Melricflash/CW_MedAbstractsAlt huggingface dataset:
How and why aztreonam works. Aztreonam is the first monocyclic beta-lactam antibiotic (monobactam) to be tested clinically. Its synthetic structure determines specific areas of activity, including enhanced activity against Pseudomonas species, exceptional activity against gram-negative bacteria, stability to beta-lactamases and lack of activity against gram-positive bacteria--all of which can be directly related to its chemical composition. Aztreonam has a high affinity for the protein-binding protein 3 (PBP-3) of aerobic gram-negative bacteria. Most of these organisms are inhibited and killed at low concentrations of the drug. Aztreonam binds poorly to PBP sites of the aerobic gram-positive and anaerobic bacteria and consequently has relatively poor inhibitory effects against these bacteria. In vitro, minimum inhibition concentration (MIC) values against almost all of the Enterobacteriaceae and against Neisseria and Haemophilus strains are typically below 1 microgram per milliliter. MIC values against Pseudomonas aeruginosa of 8 micrograms per milliliter are comparable with those of other antipseudomonal beta-lactams and the acylureidopenicillins. As combination therapy with amino-glycosides, aztreonam acts in synergy against P. aeruginosa, Acinetobacter and gentamicin-resistant gram-negative rods. Aztreonam is widely distributed in the body tissues and fluids, and the average elimination half-life is 1.7 hours. Intramuscular dosing results in peak serum levels in approximately one hour, while intravenous dosing results in peak levels within five minutes. After a 2 gram dose given intravenously, MIC90 values for most of the Enterobacteriaceae are exceeded for eight hours, and those for P. aeruginosa, for almost six hours. The steady-state volume of distribution is approximately 0.18 liter per kilogram. Concentrations above the MIC90 for most gram-negative bacteria are also present within bone, prostate and cerebrospinal fluid. Between 60 and 70 per cent of the drug is excreted unchanged in the urine, resulting in concentrations approximating 3,000 micrograms per milliliter two hours after a 1 gram dose given intravenously. Serum clearance of aztreonam is directly proportional to creatinine clearance. Dosage adjustment must, therefore, be made in the presence of reduced clearance. Dosing varies between 0.5 and 2.0 grams every six to 12 hours, depending on the severity of the infection. The characteristics of aztreonam suggest that it is a useful nonnephrotoxic drug for treatment of aerobic gram-negative infection. 

Category: general pathological conditions
A study of fatigue in systemic lupus erythematosus. Fifty-nine patients with systemic lupus erythematosus were evaluated by questionnaires, histories, physical examinations and routine laboratory studies in order to better understand their fatigue. The fatigue severity scale (scored from 1 to 7) was used to measure fatigue and yielded a mean score +/- SD of 4.6 +/- 1.5. Fifty-three percent of the patients reported that fatigue was their most disabling symptom. Although perceived as severe, the symptom of fatigue did not correlate significantly with any of the laboratory measures. However, there was a significant correlation between fatigue and the physician's rating of disease activity. Fatigue also correlated significantly with depression which accounted for 21% of the variation in fatigue scores. 

Category: general pathological conditions
Emergency laparoscopy. Unnecessary abdominal explorations in severely injured patients can be reduced by employing emergent or urgent laparoscopy in blunt abdominal trauma and the obscured, acute abdominal cases. In 150 blunt abdominal trauma cases, a mini-laparoscopy was used in the emergency room or the intensive care unit without major complications. In 56%, the findings were negative. In 19%, the laparoscopic findings were corroborated by surgery. In 25%, a minimal to moderate hemoperitoneum was found and the laparoscopic impression dictated close observation. Unnecessary exploration was avoided except in one case. In the elderly high-risk patient with a poor history, abdominal examination can be noninformative. Laparoscopy can detect acute appendicitis or organ perforation. In the young female, appendicitis can be differentiated from pelvic inflammatory disease. Laparoscopy is more accurate and gives a larger latitude for decision-making than lavage. It can also be useful in the obscured problematic abdominal case. 

Category: digestive system diseases
Kaposi's sarcoma of the colon in a young HIV-negative woman with Crohn's disease. We report a case of isolated colonic Kaposi's sarcoma in a 36-year-old HIV-negative woman with refractory Crohn's disease of the colon and perineum following 11 months' treatment with azathioprine. The clinical features of this case are quite different from those classically described in Kaposi's sarcoma. Among the known risk factors, iatrogenic immunosuppression would appear to be the most probable. 

Category: digestive system diseases
Carotid-esophageal fistula following a penetrating neck injury: case report. Carotid arterial injuries frequently are associated with injuries to adjacent structure of the neck, particularly the esophagus and trachea. Complications from these repairs are common and fistula formation is herein described between the carotid artery and esophageal repair. 

Category: general pathological conditions
Insulin-like growth factor I expression by tumors of neuroectodermal origin with the t(11;22) chromosomal translocation. A potential autocrine growth factor. Expression of insulin-like growth factor I (IGF-I) mRNA by some tumor cell lines of neuroectodermal origin has been described. To further explore the significance of IGF-I mRNA expression in these tumors, a more extensive analysis was performed. Most (9 of 10) neuroectodermal tumor cell lines with a t(11;22) translocation (primitive neuroectodermal tumor [PNET], Ewing's sarcoma, esthesioneuroblastoma) expressed IGF-I mRNA, whereas 0 of 15 cell lines without the translocation (PNET, neuroblastoma) expressed IGF-I. Furthermore, inasmuch as all neuroblastoma (12 of 12) cell lines examined expressed IGF-II RNA, the pattern of IGF expression could distinguish between these closely related tumors. CHP-100, a PNET cell line with the t(11;22) translocation, was shown to secrete both IGF-I protein and an IGF binding protein, IGFBP-2. This cell line also expressed the type I IGF receptor mRNA, and blockade of this receptor by a monoclonal antibody (alpha IR3) inhibited serum-free growth. These data demonstrate that IGF-I expression is a property of neuroectodermal tumors with a t(11;22) translocation and that interruption of an IGF-I autocrine loop inhibits the growth of these tumor cells. 

Category: general pathological conditions
Activation of Epstein-Barr virus latent genes protects human B cells from death by apoptosis. Epstein-Barr virus (EBV), a human herpesvirus, establishes a persistent asymptomatic infection of the circulating B-lymphocyte pool. The mechanism of virus persistence is not understood but, given the limited lifespan of most B cells in vivo, it seems most likely that EBV-infected cells must gain access to the long-lived memory B-cell pool. Here we show in an in vitro system that EBV, through expression of the full set of eight virus-coded 'latent' proteins, can protect human B cells from programmed cell death (apoptosis), the deletion mechanism which normally restricts entry into memory. We have found that EBV-positive Burkitt's lymphoma (BL) cell clones retaining the original tumour cell phenotype and expressing only one of the virus latent proteins, the nuclear antigen EBNA 1, are extremely sensitive to apoptosis; in this respect they resemble the tumour's normal cell of origin found in the germinal centres of lymphoid tissue. By contrast, isogenic BL cell clones which have activated expression of all eight EBV latent proteins are resistant to the induction of apoptosis. The EBV latent proteins should therefore be seen not just as activators of B-cell proliferation but, perhaps more importantly, as mediators of enhanced B-cell survival. 

Category: neoplasms
Bilateral breast cancer. A second primary breast cancer in the opposite breast can be either synchronous or metachronous. The majority are metachronous. A woman who has had breast cancer has a fivefold increase in risk for a second breast cancer. Additional risk factors include multifocal cancer, lobular carcinoma in situ, and an original cancer at an early age with long survival. Lobular carcinoma in situ is predominantly a marker for the subsequent development of a second primary breast cancer. The incidence of synchronous bilateral cancer is approximately 1% to 2% and that of metachronous cancer 5% to 6%. The cancer can be invasive or noninvasive. Mammography has increased the number of synchronous cancers found but not the overall incidence. The incidence of invasive cancer detected by random biopsy of the opposite breast is not high enough to justify routine adoption of this procedure. The remaining breast must be followed for the remainder of the patient's life by physical examination and annual mammography. The treatment of the secondary primary breast cancer should be that appropriate for the stage of the disease. The prognosis for the woman with a second primary breast cancer is quite favorable and is dependent on the stage of both the first and the second cancer. 

Category: neoplasms
Esophageal malignancies: is preoperative radiotherapy the way to go? During the period 1969 to 1988, 68 patients with esophageal malignancy were subjected to preoperative radiotherapy consisting of 30 Gy over 3 weeks followed by esophagectomy after a wait of 2 weeks. Sixty-two of 68 patients (91%) were followed up retrospectively (5-year survival rate, 17.2%; 10-year survival rate, 4.8%). Radiosensitivity of the tumor was graded by a radiation effect scoring method devised by us, and this was found to correlate with long-term prognosis (p = 0.05). Radiotherapy "sterilized" malignant involvement of adventitia and draining lymph nodes in 8 patients and thereby converted "palliative" into potentially "curative" resections with a mean survival of 57.2 months in this group of patients. Preoperative radiotherapy was found to increase the survival, decrease the incidence of residual tumor at the resected stump, reduce the incidence of local recurrence, and increase the resectability rate. 

Category: general pathological conditions
Long-term outcome after surgical repair of isolated atrial septal defect. Follow-up at 27 to 32 years BACKGROUND. Atrial septal defects have been surgically correctable for more than 30 years. The long-term survival rates among patients treated in the early era of cardiac surgery are poorly documented, but such data are of critical importance to the future medical care, employability, and insurability of these patients. METHODS. To determine the natural history of surgically corrected atrial septal defects, we studied all 123 patients who underwent repair of an isolated defect (ostium secundum or sinus venosus) at the Mayo Clinic between 1956 and 1960, 27 to 32 years after the procedure. The follow-up status of all patients was determined by written questionnaires and telephone interviews. Hospital records and death certificates were obtained if interim hospitalization or death had occurred. RESULTS. The overall 30-year actuarial survival rate among survivors of the perioperative period was 74 percent, as compared with 85 percent among controls matched for age and sex. The perioperative mortality was 3.3 percent (four deaths). Actuarial 27-year survival rates among patients in the younger two quartiles according to age at operation (less than or equal to 11 years and 12 to 24 years) were no different from rates among controls--97 percent and 93 percent, respectively. In the two older quartiles (25 to 41 years and greater than 41 years), 27-year survival rates were significantly less (P less than 0.001)--84 percent and 40 percent, respectively--than in controls (91 and 59 percent). Independent predictors of long-term survival according to multivariate analysis were age at operation (P less than 0.0001) and systolic pressure in the main pulmonary artery before operation (P less than 0.0027). When repair was performed in older patients, late cardiac failure, stroke, and atrial fibrillation were significantly more frequent. CONCLUSIONS. Among patients with surgically repaired atrial septal defects, those operated on before the age of 25 have an excellent prognosis, but older patients require careful, regular supervision. 

Category: cardiovascular diseases
Endothelin-like immunoreactivity in human breast cyst fluid. Immunoreactive endothelin has been detected in 21 of 43 samples of breast cyst fluid (21 cases; 3.5 +/- 0.6 pmol/l, mean +/- SEM. Other 22 cases; not detectable, less than 0.5 pmol/l). Fast protein liquid chromatographic analysis of the immunoreactive endothelin of pooled breast cyst fluid showed two immunoreactive peaks; one in the void volume and the other in the position of endothelin-1. It is probable that endothelin-1 is produced by the epithelial cells lining breast cysts, but significance of the presence of endothelin-1 in breast cyst fluid remains to be elucidated. 

Category: neoplasms
Evaluating tooth eruption on sealant efficacy. For patients aged 5 to 9 and 11 to 14, 100 occlusal surfaces on newly erupting permanent molars were treated with a self-curing pit and fissure sealant. All teeth were categorized according to stage of eruption and sealant thickness of the coating applied. After 36 months, 75 surfaces were examined for a final evaluation; 52 surfaces (70%) did not need retreatment. Of the 23 surfaces retreated as a result of sealant loss or marginal deterioration, 18 were retreated only once in the six recall evaluations. Those molars treated originally with the operculum covering the distal marginal ridge of the occlusal surface had twice the probability for retreatment as teeth not treated until the entire marginal ridge was exposed. The thickness of the sealant coating did not affect the early signs of sealant failure. 

Category: general pathological conditions
Prosthetic arthroplasty of the knee after resection of a sarcoma in the proximal end of the tibia. A report of sixteen cases. The results of a specific type of prosthetic reconstruction of the knee (total replacement arthroplasty) after resection of a sarcoma of the proximal part of the tibia in sixteen patients were retrospectively reviewed. The diagnosis was stage-IIB osteogenic sarcoma in nine patients, stage-IIB malignant fibrous histiocytoma in three patients, and stage-IB sarcoma of various types in four patients. The length of tibial resection ranged from 100 to 257 millimeters. Of the eleven patients who were available for functional examination (mean duration of follow-up, sixty-three months), three patients had an excellent result, seven had a good result, and one had a fair result. Of the five patients who were not available for functional testing, one who was doing well was lost to follow-up at eighty months, one had died of metastases at sixteen months, and three had had a secondary amputation for infection or for loosening of the prosthesis. 

Category: neoplasms
Prognostic indices for tumor relapse and tumor mortality in follicular thyroid carcinoma. To establish an objective basis for therapeutic decisions and follow-up programs in patients with follicular thyroid cancer, the authors developed a prognostic scoring system. The prognostic impact of nine clinical, histologic, and therapeutic parameters was quantified retrospectively based on a multivariate analysis covering 149 patients. The relative relapse risk in follicular thyroid cancer (RR) was 6.8-fold increased in the presence of a moderate when compared with a high degree of histologic tumor differentiation. The RR rose with increasing age of the patient at time of tumor diagnosis by a factor of 1.8 per 20 years. The RR was reduced by a factor of 4.3 after the performance of a neck dissection and by a factor of 2.3 after percutaneous radiation therapy of the neck. The relative mortality risk in follicular thyroid cancer (RM) rose in the absence of a tumor capsule by a factor of 10, in the presence of a moderate compared with a high degree of histologic tumor differentiation by a factor of 5.9, in the presence of distant metastases by a factor of 3.2, and with increasing age of the patient at the time of tumor diagnosis by a factor of 2.2 per 20 years. From these data prognostic indices denoting the individual risk for tumor relapse (IRR index) and tumor mortality (IMR index) were calculated. The indices categorize patients into low-risk, medium-risk, or high-risk groups with regard to tumor relapse and tumor-related death. Consequently, the IRR and IMR indices contribute to select patients with follicular thyroid cancer who need an aggressive form of treatment and an intensive follow-up program. The indices may also be used for risk stratification in prospective therapy trials. 

Category: general pathological conditions
Indwelling epidural catheters for pain control in gynecologic cancer patients. Seven patients with severe pain caused by an advanced, incurable gynecologic malignancy were treated with an indwelling epidural catheter connected to an implantable subcutaneous port through which morphine was infused. There were few major complications associated with insertion or maintenance of the system. The average usage was 60 days, although the system functioned continuously for 6 months in one patient. Pain distribution in these women ranged from the upper abdomen to the lower extremities. All patients, including one with liver metastases, reported good to excellent pain control with the epidural narcotics. Two subjects with upper abdominal pain occasionally required supplemental oral oxycodone, but the other five patients had adequate pain relief with the epidural system alone. The indwelling epidural system provides excellent analgesia for patients with advanced, incurable gynecologic cancer. 

Category: nervous system diseases
Multicenter long-term safety and efficacy study of vigabatrin for refractory complex partial seizures: an update. We followed 66 patients with refractory complex partial seizures and a favorable initial response to vigabatrin for 5 to 72 (median, 43) months. Thirty-seven patients discontinued vigabatrin for the following reasons: benefit-to-risk evaluation, 8; seizure breakthrough, 6; adverse events, 6; seizure breakthrough and adverse events, 5; moved or lost, 4; no longer eligible for study, 2; non-drug-related death, 2; narcotic abuse, 1; and patient request, three. There were no clinically significant abnormalities in laboratory studies including SMA 12, complete blood count, ECG, EEG, and visual evoked response testing, and no toxicity other than reversible, dose-dependent side effects. Based on this and other long-term data, clinical trials of vigabatrin have resumed in the United States and Canada. 

Category: nervous system diseases
Takayasu's disease with axillary, right coronary artery, and right internal mammary stenosis treated with angioplasty. A 47-year-old woman presented with progressive angina and failed medical therapy. After an unsuccessful attempt at angioplasty of a totally occluded right coronary artery, coronary artery bypass using the right internal mammary artery was performed. She presented 2 years later with stenosis in the mammary graft, right coronary artery, and axillary artery. These lesions were all treated with angioplasty. 

Category: general pathological conditions
Foreign bodies in the throat: a prospective study of 388 cases. We present the results of a prospective study of 388 patients presenting with a history of swallowing a foreign body. We indicate whether the patients' symptoms and signs were associated with a retained foreign body. While tenderness on palpation was an unreliable sign, pooling at indirect laryngoscopy invariably predicted a retained object. In many patients, initial careful examination of the oropharynx by casualty officers would have shown a retained fishbone in the tonsil or tongue and would have resulted in 16 per cent fewer radiographs and 17 per cent fewer referrals to the ENT department. Radiography only improved management in a small minority and 35 per cent of films were interpreted incorrectly by casualty officers. A follow-up barium swallow disclosed a pathological lesion in a significant proportion of patients with bolus obstruction, whether or not this was passed spontaneously. 

Category: general pathological conditions
Protamine transcript sharing among postmeiotic spermatids. Sharing of cytoplasmic constituents through intercellular bridges connecting postmeiotic spermatids can allow for functional equivalence of genetically nonequivalent spermatids. The technique of in situ hybridization was used to study postmeiotic distribution of transcripts from the mouse protamine 1 (Prm-1) gene among spermatids of mice with chromosomally unbalanced gametes. The Prm-1 gene is located on chromosome 16 and is expressed exclusively in haploid spermatids. Mice doubly heterozygous for two Robertsonian translocations involving chromosome 16 were used for the study of postmeiotic accumulation of transcripts of the Prm-1 gene in spermatogenic cells. The meiotic segregation pattern of chromosomal homologues in these mice produces some spermatids that are chromosomally unbalanced; some spermatids lack chromosome 16 while others have two. In situ hybridization with a cDNA probe for the Prm-1 gene transcript performed on both whole testis sections and spermatogenic cell suspensions showed that there was no statistical difference in distribution of grains over step-5 to step-10 spermatids from Robertsonian-translocation heterozygous mice and from control mice of normal karyotype. These results are consistent with sharing of transcripts of the Prm-1 gene among spermatids within a syncytium. 

Category: general pathological conditions
Distribution of angiographic vasospasm after subarachnoid hemorrhage: implications for diagnosis by transcranial Doppler ultrasonography. A study was undertaken to determine how frequently angiographic vasospasm occurs outside the normal access range of transcranial Doppler ultrasound in patients who have suffered a subarachnoid hemorrhage. Vasospasm located in the basal vessels is readily identifiable using transcranial Doppler ultrasound whereas spasm affecting the more distal, vertically oriented arteries is outside the standard detection range. It is therefore speculated that the sensitivity of the technique would be adversely affected by a high incidence of distal vasospasm. A total of 136 angiograms performed on 68 patients after a subarachnoid hemorrhage from anterior circulation aneurysms were reviewed to determine the typical distribution of vasospasm. Of the 40 cases that showed greater than or equal to 25% vessel narrowing, 50.0% had spasm restricted to the basal vessels, 42.5% had spasm involving both basal and distal segments, and 7.5% had spasm of the distal segments only. None of the patients with distal vasospasm alone developed delayed ischemic deficits. It is concluded that most patients with anterior circulation aneurysms who develop vasospasm will have involvement of the basal vessels, but a small number of patients may develop vasospasm only in distal vessels. 

Category: cardiovascular diseases