C-myc amplification, double minutes and homogenous staining regions in a case of AML

c-myc amplification is usually associated with lymphoid malignancies and Burkitt's lymphoma in particular. We present a case of AML with c-myc amplification which was associated with homogenous staining regions (hsr) and double minutes (dmin). The administration of GCSF following induction chemotherapy resulted in a marked increase in blast numbers. The GCSF was stopped and further courses of chemotherapy given, which resulted in complete remission. The patient relapsed 7 months after diagnosis and failed to go into a second remission with reinduction therapy. We conclude that c-myc amplification is a rare event in AML, but may be associated with chemotherapy resistance and a poor prognosis, are as dmins and hsr. Growth factors should be used with caution in these patients.

The detection of mitochondrial DNA mutations using single stranded conformation polymorphism (SSCP) analysis and heteroduplex analysis

A number of mitochondrial (mt) point mutations have been associated with inherited disorders. These pathogenic mutations are usually heteroplasmic. Here we describe the identification of three heteroplasmic mtDNA point mutations using the techniques of single stranded conformation polymorphism (SSCP) and heteroduplex analysis.

Immunodetection and comparison of melaleuca, bottlebrush, and bahia pollens

Pollen extracts of two trees, Callistemon citrinis (bottlebrush) and Melaleuca leucadendron (melaleuca), as well as the grass Paspalum notatum (bahia) were analyzed for antigenic and allergenic cross-reactivity using SDS-PAGE and Western blotting. SDS-PAGE analysis of all three pollen extracts revealed multiple antigenic components which were reactive with rabbit antisera made to each pollen extract. Comparison of reduced and nonreduced mobility patterns suggested the possible presence of multichain proteins linked by disulfide bonds. Clinical studies demonstrated that 81% of the patients skin test positive to at least one of the pollens were also positive to the other two. Sixty-three percent of allergic individuals studied showed a high correlation between skin test results and the number of IgE-binding components analyzed by immunoblotting. These IgE-reactive components were detected in the molecular weight range of 29-66 kD. Western blot analysis detected more IgE-binding components in bahia pollen extracts as compared with the tree pollens, consistent with other reports of grass pollens being more allergenic than those from trees and weeds. Each patient's serum had a unique IgE-binding pattern, indicating heterogeneity of immune response; however, common major determinants were detected by a large percentage of the allergic patient's sera.

Pharmacotherapy of the depressed patient with cardiovascular and/or cerebrovascular illness

Cardiovascular and cerebrovascular disease are associated with a high incidence of depressive disorder. Despite this high level of co-morbidity, depressive disorders appear to go largely unrecognised and remain untreated. This may have serious consequences, as concomitant depression worsens the prognosis in patients with cardiovascular or cerebrovascular disease, increases medical costs, and delays return to work. Treatment with traditional tricyclic antidepressants is difficult in these patients because of the known cardiac effects. The favourable side-effect profiles of the 5-HT reuptake inhibitors suggest that they may offer therapeutic advantages, as they have little or no effect on cardiac conduction, do not cause orthostatic hypotension, and lack serious sequelae in overdose. The pharmacological profiles and the reduced potential of these newer antidepressant drugs to cause drug interaction show important differences that may be of clinical relevance in this patient population.

Transvalvular left ventricular assistance in cardiogenic shock secondary to acute myocardial infarction. Evidence for recovery from near fatal myocardial stunning

OBJECTIVES

The purpose of this study was to test the hypothesis that transvalvular left ventricular assistance would support the circulation in patients with cardiogenic shock secondary to acute myocardial infarction and allow recovery of function in patients with a reversibly damaged (stunned) left ventricle.

BACKGROUND

Cardiogenic shock occurs in 7.5% of patients presenting with acute myocardial infarction, resulting in survival of only 20%. Despite the use of aggressive interventional therapy in patients with shock secondary to anterior myocardial infarction, survival remains as low as 33%.

METHODS

We studied 11 patients with acute myocardial infarction and cardiogenic shock, as defined by a cardiac index < 2 liters/min per m2, pulmonary capillary wedge pressure > 18 mm Hg and systolic blood pressure < 90 mm Hg during positive inotropic therapy. Patients were 57 +/- 13 years old (mean +/- SD) and had a mean left ventricular ejection fraction of 25 +/- 11%, mean arterial pressure of 69 +/- 13 mm Hg and mean cardiac index of 1.6 +/- 0.4 liters/min per m2 on admission to the study.

RESULTS

During the 1st 24 h of left ventricular assistance, pulmonary capillary wedge pressure decreased from 26 +/- 4 to 16 +/- 4 mm Hg (p = 0.01), cardiac index increased from 1.6 +/- 0.4 to 2.4 +/- 0.4 liters/min per m2, and the dopamine hydrochloride dose decreased from 51 +/- 92 to 18 +/- 12 micrograms/kg body weight per min. In survivors, cardiac index improved to 3.2 +/- 0.5 liters/min per m2 (p = 0.01), and left ventricular ejection fraction improved to 34 +/- 5% (p < 0.05). The overall survival in the study group was 4 (36%) of 11 patients (95% confidence interval [CI] 8% to 65%), and 4 (66%) of 6 patients (95% CI 29% to 100%) with a Q wave anterior myocardial infarction survived.

CONCLUSIONS

Transvalvular left ventricular support during cardiogenic shock complicating acute myocardial infarction is feasible and results in significant hemodynamic and functional improvement.

Evaluation of standard and active compression-decompression CPR in an acute human model of ventricular fibrillation

BACKGROUND

The mechanisms that underlie cardiopulmonary resuscitation (CPR) in humans remain controversial and difficult to study. This report describes a new human model to evaluate CPR during the first 1 to 2 minutes after the onset of ventricular fibrillation (VF). With this model, standard CPR was compared with active compression-decompression (ACD) CPR, a method that uses a handheld suction device to actively compress and actively decompress the chest.

METHODS AND RESULTS

During routine inductions of VF as part of a transvenous lead cardioverter/defibrillator implantation procedure, CPR was performed in 21 patients if the first defibrillation shock failed and until a successful rescue shock was delivered. Compressions during CPR were performed according to American Heart Association guidelines. For ACD CPR, decompression was performed with up to -30 lbs. Radial arterial and right atrial pressures were measured in all patients. Esophageal pressures, intratracheal pressures, or minute ventilation was measured in the last 13 patients. Application of both CPR techniques increased arterial and right atrial pressures. The mean coronary perfusion pressure was increased throughout the entire CPR cycle with ACD CPR (compression, 21.5 +/- 9.0 mm Hg; decompression, 21.9 +/- 8.7 mm Hg) compared with standard CPR (compression, 17.9 +/- 8.2 mm Hg; decompression, 18.5 +/- 6.9 mm Hg; P < .02 and P < .02, respectively). Ventilation per compression-decompression cycle was 97.3 +/- 65.6 mL with standard CPR and 168.4 +/- 68.6 mL with ACD CPR (n = 7, P < .001). Negative inspiratory pressure was -0.8 +/- 4.8 mm Hg with standard CPR and -11.4 +/- 6.3 mm Hg with ACD CPR (n = 6, P < .04).

CONCLUSIONS

Patients undergoing multiple inductions of VF during cardioverter/defibrillator implantation with transvenous leads provide a well-controlled and reproducible model to study the mechanisms of CPR. Using this model, ACD CPR significantly increased arterial blood pressure, coronary perfusion pressure, minute ventilation, and negative inspiratory pressure compared with standard CPR.

Experience of autologous blood transfusion in an obstetrics and gynaecology department

OBJECTIVE

To demonstrate the potential and effectiveness of autologous blood transfusion in an obstetric and gynaecological practice.

SETTING

The Department of Obstetrics and Gynaecology and the department of Haematology, University College Hospital, Galway, Ireland.

SUBJECTS

One hundred and sixty-eight women undergoing abdominal hysterectomy, 42 women undergoing repair procedures, and 56 women undergoing elective caesarian sections participated in this programme.

RESULTS

In the abdominal hysterectomy group 329 units of blood were collected of which 48% were transfused to the donors. In the repair group 82 units of blood were collected of which 21.9% were transfused to the donors. In the elective caesarian section group 105 units of blood were collected of which 64.7% were transfused to the donors. Overall the donation procedure was well tolerated with infrequent donor reactions.

CONCLUSION

Our experience demonstrates that autologous blood transfusion is a safe and reasonable transfusion practice in the setting of obstetrics and gynaecology.

Transfusion practices and costs in dogs

A geographically stratified sample of 25 small-animal practices administering at least six transfusions to dogs over the last 12 months was surveyed to determine how veterinarians obtain blood for transfusions, the direct costs of administering transfusions, and the impact of available blood on the management of critically ill dogs. The primary source of donor blood for each practice was a borrowed dog (12 practices) or in-house dogs kept on the premises (12 practices). Only one practice obtained blood from a nearby veterinary school. There was a wide variation in practices regarding testing for diseases and screening of donors. Thirty-six percent of practices surveyed did not screen dogs for infectious diseases or evaluate hematologic variables prior to blood donation. Twenty-four percent of the respondents evaluated the donors solely for the purposes of detecting microfilaria. The remaining 40% of the practices performed one or more of the tests generally recommended as part of a screening program for potential blood donors. The blood type of donors was determined in eight of the practices, whereas blood typing of recipients was not routinely performed. Ten of 25 practices performed blood crossmatches, but only one practice performed crossmatches in all cases. The distribution of direct costs per whole blood transfusion (500-ml unit) ranged from 25 to more than $300, with three fourths of the practices having costs less than $100. The higher-cost practices were those that maintained donors on the premises specifically for blood donation purposes.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluency versus conscious recollection in the word completion performance of amnesic patients

To examine the relative contribution of fluency and recollection to the word completion performance of amnesics, we administered a task in which patients were told specifically not to utilize previously presented words during stem completion (an Exclusion condition). This condition was contrasted with a standard word completion task in which patients were encouraged simply to complete the stem with the first word that came to mind (an Inclusion condition). Since the exclusion condition necessitated controlled respecification of the initial presentation, it was hypothesized that amnesics would be less able than controls to exclude study list items. Consistent with this hypothesis, the results indicated that the amnesics' performance, unlike that of the alcoholic controls, did not significantly differ as a function of task condition. To examine whether amnesics' conscious recollection could be enhanced, Experiment 2 presented the study list five times. The amnesics now were able to exclude a significant number of items from the study list; however, they still did so considerably less frequently than alcoholic controls. For the alcoholic controls, increasing the number of study trials had little additional effect on their exclusion performance, but it significantly enhanced their inclusion performance. Taken together, these findings suggest that for control subjects, word completion performance is likely mediated by a combination of fluency and recollection, while for amnesic patients, performance is almost exclusively based on the fluency with which an item comes to mind.

Occupational injuries among North Carolina migrant farmworkers

A population-based cross-sectional study of occupational injuries among a random sample of 287 migrant farmworkers demonstrated frequent obstacles to health care; 65% (11/17) of the more seriously injured subjects did not receive prompt care or never received care. Subjects not receiving prompt care were twice as likely to have incomplete recovery. Employers covered medical expenses for only 5/13 (38%) of the injured workers, and only 3/15 were compensated for lost work. This study indicates that comprehensive Workers' Compensation coverage is urgently needed in North Carolina.

Enhanced tumor growth of both primary and established human and murine tumor cells in athymic mice after coinjection with Matrigel

Previously we found that the reconstituted basement membrane matrix Matrigel, when premixed with human small-cell lung carcinoma cells and injected subcutaneously into athymic mice, permitted tumor growth, whereas cells injected in the absence of Matrigel did not form tumors. In the present study, we examined additional cell types and determined some of the underlying mechanisms involved in the promotion of tumor formation by Matrigel. The tumor cell lines that we studied included transformed mouse Englebreth-Holm-Swarm tumor cells (T-EHS), human submandibular carcinoma A253 cells, mouse melanoma B16F10 cells, human epidermoid carcinoma KB cells, and human primary renal cell carcinoma cells. When coinjected subcutaneously with Matrigel, these cell lines formed rapidly proliferating tumors. Primary biopsy specimens of human colon carcinoma, when dispersed and coinjected with Matrigel, also formed tumors. Only A253, KB, and B16F10 cells formed small tumors in the absence of Martrigel, but a fivefold to tenfold increase in tumor size was observed in the presence of Matrigel. These data demonstrate a useful method for improving the growth of human tumors in athymic mice.

Pearson syndrome and mitochondrial encephalomyopathy in a patient with a deletion of mtDNA

A patient is described who has features of Pearson syndrome and who presented in the neonatal period with a hypoplastic anemia. He later developed hepatic, renal, and exocrine pancreatic dysfunction. At the age of 5 years he developed visual impairment, tremor, ataxia, proximal muscle weakness, external ophthalmoplegia, and a pigmentary retinopathy (Kearns-Sayre syndrome). Muscle biopsy confirmed the diagnosis of mitochondrial myopathy. Analysis of mtDNA from leukocytes and muscle showed mtDNA heteroplasmy in both tissues, with one population of mtDNA deleted by 4.9 kb. The deleted region was bridged by a 13-nucleotide sequence occurring as a direct repeat in normal mtDNA. Both Pearson syndrome and Kearns-Sayre syndrome have been noted to be associated with deletions of mtDNA; they have not previously been described in the same patient. These observations indicate that the two disorders have the same molecular basis; the different phenotypes are probably determined by the initial proportion of deleted mtDNAs and modified by selection against them in different tissues.

Mitochondrial DNA analysis in Parkinson's disease

The reduced form of nicotinamide adenine dinucleotide coenzyme Q reductase (complex I) activity has recently been shown to be deficient in the substantia nigra of patients dying with Parkinson's disease. This biochemical defect is identical to that produced by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which also produces parkinsonism in humans. Complex I comprises 25 polypeptides, seven of which are encoded by mitochondrial DNA. Restriction fragment analysis of substantia nigra DNA from six patients with Parkinson's disease did not show any major deletion. In two cases, there were different novel polymorphisms that were not observed in control brain (n = 6) or blood (n = 34) samples.

Efficacy of metabolic support with glucose-insulin-potassium for left ventricular pump failure after aortocoronary bypass surgery

Refractory pump failure after cardiopulmonary bypass carries a high mortality. To assess the effectiveness of metabolic support for the heart in patients with refractory heart failure after hypothermic ischemic arrest for aortocoronary bypass surgery, we randomly assigned 22 patients to receive either intravenous glucose (50%), insulin (80 units/I), and potassium (100 meq/l) (GIK) infused at a rate of 1 ml/kg/hr for up to 48 hours or glucose (5%) and NaCl (0.225%) infused at the same rate (control). All patients required inotropic drug support, received intra-aortic balloon pump assistance, and had an initial mean cardiac index (CI) of 2.5 l/min/m2. At 12 and 24 hours, CI had risen significantly in the GIK but not in the control group (3.6 and 3.4 l/min/m2 vs. 2.5 and 2.7 l/min/m2, p less than 0.005). Time on the intra-aortic balloon pump (39 vs. 61 hours) and requirements for inotropic drug support were also significantly less in the GIK compared with the control group. Although the number of patients was relatively small, the GIK group also showed a trend for improved long-term survival: at 60 days after surgery, there were 10 of 11 survivors in the GIK-treated group compared with seven of 11 survivors in the control group. Although the exact mechanism for the beneficial effects of GIK on myocardial contractility remains to be elucidated, we conclude that GIK is safe and effective in the treatment of refractory left ventricular failure after aortocoronary bypass surgery.

Patch tests demonstrating immune (antibody and cell-mediated) reactions to foods

For decades food allergists have sought a simple, inexpensive test for food allergy. Intradermal tests of aqueous material have not proved reliable. When positive, they are probably only 10% accurate. The newer laboratory tests for food allergy are expensive and highly sophisticated. They are impractical for use in the laboratories of practicing allergists with whom individuals with a potential food allergy are most liable to consult. The RAST is capable of identifying only Type I of the Gell-Coombs' reaction classification. Since 1980, a patch test of individual foods suspended in dimethylsulfoxide has been used as a screen for sensitivity to foods. Controlled clinical studies suggest this might prove to be a valuable test for food allergy. Immune studies appear to confirm the accuracy and reliability of this inexpensive test. No systemic reactions have been observed in the 400 patients tested indicating it to be a safe procedure.

Improved low energy defibrillation efficacy in man with the use of a biphasic truncated exponential waveform

The standard implantable defibrillator waveform is a truncated exponential of approximately 6 msec duration. This study compares the defibrillation efficacy of a standard monophasic truncated exponential to a biphasic 12 msec truncated exponential waveform in 21 patients undergoing automatic implantable cardioverter defibrillator (AICD) surgery. For the biphasic waveform, the polarity was reversed and remaining capacitor voltage was attenuated by 75% after 6 msec. Two hundred thirty episodes of VF were induced with 115 "matched pairs" of monophasic and biphasic waveforms of identical initial capacitor voltages given over a range from 70 to 600 V (0.35 to 25.7 joules). The biphasic waveform was superior to the monophasic waveform (p less than 0.006), especially for "low energy" defibrillation. For initial voltages less than 200 V, the percent successful defibrillation was 28% for the monophasic waveform versus 64% for the biphasic waveform and from 200 to 290 V (energies less than 6.4 joules) it was 45% versus 69%. There was no difference in the two waveforms in time to the first QRS complex or in the blood pressure following defibrillation. This study shows that a 12 msec biphasic truncated exponential is superior to a 6 msec monophasic waveform for defibrillation in man, especially at energies less than 6.4 joules. The waveform can be achieved in an implanted device without any increase in capacitor size or in battery energy consumption.

5-Hydroxytryptamine releases adenosine from primary afferent nerve terminals in the spinal cord

5-Hydroxytryptamine (serotonin, 5-HT) increased the release of endogenous adenosine from dorsal, but not ventral, spinal cord synaptosomes. This release was reduced by (i) the 5-HT receptor antagonist methysergide, (ii) removal of Ca2+ from the medium, (iii) inhibition of ecto-5'-nucleotidase and (iv) capsaicin pretreatment. These data suggest that activation of 5-HT receptors on primary afferent terminals releases a nucleotide which is converted extracellularly to adenosine. This adenosine may contribute to the spinal antinociceptive effect of 5-HT.

Norplant contraceptive implants: rods versus capsules

Norplant contraceptive implants are silastic implants containing levonorgestrel. When placed subcutaneously in the medial aspect of the upper arm, they release low levels of levonorgestrel in a constant manner over an extended period of time. Comparative studies of two silastic rods versus six capsules containing levonorgestrel were studied in 250 subjects for 4,464 months of use. Only one pregnancy occurred during the study. Side effect patterns were similar in both groups; the major side effect being irregular uterine bleeding. The bleeding, however, was well tolerated by subjects in both groups and discontinuation rate was very low. The two-rod system offers the advantages of easier insertion technique and shorter insertion time as well as ease of removal as compared to the six-capsule system. Norplant contraceptive implants offer a highly effective means of contraception which is particularly suited for women who are concerned about failure and compliance with oral contraceptives. This type of contraception should become well accepted, not only in underdeveloped countries, but in developed countries as well.

The management of paroxysmal tachycardias using the Cybertach-60

The Cybertach-60 is a bipolar multiprogrammable pacemaker designed for the automatic detection and termination of reentrant tachycardias using bursts of rapid pacing. From August 1979 to March 1984 in the U.S.A., 143 patients received the device; 91 for supraventricular and 52 for ventricular tachycardia. After a mean follow-up period of 1.8 years, 82% of patients with supraventricular tachycardia remain alive with the implanted pacemaker providing the principal therapy for the arrhythmia. Of those patients with ventricular tachycardia, 30 (58%) remain alive (mean follow-up 1.1 years) and use the device for tachycardia termination. In this group there were 18 patient deaths: 14 documented and not sudden; 4 sudden and not documented. None of the 14 documented deaths were a result of arrhythmia or pacemaker activity. The Cybertach-60 has proved to be effective in the long-term management of patients with reentrant rhythms, particularly supraventricular tachycardia.