睾丸生理功能的植物性神经调节研究进展

研究发现除了内分泌调控外,睾丸神经对睾丸的发育、雄激素的分泌以及精子的发生也发挥重要的调节作用,与睾丸的内分泌调节功能相比较人们对植物性神经在睾丸生理活动调节方面的认识还很少.论文从睾丸的植物性神经分布、精索神经对睾丸发育和睾丸生理功能的影响以及睾丸不同发育时期胆碱能受体和肾上腺素能受体的分布、神经递质NE和Ach对睾丸发育和功能的影响等方面做了详细综述,并对今后的研究方向和研究意义做了展望.     

Attenuation of ischaemic injury in the equine jejunum by administration of systemic lidocaine

REASONS FOR PERFORMING STUDY: Absorption of endotoxin across ischaemic-injured mucosa is a major cause of mortality after colic surgery. Recent studies have shown that flunixin meglumine retards mucosal repair. Systemic lidocaine has been used to treat post operative ileus, but it also has novel anti-inflammatory effects that could improve mucosal recovery after ischaemic injury. HYPOTHESIS: Systemic lidocaine ameliorates the deleterious negative effects of flunixin meglumine on recovery of mucosal barrier function. METHODS: Horses were treated i.v. immediately before anaesthesia with either 0.9% saline 1 ml/50 kg bwt, flunixin meglumine 1 mg/kg bwt every 12 h or lidocaine 1.3 mg/kg bwt loading dose followed by 0.05 mg/kg bwt/min constant rate infusion, or both flunixin meglumine and lidocaine, with 6 horses allocated randomly to each group. Two sections of jejunum were subjected to 2 h of ischaemia by temporary occlusion of the local blood supply, via a midline celiotomy. Horses were monitored with a behavioural pain score and were subjected to euthanasia 18 h after reversal of ischaemia. Ischaemic-injured and control jejunum was mounted in Ussing chambers for measurement of transepithelial electrical resistance (TER) and permeability to lipopolysaccharide (LPS). RESULTS: In ischaemic-injured jejunum TER was significantly higher in horses treated with saline, lidocaine or lidocaine and flunixin meglumine combined, compared to horses treated with flunixin meglumine. In ischaemic-injured jejunum LPS permeability was significantly increased in horses treated with flunixin meglumine alone. Behavioural pain scores did not increase significantly after surgery in horses treated with flunixin meglumine. CONCLUSIONS: Treatment with systemic lidocaine ameliorated the inhibitory effects of flunixin meglumine on recovery of the mucosal barrier from ischaemic injury, when the 2 treatments were combined. The mechanism of lidocaine in improving mucosal repair has not yet been elucidated.     

Intramural jejunal leiomyoma as a cause of colic

A 15-year-old Thoroughbred gelding showjumper presented with colic after a history of chronic mild, intermittent colic. He was refractory to medical management. At surgery, he was found to have a 15-cm intramural mass in the distal jejunum, approximately 3 m orad to the ileum. Histopathology post-operatively revealed a leiomyoma. Leiomyomas in horses are rare. They have been reported most commonly in the reproductive tract, with other rare reports in the oesophagus and omentum. To the knowledge of the authors, there are no reports of identification and treatment of non-strangulating obstruction of the jejunum caused by a leiomyoma. The horse recovered from his surgery and went on to compete at the same level of showjumping as previous to the surgery with no further episodes of colic. Based on this report, leiomyoma should be a differential for small intestinal obstruction in the future.     

Polypoid cystitis as a cause of haematuria in a pony mare

A 15-year-old pony mare was presented for investigation of haematuria of 2 weeks' duration. On cystoscopy, multiple small pedunculated soft tissue structures were observed on the bladder mucosa. Histopathological analysis of the masses was consistent with chronic polypoid cystitis. The polypoid lesions and associated haematuria resolved following prolonged antibiotic treatment. Polypoid cystitis has not previously been described in horses. This condition should be considered a differential for haematuria, requiring cystoscopy and biopsy to confirm a diagnosis.     

Segmental ischaemic necrosis of the jejunum in a post-partum mare due to two mesenteric avulsions

This report describes segmental ischaemic necrosis of the small intestine 4 days after foaling in a 9-year-old Arabian mare. The jejunal mesentery was avulsed from the intestine in two locations for 20 and 200 cm, resulting in intestinal necrosis, in the absence of entrapment or strangulation. This case highlights the need to consider the possibility of mesenteric injury when a post-partum mare presents mild signs of abdominal pain.     

Klebsiella oxytoca as a cause of equine abortion--short communication

Klebsiella (K.) oxytoca infection induced the abortion of a female equine fetus in the 10th month of pregnancy. Bacteria were cultured from the liver, lung and stomach content. They were labelled with an anti-Mycobacterium bovis antibody in the thymus, liver and lungs and were stained with Giemsa and Brown-Brenn staining in the thymus and lung. The diffusely consolidated lungs contained numerous grey-whitish foci 2-4 mm in diameter, which corresponded to severe pyogranulomatous pneumonia characterised by numerous intraalveolar neutrophils and macrophages and multinucleated Langhans' giant cells. K. oxytoca was located in the cytoplasm of these cells, and extracellularly in the lumen of alveoli, bronchioles and bronchi, in the capsule of thymus and in the sinusoids of the liver. The results indicate that K. oxytoca can cause sporadic equine abortion.     

Main Drain virus as a cause of equine encephalomyelitis

Main Drain virus, which is thought to be transmitted normally among rabbits and various rodents by its natural vector, Culicoides variipennis, was isolated repeatedly from brain tissue of a sick horse from Sacramento County, California, and was implicated as the causative agent. Signs of illness were incoordination and ataxia, stiff neck, head pressing, inability to swallow, fever, and tachycardia.     

Rose bengal positive epithelial microerosions as a manifestation of equine keratomycosis

Purpose To describe the clinical appearance of corneal epithelial cell microerosions associated with keratomycosis in the horse. METHODS: Retrospective clinical study. RESULTS: Multifocal, punctate, superficial corneal opacities with positive rose bengal retention were noted in six horses with presumed 'viral keratitis'. Faint fluorescein staining was also present in three cases. Equine herpesvirus tissue culture inoculation was negative for a cytopathic effect in three cases. Aspergillus (n = 3), Curvularia (n = 1), and an unidentified fungus (n = 1) were cultured in five horses, and hyphae found on corneal cytology from the sixth. Mixed bacterial infections were present in three eyes. The eyes of two horses with Aspergillus progressed to deep melting corneal ulcers that required surgical therapy. The microerosions remained superficial, but persistent in the other four eyes. Natamycin was utilized topically in all six horses. Transmission electron microscopy from case 6 revealed mucin layer disruption, an intact corneal epithelial cell layer, and fungal attachment to degenerating epithelial cells. The visual outcome was positive in all six horses, although healing was prolonged (48.5 +/- 14.5 days on average in the horses with no surgery; 62 days on average in the two horses that required surgery). CONCLUSIONS: Complete removal or full-thickness penetration of the corneal epithelial cell barrier may not be necessary to allow fungal adherence and initiation of keratomycosis in the horse. Prior to colonization and invasion of the horse cornea, fungi may induce changes in the mucin layer of the tear film that result in or are associated with rose bengal positive microerosions of the superficial corneal epithelium. Horses with painful eyes, and eyes with superficial, multifocal corneal opacities should have their corneas stained with both fluorescein and rose bengal as fungal microerosions may stain weakly, or not at all, with fluorescein, and may thus be mistaken for presumed 'viral keratitis' of the horse.     

Evaluation of partial arytenoidectomy as a treatment for equine laryngeal hemiplegia

The efficacy of partial arytenoidectomy was assessed in 6 Standardbred horses, with surgically induced laryngeal hemiplegia, at rest (Period A) and during exercise at speeds corresponding to maximum heart rate (Period C) and 75% of maximum heart rate (Period B). Peak expiratory and inspiratory airflow rate (PEF and PIF), and expiratory and inspiratory transupper airway pressure (P_UE and P_UI) were measured and expiratory and inspiratory impedance (Z_E and Z_I) were calculated. Simultaneously, tidal breathing flow-volume loops (TBFVL) were acquired using a respiratory function computer. Indices derived from TBFVL included airflow rates at 50 and 25% of tidal volume (EF₅₀, IF₅₀, EF₂₅. and IF₂₅) and the ratios of expiratory to inspiratory flows. Measurements were made before left recurrent laryngeal neurectomy (baseline), 2 weeks after left recurrent laryngeal neurectomy (LRLN) and 16 weeks after left partial arytenoidectomy coupled with bilateral ventriculectomy (ARYT). After LRLN, during exercise Periods B and C, Z₁ and the ratio of EF₅₀/IF₅₀ significantly increased and PIF, IF₅₀ and IF₂₅ significantly decreased from baseline values. At 16 weeks after ARYT, Z₁ returned to baseline values during Periods B and C. Although PIF, IF₅₀, IF₂₅, PEF/PIF, and EF₅₀/IF₅₀ returned to baseline values during Period B, these indices remained significantly different from baseline measurements during Period C. After ARYT, TBFVL shapes from horses during Period C approached that seen at the baseline evaluation. Partial arytenoidectomy improved upper airway function in exercising horses with surgically induced left laryngeal hemiplegia, although qualitative and quantitative evaluation of TBFVLs suggested that some flow limitation remains at near maximal airflow rates. These results indicate that, although the procedure does not completely restore the upper airway to normal, partial arytenoidectomy is a viable treatment option for failed laryngoplasty and arytenoid chondropathy in the horse.     

Eye examination as part of the equine prepurchase examination

Prepurchase examination (PPE) is the most common reason for eye examination in first opinion equine practice. This paper describes a standard protocol for competent eye examination in the PPE, and reviews the interpretation of the more common clinical findings, particularly in relation to their expected influence on functional vision and their progression. The content is based on the limited existing literature, the personal opinions and experience of the author, and from discussions held with colleagues over the past 30 years.     

Tracheal necrosis as a fatal complication of endotracheal intubation

This case report describes the death of a yearling Thoroughbred colt due to segmental severe necrotising tracheitis with stenosis of the tracheal lumen, 19 days after endotracheal intubation for elective endoscopic surgery. The stenosis of the trachea leading to asphyxiation was caused by an inflammatory process accompanied by massive accumulation of necrotic material, fibrinous inflammatory exudate, oedema and granulation tissue. The cause of this inflammation was likely to be a bacterial infection secondary to traumatic damage of the tracheal mucosa. Given the clinical history and location of the lesion, the endotracheal tube used for general anaesthesia was hypothesised to be responsible for this damage. Delayed tracheal necrosis as a fatal complication of endotracheal intubation has not previously been described in the horse and should be considered as a potential catastrophic consequence following relatively innocuous clinical signs.     

Bacteroides sp. as a cause of anaerobic keratitis in a pony

This Case Report describes anaerobic infection of the conjunctiva and cornea in a pony. A 13‐year‐old pony was admitted for evaluation following suspected ocular trauma. Bacterial conjunctivitis and keratitis were diagnosed based on clinical appearance of the eye and cytological evaluation of a corneal scraping. The pony responded poorly to topical therapy, and enucleation was performed. Culture of the corneal scraping yielded Corynebacterium sp. and Bacteroides sp. Anaerobic keratitis and conjunctivitis is uncommonly reported in horses, but should be suspected when there is a history of ocular trauma or skin disease, or when a malodorous ocular discharge is identified.     

A giant nonstrangulating mesenteric lipoma as a cause of recurrent colic in a horse

Colic is a major cause of veterinary attendance in general practice and although most colic episodes remain isolated, recurrence may occur and definitive diagnosis can be difficult to obtain. This report describes an unusual presentation of a lipoma in a middle‐aged horse presented for recurrent colic. A massive lipoma causing a nonstrangulating space occupying obstruction of the small intestine was found during an exploratory celiotomy and was considered to be the most likely cause of the recurrent episodes of abdominal discomfort.     

Neoplasia of the equine urinary bladder as a cause of hematuria

In 6 horses with urinary bladder neoplasms, common clinical findings included a palpable mass in the bladder, anemia, hematuria, and/or proteinuria. Squamous cell carcinoma was found in 4 horses and appears to be the most common bladder tumor in the horse. Single cases of transitional cell carcinoma and fibromatous polyp also were identified. All horses except one were over 10 years of age. In one mare, treatment with 5-fluorouracil intracystically resulted in decreased bleeding from the bladder mass and apparent stabilization of the mass size. The mare ultimately died because of abdominal metastasis. Although rare, neoplasia of the urinary bladder should be considered when evaluating horses with hematuria.     

Oesophageal ectasia as a cause of dysphagia and milk regurgitation in a neonatal foal

Dysphagia and milk regurgitation are relatively infrequently observed clinical signs in neonatal foals but, when present, can commonly arise from anatomic or functional disorders of the upper airway. Less commonly, milk regurgitation can be caused by anatomic or neuromuscular disorders of the oesophagus. In the report presented here, a neonatal foal was examined for milk regurgitation at 4 days of age and was diagnosed with transient oesophageal ectasia via oesophagoscopy and contrast radiography. Aspiration pneumonia was treated with broad-spectrum antimicrobials and the owner was instructed to intermittently elevate the forelimbs to facilitate passage of milk out of the dilated oesophagus. The milk regurgitation resolved and reassessment of the foal at 6 weeks of age documented the absence of oesophageal ectasia and resolution of aspiration pneumonia. The foal was reported to be healthy and consuming food normally 6 months after initial examination and was in good body condition. This case is unique in that the oesophageal ectasia improved with time; furthermore, other potential causes of dysphagia and milk regurgitation of oesophageal origin in neonatal foals are discussed.     

A retrobulbar meningioma as a cause of unilateral exophthalmos and blindness in a horse

This report describes the unusual diagnosis of a retrobulbar syncytial meningioma in a 16‐year‐old Thoroughbred gelding. The horse initially presented with unilateral left sided exophthalmos and apparent blindness characterised by unilaterally absent menace and pupillary light responses. Magnetic resonance imaging (MRI) identified a well‐defined soft tissue mass intimately associated with the optic nerve. Based on the characteristic MRI appearance, a meningioma was suspected. The eye was enucleated under general anaesthesia and partial excision of the mass was achieved. Histopathology confirmed the diagnosis and the horse underwent a course of adjuvant radiotherapy. Twelve months following surgery the horse is back in work, no neurological abnormalities have been detected and follow‐up computed tomographic imaging of the skull has revealed mild bone sclerosis with no remnants of the mass identified.