Registrar perceptions on general surgical training in South Africa: A report by the South African Society of Surgeons in Training (SASSiT).

BACKGROUND: Surgical training varies significantly amongst universities within the same country. This trend is reflected in South Africa and provides an opportunity for innovation to improve the quality of general surgical training. OBJECTIVE: To assess the perceptions of South African general surgery registrars regarding surgical training. METHOD: A prospective descriptive study was performed by means of a confidential questionnaire distributed to general surgical registrars at all eight training centers in South Africa. Participants were asked to give comments regarding adequacy of formal academic teaching, level of supervision during surgical procedures, exposure to and training in minimally invasive surgery (MIS), and preparation for examinations. Descriptive statistics were generated with Microsoft Excel. Ethics clearance was obtained from the University of the Witwatersrand Human Research Ethics Committee. RESULTS: Of 200 questionnaires distributed 105 (52.5%) were returned. 44% (105/241) of all registrars from six training institutions participated. 89.5% (94/105) of respondents reported that they attended less than six hours of formal academic teaching per week and 71.4% (75/105) indicated that their institution offered less than six hours of formal academic teaching per week. 76.2% (80/105) of respondents regarded lack of protected academic time as the greatest obstacle to their surgical training and 95.2% (99/105) reported that clinical responsibilities prevented them from attending formal academic teaching regularly. Overall, only 31.4% (33/105), 41.9% (44/105) and 37.1% (39/105) were satisfied with the amount of formal academic teaching, level of supervision during theatre procedures and exposure to minimally invasive surgery respectively. Lack of resources and lack of appropriate skills were identified as a hindrance to MIS training by 47.6% (50/105) and 28.6% (30/105) of respondents respectively. CONCLUSION: Surgical registrars are dissatisfied with the amount of formal academic teaching and protected academic time, level of supervision in theatre and their exposure to MIS. These challenges compromise trainees' ability to practice independently after qualification. Numerous interventions are necessary and possible to address these challenges.

Comparing laparoscopic appendectomy to open appendectomy in managing generalised purulent peritonitis from complicated appendicitis: the uncharted path.

BACKGROUND: The objective of the study was to compare the outcomes of patients with generalised purulent peritonitis from complicated appendicitis diagnosed intraoperatively who were managed laparoscopically to those managed via the open approach in a single institution. METHOD: Data were collected from all cases admitted at Sebokeng Hospital, Johannesburg, over the past two years (2008 and 2009) with an intraoperative diagnosis of generalised purulent peritonitis from complicated appendicitis. Cases managed laparoscopically or by the open approach were analysed. The demographic findings, theatre duration, complications, days to the commencement of a full ward diet and the length of the hospital stay were the analysed parameters. RESULTS: One hundred and twenty appendectomies with generalised purulent peritonitis were performed during the study period. Of these, 58 patients underwent open appendectomy, and 62 patients had laparoscopic appendectomy. Both groups were comparable with regard to the demographics and preoperative findings. Theatre duration was significantly higher in the laparoscopic appendectomy group -116 minutes for a laparoscopic appendectomy compared to 87 minutes for an open appendectomy. The rate of intra-abdominal sepsis was also higher in the laparoscopic appendectomy group - 13% for a laparoscopic appendectomy, and 9% for an open appendectomy. A statistically significant decrease in the wound sepsis rate was shown in the laparoscopic appendectomy group. No statistical significant difference was demonstrated with regard to other postoperative complications, days to the commencement of a full ward diet and the length of hospital stay in both groups. More time (an average of 3.7 days) was spent in the intensive care unit and high care unit by those in the open appendectomy group, than those in the laparoscopic appendectomy group (an average of 2.0 days). However, age, duration of symptoms, clinical presentation and white blood cell count were influencing factors on the outcome measures in the open appendectomy group. CONCLUSION: Generalised purulent peritonitis from complicated appendicitis can be managed successfully laparoscopically. Both approaches are feasible, safe and have comparable outcomes. The laparoscopic approach resulted in fewer postoperative wound sepsis complications.

Haemangiopericytoma/solitary fibrous tumour of the greater omentum.

We report a rare case of haemangiopericytoma/solitary _brous tumour of the greater omentum in a 41-year-old woman. It presented as a large mobile abdominal mass measuring 30 × 24 × 8 cm. A computed tomography scan con_rmed the presence of a large vascular tumour, and biochemical tumour markers were non-contributory. The tumour was removed through a conventional laparotomy incision with the aid of a Ligasure dissector. There were no macroscopic metastases, and histologically it was benign. The size of >5 cm, however, suggests that it may have been malignant. In the absence of visible metastases and in view of the favourable histological features, it was decided to follow up the patient very closely and give further treatment if necessary.

Randomised controlled trial of intramuscular tramadol versus transdermal buprenorphine patch for early postoperative surgical pain.

BACKGROUND: This study assesses the efficiency of the buprenorphine patch system compared to the routine use of tramadol intramuscular injections in the context of the South African public healthcare sector. METHODS: Patients were randomised into two groups, who received routine tramadol injections 100 mg every 8 hours intramuscular and buprenorphine patches 5 mcg every hour. The study assessed the first 48 hours postoperatively. A visual discrete pain scale was used to assess the level of postoperative pain as well as all complications associated with insufficient analgesic administration. RESULTS: The sample size included 75 patients in the tramadol group and 75 patients in the buprenorphine patch group. Nine patients (12%, p-value < 0.0001) who received the buprenorphine patch subsequently required additional analgesia. The pain score was found to be significantly less in the buprenorphine patch group on both day 1 and day 2, as were complications such as vomiting, nausea, nightmares, sweating and insomnia. The pain score in the buprenorphine group as significantly lower compared to the tramadol group. The use of the buprenorphine patch showed a slight increase in costs compared to the tramadol group (R7 800.75 vs R7 537.50; p-value 0.483) in the whole study. CONCLUSION: The study showed that the use of the buprenorphine patch is a reliable and effective method of postoperative analgesia, although it is slightly more expensive compared to the routine use of tramadol. The buprenorphine patch showed significantly better results in all assessed parameters; thus, it may be recommended for use at the Dr George Mukhari Academic Hospital (DGMAH).

Failed extubation in a tertiary-level hospital intensive care unit, Pretoria, South Africa.

Background: A prospective cohort study sought to measure the incidence and outcomes of failed extubation in Dr George Mukhari Academic Hospital intensive care unit (ICU), as well as to identify possible factors associated with failed extubation. Methods: Data were collected over a 6-month period from 1 July 2015 to 31 December 2015. Pre-intubation parameters recorded on the data collection sheet included secretions, Glasgow Coma Scale (GCS), fluid balance, Tobin index, partial pressure of carbon dioxide (pCO2 ), partial pressure of oxygen (PaO2 ), comorbidities and weaning method. Results: A total of 242 patients were enrolled over the 6-month study period. Of the 242 patients, 86 were excluded owing to pre-set exclusion criteria (death before extubation; tracheostomy before extubation; re-intubation >72 hours post extubation). An extubation failure rate of 16.7% (n=26) was observed. The incidence of ventilator-associated pneumonia in the failed extubation group was 19.23%, whereas death was recorded in 42.31% of patients who failed extubation. The average length of ICU stay in the reintubated group was 11.58 days, and 4.04 days for successfully extubated patients. Only low GCS had a statistically significant impact on failed extubation: p=0.0025; odds ratio (OR) for low v. normal 5.13 (95% confidence interval (CI) 1.78 - 14.79). Other predictor variables measured did not reach statistical significance. Weaning method: p=0.3737, OR for No T-piece v. T-piece 1.65 (95% CI 0.547 - 4.976); comorbidities: p=0.5914, OR for two or more comorbidities v. no comorbidities 2.079 (95% CI 0.246 - 17.539), no comorbidities v. single comorbidity 0.802 (95% CI 0.211 - 3.043); fluid balance: p=0.6625, OR for negative v. positive fluid balance 0.571 (95% CI 0.170 - 1.916), OR for neutral v. positive fluid balance <0.001 (95% CI <0.001 - >999.999); pCO2 : p=0.7510, OR for high v. normal pCO2 1.344 (95% CI 0.346 - 5.213), OR for low v. normal pCO2 1.515 (95% CI 0.501 - 4.576); PaO2 : p=0.4405, OR for high v. normal 1.156 (95% CI 0.382 - 3.494); OR for low v. normal PaO2 2.638 (95% CI 0.553 - 12.587); Tobin index (Fischer's exact test): p=0.7476. Conclusion: Low pre-extubation GCS is a predictor of failed extubation. Contributions of the study: The study is a prospective observational study conducted in a high-volume referral hospital. It adds valuable scientific information to a growing body of data on the topic of extubation failure. It further reinforces the importance of extubation failure and the requirement for due diligence to be paid before a patient is extubated.

A step towards international prospective trials in carbon ion radiotherapy: investigation of factors influencing dose distribution in the facilities in operation based on a case of skull base chordoma.

BACKGROUND: Carbon ion radiotherapy (CIRT) has been delivered to more than 20,000 patients worldwide. International trials have been recommended in order to emphasize the actual benefits. The ULICE program (Union of Light Ion Centers in Europe) addressed the need for harmonization of CIRT practices. A comparative knowledge of the sources and magnitudes of uncertainties altering dose distribution and clinical effects during the whole CIRT procedure is required in that aim. METHODS: As part of ULICE WP2 task group, we sent a centrally reviewed questionnaire exploring candidate sources of uncertainties in dose deposition to the ten CIRT facilities in operation by February 2017. We aimed to explore native beam characterization, immobilization, anatomic data acquisition, target volumes and organs at risks delineation, treatment planning, dose delivery, quality assurance prior and during treatment. The responders had to consider the clinical case of a clival chordoma eligible for postoperative CIRT according to their clinical practice. With the results, our task group discussed ways to harmonize CIRT practices. RESULTS: We received 5 surveys from facilities that have treated 77% of the patients worldwide per November 2017. We pointed out the singularity of the facilities and beam delivery systems, a divergent definition of target volumes, the multiplicity of TPS and equieffective dose calculation approximations. CONCLUSION: Multiple uncertainties affect equieffective dose definition, deposition and calculation in CIRT. Although it is not possible to harmonize all the steps of the CIRT planning between the centers, our working group proposed counter-measures addressing the improvable limitations.

Laparoscopy for blunt abdominal trauma: a challenging endeavor.

BACKGROUND AND AIMS: Laparoscopy in blunt abdominal trauma is challenging because of multiple associated injuries, higher trauma score values and higher morbidity and mortality, as compared with patients with penetrating abdominal trauma. The aim of this study was to investigate the role of laparoscopy in the management of blunt abdominal trauma patients and to highlight related challenges. MATERIAL AND METHODS: Over a 4-year period, patients managed laparoscopically for blunt abdominal trauma were retrospectively analyzed. Perioperative details, indications for laparoscopy and conversion, complications, and length of hospital stay were discussed. RESULTS: A total of 35 stable patients underwent laparoscopy. The mean Injury Severity Score was 12 (4-38). Therapeutic laparoscopy was performed in 15 (56%) and diagnostic in 12 (44%) patients. Eight (23%) patients were converted to therapeutic laparotomy. Intraoperative bleeding, complex injuries, visualization problem, and equipment failure necessitated conversion. Three (30%) patients with negative computed tomography scan had therapeutic laparoscopy for mesenteric injuries. There were no missed injuries. The mean length of hospital stay was 11 days in both groups. CONCLUSION: Laparoscopy for stable patients is feasible and safe. Multiple injuries make laparoscopy more difficult, and advanced laparoscopic skills are required. The conversion rate is high; however, the non-therapeutic laparotomies were completely eliminated in this study.

Laterality of breast cancer at Dr George Mukhari Academic Hospital.

BACKGROUND: The purpose of this descriptive study was to determine and compare the incidence of left-sided and rightsided breast cancer at Dr George Mukhari Academic Hospital from January 2000 to June 2016. It aimed to determine if there was a significant variation in laterality of breast cancer at our institution. METHOD: A retrospective study. Medical records of breast cancer (BC) patients who were newly diagnosed from January 2000 to June 2016 were reviewed. Emphasis was on biopsy results (histology and/or cytology) and/or history of chemotherapy, and breast cancer laterality. RESULTS: Out of 1482 patients, 1427 had unilateral BC and 55 (3.7%) bilateral cancer. A total of 789 (55.3%) patients had left-sided breast cancer (LSBC) and 638 (44.7%) had right BC. Left BC was 10.6% more common than right BC with a left to right laterality ratio (LRR) of 1.24. There was a statistically significant relationship between laterality and stage (p = 0.050), with the right breast having more advanced stage cancers (88.7%) compared to the left breast (85%). There was no statistically significant difference between age, site and histological type of BC and laterality (p = 0.740, p = 0.052, p = 0.394 respectively). CONCLUSION: Left to right BC excess does exist in patients that were newly diagnosed at Dr George Mukhari Academic Hospital, South Africa, from January 2000 to June 2016.

Trauma laparoscopy: A prospect of skills training (cohort study).

BACKGROUND: Diagnostic laparoscopy is well-accepted in management of penetrating abdominal trauma (PAT) with the rate of missed injuries below 1%. However, there is a reluctance to accept therapeutic laparoscopy in trauma society. The possible reason is a lack of laparoscopic skills by trauma surgeons. Moreover, no formal laparoscopy training program for trauma exists. The aim of this study was to interrogated our laparoscopy training particularly in trauma setting, and to investigate a possible relation between the seniority of surgeons performing the procedures and the complication rates. METHODS: All patients managed laparoscopically for PAT from January 2012 to December 2015 were analyzed. The seniority of operating surgeon was correlated with adverse outcomes, and with conversion. Surgeon-consultant (SC), assistant-consultant (AC), surgeon-senior-resident (SSR) and surgeon-junior-resident (SJC) groups were identified. Laparoscopic maneuvers used in this cohort were investigated and the set of essential laparoscopic skills was identified. The laparoscopic training program at our institution was described and discussed. RESULTS: Out of 283 patients with PAT approached with laparoscopy 33 (11.7%) were converted to laparotomy. Majority (49.6%) of laparoscopy was performed by senior resident. Consultant was an operating surgeon in 21.2% and an assistant in 8% of cases. Consultant was involved in cases with higher severity of injury and the complication rate was higher in the SC and AC groups. Essential laparoscopic skills were camera navigation, mobilization of intraabdominal organs, bowel run and intracorporeal suturing. During training, a senior resident was involved in 19% of operations for trauma. Trauma constituted 16% of all laparoscopy. CONCLUSION: Laparoscopy for trauma can be safely performed by residents under appropriate supervision. Laparoscopic skills should preferably be obtained during elective non-trauma procedures and transferred to trauma setting. Multimodal goal-directed, proctored training with regular assessments and feedback is effective and skills are transferable to trauma setting.

An investigation of diverticular disease among black patients undergoing colonoscopy at Dr George Mukhari Academic Hospital, Pretoria, South Africa.

BACKGROUND: Diverticular disease was previously thought to be non-existent in the black African population. Studies over the past four decades, however, have shown a steady increase in the prevalence of the disease. OBJECTIVE: To report on the profile and current prevalence of diverticular disease in the black South African (SA) population at Dr George Mukhari Academic Hospital, Pretoria, SA. METHODS: A retrospective descriptive study was performed in black SA patients who were diagnosed with diverticular disease by colonoscopy between 1 January and 31 December 2015. RESULTS: Of 348 patients who had undergone colonoscopies and who were eligible for inclusion in this study, 47 were diagnosed with diverticular disease - a prevalence of 13.50% (95% confidence interval 10.30 - 17.50). The greatest number of patients diagnosed were in their 7th and 8th decades, with an age range of 46 - 86 (mean 67) years. There was a female predominance of 57.45%. Lower gastrointestinal bleeding was the most common (65.96%) indication for colonoscopy. The left colon was most commonly involved (72.34%), followed by the right colon (55.31%). A substantial number of patients had pancolonic involvement (27.65%). CONCLUSION: This retrospective study suggests that there has been a considerable increase in the prevalence of diverticular disease among black South Africans, possibly owing to changes in dietary habits and socioeconomic status.

Multiple concurrent bilateral groin hernias in a single patient; a case report and a review of uncommon groin hernias: A possible source of persistent pain after successful repair.

INTRODUCTION: The wide use of laparoscopy for groin hernia repair has unveiled "hidden hernias" silently residing in this area. During the open repair of the presenting hernia, the surgeon was often unaware of these occult hernias. These patients postoperatively may present with unexplained chronic groin or pelvic pain. PRESENTATION OF CASE: Rare groin hernias are defined according to their anatomical position. Challenges in the diagnosis and management of occult rare groin hernias are discussed. These problems are illustrated by a unique case report of multiple (six) coexisting groin hernias, whereof five were occult and two were rare. DISCUSSION: Rare groin hernias are uncommon because they are difficult to diagnose clinically and are not routinely looked for. They are often occult and may coexist with other inguinal hernias, thus posing a diagnostic and treatment challenge to the surgeon, especially if there is persistent groin pain after "successful" repair. MRI is the most accurate preoperative and postoperative diagnostic tool, if there is a clinical suspicion that the patient might have an occult hernia. CONCLUSION: Preperitoneal endoscopic approach is the recommended method in confirming the diagnosis and management of occult groin hernias. A sound knowledge of groin anatomy and a thorough preperitoneal inspection of all possible sites for rare groin hernias are needed to diagnose and repair all defects. The preperitoneal mesh repair with adequate overlap of all hernia orifices is the recommended treatment of choice.

The mathematics of mosaic analysis III. Analysis of structures with extent in two dimensions.

This paper derives formulae for the use of mosaic analysis to determine the sizes, shapes and locations of structures that are not points but are extended areas on the blastoderm. We consider a male patch of any convex shape and size and a structure of any convex shape and size. The probability that these two intersect in a set of mosaics is simply one-quarter the product of their perimeters. From this perimeter formula we derive equations relating the frequency of mosaicism of a structure to its size and we derive a formula for the mapping of lethal foci. We then develop a method to locate the borders of a focus that covers an area on the blastoderm.

Amino acid sequence of heat-labile enterotoxin from chicken enterotoxigenic Escherichia coli is identical to that of human strain H 10407.

The DNA sequence of heat-labile enterotoxin from the chicken enterotoxigenic Escherichia coli 21d strain was determined by direct dideoxy sequencing of polymerase chain reaction (PCR)-amplified DNA and was compared with those of heat-labile enterotoxins from porcine and human enterotoxigenic E. coli strains EWD 299 and H 10407. The structural genes of the A and B subunits of chicken heat-labile enterotoxin were identical to those of human heat-labile enterotoxin from the human H 10407 strain. Moreover, 67 base pairs of the upstream and 60 base pairs of the downstream region of the chicken heat-labile enterotoxin gene were also identical to that of the human heat-labile enterotoxin from strain H 10407. However, the patterns of plasmids from the 21d and H 10407 strains were different. The 21d strain had no band corresponding to the 42-MDa plasmid of the H 10407 strain encoding the heat-labile enterotoxin gene but it had a smaller plasmid. These data suggest that although the DNA sequence of chicken heat-labile enterotoxin is identical to that of human heat-labile enterotoxin, the plasmid encoding the chicken heat-labile enterotoxin gene in the chicken might be different from that encoding the human heat-labile enterotoxin gene in the H 10407 strain.

The morphology of the cervical giant fiber neuron of Drosophila.

The morphology of the cervical giant fiber (CGF) neuron of Drosophila melanogaster was studied by intracellular injection of Lucifer yellow dye. The CGF neuron is the command cell in a motor circuit causing visually driven escape behavior: a single action potential in a CGF axon produces patterned activity in jump and flight muscles. The present study identified the CGF cell body, a large soma located in the posterior part of the lower ipsilateral protocerebrum. The main process runs anteriorly from the cell body, extends three branches, and turns posteromedially while descending through the brain. The CGF axon courses through the cervical connective and ends within the mesothoracic neuromere of the thoracic ganglion. Thus, the CGF neuron is an interneuron, not a motoneuron as previously believed. We have been isolating mutants that affect CGF neuron-mediated behavior. Comparison of CGF neuron morphology in wildtype strains with that in these mutants will allow identification of genes that affect the development, structure, and connections of the CGF neuron.

Effects of aging on bone mineral content and bone biomarkers in female cynomolgus monkeys.

Age-related changes in bone mineral content and bone biomarkers were assessed over the complete lifespan of female cynomolgus monkeys. The bone mass of the lumbar spine increased linearly from birth to about 2.5 years of age, and this increase gradually slowed thereafter until a peak bone mass was achieved at 9 years of age. The bone mass stabilized after 9 years of age, showing no sign of further reduction with age. In contrast with the significant increase in bone mass before 2.5 years of age, significant decreases occurred in the serum concentrations of the following bone formation markers: intact osteocalcin, bone-specific alkaline phosphatase and amino-terminal propeptide of type I procollagen, but the serum concentration of carboxy-terminal propeptide of type I procollagen did not change significantly throughout the entire lifespan. Concerning the bone resorption markers, the levels of tartrate-resistant acid phosphatase fluctuated throughout the entire lifespan. The skeleton of an aging female monkey undergoes changes similar to those observed in senescent humans, but did not undergo the menopausal changes seen in women. The use of female cynomolgus monkeys to model human skeletal interventions should therefore be undertaken with consideration of the similarities and differences between cynomolgus monkeys and humans.

Regression of diet-induced atherosclerosis in Göttingen miniature swine.

The regression of diet-induced atherosclerosis in Göttingen Miniature Swine was investigated after a 6-month induction period. At 1 month after feeding a high-cholesterol and high-fat diet, levels of beta-lipoprotein, total cholesterol, free fatty acids and phospholipid had increased rapidly and the high levels were maintained throughout the 6 month induction period. Morphological features at 6 months showed fatty streaks in the thoracic aorta and fibrous plaques in the abdominal aorta. After return to the conventional diet at 6 months, serum lipids decreased rapidly and maintained the baseline level throughout the 9 month regression period. Histopathological findings showed the regression of fatty streaks but the fibrous plaques did not regress. The present study therefore confirms the regression of fatty streaks in the aorta of Göttingen Miniature Swine by the administration of a cholesterol lowering diet.

[Effect of wall thickness of left ventricle on 201Tl myocardial SPECT images: myocardial phantom study].

201Tl myocardial SPECT is known for better sensitivity, specificity, and accuracy than planar images in detecting coronary artery disease and diagnosing myocardial viability. SPECT images are also superior to planar images in diagnostic sensitivity and anatomical orientation. However, as limitation of the spatial resolution of the machine, we often encounter poor SPECT plower image quality in patients with decreased wall thickness. To test the accuracy of SPECT images in patients with marked thinning of the left ventricular wall, as occurs in dilated cardiomyopathy, we performed a experimental study using myocardial phantom with 7 mm wall thickness. Tomographic image of the phantom images were rather heterogeneous, though no artificial defect was located. Dilated cardiomyopathy is thought to be characterized by patchy defects in the left ventricle. Careful attention should be given to elucidating myocardial perfusion in patients with a thin left ventricle wall, as there are technical limitations in addition to clinical features.

Ultrastructure and movement of the ependymal and tracheal cilia in congenitally hydrocephalic WIC-Hyd rats.

The aim of the present investigation is to determine whether or not hydrocephalus occurring in hydrocephalic Wistar-Imamichi strain rats (WIC-Hyd) is caused by functional and structural disorders of ependymal cilia. Ultrastructures and movement of cilia in the ependyma of the lateral, III and IV ventricles and aqueduct of Sylvius and in the trachea walls of the animals were examined by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and light microscopy using a phase-contrast microscope equipped with a high-speed video recording system. SEM revealed that a marked decrease in the length and number of cilia in the ependymal and tracheal walls occurred in affected male WIC-Hyd. This finding was noted even before the development of ventricular dilatation and was not related to the degree of ventricular enlargement after development of hydrocephalus. A moderate decrease in length and number of cilia was also seen among the normal ciliary tufts in affected female rats which developed a mild degree of hydrocephalus. TEM cilia findings included abnormal axonemal structures such as a lack of dynein arms and displacement of microtubules. The incidence of these ultrastructural abnormalities was found to be greater in affected male rats than in affected female rats. All cilia in affected male rats before and after development of hydrocephalus were immotile. A variety of movement disorders such as immobile, rotatory, and vibratory cilia were observed beside normally beating cilia (motile cilia) in affected female rats which never developed hydrocephalus as severe as that seen in affected male rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructure of respiratory cilia of WIC-Hyd male rats. An animal model for human immotile cilia syndrome.

The WIC-Hyd rat is a mutant from the Csk: Wistar-Imamichi rat, with spontaneous hydrocephalus. In male rats, the hydrocephalus is severe and about one half of hydrocephalic male littermates possess situs inversus totalis. Ependymal cilia in these animals are immotile, and this defect is regarded as a mechanical cause of hydrocephalus. This paper presents the ultrastructural features of respiratory cilia in these rats in comparison with those in human immotile cilia syndrome. The respiratory cilia in these rats also are immotile and the dynein arms are missing, as in human cases. Previously only eight dogs with immotile cilia syndrome and a mutant hydrocephalic-polydactyl mouse were reported with respect to these phenomena. However the WIC-Hyd rat is the first useful animal model for human immotile cilia syndrome, and further studies may serve to clarify the genetic background of this condition.

[rdw rats, a new hereditary dwarf model in the rat].

A new hereditary dwarf mutation was found in Csk: Wistar-Imamichi rat breeding colony. The mutant rats and control normal rats were studied with clinical, genetical and histological examination. The result showed that the present mutation was inherited in autosomal recessive trait (gene symbol; rdw) and was provoked with the hypoplasia of pars distalis (anterior pituitary), in particular the secretory cells of GH, PRL and TSH. The characteristics of the present mutant (rdw) was very similar to dw mouse, and was usefull for endocrinological research as an animal model of human pituitary dwarfism.