Prolonged Orbital Relaxation by Locally Modified Phonon Density of States for the SiV

Coherent quantum systems are a key resource for emerging quantum technology. Solid-state spin systems are of particular importance for compact and scalable devices. However, interaction with the solid-state host degrades the coherence properties. The negatively charged silicon vacancy center in diamond is such an example. While spectral properties are outstanding, with optical coherence protected by the defects symmetry, the spin coherence is susceptible to rapid orbital relaxation limiting the spin dephasing time. A prolongation of the orbital relaxation time is therefore of utmost urgency and has been tackled by operating at very low temperatures or by introducing large strain. However, both methods have significant drawbacks: the former requires use of dilution refrigerators and the latter affects intrinsic symmetries. Here, a novel method is presented to prolong the orbital relaxation with a locally modified phonon density of states in the relevant frequency range, by restricting the diamond host to below 100 nm. Subsequently measured coherent population trapping shows an extended spin dephasing time compared to the phonon-limited time in a pure bulk diamond. The method works at liquid helium temperatures of few Kelvin and in the low-strain regime.

Combined intestine and kidney transplantation in a patient with encapsulating peritoneal sclerosis: case report.

Encapsulating peritoneal sclerosis (EPS) is a rare but devastating complication of peritoneal dialysis characterized by fibrosis and calcification of the intestine that, in severe cases, can progress to intestinal failure and total parenteral nutrition dependency. Medical and surgical interventions carry a poor prognosis in these patients. We describe a case of a 36-year-old female with end-stage kidney disease and severe EPS not amenable to surgical intervention who underwent a combined intestinal and kidney transplantation. At 3 years posttransplantation, the patient has normal intestinal and kidney function. This represents, to our knowledge, the first report of severe EPS and end-stage kidney disease treated with a combined transplant.

Post placement positional atrial fibrillation and peripherally inserted central catheters.

Arrhythmias are common in hospitalized patients and during surgery. We present a case of positional atrial arrhythmia related to a peripherally inserted central catheter (PICC). There are other documented case reports of ventricular tachycardia precipitated by body position changes with a PICC. The immediate correction of the arrhythmia with repositioning of the PICC strongly points to the PICC as the cause. This highlights the potential seriousness of cardiac arrhythmias precipitated by PICCs as well as the need for careful catheter placement and perioperative maintenance. Practitioners should consider PICC line tip position as a rare cause of positional atrial arrhythmias.

Laparoscopic hernia repair enhances early return of physical work capacity.

Several researchers have documented less postoperative pain and a quicker return to daily activities after laparoscopic herniorrhaphy. However, little objective data that validates this hypothesis exists. This study compares the rate of postoperative physical work capacity with return to preoperative levels, which is measured by a standard treadmill test in patients who underwent laparoscopic and conventional open hernia repair. Patients completed a 6-minute walking test preoperatively and 1 week postoperatively using a nonmotorized treadmill. The distance walked was recorded. If the distance that a patient achieved at 1 week was not within 0.02 miles of the preoperative values of the patient, the patient was asked to return at 1 month for repeat testing. Patients were enrolled prospectively in this study from October 1997 to February 1999. Sixty-six patients participated in the study (27 laparoscopic herniorrhaphies and 39 open herniorrhaphies were performed). There was no significant difference in age, body mass index, or preoperative distance achieved among the two groups. At 1 week, patients who underwent laparoscopic repair demonstrated a mean increase of 18 meters from preoperative distance (P = 0.07). In the open group, patients demonstrated a mean decrease of 90 meters at 1 week (P = 0.001). The change in distance at 1 week between the laparoscopic and the open groups was statistically significant (P = 0.001). However, at 1 month, there was no significant difference among the two groups. Measured using treadmill walking, laparoscopic hernia repair seems to offer an early advantage to open repair in return-to-physical-work capacity.

Recent developments in home total parenteral nutrition.

Home parenteral nutrition (HPN) support has been an advancing therapy in the past 30 years. Patients who previously had no options to sustain their lives are now able to live at home, maintain employment, and continue with most daily activities. Although this therapy has been innovative and successful, it requires great financial and professional resources. The expense of HPN makes most patients dependent on third-party payment, and the complications can result in frequent hospitalizations and may be life-threatening. For these reasons, extensive training of the patient and caregivers is necessary. Thorough and time-consuming monitoring by a multidisciplinary team of professionals is also essential. Home care and supply companies offer services that make the process of home TPN easier for the patient and the healthcare team. Advances in the area of home nutrition support are expected to continue as the demand for this therapy rises.

Foscarnet-induced electrolyte abnormalities in a bone marrow transplant patient receiving parenteral nutrition.

Cytomegalovirus (CMV) is a serious complication of immunosuppressed patients receiving bone marrow transplantation. Foscarnet, a pyrophosphate analog, has been used in the treatment of CMV infections. Renal impairment and electrolyte abnormalities are potential adverse reactions associated with the use of foscarnet. We report a case of significant electrolyte changes after initiation of foscarnet in a bone marrow transplant patient receiving parenteral nutrition.

Tunneled right atrial catheter infection presenting as renal failure.

We report two cases of progressive renal failure secondary to membranoproliferative glomerulonephritis associated with subclinical septicemia from a tunneled right atrial catheter used for home parenteral nutrition administration. Although the occurrence of line infection and septicemia is a common complication of central venous catheters, a review of the literature reveals only one case report of renal failure secondary to an infected implanted central venous device. Both patients presented with azotemia and had biopsy-proven membranoproliferative glomerulonephritis, accompanied by leukocytoclastic vasculitis. In both cases, removal of the right atrial catheter and prolonged antibiotic therapy was effective in resolving the ongoing infection and resulted in marked improvement in renal function. A high index of suspicion for catheter sepsis should be maintained in patients with tunneled right atrial catheters presenting with subacute renal failure.

Post-traumatic distal nerve entrapment syndrome.

Eleven patients with paralysis of muscle groups in the upper or lower extremity were clinically diagnosed after previous proximal direct trauma to the corresponding peripheral nerves, without complete nerve disruption. Patients were seen within an average of 8 months after trauma (minimum 3 months and maximum 2 years after). Nerve lesions were caused either by gunshot, motor-vehicle accident, and other direct trauma or, in one case, after tumor excision. All patients presented with complete sensory and motor loss distal to the trauma site, but demonstrated a positive Tinel sign and pain on testing over the "classic" (distal) anatomic nerve entrapment sites only. After surgical release through decompression of the nerve compression site distal to the trauma, a recovery of sensory function was achieved after surgery in all cases. Good-to-excellent restoration of motor function (M4/M5) was achieved in 63 percent of all cases. Twenty-five percent had no or only poor improvement in motor function, despite a good sensory recovery. Those patients in whom nerve compression sites were surgically released before 6 months after trauma had an improvement in almost all neural functions, compared to those patients who underwent surgery later than 9 months post trauma. A possible explanation of traumatically caused neurogenic paralysis with subsequent distal nerve compressions is provided, using the "double crush syndrome" hypothesis.

Micrographic surgery ('slow Mohs') in cutaneous sarcomas.

BACKGROUND: Micrographic surgery (MS) results in very low local recurrence rates in all sorts of skin tumours that grow by extensive subclinical infiltration. Therefore, MS should prove useful in the treatment of cutaneous sarcomas. OBJECTIVE: To treat cutaneous sarcoma with MS in order to minimize local recurrence rates. METHODS: We treated 5 cases of dermatofibrosarcoma protuberans and 5 cases of cutaneous sarcomas of different origin (atypical fibroxanthoma, malignant fibrous histiocytoma, malignant peripheral nerve tumour) with micrographic surgery using paraffin-embedded sections. In primary cutaneous sarcomas, tumour extensions were readily detected in HE sections. In recurrent tumours, special stains were needed to distinguish tumour extensions from scar tissue. RESULTS: All patients were treated successfully and have remained free of local recurrences as of yet. Solitary pulmonary metastasis occurred in 1 patient with high-grade malignant peripheral nerve tumour. CONCLUSION: MS is an excellent procedure to minimize local recurrence in cutaneous sarcomas. Cutaneous sarcomas with low metastatic potential can be cured with MS.

Predicting the likelihood of residual disease in women treated for ductal carcinoma in situ.

BACKGROUND: To identify women at risk for residual disease after excision of ductal carcinoma in situ (DCIS), we assessed the relationship between characteristics of the initial biopsy and the presence of residual DCIS at a subsequent operation. STUDY DESIGN: We identified 134 consecutive "paired" operations from 112 women who had undergone 2 or more operations for DCIS between February 1995 and December 1996. Cancer status of the margins, patient age and leading presentation, tumor subtype and grade, and the presence of multifocal-extensive disease were assessed as potential predictors. RESULTS: Residual DCIS was found in 60 patients (45%): in 2 of 12 patients (17%) with negative margins, in 11 of 36 (31%) with close margins (< 2 mm), in 30 of 52 (58%) with positive margins, and in 17 of 34 patients (50%) with margins of unknown status. Patients with positive or unknown margins were 7.7 and 8.3 times, respectively, more likely to have residual disease than patients with negative margins (95% CI 1.1-59.1; 1.1-66.4). Patients with clinical presentations were 8.0 times more likely to have residual disease than patients who presented with abnormal mammograms (95% CI 2.3-27.6). Multifocal-extensive DCIS was associated with residual disease (adjusted odds ratio [OR] = 7.7, 95% CI 2.9-20.5), as was comedo subtype (OR = 2.7, 95% CI 1.1-6.7). CONCLUSIONS: Positive or unknown biopsy margins, a clinical presentation, multifocal-extensive cancer, and the comedo subtype are associated with higher risk of residual DCIS.

A prospective, randomized trial comparing laparoscopic versus conventional techniques in colorectal cancer surgery: a preliminary report.

BACKGROUND: Uncontrolled studies using laparoscopic techniques in colorectal surgery have not demonstrated clear advantages to these procedures compared with conventional ones, and surgeons are concerned about unusual early recurrences reported after laparoscopic colorectal cancer surgery. STUDY DESIGN: We conducted a prospective, randomized trial in one surgical department comparing laparoscopic (LAP) and conventional (CON) techniques in 109 patients undergoing bowel resection for colorectal cancers or polyps. Postoperatively, all patients underwent measurement of pulmonary function tests every 12 hours, and were treated identically on a highly controlled protocol with regard to analgesic administration, feeding, and postoperative care. RESULTS: Of the 55 patients assigned to LAP and 54 to the CON group, there were 42 and 38 with cancer, respectively (the other patients had large adenomas). Overall recovery of 80% of forced expiratory volume in 1 second and forced vital capacity was a median of 3 days for LAP and 6.0 days for CON (p = 0.01). LAP patients used significantly less morphine than CON patients up to the second day after surgery (0.78 +/- 0.32 versus 0.92 +/- 0.34 mg/kg per day, p = 0.02). Flatus returned a median of 3.0 days after LAP versus 4.0 days after CON surgery (p = 0.006). Tumor margins were clear in all patients. After a median followup of 1.5 years (LAP) and 1.7 years (CON), there were no port site recurrences in the LAP group. Seven cancer-related deaths have occurred (three in the LAP group, four in the CON group). CONCLUSIONS: Within this prospective, randomized trial, laparoscopic techniques were as safe as conventional surgical techniques and offered a faster recovery of pulmonary and gastrointestinal function compared with conventional surgery for selected patients undergoing large bowel resection for cancer or polyps. There were no apparent shortterm oncologic disadvantages. Longer followup is needed to fully assess oncologic outcomes.

Case management in home total parenteral nutrition: a cost-identification analysis.

BACKGROUND: Home parenteral nutrition (HPN) requires intensive medical case management by practitioners with expertise in the provision of nutrition support. There is expenditure of considerable time and resources for management of these patients not covered by any of the traditional reimbursement mechanisms. The costs associated with this unreimbursed input and follow-up are most often borne by the Nutrition Support Team or individual practitioners. Reimbursement by home care agencies to physicians for management of patients after discharge cannot be done because this may be construed as a "kick-back" for referral of patients to particular home care agencies. METHODS: Time and costs associated with management of HPN patients after discharge from the hospital were assessed using a cost-identification analysis of 24 different factors. Daily activity logs were kept by the Nutrition Support Team members over a 2-week period. Costs of space and furnishings were calculated. RESULTS: On average, a total of 25 h/d was spent by members of the Nutrition Support Team on our HPN patients. Variable activities accounted for 5640.1 hours of time with fixed support at 890.3 hours. This computes to a total annual personnel cost of $168,482 ($1982 per patient). If costs of furnishings and space are also included, the overall cost of all resources was $175,989 per year or $2070 per patient. CONCLUSION: Significant and currently nonreimbursed costs are involved in HPN patient management. These costs are most often absorbed by the Nutrition Support Team and should be considered when evaluating total costs of HPN.

Current use and clinical outcome of home parenteral and enteral nutrition therapies in the United States.

BACKGROUND & AIMS: Home nutrition support, especially when delivered parenterally, is very costly. The aim of this study is to examine current usage of home parenteral and enteral nutrition (HPEN) in the United States and the quality of therapy outcome. METHODS: Medicare HPEN use from 1989 to 1992 was analyzed to assess use, growth, and costs. National Registry information collected on 9288 patients treated with HPEN from 1985 to 1992 was used to assess disease distribution and therapy outcome. RESULTS: In the United States, there were approximately 40,000 parenteral and 152,000 enteral home patients in 1992. The usage of HPEN doubled between 1989 and 1992, and a large proportion was in patients with short survival. The prevalence of HPEN in the United States was 4-10 times higher than in other Western countries. Outcome data showed both therapies were relatively safe. The primary disease strongly influenced survival and rehabilitation, and age, per se, was not a reason to deny HPEN. CONCLUSIONS: Predicted quality survival at home for several months, rather than a specific diagnosis, seems to be the soundest justification for HPEN. Its role in terminal conditions and patients without primary gastrointestinal diseases needs further evaluations.

Recurrent small bowel obstruction secondary to a dilated Kock pouch: a case report.

We report a case of recurrent bowel obstruction caused by a hugely dilated Kock pouch. The approximate capacity of the pouch was at least 1300 ml. Frequent emptying of the pouch resulted in resolution of the obstructing symptoms.

Long-term silastic catheters and chest pain.

There are multiple reports in the literature of vascular erosion in the innominate vein or superior vena cava from the use of temporary central venous catheters. Catheter malposition is likely to precede the development of superior vena cava perforations, a catastrophic complication of central venous catheters. Catheter malposition after initial adequate placement is a very unusual long-term complication and delayed recognition of this complication may have disastrous consequences. Should the catheter change position so the tip is angled toward the sidewall, the repetitive movement of the catheter tip that occurs with respiratory excursion and the cardiac cycle may lead to endothelial injury and eventual erosion of the vein. These problems are thought to be alleviated in the patient receiving long-term intravenous therapy by using a soft Silastic catheter, which may not cause as much damage to the endothelium of the vein. We report three patients with left-sided long-term indwelling Silastic catheters that had changed position over time who presented with chest pain upon infusion of their total parenteral nutrition solutions. In each case, chest x-ray revealed that the tip of the catheter had migrated and was directed against the sidewall of the superior vena cava. In each case, catheter removal and replacement with a new catheter into the right side (subclavian and jugular systems) led to prompt relief of the patient's symptoms.