Multicenter evaluation of the MicroScan Rapid Gram-Negative Identification Type 3 Panel

The accuracy and performance of the revised MicroScan Rapid Gram-Negative Identification Type 3 Panel (Dade MicroScan Inc., West Sacramento, Calif.) were examined in a multicenter evaluation. The revised panel database includes data for 119 taxa covering a total of 150 species, with data for 12 new species added. Testing was performed in three phases: the efficacy, challenge, and reproducibility testing phases. A total of 405 fresh and stock gram-negative isolates comprising 54 species were tested in the efficacy phase; 96.8% of these species were identified correctly in comparison to the identification obtained either with the API 20E system (bioMérieux Vitek, Hazelwood, Mo.) or by the conventional tube method. The number of correctly identified isolates in the challenge phase, including new species added to the database, was 221 of 247, or 89.5%, in comparison to the number correctly identified by the conventional tube method. A total of 465 isolates were examined for intra- and interlaboratory identification reproducibility and gave an agreement of 464 of 465, or 99.8%. The overall reproducibility of each individual identification test or substrate was 14,373 of 14,384, or 99.9%. The new Rapid Gram-Negative Identification Type 3 Panel gave accurate and highly reproducible results in this multiple-laboratory evaluation.

Effect of smoking cessation upon circulatory responses to reactive hyperemia and cold pressor stress

Local and sympathetic nervous system stress tests were administered prior to and following a 5-d smoking cessation program to determine the effects of short term smoking cessation upon peripheral circulation. Reactive hyperemia (RH) tests were performed on the forearm as a local dilatory stressor. Finger blood flow responses to cold pressor (CP) stresses were used to access stimulation of the sympathetic nervous system. Measures of heart rate and total forearm or finger blood flow, pulse volume and rate of blood delivery were obtained continuously during each stress test. Smoking cessation produced a significant decrease (0.01 < p < 0.05) in heart rate during both the RH and CP test sequences. Grouped mean peak forearm blood flow (Mean difference = 2.11 ml.100 ml-1.min-1; p < 0.05) and pulse volume (Mean difference = 0.04 ml.100 ml-1.pulse-1; p < 0.01) were both significantly greater following occlusion during the post-cessation RH tests than during the similar test before smoking cessation. Both finger pulse volume and rate of blood delivery were significantly greater (0.01 < p < 0.05) during the recovery portion of the post-cessation CP tests than during the same period of the pre-cessation tests. Thus, smoking cessation significantly altered both the locally mediated and central nervous system controlled responses to externally applied stressors.

Laparoscopic cholecystectomy in a community hospital: experience with 600 laparoscopic cholecystectomies

We reviewed 600 patients who underwent laparoscopic cholecystectomy (LC) in a teaching community hospital from May 1990 to August 1992. The safety, efficacy, morbidity, and mortality of LC, as performed by one surgeon or under his direct supervision, were studied. Five hundred forty-eight patients (91.3%) were treated electively; 52 (8.7%) were admitted for acute cholecystitis (41) or gallstone pancreatitis (11). Mean operating time was 54 min, with a range of 20 to 145 min. Twenty-four (4%) patients required conversion to traditional (open) cholecystectomy. Operative cholangiograms were completed in 106 patients. These revealed choledocholithiasis in 7. Five hundred thirty-seven patients (89.5%) were discharged within 24 h and 564 (94%) within 48 h. The overall morbidity of 9.2% compared favorably with both open and laparoscopic series previously reported. Three patients (0.5%) had small lacerations of the anterior wall of the common duct. Two were recognized and repaired immediately. The third patient came for treatment on the fifth postoperative day and was stented by a T-tube. There was 1 death in this group--a myocardial infarction on postoperative day 4.

Differences in outcome of transurethral resection of the prostate for benign prostatic hypertrophy between three diagnostic categories

As part of a prospective cohort study of 388 men undergoing transurethral resection of the prostate (TURP) for benign prostatic hypertrophy, pre-operative factors and the outcome of surgery during the first post-operative year were compared between patients in whom their surgeon felt the principal reason for operating was chronic retention (37%), acute retention (with no chronic retention) (28%), or symptomatic prostatism (with no history of chronic or acute retention) (35%). Although in many respects the patients in the 3 diagnostic categories were similar, patients with chronic retention were more likely to be younger, of higher social class and to have worse general health. Patients with acute retention were more likely to present with a urinary tract infection and to have electrocardiographic abnormalities, and symptomatic patients presented with more severe urinary symptoms. Minor differences between the categories with regard to post-operative morbidity and mortality were not statistically significant at the 5% level. However, some significant differences did exist. Patients with acute retention were more likely to experience urinary and non-urinary infections and impotence after surgery, while symptomatic patients reported less improvement in their health status as regards pain and social isolation. These results suggest that the method of categorisation is clinically valid and a necessary distinction to make when auditing TURP.

Mortality, morbidity and complications following transurethral resection of the prostate for benign prostatic hypertrophy

A total of 388 men undergoing transurethral resection of the prostate for benign prostatic hypertrophy during 1988 entered a prospective cohort study designed to examine the outcome of surgery during postoperative year 1. Self-administered questionnaires were completed preoperatively, and at 3, 6 and 12 months postoperatively. The surgeons completed 1 questionnaire shortly after surgery and another questionnaire 3, 6 or 12 months later. The mortality rate during the 12 months of followup was 2.8% (11 deaths). The surgeons reported perioperative complications in 14% of the patients and immediate postoperative complications, excluding urinary tract infections, in 17%. During the first 3 months postoperatively 38% of the patients reported incontinence and 25% had a urinary tract infection. Between 6 and 12 months postoperatively only 12% of the patients were troubled by either condition. The postoperative prevalence of impotence (24%) did not alter during followup and was similar to that reported preoperatively (22%). Of the patients 74% reported feeling better and 78% experienced a decrease in the overall level of symptoms postoperatively. The improvement in symptom levels was greatest in those with the most severe preoperative symptoms, and obstructive symptoms were alleviated slightly more than irritative symptoms.

Rapid Clonal Growth Measurements at the Single-Cell Level: Gel Microdroplets and Flow Cytometry

We describe a new, general method for rapidly measuring clonal growth of large numbers of individual members of a cell population. This method is based on microculture of individual colony-forming units in gel microdrops (GMDs; here agarose; 20 to 90 mu in diameter), which are sufficiently robust to be handled much like cells, and diffusionally transparent for molecules of interest. Flow cytometry provides rapid measurements of GMD-entrapped microcolonies, and permits subpopulation analysis. Here the method is demonstrated with mammalian, fungal and bacterial species. Additional results illustrate rapid determination of a drug-resistant subpopulation in a mixed species sample, and nutrient sensitivity for a murine hybridoma.

Urothelial grafts in mice

Mouse bladder epithelium has been successfully transplanted to the bladders of syngeneic mice and has survived for at least twenty weeks. The fate of the transplanted tissue was followed using a fluorescein label. The recipient bladders were prepared by stripping the urothelium either by a surgical or a chemical method. The possibility of adopting a comparable technique for the treatment of early bladder cancer in man is discussed.

Rapid microbial detection and enumeration using gel microdroplets and colorimetric or fluorescence indicator systems

A new micromethod employing gel microdroplets (GMDs) and optical measurements can be used for rapid detection and enumeration of viable microorganisms (J. C. Weaver, G. B. Williams, A. M. Klibanov, and A. L. Demain, Bio/Technology 6:1084-1089, 1988) and has several potential applications in clinical microbiology. This method involves entrapping microorganisms in GMDs (10 to 100 microns in diameter) which are surrounded by a hydrophobic (low dielectric) fluid, subsequently distinguishing occupied and unoccupied GMDs with colorimetric or fluorescence indicators, counting both occupied and unoccupied GMDs, and applying Poisson statistical analysis. Acid-producing microorganisms were used to compare colorimetric and fluorescence pH indicator systems. Fluorescence systems were generally superior, particularly for detection before microbial growth occurred. Although colorimetric detection was reasonably fast for fast-growing microorganisms, significantly longer times were needed for slow-growing microorganisms. We investigated the dependence of the detection time on microbial division time, GMD size, and buffering capacity of the medium within GMDs. It was found possible to use a single preparation of GMDs, containing a range of GMD sizes, to simultaneously provide a viable enumeration of growing and nongrowing (e.g., stressed) cells. This was possible because small GMDs responded rapidly to both growing and nongrowing cells, while large GMDs, although slower, responded much more rapidly to growing cells than to nongrowing cells. Separate analysis of small and large GMDs in the same preparation yielded two enumerations, one of nongrowing cells and the other of growing cells. GMDs can also be used with conventional light microscopy to detect and enumerate fast-growing acid-producing bacteria much more quickly than conventional plating methods.

Doctoral preparation of nursing faculty

Is the doctorate necessary for all nurse educators? Should nurse educators hold a doctorate or is a non-nursing doctorate acceptable? The authors report on a survey which looked at information concerning the number of doctorally prepared nursing faculty and the institutional requirement of a doctorate as the terminal degree in nursing.

Cholecystectomy in the elderly

A series of 347 elderly patients undergoing cholecystectomy has been presented. The older a patient is at the time of cholecystectomy, the more likely it is for that patient to present with an acute biliary complication. The elderly tolerate biliary tract operations quite well, especially before acute complications of cholelithiasis occur. Early cholecystectomy can prevent the morbidity associated with the natural progression of cholelithiasis. Whether prophylactic cholecystectomy for asymptomatic cholelithiasis would be cost effective is an issue that can be resolved only when further data regarding the natural history and incidence of cholelithiasis in the elderly is known.

Albumin adsorption and retention on C18-alkyl-derivatized polyurethane vascular grafts

The short-term albumin affinity and thrombo-resistance of a polyether polyurethane vascular graft have been improved. The method is based on the C18 alkylation of the polymer. Thrombus formation by a planimetric technique and albumin retention on wire-reinforced polyurethane tubes, both C18 alkylated and untreated, were measured in short-term (4-h) exposure at femoral arterial sites in the dog. 125I-Albumin was preabsorbed on tubes and then exposed to blood for successive 2-h periods. Albumin uptake on alkylated tubes prior to blood exposure and retention following 2 h of blood exposure were significantly greater than on controls. Following a fast desorption phase in blood, the remaining albumin was more slowly desorbed from alkylated than from control tubes. Reincubation with albumin and blood reexposure produced a similar tendency, suggesting blood conditioning does not reduce the albumin affinity-enhancing property of C18 alkylation in the short term. Blood-preconditioning experiments suggested endogenous albumin has a high affinity for the C18-alkylated surface. Scanning electron microscopic examination showed thrombus and platelet densities were higher on control than on alkylated surfaces. These results suggest in vivo albumin affinity is increased for C18-alkylated polyurethane, which may be linked to decreased thrombus formation on these surfaces.

Primary squamous cell carcinoma of the colorectum: case report and literature review of a rare entity

A case of primary squamous cell carcinoma of the rectum is presented. Although it is a rare condition, the diagnosis, treatment, and natural history of the disease are similar to that of adenocarcinoma of the colorectum. The patient in this report has done well to date with an abdominal perineal resection and early post-operative radiation. A review of the literature reveals that the precise etiology of this entity remains unknown.

Distal duodenal carcinoma and intussusception

Adenocarcinoma of the duodenum is an uncommon malignancy that usually presents itself with either obstructive symptoms or jaundice, depending on its location. The diagnosis should be suspected in any patient with a high small bowel obstruction, weight loss, or chronic abdominal pain. Endoscopy and barium contrast x-ray films are the preferred initial studies; enteroclysis may provide additional information. Surgical resection offers the only hope for long-term survival, which should approach 50% with resectable tumors.

Management of intra-abdominal aneurysms associated with periarteritis nodosa

Periarteritis nodosa is a disease of small and medium-sized arteries, frequently associated with multiple visceral artery aneurysms. Infrequently, these aneurysms rupture, usually with fatal results. A case of spontaneous rupture of a middle colic artery aneurysm in a patient with periarteritis nodosa is reported, and similar cases in the literature are reviewed. Treatment of a ruptured visceral artery aneurysm requires ligation or resection of the aneurysm without delay. Residual aneurysms are treated with cyclophosphamide and/or prednisone in an attempt to induce regression of the aneurysms. An arteriogram performed after 3 to 4 months of medical therapy determines the need for further surgical intervention.

Total parenteral nutrition by a nutrition support team: improved quality of care

Most of the studies that have examined the effect of nutrition support teams (NST) on the quality of total parenteral nutrition (TPN) have found reductions in the frequency of metabolic and central venous catheter related complications. Previous studies have not examined the patterns of nutrient delivery (eg, calories and protein) when TPN is provided either by a primary physician or by a NST. We compared the quality of TPN care provided by our NST or by primary physicians utilizing nonspecialized hospital personnel and resources. As expected, catheter complications were significantly less frequent in NST patients. Assessment of nutritional status and nutrient requirements as well as nitrogen balance were performed and documented significantly more often in NST patients. In addition, nutritional goals for calories and protein were achieved and positive nitrogen balance documented more often in NST patients. The need to consult the NST physician to utilize the NST was not well received by primary attending and resident physicians and resulted in nonuse of the team. In the future, modification of NST policies will be explored to encourage greater utilization of the NST without compromising the high standard of nutrition care delivered by the NST.

NH3 and propionate modulate the morphological response of aggregation-competent Dictyostelium discoideum to cAMP

Two metabolites, NH3 and propionic acid, are known to act as morphogens during the development of Dictyostelium discoideum, specifically altering the course of morphogenesis and cytodifferentiation. They have also been shown to modulate the cAMP relay in this organism: NH3 by restricting intracellular accumulation, and propionate by inhibiting extracellular release. In the present study, we utilized the light-scattering properties of aggregation-competent cells in agitated suspension to demonstrate that the morphological responses of such cells to exogenous cAMP are also modulated by NH3 and propionate in a manner that has interesting implications for the overall control of morphogenetic movements in D. discoideum. Our experiments were conducted using a newly designed continuous-flow apparatus that represents a significant improvement in the technique. The apparatus is described in detail.

Modulation of the cAMP relay in Dictyostelium discoideum by ammonia and other metabolites: possible morphogenetic consequences

Using a perfusion technique (P.N. Devreotes, P.L. Derstine, and T.L. Steck, 1979, J. Cell Biol. 80, 291-299), it has been shown that cAMP secretion by aggregation-competent cells in response to an exogenous cAMP signal is significantly reduced by exposure to NH4Cl or any of a set of carboxylic acids that includes propionate, succinate, pyruvate, and acetate. The effects of NH4Cl and any of the carboxylic acids are additive and the combinations restrict cAMP secretion to barely detectable or insignificant levels. The inhibitions are rapidly expressed, and are reversible. The activity of NH4Cl is marked at pH 7.2 and undetectable at pH 6.2. Hence, NH3 is presumably the active molecular species. Propionate activity is significantly greater at pH 6.2 than 7.2, indicating that the un-ionized acid is the active species. The data presented herein indicate that these effects are exerted via two separate and independent routes. During exposure of cAMP-stimulated cells to NH4Cl, the decrease in intracellular cAMP accumulation was even greater than the decrease in extracellular accumulation. Hence, NH3 appears to act as a cAMP accumulation inhibitor (CAI). In contrast, exposure to carboxylic acid concentrations that drastically reduce extracellular cAMP accumulation can actually enhance or, at worst, only slightly reduce intracellular accumulation. Hence, the carboxylic acids appear to act as cAMP release inhibitors (CRI). Stationary phase cells incubated on solid substratum in the presence of NH4Cl plus succinate (or propionate) for 18 hr failed to exhibit even the earliest signs of aggregation. If then harvested and redeposited in the absence of the metabolites, they proceeded through the morphogenetic sequence with approximately normal kinetics, suggesting that no significant morphogenetic competence had been achieved during their previous tenure. The morphogenetic implications of cAMP relay modulation are discussed.

Reversible inhibition of aggregation-related cohesivity in Dictyostelium discoideum by diffusible metabolites

Evidence presented elsewhere (G.B. Williams, E.M. Elder, and M. Sussman 1984, Dev. Biol. 105, 377-388) indicates that NH3 and certain carboxylic acids including propionate, succinate, and acetate modulate the cAMP relay in Dictyostelium discoideum. The former appears to act as a cAMP accumulation inhibitor, the latter as cAMP release inhibitors. The cohesive properties of aggregation competent cells have been assayed quantitatively in the presence of these modulators. The following results were obtained: (1) At pH 7.5, EDTA-resistant cohesivity was greatly inhibited by NH4C within the concentration range tested (30-3.8 mM). Even at the higher concentrations the effect was not immediate but required ca. 10 min for full expression. At the lower concentrations, the inhibitory level was only slightly reduced but the time for full expression progressively increased. At pH 6.5, the level of inhibition was marginal, indicating that NH3 is the active molecular species. By themselves, neither ambient pH nor ionic strength appeared to affect cohesive performance within the ranges employed. The inhibition was immediately and completely reversed upon removal of NH4Cl or a shift of ambient pH from 7.5 to 6.5. The presence of cycloheximide did not affect the recovery of cohesivity after NH4Cl removal. (2) The presence of 15 mM succinate, propionate, or acetate also reduced cell cohesivity. The timing and extent of the inhibition were identical at pH 7.5 and 6.5. The inhibition was expressed immediately and was reversible. Each of the acids acted synergistically with NH4Cl. The relative potencies of these metabolites acting singly or in combination as inhibitors of cohesivity corresponded roughly to their potencies as modulators of the cAMP relay (Williams et al., 1984). (3) The sensitivity to the metabolites was stage specific, being maximal during and shortly after aggregation and disappearing abruptly at 11-12 hr. This corresponds to the time at which this cohesive system, responsible for the end-to-end cell associations evident during aggregation (H. Beug, G. Gerisch, S. Kempff, V. Riedel, and G. Cremer, 1970, Exp. Cell. Res. 63, 147-158) is supplanted by a newly arisen, serologically and genetically distinct system which thereafter maintains the integrity of the aggregate (C. Steinemann and R.W. Parish, 1980, Nature (London) 286, 721-724; D.K. Wilcox and M. Sussman, 1981, Dev. Biol. 82, 102-112, and Proc. Natl. Acad. Sci. USA 78, 358-362; C.L. Saxe III and M. Sussman, 1982, Cell 29, 755-759). The activities of the metabolites, detailed above, are discussed in relation to their previously demonstrated activities as morphogens.

The multidisciplinary team approach to exenteration of the pelvis

The experience of a newly formed, multidisciplinary, pelvic exenteration team is presented which consists of a gynecologic oncologist, a general surgeon and a urologist. The first 20 exenterations performed by this team are reviewed. Nine patients had no postoperative problems, and of the 11 patients who did have complications, all but two, which resulted in death, were corrected without resultant debilitation. Fourteen of the 18 patients who survived the operation are tumor-free for as long as three years postoperatively. Operative proficiency as well as operative mortality and morbidity have certainly improved quite significantly as the team has gained experience.

The role of parathyroidectomy in the management of hyperparathyroidism in patients on maintenance haemodialysis and after renal transplantation

Between March 1964 and March 1980, 36 (34 dialysis, 2 transplant) of 327 patients accepted for the maintenance dialysis/transplantation programme at Charing Cross Hospital were submitted to parathyroidectomy. There were four main indications: persistent hypercalcaemia, progressive phalangeal erosions, aseptic necrosis of the femoral head and height loss with abnormal bone biopsy despite normal hand radiographs. At parathyroidectomy, 4 glands were removed in 1 patient, 3 1/2 glands in 24, 3 glands in 7, 2 glands in 3 and a single large gland in 1 patient. The operation was followed by improvement in 28 patients, no change in 5, and progression of hyperparathyroidism in 3.2 of the 28 patients who improved later relapsed and were treated with 1,25-(OH)2 vitamin D3. 4 patients were submitted to a further parathyroidectomy and improved considerably. We would conclude that, although parathyroidectomy is an effective and safe procedure, it is to be hoped that careful monitoring of bone state and early administration of 1,25-(OH)2 vitamin D3 may reduce the need for parathyroidectomy.