A 62-minute orbital period black widow binary in a wide hierarchical triple.

Over a dozen millisecond pulsars are ablating low-mass companions in close binary systems. In the original 'black widow', the eight-hour orbital period eclipsing pulsar PSR J1959+2048 (PSR B1957+20)1, high-energy emission originating from the pulsar2 is irradiating and may eventually destroy3 a low-mass companion. These systems are not only physical laboratories that reveal the interesting results of exposing a close companion star to the relativistic energy output of a pulsar, but are also believed to harbour some of the most massive neutron stars4, allowing for robust tests of the neutron star equation of state. Here we report observations of ZTF J1406+1222, a wide hierarchical triple hosting a 62-minute orbital period black widow candidate, the optical flux of which varies by a factor of more than ten. ZTF J1406+1222 pushes the boundaries of evolutionary models5, falling below the 80-minute minimum orbital period of hydrogen-rich systems. The wide tertiary companion is a rare low-metallicity cool subdwarf star, and the system has a Galactic halo orbit consistent with passing near the Galactic Centre, making it a probe of formation channels, neutron star kick physics6 and binary evolution.

Detection of a radio counterpart to the 27 December 2004 giant flare from SGR 1806-20.

It was established over a decade ago that the remarkable high-energy transients known as soft gamma-ray repeaters (SGRs) are located in our Galaxy and originate from neutron stars with intense (< or = 10(15)G) magnetic fields-so-called 'magnetars'. On 27 December 2004, a giant flare with a fluence exceeding 0.3 erg cm(-2) was detected from SGR 1806-20. Here we report the detection of a fading radio counterpart to this event. We began a monitoring programme from 0.2 to 250 GHz and obtained a high-resolution 21-cm radio spectrum that traces the intervening interstellar neutral hydrogen clouds. Analysis of the spectrum yields the first direct distance measurement of SGR 1806-20: the source is located at a distance greater than 6.4 kpc and we argue that it is nearer than 9.8 kpc. If correct, our distance estimate lowers the total energy of the explosion and relaxes the demands on theoretical models. The energetics and the rapid decay of the radio source are not compatible with the afterglow model that is usually invoked for gamma-ray bursts. Instead, we suggest that the rapidly decaying radio emission arises from the debris ejected during the explosion.

Vascular laboratory prediction of pedal pressure following femoropopliteal bypass.

This study examines the hypothesis that postoperative ankle-brachial pressure index (postop ABI) can be accurately predicted using noninvasive preoperative segmental leg pressure measurements. Seventy-three patients who underwent successful reverse autogenous vein femoropopliteal bypass and who had pre- and postoperative segmental leg pressure measurements were examined. Predicted postop ABI was estimated using the following formula: Postop ABI = 1 + (Preop ABI) - (Preop BKI). (BKI = below-knee brachial pressure index). Using this formula, 56 out of 73 (81%) patients had a measured postop ABI +/- 20% of predicted postop ABI. Five out of 73 (7%) patients had postop ABI less than 80% predicted, while 12 out of 73 (16%) patients had postop ABI greater than 120% of predicted. All patients with postop ABI greater than 120% of predicted had apparent tibial artery occlusive disease as indicated by preoperative gradients (BKI-ABI) greater than 0.15.

Autogenous reversed vein bypass for lower extremity ischemia in patients with absent or inadequate greater saphenous vein.

This report has presented the results of 329 reversed vein bypasses performed for lower extremity ischemia over a 6 3/4 year period. One hundred eighty-nine bypasses were formed from intact ipsilateral greater saphenous veins of adequate size and length. One hundred forty bypasses were formed in patients in whom the ipsilateral greater saphenous vein was absent or of inadequate size or length to complete the bypass. The grafts in these patients were accomplished using a variety of techniques including distal graft origin, use of arm veins and lesser saphenous veins, and use of vein splicing. The patency rates of these grafts were equivalent to those achieved using adequate intact ipsilateral greater saphenous vein. In view of these results, we conclude that the absence of a greater saphenous vein does not preclude successful autogenous lower extremity vein bypass and that prosthetic bypass is rarely justified.

Reversed vein bypass to infrapopliteal arteries. Modern results are superior to or equivalent to in-situ bypass for patency and for vein utilization.

In recent years many reports have attributed improved patency and improved vein utilization with lower extremity arterial bypass to infrapopliteal arteries to the use of the in-situ vein graft technique (ISVB). This report describes 110 reversed vein bypasses (RVB) to infrapopliteal arteries performed from 1980-1986. Thirty-three per cent of these patients did not have an intact ipsilateral greater saphenous vein. One hundred per cent of patients had autogenous RVB performed using a variety of techniques, including vein splicing, use of arm veins, lesser saphenous veins, branch veins, and use of graft origins distal to the common femoral artery. The life table patency figures for these grafts are 90%, 85%, and 85% at 1 year, 3 years, and 5 years, respectively. The life table limb salvage at 5 years is 93%. These figures for patency, vein utilization, and limb salvage for modern RVB to infrapopliteal arteries are clearly equal to or superior to any reported figures for ISVB. Results for RVB are greatly improved when compared with historic controls, as are results for ISVB. There is no evidence to date demonstrating superiority of one technique versus another.

Alpha 2-adrenergic receptor levels in obstructive and spastic Raynaud's syndrome.

The present study examines the hypothesis that alterations in the activity of alpha 2-adrenergic receptors (A2R) may underlie the clinical vasospasm seen in patients with Raynaud's syndrome. Platelets were isolated from 13 normal subjects, from 50 patients with vasospastic Raynaud's syndrome, and from 20 patients with obstructive Raynaud's syndrome and A2R levels measured. Binding capacity as determined in femtomoles per milligram of protein (fmol/mg of protein) and affinity were measured by Scatchard plot analysis. In a separate experiment normal human platelets were incubated with either buffer, normal serum, or serum from patients with spastic Raynaud's syndrome and A2R levels were measured. A2R levels in normal subjects averaged 112 +/- 18 fmol/mg; in the patients with spastic Raynaud's syndrome, 191 +/- 14 fmol/mg, p less than 0.01; and in the patients with obstructive Raynaud's syndrome, 164 +/- 31 fmol/mg, p greater than 0.05 (ns). Of the patients with spastic Raynaud's syndrome, 26% had values that were less than the mean value of the normal subjects (69 +/- 7 fmol/mg, p less than 0.05). The A2R levels decreased after incubation with serum from patients who had spastic Raynaud's syndrome by 17.4 +/- 3.1 fmol/mg (p less than 0.05). These results indicate that most patients with vasospastic Raynaud's syndrome have increased platelet A2R levels, which may constitute a primary pathophysiologic abnormality underlying this condition. The presence of subnormal A2R levels in a portion of the patients and the finding of a decrease in measurable A2R levels after incubation in serum from patients with spastic Raynaud's syndrome suggests the possibility of receptor modulation as a mechanism for increased cellular receptor synthesis.

Long-term hemodynamic and clinical sequelae of lower extremity deep vein thrombosis.

Forty-seven patients with phlebographically confirmed lower extremity deep vein thrombosis (DVT) were reexamined 5 to 10 years (mean, 7 years) after the thrombotic event. Clinical symptoms were recorded and the following noninvasive venous vascular laboratory tests were performed: Doppler examination to determine venous valve competence and photoplethysmography to measure ambulatory venous pressure and venous recovery time. Twenty-eight control subjects underwent similar examination. Although only 10 of 47 patients (21%) were asymptomatic, venous ulceration had developed in only two patients. The symptomatic patients had varying degrees of edema, pigmentation, and varicosities. Eighty-three percent of DVT patients had abnormal vascular laboratory findings. Both the severity of clinical symptoms and the magnitude of the hemodynamic abnormalities generally correlated with the extent of the initial thrombus. However, only 47% of patients whose initial thrombus appeared limited to the calf were asymptomatic, and only 25% of this group had normal venous hemodynamic findings. This study indicates that 5 to 10 years after lower extremity DVT 80% of patients will have both symptoms and abnormal venous hemodynamics regardless of the initial site of the thrombosis.

Present status of reversed vein bypass for lower extremity revascularization.

During the past 4 years we have performed 239 reversed vein bypasses for leg ischemia in 196 patients including 45 to the above-knee popliteal artery, 118 to the below-knee popliteal artery, and 76 to infrapopliteal arteries. The cumulative primary patency results by the life-table method through 24 months are 97% at 6 months, 91% at 1 year, and 88% at 2 years. No difference was evident in patency rates with respect to site of distal anastomosis or reason for graft performance (i.e., for claudication [31%] or for limb salvage [69%]). Twenty-two percent of these patients did not have an intact ipsilateral greater saphenous vein. By a variety of techniques including the use of cephalic and lesser saphenous veins, vein splicing, and proximal superficial femoral endarterectomy, we have been able to perform autogenous vein bypass in 94% of all patients who require lower extremity revascularization. The patency of bypasses made from conduits other than greater saphenous vein does not differ from that of the entire series. Both the graft patency and vein utilization rates in the present report are equal to those of recently published series of in situ saphenous vein bypasses and are clearly better than the published results with reversed vein bypass a decade and more ago. We conclude that, although in situ saphenous vein bypass is a good procedure, it is not superior to reversed vein bypass performed in the same time period. This report again emphasizes the hazards of evaluating any new treatment by use of historic controls.

Lumbar sympathectomy for lower extremity vasospasm.

Ten patients, 8 female and 2 male, with refractory episodic lower extremity vasospasm were encountered during a 15 year period in which over 600 patients with upper extremity vasospasm were studied. Seven patients had associated upper extremity vasospasm. No patient had evidence of autoimmune disease. Lower extremity reserpine Bier block produced symptomatic relief for 1 to 3 days in all patients in whom it was used. Oral medications were ineffectual. A diagnostic toe photoplethysmographic pattern was noted in these patients, consisting of a normally pulsatile tracing after warming and a flat, nonpulsatile or minimally pulsatile tracing after cooling. Each patient underwent lumbar sympathectomy. During follow-up, which averaged 4 years, each patient remained free of episodic vasospasm on the side of surgery. We conclude that lumbar sympathectomy is an effective and durable treatment for lower extremity vasospasm.

Chronic subdural empyema.

A review of the literature reveals that most chronic subdural empyemas occur within four to six months of the initial insult. It appears that only 1 case of a chronic subdural empyema, which occurred four years after extensive facial trauma, has been described. Our patient developed chronic subdural empyema thirteen years after drainage of a subdural hematoma. Current treatment modalities are reviewed.