Consensus categorization of cheese based on water activity and pH-A rational approach to systemizing cheese diversity.

Development of science-based interventions in raw milk cheese production is challenging due to the large diversity of production procedures and final products. Without an agreed upon categorization scheme, science-based food safety evaluations and validation of preventive controls would have to be completed separately on each individual cheese product, which is not feasible considering the large diversity of products and the typically small scale of production. Thus, a need exists to systematically group raw milk cheeses into logically agreed upon categories to be used for food safety evaluations. This paper proposes and outlines one such categorization scheme that provides for 30 general categories of cheese. As a base for this systematization and categorization of raw milk cheese, we used Table B of the US Food and Drug Administration's 2013 Food Code, which represents the interaction of pH and water activity for control of vegetative cells and spores in non-heat-treated food. Building on this table, we defined a set of more granular pH and water activity categories to better represent the pH and water activity range of different raw milk cheeses. The resulting categorization scheme was effectively validated using pH and water activity values determined for 273 different cheese samples collected in the marketplace throughout New York State, indicating the distribution of commercially available cheeses among the categories proposed here. This consensus categorization of cheese provides a foundation for a feasible approach to developing science-based solutions to assure compliance of the cheese processors with food safety regulations, such as those required by the US Food Safety Modernization Act. The key purpose of the cheese categorization proposed here is to facilitate product assessment for food safety risks and provide scientifically validated guidance on effective interventions for general cheese categories. Once preventive controls for a given category have been defined, these categories would represent safe havens for cheesemakers, which would allow cheesemakers to safely and legally produce raw milk cheeses that meet appropriate science-based safety requirements (e.g., risk to human health equivalent to pasteurized milk cheeses).

Humoral immune response to allograft valve tissue pretreated with an antigen reduction process.

The humoral immune response to allograft heart valves as measured by PRA was absent in 52 of 57 (91%) patients at 1 month and was absent in 43 of 49 (88%) at 3 months in allograft valves treated with the SynerGraft process for antigen reduction. Short-term valve function is satisfactory. This may be associated with improved durability and long-term function.

Ross operation in children: late results.

BACKGROUND AND AIM OF THE STUDY: Although the Ross operation has become the accepted aortic valve replacement in children, the long-term fate of the pulmonary autograft valve remains unknown. To assess mid-term and late results of autograft valve durability, patient survival and valve-related morbidity, a retrospective review of patients (age range: 3 days to 17 years) having a Ross operation between November 1986 and May 2001 were reviewed. METHODS: Medical records and patient contacts with all but two of 167 current survivors of 178 consecutive patients having an aortic valve replacement as a Ross operation have been completed during the past two years. The most recent echocardiographic evaluation was reviewed for autograft valve and homograft valve function. RESULTS: Operative mortality was 4.5% (8/178), with three late deaths (two were non-valve-related) for an actuarial survival of 92+/-3% at 12 years. Actuarial freedom from autograft valve degeneration (reoperation or severe insufficiency of autograft valve or valve-related death) was 90+/-4% at 12 years. Autograft valve degeneration was not affected by technique of insertion (141 root replacement, 37 intra-aortic), aortic valve morphology (157 bicuspid or unicuspid, 26 tricuspid), or age at operation. Autograft valve degeneration was worse in patients with a primary lesion of aortic insufficiency than in those with aortic stenosis (p = 0.03). Autograft valve reoperation was required in 12 patients, with autograft valve replacement in seven. Actuarial freedom from autograft replacement was 93+/-3% at 12 years. Homograft valve replacement was required in seven patients, with actuarial freedom from replacement of 90+/-4% at 12 years. Eight additional patients have homograft valve obstruction (gradient > or =50 mmHg), and seven have severe pulmonary insufficiency. CONCLUSION: Survival and freedom from aortic valve replacement are excellent in children. Homograft valve late function remains a concern, and efforts to improve homograft durability should be encouraged.

Aortic valve replacement: comparison of late survival between autografts and homografts.

BACKGROUND: Autografts (AG) and homografts (HG) are currently considered the best choices for replacement of the diseased aortic valve in young adults, although few data exist comparing their late outcome. Nonhomogeneous populations and evolving operative techniques confound existing comparisons. METHODS: To help clarify these issues, we reviewed our results with 238 hospital survivors (aged 17 to 82 years) undergoing operation between 1986 and 1999. All operations were done as root replacements, and patients needing concomitant valve replacement were excluded. RESULTS: Mean age of the 145 AGs and 93 HGs was 35 +/- 13 years and 49 +/- 17 years, respectively (p < 0.001). Previous aortic valve replacement was done in 12 (8%) AG and 32 (34%) HG patients (p = 0.001), and active endocarditis was present at time of current operation in 10 (7%) AG and 25 (27%) HG patients (p = 0.001). Maximum follow-up was 12.2 years for AGs and 12.8 years for HGs. Late survival at 10 years was 77% +/- 11% for AGs and 67% +/- 9% for HGs (p = 0.13). Freedom from AG or HG degeneration at 10 years was 97% +/- 2% and 79% +/- 10% (p = 0.63). Freedom from valve-related complications at 10 years was 73% +/- 10% and 64% +/- 10% (p = 0.93), respectively. Freedom from all reoperations at 10 years was 88% +/- 5% for AG and 72% +/- 11% for HG (p = 0.67). CONCLUSIONS: Autografts and HGs have comparable late survival. The incidence of valve degeneration is low for both AG and HG up to about 8 years at which point there may be a trend toward an advantage for AG over the HG, suggesting benefit for the younger patient.

Pulmonary autograft root replacement: mid-term results.

BACKGROUND AND AIMS OF THE STUDY: The Ross operation was first performed as a root replacement in 1974, and only limited mid- and long-term results assessing durability and adaptation of the pulmonary root to systemic pressures are available. We reviewed our experience to assess function of the autograft valve and the autograft pulmonary root, and its adaptation to systemic pressures. METHODS: A total of 244 operative survivors (median age 22 years; range: 1 week to 62 years) were reviewed. Clinical follow up (within one year) was available on 98% of cases, and echocardiographic assessment within one year on 93%. Autograft and homograft valve function, aortic annulus diameter, autograft root sinus diameter and ascending aortic diameter were determined on the most recent echocardiogram. RESULTS: Actuarial freedom from autograft valve degeneration (non-endocarditis autograft valve reoperation or severe autograft valve insufficiency or valve-related death) was 95 +/- 3% at 5 years and 93 +/-4% at 10 years. Actuarial freedom from all valve-related complications (autograft valve degeneration, autograft valve reoperation, homograft valve reoperation or valve-related death) was 90 +/- 4% at 5 years and 83 +/-6% at 10 years. Actuarial freedom from autograft valve replacement was 98 +/- 2% at 5 years and 96 +/- 4% at 10 years. Actuarial survival rate was 98 +/- 2% at 5 years and 86 +/- 9% at 10 years. Aneurysmal dilation of the autograft root occurred in two patients; this was not associated with autograft valve degeneration, and these patients were followed closely. CONCLUSIONS: At 10 years, the Ross root replacement has a low risk of valve degeneration, valve-related complications and autograft valve replacement, and patient survival is excellent. Autograft valve reoperation and homograft valve reoperation have been the only significant late valve-related complications. Techniques to reduce autograft reoperation have been introduced, and hopefully methods to mediate the immunological response to the homograft valve will reduce the incidence of failure. Significant aneurysmal dilation of the pulmonary autograft root is rare.

Ross procedure for ascending aortic replacement.

BACKGROUND: Patients with aortic valve disease and aneurysm or dilatation of the ascending aorta require both aortic valve replacement and treatment of their ascending aortic disease. In children and young adults, the Ross operation is preferred when the aortic valve requires replacement, but the efficacy of extending this operation to include replacement of the ascending aorta or reduction of the dilated aorta has not been tested. METHODS: We reviewed the medical records of 18 (5.9%) patients with aortic valve disease and an ascending aortic aneurysm and 26 (8.5%) patients with dilation of the ascending aorta, subgroups of 307 patients who had a Ross operation between August 1986 and February 1998. We examined operative and midterm results, including recent echocardiographic assessment of autograft valve function and ability of the autograft root and ascending aortic repair or replacement to maintain normal structural integrity. RESULTS: There was one operative death (2%) related to a perioperative stroke. Forty-two of 43 survivors have normal autograft valve function, with trace to mild autograft valve insufficiency, and one patient has moderate insufficiency at the most recent echocardiographic evaluation. None of the patients has dilatation of the autograft root or of the replaced or reduced ascending aorta. CONCLUSIONS: Early results with extension of the Ross operation to include replacement of an ascending aortic aneurysm or vertical aortoplasty for reduction of a dilated ascending aorta are excellent, with autograft valve function equal to that seen in similar patients without ascending aortic disease.

Ross operation and aneurysm or dilation of the ascending aorta.

Aortic valve disease and aneurysmal dilation of the ascending aorta are managed by prosthetic valve conduit replacement or homograft replacement. Requirement of anticoagulation, risk of thromboembolism or bleeding, and increased risk for homograft degeneration in young patients suggest that a Ross root replacement with replacement or reduction of the ascending aorta could be a preferred alternative. To assess efficacy, the present review was undertaken. Between April 19, 1995, and February 1999, 64 patients (age, 8 months to 59 years; median age, 37 years) had a Ross operation, with resection of the ascending aorta in 30 and reduction aortoplasty in 34. Annular fixation was performed in 57 patients, with aortic annulus reduction in 39. Clinical evaluation with echocardiogram was completed within 1 year of closure in 62 patients. There was one operative death and one non-valve-related late death. Autograft valve insufficiency (AI) was 0 to trace in the perioperative period in all patients. One patient developed progressive annular dilation with moderate AI at 2 months. Reoperation with annular reduction and fixation restored autograft valve function. Postoperative mean aortic annulus diameter was 22.5+/-0.4 mm (Z-value, -0.2+/-0.2) and 23.2+/-0.8 mm (Z-value, -0.02+/-0.5) at 1 year. Aortic sinus diameter was 33+/-6 postoperative and 36+/-5 at 1 year. The autograft root sinus diameter was greater than 39 mm in 11 patients at the most recent echocardiogram. Mean echocardiography measurements of the aortic root have been constant during the postoperative follow-up period. Two patients have required reoperation for homograft obstruction 1.3 and 2.1 years after operation. Ross root replacement of the aortic valve with resection or reduction aortoplasty can be performed with a low operative risk and limited morbidity. Its early durability appears to be similar to other Ross operations.

A 26-year experience with surgical management of tetralogy of Fallot: risk analysis for mortality or late reintervention.

BACKGROUND: Over the past decade repair of tetralogy of Fallot (TOF) in infancy has gained favor. It is still uncertain what effect early complete repair will have on survival or late reoperation on the right ventricular outflow tract. METHODS: To assess these outcomes, we reviewed our experience (1971-1997) with 294 patients undergoing operation at one institution. Median follow-up was 10.6 years (range, 0.1 to 26 years), and was complete for 90.2% patients. RESULTS: Primary complete repair was done in 199 patients (68%), and a staged repair in 62 patients (21%). Thirty-three patients had only a palliative procedure. Sixty-eight patients (23.1%) had complex pathologic processes, including pulmonary atresia in 53. Hospital mortality for primary repair was 11.1% (22/199), for staged repair was 17.7% (11/62), and for palliative procedures was 15.5% (16/103 procedures). Since 1990 mortality has been 2.1%, 11.8%, and 0% respectively (p < 0.001), despite younger age at repair (0.6+/-0.1 versus 2.1+/-0.2 years; p < 0.001). Multivariate analysis identified longer period of hypothermic circulatory arrest, pulmonary artery patch angioplasty, earlier year of operation, and closure of the foramen ovale as risk factors for hospital death. For hospital survivors 20-year survival was 98%+/-3% for TOF with pulmonary stenosis and 88%+/-9% for TOF with pulmonary atresia (p=0.09). Reintervention on the right ventricular outflow tract was needed in 14.1% (37/261) patients. Freedom from reintervention on the right ventricular outflow tract at 20 years was 86%+/-4% for TOF with pulmonary stenosis and 43%+/-16% for TOF with pulmonary atresia (p=0.001). For the subgroup TOF with pulmonary stenosis, this was 85%+/-5% after primary repair and 91%+/-8% after staged repair (not significant). At 15-year follow-up, this was 78%+/-10% for patients not older than 1 year at operation compared with 88%+/-4% for older patients (not significant). CONCLUSIONS: Early mortality after primary repair of TOF has significantly improved and late survival is excellent. Primary repair in infancy does not increase risk for reintervention on the right ventricular outflow tract.

Congenital aortic valve disease. Improved survival and quality of life.

OBJECTIVE: The purpose of the study was to assess the effect of recent trends in surgical management, including use of the Ross Operation, on improved survival and quality of life in patients treated surgically for aortic valve (AV) disease at Oklahoma Children's Hospital. BACKGROUND: Surgical treatment of congenital AV disease has proved to be palliative, but newer procedures may be improving outcomes. METHODS: A retrospective review of 301 patients, age 1 day to 26 years (median, 5 years), having a surgical AV procedure or aortic balloon valvuloplasty at Children's Hospital of Oklahoma between 1960 and February 1996, was conducted. Information was collected on all prior and subsequent operations, and follow-up within 1 year was 96% complete. RESULTS: Survival for all patients was 90% +/- 2% at age 10 years and 73% +/- 8% at age 25. By age 5, 52% +/- 4% had required an AV procedure, 89% +/- 3% by age 15. Patient survival was affected adversely by the diagnosis of valvar aortic stenosis, 79% +/- 6% at age 25 compared to 95% +/- 4% for subvalvar aortic stenosis or aortic insufficiency (p = 0.01). The AV morphology did not affect survival, but patients with a bicuspid or unicuspid valve required operative intervention at an earlier age. Survival after autograft replacement of the AV (Ross Operation) was significantly better than for other types of valve replacement (p = 0.0043). Quality of life as assessed by need for reoperation favors the use of the Ross Operation, with freedom from reoperation at 9 years of 87% +/- 7% compared to 55% +/- 5% in all patients after first AV surgery (p = 0.003). CONCLUSIONS: The Ross Operation appears to have a significant advantage in survival and quality of life in children requiring a valve replacement as a first operation or after a prior AV procedure.

Pulmonary autograft reoperation: incidence and management.

BACKGROUND: Pulmonary autograft replacement of the aortic valve is accepted in the young, those with an active life style, and those who are not candidates for anticoagulation. However, concern remains about autograft or homograft valve failure. METHODS: One hundred ninety-five operative survivors of the Ross operation (August 1986 through December 1995) were reviewed for operative pathology and factors associated with reoperation or valve dysfunction. RESULTS: Actuarial freedom from reoperation (autograft or homograft) is 89% +/- 3% at 5 years, 92% +/- 3% for the autograft alone. Early autograft valve failures (< 6 months) were due to technical error in 2 patients and persistent endocarditis in 1. Late autograft valve failure (1 to 6.2 years) was due to aortic annulus dilatation in 5 patients, bacterial endocarditis in 1, and valve degeneration in 2. Six autograft valves were replaced and five were repaired. Five patients required reoperation for pulmonary homograft stenosis (1 to 5.4 years) involving obstruction of the conduit distal to the pulmonary valve. CONCLUSIONS: Pulmonary autograft replacement of the aortic valve has a low incidence of reoperation for autograft dysfunction or homograft obstruction. Autograft dysfunction can be corrected by autograft repair in patients with central insufficiency and aortic annular dilatation.

Pulmonary autograft in children: realized growth potential.

Pulmonary autograft replacement of the aortic valve has the potential to remain viable and grow in proportion to the somatic growth of the child. Changes in aortic annulus and sinotubular dimensions were compared early and late postoperatively, and related to normal. Eighty-six children, 0.9 to 21 years, were operated on between 1986 and 1993: 42 had a root replacement, 24 an inclusion cylinder, and 20 a scalloped subcoronary implant. Actuarial survival at 7 years was 96.5% +/- 2.0%. Freedom from reoperation for the pulmonary autograft or the homograft reconstruction of the right ventricular outflow tract was 92% +/- 4%. Freedom from reoperation on the autograft in root replacements was 96% +/- 4%, in the inclusion cylinder was 100%, and in the scalloped subcoronary was 90% +/- 7% (not significant). Aortic annulus and sinotubular junction diameters were compared with normal values predicted by body surface area. In 22 intraaortic implants, early and late postoperative annulus diameter mean Z values are in the normal range. In the 23 root replacements, early annulus diameter was within the normal range, but late Z values were larger than normal (p < 0.02). Intraaortic implant annulus diameter increased proportionally to somatic growth, but the sinotubular junction, which was small, remained small but increased toward normal. In the root replacements, the annulus increased in diameter and became dilated. The sinotubular junction, which was small early, increased and was within the normal range late. Lower operative risk and valve durability without failure suggest improved results with inclusion cylinder technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Homograft replacement of the aortic valve and root as a functional unit.

Homograft replacement of the aortic valve has inherent advantages for the patient in terms of decreased incidence of thromboembolism, endocarditis, and anticoagulation-related complications. Limitations in its use stem from a significant incidence of postoperative aortic regurgitation, related to difficulty with consistent commissural and sinotubular geometry when inserted in the subcoronary position. To minimize this complication, we used a homograft as a functional unit in 71 patients between 1986 and May 1993, either as a root replacement (n = 58) or as an intraaortic inclusion cylinder (n = 13). There were 4 pulmonary and 67 aortic homografts. Mean age of the 16 female and 55 male patients was 42 +/- 19 years (range, 0.6 to 84 years). Thirty patients had predominantly aortic regurgitation, 19 aortic stenosis, 18 mixed aortic valve disease, and 4 primary aneurysmal disease. Eighteen (25.4%) had infective endocarditis. Thirty-five patients (49%) had a previous operation on the aortic valve. Hospital mortality was 14.1% (10/71), 0% for inclusion cylinders and 17.2% (10/58) for root replacements (p = not significant). Recent follow-up was obtained in all hospital survivors. Mean follow-up period was 35 months (range, 1 to 81 months). There were six late deaths, 1/13 for inclusion cylinders and 5/48 for root replacements. Actuarial survival at 5 years was 74.9% +/- 5.6%. Reoperation was required in 3 patients (all with root replacements), 1 for postoperative endocarditis, 1 for left coronary ostial obstruction, and 1 for late onset of aortic dilatation and regurgitation (pulmonary homograft used as a root replacement). Two patients currently have asymptomatic greater than 2/4 aortic regurgitation. Freedom from significant aortic regurgitation was 88% +/- 7% at 6-year follow-up. More consistent maintenance of the sinotubular and commissural geometry of the aortic homograft may be achieved with the root replacement or the inclusion cylinder techniques. This may reduce the incidence of postoperative aortic regurgitation and further benefit the patient by reducing the need for reoperation in the future.

Neonatal coarctation repair. Influence of technique on late results.

BACKGROUND: Coarctation repair in the neonate (< or = 28 days) is associated with higher mortality and increased incidence of restenosis compared with older infants. It has been suggested that resection of pericoarctation ductal tissue may reduce this risk of restenosis. METHODS AND RESULTS: To further clarify these issues, we reviewed our experience with 111 consecutive neonates undergoing primary repair between 1973 and 1991. Hospital mortality was 14.4% (16 of 111) and was not significantly different for the type of repair:resection and end-to-end anastomosis (RETE) 10.7% (6 of 56), subclavian flap angioplasty (SFA) 16.7% (6 of 36), and patch angioplasty (PA) 16.7% (3 of 18). Associated complex cardiac pathology was associated with higher operative risk: 25% (10 of 40) versus 8.4% (6 of 71) (P = .02). Median follow-up of 4.2 years (range, 0.1 to 18.5 years) was 99% complete. Late mortality was 13.6% (13 of 95), of which 92% occurred within 1 year of repair. Twenty percent (19 of 95) needed reintervention for restenosis, RETE 16% (8 of 50), SFA 13% (4 of 30), and PA 47% (7 of 15) (P = .02). Of these, 84.2% (16 of 19) required reintervention within 1 year of repair. Freedom from reintervention 1 and 8 years after operation was 80 +/- 4% and 77 +/- 5%, respectively. Actuarial survival 8 years after operation was 73 +/- 4%; for simple coarctation, this was 90 +/- 4%. By multivariate analysis, survival was negatively influenced only by presence of associated cardiac pathology (P = .002) and reintervention only by patch angioplasty technique of repair (P = .007). CONCLUSIONS: In the neonate, resection of coarctation (RETE) does not diminish the risk for reintervention compared with SFA. The risk for both late death and recurrent coarctation are highest within the first year after repair, and follow-up should be particularly vigilant during this period.

Pulmonary arteriovenous malformations related to Rendu-Osler-Weber syndrome.

Interest in Rendu-Osler-Weber (ROW) syndrome has been renewed because of new treatment for the pulmonary artery fistulae that occur in approximately one-half of the patients. Pulmonary arteriovenous malformations (AVM) can be occluded safely by the transvenous placement of a silicone balloon thus avoiding the many potential complications of thoracotomy. Thirty-three members of four generations of a family with ROW illustrate the varied manifestations of the syndrome and provide a basis for review of clinical findings and therapeutic approaches to the management of pulmonary AVMs during the last 25 years. Special attention is given to early detection and prevention of major complications. Since ROW syndrome is an inherited trait, informed genetic counseling is an important component of the overall management of families with this disorder.

Exercise testing in children and adolescents with cardiovascular disease.

Exercise testing was the means of finding functional cardiovascular abnormalities in two-thirds of the 400 young patients studied for this report. No complications occurred, and the test results were valuable in counseling and managing the patients.

Adolescent blood pressure in Richmond, Virginia, schools.

The blood pressure of 3,166 adolescents was measured periodically in Richmond during the period 1974-1977. The subjects were students in public and private schools and ranged in age from 14 to 18 years. Analysis of the readings showed minimal differences relating to age, sex, school and race but a strong correlation with obesity. Only two organic renal causes of hypertension were discovered. A 3 1/2-year followup of 902 students indicated significant tracking, with a correlation coefficient of .385 for systolic and .305 for diastolic pressure. At the conclusion of the study, 340 students (10.7%) were identified as needing followup for hypertension.

Lack of connection between the atria and the peripheral conduction system in a case of corrected transposition with congenital atrioventricular block.

This is the first documented histologic study of the heart of a patient with corrected transposition of the great vessels and congenital atrioventricular (A-V) block with no connection between the atria and an anterior type of peripheral conduction system. Musculature in the superior (anterior) walls of both atria was absent, as was the anterior A-V node. The peripheral conduction system began with the bundle of His. In place of the absent atrial musculature, fibrosis and calcification were present. The relation of laboratory evidence of connective tissue dyscrasia in the mother to the congenital A-V block in the child is discussed.