Seasonal effects on gestation length and birth weight in alpacas.

Gestation lengths and birth weights were measured in 162 pregnancies in alpacas (Lama pacos) farmed in the high country of the South Island of New Zealand. A comparison of pregnancies from spring (mid-October to mid-December) and autumn (mid-February to late April) matings showed that gestation lengths were 12.5 days longer in spring (348.9 +/- 1.4 days vs. 336.4 +/- 1.2 days; P < 0.0001). For each day later in spring that a female was mated there was an increase in gestation length of 0.11 days (P < 0.05), whereas for each day later in autumn the gestation was reduced by 0.24 days. There were no significant effects of sex of cria or age of dam on gestation length. After adjustment for gestation length, crias born in autumn weighed 1.0 kg more than those born in spring (8.8 +/- 0.15 kg vs. 7.8 +/- 0.18 kg: P < 0.001). Female crias weighed 0.4 kg less than males at birth (P < 0.05). The results suggest that in this environment it will be difficult to maintain spring-mated females in a 12 month breeding cycle.

Fixation of intracapsular femoral neck fractures with a one-hole plate dynamic hip screw.

The results of internal fixation of 55 subcapital fractures of the femoral neck with a one-hole plate dynamic hip screw are presented. Two fractures could not be satisfactorily fixed and the procedures were converted to hemi-arthroplasties, but the remainder united within 6 months. The rate of avascular necrosis after union was 3 per cent in undisplaced and 31 per cent in displaced fractures. This method of fixation appears to produce a lower non-union rate than multiple pins in suitable fractures without affecting the incidence of late avascular necrosis.

Untreated diabetes mellitus promotes intestinal microbial overgrowth.

Gastrointestinal dysfunction is a common secondary complication of insulin-dependent diabetes mellitus, yet its etiology is unclear. Enteric microbial overgrowth may play a role. To quantitate the changes in mucosal-adherent enteric microbial populations in untreated diabetes mellitus and to assess the impact of two forms of insulin replacement therapy upon enteric microbial populations, age-matched male Lewis rats were rendered diabetic by the administration of intravenous streptozotocin (55 mg/kg). After diabetes was confirmed (blood glucose level greater than 250 mg/dL), rats were divided into three groups: no treatment (no insulin), treatment with daily insulin to maintain normoglycemia (3 to 7 units of protamine zinc insulin subcutaneously), or transplantation with a vascularized heterotopic duct-ligated pancreatic isograft. After 1 month, rats were killed, and segments of the proximal, middle, and distal small bowel were obtained. Mucosal samples were rinsed in phosphate-buffered saline to remove nonadherent bacteria prior to aerobic and anaerobic culturing. Microbial recovery was expressed as the log10 colony-forming unit/mg tissue wet weight. Untreated diabetes resulted in an overgrowth of mucosal-associated small bowel aerobic and anaerobic microbial populations compared with populations in normal nondiabetic age-matched control rats. Insulin treatment and pancreatic transplantation prevented microbial overgrowth in the diabetic small intestine. Pancreatic transplantation resulted in strict normoglycemia equivalent to that in nondiabetic control rats, whereas insulin treatment resulted in slightly higher blood glucose levels at sacrifice and wide fluctuations in blood glucose levels compared with nondiabetic control rats. These data suggest that sustained normalization of glucose levels is not required to prevent microbial overgrowth in diabetic rats.

Small bowel transplantation promotes bacterial overgrowth and translocation.

Alterations in the symbiotic relationship between immunocompromised hosts and their resident gut microflora may lead to serious complications following small bowel transplantation (SBT). This study examined the effects of SBT and cyclosporine (CsA) immunosuppression on gut bacterial populations and translocation to the mesenteric lymph nodes. Sixty adult male meat-fed Lewis rats were divided into six groups: normal controls, CsA alone (24 mg/kg im qod), CsA carrier vehicle alone, isografts, isografts given CsA, and allografts given CsA. Rats were killed after 3 weeks and segments of small bowel and colon were harvested for quantitative tissue culture. Mesenteric lymph nodes and blood were cultured to identify translocation. Transplantation alone led to an increase in gram-negative aerobes from 2.6 to 4.6 colony forming units/100 mg tissue (P less than 0.05) in the distal ileum (transplanted segment). Eighty-four percent of transplanted animals receiving CsA had bacteria recovered from their mesenteric lymph nodes compared to none in controls (P less than 0.001) and 20% in isografts not receiving CsA (P less than 0.02). Intestinal transplantation alone appears to promote gram-negative overgrowth while the addition of CsA therapy facilitates translocation to the mesenteric lymph nodes and may predispose to gut-associated sepsis following SBT.

Effects of axotomy on the cholinesterase and carbonic anhydrase activities of axons in the proximal and distal stumps of rabbit sciatic nerves: a temporal study.

The temporal changes in transected sciatic nerves of rabbits were studied using recently developed histochemical techniques for discriminating between sensory and motor axons. A segment of the nerve was removed to inhibit spontaneous regeneration across the gap. Staining characteristics of the proximal and distal nerve stumps were studied at 1, 2, 3, 4, 9, and 35 days following axotomy and compared with control sciatic nerves. In the control and test nerves, subpopulations of myelinated sensory axons were identified histochemically by carbonic anhydrase (CA) staining, and a subset of alpha motor axons were visualized by cholinesterase (CE) staining. Axon staining patterns were reciprocal; i.e., sensory axons were CA-positive and CE-negative, whereas motor axons were CE-positive and CA-negative. Histochemical activities persisted at day 35 after axotomy in the proximal stump and until day 9 after axotomy in the distal stump. This implies that these techniques may aid in both immediate and delayed primary nerve repair. With time, there is buildup of scar tissue adding to the proximal and distal stumps. Therefore, sections for demonstrating sensory and motor axons must be taken progressively further back from the nerve stump ends. Histochemical axon typing indicated that sensory axons regenerated earlier and to a greater degree than motor axons in the developing neuroma. Use of both the carbonic anhydrase and cholinesterase staining methods is more accurate than either technique alone as an adjunct for examining normal and injured peripheral nerves.

Freemartinism in red deer (Cervus elaphus L.).

Several mixed-sex twins were produced by red deer treated with progesterone and pregnant mare's serum gonadotrophin. Of seven females karyotyped, two were 68,XX/68,XY chimeras. One male had the same chimeric karyotype as its female co-twin. These are the first reported cases of freemartinism in deer.

Small bowel transplantation in the rat with immediate restoration of intestinal continuity.

Compared with other rat transplant models, small bowel transplantation (SBT) is associated with higher peritransplant morbidity and mortality. We describe a two-stage technique of SBT in the rat that minimizes perioperative complications and also allows immediate restoration of intestinal continuity. Inbred Lewis strain rats were used as donors and recipients. A one-stage technique was originally adopted whereby the distal 50% of the jejunoileum was transplanted followed by near-total resection of the native small intestine and restoration of intestinal continuity. Among 20 rats transplanted with this technique, only one survived longer than 30 days. With the two-stage technique, transplantation of the donor jejunoileum in continuity was performed, followed by native enterectomy 7 days later. With the two-stage technique 17 of 20 rats survived indefinitely (greater than 50 days). Other important technical modifications are described. In the hands of a skilled microvascular surgeon, the two-stage SBT technique results in consistently improved survival and minimal morbidity.

Identifying motor and sensory myelinated axons in rabbit peripheral nerves by histochemical staining for carbonic anhydrase and cholinesterase activities.

Carbonic anhydrase (CA) and cholinesterase (CE) histochemical staining of rabbit spinal nerve roots and dorsal root ganglia demonstrated that among the reactive myelinated axons, with minor exceptions, sensory axons were CA positive and CE negative whereas motor axons were CA negative and CE positive. The high specificity was achieved by adjusting reaction conditions to stain subpopulations of myelinated axons selectively while leaving 50% or so unstained. Fixation with glutaraldehyde appeared necessary for achieving selectivity. Following sciatic nerve transection, the reciprocal staining pattern persisted in damaged axons and their regenerating processes which formed neuromas within the proximal nerve stump. Within the neuromas, CA-stained sensory processes were elaborated earlier and in greater numbers than CE-stained regenerating motor processes. The present results indicate that histochemical axon typing can be exploited to reveal heterogeneous responses of motor and sensory axons to injury.

Diagnosis of adenocarcinoma in transurethral resectates of the prostate gland.

The often-posed question of how much prostate tissue should be examined microscopically to detect carcinoma in transurethral prostatectomy specimens was approached by prospective study and probability analysis. Transurethrally resected prostate specimens were weighed, totally embedded, and examined histologically in 151 consecutive cases. Resected fragments and fragments involved by carcinoma were enumerated for each case. Adenocarcinoma was diagnosed in 39 (25.8%) of the cases. Specimens containing carcinoma had a mean of 111 total fragments, with a median of 3 and mean of 7 positive fragments. In two clinically unsuspected cases of poorly differentiated adenocarcinoma, the number of fragments involved by carcinoma was small (2 of 164 and 4 of 190 fragments). Assuming that study of a single microscopic section of a fragment determines whether carcinoma is present, probability formulations are presented expressing the likelihood that at least one fragment containing cancer is found in randomly selected fragments from a specimen. To achieve a 95% probability of detecting carcinoma in TUR specimens, a minimum of 95% of the fragments must be examined if one fragment contains a carcinoma, 63.1% of the fragments if three contain carcinoma and 25.8% of the fragments if 10 contain carcinoma. Literature review indicates many authors recommend examining fewer fragments of transurethrally resected prostate tissue than this study indicates are required to diagnose carcinoma.

Subtrochanteric fractures of the femur through the track of the lower Garden screw--treatment with a Richards sliding screw.

Four cases of subcapital femoral fractures, initially treated by internal fixation with Garden screws and subsequently complicated by subtrochanteric fractures through the lower screw hole, have been successfully treated by substitution of a Richards sliding screw of corresponding angle for the lower screw. All 4 subtrochanteric fractures united without implant failure. One subcapital fracture failed to unite and secondary femoral head replacement was unimpeded.

Wrinkle corner. A jig for accurate section of the femoral neck.

A jig is described which allows the femoral neck to be cut to the correct length when performing a hemi-arthroplasty for subcapital fracture.

Resistant tennis elbow.

Fifty cases of resistant tennis elbow were studied, thirty seven of these had been treated by lengthening the tendon of extensor carpi radialis brevis, and thirteen by decompression of the radial tunnel. The two groups were well matched in terms of age, sex and pre-operative symptoms and signs. It was found that the results of surgery were very similar in the two groups and this observation is explained by anatomical study showing that surgical division of the fibrous arch of the superficial leaf of supinator will relieve tension on the lateral epicondyle and its adjacent structures thus allowing relief of symptoms independently of radial or posterior interosseous nerve decompression. This elaborates previously published work showing that there is no clinical or electrical evidence of radial nerve entrapment in resistant tennis elbow.

Ionizing radiation alters beta-endorphin-like immunoreactivity in brain but not blood.

Previous behavioral and pharmacological studies have implicated endorphins in radiation-induced locomotor hyperactivity of the C57BL/6J mouse. However, the endogenous opiate(s) responsible for this behavioral change have not been identified. The present study measured beta-endorphin-like immunoreactivity (beta-END-LI) in brain, blood, and combined brain and pituitary samples from irradiated and sham-irradiated C57BL/6J mice. After radiation exposure, levels of beta-END-LI decreased significantly in the brain. A similar, but not statistically significant, decline was measured in combined brain and pituitary samples. Concentrations of blood beta-END-LI were not changed by irradiation. These radiogenic changes in beta-END-LI are in some ways similar to those observed after other stresses. However, radiation-induced locomotor hyperactivity may be mediated more by alterations of beta-END-LI in the brain than in the periphery. Other endogenous opiate systems may also contribute to this behavioral change in the C57BL/6J mouse.

Stable intertrochanteric femoral fractures. A misnomer?

Intertrochanteric fractures of the femur are usually classified into stable and unstable groups, partly to predict the likelihood of displacement with early weight-bearing after internal fixation. Of 82 internally fixed intertrochanteric fractures which would normally be classified as stable, 25 subsequently underwent impaction along the axis of the nail or screw; varus displacement occurred in another six. Of these 31 fractures, 10 were two-part fractures which had been anatomically reduced, and 12 were originally undisplaced. It did not seem possible to predict the subsequent instability from the pre-operative radiographs. Of the 82 fractures, 47 had been treated with a Jewett nail-plate and 35 by a Richards compression screw-plate. Two groups of stable fractures were recognised: Group 1 was undisplaced and Group 2 displaced. Axial impaction occurred in a quarter of all Group 1 fractures however treated. In Group 2 fractures it occurred in a quarter of those treated with a nail-plate, and in over a third of those treated with a sliding screw-plate. The six fractures that underwent varus displacement had all been treated with Jewett nail-plates. Penetration into the joint occurred in 10 patients, all of them in the group treated with Jewett nail-plates; four required re-operation.

Treatment of intertrochanteric fractures of the femur. A comparison of the Richards screw-plate with the Jewett nail-plate.

One hundred and seven patients with intertrochanteric fractures of the femur treated with a Richards screw-plate were compared retrospectively with 103 patients treated with a Jewett nail-plate. The mortality and morbidity were similar in the two groups. In patients with comparable fractures, those treated with a Richards device mobilised more quickly and left hospital sooner, and more of them returned to their homes. Failures of stabilisation, both clinically and radiographically, were fewer in this group. The reliability of fixation with a correctly positioned Richards screw-plate could justify the omission of outpatient follow-up in all but a small group of patients with severe unstable fractures or grossly defective bone stock. The higher cost of a Richards implant and the slightly longer operative procedure were outweighed by savings in occupancy of acute and long-stay hospital beds.

Plasma concentrations of LH, prolactin, oestradiol and progesterone in female red deer (Cervus elaphus) during pregnancy.

Peripheral blood samples were collected throughout pregnancy from 11 red deer hinds. During the same period, 6 other hinds which mated but failed to produce calves were also sampled. Pretreatment of some of these hinds included synchronization of oestrus alone (N = 3) or with injection of 1000 i.u. PMSG (N = 9). During early and mid-pregnancy, LH and prolactin were frequently undetectable. Prolactin concentrations in pregnant and non-pregnant hinds were high (greater than 250 ng/ml) in December-January. The results of the hormone analyses suggested that the amount of progesterone in plasma correlates with the number of corpora lutea (CL) present. The concentrations of oestradiol and progesterone were low from mid-winter onwards in the non-pregnant hinds, suggesting a reduction in ovarian activity at this time. In pregnant animals, progesterone concentrations were high for the first 200 days of gestation. Oestradiol rose to peak values concomitant with declining progesterone concentrations just before parturition.