Low temperature aqueous electrospray ionization mass spectrometry of noncovalent complexes

In the present study we describe conditions that permit the characterization of noncovalent protein-substrate complexes in aqueous solution by microspray electrospray ionization-mass spectrometry (ESI-MS), using a heated transfer capillary at low temperature (45 degrees C). Specifically, we examined the binding of calmodulin to two polypeptides; the calmodulin-binding domain of calmodulin-dependent protein kinase II (CamK-II) and melittin. Calmodulin, a well known calcium-binding protein, binds to a number of small amphipathic peptides in a calcium-dependent manner. Our results directly show that both peptides form equimolar complexes with calmodulin only in the presence of calcium. The stoichiometry necessary for the formation of each complex was 1:1:4 for calmodulin:peptide (melittin or CamK-II):Ca2+, respectively. Furthermore, it is demonstrated that the detection of the complex in ESI-MS is source temperature dependent.

Hypersensitivity myocarditis caused by an allergic reaction to cefaclor

An adolescent girl was seen with acute heart failure 6 days after the onset of a viral illness and otitis media treated with cefaclor. An endomyocardial biopsy specimen revealed active myocarditis with an eosinophilic infiltrate typical of hypersensitivity myocarditis. The patient showed dramatic improvement within 48 hours after withdrawal of the drug and administration of corticosteroids and immunoglobulin.

A phase I trial and pharmacokinetic evaluation of CI-980 in patients with advanced solid tumors

CI-980 is a synthetic mitotic inhibitor that binds to the colchicine binding site of tubulin. It demonstrates broad activity against human and murine tumor models and shows no cross resistance with tumor models whose mechanism of resistance is mediated by P-glycoprotein (MDR-1). A phase I study was completed in 25 patients with solid tumors using a 24-hour infusion schedule, with courses repeated every 3 weeks. Eight dose levels were tested between 1.2 and 15.6 mg/m2. The maximum tolerated dose was 14.4 mg/m2. Neutropenia was dose-related but not dose-limiting; thrombocytopenia was infrequent. CNS toxicities were dose-limiting and consisted of dizziness, headache, loss of coordination, loss of consciousness, nervousness, and other symptoms. These events occurred near the end of the infusion and were reversible, usually within 24 hours. One patient who was to be treated at dose level 8 (intended dose was 19.2 mg/m2; actual dose was 15.6 mg/m2) became encephalopathic prior to completion of the infusion. Other adverse events included gastrointestinal toxicities (nausea, vomiting, anorexia, constipation, stomatitis, dyspepsia, bleeding, cheilitis), IV site erythema, fever, and fatigue. A partial response was observed in one patient with colon cancer and reductions in CA-125 levels were observed in 2 patients with ovarian cancer. Pharmacokinetics were linear and dose-proportional. Results indicate high systemic clearance and wide tissue distribution. Mean pharmacokinetic parameter values: T1/2 = 5.52 hours, plasma clearance 1163 mL/min/m2, and Vdss 376 L/m2.

Complication of ventricular demand pacing after orthotopic heart transplantation: unusual case of pacemaker syndrome in an infant

BACKGROUND

Sinus node dysfunction is the most common indication for antibradycardiac permanent pacing after heart transplantation. Lack of atrioventricular synchrony during pacing can result in symptoms ranging from mild chest discomfort to severe manifestations such as dyspnea, hypotension, and cardiovascular collapse, all of which are ascribed to pacemaker syndrome. In infants pacemaker syndrome is often only recognized in the face of marked hemodynamic compromise.

RESULTS

This report details an unusual account of pacemaker syndrome in an infant after orthotopic heart transplantation.

CONCLUSIONS

Careful assessment of atrioventricular synchrony is important after infant transplantation.

Supramitral valve obstruction from hypertrophied native atrial tissue as a complication of orthotopic heart transplantation

An acquired form of cor triatriatum, resulting in significant supramitral valve obstruction, complicating a pediatric orthotopic heart transplantation was diagnosed by transesophageal echocardiography. Surgical resection of the hypertrophied atrial septum and atrial wall corrected the anatomic obstruction and improved the hemodynamics.

Balloon angioplasty of recurrent coarctation: a 12-year review

OBJECTIVES

This study was undertaken to investigate the long-term outcome of balloon angioplasty for recurrent coarctation of the aorta in a large series of patients.

BACKGROUND

Balloon angioplasty has become the standard treatment for residual or recurrent aortic coarctation. Despite the widespread use of this treatment modality, there are few data outlining the long-term outcome of a large patient cohort.

METHODS

Clinical, echocardiographic, hemodynamic and angiographic data on 90 consecutive patients who underwent balloon angioplasty between January 1984 and January 1996 were reviewed.

RESULTS

Mean systolic pressure gradients were reduced from 31 +/- 21 to 8 +/- 9 mm Hg after dilation (p = 0.0001). The mean diameter of the stenotic site, measured in the frontal and lateral views, increased by 38% and 35%, respectively (p = 0.001). Neurologic events occurred in two patients, with one death. An aortic tear occurred in one patient, requiring surgical intervention. Optimal results were defined as a postprocedure gradient < 20 mm Hg and were obtained acutely in 88% of patients. At long-term follow-up (12 years), 53 (72%) of 74 patients with an early optimal result remained free from reintervention. Transverse arch hypoplasia, defined as an arch dimension < 2 SD below the mean for age, was the primary predictor of the need for reintervention.

CONCLUSIONS

Although the majority of patients undergoing percutaneous balloon angioplasty for recoarctation of the aorta will achieve long-term benefit, the need for further surgical intervention in those with transverse arch hypoplasia remains high.

HMO partnering: the provider dilemma

While the growth of HMOs has slowed patient visits to doctors, it also has created a deluge of press clippings. On July 16, 1996, three articles on the subject appeared in the Wall Street Journal, front section. The headlines painted a vivid picture of the forces acting on HMOs and providers alike (Figure 1). The articles portended more change for healthcare. The "shake-out," a term applied to industries in serious transformation, brings shedding of excess capacity and loss of jobs and income. Providers, in particular, find themselves in a difficult dilemma. They must not only cut costs as reimbursement drops, but also retain patients with good outcomes and high quality service. Patient retention means keeping the individual patient from switching to another provider and keeping the insurer's group of patients as an authorized provider for that insurer. The relationship between provider and HMO lies at the heart of the provider dilemma. The HMO structure, which shifts financial risk for care, is quickly setting the standard, for healthcare pricing, medical standards, and management practices. Understanding and responding to HMO needs are vital to competitive advantage and survival. The article discusses the inherent dilemma of HMO and provider partnering and suggests provider responses.

Natural history of Alström syndrome in early childhood: onset with dilated cardiomyopathy

Alström syndrome is an autosomal recessive disorder characterized by cone-rod dystrophy, obesity, hearing impairment, and diabetes caused by insulin resistance. By reviewing the charts of eight patients followed for periods of 2 to 22 years, we established the natural history of this syndrome during childhood. Five patients, in four families, were seen between the ages of 3 weeks and 4 months with a dilated cardiomyopathy, a previously unrecognized feature of the syndrome. Photophobia and nystagmus were first documented in the eight patients between the ages of 5 months and 15 months. In all patients, electroretinography initially showed a severe cone impairment with mild (2/8) or no (6/8) rod involvement. Electroretinograms, obtained again at ages 9 to 22 years for four patients, revealed extinguished rod-and-cone responses. Obesity developed during childhood in seven patients, in at least three of them before age 2 years. Hearing impairment (5/8) and diabetes/glucose intolerance (4/8) were diagnosed at the end of the first decade or during the second decade. This constellation of features should facilitate early diagnosis of the syndrome.

An additional mitochondrial tRNA(Ile) point mutation (A-to-G at nucleotide 4295) causing hypertrophic cardiomyopathy

A third point mutation in the mitochondrial tRNA(Ile) gene associated with hypertrophic cardiomyopathy and respiratory chain dysfunction in heart is reported. An A-to-G transition at nucleotide position 4295 was shown to be highly evolutionarily conserved, never present in control individuals, and to segregate with the disease. A PCR-based diagnostic test and endomyocardial biopsies were used to detect both the biochemical deficiency and the level of heteroplasmy in heart. The implications of this new mitochondrial DNA point mutation are discussed.

Nurses' perceptions of their role and role conflicts

Nurses' perceptions of their professional role and their experience of role conflict were explored in a sample of certified general rehabilitation nurses. Nonnurse healthcare professionals who are on the same teams as the participating nurses also were assessed for their expectations of the nurse's role. The level of locus of control was identified among the various professions. The major finding of the study was that the rehabilitation nurses shared a consistent view of their professional role and of how they believed other professionals saw this role. The results showed that the nonnurse professionals were to some extent unaware of the expectations that the nurses held for the nursing role. There was no appreciable difference in the level of locus of control among team members, a situation which may have a leveling effect on the team dynamics. These findings have implications for professional role clarity, the promotion of locus of control, and interdisciplinary team dynamics.

Cardiac dysfunction late after cardiotoxic therapy for childhood cancer

Despite a wealth of data documenting acute cardiac injury from anthracycline therapy and/or mediastinal radiotherapy used for childhood cancer, little information is available on the long-term consequence of these insults. Twenty-nine patients (mean age 15 +/- 4.3 years) from The Late Effects Follow-Up Clinic For Childhood Cancer study, who had been in continuous, complete remission and off chemotherapy for a minimum of 2 years (mean follow-up 7.2 +/- 3.2) were studied. All patients had normal ejection fractions before and during cancer therapy and all were in New York Heart Association class I at the time of study. Systolic and diastolic functions were assessed by 2-dimensional echocardiography, Doppler flow velocity, and radionuclide angiography, and results were compared with normal control subjects. Left ventricular mass and mass index were significantly reduced in the patient population. Fractional shortening was decreased overall and end-systolic wall stress was much higher in patients than in controls. However, contractility, as assessed by the relation of wall stress to rate-corrected velocity of shortening, was decreased by > or = 2 SDs in only 6 of 28 patients, and the force-mass relation was actually increased in the patient group as a whole. Mitral valve inflow velocities were significantly increased but the pattern was abnormal. These results suggest a pattern consistent with a thin-walled, complaint left ventricle with reduced muscle mass performing under above-normal levels of wall stress. Contractility measurements were normal or increased in the group, but some patients clearly demonstrated development of reduced contractile function.(ABSTRACT TRUNCATED AT 250 WORDS)

Maternally inherited hypertrophic cardiomyopathy due to a novel T-to-C transition at nucleotide 9997 in the mitochondrial tRNA(glycine) gene

We report a unique heteroplasmic T-to-C transition at nucleotide 9997 in the mitochondrial tRNA(glycine) gene in a multiplex family who manifested nonobstructive cardiomyopathy. The degree of mtDNA heteroplasmy generally correlated with the severity of the symptoms. This T-to-C transition disrupts hydrogen bonding in the region adjacent to the acceptor stem of the tRNA molecule. The thymine residue at position 9997 is highly conserved in mammals, as well as in various vertebrates and invertebrates. A PCR diagnostic test for the presence of the 9997 T-to-C transition revealed that the base change was always present in high proportion in affected family members, not present in unaffected family members, and never present in control subjects from various ethnic groups (25 groups sampled, 42 individuals), thus ruling out the possibility that this change represents a polymorphic variant in the general population. The degree of heteroplasmy in lymphoblast cultures also correlated with the level of enzyme activity present for cytochrome c oxidase (complex IV) and succinate cytochrome c oxidoreductase (complexes II and III). The absence of previously reported mtDNA mutations associated with hypertrophic cardiomyopathy was verified by both PCR diagnostic procedures and sequence analysis. All mitochondrial tRNA genes, as well as genes encoding ATPase subunits 6 and 8, were sequenced and found not to possess base changes consistent with the clinical profile. More detailed biochemical and molecular biological investigations are discussed.

Polyethylene glycolated interleukin-2 as maintenance therapy for acute myelogenous leukemia in second remission

Seven patients in second complete remission of acute myeloid leukemia (AML) aged 19-65 years were treated with polyethylene glycolated interleukin-2 (PEG IL-2), 1 x 10(6) U/M2 IV weekly as the sole postremission therapy. Second remission duration was in the range of 4-49+ months, and three patients had a second remission duration substantially longer than their first (6, 21+, and 42+ months). The results suggest that PEG IL-2 may prolong second remission duration in AML and that a prospective randomized study designed to test that idea is warranted.

Heparin therapy in pediatric patients: a prospective cohort study

Current guidelines for heparin therapy in pediatric patients have been extrapolated from trials in adult patients without rigorous evaluation of efficacy and safety. We prospectively monitored consecutive pediatric patients receiving systemic doses of heparin over 10 mo at one institution using a predetermined nomogram to monitor maintenance therapy. Sixty-five consecutive children; 38 males and 27 females, received systemic doses of heparin. Thirty children had deep venous thrombosis and/or pulmonary embolism; 11 had arterial thrombi, most frequently after diagnostic angiography; and the remaining 24 received heparin prophylactically, for congenital heart disease. Twenty-nine (45%) of the 65 patients were less than 1 y of age and 22 (34%) were 10 y or older. Congenital heart disease was the predominant diagnosis under 1 y and deep venous thrombosis in older children. After a bolus dose of 50 U/kg, 39% of children (n = 30) achieved a minimal level activated partial thromboplastin time (APTT). Sixty-eight percent of children achieved a minimal level APTT by 24 h and 81% by 48 h. For all 65 children, APTT values were within the therapeutic range 43% of the time. APTT values outside the therapeutic range were twice as likely to be low as high. The average amount of heparin required to maintain therapeutic APTT values for children was 22 U/kg/h: 28 U/kg/h for infants < 1 y and 20 U/kg/h for the rest. Bleeding was rare (2%) and mild. Documented recurrent thrombotic disease was more common (7%) with associated morbidity.(ABSTRACT TRUNCATED AT 250 WORDS)

Phase I clinical and pharmacokinetic study of menogaril (7-con-O-methylnogarol) in previously treated patients with acute leukemia

Fifteen patients with relapsed or refractory acute leukemia were treated in this phase I study of menogaril (7-con-O-methylnogarol), a nogalamycin anthracycline derivative. Doses ranged from 50 mg/m2/day to 130 mg/m2/day, administered daily for 5 days. Pharmacokinetic studies were performed at each dose level and confirmed the findings of pharmacokinetic data derived from previous studies in patients with solid tumors. All patients experienced grade 4 hematologic toxicity and the dose limiting toxicity was mucositis. Two patients, one with acute myeloid leukemia and one with acute lymphoid leukemia, achieved complete responses. The AML complete response lasted 10 months and the ALL patient died in CR at 2+ months. Both patients were treated at a dose of 100 mg/m2/day for five days. At this dose, a second induction or consolidation course could be given without severe mucositis, and this is the dose recommended for further phase II studies in leukemia using this schedule.

Long-term follow-up of treatment and potential cure of adult acute lymphocytic leukemia with MOAD: a non-anthracycline containing regimen

A total of 55 previously untreated adults with acute lymphocytic leukemia (ALL), median age 38 years (range 15-73 years), were treated with MOAD (methotrexate, vincristine, L-asparaginase, and dexamethasone). This regimen includes five phases--induction, consolidation, cytoreduction, maintenance, and central nervous system (CNS) prophylaxis with parenteral high-dose methotrexate. Of the 55 evaluable patients, 42 achieved complete remission 76%), with a median CR duration of 12+ months (range 0.5-195+ months). The median survival in remission is 22+ months (range 1-198+ months), with 33% of remitters continuing in long-term remissions (> 5 years). Two out of four patients who developed CNS leukemia did so without marrow relapse, were successfully treated for that complication, and continue in total complete remission at 8+ and 16+ years. Another patient with extramedullary relapse (breast) was treated with radiation to that site and remains in total CR at 16+ years. Expected toxicities included myelosuppression during the induction phase of treatment, with 65% of patients requiring intravenous antibiotics. Mucositis was the next most frequent toxicity and required dose-reduction in seven patients. Minimal toxicity was seen during the post-remission phases of treatment. L-Asparaginase toxicity was more prominent during intravenous administration (24 patients) than when the intramuscular route of administration (30 patients) was used. The remission rate and long-term survivorship achieved with this regimen, without the use of an anthracycline, is comparable to that of other regimens for adult ALL. MOAD was well-tolerated by young and old adults with ALL. Aseptic necrosis of bone, successfully treated in each instance, occurred in four long-term disease-free survivors. The effect of this complication and its treatment on quality of life has been negligible.

Tumour-like localized amyloid of the brain is derived from immunoglobulin light chain

A patient is presented in whom the amyloid component of an intracerebral 'amyloidoma' has been purified and characterized by amino acid sequence analysis. The material originated from an autopsy of a 76-year-old man who 15 years earlier had been operated for an intracerebral 'amyloid tumour'. The tumour had recurred and grown to an almost walnut-sized mass in the right cerebral hemisphere. It was located in the parietal lobe close to the lateral ventricle and had a close connection to the choroid plexus. Histological examination showed large masses of amyloid surrounded by some plasma cells and a few macrophages of the foreign body type. Amino acid sequence analysis of a major fibril subunit protein showed homology with the variable region of a monoclonal lambda immunoglobulin light chain, subgroup III or IV. This shows that the amyloid in the 'tumour' was of AL type and presumably derived from local synthesis by plasma cells.

The prevalence of occupational injuries in EMTs in New England

OBJECTIVE

To characterize the prevalence and morbidity of injuries to emergency medical technicians EMTs) in New England [United States].

DESIGN

A survey was mailed to a 2% random sample of all registered EMTs in the six New England States. The identity of the EMTs remained anonymous, and a second mailing was used to improve return rate. The EMTs were requested to recall events that occurred during the previous six months.

RESULTS

A total of 439 of the 786 (56%) surveys were returned representing 13,875 hours of duty time in the six-month period. Seventy-one percent of the EMTs were male with a mean age of 35 years. Sixty-six percent were basic-EMTs. Injury attack rates (number of injuries/100 EMTs/6 months) were: stress, 11.2; back, 10.5; extremity, 9.8; assault, 8.4; ambulance collision, 4.1; hearing loss, 2.5; and eye injury, 1.4. Twelve percent of the EMTs were injured more than once in the six-month period. The paramedics more frequently were involved in ambulance collisions, suffered from stress, and were less likely to injure their back. There were minor interstate differences. Disability due to back injury affected 2.5% of those surveyed, four EMTs lost duty time secondary to an assault, and 0.5% of the EMTs were out of work due to stress.

CONCLUSIONS

This survey begins to characterize the occupational risks of EMTs. The prevalence of back injuries, assault, stress, and extremity injuries seems to be too high. Educational programs and preventive interventions should be designed to minimize back injuries, stress, and assault. There is a need for more research nationwide in order to better characterize these injuries.