Isolation and characterization of mutants as an approach to a transformation system in Kluyveromyces marxianus

 A method to obtain K. marxianus mutants has been developed. Different auxotrophic mutants were isolated by nystatin and snail-enzyme enrichment procedures using an incubation time of 2 h before adding the antibiotic or the enzyme respectively. All his mutants analyzed by complementation tests turned out to belong to the same complementation group. Some of them were transformed and complemented by the S. cerevisiae HIS3 gene. These non-reverting his3 mutants contain no heterologous sequence, which is essential to make them acceptable for application in the food industry. Received: 15 November/21 December 1995     

Reversion of gingival hyperplasia in a heart transplant patient upon interruption of cyclosporine therapy

A heart transplant patient undergoing a combined cyclosporine and prednisone treatment was monitored during the 18 months following transplantation. A complete oral and dental examination was performed in each of the first six months after transplantation, and then in the 9th, 12th, 15th, and 18th months. The data collected included gingival hyperplasia secondary to cyclosporine use, and clinical and periodontal variables. Histological studies were also conducted on gingival tissue samples in months 1, 3, 9, 15, and 18. Cyclosporine treatment was replaced by azathioprine treatment in month 10 because the patient was experiencing nephrotoxicity. Between months 9 and 18, gingival hyperplasia regressed by 26.5% due to a reduction in the fibrous connective tissue mass, fibroblasts, and inflammatory infiltration. The control group included 13 heart transplant patients subject to equivalent conditions except discontinuance of cyclosporine treatment; seven of the patients had developed hyperplasia by month 9. Average hyperplasia in the control group increased by 2% between months 9 and 18; only one patient showed a 6.2% decrease in hyperplasia. This provides further evidence for the causal relationship between cyclosporine therapy and gingival hyperplasia, and suggests that this side-effect is reversible .     

The heterogeneous temporal evolution of focal ischemic neuronal damage in the rat

Summary Male Fisher rats (n=61) underwent permanent focal cerebral ischemia induced by left middle cerebral artery (MCA) occlusion, in conjunction with ipsilateral common carotid artery ligation. The experiments were terminated at time points ranging from immediately following occlusion to 30 days post MCA occlusion. A coronal histological section, in close proximity to the site of the arterial occlusion, was taken from each brain and divided into six areas encompassing the affected cortex and caudate putamen. Each area was analyzed for ischemic damage according to a grading scale that reflects changes in neuronal morphology. Differential neuronal counts were also made on a 0.5-mm² field in each of the six areas. The areas closest to the occluded vessel showed accelerated ischemic damage between 8 and 12 h after occlusion, leaving open the possibility that before 8 h, therapeutic intervention may be effective. After 12 h, changes in these areas progressed to complete necrosis and eventual cavitation with a complete loss of neurons after 10 days. The areas more peripheral to the occluded vessel exhibited mild ischemic damage, with an apparent reversal of damage grading at later time points and no loss of neurons. This reversal of ischemic damage in the peripheral areas is suggestive of a histological equivalent of the penumbra.Supported by NIH Grants NS23393 and NS29463     

Acute nonlymphocytic leukemia with severe hypodiploidy and one double minute chromosome

We present a case of acute nonlymphocytic leukemia with severe hypodiploidy (38 chromosomes), complex karyotype, and one double minute chromosome. These unusual chromosome findings could be related to the rapid course of the patient's disease.     

Coarctation of the aorta and severe aortic insufficiency: What to repair first?

A new surgical approach is proposed for patients with coarctation of the aorta associated with severe aortic valvular insufficiency. The valvular lesion should be repaired first and the coarctation corrected during a second operation; both interventions should be done during the same hospital stay. We base our approach on the belief that improved coronary perfusion can be achieved when the aortic insufficiency is corrected first. The disadvantages of the opposite surgical approach, such as anticoagulation problems, renal underperfusion, and hypertensive complications are easily avoided.     

Mycobacterium chelonei Infection: Successful Treatment Based on a Radiometric Susceptibility Test

A patient with Mycobacterium chelonei infection was treated with erythromycin stearate and streptomycin. The choice of antibiotics was based on a rapid radiometric susceptibility test developed in our laboratory.     

The Sutureless Electrode: Comparison with Transvenous and Sutured Epicardial Electrode Placement for Permanent Pacing

Consecutive series of 50 transvenous and 50 sutureless pacemaker insertions were reviewed and compared with a nonsimultaneous series of 50 patients who received sutured epicardial pacemakers. It is concluded that: (1) the sutureless electrode has a lower initial stimulation threshold than the transvenous type; (2) complications from sutureless electrodes are greater than with transvenous electrodes and similar to the incidence with sutured epicardial pacemakers; (3) initial pacing is more satisfactory with the sutureless electrode compared with the transvenous model; and (4) late electrode failure due to threshold rise is greater with the sutureless electrode than with the transvenous or sutured epicardial type.     

Intravascular stenting: from basic research to clinical application

Although the use of intravascular stents is approaching widespread clinical use, several questions remain regarding their safety and efficacy. Several factors have direct bearing on the immediate and long-term results of intravascular stenting. The technical results of stenting are dependent on the mechanical characteristics of the device and long-term patency is closely related to thrombogenicity and endothelialization. Although stents are used most frequently for the treatment of atherosclerotic disease there is no clear understanding of how they influence the atheromatous lesion.     

Effects of a controlled program of moderate physical exercise on insulin sensitivity in nonobese, nondiabetic subjects.

OBJECTIVE: To study the effect of a moderate, aerobic physical exercise program on insulin resistance and its accompanying metabolic changes in a group of healthy, middle-age, nonobese subjects, without modifying oxygen consumption and body weight. DESIGN: The inclusion of subjects was carried out among volunteers from the health personnel of our center, who complied with the inclusion criteria. PARTICIPANTS: Twelve subjects (age 30-60 years, 5 females), nonsmokers, body mass index (BMI) <27 kg/m2 and fasting plasma glucose <6.1 mmol/L. INTERVENTIONS: Insulin resistance was assessed using the Bergmann minimal model modified with insulin, and basal and maximum metabolic rate were measured with standard methods. All subjects completed a 2-month program of aerobic exercise using the American College of Sports Medicine guidelines, consisting of aerobic exercise of moderate, regular, and continual intensity (3 times per week), with a duration of 45 to 50 minutes per session. RESULTS: Following controlled exercise, no significant differences in BMI, waist-hip ratio, blood pressure, lipids, free fatty acids, and leptin plasma values were observed. Plasma glucose and insulin values decreased significantly (-0.37 mmol/L and -16.5 pmol/L, respectively). Insulin sensitivity showed an increase of 2.1 x 10(-4) mU L(-1) min(-1) (P = 0.001). Basal and maximum metabolic rate showed no significant differences after the exercise program. CONCLUSIONS: Moderate aerobic exercise increases insulin sensitivity in nonobese, nondiabetic subjects in the absence of significant changes in weight, BMI, waist-hip ratio, lipid profile, and oxygen consumption.     

Systemic lupus erythematosus presenting as chronic serositis with no demonstrable antinuclear antibodies

Approximately 5 percent of patients with systemic lupus erythematosus by clinical and pathologic criteria have no demonstrable antinuclear antibodies. This figure is likely to be an underestimate, as it does not include the antinuclear antibody-negative patients with limited manifestations in whom the diagnosis of systemic lupus erythematosus is missed. A 23-year-old woman is described who had a history of perplexing bilateral pleural effusions with development of peritoneal effusion after 18 months and positive antinuclear antibody results after 22 months. Tissue pathologic features, initially interpreted as nonspecific, on review revealed striking lymphocytic periarteritis with endothelial swelling and leukocytoclastic vasculitis often seen in systemic lupus. A selective defect in the suppression of T cell effector function, such as direct cell-mediated cytotoxicity, with intact suppressor systems for B cell effector function, such as antibody production, can be postulated in this patient. This would explain the active cellular tissue pathology with the lack of prominent antinuclear antibody production.