Myxoma of the breast: report of a case and ultrastructural study

A case of myxoma of the breast is presented. The differential diagnosis with respect to other myxoid tumours of the breast is discussed. Ultrastructurally the tumour cells show features of a primitive mesenchymal cell with possible pericytic or modified myoepithelial cell differentiation. The histogenesis is discussed.     

Changing patterns of susceptibilities of blood, urinary and respiratory pathogens in Hong Kong

The incidence and antimicrobial susceptibility of organisms isolated from blood, urine and respiratory specimens at a teaching hospital in Hong Kong were studied retrospectively from 1986–1993. The incidence of Gram-positive bacteraemia, particularly coagulase-negative staphylococci (CNS), increased significantly from 33·6 to 47·3% (P < 0.001) while that of Gram-negative bacteraemia fell from 60·0 to 47·0% (P < 0.001). Among blood isolates, methicillin resistance of CNS increased from 17·0 to 58·0% (P < 0.001) and cefuroxime resistance of Enterobacter spp. increased from 21·0 to over 50% (P < 0.001). Among urinary isolates, cefuroxime resistance of Klebsiella spp. (11·0 to 24·0%, P < 0.001) and Enterobacter spp. (32·0 to 75·0%, P < 0.001) increased. Nalidixic acid resistance among Gram-negative urinary isolates, except Proteus mirabilis, rose by three- to sixfold. For Streptococcus pneumoniae, isolated from the respiratory tract, penicillin resistance increased dramatically (2 to 18%, P < 0.001). For respiratory isolates of Haemophilus influenzae, ampicillin resistance increased from 17·0 to 29·0% (P < 0.001). These data are useful in guiding empirical treatment of nosocomial infections.     

Species comparison of pharmacokinetics and metabolism of diltiazem in humans, dogs, rabbits, and rats

Diltiazem (DTZ) is a calcium antagonist widely used in the treatment of angina and related heart diseases. It is extensively metabolized into a host of metabolites, some of which have potent pharmacological activities. In this study, the pharmacokinetics and metabolism of DTZ was investigated in humans, dogs, rabbits, and rats after each species (n = 4 or 5) was given a single oral dose of DTZ. After the drug administration, blood and urine samples were collected for 12 and 48 hrs, respectively. DTZ and six of its metabolites were quantitated in our laboratory by HPLC. The results indicated that, in humans, the major metabolites in plasma were N-monodesmethyl diltiazem (MA), deacetyl diltiazem (M1), and deacetyl N-monodesmethyl diltiazem (M2). These metabolites were also detected in the plasma of dogs, rabbits, and rats. However, there were quantitative differences. For example, in the humans and dogs, MA was the most abundant metabolite in plasma, while M1 and M2 were most prominent in the rabbits and rats, respectively, and M2 was a relatively minor metabolite in dog plasma. Less than 5% of the dose was recovered as unchanged DTZ in the urine of all the tested species. The most abundant metabolites in urine appeared to be MA and deacetyl N,O-didesmethyl diltiazem, although there were considerable inter- and intra-species variations. Two additional metabolites were detected in the urine of the humans, dogs, and rabbits, but not in the rats. They were tentatively identified as O-desmethyl diltiazem and N-O-didesmethyl diltiazem, using electron impact and ammonia chemical ionization mass spectrometry.(ABSTRACT TRUNCATED AT 250 WORDS)     

Contrasting effects of varicose vein surgery on endothelial-dependent and -independent cutaneous vasodilation in the perimalleolar region.

OBJECTIVES: To evaluate the effects of varicose vein surgery on cutaneous microvascular perfusion and vasodilator responses to acetylcholine (Ach) and sodium nitroprusside (SNP) in the gaiter area of patients with great saphenous vein insufficiency. METHODS: Twenty-nine patients with isolated great saphenous vein incompetence attended three study mornings (before surgery, and 6-8 weeks and 6 months after sapheno-femoral ligation+partial stripping) during which cutaneous microvascular responses were measured in the supine and standing positions using laser Doppler fluximetry (LDF) combined with incremental-dose iontophoretic administration of endothelial-dependent (Ach) and -independent (SNP) vasodilators. RESULTS: Varicose vein surgery had no significant effect on baseline cutaneous perfusion or the microvascular response to Ach: e.g. peak vasodilator responses to the 1000 microC stimulus were mean 58 SEM 7, 64 SEM 6 and 65 SEM 7PU on the pre-operative, 6-8 weeks and 6 months assessments. In contrast, the corresponding responses to SNP were significantly increased following surgery: e.g. at 2000 microC, mean 63 SEM 9, 142 SEM 4 and 157 SEM 9PU (p<0.0001) in the upright position. CONCLUSIONS: Sapheno-femoral ligation and partial stripping in patients with great saphenous vein insufficiency improves endothelial-independent cutaneous vasodilator function at the gaiter area, which may at least partly explain the benefits of surgery in reducing the risk of venous ulceration.     

Quetiapine improves psychotic symptoms and cognition in Parkinson's disease.

Twenty-nine elderly patients who failed treatment with clozapine, risperidone, or olanzapine entered this 24-week, single-center, open-label trial to assess the efficacy of quetiapine (12.5-400 mg/day) for psychosis in patients with Parkinson's disease (PD). Psychiatric, motor, and cognitive assessments were administered at baseline and at periodic intervals for 24 weeks. These included the Brief Psychiatric Rating Scale (BPRS), Neuropsychiatric Inventory (NPI), Unified Parkinson's Disease Rating Scale (UPDRS) and tests of intellectual functioning, attention, and memory. Repeated measures statistical analysis was used to assess change from baseline. The results revealed significant improvements in the 24-week BPRS total score and NPI psychosis subscale scores, with no decline in UPDRS total or motor subscale scores. There was also significant improvement in recall scores on cognitive measures. These results indicate that quetiapine may treat psychotic symptoms and improve cognition without worsening motor function in patients with PD, suggesting that quetiapine is an effective and well-tolerated antipsychotic in this population.     

Prostatic non-Hodgkin's lymphoma causing acute urinary retention in childhood

An 8-year-old boy presented with dysuria and acute retention of urine. Rectal examination showed a hard mass arising from the prostate. CT scan of the pelvis confirmed the presence of a large prostatic tumor causing bladder outflow obstruction. A provisional diagnosis of pelvic sarcoma was initially made. Biopsy of the tumor mass however, revealed non-Hodgkin's lymphoma of T-cell type. The tumor showed very good response to chemotherapy and the urinary obstruction significantly improved with a week after starting therapy. © 1995 Wiley-Liss, Inc.     

Molecular epidemiology of Vibrio cholerae in Hong Kong.

We studied restriction fragment length polymorphism of the enterotoxin genes of isolates of Vibrio cholerae El Tor, indistinguishable by bacteriophage typing, which were collected in Hong Kong since 1978. Using this approach, we could distinguish indigenous and exogenous strains obtained from different sources and epidemiological settings.     

The role of cross sectional echocardiography and pulsed Doppler ultrasound in the management of neonates in whom congenital heart disease is suspected. A prospective study.

The application of cross sectional echocardiography and pulsed Doppler ultrasound to the management of symptomatic neonates with suspected congenital heart disease was studied in 96 consecutive cases. The ability of echocardiography to establish a complete and accurate diagnosis and a correct management plan was evaluated. Sequential segmental analysis of data from cardiac catheterisation and necropsy identified 536 cardiovascular anomalies. Of the 536 anomalies 512 were correctly diagnosed by echocardiography (sensitivity 95.5%). Seven false positive echocardiographic diagnoses were made (specificity 98.6%). Nearly all the missing diagnoses and all the false positive diagnoses made by echocardiography were extracardiac vascular anomalies. Normal cardiovascular anatomy was at all times correctly identified by echocardiography. In 12 babies (12.5%) a management plan could not be established because of inconclusive echocardiographic findings. Of the 84 proposed plans based on the echocardiographic findings, eight were found to be inappropriate after catheterisation. Thus, 76 babies (79.2%) could have been correctly managed without cardiac catheterisation. The combination of cross sectional echocardiography and pulsed Doppler ultrasound not only allows diagnosis of congenital cardiac anomalies in most neonates but can facilitate appropriate clinical management. Only a minority of neonates with suspected congenital heart disease require cardiac catheterisation and angiography.     

Magnetization transfer contrast with periodic pulsed saturation.

Magnetic resonance imaging with magnetization transfer contrast (MTC) was implemented on a 0.5-T clinical system by using a stream of binomial radio-frequency pulses for the selective saturation of the bound protons in tissues. Images were obtained of an egg phantom and of the calf, head, and abdomen in healthy human volunteers. Nonspecific saturation resulting in diminished signal intensity was manifested in the plots of the ratio of MTC signal to control signal for egg yolk, raw egg white, cerebrospinal fluid, and bone marrow fat. This signal degradation resulted partly from the cumulative effects of T2 on the observed transverse magnetization during presaturation. MTC imaging is dependent on repetition time; this dependence arises from the dual but conflicting effect of the selective saturation on tissues rich in macromolecular constituents. Substantial changes in tissue contrast were observed with MTC presaturation. The effect was most marked in muscle, as expected from the high protein content of this tissue.