The cholecysto-colic relationships. A roentgen-anatomic study of the colonic manifestations of gallbladder disorders.

In approximately 80 per cent of cases the gallbladder is closely applied to the superior medial aspect of the right colic flexure. This intimate anatomic relationship provides pathways for direct extension of both inflammatory and neoplastic lesions of the gallbladder to involve the adjacent colon. The resultant secondary colonic abnormalities noted in 15 patients have been analyzed and correlated with surgical-pathologic findings. In acute cholecystitis, barium enema examination shows evidence of indentation by an enlarged gallbladder, spasm and mucosal edema in the anterior hepatic flexure. Chronic cholecystitis results in involvement of the adjacent colon by fibrous adhesions and inflammatory reaction. These may further lead to the development of pseudotumors simulating primary carcinoma of the colon. Similar findings including cholecysto-colic fistulae may be the initial manifestations of carcinoma of the gallbladder. The spectrum of pathologic-roentgenographic alterations in the cholecysto-colic interface is described and illustrated. Recognition of these features is of critical importance for the correct interpretation of barium enema findings and the subsequent management of patients with gallbladder disorders.


Perforated viscus presenting with gas in the soft tissues (subcutaneous emphysema).

We have reviewed the spectrum of gaseous densities in the soft tissues secondary to a perforated viscus. All patients presented late and most were elderly. The most common surgical procedure was diversion of the fecal stream proximal to the perforation. In our series 4 of 7 patients died in the immediate postoperative period. Knowledge of the mechanism and differential diagnosis of this entity will prevent overlooking this possibility, as occurs too frequently, particularly with subcutaneous emphysema of the leg.


Electronic anal sphincter stimulation in barium enema examination. A preliminary communication.

Electronic stimulation of the external and sphincter muscle was successful in preventing premature evacuation of barium in 28 of 30 patients. All of them were unable on 1 or more occasions to retain the barium during previously attempted studies by conventional methods. None of the patients had an underlying neurologic problem affecting the anal sphincter. No adverse reactions were noted.


Non-contractile movement of tantalum powder in the canine rectum.

Caudad movement of trantalum particles in the rectum was observed in 5 recumbent anesthetized beagle bitches in the absence of muscular contractions as monitored by intrarectal balloons. The movement did not occur after injections of atropine or glucagon alone but did occur when a bisacodyl suppository was introduced in addition to the injection of glucagon. Along with direct observation of rectal mucosa, this strongly suggests the role of mucus as a carrier of the particles.


Angiocardiography with small-size rapid cassette changer films.

The disadvantages of small-size 10 X 10 cm. films in angiocardiography do not preclude correct diagnosis in a well equipped cardiac laboratory. On the contrary, the advantages are such as to recommend a more extensive use. In our department the method has been limited to pediatric patients, mainly because of excessive scattered radiation at high kVp. It is hopeful that improvement in recording and combination with image intensification will make the system available in the future for adult use.


Anatomy of the colon. Guide to intra-abdominal pathology. Hickey Lecture, 1975.

The normal contours and relationships of the colon have been described in a previous publication. I have attempted to show how enlargement of these organs or tumefactions arising within them affect the colon in a characteristic manner. Hopefully this will become useful in: (1) determining the normality of the external contour and variation of the external contour of the colon; (2) detecting a clinically unsuspected mass by an abnormal indentation on the colon; and (3) providing, for the diagnostic work-up of abdominal masses, a primary classification fo abdominal masses. Further, I have tried to emphasize that the lateral aspects of both colic flexures are posterior and tend to reflect abnormality of the posterior structures. The medial aspects of the colic flexures are anteior and likewise reflect abnormality of anterior structures. In addition, I reemphasize that what in the past has been called the splenic flexure (the area of marked angulation of the colon in the left upper quadrant) in reality is merely a portion of distal transverse colon. The more subtle angulation of the colon related to the "splenic angle" and left kidney is the true splenic flexure, the area of the phrenicocolic ligament.


A feasibility study for percutaneous retroperitoneal lymph node biopsy.

A percutaneous technique for the biopsy of retroperitoneal lymph nodes was studied in animals and cadavers. Access to the retroperitoneal space from the groin to the diaphragm has been achieved, and satisfactory biopsies of iliac and lumbar lymph nodes opacified by pedal lymphangiography have been obtained. Further investigations, however, are needed to improve the technique and to minimize the potential hazards associated with this procedure.


Gray scale ultrasound diagnosis of obstructive biliary disease.

B-mode ultrasound examinations have been useful in demonstrating cholelithiasis and obstructive dilatation of the gallbladder. It is now possible with gray scale ultrasound technique to demonstrate dilatation of the common bile duct, as differentiated from the gallbladder, and also to show fluid containing spaces within the liver. Discrimination between solid and fluid filled intrahepatic structures is readily made, and dilated biliary radicles are frequently discernible.


Evaluation of pelvic masses during infusion excretory urography.

Infusion excretory urography not only clearly delineates the urinary tract structures, but provides additional information about the type of pelvic mass present. Benign uterine fibroids show contrast enhancement in a significant number of cases, whereas endometrial and cervial malignancies give no specific pattern. Cystic and mixed ovarian neoplasms show rim opacification in over 50 per cent of cases, and the presence of this rim sign points strongly to an ovarian lesion. The opacification of solid ovarian tumors cannot be differentiated from that of uterine fibroids unless other identifying features such as specific calcification or visualization of a normal uterus are present. Pelvic inflammatory disease shows no specific type of opacification. Excretory urography is part of the preoperative evaluation in most patients with pelvic mass lesions. By utilizing the infusion method, high quality excretory urograms are obtained, and, in addition, helpful information is obtained regarding the type of pelvic mass present.


The utilization and efficacy of pelvimetry.

Data from non random groups of deliveries with some identical clinical factors were compared and certain conclusions are suggested. Most x-ray examinations which cause significant fetal exposure are pelvimetries. There appears to be no uniform set of indications for performing pelvimetry. Instead, the criteria seem to vary from hospital to hospital and even from physician to physician within the same hospital. A normal pelvimetry gives the physicina little confidence that a cesarean section will not be necessary. The duration of labor is not significantly altered by pelvimetry in those cases needing a cesarean section for cephalopelvic disproportion or following unsuccessful oxytocin stimulation.


Intestinal perforation as a complication of the neonatal small left colon syndrome.

Intestinal perforation can occur as a complication of the neonatal small left colon syndrome. Four such infants are reported. Early diagnosis and treatment, utilizing water soluble contrast enema examination, are recommended to reduce the frequency of this complication.


The "starry night" splenic angiogram. Contrast material opacification of the malpighian body marginal sinus circulation in spleen trauma.

In traumatized human spleens, focal 0.3-1 cm. areas of contrast material staining appear to represent the malpighian marginal sinus circulation. This circulation, when seen, is static or very slow moving. Extravasation of blood and contrast material also may be present in the marginal sinus network. The identification of diffuse or localized small areas of contrast material in the splenic angiogram of the traumatized patient suggests splenic contusion, intrasplenic hematoma, or both. The splenic angiographic appearance described may be compared to the globular appearance of stars, as depicted by van Gogh in his painting "The Starry Night."


Experimental use of prostaglandin E1 in nonocclusive mesenteric ischemia.

Nonocclusive mesenteric ischemia was produced in dogs by intraarterial infusion of digoxin and by hemorrhage of 1/3 of total blood volume. Both methods produced a substantial drop in the superior mesenteric arterial blood flow rate. In each case, a superior mesenteric arterial infusion of 0.1 mug./kg. per minute of prostaglandin E1 allowed the blood flow rate to increase to above the control level without significantly altering heart rate or systemic arterial pressure. The improved arterial blood flow rates were accompanied by a reversal of the diffuse mesenteric vasoconstriction that was seen in the ischemic state. These findings were demonstrated by superior mesenteric arteriography performed prior to and following the production of mesenteric ischemia and again following the infusion of prostaglandin E1.


The specificity of renal vein thrombosis.

Clinical and roentgenographic features of renal vein thrombosis are discussed. The authors' experience with 17 cases is presented. The roentgenologist with a high degree of suspicion can, by correlation of clinical and urographic findings, make the specific diagnosis of renal vein thrombosis in a high percentage of cases.


Control of renal hemorrhage by selective arterial embolization.

An attempt was made to control renal hemorrhage by selective embolization of the renal artery in 7 patients. In 2 patients the bleeding site was single, but in 2 others, several sites of arterial extravasation were present. Two patients had arteriovenous fistulas, and 1 had an unsalvageable, macerated kidney. Six of the 7 patients (86 per cent) were treated successfully. Nephrectomy was avoided in 5. No patient developed hypertension during the follow-up of 4 months to 2 years. Our results in these patients indicate that selective arterial embolization should have an important place in the management of patients with renal trauma.


Circumaortic renal collar. A potentially hazardous anomaly of the left renal vein.

The circumaortic renal collar is a potentially hazardous anomaly of the left renal vein. Failure to recognize the dorsal component during retroperitoneal surgery may lead to hemorrhage, nephrectomy or death. The angiographer can make a significant contribution in documenting this anomally in patients who are candidates for surgery in this area.


Submucosal hemorrhage of the renal collecting system.

Two cases of submucosal hemorrhage in the renal pelvis and ureter are presented. The roentgenographic appearance was identical to that of pyeloureteritis cystica but without evidence of urinary tract infection and, in 1 case, the submucosal impression resolved rapidly. When nodular, submucosal filling defects are demonstrated in the renal collecting system in the clinical setting of anticoagulant therapy or trauma, a diagnosis of submucosal hemorrhage should be considered.


Vesicoureteral reflux in adults.

Vesicoureteral reflux was detected in 200 adults seen in a 4 year period. In group 1 (no history of urinary tract infection and negative urine cultures), all patients had abnormalities on excretory urograms that were suggestive of reflux. In patients with a history of recurrent urinary tract infection (groups 2 and 3), the excretory urograms showed an abnormality in 79 per cent of those with negative cultures and in 83 per cent of those with positive cultures. Thus, reflux should be suspected in patients with a history of recurrent urinary tract infection even if infection cannot be documented with urine culture. Urographic evidence of renal parenchymal scarring, ureteral dilatation, or mucosal striations should also suggest the possibility of vesicoureteral reflux even when the patient may have no urinary tract symptoms. Voiding cystourethrography should be performed in all adults with these findings to exclude the possibility of vesicoureteral reflux.


Tomography of pelvic-abdominal masses during intravenous urography. An added dimension.

Experience with a wide variety of pelvic-abdominal masses indicates that good quality tomography during high dose urography permits separation of solid from cystic lesions in almost all cases, even with minimal mass opacification. Evaluation of surface contour, absence or presence of a wall and its features, opacification, calcification, and uterine status provides the framework for characterization of the mass. Multiple masses can be identified and evaluated separately. While titration of the above criteria permits an accurate assessment independent of the clinical diagnosis, the latter information is important in separating a probable abscess from other cystic lesions. Since urography continues to be a pivotal preoperative roentgenologic investigation (ureteral status, pelvic kidney exclusion, etc.), the addition of tomography provides an added dimension to its usefulness. With the exception of the premenopausal female in whom radiation exposure is a consideration, tomography appears to preclude the routine necessity for subsequent ultrasound study which has been used to separate cystic from solid lesions.


Tomography of the kidney bed as an aid in differentiating renal pelvic tumor and stone.

Plain film tomography is of value in detecting small amounts of calcium in "non-opaque" stones. The use of this technique to help differentiate renal pelvic tumor from stone in patients presenting with a filling defect in the renal pelvis is suggested. Four cases in which plain film tomography detected calcium in a renal pelvic stone that could not be seen on routine roentgenograms are presented.


Renal osteodystrophy in patients on hemodialysis as reflected in the bony pelvis.

Roentgen studies in a group of 131 patients on maintenance hemodialysis reveal renal osteodystrophy in 25 patients (19 per cent). In 24 patients of the latter group (98 per cent), the various manifestations of renal osteodystrophy appear in the bony pelvis. These include: osteomalacia; osteitis fibrosa; osteosclerosis; dialysis osteopenia; and extraosseous calcifications. Some of the changes, i.e., bending of bone, Looser's lines, metaphyseal fractures and dialysis osteopenia, are due, at least in part, to the weight bearing nature of the bony pelvis. These findings are ararely, if ever, seen in the digits or in other non-weight bearing bones. It is therefore proposed to evaluate the bony pelvis, together with the magnification digital roentgenogram, when a less costly and less time consuming skeletal survey is needed in hemodialized patients.


Crohn's disease of the esophagus.

Two cases of Crohn's disease involving the esophagus are described. Both patients had Crohn's disease elsewhere. Multiple intramural fistulous tracts are seen in both patients, and this is a characteristic feature of Crohn's disease. One patient developed a spontaneous esophago-bronchial fistula. Even though the esophageal involvement of Crohn's disease is rare, it should be suspected when a chronic esophageal inflammatory lesion develops in a patient who has Crohn's disease elsewhere, especially without hiatus hernia or other chronic disease.


Yeast bezoar formation following gastric surgery.

Yeast bezoar seems to be a relatively common late complication after various gastric operations. The incidence of bezoar depends decisively on the nature of the operation. Vagotomy in particular is conducive to the formation of a bezoar. Vagotomy + Billroth I resection proveded the most propitious conditions for the growth of yeast, for every one-half of the patients in this group developed a bezoar. Yeast bezoars usually appear within a year of the operation. The majority disappear during the first follow-up year, many without any therapy. However, in some cases the bezoar was a rather inconvenient late complication of gastric surgery and one that gave symptoms. It is difficult to draw any definite conclusions concerning the effect of therapy on the disappearance of the bezoar. We used gastric lavage and antimycotics as well as substances that increase gastric acidity. There is still no known method of preventing the formation of yeast bezoars. In the present consensus, a change in the acid conditions and disturbed gastric motility postoperatively are conducive to the formation of a bezoar.


Gallstone ileus. The importance of contrast examinations in the roentgenographic diagnosis.

Our experience based on the analysis of 12 proved cases of gallstone ileus is presented emphasizing the fact that the plain abdominal roentgenogram may be inconclusive or deceiving. It allowed us to suggest the correct diagnosis in only 4 cases. A high index of suspicion, particularly in elderly female patients, followed by barium examination of the upper gastrointestinal tract leads to a correct and rapid diagnosis. The demonstration of a diverticulum-like structure or a fistulous tract adjacent to the first portion of the duodenum associated with jejunal dilatation and barium dilution is highly reliable.


Mediastinal neuroblastoma and ganglioneuroma. The differentiation between primary and secondary involvement on the chest roentgenogram.

The roentgenologic diagnosis and differentiation of mediastinal neurogenic tumors are possible on the chest roentgenogram as a rule. The soft tissue mass may be ill-defined and the tumor "ghost-like" in the case of primary neuroblastoma, but it is usually obvious in ganglioneuroma and metastatic disease. The presence of calcifications differentiates neurogenic tumors from other posterior mediastinal tumors of childhood. They are common in primary and rare in secondary disease. Rib erosions and displacement are striking in neuroblastoma (after a few months of age), more subtle in ganglioneuroma, and absent with secondary involvement. In 3 out of 7 posterior mediastinal neuroblastomas the diagnosis and treatment were delayed, as the adjacent rib changes were not appreciated for some time. "Dumbbell" shaped tumors are usually associated with vertebral changes and myelography is indicated even in the absence of neurologic deficit. Thoracic deformity and disability subsequent to laminectomy, radiation therapy, or both, are present in all survivors.


Benign, solitary schwannomas of the lesser peritoneal sac.

Two cases of a large schwannoma of the lesser omental sac are described. One arose from the lesser omentum itself. This schwannoma also had roentgenographically visible calcifications, a finding never before reported to have been seen in the abdomen. Emphasis is upon the uniqueness of the site of the tumor.


Ebstein's anomaly of tricuspid valve: critical review of roentgenological features and additional angiographic signs.

The plain roentgenographic and angiocardiographic features of 15 patients with Ebstein's anomaly of the tricuspid valve were reviewed. Of note on the plain roentgenogram was the fact that the "posterior bulge" seen on the lateral view was demonstrated to be due to either a markedly enlarged right atrium or the posterior displacement of normal left heart structures. The angiocardiographic features described in the literature were reviewed. Two main features seen were the "sail-like" appearance of the anterior leaflet of the tricuspid valve, which sometimes produces a tumor like picture, and the 2 notches seen when the ventricle contracts. One notch corresponds to the true tricuspid annulus. The other represents the site of attachment of the displaced tricuspid valve. The previously undescribed features were noted: (a) all three leaflets could sometimes be identified; (b) fenestrations in the anterior leaflet were demonstrated in 5cases; and (c) the sinus portion of the ventricle was sometimes filled in a retrograde fashion from the infundibular chamber.


Transarterial electrocoagulation therapy of a pseudoaneurysm in the head of the pancreas.

Because chemical and transcatheter embolizations for control of bleeding were inappropriate, electrocoagulation through a guidewire was used for arterial occlusion. The power was alternating current. The effectiveness of the procedure was confirmed by arteriograms done immediately and 5 months later.


Technique and complications of transumbilical catheterization of the portal vein and its tributaries.

In 120 patients who had 127 transumbilical catheterizations of the portal vein, 33 of pancreatic veins, and 15 for other portal tributaries, the surgical success rate was 91 per cent over-all, increasing to 95 per cent during the last year. Catheterization was made with the same technique as is used for arteriography. The most important complication was thrombosis of the portal vein, giving slight transient symptoms in 2 patients. Other complications were wound infection, suture granuloma, herniation in the linea alba, bleeding from the operative wound, and subintimal injections. As the technique may yield good results in studies of drug resorption, flow studies, detection of metastases, and investigation of pancreatic veins, it seems justified in suitable patients despite the complication rate. None of the complications produced lasting disability.


External iliac artery blood flow in patients with arteriosclerosis obliterans.

Blood flow in the left external iliac artery was measured by means of a densitometric technique in 21 patients with arteriosclerosis of the lower extremities and in 21 controls. Normal flow volumes were (mean +/- S.D.) 604 +/- 104 ml./min. for males and 478 +/- ml./min. for females. Flow volume was significantly lower in the patients with ischemia of the legs. There was no correlation between flow volume through the artery and the degree of stenosis at its narrowest point. The diameter of the iliac artery and the flow volume were significantly larger in males than in females; however, flow velocity was significantly larger in females.


Mesenteric angiography of non-tropical sprue.

Detailed angiographic findings in 2 cases of proved sprue are described. There are dilatation of the superior mesenteric artery and its small bowel branches selectively, and increased capillary blush. Early draining into dilated veins is also noted. These findings are similar to those of the superior mesenteric arteriogram performed with pharmacological vasodilators. This similarity suggests that the dilated vessels in non-tropical sprue may be due to capillary dilatation.


Persistent hyperextension of the neck in breech ("star-gazing fetus") and in transverse lie ("flying-fetus"): indication for cesarean section.

All pregnancies with a breech or transverse lie should be examined roentgenologically, at least after the onset of labor, and those in whom hyperextension of the neck persists should be sectioned to avoid the real danger of injury to the cervical cord incurred in vaginal delivery. The radiologist should not assume a seriously deformed fetus just from the hyperextension; most of these fetuses are otherwise normal.


Calcified intraluminal meconium in newborn males with imperforate anus. Enterolithiasis in the newborn.

Five cases are reported and reference is made to 3 previous similar cases of calcified intraluminal meconium in newborn males with "imperforate anus." A rectourinary fistula was found in most of the patients; none of the cases had meconium peritonitis. The calcifications may develop in areas of prolonged stasis; the possible added role of the mixture of urine and meconium in utero is raised.


Pancreatitis and the battered child syndrome. Report of 2 cases with skeletal involvement.

Two cases of pancreatitis associated with the trauma of child abuse are reported. In the first case the skeletal survey was initially negative but the child later showed widespread roentgen evidence of intramedullary necrosis and periosteal new bone reaction. These lesions healed without treatment. In the second patient, the pancreatitis was accompanied by ascites and subsequently by bile peritonitis, duodenal obstruction, and a bile-filled abscess in the pancreas. This patient had skeletal fractures. The clinical problems of these 2 patients emphasize the need not only to relate pancreatitis to the battered child syndrome but also to distinguish between the bone changes due to direct trauma and those related to pancreatitis.


Ultrasound in the management of elective abortion.

Diagnostic ultrasound has an important place to play in aiding the obstetrician who has an abortion practice. It is most useful in accurately dating the time of conception. Based on sonographic dating, an abortion may be possible in patients with multiple pregnancy or in whom there is a mass in addition to pregnancy. The performance of a saline or urea abortion is made easier since the precise site of the uterus can be mapped out. Once an abortion has commenced, the presence or absence of retained products can be easily verified by ultrasound.


Roentgenologic evaluation of a new prosthetic sphincter for the treatment of urinary incontinence.

A new prosthetic device for the treatment of urinary incontinence, caused by a variety of etiologies, has been used 8 times at the University of Michigan Medical Center. Since the entire device is filled with contrast medium, the radiologist plays a major role in its evaluation. A brief description of the implantable urinary sphincter and its normal and abnormal roentgenographic appearances are presented and discussed. Roentgenologic findings which could lead to early clinical detection of mechanical failure are illustrated.


Xerographic evaluation of radical vulvectomy specimens.

Xerography of the radical vulvectomy specimen provides a permanent and visible record of the major lymph node distribution within the specimen. Such documentation is valuable to both pathologist and surgeon alike when making decisions regarding the necessity of further therapy. The combined effort represented by this "team" approach results in a high degree of accuracy not available with other techniques. Only if this kind of lymph node assessment is applied to each and every case will it be possible to evaluate accurately the logic and efficacy of the new therapeutic concepts regarding invasive carcinoma of the vulva.


Trivittatus virus infections in wild mammals and sentinel rabbits in central Iowa.

A serological survey was conducted in Iowa to determine the prevalence rate of California group virus antibodies in sera of several vertebrate species. Serum specimens were assayed for infectivity-neutralizing antibody in a microneutralization system with baby hamster kidney cell culture. Of 77 sera assayed, 21 (27%) neutralized trivittatus (TVT) virus infectivity. The antibody prevalence rate was highest for eastern cottontail rabbits inasmuch as 46% (10/22) of the serum specimens form this species possessed neutralizing activity. Other vertebrate species having TVT virus antibody included the fox squirrel, 29% (7/24), opossum, 12% (3/25), and raccoon, 17% (1/6). One cottontail rabbit serum neutralized both TVT virus and Jamestown Canyon (JC) virus infectivity, and one opossum serum specimen neutralized JC virus. None of the vertebrate sera neutralized La Crosse, St. Louis encephalitis, or western equine encephalomyelitis virus infectivity. Trivittatus virus neutralizing antibody was detected in the sera of sentinel rabbits, and TVT virus was isolated from the blood collected from one of these sentinels shortly after the first population peak of adult Aedes trivittatus mosquitoes in 1973. The implications of these data and the possibility of trans-ovarial transmission of TVT virus in A. trivittatus are discussed.


Soldado virus (Hughes group) from Ornithodoros (Alectorobius) capensis (Ixodoidea: Argasidae) infesting Sooty Tern colonies in the Seychelles, Indian Ocean.

In the summer of 1973, about 5,000 pairs of adult Sooty Terns abandoned a specific part of their breeding grounds on Bird Island in the Seychelles. Incubated eggs and newly hatched chicks were left unattended and the area was not reoccupied in 1974. Numerous Ornithodoros (Alectorobius) capensis occurred in the deserted part in both years, but few or none in the area where bird breeding was normal. Persons visiting the deserted area were bitten by many ticks and experienced severe pruritus persisting for several days. In 1973 and 1974, Soldado (SOL) virus (Hughes serogroup) was isolated from the ticks taken on Bird Island from the ground and from sick and not visibly sick chicks of the Sooty Tern, and also from nests of the Blue-faced Booby on Des Noeufs Island. When ticks from the ground and from Sooty Tern chicks were fed on domestic chicks, they transmitted SOL virus and caused the death of their hosts. Soldado virus was previously known only from O. (A.) capensis-group ticks infesting marine bird colonies on islands off Trinidad and in a lake in Ethiopia. We have also isolated SOL virus from another species of the subgenus Alectorobius from Wales, Great Britain. Marine bird migrations undoubtedly account for the remarkably extensive distribution of SOL virus. The role of migration in the mechanisms and dynamics of tick and virus distribution, and the comparative growth cycles of Hughes serogroup viruses in Ornithodoros ticks, remain to be determined for a better epidemiological understanding of this agent.


Eosinophilic meningitis in Thailand. Clinical studies of 484 typical cases probably caused by Angiostrongylus cantonensis.

Six hundred and forty-six patients with an eosinophilic pleocytosis were studied in Thailand over a 3-year period ending in March 1968. It was possible to segregate the cases into two clinical entities, which were termed typical eosinophilic meningitis and eosinophilic myeloencephalitis respectively. The clinical and laboratory finding of 484 cases of typical eosinophilic meningitis are reported here. The latter entity was generally benign and self-limited with a case mortality ratio of less than 0.5%. Acute severe headache was the most significant symptom. Fever was uncommon and abnormal neurologic findings were absent in 58% of cases. Sixteen percent of patients had visual impairment and 12% had an abnormal fundus. Impairment of the sensorium of a slowly progressive type and weakness of the extremities without localization were noted in 5% and less than 1% of patients, respectively. These signs occurred only in severely ill patients. Involvement of the cranial nerves was found in 17% of patients. Paralysis of the external rectus muscle of the eye and facial paralysis were found in 3% and 4%, respectively. The cerebrospinal fluid was characteristically turbid with a leucocyte count of more than 500 cells per mm3 in 75% of cases. It appeared that specific treatment of the disease was not indicated and that steroids and antibiotics did not have a definite beneficial effect on the course of the illness.


Diagnosis and management of bile duct strictures.

In the majority of patients, strictures of the common bile duct result from an injury to the duct. The earlier the injury is repaired or the more quickly the diagnosis of stricture is made and repaired, with antibiotics to prevent infection, the better are the results of the repair. Five types of repair have been utilized: (1) choledochoduodenostomy, (2) duct-to-duct repair, (3) choledochojejunostomy, (4) plastic revision of the stricture, or (5) dilatation of a previous stricture when multiple, previous operative procedures or the difficulty of operative exposure proves too great for adequate repair. Our overall results after repair of biliary stricture are good or excellent in 84 per cent of patients. We have had the best results in patients in whom choledochoduodenostomy was performed.


Complications of surgery of the abdominal aorta.

Surgery of the aorta has become a routine since Astley Cooper first attempted to ligate the aorta. It is major surgery that requires careful technic, understanding of the disease process, and a full knowledge of the complications that may ensue. Most of the complications are preventable, and if the operator recognizes their possibility, most can be prevented. When complications occur, the operator must be prepared to handle them immediately since most of them are catastrophic and usually life-threatening to the patient. Surgery of the aorta should never be performed in a hospital that does not have the backup facilities to manage these complications. This requires the immediate availability of large quantities of blood and the various clotting factors that may be necessary in some patients. In addition, arteriography must be available constantly and on a moment's notice, because it is often necessary in making the diagnosis. Finally, a good intensive care unit with skilled respiratory therapists is mandatory in handling the complications of this type of operation. Many such patients have had at least one myocardial infarction before operation on the aorta and many of the complications will lead to massive distension of the abdomen with high diaphragm, atelectasis, and the need for continual respiratory care if the patient is to survive.


The functional consequences of colectomy.

The colon plays a decisive role in salt and water conservation in the intact human, normally removing from the terminal intestine approximately one liter of isotonic fluid that escapes small bowel absorption. The primary purpose of this colon function is probably to prevent extracellular fluid volume depletion and only incidentally to produce a normal solid stool. The patient with an ileostomy can partly adapt to replace the absorptive capacity lost after colectomy but is still vulnerable if salt and water intake ceases completely. In contrast, patients with ileorectostomies and some patients with continent ileostomies can almost totally adapt to loss of the colon. These findings suggest that the ileal mucosa can adapt under certain conditions to absorb at rates and concentrations previously thought impossible. This property of ileal mucosa might be utilized in the future to significantly improve the condition of patients who require total colectomy.


Ineffectiveness of methylprednisolone in the treatment of pulmonary dysfunction after cardiopulmonary bypass.

Fifty consecutive adults undergoing elective cardiac surgery with cardiopulmonary bypass received a single dose of methylprednisolone (30 mg/kg) at the time of anesthesia. The results were compared with those in the immediately preceding fifty adult patients who underwent elective cardiac surgery and who did not receive corticosteroids. The age, sex, and weight of the patient, mortality, nature of the lesions treated surgically, bypass time, smoking history, physiologic evidence of preexisting lung disease, preoperative New York Heart Association class, preoperative left ventricular end diastolic pressure, incidence and duration of the postoperative low cardiac output syndrome, postoperative arrhythmias, operative and postoperative blood loss and postoperative hours of respiratory support, dynamic lung-thorax compliance, alveolar arterial oxygen gradient, fraction of wasted ventilation, and incidence of tracheostomy were tabulated and statistically contrasted. The two groups were comparable relative to all preoperative factors, except for a slightly higher end diastolic pressure in the patients who received steroids. Methylprednisolone given at the time of anesthesia was associated with a higher intraoperative blood loss, a higher incidence of low cardiac output syndrome, and an increased requirement for postoperative mechanical ventilation. As bypass time approached three hours, the proportion of patients requiring prolonged support in both groups became similar. It was concluded that pretreatment with methylprednisolone in massive doses had an overall adverse cardiopulmonary effect.


Role of cortisol in the restitution of blood volume after hemorrhage.

The restitution of blood volume and plasma protein after 10 per cent hemorrhage was studied in intact dogs and in dogs subjected to adrenalectomy and infused with cortisol at basal or physiologically increased rates. The results suggest that increased extracellular osmolality, mediated by an increased secretion of cortisol, mediates, in turn, the restitution of protein and plasma volume. The results are best explained by the hypothesis that after hemorrhage, as a direct result of an increased secretion of cortisol, extracellular osmolality increases. A shift of fluid from cells to interstitium follows, increasing the interstitial pressure. This latter increase leads to an increased return of protein through the lymphatics and to an increased return of fluid through both lymphatics and capillaries.


Thoracic outlet compression syndrome.

Forty-nine patients underwent sixty-four procedures for the treatment of the thoracic outlet compression syndrome. Detailed history and careful physical examination are of paramount importance in diagnosing this disease. Our findings strongly suggest that a positive arteriogram is confirmatory evidence of the thoracic outlet compression syndrome. Two problems are identified as the source of unsatisfactory results in this series: poor selection of patients and the regeneration of rib and dense scar tissue with recurrence of compression symptoms. We favor the transaxillary approach to resection of the first rib because it provides satisfactory exposure for removal of the entire rib and utilizes a more cosmetically pleasing incision. Division of muscles, traction on nerves, and entrance into a body cavity are not required, operating time and hospital stay are shortened, and blood loss is minimized. Favorable long-term results were seen in 86 per cent of the patients treated.


The staging of Hodgkin's disease. Preoperative clinical assessment versus operative evaluation.

Fifty consecutive patients with the diagnosis of Hodgkin's disease, confirmed by lymph node biopsy, underwent preoperative clinical assessment and staging laparotomy between 1969 and 1974. Preoperative evaluation consisted of bone marrow examination, liver and spleen scans, intravenous pyelograms, lymphangiograms, and standard chemical laboratory tests. Operative evaluation consisted of splenectomy, liver biopsy, periaortic, mesenteric, and celiac lymph node biopsy, appendectomy, and iliac crest bone biopsy. Twenty-three patients (46 per cent) were improperly staged by preoperative clinical assessment, with twelve patients being overstaged and eleven patients being understaged. Liver and spleen scans, and intravenous pyelograms were of little value in assessing organ involvement with Hodgkin's disease. Lymphangiograms similarly were of questionable value, being interpreted as positive in twenty-one patients but histologically involved in only seven patients (overread, 67 per cent. Fourteen patients had negative lymphangiograms, with five being histologically involved (underread, 36 per cent). There was a 22 per cent incidence of pulmonary complication (atelectasis, pneumonitis) but no deaths or life-threatening complications.


Soft tissue sarcomas of the extremity. Multidisciplinary therapy employing hyperthermic perfusion.

Cultured human sarcomatous cells that have been tested in our laboratory are more sensitive to the lethal effects of heat than are the normal cells from which they are derived. During an eight year period from March 1967 to March 1975, thirty-seven patients with soft tissue sarcomas of the extremities were treated with hyperthermic perfusion and, when possible, radiation therapy and radical local excision. Despite the fact that these tumors arise on the extremity, diagnosis was often delayed. With meticulous attention to all details, hyperthermic perfusion was performed with a minimum of morbidity and mortality. The combined use of hyperthermic perfusion, radiation therapy, and delayed excision has greatly reduced the necessity for amputation. Many useful limbs, heretofore not considered salvageable, can be saved with this method of treatment. Also, the possibility exists that destruction of tumor within the extremity followed by delayed excision enhances the immune response of the patient.


Major surgery in leukemia.

Complications of leukemia that required surgery in twenty-five patients over a five year interval were reviewed. Sixteen patients with chronic leukemia underwent a total of twenty-one operations with one operative death. Nine patients with acute leukemia required ten operations, with two operative deaths. These patients tend to have specific types of complications that are particular to leukemic patients, and with proper support the majority of these patients can be benefited.


Major complications of median sternotomy.

Major sternal infections developed in eleven of 1,550 patients undergoing median sternotomy for operations on the heart. Nine patients had myocardial revascularization, six with internal mammary artery as the conduit. Seven of these patients have been salvaged by aggressive local wound management and systemic support. These survivors have a good outlook for treatment of their basic cardiac disease.


Gastric outlet obstruction after omentopexy for perforated "acute" and "chronic" duodenal ulceration.

One hundred and eighty-seven men, aged twenty to eighty years with an average of forty-eight years, underwent surgery for perforated duodenal ulcer. Seventeen received an immediate definitive procedure; none died. Nine (5 per cent) of the remaining 170 who had omentopexy died one to fifteen days postoperatively. They were older and waited longer. One hundred and twenty-one patients (76 per cent) were adequately followed. Thirty-nine (32 per cent) had "acute" perforation and eighty-two had "chronic" perforation. Twenty-four (30 per cent) of the latter underwent definitive operation within three months without mortality. Overall, 25 per cent of the ninety-nine patients followed after omentopexy required reoperation within twelve months. However, only three (8 per cent) of the thirty-nine with "acute" perforation required operation as compared with twenty-one (37 per cent) of the fifty-eight with "chronic" perforation. The main reason for early operation in the "chronic" group was obstruction; 21 per cent failed to empty their stomach immediately or soon after omentopexy and half as many either had pain or bled severely within twelve months and also required reoperation. The "acute" and "chronic" groups continued to differ in their need for further operation. Overall, 57 per cent of the ninety-seven patients required a definitive operation one to twenty-four years later. However, only ten of the thirty-nine patients (26 per cent) in the "acute" group required definitive operation as compared with forty-five of the fifty-eight patients (77 per cent) in the "chronic" group. Outlet obstruction of the stomach was the main indication for definitive surgery in twenty-six of the fifty-five (47 per cent) reoperations. This high incidence of gastric obstruction after omentopexy was not peculiar to our institution since, over the past six years, eighteen patients having omentopexy elsewhere had to be operated on for this complication. We recommend that patients with "chronic" perforation should not undergo omentopexy but rather immediate vagotomy and a drainage procedure.


Repair of peristomal colostomy hernias.

Peristomal herniation represents the second most common late complication of abdominal wall enterostomy. Early herniation results from the creation of too large of a fascial defect. Late herniation is caused by a gradual enlargement of the fascial defect because of a poor selection of the colostomy site or an intrinsic weakness of the fascia due to the patient's age or general condition. Once peristomal herniation occurs, operative repair should be considered in an otherwise healthy person. Previous reports advocate primary repair of the herniation. In the present series of nine patients, three patients developed recurrence of the hernia six to eight months after primary repair. Six patients had colostomy hernia repairs that involved moving the site of the original stoma. All of these repairs remain intact at an average of two years, nine months (range, four months to six years). We therefore believe that the solution to the problem of recurrent colostomy herniation lies in the transposition of the site of the original colostomy.


Thoracic outlet compression. Application of positional arteriographic and nerve conduction studies.

Positional arteriography has not proved to be of significant assistance in the evaluation of patients with thoracic outlet compression and should be reserved for those patients presenting with an obvious arterial problem such as aneurysm, obstruction, or embolic phenomena. Positional ulnar nerve conduction times were positive in 88 per cent of all patients operated on for thoracic outlet compression. Patients with normal neutral and elevated velocities through the outlet should be approached cautiously from a surgical standpoint. We believe that positional ulnar nerve conduction times are a desirable addition to the diagnostic armamentarium of the physician evaluating the patient presenting with symptoms and signs of the thoracic outlet compression syndrome.


Penetrating wounds of the cervical esophagus.

To determine trends in management, twenty-two years' experience with penetrating wounds of the cervical esophagus in thirty-nine patients has been evaluated. There were three deaths, all as a result of delayed operative repair. Experience gained from the earlier years of this study led to a marked reduction in mortality in the later years as a result of an increased index of clinical suspicion, coupled with an aggressive operative approach with primary closure and adequate drainage. A nonoperative approach has been suggested by others for small esophageal perforations after endoscopy and perforation from foreign objects. For penetrating injuries of the esophagus, operation and definitive repair is mandatory.


Elective vascular reconstruction after trauma.

Elective vascular reconstruction was performed to correct 135 vascular lesions at Walter Reed Army Medical Center in patients who had sustained earlier vascular trauma. This represents approximately 7 per cent of the operations performed from 1967 to 1974. Approximately three fourths of the lesions resulted from combat wounds and the remaining one fourth from civilian trauma. Of the 135 lesions, fifty-two were arteriovenous fistulas, thirty-five were false aneurysms, and the remaining forty-eight lesions involved thrombosis or stenosis. The popliteal artery was involved most frequently (nineteen lesions), closely followed by eighteen injuries to the superficial femoral artery and fourteen injuries to the brachial artery. In managing both false aneurysms and arteriovenous fistulas, repair of the arterial injury was the major objective. However, particular effort was made to repair larger veins in the arteriovenous fistula category. Patients with arterial thrombosis and stenosis who had symptoms interfering with their daily activity have had successful vascular reconstruction utilizing a variety of technics. No operative or related postoperative deaths occurred in this group of patients. There was only one early postoperative graft occlusion, (0.7 per cent of the operations) and two late graft occlusions (1.5 per cent). Subsequently, additional vascular reconstruction was successful.


Management of acute combined injuries to the aorta and inferior vena cava.

Major abdominal vascular injuries present problems in diagnosis, exposure, and management. Combined injuries to the abdominal aorta and vena cava are particularly lethal due to extensive blood loss, difficulty in sequential exposure, and the high incidence of associated injuries. Between 1953 and December 1974, ninety-one patients required emergency operations for abdominal aortic trauma at our city-county charity hospital. Twenty-nine of these had combined injuries to the abdominal aorta and vena cava, ten of whom had either an audible bruit preoperatively or a palpable thrill at exploration suggesting acute fistulas. Twenty-three injuries were secondary to gunshot wounds. Ten were located in the suprarenal aorta and vena cava. Management involved a variety of technics including intravascular shunts, adaptive exposures, Dacron prostheses, and autotransfusion. Survival rate was 27 per cent. Sixty-two per cent of the deaths were a function of extreme difficulty in controlling hemorrhage and exposure. There were no late recurrences of arteriovenous fistulas. Successful management of acute traumatic injury to both the abdominal aorta and vena cava requires rapid, aggressive surgical management, adaptive sequential control maneuvers, and application of technics and principles developed for elective vascular surgery.


Villous adenomas of the colon and rectum.

Our thirteen year experience with villous adenomas of the colon and rectum, embracing 264 patients, is reported. The average age of patients was sixty-two years with an almost equal sex distribution. Seventy-two per cent of the lesions occurred in the rectum and rectosigmoid and the most frequent symptoms were rectal bleeding and diarrhea. A positive correlation between size of adenoma and incidence of malignancy was noted. Although 55 per cent of the lesions were malignant, only 22 per cent harbored invasive carcinoma and only 10 per cent of the deaths were due to metastatic carcinoma. It is concluded that in the absence of invasive carcinoma, the clinical behavior of this tumor is relatively benign and a more conservative approach to the surgical management of this neoplasm should be encouraged.


Interposition grafting for portal hypertension.

During the past six years, thirty-seven patients underwent interposition graft shunting for thirty-three instances of bleeding from varices and five instances of intractable ascites, either electively (twenty-seven instances) or as an emergency (eleven instances). Autogenous jugular vein was used in twenty-five instances, homologous vena cava in nine, and Dacron in four. Portacaval and mesocaval anastomoses were done in equal numbers (nineteen). Using Childs' method of clinical evaluation, thirty-three patients were Class C and four Class B. There were five (13.2 per cent) early deaths with one (3.5 per cent) in the elective and four (36 per cent) in the emergency group. Twelve grafts were open at autopsy, fifteen at splenoportography, and seven assumed patent because patients were asymptomatic. Two Dacron grafts and two homografts thrombosed. There were ten late deaths, only one related to graft failure. Apparently, the operation controls ascites, with autogenous jugular vein being the ideal material. Interposition grafting is a simple, safe procedure that can be used for portal decompression in patients with bleeding varices.


Significance of serum amylase level in evaluating pancreatic trauma.

A series of fifty-one patients who underwent exploratory laparotomy for blunt abdominal trauma is reviewed. Attempts to correlate preoperative serum amylase levels with pancreatic injury were unsuccessful. We could find no statistically significant correlation between elevated serum amylase and pancreatic injury. The accuracy of the test improved somewhat with markedly abnormal serum amylase levels (greater than 300 Somogyi units/100 ml), but even at these levels the correlation was not significant. One must conclude that there is no correlation between elevated serum amylase and pancreatic injury in blunt abdominal trauma. Decisions as to the advisability of operation in patients with such trauma should therefore be based on other parameters.


Pseudocalculus of the common bile duct. A dynamic radiographic differentiation from true retained stone.

Static T-tube cholangiographic evidence of distal common duct calculi may in fact be only "pseudocalculi," which might be elucidated by a dynamic fluoroscopic study. We have seen five such cases. X-ray evidence for this phenomenon is presented. Pertinent anatomy, physiology, and clinical considerations are discussed.


Jaundice in patients with acute cholecystitis. Its validity as an indication for common bile duct exploration.

Our study demonstrates that (1) mild to moderate jaundice is frequently seen in patients with acute cholecystitis; (2) severe degrees of jaundice were seen in two patients without the presence of common duct stone or recognizable obstruction of the common bile duct; (3) only one of forty-one patients with acute cholecystitis had common bile duct stone; (4) jaundice does not appear to be a compelling reason for choledochotomy; and (5) less invasive technics such as intravenous and intraoperative cholangiography should suffice to exclude the possibility of common bile duct stone in patients with acute cholecystitis.


Carcinoid tumor metastases. Prospective study of twenty-two patients.

Twenty-two patients with advanced metastatic carcinoid disease, most of whom were moribund were subjected to oral administration of 200 mg of 5-fluorotryptophan three times daily. Seven patients died from complications of the tumor before completing the course of one year's treatment. Of the fifteen patients who survived long enough to complete the year of therapy, the average additional survival time was 2.3 years, varying from one to over nine years. The average survival time after the diagnosis of advanced metastatic carcinoid disease was made and prior to the initiation of treatment with 5-fluorotryptophan in these patients was 5.5 years, varying from one to eight years. Side effects of the analog were limited to gastric upset in one patient only. The control of serotonin production and its associated symptoms was considered excellent. Slowly progressive tumor growth led ultimately to death in thirteen of the fifteen patients which was considered due to mechanical factors and not to hormone abnormalities. Two patients continue to survive with good quality of life nine and six years, respectively, after analog therapy. Life in patients with advanced metastatic carcinoid disease has been extended with good to excellent quality by the simple oral administration of the tryptophan analog, 5-fluorotryptophan. Tumor growth does not seem to have been affected by the analog.


Carotid endarterectomy: Is a shunt necessary?

Seventy-seven carotid endarterectomies performed on fifty-nine patients, using induced systemic hypertension during carotid artery clamping, were reviewed. The risk of cerebral ischemia is reduced to a minimum by this technic. The measurement of the internal carotid artery stump pressure is an excellent guideline for the need of additional brain protection. An internal shunt is rarely necessary. Thromboembolic phenomena contributed to the major neurologic complications encountered (two deaths and one stroke). Extreme gentleness and careful surgical technic cannot be overemphasized.


Transmission and scanning electron microscope studies of calcified cartilage resorption.

The authors' previous report (Savostin-Asling and Asling, '73) demonstrated that Meckel's carilage is a favorable site for study of calcified cartilage resorption. In the present study the ultrastructural features at this resorption front have been examined by transmission and scanning electron microscopes (19-day rat retus). Multinucleated giant cells chondroclasts) dominated the erosion front. The many features which they showed in common with osteoclasts included abundant mitochondria, vacuolation, lysonsomes, sparsity of rough-sufaced endoplasmic reticulum, and deep infoldings at loci of contact with calcified matrix. Crumbling of matrix (with mineral crystals penetrating between these foldings) and fragmentation of collagen fibrils were also seen. The propensity of chondroclasts for spanning several opened lacunae provided special opportunity to demonstrate cell surface modifications in presence or absence of matrix contact. Amebiod processes extending into lacunae were seen by both transmission and scanning procedures; they were sometimes tipped with a veil of filamentous processes as small as 0.3 mum in diameter. Most hypertrophic chondrocytes. when released from lacunae, appeared to be disintegrating. However, in accord with previous evidence of their possible merger with chondroclasts (in light microscopic studies) there was also evidence for breakdown of cell walls between a chondroclast and a chondrocyte in intimate contact, with possibility of cytoplasmic continuity.


Kinetics of pulmonary epithelial proliferation during prenatal growth of the mouse lung.

Autoradiographic methods were used to analyze cell kinetics in peripheral epithelium of the fetal mouse lung, days 15-18. The 3H labeling index decreased in proportion to increases in fetal lung and body weight from day 15 to day 18. Cell-cycle determination estimated from the percent of labeled metaphases at intervals after 3H thymidine injection showed the shortest cell-cycle time (12.25 hours) on day 15 during the precanal stage of growth. Total cycle time (Tc) increased by approximately one hour on each subsequent day. Between days 15 and 16 Tc increased due to a 1-hour increase in the post mitotic interphase (G1); thereafter, increases in Tc could be ascribed almost entirely to lengthening of the DNA symthetic period. A comparison of cell-cycle time in central and peripheral tubules of the same lungs on day 15 showed a slower cell cycle in the central tubules than in the peripheral branches. An estimate of the growth fraction (GF) on each day based on calculated and ovserved cell-cycle time showed that GF was 1 on days 15 and 16, decreasing to 0.69 on day 17 and 0.27 on day 18. Thus cell-cycle time increases with lung maturation and it increases from peripheral to central zones of the bronchial tree. The greater part of the observed decline in growth rate as the prenatal phase of growth is completed was due largely to a decrease in the fraction of cells in the cell cycle.


Morphological studies on the synthesis of secretory granules in convoluted tubules of mouse submandibular gland.

The synthesis of zymogen-like secretory granules in convoluted tubules of mouse submandibular gland (SMG) was investigated by histometry, light microscopy and electron microscopy. In normal males secretory granules in the SMG increased greatly from 25 days after birth and reached a maximum level 50 days after birth. Castration of adult male mice markedly decreased the level, but it was completely restored by testosterone administration. A parallel was found between change in the granule level and the amount of rough endoplasmic reticulum (RER) in the convoluted tubular cells during development or after various treatments. Development of the Golgi apparatus was also observed in the cells when the granules increase. Both the increase in the granules and in the RER induced by testosterone were prevented by actinomycin D or puromycin. These results indicate that the granule contents are synthesized on the RER under the control of testosterone, and then condensed in the Golgi apparatus.


Morphogenesis of the carpal elements in the regenerating forelimb of adult Notophthalmus viridescens viridescens.

This study is concerned with the morphogenesis of the carpal elements in the regenerating forelimb of the adult newt. Blastema cells surrounding the remnant bony stumps begin to differentiate into cartilage on the twentieth post-amputation day. Subsequently, masses of carilage build up from the radial and ulnar stumps. The radial mass is larger and differentiates more rapidly than the ulnar mass. By the fifty-fifth post-amputation day, the eight basic carpal elements are formed, with fusion of two of the units, intermedium with ulmare, occurring by the seventieth day. The completed regenerate possesses the seven carpal elements characteristic of the normal adult limb. The present results show that during limb regeneration in the adult newt the carpal elements are restored to their original number and position and that the pattern of such carpal differentiation proceeds in a proximodistal direction influenced by the stump remnants of the radius and ulna.


Dissection casts of the human brain.

A simple, inexpensive method of making accurate permanent casts of brain dissections is described. Dissected brain preparations are used to produce silicone rubber molds. Methyl methacrylate is used to make the hard plastic models.


Skeletal effects of magnesium deficiency in normal, ovariectomized, and estrogen-treated rats.

The effects of magnesium deficiency in ovariectomized and estrogen-treated rats were examined in histological sections of bones and various soft tissues. The changes observed in the femora of intact rats deprived of magnesium for three weeks were: 1. a general increase in diaphyseal thickness, 2. the presence of localized fibrous or bony-like masses in subperiosteal and metaphyseal sites, and 3. the occurrence, although rare, of endosteal hyperplasia. In ovariectomized, magniesium-deprived animals, the incidence and location of fibrous masses were similar to that in the femora of magnesium-deficient intact rats; however, no increase in diaphyseal thickness was noted. Daily injections of 25 mug estradiol caused a reduction of the frequency of skeletal hyperplasia from 80% to 20%, as well as a reduction in femoral diaphyseal thickness. Estradiol hormone administration also brought about a marked alleviation of the dermal and neural manifestations of magnesium deficiency, but, at the same time, caused an exacerbation of renal calcinosis.


Post-natal development of the median eminence of the guinea pig.

The ultrastructure of the median eminence of neonatal (newborn) 1-, 3-, 5-, and 10-day old) and adult guinea pigs was studied to determine the dynamic changes occurring in this structure during early life. At birth the portal vasculature consists of the Mantelplexus and a few, non-fenestrated capillary loops. The number of ansae and the degree of fenestration increase rapidly after birth. The abundance of cytoplasmic and ciliary projections into the ventricular recess and the large numbers of organelles indicate that the ependymal cells are more active in the neonatal period than in the adult male. Moreover, the ependymal endfeet cover most of the surface area of the primary portal plexus during this time. The neuronal layers of the median eminence are difficult to distinguish at birth due to the lack of myelinated fibers in the zona interna. Significant myelination appears on day 3 but is not complete until day 10. There is a progressive increase in the numbers of Herring bodies and large neuro-secretory granules (1,500-1,700 A) during this same time period. In the zona externa, few nerve terminals abut on the perivascular space until day 3. Increases in numbers of granules per axon profile were noted for each day after birth. Despite the relatively long gestation period of the guinea pig (68-72 days), the morphologic appearance of the median eminence at birth suggests that the neurovascular link controlling anterior pituitary function is not yet complete.


Intercellular junctions of rat endocardium.

The ultrastructure of the intercellular junctions of rat endocardium has been characterized following lanthanum exposure in vitro and uranyl acetate staining en bloc. The interendothelial clefts of the endocardium run either a relatively straight or convoluted course and posses one or two loci where the plasma membranes are in close apposition or form punctate fusions. Elongate restrictions, that exhibit hexagonal arrays of subunits following lanthanum immersion (gap junctions), are also present in the intercellular endocardial clefts. The occurrence of interendothelial clefts of endocardium lacking occlusive foci can account for the permeability properties of ventricular endocardium, where the direction of diffusion of macromolecules has been attributed to pressure gradients between ventricular cavity and myocardium. The relationship of gap junctions to possible electrical phenomena within the endocardium is also discussed.


[The biological significance of zinc (author's transl)].

Zinc takes part in the catalytic function of many metalloenzymes. In others it plays a role in conformational stability. In zinc deficient animals protein synthesis is disturbed. Conversely zinc metabolism is influenced by protein deficiency. Zinc takes part in drug metabolism, in mobilizing vitamin A from the liver, and in a system defending the organism against free radical damage. Zinc distribution in the organism is influenced by steroid hormones and leucocytic endogenous mediators. Of the intracellular zinc only a small part is bound to metalloenzymes, most being coordinated to binding sites of nonspecific proteins. Thus the organism defends itself against conformational changes of irritable enzymes which may bind excess zinc to side chains. Zinc can protect the organism against cadmium toxicity. In the serum the smaller part of zinc is firmly bound to several specific proteins, the majority being loosely bound to albumin. Some aspects of human zinc metabolism in health and disease are reviewed. Zinc deficiency in man is rare. In Iran and Egypt a syndrome of iron and zinc deficiency associated with anaemia, hepatosplenomegaly, dwarfism, and hypogonadism is known. In wound healing and tissue repair substitution of zinc is beneficial only if a zinc deficiency exists. For purposes of long term parenteral nutrition zinc should be added to the different infusion solutions.


[Effect of ethrane on the circulatory parameters of geriatric patients (author's transl)].

The cardiovascular effects of enflurane in geriatric patients have been compared with the effects of this anaesthetic agent in a group of young patients. The degree of cardiovascular depression in geriatric patients was much greater than in the young patients despite the smaller inspired concentration of enflurane necessary to produce a similar depth of anaesthesia. In comparison with halothane and neuroleptanaesthesia, enflurane produced the greatest decrease in cardiac output. The mean arterial pressure, however, was quite well maintained due to a simultaneous increase in total peripheral resistance.


The effects of ketamine and innovar on the renal cortical and medullary blood flow of the dog.

To study the effects of Ketamine and Innovar on renal function, the renal cortical and medullary blood flows of dog were measured using a thermo-electrical flowmeter, along with the urine output, blood pressure and pulse rate. Ketamine decreased the renal cortical blood flow and the urine output. Innovar increased the renal cortical blood flow, but did not alter the medullary blood flow appreciably, and decreased the urine output. Neither of these variations in renal blood flows ran parallel with variations in the arterial pressure nor did variations in the urine output run parallel with those in the blood flows. All anaesthetic agents are inhibitory to kidney, but Innovar may be preferred to other anaesthetics in view of the finding that the renal blood flows are well maintained even under anaesthesia with this agent.


[Chlorprothixene for premedication in children: oral versus intramuscular route (author's transl)].

The effect of chlorprothixene (Taractan), a neuroleptic agent, administered either intramuscularly (1 mg/kg) or orally as a 4% solution (1,5-2 mg/kg), was compared in a double-blind study in 200 children between 11 months and 10 years of age. In addition, intramuscular 1-hyoscyamine (Bellafolin) was given to all patients 30 minutes before the induction of anaesthesia (0.005-0.01 mg/kg). With regard to antisalivary action, suppression of reflex irritability, frequency of post-anaesthetic vomiting, postoperative sedation and requirement of postoperative analgesics, there was no significant difference between the two methods. Preoperative sedation was slightly more pronounced with the intramuscular technique. An undesirable side-effect, hypotension, was observed more often after intramuscular than oral premedication. To obtain optimum effect, an interval of 2 hours between the oral premedication and induction of anaesthesia is recommended.


[Ophthalmodynamographic and ophthalmodynamometric findings following irreversible loss of cerebral function (author's transl)].

In 12 patients with irreversible cessation of cerebral function (so-called "brain death") ophthalmodynamographic (ODG) measurements were made. In 8 of these ophthalmodynamometric (ODM) investigations were also made. ODG results were abnormal in all cases, pulsation volumes showing a deep decrease (x:16.8 mm3;x of mean arterial pressure 79,1 mm Hg). ODM measurements revealed highly scattered results, ophthalmic artery pressure being normal in 3, increased in 1, severely reduced in 2 patients.--In 2 other cases mere touching of the eye bulb by the ophthalmodynamometer caused a sudden complete collapse of the central retinal artery. Whereas the ODG results might already be considered as useful auxiliary findings, for definite evaluation of the clinical significance of ODG and ODM in diagnosing an intracranial circulatory, additional comparative investigations may be necessary.


[The treatment of respiratory failure in severe chest injury (author's transl)].

The use of artificial ventilation versus conservative treatment in 101 patients with severe chest injuries is reconsidered, because major ventilation therapy carries a high incidence of complications. This technique within the past few years has increasingly been replaced by differentiated conservative respiratory treatment. On the basis of a retrospective study it is concluded that under special conditions even the unstable chest accompanied by respiratory insufficiency may be treated successfully by this technique.


[A valve to facilitate indirect measurement of arterial blood pressure (author's transl)].

A conveniently sized valve has been designed to replace the customary bellows used for inflation of a sphygmomanometer or oscellotonometer cuff. It can be inserted in a length of thin plastic tubing connecting the cuff with the usual wall socket for compressed air. The arterial pressure is measured in the usual manner.


[Qualitative and quantitative studies on the corpus geniculatum laterale (Cgl) of the laboratory rat. IV. Qualitative structure analysis of the pars dorsalis an on India-ink-injected Nissl preparation].

1. The histological organization of the rat dorsal lateral geniculate nucleus (Cgld) has been analysed in Nissl-preparations following vessel injection with india ink. 2. The findings have been collected by means of a non-automatically visual scanning method. Every point is defined by 3 coordinates. 3. Different parameters have been collected in every point: the number of the 5 structural elements of the nervous tissue (neurons, fragments of capillaries, nuclei of astrocytes, oligodendrocytes and microglia) and the hit points per structural element. 4. In addition the differentiation of about 15500 neurons in relay neurons and interneurons has been carried out. The ratio of the 2 types of neurons is about 14:1. 5. The collected values have been statistically analysed by correlation, regression and discriminatory analyses. 6. The results relate to the correlation between the structural elements and the rostrocaudal, lateromedial and ventrodorsal directions as well as the structural elements with another. 7. At 5 levels the Cgld has been mapped on the basis of neuron size, neuron density, capillary density, density of the 3 types of glial nuclei and the relative number of hit points per structural element. 8. In the Cgld we distinguish 2 portions regarding the neuron size. The mediocellular portion occupies the lateral, ventral and caudal parts and encloses a magnocellular portion like a coat. 9. The distribution pattern of the interneurons does not correlate with the size of neurons. 10. The capillaries tend to have a greater density in the lateral area of the Cgld. 11. The correlation and regression coefficientes and the distribution pattern of the astrocytes and oligodendrocytes suggest that both glial types show a reciproke ratio in the Cgld. 12. The distribution pattern of the microglia is relatively uniform. 13. Mapping the Cgld we have got a model conception of its structural condition corresponding with the common mammalian scheme. 14. By the discriminatory analysis zones of input and fields of projection have been discriminated. It was possible to discriminate the ipsi- and contralateral input zones, but not the binocular and monocular projection fields. 15. The discriminatory analysis allows to show the collective biological effect of all structural elements in a uniform mathematical value.


[Rhythmic nuclear growth of adequately stimulated ganglia cells of acoustic nuclei (rat)].

Ganglia cells of the dorsal and ventral cochlear nuclei of white rats were irritated adequately for different periods or left untreated, respectively, and investigated karyometrically. The frequency distribution curves of the nuclear volumes were separated by means of an electronic curve resolver into the component curves, i.e. into groups of nuclei obeying exactly a Gaussian normal distribution and thus representing biologically uniform populations. The analysis of the mean values of the component curves led to the following results: 1. The mean values of the component curves can be arranged in 2 series having the pattern V1, V1 square root 2, V2, V2 square root 2, V4, V4 square root 2...2. The series V1, V1 square root 2, V2, V2 square root 2...is based on a geometrical series of the general formula an = k-qn. 3. It follows from these results that the nuclear volumes grow rhythmically by a factor of square root 2 and, consequently, that there is a periodical doubling in in the growth of the surface.


[Double-barrelled connections between the striatum and substantia nigra in the light and electron microscopy picture in the cat].

Following coagulation of either the substantia nigra or the caudate nucleus and fundus caudati of the cat, the distribution of degenerating terminals in the sections of the striatum has been determined especially in the fundus caudati on one side and in the various cell groups of the substantia nigra compacta on the other side; and the types of synapses have been described. There are reverberating circuits between the fundus caudati and the medial groups of the nigra characterized by their small cells, between the putamen and the postero-lateral cell groups of the nigra, between the caudatum and the rostral cell groups of the nigra, presumably with the specialization that the lateral caudatum is in two-way connection with the rostro-lateral cell groups of the nigra as is the medial caudatum with the rostro-medial cell group. The transmitter for the striatofugal terminals in the nigra which have pleomorphic synapses is probably GABA. Dopamine is the transmitter of the axo-spinous synapses of the nigrostriatal neurons with the small striatal nerve cells for which the transmitter seems to be Acetylcholine. The nigro-striatal reverberating circuits have three outputs available; 1. from parts of the striatum to the entopeduncular nucleus (internal segment of pallidum) and from there through the H2 and H1 fields of Forel to the oral ventral nucleus of the thalamus (V.o.a) which directly projects to the area 6 a alpha of motor cortex; 2. also from parts of the striatum to the pallidum (outer segment) and continuing through the descending pallido-reticulospinal pathway and 3. from the postero-lateral cell groups of the nigra probably through descending fibers which cross the midline in the commissura colliculi superioris and extend through the reticular formation directly or indirectly to the spinal cord.


[Sports and the spine].

The flexibility of the vertebral column in 160 male athlets and 105 female athlets has been measured. The instrument used by us was the Hydrogoniometer (Rippstein) which has been put exactly on the determined points of the back of all probands. Having moved the vertebral column in all directions the measurements have been registered and statistically analysed with standard measurements. We find a lot of differences in the different movments of the vertebral column regions between the athlets and the non-athlets. These persons with untrained vertebral columns are partly more flexibel then the probands with active trained vertebral columns.


The musculature of the hip and thigh of the white-tailed deer (Odocoileus virginianus, Rafinesque, 1832).

The musculature of the hip and thigh of the white-tailed deer (Odocoileus virginianus) is illustrated and described with emphasis on origins and insertions of individual muscles. Published works on the myology of domestic Bovidae (Bos taurus; Ovis aries; Capra hircus), Camelidae (Camelus bactrianus; Lama glama) and Cervidae (Cervus nannodes-canadensis) have been used for comparisons of individual muscles. The musculature of the hip and thigh of Odocoileus is substantially similar to that of other Artiodactyla investigated, except for slight differences of individual muscles. The most obvious differences involve the mm. obturatorius externus, obturatorius internus and pectineus. In Odocoileus as in domestic Bovidae and Cervus, the m. obturatorius externus is divided into an intrapelvic and an extrapelvic part whereas in Camelidae the intrapelvic part of the muscle is lacking. In the species considered, the m. obturatorius internus is present only in Camelus and Lama. In Odocoileus, the m. pectineus is divided into two distinct parts whereas in other Artiodactyla investigated the division lies apparent only toward its insertion.


Morpho-histology of the intestine in a freshwater major carp, Cirrhinus mrigala (Hamilton) during the different life-history stages in relation to food and feeding habits.

The morpho-histology in relation to food and feeding habits of the intestine in the fry, fingerling and adult of Cirrhinus mrigala (Hamilton), a freshwater major carp, has been described. The intestine has been observed to be shortest in the fry (carnivorous) and longest in the adults (herbivorous) with intermediate values in the fingerlings (omnivorous). The mucosal folds of the intestine have also been observed to be adapted according to the nature of the dietary prevailing in the different life history stages. The food appears to have a marked influence on the morpho-histology of the villi and the number of mucous cells/unit area of the fry, fingerling and adult. The sub-mucosa, muscularis and tunica propria are characteristic in the fry, fingerling and adult.


[Absence of the vena cava inferior during simultaneous absence of the left kidney in a human fetus].

Atypical pattern of inferior cava (human embryo, sex: male, age: 6 month) is described. The left kidney is absent. The pelvis of the right kidney send two ureters to bladder. Pars hepatica of normal V. cava inferior is missed. Blood transport is formed by a vessel lateral of left suprarenal gland. This vessel is penetrating through pars lumbalis of diaphragm to thorax, goes in analogy to V. hemiazygos later to V. hemiazygos accessoria and flows into the right atrium.


The ultrastructure of the thin loop limbs of the mouse kidney.

The thin limbs of the loops of Henle in the mouse kidney have been investigated by conventional electron microscopy. Resulting from light microscopic investigations, a distinction in the epithelia of short and long loops can be demonstrated. Ultrastructurally, the thin limbs (descending) of short loops are composed of a uniformly thin and simple epithelium. In contrast, long loops (thin descending and ascending) are composed of three different epithelial types which are representative of a distinctly more complex epithelial system. Two epithelial types were observed in the thin descending limbs of long loops and the third type was observed in the ascending thin limbs. Based upon these findings it is suggested that the thin descending limbs of short and long loops of Henle in the mouse kidney cannot perform the same functions in the renal concentrating mechanism.


On the existence of intrahepatic bile duct shunts.

A combined scintigraphic-radiological method has been used to study the existence of intrahepatic shunts between the bile ducts of the right and left duct systems. With this method no shunts were found between the left and the right system. The results are compared with the findings reported in the literature.


Ultrastructure of gonadal ridge in male and female pig embryos.

Pig embryos aged 21-22 days (d) obtained from artificially inseminated sows for an ultrastructural study of the development and sex differentiation of the gonadal ridge. The chromosomal sex of the embryos was identified by a chromosome analysis. At the age of 21 d the gonadal ridge consisted of three different tissues: the surface epithelium, the primitive cords, and the mesenchyme. The surface epithelial cells contained elongate mitochondria with lamellar cristae, granular endoplasmic reticulum (GER), the Golgi complex, free polysomes, coated vesicles and fine filaments. The epithelium was continuous with the primitive cords, which were composed of ultrastructurally similar cells. The epithelial basal lamina followed the cord surface, but covered it incompletely. Primordial germ cells (PGC) were located under the surface epithelium in the mesenchyme and in the cords. The nucleus with a prominent nucleolus, and the large mitochondria were round. The cytoplasm contained a pair of centrioles, the Golgi complex, solitary lamellae of the GER, free polysomes, lipid droplets and some coated vesicles. The PGC entered the gonadal cords before these were surrounded by the continuous basal lamina. A day later (22 d) the number and length of the cords were increased. The PGC were more frequent and seen also in deeper layers. All the structures studied at the age of 21-22 d showed that the gonadal ridge also at the ultrastructural level is at the sexually indifferent stage.


The structure of the myosatellite cells in axial muscles of the shark Geleus melastomus.

The myosatellite cells in the axial muscles of the shark Geleus melastomus is found more frequently in the red muscle fibers than in the white fibers. The total length of the cell extensions is about 100 mum. In about 20% of all cases, the extensions were present in pairs, and it is concluded that the satellite cell processes bifurcate. Processes towards the intercellular space and towards the interior of the muscle fiber are also described. The cytoplasm of the satellite cells contain glycogen, Golgi elements, lysosome-like vesicles, granular endoplasmic reticulum and microtubules. It is concluded that the morphology of the satellite cells indicates a more active function than that of a dormant reserve myoblast.


Ultrastructure of cleavage stages and preimplantation embryos of the baboon.

The baboon preimplantation stages were examined using light and electron microscopy. Six cases were studied at 2, 3, 4, 5, 7 and 8 days estimated fertilization age. The first 3 specimens were composed of 2, 8 and 24 blastomeres respectively. At 5 days, 30 to 40 cells were counted and more than 60 cells in later stages. Primitive "trophoblast cells" differentiate at 7 days and a crescentic blastocoele appears at 8 days. Shedding of the zona pellucida is not observed in the 7 and 8 day specimens. The preimplantation period is longer in the baboon than in man. C-type viruses are observed in the zona pellucida, in the perivitelline and interblastomeric spaces. Microvilli and caveolae cover ther periphery of the baboon conceptus. As in many other mammals, transformation of the mitochondria, changes in the ribosomes distribution, multivesicular bodies, myelin figures, nucleoli and intranuclear clusters of granules are described in the baboon. Cytoplasmic fibrous strands are not present as in the mouse. Experiments on the influence of hormones and drugs on ultrastructural changes would help to evaluate the importance of biohazards during the early development of primates.


[Ontogenesis of the endocardial cushions in the vertebrate heart. An experimental- and comparative embryological study (author's transl)].

By means of comparative ontogenetical findings and organ cultured whole hearts of tadpoles (Xenopus laevis) there has been evidence that the localization of the endocardial cushions in the embryonic heart tube of landliving vertebrates is phylogenetically caused. On the contrary ontogenetically the shape of these cushions are dependent on the varying hemodynamic conditions in heart development. By this the anlage of endocardial cushions are the presupposition of the phylogeny and ontogeny in the septation of the heart in tetrapodes.


The distribution of primary afferents to the cochlear nuclei in the domestic hen (Gallus domesticus).

The normal anatomy of the three cochlear nuclei in the hen, the nucleus laminaris, the nucleus angularis and the nucleus magnocellularis is described. Following lesions of the cochlear nerve, all three nuclei are shown to receive primary cochlear fibers (silver impregnation methods). The part of nucleus laminaris which consists of a ventral convex sheet of cells is shown to receive cochlear nerve fibers from both ears, the nerve fibers from the ipsilateral ear terminating dorsal to the cell sheet while contralateral nerve fibers terminate ventral to the nerve cells. The cochlear ganglion cells projecting to the nucleus laminaris are apparently situated in other parts of the ganglion that the cells projecting to the nucleus angularis and magnocellularis. The findings are discussed in the light of known data on the organization and function of the cochlear nuclei in birds.


A geometric model of the rat kidney.

Firstly details are collected concerning the required parameters of a simple linear regression in order to evaluate statistically results of measurements, which can also be present in the form (chii, yi +/- SDi). In this way lines of regression are determined for connections between the kidney weight and the body weight, between the lengths of the proximal tubules (and the proximal convolution) of the three various types of nephron and the kidney weight, between the length of the distal convoluted tubule, likewise the number of glomerula, and the kidney weight and finally between the single nephron filtration rate and the length of the proximal tubule. Starting from a model body weight for the rat of 200 g and considering the percentage of thin segments in the tissue of the renal pyramid, a loop of Henle with a length of 8.1 mm for the thin part and a length of 2.4 mm for the ascending thick limb was calculated for the model nephron from the lengths of the loops of the three types of nephrons. In contrast to former model formulations concerning the collecting duct system, the tree-like branched structure was considered for the first time and a linear approximation to the relation between both the circumference line and the cross section area and the lenggh of the collecting ducts was determined. The geometric model relates only to the tubular system and takes no notice of the blood vessels.


The effects of prostaglandin F2alpha on the fine structure of the corpus luteum of the hysterectomized guina pig.

Luteal cell fine structure was studied in hysterectomized control and hysterectomized, prostaglandin-treated (1-5 days) guinea pigs. In hysterectomized control animals, luteal cells were hypertrophied and were characterized by an abundance of agranular endoplasmic reticulum (AER) suggesting steroidogenic activity. With one day of prostaglandin treatment, little change in the cytological appearance had occurred. After two, or three days of treatment, cells showed a decrease in size and an apparent increase in the number of lipid droplets. Following four days of prostaglandin treatment, luteal tissue was characterized by the presence of large amounts of collagen in the intercellular spaces and by the invasion of fibroblasts. Areas of degenerating luteal cells with numerous myelin figures and lipid droplets were observed. After five days of prostaglandin treatment, most of the luteal cells had undergone extensive luteolytic changes. Typically they contained coalescing lipid droplets, myelin figures and crystalloids, and were surrounded by collagen fibers. These observation suggest that prostaglandin F2alpha does effect structural luteolysis in this species in the absence of uterine tissue.


The "imaged-desmosome": a component of intercalated discs in embryonic guinea pig myocardium.

A heretofore undescribed structural variation of the desmosomes of the intercalated disc is found in myocardial cells of the embryonic guinea pig. These desmosomes consist of the usual pair of opaque leaflets, each of the pair contributed by one of the apposed muscle cells. In addition, in the cytoplasm of one of the cells there appears a pair of linear densities (facsimile-lines) parallel to the nearest desmosomal plaque and separated from it by a 60 mm space. The facsimile lines superficially resemble the desmosomal leaflets in length and thickness, thus forming a cytoplasmic "image" of the desmosome. These "imaged-desmosomes" are found predominantly in the longitudinally-running portions of the intercalated discs and are common in 7-week embryos. Their incidence drops sharply by eight weeks of gestation, and they are virtually absent from the heart of the newborn animal. Often tubules of the sarcoplasmic reticulum (SR) are found in apposition to the facsimile-lines; thus it appears that association of SR tubules with desmosomes is responsible for the formation of imaged-desmosomes.


Electron microscopy of endothelial microvilli of large arteries.

Scanning electron microscopic investigations by others have revealed "hair-like" projections from the endothelial surface of the rabbit aorta. We have confirmed by transmission electron microscopy that endothelial microvilli are found, in a limited number of areas in the aortic arch, particularly at the presumed site of fetal origin of the ductus arterious and near the origin of the subclavian artery. The microvilli are almost uniform in diameter (about 0.1 mum) and are as long as 3 mum in length. The outer leaflet of the limiting membrane shows a fuzzy appearance, and thin filaments are recognized in their interiors. A profuse array of endothelial microvilli was also found over the entire surface of the large arteries of human fetuses. The possible hemodynamic significance of these processes is discussed.


The Sertoli cell junctional specializations and their relationship to the germinal epithelium as observed after efferent ductule ligation.

Seminiferous tubules from testes of normal and efferent ductule ligated mice were examined with the electron microscope. The tubules in the ligated animals were markedly distended and at most stages of the seminiferous cycle the epithelium exhibited a series of circumferentially-oriented ridges. Cross-sectional profiles of these ridges were studied with particular emphasis on the Sertoli cell junctional specializations and their relationship to the germinal cells. In the ligated specimen the basal cytoplasm of the Sertoli cells is highly attenuated, often appearing as a thin process resting on the basement lamina. Where the cytoplasm of one Sertoli cell ends, it meets in apposition with the cytoplasm of an adjoining Sertoli cell, and at these sites, junctional specializations are present. The ridges are comprised of a stalk of apical Sertoli cell cytoplasm, often appearing like an inverted cone, with young spermatids aligned along the lateral surfaces and the more mature spermatid population embedded within the apical cytoplasm. Junctional specializations were observed along these lateral Sertoli cell surfaces. In some instances, they formed a free surface, but usually early spermatids were in contact with the junctional specializations. With respect to the more mature spermatids, the acrosomal component was typically found in relation to a junctional specialization. Germ cells at the spermatocyte stage were also noted in relation to the Sertoli cell junctional specializations. The findings suggest that spermatocytes cross the Sertoli cell barrier and gain access to the adluminal compartment of the seminiferous tubule through the disengagement of the inter-Sertoli cell junctional complex. It is proposed that when the inter-Sertoli cell junctional specializations separate, the spermatocytes come in apposition with the newly freed junctional surfaces and remain in relation with them through the ensuing divisions. It appears that at some point, firm adhesion between germ cells and the junctional specializations occurs; the spermatid progeny may thus maintain contact with the original inter-Sertoli cell junctional specializations until their release into the tubule lumen.


The effect of strontium, cobalt and fluoride on rat incisor enamel formation.

This investigation examined ultrastructurally the entire period of development of alterations in formative ameloblasts and the enamel which they produce following injection with fluoride, strontium, and cobalt ions. Rats injected with these ions were sacrificed at intervals of 1, 2, 4, 8, 16, 24 and 48 hours to elucidate the sequence and detail of cytologic and cell product alterations which occur. Undecalcified sections of rat incisor teeth were studied using electron microscopy and microradiography. All three ions initially produced disturbances in cell morphology and enamel formation consisting of dark globules, vacuoles, and pooling of stippled material on the enamel surface. While a period of decreased crystal formation occurred after injection with all three ions, only cobalt responses included a period of apparently complete absence of crystal formation. The hypermineralized layers occurring in the altered enamel are attributed to changes in the rate of enamel matrix formation and duration of its exposure to tissue fluids. Morphologic changes in Tomes' process were observed at the time of formation of abnormel following injection of all three ions. These observations are compared with previous studies of altered enamel formation and analyzed with the goal of learning more about the mechanisms of amelogenesis.


Ultrastructural studies on postnatal differentiation of neurons in the substantia gelatinosa of rat cervical spinal cord.

Neuroblasts of the substantia gelatinosa at birth were small with large oval nuclei and scanty cytoplasm. The cytoplasm possessed ribosomes and mitochondria. Granular endoplasmic reticulum and Golgi complexes were generally absent or rudimentary. Electron dense bodies were seldom observed. By the end of the first week, the nuclei of several cells demonstrated early nuclear invaginations; cytoplasm exhibited growth cones, a well developed granular endoplasmic reticulum and Golgi complexes. At several points the channels of endoplasmic reticulum became continuous with the perinuclear space. By the end of the second week, differentiation of the neuroblasts was more advanced. More nuclei showed invagination of their contour. The cytoplasm revealed well dev-loped granular endoplasmic reticulum and multiple Golgi complexes. Numerous vesicles and dense bodies were found adjacent to the Golgi complexes. Arrays of agranular endoplasmic reticulum also appeared late in the second week. By the third week, features of neuronal differentiation, such as nuclear invagination, granular endoplasmic reticulum agranular membrane configurations, multiple Golgi complexes and dense bodies in the cytoplasm became well established.


The normal human thymic vasculature: an ultrastructural study.

Electron microscopy of the normal human thymus demonstrates a characteristic vascular-parenchymal relationship. The vascular lumen is always separated from the thymic parenchyma by: the endothelial cell cytoplasm, a muscular coat in arterioles and veins, the vascular basal lamina, a perivascular space containing collagen fibers and cells, the epithelial-reticular cell basal lamina and the epithelial-reticular cell cytoplasm. The width of this perivascular space is proportional to the size of the vessel it surrounds; it is wide around the vessels in the septa and at the cortical-medullary junction, but narrow around capillaries. While many cells are present in this space around larger vessels, only collagen is observed around the capillaries. Lymphocytes are the predominant cell type in the space; however, plasma cells, eosinophils, histiocytes, polymorphonuclear leukocytes, mast cells and unidentified granulated cells are also seen. The vascular complex described above may function as a blood-thymus barrier, as the initial site of exposure of the lymphocytes to circulating antigen and as the route of lymphocytes from the thymus.