Search PubMed⌕ Search

Biomedical subjects

R C Russell

Publications and source records attributed to R C Russell.

At least 163 records · Page 9Linked to original sources
PubMed1987

Survival of insects in the wheel bays of a Boeing 747B aircraft on flights between tropical and temperate airports.

Mosquitos (Culex quinquefasciatus), house flies (Musca domestica), and flour beetles (Tribolium confusum) located in cages within the wheel bays of a Boeing 747B aircraft, survived travel on the following normal commercial routes: Sydney-Melbourne; Melbourne-Singapore; Singapore-Bangkok; Bangkok-Singapore; and Singapore-Melbourne. Survival of all three species was high, averaging 84% for mosquitos and higher for flies (93%) and beetles (>99%). Although external temperatures were -42 degrees C to -54 degrees C for aircraft cruising at 10 700-11 900 m, minimum temperatures within the wheel bays ranged from +8 degrees C to +25 degrees C.

Aircraft↗
PubMed1986

Surgical biopsy for persistent generalized lymphadenopathy.

Lymph node biopsy was performed in 39 homosexual men with unexplained persistent generalized lymphadenopathy (PGL). Thirty-seven (95 per cent) of these patients had antibodies to human T-lymphotropic virus type III (HTLV-III), at the time of biopsy. Histology in all but one showed only follicular hyperplasia, the exception showed caseating granulomata typical of tuberculosis. Clinical differentiation between lymphadenopathy associated with HTLV-III and other causes of generalized lymphadenopathy is difficult; however, the presence of antibodies to HTLV-III probably identifies patients in whom surgical biopsy will only occasionally reveal a specific histological diagnosis. It is suggested that the presence of antibodies to HTLV-III in patients with PGL justifies a more selective approach to lymph node biopsy.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Seasonal activity and abundance of the arbovirus vector Culex annulirostris skuse near Echuca, Victoria, in the Murray Valley of Southeastern Australia 1979-1985.

Abundance of Culex annulirostris in a state forest near Echuca, northern Victoria, was sampled with a dry ice-baited EVS trap from 1979 to 1985, generally on a fortnightly basis. The species regularly became active from October, the population reached peak abundance in mid summer and then declined to become undetectable from late May. Abundance varied between years, related to availability of larval habitats. The results confirm a pattern of seasonal activity in the Murray Valley that is relevant to arbovirus epidemiology and to vector control.

Animals↗
PubMed1986

Population age composition and female longevity of the arbovirus vector Culex annulirostris skuse near Echuca, Victoria, in the Murray Valley of southeastern Australia 1979-1985.

A population of Cx annulirostris in a state forest near Echuca, Vic., was sampled with a dry ice-baited encephalitis virus surveillance (EVS) trap from 1979 to 1985, generally on a fortnightly basis. These collections were combined for monthly samples which were dissected for parity and population age composition. The proportion parous varied between months and between years; for mid-summer (February) proportion parous ranged from 0.54 to 0.83. There was no evidence that the population was autogenous. Monthly average duration of the gonotrophic cycle was estimated for October to May, and ranged from 4 days to 12 days. The probability of survival through one day in summer, taken from the proportion surviving from 1-parous to 2-parous, averaged 0.75 over 3 years. This average was higher (0.89) if calculated from the proportion parous. Females old enough to transmit Murray Valley Encephalitis (MVE) virus were recorded from October to May, and represented up to 15.8% of the total collection in one season (1979-80).

Animals↗
PubMed1986

Experimental evaluation of free-tissue transfer to promote healing of infected wounds in dogs.

An experimental model was designed to evaluate the course of healing and the changes in bacterial concentrations of infected forelimb wounds with devascularized bone in dogs. Infected leg wounds were allowed to heal by secondary intention or were covered with a full-thickness or split-thickness skin graft, an epigastric skin/fat flap, or a gracilis musculocutaneous flap. All skin grafts failed. Gracilis muscle flaps were superior to epigastric skin/fat flaps in decreasing soft-tissue bacterial concentrations. Quantitative bone cultures, however, were positive at reexploration 6 weeks later in 33% of all legs covered with a flap. X-ray films were successful in predicting the presence or absence of bone infection in 70% of all legs. Postmortem arteriograms of legs covered with muscle flaps showed neovascularity to bone. This study suggests muscle flap coverage of wounds debrided of contaminated, necrotic, or infected bone and soft tissue to be an excellent method of providing well-vascularized soft tissue promoting healing and resolution of infection.

Animals↗
PubMed1986

A comparative study of free and pedicle flaps for lower extremity wounds.

Sixty-four flaps were used to treat wounds in 58 patients over a 5-year period. In this series there was a high incidence of healing of both tibial fractures and chronic osteomyelitis when covered with muscle. Better contour is achieved with muscle covered with meshed skin grafts than with musculocutaneous flaps. The survival rate for free flaps was 93% and for pedicle flaps, 100%. Complication rates were higher for pedicle flaps (45%) than for free flaps (30%), although major complications for free flaps (14%) were higher than for pedicled flaps (9%).

Adolescent↗
PubMed1986

The growth potential of small arteries repaired by microsurgical technique.

A study to determine the growth potential of immature microvessels was carried out using rat femoral arteries. Immature rat arteries repaired with interrupted 10-0 nylon sutures grew in proportion to the animal. There were no areas of stenosis at repair sites, which in some animals appeared slightly dilated compared with control vessels. The ultrastructure of repaired arteries after growth was mildly altered in the internal and external elastic membrane layers while the intima and media appear normal. Neovascularization around anastomoses may explain an apparent increased blood flow velocity at repair sites and does not correspond to arterial narrowing in this model.

Animals↗
PubMed1986

Polyglycolic acid tubing as a conduit for nerve regeneration.

Rabbit common peroneal nerves will regenerate across a 1-cm gap inside polyglycolic acid tubing. Regenerated nerves are separated histologically into "minifascicles," which persist in distal segments. The conduction velocities and evoked action potential amplitudes following this type of regeneration are inferior to those seen in nerves repaired directly or by interpositional grafting. The strength of reinnervated muscles is equal following direct nerve suture, interpositional grafting, or polyglycolic acid conduit repairs.

Animals↗
PubMed1986

Extremity reconstruction using the "fillet of sole" flap.

Foot skin can be used in traumatic nonreplantable leg amputations as an immediate neurovascular free flap for proximal stump reconstruction. The thick, glabrous skin on the sole of the foot provides durable, sensate coverage. The flap is large, avoids a secondary donor site, and can survive on either the dorsalis pedis or posterior tibial artery if one preserves the connecting deep plantar branch of the dorsalis pedis artery. Two cases of immediate stump reconstruction using the "fillet of sole" flap are presented.

Adult↗
PubMed1986

Effect of temperature on blood flow and metabolism in a neurovascular island skin flap.

Using the buttock flap in 29 white Yorkshire pigs, blood flow and O2 consumption were measured at dermal temperatures between 35 degrees C and 15 degrees C. Flow was measured with an electromagnetic flowmeter and O2 consumption was calculated as the product of blood flow and the difference in flap A-VO2. Baseline flow was 6.6 +/- .9 (SE) ml/100 g/min at 35 degrees C and 3.1 +/- .02 (SE) ml/10 g/min at 15 degrees C. Blood flow through the flap stopped completely at a dermal temperature of 14 degrees C. Oxygen consumption was 0.16 +/- .02 (SE) ml/100 g/min at 35 degrees C and 0.04 +/- 0.01 (SE) ml/100 g/min at 15 degrees C. At 20 degrees C blood flow was 4.3 ml/100 g/min and metabolism was .04 ml/100 g/min. In other words, blood flow was 65% of baseline, while O2 consumption was only 25% of baseline. The therapeutic effect of local cooling at 20 degrees C deserves further investigation. The cessation of flow at 14 degrees C may be caused by increased plasma viscosity.

Animals↗
PubMed1986

Free microneurovascular gracilis muscle transfer in the dog for enterostomal sphincter construction and control: an experimental study.

Hundreds of thousands of individuals struggle today with the morbidity of an abdominal wall enterostoma. This study explored two ways of constructing abdominal wall sphincter mechanisms in dogs using gracilis muscles transferred by free microneurovascular technique. Transferred muscles successfully generated pressures greater than the normal external anal sphincter but could not maintain this level of contraction for tonic sphincter closure. Other transferred muscles were designed to straighten the course of stomas continent at rest. They provided strong linear pull uncoiling the stomas but simultaneously pinched off the orifices during contraction. This opening model shows promise if the muscle attachments around the stoma orifices could be made less constricting.

Abdominal Muscles↗
PubMed1986

Fournier's gangrene of the penis: a report of two cases.

Fournier's gangrene is a rare disease involving the scrotum and penis with occasional extension up the abdominal wall. Both of our cases were unusual in that only the penis was involved. In addition, the occurrence of squamous cell carcinoma in an area previously affected by Fournier's gangrene has never been reported. The usual organism is an anaerobic streptococcus synergistic with some second organism. Early therapy is key, including debridement of the entire shaft of the penis distal to the devastated area, intravenous broad-spectrum antibiotics, and skin grafting.

Carcinoma, Squamous Cell↗
PubMed1986

Microvenous graft length determination for arterial repair.

Varying lengths of femoral vein grafts from 36 New Zealand rabbits were used to bridge defects in the ipsilateral femoral artery in an attempt to estimate the correct length of vein graft needed to replace an arterial defect. Harvested venous segments contracted by 35% to 55% of their in vivo length. Short grafts subjected to linear tension had poor patency rates. Increasing the length improved patency. Long redundant grafts were initially tortuous, but lost their redundancy when studied long term. Silicone perfusion studies, however, revealed a persistence of luminal irregularity and tortuosity. Histologically, arterialized vein grafts thickened by accumulation of fibrous tissue in the medial layer, but otherwise maintained identifiable venous morphological characteristics. Scanning electron microscopic studies identified endothelial changes in vein grafts after arterialization. Based on these results, the ideal microvenous graft should be approximately 35% longer than the arterial defect to be bridged when measured in vivo to permit optimal balance between linear and radial deforming forces.

Anastomosis, Surgical↗
PubMed1986

Experimental evaluation of tissue revascularization using a transferred muscular-vascular pedicle.

Skin and cartilage can be revascularized from a transferred muscular-vascular pedicle. Muscle vessels appear to connect with existing vessels in the subdermal plexus or perichondrium and determine the ultimate distribution of the skin or cartilage revascularized. The ideal timing for flap elevation following revascularization in this model is 21 to 28 days following transfer. Isolation of the muscular-vascular pedicle from underlying tissue by a silicone sheet does not appear to augment tissue revascularization. Delay procedures do not improve surviving flap length. Composite flaps of cartilage and skin can be revascularized using this technique.

Animals↗
PubMed1986

Functional evaluation of latissimus dorsi donor site.

A study was undertaken to determine the cosmetic and functional problems associated with the latissimus dorsi muscle donor site. Twenty-four patients undergoing both free and pedicle muscle and myocutaneous flap procedures for a wide variety of reconstructive problems were studied. All patients had a contour defect at the donor site, a scar which varied with the patient's age and whether overlying skin had been taken with the muscle flap. Mild to moderate shoulder weakness and some loss of motion were noted in most patients which improved over the course of several months. An upper extremity disability in strength and shoulder motion should be anticipated following latissimus dorsi transfer, which in most cases is minimized by the recruitment of synergistic muscle units. Vigorous range-of-motion exercises following surgery should be encouraged to minimize adhesions and joint capsule stiffness. Social changes in occupation and daily living activities were noted which were not a problem for most patients. Twenty-three of 24 patients were pleased with the overall outcome of their surgery and would recommend the procedure to others. A prospective study before and after latissimus dorsi transfer followed by a second evaluation 2 to 3 years postoperatively would help to clarify the role synergistic muscle units play in "taking over" latissimus dorsi function.

Adolescent↗
PubMed1986

Granular cell tumour of the common bile duct.

Granular cell tumors are a rare cause of benign biliary stricture. A case is reported which is unusual in that the diagnosis was made before the onset of jaundice. We emphasize the importance of accurate histology of biliary strictures, to eliminate confusion between those of benign and malignant nature and to ensure that the appropriate management is undertaken. Immunohistochemical evidence for the neural origin of this rare tumour is presented.

Adult↗