Investigation into white spots in the carapace of a moribund mud crab (Scylla serrata) from a white spot syndrome virus (WSSV) positive zone in Moreton Bay, Australia.

BACKGROUND: A freshly deceased mud crab (Scylla serrata) exhibiting multiple white spots under the carapace was found in Pumicestone Passage, northern Moreton Bay in May 2018. This crab was taken from within a biosecurity zone established due to a recent incursion of White Spot Syndrome Virus (WSSV) into populations of wild penaeids (Penaeus spp., Metapenaeus spp.) and crabs (Thalamita crenata) in the area. Because grossly visible white spots have been previously observed under the carapace of moribund S. serrata with white spot disease (WSD) in India, an investigation into the cause of death was undertaken. CASE REPORT: The affected S. serrata was negative for WSSV DNA when gill samples were tested by real-time PCR. Histopathology found no evidence of WSD lesions in the form of basophilic hypertrophied intranuclear inclusions in any tissues of ectodermal or mesodermal origin. Histopathology of the affected carapace showed that the white spots consisted of multiple lighter coloured foci in the exocuticle formed from concentric crystalline-like rings, which extended into the endocuticle. These were interpreted as evidence of mineral mobilisation within the carapace during the pre-moult (D1 or D2) stage of the moult cycle. The cause of death in this case therefore may have been due to moult-related complications. CONCLUSION: These observations confirm that formation of grossly visible white spots under the carapace of S. serrata are not pathognomonic for infection with WSSV. Similar observations in previous studies where WSSV was detected by PCR in this same host may have been incidental findings.

Signaling mechanisms mediating muscarinic enhancement of GABAergic synaptic transmission in the spinal cord.

Activation of muscarinic acetylcholine receptors (mAChRs) inhibits spinal nociceptive transmission by potentiation of GABAergic tone through M(2), M(3), and M(4) subtypes. To study the signaling mechanisms involved in this unique mAChR action, GABAergic spontaneous inhibitory postsynaptic currents (sIPSCs) of lamina II neurons were recorded using whole-cell patch clamp techniques in rat spinal cord slices. The mAChR agonist oxotremorine-M caused a profound increase in the frequency of GABAergic sIPSCs, which was abolished in the Ca(2+)-free solution. Inhibition of voltage-gated Ca(2+) channels with Cd(2+) and Ni(2+) largely reduced the effect of oxotremorine-M on sIPSCs. Blocking nonselective cation channels (NSCCs) with SKF96365 or 2-APB also largely attenuated the effect of oxotremorine-M. However, the KCNQ channel blocker XE991 and the adenylyl cyclase inhibitor MDL12330A had no significant effect on oxotremorine-M-induced increases in sIPSCs. Furthermore, the phosphoinositide-3-kinase (PI3K) inhibitor wortmannin or LY294002 significantly reduced the potentiating effect of oxotremorine-M on sIPSCs. In the spinal cord in which the M(3) subtype was specifically knocked down by intrathecal small interfering RNA (siRNA) treatment, SKF96365 and wortmannin still significantly attenuated the effect of oxotremorine-M. In contrast, SKF96365 and wortmannin both failed to alter the effect of oxotremorine-M on sIPSCs when the M(2)/M(4) mAChRs were blocked. Therefore, our study provides new evidence that activation of mAChRs increases synaptic GABA release through Ca(2+) influx and voltage-gated Ca(2+) channels. The PI3K-NSCC signaling cascade is primarily involved in the excitation of GABAergic interneurons by the M(2)/M(4) mAChRs in the spinal dorsal horn.

Nutritional status and clinical outcome in elderly female surgical orthopaedic patients.

The possible relationship between nutritional status and clinical outcome following orthopaedic hip surgery was investigated. The nutritional status of 60 elderly female patients admitted for elective total hip replacement (THR) and emergency fractured neck of femur surgery (FNF) was measured over time. Specific measures of clinical outcome, including well-being and functional status, were monitored during hospital stay and at 4, 8 and 26 weeks following discharge. Patients were allocated to a high nutritional risk group where any three of the following were less than the 5th percentile value: serum albumin, haemoglobin, triceps skinfold thickness, mid-upper arm muscle circumference and body weight. Using this definition, malnutrition was present in 4% of THR patients and 41% of FNF patients. It was found that the high risk patients had significantly longer convalescence periods, (median stay 27.5 days compared with 0 days, P < 0.0009), and a greater proportion were dependent upon walking frames at 6 months (46% compared with 11%, P < 0.01). Fifty percent of the high risk patients had been living independently prior to admission, in contrast only 29% had returned to their homes at 6 months after discharge. The results indicate an apparent link between clinical outcome and nutritional status based upon the allocation procedure employed, which has the potential for ensuring cost-effective nutritional intervention.

A controlled trial of sip-feed supplements in elderly orthopaedic patients.

The potential nutritional and clinical benefits of sip-feed supplements were investigated by means of a controlled trial in elderly female patients admitted for orthopaedic surgery. A nutritional risk assessment procedure (Nutritional Risk Questionnaire, NRQ) was used to identify patients who might benefit from supplementation. Patients identified as high risk who did not receive supplements showed significant losses in triceps skinfold thickness (TSF) and mid-upper arm muscle circumference (MUAMC) measurements during hospitalization. Such changes were not observed in high-risk supplemented patients, but significant losses of MUAMC were also recorded in a group of patients who failed to comply with the supplement. No differences in biochemical parameters, muscle function, or clinical outcome were observed between supplemented and unsupplemented and non-compliant patients. The problems of poor compliance to sip-feed supplements and failure to observe clinical benefit in supplemented patients are discussed.

Synagis: an anti-RSV monoclonal antibody.

Palivizumab is a new anti-RSV monoclonal antibody product indicated for the prevention of serious lower respiratory tract disease caused by RSV in pediatric patients at high risk of developing RSV disease ("Synagis," 1998). Palivizumab was evaluated in a single, large clinical trial (IMpact) (Connor et al., 1998). In this trial, RSV hospital admissions were reduced by 55% in children 24 months of age with BPD or in infants born prematurely (35 weeks gestation). Additionally, the severity of illness was also reduced as evidenced by a decrease in total days of RSV hospitalization and decreased incidence of RSV intensive care unit admissions. Palivizumab is expensive--with an estimated cost for a season ranging from $3,500-$10,700 per infant, depending on the child's weight and length of RSV season in the area where the child resides. Although palivizumab prophylaxis has been shown to reduce hospital admissions, the cost effectiveness of using this product needs to be formally evaluated. The AAP has provided guidance to determine the best candidates for RSV prophylaxis.

Nutrition in the older hospital patient.

The importance of nutrition in the treatment of the older hospital patient has often been underestimated. This may be because of a failure to recognize the special nutritional problems of this age group. It is important to recognize that the older patient is more likely to be admitted to hospital suffering some degree of malnutrition and the nutritional consequences of the metabolic response to trauma may be more severe in this group. More attention needs to be placed on nutritional requirements and nutrient provision during rehabilitation. Adverse nutritional consequences of illness may be prolonged in the older subject and an extended period of nutritional supplementation may be required to produce benefit. It should be emphasized that adverse clinical consequences of nutritional deficit, and advantages of nutritional support, may not be evident in the short term. Long term follow up of nutritionally disadvantaged patients, and patients who have received specialized forms of nutritional support, will be required if the true contribution of nutrition to clinical outcome is to be evaluated.