Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm

We present a new measurement of the positive muon magnetic anomaly, a_{μ}≡(g_{μ}-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, ω[over ˜]_{p}^{'}, and of the anomalous precession frequency corrected for beam dynamics effects, ω_{a}. From the ratio ω_{a}/ω[over ˜]_{p}^{'}, together with precisely determined external parameters, we determine a_{μ}=116 592 057(25)×10^{-11} (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain a_{μ}(FNAL)=116 592 055(24)×10^{-11} (0.20 ppm). The new experimental world average is a_{μ}(exp)=116 592 059(22)×10^{-11} (0.19 ppm), which represents a factor of 2 improvement in precision.

Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: Long term oncologic outcomes from the international PSOGI registry

The laparoscopic approach for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (L-CRS + HIPEC) in highly selected patients was previously reported from the PSOGI registry with a demonstrable reduction in length of stay and post-operative morbidity. This study aims to update this international PSOGI registry with a larger cohort of patients and a longer follow-up period.

METHODS

An international registry was designed through a networking database (REDCAP®). All centers performing L-CRS + HIPEC were invited through PSOGI to submit data on their cases. Variables such as demographics, clinical outcomes, and survival were analyzed.

RESULTS

A total of 315 L-CRS + HIPEC cases were provided by 14 worldwide centers. A total of 215 patients were included in the L-CRS + HIPEC group. The median peritoneal cancer index (PCI) was 3 (3-5). The median length of stay was 7 days (5-10) and the major morbidity (Clavien-Dindo ≥3) was 6.1% after 30 days. The 5-year disease-free survival (DFS) per tumor origin was: 94% for PMP-LG, 85% for PMP-HG, 100% for benign multicyst peritoneal mesothelioma (MPM), 37.4% for colonic origin, and 54%(at 3 years) for ovarian origin. The 5 years overall survival (OS) per tumor origin was: 100% for PMP-LG, PMP-HG and MPM; 61% for colonic origin, and 74% (at 3 years) for ovarian origin. In addition, a total of 85 patients were analyzed in the laparoscopic risk-reducing HIPEC (L-RR + HIPEC). The median length of stay was 5 days (4-6) and the major morbidity was 6% after 30 days. The 5-year DFS per tumor origin was: 96% for perforated low grade appendiceal mucinous neoplasm (LAMN II) and 68.1% for colon origin. The 5 years OS per tumor origin was: 98% for LAMN II and 83.5% for colonic origin.

CONCLUSIONS

Minimally invasive CRS + HIPEC is a safe procedure for selected patients with peritoneal carcinomatosis in specialized centers. It improves perioperative results while providing satisfactory oncologic outcomes. L-RR + HIPEC represents a promising strategy that could be evaluated in patients with high risk of developing peritoneal carcinomatosis into prospective randomized trials.

Role of Molecular Modification and Protein Folding in the Nucleation and Growth of Protein-Metal-Organic Frameworks

Metal-organic frameworks (MOFs) are a class of porous nanomaterials that have been extensively studied as enzyme immobilization substrates. During in situ immobilization, MOF nucleation is driven by biomolecules with low isoelectric points. Investigation of how biomolecules control MOF self-assembly mechanisms on the molecular level is key to designing nanomaterials with desired physical and chemical properties. Here, we demonstrate how molecular modifications of bovine serum albumin (BSA) with fluorescein isothiocyanate (FITC) can affect MOF crystal size, morphology, and encapsulation efficiency. Final crystal properties are characterized using scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), fluorescent microscopy, and fluorescence spectroscopy. To probe MOF self-assembly, in situ experiments were performed using cryogenic transmission electron microscopy (cryo-TEM) and X-ray diffraction (XRD). Biophysical characterization of BSA and FITC-BSA was performed using ζ potential, mass spectrometry, circular dichroism studies, fluorescence spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. The combined data reveal that protein folding and stability within amorphous precursors are contributing factors in the rate, extent, and mechanism of crystallization. Thus, our results suggest molecular modifications as promising methods for fine-tuning protein@MOFs' nucleation and growth.

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{μ}≡(g_{μ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over ˜]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over ˜]_{p}^{'}, together with known fundamental constants, determines a_{μ}(FNAL)=116 592 040(54)×10^{-11} (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ^{+} and μ^{-}, the new experimental average of a_{μ}(Exp)=116 592 061(41)×10^{-11} (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.

Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for limited peritoneal metastasis. The PSOGI international collaborative registry

INTRODUCTION

A laparoscopic approach for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (L-CRS+HIPEC) in highly selected patients has been reported in small cohorts with a demonstrable reduction in length of stay and post-operative morbidity. This study aims to analyse individual patient data from these international centres collected through the Peritoneal Surface Oncology Group International (PSOGI) L-CRS+HIPEC registry.

METHODS

An international registry was designed through a networking database (REDCAP®). All centres performing L-CRS+HIPEC were invited through PSOGI to submit data on their cases. Patient's characteristics, postoperative outcomes and survival were analysed.

RESULTS

Ten international centres contributed a total of 143 L-CRS+HIPEC patients during the study period. The most frequent indication was low grade pseudomyxoma peritonei in 79/143 (55%). Other indications were benign multicyst mesothelioma in 21/143(14%) and peritoneal metastasis from colon carcinoma in 18/143 (12,5%) and ovarian carcinoma in 13/143 (9%). The median PCI was 3 (2-5). The median length of stay was 6 (5-10) days, with 30-day major morbidity rate of 8.3% and 30-day mortality rate of 0.7%. At a median follow-up of 37 (16-64) months 126/143 patients (88.2%) were free of disease.

CONCLUSIONS

Analysis of these data demonstrates that L-CRS+HIPEC is a safe and feasible procedure in highly selected patients with limited peritoneal disease when performed at experienced centres. While short to midterm outcomes are encouraging in patients with less invasive histology, longer follow up is required before recommending it for patients with more aggressive cancers with peritoneal dissemination.

First Measurement of Inclusive Muon Neutrino Charged Current Differential Cross Sections on Argon at E_{ν}∼0.8 GeV with the MicroBooNE Detector

We report the first measurement of the double-differential and total muon neutrino charged current inclusive cross sections on argon at a mean neutrino energy of 0.8 GeV. Data were collected using the MicroBooNE liquid argon time projection chamber located in the Fermilab Booster neutrino beam and correspond to 1.6×10^{20} protons on target of exposure. The measured differential cross sections are presented as a function of muon momentum, using multiple Coulomb scattering as a momentum measurement technique, and the muon angle with respect to the beam direction. We compare the measured cross sections to multiple neutrino event generators and find better agreement with those containing more complete treatment of quasielastic scattering processes at low Q^{2}. The total flux integrated cross section is measured to be 0.693±0.010(stat)±0.165(syst)×10^{-38}  cm^{2}.

The Pandora multi-algorithm approach to automated pattern recognition of cosmic-ray muon and neutrino events in the MicroBooNE detector

The development and operation of liquid-argon time-projection chambers for neutrino physics has created a need for new approaches to pattern recognition in order to fully exploit the imaging capabilities offered by this technology. Whereas the human brain can excel at identifying features in the recorded events, it is a significant challenge to develop an automated, algorithmic solution. The Pandora Software Development Kit provides functionality to aid the design and implementation of pattern-recognition algorithms. It promotes the use of a multi-algorithm approach to pattern recognition, in which individual algorithms each address a specific task in a particular topology. Many tens of algorithms then carefully build up a picture of the event and, together, provide a robust automated pattern-recognition solution. This paper describes details of the chain of over one hundred Pandora algorithms and tools used to reconstruct cosmic-ray muon and neutrino events in the MicroBooNE detector. Metrics that assess the current pattern-recognition performance are presented for simulated MicroBooNE events, using a selection of final-state event topologies.

Consensus guidelines from The American Society of Peritoneal Surface Malignancies on standardizing the delivery of hyperthermic intraperitoneal chemotherapy (HIPEC) in colorectal cancer patients in the United States

BACKGROUND

The American Society of Peritoneal Surface Malignancies (ASPSM) is a consortium of cancer centers performing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). This is a position paper from the ASPSM on the standardization of the delivery of HIPEC.

METHODS

A survey was conducted of all cancer centers performing HIPEC in the United States. We attempted to obtain consensus by the modified method of Delphi on seven key HIPEC parameters: (1) method, (2) inflow temperature, (3) perfusate volume, (4) drug, (5) dosage, (6) timing of drug delivery, and (7) total perfusion time. Statistical analysis was performed using nonparametric tests.

RESULTS

Response rates for ASPSM members (n = 45) and non-ASPSM members (n = 24) were 89 and 33 %, respectively. Of the responders from ASPSM members, 95 % agreed with implementing the proposal. Majority of the surgical oncologists favored the closed method of delivery with a standardized dual dose of mitomycin for a 90-min chemoperfusion for patients undergoing cytoreductive surgery for peritoneal carcinomatosis of colorectal origin.

CONCLUSIONS

This recommendation on a standardized delivery of HIPEC in patients with colorectal cancer represents an important first step in enhancing research in this field. Studies directed at maximizing the efficacy of each of the seven key elements will need to follow.

Accuracy and clinical relevance of computed tomography scan interpretation of peritoneal cancer index in colorectal cancer peritoneal carcinomatosis: a multi-institutional study

BACKGROUND

Evaluation of peritoneal metastases by computed tomography (CT) scans is challenging and has been reported to be inaccurate.

METHODS

A multi-institutional prospective observational registry study of patients with peritoneal carcinomatosis from colorectal cancer was conducted and a subset analysis was performed to examine peritoneal cancer index (PCI) based on CT and intraoperative exploration.

RESULTS

Fifty-two patients (mean age 52.6 ± 12.4 years) from 16 institutions were included in this study. Inaccuracies of CT-based assessment of lesion sizes were observed in the RUQ (P = 0.004), LLQ (P < 0.0005), RLQ (P = 0.003), distal jejunum (P = 0.004), and distal ileum (P < 0.0005). When CT-PCI was classified based on the extent of carcinomatosis, 17 cases (33%) were underestimations, of which, 11 cases (21%) were upstaged from low to moderate, 4 cases (8%) were upstaged from low to severe, and 2 cases (4%) were upstaged from moderate to severe. Relevant clinical discordance where an upstage occurred to severe carcinomatosis constituted a true inaccuracy and was observed in six cases (12%).

CONCLUSIONS

The actual clinical impact of inaccuracies of CT-PCI was modest. CT-PCI will remain as a mandatory imaging tool and may be supplemented with other tools including positron emission tomography scan or diagnostic laparoscopy, in the patient selection for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

Cytoreduction and intraperitoneal chemotherapy for the management of non-gynecological peritoneal surface malignancy

Peritoneal surface malignancy can arise from pseudomyxoma peritonei, gastrointestinal carcinoma, abdomino-pelvic sarcoma and peritoneal mesothelioma. In the past, only palliative treatments were offered and the results were poor. We have proposed a new concept in managing patients with peritoneal surface malignancy. It involves an aggressive combined treatment modality of cytoreduction and perioperative intraperitoneal chemotherapy. The results are promising for patients with pseudomyxoma peritonei, peritoneal mesothelioma and well-selected patients with invasive peritoneal surface malignancies. The success in such comprehensive treatment depends on tumor biology, patient's co-morbidities, the completeness of cytoreduction, the efficacy of intraperitoneal chemotherapy administration and the surgeon's experience. The importance of patient selection is emphasized. The rationales and the outline of the current management strategies are described. Large phase II studies have demonstrated the marked survival advantage in this aggressive approach to peritoneal surface malignancy.

Second-look surgery in patients with peritoneal dissemination from appendiceal malignancy: analysis of prognostic factors in 98 patients

OBJECTIVE

To establish selection criteria for reoperation in patients with peritoneal dissemination from appendiceal malignancy.

SUMMARY BACKGROUND DATA

The outcome of patients with mucinous appendiceal neoplasms with peritoneal surface dissemination has changed as a result of a better understanding of the clinical and pathologic features of this disease. This knowledge, combined with aggressive strategies for the use of perioperative intraperitoneal chemotherapy and peritonectomy procedures, has resulted in long-term disease-free survival in many of these patients. However, some of the patients develop progressive disease, and a question regarding additional surgery is appropriate. A critical analysis of the results of second-look surgery should assist in the management of patients with recurrent peritoneal surface dissemination of an appendiceal neoplasm.

METHODS

Three hundred twenty-one patients with epithelial peritoneal surface malignancy of appendiceal origin underwent surgery during a 12-year period. Ninety-eight of these patients (30.5%) underwent a second-look procedure. A database of selected clinical features regarding these 98 patients was gathered from the clinical records. A critical statistical analysis of these clinical features and their prognostic impact was performed using survival as an endpoint. All patients were managed by a treatment regimen that used cytoreductive surgery and intraperitoneal chemotherapy.

RESULTS

The overall 5-year survival rate of these 98 patients was 73.6%. This compared favorably with a 68% survival rate of 223 patients who did not undergo reoperation. Survival based on the number of cytoreductive surgeries and the free interval between them showed no significant difference. Patients who had second-look surgery with bowel obstruction as a symptom and those in whom the amount of tumor was increased or minimally decreased at the first and second cytoreductions had a significantly inferior 5-year survival rate. A complete second cytoreduction was associated with an improved 5-year survival rate.

CONCLUSIONS

Follow-up of patients treated for peritoneal dissemination from neoplasms of appendiceal origin is indicated. Selected patients in whom recurrence develops are candidates for repeat cytoreductive surgery plus intraperitoneal chemotherapy with curative intent.

An economic model to assess the cost and benefits of the routine use of silver alloycoated urinary catheters to reduce the risk of urinary tract infections in catheterized patients

Prevalence studies generally find nosocomial urinary tract infections to be the most common type of nosocomial infection, accounting for between 21% and 45% of all HAIs. The main risk factor appears to be the presence of a urinary catheter, with an estimated 80% of these infections being associated with their use. This paper describes a model which quantifies the extent of the burden of these infections in terms of the number of patients affected and the costs incurred by the hospital sector; and identifies the potential benefits of the routine use of silver alloy coated catheters, as a means of reducing the incidence of this type of infection. An illustrative model of the annual costs and benefits associated with the routine use of this intervention in adult, non-day case patients admitted to the medical and surgical specialties of NHS hospitals throughout England is presented. The results suggest that a 14.6% reduction in the incidence of urinary tract infections in catheterized medical patients, and a 11.4% reduction in catheterized surgical patients, would cover the cost of the intervention. Any further reduction in incidence would result in net positive benefits.

Pseudomyxoma peritonei in a hernia sac: analysis of 20 patients in whom mucoid fluid was found during a hernia repair

INTRODUCTION

Pseudomyxoma peritonei syndrome is a rare disease that causes extensive accumulation of non-invasive mucinous tumour and mucinous fluid throughout the abdomen and pelvis. The primary tumour is a perforated appendiceal adenoma or mucinous adenocarcinoma. In patients with an open processus vaginalis or other peritoneal defect, the adenomatous epithelial cells may accumulate within the hernia sac, causing mucoid fluid to be present at the time of hernia repair.

MATERIALS AND METHODS

From February 1991 to September 1997, the diagnosis of pseudomyxoma peritonei syndrome was established in 20 patients in whom mucoid material was found in a hernia sac during a hernia repair. Clinical features of these patients were critically evaluated using the completeness of cytoreduction as an endpoint.

RESULTS

The treatments delivered at the time of hernia repair had no impact on the outcome. A lack of interim events vs the use of interim treatments between hernia repair and definitive cytoreduction was significant in relation to a complete vs incomplete cytoreduction. Non-aggressive histology and an interval of less than 1 year was statistically significantly associated with a favourable outcome from surgical intervention.

CONCLUSION

When mucoid fluid is encountered at the time of a hernia repair, recovery of that fluid and the hernia sac for histologic study is important. When adenomatous epithelial cells are present, a CT scan should be performed to look for the typical distribution of mucinous tumour and fluid that suggests the pseudomyxoma peritonei syndrome. If the diagnosis can be confirmed, referral to a centre experienced in the treatment of this rare disease is suggested.

Clinical presentation of the Pseudomyxoma peritonei syndrome

BACKGROUND

Pseudomyxoma peritonei syndrome is characterized by a gradual expansion of mucoid tumour and fluid at specific sites within abdominopelvic regions as a result of a perforated appendiceal adenoma. The aim was to analyse the presenting symptoms and signs of patients with this condition.

METHODS

Of 410 patients with appendiceal tumours 217 had the diagnosis of pseudomyxoma peritonei syndrome with histological confirmation. A retrospective review of the clinical characteristics that determine presentation was performed.

RESULTS

Overall, suspected acute appendicitis was the most common presentation (27 per cent). For women the diagnosis was most commonly made while being evaluated for an ovarian mass (39 per cent). Increasing abdominal girth was the second most common presentation overall (23 per cent). Thirty patients (14 per cent) presented with new-onset hernia, of which the majority (26) were inguinal hernias.

CONCLUSION

Consideration of appendicitis, increased abdominal girth, ovarian mass and new-onset hernia as caused by this syndrome may facilitate diagnosis and definitive treatment.

Hemodynamic and cardiac function parameters during heated intraoperative intraperitoneal chemotherapy using the open "coliseum technique"

BACKGROUND

Heated intraoperative intraperitoneal chemotherapy achieves high peritoneal concentrations with limited systemic absorption and has become an important tool in the management of patients with peritoneal carcinomatosis from low-grade malignancies such as pseudomyxoma peritonei and in selected cases of high-grade tumors such as colon adenocarcinoma. When the closed abdomen technique is used, its perioperative toxicity seems to be related to the hemodynamic and cardiac function changes associated with increased body temperature and increased intra-abdominal pressure.

METHODS

Hemodynamic and cardiac function variables during heated intraoperative intraperitoneal chemotherapy, using an open abdomen "coliseum technique," were measured in 15 patients with the use of a noninvasive esophageal Doppler monitor.

RESULTS

The hemodynamic and cardiac function changes were characterized by an increased heart rate, increased cardiac output and decreased systemic vascular resistance associated with an increased body temperature, and decreased effective circulating volume with the urinary output tending to decrease as the therapy progressed.

CONCLUSION

Heated intraoperative intraperitoneal chemotherapy with the open abdomen coliseum technique induces a hyperdynamic circulatory state with an increased intravenous fluid requirement and avoids changes because of increased intra-abdominal pressure. Hemodynamic and cardiac stability, as documented by normal blood pressure and adequate urinary output, can be achieved by liberal intravenous fluids, titrated to frequent urinary output determination.

Pleural extension of mucinous tumor in patients with pseudomyxoma peritonei syndrome

BACKGROUND

Pseudomyxoma peritonei syndrome is a rare disease arising from perforation of an adenoma of the appendix. The syndrome is characterized by progressive accumulation of mucinous fluid and tumor within the abdomen and pelvis. Although this tumor is only superficially invasive and does not metastasize, it is a fatal disease. Extra-abdominal spread of pseudomyxoma peritonei is a rare occurrence, with few reports in the medical literature. This review focuses on pleural extension of mucinous tumor in patients with pseudomyxoma peritonei syndrome.

METHODS

From December 1983 to April 1999, all patients who underwent cytoreductive surgery for pseudomyxoma peritonei syndrome were assessed for pleural involvement at the time of the presentation or follow-up. Clinical information on these patients, including chest computed tomographic scan, was retrospectively reviewed. The mechanisms of extension of mucinous tumor from peritoneal cavity to pleural surface and the results of treatment were of special interest.

RESULTS

Twenty-three of 426 patients (5.4%) showed pleural extension of pseudomyxoma peritonei syndrome. In four patients (17%), extension into the chest occurred before cytoreductive surgery. In 18 patients, the pleural space was entered during a subdiaphragmatic peritonectomy; and, in 12 patients, extension of disease from peritoneal to pleural space occurred. In six patients (26%), surgical interventions were required to excise tumor that had invaded the hemidiaphragm; and, in the six other patients (26%), there was a minor penetration during subphrenic peritonectomy, which was closed immediately. Finally, in seven patients (30%), the mechanism of spread was unknown. Twelve patients were treated for pleural thoracotomy. Eight patients had an attempt to completely eradicate pleural mucinous tumor, and five patients are currently disease free in the chest (22%); four of these five had intrapleural cytoreduction plus intrapleural chemotherapy. The median survival for all 23 patients is 55 months.

CONCLUSION

Pleural spread of pseudomyxoma peritonei syndrome may be a direct result of cytoreductive surgery and the subphrenic peritonectomy procedure. In some patients, dissecting mucinous tumor may infiltrate through the diaphragm and result in pleural extension. Pleural extension of pseudomyxoma peritonei syndrome carries a poor prognosis. Intrapleural chemotherapy combined with cytoreductive surgery may be of considerable value in treatment and prevention of disease dissemination; it should be considered when pleural extension of mucinous tumor is feared or confirmed at the time of cytoreductive surgery.

Morbidity and mortality analysis of 200 treatments with cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemotherapy using the coliseum technique

BACKGROUND

Peritoneal carcinomatosis from gastrointestinal cancers is a fatal diagnosis without special combined surgical and chemotherapy interventions. Guidelines for cytoreductive surgery and hyperthermic intraoperative intraperitoneal chemotherapy (HIIC) by using the Coliseum technique have been developed to treat patients with peritoneal carcinomatosis and other peritoneal surface malignancies. The purpose of this study was to analyze the morbidity and mortality of patients undergoing cytoreductive surgery and HIIC by using mitomycin C.

METHODS

Data were prospectively recorded on 183 patients who underwent 200 cytoreductive surgeries with HIIC between November 1994 and June 1998. Seventeen of the 183 patients returned for a second-look surgery plus HIIC. All HIIC administrations occurred after cytoreduction and used continuous manual separation of intra-abdominal structures to optimize drug and heat distribution. Origins of the tumors were as follows: appendix (150 patients), colon (20 patients), stomach (7 patients), pancreas (2 patients), small bowel (1 patient), rectum (1 patient), gallbladder (1 patient), and peritoneal papillary serous carcinoma (1 patient). Morbidity was organized into 20 categories that were graded 0 to IV by the National Cancer Institute's Common Toxicity Criteria. In an attempt to identify patient characteristics that may predispose to complications, each morbidity variable was analyzed for an association with the 25 clinical variables recorded.

RESULTS

Combined grade III/IV morbidity was 27.0%. Complications observed included the following: peripancreatitis (6.0%), fistula (4.5%), postoperative bleeding (4.5%), and hematological toxicity (4.0%). Morbidity was statistically linked with the following clinical variables: duration of surgery (P < .0001), the number of peritonectomy procedures and resections (P < .0001), and the number of suture lines (P = .0078). No HIIC variables were statistically associated with the presence of grade III or grade IV morbidity. Treatment-related mortality was 1.5%.

CONCLUSIONS

HIIC may be applied to select patients with peritoneal carcinomatosis from gastrointestinal malignancies with 27.0% major morbidity and 1.5% treatment-related mortality. The frequency of complications was associated with the extent of the surgical procedure and not with variables associated with the delivery of heated intraoperative intraperitoneal chemotherapy. The technique has shown an acceptable frequency of adverse events to be tested in phase III adjuvant trials.

Rosai-Dorfman disease (sinus histiocytosis with massive lymphadenopathy) of the pancreas: first case report

Rosai-Dorfman Disease is a histiocytic proliferative disorder which primarily affects lymph nodes. Extranodal involvement occurs in about one half of the patients and the head and neck area represents the region most commonly involved. We present the case of a 48 year-old female who was found with a pancreatic mass during evaluation for abdominal pain. She underwent a distal pancreatectomy and splenectomy. Her pathology showed sinus histiocytosis with massive lymphadenopathy (SHML) involving the pancreas and lymph nodes and focally the spleen. The histiocytes characteristically contained one or more viable lymphocytes in the cytoplasm. The lymphocytes had penetrated the cytoplasm in a process known as "emperipolesis", where the lymphocytes continued to have free movement in the histiocyte. The histiocytic cells were positive with S-100 protein and CD68. Rosai-Dorfman Disease (SHML) can affect the peripancreatic lymph nodes with possible secondary pancreatic involvement and present as a pancreatic mass.

[Elective surgery in recurrent colon cancer with peritoneal seeding: when to and when not to proceed]

Peritoneal carcinomatosis occurs in about 10% of patients with colon cancer. Patients with progressive disease develop complications, with a median survival of 9 months. Our goal is to present a new quantitative scoring system by which to evaluate patients with peritoneal carcinomatosis. The Peritoneal Cancer Index and Completeness of Cytoreduction Score represent quantitative and prognostic indicators that permit the creation of a clinical pathway. Based on the scores, patients can undergo systemic chemotherapy, exploratory laparotomy or cytoreductive surgery. If there is a complete cytoreduction, perioperative intraperitoneal chemotherapy is given and these patients are considered potential long-term survivors.

Portal vein gas, a changing clinical entity. Report of 7 patients and review of the literature

OBJECTIVE

To assess the clinical significance of portal vein gas (PVG) demonstrated by computed tomography (CT).

DESIGN

Review of medical records.

SETTING

Three network-affiliated hospitals providing both primary community-based and tertiary services.

METHODS

Review of diagnosis, clinical circumstances, and significance of PVG in 7 patients detected by CT during a 3-year period in 3 affiliated hospitals.

RESULTS

Four of 7 patients underwent laparotomy; 1 patient refused surgery. Two patients were treated with intravenous antibiotics only and had uneventful clinical courses. Of the 3 patients who died, 1 refused and 2 underwent laparotomy.

CONCLUSIONS

This series indicates that more sensitive imaging and more widespread use of endoscopic retrograde cholangiopancreatography, colonoscopy, and liver transplantation have changed the clinical presentation of PVG; PVG may be found in various clinical settings that do not mandate laparotomy; and the significance of PVG must be derived from the clinical context of the individual patient.

Morbidity and mortality of cytoreductive surgery and intraperitoneal chemotherapy

BACKGROUND

Peritoneal carcinomatosis has been regarded as a uniformly lethal clinical entity. Recently, dose-intensive treatments combining cytoreductive surgery and intraperitoneal chemotherapy have resulted in long-term survival in selected patients.

METHODS

This article reports the morbidity and mortality associated with this new treatment strategy in 45 consecutive treatments of 43 patients with peritoneal carcinomatosis treated during an 18-month interval.

RESULTS

The duration of median postoperative ileus was 21 days, and increased age of the patient and extent of cytoreduction caused an increased incidence of ileus. Twenty-one complications occurred in 17 patients (37.7%). Complications related to enteric function included fistula (n = 4), bile leak (n = 1), pancreatitis (n = 1), and anastomotic disruption (n = 1). There were two early and two late episodes of postoperative bleeding requiring reoperation. Six patients had pneumonia and one had deep vein thrombosis. There were no deaths. Six of the seven complications related to enteric function occurred in patients who had undergone induction intraperitoneal chemotherapy before cytoreductive surgery plus early postoperative intraperitoneal chemotherapy.

CONCLUSIONS

As a result of these findings, induction intraperitoneal chemotherapy is only recommended for patients with low-volume intraabdominal cancer. In most patients surgical removal of peritoneal carcinomatosis before intraperitoneal chemotherapy is recommended. Because of the significant morbidity related to treatment of peritoneal carcinomatosis, careful patient selection and favorable long-term results of treatment are required.

[Clinical features of idiopathic mitral valve prolapse]

This paper ask a question; is there a generalized defect of the connective tissue among subjects with primary mitral valve prolapse? Based on clinical methods it was found that paired subjects with and without primary mitral valve prolapse, are different in respect of an arbitrary score of joint hypermobility and phenotypic features. This is a statistically significant difference and suggest a possible molecular defect affecting connective tissue in people with primary mitral valve prolapse. Therefore, biochemical and molecular studies should be done to further characterize this abnormality.

[Supraventricular paroxysmal tachycardias with normal electrocardiogram in sinus rhythm]

Paroxysmal supraventricular tachycardia (SVT) was studied in 46 patients with normal electrocardiogram (ECG) during sinus rhythm (SR), All of them had had at least one SVT crisis. They all complained of palpitations starting and ending abruptly, and of more than one hour duration. There were never seen ECG alterations suggesting ventricular preexcitation during SR. An electrophysiologic study using atrial and ventricular programmed stimulation and intracardiac electrograms, was used to establish the diagnosis. There was no significant difference in sex or age distribution according to the ethiologic diagnosis. It was found that 67.4% had a concealed accessory bundle, responsible of the SVT, 32.6% had A-V nodal reentry (p less than 0.01). Of all concealed accessory bundles, 67.7% were left lateral Kent (45.6% of all patients). It is discussed the possibility of antegrade conduction through concealed bundles during SR and that this may be seen by means of a M-mode echocardiography. We conclude that neither sex nor age help to suspect ethiologic diagnosis; the most common accessory bundle is the left lateral Kent and that in some cases it can be detected by M-mode echocardiography. This accessory bundle is the most usual cause of SVT in patients with normal ECG during SR.

[2-dimensional echocardiography in fixed fibrous subaortic stenosis. Correlation with hemodynamics and M-mode echocardiography]

Comparative diagnostic capacity is analyzed between two dimensional echocardiography (E-BD), hemodynamics, surgery and the M-Mode, to accurately establish the diagnosis, variety and severity of fixed fibrous subaortic stenosis, in 29 patients, whose previous diagnosis were made by two dimensional images, using paraesternal, apical and subxiphoid long axis. Group I is made up of 17 patients who had two dimensional echocardiography, M-Mode, and catheterization; Group II is composed of 12 patients who only had two-dimensional echocardiography and M-Mode. Within Group I, hemodynamics showed subaortic gradient in 81%, transvalvular in 13% and no gradient in 6%; the ventriculography showed subaortic obstruction only in 59% of the patients and was normal in 41%. The M-Mode echocardiography registered protosystolic aortic closure (CPSAo) in 50%; the subaortic obstruction was seen as a band, in 44%, non-specific echoes in the outflow tract in 12% and this was normal in 44%. The two cases with transvalvular gradient, the M-Mode registered the subaortic band, and in the case without gradient, the ventriculography showed the subvalvular obstruction. In Group II, the diagnostic signs of M-Mode were: CPSAo in 58%, band in 17%, non specific echoes in the outflow tract in 8%, and this was normal in 75%. The results support other data in that two-dimensional Echocardiography is more sensitive and more specific than M-Mode, intraventricular pressure curves and ventriculography.(ABSTRACT TRUNCATED AT 250 WORDS)

[Congenital abnormalities of the tricuspid valve and Ebstein's anomaly with pulmonary valvular stenosis]

We are reporting a case of Ebstein's anomaly of the tricuspid valve and another case of a congenital double tricuspid lesion, both associated with pulmonary valve stenosis and with similar hemodynamics and physiopathology. Given that there are few reported cases in the literature, we analyzed the clinical and electrocardiographic findings of both. The utility of the echocardiogram is discussed in the diagnosis of such abnormalities and the angiographic and hemodynamic data commented upon. It is emphasized that right ventricular hypertension (105 mm Hg, and 98 mmHg, respectively) modifies the cardiopathic hemodynamics and its natural history, that was favorably modified by isolated corrective surgery of the pulmonary obstruction. The postoperatory transvalvular gradients were measured at 27 and 11 mm Hg, respectively. After having revised the pertinent bibliographic literature, we commented upon the factors that give such a high mortality rate in Ebstein's surgery and the congenital abnormalities which are most frequently associated.

[Turner's syndrome and heart surgery. Presentation of 3 clinical cases]

Three patients with Turner's Syndrome are shown; one associated with coarctation of the aorta, other with patent ductus arteriosus and the last one with congenital valvular aortic stenosis. The cytogenetic and clinical picture of the disease are reviewed, also its association with some cardiovascular malformations. The results of the surgical treatment of the congenital heart disease are reported. The difficulties to establish the operatory indication are described and besides the technical problems that occur frequently in these patients.

[Surgical correction of acute congenital cardiopathies in the newborn infant]

The experience of the Cardiac Surgery Service at the Hospital del Niño IMAN with the deep hypothermia method and hemodynamic arrest is shown in 30 infants with severe congenital cardiac malformations. The procedures followed before and during the operation are carefully described in their three aspects; anesthesia, extracorporeal circulation and surgery, including postoperative care. Ventilatory assistance is stressed. Results are analyzed considering postoperative evolution; stress is made on the causes of morbidity and mortality. Considering the results of this and other similar reports, we believe that the deep hypothermia method and heart arrest in treating severe cardiac malformations in infants are of outstanding importance since they have significantly improved results in these problems.

Clinical trial of a combination of lynestrenol and mestranol (Lyndiol) as an oral contraceptive agent

Contraception with lynestrenol-mestranol (Lyndiol) was studied in 332 Mexican women during a period of two and one-half years. Side effects were minimal or transient. No pregnancies occurred in those who took the medication according to instructions. The women were followed with yearly pelvic examinations and Papanicolaou smears, serial endometrial biopsies and extensive studies of blood, liver and glandular function. Complete ophthalmological studies were done on 30 patients. No clinical or laboratory evidence of harmful effects could be demonstrated. Return to ovulation (using pregnanediol excretion and endometrial biopsies as parameters) occurred in all of 22 women studied in the first three post-treatment cycles. Eight posttreatment pregnancies and the resulting offspring were normal. The first post-treatment cycle, as with other oral contraceptives, was unpredictable and tended to be prolonged. It varied in length from 22 to 60 days.