shukoor65/lab-rag-model huggingface dataset:
Biomechanics of fixation systems to the cervical spine. The biomechanical evaluation of a cervical spine implant must include flexural and torsional testing if it is used for stabilizing a traumatic unstable motion segment. A cadaveric model is presented that allows flexural and torsional testing of a cervical spine motion segment, measuring the tilting angle, the translation, and the torsional angle. After measuring the intact segments, in the first series, a so-called posterior instability was created and stabilized posteriorly with the hook-plate and sublaminar wiring; anteriorly with the H-plate; and with combinations of these implants. In a second series, their stabilizing effect after complete discoligamentous instability was tested. With isolated posterior instability, it was found that the flexural stability is preserved, whereas torsional stability is markedly reduced. In cases of isolated posterior instability, only hook plating alone or its combination with anterior H-plating seemed to bring about a higher torsional stability than the intact specimen. In cases of complete discoligamentous instability, only anterior H-plate and posterior hook plate procedures combined or the hook plate alone was able to guarantee both torsional and flexural stability higher than the intact spine. Exclusive posterior wiring without postoperative external immobilization in complete discoligamentous instability may result in permanent subluxation of the functional unit. Exclusive anterior H-plate fixation in complete discoligamentous instability requires additional external immobilization in the postoperative phase to prevent flexion and torsion.
Postoperative vasospasm after antegrade mesenteric revascularization: a report of three cases. Vascular reconstruction for chronic intestinal ischemia can be accomplished by endarterectomy or aortomesenteric bypass. In our practice, antegrade bypasses from the supraceliac aorta to the celiac axis and superior mesenteric artery are currently the most frequently used techniques. Such reconstructions often use multiple or bifurcated large diameter vascular prostheses and have demonstrated excellent long-term patency. Despite these salutory results, we have noted an unusual perioperative response in three of these patients, which is the subject of this report. All three patients underwent uncomplicated elective mesenteric revascularization with grafts (diameter greater than or equal to 6 mm) originating in the supraceliac aorta. Indications for operation included (1) history of postprandial pain, (2) documentation of weight loss, and (3) angiographic evidence of advanced atherosclerotic disease with appropriate collateral development. Episodes of abdominal pain occurred 5 to 20 days after operation when normal food intake was reinstituted. In two patients immediate angiograms revealed patent grafts with diffuse mesenteric vasospasm. Treatment with intravenous hyperalimentation and nifedipine for 10 days resulted in complete resolution of symptoms. In the third patient, symptoms were totally relieved by temporary reduction in oral intake and administration of nifedipine. A later angiogram revealed a patent graft. All patients have remained asymptomatic and regained normal weight. This pattern of postrevascularization pain has not been seen in our patients undergoing revascularization with small (i.e., venous) conduits originating in the infrarenal aorta. The cause appears to be a heightened myogenic response of a "protected" vascular bed when suddenly exposed to the high perfusion pressure and blood flow of large caliber antegrade conduits. Prophylaxis with calcium channel blockers and use of smaller diameter grafts (5 mm) may avoid this disturbing syndrome.
Immunohistological diagnosis of "plasmacytoid T cell lymphoma" in paraffin wax sections. An immunohistological study of paraffin wax embedded tissue from three cases of plasmacytoid monocyte neoplasms, using a panel of antibodies which react with fixation resistant leucocyte markers, is reported. This neoplasm was found to have a distinctive antigenic profile, being negative for CD3 and elastase, but positive for CD43 and CD68. This immunological phenotype, coupled with its characteristic morphological features, should facilitate the recognition of this rare neoplasm in routinely processed tissue. Furthermore, the term "plasmacytoid monocyte sarcoma" is proposed to designate it because it is inappropriate to refer to it as a lymphoma. As all cases have been associated with a myeloproliferative disorder (usually an acute or chronic myeloid leukaemia), these tumours probably represent the accumulation in lymphoid tissue of neoplastic cells which have differentiated along the plasmacytoid monocyte pathway.
Migraine--why and how a cortical excitatory wave may initiate the aura and headache. A large number of clinical and neurophysiological observations are reviewed that clearly indicate that the symptoms of migraine aura result from a spread of an excitatory wave along the cortex from a primary focus. This excitation may start as a consequence of information overload to a low threshold cortical area. The transient neuronal excitation is followed by a long-lasting period of reduced cortical flow, which involves a substantial component of active constriction of resistance vessels, even persisting for several hours during the headache phase. When the excitatory wave has reached and activated free pain fiber endings in sufficiently many cortical vessels, off-branching peripheral motor endings of these fibers may become activated via axon reflexes. These motor endings may be located in cortical microvessels or in small vessels around large dural vessels. This leads to a neurogenic inflammation in the vessel walls, experienced as headache by the sufferer. The wall of dural sinuses offers a rational explanation for the beneficial effect of most medications used in migraine.
Pelvic denervation for chronic pain associated with endometriosis: fact or fancy? The efficacy of presacral neurectomy and amputation of the uterosacral ligaments in the treatment of chronic pelvic pain has been debated for decades. These procedures used to be done mainly in women with normal pelves, but more recently they have been performed during conservative surgery for treatment of endometriosis. In the 1980s the rapid spread of laparoscopic surgery has led to an increasing number of endoscopic denervations in patients with chronic pelvic pain associated with endometriosis. However, an analysis of literature data has failed to prove that presacral neurectomy and amputation of the uterosacral ligaments are effective and did not demonstrate better results with the use of lasers rather than electrocoagulation. Moreover, no valid comparison has yet been made between laparotomy and laparoscopic methods.
A phase II study of days 1 and 8 cisplatin and recombinant alpha-2B interferon in advanced non-small cell lung cancer. Preclinical data from studies of human lung cancer xenografts suggest that the cytotoxic effects of cisplatin are enhanced by alpha-interferon. To verify the above observations, the authors initiated a Phase II trial in advanced non-small cell lung cancer (NSCLC). Cisplatin was given at 100 mg/m2 during a 28-day cycle in a divided day 1 and day 8 schedule. Starting on day 1, alpha-2B interferon was administered intramuscularly at a dose of 5 million units three times a week continuously for a minimum of 2 months. Between January 1989 and September 1989, 30 patients were evaluated for response and toxicity. According to the staging system proposed by Mountain, 20 patients had Stage IV disease, 7 had Stage IIIB disease, and 3 had Stage IIIA disease. Expression of neuron-specific enolase (NSE) and Leu-7 was immunohistochemically investigated to evaluate possible relationship to treatment response. The response rate was 13.3% (95% confidence interval [CI]: 1.2% to 25%). The four responders showed positivity for NSE, and two of them were positive for Leu-7. An average of three cycles was given. The mean dose intensity administered was 83% of the projected dose for cisplatin and 92% of the projected dose for alpha-2B interferon. A standard scale was used to assess interferon toxicity. Hematologic, renal, and systemic side effects were not significant. In advanced NSCLC the addition of alpha-2B interferon did not increase the cisplatin-induced response rate. Further studies should be performed to determine the real value of chemotherapy response in tumors showing positive immunoreactivity for neural markers such as NSE and Leu-7.
Gastrointestinal carcinoid tumors. Fifty-five patients were evaluated and treated for gastrointestinal (GI) carcinoid tumors at our institution from 1968 through 1988. Thirty patients had primary tumors smaller than 1 cm and were treated surgically or endoscopically by local excision, whereas 25 underwent resection with regional lymphadenectomy for larger primaries. At the time of initial treatment 17 patients demonstrated metastasis. Although 13 of these patients had primary tumors larger than 2 cm, in four patients with ileal carcinoids, the primary measured 0.8 to 1.5 cm. Serosal involvement was present in nine of 17 patients with metastasis. With a follow-up range of 3 months to 20 years, six patients have died with metastatic carcinoid tumor, two patients died without evidence of disease, 12 patients are alive with metastasis, and 35 patients are alive, free of disease. In this series three determinants for risk of metastasis in GI carcinoid tumors were evident: primary size, serosal penetration, and primary site in the small intestine. In patients with any of these risk factors, resection with regional lymphadenectomy is recommended.
Adrenocorticotropic hormone-independent bilateral adrenocortical macronodular hyperplasia as a distinct subtype of Cushing's syndrome. Enzyme histochemical and ultrastructural study of four cases with a review of the literature. Four patients with adrenocorticotropic hormone (ACTH)-independent bilateral adrenocortical macronodular hyperplasia (AIMAH) were examined. All of them were men whose ages ranged from 37 to 52 years. Plasma cortisol levels were high, with a loss of diurnal rhythmicity, and plasma ACTH was undetectable. Adrenal cortisol secretion was not suppressed by dexamethasone, but it was ACTH responsive. Test results for corticotropin-releasing hormone (CRH) also were negative. Image analyses revealed a normal sella turcica and significantly enlarged adrenal glands, which showed enhanced uptake of isotope. Both adrenal glands in all cases were between 72 and 176 g in combined weight and were composed of, and distorted by, yellow nodules. Histologically, small cortical cells with or without lipid, occasional clear cells, and rare compact cells of the usual size were increased in number in the glandular cords. Enzyme histochemically, cortical cells showed weaker activity for 3 beta hydroxysteroid dehydrogenase and other enzymes than did usual cortisol-producing adenomas. Ultrastructurally, they had moderately to poorly developed smooth endoplasmic reticulum. Nonnodular areas of the cortex consisting of nonproliferating cells were atrophic and contained no compact cell zone. This is similar to the adrenal cortices attached to cortisol-producing adenomas. These features are unique to AIMAH and suggest the presence of a distinct subtype of Cushing's syndrome.
Correlates of postural hypotension in a community sample of elderly blacks and whites. Postural hypotension is thought to be prevalent among the elderly, but few community-based studies of this condition have been conducted. In addition, little is known about postural hypotension in blacks despite well documented racial differences in hypertension and stroke. Data on 659 elderly (greater than or equal to 60 years of age) participants in a survey of two rural, biracial townships were analyzed to describe the frequency and correlates of postural hypotension. Twelve percent of the 659 adults experienced a drop of 10 mmHg or greater in systolic blood pressure on going from sitting to standing (supine measures were not available). This degree of postural hypotension was twice as common for whites as for blacks (14.5% vs 7.5%, P = 0.01). Postural hypotension was associated with elevated sitting blood pressure and showed positive but statistically non-significant relationships with anti-hypertensive medications and leanness. The association between race and postural hypotension persisted after adjusting for these and other risk factors (OR = 2.2, 95% CI:1.2,4.0).
Gall stone disease in African patients with sickle cell anaemia: a preliminary report from Yaounde, Cameroon. Cholecystosonography was undertaken in 90 patients with sickle cell disease aged 15 years and over. Gall stones were found in 26 (28.9%) patients. There was no sex difference, but the incidence increased with age from 13.2% at under 20 years to 75% at 30 years and over. The mean serum cholesterol and total and unconjugated bilirubin concentrations were not significantly different between patients with and without gall stones. As most (80.8%) stones were radiolucent they were probably of pigment type, containing little or no calcium, and further investigation into how they are produced is needed. Sickle cell patients with acute abdominal crisis should have gall bladder disease excluded before a diagnosis of vascular crisis is made.
Coronary heart disease risk factor profiles in black patients with non-insulin-dependent diabetes mellitus: paradoxic patterns. PURPOSE: Non-insulin-dependent diabetes mellitus (NIDDM) in black Americans consists of two variants: one with insulin resistance and one with normal insulin sensitivity. This study examined whether cardiovascular disease risk factors are significantly different between the two variants. PATIENTS AND METHODS: Twenty-two black patients with NIDDM in near-normoglycemic remission who were receiving no pharmacologic therapy for NIDDM were evaluated for insulin sensitivity by the euglycemic insulin clamp, plasma insulin levels, degree of obesity, glucose metabolism, serum total, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol levels, and fasting plasma triglyceride levels. RESULTS: Fifty-nine percent of these patients had normal insulin sensitivity (glucose disposal rate in response to a 1 mU.kg-1.minute-1 insulin infusion greater than 6.0 mg.kg-1.minute-1). The insulin-sensitive patients were less obese (body mass index [BMI] 26.5 +/- 0.6 versus 30.8 +/- 0.9 kg/m2) and had lower fasting plasma insulin levels (56.9 +/- 7.8 versus 88.0 +/- 6.0 pmol/L), lower serum cholesterol (4.47 +/- 0.30 versus 6.39 +/- 0.26 mmol/L), lower serum LDL cholesterol (2.77 +/- 0.31 versus 4.51 +/- 0.27 mmol/L), and lower fasting plasma triglyceride levels (0.83 +/- 0.08 versus 1.45 +/- 0.16 mmol/L) than the insulin-resistant patients. Serum HDL cholesterol was not different between the two groups and was in the high-normal range (1.31 +/- 0.08 and 1.19 +/- 0.07 mmol/L). Univariate analysis demonstrated that serum total cholesterol, LDL cholesterol, and fasting plasma triglycerides were highly correlated with insulin-mediated glucose disposal and fasting plasma insulin. The differences in insulin sensitivity and lipid profiles were independent of obesity, as they were present in six insulin-resistant and six insulin-sensitive patients matched for BMI. CONCLUSIONS: Black patients with the insulin-sensitive variant of NIDDM have a low risk factor profile for cardiovascular disease as compared with those with the insulin-resistant variant, who have a high risk factor profile. A high prevalence of the insulin-sensitive variant of NIDDM in the black population might explain the lower prevalence of angina and myocardial infarction in black patients with NIDDM as compared with white patients with NIDDM.
Decreased adherence of interleukin 6-treated breast carcinoma cells can lead to separation from neighbors after mitosis. Interleukin 6 (IL-6) has been shown to inhibit the proliferation, but increase the motility, of wild-type ZR-75-1 human ductal breast carcinoma cells, a line of cells that resemble closely the malignant cells cultured from the ascitic effusion. IL-6-treated cells lose their epithelial character, become stellate or fusiform in shape, and migrate away from neighbors. In the wild-type ZR-75-1 cells, IL-6 causes cell-cell separation in preformed colonies as well as postmitotically. We have now investigated the action of IL-6 in clone B ZR-75-1 cells, which are morphologically distinct from wild-type ZR-75-1 cells. In the more polygonal rather than cuboidal clone B cells, IL-6 did not cause early inhibition of DNA synthesis and it caused little cell-cell separation in preformed colonies. However, IL-6 treatment markedly prolonged the interval between mitosis and readherence of daughter cells to their neighbors and the substratum. Supernatants from IL-6-treated cultures contained detached viable cells in increased numbers. Intermitotic intervals were prolonged in IL-6-treated cultures. IL-6-treated dividing breast carcinoma cells are characterized by an increased probability of separation from neighbors and the substratum.
Visual function in patients undergoing long-term total parenteral nutrition. To evaluate the effects of long-term total parenteral nutrition (TPN) on eye function, 27 adults and 12 children in the UCLA Home TPN Clinic underwent ophthalmoscopic examination and visual-function testing. Direct inspection of the fundus showed a marked granularity of the retinal pigmented epithelium in some patients. About one-half of the children and one-third of the adults tested had at least one and usually two abnormalities in their electroretinogram. Determination of blood nutrients thought to affect vision revealed that zinc and vitamin E were within normal range. Vitamin A concentrations were above normal in 10 of 19 adults and selenium concentrations were below normal in 10 of 10 children and 17 of 21 adults tested. Linoleic and linolenic acid concentrations were low; plasma, platelet, and urine taurine concentrations were significantly lower than normal. Despite these diffuse nutrient abnormalities, only zinc and vitamin E concentrations correlated significantly with any index of visual function.
Lymphomas in University College Hospital, Ibadan, Nigeria. The authors reviewed 508 cases of lymphoma seen during a 16-year period in University College Hospital, Ibadan, Nigeria. Hodgkin's disease was diagnosed in 95 (18.6%) patients, of which 45% had mixed cellularity type; 19%, lymphocyte predominance; 18%, nodular sclerosis; and 18%, lymphocyte depletion. The age distribution showed a single mode in the 11 to 25-year-old group. Male preponderance was more marked in children who made up 32% of the Hodgkin's disease patients. Non-Hodgkin's lymphoma occurred in 413 cases, of which 296 (71.7%) were high-grade malignancies. Burkitt's tumor occurred in 211 (41.5%) patients, 95% of whom were children, and showed a male to female ratio of 1.7:1. Compared with previous findings in this hospital, Hodgkin's disease showed increased proportions of the lymphocyte predominant and nodular sclerosing types. However, the characteristics of Burkitt's lymphoma did not change appreciably in the last three decades.
Influence of environmental temperature on the blood pressure of hypertensive patients in Montreal. To assess the influence of environmental temperature on blood pressure, we analyzed 42,813 readings of systolic and diastolic blood pressures in recumbent and upright positions in 2,000 hypertensive patients in our clinic in correlation to noon temperature and mean daily temperature in Montreal. The sample comprised 860 men and 1140 women with an average age of 55 years. Analysis of variance showed highly statistically significant negative correlations for all blood pressure values between different noon temperature, as well as mean daily temperature, groups. The greatest difference for systolic blood pressure was 7 mm Hg, and for diastolic blood pressure it was 3 mm Hg, within the -24 degrees C to 27 degrees C temperature range. The same relationship between blood pressure and different environmental temperatures was also seen when the blood pressure recordings were divided between temperature below 0 degree C and above 0 degree C, ie, within the winter or summer months. This environmental effect may have a clinically significant impact because thermosensitivity appears to be related to hypertension.
Increased tryptase levels in suction-blister fluid from patients with urticaria. The levels of tryptase in the suction-blister fluid from patients with chronic urticaria, urticaria pigmentosa, cholinergic urticaria, urticarial dermographism, prurigo of unknown origin, eczema, psoriasis, atopic dermatitis, and from healthy controls were studied. The blister fluid from controls contained up to 15 micrograms/l of tryptase, whereas that from patients with active urticaria contained greater than 50 micrograms/l. This study demonstrates that patients with urticaria have mast cells that readily release tryptase in both the lesional and non-lesional areas of skin.
Nephrogenic rests in Wilms tumor patients with the Drash syndrome. The histological specimens from 12 patients with the Drash syndrome were identified from the National Wilms Tumor Study Group and reviewed for the presence of nephrogenic rests. Of 7 patients with the complete Drash syndrome 6 were evaluable for nephrogenic rests, including 5 (83%) who demonstrated intralobar nephrogenic rests. Of 5 (80%) partial Drash syndrome cases 4 (80%) were also intralobar nephrogenic rest positive. Neither group had perilobar nephrogenic rests identified. In a control population of Wilms tumor patients without the Drash syndrome only 39 of 274 (14%) with unilateral tumor had intralobar nephrogenic rests identified, whereas 26 of 92 (28%) bilateral cases had intralobar nephrogenic rests. There was a significantly higher rate of intralobar nephrogenic rests in complete and partial Drash syndrome cases than in the general Wilms tumor population (p less than 0.001). Wilms tumor patients with intralobar nephrogenic rests and the Drash syndrome present at a younger age and have a higher rate of bilaterality than rest negative Wilms tumor patients. The strong association of intralobar nephrogenic rests in the Drash syndrome approaches that found in the aniridia complex. However, in other syndromes associated with Wilms tumor, such as the Beckwith-Wiedemann syndrome and hemihypertrophy, there is a high prevalence of perilobar nephrogenic rests. In view of the high incidence of intralobar nephrogenic rests in complete and partial Drash syndrome patients, it is probable that events leading to Wilms tumor in patients with the Drash syndrome occur at an early stage in nephrogenesis.
Nonfunctioning parathyroid carcinoma. Parathyroid carcinoma is a rare clinical entity accounting for only 4 per cent of all cases of parathyroid neoplasia. Nonfunctioning parathyroid carcinoma is even rarer. Previously, virtually all patients with these lesions were treated for a nonspecific neck mass. However, in the present case, a preoperative diagnosis of nonfunctioning parathyroid carcinoma was made based on the technetium pertechnetate/thallium 201 subtraction scan. The authors report on the 14th case of nonfunctioning parathyroid carcinoma, a review of the literature, and guidelines for the preoperative and operative evaluation of neck masses suspected to be parathyroid carcinoma.