Gaps in the tuberculosis preventive therapy care cascade in children in contact with TB

BACKGROUND

Young children (<5 years) and children living with HIV in contact with an adult with tuberculosis (TB) should receive TB preventive therapy (TPT), but uptake is low.

AIMS

To determine gaps in the uptake of and adherence to TPT in child TB contacts under routine primary care clinic conditions.

METHODS

A cohort of child TB contacts (age <5 years or living with HIV <15 years) was followed at a primary care clinic in Johannesburg, South Africa.

RESULTS

Of 170 child contacts with 119 adult TB cases, only 45% (77/170) visited the clinic for TPT eligibility screening, two of whom had already initiated TPT at another clinic. Of the 75 other children, 18/75 (24%) commenced TB treatment and 56/75 (75%) started TPT. Health-care workers followed the guidelines, with 96% (64/67) of children screened for symptoms of TB and 97% (36/37) of those symptomatic assessed for TB, but microbiological testing was low (9/36, 25%) and none had microbiologically confirmed tuberculosis. Only half (24/46, 52%) of the children initiating TPT completed the 6-month course. Neither sociodemographic determinants (age, sex) nor clinical factors (HIV status, TB source, time to TPT initiation) was associated with non-adherence to TPT.

CONCLUSION

Most child contacts of an adult TB case do not visit the clinic, and half of those initiating TPT did not adhere to the full 6-month course. These programme failures result in missed opportunities for early diagnosis of active TB and prevention of progression to disease in young and vulnerable children.

Novel health system strategies for tuberculin skin test-guided Isoniazid preventive therapy

Background

Global TB elimination demands a scale-up of Isoniazid preventive therapy (IPT) but tuberculin skin test (TST)-guided IPT poses great logistical and human resource challenges.

Objectives

Performance of TST self-reading by patients and fast-track TST reading by trained low cadre health care workers (task-shifting) was compared to formal TST reading by high cadre staff in a cohort of 278 South African adults living with HIV. Health economic impact of these novel strategies was assessed from a provider and societal perspective and simulations were performed for 5 other countries (USA, Germany, Brazil, India, Russia) to evaluate generalizability. In addition, accuracy of TST at antiretroviral treatment (ART) initiation was assessed by a repeat TST 6 and 12 month later.

Results

TST self-reading was highly accurate, with 89% sensitivity (95% CI 80, 95) and 100% specificity (95% CI 97,100) for detecting presence/absence of any induration. Agreement in TST reading between low and high cadre health care workers was very high (kappa 0.97). Compared to standard of care, a combined fast-track, task-shifting and self-reading strategy reduced TST reading costs in South Africa from a patient perspective by 81% and from a provider perspective by 92%. In all 5 countries simulated, TST reading cost was reduced by ≥ 78 % from a provider perspective. Repeat testing at 6 and 12 months showed high (31%, 95% CI 23, 40) TST conversion during the first 12 months of ART.

Conclusions

Empiric IPT for all people living with HIV followed by TST assessment after 6 or 12 months to identify those in need for lifelong IPT could increase the effectiveness of IPT programs. TST self-reading to reduce the number of patients that need to return for TST reading (to only those patients with self-determined presence of any induration) together with fast-tracking and task-shifting of TST reading could increase cost-effectiveness and reduce patient costs associated with IPT programs.

Key messages

Novel strategies are essential to control TB. Task-shifting, fast-tracking and patient TST self-reading empower patients and HCWs; optimal TST timing can increase cost-effectiveness of IPT programs.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Incident tuberculosis in HIV-positive children, adolescents and adults on antiretroviral therapy in South Africa

OBJECTIVE

To evaluate the association between age and incident tuberculosis (TB) among human immunodeficiency virus (HIV) infected patients receiving antiretroviral treatment (ART) in South Africa.

DESIGN

Prospective cohort analysis among HIV-infected patients initiating ART between April 2004 and April 2012. Generalized estimating equations (GEE) were used with modified Poisson regression clustered by treatment site as a function of sex, age, nucleoside reverse transcriptase inhibitor, CD4 count, hemoglobin levels and year of ART initiation. Cumulative incidence functions stratified by age and controlling for death as a competing risk were used to graphically display incident TB.

RESULTS

Although non-significant, GEE models showed that patients aged <1 year had a 40% increase in risk of TB compared to those aged 30-39.9 years. Results also showed that male patients, those with low CD4, those with low hemoglobin and those who initiated ART before 2010 were at increased risk of TB.

CONCLUSIONS

Our results show that patients aged <1 year, males, patients with low CD4 and those with low hemoglobin at ART initiation are at increased risk of incident TB in the first 24 months of ART. Given the known transmission risk factors for children living in households with a TB contact, reducing TB incidence in HIV-positive adults could substantially impact the risk of TB in young children.

Depression and Engagement in Care Among Newly Diagnosed HIV-Infected Adults in Johannesburg, South Africa

Delayed engagement in HIV care threatens the success of HIV treatment programs in sub-Saharan Africa and may be influenced by depression. We examined the relationship between depression prior to HIV diagnosis and engagement in HIV care at a primary care clinic in Johannesburg, South Africa. We screened 1683 patients for depression prior to HIV testing using the Patient Health Questionnaire-9. Among patients who tested positive for HIV we assessed linkage to HIV care, defined as obtaining a CD4 count within 3 months. Among those who linked to care and were eligible for ART, we assessed ART initiation within 3 months. Multivariable Poisson regression with a robust variance estimator was used to assess the association between depression and linkage to care or ART initiation. The prevalence of HIV was 26 % (n = 340). Among HIV-infected participants, the prevalence of depression was 30 %. The proportion of linkage to care was 80 % among depressed patients and 73 % among patients who were not depressed (risk ratio 1.08; 95 % confidence interval 0.96, 1.23). Of the participants who linked to care, 81 % initiated ART within 3 months in both depressed and not depressed groups (risk ratio 0.99; 95 % confidence interval 0.86, 1.15). Depression was not associated with engagement in HIV care in this South African primary care setting. Our unexpected findings suggest that some depressed HIV-infected patients might be more likely to engage in care than their counterparts without depression, and highlight the complex relationship between depression and HIV infection. These findings have led us to propose a new framework relating HIV infection, depression, and the population under study.

Outcomes of combined tibial tuberosity transfer and medial patellofemoral ligament reconstruction for recurrent patellar instability

Patellofemoral instability is multifactorial and is associated with pathomechanics secondary to anatomical variance. Surgical management of this problem must be tailored to each patient and a thorough clinical and radiological assessment of the anatomical alignment should be carried out pre-operatively. The aim of this study is to assess the role of medial patellofemoral ligament reconstruction combined with tibial tuberosity transfer in patients with increased tibial tuberosity to trochlear groove (TT-TG) distance. Twenty-four patients (27 knees) over 2-years were operated on by a single surgeon, with standardised post-operative rehabilitation and follow up. Mean follow up was 31-months. Two patients had problems with recurrent instability, 1 had a -traumatic re-dislocation at 2 years and a total of 4 required further operation for complications. Mean post--operative Kujala scores were 87.4 (SD 9.8). Combined medial patellofemoral ligament reconstruction and tibial tuberosity transfer is an appropriate treatment for patients with increased TT-TG distance.

Risk Assessment or Assessment of Risk? Developing an Evidence-Based Approach for Primary Producers of Leafy Vegetables To Assess and Manage Microbial Risks

Over the last 10 years, some high-profile foodborne illness outbreaks have been linked to the consumption of leafy greens. Growers are required to complete microbiological risk assessments (RAs) for the production of leafy crops supplied either to retail or for further processing. These RAs are based primarily on qualitative judgements of hazard and risks at various stages in the production process but lack many of the steps defined for quantitative microbiological RAs by the Codex Alimentarius Commission. This article is based on the discussions of an industry expert group and proposes a grower RA approach based on a structured qualitative assessment, which requires all decisions to be based on evidence and a framework for describing the decision process that can be challenged and defended within the supply chain. In addition, this article highlights the need for evidence to be more easily available and accessible to primary producers and identifies the need to develop hygiene criteria to aid validation of proposed interventions.

The patient impact of point-of-care vs. laboratory placement of Xpert(®) MTB/RIF

BACKGROUND

The Xpert(®) MTB/RIF assay can diagnose tuberculosis (TB) rapidly and with great accuracy. The effect of Xpert placement at point of care (POC) vs. at an off-site laboratory on patient management remains unknown.

DESIGN

At a primary care clinic in Johannesburg, South Africa, we compared TB diagnosis and treatment initiation among 1861 individuals evaluated for pulmonary TB using Xpert performed either at POC or offsite.

RESULTS

When Xpert was performed at POC, a higher proportion of Xpert-positive individuals started treatment (95% vs. 87%, P = 0.047) and time to treatment initiation was shorter (median 0 vs. 5 days, P < 0.001). In contrast, among Xpert-negative TB cases, a higher proportion (87% vs. 72%, P = 0.001) started treatment when the sample was sent to the laboratory, with a shorter time to treatment (median 9 vs. 13 days, P = 0.056). While the overall proportion of presumed TB patients starting treatment was independent of Xpert placement, the proportion started based on a bacteriologically confirmed diagnosis was higher when Xpert was performed at POC (73% vs. 58%, P = 0.006).

CONCLUSIONS

Placement of Xpert at POC resulted in more Xpert-positive patients receiving treatment, but did not increase the total number of presumed TB patients starting treatment. When samples were sent to a laboratory for Xpert testing, empiric decision making increased.

A home tracing program for contacts of people with tuberculosis or HIV and patients lost to care

SETTING

Primary care clinic serving a high tuberculosis (TB) and human immunodeficiency virus (HIV) prevalence community in South Africa.

OBJECTIVE

To evaluate a program combining TB and HIV contact investigation with tracing of individuals lost to TB or HIV care.

DESIGN

Contacts were offered home-based HIV testing, TB symptom screening, sputum collection and referral for isoniazid preventive therapy (IPT). Effectiveness was assessed by the number needed to trace (NNT).

RESULTS

Only 419/1197 (35.0%) households were successfully traced. Among 267 contacts, we diagnosed 27 new HIV cases (10 linked to care) and two TB cases (both initiated treatment) and three started IPT. Of 630 patients lost to care, 132 (21.0%) were successfully traced and 81 (61.4%) re-engaged in care. The NNT to locate one individual lost to care was 4.8 (95%CI 4.1-5.6), to re-engage one person in care 7.8 (95%CI 6.4-9.7), to diagnose one contact with HIV 44.3 (95%CI 30.6-67.0), to link one newly diagnosed contact to HIV care 120 (95%CI 65.3-249.2) and to find one contact with active TB and initiate treatment 599 (95%CI 166.0-4940.7).

CONCLUSION

The effectiveness of this contact tracing approach in identifying new TB and HIV cases was low. Methods to optimize contact investigation should be explored and their cost-effectiveness assessed.

Applications of omics approaches to the development of microbiological risk assessment using RNA virus dose-response models as a case study

T e in the amount of ‘omics’ data available and in our ability to interpret those data. The aim of this paper was to consider how omics techniques can be used to improve and refine microbiological risk assessment, using dose–response models for RNA viruses, with particular reference to norovirus through the oral route as the case study. The dose–response model for initial infection in the gastrointestinal tract is broken down into the component steps at the molecular level and the feasibility of assigning probabilities to each step assessed. The molecular mechanisms are not sufficiently well understood at present to enable quantitative estimation of probabilities on the basis of omics data. At present, the great strength of gene sequence data appears to be in giving information on the distribution and proportion of susceptible genotypes (for example due to the presence of the appropriate pathogen‐binding receptor) in the host population rather than in predicting specificities from the amino acid sequences concurrently obtained. The nature of the mutant spectrum in RNA viruses greatly complicates the application of omics approaches to the development of mechanistic dose–response models and prevents prediction of risks of disease progression (given infection has occurred) at the level of the individual host. However, molecular markers in the host and virus may enable more broad predictions to be made about the consequences of exposure in a population. In an alternative approach, comparing the results of deep sequencing of RNA viruses in the faeces/vomitus from donor humans with those from their infected recipients may enable direct estimates of the average probability of infection per virion to be made.

Quantitative X-ray microradiography for high-throughput phenotyping of osteoarthritis in mice

OBJECTIVE

To investigate and validate digital X-ray microradiography as a novel, high-throughput and cost-effective screening approach to identify abnormal joint phenotypes in mice.

METHOD

Digital X-ray microradiography was used to quantify the subchondral bone mineral content (BMC) in the medial tibial plateau. Accuracy and reproducibility of the method were determined in 22 samples from C57BL/6(B6Brd;B6Dnk;B6N-Tyr(c-Brd)) wild-type mice. The method was then validated in wild-type mice that had undergone surgical destabilisation of medial meniscus (DMM) and in a genetically modified mouse strain with an established increase in trabecular bone mass.

RESULTS

The measurement of subchondral BMC by digital X-ray microradiography had a coefficient of variation of 3.6%. Digital X-ray microradiography was able to demonstrate significantly increased subchondral BMC in the medial tibial plateau of male mice 4 and 8 weeks after DMM surgery and in female mice 8 weeks after surgery. Furthermore, digital X-ray microradiography also detected the increase in subchondral BMC in a genetically modified mouse strain with high trabecular bone mass.

CONCLUSION

Quantitation of subchondral BMC by digital X-ray microradiography is a rapid, sensitive and cost-effective method to identify abnormal joint phenotypes in mice of both genders at several ages.

Point-of-care Xpert® MTB/RIF for smear-negative tuberculosis suspects at a primary care clinic in South Africa

OBJECTIVE

To assess the clinical utility and cost of point-of-care Xpert® MTB/RIF for the diagnosis of smear-negative tuberculosis (TB).

DESIGN

Cohort study of smear-negative TB suspects at a South African primary care clinic. Participants provided one sputum sample for fluorescent smear microscopy and culture and an additional sample for Xpert. Outcomes of interest were TB diagnosis, linkage to care, patient and provider costs.

RESULTS

Among 199 smear-negative TB suspects, 16 were positive by Xpert, 15 by culture and 7 by microscopy. All cases identified by Xpert began anti-tuberculosis treatment the same or next day; only one of five Xpert-negative culture-positive cases started treatment after 34 days. Xpert at point of care offered similar diagnostic yield but a faster turnaround time than smear and culture performed at a centralized laboratory. Compared to smear plus culture, Xpert (at US$9.98 per cartridge) was US$3 less expensive per valid result (US$21 vs. US$24) and only US$6 more costly per case identified (US$266 vs. US$260).

CONCLUSION

Xpert is an effective method of diagnosing smear-negative TB. It is cost saving for patients, especially if performed at point of care, but it is costly for health care providers. Data-driven studies are needed to determine its cost-effectiveness in resource-poor settings with diverse diagnostic practices.

TB/HIV integration at primary care level: A quantitative assessment at 3 clinics in Johannesburg, South Africa

BACKGROUND

In 2004 the World Health Organization WHO) released the Interim Policy on Collaborative TB/ HIV activities. According to the policy, for people living with HIV (PLWH), activities include intensified case finding, isoniazid preventive therapy (IPT) and infection control. For TB patients, activities included HIV counselling and testing HCT), prevention messages, and cotrimoxazole preventive therapy (CPT), care and support, and antiretroviral therapy ART) for those with HIV-associated TB. While important progress has been made in implementation, targets of the WHO Global Plan to Stop TB have not been reached.

OBJECTIVE

To quantify TB/HIV integration at 3 primary healthcare clinics in Johannesburg, South Africa.

METHODS

Routinely collected TB and HIV data from the HCT register, TB 'suspect' register, TB treatment register, clinic files and HIV electronic database, collected over a 3-month period, were reviewed.

RESULTS

Of 1 104 people receiving HCT: 306 (28%) were HIV-positive; a CD4 count was documented for 57%; and few received TB screening or IPT. In clinic encounters among PLWH, 921 (15%) had documented TB symptoms; only 10% were assessed by smear microscopy, and few asymptomatic PLWH were offered IPT. Infection control was poorly documented and implemented. HIV status was documented for 155 (75%) of the 208 TB patients; 90% were HIV-positive and 88% had a documented CD4 count. Provision of CPT and ART was poorly documented.

CONCLUSION

The coverage of most TB/HIV collaborative activities was below Global Plan targets. The lack of standardised recording tools and incomplete documentation impeded assessment at facility level and limited the accuracy of compiled data.

TB/HIV integration at primary care level: A quantitative assessment at 3 clinics in Johannesburg, South Africa

Background. In 2004 the World Health Organization (WHO) released the Interim Policy on Collaborative TB/HIV activities. According to the policy, for people living with HIV (PLWH), activities include intensified case finding, isoniazid preventive therapy (IPT) and infection control. For TB patients, activities included HIV counselling and testing (HCT), prevention messages, and cotrimoxazole preventive therapy (CPT), care and support, and antiretroviral therapy (ART) for those with HIV-associated TB. While important progress has been made in implementation, targets of the WHO Global Plan to Stop TB have not been reached. Objective. To quantify TB/HIV integration at 3 primary healthcare clinics in Johannesburg, South Africa. Methods. Routinely collected TB and HIV data from the HCT register, TB ‘suspect’ register, TB treatment register, clinic files and HIV electronic database, collected over a 3-month period, were reviewed. Results. Of 1 104 people receiving HCT: 306 (28%) were HIV-positive; a CD4 count was documented for 57%; and few received TB screening or IPT. In clinic encounters among PLWH, 921 (15%) had documented TB symptoms; only 10% were assessed by smear microscopy, and few asymptomatic PLWH were offered IPT. Infection control was poorly documented and implemented. HIV status was documented for 155 (75%) of the 208 TB patients; 90% were HIV-positive and 88% had a documented CD4 count. Provision of CPT and ART was poorly documented. Conclusion. The coverage of most TB/HIV collaborative activities was below Global Plan targets. The lack of standardised recording tools and incomplete documentation impeded assessment at facility level and limited the accuracy of compiled data.

Prevalence of esophageal dysmotility in a cohort of patients with esophageal biopsies consistent with eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is increasingly being diagnosed in adults presenting with dysphagia, food impactions, and chest pain. Studies to date provide conflicting data on the association of EoE and esophageal dysmotility. The objective of this study was to evaluate the prevalence of esophageal dysmotility in a cohort of patients with biopsies consistent with EoE at a military treatment facility. This is a prospective evaluation of consecutively identified patients at our institution diagnosed with EoE from March 1, 2005 to June 1, 2007. Thirty-two patients with biopsies consistent with EoE completed a symptom survey and 30 underwent esophageal manometry. The majority of EoE patients (23/30, 77%) had a normal end-expiratory lower esophageal sphincter (LES) pressure (normal range 10-35), whereas six patients had a low-normal LES pressure (6-9 mm Hg) and one patient had a decreased LES pressure (<5 mm Hg). Five patients (15.6%) were diagnosed with a nonspecific esophageal motor disorder (NSEMD). Two patients had high mean esophageal amplitude contractions >180 mm Hg (188 mm Hg, 209 mm Hg). No patient was diagnosed with nutcracker esophagus or diffuse esophageal spasm. Patients with and without NSEMD reported a similar degree of swallowing difficulty, heartburn, belching, chest pain, regurgitation, symptoms at night, and total symptom score. Likewise, eosinophil count on mucosal biopsy was similar between patients with and without a NSEMD. In this cohort, we found the prevalence of an NSEMD to be similar to that of a 10% prevalence found in a gastroesophageal reflux population.

A probabilistic modeling approach in thermal inactivation: estimation of postprocess Bacillus cereus spore prevalence and concentration

The survival of spore-forming bacteria is linked to the safety and stability of refrigerated processed foods of extended durability (REPFEDs). A probabilistic modeling approach was used to assess the prevalence and concentration of Bacillus cereus spores surviving heat treatment for a semiliquid chilled food product. This product received heat treatment to inactivate nonproteolytic Clostridium botulinum during manufacture and was designed to be kept at refrigerator temperature postmanufacture. As key inputs for the modeling, the assessment took into consideration the following factors: (i) contamination frequency (prevalence) and level (concentration) of both psychrotrophic and mesophilic strains of B. cereus, (ii) heat resistance of both types (expressed as decimal reduction times at 90 degrees C), and (iii) intrapouch variability of thermal kinetics during heat processing (expressed as the time spent at 90 degrees C). These three inputs were established as statistical distributions using expert opinion, literature data, and specific modeling, respectively. They were analyzed in a probabilistic model in which the outputs, expressed as distributions as well, were the proportion of the contaminated pouches (the likely prevalence) and the number of spores in the contaminated pouches (the likely concentration). The prevalence after thermal processing was estimated to be 11 and 49% for psychrotrophic and mesophilic strains, respectively. In the positive pouches, the bacterial concentration (considering psychrotrophic and mesophilic strains combined) was estimated to be 30 CFU/g (95th percentile). Such a probabilistic approach seems promising to help in (i) optimizing heat processes, (ii) identifying which key factor(s) to control, and (iii) providing information for subsequent assessment of B. cereus resuscitation and growth.

Using a high-resolution magnetic sector mass spectrometer for fast analysis of transient reaction processes in automotive catalytic converters

A high-resolution magnetic sector mass spectrometer has been developed and used for transient kinetic measurements on reactions that are important for automotive exhaust gas catalysis. This instrument allows separation of the isobaric masses of CO and N2 as well as CO2 and N2O, which are separately monitored in time at a sampling rate of 48 Hz. The time resolution is sufficient to determine individual kinetic rate parameters for reactions under transient conditions. A description of the experimental set-up as well as the software used is given. The results are illustrated by the catalytic reduction of NO by CO. To the best knowledge of the authors, this is the first application of a magnetic sector mass spectrometer for kinetic research under dynamic operation conditions.

Operative treatment of supracondylar fractures of the humerus in children. The consequences of pin placement

BACKGROUND

The commonly accepted treatment of displaced supracondylar fractures of the humerus in children is fracture reduction and percutaneous pin fixation; however, there is controversy about the optimal placement of the pins. A crossed-pin configuration is believed to be mechanically more stable than lateral pins alone; however, the ulnar nerve can be injured with the use of a medial pin. It has not been proved that the added stability of a medial pin is clinically necessary since, in young children, pin fixation is always augmented with immobilization in a splint or cast.

METHODS

We retrospectively reviewed the results of reduction and Kirschner wire fixation of 345 extension-type supracondylar fractures in children. Maintenance of fracture reduction and evidence of ulnar nerve injury were evaluated in relation to pin configuration and fracture pattern. Of 141 children who had a Gartland type-2 fracture (a partially intact posterior cortex), seventy-four were treated with lateral pins only and sixty-seven were treated with crossed pins. Of 204 children who had a Gartland type-3 (unstable) fracture, fifty-one were treated with lateral pins only and 153 were treated with crossed pins.

RESULTS

There was no difference with regard to maintenance of fracture reduction, as seen on anteroposterior and lateral radiographs, between the crossed pins and the lateral pins. The configuration of the pins did not affect the maintenance of reduction of either the Gartland type-2 fractures or the Gartland type-3 fractures. Ulnar nerve injury was not seen in the 125 patients in whom only lateral pins were used. The use of a medial pin was associated with ulnar nerve injury in 4% (six) of 149 patients in whom the pin was applied without hyperflexion of the elbow and in 15% (eleven) of seventy-one in whom the medial pin was applied with the elbow hyperflexed. Two years after the pinning, one of the seventeen children with ulnar nerve injury had persistent motor weakness and a sensory deficit.

CONCLUSIONS

Fixation with only lateral pins is safe and effective for both Gartland type-2 and Gartland type-3 (unstable) supracondylar fractures of the humerus in children. The use of only lateral pins prevents iatrogenic injury to the ulnar nerve. On the basis of our findings, we do not recommend the routine use of crossed pins in the treatment of supracondylar fractures of the humerus in children. If a medial pin is used, the elbow should not be hyperflexed during its insertion.

Ovine male genital duct epithelial cells differentiate in vitro and express functional CFTR and ENaC

To investigate the biology of the male genital duct epithelium, we have established cell cultures from the ovine vas deferens and epididymis epithelium. These cells develop tight junctions, high transepithelial electrical resistance, and a lumen-negative transepithelial potential difference as a sign of active transepithelial ion transport. In epididymis cultures the equivalent short-circuit current (I(sc)) averaged 20.8+/-0.7 microA/cm(2) (n = 150) and was partially inhibited by apical application of amiloride with an inhibitor concentration of 0.64 microM. In vas deferens cultures, I(sc) averaged 14.4+/-1.1 microA/cm(2) (n = 18) and was also inhibited by apical application of amiloride with a half-maximal inhibitor concentration (K(i)) of 0.68 microM. The remaining amiloride-insensitive I(sc) component in epididymis and vas deferens cells was partially inhibited by apical application of the Cl(-) channel blocker diphenylamine-2-carboxylic acid (1 mM). It was largely dependent on extracellular Cl(-) and, to a lesser extent, on extracellular HCO(-)(3). It was further stimulated by basolateral application of forskolin (10(-5) M), which increased I(sc) by 3.1+/-0.3 microA/cm(2) (n = 65) in epididymis and 0.9+/-0.1 microA/cm(2) (n = 11) in vas deferens. These findings suggest that cultured ovine vas deferens and epididymis cells absorb Na(+) via amiloride-sensitive epithelial Na(+) channels (ENaC) and secrete Cl(-) and HCO(-)(3) via apical cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channels. This interpretation is supported by RT-PCR data showing that vas deferens and epididymis cells express CFTR and ENaC mRNA.

Intraoperative angiography to assess graft patency after minimally invasive coronary bypass

BACKGROUND

Intraoperative angiography was performed to confirm graft patency immediately after minimally invasive coronary bypass operations.

METHODS

In 26 patients who had internal mammary artery grafting, intraoperative coronary angiography was performed with a portable digital fluoroscope.

RESULTS

High-resolution angiograms were obtained in all cases. Angiography documented vasospasm of the graft or native vessel in 9 patients (graft in 3, native in 2, graft and native in 4 others), which responded promptly to intracoronary vasodilators in all. Angiography identified technically unsuspected and clinically silent fixed stenoses (>50%) in 11 patients, attributable to graft kinking in 2, anastomotic obstruction in 6 (total occlusion in 4), and stenosis of the left anterior descending artery just distal to the anastomosis in three cases (total occlusion in one). In 9 of 11 patients, fixed stenoses were sufficiently severe to warrant intraoperative intervention by surgical revision (n = 5) or angioplasty via the graft (n = 4).

CONCLUSIONS

Intraoperative angiography after minimally invasive coronary artery bypass operations can immediately identify dynamic and fixed obstructions and facilitate their prompt treatment, thereby ensuring that each patient leaves the operating room with an optimal surgical result.

Timing of coronary artery bypass grafting after acute myocardial infarction

Appropriate timing for coronary artery bypass grafting (CABG) after acute myocardial infarction (AMI) remains controversial. We retrospectively examined 423 patients who underwent CABG within 21 days of an AMI between 1992 and 1995, mainly for postinfarction angina and complex anatomy. The operative mortality rates associated with increasing time intervals between AMI and CABG were 17.4, 9.1, 4.0, and 5.8 per cent, for less than 6 hours, 6 to 24 hours, 1 to 7 days, and 7 to 21 days, respectively. There were 25 (5.9%) deaths overall. Statistical analysis was performed to evaluate the following preoperative parameters: age, sex, reoperation, previous myocardial infarction (MI), MI type and location, anatomy, cardiogenic shock, unstable angina, ventricular arrhythmias, extending MI, ejection fraction, indications for surgery, cardiac index, and interval from infarction to CABG. Interval between operation and AMI did not have a significant impact on patient outcome. Factors associated with an increased hospital mortality were ejection fraction < 30 per cent, age > 70 years, presence of cardiogenic shock, and cardiac index < 1.5. Only cardiac index proved to be a significant predictor of mortality (P < 0.001). We conclude that the timing of CABG, in and of itself, has no significant effect on hospital mortality of symptomatic patients within 3 weeks of AMI.

Complications of coronary artery surgery in diabetic patients

Postoperative mortality and morbidity of diabetic versus nondiabetic patients undergoing primary coronary artery bypass grafting (CABG) were analyzed. In 1988, 711 patients had CABG procedures, of which 565 were nondiabetic and 146 diabetic. The two groups of patients were statistically similar in regard to age, weight, tobacco and ethanol use, and preoperative levels of cholesterol, triglycerides, blood urea nitrogen (BUN), and creatinine. Preoperative serum glucose levels were significantly elevated in diabetic patients (182 vs. 106, P less than .001). Cardiac output, ejection fraction, and bypass, crossclamp time, and total operating room times were not different for the two groups. Emergent and urgent procedures had a significantly higher mortality rate than elective cases (11.3% and 6.6% vs. 1.7%, respectively; P less than 0.05), but this was independent of the patient's diabetic status. Women had a higher mortality rate than men (6.5% vs. 2.9%; P = 0.05) although within each gender group, there were no differences between diabetics and nondiabetics. There were 27 patients with complications in the diabetic group (18.5%) and 47 in the nondiabetic group (8.3%; P less than .001). The types of complications within the two groups differed in that wound infections (7.5%), postoperative arrhythmias (4.8%), respiratory failure (4.1%), and intra-aortic balloon pump use (4.1%) were significantly greater (P less than .05) in the diabetic patients compared to the nondiabetic (0.9%, 1.8%, 0.4%, and 1.4%, respectively). Occurrences of postoperative pneumothorax, reoperation, myocardial infarction, stroke, urinary tract infection, and pneumonia were similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic and metabolic effects of venoarterial cardiopulmonary support in coronary artery disease

Coronary angioplasty was performed on 14 high-risk patients supported with venoarterial partial cardiopulmonary bypass. Hemodynamic, metabolic and physiologic parameters were monitored to assess the effect of cardiopulmonary support in conscious patients. Cardiopulmonary support caused a decrease in systolic (45 +/- 17 to 27 +/- 14 mm Hg, p less than 0.001), diastolic (23 +/- 12 to 14 +/- 8 mm Hg, p less than 0.005) and mean (29.7 +/- 13.2 to 18 +/- 9 mm Hg, p less than 0.001) pulmonary artery pressures. Aortic systolic (129 +/- 18 to 106 +/- 17 mm Hg, p less than 0.001), mean (89 +/- 19 to 84 +/- 19 mm Hg, p less than 0.05) and pulse (64 +/- 17 to 37 +/- 16 mm Hg, p less than 0.00001) pressures also decreased. Heart rate and aortic diastolic pressures were unchanged. End-systolic wall stress (122 +/- 48 x 10(3) to 96 +/- 44 x 10(3) dynes/cm2, p less than 0.001) and left ventricular end-diastolic diameter (5.7 +/- 0.8 to 5.5 +/- 0.9 cm, p less than 0.05) were reduced during partial cardiopulmonary bypass. After initiation of cardiopulmonary support, normal lactate extraction across the coronary circulation was diminished or converted to lactate production (38 +/- 23 to 2 +/- 29%, p less than 0.005). There was a marked reduction in hematocrit (41 +/- 4 to 28 +/- 5%, p less than 0.0001) and platelet count (259,000 +/- 57,600/ml to 145,900 +/- 46,000/ml, p less than 0.0001) after bypass. Cardiopulmonary bypass successfully supported all patients during balloon inflation, for an optimal angioplasty result.(ABSTRACT TRUNCATED AT 250 WORDS)

Testes and scrotum: MR imaging at 1.5 T

Magnetic resonance (MR) images of the scrotum were obtained at 1.5 T in 20 subjects, 13 patients with intrascrotal pathologic conditions and seven healthy subjects. Characteristic MR imaging signals obtained on T1- and T2-weighted images allowed differentiation of testis from epididymis and spermatic cord. Masses were differentiated from normal testicular parenchyma in all cases. Atrophic or ischemic testes had lower signal intensity than normal testes on T2-weighted images. Hematoma displayed a characteristic high intensity on both T1- and T2-weighted images. Intratesticular and extratesticular pathologic conditions were readily differentiated. These results suggest that MR imaging is useful in the diagnosis of scrotal and testicular abnormalities.

Anaerobic threshold and lactate turnpoint

Venous lactate concentration and ventilatory responses to progressively increased work rates were studied in 16 men who performed an incremental exercise test to exhaustion on an electrically braked cycle ergometer. In this test the characteristic curvilinear increase in venous lactate concentrations was observed. In addition to the anaerobic threshold (AT), a second breakpoint was observed and named the lactate turnpoint (LTP). Eight of the 16 subjects performed a second incremental exercise test initiated during lactic acidosis. In this test the direction of change in venous lactate concentrations was different. The work rate at which lactate concentrations again increased, after a steady decline (previously described as the AT2), was similar to the work rate established for the LTP in the first test. In the second test removal of lactate was demonstrated at work rates exceeding the AT. Although the lactate response to the two tests was different the pattern of change was similar, with the two breakpoints occurring at the same work rates. Collectively these results lend a measure of support to the hypothesis of a positive relationship between the AT, LTP, and a pattern of recruitment of motor units with different enzyme profiles. Both the AT and LTP were predictable from the ventilatory response to incremental exercise.

Oxygen deficit during incremental exercise

The oxygen deficit and debt have conventionally been determined during exercise at constant work rates. During this study these were calculated during and after exercise at progressively incremented work rates. Five men performed two successive incremental exercise tests to exhaustion on an electronically braked cycle ergometer. The two tests were separated by a 5 min rest period. The oxygen deficit was defined as the sum of the minute differences between the measured oxygen uptake and the oxygen uptake occurring during steady state work at that same rate. The oxygen deficit was quantified for the work periods before and after the anaerobic threshold (AT) as determined from respiratory gas analysis (ATR). The measured deficit for the period before the ATR was smaller than the deficit measured in the same subjects during steady state work at low intensity (below the ATR) and was also less than the rapid component of the oxygen repayment as determined after the second incremental test. It was concluded that this test could be used for the determination of anaerobic capacity as represented by the total oxygen deficit (within motivational limits), but that the lactacid and alactacid components of the deficit could not be differentiated. A considerable portion of the alactacid component of the deficit was incurred after the onset of the ATR.

Atypical progressive angina pectoris caused by a congenital coronary-pulmonary shunt and coronary atherosclerosis

A 57-year-old man with atypical progressive angina caused by congenital coronary-pulmonary shunt and coronary atherosclerosis is described. The angina was rather consistently unresponsive to nitroglycerin. Following closure of the shunt and aortocoronary bypass surgery, the patient became asymptomatic and has remained free of angina 2 year postoperatively. Although the congenital anomaly is rare in adults, it may be considered in the differential diagnosis of atypical angina pectoris, particularly when there is either continuous murmur or systolic murmur over the lower parasternal area.