Effects of Two Stains on Blastoconidia of Candida albicans: Scanning Electron Microscope Studies. Wirkungen von zwei Farbstoffen auf die Blastosporen von Candida albicans: Untersuchungen mit dem Rasterelektronenmikroskop

Summary:  The authors report observations using scanning electron microscopy (S.E.M.) of cell morphological alterations induced by two stains (crystal violet and malachite green) in cultures of Candida albicans. A marked ultrastructural polymorphism was found. Thus it is suggested that the two stains induced a cellular suffering of the mycete whose functions are then inhibited.
Zusammenfassung:  Die Verfasser berichten über die morphologischen Veränderungen, die von den Farbstoffen Kristallviolett und Malachitgrün bei pathogenen Candida albicans-Stämmen verursacht werden. Auffälliger ultrastruktureller Polymorphismus wurde bei den Sproßzellen festgestellt. Es wird angenommen, daß durch den Farbstoffkontakt die Sproßzellen biologisch inaktiviert werden.     

Gastro-esophageal reflux and asthma. Clinical experience

Gastroesophageal reflux (GER) may contribute to the persistence of asthma and may be triggered and/or exacerbated by treatment with bronchodilatory and cortisone drugs. For this reason, GER should be suspected in patients with asthma non-responsive to treatment. In fact in this series 24 hour pH monitoring revealed GER in 7 out of 9 (77%) patients with persistent asthma. The use of a personally developed diagnostic protocol permitted the identification of various situations in 4 patients who completed the study: one coincidental association, one GER caused by theophylline and constituting the main cause of the bronchial obstruction.     

Race, presenting signs and symptoms, use of carotid artery imaging, and appropriateness of carotid endarterectomy.

BACKGROUND AND PURPOSE: We sought to determine whether there are racial differences in use of carotid artery imaging after controlling for clinical factors and to ascertain racial differences in presenting signs and symptoms and overall appropriateness for carotid endarterectomy (CE). METHODS: We performed a retrospective cohort study of 803 patients older than 45 years, hospitalized between 1991 and 1994 at any of 4 Veterans Affairs Medical Centers, with a discharge diagnosis of transient ischemic attack or ischemic stroke. Clinical data were abstracted from the medical record, including presenting symptoms, diagnostic test results, and use of surgical procedures. Appropriateness for CE was determined according to RAND criteria. RESULTS: Black patients were more likely than white patients to present with stroke (78% versus 55%) but less likely to present with transient ischemic attack (22% versus 45%; P=0.001). There was no racial difference in medical comorbidity or preoperative risk. Black patients were less likely to have an imaging study of their carotid arteries (67% versus 79%; P=0.001). Race remained an independent predictor of imaging after adjustment for clinical factors (odds ratio=1.50; 95% CI, 1.06 to 2.13). Because of higher prevalence of significant carotid artery stenosis, whites were significantly more likely than blacks to be assessed as appropriate candidates for surgery with the use of RAND criteria (18% versus 4%; P=0.001). CONCLUSIONS: Use of carotid artery imaging, a critical step in determining eligibility for CE, is influenced by the patient's race after controlling for clinical presentation. Adjustment for appropriateness of CE reduces but does not eliminate the importance of race.     

Cutaneous larva migrans in travelers: a prospective study, with assessment of therapy with ivermectin.

The purpose of this prospective study was to update epidemiological data on cutaneous larva migrans (CLM) and to assess the therapeutic efficacy of ivermectin. We performed the study between June 1994 and December 1998 at our travel clinic. Ivermectin (a single dose of 200 microg/kg) was offered to all the patients with CLM, and its efficacy and tolerability were assessed by a questionnaire. Sixty-four patients were enrolled. All were European and had stayed in tropical areas. After the patients had returned from their destinations, 55% had lesions occur within a mean of 16 days (range, 1-120 days; >1 month in 7 patients). The initial diagnosis was wrong in 55% of patients. The mean number of lesions was 3 (range, 1-15), and the main sites were the feet (48%) and buttocks (23%). The cure rate after a single dose of ivermectin was 77%. In 14 patients, 1 or 2 supplementary doses were necessary, and the overall cure rate was 97%. The median time required for pruritus and lesions to disappear was 3 and 7 days, respectively. No systemic adverse effects were reported. Physicians' knowledge of CLM, which can have a long incubation period, is poor. Single-dose ivermectin therapy appears to be effective and well tolerated, even if several treatments are sometimes necessary.     

Improving the clinical examination for a low ankle-brachial index

We sought to determine clinical examination features that predict an abnormal ankle-brachial index (ABI). Eleven United States and Canadian university-affiliated practices participated. Patients over age 55 (n=218) presenting for an outpatient appointment in a general medical clinic. We excluded patients with amputations or acute leg pain. A standard clinical examination was performed consisting of historical features and physical examination findings with Doppler ausculation. The most efficient findings were a. presence of only one Doppler-auscultated posterior tibial artery component [LR=7.0; (95% CI 4.4, 11.6)], and b. absence of a palpable pulse [LR=4.6; (95% CI 3.2, 6.6)]. We derived a score based on the number of auscultated components, grade of palpated pulse, and history of myocardial infarction (LR_score<6=7.8; LR_score≥6=0.2; c index=0.93). Clinicians required a median 2.5 min to collect the clinical information and derive the score (interquartile range 1.8 to 3.6 min), versus 8.5 min for the ABI (interquartile range 7.4 to 9.4 min). Palpation and Doppler auscultation of the posterior tibial artery, combined with knowledge of prior myocardial infarctions, were the most effective and efficient findings for patients in general medical clinics. A score based on these findings appears promising as a screening tool for a low ABI.     

Type IIB von Willebrand factor with normal sialic acid content induces platelet aggregation in the absence of ristocetin. Role of platelet activation, fibrinogen, and two distinct membrane receptors.

Three preparations of purified von Willebrand factor (vWF), obtained from unrelated patients affected by type IIB von Willebrand disease, were found to have normal sialic acid content (between 129 and 170 nmol/mg of vWF, as compared with 158 +/- 17 nmol/mg in four normal preparations) and to induce platelet aggregation in the presence of physiologic levels of divalent cations and without addition of ristocetin. A monoclonal antibody that blocks the vWF binding domain of the platelet glycoprotein (GP)Ib caused complete inhibition of IIB vWF-induced aggregation. In contrast, a monoclonal antibody that blocks the receptor for adhesive proteins on the platelet GPIIb/IIIa complex failed to inhibit the initial response of platelets to high concentrations of IIB vWF. Moreover, IIB vWF caused agglutination of formalin-fixed platelets that was blocked only by the anti-GPIb antibody, suggesting that the binding of vWF to GPIb, even in the absence of ristocetin, results in platelet-platelet interaction that is followed by exposure of the GPIIb/IIIa receptors for adhesive proteins. Endogenous ADP, normally active platelet metabolism and fibrinogen binding to GPIIb/IIIa were necessary for maximal and irreversible platelet aggregation. In the absence of fibrinogen, however, aggregation was mediated by vWF binding to GPIIb/IIIa. A 52/48-kD tryptic fragment containing the GPIb binding domain of normal vWF completely blocked the aggregation induced by all three IIB vWF preparations. The present study defines in detail the mechanisms involved in IIB vWF-induced platelet aggregation. Moreover, it establishes that the GPIb binding domain of normal and IIB vWF are closely related and that desialylation is not required for the direct interaction of IIB vWF with GPIb.     

Variant von Willebrand''s Disease: CHARACTERIZATION OF TWO SUBTYPES BY ANALYSIS OF MULTIMERIC COMPOSITION OF FACTOR VIII/VON WILLEBRAND FACTOR IN PLASMA AND PLATELETS

We have examined the multimeric composition of factor VIII/von Willebrand factor in plasma and platelet lysates by means of sodium dodecyl sulfate agarose electrophoresis followed by staining with ¹²⁵I-labeled affinity-purified antibody. In normal plasma and platelet lysates, factor VIII/von Willebrand factor displayed 10 distinct multimers that ranged in apparent molecular weight from 0.86 to 9.9 × 10⁶. The molecular weight difference between adjacent bands was 0.8−1.1 × 10⁶. Larger material, not resolved into discrete bands, was also present with an average M_r of 14.5 × 10⁶. Though the dimer (apparent M_r = 0.48 × 10⁶) and the monomer (apparent M_r = 0.28 × 10⁶) generated by reduction of disulfide bonds were readily identified in this system, they were not detected in normal plasma or platelets. No differences were observed between fresh plasma prepared without anticoagulant and fresh or frozen plasma anticoagulated with either citrate or heparin. “Variant” (type II) von Willebrand's disease could be divided into two subtypes. In subtype IIA, factor VIII/von Willebrand factor in plasma consisted predominantly of the five smaller multimers with traces of the sixth and seventh (M_r up to 4.5 × 10⁶). In subtype IIB, all these multimers were easily detected and, in addition, bands of intermediate size (M_r = 8.5 × 10⁶ and smaller) were present. In contrast, the multimeric composition of IIB platelet factor VIII/von Willebrand factor was identical to normal, whereas in subtype IIA the larger multimers were absent from platelets as well as from plasma. In subtype IIB, binding of factor VIII/von Willebrand factor to platelets occurred at lower concentrations of ristocetin than required for normal and multimers of smaller size than in normal bound. On the contrary, in subtype IIA, binding was minimal, as was true of normal factor VIII/von Willebrand factor of equivalent size. Thus, physical as well as functional differences in the two subtypes of variant von Willebrand's disease described suggest that different pathogenetic mechanisms underlie the factor VIII/von Willebrand factor abnormalities in these patients.     

Quality of care for patients diagnosed with diabetes at screening

OBJECTIVE: Screening for diabetes has the potential to be an effective intervention, especially if patients have intensive treatment of their newly diagnosed diabetes and comorbid hypertension. We wished to determine the process and quality of diabetes care for patients diagnosed with diabetes by systematic screening. RESEARCH DESIGN AND METHODS: A total of 1,253 users of the Durham Veterans Affairs Medical Center aged 45-64 years who did not report having diabetes were screened for diabetes with an HbA(1c) test. All subjects with an HbA(1c) level > or =6.0% were invited for follow-up blood pressure and fasting plasma glucose (FPG) measurements. A case of unrecognized diabetes was defined as HbA(1c) > or =7.0% or FPG > or =126 mg/dl. For each of the 56 patients for whom we made a new diagnosis of diabetes, we notified the patient's primary care provider of this diagnosis. One year after diagnosis, we reviewed these patients' medical records for traditional diabetes performance measures as well as blood pressure. Follow-up blood pressure was also ascertained from medical record review for all subjects with HbA(1c) > or =6.0% who did not have diabetes. We compared blood pressure changes between patients with and without diabetes. RESULTS: Among patients diagnosed with diabetes at screening, 34 of 53 (64%) had evidence of diet or medical treatment for their diabetes, 42 of 53 (79%) had HbA(1c) measured within the year after diagnosis, 32 of 53 (60%) had cholesterol measured, 25 of 53 (47%) received foot examinations, 29 of 53 (55%) had eye examinations performed by an eye specialist, and 16 of 53 (30%) had any measure of urine protein. The mean blood pressure decline over the year after diagnosis for patients with diabetes was 2.3 mmHg; this decline was similar to that found for 183 patients in the study without diabetes (change in blood pressure, -3.6 mmHg). At baseline, 48% of patients with diabetes had blood pressure <140/90, compared with 40% of patients without diabetes; 1 year later, the same 48% of patients with diabetes had blood pressure <140/90, compared with 56% of patients without diabetes (P = 0.31 for comparing the change in percent in control between groups). CONCLUSIONS: Patients with diabetes diagnosed at screening achieve less tight blood pressure control than similar patients without diabetes. Primary care providers do not appear to manage diabetes diagnosed at screening as intensively as long-standing diabetes and do not improve the management of hypertension given the new diagnosis of diabetes.