VISUAL EVOKED POTENTIALS AND CHANGES IN SERUM GLYCINE CONCENTRATION DURING TRANSURETHRAL RESECTION OF THE PROSTATE

Visual evoked potentials were recorded in 10 patients undergoingtransurethral prostatectomy under subarachnoid anaesthesia.They were compared with those obtained in a control group (n=5) having other operative procedures also under spinal anaesthesia.Serum concentrations of glycine, ammonia, glucose and sodium,and osmolality, were determined during the perioperative period.The prostatectomy group demonstrated a significant prolongationof visual evoked potential P₂ latency in the postoperative periodwhen compared with preoperative values (P<0.01). No significantchanges in latency occurred in the control group when measuredat similar times. The prostatectomy group demonstrated a significantincrease in serum glycine concentration (P<0.01); changesin serum ammonia and sodium concentrations and osmolality werenot significant. There was no correlation between visual evokedpotential latency and changes in serum glycine concentration.Changes in visual evoked potential during transurethral prostatectomymay be the result of an accumulation of a metabolite of glycine.     

Transurethral resection of the prostate, serum glycine levels, and ocular evoked potentials

Complications of transurethral resection of the prostate (TURP syndrome) when glycine is used as the irrigating fluid include cardiovascular and central nervous system abnormalities that occasionally include transient blindness. Serum sodium, glycine, potassium, chloride, ammonia, osmolality, carbonate, and blood urea nitrogen of 17 patients having TURP and 10 having cystoscopic examination were measured. Electroretinograms and visually evoked potentials (VEPs) were recorded in the preanesthetic preparatory area and in the recovery room immediately after surgery. Four patients reported visual aberrations coincident with increases in serum levels of glycine from a mean before surgery of 137.7 +/- 45.1 to 7,812.2 +/- 2,486.6 microM/l, mean +/- SD, after TURP. These patients also showed a reduction of serum sodium from 138 +/- 4.5 to 122 +/- 8.6 mEq/l that correlated significantly with serum levels of glycine (rho = -0.81). There were no statistically significant changes of serum ammonia and osmolality. Electroretinograms consistently demonstrated complete loss of oscillatory potentials. Thirty hertz flicker-following was also abolished. VEPs were more variably affected with prolongation of component "P100" latency found in both groups and probably resulting from sedative effects of diazepam. Patients experiencing the TURP syndrome showed abolishment of 30 Hz flicker-following in their VEPs. The elevated serum levels of glycine may contribute directly to visual aberrations resulting from glycine's role as an inhibitory transmitter in the retina.     

Visual disturbances, serum glycine levels and transurethral resection of the prostate

Transient visual disturbances have been noted in patients undergoing transurethral resection of the prostate. It has been suggested recently that these visual aberrations were secondary to high serum concentrations of glycine from the intravasation of irrigant solutions used during the procedure. We prospectively studied visual acuity, serum electrolytes, glucose, ammonia and glycine concentrations in 18 patients undergoing transurethral resection of the prostate. Of our patient population 22% experienced significant decreases in visual acuity. We found that all patients had significantly elevated serum glycine concentrations but that there was no correlation of visual symptomatology with serum electrolyte or glucose concentrations. Our data further suggest that impeded metabolism of glycine may be more important than the absolute serum concentration in symptomatic patients.     

Effects of glycine on hemodynamic responses and visual evoked potentials in the dog

To study the potential contribution of glycine toxicity in the transurethral resection syndrome, we evaluated hemodynamic and visual evoked potential responses to glycine infusion (1 g/kg) in 22 dogs anesthetized with halothane (1.0-1.2% end tidal. Three dogs received 5% glucose in normal saline without glycine; three received arginine (4 mg/kg) in normal saline without glycine; three received arginine (4 mg/kg) in normal saline without glycine; 10 received glycine (1 g/kg), then arginine (4 mg/kg) 120 min after the completion of glycine infusion; and six received arginine 30 min after the completion of glycine infusion. Arginine was infused to evaluate potential antagonistic effects of glycine toxicity. Blood levels of glycine, ammonia, arginine, urea, and formate were determined after infusions of glycine or arginine. All animals received about 5 ml X kg-1 X hr-1 of normal saline during the 2-4 hr of study. Immediately after glycine infusion, cardiac output increased 57%, whereas systemic vascular resistance and mean arterial pressure decreased 32% and 8%, respectively. Later cardiac output and mean arterial pressure were 41% and 18% less than control levels, whereas systemic vascular resistance returned to control levels. Both amplitude and latency of visual evoked potential waveforms were altered in the animals receiving glycine infusion but not in the control animals. These responses were associated with elevations of blood glycine (149 +/- 5 to 9591 +/- 809 microM/L, mean + SEM) and blood NH3 (10.5 +/- 2.8 to 100.0 +/- 13.6 microM/L), but not with formate levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Eye symptoms, visual evoked potentials and EEG during intravenous infusion of glycine

Disturbance of vision is a complication that may occur from absorption of the glycine solution used to irrigate the bladder during transurethral operations. We examined for a possible dose-response relationship between glycine dose, eye symptoms and neurophysiological changes after repeated intermittent intravenous infusions of 4.4 g of glycine for up to 22 g over 1 h in 10 male volunteers. The serum glycine concentration increased from 230±75 to 5,232±1,088 μmol/1 (mean±s.d.) during the infusions. We found an increase in diastolic arterial pressure but no significant changes in systolic pressure, heart rate or mental status. Five of the volunteers developed blurring of vision which lasted for 10 30 min. The visual evoked potentials (VEP) of these subjects showed an increase of the P100 and N70 latencies which started after no more than 4.4 g of glycine had been administered. The amplitude of the VEP was preserved and the main frequency of the EEG did not change, indicating that VEP changes were not due to cortical dysfunction. There was no dose-response relationship between glycine infusion and eye symptoms but a sub-group of volunteers responded with both visual disturbances and VEP changes.     

Prediction of post cataract extraction visual acuity: 10 Hz visually evoked potentials

Cataract patients suspected of having disease that might interfere with good postoperative visual function were evaluated by eliciting monocular steady-state luminance visual evoked potentials (VEPs) with closed eyes at a stimulus rate of 10 flashes/sec. VEPs were rated as either normal or abnormal. Patients with normal VEPs were predicted to have visual acuity of 6/15 (20/50) or better. Patients with abnormal VEPs were predicted to have acuities of 6/18 (20/60) or worse. Postoperative acuities were determined for all patients who underwent surgery and who had no intraoperative or early postoperative complications. The predicted and observed postoperative acuities were quantitatively compared for the 59 patients who met these criteria, using a 2 X 2 contingency table. The chi-square was significant (p less than .001). The overall accuracy of prediction was 80%. Accuracy of the predictions for patients with preoperative acuities of 6/60 (20/200) or better was compared with the accuracy of the predictions for those with preoperative acuities of 60/120 (20/400) or worse. There was no significant difference (p greater than 0.10).     

Blood ammonia levels after intravenous infusion of glycine solution with and without ethanol.

OBJECTIVE: Absorption of glycine 1.5% during transurethral resection of the prostate may increase blood ammonia levels, but hyperammonaemia has not been described when the fluid also contained ethanol 1%. The aim of this experimental study was to evaluate whether ethanol 1% reduces glycine-induced hyperammonaemia. MATERIAL AND METHODS: Two intravenous infusions of glycine solution with and without ethanol 1% added were given on different occasions to 20 male volunteers (mean age 30 years). Half of them received 22 g of glycine over 50 min and the others approximately 18 g over 30 min. Blood ammonia was measured before and 30 min after the infusion. The serum levels of free amino acids were measured on 7 occasions during 10 of the experiments. RESULTS: The glycine infusions increased blood ammonia levels from 37 micromol/l (median, 10th and 90th percentile limits 34-53) to 57 micromol/l (27-110; p < 0.001). The change was greater after the larger glycine dose, regardless of whether the fluid contained ethanol (p < 0.05). The only amino acid concentration correlating with blood ammonia was glycine, which showed higher levels in those who had a rise in blood ammonia of 50% or more. CONCLUSIONS: Ethanol 1% did not reduce the increase in blood ammonia concentration after the administration of glycine solution.     

Evaluation of post-traumatic coma using evoked potentials

In 130 cases of post-traumatic coma a study of multimodality evoked potentials (MEP) was carried out shortly after the traumatism (within 72 h). According to the morphology of the records they were classified in grades (I-IV) in agreement with Greenberg et al. The worst grade of EP in the different types was related to the outcome at 6 months, distinguishing between focal lesions and diffuse lesions. Only a group (22.9%) of the 109 patients in which the auditory brain-stem evoked potentials (ABEP) could be studied, showed severe disorders (grade III-IV). There was a significant correlation between the ABEP grades and the outcome in the focal lesions (p less than 0.001). In the diffuse lesions the ABEP grades did not show significant differences with the outcome. A 22.4% of the patients with diffuse lesions had some visual evoked potentials (VEP) in grades III-IV against almost the double (41.6%) in the focal lesions. The grades of the VEP in the focal lesions did not have differences with outcome and in the diffuse lesions they did (p less than 0.05). Approximately half of the cases with focal lesions and one third of the diffuse lesions showed severe disorders (grades III-IV) of the somatosensory evoked potentials (SEP). In the two types of lesions there were significant differences with the outcome (p less than 0.001) and (p less than 0.01). The multimodality evoked potentials (MEP) are useful for predicting the outcome, especially in the patients where the neurological examination is impossible. Among the different modalities, the SEP were shown to be more predictive.(ABSTRACT TRUNCATED AT 250 WORDS)     

Human duodenal myoelectric activity after operation and with pacing

We sought to determine the influence of operation on the pattern of human duodenal myoelectric activity and to assess whether electrical pacing might correct any postoperative disturbances. Three pairs of temporary bipolar serosal electrodes were placed on the duodenums of ten patients undergoing cholecystectomy. Electrical recordings were obtained daily until the patients' discharge, at 3 to 7 days, after operation. On each postoperative day, a regular rhythmic pattern of pacesetter potentials (PPs) was detected in all patients. The PP frequency (mean +/- SEM) was greater at the proximal electrode than at the distal electrode on the first postoperative day (12.3 +/- 0.1 cpm vs 11.9 +/- 0.1 cpm, p less than 0.01) and on the day of feeding (12.0 +/- 0.2 cpm vs 11.6 +/- 0.2, p less than 0.01). Spontaneous periods when spike potentials accompanied each PP (phase III of the migrating myoelectric complex), were found in only one patient on the day after operation, while they were recorded in five patients after 3 to 7 days, when postoperative ileus had resolved (p less than 0.05). Pacing with electric pulses (50 msec, 5 to 15 mA, 11 to 13 cpm) did not alter the pattern of duodenal PPs or entrain them in the duodenum of any patient at any time after operation. In conclusion, the pattern of duodenal pacesetter potentials changed little during the period of postoperative ileus, while the incidence of phase IIIs of the migrating myoelectric complex was greatly decreased.(ABSTRACT TRUNCATED AT 250 WORDS)     

Somatosensory Evoked Potentials in Patients With Primary Premature Ejaculation

Purpose

Premature ejaculation has been believed to be psychological in the majority of patients. With few exceptions organic conditions are rarely implicated. We investigated the possible role of sensory function in patients with primary premature ejaculation to determine whether there is an etiological basis for this condition.

Materials and Methods

We performed somatosensory evoked potentials from the penis in 34 patients with primary premature ejaculation and in 30 normally potent men. The latencies and amplitudes of the evoked potentials were measured at the penile shaft (dorsal nerve) and at the glans penis.

Results

Mean latency of dorsal nerve and glans penis somatosensory evoked potentials was 1.51 and 6.80 (significant) msec. shorter, respectively, in the patients than in the normal subjects. In the normal subjects the mean latency of glans penis somatosensory evoked potentials was 0.99 msec. longer than that of the dorsal nerve (not significantly different) but in patients the mean latency in the glans penis was 4.30 msec. shorter (p <0.001). Mean amplitude of glans penis somatosensory evoked potentials was less than that of the dorsal nerve in both groups. However, mean amplitudes of dorsal nerve and glans penis somatosensory evoked potentials were significantly greater in patients than in normal men.

Conclusions

Patients with premature ejaculation have hypersensitivity and hyperexcitability of the glans penis, which may give rise to uncontrolled ejaculation and are believed to be organic implications for premature ejaculation.     

Failure of motor evoked potentials to predict neurologic outcome in experimental thoracic aortic occlusion

Motor evoked potential monitoring was tested as an alternative to somatosensory evoked potential monitoring in evaluating spinal cord function during thoracic aortic occlusion in dogs. Twenty-seven animals underwent 60 minutes of cross-clamping of the proximal descending thoracic aorta with (n = 18) or without (n = 9) cerebrospinal fluid drainage. Spinal cord blood flow was measured with microspheres, and neurologic outcome was evaluated at 24 hours with Tarlov's scoring system. Cerebrospinal fluid drainage improved neurologic outcome (p less than 0.05). Motor evoked potentials recorded over the lumbar spinal cord were lost in 9 of 20 dogs with ischemic cord injury and were not lost in any of the 7 dogs that were neurologically normal. Somatosensory evoked potential were lost in 19 of 20 paraplegic/paraparetic dogs and lost in 3 of 7 normal dogs (p less than 0.01). After reperfusion, motor evoked potentials returned in all nine neurologically injured dogs that lost the potentials and were still present at 24 hours. Changes in amplitude, latency, or time until loss or return of motor evoked potentials or somatosensory evoked potentials did not predict neurologic injury. Loss of somatosensory evoked potentials had a high sensitivity (95%) but had low specificity (67%) because of peripheral nerve ischemia. Loss of motor evoked potentials recorded from the spinal cord had high specificity (100%) but a low sensitivity (46%) and was therefore not a reliable predictor of neurologic injury. Return of motor evoked potentials during reperfusion did not correlate with functional recovery. Motor evoked potentials stimulated in the cortex and recorded from the spinal cord had low overall accuracy (59%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Mesenteric venous stenosis reduces hyperammonemia in the portacaval-shunted rat

Hyperammonemia is a constant finding following portacaval anastomosis (PCA), and has been incriminated in the neurologic deterioration observed following portasystemic shunt in humans. We developed a rat model for mesenteric venous hypertension by modification of a commonly used technique for studying extrahepatic portal hypertension. We then examined serum ammonia levels in rats undergoing sham operation, mesenteric vein stenosis (MVS) alone, PCA alone, and MVS plus PCA. All MVS animals had a significant (p less than 0.05) elevation in mesenteric venous pressures 2-3 weeks after operation. Serum ammonia levels were normal in rats undergoing sham operation and MVS, and were significantly elevated (p less than 0.001) in rats with PCA. However, a significant (p less than 0.01) reduction in serum ammonia levels was realized when PCA and MVS were combined. These data suggest that intestinal ammonia absorption is a function of splanchnic venous pressure. These findings may be relevant to the management of the neuropsychiatric deterioration seen following PCA in man.     

The "jaundiced heart": a possible explanation for postoperative shock in obstructive jaundice

Patients with obstructive jaundice are susceptible to postoperative shock and kidney failure. The cause of these potentially fatal complications has not been fully clarified. The present study was designed to assess the role of myocardial dysfunction in the hemodynamic disturbance of obstructive jaundice. We studied the effect of isolated cholemia on left ventricular performance in five conscious dogs before and 2 weeks after choledochocaval anastomosis by using measurements of systolic time intervals (STIs) and maximal dp/dt. Mean left ventricular ejection tiem (LVET) decreased after cholemia from 159 +/- 2.8 msec to 139 +/- 2.6 msec (p less than 0.005), while mean preejection period (PEP) and mean PEP/LVET were increased from 41 +/- 8.5 msec to 87 +/- 14 msec (p less than 0.05) and from 0.39 +/- 0.06 to 0.62 +/- 0.1 (p less than 0.01), respectively. During cholemia, STIs were unchanged after intravenous administration of ouabain, whereas in the control period, there was shortening of mean PEP from 71 +/- 8.8 msec to 58 +/- 7.6 msec (p less than 0.05) and of Q-S2 from 257 +/- 12 msec to 235 +/- 14 msec (p less than 0.005) in response to ouabain. Maximal dp/dt decreased after choledochocaval anastomosis from 4543 +/- 593 mm Hg/sec to 3666 +/- 648 mm Hg/sec (p less than 0.025). We conclude that cholemia in the dog is clearly associated with impaired left ventricular performance. The present data also support a previously published in vitro study from our laboratory showing that cholemia blunts the myocardial contractile response to sympathomimetic agents. The cardiodepressor effect of cholemia may explain the increased tendency of patients with obstructive jaundice to postoperative shock and renal failure.     

Somatosensory evoked potentials and biochemical markers of neuronal deficits in patients undergoing carotid endarterectomy under regional anesthesia

OBJECTIVE OF THE STUDY: Carotid endarterectomy (CEA) remains the standard procedure for primary and secondary prevention of stroke. Somato-sensory evoked potentials (SEP) are frequently used in carotid endarterectomy under general anaesthesia and recommended for monitoring cerebral functions. The aim of the study was to compare changes in SEP and serum levels of S-100 beta protein and neuron-specific enolase (NSE) with perioperative clinical neurological deficits in patients undergoing regional anaesthesia (RA). PATIENTS AND METHODS: After approval of the ethics committee of the Otto-von-Guericke-University, Magdeburg fifty patients undergoing elective CEA under RA were prospectively investigated. RA was performed by combined deep and superficial cervical plexus blockade. SEP was monitored continuously during the surgical procedure. A more of 50 % decrease of potentials (N 20 / P 25 amplitude) compared to potentials before clamping was considered to be significant. Arterial blood samples were collected preoperatively, before declamping and on the first postoperative day to determine serum levels of S-100 beta and NSE. RESULTS: 12 patients developed intraoperatively neurological deficits with carotid clamping. The symptoms were transient and regressed in one minute after shunting. One patient was discharged with persistent hemiparesis. In 8 of 12 patients (66 %) with neurological deficits a more of 50 % decrease of potentials was observed. In one patient with loss of consciousness and hemiparesis changes in SEP or decrease in N 20 / P 25 amplitude were absent. Decrease in amplitude was in patients with intraoperative neurological deficits with 78 % versus 34 % in patients without any deficits significantly reduced (p = 0.01). The sensitivity of monitoring was 67 % at a specificity of 74 %. Serum levels of S-100 beta increased before declamping between patients with and without any neurological deficits significantly (p = 0.02). On the first postoperative day, increased levels of S-100 beta correlated with decrease in amplitude (p = 0.001). CONCLUSION: Compared to SEP, CEA under regional anaesthesia is a safer method to detect patients with cerebral ischaemia before irreversible cellular brain damage occurs. Measuring blood levels of S-100 beta could help to evaluate patients with risk to develop cerebral ischaemia during clamping.     

Somatosensory evoked potentials as a measure of experimental cerebral ischemia

Somatosensory evoked potentials (SEP's) reflect the integrity of the central neuronal pathway, and as such may be used to assess function that remains during a variety of cerebral insults. To evaluate the natural history and utility of SEP's during experimental cerebral ischemia and infarction, SEP's were measured in 17 adult cats at 24 hours and 1 hour prior to right middle cerebral artery (MCA) occlusion, and again immediately afterward and at either 6 hours (five cats) or 24 hours (six cats) post-occlusion. Before occlusion of the right MCA, the SEP's were identical in the right and left hemispheres. After occlusion, there was a significant slowing of the interpeak latency of the first positive peak (P1) in the right hemisphere (3.53 +/- 0.6 msec before compared to 3.99 +/- 0.6 msec after occlusion, p less than 0.001). Maximal slowing in right hemisphere P1 latency was seen in those animals in which the stroke extended into the thalamus (4.38 +/- 0.1 msec). This was significantly slower than left hemisphere values (3.92 +/- 0.32 msec, p less than 0.01). The ipsilateral cortical components of the SEP's, the second positive peak (P2), and the major negative deflection (MN) were slowed in all cats immediately after right MCA occlusion compared to preocclusion measurements (p less than 0.001). Severe infarcts in the mid-suprasylvian and posterior ectosylvian gyri (including the somatosensory cortex) resulted in a greater slowing of the latency of MN compared to less severe infarcts in that region (20.6 +/- 3.9 msec versus 16.4 +/- 1.1 msec, p less than 0.05). There was a precipitous decrease in the amplitude or voltage of the ipsilateral P2-MN complex immediately after occlusion (5.32 +/- 0.4 microV before compared to 0.98 +/- 0.3 microV after occlusion, p less than 0.001). Therefore, the central latencies and cortical amplitudes of the SEP's are sensitive experimental tools as indicators of the onset and extent of a cerebral ischemic insult.     

Vision of the body modulates somatosensory intracortical inhibition

The magnitude of somatosensory evoked potentials (SEPs) elicited by simultaneous electrical stimulation of adjacent digits is generally less than the sum of potentials evoked by stimulation of each digit individually. This under-additivity suggests suppression between representations of adjacent skin regions and may reflect a process of lateral inhibition by interneurons in somatosensory cortex. Given that simply viewing the body enhances tactile acuity and that tactile acuity depends on cortical lateral inhibition, we investigated how viewing the body modulates suppressive interactions between simultaneous afferent volleys from adjacent fingers. We recorded SEPs evoked by electrical stimulation of the right index and middle fingers, either individually or simultaneously, while participants viewed either their own hand or an object. In between trains of electrical stimuli, participants discriminated the orientation of tactile gratings applied to either finger. Consistent with previous findings, viewing the hand enhanced tactile acuity. Furthermore, viewing the hand increased the suppression of the P50 potential due to simultaneous electrical stimulation of both fingers. Moreover, the visual enhancement of tactile performance correlated across participants with the visual modulation of suppression. These results demonstrate that vision enhances somatosensation by modulating activity of inhibitory interneuronal circuits in the somatosensory cortex.     

Phrenic nerve conduction disorder after open heart surgery--electrophysiological study

In 32 consecutive adult patients undergoing heart surgery, the induced diaphragmatic muscle action potential was measured. Phrenic nerve conduction disorder was defined as disappearance of muscle action potential (Edi) and conduction time (CT). Phrenic nerve conduction disorder was observed in 10 patients (31%); 8 patients on the left side and 2 patients on both sides. In non-conduction disorder group (22 patients), Edi and CT were measured. Edi of the right side decreased significantly from preoperative value of 705 +/- 318 microV to 445 +/- 285 microV at 1-3 days after operation (stage I) and to 559 +/- 314 microV at 7-10 days after operation (stage II) (p less than 0.05). CT of the right side prolonged significantly from 7.1 +/- 0.7 msec before operation to 7.44 +/- 0.97 msec at postoperative stage I and to 7.40 +/- 0.21 msec at postoperative stage II (p less than 0.05). For the left phrenic nerve, Edi showed significant (p less than 0.05) decrease from 803 +/- 338 microV before operation to 429 +/- 251 microV at the postoperative stage I and 620 +/- 350 microV at the postoperative stage II. In the conduction disorder group, incidence of atelectasis, diaphragm elevation and pleural effusion as documented by chest roentgenographic findings were higher than those of non-conduction disorder group (p less than 0.01). Moreover, the lowest temperature of the myocardium during operation was significantly (p less than 0.05) lower for conduction disorder group as compared to non-conduction disorder group. We believed that it is necessary to develop a innovative method for preventing the phrenic nerve from cold injury.     

Recovery and morbidity after daycase anaesthesia

The anaesthetic conditions, recovery and side effects for 48 hours postoperatively were compared after anaesthesia for day surgery using propofol or thiopentone-enflurane with and without alfentanil. Propofol provided good conditions for surgery with faster immediate recovery (p less than 0.001); patients who received it were fit for discharge significantly sooner (p less than 0.001). Visual analogue scores of postoperative wellbeing showed an improvement in both propofol groups (p less than 0.01); after thiopentone and enflurane the scores were reduced and took 2 days to return to the pre-operative values. There was a significant (p less than 0.001) reduction in postoperative morbidity in both the groups that received propofol up to 24 hours after discharge. The addition of alfentanil improved anaesthetic conditions and reduced postoperative morbidity with both propofol and thiopentone-enflurane.     

Factors affecting pseudophakic cystoid mascular edema: five randomized trials

We summarize the findings of five randomized prospective, controlled studies that evaluated the following factors associated with the development of cystoid macular edema (CME) following cataract surgery: ultraviolet (UV) light from the operating microscope; postoperative UV light exposure; primary capsulotomy; retrobulbar hyaluronidase; and prostaglandin synthesis in the eye. The following were the major findings: (1) The presence of a UV-light filter on the operating microscope during cataract surgery made no statistically significant difference in the early postoperative (two to six months) angiographic incidence of CME or the visual outcome. (2) A UV-filtering posterior chamber intraocular lens (IOL) resulted in a statistically significant decrease in the early postoperative incidence of angiographic CME in postcataract-surgery patients but did not affect visual acuity. (3) Patients receiving primary capsulotomy during extracapsular cataract surgery showed a statistically significant higher incidence of early postoperative angiographic CME than did patients with an intact posterior capsule. Again there was no difference in visual acuity. (4) The addition of hyaluronidase to the retrobulbar anesthetic injection made no significant difference in the CME rate or postoperative visual results of patients undergoing extracapsular cataract surgery. (5) Patients undergoing IOL implant surgery who received topical indomethacin before surgery and for nine months postoperatively to inhibit prostaglandin synthesis in the eye showed a statistically significant lower incidence of early postoperative angiographic CME than did placebo-treated patients, but there was no significant difference between the two groups in postoperative visual acuity.     

Impaired in vitro Testicular Endocrine Function in Elderly Men

Measurements of testosterone concentrations in peripheral and spermatic venous blood have yielded conflicting results concerning testosterone production in elderly men. To further elucidate the testicular endocrine capacity during aging, peripheral serum hormone levels and the in vitro conversion of progesterone and pregnenolone in histopathologically normal testicular tissue have been investigated in 22 elderly men and 28 younger adult males. The conversion mediated by 3 beta-hydroxysteroid-dehydrogenase and 17 alpha-hydroxylase was significantly higher (p less than 0.05 and p less than 0.01 respectively) in testicular tissue from the younger adult men, than in testicular tissue from elderly men. Since serum LH levels were significantly higher (p less than 0.01) and serum testosterone levels were significantly lower (p less than 0.01) in the elderly men, these data indicate that there was a primary endocrine impairment at the testicular level in the elderly men.