Decreased Success Rate Research Articles

A Poster Session in Organic Chemistry That Markedly Enhanced Student Learning

Chemistry courses worldwide have experienced dwindling student numbers and decreasing success rates in recent years. This has led to many proposals on ways to get students actively involved in their courses. At the University of the Witwatersrand, South Africa, our ChemII course has suffered a similar fate and the introduction of cooperative small group tutorials to get students actively involved in the learning process has met with limited success. Further innovations were introduced into the Organic II module, but students' perception of the module remained negative and their commitment to it has dwindled over the years. In the first semester of 1998 the ChemII class at Wits performed particularly poorly and only 23% of the students passed. In an attempt to improve this situation in the second semester, a poster presentation session was introduced into the Organic II module. The choice of topic for the poster was found to be crucial to the success of the innovation, which resulted in students' increased enthusiasm for, commitment to, and understanding of organic chemistry. Relative to the previous year, the class average for the Organic II module increased by 10% and the pass rate by 30% while the class average and pass rates in the other three ChemII modules (inorganic, analytical and physical) dropped by comparable amounts. This improvement in performance in the Organic II module is credited to the poster presentations shifting most students from a "futile learning cycle" into a "productive" one.

Computed tomography-guided percutaneous abscess drainage in intestinal disease: factors associated with outcome.

This study was designed to assess the efficacy of computed tomography-guided percutaneous abscess drainage in intestinal disease. Retrospective chart review of patients who underwent percutaneous abscess drainage for complications of intestinal disease with or without surgery between 1990 and 1994. Eighty-two patients with 111 abscesses were identified. Causes of abscess included anastomotic leaks (35 percent), postoperative complications without leak (30 percent), and diverticular disease (23 percent). Complete success (no surgery necessary) was achieved in 53 of 82 patients (65 percent). Nine patients (11 percent) who underwent interval surgery were classified as having partial successes. Twenty-six of 26 (100 percent) well-defined unilocular collections containing pus were successfully drained. Complex abscesses (loculated, poorly defined, multiple, associated with fistula, draining feces) were successfully drained in 35 of 55 patients (63 percent). Success rates varied inversely with the number of complicating factors present. Apache II scores of 15 or higher were associated with decreased success rates. Percutaneous abscess drainage is a highly successful technique for treatment of patients with intra-abdominal infection related to intestinal disease. Although several factors are associated with decreased success rates and multiple complicating factors combine to reduce success rates, no identifiable factor or combination of factors preclude the possibility of a successful outcome.

Factors influencing successful intubation in the prehospital setting.

To explore the determinants influencing oral/nasal endotracheal intubation (OETI/NETI) and determine which cognitive, therapeutic, and technical interventions may assist prehospital airway management. Prospective review of run reports and structured interviews of paramedics involved in OETI/NETI attempts were conducted in a high-volume, inner-city, advanced life support (ALS) system during an eight-month period (July 1991 to February 1992). Data were abstracted from run reports, and paramedics were asked in structured interviews to describe difficulties in OETI/NETI attempts. Of 236 patients studied, 88% (208) were intubated successfully. Success/failure rate was not related statistically to patients' ages (p = 0.78), medical or trauma complaint (89% vs 85%, p = 0.35), oral versus nasal route (88% vs 85%, p = 0.38), care time (scene+transport times: success, 18 minutes; failure, 20 minutes, p = 0.30), paramedic seniority (p = 0.13), or number of attempts per paramedic (p > 0.05). Increased level of consciousness (LOC) was associated with decreased success rate (p = 0.04). Paramedics reported difficulties in endotracheal intubation (ETI) attempts in 110 (46.6%) of patients. Factors reported to increase ETI difficulty were: 1) technical problems (35.6%); 2) mechanical problems (15.6%); and 3) combative patients (12.7%). Oral endotracheal intubation and NETI success rates identified in this study are similar to those described in the literature, although innovative strategies could be used to facilitate prehospital airway management. Many of the factors found to increase ETI difficulty could be ameliorated by the administration of paralytic agents, that is, for combative patients. Focused training in cadaver and animal labs coupled with recurrence training in the operating suites should be used on a regular basis to decrease difficulties in visualization. Interventions directed at alleviating mechanical difficulties that should be explored include new-to-the-field techniques, such as retrograde intubation, fiber-optic technology, and surgical tracheal access.

Directional coronary atherectomy can be successfully performed in the elderly

The influence of age on the clinical and angiographic outcome of directional coronary atherectomy is evaluated. Results demonstrate that DCA can be performed successfully in the vast majority (78.7-90%) of patients in all age groups. However, there is a non-statistical trend toward decreased success rates in the elderly (P > .05). Major ischemic complications and groin complications tend to be more common in the elderly (P > .05). Blood transfusions are required significantly more often in the elderly (P < .05). Directional coronary atherectomy is a useful method of coronary artery revascularization in all age groups, including the elderly.

Behavioral effects of smokeless tobacco on the neonate and young sprague Dawley rat

Three dosages of Smokeless Tobacco (ST) extract were given to pregnant Sprague-Dawley rats by oral gavage on gestational days (GD) 6-20. The three dosages contained ST extract equivalent to 1.33 mg/kg nicotine (STD-1), 4.0 mg/kg nicotine (STD-2), and 6.0 mg/kg nicotine (STD-3). Dams were intubated three times per day at 8 a.m., 11 a.m., and 2 p.m., providing total daily ST dosages of 4 mg/kg, 12 mg/kg, and 18 mg/kg, respectively. Controls received equivalent volumes of water by gavage. Dams were allowed to deliver, and all biological mothers raised their own pups. On postnatal day 1 (PND 1), litters were culled to 4 +/- 1 females and 4 +/- 1 males. Weights, physical landmark development, and behavioral performance of pups were monitored during pre- and post-weaning periods. Behavioral tests included surface righting, negative geotaxis, swimming development, open field activity, and active avoidance in shuttle box. Our results show that the two higher doses resulted in reduced maternal weight gain. During the pre-weaning period, significant pup weight reductions were noted in the STD-2 pups until PND6, and in the STD-3 group until PND15. In the STD-1 group no statistically significant weight reduction was noted on PNDs 1 and 3, but starting with PND6, pup weights surpassed control group weights. This weight difference persisted throughout the post-weaning period also (P < .05 on PND30 and PND42). The STD-3 pup weights continued to be consistently and significantly (P < .05) reduced throughout the post-weaning period (except on PND24); likewise, the STD-2 pups continued to have lower weights, but at a significant level (P < .05) on PND30 only. The incidence of deaths was increased in a dose-related manner. No significant differences were noted for pinna detachment and incisor eruption; however ST-treatment was significant in affecting earlier eye opening and vaginal patency. N significant ST treatment effects were seen on negative geotaxis, but for surface righting a decreased success rate was noted for the ST-treated groups. Significant differences were noted in swimming development, with the STD-2 pups performing best. Open field activity, as expected, increased from the pre-weaning to post-weaning periods. During the pre-weaning period the STD-3 pups were more active, and during post-weaning the STD-1 pups were more active, but no differences were noted in vertical activity or in the number of stereotypical movements. No treatment-related differences were noted in the active avoidance shuttle box.(ABSTRACT TRUNCATED AT 400 WORDS)

Congenital glaucoma in the West Bank and Gaza Strip.

This study presents the results of all patients with congenital glaucoma who were managed at St John Ophthalmic Hospital, Jerusalem from 1981 to 1990. This involved 118 eyes, 174 surgical procedures, and 460 examinations under anaesthesia. All procedures showed decreasing success rates with time. However, trabeculectomy was clearly the most successful in the hands of general ophthalmologists. Careful, long term follow up with particular regard to both intraocular pressure and detection and treatment of amblyopia are emphasised.

Chronic Total Obstruction and Short-Term Outcome: The Excimer Laser Coronary Angioplasty Registry Experience

Percutaneous transluminal coronary angioplasty for chronic total obstructions is associated with significantly decreased success rates in comparison with those for dilation of subtotal stenoses. Failure usually results from inability to cross the occlusive lesion with a guidewire, although it may result from inability to pass the balloon catheter after the guidewire has been passed. In the Excimer Laser Coronary Angioplasty Registry, 172 chronic total obstructions were treated in 162 patients (10.3% of the 1,569 patients entered). For chronic total obstructions, passage of a guidewire is a prerequisite for laser angioplasty. Once a guidewire crossed an occlusion, the overall laser success rate for treatment of chronic total obstructions was 83%; the extent of stenosis decreased from 100% to 55 +/- 26%. Success was independent of length of the occlusive lesion. In 74% of patients, adjunctive percutaneous transluminal coronary angioplasty was used after laser angioplasty. A final procedural success, defined as residual stenosis of less than 50% and no major complication (coronary artery bypass grafting, myocardial infarction, or death), was achieved in 90%. Major complications were infrequent; 1.2% of patients required coronary artery bypass grafting, and 1.9% had a Q-wave myocardial infarction. Only one death occurred. The use of laser angioplasty may be of particular value when chronic total obstructions can be crossed with a guidewire but not with a conventional balloon catheter or when the occlusion is confirmed to be extremely long.

Verhulstian analysis of the growth of transplantable mammary tumours in sialoadenectomized mice

In this report we have analysed data published in 1989 by Inui et al. (Incidence of precancerous foci of mammary glands and growth rate of transplantable mammary cancers in sialoadenectomized mice. J. Natl Cancer Inst. 81, 1660) involving the effects of perturbation of the epidermal growth factor (EGF) status of mammary tumour-bearing mice on subsequent volumetric responses. Removal of an endogenous EGF stimulus by surgical ablation of the submaxillary glands, the major EGF-producing organ in mice, produced significantly slower growth of rodent mammary neoplasms, decreased success rate of transplantation, and an increase in the latent period before growth occurred. Administration of i.p. EGF (5 micrograms/mouse/day) to sialadectomized tumour-bearing mice would however, increase tumour growth rate. Data were analysed using the Verhulst equation which indicated that the observed effects on tumour volumetrics by either sialoadenectomy or EGF administration could be interpreted as being produced through paracrine pathways. The use of the Verhulstian analysis indicates that it is possible to analyse neoplastic responses and infer whether paracrine or autocrine pathways are involved.

In-vitro fertilization: influence of women's age on pregnancy rates

An analysis of the influence of women's age on the results of in-vitro fertilization was performed, using 5590 attempts collected during the year 1986. Increasing age was found to be related to decreased success rates from 19.8% per attempt below the age of 25 years, to 9% per attempt at 40 years or more. A cut-off point was found between the ages of 36 and 37 years, using a mathematical model. The decrease was related to a reduction in oocyte production (4.3 +/- 2.8 at 25 years or less and 3.3 +/- 2.1 at 40 years or more, P less than 0.001), and to a reduced implantation rate, whatever the number of transferred embryos. These findings were not due to spouse's age, rank of attempt, infertility diagnosis or oocyte stimulation regimen, since the effect of age remained significant when a logistical model including these confounders was applied. Finally, a woman's age must be considered as a prognostic factor when IVF is proposed to infertile couples.

Emergency percutaneous transluminal coronary angioplasty during acute myocardial infarction for patients more than 70 years of age

Thirty-five patients >70 years of age with acute myocardial infarction (AMI) were treated with emergency percutaneous transluminal coronary angioplasty (PTCA). Seventeen (49%) patients received previous thrombolytic therapy: streptokinase (10 patients), tissue plasminogen activator (6) and combined tissue plasminogen activator and urokinase (1). Infarct-related artery patency was achieved in 26 patients (74%) after PTCA. Total in-hospital mortality was 34%. Univariate analysis showed a higher in-hospital mortality in patients with an occluded vessel after PTCA (78%) than in those patients with a patent infarct-related artery (19%) (p = 0.003). Symptomatic coronary reocclusion occurred in 3 patients (15%) during the hospital stay. Compared with emergency PTCA in 200 consecutively treated patients <70 years of age, the in-hospital mortality was increased (34 vs 6%, p < 0.001), and the primary success rate was reduced (66 vs 90%, p < 0.001). At a mean follow-up of 28 months, there has been a 13% out-of-hospital mortality rate in the elderly patients (3 patients died). Of the 20 surviving patients, 14 are asymptomatic and 6 have class II angina. In conclusion, emergency PTCA for AMI in elderly patients is associated with a decreased success rate and a higher mortality rate. However, the in-hospital mortality rate is not dissimilar to that in elderly AMI patients treated with conventional therapy or thrombolytic therapy alone, and the postdischarge mortality rates are low.

Antimitotic drugs in the male rat. Behavioral abnormalities in the second generation.

The second generation descended from rats treated either with cyclophosphamide alone or with both cyclophosphamide and vinblastine were investigated. As in the first generation, the offspring were evaluated for mean litter size, sex ratio, frequency of gross external malformations and, within the first 4 months of life, growth and mortality. When they reached adulthood, between 12 and 16 weeks of age, the offspring were also tested for spontaneous activity and learning capacity. At birth, the progeny of the treated grandfathers did not show malformations or any other obvious disorder. However, when compared with the control population, the experimental animals showed significantly decreased success rates in a learning task, whatever the learning performance of their parents. Furthermore, decreased spontaneous activity was observed in the male subjects from unsuccessful parents. The similarities between the anomalies found in the first and the second generations argue for the induction of mutations by antimitotic drugs. This hypothesis and the subtle differences between generations and between sexes are discussed.

Towards a more rational approach to fungicide design

Whereas insignificant progress has been made in the chemical control of viruses, mycoplasmas and bacteria, the control of fungal diseases has been significantly improved by the recent introduction of more potent chemicals. However, the shortcomings of these chemicals, the changing background of world agriculture and the decreasing success rate call for more rational approaches in fungicide research. The increasing research efforts in the basic biochemistry of target organisms and host-parasite interactions hold promise for the design of new types of chemicals for plant protection.