Allergy: etiology and epidemiology

The occurrence of atopic disease throughout the world is subject to many variables. Differences in methodology and diagnostic criteria for measuring the incidence could account for some disparities, but they cannot explain all of them. Despite our increasing knowledge of the atopic diseases, improved treatments, and early diagnosis, the incidence and prevalence of asthma, allergic rhinitis, and atopic dermatitis continue to rise. Ongoing research into the etiology and potential risk factors for atopic diseases could lead to the early diagnosis, effective treatment, and prevention.

The use of automated data to identify complications and comorbidities of diabetes: a validation study

We evaluated the accuracy of administrative data for identifying complications and comorbidities of diabetes using International Classification of Diseases, 9th edition, Clinical Modification and Current Procedural Terminology codes. The records of 471 randomly selected diabetic patients were reviewed for complications from January 1, 1993 to December 31, 1995; chart data served to validate automated data. The complications with the highest sensitivity determined by a diagnosis in the medical records identified within +/-60 days of the database date were myocardial infarction (95.2%); amputation (94.4%); ischemic heart disease (90.3%); stroke (91.2%); osteomyelitis (79.2%); and retinal detachment, vitreous hemorrhage, and vitrectomy (73.5%). With the exception of amputation (82.9%), positive predictive value was low when based on a diagnosis identified within +/-60 days of the database date but increased with relaxation of the time constraints to include confirmation of the condition at any time during 1993-1995: ulcers (88.5%); amputation (85.4%); and retinal detachment, vitreous hemorrhage and vitrectomy (79.8%). Automated data are useful for ascertaining potential cases of some diabetic complications but require confirmatory evidence when they are to be used for research purposes.

Influence of temperature on tracheal tube cuff pressure during cardiac surgery

BACKGROUND

Lateral wall pressure may cause tracheal injury by affecting tracheal capillary blood flow. Damage to the trachea is less severe when lateral wall pressure exerted by the endotracheal tube cuff does not exceed the mean capillary perfusion pressure of the mucosa. The purpose of this study was to determine the effects of hypothermic and normothermic cardiopulmonary bypass (CPB) on tracheal tube cuff pressure dynamics.

METHODS

Twenty-two patients were studied during normothermic CPB (pulmonary artery blood temperature in the CPB period between 36 and 35 degrees C), and 22 patients during hypothermic CPB (pulmonary artery temperature in the CPB period between 32 and 28 degrees C). A Mallinckrodt Medical Lo-Contour Murphy tracheal tube, with high-volume, low-pressure cuff was used without lubricant. Intracuff pressure (ITCP) was recorded at end-expiration before, during and after cardiopulmonary bypass.

RESULTS

ITCP measurements were different between groups during CPB at aortic cross-clamping (13.9 +/- 0.8 mmHg in the normothermic group versus 11.3 +/- 0.4 mmHg in the hypothermic group, P < 0.05), and respectively during CPB after aortic declamping (15.3 +/- 0.8 mmHg and 12.6 +/- 0.8 mmHg, P < 0.05) and after CPB at the end of surgery (16.8 +/- 0.7 mmHg and 18.6 +/- 0.3 mmHg, P < 0.05).

CONCLUSION

We conclude that the ITCP is higher in normothermic CPB than in hypothermic CPB; however, the clinical significance of this observation needs further investigation.

Are therapists aware of the needs of people with disabilities?

This article challenges therapists to find out what the needs of people with disability are before planning community based rehabilitation services. It also establishes that therapists and people with disabilities have different ideas about the needs of people with disability.

Evaluation of the biochemical effects of administration of intravenous nutrients using erythrocyte ATP/ADP ratios

Regardless of clinical diagnosis, many acutely and chronically sick patients benefit from intravenous vitamins and minerals, which are usually administered in multiple infusions before observing obvious benefit. We hypothesized this effect was due to improved cellular energy, and attempted to find laboratory evidence via this study. Two groups of patients, chosen at random, received a single infusion of vitamins and minerals in two different dose schedules. Controls received no treatment. Study subjects were patients who presented specifically for a nutritional therapeutic approach, and although all were treated with multiple infusions, a single infusion was selected at random for this study. Thirty patients received a single infusion of a lower dose nutritional formula, sometimes known as a Myer's Cocktail (MC), and 34 had a single infusion of a higher dose nutritional I/V (NIV). Immediately prior to and after the infusion, blood was drawn and an erythrocyte ATP/ADP ratio (EADR) was determined. The results showed that in both infusion groups if the EADR was initially low, it would increase. If it were initially high, it would decrease. This effect was not observed in control subjects. Pre-test EADR boxplot analyses, derived from the results of each protocol, showed these results were statistically predictable. An analysis of variation (ANOVA) calculation indicated the differences were significant. The family error rate used was 0.05. We conclude that this regression of the EADR to the mean, as a result of either of the two infusions and not seen in control subjects, is biochemically significant.

Effects of dopexamine on blood flow in multiple splanchnic sites measured by laser Doppler velocimetry in rabbits undergoing cardiopulmonary bypass

Decreased gut perfusion has been reported during cardiopulmonary bypass (CPB). Studies of treatments to avoid splanchnic ischaemia during CPB have given conflicting results. We studied 12 rabbits during mild hypothermic non-pulsatile CPB. Tissue blood flow in three different splanchnic areas (gastric, jejunum and ileum) was measured by laser Doppler velocimetry (LDV) before CPB (T0), after steady state (T1), after administration of dopexamine 2 micrograms kg-1 min-1 (T2) and 4 micrograms kg-1 min-1 (T3), and after return to baseline (T4). Splanchnic blood flow decreased during CPB. Dopexamine increased significantly jejunum LDV (100% at T1 to mean 271 (SD 210)% at T2) and ileum LDV (100% at T1 to 187 (112)% at T2). Gastric LDV was not altered by infusion of dopexamine during CPB. This could partly explain the conflicting results on the value of gastric tonometry as an index of splanchnic injury.

Rates of growth and loss of bone mineral in the spine and femoral neck in white females

This study characterizes the rates of growth and loss of bone mass as a function of age in white females. It combines longitudinal data from several studies of bone mass on healthy white female subjects ranging from age 6 to 90 years. Rates of change in bone area, bone mineral content (BMC) and bone mineral density (BMD) are estimated separately for the spine and the femoral neck of each individual using linear regression. The individual rates of change are then fitted as a nonparametric function of age using weighted moving averages, resulting in a curve of age-specific mean change as a function of age. When the curves of BMD were compared between the hip and the femoral neck, the cessation of bone growth and the onset of bone loss were found to occur at an earlier age at the hip than at the spine. No significant differences in the ages of maximum rates of growth or maximum loss were found between the two skeletal sites. This information will be useful for designing interventions to promote bone growth or retard bone loss.

Isolation of Borrelia burgdorferi from ticks in the Highlands of Scotland

Borrelia burgdorferi, the causative agent of Lyme disease, was first isolated in 1982 and since then has been regularly isolated from ticks and clinical material in both Continental Europe and the USA. However, only three isolations have been reported in Britain. During the summer of 1997, 128 ticks were collected from two sites in the Highlands of Scotland and examined by the polymerase chain reaction (PCR) and culture. Eleven fresh isolates were obtained from culture and passed up to 22 times. Seven of the tick emulsions were also positive by flagellin gene PCR, and a further one was positive by PCR but negative on culture. All 11 isolate cultures were positive by the flagellin gene PCR. Further studies on four of these isolates confirmed their identity by immunofluorescence, but also detected possible differences between them and B. burgdorferi ACA-1 by enzyme profiles and by PCR with OspA gene primers. Culture of these new strains provides antigens that should improve diagnostic serological tests in Britain.

Combination chemotherapy and IL-15 administration induce permanent tumor regression in a mouse lung tumor model: NK and T cell-mediated effects antagonized by B cells

Previous studies have demonstrated that IL-15 administration after cyclophosphamide (CY) injection of C57BL/6J mice bearing the i.m. 76-9 rhabdomyosarcoma resulted in a significant prolongation of life. In the present study, we investigated the immune response against the 76-9 experimental lung metastases after CY + IL-15 therapy. Administration of CY + IL-15, but not IL-15 alone, induced prolongation of life and cures in 32% of mice bearing established experimental pulmonary metastases of 76-9 tumor. The CY + IL-15 therapy resulted in increased levels of NK1.1+/LGL-1+ cells, and CD8+/CD44+ T cells in PBL. In vitro cytotoxic assay of PBL indicated the induction of lymphokine-activated killer cell activity, but no evident tumor-specific class I-restricted lytic activity. Survival studies showed that the presence of NK and T lymphocytes is necessary for successful CY + IL-15 therapy. Experiments using knockout mice implied that either alphabeta or gammadelta T cells were required for an antitumor effect induced by CY + IL-15 therapy. However, mice lacking in both alphabeta and gammadelta T cells failed to respond to combination therapy. Cured B6 and alphabeta or gammadelta T cell-deficient mice were immune to rechallenge with 76-9, but not B16LM tumor. B cell-deficient mice showed a significant improvement in the survival rate both after CY and combination CY + IL-15 therapy compared with normal B6 mice. Overall, the data suggest that the interaction of NK cells with tumor-specific alphabeta or gammadelta T lymphocytes is necessary for successful therapy, while B cells appear to suppress the antitumor effects of CY + IL-15 therapy.

Trauma admissions in the elderly: how does a patient's age affect the likelihood of their being admitted to hospital after a fracture?

In two projects we have studied patients presenting to Accident and Emergency (A&E) departments with a fracture, to examine how their age influences their likelihood of admission. Over 1 year from April 1994 we collected data on all 6467 Cardiff residents who presented to the city's A&E department with a fracture. In total 1226 (19%) were admitted. Overall, only 12% of those under 65, but 47% of older patients required admission. This was largely a reflection of the age-distribution of hip fracture, an injury for which admission is inevitable. In a subsequent study of eight A&E departments in South Wales we therefore considered the proportion of patients admitted following fractures at specific anatomical sites. In people over the age of 55 we identified 6889 fractures, 2115 (31%) of which led to admission. After standardisation to control for the age-distribution of incidence for different fracture sites, we found that the likelihood of admission was 22% greater for people aged over 65 years. Elderly people very often require hospital admission after a fracture, primarily as a consequence of the types of fractures that they tend to sustain. Admissions directly attributable to the effects of age and age-related medical, psychiatric and social comorbidity appear of more limited significance.

CSF-1 regulation of Il6 gene expression by murine macrophages: a pivotal role for GM-CSF

We test the hypothesis that the monocyte-macrophage colony-stimulating factor (CSF-1 or M-CSF) plays a major role in the inflammatory responses of Mphi by acting as a priming agent that heightens their responsiveness to secondary stimulation by other mediators. We previously reported that CSF-1 induced peritoneal Mphi (PMphi) to transcribe several genes including interleukin-6 (Il6) and granulocyte-macrophage colony-stimulating factor (Csfgm). It was reported that the Il6 and Csfgm genes were individually regulated by different pathways but it was not clear to what extent the two genes interacted during Mphi-mediated inflammatory responses. We now show that CSF-1 induces the release of bioactive GM-CSF from mouse resident PMphi. GM-CSF induces Il6 gene expression and synergizes with CSF-1 to induce the release of large amounts of IL-6. PMphi from C57BL/6J-Csfgm(null) mice were shown to release minimal IL-6 in response to CSF-1 and to express a much reduced response to the highly stimulatory combination of CSF-1 and lipopolysaccharide (LPS). Exogenous recombinant GM-CSF restored the IL-6 response of GM-CSF null PMphi to a great extent but not completely. As controls, three other recombinant proteins were tested but of these only tumor necrosis factor alpha (TNF-alpha) was shown to synergize with both CSF-1 and GM-CSF. Using PMphi from mice deficient in the expression of the Il6 gene, it was shown that they released two- to threefold more GM-CSF in response to CSF-1 than their control counterparts. However, an exogenous supply of recombinant IL-6 had no effect on GM-CSF release. The data indicate that the pathways regulating Il6 gene expression are under the control of a complex network of cytokine interactions involving at least CSF-1, GM-CSF, and TNF-alpha, with the added possibility that IL-6 may exert modulatory activity within this network.

Regulation of proximal tubular osteopontin in experimental hydronephrosis in the rat

BACKGROUND

Osteopontin is a tubular-derived glycoprotein with macrophage chemoattractant properties. Our previous observations demonstrate that osteopontin is involved in the accumulation of macrophages within the renal cortex of rats following unilateral ureteral obstruction (UUO).

METHODS

The present study performed Northern and Western blot analyses of isolated proximal tubular cells exposed to exogenous angiotensin II, and cultured rat proximal tubular cells subjected to one hour of cyclic mechanical stretch, which provided insight into mechanisms involving the proximal tubular renin-angiotensin system in the increased expression of cortical osteopontin following hydronephrosis.

RESULTS

In situ hybridization, using a 35S-labeled antisense riboprobe, showed osteopontin mRNA transcription localized to the cortical tubules of the obstructed kidney. Freshly isolated proximal tubules incubated with angiotensin II (10-5 M) for one hour had increased osteopontin mRNA and protein expression by Northern and Western blot analyses, respectively. Pre-treatment of proximal tubules with losartan (10-5 M) for one hour prior to the addition of exogenous angiotensin II (10-5 M) decreased osteopontin mRNA and protein expression. Rat proximal tubule cells subjected to cyclic mechanical stretch for one hour exhibited a 2.1-fold increment in osteopontin mRNA levels, which was normalized following pre-treatment with losartan.

CONCLUSIONS

This study provides evidence that angiotensin II, produced by the proximal tubule in the obstructed kidney as a result of mechanical injury, possibly mechanical stretch, may stimulate angiotensin II type I receptor activation, leading to up-regulated osteopontin expression and secretion by the proximal tubule, thereby facilitating macrophage recruitment into the renal interstitium.

Jarvik 2000 heart: potential for bridge to myocyte recovery

BACKGROUND

Mechanical bridge to left ventricular recovery is an emerging strategy for the treatment of heart failure. We sought to validate the use of a new intracardiac axial flow impeller pump for this purpose.

METHODS AND RESULTS

The Jarvik 2000 Heart was implanted into 30 sheep to ascertain mechanical reliability, biocompatibility, and hemodynamic function. We attempted but failed to anticoagulate with warfarin. Elective explants with survival were performed in 3 animals to simulate bridge to recovery. Extensive autopsy studies were performed in all other animals. At speeds between 8000 and 12 000 rpm the device pumped up to 8 L/min, captured all mitral flow, and augmented cardiac output with elevation of mean arterial pressure. The pump was silent and hemolysis negligible. Nonpulsatile flow did not adversely affect neurological or renal function. Device removal proved straightforward and safe. A fractured inflow bearing occurred in 1 early model. There were no other pump failures, but power interruption occurred when the sheep chewed the cables or head-butted the percutaneous pedestal. At autopsy, there was no thromboembolism or primary thrombus formation in any device. Pump occlusion occurred in 2 sheep with bacterial endocarditis. One electively explanted pump, previously switched off for 5 months, had no thrombus in the device or vascular graft.

CONCLUSIONS

The Jarvik 2000 Heart is a major advance in blood-pump technology and increases the scope of mechanical circulatory support. Reliability and ease of removal favor its use for bridge to myocyte recovery, as well as for bridge to transplantation or long-term support.

The efficacy of spinal manipulation, amitriptyline and the combination of both therapies for the prophylaxis of migraine headache

BACKGROUND

Migraine headache affects approximately 11 million adults in the United States. Spinal manipulation is a common alternative therapy for headaches, but its efficacy compared with standard medical therapies is unknown.

OBJECTIVE

To measure the relative efficacy of amitriptyline, spinal manipulation and the combination of both therapies for the prophylaxis of migraine headache.

DESIGN

A prospective, randomized, parallel-group comparison. After a 4-wk baseline period, patients were randomly assigned to 8 wk of treatment, after which there was a 4-wk follow-up period.

SETTING

Chiropractic college outpatient clinic.

PARTICIPANTS

A total of 218 patients with the diagnosis of migraine headache.

INTERVENTIONS

An 8-wk course of therapy with spinal manipulation, amitriptyline or a combination of the two treatments.

MAIN OUTCOME MEASURES

A headache index score derived from a daily headache pain diary during the last 4 wk of treatment and during the 4-wk follow-up period.

RESULTS

Clinically important improvement was observed in both primary and secondary outcomes in all three study groups over time. The reduction in headache index scores during treatment compared with baseline was 49% for amitriptyline, 40% for spinal manipulation and 41% for the combined group; p = .66. During the posttreatment follow-up period the reduction from baseline was 24% for amitriptyline, 42% for spinal manipulation and 25% for the combined group; p = .05.

CONCLUSION

There was no advantage to combining amitriptyline and spinal manipulation for the treatment of migraine headache. Spinal manipulation seemed to be as effective as a well-established and efficacious treatment (amitriptyline), and on the basis of a benign side effects profile, it should be considered a treatment option for patients with frequent migraine headaches.

Cervical lymphadenopathy: sonographic differentiation between tuberculous nodes and nodal metastases from non-head and neck carcinomas

PURPOSE

Clinical examination alone cannot differentiate between cervical tuberculous lymphadenitis and cervical nodal metastases from non-head and neck (NHN) carcinomas because the distributions of involved lymph nodes are similar. We evaluated the sonographic features of cervical lymph nodes that could be used to differentiate between the 2 categories of nodes.

METHODS

We retrospectively reviewed sonograms of abnormal cervical lymph nodes in 47 patients with proven cervical tuberculous lymphadenitis and in 22 patients with proven nodal metastases from NHN carcinomas.

RESULTS

Abnormal nodes in tuberculous lymphadenitis and nodal metastases from NHN carcinomas were commonly found in the supraclavicular fossa (15% and 38%, respectively) and the posterior triangle (70% and 41%, respectively). Statistically significant (p < 0.05) features for differential diagnosis were lymph nodes' longest diameter, echogenicity, short-to-long axis ratio, appearance of surrounding soft tissues, and presence of intranodal cystic necrosis, matting, and posterior enhancement. Nodal size, echogenicity, presence of an echogenic hilum, calcification, coagulation necrosis, and sharpness of borders helped in identifying the abnormal lymph nodes.

CONCLUSIONS

Sonographic features that helped to differentiate between the 2 categories of nodes were shape, edema of surrounding soft tissue, homogeneity, intranodal cystic necrosis, matting, and posterior enhancement.

Three new ellagic acid derivatives from the bark of Eschweilera coriacea from the Suriname rainforest

Bioassay-guided fractionation of Eschweilera coriacea collected in the lowland wet forest of Suriname yielded the new but only weakly active ellagic acid derivative eschweilenol A (1) and the two new but inactive ellagic acid derivatives eschweilenol B (2) and eschweilenol C (3). The four known compounds, sucrose, ellagic acid, 3-O-galloylepigallocatechin, and epigallocatechin, were also isolated. The structures of the three new compounds were determined by spectrometric methods, primarily from the HMQC, HMBC, NOESY, and ROESY NMR techniques, and chemical methods, including methylation and triethylsilylation. The location of a hydroxyl group in one ellagic acid derivative was determined by a new technique involving an NOE correlation of the protons of a triethylsilyl derivative with a proton on a neighboring aromatic ring.

Progression of Pneumocystis carinii infection in an animal model

The development of Pneumocystis carinii infection in immunosuppressed rats is important not only in understanding the infection, but also as a source of P. carinii antigen for use in diagnostic serological tests. The aims of this study were to monitor the progression of P. carinii infection in the Sprague Dawley rat model and then determine parameters that indicate the maximum production of P. carinii antigen. Seventeen Sprague Dawley rats were killed at intervals up to 9 weeks after the start of immunosuppressive therapy. The progression of P. carinii lung infection was observed by Giemsa staining of lung imprints and by a hemi-nested polymerase chain reaction (PCR). Body weight, food and water intake and the appearance and activity of the rats were measured daily. Seven control rats were kept under the same conditions. P. carinii infection was detected in the lung 2 weeks after immunosuppression by hemi-nested PCR and after 3 weeks by Giemsa staining. No P. carinii DNA was detected in any of the blood samples. Rats with moderate or severe lung infection had been immunosuppressed for > or = 6 weeks. Body weight was significantly greater in control rats than in the immunosuppressed rats. Six weeks of immunosuppression was used as a cut-off to determine measurements to identify those rats with moderate or severe infections in their lungs. A combination of > 34% body weight loss at 6 weeks after immunosuppression and the condition of the animals with scores < or = 9 used in conjunction with duration of immunosuppression may be useful to maximise the yield of P. carinii infection from individual rats.

Self-reported adherence, management behavior, and barriers to care after an emergency department visit by inner city children with asthma

OBJECTIVE

The inability to adhere to a prescribed therapeutic program for the treatment of a chronic disease may be responsible in part for continued disease activity. This problem may be more of an issue in the treatment of asthma, a common, potentially lethal chronic condition in which the lack of symptoms may be interpreted as remission. Adherence was one of the key areas of interest for the National Cooperative Inner-City Asthma Study. The focus of this study was to identify those issues reported by families that could adversely affect their adherence to an asthma care program. The identification of barriers to adherence could then form the basis of a successful intervention program. This study describes barriers to adherence, asthma management behavior, and self-reported adherence.

METHODS

Patients presenting during an acute attack of asthma at an emergency department (ED) were recruited for this study. The medical record of the ED encounter was abstracted and compared with information that was obtained during a baseline interview 3 to 5 weeks later. During the baseline interview, parents were asked about health care behaviors related to adherence.

RESULTS

There were 344 children 4 to 9 years of age living in inner city census tracts in the study. Four areas of adherence (medicine use, appointment-keeping, emergency actions, and asthma attack prevention) were investigated. The parental report of medications prescribed at the ED and the information on the abstracted ED report agreed 94.9% of the time for the beta-agonists, 86.8% for steroids, and 69.4% for cromolyn. Among respondents, 85.4% of parents reported that they are able to follow the ED recommendations almost all of the time; side effects of medicines were a concern for 81.1% of caretakers who were adherent and for 89.5% of caretakers who were nonadherent. Doubts regarding the usefulness of medications occurred in 34.4% of those considered adherent and 54.2% who admitted nonadherence. Medications were forgotten some of the time by 45.2% of the children, and 52.8% tried to get out of taking medicine. Appointments for follow-up care were kept by 69% of those given an appointment in the ED, by an estimated 60.0% of those who were told specifically to call for an appointment, and by an estimated 25.2% of those who were neither given an appointment nor told specifically to make one. Only one third of parents report that they were able to keep the child away from known asthma triggers nearly all of the time. Approximately half avoided allergens; however, only 37.5% reported avoidance of cigarette smoke. The use of preventive medicines occurred in 23.5%. Using a medicine and taking the child to a physician were reported as the first or second action during an acute attack of asthma by 72.1% of respondents.

CONCLUSIONS

Adherence to an asthma-management program involves a number of areas: medication, appointment-keeping, prevention, and applying an emergency plan of action. Barriers to adherence may exist in one or all four of these areas, leading to ineffective control of asthma. Recommendations are made for improving the patient-physician partnership to improve adherence.