Melricflash/CW_MedAbstractsAlt huggingface dataset:
Evaluation of the perforating veins of the lower extremity using high resolution duplex imaging. The purpose of this study was to evaluate duplex imaging as a means of assessing perforating veins in patients with longstanding venous stasis ulceration. Thirty patients with nonhealing venous stasis ulcers and twenty normal volunteers serving as controls were evaluated with a standard 8-MHz imaging probe and integrated pulsed Doppler. The internal diameter of perforating veins was measured and perforators were grouped into one of four categories based on functional criteria: competent perforator with venous flow (C); incompetent perforator with venous flow (IC); competent perforator with arteriovenous flow (C-AVC); incompetent perforator with arteriovenous flow (IC-AVC). Sixteen of the patients with ulcers were subsequently studied by ascending venography and in 11 patients, intraoperative identification of perforating veins was made during the Rob procedure. In this subset of patients the vessel was categorized as competent or incompetent regardless of flow signal. There were significant differences in mean perforator diameter between ulcer patients and normal volunteers. Duplex imaging identified 93 perforators and venography a total of 70. In all 16 extremities, duplex imaging made the diagnosis of significant perforating vein incompetence, verified by venography. Intraoperative findings demonstrated an excellent correlation with duplex imaging. We believe duplex imaging to be a promising new modality for evaluation of the perforating veins of the lower extremity. 

Category: cardiovascular diseases
Respiratory input impedance in anesthetized paralyzed patients. Respiratory impedance (Zrs) was measured between 0.25 and 32 Hz in seven anesthetized and paralyzed patients by applying forced oscillation of low amplitude at the inlet of the endotracheal tube. Effective respiratory resistance (Rrs; in cmH2O.l-1.s) fell sharply from 6.2 +/- 2.1 (SD) at 0.25 Hz to 2.3 +/- 0.6 at 2 Hz. From then on, Rrs decreased slightly with frequency down to 1.5 +/- 0.5 at 32 Hz. Respiratory reactance (Xrs; in cmH2O.l-1.s) was -22.2 +/- 5.9 at 0.25 Hz and reached zero at approximately 14 Hz and 2.3 +/- 0.8 at 32 Hz. Effective respiratory elastance (Ers = -2pi x frequency x Xrs; in cmH2O/1) was 34.8 +/- 9.2 at 0.25 Hz and increased markedly with frequency up to 44.2 +/- 8.6 at 2 Hz. We interpreted Zrs data in terms of a T network mechanical model. We represented the proximal branch by central airway resistance and inertance. The shunt pathway accounted for bronchial distensibility and alveolar gas compressibility. The distal branch included a Newtonian resistance component for tissues and peripheral airways and a viscoelastic component for tissues. When the viscoelastic component was represented by a Kelvin body as in the model of Bates et al. (J. Appl. Physiol. 61: 873-880, 1986), a good fit was obtained over the entire frequency range, and reasonable values of parameters were estimated. The strong frequency dependence of Rrs and Ers observed below 2 Hz in our anesthetized paralyzed patients could be mainly interpreted in terms of tissue viscoelasticity. Nevertheless, the high Ers we found with low volume excursions suggests that tissues also exhibit plasticlike properties. 

Category: general pathological conditions
White matter hyperintensities in dementia of Alzheimer's type and in healthy subjects without cerebrovascular risk factors. A magnetic resonance imaging study. T2-weighted (0.5 T) magnetic resonance images were used to study the prevalence of subcortical white matter hyperintensities (WMHIs) in 22 patients with dementia of Alzheimer's type (DAT), 20 age-matched older healthy control subjects, and 10 younger healthy control subjects. Exclusionary criteria for all groups included cerebrovascular risk factors. All subjects had Hachinski Ischemic Index scores of less than 2 and computed tomographic scans showing no infarct. The WMHIs were classified as periventricular WMHIs or deep WMHIs and graded 0 through 3 (0 indicated absent, and 3, severe). For the group with DAT and older control subjects, periventricular WMHIs and deep WMHIs were graded 2 or 3 in fewer than 17% and 27% of subjects, respectively, whereas in the younger control subjects, all ratings were grade 1 or less. Serum cholesterol and systolic blood pressure values, although within the normal range, were elevated significantly in older control subjects when compared with those in younger control subjects. No significant differences in WMHI ratings, blood pressure, cholesterol, or triglyceride levels were found between patients with DAT and age-matched control subjects. Systolic blood pressure levels correlated with the severity of periventricular WMHIs only in older control subjects. Age correlated with periventricular WMHIs and deep WMHIs within both the older control subjects and the patients with DAT. There was no significant correlation between WMHIs and the severity of dementia in the group with DAT. These results suggest that, in subjects screened for cerebrovascular risk factors, WMHIs are rare and occur with identical frequency in patients with DAT as in age-matched healthy control subjects. 

Category: nervous system diseases
Creutzfeldt-Jakob disease from allogeneic dura: a review of risks and safety. Surgeons and the lay public have recently expressed concern over the safety of allogeneic dura as it relates to the transmission of Creutzfeldt-Jakob Disease. Indeed, two cases have resulted from use of tissue procured from a commercial agency that did not adhere to criteria accepted by the American Association of Tissue Banks or the Southeast Organ Procurement Foundation. This review discusses the risks and safety of allogeneic dura. The findings should reassure the surgeon of the safety of allogeneic dura when it is properly processed and catalogued by a bona fide, reputable tissue bank. To date, there have been no documented cases reported to the Center for Disease Control in which Creutzfeldt-Jakob Disease was transmitted from allogeneic dura obtained from a registered tissue bank. 

Category: nervous system diseases
The effect of quinidine and mexiletine on the adaptation of ventricular refractoriness to an increase in rate. The purpose of this study was to determine the effects of quinidine and mexiletine on the adaptation of ventricular refractoriness to a change in heart rate. The ventricular effective refractory period was measured at a basic drive cycle length of 500 msec with basic drive train durations of two beats, eight beats, 20 beats and 3 minutes. The ventricular refractory periods were measured in the baseline state and after oral treatment with quinidine or mexiletine in 20 subjects each. In the baseline state, there was progressive shortening of the ventricular refractory period as the drive train duration increased from two beats to 3 minutes. Quinidine prolonged refractoriness by 5% (p less than 0.001) at each drive train duration. Mexiletine did not affect the ventricular effective refractory period at any of the drive train durations. In a control group of 20 subjects, there were no significant differences between two determinations of refractoriness at each basic drive train duration. In conclusion, neither quinidine nor mexiletine affect the adaptation of ventricular refractoriness to an increase in rate. Although the ventricular effective refractory period measured with a conventional basic drive train duration of eight beats is often more than 20 msec longer than the actual ventricular effective refractory period measured with a drive train duration of 3 minutes, the effects of quinidine and mexiletine on the conventionally measured ventricular effective refractory period accurately reflect the effects of these drugs on the actual ventricular effective refractory period. 

Category: nervous system diseases
The long-term effectiveness of hysteroscopic treatment of menorrhagia and leiomyomas. One hundred fifty-six of 177 patients admitted to the St. Luke's/Roosevelt Hospital Center between November 1973 and November 1988 for hysteroscopic treatment of menorrhagia and/or uterine leiomyomas were followed for long-term complications and necessity for repeat surgery. Ninety-four patients underwent submucous resection alone and 62 patients underwent endometrial ablation with or without submucous resection. Among the submucous-resection group, 24.5% reported late postoperative problems and 15.9% underwent further surgery. After 9 years of followup, 83.9% of the patients had not required further surgery. Among the ablation group, 22.5% experienced recurrence of increased bleeding and 8.1% had another surgical procedure. After 6 years of follow-up, 91.3% of the patients had not required further surgery. Twenty-one patients became pregnant after submucous resection, with 18 infants delivered. No patients who underwent endometrial ablation became pregnant. This modality of treatment appears to be effective over the long term, although effectiveness appears to diminish with time. 

Category: general pathological conditions
Hemopump ventricular support for patients undergoing high risk coronary angioplasty. Prophylactic implantation of a Hemopump (Johnson and Johnson, Skillman, NJ) has been evaluated in nine patients selected for high risk coronary angioplasty. They were unstable patients, refractory to maximal pharmacology, with indications for revascularization, but contraindications for surgery such as low ejection fraction and lack of material for bypass. In all, the target lesion was located on the last patent vessel. The pump was inserted under local anesthesia, without any graft. A specially designed occluder permitted avoidance of retrograde bleeding during implantation. The bypass flow ranged from 2.5 to 3.2 L/min, and permitted a rise in cardiac index from 2.05 to 2.55 L/min/m2, with a drop in capillary wedge pressure from 13 (7-18) to 10 (7-13) mmHg. During balloon inflation, no electrocardiographic changes were observed, because only minor ventricular arrhythmias occurred. No significant hemolysis was seen (plasma free hemoglobin less than 10 mg/dl in all) after 2 hr of pumping. The only limitation of the technique appears to be difficulty at the time of implantation from narrow, stenosed, or tortuous iliofemoral arteries (3 patients). This experience strongly supports the benefit of temporary left ventricular Hemopump support in high-risk situations and clearly shows the need for a smaller pump. 

Category: cardiovascular diseases
The effects of epidural anesthesia on the Doppler velocimetry of umbilical and uterine arteries in normal and hypertensive patients during active term labor. To study the effects of epidural anesthesia on uterine and umbilical artery blood flow in preeclampsia, we observed 25 patients in active labor at 36 or more weeks' gestation. Seven had preeclampsia, eight had chronic hypertension, and ten had no complications. Doppler velocimetry of the uterine and umbilical arteries was performed before and after intravenous fluid loading and at 30 and 60 minutes after epidural blockade. Maternal vital signs and fetal heart rate were monitored continuously. After epidural block, mean maternal blood pressure fell significantly in all groups, but no maternal hypotension was observed. Mean maternal and fetal heart rates were unchanged. After epidural block, mean uterine artery systolic-diastolic (S-D) ratios did not change in the chronic-hypertension and normal groups, but fell significantly in the preeclamptic group to values similar to those of the normal group. Umbilical artery S-D ratios did not change in any group. In preeclamptic pregnancy, epidural anesthesia may help to reduce uterine artery vasospasm and may benefit intrapartum fetal well-being. 

Category: cardiovascular diseases
Inflammatory abdominal aortic aneurysms. In a series of 517 operations for abdominal aortic aneurysm from 1971 to 1988 there were 45 cases (8.7%) with an inflammatory aneurysm with a typical thick glistening whitish fibrous layer. Almost two-third of the patients had rather severe chronic or acute progressive pain in the abdomen, the back or the flank. Unilateral (7) or bilateral (2) hydronephrosis due to ureteral compression occurred in 9 patients (20%). A diagnosis of inflammatory aneurysm was made preoperatively only in 10 patients. In 8 of the 9 patients with hydronephrosis ureterolysis was done, unilaterally (6) or bilaterally (2). After ureterolysis all had complete resolution of the hydronephrosis. Preoperative diagnostic methods are excretory urography, showing medial deviation, ultrasonography and CT-scanning of the abdominal aorta. All patients with an inflammatory aneurysm should undergo aortic replacement to prevent rupture and achieve pain relief. Ureterolysis in cases of hydronephrosis is strongly recommended and may be performed safely and with excellent results. 

Category: cardiovascular diseases
Mental activity, adrenergic modulation, and cardiac arrhythmias in patients with heart disease. All of the electrophysiological mechanisms of arrhythmias are sensitive to the influences of the autonomic nervous system, particularly to its adrenergic limb. Arrhythmogenic areas may also be dependent on the inhomogeneity of these influences because of their pathophysiological structure and/or the neurogenic or humoral nature of the vector of modulation. The complexity of the various possible scenarios, combined with the role of the rate dependence, explains why standardized protocols exploring the autonomic nervous system in clinical arrhythmias are difficult to define. Invasive electrophysiology is not adapted to address the problem. Isoprenaline infusion only reproduces the humoral adrenergic stimulation to which only a few types of arrhythmias are sensitive. The exercise test is a very complex investigation if the multiple parameters involved are considered. Only a part of its limitations are obviated by the mental stress. Under natural conditions, the neurogenic origin, the intensity of the sympathetic stimulation, and its suddenness are all critical factors responsible for severe tachyarrhythmias. Arrhythmias of the long QT syndrome are particularly demonstrative of the importance of the autonomic nervous system, but this evidence can also be documented in more trivial circumstances of diseased or apparently undiseased hearts. Exploring the autonomic nervous system behavior through heart rate variability in ambulatory recordings is the most recent and fruitful method of investigation. This nonprovocative approach has technical obstacles and practical and theoretical limitations related to the fundamental nature of the autonomic nervous system, which is both a marker of the cardiac status and a determinant of arrhythmias. 

Category: cardiovascular diseases
Facial bone fracture associated with carotid-cavernous sinus fistula. Out of 989 cases of facial bone fracture, ten patients had carotid-cavernous sinus fistulas (1.01%). Their ages ranged from 25 to 48 years. Seven were male and three female. Two of the ten patients had lower third, three patients had middle third, three patients had upper third, and two patients had combined middle and lower third facial bone fractures. The signs and symptoms of a fistula appeared from the first postinjury day up to 50 days after the injury (mean, 21 days). Four patients had symptoms after operation for facial bone fracture. Most fistulae were identified by arteriography before treatment. Followup ranged from 1 year, 8 months, to 5 years, 9 months (mean, 2 years, 9 months). One patient had a malocclusion. Nine patients had complete resolution of their bruits. Complications included unilateral complete visual loss (two), CSF rhinorrhea (two), and stroke in one of the two CSF rhinorrhea patients. One patient expired due to a severe head injury, and there was one death from an unrelated cause. 

Category: nervous system diseases
Nephropathy in model combining genetic hypertension with experimental diabetes. Enalapril versus hydralazine and metoprolol therapy. We compared the effects of the angiotensin-converting enzyme inhibitor enalapril and a conventional antihypertensive regimen (hydralazine and metoprolol) on kidney function, albuminuria, and glomerular ultrastructure in hypertensive diabetic and nondiabetic rats. Diabetes was induced with streptozocin at 8 wk of age in spontaneously hypertensive (SHR) rats. Antihypertensive drugs were administered in drinking water from the time of induction of diabetes in all groups. Blood pressure reduction was equal in the diabetic and nondiabetic SHR rats receiving either enalapril or hydralazine plus metoprolol. In diabetic SHR rats, there was a rise in serum creatinine after 32 wk, which did not occur in diabetic rats treated with either antihypertensive regimen or in nondiabetic rats. Both drug regimens reduced albuminuria in diabetic and nondiabetic SHR rats to a similar degree. Enalapril and the combination of hydralazine and metoprolol were associated with decreased glomerular basement membrane thickness and glomerular volume in diabetic and nondiabetic SHR rats without significant effect on fractional mesangial volume. Thus, antihypertensive therapy retards the development of albuminuria, glomerular basement membrane thickening, and glomerular hypertrophy in the rat in the presence or absence of diabetes. No specific benefit of angiotensin-converting enzyme inhibition was observed in these hypertensive models of nephropathy. Human studies comparing the effects of different classes of antihypertensive drugs on kidney function, proteinuria, and glomerular morphology are warranted. 

Category: cardiovascular diseases
Endoscopic appearance and significance of functional lymphangiectasia of the duodenal mucosa. Intestinal lymphangiectasia is found in a wide variety of pathologic conditions. Functional lymphangiectasia has not been well characterized. We report 20 patients followed for 9 to 55 months (mean 30 months) after incidental detection at endoscopy of lymphangiectasia. Our study indicates that functional lymphangiectasia is not pathologic and does not warrant repeat endoscopy in the absence of other clinical indications. 

Category: digestive system diseases
Postictal psychosis after partial complex seizures: a multiple case study. Bouts of unusually frequent partial complex seizures originating in the temporal lobe, that sometimes became secondarily generalized, induced psychotic episodes in 9 patients. In 7, the increase in seizures occurred at a time when antiepileptic drugs (AEDs) were being reduced during intensive EEG monitoring with a view to surgical treatment of intractable epilepsy. According to DSM-III-R criteria, the postictal psychosis resembled an organic delusional syndrome which was paranoid in 7 and schizophreniform in 1 and an organic mood syndrome in 1. A high incidence of ictal fear, of bilateral independent epileptogenic discharge, and of small foreign tissue lesion were unexpected findings and appeared to represent risk factors, especially in patients otherwise handicapped by an epileptic personality disorder. Recognition of postictal psychosis in this setting and in others is important both prognostically and therapeutically. Postictal psychosis does not constitute a contraindication to surgical treatment of epilepsy. 

Category: nervous system diseases
Popliteal artery aneurysms. Long-term follow-up of aneurysmal disease and results of surgical treatment. The natural history of aneurysmal disease was analyzed in 50 patients who were treated for 71 popliteal aneurysms. No patients were lost to follow-up (mean, 5.0 years). Initially, 25 popliteal aneurysms (25/71; 35%) were treated nonsurgically, and 46 (46/71; 65%) were treated surgically. Complications developed in 12 of the 21 asymptomatic popliteal aneurysms (57%) and in 2 of the 4 symptomatic popliteal aneurysms (50%), which were treated nonsurgically. The probability of developing complications increased with time to 74% within 5 years. When reconstruction of a popliteal aneurysm was performed, graft patency and foot salvage were 64% and 95% at 10 years, respectively. Particularly acute arterial thromboembolism was a severe presenting complication. Another important finding was the development of 23 arteriosclerotic aneurysms at other locations during follow-up in 16 patients (32%). The probability of developing these new aneurysms increased to 49% 10 years after repair of the initial popliteal aneurysm. The presence of multiple isolated aneurysms at the initial examination was the most significant risk factor limiting the survival of these patients. Consequently patients at risk could be identified early. This study confirms the limb-threatening potential of popliteal aneurysms when left untreated. Therefore prophylactic reconstructive surgery should be undertaken. Moreover, this study demonstrates that patients with a popliteal artery aneurysm have an increased risk of new aneurysm formation, both in the popliteal artery and at other locations. Therefore these patients should be followed and, in the event that new aneurysms develop, should be considered for elective reconstructive surgery to prevent limb-threatening or life-endangering complications. 

Category: cardiovascular diseases
Malnutrition and carbohydrate malabsorption in children with vertically transmitted human immunodeficiency virus 1 infection. The nutritional needs of children with human immunodeficiency virus infection are poorly understood. Twenty-eight children with vertically transmitted human immunodeficiency virus infection were evaluated for carbohydrate malabsorption using lactose hydrogen breath tests and d-xylose absorption studies. Lactose malabsorption was a common finding in human immunodeficiency virus-infected children and occurred in 8 of 20 patients who had no identifiable enteric pathogen. Lactose malabsorption occurred at an earlier age in human immunodeficiency virus-infected children than in an age-matched group of 45 symptomatic control children (P = 0.02). However, lactose malabsorption was not associated with higher rates of diarrhea or growth failure. Abnormalities in d-xylose absorption were not significantly associated with either diarrhea or growth failure. However, 39% of d-xylose studies (9 of 23) showed abnormal results and were significantly associated with enteric infections (P = 0.004). Abnormalities in small-bowel morphology were found in 4 of 9 children with growth failure, 3 of whom had an enteric infection and low d-xylose absorption. Lactose hydrogen breath testing and d-xylose testing showed carbohydrate malabsorption in 61% of children (17 of 28). This study demonstrates that human immunodeficiency virus-infected children are at risk for malabsorptive disorders, which are not always related to clinical symptoms. We speculate that human immunodeficiency virus may be directly involved in the development of lactose malabsorption. Carbohydrate malabsorption in human immunodeficiency virus-infected children may not be the only factor responsible for growth failure. 

Category: digestive system diseases
Ogilvie's syndrome. Would you recognize it? Numerous conditions predispose to Ogilvie's syndrome, a process that mimics bowel obstruction. Characteristic radiographic findings of acute pseudo-obstruction include dilatation of the cecum and the remainder of the colon but not the small intestine. Treatment is individualized. Massive cecal dilatation carries the risk of cecal perforation and its attendant high mortality rate. Conservative therapies, such as nasogastric suction, gentle enemas, and use of a rectal tube, may be beneficial. Decompression by colonoscopy or other means may be necessary. 

Category: digestive system diseases