Multiple organ dysfunction after mitral valve replacement in a patient with systemic lupus erythematosus complicated by Libman-Sacks endocarditis: a case report and literature review

This case report describes a 47-year-old woman with systemic lupus erythematosus (SLE) complicated by Libman-Sacks endocarditis (LSE) who developed multiple organ dysfunction after mitral valve replacement surgery. The patient presented with a 5-day history of cough, sputum, and fever. Transthoracic echocardiography showed significant vegetations on the mitral valve. Biopsy was performed, and the pathological diagnosis was SLE complicated by LSE. After the mitral valve replacement surgery, the patient developed clinical manifestations of hepatic and renal dysfunction, cardiopulmonary failure, oliguria, and shock. The clinical symptoms significantly improved after administration of mechanical ventilation, continuous renal replacement therapy, plasma exchange, anti-inflammatory and anti-infection treatments, immunomodulatory and immunosuppressive therapies, and low-molecular-weight heparin anticoagulation. Multiple organ dysfunction after mitral valve replacement in patients with SLE complicated by LSE has rarely been reported. This report discusses the clinical manifestations, pathogenesis, and treatment of this severe complication. We hope the sharing of our experience in this case will provide a clinical basis for the treatment of severe multiple organ dysfunction after mitral valve replacement in patients with SLE complicated by LSE.

[Effect of hypochloric acid on Escherichia coli biofilm and the clinical efficacy of hypochloric acid for wounds with Escherichia coli infection]

Objective: To investigate the effect of hypochloric acid on Escherichia coli biofilm and the clinical efficacy of hypochloric acid for wounds with Escherichia coli infection. Methods: One strain of Escherichia coli with the strongest bacterial biofilm forming ability among the strains isolated from specimens in 25 patients (16 males and 9 females, aged 32-67 years) from five clinical departments of the 940th Hospital of the Joint Logistic Support Force was collected for the experimental study from September to December 2019. The Escherichia coli was cultured with hypochloric acid at 162.96, 81.48, 40.74, 20.37, 10.18, 5.09, 2.55, 1.27, 0.64, and 0.32 μg/mL respectively to screen the minimum bactericidal concentration (MBC) of hypochloric acid. The Escherichia coli was cultured with hypochloric acid at the screened MBC for 2, 5, 10, 20, 30, and 60 min respectively to screen the shortest bactericidal time of hypochloric acid. The biofilm formation of Escherichia coli was observed by scanning electron microscopy at 6, 12, 24, 48, 72, and 96 h of incubation, respectively. After 72 h of culture, hypochloric acid at 1, 2, 4, 8, and 16 times of MBC was respectively added to Escherichia coli to screen the minimum biofilm eradicate concentration (MBEC) of hypochloric acid against Escherichia coli. After hypochloric acid at 1, 2, 4, and 8 times of MBEC and sterile saline were respectively added to Escherichia coli for 10 min, the live/dead bacterial staining kit was used to detect the number of live and dead cells, with the rate of dead bacteria calculated (the number of samples was 5). From January to December 2020, 41 patients with infectious wounds meeting the inclusion criteria and admitted to the Department of Burns and Plastic Surgery of the 940th Hospital of Joint Logistic Support Force of PLA were included into the prospective randomized controlled trial. The patients were divided into hypochloric acid group with 21 patients (13 males and 8 females, aged (46±14) years) and povidone iodine group with 20 patients (14 males and 6 females, aged (45±19) years) according to the random number table. Patients in the 2 groups were respectively dressed with sterile gauze soaked with hypochloric acid of 100 μg/mL and povidone iodine solution of 50 mg/mL with the dressings changed daily. Before the first dressing change and on the 10th day of dressing change, tissue was taken from the wound and margin of the wound for culturing bacteria by agar culture method and quantifying the number of bacteria. The amount of wound exudate and granulation tissue growth were observed visually and scored before the first dressing change and on the 3rd, 7th, and 10th days of dressing change. Data were statistically analyzed with one-way analysis of variance, Dunnett-t test, independent sample t test, Mann-Whitney U test, Wilcoxon signed-rank test, chi-square test, or Fisher's exact probability test. Results: The MBC of hypochloric acid against Escherichia coli was 10.18 μg/mL, and the shortest bactericidal time of hypochloric acid with MBC against Escherichia coli was 2 min. Escherichia coli was in a completely free state after 6 and 12 h of culture and gradually aggregated and adhered with the extension of culture time, forming a mature biofilm at 72 h of culture. The MBEC of hypochloric acid against Escherichia coli was 20.36 μg/mL. The Escherichia coli mortality rates after incubation with hypochloric acid at 1, 2, 4, and 8 times of MBEC for 10 min were significantly higher than that after incubation with sterile saline (with t values of 6.11, 25.04, 28.90, and 40.74, respectively, P<0.01). The amount of bacteria in the wound tissue of patients in hypochloric acid group on the 10th day of dressing change was 2.61 (2.20, 3.30)×104 colony forming unit (CFU)/g, significantly less than 4.77 (2.18, 12.48)×104 CFU/g in povidone iodine group (Z=2.06, P<0.05). The amounts of bacteria in the wound tissue of patients in hypochloric acid group and povidone iodine group on the 10th day of dressing change were significantly less than 2.97 (2.90, 3.04)×106 and 2.97 (1.90, 7.95)×106 CFU/g before the first dressing change (with Z values of 4.02 and 3.92, respectively, P<0.01). The score of wound exudate amount of patients in hypochloric acid group on the 10th day of dressing change was significantly lower than that in povidone iodine group (Z=2.07, P<0.05). Compared with those before the first dressing change, the scores of wound exudate amount of patients in hypochloric acid group on the 7th and 10th days of dressing change were significantly decreased (with Z values of -3.99 and -4.12, respectively, P<0.01), and the scores of wound exudate amount of patients in povidone iodine group on the 7th and 10th days of dressing change were significantly decreased (with Z values of -3.54 and -3.93, respectively, P<0.01). The score of wound granulation tissue growth of patients in hypochloric acid group on the 10th day of dressing change was significantly higher than that in povidone iodine group (Z=2.02, P<0.05). Compared with those before the first dressing change, the scores of wound granulation tissue growth of patients in hypochloric acid group on the 7th and 10th days of dressing change were significantly increased (with Z values of -3.13 and -3.67, respectively, P<0.01), and the scores of wound granulation tissue growth of patients in povidone iodine group on the 7th and 10th days of dressing change were significantly increased (with Z values of -3.12 and -3.50, respectively, P<0.01). Conclusions: Hypochloric acid can kill Escherichia coli both in free and biofilm status. Hypochloric acid at a low concentration shows a rapid bactericidal effect on mature Escherichia coli biofilm, and the higher the concentration of hypochloric acid, the better the bactericidal effect. The hypochloric acid of 100 μg/mL is effective in reducing the bacterial load on wounds with Escherichia coli infection in patients, as evidenced by a reduction in wound exudate and indirect promotion of granulation tissue growth, which is more effective than povidone iodine, the traditional topical antimicrobial agent.

[Effects of acute paraquat poisoning on cognitive ability in humans]

Objective: To explore the effects of acute paraquat poisoning on cognitive function of patients through neuropsychologic test. Methods: In June 2019, 36 patients with acute paraquat poisoning in the emergency department of a provincial hospital in Hebei Province were selected as the case group. 36 healthy individuals were selected as control group. The cognitive function and depressive state were assessed by mini mental state scale, auditory word learning test, digit span test, connection test, Boston Naming Test and geriatric depression scale. Results: The results of Mini-Mental State examination showed that the total score of the case group was lower than that of the control group, the difference was statistically significant (P<0.05) . The results of the Auditory Vocabulary Learning test showed that the scores of delayed recall, clue recall, corrective ability and semantic learning strategies of the case group were significantly lower than those in the control group (P<0.05) . There was no significant difference in the scores of immediate memory between the two groups (P>0.05) . The scores of Digit Span test and Boston Naming test in the control group were higher than those in the case group, the Trail Making test time in the control group was shorter than that in the case group, and the differences were statistically significant (P<0.05) . Conclusion: Acute paraquat poisoning can impair human cognitive ability to a certain extent.

Dual heterogeneous structures lead to ultrahigh strength and uniform ductility in a Co-Cr-Ni medium-entropy alloy

Alloys with ultra-high strength and sufficient ductility are highly desired for modern engineering applications but difficult to develop. Here we report that, by a careful controlling alloy composition, thermomechanical process, and microstructural feature, a Co-Cr-Ni-based medium-entropy alloy (MEA) with a dual heterogeneous structure of both matrix and precipitates can be designed to provide an ultra-high tensile strength of 2.2 GPa and uniform elongation of 13% at ambient temperature, properties that are much improved over their counterparts without the heterogeneous structure. Electron microscopy characterizations reveal that the dual heterogeneous structures are composed of a heterogeneous matrix with both coarse grains (10∼30 μm) and ultra-fine grains (0.5∼2 μm), together with heterogeneous L1₂-structured nanoprecipitates ranging from several to hundreds of nanometers. The heterogeneous L1₂ nanoprecipitates are fully coherent with the matrix, minimizing the elastic misfit strain of interfaces, relieving the stress concentration during deformation, and playing an active role in enhanced ductility.

Improving both strength and ductility simultaneously in structural metals and alloys remains a challenge. Here, the authors design a heterogeneous structure in a Co-Cr-Ni alloy that results in ultrahigh strength and significant uniform elongation.

[Advances in the research of antibacterial properties and composite materials of nanometer zinc oxide]

Nanometer zinc oxide has become a new hotspot in the research of tissue engineering materials due to its excellent antibacterial properties, biocompatibility, and anti-tumor properties. In this paper, the existing research results were summarized, generalized, and analyzed. The antibacterial mechanism of nanometer zinc oxide was discussed in depth. The antibacterial properties and advantages of the latest nanometer zinc oxide composite materials were introduced in detail. In this review, we made prospect of the future application of nanometer zinc oxide.

[Clinical investigation of ultrasound-guided percutaneous nephrolithotomy accessed by SVOF-principle and two-step puncture techniques]

Objective: To evaluate the safety and effectiveness of ultrasound-guided percutaneous nephrolithotomy (PCNL) accessed by SVOF-principle and two-step puncture techniques. Methods: A total of 838 cases with upper urinary stones underwent percutaneous nephrolithotomy successfully accessed by ultrasound-guided between June 2007 and December 2015 at Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. Of all cases were divided in two groups: hydronephrosis calyces puncture group include 425 cases and SVOF-principle puncture group include 413 cases. The access establishment time, operation time, stone free rate (SFR), postoperative complications, and postoperative hospitalization time between the two groups we compared by t test or χ² test. Results: Statistically significant differences were observed between hydronephrosis calyces puncture group and SVOF-principle puncturegroup in the first access establishment time ((16.5±8.4) minutes vs. (11.2±5.9) minutes, t=3.931, P=0.013), one-stage SFR (74.3% vs. 85.7%, χ²=16.868, P=0.000), postoperative hospitalization time ((6.4±2.1) days vs. (4.8±1.8)days, t=4.574, P=0.000), transfusion rate (7.1% vs. 2.9%, χ²=8.027, P=0.006), and embolization rate (3.3% vs. 1.0%, χ²=5.390, P=0.020). There were no statistically significant differences in operation time, total SFR, postoperative fever and sever infection between these two groups (all P>0.05). In both two groups, no serious complications such as peripheral organ injury and death occurred. Conclusions: PCNL accessed guided by ultrasound with SVOF-principle and two-step puncture techniques has advantages of quick puncture location, high stone free rate, fewer complications and fast recovery. This technique is an effective and safe treatment option for upper urinary stones and deserved promotion and application in clinic.

Autism-associated Dyrk1a truncation mutants impair neuronal dendritic and spine growth and interfere with postnatal cortical development

Autism is a prevailing neurodevelopmental disorder with a large genetic/genomic component. Recently, the dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 1 A (DYRK1A) gene was implicated as a risk factor for autism spectrum disorder (ASD). We identified five DYRK1A variants in ASD patients and found that the dose of DYRK1A protein has a crucial role in various aspects of postnatal neural development. Dyrk1a loss of function and gain of function led to defects in dendritic growth, dendritic spine development and radial migration during cortical development. Importantly, two autism-associated truncations, R205X and E239X, were shown to be Dyrk1a loss-of-function mutants. Studies of the truncated Dyrk1a mutants may provide new insights into the role of Dyrk1a in brain development, as well as the role of Dyrk1a loss of function in the pathophysiology of autism.

[The relationship between myocardial bridge in mural coronary artery segment and coronary atherosclerosis]

Objective: The myocardial bridging (MB) prevalence, anatomic characteristics of MB, and the relationship between characteristics of MB in mural coronary artery segment and coronary atherosclerosis were analyzed. Methods: In this perspective nonrandomized controlled study, a total of 1 132 patients who admitted to our hospital for suspected or known coronary artery disease from January 2012 to June 2013 were enrolled. All patients underwent dual-source 64-slice spiral CT coronary angiography. The general patient characteristics including gender, age, history of hypertension, diabetes, hyperlipidemia and smoking, serum level of total cholesterol (TC) and LDL-C were recorded. The length, depth and the degree of compression of myocardial bridge in systolic or diastolic phase were also analyzed in patients with MB. The relationship between MB and coronary atherosclerosis, the characteristics of MB and coronary atherosclerosis were analyzed by Spearman correlation analysis, univariate logistic regression analysis, variate logistic regression analysis and linear regression analysis. Results: Myocardial bridging was detected in 330 out of 1 132 patients, and MB was mostly located in the mural coronary artery (329/330) and at the mid-distal segment of the left anterior descending artery (LAD). Average MB length was 20.1 mm (3.3-95.5 mm) and the average depth was 2.13 mm (0.24-12.40 mm). There were 140 patients with intramyocardial MB (42.6%) and 189 patients with superficial MB (57.4%). Myocardial bridging was an independent protective factor of coronary atherosclerosis (OR=0.361, P=0.000) and the proximal segment of MB was more susceptible to atherosclerosis compared to the distal segment of MB (P=0.000). Multivariate analysis revealed that age, hypertension and the degree of compression of myocardial bridge in diastolic phase were independent factors related to the atherosclerosis (odds ratio: 1.064, 2.186 and 1.049 respectively, P value: 0.000, 0.002 and 0.000). The depth of MB was significantly correlated with systolic or diastolic narrowing(OR: 4.227, 3.398 and P value: 0.000, 0.001). Conclusions: The prevalence of myocardial bridging is 29% in this patient cohort. The proximal segment of myocardial bridging in mural coronary artery is more susceptible to atherosclerosis. In addition, the depth of myocardial bridging and the degree of compression of myocardial bridge in diastolic phase are the independent factors related to atherosclerosis.

Association analysis between HFM1 variation and primary ovarian insufficiency in Chinese women

HFM1 is a meiosis-specific gene and expressed in germ-line tissues. More recently, evidence has indicated that variations in HFM1 gene could be causative for primary ovarian insufficiency (POI), also known as premature ovarian failure. The aim of this study was to investigate the association between HFM1 gene variants and sporadic POI in Chinese women. A total of 138 POI patients and 316 healthy controls (matched for ethnic background, sex, and age of the patients) were recruited in this study. We screened the entire HFM1 coding region by direct sequencing in all subjects and identified six variants of HFM1 gene in POI group, namely c.148G>A/p.Glu50Lys, c.1241A>C/p.His414Pro, c.2325C>A/p.Phe775Leu, c.3367T>C/p.Ser1123Pro, c.3580C>T/p.Arg1194Cys, and c.1686-1G>C. The variation rate of HFM1 in POI group is significantly higher than control group (p < 0.01). The p.His414Pro and p.Arg1194Cys were predicted to be probably damaging to the HFM1 protein function, while p.Glu50Lys, p.Phe775Leu and p.Ser1123Pro mutants might not have any deleterious effect on the structure or function of the protein by online predictors. Taken together, our data suggested that HFM1 gene might be associated with primary ovarian insufficiency in Chinese population.

Reduced Penetrance of PRRT2 Mutation in a Chinese Family With Infantile Convulsion and Choreoathetosis Syndrome

Paroxysmal kinesigenic dyskinesia is a rare episodic movement disorder that can be isolated or associated with benign infantile seizures as part of choreoathetosis syndrome. Mutations in the PRRT2 gene have been recently identified as a cause of paroxysmal kinesigenic dyskinesia and infantile convulsion and choreoathetosis (ICCA). We reported a PRRT2 heterozygous mutation (c.604-607delTCAC, p.S202Hfs*25) in a 3-generation Chinese family with infantile convulsion and choreoathetosis and paroxysmal kinesigenic dyskinesia. The mutation was present in 5 family members, of which 4 were clinically affected and 1 was an obligate carrier with reduced penetrance of PRRT2. The affected carriers of this mutation presented with a similar type of infantile convulsion during early childhood and developed additional paroxysmal kinesigenic dyskinesia symptoms later in life. In addition, they all had a dramatic clinical response to oxcarbazepine/phenytoin therapy. Reduced penetrance of the PRRT2 mutation in this family could warrant genetic counseling.

Prenatal diagnosis of chromosomal abnormalities in fetuses with abnormal cardiac ultrasound findings: evaluation of chromosomal microarray-based analysis

OBJECTIVES

To assess the frequency of karyotype abnormalities and chromosome 22q11.2 deletion syndrome among fetuses with abnormal cardiac ultrasound findings, and to evaluate the clinical value of chromosomal microarray-based analysis (CMA) in the study of such pregnancies.

METHODS

First, we carried out retrospective analysis of karyotype abnormalities and 22q11.2 deletion syndrome cases diagnosed between January 2009 and December 2011 in our center among fetuses with abnormal cardiac ultrasound findings (n = 276). Second, CMA was performed in 51 of the fetuses with such findings, normal karyotype and negative or no 22q11.2 deletion syndrome study, and in the only fetus with a heart defect and an apparently balanced de novo chromosomal rearrangement.

RESULTS

Out of the 276 pregnancies with abnormal cardiac ultrasound findings, karyotyping revealed a chromosomal abnormality in 44 (15.9%). Of fetuses with normal karyotype in which 22q11.2 deletion syndrome studies were performed, 6.4% (5/78) had this microdeletion syndrome. Among fetuses with abnormal cardiac findings, normal karyotype and negative or no 22q11.2 deletion syndrome study that underwent CMA, the detection rate of pathogenic copy number variants not detected by conventional cytogenetics was 2.0% (1/51), and no variants of uncertain clinical significance were found. In the fetus with a heart defect and an apparently balanced de novo chromosomal rearrangement, CMA revealed that the rearrangement was not truly balanced.

CONCLUSIONS

In the assessment of genetic abnormalities in pregnancies with abnormal cardiac ultrasound findings, the diagnostic yield may be increased by 2% if CMA is used as a complementary tool to conventional cytogenetics. Our results suggest that CMA could be a good alternative to karyotyping in these pregnancies.

ERCC6 founder mutation identified in Finnish patients with COFS syndrome

Cerebro-oculo-facio-skeletal (COFS) syndrome is an autosomal recessive disorder characterized by microcephaly, congenital cataracts, facial dysmorphism, neurogenic arthrogryposis, growth failure and severe psychomotor retardation. We report a large consanguineous pedigree from northern Finland with six individuals belonging into four different sibships and affected with typical COFS syndrome phenotype. Two deceased patients have been published previously in 1982 as the first cases exhibiting cerebral calcifications typical for this disorder. Two living and one of the deceased patients were all shown to possess a novel homozygous mutation in the ERCC6 [Cockayne syndrome B (CSB)] gene, thereby confirming the diagnosis on molecular genetic level even for the earlier published cases. Genealogical investigation showed a common ancestor living in a northeastern village in Finland in the 18th century for all six patients implying a founder effect.

Effect of antisense oligonucleotide against mouse dentine matrix protein 1 on mineralization ability and calcium ions metabolism in odontoblast-like cell line MDPC-23

AIM

To study the mineralization ability and the dynamic changes of intracellular and extracellular concentrations of calcium ions in the odontoblast-like cell line MDPC-23 affected by antisense oligonucleotide (AS-ODN) against mouse dentine matrix protein 1 (DMP1).

METHODOLOGY

The expression of DMP1 in MDPC-23 cells was detected by an immunohistochemical method and its blocking outcome by the Western blot method. The alkaline phosphatase (ALP) activity, size and number of mineralized nodules, and the intracellular free ([Ca2+]if), total ([Ca2+]it) and the extracellular ([Ca2+]e) calcium ion concentrations in MDPC-23 cells in the experimental group affected with AS-ODN were compared with those in the control group (paired-samples t-test).

RESULTS

Dentine matrix protein 1 was stably expressed in a stable way in MDPC-23 cells; the expression was only just detectable at 12 h and became negative after 24 h affected by AS-ODN. Compared with the control groups, ALP activity of MDPC-23 cells in the AS-ODN group was decreased (P < 0.05), and both the number and size of mineralized nodules were smaller than those in the control group. [Ca2+]if in the AS-ODN group increased and then decreased after 24 h. [Ca2+]it dropped substantially to the lowest point at 24 h (P < 0.01). [Ca2+]e increased before treatment for 24 h and then dropped, however, it was still higher than that of the control group.

CONCLUSIONS

Antisense oligonucleotide against DMP1 could decrease mineralization ability and affect the intracellular and extracellular concentrations of calcium ions in MDPC-23 cells. This would indicate that DMP1 regulates the metabolism and transportation of calcium ions in odontoblasts, and thus boosts dentine mineralization.

Preparation of sodium fluoride-loaded gelatin microspheres, characterization and cariostatic studies

Sodium fluoride-loaded gelatin microspheres (NaF-GMS) were prepared using double-phase emulsified condensation polymerization. The average diameter of microspheres was (11.33+/-5.56) microm. The drug content and encapsulation efficiency were 8.80% and 76.73%, respectively. The fluoride releasing profiles of NaF-GMS in physiological saline and artificial saliva (pH 4.5, pH 6.8) showed that NaF-GMS had a sustained-release property and fluoride release rate was increased in pH 4.5 artificial saliva. Experiments conducted in rabbits' oral cavity using NaF-GMS and NaF solution as control revealed NaF-GMS could maintain oral fluoride retention longer than NaF solution. Cariostatic abilities of NaF-GMS including demineralization prohibition in vitro, fluoride deposition in artificial dental plaque and the ability of targeting to cariogenic bacteria were investigated in artificial dental plaque. The results indicated NaF-GMS with lower fluoride concentrations could achieve equivalent cariostatic effect to the concentrated NaF solution, at the same time, could prolong fluoride retention in dental plaque. Microscopic observation showed that NaF-GMS carrying fusion protein of glucan-binding domain could adhere more bacteria than NaF-GMS and this might indicate the possibility of targeting to cariogenic bacteria when NaF-GMS were properly modified.

Connexin 26 studies in patients with sensorineural hearing loss

OBJECTIVE

To determine the spectrum of connexin 26 (Cx26) mutations and their phenotypes in children with sensorineural hearing loss (SNHL) or mixed hearing loss (MHL).

DESIGN

Children with SNHL or MHL were prospectively tested for mutations in the entire coding region of the Cx26 gene.

PATIENTS

Children with SNHL or MHL with no obvious etiology for the hearing loss.

RESULTS

Between December 1, 1998, and July 1, 2000, 107 patients with SNHL or MHL from 99 families underwent Cx26 testing. Most patients were aged 1 week to 16 years (61 boys and 46 girls). Thirty (30%) of 99 probands had Cx26 mutations: biallelic mutations were detected in 18 (9 homozygous and 9 compound heterozygous) and single mutations were detected in 12. Twelve previously reported mutations (35delG, 167delT, E47X, L90P, M34T, G12V, V37I, R143W, V84L, V153I, V27I, and 310del14) and 3 novel mutations (E129K, T8M, and N206S) were found. Hearing loss in patients with biallelic Cx26 mutations ranged from unilateral high frequency to bilateral profound. Four children, 2 with biallelic mutations, had temporal bone abnormalities.

CONCLUSIONS

Connexin 26 mutations are common in children with SNHL, and it is likely that the homozygous and compound heterozygous mutations cause the SNHL. However, pathogenicity is less certain when only a single Cx26 mutation is present. Patients with biallelic Cx26 mutations had a slightly higher incidence of milder hearing loss than in previous studies. Children with SNHL or MHL should be tested for Cx26 mutations early in their evaluation.

Townes-Brocks syndrome versus expanded spectrum hemifacial microsomia: review of eight patients and further evidence of a "hot spot" for mutation in the SALL1 gene

PURPOSE

It can be difficult to differentiate clinically between hemifacial microsomia (HFM) and Townes-Brocks syndrome (TBS). The distinction is important because TBS is inherited as an autosomal dominant trait, whereas HFM is sporadic.

METHODS

We performed a retrospective analysis of eight patients with HFM-expanded spectrum and anal anomalies to determine whether this subset has TBS.

RESULTS

Two patients had major phenotypic findings of TBS. Sequencing of SALL1, the gene mutated in TBS, in four of the eight patients revealed one with a C --> T transition (resulting in a nonsense mutation R276X) at a previously identified mutational "hot spot."

CONCLUSION

Patients with overlapping features of both syndromes should be screened for SALL1 mutations.

Prenatal sonographic detection of adrenal hemorrhage confirmed by postnatal surgery

We report a case of adrenal hemorrhage in a newborn first detected by sonography at a menstrual age of 21 weeks 4 days. An echogenic mass was noted above the right kidney. The mass became larger and hypoechoic on follow-up sonograms after birth. The mass was also seen on abdominal CT. Because it was difficult to differentiate the lesion from cystic neuroblastoma and because it shrank only modestly by 2 months after birth, we performed a surgical exploration when the patient was 2 months old, and adrenal hemorrhage was confirmed. This case suggests that adrenal hemorrhage can occur as early as the second trimester of pregnancy.

Botulinum toxin decreases salivation from canine submandibular glands

The objective of this study was to determine whether botulinum toxin types A and D reduced the production of saliva from the submandibular glands of 18 dogs. The left submandibular glands of 8 dogs were injected with increasing doses of botulinum type A toxin (range 10 to 70 units), and the left glands of 10 dogs were injected with botulinum type D toxin (50 or 100 units). The right gland of each dog was injected with equivalent volumes of saline solution to serve as control. Six days after the injection, the lingual nerve was electrically stimulated for 10 minutes (3 mAmp, 20 Hz). The resulting volume of saliva was collected and weighed. Overall, the glands injected with types A or D toxin produced significantly less saliva than comparable glands injected with saline solution. Six of 8 dogs injected with type A toxin showed a significant decrease in saliva production (range 10.1% to 19.2%, one-sided p value = 0.0375) when compared with the controls. Nine of 10 dogs injected with type D toxin demonstrated a highly significant reduction in saliva production (total average decrease = 60%, two-sided pvalue = 0.001) when compared with the controls. We concluded that intraglandular injections of botulinum toxin types A and D significantly reduced the production of saliva from canine submandibular glands. The potential applications of intraglandular injections of botulinum toxin are discussed.

Deletion of the entire NF1 gene causing distinct manifestations in a family

We identified a father and son with neurofibromatosis type 1 (NF1) due to a deletion of the entire NF1 gene detected by fluorescence in situ hybridization (FISH). As is the case for others reported to have such large deletions, father and son had severe NF1, including a large number of cutaneous neurofibromas, facial anomalies, large hands, feet, and head, and developmental impairment. They were discordant in that seizures and plexiform neurofibromas occurred only in the propositus. Large NF1 deletions can be compatible with familial transmission and appear to be associated with a distinct phenotype.

Somatic mosaicism for deletion of the entire NF1 gene identified by FISH

We report a young child with a large congenital cervical plexiform neurofibroma and multiple café-aul-ait spots in a generalized distribution who has mosaicism for complete deletion of the NF1 gene. The deletion was demonstrated with intragenic cosmid probes as well as YACs spanning a 700-kb contig including NF1, by two-color FISH with an NF1 and a control probe. Using different intragenic probes, deletion was found in 77-84% of cultured peripheral blood lymphocytes but not in cultured skin fibroblasts. Neither parent has signs of neurofibromatosis type 1 (NF1) or a gene deletion. This is the first report of mosaicism for complete deletion of the NF1 gene. The child did not have typical NF1 or display segmental features of NF1.

Allele-specific replication of 15q11-q13 loci: a diagnostic test for detection of uniparental disomy

Allele-specific replication differences have been observed in imprinted chromosomal regions. We have exploited this characteristic of an imprinted region by using FISH at D15S9 and SNRPN (small nuclear ribonucleo protein N) on interphase nuclei to distinguish between Angelman and Prader-Willi syndrome patient samples with uniparental disomy of chromosome 15q11-q13 (n = 11) from those with biparental inheritance (n = 13). The familial recurrence risks are low when the child has de novo uniparental disomy and may be as high as 50% when the child has biparental inheritance. The frequency of interphase cells with asynchronous replication was significantly lower in patients with uniparental disomy than in patients with biparental inheritance. Within the sample population of patients with biparental inheritance, those with altered methylation and presumably imprinting center mutations could not be distinguished from those with no currently detectable mutation. This test is cost effective because it is performed on interphase cells from the same hybridized cytological preparation in which a deletion is excluded, and additional specimens are not required to determine the parental origin of chromosome 15.

Distal 8p deletion (8)(p23.1): an easily missed chromosomal abnormality that may be associated with congenital heart defect and mental retardation

We describe the clinical manifestations and molecular cytogenetic analyses of three patients with a similar distal deletion of chromosome 8. Each child had mild developmental delay and subtle minor anomalies. Two had cardiac anomalies but no other major congenital anomalies were present. High resolution G and R banding showed in all three patients del(8)(p23.1), but the breakpoint in case 1 was distal to 8p23.1, in case 2 was in the middle of 8p23.1, and in case 3 proximal to 8p23.1. Fluorescence in situ hybridization (FISH) studies with a chromosome 8 paint probe confirmed that no other rearrangement had occurred. FISH with a chromosome 8-specific telomere probe indicated that two patients had terminal deletions. Chromosome analysis of the parents of case 1 and mother of case 2 were normal; the remaining parents were not available for study. Thirteen individual patients including the three in this study, and three relatives in one family with del(8)(p23.1), have been reported in the past 5 years. Major congenital anomalies, especially congenital heart defects, are most often associated with a breakpoint proximal to 8p23.1. Three patients were found within a 3-year period in this study and five cases were found within 4 years by another group, indicating that distal 8p deletion might be a relatively common chromosomal abnormality. This small deletion is easily overlooked (i.e., cases 1 and 2 were reported as normal at amniocentesis) and can be associated with few or no major congenital anomalies.

Deletion of the entire NF1 gene detected by the FISH: four deletion patients associated with severe manifestations

Genetic analysis of NF1 has indicated a wide diversity of mutations, including chromosome rearrangements, deletions, insertions, duplications, and point mutations. Recently, five severely affected individuals have been found by Kayes et Al. [1994] to have deletions encompassing the entire gene. These deletions were detected by quantitative Southern analysis. To simplify deletion detection, we have employed fluorescence in situ hybridization (FISH) using intragenic probes. Thirteen unrelated individuals with NF1 have been studied. Among six with severe manifestations, four have been found to have deletions detected by probes cFF13, cFB5D, cP5, yA43A9, yA113D7 and yD8F4. All four deletions patients have severe developmental delay, minor and major anomalies (including one with bilateral iris colobomas), and multiple cutaneous neurofibromas or plexiform neurofibromas which were present before age 5 years. FISH provides a simple and rapid means of identification of NF1 gene deletions and will allow more rigorous testing of the hypothesis that such deletions are associated with severe manifestations.

Cytogenetic and molecular cytogenetic studies of a case of interstitial deletion of proximal 15q

A 4-month-old child with multiple anomalies was determined to have an interstitial deletion of chromosome 15, i.e., del(15) (q12q14). The deletion appears not to be a typical deletion of 15q12 such as seen in Angelman and Prader-Willi syndromes, but appears to be more distal, involving either loss of all of 15q12 and part of 15q14, or part of 15q12 and most of 15q14. In either case, 15q13 is missing. Fluorescent in situ hybridization with probes for 15 centromere (D15Z), pericentromeric satellite sequences (D15Z1), and chromosome 15 painting probes shows the deleted chromosome to involve only 15 and no other acrocentric chromosome. Hybridization with probes for the AS and PWS loci (D15S11 and GABAB3, Oncor) show both sites to be intact in the deleted 15. The case is compared with two other reports with overlapping interstitial deletions of proximal 15q, neither of which shows typical features of Angelman or Prader-Willi syndromes.

CHARGE association in a child with de novo inverted duplication (14)(q22-->q24.3)

We report on a 4-1/2 year old girl with apparent CHARGE association who had a de novo inverted duplication (14)(q22-->24.3), iris colobomas, ventricular septal defect, soft tissue choanal atresia, intellectual impairment, growth retardation, sensorineural deafness, apparently low set ears, and upslanting palpebral fissures. Family history was unremarkable and parental chromosomes were normal. Similarities between this and previously reported cases of 14q duplication suggest that a locus for a gene or genes causing some of the anomalies of CHARGE association may reside in the region 14q22 to 24.3.

Rhinorrhea is decreased in dogs after nasal application of botulinum toxin

At this time no effective long-term therapy exists for the excessive secretion of vasomotor rhinitis. Because rhinorrhea is under parasympathetic control, it was theorized that botulinum toxin--a powerful and long-acting cholinergic blocker that has been successful in the treatment of dystonia--might be useful in blocking the cholinergic control of rhinorrhea. Four male mongrel dogs were studied. Fifty units of type A botulinum toxin was soaked into sterile gauze, which was then packed into the left nasal cavity of each dog for 1 hour. Saline-soaked gauze was similarly introduced into the right nasal cavity to serve as control. Six days later, rhinorrhea was produced by inserting a bipolar needle electrode into the sphenopalatine ganglion and electrically stimulating for 10 minutes (6 mA, 50 Hz). Nasal secretions were collected with a suction catheter placed in the nasal vestibule. Three of four dogs exposed to the toxin showed a 41% average decrease in rhinorrhea (specifically 53%, 41%, and 30%). One dog showed a 10% increase in secretion after exposure to the toxin. We conclude that topically applied botulinum toxin reduced neurally evoked rhinorrhea by an average of 41%. Because some secretion is mediated by noncholinergic neurotransmitters such as vasoactive intestinal peptide, topical application of an anticholinergic substance has limitations. However, because all the nasal parasympathetic nerves appear to originate from cholinergic synapses in the sphenopalatine ganglion, direct injections of toxin into this ganglion may possibly allow complete blockade of all cholinergically mediated rhinorrhea.

The human communicating nerve. An extension of the external superior laryngeal nerve that innervates the vocal cord

OBJECTIVE

A second source of motor innervation for the thyroarytenoid (TA) muscle, other than the recurrent laryngeal nerve, has been suggested by clinical and experimental observations. Early anatomists noted what appeared to be small nerves connecting the cricothyroid and TA muscles; however, these observations were disputed by later anatomists and subsequently forgotten.

METHOD

In this study, we processed 27 human hemilarynges with Sihler's stain, a technique that clears soft tissue and counterstains nerve. In addition, four communicating nerves (CNs) were frozen sectioned and stained for acetylcholinesterase, a marker for motor neurons.

RESULTS

In 12 (44%) of the 27 specimens, a neural connection was found that exited the medial surface of the cricothyroid muscle and then entered into the lateral surface of the TA muscle. In general, this CN was composed of two parts: an intramuscular branch usually combined with the recurrent laryngeal nerve or terminated within the TA muscle directly and an extramuscular branch that passed through the TA muscle and terminated in the subglottic mucosa and around the cricoarytenoid joint. All four CNs tested positive for acetylcholinesterase. Specifically, the CNs contained an average of 2510 myelinated axons, of which 785 (31%) were motor neurons.

CONCLUSION

The results suggest that when the CN is present, it supplies a second source of motor innervation to the TA muscle and extensive sensory innervation to the subglottic area and cricoarytenoid joint. In addition, the CN may be the nerve of the fifth branchial arch, a structure that has never been identified (to our knowledge).

The innervation of the human posterior cricoarytenoid muscle: evidence for at least two neuromuscular compartments

Recent work has demonstrated that the dog posterior cricoarytenoid (PCA) muscle is composed of three neuromuscular compartments: a vertical, an oblique, and a horizontal. In this study, the human PCA muscle was examined for evidence of neural compartments. Fifteen human PCA muscles were processed by Sihler's stain, which renders the muscle translucent while counterstaining the nerve supply. The results clearly show that in all specimens the nerve supply of the human PCA muscle is separated into at least two main branches: one supplies the horizontal compartment and a second further subdivides to innervate both the vertical and oblique compartments. In 10 of the specimens, these nerve branches arose as separate branches from the recurrent laryngeal nerve. In all specimens, the nerve branch to the horizontal compartment was either combined or connected with the nerve branch to the interarytenoid muscle. The results suggest that the different compartments of the PCA muscle have distinct functions. In addition, the strong connections with the interarytenoid nerve complicate reinnervation procedures to reanimate a paralyzed or transplanted larynx.

The intramuscular innervation of the human interarytenoid muscle

The nerve supply of the human interarytenoid (IA) muscle has been controversial for more than a century. In this study the contribution of the recurrent and superior laryngeal nerves to the IA was investigated in 10 adult human larynges. The larynges were obtained from autopsies and processed with the modified Sihler's technique which clears soft tissue while staining nerve. The IA muscles were dissected off the specimens and transilluminated to demonstrate their nerve supply. The results demonstrated that all 10 IA muscles were bilaterally innervated by both recurrent laryngeal nerves (RLNs) as well as branches of both superior laryngeal nerves (SLNs). These nerves combined within the IA muscles to form a dense anastomotic plexus which was highly variable between specimens. The exact nature of the internal SLN neurons, whether motor or sensory, their innervation targets, or their function, were not discernible. Additional anatomic findings were the presence of large neural communications directly between the SLN and RLN, and smaller neural connections from side to side. All of these results disagree with currently accepted descriptions of laryngeal neuroanatomy.

Localization of the gene for human heart fatty acid binding protein to chromosome 1p32-1p33

Heart fatty acid binding protein (hFABP) is an abundant 14-kDa cytosolic protein thought to be involved in trafficking of fatty acids from the plasma membrane to sites of beta-oxidation in mitochondria and peroxisomes and to the endoplasmic reticulum for lipid synthesis. A human hFABP cDNA isolated by polymerase chain reaction was used as a probe for in situ hybridization to metaphase chromosomes. A fragment of the gene for human hFABP was used as a probe for fluorescence in situ hybridization to metaphase chromosomes. The cDNA and genomic probes both localized the gene for human hFABP to chromosome 1p32-1p33.

The intramuscular nerve supply of the human lateral cricoarytenoid muscle

The lateral cricoarytenoid (LCA) muscle is one of the adductors of the vocal cords; however, some investigators believe that the lateral edge of the muscle may be involved in abduction. The possibility of functionally distinct compartments within the LCA was investigated by observing the pattern of the intramuscular nerve supply. This technique has previously clearly demonstrated neural compartments in the posterior cricoarytenoid, thyroarytenoid and cricothyroid muscles. Five adult human larynges were processed by the Sihler's stain which clears all soft tissue while counterstaining the nerves. The results of our study showed that the innervation pattern of the human LCA muscle is composed of a homogenous nerve plexus localized to the middle region of the muscle. This pattern correlates with the location of motor endplates described by prior investigators. The consistent neural pattern suggests that the LCA is composed of a single neuromuscular compartment.

The innervation of the human larynx

OBJECTIVE

To investigate the gross anatomy of the recurrent and superior laryngeal nerves (RLNs and SLNs) in 10 human larynges.

METHODS

Whole larynges were processed to clear all soft tissue while leaving nerves stained. Then the main laryngeal nerves and the muscles they innervate were dissected and analyzed.

RESULTS

It was found that in all larynges the RLNs and SLNs are connected by nerve branches other than Galen's anastomosis. The most consistent connection is in the interarytenoid muscle, where RLNs and internal SLNs combine in a neural plexus. A less consistent connection occurs in the piriform fossa, where a continuation of the external SLN passes from the cricothyroid muscle to the thyroarytenoid muscle.

CONCLUSION

Based on these findings it is proposed that there are significant neural connections between the RLN and SLN systems. In addition, limited cross-innervation is seen from side to side in the area of the interarytenoid muscle. Other findings concern the innervation patterns within the laryngeal muscles. The posterior cricoarytenoid, cricothyroid, and thyroarytenoid muscles all appear to be composed of separate bellies based on the configuration of their nerve supply. Most notable is the region of the thyroarytenoid muscle at the vocal cord margin that is innervated by a nerve plexus of extreme complexity. The details of the innervation patterns suggest functional differences within and between laryngeal muscles.

High-resolution mapping of probes near the X-linked lymphoproliferative disease (XLP) locus

Fluorescence in situ hybridization (FISH) was employed in high-resolution mapping of probes near the X-linked lymphoproliferative disease (XLP) locus. The map includes the DXS42, DXS12, DXS6, DXS982, DXS739, DXS75, DXS100, DXS10, and DXS177 loci. Metaphase analysis showed that DXS12 and DXS42 mapped to proximal Xq25, while DXS10 and DXS177 mapped to proximal Xq26.1. DXS6, DXS982, DXS739, DXS75, and DXS100 were in Xq25. The order of probes deduced from interphase FISH was: Xq24-(DXS12, DXS42)-DXS6-DXS982-DXS739-DXS75-DXS100+ ++-DXS10-DXS177-Xq26.2. We estimate that the entire region between DXS12 and DXS177 is about 7 Mb. Our previous study indicated that all three XLP deletions (63-3, 66-1, and 43-4) lacked DXS739. We now report that DXS75 and DXS982 are also missing in these deletions. Using interphase FISH measurements, we estimate that 2 Mb are absent in 63-3, and 4 Mb are absent in 66-1 and 43-4. This FISH map confines the XLP candidate gene region to a 2-Mb interval between DXS6 and DXS100 and places DXS100 distal to the XLP locus. This study also demonstrates that small probes (0.6 to 3.6 kb) can be utilized in FISH.

Characterization of three overlapping deletions causing X-linked lymphoproliferative disease

Blot hybridization was used to find DNA sequences missing in a male who lacked two-thirds of Xq25. The probes were used to discover two additional males with deletions resulting in X-linked lymphoproliferative disease (XLP). All three deletions have a region in common, and DXS739 is within this candidate region. The new deletions were also detectable using chromosome banding, and the smallest removes only one-third of Xq25. XLP is the only consequence of the deletions.

A technique for displaying the entire nerve branching pattern of a whole muscle: results in 10 canine posterior cricoarytenoid muscles

There is anatomical and histological evidence for three functionally distinct muscle bellies in the canine posterior cricoarytenoid (PCA) muscle. This study attempted to define the exact nerve branching pattern to each muscle belly in 10 dogs using a modification of Sihler's neural staining technique. The results are presented here as photographs and schematic nerve maps which illustrate the following points. 1. the final terminal branches within the PCA do correspond to the three bellies of the PCA; 2. the initial nerve branch to the PCA is usually composed of multiple fascicles which rearrange before their final branching to the three bellies; 3. there is tremendous variability of the nerve branching patterns including bilateral asymmetry within the same animal; 4. the terminal branching within each belly can be surprisingly complex and contain multiple anastomoses; 5. the fast- and slow-twitch bellies of the PCA have different terminal branching patterns. These results support the functional subdivision of the canine PCA into three distinct neuromuscular compartments. This microanatomical technique appears useful for studying the basic neuromuscular organization of laryngeal muscles and their developmental and pathological changes.

The three bellies of the canine posterior cricoarytenoid muscle: implications for understanding laryngeal function

The posterior cricoarytenoid (PCA) muscle is known to be active during phonation and respiration. The presence of muscle compartments (bellies) that might subserve these functions was investigated in the canine PCA by anatomical dissection and muscle fiber histochemistry. Five PCA muscles were microdissected and the origins and insertions of all muscle bundles were recorded. An additional six PCA muscles were frozen, sectioned, and stained for adenosine triphosphatase (ATPase) activity. The total number of fast- and slow-twitch fibers were counted and their proportion was determined for each region of the muscle. The PCA muscle was found to contain three distinct neuromuscular compartments. The vertical compartment is oriented at 24 degrees from true vertical, inserts on the lateral aspect of the muscular process of the arytenoid, and is composed of 65% type 2 (fast) muscle fibers. The oblique is oriented at 44 degrees from vertical, inserts on the top of the muscular process of the arytenoid, and is composed of 77% type 2 muscle fibers. The horizontal is oriented at 63 degrees from vertical, inserts on the medial aspect of the muscular process of the arytenoid, and is composed of 59% type 2 muscle fibers. The cricoarytenoid joint is capable of three arcs of motion and the physical arrangement of each compartment appears to correspond to each of these motions. Moreover, the histochemical profiles show that the activity of the three bellies is quite different. These results suggest that the different compartments of the PCA perform distinctive motions during phonation and inspiration.

In situ hybridization applied to Waardenburg syndrome

Multilocus linkage analysis has suggested that the Waardenburg syndrome type 1 (WS1) locus is flanked by placental alkaline phosphatase (ALPP) and fibronectin 1 (FN1). We used fluorescence in situ hybridization (FISH) to map ALPI (intestinal alkaline phosphatase) to 2q36.3-q37.1 and FN1 to 2q34. FISH also showed that a WS1 patient with a de novo interstitial deletion of 2q35-q36.1 retained both API and FN1 on the deleted chromosome. The human PAX3 gene has been shown previously to be mutated in at least two WS1 patients. We mapped a PCR product from the PAX3 gene to 2q35 and found it was absent in the deleted chromosome. Thus, our FISH mapping results confirm the conclusions from previous linkage analysis and support the conclusion that mutation of the PAX3 gene can cause Waardenburg syndrome.

Quantitative mapping of the effect of botulinum toxin injections in the thyroarytenoid muscle

Spasmodic dysphonia has been successfully treated by thyroarytenoid muscle injections of botulinum toxin (Botox) with dosages ranging from 0.625 to 25 U. In some patients, excessive paralysis with resulting breathiness and aspiration have been noted. In order to maximize the efficiency of Botox injections, the histologic effects of various Botox dosages were examined in the dog. Nine canine thyroarytenoid muscles were injected with 0.5 to 12.5 U of Botox. After 24 hours, the recurrent laryngeal nerve to the injected muscle was electrically stimulated in order to deplete the glycogen within the muscle fibers. Frozen sections of this muscle were then stained for glycogen. Those fibers that retained their glycogen were presumed paralyzed by the Botox injection. The extent of paralysis was found to be dose-related from 1.0 to 7.5 U. At 10 U and above the muscle was completely paralyzed. Spread of the toxin to the lateral cricoarytenoid muscle was seen at doses as low as 1.0 U. Clearly, doses less than 10 U appear sufficient for clinical paralysis.

A technique for demonstrating the nerve supply of whole larynges

At present there is a large gap in our understanding of the exact distribution of sensory and motor nerves within the larynx. Gross dissection is only accurate for large-caliber nerves, whereas microscopic sections show only isolated examples of terminal branching. To fill this gap, we modified an old technique called Sihler's stain to process five whole canine larynges. The technique requires eight steps that take approximately 3 months. The result is an entire larynx in which muscle and cartilage are rendered translucent, while nerve is counterstained. Nerve branching can be continuously traced from the large-caliber nerves to the terminal branches. We found that the nerve patterns are surprisingly complex and contain frequent anastomotic networks. This technique is a powerful tool for studying certain neurolaryngological problems.

The intramuscular nerve supply of the posterior cricoarytenoid muscle of the dog

The paired posterior cricoarytenoid (PCA) muscle has three separate muscle bellies that differ in muscle fiber type (percentage of fast vs. slow twitch) and electromyelographic activity, and, in addition, produce different movements of the arytenoids when stimulated. An investigation of the innervation of the muscle was undertaken to demonstrate the existence of separate functional units. The intramuscular nerve supply of the PCA from five sacrificed dogs were microdissected. The intramuscular nerves of three additional dogs were removed and stained for acetylcholinesterase, which differentiates axons bound for fast- and slow-twitch muscle, and sensory end organs. Three separate fascicles are described entering the PCA muscle from a single branch of the recurrent laryngeal nerve. The three fascicles differ in axon type composition and in sensory, autonomic, and motor percentages, with the ratio of fast twitch to slow twitch varying from 0.78 to 1.5 to 1.7 (P less than .05). This variation supports separate functional capabilities for the three muscle bellies of the PCA.

Quantifying the spread of botulinum toxin through muscle fascia

Botulinum toxin was recently approved for treating several head and neck dystonias. Paralysis of neighboring muscles is the major complication of its use. Spread of toxin from the injected muscle has been suggested as an etiology. This study examines how botulinum toxin crosses muscle fascia by a novel method of quantifying muscular paralysis. Botulinum toxin (0.2 to 10 U) was placed onto the fascia of rat tibialis anterior (TA) muscles (n = 6). Toxin was also placed on dose-matched muscles that had their fascia surgically removed (n = 6). Twenty-four hours later, the nerve to the tibialis anterior was electrically stimulated to deplete the muscle fibers of glycogen. Toxin-paralyzed fibers retained their glycogen and appeared purple on periodic acid-Schiff (PAS) stain. Botulinum toxin easily passed through muscle fascia even at subclinical doses. The presence of fascia reduced the spread of botulinum toxin by 23%. These results suggest that spread of botulinum toxin can be prevented only by delivering small doses to the center of a target muscle.

Reinnervation of the canine posterior cricoarytenoid muscle with sympathetic preganglionic neurons

This experiment investigated the reinnervation of the canine posterior cricoarytenoid (PCA) muscle with preganglionic neurons of the sympathetic nervous system. Six dogs had their right recurrent laryngeal nerve (RLN) sectioned. Four of these dogs had the sympathetic cervical trunk (SCT) implanted into the right PCA muscle, and the two remaining dogs served as denervated controls. Four months later all dogs underwent videolaryngoscopy, electromyography, and electrical stimulation of the SCT. The PCA muscles were excised, sectioned, and stained for glycogen and ATPase. All four experimental PCA muscles demonstrated electrically evoked abduction and tonic electromyographic activity. In two of the specimens, staining (ATPase and PAS) revealed areas of reinnervation with fiber type grouping and glycogen depletion. These results are consistent with the successful reinnervation of the PCA muscle. Further refinement of this technique could be of benefit to patients with bilateral vocal cord paralysis.

Transmucosal electrical stimulation of laryngeal muscles

A new technique is described that enables discrete activation of individual laryngeal muscles by electrical stimulation across overlying mucosa. In 15 dogs, we defined six distinct motor points by transmucosal stimulation at 3 mA while observing the resulting characteristic position of the arytenoid and true vocal cord. Five dogs were then paralyzed with succinylcholine in order to simulate bilateral vocal cord paralysis. Application of a 3-mA stimulus at each motor point yielded no motion of the cords, but when the current was increased to 20 mA, characteristic responses were elicited. In five other dogs, botulinum toxin was injected directly into laryngeal muscles. Stimulation was used in an attempt to quantify the degree of neuromuscular blockade. In the last group of five dogs, we simulated cricoarytenoid arthritis by scarifying the joint. The extent and nature of the joint's impairment could be demonstrated by stimulation. Transmucosal stimulation appears promising as a clinical technique for correlating particular vocal cord movements and thresholds of activation with specific laryngeal disorders. Additionally, such a technique may be useful in clarifying how each laryngeal muscle acts upon the cricoarytenoid joint.

Overcoming laryngospasm by electrical stimulation of the posterior cricoarytenoid muscle

The intent of this study was to demonstrate that the technique of transmucosal electrical stimulation of laryngeal muscles may be of clinical use in airway management. Specifically, its ability to overcome laryngospasm was evaluated. Laryngospasm was induced in eight tracheotomized dogs by hyperventilating each dog, and then applying 0.1 M ammonia to the laryngeal mucosa while administering continuous positive airway pressure (CPAP). Laryngospasm was defined by steady apposition of the vocal cords, massive electromyographic activity in the laryngeal adductor muscles, absence of such activity in the posterior cricoarytenoid muscle (PCA), and intraglottic pressure greater than 80 mm Hg. Upon transmucosal application of 10 mAmp current to the PCA bilaterally, the vocal cords abducted for the duration of the stimulus. We theorize that overcoming laryngospasm by electrostimulation involves a reflexive inhibition of the laryngeal adductors. This study provides an objective model for laryngospasm, and demonstrates that electrical manipulation of the vocal cords may have clinical relevance.

Studies of fish zona pellucida by high-performance ion-exchange chromatography on agarose columns and free zone electrophoresis

By either free zone electrophoresis or high-performance ion-exchange chromatography on DEAE agarose, zona pellucida from Baltic small herring (Clupea harengus L.) was separated into several fractions. These fractions had very similar protein compositions, since on polyacrylamide gel electrophoresis in sodium dodecyl sulphate they all gave the same pattern: chiefly one major and three minor bands corresponding to proteins with the following estimated molecular weights: 78 000, 96 000 (the major component), 115 000, and 125 000. It is likely that these proteins constitute the so-called supramolecular complexes of zona pellucida from Baltic small herring. Only one electrophoretic and one chromatographic fraction gave precipitin arcs on immunodiffusion with rabbit antiserum against zona pellucida from the fish Aristichthys nobilis (Richardson).