A longitudinal study of CMT1A using Rasch analysis based CMT neuropathy and examination scores

OBJECTIVE

To evaluate the sensitivity of Rasch analysis-based, weighted Charcot-Marie-Tooth Neuropathy and Examination Scores (CMTNS-R and CMTES-R) to clinical progression in patients with Charcot-Marie-Tooth disease type 1A (CMT1A).

METHODS

Patients with CMT1A from 18 sites of the Inherited Neuropathies Consortium were evaluated between 2009 and 2018. Weighted CMTNS and CMTES modified category responses were developed with Rasch analysis of the standard scores. Change from baseline for CMTNS-R and CMTES-R was estimated with longitudinal regression models.

RESULTS

Baseline CMTNS-R and CMTES-R scores were available for 517 and 1,177 participants, respectively. Mean ± SD age of participants with available CMTES-R scores was 41 ± 18 (range 4-87) years, and 56% were female. Follow-up CMTES-R assessments at 1, 2, and 3 years were available for 377, 321, and 244 patients. A mixed regression model showed significant change in CMTES-R score at years 2 through 6 compared to baseline (mean change from baseline 0.59 points at 2 years, p = 0.0004, n = 321). Compared to the original CMTES, the CMTES-R revealed a 55% improvement in the standardized response mean (mean change/SD change) at 2 years (0.17 vs 0.11). Change in CMTES-R at 2 years was greatest in mildly to moderately affected patients (1.48-point mean change, 95% confidence interval 0.99-1.97, p < 0.0001, for baseline CMTES-R score 0-9).

CONCLUSION

The CMTES-R demonstrates change over time in patients with CMT1A and is more sensitive than the original CMTES. The CMTES-R was most sensitive to change in patients with mild to moderate baseline disease severity and failed to capture progression in patients with severe CMT1A.

CLINICALTRIALSGOV IDENTIFIER

NCT01193075.

Variation in SIPA1L2 is correlated with phenotype modification in Charcot- Marie- Tooth disease type 1A

OBJECTIVE

Genetic modifiers in rare disease have long been suspected to contribute to the considerable variance in disease expression, including Charcot-Marie-Tooth disease type 1A (CMT1A). To address this question, the Inherited Neuropathy Consortium collected a large standardized sample of such rare CMT1A patients over a period of 8 years. CMT1A is caused in most patients by a uniformly sized 1.5 Mb duplication event involving the gene PMP22.

METHODS

We genotyped DNA samples from 971 CMT1A patients on Illumina BeadChips. Genome-wide analysis was performed in a subset of 330 of these patients, who expressed the extremes of a hallmark symptom: mild and severe foot dorsiflexion strength impairment. SIPA1L2 (signal-induced proliferation-associated 1 like 2), the top identified candidate modifier gene, was expressed in the peripheral nerve, and our functional studies identified and confirmed interacting proteins using coimmunoprecipitation analysis, mass spectrometry, and immunocytochemistry. Chromatin immunoprecipitation and in vitro siRNA experiments were used to analyze gene regulation.

RESULTS

We identified significant association of 4 single nucleotide polymorphisms (rs10910527, rs7536385, rs4649265, rs1547740) in SIPA1L2 with foot dorsiflexion strength (p < 1 × 10^-7 ). Coimmunoprecipitation and mass spectroscopy studies identified β-actin and MYH9 as SIPA1L2 binding partners. Furthermore, we show that SIPA1L2 is part of a myelination-associated coexpressed network regulated by the master transcription factor SOX10. Importantly, in vitro knockdown of SIPA1L2 in Schwannoma cells led to a significant reduction of PMP22 expression, hinting at a potential strategy for drug development.

INTERPRETATION

SIPA1L2 is a potential genetic modifier of CMT1A phenotypic expressions and offers a new pathway to therapeutic interventions. ANN NEUROL 2019;85:316-330.

Modifier Gene Candidates in Charcot-Marie-Tooth Disease Type 1A: A Case-Only Genome-Wide Association Study

BACKGROUND

Charcot-Marie-Tooth disease type 1A (CMT1A) is caused by a uniform 1.5-Mb duplication on chromosome 17p, which includes the PMP22 gene. Patients often present the classic neuropathy phenotype, but also with high clinical variability.

OBJECTIVE

We aimed to identify genetic variants that are potentially associated with specific clinical outcomes in CMT1A.

METHODS

We genotyped over 600,000 genomic markers using DNA samples from 971 CMT1A patients and performed a case-only genome-wide association study (GWAS) to identify potential genetic association in a subset of 644 individuals of European ancestry. A total of 14 clinical outcomes were analyzed in this study.

RESULTS

The analyses yielded suggestive association signals in four clinical outcomes: difficulty with eating utensils (lead SNP rs4713376, chr6 : 30773314, P = 9.91×10-7, odds ratio = 3.288), hearing loss (lead SNP rs7720606, chr5 : 126551732, P = 2.08×10-7, odds ratio = 3.439), decreased ability to feel (lead SNP rs17629990, chr4 : 171224046, P = 1.63×10-7, odds ratio = 0.336), and CMT neuropathy score (lead SNP rs12137595, chr1 : 4094068, P = 1.14×10-7, beta = 3.014).

CONCLUSIONS

While the results require validation in future genetic and functional studies, the detected association signals may point to novel genetic modifiers in CMT1A.

Carpal tunnel syndrome in inherited neuropathies: A retrospective survey

INTRODUCTION

This study evaluates carpal tunnel syndrome (CTS) symptom severity, functional status, and outcome of CTS therapies in patients with inherited neuropathies.

METHODS

Validated questionnaires were used to compare symptom severity and functional status in patients with and without a diagnosis of CTS and a diagnosis of an inherited neuropathy.

RESULTS

309 patients with inherited neuropathies participated in this study. The CTS symptom severity score (SSS) was found to be the most useful tool in assessing CTS severity in patients with inherited neuropathy. Splint therapy and surgery were associated with significant improvement in carpal tunnel symptoms as measured through the SSS.

DISCUSSION

This study provides insight into the assessment of CTS symptom severity and patient-reported outcomes to CTS therapy in individuals with inherited neuropathies. The SSS appears useful for evaluation of CTS symptoms and patient-reported outcomes following CTS interventions in individuals with inherited neuropathies. Muscle Nerve 57: 388-394, 2018.

Relationship of adiponectin and its multimers to metabolic indices in cats during weight change

Adiponectin is an important anti-inflammatory hormone secreted from adipose tissue. The high-molecular-weight form of adiponectin (HMW) closely correlates with insulin sensitivity in human beings. This study uses a novel method of size-exclusion gel chromatography combined with enzyme-linked immunosorbent assay to measure HMW feline adiponectin and determine its relationship to leptin, cholesterol, and insulin sensitivity as cats gain and lose weight. In addition, total adiponectin and its messenger RNA expression in subcutaneous adipose tissue were measured. No correlations were found between total serum adiponectin and subcutaneous adipose messenger RNA expression, fat mass, or measures of insulin sensitivity. This study demonstrates that cats have high percentages of HMW adiponectin. Although weak correlations between HMW adiponectin and fat mass were detected, additional cats are needed to determine if the correlations are significant.

CMT subtypes and disease burden in patients enrolled in the Inherited Neuropathies Consortium natural history study: a cross-sectional analysis

BACKGROUND

The international Inherited Neuropathy Consortium (INC) was created with the goal of obtaining much needed natural history data for patients with Charcot-Marie-Tooth (CMT) disease. We analysed clinical and genetic data from patients in the INC to determine the distribution of CMT subtypes and the clinical impairment associated with them.

METHODS

We analysed data from 1652 patients evaluated at 13 INC centres. The distribution of CMT subtypes and pathogenic genetic mutations were determined. The disease burden of all the mutations was assessed by the CMT Neuropathy Score (CMTNS) and CMT Examination Score (CMTES).

RESULTS

997 of the 1652 patients (60.4%) received a genetic diagnosis. The most common CMT subtypes were CMT1A/PMP22 duplication, CMT1X/GJB1 mutation, CMT2A/MFN2 mutation, CMT1B/MPZ mutation, and hereditary neuropathy with liability to pressure palsy/PMP22 deletion. These five subtypes of CMT accounted for 89.2% of all genetically confirmed mutations. Mean CMTNS for some but not all subtypes were similar to those previously reported.

CONCLUSIONS

Our findings confirm that large numbers of patients with a representative variety of CMT subtypes have been enrolled and that the frequency of achieving a molecular diagnosis and distribution of the CMT subtypes reflects those previously reported. Measures of severity are similar, though not identical, to results from smaller series. This study confirms that it is possible to assess patients in a uniform way between international centres, which is critical for the planned natural history study and future clinical trials. These data will provide a representative baseline for longitudinal studies of CMT.

CLINICAL TRIAL REGISTRATION

ID number NCT01193075.

Quality-of-life in Charcot-Marie-Tooth disease: the patient's perspective

This study determines the impact of symptoms associated with Charcot-Marie-Tooth disease on quality-of-life. Charcot-Marie-Tooth patients in the Inherited Neuropathies Consortium Rare Diseases Clinical Research Network Contact Registry were surveyed. The survey inquired about 214 symptoms and 20 themes previously identified as important to Charcot-Marie-Tooth patients through patient interviews. Symptom population impact was calculated as the prevalence multiplied by the relative importance of each symptom identified. Prevalence and symptom impact were analyzed by age, symptom duration, gender, Charcot-Marie-Tooth type, and employment status. 407 participants returned the survey, identifying foot and ankle weakness (99.7%) and impaired balance (98.6%) as the most prevalent themes. Foot and ankle weakness and limitations with mobility were the themes with the highest impact. Both symptom prevalence and impact gradually increased with age and symptom duration. Several themes were more prevalent in women with Charcot-Marie-Tooth, including activity limitations, pain, fatigue, hip-thigh weakness, and gastrointestinal issues. All of the themes, except emotional or body image issues, were more prevalent among unemployed individuals. There were minimal differences in symptom prevalence between Charcot-Marie-Tooth types. There are multiple symptoms that impact Charcot-Marie-Tooth quality-of-life in adults. These symptoms have different levels of importance, are readily recognized by patients, and represent critical areas of Charcot-Marie-Tooth health.

Effects of L-asparaginase on plasma amino acid profiles and tumor burden in cats with lymphoma

BACKGROUND

L-Asparaginase (Elspar(a)), is an Escherichia coli-derived enzyme that depletes lymphoma cells of asparagine, inhibiting protein synthesis and resulting in cell death. The single agent response rate in cats with lymphoma and impact of L-asparaginase on plasma amino acid concentrations is unknown.

HYPOTHESES

L-Asparaginase significantly reduces plasma asparagine concentrations and has demonstrable efficacy against untreated lymphoma in cats.

ANIMALS

Thirteen cats with confirmed lymphoma (LSA) of any anatomic site were given 1 dose 400 IU/kg IM) of L-asparaginase for initial LSA treatment.

METHODS

Plasma collected at 0, 2, and 7 days after L-asparaginase therapy was assayed for ammonia, asparagine, aspartic acid, glutamine, and glutamic acid concentrations. Cats were restaged 7 days later to assess tumor response.

RESULTS

Eight cats had T-cell LSA, 4 cats had B-cell LSA, and 1 cat's immunophenotype was unknown. Two complete and 2 partial responses to L-asparaginase were seen. Four cats had stable disease, and 5 cats had progressive disease. Ammonia and aspartic acid concentrations were increased from baseline at 2 and 7 days posttreatment. Asparagine concentrations were decreased from baseline at 2 days but not 7 days posttreatment. Glutamic acid concentrations were increased at day 2 compared to day 7 posttreatment but not compared to baseline. Glutamine concentrations were unchanged.

CONCLUSIONS AND CLINICAL IMPORTANCE

L-asparaginase significantly reduced asparagine concentrations within 2 days of treatment, but this effect was lost within 7 days. The apparent overall response rate of feline LSA to L-asparaginase in this study was 30%.

Influence of dirlotapide, a microsomal triglyceride transfer protein inhibitor, on the digestibility of a dry expanded diet in adult dogs

The objectives of this study were to evaluate the effects of dirlotapide, a microsomal triglyceride transfer protein inhibitor, on apparent nutrient digestibility of an expanded dry dog food, on defecation frequency and fecal consistency. Eighteen beagles were randomized to either placebo (n = 6) or dirlotapide (n = 12). Testing was divided into a 21-day adaptation phase (days -21 to -1) and a 35-day treatment (digestibility testing) phase (days 0-35). During the treatment phase, dogs were administered oral dirlotapide (0.3 mg/kg) or placebo (0.06 mL/kg) once daily. For digestibility testing, feces were collected over two periods for 7 days each starting on days -9 and 28. All dogs were fed a commercial adult dog food throughout the study. Food intake was adjusted to maintain body weight during adaptation, followed by pair-feeding placebo dogs the amount of food ingested by the dirlotapide dogs during the treatment period. Dogs in both groups had reduced food intake and lost similar amounts of body weight during treatment. Dogs receiving 0.3 mg dirlotapide/kg once daily had a small but significant (P = 0.018) decrease (6.16 +/- 2.22%, mean +/- SD) in crude fat digestibility compared with the placebo-treated food-restricted dogs, but no difference in crude protein, dry matter, or energy digestibility was observed. Fecal consistency and volume and defecation frequency were similar between groups. Dirlotapide effectively reduced appetite and energy intake without affecting nutrient digestibility, except for a minimal decrease in fat digestibility.

Primary hair growth in dogs depends on dietary selenium concentrations

Selenium (Se) plays an important role in hair growth. The objective of this study was to investigate the effect of dietary selenium concentration on hair growth in dogs. Thirty-six beagles were stratified into six groups based on age, gender and body condition score. The dogs were fed a torula yeast-based canned food for 3 weeks. Then the dogs were fed varying amounts of selenium supplied as selenomethionine for an additional 24 weeks. Analysed selenium concentrations in the experimental foods for the six groups were 0.04, 0.09, 0.12, 0.54, 1.03 and 5.04 mg/kg dry matter respectively. Body weight and food intake were not affected by the selenium treatments. Serum selenium concentration was similar initially but was significantly different at the end of the study among groups. Dietary selenium concentration below 0.12 mg/kg diet may be marginal for an adult dog. Dietary treatment had no effect on serum total thyroxine (TT(4)), free thyroxine (FT(4)), and free 3,3',5-triiodothyronine (FT(3)). There was a significant diet and time interaction (p = 0.038) for total 3,3',5 triiodothyronine (TT(3)). Hair growth was similar among groups initially but significantly reduced in dogs fed diets containing 0.04, 0.09 or 5.04 mg Se/kg when compared with 0.12, 0.54 and 1.03 mg Se/kg at week 11 (p < 0.05) and week 22 (p = 0.061). These results demonstrated that both low and high selenium diets reduce hair growth in adult dogs.

Association between dietary factors and calcium oxalate and magnesium ammonium phosphate urolithiasis in cats

OBJECTIVE

To identify dietary factors associated with the increase in occurrence of calcium oxalate (CaOx) uroliths and the decrease in occurrence of magnesium ammonium phosphate (MAP) uroliths in cats.

DESIGN

Case-control study.

ANIMALS

173 cats with CaOx uroliths, 290 cats with MAP uroliths, and 827 cats without any urinary tract diseases.

PROCEDURE

Univariate and multivariate logistic regression were performed.

RESULTS

Cats fed diets low in sodium or potassium or formulated to maximize urine acidity had an increased risk of developing CaOx uroliths but a decreased risk of developing MAP uroliths. Additionally, compared with the lowest contents, diets with the highest moisture or protein contents and with moderate magnesium, phosphorus, or calcium contents were associated with decreased risk of CaOx urolith formation. In contrast, diets with moderate fat or carbohydrate contents were associated with increased risk of CaOx urolith formation. Diets with the highest magnesium, phosphorus, calcium, chloride, or fiber contents and moderate protein content were associated with increased risk of MAP urolith formation. On the other hand, diets with the highest fat content were associated with decreased risk of MAP urolith formation.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that diets formulated to contain higher protein, sodium, potassium, moisture, calcium, phosphorus, and magnesium contents and with decreased urine acidifying potential may minimize formation of CaOx uroliths in cats. Diets formulated to contain higher fat content and lower protein and potassium contents and with increased urine acidifying potential may minimize formation of MAP uroliths.

Oral chromium picolinate and control of glycemia in insulin-treated diabetic dogs

Chromium is an essential dietary trace mineral involved in carbohydrate and lipid metabolism. Chromium is required for cellular uptake of glucose, and chromium deficiency causes insulin resistance. Chromium supplementation may improve insulin sensitivity and has been used as adjunct treatment of diabetes mellitus in humans. In this study, 13 dogs with naturally acquired diabetes mellitus were treated with insulin for 3 months, then with insulin and chromium picolinate for 3 months. Dogs weighing <15 kg (33 lb: n = 9) were administered 200 microg of chromium picolinate PO once daily for I month, then 200 microg of chromium picolinate twice daily for 2 months. Dogs weighing >15 kg (n = 4) received 200 microg of chromium picolinate once daily for 2 weeks, then 200 microg twice daily for 2 weeks, then 400 microg twice daily for 2 months. Type of insulin, frequency of insulin administration, and diet were kept constant, and insulin dosage was adjusted, as needed, to maintain optimal control of glycemia. Mean body weight, daily insulin dosage, daily caloric intake, 10-hour mean blood glucose concentration, blood glycated hemoglobin concentration, and serum fructosamine concentration were not markedly different when dogs were treated with insulin and chromium picolinate, compared with insulin alone. Adverse effects were not identified with chromium picolinate administration. Results of this study suggest that, at a dosage range of 20-60 microg/kg/d, chromium picolinate caused no beneficial or harmful effects in insulin-treated diabetic dogs.

Effects of hydrochlorothiazide and diet in dogs with calcium oxalate urolithiasis

OBJECTIVE

To determine whether hydrochlorothiazide (HCTZ) reduces urinary calcium excretion in dogs with calcium oxalate urolithiasis.

DESIGN

Original study.

ANIMALS

8 dogs with calcium oxalate urolithiasis.

PROCEDURE

4 treatment protocols were evaluated in each dog (a low calcium, low protein diet designed to prevent calcium oxalate urolith formation with and without administration of HCTZ [2 mg/kg (0.9 mg/lb) of body weight, PO, q 12 h] and a maintenance diet with higher quantities of protein and calcium with and without administration of HCTZ). At the end of each 2-week treatment period, 24-hour urine samples were collected. Blood samples were collected during the midpoint of each urine collection period. Analysis of variance was performed to evaluate the effects of HCTZ and diet on urine and serum analytes.

RESULTS

Hydrochlorothiazide significantly decreased urine calcium and potassium concentration and excretion. Hydrochlorothiazide also significantly decreased serum potassium concentration. Compared with the maintenance diet, the urolith prevention diet significantly decreased urine calcium and oxalic acid concentration and excretion. Dogs consuming the urolith prevention diet had significantly lower serum concentrations of albumin and urea nitrogen.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of HCTZ decreased urine calcium excretion in dogs with a history of calcium oxalate urolith formation. The greatest reduction in urine calcium concentration and excretion was achieved when dogs received HCTZ and the urolith prevention diet. Results of this study suggest that the hypocalciuric effect of HCTZ will minimize recurrence of calcium oxalate urolith formation in dogs; however, long-term controlled clinical trials are needed to confirm the safety and effectiveness of HCTZ.

New concepts in pediatric nutrition

The ultimate goal of feeding puppies and kittens is to ensure a healthy adult. The specific objectives, however, are to optimize growth, minimize risk factors for disease, and achieve optimal health and longevity. Minimum nutrient requirements are easiest to determine in growing animals using growth rates as the nutritional marker. These levels ensure a minimum level of good health in most animals. Nevertheless, the optimal nutrient levels for growth may not represent the optimal levels for other physiologic functions (e.g., immune function, disease prevention, behavior). Nutritional requirements for growing animals are being redefined using physiologic parameters other than growth rate. The most common causes of malnutrition in the neonate seem to be protein-energy deficiency or overnutrition in the perinatal period. Single micronutrient abnormalities are relatively uncommon. Nevertheless, the nutritional status during neonatal development is known to affect genetic expression and to have a lifelong impact. It is thus important to tailor the nutritional plan to the individual at each life stage and to remember that pediatric nutrition should start before conception.

Binding of human immunodeficiency virus type 1 nucleocapsid protein to psi-RNA-SL3

The interaction of the nucleocapsid protein NCp7, from the pNL4-3 isolate of HIV-1, with psi-RNA-SL3, with the sequence 5'-GGACUAGCGGAGGCUAGUCC, was studied using non-denaturing gel electrophoresis. Two kinds of experiments were performed, using buffered solutions of radiolabeled RNA and unlabeled protein. In the 'dilution' experiments, the total RNA concentration, RT, was varied for a series of solutions, but kept equal to the total protein concentration, PT, In the 'titration' experiments, solutions having RT constant but with varying PT were analyzed. The solutions were electrophoresed and the autoradiographic spot intensities, proportional to the amounts of the different species present, were measured. The intensities were fit to a number of equilibrium models, differing in species stoichiometries, by finding the best values of the binding constants. It was shown that NCp7 protein and SL3 RNA combine to form at least two complexes. When PT is below approximately 10 microM, a complex that contains two RNAs and one protein forms. Increasing PT to approximately 100 microM causes the 2:1 complex to oligomerize, forming a species having eight RNAs and four proteins. For the dilution experiments, run at 5 degrees C at an ionic strength of 31 mM, we found K1 for the 2:1 complex is approximately 10(11) M(-2) and K2 for the 8:4 complex is approximately 10(16) M(-3). The titration experiments returned K1 approximately 10(7) M(-2) (poorly determined) and K2 approximately 10(19) M(-3). The analysis was complicated by the loss of RNA at higher protein concentrations, due to formation of an insoluble species containing both RNA and protein, which does not enter the gel. Correcting for this changes the calculated values of equilibrium constants, but not the molecularities determined by our analysis. The observation that a small complex can oligomerize to form a larger species is consistent with the fact that NCp7 organizes and condenses the genome in the virus particle.

Hepatotoxicity of stanozolol in cats

OBJECTIVE

To determine hepatotoxicity of stanozolol in cats and to identify clinicopathologic and histopathologic abnormalities in cats with stanozolol-induced hepatotoxicosis.

DESIGN

Clinical trial and case series.

ANIMALS

12 healthy cats, 6 cats with chronic renal failure, and 3 cats with gingivitis and stomatitis.

PROCEDURES

Healthy cats and cats with renal failure were treated with stanozolol (25 mg, i.m., on the first day, then 2 mg, p.o., q 12 h) for 4 weeks. Cats with gingivitis were treated with stanozolol at a dosage of 1 mg, p.o., every 24 hours.

RESULTS

Most healthy cats and cats with renal failure developed marked inappetence, groomed less, and were less active within 7 to 10 days after initiation of stanozolol administration. Serum alanine transaminase (ALT) activity was significantly increased in 14 of 18 cats after stanozolol administration, but serum alkaline phosphatase activity was mildly increased in only 3. Four cats with serum ALT activity > 1,000 U/L after only 2 weeks of stanozolol administration had coagulopathies; administration of vitamin K resolved the coagulopathy in 3 of the 4 within 48 hours. All 18 cats survived, and hepatic enzyme activities were normal in all cats tested more than 4 weeks after stanozolol administration was discontinued. Two of the 3 cats with gingivitis developed evidence of severe hepatic failure 2 to 3 months after initiation of stanozolol treatment; both cats developed coagulopathies. Histologic evaluation of hepatic biopsy specimens from 5 cats revealed diffuse hepatic lipidosis and cholestasis without evidence of hepatocellular necrosis.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that stanozolol is hepatotoxic in cats.

Health status and population characteristics of dogs and cats examined at private veterinary practices in the United States

OBJECTIVE

To determine age, breed, sex, body condition score, and diet of dogs and cats examined at private veterinary practices in the United States during 1995, and estimate prevalences of the most common disorders for these animals.

DESIGN

Cross-sectional study.

ANIMALS

31,484 dogs and 15,226 cats examined by veterinary practitioners at 52 private veterinary practices.

PROCEDURE

Information on age, breed, sex, body condition score, diet, and assigned diagnostic codes were collected electronically from participating practices and transferred to a relational database. Prevalence estimates and frequencies for population description were generated using statistical software.

RESULTS

Dental calculus and gingivitis were the most commonly reported disorders. About 7% of dogs and 10% of cats examined by practitioners during the study were considered healthy. Many conditions were common to both species (e.g., flea infestation, conjunctivitis, diarrhea, vomiting). Dogs were likely to be examined because of lameness, disk disease, lipoma, and allergic dermatitis. Cats were likely to be examined because of renal disease, cystitis, feline urologic syndrome, and inappetence.

CLINICAL IMPLICATIONS

Results can be used by veterinary practitioners to better understand and anticipate health problems of importance in cats and dogs they examine and to better communicate with clients regarding the most prevalent disorders in cats and dogs.

Comparison of gastric emptying times in healthy cats simultaneously evaluated with radiopaque markers and nuclear scintigraphy

Gastric emptying in 18 healthy cats was assessed simultaneously using scintigraphy and barium-impregnated polyethylene spheres (BIPS). Canned Prescription Diet Feline c/d (Hill's Pet Nutrition, Inc., Topeka, KS) labeled with 99mTc-disofenin (Hepatolite, DuPont Merck Pharmaceutical Co., Billerica, Mass.) was fed on four separate days. Scintigraphic images were obtained at time 0 and then every 30 minutes to 6 hours. On the fourth scan day, 30 small (1.5 mm) and 10 large (5 mm) BIPS (Chemstock Animal Health Ltd., Christchurch, New Zealand) were mixed with the labeled meal, and in addition to scintigraphy, radiographs were made at 60-minute intervals for 6 hours. Gastric emptying was 11 to 15% slower on the day of simultaneous radiography as compared with the 3 days when only scintigraphy was performed (p < or = .05). Percentage retention of 1.5 mm BIPS in the stomach was significantly greater than the percentage retained gastric activity at hours 1, 2, 3, 4, 5, and 6 (p < or = .05). BIPS were clustered in the pyloric region of the stomach by 3 hours in all cats. In 10/18 animals, all BIPS were retained in pyloric region of the stomach at 6 hours, despite observable decreased size of the gastric silhouette and < or =15% retained gastric activity. In conclusion, gastric emptying of 1.5-mm BIPS does not parallel gastric emptying of 99mTc-disofenin labeled canned Prescription Diet Feline c/d. Stress associated with radiography may delay gastric emptying. Diet type should be considered when evaluating clinical radiographic studies where BIPS have been used.

Taurine status in cats is not maintained by dietary cysteinesulfinic acid

Endogenous synthesis of taurine by cats is limited. Putative precursors of taurine, cysteinesulfinic acid and cysteic acid, were fed to cats to determine whether they were utilized. Groups of five cats were depleted of taurine by a resin (Colestipol(R)) diet, then given 6 dietary treatments containing (g/kg diet): 0.0, 0.4, or 0.8 taurine; or 0.98 or 1.96 cysteinesulfinic acid, or 0.4 taurine + 1.0 cysteic acid for 12 wk. Plasma and whole blood taurine concentrations and body weights were measured weekly. Concentration of taurine in semitendinosus muscle was measured initially, after 2 wk of taurine depletion (after resin-diet), and monthly thereafter. The resin diet decreased concentrations of taurine in plasma, whole blood, and muscle to 0.20, 0.49, and 0.37 of initial values, respectively. Cysteinesulfinic acid diets resulted in no significant (P > 0.05) increase in the concentration of taurine in plasma, whole blood, or muscle, and no increased excretion of cysteinesulfinate or taurine in urine or feces. Cats fed the diets containing 1.0 g cysteic acid + 0.4 g taurine, or 0.8 g taurine/kg diet had similar concentrations of taurine in plasma, whole blood, and muscle. Aminotransferase activity for cysteinesulfinic acid in the liver and intestinal mucosa of cats and rats was higher than that for aspartic or cysteic acids. Transamination of dietary cysteinesulfinic acid to beta-sulfinylpyruvate (which spontaneously decomposes), rather than decarboxylation is postulated as the basis for no detectable conversion to taurine. In contrast, cysteic acid is reversibly transaminated to beta-sulfopyruvate which is stable and thereby is a precursor for taurine in cats.

Kinetics of cleavage of intra- and extracellular simian virus 40 DNA with the enediyne anticancer drug C-1027

A kinetic analysis of cleavage of simian virus DNA (SV40 DNA) inside and outside green monkey BSC-1 cells by the enediyne-protein antibiotic C-1027 and its free chromophore is described. Information on rate constants was obtained by fitting populations of forms I (closed circular DNA), II (nicked circular DNA) and III (linear DNA) SV40 DNA as a function of drug concentration to a kinetic model which includes: cutting of form I to give form II with rate constant k1, cutting of form I to give form III with rate constant K4, and cutting of form II to give form III with rate constant k2. The ratio of single-strand (ss) to double-strand (ds) cutting for the holoantibiotic and the free chromophore, k1/k4, is approximately 1.8 for extracellular SV40 DNA. For intracellular DNA and extracellular DNA which has been post-treated with putrescine, ds cutting is much more probable, with k4 about four times as large as k1. This observation suggests that amine groups present in the cell are able to convert abasic sites opposite an ss break into a ds break in SV40 chromatin. The overall rate of cleavage of form-I DNA inside the cell is much larger than the rate outside, the sum k1 + k4 being about three times as large for intracellular DNA as for extracellular DNA.

Evaluation of factors associated with development of calcium oxalate urolithiasis in cats

OBJECTIVE

To evaluate dietary and environmental factors as potential risk factors for calcium oxalate urolithiasis in cats.

DESIGN

Case-control study.

ANIMALS

84 cats with uroliths composed of at least 90% calcium oxalate and 258 age- and gender-matched control cats.

PROCEDURE

Owners of cats with calcium oxalate urolithiasis and control cats were surveyed between November 1990 and August 1992. Owners completed a standard questionnaire administered during a single telephone interview. Data collected included information regarding signalment, environment, urination and defecation, diet, and medical history.

RESULTS

Calcium oxalate uroliths tended to develop in middle- to older-aged, domestic shorthair cats of typical weight. A gender predilection was not detected. Factors associated with an increase in the risk of calcium oxalate urolithiasis in cats were feeding urine-acidifying diets, feeding a single brand of cat food without providing additional foods or table scraps, maintaining cats in an indoor-only environment, and being of the Persian breed.

CLINICAL IMPLICATIONS

Control of diet and environment may help prevent calcium oxalate urolithiasis.

Experimental induction of hepatic lipidosis in cats

The effect of long-term voluntary fasting on hematologic variables, biochemical profiles, and liver histologic findings was assessed in 15 obese cats (> 40% overweight). Clinical signs and laboratory results consistent with hepatic lipidosis were observed in 12 of 15 cats after 5 to 7 weeks of fasting, and were associated with 30 to 35% reduction of initial body weight. Histologic examination of successive liver biopsy specimens revealed that obesity was not associated with liver parenchymal lipid accumulation, but that fasting resulted in lipidosis in all 15 cats. The long-term fast was associated with an early (after 2 to 4 weeks of fasting) and significant (P < 0.05) reduction in serum urea, glucose, and albumin concentrations, and RBC mass. Fasting for 5 to 7 weeks was associated with a significant (P < 0.05) increase in hepatic-associated enzyme activities and in total and direct serum bilirubin concentrations. Significant (P < 0.05) changes in serum alkaline phosphatase developed as early as 3 weeks before the onset of hyperbilirubinemia. Except for development of hepatic lipidosis, cats appeared to tolerate the fast without other adverse effect. This study confirmed that long-term fasting may induce clinical hepatic lipidosis in obese cats. Fasting appears to induce a syndrome of hepatic lipidosis that is indistinguishable from feline idiopathic hepatic lipidosis and may be an appropriate model to study the pathophysiologic features and treatment of hepatic lipidosis.

Diagnosis of naturally acquired type-I and type-II diabetes mellitus in cats

After IV administration of 0.5 mg of glucagon/cat, glucose tolerance and insulin secretory response were evaluated in 10 lean cats, 10 obese cats, and 30 cats with diabetes mellitus. Blood samples for glucose and insulin determinations were collected immediately before and at 5, 10, 15, 30, 45, and 60 minutes after IV administration of glucagon. Baseline serum insulin concentration and insulin secretory response were used to classify diabetes mellitus in the 30 cats as type I or type II. Mean (+/- SEM) baseline and 30-minute serum glucose concentrations in obese cats were significantly (P < 0.05) decreased, compared with values in lean cats, but were similar at all other blood sample collection times. Serum glucose concentration in diabetic cats was significantly (P < 0.05) greater than values in obese and lean cats at all blood sample collection times. Two statistically different insulin responses to IV administration of glucagon were seen in diabetic cats. Of the 30 diabetic cats, 23 had minimal insulin secretory response after glucagon administration (ie, serum insulin concentration was at or below sensitivity of the insulin assay). Seven diabetic cats had baseline serum insulin concentration similar to that of obese cats and significantly (P < 0.05) greater than that of lean cats and of the other 23 diabetic cats. In these 7 diabetic cats, serum insulin concentration increased after glucagon administration. Total insulin secretion was not significantly different between these 7 diabetic cats and the lean and obese cats, and was significantly (P < 0.05) greater than total insulin secretion in the other 23 diabetic cats.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of glipizide on serum insulin and glucose concentrations in healthy cats

With the recent identification of non-insulin-dependent diabetes mellitus (NIDDM) in cats, new possibilities arise for the use of oral hypoglycaemic agents in the treatment of feline NIDDM, similar to their use in humans. To identify the future applicability of the oral hypoglycaemic agent, glipizide, in the treatment of feline NIDDM, its effects on serum insulin and glucose concentrations in healthy cats was examined. In addition, adverse effects seen clinically or on bloodwork following short-term use of the drug were looked for. Serum insulin and glucose concentrations were evaluated after the oral administration of 2.5, 5.0 and 10.0 mg glipizide and placebo in 10 healthy cats. For each drug trial, blood was obtained five minutes before, immediately before, and 7.5, 15, 30, 45, 60, 90 and 120 minutes after glipizide or placebo administration. Mean serum insulin concentration increased after glipizide administration, with peak mean serum insulin concentration occurring 15 minutes after administration and declining to baseline by 60 minutes. There was no significant difference in peak mean serum insulin concentration, mean serum insulin concentration at 60 minutes after glipizide administration, or mean total insulin secretion between the three glipizide dosages. Mean serum glucose concentration decreased within 15 minutes of glipizide administration, with the glucose nadir occurring 60 minutes after glipizide administration. Placebo trials showed no significant change in mean serum insulin or glucose concentrations from baseline concentrations.

Measurement of axial rotation: its relevance to screening for night-time hypokinesia in old age and parkinsonism

A novel device for continuous monitoring of axial rotation of a recumbent person is described. It is self-applicable and small enough to be mailed. A field trial showed that parkinsonian patients change their position less frequently than did their spouses: the difference became smaller where the age of the spouse was equal to or greater than that of the sufferer. The most marked difference between sufferers and their spouses was with respect to total angular displacement, which was nearly four times greater in the spouses. Further work is needed to show whether impaired rotation predates clinical idiopathic Parkinson's disease and so acts as a useful predictor. Measurement of axial rotation seems valuable in judging risk of pressure sores and gauging improvement in mobility in response to therapeutic interventions.

The diagnosis and treatment of insulin-dependent and non-insulin-dependent diabetes mellitus in the dog and the cat

Diabetes mellitus is often a frustrating disorder to treat. Many animals appear resistant to the effects of insulin, while others, especially cats, are very sensitive to its effects and therefore prone to bouts of hypoglycemia. Because of difficulties in glucose regulation, many veterinarians have referred to the treatment of diabetes mellitus as an art rather than a science. Fear of over-regulation with resultant hypoglycemia has led to the practice of "loose control" (wide fluctuations of glucose are allowed to occur throughout the day). Fortunately, long-term side effects of poor glycemic control seen in people (eg, retinal, glomerular, vascular, and nerve problems) are uncommon in dogs and cats; however, excessive polyuria and polydipsia, weight loss, and recurrent urinary tract infection in most cases is unacceptable. This chapter will focus on many of the problems associated with regulating the uncomplicated diabetic and discuss newer glucose control techniques, the use of oral hypoglycemic agents, and the role of diet in the acute treatment and long-term management of diabetes mellitus in the dog and cat.

The syndrome of Karl Ludwig Kahlbaum

Karl Ludwig Kahlbaum was the first to describe catatonia in 1868. There has been a tendency to consider catatonia as a psychiatric disease despite many case reports demonstrating a wide range of medical and neurological as well as psychiatric causes. We present our accumulated experience of the catatonic syndrome. Most cases (36%) were associated with affective illness but five cases (20%) had a defined organic disorder. A significant minority had no identifiable cause and there was only one case of schizophrenia. The idiopathic and affective groups had a high incidence of recurrent catatonic episodes and many had a family history of a similar problem. The prognosis was excellent, except for the few patients who presented with the acute and rapidly progressive form of the syndrome which led to acute renal failure.

CNS-related side-effects with metoprolol and atenolol

Vivid and bizarre dreams, hallucinations, sleep disturbance and psychosis have all been described following treatment with beta-blockers. It has been suggested that these central nervous system (CNS) side-effects are related to the degree of lipophilicity of the beta-blocker. A randomized double-blind crossover study was performed to compare the incidence of CNS side-effects with atenolol and metoprolol in hypertensive patients who had reported CNS side-effects with lipophilic beta-blockers. Eleven women and six men completed the study, in which a 30-item psychiatric questionnaire was used to detect changes in psychological status and possible CNS side-effects. Discontinuation of the original lipophilic beta-blocker produced a significant improvement in quality of sleep, dreams, concentration, memory, energy, and anxiety. No significant CNS side-effects were reported with atenolol, but introduction of metoprolol caused a significant increase in the incidence of sleep disturbance (p less than 0.01) and restless nights (p less than 0.05), as well as failure to achieve satisfactory sexual intercourse (p less than 0.05). When compared with atenolol, metoprolol was associated with a significantly higher incidence of restless disturbed nights (p less than 0.05). Blood pressure control was identical for both beta-blockers. This study appears to confirm the association between CNS-related side-effects and the lipophilicity of beta-blockers.

A comparison between atenolol and metoprolol in respect of central nervous system side effects

A double-blind crossover study was performed to compare the incidence of central nervous system (CNS) side effects with atenolol and metoprolol. Eleven women and 6 men who had previously developed such side effects on lipophilic beta-blockers were identified by means of a preliminary questionnaire. A 30-item psychiatric questionnaire was then used to detect changes in psychological status and possible CNS side effects. Discontinuation of the original lipophilic beta-blocker produced a significant improvement in quality of sleep, dreams, concentration, memory, energy and anxiety. Introduction of atenolol did not result in any significant CNS effects. With metoprolol, however, some effects occurred but not to the extent experienced prior to study on other more lipophilic beta-blockers. Blood pressure control was identical with both drugs.

Psychiatric illness in a neurological out-patient department in North East England. Use of the General Health Questionnaire in the prospective study of neurological out-patients

342 patients referred to a neurological out-patient department in North East England between November 1975 and November 1976 were studied prospectively using two methods of psychiatric case identification, by clinical interview and by use of the General Health Questionnaire. The population of psychiatric patients identified by clinical techniques is different from that identified by the GHQ and it is concluded that GHQ cannot be used for routine screening in the neurological clinic. Clinical data were compared with a previous retrospective study. Clinical assessment revealed 27% with psychiatric disorders whilst GHQ showed a probable psychiatric morbidity of 48% with a cut off score of 11/12 and 21% with our best cut off score of 26/27. Statistical problems with this method are discussed and the results of this study compared with others using the same questionnaire. Aspects of organic and psychiatric disorder in a neurological clinic are discussed.