Biological effects monitoring of the North Sea employing fish embryological data

Using the reproductive capacity of fish appears to be a suitable approach for risk assessment in the aquatic environment since fish are a typical representative thereof and in addition they are of considerable societal value. Generally the early embryonic stages are considered to be one of the most sensitive parts of a fish's life cycle. A method has been developed to use the state of health of live, naturally spawned fish embryos from plankton samples for biological effects monitoring. During the years 1985-1987 in the southern North Sea and in 1991-1992 in the whole of the North Sea fish eggs were sampled from surface waters and examined for developmental abnormalities. Elevated embryo malformation rates were detected in the plume of the major rivers Elbe and Rhine as well as along the eastern coast of England. Occurring malformations are thought to be pollution-related and may be used to define areas of environmental deterioration. The method is discussed in view of its suitability for biological effects monitoring using malformations in fish embryos as biomarkers.

Quality of life in COPD patients using transtracheal oxygen

Transtracheal oxygen offers patients with chronic obstructive pulmonary disease many benefits. A qualitative study was conducted to examine patients' perceptions of how the technology affects quality of life. This study has several implications for nurses working in hospital and home settings.

Transcranial Doppler detection of microemboli in prosthetic heart valve patients: dependency upon valve type

Transcranial Doppler ultrasound has revealed the existence of cerebrovascular microemboli in asymptomatic patients with prosthetic heart valves. We investigated the relation between the presence and number of emboli signals and valve type. Patients with six types of prosthetic valves (Björk-Shiley monostrut, Medtronic-Hall, Carbomedics, ATS, Carpentier-Edwards standard, Carpentier-Edwards supraannular) were examined using transcranial Doppler ultrasound in two centers. The monitoring time was 30 min over the right middle cerebral artery. All patients were stabilized on warfarin at the time of study. Microemboli signals were identified by their characteristic audiovisual signal and on subsequent spectral analysis, based on accepted criteria. A standard neurologic questionnaire was completed by all patients. The prevalence of microemboli signals varied between 49% (Medtronic Hall) and 97% (Björk-Shiley monostrut), while their number varied between 1 [0-3] (Carpentier-Edwards standard) and 187 [136-240] (Björk-Shiley monostrut) per hour (median and 95% CI). Both parameters were significantly higher in patients with Björk-Shiley monostrut valves compared to the other patient groups. There were no significant differences in the prevalence of neurologic complications among the groups examined (overall 16%), or in emboli numbers between symptomatic and asymptomatic patients. The prevalence and quantity of microemboli signals in patients with prosthetic heart valves, as detected by transcranial Doppler, is dependent upon valve type. The clinical significance of these microemboli signals remains to be further evaluated.

Canine osteosarcoma: amputation and chemotherapy

One of the most important advances in veterinary oncology during the past 10 years has been the use of adjuvant chemotherapy for treatment of the micrometastases of canine osteosarcoma. This article reviews the biologic behavior of osteosarcoma and discusses chemotherapy with the two agents known to be effective: cisplatin and doxorubicin.

Ultrasonography of the brain and vertebral canal in dogs and cats: 15 cases (1988-1993)

Medical records of 3 cats and 12 dogs with lesions of the brain (3 cats, 2 dogs) or vertebral canal (10 dogs) that underwent intraoperative ultrasonography were reviewed. Ultrasonography was performed after craniotomy, a ventral slot procedure, or laminectomy, using a real-time sector scanner with a 7.5- or 10-MHz transducer. In the 3 cats and 2 dogs with brain lesions, cerebral masses were hyperechoic, compared with normal brain, and were easily located. In the 2 dogs, ultrasonography was necessary to localize deep-seated cerebral lesions that could not be seen following craniotomy. In 7 dogs that underwent a ventral slot procedure because of prolapse of an intervertebral disk, ultrasonography was successfully used to assess completeness of disk removal. The remaining 3 dogs underwent dorsal laminectomy because intradural enlargement of the spinal cord (1 dog) or an intradural mass (2 dogs) could be seen myelographically. In the 2 dogs with intradural masses, intraoperative ultrasonography helped to delineate the extent of the tumor. In the third dog, spinal cord swelling was seen ultrasonographically; the histologic diagnosis was spinal cord edema.

CAVIAR: a tool to improve serial analysis of the 12-lead electrocardiogram

An important part of an electrocardiogram (ECG) interpretation is the comparison between the present ECG and earlier recordings. The purpose of the present study was to evaluate a combination of two computer-based methods, synthesized vectorcardiogram (VCG) and CAVIAR, in this comparison. The methods were applied to a group of 38 normal subjects and to a group of 36 patients treated with anthracyclines. A fraction of these patients are likely to develop cardiac injury during or after the treatment, since anthracyclines are known to cause heart failure and cardiomyopathy. Two ECGs were recorded on each patient, one before and one after the treatment. On each normal subject, two ECGs were recorded with an interval of 8-9 years. A synthesized VCG was calculated from each ECG and the two synthesized VCGs from each subject were analysed with the CAVIAR method. The CAVIAR analysis is a quantitative method and normal limits for four measurements were established using the normal group. Values above these limits were more frequent in the patient group than in the normal group. The conventional ECGs were also analysed visually by an experience ECG interpreter without knowledge of the result of the CAVIAR analysis. No significant serial changes were found in 10 of the patients with high CAVIAR values. Changes in the ECGs were found in two patients with normal CAVIAR values. In summary, synthesized VCG and CAVIAR could be used to highlight small serial changes that are difficult to find in a visual analysis of ECGs.

Opitz BBBG syndrome: new family with late-onset, serious complication

The Opitz BBBG syndrome is characterized by hypertelorism and (in male patients) hypospadias, in addition to a number of midline abnormalities: posterior laryngeal cleft, stridor, swallowing dysfunction, cardiac defects, imperforate anus, and urinary tract and CNS anomalies. Inheritance is autosomal dominant (McKusick number *145410) with partial male sex limitation in most pedigrees. We report a Dutch family with Opitz BBBG syndrome in which the proband developed late-onset symptoms of a structural laryngeal abnormality.

Results of surgery and doxorubicin chemotherapy in dogs with osteosarcoma

Thirty-five dogs with appendicular osteosarcoma were treated with 5 doses of doxorubicin (30 mg/m2 of body surface, i.v., every 2 weeks). Surgical excision of the primary tumor was performed 13 days after the second (n = 18) or third (n = 17) treatment, and the subsequent doxorubicin treatment was given the day following surgery. Resected tumors were evaluated histologically to determine response to preoperative chemotherapy (ie, percentage of the tumor that was necrotic). Survival data for the 35 dogs were compared with survival data for a historical control group, consisting of 162 dogs with appendicular osteosarcoma treated by amputation alone. Administration of doxorubicin at 2 week intervals was well tolerated. Three dogs were alive and did not have evidence of disease at the time of reporting. Of the remaining 32 dogs, 3 died or were euthanatized because of cardiomyopathy presumably caused by doxorubicin; 1 died suddenly 116 weeks after initiation of treatment; and the remaining 28 were euthanatized because of problems documented to be related to distant metastases. Thirteen dogs (40.6%) were euthanatized because of pulmonary metastases, 10 dogs (31.3%) were euthanatized because of bone metastases, and 5 dogs (15.6%) were euthanatized because of metastases in other sites. The proportion of dogs euthanatized because of bone metastases was significantly (P < 0.001) higher for the study group than for the control group. Median survival time for the 35 dogs that received doxorubicin was estimated to be 52.3 weeks, and 1- and 2-year survival rates were estimated to be 50.5 and 9.7%, respectively. Survival time was significantly (P < 0.0001) longer for these dogs than for control dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Variability of Doppler microembolic signal counts in patients with prosthetic cardiac valves

BACKGROUND AND PURPOSE

The purpose of this study was the evaluation of intraobserver, interobserver, and intrasubject variability in the Doppler detection of microembolic signals in patients with mechanical prosthetic valves. Simultaneously, the feasibility of automated embolus detection by means of a neuronal network was investigated.

METHODS

From 25 patients with mechanical prosthetic heart valves, single transcranial Doppler monitoring sessions of 30 minutes' duration were recorded on videotape, randomized, and subsequently analyzed by eight independent trained observers from three centers. Three observers evaluated these tapes on three separate occasions, blinded to their previous results. An additional 48 patients with prosthetic heart valves were repetitively monitored with transcranial Doppler ultrasonography for 30 minutes three times within 1 year to examine the long-term variability in the occurrence of microembolic signals. Finally, in an effort to assess the short-term intrasubject variability, 20 patients were examined for 90 minutes, and the results of the three 30-minute periods were compared. The interobserver, intraobserver, and intrasubject (both short- and long-term) variability was evaluated.

RESULTS

No significant differences in microembolic signal counts were found among the different observers, between the human observers and the neuronal network, or among the three separate evaluations of stored data by the same observer. The same was true for repeat examinations of the same patient (P > .05, Student's two-paired t test and Friedman's test).

CONCLUSIONS

The detection of microembolic signals in patients with prosthetic cardiac valves is a reproducible technique. The reliable performance of the neuronal network argues for a broader use of this device. The intrasubject stability of the microembolic rate over 1 year supports the concept that the underlying emboligenic process is associated with intrinsic mechanical properties of the valve implant and not due to a thromboembolic process in the heart.

Variability of Doppler Microembolic Signal Counts in Patients With Prosthetic Cardiac Valves

Background and Purpose The purpose of this study was the evaluation of intraobserver, interobserver, and intrasubject variability in the Doppler detection of microembolic signals in patients with mechanical prosthetic valves. Simultaneously, the feasibility of automated embolus detection by means of a neuronal network was investigated.

Methods From 25 patients with mechanical prosthetic heart valves, single transcranial Doppler monitoring sessions of 30 minutes’ duration were recorded on videotape, randomized, and subsequently analyzed by eight independent trained observers from three centers. Three observers evaluated these tapes on three separate occasions, blinded to their previous results. An additional 48 patients with prosthetic heart valves were repetitively monitored with transcranial Doppler ultrasonography for 30 minutes three times within 1 year to examine the long-term variability in the occurrence of microembolic signals. Finally, in an effort to assess the short-term intrasubject variability, 20 patients were examined for 90 minutes, and the results of the three 30-minute periods were compared. The interobserver, intraobserver, and intrasubject (both short- and long-term) variability was evaluated.

Results No significant differences in microembolic signal counts were found among the different observers, between the human observers and the neuronal network, or among the three separate evaluations of stored data by the same observer. The same was true for repeat examinations of the same patient ( P >.05, Student’s two-paired t test and Friedman’s test).

Conclusions The detection of microembolic signals in patients with prosthetic cardiac valves is a reproducible technique. The reliable performance of the neuronal network argues for a broader use of this device. The intrasubject stability of the microembolic rate over 1 year supports the concept that the underlying emboligenic process is associated with intrinsic mechanical properties of the valve implant and not due to a thromboembolic process in the heart.

Is there a hemispheric side preference of cardiac valvular emboli?

Microaggregates arising from prosthetic cardiac valves offer the opportunity to examine the distribution of valvular emboli in the human cerebral circulation. Forty-four patients with different kinds of prosthetic valves underwent bilateral transcranial Doppler monitoring for 1 h to detect high intensity Doppler signals representing microemboli. Comparing the total number of embolic signals in both middle cerebral arteries (N = 1066), a side preference was not statistically evident. However, clear side preferences were obvious in some individuals. The lack of statistical evidence for hemispherical preferences of cardiac microembolism in general does not exclude selective streaming in individuals, explaining the clinical observation of lodging preferences of recurrent cardiac embolism. A cardiac source of microembolism may mimic disease activity of extracranial carotid artery stenosis and bias the localization of embolic source.

Chylous ascites in cats: nine cases (1978-1993)

Medical records of 9 cats with chylous ascites that underwent exploratory celiotomy were reviewed. In 7 cats, chylous ascites was associated with intra-abdominal neoplasia: 4 cats had an unresectable tumor (hemangiosarcoma, 3 cats; paraganglioma, 1 cat) within the mesenteric root; 2 had malignant lymphoma of the small intestine and mesenteric lymph nodes; and 1 had lymphangiosarcoma of the abdominal wall. In 2 cats, chylous ascites was associated with nonneoplastic diseases: 1 cat had severe biliary cirrhosis and an extrahepatic portosystemic shunt; the other had steatitis caused by vitamin E deficiency. Three cats were euthanatized or died at the time of surgery, and 5 cats were euthanatized within 3 months of surgery. One cat with malignant lymphoma responded well to chemotherapy and lived for 14 months after surgery.

Third- and fourth-generation implantable cardioverter defibrillators: current status and future development

Implantable cardioverter defibrillator (ICD) therapy has become the mainstay of therapy for patients with a history of sudden cardiac death or life-threatening ventricular arrhythmias. The current generation of ICDs used for secondary prevention combines features for tachycardia reversion with demand ventricular pacing, antitachycardia pacing, programmable shock therapy, and tachycardia events memory. Although demand pacing and defibrillation is indicated for primary prevention usage of ICDs, the application of antitachycardia pacing modes is more controversial. High energy cardioversion and defibrillation shocks remaining the mainstay of sudden death prevention will be redefined as more effective defibrillation shock modes and lead systems are developed. Fourth-generation ICD systems accomplished a significant reduction of device size and almost universal success using an endocardial lead configuration and pectoral implant. A variety of new directions of ICD therapy in clinical practice such as primary prevention applications and the adjunctive role of antiarrhythmic drug therapy are currently being examined in clinical trials. The concepts underlying initiation of tachyarrhythmias are being studied to develop new approaches to tachycardia prevention. These include rate support, subthreshold stimulation, and multiple site pacing. The current developments of ICD therapy promise continued growth of this technology.

Characterization of a psychrotrophic Clostridium causing spoilage in vacuum-packed cooked pork: description of Clostridium algidicarnis sp. nov

A Clostridium species causing spoilage of vacuum-packed refrigerated pork was isolated and characterized. The unknown organism differed phenotypically from other clostridial species usually associated with spoilage. Phylogenetic analyses based on 16S rRNA gene sequencing demonstrated that the psychrotroph represents a distinct line of descent within the genus Clostridium. It is proposed that the organism be classified as a new species of the genus Clostridium, Clostridium algidicarnis.

Evaluation of butorphanol and cyproheptadine for prevention of cisplatin-induced vomiting in dogs

Cisplatin was administered at a dosage of 50 mg/m2 of body surface to 69 dogs with various neoplasms. Dogs were randomly assigned to receive antiemetics according to 1 of the following 5 protocols: group 1, no antiemetic (control, n = 45 treatments); group 2, 0.4 mg of butorphanol/kg of body weight (n = 52 treatments); group 3, 0.2 mg of butorphanol/kg (n = 19 treatments); group 4, 2 mg of cyproheptadine/kg (n = 48 treatments); and group 5, 1 mg of cyproheptadine/kg (n = 10 treatments). Randomization was performed for each dog prior to each treatment. Butorphanol was administered IM immediately after completion of cisplatin infusion. Cyproheptadine was given orally 12 to 14 hours before and again immediately before cisplatin administration. The proportion of dogs that vomited in group 1 was 40 of 45 (89%). Butorphanol at a dosage of 0.4 mg/kg proved highly effective in preventing cisplatin-induced vomiting, reducing the proportion of dogs that vomited (10/52, 19%) compared with the control group.

Surgical treatment of thymoma in cats: 12 cases (1987-1992)

Twelve cats with thymoma were treated by surgical excision of the tumor alone. None of the cats received radiotherapy or chemotherapy. Two cats died or were euthanatized during the immediate postoperative period: 1 because of postsurgical hemorrhage, and the other because of an associated fungal pleuritis. None of the remaining 10 cats developed evidence of local tumor recurrence or metastases. Six of the cats were alive after follow-up periods ranging from 6 to 36 months (mean, 21 months; median, 21 months). Three cats were euthanatized 18 months, 32 months, and 45 months following surgery for unrelated problems, and 1 cat died as a result of trauma sustained 62 months postoperatively. Myasthenia gravis developed postoperatively in 2 of the cats.

Homozygous Tangier disease and cardiovascular disease

Decreased levels of plasma high density lipoprotein (HDL) cholesterol have been associated with premature cardiovascular disease (CVD). Tangier disease is an autosomal co-dominant disorder in which homozygotes have a marked deficiency of HDL cholesterol and apolipoprotein (apo) A-I levels (both < 10 mg/dl), decreased low density lipoprotein (LDL) cholesterol levels (about 40% of normal), and mild hypertriglyceridemia. Homozygotes develop cholesterol ester deposition in tonsils (orange tonsils), liver, spleen, gastrointestinal tract, lymph nodes, bone marrow, and Schwann cells. Our purpose was to assess the prevalence of CVD in Tangier disease. We reviewed published clinical information on 51 cases of homozygous Tangier disease, report 3 new cases and provide autopsy information on 3 cases. Mean (+/- S.D.) lipid values of all cases were as follows: total cholesterol 68 +/- 30 mg/dl (32% of normal), triglycerides 201 +/- 118 mg/dl (162% of normal), HDL cholesterol 3 +/- 3 mg/dl (6% of normal) and LDL cholesterol 50 +/- 38 mg/dl (37% of normal). The most common clinical finding in these subjects (n = 54) was peripheral neuropathy which was observed in 54% of cases versus < 1% of control subjects (n = 3130). CVD was observed in 20% of Tangier patients versus 5% of controls (P < 0.05), and in those that were between 35 and 65 years of age, 44% (11 of 25) had evidence of CVD (either angina, myocardial infarction or stroke) versus 6.5% in 1533 male controls and 3.2% in 1597 female controls in this age group (P < 0.01). In 9 patients who died, 2 died prior to age 20 of probable infectious diseases, 3 of documented coronary heart disease at ages 48, 64, and 72, 2 of stroke at ages 56 and 69, one of valvular heart disease, and 1 of cancer. In three autopsy cases, significant diffuse atherosclerosis was observed in one at age 64, moderate atherosclerosis and cerebral infarction in another at age 56, but no atherosclerosis was noted in the third case who died of lymphoma at age 62. In one patient with established coronary heart disease, none of the lipid lowering agents used (niacin, gemfibrozil, estrogen or lovastatin) raised HDL cholesterol levels above 5 mg/dl. However, these agents did have significant effects on lowering triglyceride and LDL cholesterol levels. Our data indicate that there may be heterogeneity in these patients with regard to CVD risk, that peripheral neuropathy is a major problem in many patients, and that CVD is a significant clinical problem in middle aged and elderly Tangier homozygotes.(ABSTRACT TRUNCATED AT 400 WORDS)

Prognosis after surgical excision of cerebral meningiomas in cats: 17 cases (1986-1992)

Long-term follow-up information was obtained for 17 cats with cerebral meningiomas treated by surgical excision. Three cats died or were euthanatized in the immediate postoperative period: 2 cats, because of brain herniation and 1 cat, because of acute renal failure. In the remaining 14 cats, most clinical signs resolved within 1 week of surgery. Three cats (21.4%) had confirmed or presumed local tumor recurrence. Two of these cats developed recurrent neurologic signs, and died or were euthanatized at 3 and 9 months, respectively, after surgery. One cat was euthanatized for an unrelated problem 72 months after surgery, and on postmortem examination, had a recurrent meningioma at the surgery site. The remaining 11 cats (78.6%) did not develop evidence of local tumor recurrence within follow-up periods ranging from 18 to 47 months (median, 27 months).

Effect of protamine sulfate on the permeability properties of the mammalian urinary bladder

Protamine sulfate (PS, an arginine-rich protein of molecular weight 5,000) has been reported to affect the ionic permeability of gallbladder epithelium, the permeability of cultured epithelial cells to mannitol, and the permeability of endothelial cell layers to albumin. Although the effect of PS has been widely investigated, the mechanism of its action on membrane permeability is presently unknown. The effect of PS on the rabbit urinary bladder epithelium was studied using both transepithelial and intracellular microelectrode techniques in conjunction with equivalent circuit analysis. The addition of 100 micrograms/ml of PS to a NaCl-containing mucosal solution caused (over a 40-min period) a large increase in the transepithelial conductance (Gt) and a transient hyperpolarization of the transepithelial voltage (Vt) followed by a depolarization of Vt. This secondary depolarization of Vt was not present if the mucosal solution was a KCl or a K-gluconate Ringer. The PS-induced increase in Gt was due to an increase in the apical membrane permeability to both cations (Na+ or K+) and anions (Cl- or gluconate). Further studies revealed the following features of the PS-induced conductance. (i) Trypsin inhibits the PS effect; however, this was due to PS hydrolysis by trypsin and not a membrane effect. (ii) Mucosal PS partially inhibited the PS-induced apical membrane conductance. (iii) The ability of PS to increase the membrane conductance was enhanced when the apical membrane potential was cell interior negative. (iv) The rate of conductance change (at any given membrane potential) was a saturating function of the PS concentration. This finding suggests that PS must interact with a membrane binding site before it can induce a change in the membrane conductance. (v) Lanthanum inhibited the PS-dependent conductance by two different mechanisms. One was as a reversible blocker of the PS-induced conductance. The other was by inhibiting the interaction between PS and a membrane binding site. A kinetic model is developed to describe the steps involved in the increase in membrane conductance.

Coronary risk factors in middle-aged men as related to smoking, coffee intake and physical activity

The relationship between lifestyle and coronary risk factors in blood was investigated in 165 middle-aged men. Plasma fibrinogen, serum triacylglycerols (TG), and apolipoprotein B (apo B) were higher, and high density lipoprotein cholesterol (HDLc) lower in smokers (n = 69) than in non-smokers (n = 96). By linear regression analysis there was a significant positive association between degree of smoking and either total cholesterol (TC), apo B, or plasma fibrinogen, whereas smoking was inversely related to HDLc. Smoking and coffee intake were positively correlated with an atherogenic index, reflecting the balance between low and high density lipoproteins. Sedentary men (n = 59) had higher mean TC, apo B, and atherogenic index than physically active men (n = 104). Smokers used salt more often than non-smokers. Physically active men used vegetables more often than sedentary men. Combining several habits into a "bad habit" score gave a high level of significance for its association with TC, apo B, and the atherogenic index. The results indicate that lifestyle may influence several blood factors involved in atherosclerosis development.

Treatment by digital amputation of subungual squamous cell carcinoma in dogs: 21 cases (1987-1988)

Malignant digital tumors were diagnosed in 62 dogs during a 1-year period. Twenty-one (33.9%) of the dogs had subungual squamous cell carcinoma. Each of these dogs had involvement of single digits. Sixteen (76.2%) of the dogs with squamous cell carcinoma were large-breed dogs, and 15 (71.4%) had predominantly black coats. Labrador Retrievers (n = 5, 23.8%) and Standard Poodles (n = 3, 14.3%) were the most commonly represented purebreeds. None of the dogs had evidence of metastases prior to treatment. All 21 tumors were treated by amputation of the involved digit. Histologic evidence of neoplastic bone invasion was found in 15 of the 21 amputated digits (71.4%). Local tumor recurrences were not observed. Only 1 dog developed documented metastatic disease; this dog was euthanatized because of pulmonary metastases 5 months after surgery. At the time of this report, 9 dogs (42.9%) were alive with no evidence of disease (median, 26 months after surgery), and 11 dogs (52.4%) had died or were euthanatized (median, 20 months after surgery). The cause of death in 7 dogs was known to be unrelated to squamous cell carcinoma, and the cause of death in 4 dogs was unknown. The 1-year and 2-year survival rates were 76.2% and 42.9%, respectively.

Treatment of dogs with osteosarcoma by administration of cisplatin after amputation or limb-sparing surgery: 22 cases (1987-1990)

Twenty-two dogs with appendicular osteosarcoma were treated by amputation (n = 17) or limb-sparing surgery (n = 5). All dogs were given cisplatin (60 mg/m2 of body surface, IV) at 3-week intervals, beginning 1 week after surgery. Number of cisplatin treatments ranged from 1 to 6. Survival data for the 22 dogs were compared with survival data from a historical control group consisting of 162 dogs with appendicular osteosarcoma treated by amputation alone. Median survival time for the 22 dogs given cisplatin was estimated to be 46.4 weeks, and 1- and 2-year survival rates were estimated to be 45.5 and 20.9%, respectively. Survival time was significantly (P less than 0.0001) longer for treated dogs than for control dogs. Statistically significant relation was not found between survival time and number of cisplatin treatments. Three dogs were alive with no evidence of disease at the time of reporting. Of the remaining 19 dogs, 14 (73.4%) were euthanatized for problems documented to be related to metastases. Nine (47.4%) dogs were euthanatized because of bone metastases, and 5 (26.3%) were euthanatized because of pulmonary metastases. The proportion of dogs euthanatized because of bone metastases was significantly (P less than 0.0001) higher for treated than for control dogs. Median survival times for dogs developing bone and lung metastases were estimated to be 51.2 weeks and 21.2 weeks, respectively; however, this difference was not statistically significant. One local tumor recurrence was observed among dogs that had limb-sparing surgery. Significant difference in survival time was not observed between dogs that had limb-sparing surgery and dogs that underwent amputation.

Prognosis for dogs with appendicular osteosarcoma treated by amputation alone: 162 cases (1978-1988)

Long-term follow-up information pertaining to 162 dogs with appendicular osteosarcoma treated by amputation alone was collected from 17 veterinary institutions. The majority (72.5%) of dogs died or were euthanatized because of problems documented to be related to metastases. The first clinically apparent sites of metastasis were the lungs (60.8% of total), the skeleton (5.2%), or both (4.6%). A Kaplan-Meier survivorship distribution was plotted on the basis of available survival time data in all 162 dogs. The mean and median survival times were estimated to be 19.8 and 19.2 weeks, respectively, and the 1- and 2-year survival rates were estimated to be 11.5 and 2.0% respectively. Statistically significant relationships were not found between survival time and reporting institution, gender, site of primary tumor, whether the primary tumor was proximally or distally located, whether the primary tumor was located in the forelimb or hind limb, whether presurgical biopsy was performed, and whether death was tumor related. A significant (P less than 0.01) quadratic relationship was found between age and survival time. Survival time was longest in dogs 7 to 10 years old and was shorter in older and younger dogs.

Effects of four preparations of 0.05% chlorhexidine diacetate on wound healing in dogs

Four chlorhexidine diacetate (CHD) antiseptic wound lavage preparations were evaluated in vivo to determine their effects on second intention wound healing in the dog in vitro to determine their relative antibacterial activity against Staphylococcus intermedius. Chlorhexidine was diluted to 0.05% in sterile water, 0.9% sodium chloride, lactated Ringers solution (LRS), and LRS that was allowed to form a precipitate with CHD. Control solutions included sterile water and LRS. There were no significant differences in wound contraction or epithelialization. All 0.05% CHD preparations provided 100% bacterial kill.

Determinants of a genotoxic effect of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in human diploid fibroblasts

The induction of micronuclei was studied in human diploid fibroblasts incubated in the presence of the tobacco-specific nitrosamine NNK. We used four fibroblast strains having a high capacity of O6-alkylguanine DNA alkyltransferase (13.0-23.3 pmol O6-methylguanine repaired per 8 x 10(6) cells) and four strains that showed no detectable repair capacity. Incubation with NNK doubled the frequency of micronuclei in repair-deficient cells but failed to evoke any effect in the proficient cell strains. Control experiments were performed with the direct methylating agent MNNG and in the presence of inhibitors of either metabolic activation or alkyltransferase. The results showed that the genotoxicity of NNK is dependent on the relationship between its metabolic activation and the constitutive DNA repair. This supports earlier findings that low constitutive levels of O6-alkylguanine DNA alkyltransferase may increase susceptibility to lung cancer after exposure to DNA methylating agents.

Modifying the request behaviour of clinicians

AIM

To evaluate whether the feedback of laboratory use and cost data to clinicians modifies their request behaviour.

METHODS

Over two years the effect of monthly feedback of clinical chemistry test use and revenue expenditure to three consultant physicians on their clinical chemistry and haematology requesting patterns was evaluated. Two physicians who received no information served as controls.

RESULTS

Feedback over one year led to an immediate and sustained decrease of 15%, 27%, and 21% in clinical chemistry requests (p less than 0.01), tests (p less than 0.001), and revenue expenditure (p less than 0.001), respectively, and a 10% reduction in haematology tests (p less than 0.05) per outpatient visit. These changes persisted in the six months after the feedback was stopped.

CONCLUSIONS

These results suggest that feedback of laboratory data to clinicians modifies their request behaviour and that supplying clinicians with information on what they do can influence the way they make decisions.

Spinal lymphoma in cats: 21 cases (1976-1989)

Medical records of 21 cats with spinal lymphoma were reviewed. All cats were evaluated for neurologic deficits, although 85% of cats necropsied had multicentric disease. Eighty-one percent of cats had hind limb paresis. Results of FeLV tests were positive in 84.2% (16/19) of the cats, and 68.7% (11/16) of the cats had leukemic bone marrow. Spinal lymphoma was confirmed by necropsy in 13 cats, by examination of a biopsy specimen in 1 cat, and by examination of cells aspirated from an epidural lesion in 2 cats. In the remaining 5 cats, a presumptive diagnosis was made on the basis of neurologic examination findings, positive FeLV test results, and leukemic bone marrow. Nine cats were treated with chemotherapy alone. The complete remission rate was 50% in 6 cats given cyclophosphamide, vincristine, and prednisone. The median duration of complete remission was 14 weeks. Complete remissions were not observed in 3 cats given only corticosteroids. A single cat treated by laminectomy and postoperative chemotherapy had a prolonged remission (62 weeks). At necropsy, lymphoma of the CNS was limited to the vertebral canal in 10 of 13 cats; 2 cats had malignant tissue in the brain and vertebral canal, and in the remaining cat, the tumor extended into the brachial plexus. Most tumors extended over multiple vertebral bodies, and 4 cats had more than 1 level of spinal cord involvement. The lymphoma was high-grade lymphoblastic or immunoblastic type in all cats.

In vitro assay of nuclear uptake of doxorubicin hydrochloride in osteosarcoma cells of dogs

A rapid, simple chemosensitivity assay, assessing tumor cell nuclear uptake of doxorubicin hydrochloride, was evaluated in 16 dogs with appendicular osteosarcoma. Doxorubicin was administered to dogs in 5 biweekly treatments, and surgical resection was performed after the second or third treatment. The chemosensitivity assay was performed on biopsy specimens from all dogs before chemotherapy. It was repeated on tissue from resected tumors, and tumors were evaluated histologically to determine the degree of necrosis resulting from chemotherapy. Disease-free and total survival time correlated significantly (P less than 0.05 in both cases) with the degree of postchemotherapy necrosis of the primary tumors. Significant correlation was not apparent between the percentage of tumor cells with nuclear uptake of doxorubicin (in either biopsy or resection samples) and disease-free or total survival time. The percentage of cells with nuclear uptake of doxorubicin in surgically resected tumors correlated significantly (P less than 0.05) with percentage of necrosis.

HeLa-LAV, an epithelial cell line stably infected with HIV-1

An HeLa-LAV cell line was established by infecting and subcloning previously described CD4-expressing HeLa cells with HIV-1. Cells of this line stably synthesize all major HIV proteins, release infectious particles of HIV-1, but do not die even after long term culture. More than 90% of the cells express the envelope protein gp120 on the surface. The cells can be easily and efficiently labeled with 51chromium, and exhibit a low spontaneous release. Because they are susceptible to killing by allogeneic cytotoxic T cells (CTL) when targeted to gp120, they ought to be a useful source of target cells in any kind of HIV-specific killing assays. The cells may also help studies on HIV replication in non-lymphatic/non-monocytic cells. The HeLa-LAV cell line will be freely available from the AIDS Research and Reference Reagent Program.

Bispecific antibodies that mediate killing of cells infected with human immunodeficiency virus of any strain

Although AIDS patients lose human immunodeficiency virus (HIV)-specific cytotoxic T cells, their remaining CD8-positive T lymphocytes maintain cytotoxic function. To exploit this fact we have constructed bispecific antibodies that direct cytotoxic T lymphocytes of any specificity to cells that express gp120 of HIV. These bispecific antibodies comprise one heavy/light chain pair from an antibody to CD3, linked to a heavy chain whose variable region has been replaced with sequences from CD4 plus a second light chain. CD3 is part of the antigen receptor on T cells and is responsible for signal transduction. In the presence of these bispecific antibodies, T cells of irrelevant specificity effectively lyse HIV-infected cells in vitro.

Treatment of posttraumatic carinal stenosis by balloon dilation during thoracotomy in a cat

A cat with posttraumatic stenosis of the terminal part of the thoracic portion of the trachea and carina was successfully treated by balloon dilation of the stenosis during thoracotomy. Thoracotomy was performed at the right fifth intercostal space, and the stenosis was dilated, using a balloon-tipped catheter passed through an endotracheal tube. A 6-week course of orally administered corticosteroids was instituted after surgery. Balloon dilation during thoracotomy is a technically simple procedure for treatment of stenosis of the thoracic portion of the trachea.

Craniolateral approach to the humerus with transection of the brachialis muscle

Six fractures of the midshaft or distal third of the humerus were repaired through a modified craniolateral approach in which the brachialis muscle was transected rather than retracted to improve exposure of the bone. The approach simplified fracture reduction and fixation. Normal fracture healing and excellent limb function resulted in each case.

Feedback of laboratory usage and cost data to clinicians: does it alter requesting behaviour?

In a 1 year prospective study we evaluated the effect of feedback of laboratory data on the requesting behaviour of physicians in general medicine. Data on within-hours and out-of-hours clinical chemistry laboratory usage and revenue expenditure for inpatients and outpatients, expressed in terms of clinical workload, were supplied monthly to a group of three consultant physicians in general medicine. With these data the physician could monitor his performance over a period of time and compare it with that of his peers. Two consultants in general medicine who received no information served as controls. Over a period of 6 months, there was a 25%, 13% and 18% decrease in tests (P less than 0.01), requests (P less than 0.05) and revenue expenditure (P less than 0.01) per outpatient visit, respectively, in the intervention group of physicians following the introduction of feedback when compared to their baseline period and to the control group. The decrease (P less than 0.01) was in the commonly requested and 'seemingly cheap' tests. There was no significant change in laboratory use and expenditure on inpatients. The feedback of laboratory data was acceptable to the physicians, raised their awareness of laboratory usage and costs and decreased laboratory workload and expenditure.

Giant cell tumor of the accessory carpal bone in a dog

A 4-year-old Springer Spaniel was referred because of a 6-week history of progressive left forelimb lameness. A marked pain response was elicited by palpation over the left accessory carpal bone. Radiography revealed a lytic, markedly expansile lesion of the accessory carpal bone. The bone was excised, and pancarpal arthrodesis was performed. Histologic examination of the excised bone revealed giant cell tumor. At 14 months after surgery, the dog was using the limb normally. Radiography of the carpus revealed satisfactory progression of the arthrodesis, and thoracic radiographs were negative for metastases.

Preoperative measurement of canine primary bone tumors, using radiography and bone scintigraphy

Specimens of 20 canine primary bone tumors (18 osteosarcoma, 2 fibrosarcoma) were examined to compare the maximal axial length of gross tumor with the length of the lesion seen on preoperative radiographs and 99mTc methylene diphosphonate bone scintigraphic images. Radiographs defined the length of the tumor to within +/- 10% of the gross measurement for 6 (30%), underestimated it for 12 (60%), and overestimated it for 2 (10%) specimens. Bone scintigraphy defined tumor length within +/- 10% for 8 (40%), underestimated it for 1 (5%), and overestimated it for the remaining 11 (55%) specimens. Use of radiographic evaluation alone could result in underestimation of the diaphyseal extent of a primary bone tumor, with risk of incomplete resection. Bone scan images tend to overestimate tumor length and, therefore, may provide safer resection guidelines.

Bone scintigraphy in the initial evaluation of dogs with primary bone tumors

Bone scintigraphy was performed as part of an initial diagnostic evaluation of 70 dogs admitted with primary bone tumors during a 2-year period. Tumors involved major long bones of the appendicular skeleton and included 62 osteosarcomas, 6 fibrosarcomas, and 2 chondrosarcomas. All dogs were free of radiographically detectable pulmonary metastases. Bone scintigraphy was not of value in distinguishing among various types of primary tumors. One dog with an ulnar chondrosarcoma had a scintigraphically detectable occult osseous metastasis or synchronous primary tumor, and 1 dog with osteosarcoma had a scintigraphically detectable lymph node metastasis. Pulmonary metastases were not detected scintigraphically. Of the 70 dogs, 44.3% had areas of increased isotope uptake associated with nonneoplastic disease processes.

Immunoglobulin lambda gene rearrangement can precede kappa gene rearrangement

Immunoglobulin genes are generated during differentiation of B lymphocytes by joining gene segments. A mouse pre-B cell contains a functional immunoglobulin heavy-chain gene, but no light-chain gene. Although there is only one heavy-chain locus, there are two light-chain loci: kappa and lambda. It has been reported that kappa loci in the germ-line configuration are never (in man) or very rarely (in the mouse) present in cells with functionally rearranged lambda-chain genes. Two explanations have been proposed to explain this: (a) the ordered rearrangement theory, which postulates that light-chain gene rearrangement in the pre-B cell is first attempted at the kappa locus, and that only upon failure to produce a functional kappa chain is there an attempt to rearrange the lambda locus; and (b) the stochastic theory, which postulates that rearrangement at the lambda locus proceeds at a rate that is intrinsically much slower than that at the kappa locus. We show here that lambda-chain genes are generated whether or not the kappa locus has lost its germ-line arrangement, a result that is compatible only with the stochastic theory.