Relationship of CD4 lymphocyte counts to survival in a cohort of hemophiliacs infected with HIV. Multicenter Hemophilia Cohort Study

Although CD4 positive lymphocyte counts are important predictors of clinical events in persons infected with human immunodeficiency virus (HIV), little is known about their predictive value for survival. We analyzed CD4 counts obtained regularly since 1983 with regard to survival in a multicenter cohort study of 921 HIV-infected hemophiliacs of whom 177 have died. Dates of seroconversion were determined from stored serum samples. Cumulative mortality and actuarial survival rates were calculated from the first time the mean of two consecutive CD4 counts decreased from levels of > 500 to 200-499, 100-199, 50-99, and < 50 cells/microliter. The death rate per 100 patient years of observation was 0.87 (95% CI 0.27, 1.47) for those with CD4 counts of > 500 cells/microliter and increased progressively to 26.23 (95% CI 21.29, 31.17) for those with CD4 counts of < 50/microliter. HIV-related deaths occurred in 50 of 58 who died with CD4 counts of < 300/microliter compared to 0 of 6 who died with CD4 counts of > 500/microliter. The median CD4 count most proximal to death was 39.5 (range, 1-945). The 10-year actuarial estimate of survival from seroconversion was 77.3 +/- 2% for 546 persons who seroconverted at age > or = 18 years compared to 90.5 +/- 2% for 375 persons who seroconverted at age < 18. Survival decreased at each CD4 level to a median of 27 months at CD4 counts of < 50/microliter. At each CD4 level, younger patients survived longer than older patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Leukocyte CD11b and CD18 expression are increased in blood salvaged for autotransfusion

To investigate whether activated leukocytes are present in salvaged blood, we measured complete blood counts and quantified the surface expression of the leukocyte adhesion receptors CD11b and CD18 in salvaged blood and arterial blood from six male patients undergoing elective abdominal aortic aneurysm repair. Salvaged blood contained 5,450 +/- 1010 leukocytes/microL and 7600 +/- 6200 platelets/microL and had a hematocrit of 50.6 +/- 3.7%. CD 11b expression was 3.3 +/- 0.5 fold higher on neutrophils and 3.8 +/- 1.0 fold higher on monocytes from salvaged blood compared with arterial blood (P < 0.05 for both). CD18 expression was increased 3.2 +/- 0.2 fold on neutrophils and 2.5 +/- 0.4 fold on lymphocytes (P < 0.05) in salvaged compared to arterial blood (P < .05). Monocyte expression of CD18 was increased 4.50 +/- 1.1 fold in salvaged blood, but this difference was not statistically significant. We conclude that a substantial number of activated leukocytes are present in salvaged blood. Because activated leukocytes could potentially be detrimental to the recipient, our findings raise theoretical concerns about the use of salvaged blood and emphasize the need for further refinement of the procedure.

A latent form of protein phosphatase 1 alpha associated with bovine heart myofibrils

The catalytic subunit of the major protein phosphatase associated with bovine cardiac myofibrils was purified to homogeneity. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the enzyme revealed only one band with an apparent molecular weight of 37,000. On gel filtration chromatography, the phosphatase activity and the protein co-eluted as a single peak with an apparent molecular weight of 37,000. The purified enzyme was identified as the catalytic subunit of protein phosphatase 1, as determined by sensitivity to inhibitor 1, inhibitor 2, okadaic acid and by specific immunostaining. Evidence obtained with specific antipeptide antibodies demonstrated that this myofibril protein phosphatase was predominantly the alpha isoform of protein phosphatase 1. The purified catalytic subunit was completely inactive. It was activated by pretreatment with Co2+/trypsin in the presence of high ionic strength. Treatment with trypsin alone did not activate the latent enzyme. The enzyme was also activated by Co2+ or Mn2+ alone but not by Ca2+, Mg2+, Ni2+, Cu2+ or Zn2+. Activation of the enzyme was not reversed by removal of Co2+, but Mn(2+)-activated phosphatase activity was partially reversed when Mn2+ was removed. The catalytic subunit could form a 1:1 complex with inhibitor 2 in vitro. The resulting holoenzyme was also activated by pretreatment with Co2+. Since phosphatase 1 alpha is the major phosphatase associated with cardiac myofibril, it is suggested that it is responsible for the dephosphorylation of myosin and other myofibril phosphoproteins.

A critical analysis of recent innovations in the treatment of intra-abdominal infection

Toward the end of the last decade, clinical trial results in the surgical literature reported a major improvement in survival from serious intra-abdominal infection. Mortality rates for certain complex infections, such as necrotizing pancreatitis and postoperative abscess, decreased by almost 50 percent when compared with both hospital controls and the predicted mortality rate according to severity of illness (1-3). This remarkable improvement in outcome can be attributed to innovations in perioperative methods, image-guided therapy for management of postoperative abscesses and other complications and more effective antimicrobial therapy. Advances in each area, along with supporting data and the limitations of therapy, will be reviewed critically. Methods that have been proved by clinical trial will be emphasized.

Changes in internal carotid blood flow after carotid endarterectomy correlate with preoperative stenosis

BACKGROUND

The relationship between preoperative stenosis and the effect of carotid endarterectomy (CEA) upon internal carotid blood flow (ICF) is not well understood. With the intention of better characterizing this, we compared intraoperative measurements of internal carotid blood with the maximum single diameter stenosis found in preoperative angiograms.

METHODS

Fifty-two patients undergoing 64 carotid endarterectomies (12 bilateral) had transit-time ultrasound perivascular probes used to measure ICF before and after CEA, and the percent change in ICF (% delta ICF) achieved was calculated. Maximum single-diameter stenosis was determined by comparing the least diameter in the flow path from the common carotid to the normal-appearing internal carotid just distal to bifurcation disease.

RESULTS

The entire group had a mean of 53 +/- 21% stenosis found on preoperative angiograms, and % delta ICF averaged 64 +/- 92%. When divided into subgroups based on degree of stenosis, patients with 0% to 40% stenosis (n = 17) had % delta ICF of 32 +/- 46%, patients with 41% to 70% stenosis (n = 30) had % delta ICF of 72 +/- 105%, and patients with more than 70% stenosis had % delta ICF of 168 +/- 160%. The differences in % delta IC were significant for the > 70% group compared with the other groups (analysis of variance, P < 0.005), and marginally significant (P = 0.056) between the 0% to 40% and the 41% to 70% groups. The scatter plot of % delta ICF versus stenosis showed a significant second order direct correlation (r = 0.428, P < 0.001) and disproportionate increases in ICF above 60% stenosis.

CONCLUSION

A curvilinear relationship between stenosis and immediate increase in ICF after CEA was demonstrated in agreement with theory, and in those patients with more than approximately 60% single-diameter stenosis, large disproportionate increases in blood flow were more frequently observed.

Determinants of patency after percutaneous angioplasty and atherectomy of occluded superficial femoral arteries

BACKGROUND

Patients undergoing percutaneous recanalization of chronically occluded superficial femoral arteries were studied to determine which factors correlated with 1-year patency. Immediate change in ankle:brachial index (ABI), length of occlusion, tibial run-off, and the performance of supplemental catheter atherectomy were evaluated.

METHODS

Eligible patients had at least one patient tibial run-off vessel and the absence of limb-threatening ischemia. Recanalization was performed via passage of a guidewire followed by balloon angioplasty. Tibial run-off was scored based on a modification of the angiogram scoring system of the Society for Vascular Surgery and the International Society for Cardiovascular Surgery. Supplemental transcutaneous extraction catheter atherectomy was randomly assigned to a sub-group of patients after initial experience with the recanalization technique. Clinical follow-up was employed to determine patency.

RESULTS

Forty-two of 57 attempts (74%) at recanalization were immediately successful. Overall 1-year patency was 40% in 40 limbs that could be followed. In limbs with balloon angioplasty alone (n = 23), patency was 43% compared with 35% in those having supplemental atherectomy. Tibial run-off did not vary significantly between patent and occluded groups. When ABI increased by 0.3 or more, patency was 56% compared with 26% when the ABI increase was less than or equal to 0.1 (P = 0.13). Occlusion length averaged 18.1 +/- 10.6 cm for all limbs and did not vary significantly between early successes and failures. Limbs with short occlusions (less than or equal to 5 cm, n = 8) had 63% patency compared with 38% patency for limbs with long occlusions (greater than 25 cm, n = 16), but the difference was not significant by analysis of variance.

CONCLUSIONS

An initial change in ABI was most predictive for patency, whereas no correlation with tibial run-off was demonstrated. Atherectomy did not increase patency. Short occlusions were more likely to remain patent than long ones, but overall patency was lower than described in other series.

Design of the abdominal aortic Aneurysm Detection and Management Study. ADAM VA Cooperative Study Group

PURPOSE

This study describes the design of an ongoing randomized trial intended to determine which of two strategies is superior for managing small abdominal aortic aneurysms (AAA).

METHODS

Patients aged 50 to 79 years with AAA 4.0 to 5.4 cm in diameter as determined by computed tomography (CT) who are not at high surgical risk are randomized to either repair of the AAA, called "immediate surgery," or follow-up of the AAA with ultrasonography or CT every 6 months, reserving surgery for those aneurysms that enlarge to 5.5 cm, enlarge rapidly, or become symptomatic, called "selective surgery."

RESULTS

The primary outcome measure is all-cause death, and secondary outcome measures are AAA-related death, morbidity, and general health status. The study design calls for 1350 patients to be randomized and monitored for a mean of 5 years. A second objective of the study is to accurately define the prevalence and risk factors for AAA with use of information from the large screening program established to detect AAA for recruitment into the randomized trial.

CONCLUSIONS

By the end of 1993, 38,697 patients had been screened with ultrasonography, accounting for about three fourths of new randomizations, and 330 patients had been enrolled (70% of the target rate).

Epidermal growth factor, transforming growth factor alpha, transforming growth factor beta, acidic fibroblast growth factor, basic fibroblast growth factor, and interleukin-1 proteins in the cornea

The purpose of this study was to determine whether epidermal growth factor (EGF), EGF receptor, transforming growth factor alpha (TGF-alpha), transforming growth factor beta (TGF-beta), acidic fibroblast growth factor (acidic-FGF), basic fibroblast growth factor (basic-FGF), and interleukin-1-alpha (IL-1-alpha) proteins were present in cultures of human corneal cells and/or in sections of human corneal tissue. Immunohistochemistry was performed on human corneal sections. Immunofluorescent cell staining was used to evaluate corneal epithelial, stromal fibroblast, and endothelial cells in primary culture. Basic-FGF production was evaluated in culture cells using immunoprecipitation. EGF, TGF-alpha, TGF-beta-1, and IL-1-alpha were detected by immunohistochemistry in cells in all three layers of the cornea. EGF receptor and acidic FGF were detected by immunohistochemistry in epithelial and endothelial cells, but not in stromal fibroblast cells. Differences in distribution of the growth factors were noted within individual layers of the cornea. EGF and basic-FGF proteins were detected in all three predominant cell types of the cornea using immunocytology. IL-1-alpha protein was detected by immunocytology in corneal epithelial and endothelial cells, but not stromal fibroblasts. Immunoprecipitation confirmed the production of basic-FGF in all three cell types. IL-1-alpha protein detection in the corneal stroma by immunohistology, but not by immunocytology in first passage stromal fibroblasts, suggests that IL-1-alpha may localize to the corneal stroma after production by corneal epithelial and/or endothelial cells.

Nasal colonization with methicillin-resistant Staphylococcus aureus on admission to the surgical intensive care unit increases the risk of infection

We prospectively studied the relationship of perioperative methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization and subsequent infection in surgical intensive care unit (SICU) patients. In addition, risk factors for MRSA nasal colonization were examined. All patients admitted to the 15-bed SICU between August 1991 and July 1992 had their anterior nares cultured. Cultures positive for S. aureus were subsequently placed on oxacillin-containing plates to screen for methicillin-resistance. Of 484 patients, 19 had MRSA nasal colonization (3.9%). There were five infections in the 19 patients with positive perioperative nasal cultures versus six infections in the remaining 465 patients (P < 0.0001). Immunoblot typing confirmed the concordance of colonizing and infecting strains. Prior exposure to the spinal cord injury center (P < 0.001) and prior antibiotic therapy (P < 0.003) were also significant multivariate risk factors for perioperative nasal colonization. Patients with perioperative MRSA nasal colonization are at significantly increased risk of subsequent postoperative MRSA infection.

Mooren-type hepatitis C virus-associated corneal ulceration

BACKGROUND

Two patients with bilateral Mooren-type ulcers had underlying chronic hepatitis C virus (HCV) infection. Both patients also had chronic, pruritic dermatitis, which in one patient was diagnosed as hidradenitis suppurativa.

METHODS

Serum from the first patient and serum, conjunctiva, and liver from the second patient were analyzed for HCV genomic RNA using the reverse transcriptase-polymerase chain reaction. Serum anti-HCV antibodies were monitored with a commercially available second-generation test. Liver and conjunctival biopsies were evaluated histopathologically.

RESULTS

Liver biopsy showed severe hepatitis in the first patient, but normal liver tissue in the second. Hepatitis C virus genomic RNA was detected in the serum of both patients. In the first patient, the virus was detected 4 months after completion of interferon alfa-2b treatment for chronic active hepatitis. In the second patient, HCV genomic RNA was detected in serum, but not in conjunctiva or liver tissue. Hepatitis C virus could not be detected in the serum of the second patient after 2 weeks of interferon alfa-2b treatment. Both patients had serum anti-HCV antibodies. In case 1, there was a marked improvement in the corneal disease during and after 6 months of interferon alfa-2b treatment for chronic active hepatitis that paralleled a return of serum liver enzyme levels to the normal range. In the second patient, the corneal disease improved after 6 weeks of interferon alfa-2b treatment, but abruptly worsened when the patient discontinued therapy. The corneal disease improved again after interferon alfa-2b was reinstituted.

CONCLUSIONS

Chronic HCV virus infection is associated with Mooren-type peripheral ulcerative keratitis. All patients with Mooren-type ulcers should be tested for evidence of HCV infection in consultation with a liver specialist. Even when improvement is obtained with interferon alfa-2b treatment, however, continued follow-up is important because relapse is common and repeat treatment may be effective.

An operator associated with autoregulation of the repressor gene in actinophage phiC31 is found in highly conserved copies in intergenic regions in the phage genome

Previous reports have suggested that the repressor gene, c, of phiC31 is autoregulated and that likely operators are conserved inverted repeat sequences (CIRs1&2) located just upstream of the promoters, cp1 and cp2. Evidence is now presented that the CIRs 1&2 are indeed binding sites for one of the three inframe, N-terminally different protein isoforms of 42, 54 and 74 kDa produced by the c gene. A cp1-aphII fusion was repressed in a Streptomyces coelicolor A3(2) phiC31 lysogen and characterisation of an operator-constitutive (Oc) mutant showed a single mutation in CIR-1. CIR-1 containing fragments were retarded in electrophoresis gels by the 42 kDa repressor protein isoform and this retardation was inhibited by the addition of competing DNA fragments containing either CIR-1 or CIR-2. Using a combination of Southern blotting and analysis of available DNA sequence we also show that at least 18 copies of the CIRs are present throughout the phiC31 genome. Alignment of 9 CIR sequences showed that 8 contained a perfectly conserved 17 bp core whilst the exception had a single mismatch. The core includes a 16 bp inverted repeat (IR), and is usually part of a more extensive and less highly conserved palindrome. When superimposed on a previously derived transcription map of the early region, the CIRs lie in intergenic regions associated with transcription initiation and/or termination.

Superiority of aztreonam/clindamycin compared with gentamicin/clindamycin in patients with penetrating abdominal trauma

There were 73 evaluable patients entered into a prospective, double-blinded trial comparing aztreonam/clindamycin (A/C) to gentamicin/clindamycin (G/C) for the prevention of infection after penetrating abdominal trauma. Aztreonam was administered at a dosage of 2 g every 8 hours and gentamicin at 5 mg/kg for the first 24 hours and then adjusted by serum monitoring to a peak of 6 to 8 micrograms/mL and a trough of less than 2 micrograms/mL; all patients received 900 mg of clindamycin every 8 hours. Patients with colon wounds received 4 days of antibiotics, and the remaining patients received a 24-hour course. Gunshot wounds occurred in 69% of patients: 74% of all patients had some hollow viscus injury, and 26% had only solid viscus injury. The groups were well matched according to abdominal trauma index, percentage with colon injury, and transfusion requirements. Failures occurred in eight patients (11%): two wound infections, five intra-abdominal infections, and one case of necrotizing fasciitis. Seven infections occurred in 36 (19%) G/C patients compared with 1 in 37 (3%) A/C patients (p < 0.03). The hospital stay was 12 +/- 11 days for G/C patients and 8 +/- 7 for A/C patients (p < 0.12). The superiority of the A/C regimen may be partially attributable to relative underdosing of gentamicin (approximately half of the patients had inadequate levels after 24 hours) combined with a favorable pharmacokinetic profile (significantly prolonged half-life) of aztreonam in this clinical setting.

Screening for corneal topographic abnormalities before refractive surgery

PURPOSE

The purpose of this prospective study is to evaluate the corneal topography of patients who sought an opinion regarding refractive surgery for the correction of myopia.

METHODS

Both eyes of 53 patients were evaluated with a topographic modeling system. Forty-two patients wore contact lenses (84 eyes: 36 rigid contact lenses and 48 soft contact lenses). Ten patients (20 eyes) wore glasses alone and one patient (2 eyes) wore neither glasses nor contact lenses for correction of myopia.

RESULTS

Thirty-five (33%) of 106 eyes were found to have abnormal corneal topography. Of the 42 patients (84 eyes) who wore contact lenses, 32 eyes (38%) had irregular astigmatism, loss of radial symmetry, or absence of the normal progressive flattening from the center to the periphery of the cornea, consistent with contact lens-induced corneal warpage. Alterations were more frequent and severe in rigid contact lens wearers. Three patients (5.7%) received a diagnosis of definite keratoconus, a higher incidence than has been reported in the general population. Topographic abnormalities in most, if not all, of the eyes would not have been detected by visual inspection of the photokeratoscopic images alone.

CONCLUSIONS

Appropriate preoperative detection and management of corneal topographic abnormalities are essential steps in every refractive surgical procedure. The overall efficacy and safety of procedures such as radial keratotomy and photorefractive keratectomy likely will be improved once the unpredictable variables of contact lens-induced warpage and occult ectatic disease are eliminated by topographic screening before surgery. Patients with keratoconus may be over-represented in the refractive surgery population due to self-selection.

Glucocorticoid receptor and interleukin-1 receptor messenger RNA expression in corneal cells

Interleukin-1 receptor and glucocorticoid receptor messenger ribonucleic acid (RNA) sequences coding for the corresponding proteins were detected in corneal epithelium, stromal fibroblast, and endothelial cells using the polymerase chain reaction and hot blotting. Identification of interleukin-1 receptor mRNA in each of the three major cell types of the cornea suggests that interleukin-1 alpha has autocrine and/or paracrine roles in the cornea, since previous studies have found that interleukin-1 alpha mRNA is produced in corneal epithelial, stromal fibroblast, and endothelial cells. Further investigation is needed to determine the functions regulated by the interleukin-1 receptor and glucocorticoid receptor in the cornea and the role of each in corneal wound healing.

Susceptibility of intra-abdominal isolates at operation: a predictor of postoperative infection

Antimicrobial resistance of operative site flora was correlated with postoperative infection in 175 patients undergoing operation for intra-abdominal sepsis: Diagnoses for study patients were acute or gangrenous appendicitis in 48 (27%), complicated appendicitis in 98 (56%), perforated viscus other than appendix in 21 (12%), and eight (5%) had other intra-abdominal infections. One hundred thirty-six (78%) patients were males. The average age was 33 +/- 14 years, average number of hospital days was 11.6 +/- 13.5, and average number of days on antibiotics was 6.9 +/- 2.5. Overall recovery without infection was 75 per cent (131/175). Analysis of susceptibility of 939 intraoperative isolates indicated a significant relationship (P = 0.0002) between resistance to the empiric antimicrobials received and postoperative infection. Of 131 patients with resolution of the intra-abdominal infection, 57 (44%) had resistant isolates while 36 (82%) of 44 patients with postoperative infectious complications had resistant isolates. Streptococcus Group D, Escherichia coli, and Bacteroides fragilis were the most prevalent resistant organisms isolated from both intra- and postoperative cultures. Other variables that were significantly different between those without complications and those who had complications were, respectively: average age 31 versus 38; admission WBC 14.5 versus 16.7; and diagnosis, acute appendicitis 28 per cent versus 2 per cent. A stepwise logistic regression analysis confirmed the predictive value of intraoperative isolate resistance, age, and admission WBC, in that order, on outcome.

Impact of endoscopic therapy on outcome of operation for bleeding peptic ulcers

Since elective surgery for bleeding peptic ulcer disease has declined, the surgical opinion is that patients who undergo emergency operation have more advanced disease and possibly a poorer outcome. We examined current mortality for surgical correction of upper gastrointestinal (UGI) bleeding from peptic ulcer disease. Between July 1, 1986, and December 31, 1990, 1,213 patients had esophagogastroduodenoscopy for UGI bleeding (659 with peptic ulcer disease, 219 with gastroesophageal varices, 152 with esophagitis, 83 with other causes, and 100 with no source found). Of 110 patients with peptic ulcer disease treated by endoscopic methods, bleeding was controlled in 90, and 20 required operation for failed endoscopic control. Another 22 patients had primary operation for exigent bleeding with diagnostic endoscopy only. The overall results in our series compared favorably with two pre-therapeutic endoscopy index series (Nottingham, 1982; University of Pittsburgh, 1982). Our operation rate was 6%, with a mortality rate of 7%, compared with operation rates of 15% to 27%, with mortality rates of 21% to 22% in the historical control series. In conclusion, we found that: (1) endoscopic control of UGI bleeding from peptic ulcer disease has decreased the incidence of operation compared with historical series; (2) overall operative mortality is decreasing; and (3) the major postoperative complication is rebleeding.

In vivo study of a high-porosity polytetrafluoroethylene graft: endothelialization, fluid leakage, and the effect of fibrin glue sealing

Standard polytetrafluoroethylene (PTFE) grafts (30-microns internodal distance, ID) (ST grafts), high-porosity PTFE grafts (90 microns ID) (HP grafts), high-porosity PTFE grafts preclotted with autogenous blood (BHP grafts), and high-porosity PTFE grafts presealed with fibrin glue (FHP grafts) were implanted in both common carotid and femoral arteries of 18 dogs. Of the three high-porosity groups, the FHP graft showed the shortest bleeding time. Seromas and/or hematomas occurred as follows: ST grafts 1, HP grafts 7 (P < .05 vs ST), BHP grafts 5 and 2 with FHP grafts. Fibrin glue was observed in all histological sections of 1-week samples, but by 4 weeks it was almost totally absorbed. No endothelialization (ET) was measurable at 2 weeks. By 4 weeks ET extended for a short distance from each anastomosis and there were no significant differences between the four graft groups. At 18 weeks, the HP, BHP, and FHP grafts showed a significant increase in ET compared with the ST graft (P < .01) but there were no significant differences between the three types of high-porosity graft. The differences in patency rates and neointimal thicknesses did not reach statistical significance. High-porosity PTFE grafts showed superior endothelialization in dogs; however, the enlarged ID of PTFE grafts increased intraoperative bleeding and postoperative seroma formation. Fibrin glue sealant controlled bleeding through the graft wall without affecting graft healing, but its sealant effect was not enough to prevent late fluid leakage.

Standardized color-coded maps for corneal topography

PURPOSE

Modern videokeratoscopy is useful in assessing corneal shape. The purpose of this study is to compare color-coded topographic maps using standardized scales with 1.0- and 1.5-diopter (D) intervals. The authors assessed the use of the two scales for detecting clinically relevant features of corneal topography such as regular astigmatism, irregular astigmatism, early keratoconus, and contact lens-induced corneal warpage.

METHODS

A total of 50 normal corneas, 50 corneas with contact lenses, 50 that had keratoconus (25 early to moderate and 25 advanced), 50 that had penetrating keratoplasty, 20 that had extracapsular cataract surgery, 17 that had excimer laser photorefractive keratectomy for myopia, 10 that had radial keratotomy, 3 that had aphakic epikeratophakia, and 2 that had myopic epikeratophakia were analyzed with a corneal topographic analysis system. Color-coded maps with 1.0-D intervals (Maguire/Waring scale) and 1.5-D intervals (Klyce/Wilson scale) were compared.

RESULTS

There were no topographic characteristics that were not appreciated with either scale for corneas with dioptric powers that fell within their ranges. Conversely, for corneas that had powers outside the range of the 1.0-diopter scale, but within the range of the 1.5-diopter scale, the former produced a map in which the flattest or steepest areas were artifactually smoothed.

CONCLUSIONS

This study suggests that the Klyce/Wilson scale (constant, 1.5-D intervals) provides the best combination of sensitivity for detection of clinically significant topographic features and the widest range of coverage of powers that are found on a variety of normal, pathologic, and surgically altered corneas. The adoption of the Klyce/Wilson scale by all manufacturers of corneal topographic instruments as a primary standard will facilitate communication and will make the interpretation of corneal topography easier for both the expert and the novice.

Surgery or balloon angioplasty for peripheral vascular disease: a randomized clinical trial. Principal investigators and their Associates of Veterans Administration Cooperative Study Number 199

PURPOSE

Surgical revascularization and angioplasty (PTA) are effective therapies for patients with peripheral arterial disease, but there are no data on long-term survival, limb salvage, and hemodynamic status from a randomized study of such patients. A multicenter, prospective trial compared PTA with bypass surgery (BP) in 263 men who had iliac, femoral, or popliteal artery obstruction.

PATIENTS AND METHODS

Lesions in the iliac versus the femoropopliteal artery and rest pain versus claudication were separately randomized to the two treatment interventions. One hundred twenty-six patients underwent BP, 129 patients underwent PTA, and eight patients were not treated for lower extremity ischemia.

RESULTS

Three operative deaths occurred in the BP group and none in the PTA group. For the entire study, average annual mortality was higher in the BP group, but survival was not significantly different on life-table analysis (P = .08). Primary success favored BP, while limb salvage favored PTA, but differences were not statistically significant (P = .08 and .35, respectively). Patients with iliac disease or claudication fared better, but there was no statistical difference in response to PTA or BP.

CONCLUSION

Patients in both treatment groups had prompt and sustained increases in hemodynamics and quality of life. This study of patients randomly assigned to BP or PTA shows no significant difference in outcomes during a median follow-up of 4 years.

Prospective randomized study of piperacillin/tazobactam therapy of surgically treated intra-abdominal infection. The Piperacillin/Tazobactam Intra-Abdominal Infection Study Group

A randomized prospective trial was undertaken in adult patients with serious intra-abdominal infections to determine whether a new combination of antibiotic therapy could prove as efficacious as the combination that has been widely used in practice in the recent decade (clindamycin and gentamicin). Three hundred thirty-one patients were randomized in a 2:1 ratio, with the larger number of patients being treated parenterally with piperacillin and tazobactam. The results showed that both the clinical and microbiologic performance of the piperacillin/tazobactam combination was better than that of clindamycin and gentamicin. This clinical equivalence permits overall cost savings without compromising the existing quality of antimicrobial therapy for intra-abdominal infection.

High porosity PTFE improves endothelialization of arterial grafts without increasing early thrombogenicity

OBJECTIVE

High porosity (HP) (90 micron internodal distance) PTFE grafts were implanted into the carotid and femoral arteries of dogs to investigate early thrombogenicity, patency, and endothelialization.

EXPERIMENTAL DESIGN

Standard PTFE (STD) grafts (30 micron internodal distance) were used as controls. 12 HP and 12 STD grafts were implanted into 6 dogs. Indium-111 labeled platelets were infused intravenously after graft implantation. A graft platelet accumulation index (GPAI) was calculated as the ratio of radioactive emission from the PTFE grafts excised at 48 hours to the emission from a native arterial segment. Another 12 HP and 12 STD grafts were implanted into femoral and carotid arteries to assess patency and endothelialization at 4 and 18 weeks.

RESULTS

There was no significant difference in the GPAI of the HP and STD grafts at either the carotid (HP = 31.5 +/- 9.7, STD = 30.6 +/- 11.8; p > 0.05) or femoral (HP = 34.0 +/- 5.0, STD = 31.5 +/- 7.9; p > 0.05) positions. Combined data (carotid and femoral HP vs. carotid and femoral STD) also did not demonstrate a difference in GPAI (HP = 32.8 +/- 7.5, STD = 31.1 +/- 9.6; p > 0.05). Patency rates were the same at 4 weeks (75%), but greater in the HP grafts at 18 weeks (HP = 75%, STD = 37%; p > 0.05). No difference was noted in the percentage of graft endothelialization at 4 weeks (HP = 5.2 +/- 5.8, STD = 5.0 +/- 4.0; p > 0.05), however, at 18 weeks the HP graft had significantly more endothelial coverage compared to STD grafts (HP = 75.2 +/- 13.9, STD = 22.6 +/- 9.5; p < 0.01).

CONCLUSIONS

Given that HP PTFE is no more thrombogenic than STD PTFE, and that it provides superior endothelialization, HP grafts should continue to be developed and studied for potential clinical use.

Vascular access surgery as an outpatient procedure

Construction of a vascular access site for hemodialysis has traditionally been done on an inpatient basis or more recently in a hospital operating room as a 1-day admission. Over 18 months we performed 49 vascular access procedures on 45 patients in a freestanding ambulatory surgical center. Four patients had an arteriovenous radiocephalic autogenous fistula constructed, 30 patients had a polytetrafluoroethylene (PTFE) prosthesis inserted as an arteriovenous bridge graft, 11 patients had a planned reconstruction of a previously placed graft, 1 patient had a false aneurysm corrected, 1 patient had a chronically infected graft removed, and 2 patients had a thrombectomy. All procedures were in the upper extremities except for one femorosaphenous PTFE graft and one excision of a false aneurysm in a thigh prosthesis. Only one patient, an 84-year-old woman, required hospitalization following the outpatient procedure because she was unable to care for herself. No postoperative infection had occurred at 1 month follow-up. A left upper extremity graft performed at another inpatient facility was removed because of infection. The protocol for outpatient vascular access surgery includes preoperative evaluation of the patient for determination of the access site within a week of operation; duplex scan of subclavian veins if central venous lines have been in place for more than 2 weeks; scheduling surgery for the afternoon or morning following routine hemodialysis; obtaining a hemoglobin level, serum/electrolyte study, and an ECG following the last hemodialysis; parenteral antimicrobial prophylaxis; local infiltration anesthesia with standby; a minimum of 1 hour of observation in the recovery room; and a repeat hematocrit study prior to discharge.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatocyte growth factor, keratinocyte growth factor, their receptors, fibroblast growth factor receptor-2, and the cells of the cornea

PURPOSE

The purpose of this study was to determine whether messenger RNA coding for hepatocyte growth factor (HGF), HGF receptor (MET), keratinocyte growth factor (KGF), KGF receptor, and fibroblast growth factor (FGF) receptor-2 were produced in primary cultures of human corneal epithelial, stromal fibroblast, and endothelial cells, as well as ex vivo corneal epithelium, endothelial cells transfected with the SV40 large T antigen, and control embryonic lung fibroblasts. The effects of exogenous HGF and KGF, compared to epidermal growth factor, on the proliferation of first passage corneal cells were also examined.

METHODS

Polymerase chain reaction was used to amplify complementary DNA for each modulator from each cell type. Hot blotting was used to demonstrate the specificity of amplification products. Proliferation of first passage corneal epithelial, stromal fibroblast, and endothelial cells in response to varying concentrations of HGF, KGF, and epidermal growth factor was measured.

RESULTS

Specific amplification products for messenger RNA coding for each modulator were detected in each corneal cell type, although very low levels of HGF and KGF messenger RNA appeared to be present in corneal epithelial cells relative to stromal fibroblasts and corneal endothelial cells. Amplification products that may have been derived from alternative transcripts were detected for several of the modulators. HGF and KGF stimulated proliferation in a dose-response manner in first passage corneal epithelial and endothelial cells, but not stromal fibroblast cells.

CONCLUSIONS

Human corneal epithelial, stromal fibroblasts, and endothelial cells produce messenger RNA coding for HGF and KGF, although low levels appear to be present in the epithelial cells. All three major cell types of the cornea produce messenger RNA coding for HGF receptor, KGF receptor, and FGF receptor-2. The proliferation of human corneal epithelial and endothelial cells, but not stromal fibroblasts, was stimulated by exogenous HGF and KGF. HGF and KGF likely have intracrine, autocrine, and/or paracrine functions in the cornea. Exogenous HGF and KGF may be useful in corneal preservation and for regulating corneal wound healing.