore, marked bell-shaped responses were apparent for frovatriptan in coronary arteries, with relaxation occurring at concentrations >6 microM in some tissues. In contrast, no bell-shaped concentration-response curves were apparent for sumatriptan or 5-HT. Threshold concentrations for frovatriptan-induced contractions were also different between basilar (>2 nM) and coronary arteries (>20 nM). No separation of threshold activity was observed with sumatriptan or 5-HT. These data show that frovatriptan produces constriction of human isolated basilar and coronary arteries. However, frovatriptan produces a complex pharmacologic response in the coronary artery, with threshold contractile activity requiring approximately 10-fold greater concentrations of agonist than in the basilar artery. Frovatriptan also shows a differential pharmacologic profile compared with sumatriptan in coronary arteries, with reversal of tone predominating at high concentration.

Subtype- and response element-dependent differences in transactivation by peroxisome proliferator-activated receptors alpha and gamma

Peroxisome proliferator-activated receptors (PPAR) modulate transcription by binding to specific peroxisome proliferator-response elements (PPRE) through heterodimerization with the 9-cis retinoic acid receptor (RXR). To investigate potential subtype- and response element-dependent differences in transcriptional activation by PPARs, we expressed PPARalpha or PPARgamma2, along with RXRalpha, in the yeast Saccharoromyces cerevisiae and compared their ability to activate transcription of reporter genes containing a PPRE from either the rat acyl-CoA oxidase (AOx) or hydratase-dehydrogenase (HD) gene. PPARgamma2 and RXRalpha, when coexpressed from low copy vectors, potently and synergistically activated transcription of the AOx-PPRE reporter gene, but only weakly stimulated transcription of the HD-PPRE reporter gene. This response element preference, which was also observed in mammalian cells, could not be attributed to differences in binding affinity of PPARgamma2/RXRalpha heterodimers to these elements in vitro. Interestingly, PPARgamma2 expressed from a high copy vector was able to strongly activate transcription of the HD-PPRE reporter gene, even in the absence of coexpressed RXRalpha. In comparison to the findings with PPARgamma2, the HD-PPRE served as a significantly more robust response element for PPARalpha as compared to the AOx-PPRE. PPRE-dependent transcriptional activation by PPARalpha correlated with binding efficiencies of PPARalpha/RXRalpha to the response element. Our findings demonstrate that the transactivation potential of PPAR subtypes can be differentially modulated by distinct PPREs.

Pancreatic necrosis: results of necrosectomy, packing, and ultimate closure over drains

OBJECTIVE

The treatment of pancreatic necrosis at a tertiary referral center was reviewed to effect better patient outcome.

SUMMARY BACKGROUND DATA

Pancreatic necrosis is a devastating disease that leads to death in 10% to 50% of cases. Infected necrosis is particularly deadly because 80% of deaths from necrosis are due to infection or its complications. Therapeutic strategies center on aggressive support of organ systems and prevention and treatment of infectious complications.

METHODS

Records of all patients who underwent pancreatic necrosectomy from 1990 to 1996 at Emory University Hospital were reviewed. Patients with infected necrosis were debrided as soon as the diagnosis was made. Reoperation for completion necrosectomy with ultimate closure over lavage catheters was performed as necessary.

RESULTS

Of the 244 patients admitted with acute pancreatitis in the study period, 50 underwent pancreatic debridement. The mean age was 52 years, and 74% of patients were transferred from other institutions. Eighty-four percent of patients had infected necrosis, and all patients underwent sequential debridement with eventual closure over drains. Organ failure occurred in 72% of cases, and the overall mortality rate was 12%. The mean length of stay was 54 days.

CONCLUSIONS

The management of pancreatic necrosis demands the allocation of extensive resources. An aggressive operative strategy of multiple debridements with ultimate closure over drains can lead to a low mortality rate in patients with this complex disease, but the determination of when to explore patients with sterile necrosis remains difficult.

A group therapy approach to facilitate integration of risk information for women at risk for breast cancer

OBJECTIVE

To describe and illustrate elements of a group counselling approach designed to enhance the communication of risk information on breast cancer (BC) to women with a family history of this disease. Breast cancer is a leading cause of female cancer death. The most important risk factor for BC is a positive family history in at least 1 first-degree relative, and approximately one-third of women with BC have a family history of the disease. Recent evidence suggests that there is a significant psychological impact associated with having a family history of BC, and this may influence the psychological adjustment and response to being counselled for personal risk. New counselling approaches are required.

METHOD

This paper describes a group therapy approach that incorporates principles of supportive-expressive therapy designed to address the emotional impact of being at risk for BC and to promote accuracy of perceived risk. The key elements of the intervention are described along with clinical illustrations from groups that are part of an ongoing study to develop and standardize the group therapy.

CONCLUSION

Qualitative data from the groups suggest that this model of therapy is both feasible and effective.

Down-regulation of the novel gene melastatin correlates with potential for melanoma metastasis

We have used differential cDNA display to search for genes whose expression correlates with an aggressive phenotype in variants of the B16 murine melanoma line, B16-F1 and B16-F10. This analysis identified a novel gene, termed melastatin, that is expressed at high levels in poorly metastatic variants of B16 melanoma and at much reduced levels in highly metastatic B16 variants. Melastatin was also found to be differentially expressed in tissue sections of human melanocytic neoplasms. Benign nevi express high levels of melastatin, whereas primary melanomas showed variable melastatin expression. Melastatin transcripts were not detected in melanoma metastases. Within the set of human primary cutaneous melanomas examined, melastatin expression appeared to correlate inversely with tumor thickness. The expression pattern observed suggests that loss of melastatin expression is an indicator of melanoma aggressiveness.

Rotational imaging of complex acetabular fractures

Understanding complex acetabular fractures is difficult and may require three-dimensional reformatted computed tomographic (CT) images. This paper evaluates a technique, digital rotational imaging (DRI), that displays multiple oblique images of the pelvis and acetabulum. When viewed statically, DRI provides optimal iliac and obturator oblique projections, often differing in obliquity from the conventional 45-degree orthogonal views. Dynamic DRI viewing in rapid sequence provides a three-dimensional effect that improves perception of acetabular fracture relationships.

Skeletal status of men with early and late ankylosing spondylitis

PURPOSE

To assess the influence of extent of disease on the skeletal status of men with ankylosing spondylitis (AS).

PATIENTS AND METHODS

Fourteen men with AS were studied at entry and again after 15 months. Bone mineral density (BMD) was assessed by single photon absorptiometry (SPA), dual energy x-ray absorptiometry (DXA), and quantitative computed tomography (QCT). Calciotropic hormones and bone turnover were also assessed, and biopsies of iliac crest and skin were taken after tetracycline double-labeling from 10 subjects. Clinical evaluation and Health Assessment Questionnaires were used to assess functional status.

RESULTS

Of the 14 participants, 7 had sacroiliitis alone without radiologic evidence of spinal involvement (early disease) and 7 had sacroiliitis with extensive vertebral calcifications and immobilization (late disease). QCT baseline lumbar spine BMD was very low in both groups compared with normative standards (Z score = -3.08 +/- 1.83, P < 0.0001) and did not change significantly over 15 months. This low BMD was more marked in late disease than in early disease subjects (P < 0.01). DXA BMD at the lumbar spine was lower than predicted in early disease subjects (Z score = -1.08 +/- 0.67, P = 0.005) but not in the late disease group. DXA BMD was also low at the all three hip sites (Z score = -0.96 +/- 0.86, P < 0.01). Significant differences between late disease group and normative values were apparent at all hip sites. Values in early disease subjects, however, did not differ from age-predicted norms. Bone mineral status did not change significantly over the 15-month period of observation. Circulating parathyroid hormone (PTH) and vitamin D metabolites were normal in both groups as were creatinine clearance and urinary excretion of calcium and hydroxyproline. Osteocalcin levels were normal in all but the two youngest subjects in the early disease group. Histomorphometry of the iliac crest showed no consistent change in bone turnover. Bone volume and trabecular width were low in many cases. Cancellous bone volume correlated with lumbar spine BMD by QCT (r = 0.69, P = 0.026) but not with DXA. Although beneficial changes occurred in exercise tolerance and pain over time, anthropometric measurements did not improve.

CONCLUSION

BMD is low in both the axial and peripheral skeleton in men with AS and is independent of spinal immobilization. Anterioposterior lumbar spine DXA in late AS is less useful than QCT in determining the degree of osteopenia in late AS. Bone mineral deficits in AS do not reflect measurable metabolic derangement or hypogonadism. Although bone histomorphometry suggests both trabecular thinning and loss of structural elements as mechanisms involved in low bone volume, the exact cause of osteopenia in AS remains to be determined.

Factor V Leiden mutation: an unrecognized cause of hemiplegic cerebral palsy, neonatal stroke, and placental thrombosis

Activated protein C resistance caused by an Arg506Gln mutation in the factor V gene (factor V Leiden mutation) is the most common cause of familial thrombosis. This mutation is associated with arterial and venous thromboembolic disease in neonates, infants, and children, but is not a significant risk factor for ischemic stroke in adults. We report on 3 babies with different neonatal cerebrovascular disorders including ischemic infarction and hemorrhagic stroke who are heterozygous for factor V Leiden mutation. One infant had multiple thrombi in the fetal placental vasculature. This is the first reported association between hemiplegic cerebral palsy, placental thrombosis, and factor V Leiden mutation. We suspect that activated protein C resistance may be an important cause of in utero cerebrovascular disease and hemiplegic cerebral palsy.

Random dot stereoacuity of preschool children. ALSPAC "Children in Focus" Study Team

PURPOSE

Commercially available book-format random dot stereopsis tests for children are quick and simple to use, but provide accurate measurement of stereoacuity only in children age 5 years or older. Alternative methods for preschool children provide only pass/fail information or require lengthy laboratory-based protocols. To address the need for a quick and accurate measure of random dot stereoacuity in the preschool age range, we developed a new book-format random dot stereoacuity test.

METHODS AND RESULTS

A total of 25 potential shapes for the new test were evaluated in a group of 43 healthy full-term children aged 3 years +/- 2 months. Eleven shapes that were identified successfully by more than 95% of the 3-year-olds were selected to be incorporated into the preschool stereotest. The preschool random dot stereotest books were administered to more than 1000 normal children and pediatric patients in multiple settings: a research laboratory (Retina Foundation SW), a population screening project (University of Bristol, UK), eye clinics (Children's Medical Center, Dallas, Tex), and a day care center (Federal University, São Paulo, Brazil). Randot, Lang 1, Frisby, or Titmus stereoacuity tests also were administered. Orthoptic or ophthalmic examinations were obtained for all children as a gold standard. Outcome measures were success rate and concordance with the clinical examination. Sensitivity, specificity, and accuracy exceeded 0.90 both in clinical and screening settings.

CONCLUSIONS

The preschool random dot books had a higher success rate than other tests in the preschool age range and provided accurate measurement of stereoacuity in the 3- to 5-year-old age range.

Standardizing laparoscopic procedure time and determining the effect of patient age/gender and presence or absence of surgical residents during operation. A prospective multicenter trial

BACKGROUND

Most of the expense of laparoscopic cholecystectomy (LC) is incurred while the patient is in the operating room (OR). Half of this operating room cost is equipment and the other half is personnel. What is an acceptable LC procedure time and how much variation is there? What are the effects of age, gender, and expertise on the mean LC procedure time?

METHODS

A prospective, multicenter gathering of LC procedure times and task component times was performed through the cooperative effort of members of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) at 11 hospitals. The effect of LC time of age, gender, and surgical resident was recorded.

RESULTS

The mean LC time for 359 cases was 73 +/- 28 min. The percent of this LC time for the following component tasks included: to place and remove trocars, 34%; total dissection time, 40%; intraoperative cholangiogram, 15%; and removing the gallbladder, 7%. Age and gender did not change LC time, but the presence of a surgical resident prolonged LC time from 53 to 79 min due to an increase in all LC component task times.

CONCLUSIONS

LC time was globally calibrated in 11 North American hospitals and was found to be affected by expertise but not by gender or age. The mean and standard deviation of LC time can be used for purposes of self-assessing quality performance.

A process-oriented reasoner about physiology

This paper presents the RAP system: a reasoner about physiology. RAP performs two tasks: (1) it infers the behaviour of a complex physiological process using the behaviours of its subprocesses and the relationships between them; (2) it reasons about the effect of introducing a fault into the model. In order to reason about the behaviour of a complex process, RAP uses a mechanism which: (i) represents how subprocesses behave; (ii) establishes how these subprocesses affect each others behaviors; (iii) 'aggregates' these behaviors together to obtain the behavior of the top level process; (iv) gives that process a temporal context in which to act. RAP uses limited common sense knowledge about faults to reason about their effect in terms of the generation of new processes and the misbehavior of existing ones. The effects are then propagated throughout the model to obtain the overall effect of the fault.

National Reactive Phosphate Rock Project —aims, experimental approach and site characteristics

Summary. Field-based cutting trials, which formed part of the National Reactive Phosphate Rock Project, were established across Australia in a range of environments to evaluate the agronomic effectiveness of 5 phosphate rocks, and 1 partially acidulated phosphate rock, relative to either single superphosphate or triple superphosphate. The phosphate rocks differed in reactivity. Sechura (Bayovar) and North Carolina phosphate rocks were highly reactive (>70% solubility in 2% formic acid), whilst Khouribja (Moroccan) and Hamrawein (Egypt) phosphate rock were moderately reactive. Duchess phosphate rock from Queensland was relatively unreactive (<45% solubility in 2% formic acid). Phosphate rock effectiveness was assessed by measuring pasture production over a range of phosphorus levels, and by monitoring bicarbonate-soluble phosphorus extracted from soil samples collected before the start of each growing season. Other treatments included single large applications of triple superphosphate, partially acidulated phosphate rock and North Carolina phosphate rock applied at 2 rates, and the application of monocalcium phosphate and North Carolina phosphate rock sources without sulfur to evaluate the importance of sulfur in the potential use of phosphate rock fertilisers at each site. A broad range of environments were represented over the 30 sites which were based on pastures using annual and/or perennial legumes and perennial grasses. Rainfall across the network of sites ranged from 560 to 4320 mm, soil pH (CaCl2) from 4.0 to 5.1, and Colwell-extractable phosphorus ranged from 3 to 47 µg/g before fertiliser application. Two core experiments were established at each site. The first measured the effects of phosphate rock reactivity on agronomic effectiveness, while the second measured the effects of the degree of water solubility of the phosphorus source on agronomic effectiveness. The National Reactive Phosphate Rock Project trials gave the opportunity to confirm the suitability of accepted procedures to model fertiliser response and to develop new approaches for comparing different fertiliser responses. The Project also provided the framework for subsidiary studies such as the effect of fertiliser source on soil phosphorus extractability, cadmium and fluorine concentrations in herbage, evaluation of soil phosphorus tests, and the influence of particle size on phosphate rock effectiveness. The National Reactive Phosphate Rock Project presents a valuable model for a large, Australia-wide, collaborative team approach to an important agricultural issue. The use of standard and consistent experimental methodologies at every site ensured that maximum benefit was obtained from data generated. The aims, rationale and methods used for the experiments across the network are presented and discussed.

Inherited resistance to HIV-1 conferred by an inactivating mutation in CC chemokine receptor 5: studies in populations with contrasting clinical phenotypes, defined racial background, and quantified risk

BACKGROUND

CC chemokine receptor 5 (CCR5) is a cell entry cofactor for macrophage-tropic isolates of human immunodeficiency virus-1 (HIV-1). Recently, an inactive CCR5 allele (designated here as CCR5-2) was identified that confers resistance to HIV-1 infection in homozygotes and slows the rate of progression to AIDS in heterozygotes. The reports conflict on the effect of heterozygous CCR5-2 on HIV-1 susceptibility, and race and risk levels have not yet been fully analyzed. Here we report our independent identification of CCR5-2 and test its effects on HIV-1 pathogenesis in individuals with contrasting clinical outcomes, defined race, and quantified risk.

MATERIALS AND METHODS

Mutant CCR5 alleles were sought by directed heteroduplex analysis of genomic DNA from random blood donors. Genotypic frequencies were then determined in (1) random blood donors from North America, Asia, and Africa; (2) HIV-1+ individuals; and (3) highly exposed-seronegative homosexuals with quantified risk.

RESULTS

CCR5-2 was the only mutant allele found. It was common in Caucasians, less common in other North American racial groups, and not detected in West Africans or Tamil Indians. Homozygous CCR5-2 frequencies differed reciprocally in highly exposed-seronegative (4.5%, n = 111) and HIV-1-seropositive (0%, n = 614) Caucasians relative to Caucasian random blood donors (0.8%, n = 387). This difference was highly significant (p < 0.0001). By contrast, heterozygous CCR5-2 frequencies did not differ significantly in the same three groups (21.6, 22.6, and 21.7%, respectively). A 55% increase in the frequency of heterozygous CCR5-2 was observed in both of two cohorts of Caucasian homosexual male, long-term nonprogressors compared with other HIV-1+ Caucasian homosexuals (p = 0.006) and compared with Caucasian random blood donors. Moreover, Kaplan-Meier estimates indicated that CCR5-2 heterozygous seroconvertors had a 52.6% lower risk of developing AIDS than homozygous wild-type seroconvertors.

CONCLUSIONS

The data suggest that homozygous CCR5-2 is an HIV-1 resistance factor in Caucasians with complete penetrance, and that heterozygous CCR5-2 slows the rate of disease progression in infected Caucasian homosexuals. Since the majority (approximately 96%) of highly exposed-seronegative individuals tested are not homozygous for CCR5-2, other resistance factors must exist. Since CCR5-2 homozygotes have no obvious clinical problems, CCR5 may be a good target for the development of novel antiretroviral therapy.

Effects of phosphate rock products on soil pH

Summary. Changes to soil pH (CaCl2 ) following annual applications of phosphate rock (PR) and water-soluble phosphorus products were investigated in the National Reactive Phosphate Rock Project. It was difficult to measure small changes in pH due to variation in pH within each site and across years. pH (the change over time from the initial soil pH at that plot) was significantly influenced by fertiliser product at 13 of the 27 sites examined. At 5 sites, one or more of the PR products had pH of 0.07–0.21 units greater than the pH of the control. At the other 8 sites, the pH of the control plot was greater than or equal to the that of the PR plots, or significant increases in pH occurred in the single superphosphate plots. The changes in soil pH following application of the fertiliser products were inconsistent both within and between sites. Chemically the PR products have the potential to reduce the rate of acidification in soils where the products dissolve readily, however, this was not generally reflected in the field, where the application of PR products only increased soil pH at a limited number of sites.

Coordinating a large multicentered HIV research project

Coordinating a large multicentered pediatric HIV clinical research study is particularly challenging for nurses. The cohort of patients and their families face multiple stressors, which make recruitment and compliance difficult. Additionally, when many departments within the institution are involved, coordination is often problematic. Ethical issues sometimes arise. Nurses must find ways to adapt what they learn from the study to their nursing practice. The nurse coordinators of the Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV (P2C2HIV) study discuss the unique challenges of such a project and the various strategies for successful completion.

Inotropic agents in the critically ill

Inotropic agents are commonly used in critically ill patients. This heterogeneous group of drugs are potentially hazardous if used without a good understanding of cardiovascular physiology and pathophysiology and without due attention to some general principles for their use. We suggest guidelines for the administration of these agents in all clinical settings.

Disappearing subdural hematomas in children

Subdural hematomas in infants and young children are uncommon, usually occurring from nonaccidental trauma in infants or from trauma associated with motor vehicles. We report 4 children with apparent unilateral convexity subdural hematomas, 3 of which occurred from household falls and 1 occurring from a fall out of a window. These injuries were characterized by clinical symptoms consistent with the apparent forces involved, which were relatively minor in the first three instances. The clots resolved spontaneously within the first 1-2 days after injury. Such collections are likely located at least partly within the subarachnoid space, but may mimic more clinically significant subdural hematomas. Their recognition may influence decisions regarding both surgical evacuation and the likelihood of nonaccidental injury. Clinical and radiographic features distinguishing these 'disappearing subdurals' from more typical subdural hematomas are discussed.

Systematic literature review: outcome measures for child and adolescent mental health services

BACKGROUND

Outcome measurement is an important component of health care service evaluation. The aim of this paper is to review child and adolescent mental health outcome measures and identify outcome measurement tools for use in routine clinical practice.

METHOD

A systematic literature review was undertaken, using Medline and Psych Info and supplemented by correspondence with relevant institutions and authorities in the field. The review identifies potential specific outcome measurement tools. These tools are evaluated using the scientific criteria of validity and reliability, responsiveness to change, and appropriateness of each tool's format for use in routine clinical practice.

RESULTS

Three broad categories of outcome are identified: population outcomes, specific outcome and performance indicators. Nineteen specific outcome measurement tools are short-listed and compared in detail. No single tool is suitable for use as a comprehensive outcome measurement tool in routine clinical practice.

CONCLUSION

A combination of some of the tools short-listed will cover all the necessary outcome items. However, the increase in assessment time will reduce clinical usefulness. Further research is needed to modify or created appropriate outcome measurement tools for use in routine clinical practice.

Crosstalk between the thyroid hormone and peroxisome proliferator-activated receptors in regulating peroxisome proliferator-responsive genes

Peroxisome proliferators and thyroid hormones have overlapping metabolic effects and regulate a similar subset of genes involved in maintaining lipid homeostasis. Transcriptional activation by peroxisome proliferators is mediated by peroxisome proliferator-activated receptors (PPARs) that bind to specific peroxisome proliferator-response elements (PPREs) through heterodimerization with retinoid X receptors (RXRs). We examined the effect of thyroid hormone receptor alpha (TR alpha) on DNA binding in vitro and transcriptional activation in vivo by rat PPAR. Gel mobility shift assays using in vitro translated receptors demonstrated that TR alpha was capable of binding on its own and cooperatively with RXR alpha to the rat acyl-CoA oxidase PPRE and of inhibiting the binding of rat PPAR/RXR alpha heterodimers to this element. This inhibition was the result of competition between TR alpha and PPAR for limiting amounts of the heterodimerization partner RXR alpha and for binding to the PPRE. Interestingly, cotransfection of a TR alpha expression plasmid into mammalian cells resulted in potentiation of the peroxisome proliferator- and PPAR/RXR alpha-dependent transcriptional induction of a reporter gene containing the acyl-CoA oxidase PPRE. TR alpha therefore appears to cooperate with RXR and PPAR to positively modulate peroxisome proliferator-dependent transactivation in vivo. Our findings suggest that there is crosstalk between the thyroid hormone and peroxisome proliferator signaling pathways in the regulation of peroxisome proliferator-responsive genes.

What happens to patients awaiting arthritis surgery?

The length of orthopaedic waiting lists attracts much interest, but the needs of patients awaiting surgery gain little attention. We studied 97 patients awaiting lower-limb surgery (49 osteoarthritis, 41 rheumatoid arthritis, seven other diagnoses). Ninety had pain; 44 significant night pain. Psychological and social problems were common (44 and 45 cases respectively). Only 11 were employed full-time. Sixty-eight required help with daily activities, usually from relatives and neighbours. Forty-three patients walked less than 120 metres in 12 minutes. After review we recommended further aids in 32, medication changes in 27, and additional professional support in six cases. Clinical changes whilst on the waiting list caused alterations in the priority for surgery in 32 cases; the planned procedure was no longer appropriate in 12 of these. We suggest that patients awaiting surgery require clinical review to maintain quality of life; and that waiting lists require administrative review so that patients in need of surgery receive it as soon as possible.

Frontonasal malformation and cloacal exstrophy: a previously unreported association

We report on a child with frontonasal malformation (FNM) and cloacal exstrophy, a combination of findings that have not been reported previously. In FNM and cloacal exstrophy, associated malformations are rare. FNM and cloacal exstrophy both represent abnormalities of the development of the midline field; this combination of anomalies in this patient suggests an impairment of caudal and cranial midline development during blastogenesis.

An experimental study of the effects of craniofacial growth on the long-term positional stability of microfixation

Recent clinical reports have documented a potential problem associated with the use of microfixation in the growing craniofacial skeleton, i.e., the finding of microplates and microscrews within the endocranial cavity during repeat surgery. This animal experiment using Yorkshire pigs was designed to determine if this type of passive internal displacement could be demonstrated in an animal model, the frequency of internal displacement, and the potential consequence of such events from a neurohistological standpoint. Ten female Yorkshire piglets underwent left unilateral fronto-orbital advancement at age 3 weeks, fixation being achieved with microplates and screws. The position of the hardware was determined by direct inspection, after they were killed at 6 months of age (skeletal maturity). Ten microplates (28%) showed complete intracranial translocation, whereas nine (27%) remained on the ectocranial surface. The majority, 16 (44%), were between the outer and inner cortices of the calvaria. Gross examination of the brain tissue underlying the translocated hardware showed indentation "pits" forming as a result of such translocation. Histological examination of the cerebrum and meninges of these pits revealed loss of the most superficial connecting cell layer, with focal neuronal distortion. The leptomeninges were intact and there was no cerebritis, gliosis, or hypoxic change. These findings confirm that in this pig model microfixation hardware will undergo passive intracranial ranial translocation and that there are demonstrable histological alterations in the underlying brain and meninges. The long-term effects of these observed anatomical changes are unknown.

Community attitudes on the family of issues surrounding the death of terminal patients

In two studies, respondents made recommendations for the medical treatment of a terminally ill elderly woman. The woman was or was not experiencing intractable pain, and had requested either heroic medical efforts or euthanasia. Respondents' recommendations were influenced by both the specific wishes of the patient and the pain the person was experiencing. However, participants were not completely swayed by the patient's wishes: only about half of the sample recommended euthanasia even when the patient was in intractable pain and had requested death; also, many subjects would not resuscitate the patient whose heart or lungs failed, even though she had requested heroic measures. Respondent attitudes toward euthanasia predicted recommendations in the expected directions. We suggest that there is less dissent on the issues that arise for medical treatments at the end of life than has been widely assumed.