Kisspeptin, gonadotrophin-releasing hormone and oestrogen receptor α colocalise with neuronal nitric oxide synthase neurones in prepubertal female sheep.

Puberty is a process that integrates multiple inputs ultimately resulting in an increase in gonadotrophin-releasing hormone (GnRH) secretion. Although kisspeptin neurones play an integral role in GnRH secretion and puberty onset, other systems are also likely important. One potential component is nitric oxide (NO), a gaseous neurotransmitter synthesised by nitric oxide synthase (NOS). The present study aimed to neuroanatomically characterise neuronal NOS (nNOS) in prepubertal female sheep and determine whether oestradiol exerts effects on this system. Luteinising hormone secretion was reduced by oestradiol treatment in prepubertal ovariectomised ewes. Neurones immunoreactive for nNOS were identified in several areas, with the greatest number present in the ventrolateral portion of the ventromedial hypothalamus, followed by the ventromedial hypothalamus, preoptic area (POA) and arcuate nucleus (ARC). Next, we determined whether nNOS neurones contained oestrogen receptor (ER)α and could potentially communicate oestradiol (E2 ) feedback to GnRH neurones. Neuronal NOS neurones contained ERα with the percentage of coexpression (12%-40%) depending upon the area analysed. We next investigated whether a neuroanatomical relationship existed between nNOS and kisspeptin or nNOS and GnRH neurones. A high percentage of kisspeptin neurones in the POA (79%) and ARC (98%) colocalised with nNOS. Kisspeptin close contacts were also associated with nNOS neurones. A greater number of close contacts were observed in the ARC than the POA. A high percentage of POA GnRH neurones (79%) also expressed nNOS, although no GnRH close contacts were observed onto nNOS neurones. Neither the numbers of nNOS neurones in the POA or hypothalamus, nor the percentage of nNOS coexpression with GnRH, kisspeptin or ERα were influenced by oestradiol. These experiments reveal that a neuroanatomical relationship exists between both nNOS and kisspeptin and nNOS and GnRH in prepubertal ewes. Therefore, nNOS may act both directly and indirectly to influence GnRH secretion in prepubertal sheep.

Obesity: is it really a risk factor in thrombophlebitis?

Obesity is assumed to be a risk factor in the occurrence of thrombophlebitis. We studied 168 consecutive patients retrospectively; 33 were men and 135 women, with an average age of 34 (range 27 to 41) years. All patients had a gastric bypass because of obesity, with a minimum of 100 lb over normal weight. The mean weight was 279.2 lb (range 191 to 500). Only three patients had a history of deep vein thrombophlebitis, with no thromboembolism. Eighty-four of the patients were studied preoperatively by noninvasive means (Doppler, impedance plethysmography [IPG], phleborheography [PRG]); 12 had evidence of old disease, and two had a history of treated deep vein thrombophlebitis. No patient had prophylactic therapy. The incidence of clinical deep vein thrombophlebitis was zero; noninvasive evaluation in 64 patients demonstrated no abnormality. Postoperative thromboembolism, which occurred in three of 168 (1.8%) patients, was confirmed by ventilation-perfusion scan and pulmonary angiogram. The mortality from thromboembolism was less than 1% (1/168 patients). Extreme obesity may not necessarily constitute a major risk factor in the occurrence of postoperative deep vein thrombophlebitis and thromboembolism. Prophylactic medications and therapy may add inappropriate risk, undue cost, and unnecessary discomfort, and must be weighed against a mortality of less than 1%.

Venous injury: to repair or ligate, the dilemma.

Surgical management of major venous injuries remains controversial. The medical records of 184 patients with major venous injury were reviewed. Forty-three patients had isolated venous injury; 31 of 43 patients (72%) underwent ligation to treat their vein injury. Another 141 patients had combined arterial and venous injury; 117 of these patients (83%) had ligation. Injured were the inferior vena cava, iliac, femoral, popliteal, distal leg, and arm veins; all patients underwent surgical exploration. Arterial injuries were repaired by standard techniques and venous injuries were either ligated or repaired by end-to-end or lateral phleborrhaphy. Adjunctive fasciotomy was used when clinically indicated. The patients were followed up for 1 month to 9 years. No permanent sequelae of venous ligation were identified. Transient extremity edema developed in up to 32% of patients, regardless of whether vein ligation or repair was performed. This edema resolved completely within 12 weeks of the injury. No extremity was lost after ligation of a venous injury. Although it may be ideal to repair all venous vascular injuries, selective management reflecting mechanism of injury, blood loss, anesthesia requirements, associated organ injury, and other concerns may mitigate against extensive venous repair.

Traumatic arterial injuries of the upper extremity: determinants of disability.

Of 233 patients who sustained vascular injuries during a 13 year period, 99 had involvement of the upper extremity. The primary site of upper extremity injuries was the brachial artery (43 patients), and the primary cause of injury was gunshot wounds. The majority of the vascular injuries were repaired primarily. Nerve injuries occurred in 56 of the patients, and they were the primary cause of disability. Edema and infection were not significant determinants of limitations in function. Gunshot wounds to the brachial artery resulted in the highest incidence of disability and limb loss.

Amputations after vascular trauma in civilians.

In a ten-year retrospective study of 233 patients who sustained a vascular injury to an extremity, eight (3.4%) extremities were amputated. Factors that affect the incidence of amputation after peripheral vascular trauma include early operation, fasciotomy, preoperative antibiotics, appropriate vascular reconstruction with adequate tissue coverage, use of arteriography during and after reconstruction, and early reoperation for postoperative complications. Some patients benefit psychologically and physically from early definitive amputation.

Management of traumatic peripheral vein injuries. Primary repair or vein ligation.

The management and outcome of 83 patients who had 86 venous injuries were retrospectively reviewed to identify optimal management techniques in patients with peripheral vein injuries. Venous injuries of the arms were associated with no long-term sequelae, and management with vein ligation appears safe. In patients with venous injuries of the legs, primary repair by lateral suture or primary end-to-end reanastomosis is recommended when technically easy. In patients who are unstable or in whom primary repair cannot be performed, vein ligation is recommended. Autogenous vein interposition grafting appears indicated only in the popliteal area when vein reconstitution should be aggressively sought. Vein ligation in peripheral vein injuries should be followed with aggressive postoperative management to prevent the development of distal edema. Limb elevation is effective in minimizing the development of adverse sequelae.

Sonography of the bile ducts after a fatty meal: an aid in detection of obstruction.

The sonographic response of the biliary tree to a fatty meal was assessed in 78 individuals by measuring common hepatic duct caliber before and after fat ingestion. In the normal cases, the common hepatic duct remained the same or decreased in caliber. Abnormal responses consisted of a normal-caliber duct that increased in size or a slightly dilated duct that remained the same or increased in size. By employing these criteria, we discovered patients with ampullary stenosis, common duct stones, cholangiocarcinoma, and chronic pancreatitis. It is concluded that biliary sonography after ingestion of a fatty meal can aid in the evaluation of a common hepatic duct that is equivocally or mildly dilated and can indicate the need for further invasive studies.

Nitrogen sparing by carbohydrate in man: Intermittent or continuous enteral compared with continuous parenteral glucose.

To test whether oral carbohydrate would provide greater conservation of body protein than would intravenous carbohydrate, healthy normal human subjects were infused with high doses of glucose either continuously intravenously or by nasogastric tube in both continuous and intermittent regimes. Metabolic responses to high calorie, nitrogen-free infusions in normal man were documented in the blood hormone and substrate changes, and protein sparing was assessed by urinary nitrogen excretion. Continuous glucose produced a lower urinary "nitrogen floor" than did the intermittent regime, and intravenous glucose was more effective than was oral glucose. The insulin responses to continuous nasogastric and continuous intravenous glucose were similar, and nitrogen excretion did not differ between those two groups. The increased insulin levels seen with intermittent glucose were not accompanied by greater protein sparing.