Another smoking hazard: raised serum IgE concentration and increased risk of occupational allergy

Individual smoking histories of a general population sample and of two groups of workers exposed to occupational allergens were related to serum IgE concentrations and results of radioallergosorbent and prick tests in the workers. The geometric mean IgE concentration was higher in smokers than in non-smokers. The distribution of serum IgE values in the two groups showed an apparent difference, with a bimodal appearance in the smokers. Evidence of sensitisation against occupational allergens was more common in workers who smoked. The adjuvant effect of smoking on IgE antibody production might be due to damage to airways mucosa and supports the mucosal theory of atopy.

Predictive value of novel stimuli modifies visual event-related potentials and behavior

OBJECTIVE

We examined how behavioral context influences novelty processing by varying the degree that a novel event predicted the occurrence of a subsequent target stimulus.

METHODS

Visual event-related potentials (ERPs) and reaction times (RTs) were recorded in 3 detection experiments (23 subjects). The predictive value of a novel stimulus on the occurrence of a subsequent target was varied as was novel-target pairing intervals (200-900 ms). In Experiment 1, novel stimuli always preceded a target, in Experiment 2, 40% of novel stimuli were followed by a target, and in Experiment 3, novel stimuli occurred randomly.

RESULTS

In Experiment 1, RTs following 100% predictive novels were shortened for targets at all spatial locations and novel-target pairing intervals. Novel stimuli predicting a target generated a central negativity peaking at 300 ms and reduced P3a and P3b ERPs. In Experiments 2 and 3, target RTs were prolonged only when novel and target stimuli were presented in the same spatial location at short ISIs (200 ms). The central novel N2 was smaller in amplitude in comparison to Experiment 1, and novelty P3a and target extrastriate N2 and posterior scalp P3b ERPs were enhanced.

CONCLUSIONS

The enhanced N2 for 100% predictive novel stimuli appears to index an alerting system facilitating behavioral detection. The same novel stimuli with no predictive value distract attention and generate a different ERP pattern characterized by increased novelty P3a and target P3b responses. The results indicate that behavioral context determines how novel stimuli are processed and influence behavior.

Predicting outcomes and complications of percutaneous endoscopic gastrostomy

BACKGROUND AND STUDY AIMS

Percutaneous endoscopic gastrostomy (PEG) is the preferred route for long-term enteral feeding. Our aims were to prospectively evaluate the outcome ("PEG status") and complications of PEG and to determine whether these can be predicted by patients' baseline characteristics.

PATIENTS AND METHODS

We conducted a prospective study in two tertiary hospitals between August 2003 and January 2005, enrolling all patients who were undergoing PEG placement. We completed a questionnaire with details of demographic data, diagnosis, indication for PEG, Charlson's co-morbidity index, Barthel's index, laboratory tests, complications, and date and cause of death. Patients were followed at scheduled appointments. Univariate and multivariate analyses were performed.

RESULTS

168 patients (48% male, 52% female; mean age +/- standard deviation 74 +/- 16 years) underwent PEG using the pull technique. The main indication was neurogenic dysphagia (156 patients, 92.9%). Although most indications were appropriate, in half the cases these were established too late. There were no procedure-related deaths. Major complications occurred in four patients (2.4%); minor complications occurred in 52 patients (31%). No single variable could predict complications. Fifteen patients (9%) had the PEG removed. No single variable was independently associated with PEG removal. The mortality was 6.5% at 30 days, 17.3% at 90 days and 33.9% at 1 year. The C-reactive protein was the only predictive factor of early mortality (< or = 30 days), and Charlson's co-morbidity index was the only predictive factor of late mortality (> 30 days).

CONCLUSIONS

PEG placement is an easy and safe procedure, although it is often requested too late. No single variable could predict complications or PEG removal. C-reactive protein was found to be predictive of early mortality and Charlson's index was predictive of late mortality.

Factors in the development of secondary hyperparathyroidism during graded renal failure in the rat

Secondary hyperparathyroidism (2 degree HPT) develops as a result of renal failure. Hypocalcemia, phosphorus retention, calcitriol deficiency and skeletal resistance to the calcemic action of parathyroid hormone (PTH) are closely interrelated pathogenic factors important for the development of 2 degrees HPT in renal failure. Since previous studies have mainly focused on advanced renal failure, only limited data are available in early renal failure. The goal of the present study was to evaluate how alterations in the dietary calcium and phosphorus composition affect the factors known to contribute to the genesis of 2 degrees HPT in early and more advanced renal failure. To achieve this goal, graded differences in renal function were surgically induced in 453 rats while the dietary content of calcium and phosphorus was varied. Three different diets were used: (1) a high phosphorus diet (HPD), to induce phosphorus retention and stimulate 2 degrees HPT; (2) a high calcium diet (HCaD), to inhibit calcitriol synthesis; and (3) a moderate calcium-moderate phosphorus diet (MCaPD), to separate the effects of high dietary phosphorus and calcium. Based on the serum creatinine (SCr) concentration rats were assigned to one of four different groups: (1) normal renal function (SCr < or = 0.3 mg/dl); (2) mild renal failure (SCr 0.4 to 0.6 mg/dl); (3) moderate renal failure (SCr 0.7 to 0.8 mg/dl); or (4) advanced renal failure (SCr > or = 0.9 mg/dl). As the severity of renal failure increased, progressive 2 degrees HPT developed in each of the dietary groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Spatial repetition blindness is modulated by selective attention to color or shape

Subjects reported either the colors or shapes of two simultaneous masked letters. Our first study found that they were less accurate when the reported features were identical ("repetition blindness," or RB), while repetition along the unreported dimension had no effect. Three follow-up studies confirmed that when the same dimension was judged (overtly or covertly) for both stimuli, performance was only affected by repetition along that dimension. However, when different dimensions were judged for the two stimuli, performance was affected by repetition on both dimensions. These findings support new conclusions about both RB and visual attention. First, RB depends critically on visual attention, rather than simply on the stimulus presented or the overt response required. Second, while attention can be restricted to a single visual dimension, this is efficient only when the same dimension is selected for both objects. Selecting the color of one object and the shape of another simultaneous object results in both dimensions being accessed for both objects.

The combined effects of undersized drilling and implant macrogeometry on bone healing around dental implants: an experimental study

This study investigated the effect of undersized preparations with two different implant macrogeometries. There were four experimental groups: group 1, conical implant with an undersized osteotomy of 3.2mm; group 2, conical implant with an undersized osteotomy of 3.5mm; group 3, cylindrical implant with an undersized osteotomy of 3.2mm; group 4, cylindrical implant with an undersized osteotomy of 3.5mm. Implants were placed in one side of the sheep mandible (n=6). After 3 weeks, the same procedure was conducted on the other side; 3 weeks later, euthanasia was performed. All implants were 4mm×10mm. Insertion torque was recorded for all implants during implantation. Retrieved samples were subjected to histological sectioning and histomorphometry. Implants of groups 1 and 2 presented significantly higher insertion torque than those of groups 3 and 4 (P<0.001). No differences in bone-to-implant contact or bone area fraction occupied were observed between the groups at 3 weeks (P>0.24, and P>0.25, respectively), whereas significant differences were observed at 6 weeks between groups 1 and 2, and between groups 3 and 4 (P<0.01). Undersized drilling affected the biological establishment of bone formation around both dental implant macrogeometries.

Improvement of parameters of freezing medium and freezing protocol for bull sperm using two osmotic supports

The aim of this study was to improve the freezing protocol of bull sperm, by investigating the influence on sperm viability after freeze/thawing of different freezing medium components, as well as the effect of cooling rates in the different stages of the cooling protocol, in single factor experiments. The experimental variables were: (1) salt-based versus a sugar-based medium (Tris versus sucrose); (2) glycerol concentration; (3) detergent (Equex) concentration; (4) presence of bicarbonate; (5) rate of cooling from 22 degrees C to holding temperature (CR1); (6) holding temperature (HT); (7) rate of cooling from holding temperature to -6 degrees C (CR2); (8) rate of cooling from -10 to -100 degrees C (CR3). All experiments were performed using five bulls per experiment (three ejaculates per bull). Sperm motility after freezing and thawing was assessed by CASA system, and sperm membrane integrity was assessed by flow cytometry. Sucrose-based medium did not offer a clear significant benefit compared to Tris medium. The concentration of Equex that gave the best results in Tris-based media group and sucrose-based media group was in a range between 2-7 and 4-7 g/l, respectively. In both media groups, a glycerol concentration of 800 mM was the best in any post-thaw viability parameters. In the Tris media group, the presence of bicarbonate had a negative effect on sperm viability. CR1 and CR2 had no significant effect on any of the post-thaw sperm viability parameters, but a CR1=0.2 degrees C/min and CR2=4 degrees C/min appeared to give better results in both media. The holding temperature (HT) that gave the best results was found to be in the range of 5-9 degrees C. There was a significant disadvantage of using a low CR3 of 10 degrees C/min, while 150 degrees C/min appeared to be the best cooling rate for either medium.

A novel post-translational modification of yeast elongation factor 1A. Methylesterification at the C terminus

Protein methylation reactions can play important roles in cell physiology. After labeling intact Saccharomyces cerevisiae cells with S-adenosyl-l-[methyl-(3)H]methionine, we identified a major methylated 49-kDa polypeptide containing [(3)H]methyl groups in two distinct types of linkages. Peptide sequence analysis of the purified methylated protein revealed that it is eukaryotic elongation factor 1A (eEF1A, formerly EF-1alpha), the protein that forms a complex with GTP and aminoacyl-tRNAs for binding to the ribosomal A site during protein translation. Previous studies have shown that eEF1A is methylated on several internal lysine residues to give mono-, di-, and tri-N-epsilon-methyl-lysine derivatives. We confirm this finding but also detect methylation that is released as volatile methyl groups after base hydrolysis, characteristic of ester linkages. In cycloheximide-treated cells, methyl esterified eEF1A was detected largely in the ribosome and polysome fractions; little or no methylated protein was found in the soluble fraction. Because the base-labile, volatile [methyl-(3)H]radioactivity of eEF1A could be released by trypsin treatment but not by carboxypeptidase Y or chymotrypsin treatment, we suggest that the methyl ester is present on the alpha-carboxyl group of its C-terminal lysine residue. From the results of pulse-chase experiments using radiolabeled intact yeast cells, we find that the N-methylated lysine residues of eEF1A are stable over 4 h, whereas the eEF1A carboxyl methyl ester has a half-life of less than 10 min. The rapid turnover of the methyl ester suggests that the methylation/demethylation of eEF1A at the C-terminal carboxyl group may represent a novel mode of regulation of the activity of this protein in yeast.

Hydroxylapatite cranioplasty directly over dura

Seven patients who had noticeable defects of their frontal bone were reconstructed with dense hydroxylapatite (HA) particles with or without autogenous bone placed directly over the dura. The results indicate that HA is well tolerated over dura; no meningitis occurred with follow-up of one to 3 1/2 years. The clinical response was excellent and complications were minor, generally related to particle control and settling.

Strategic control over saccadic eye movements: studies of the fixation offset effect

We studied the strategic (presumably cortical) control of ocular fixation in experiments that measured the fixation offset effect (FOE) while manipulating readiness to make reflexive or voluntary eye movements. The visual grasp reflex, which generates reflexive saccades to peripheral visual signals, reflects an opponent process in the superior colliculus (SC) between fixation cells at the rostral pole, whose activity helps maintain ocular position and increases when a stimulus is present at fixation, and movement cells, which generate saccades and are inhibited by rostral fixation neurons. Voluntary eye movements are controlled by movement and fixation cells in the frontal eye field (FEF). The FOE--a decrease in saccade latency when the fixation stimulus is extinguished--has been shown to reflect activity in the collicular eye movement circuitry and also to have an activity correlate in the FEF. Our manipulation of preparatory set to make reflexive or voluntary eye movements showed that when reflexive saccades were frequent and voluntary saccades were infrequent, the FOE was attenuated only for reflexive saccades. When voluntary saccades were frequent and reflexive saccades were infrequent, the FOE was attenuated only for voluntary saccades. We conclude that cortical processes related to task strategy are able to decrease fixation neuron activity even in the presence of a fixation stimulus, resulting in a smaller FOE. The dissociation in the effects of a fixation stimulus on reflexive and voluntary saccade latencies under the same strategic set suggests that the FOEs for these two types of eye movements may reflect a change in cellular activity in different neural structures, perhaps in the SC for reflexive saccades and in the FEF for voluntary saccades.

Artificial intelligence for diagnostic and prognostic neuroimaging in dementia: A systematic review

INTRODUCTION

Artificial intelligence (AI) and neuroimaging offer new opportunities for diagnosis and prognosis of dementia.

METHODS

We systematically reviewed studies reporting AI for neuroimaging in diagnosis and/or prognosis of cognitive neurodegenerative diseases.

RESULTS

A total of 255 studies were identified. Most studies relied on the Alzheimer's Disease Neuroimaging Initiative dataset. Algorithmic classifiers were the most commonly used AI method (48%) and discriminative models performed best for differentiating Alzheimer's disease from controls. The accuracy of algorithms varied with the patient cohort, imaging modalities, and stratifiers used. Few studies performed validation in an independent cohort.

DISCUSSION

The literature has several methodological limitations including lack of sufficient algorithm development descriptions and standard definitions. We make recommendations to improve model validation including addressing key clinical questions, providing sufficient description of AI methods and validating findings in independent datasets. Collaborative approaches between experts in AI and medicine will help achieve the promising potential of AI tools in practice.

HIGHLIGHTS

There has been a rapid expansion in the use of machine learning for diagnosis and prognosis in neurodegenerative disease Most studies (71%) relied on the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset with no other individual dataset used more than five times There has been a recent rise in the use of more complex discriminative models (e.g., neural networks) that performed better than other classifiers for classification of AD vs healthy controls We make recommendations to address methodological considerations, addressing key clinical questions, and validation We also make recommendations for the field more broadly to standardize outcome measures, address gaps in the literature, and monitor sources of bias.

Factors influencing the occurrence of late bronchial reactions after allergen challenge

Forty-seven patients with allergic bronchial asthma were challenged with the relevant allergen. Forty-eight per cent of the provocations resulted in a positive immediate reaction followed by a late bronchial response. Late bronchial obstruction was more common among patients with a high than with a low RAST score. Ten patients were challenged with different allergens on two different occasions, but the same type of bronchial response was observed in only six of them. Nine patients with an isolated immediate response were rechallenged with higher allergen doses, the early bronchial response being partially counteracted by terbutaline inhalations in clinically appropriate doses before and during the inhalation of allergen. The treatment alleviated the early reaction in six of the patients. A late reaction occurred in all patients with an immediate response. The non-specific bronchial reactivity to methacholine was assessed in 24 patients before allergen challenge. No relation was found between this reactivity and the observed patterns of reactions to allergen. It was concluded that the occurrence of a late bronchial response probably depends on the dose of allergen administered but is independent of the degree of unspecific bronchial responsiveness to methacholine prior to the challenge.

Isolated pericardial effusion in the human fetus: a report of three cases

OBJECTIVE

Our objective was to determine the possible underlying etiologies and outcome in isolated fetal pericardial effusion.

METHODS

Doppler fetal echocardiography allowed the diagnosis of pericardial effusion in three patients and revealed the etiology in two.

RESULTS

We present the findings in three cases of isolated pericardial effusion. In the first, the pericardial effusion was a manifestation of trisomy 21 associated with a myeloproliferative disorder. In the second, the pericardial fluid collection was the first sign of an autosomal recessive disease, idiopathic infantile arterial calcification. The third case was remarkable because of the spontaneous resolution of a large pericardial fluid collection.

CONCLUSION

Isolated fetal pericardial effusion covers a wide spectrum of etiologies from severe genetic and chromosomal diseases to transient forms.

A rare association of synchronous intraductal carcinoma of the breast and invasive carcinoma of ectopic breast tissue of the vulva: case report and literature review

Only 17 cases of breast carcinoma arising in vulvar ectopic mammary tissue have been reported. We present a unique case of synchronous pure intraductal carcinoma of the breast (DCIS) and invasive carcinoma of ectopic breast tissue of the vulva. A 53-year-old woman presented with a 2-cm nodule in left labium major of the vulva. A surgical biopsy revealed an invasive carcinoma of ectopic mammary tissue. The mammography showed irregular microcalcifications of the right breast. The patient underwent left hemivulvectomy, bilateral inguinal sentinel lymph node biopsy, and radioguided breast resection (radioguided occult lesion localization) of the microcalcifications. The definitive histology revealed negative inguinal sentinel nodes, no further residual tumor in the vulva, and a high-grade (grade 3) DCIS in the breast. The synchronous occurrence of primary breast carcinoma and ectopic breast tissue carcinoma in the vulva is an extremely rare finding, only once previously being reported and leading to unsolved problems of differential diagnosis. The presence of a pure DCIS of the breast makes this case really unique, definitively confirming the independent primary origin of both mammary tumors. The inguinal sentinel node biopsy avoided a bilateral inguinal dissection.

Occupational allergy in nurses to a bulk laxative

Finely ground psyllium (Plantago ovata) seeds, so-called ispaghula powder is used in bulk laxatives. During the dispensing of these medicines some dust is generated. Allergic symptoms from exposure to this dust was reported by two nurses, one of whom was wroking in a department where exposure to the powder could be considered high. Nineteen other subjects working in the same department were investigated with regard to allergy to ispaghula powder. An extract from ispaghula powder was made and used in RAST and skin tests. Exposure tests with ispaghula powder mixed with crushed rusks were made in symptomatic subjects. Eight out of the 20 investigated subjects from this department reported symptoms which could possibly have been elicited by ispaghula powder. Evidence of sensitization was found in five of them. The use of less dusty (granulated) forms of ispaghula laxatives might diminish the risk of sensitization.

Control of eye movement reflexes

We investigated the effect of strategic suppression of reflexive eye movements on external control over fixation using a fixation offset paradigm. A visual signal at fixation facilitates the fixation reflex and inhibits eye movements. Certain preparatory states render the fixation reflex less reactive to visual stimulation at fixation, as evidenced by a reduction in the fixation offset effect (FOE). For example, past studies have suggested that the reduced FOE during anti-saccade tasks results from the requirement to inhibit reflexive eye movements. We tested whether suppressing reflexive saccades reduces external control over ocular fixation using a go-nogo saccade paradigm. During each trial, one of two targets appeared in the periphery. Participants were instructed to saccade to one target (go), but when the other target appeared they either had to maintain fixation (nogo) or move their eyes in the direction opposite the target (anti). When nogo trials were admixed with target-directed saccades a large FOE was observed compared to when target-directed saccades occurred alone (experiment 1); however, when anti-saccades were mixed with target-directed saccades, a small FOE was observed for both types of eye movements (experiment 2). We conclude that suppressing reflexive eye movements does not reduce external control over fixation. Further research is necessary to elucidate which other component of preparing to make an anti-saccade diminishes the FOE.

Comparison of clinical significance and allergenic cross-reactivity of storage mites Blomia kulagini and Lepidoglyphus destructor in Sweden and Brazil

Comparison of the clinical significance and allergenic cross-reactivity of Blomia kulagini (B. kulagini) and Lepidoglyphus destructor (L. destructor) was made on sera from Sweden and Brazil using the radio-allergo-sorbent test (RAST) and the RAST inhibition technique. RAST-positive sera were obtained from 53 allergic Swedish farmers and 31 allergic subjects from Brazil who were positive to B. kulagini and/or L. destructor. B. kulagini was shown to be a common cause of sensitization especially in Brazil. There was a fairly high correlation between positive RAST results to L. destructor and B. kulagini based on sera from both Sweden and Brazil. The highest RAST scores were found against L. destructor in Swedish sera and against B. kulagini in Brazilian sera. The RAST inhibition studies showed that the L. destructor extract was able to inhibit the B. kulagini system (a positive RAST to B. kulagini allergen disc) in Swedish but not in Brazilian sera. In contrast, the B. kulagini extract was only able to inhibit the L. destructor system in sera from Brazil and not in sera from Sweden. This study shows that results obtained with RAST inhibition are not entirely dependent on the overall specificity of the IgE antibodies in the patient's sera, since the more subtle specificity of the primarily sensitizing allergen will dominate. Thus, conclusions drawn regarding allergenic cross-reactivity are dependent on the populations tested, and conclusions on the existence or absence of cross-reactivity, e.g. between two species of mites may be contradictory.

Laparoscopic vaginoplasty: using a sliding peritoneal flap for correction of complete vaginal agenesis

In this technique of peritoneal neo-vaginoplasty, the recto-vesical space is dissected through the vulva under synchronous laparoscopic monitoring. Then the cranial limit of the pelvic peritoneum is incised circumferentially by laparoscopic approach and the two circular edges sutured sequentially. The isolated pelvic peritoneal sleeve is opened inferiorly and sutured to introital mucosal flaps.

Accomplishing esthetics using enamel microabrasion and bleaching-a case report

This case report describes the sequential steps that were used to treat unesthetic, white, hard-texture enamel stains of unknown etiology. A tapered fine diamond bur was used to remove superficial enamel followed by the use of an enamel microabrasion compound Opalustre (Ultradent Products Inc). This technique removed the stains and was followed by polishing with a fluoride paste to restore the enamel to a smooth finish. The teeth were subsequently bleached with carbamide peroxide (Opalescence 10%, Ultradent Products), which achieved the patient's desired esthetic results.

Increased bronchial hypersensitivity after early and late bronchial reactions provoked by allergen inhalation

The non-specific bronchial reactivity following bronchial allergen challenge was studied in 40 patients with allergic bronchial asthma, particularly in subjects without definite late reactions 6 h after the provocations (reduction in peak expiratory flow or forced expiratory volume in 1 s of less than 15% of the control value at this time). Among a group of 21 patients submitted to bronchial provocation tests, 13 carried out maximal exercise tests 6 and 1 week after the allergen challenge. In another group of 19 patients, the bronchial hyperreactivity to methacholine was assessed before and 6 h and 1 week after challenge. Two patients with a dual response (early & late) reacted with bronchial obstruction to the exercise. Exercise tests performed after 1 week did not provoke asthma in any patient. In the methacholine group a marked increase in responsiveness to methacholine 6 h after the provocation was observed in those patients with a dual response who were tested and in those with equivocal late reactions and even in three patients with an isolated immediate reaction. The increases responsiveness was still present in many patients 1 week after challenge. The airway caliber did not influence the degree of responsiveness to methacholine. Nor did the degree of responsiveness have any influence on the patterns of reactions observed after allergen exposure. It was concluded that in some individuals exposure to the relevant allergen predisposes them to exercise-inducible bronchial obstruction. Further, it was confirmed that non-specific bronchial reactivity can be increased not only in patients with late responses - both definite and equivocal--but also in some patients with immediate reactions alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of lesions of the human posterior thalamus on ocular fixation during voluntary and visually triggered saccades

OBJECTIVE

To investigate the role of the posterior thalamus in controlling voluntary and visually triggered eye movements and ocular fixation.

METHODS

The latency to initiate saccades to peripheral targets (visually triggered) and in response to verbal commands (voluntary) was measured in three patients with unilateral lesions of the posterior thalamus, in normal controls, and in neurological controls with Parkinson's disease. On half the trials a fixation point offset simultaneously with target onset, and on half it remained visible.

RESULTS

Offset of the fixation point simultaneous with target onset decreased saccade latency for both voluntary and visually triggered eye movements in controls, but only for voluntary saccades in patients with thalamic lesions.

CONCLUSIONS

These findings suggest that separate neural systems control fixation when making voluntary and visually triggered eye movements, and that the thalamus is involved in the control of fixation for visually triggered but not for voluntary saccades.

Immune response to Blomia kulagini and Dermatophagoides pteronyssinus in Sweden and Brazil

The immune responses to the non-pyroglyphid mite Blomia kulagini and the pyroglyphid mite Dermatophagoides pteronyssinus were compared in 440 Swedish farmers and 34 allergic subjects from Brazil using the radioallergosorbent test (RAST). Both B. kulagini and D. pteronyssinus were shown to be a common cause of sensitization, particularly in Brazil. The highest RAST scores were found against D. pteronyssinus in sera from both countries. Allergenic cross-reactivity between the two mites was studied by the RAST inhibition technique. Both B. kulagini and D. pteronyssinus possess their own unique allergens as well as allergens in common. Thus, besides mites belonging to the Dermatophagoides genus, other pyroglyphid and non-pyroglyphid mites in different countries should be taken into consideration before starting hyposensitization treatments.

Early and late allergic bronchial reactions: physiological characteristics

Twenty-four patients with asthma of suspected allergic origin were subjected to a total of twenty-five bronchial provocations with the relevant allergen. Eighteen of them reacted with bronchial obstruction: eleven with an isolated early reaction, five with a dual reaction and two with only a late reaction. Extensive lung function tests were performed. The patterns of early and late reactions were qualitatively very similar regarding variables of pulmonary physiological function, but there were quantitative differences. Patients with dual reactions showed significantly greater changes in FEV1, RV and TGV during the early response than those with isolated early reactions. Maximum mid-expiratory flow rates with the patients breathing air and a mixture of He and O2 were measured before and 6 hr after the challenges. Four of five patients with both an immediate and a late response showed a decrease in the response to helium during the latter phase, suggesting increasing involvement of the small airways. An increase in the slope of the alveolar plateau (phase III) was observed in four of the five patients with dual responses and all five had increased CC%. It was concluded that the changes in pulmonary function occurring during the dual responses were widespread, involving the airways generally and resembling those in the clinically more severe asthma. Usually, individuals with dual reactions showed stronger reactions. In two cases, however, a late reaction was obtained without any preceding early reaction.

The relationship between serum calcitonin and calcium in the hemodialysis patient

An increase in the serum calcium level is known to stimulate calcitonin secretion, but whether calcitonin contributes to calcium regulation in the dialysis patient is not known. Because we recently observed in the rat that (1) a sigmoidal calcitonin-calcium curve was present, and (2) calcitonin stimulation decreased the calcemic response to parathyroid hormone (PTH), the relationship between serum calcitonin and calcium was studied in six hemodialysis patients. To evaluate both the calcitonin-calcium and PTH-calcium relationships, hemodialysis with a low-calcium dialysate (2 mg/dL) was performed and followed 1 week later by hemodialysis with a high-calcium dialysate (8 mg/dL). The calcitonin-calcium relationship was best represented as a sigmoidal curve that was opposite in direction to the PTH-calcium curve. The range of the calcitonin-calcium curve was less than the PTH-calcium curve; as a percent of maximal, the minimal calcitonin was higher than the minimal PTH, 61% +/- 5% versus 26% +/- 4% (P < 0.001). As opposed to the PTH-calcium curve in which the basal PTH value was intermediate between the minimal and maximal PTH, the basal calcitonin value was close to the minimal calcitonin. Despite a wide range of ionized serum calcium concentrations (3.5 to 5.3 mg/dL), maximal stimulation was greater than maximal inhibition of calcitonin, 60% +/- 13% versus 3% +/- 2% (P = 0.01). Finally, a significant correlation was observed between basal and maximal calcitonin (r = 0.99, P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)