Ultrasonic myocardial tissue characterization in the operating room: initial results using transesophageal echocardiography.

Ultrasonic tissue characterization provides quantitative assessment of myocardial function and viability. We have previously reported that normal myocardium is characterized by a diastolic-to-systolic cyclic variation of integrated backscatter (IB), whereas ischemic myocardium exhibits blunting of this pattern. To define the applicability of this measurement to characterize the left ventricular myocardium in the operating room, we studied 26 consecutive patients undergoing open heart surgery (12 coronary artery bypass graft, 13 valvular, 1 other) with 5 MHz transesophageal echocardiography. Images of the left ventricle were obtained in the short-axis plane (papillary muscle level) before cardiopulmonary bypass. M-mode acquisition of myocardial IB was attempted from the anterior and inferior segments in each patient. The cyclic variation of IB was measured in at least two consecutive cycles in addition to a qualitative assessment of wall motion. Quantitative measurement of IB was possible in 39/52 (75%) myocardial segments. Cyclic variation of IB averaged 5.7 +/- 1.4 dB (SD) in segments with normal wall motion (n = 25); no difference was noted in the cyclic variation of IB among anterior or inferior walls. Hypokinetic segments demonstrated significant reduction of the cyclic variation (3.8 +/- 1.8 dB; p less than 0.001). Difficulty with obtaining myocardial IB was related to near-field artifact or lateral displacement of the left ventricular wall during systole. Transesophageal echocardiography holds promise for the evaluation of myocardial function and its preservation during cardiac surgery.     

Cisplatin ototoxicity in guinea pigs with special reference to toxic effects in the stria vascularis

The toxic effects of cisplatin (cis-diamminedichloroplatinum [II]) on the organ of Corti are well established. Few and conflicting data on this drug's effects on the stria vascularis exist. The present study presents animal experiments on the toxic effects of cisplatin in the stria vascularis and in the organ of Corti. Cisplatin-induced toxicity in albino and pigmented guinea pigs was evaluated morphologically and functionally, using light and transmission electron microscopy as well as auditory brainstem-evoked potentials on the organ of Corti and the stria vascularis. The results showed variability in hearing thresholds, ranging from no change to hearing loss of 30 dB, and prominent damage in the organ of Corti and in the stria vascularis. The toxic effects to both the organ of Corti and the stria vascularis should be considered when cisplatin is used in chemotherapy.     

Effect of a calcium-enriched diet on the colonic epithelial hyperproliferation induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats on a low calcium and fat diet

We examined whether hyperproliferation of colonic crypt epithelium during cancer induction by N-methyl-N-nitro-N-nitrosoguanidine (MNNG), in rats on a low fat and calcium diet could be reduced by added calcium p.o. From the age of 4 weeks, 104 male Sprague-Dawley rats received a low fat (3.5%), low calcium (0.05% calcium ion), and low vitamin D (0.4 IU/g) diet. Sixty-four also had calcium salts, derived from either calcium lactate or solubilized calcium carbonate, added to their drinking water; therefore their total calcium intake was about 1% of daily diet. At age 12 weeks the rats were divided into 4 treatment groups: 8 rats, not receiving added calcium, had rectal saline instillations weekly (saline control group) and were sacrificed after a further 28 weeks; 3 groups of 32 rats each received intrarectal MNNG (1.5 mg) weekly. One group, not receiving added calcium, was the MNNG control group; while the second group also received added calcium lactate, and the third group received calcium carbonate. Groups of 24 were sacrificed periodically until 28 weeks of treatment. Rats were sacrificed and epithelial proliferation was estimated, 1 week after the last intrarectal instillation, by in vivo labeling with tritiated thymidine and measuring the ratio of labeled to total colonic crypt epithelial cells. The mean labeling index of the MNNG treated and added calcium groups were significantly higher (8.7-9.5%) than that of the saline controls (2.8%) only at week 28; however, it was then still significantly less than that of the MNNG controls not having added calcium (17.9%). Hyperproliferation, during induction of colonic cancer by MNNG in rats on a low calcium diet, can be reduced by a calcium enriched diet even in the presence of a low fat intake.     

Ultrasound screening for abdominal aortic aneurysms in patients with atherosclerotic peripheral vascular disease

The rapidly rising incidence of abdominal aortic aneurysm (AAA) and the grave prognosis in cases of rupture call for early detection and operative intervention. However, there is as yet no consensus on which groups in the population should be selected for screening. Some Authors have suggested the screening of populations at risk by virtue of their age, sex and/or the presence of arterial hypertension, and report the incidence of AAA in these populations as 5.3%, 3.4% and 0.25%, respectively. In this study we screened a group of patients with atherosclerotic peripheral vascular disease. Within this group the incidence of aneurysms was found to be 5.9%, which is at least twice the estimated incidence in the general population. Three of the six patients discovered, successfully underwent surgery. We conclude that screening of this specific population group is considerably more cost-effective than universal screening.     

The risk for severe COVID 19 in patients with autoimmune and/or inflammatory diseases: First wave lessons

Data regarding the risk for severe COVID19 in patients with autoimmune or inflammatory diseases are scarce. To estimate the risk of those patients to develop a more severe COVID19 infection All active patients and those with dermatologic and/or rheumatologic autoimmune/inflammatory diseases were identified in a single tertiary center. The charts of those tested positive for COVID19 between 1 March 2020 and 31 May 2020 reviewed including demographics, co‐morbidities, and medications. COVID19 outcome of those with dermatologic and/or rheumatologic autoimmune/inflammatory diseases were compared to COVID19 infected matched controls without an autoimmune/inflammatory background. Overall, 974 of 381 268 active patients were tested positive for COVID19, including 35 out of 13 225 with dermatologic and/or rheumatologic autoimmune/inflammatory diseases. No statistically significant difference in severity of COVID19 infection or mortality rate was found. The rate of asymptomatic, mild, moderate, severe/critical and fatal COVID19 infection was 11.4%, 37.1%, 22.8%, 11.4%, and 17.1%, respectively, for the patients with autoimmune diseases and 17.8%, 45.8%, 10.9%, 6.8%, and 18.4%, respectively for the controls . Patients with autoimmune/inflammatory diseases seem not to develop a more severe COVID19 infection than controls.     

A single intact ATPase site of the ABC transporter BtuCD drives 5% transport activity yet supports full in vivo vitamin B12 utilization

In all kingdoms of life, ATP binding cassette (ABC) transporters are essential to many cellular functions. In this large superfamily of proteins, two catalytic sites hydrolyze ATP to power uphill substrate translocation. A central question in the field concerns the relationship between the two ATPase catalytic sites: Are the sites independent of one another? Are both needed for function? Do they function cooperatively? These issues have been resolved for type I ABC transporters but never for a type II ABC transporter. The many mechanistic differences between type I and type II ABC transporters raise the question whether in respect to ATP hydrolysis the two subtypes are similar or different. We have addressed this question by studying the Escherichia coli vitamin B₁₂ type II ABC transporter BtuCD. We have constructed and purified a series of BtuCD variants where both, one, or none of the ATPase sites were rendered inactive by mutation. We find that, in a membrane environment, the ATPase sites of BtuCD are highly cooperative with a Hill coefficient of 2. We also find that, when one of the ATPase sites is inactive, ATP hydrolysis and vitamin B₁₂ transport by BtuCD is reduced by 95%. These exact features are also shared by the archetypical type I maltose ABC transporter. Remarkably, mutants that have lost 95% of their ATPase and transport capabilities still retain the ability to fully use vitamin B₁₂ in vivo. The results demonstrate that, despite the many differences between type I and type II ABC transporters, the fundamental mechanism of ATP hydrolysis remains conserved.     

A Common Cognitive Profile in Elderly Fallers and in Patients with Parkinson's Disease: The Prominence of Impaired Executive Function and Attention

The present study examined the cognitive profile of elderly fallers relative to healthy elderly controls and patients with Parkinson's disease (PD), a positive-control group, using a computerized battery. Fallers performed more poorly than controls on executive function, attention, and motor skills, but performed comparably on memory, information processing and the Mini-Mental State Examination. A similar profile was evident for PD patients. However, unlike PD patients, fallers were abnormally inconsistent in their reaction times. These findings indicate that elderly fallers may have a unique cognitive processing deficit (i.e., variability of response timing) and underscore the importance of executive function and attention as potential targets for fall risk screening and interventions.     

Descemet membrane endothelial keratoplasty in iridocorneal endothelial syndrome and posterior polymorphous corneal dystrophy

Objective

To report the clinical outcome of Descemet membrane endothelial keratoplasty (DMEK) in cases of corneal decompensation secondary to iridocorneal endothelial syndrome (ICE) or posterior polymorphous corneal dystrophy (PPCD).

NB‐UVB (311–312 nm)‐induced lentigines in patients with mycosis fungoides: a new adverse effect of phototherapy

Background Lentigines are a common pigmentary disorder in adults and in patients treated by psoralen and ultraviolet A (PUVA) radiation. Their appearance following treatment with narrow‐band ultraviolet B (NB‐UVB) radiation has been reported in only two patients. Objective To describe the clinical and histological features of NB‐UVB‐induced lentigines their relation to dosimetry and the course of the eruption in patients with mycosis fungoides (MF). Methods The files of all patients with MF treated in our department in 2003–2010 were searched to identify those in whom lentigines appeared following monotherapy with NB‐UVB radiation. Results Of the 73 patients with early stage MF identified, 10 met the study criteria. Lentigines were detected in skin previously involved by MF in seven patients, and in both involved and uninvolved skin in three patients. They appeared during therapy in three patients, after a mean of 56 exposures (range 50–61), and several months (mean 7.8) following completion of treatment in seven patients, after a mean of 69 exposures (range 32–157). Histopathological study of lesions from five patients revealed basal hyperpigmentation relative to adjacent normal‐looking skin. Two lesions had a slight increased number of normal‐looking melanocytes on immunohistochemical staining with melanoma cocktail. One lesion had elongated rete ridges. The lesions persisted throughout follow‐up (mean 26.7 months) in 8 patients. Conclusions Patients with MF treated with NB‐UVB may acquire lentigines. As opposed to PUVA‐induced lentigines which are a known common side‐effect of long‐term treatment, NB‐UVB‐induced lentigines are uncommon but appear earlier, even after a few months of treatment.