Cocaine-associated intestinal gangrene in a pregnant woman

A 31-year-old pregnant woman who was an active cocaine abuser presented to our emergency department five times in 1 week for abdominal pain and vomiting. She continued to use cocaine regularly despite having abdominal pain. Her fifth admission was for seizures. There were no objective signs of peritoneal inflammation and the rectal guiac examination was repeatedly negative. The patient progressed to severe septic shock. Intraabdominal sepsis and/or bowel perforation was suspected. Exploratory laporatomy revealed gangrene and perforation of the small intestine and fecal peritonitis. She rapidly developed multiorgan failure and died. Gastrointestinal complications resulting from cocaine use are uncommon. Our case is unique in that the patient was pregnant, used cocaine by the intranasal route, and lacked objective signs of acute abdomen. Emergency physicians should be aware of the morbidity associated with the use of cocaine.

Hemodynamic, electrocardiographic, metabolic, and hematologic abnormalities resulting from lithium intoxication. A case report

The authors report a unique case that presented with hemodynamic abnormalities and severe bradycardia, necessitating the insertion of a temporary pacemaker, as well as metabolic disturbances, hematologic changes, and hepatic and renal dysfunction in an elderly individual owing to lithium intoxication. This case also demonstrates that these various serious side effects of lithium resolved with prompt recognition and discontinuation of lithium. Lithium should be used with extreme caution and frequent monitoring especially in the elderly.

Small cell carcinoma of gallbladder: report of two cases

Extrapulmonary small cell carcinoma has been reported from multiple sites, including the gallbladder. Small cell carcinoma of the gallbladder is a very rare tumor, found usually in elderly women and associated with cholelithiasis. It carries a grave prognosis, metastasizing early and causing death shortly after diagnosis. Treatment of metastatic disease with two different chemotherapeutic regimens has been shown to improve survival. To the best of our knowledge, this tumor has not been previously reported in a black individual, or in any subject less than 49 yr or more than 79 yr old. We report two cases: one is the first black and youngest reported case. The second is the oldest person reported with this rare malignancy. Radiological studies such as ultrasound and CT scan were useful in evaluating tumor spread and follow-up.

Pulmonary botryomycosis in a patient with AIDS

We describe the clinical and pathologic findings of the first reported case of pulmonary botryomycosis in a patient with AIDS. Botryomycosis is an uncommon, chronic, suppurative disease that is often mistaken clinically and histologically for a fungal infection. The patient responded to systemic antibiotic therapy.

Wandering spleen with torsion in a geriatric patient. Report of an unusual case with a brief review of the clinical picture and management

Wandering spleen is a rare condition that is extremely uncommon in the elderly. A case of wandering spleen with torsion in a 73-year-old female is described in detail. Our patient's presentation is unusual because in 1972, during a total hysterectomy, she had no evidence of a wandering spleen. Preoperative technetium-99 radionuclide liver-spleen studies were utilized to minimize the potential for vascular difficulties. Splenectomy was the treatment of choice for this condition and was performed to avoid splenic infarction. A review of the literature and etiologic considerations are discussed.

Long-term effects of partial denervation on sprouting and muscle fiber area in rat plantaris

The long-term effects of partial denervation on the muscle fiber cross-sectional area, degree of axonal sprouting, and end-plate morphology were examined 1, 3, 6, 9, and 12 months postsurgery in rat plantaris muscle. After 1 month of partial denervation, mean cross-sectional areas of type I and type II myofibers were significantly lower than that of sham-operated controls; fiber atrophy and hypertrophy was observed. After 3 months, we found no statistical difference in the mean cross-sectional fiber area between the two experimental groups. After 6 months, the fiber areas were now significantly larger than controls, possibly the result of compensatory work hypertrophy, due to the overuse of remaining hyperexpanded motor units. Preterminal, intranodal, and intraterminal sprouting were found to significantly increase from 1 to 6 months following partial denervation. While sprouting was enhanced, the number of terminal branch points per end plate did not change. Following 9 months of partial denervation and overuse, the mean fiber areas significantly decreased as compared to controls. The former muscles were found to contain angulated fibers, group atrophy, and increased levels of axonal sprouting. The number of terminal branches per end plate was now significantly increased over control values, possibly a compensatory response to reduced synthesis of neurotrophic factor(s) and/or transmitter-related components. At 12 months, fiber areas, axonal sprouting, and the number of terminal branches per end plate have all decreased. Degenerating end plates, denervated myofibers, angulated fibers, and group atrophy were observed. It would appear that aging-like changes are occurring earlier in chronically stressed, partially denervated muscles.

Recovery and loss of muscle force of rat plantaris after partial denervation

The isometric contractile characteristics of rat plantaris muscles were assessed 1, 3, 6, 9, and 12 months after resection of the L4 radicular nerve. After 1 month of partial denervation, twitch and tetanus were significantly lower (26.1 and 22.1%, respectively) than those of sham-operated rats. Plantaris muscle weight was reduced (22.5%), but twitch-to-tetanus ratio (TW/TT), time-to-peak, and one-half relaxation time were not changed significantly. At 3 months, average twitch force was normal but average tetanic force was significantly lower (27.1%) than control value. Muscle weight was reduced (28.9%), but TW/TT was increased by 31%. After 6 months, twitch, tetanus, and all other variables were similar to those of control rats. Normal twitch at 3 months indicates that all muscle fibers have been reinnervated by sprouting from L5 motor axons; however, the new synaptic contacts may not support the tetanic response. At 9 months, muscle force was again reduced and remained at about the same level at the 12-month interval. These results are consistent with the recovery and loss of function seen in poliomyelitis and the postpolio syndrome.

A rat model of the post-polio motor unit

We examined the long-term effects of muscle usage on a rat model of the post-polio motor unit. Isometric tensions, type I and type II muscle fiber areas, the incidence of collateral sprouting, and motor endplate morphology were examined following 1, 3, 6, and 9 months of partial denervation in rat plantaris muscle. Full morphologic and functional stability of the expanded motor units occurred at 6 months post-partial denervation. Fiber hypertrophy was observed, possibly the result of compensatory work hypertrophy due to muscle overuse. Following 9 months of partial denervation and muscle overuse, the twitch and tetanic tensions and type I and type II muscle fiber areas were significantly reduced as compared to sham controls; angulated myofibers and group atrophy also were seen. The percent collateral sprouting, the number of terminal branches per endplate, and the endplate area were all increased, possibly a compensatory response to a decreased synthesis of neurotrophic factor(s) and/or transmitter-related components. These aging-like changes seem to occur earlier in chronically stressed, overenlarged, and overworked motor units.

Nerve sprouting and endplate growth induced in normal muscle by contralateral partial denervation of rat plantaris

The incidence of motor nerve and terminal sprouting was quantitatively analyzed in normal unoperated muscles, in homologous muscles contralateral to muscles which have been partially denervated, in partially denervated muscles, and in sham-operated muscles. Muscles were studied by light microscopy after staining motor endplates by a combined silver-cholinesterase stain. In addition, the incidence of endplates containing terminal sprouts, the number of terminal branch points per endplate, and endplate, and endplate size were also assessed in the various groups examined. We observed that following section of the L4 spinal nerve, the incidence of sprouting (preterminal and intranodal) in the contralateral muscle exhibited a 2-fold increase over sham-operated controls. We also found a correlation between nerve terminal sprouting, terminal branch point number and endplate size. All of these parameters were significantly increased in the contralateral muscles as compared to the sham-operated control muscles. These findings suggest that normal muscles undergo sprouting which can be enhanced by contralateral partial denervation. The possible underlying mechanism may be the transneuronal induction of sprouting.

Tenotomy-induced motor endplate alterations in rat soleus muscle

The effects of tenotomy on the ultrastructure of rat soleus muscle motor endplates were examined both qualitatively and quantitatively. Rat soleus muscle was studied 2 weeks following tenotomy and compared with normal littermates. The motor endplates from the tenotomized muscles were found to exhibit both degenerative and regenerative changes. Degeneration consisted of postjunctional fold breakdown, exposed junctional folds, myelin-like bodies within the sub-junctional sarcoplasm, and dense bodies within the Schwann cell cytoplasm. The regenerative changes consisted of several small nerve terminals occurring within the same primary synaptic cleft and several axons wrapped by the same Schwann cell. The results demonstrate that tenotomy induces denervation-like changes at endplates that lead to terminal sprouting within the neuromuscular junctional area and remodelling.

Passive exercise and reinnervation of the rat denervated extensor digitorum longus muscle after nerve crush

Denervated extensor digitorum longus muscles of Wistar rats were passively exercised for 4 days (2 h/day) after peroneal nerve crush 1 cm from the muscle. Isometric contractile properties and endplate ultrastructure were measured 11 days postcrush. No significant differences were observed in tension characteristics between the exercised and nonexercised muscles on day 11. However, the postsynaptic area of endplates for exercised muscles were closer in size to controls than those for the nonexercised ones. In addition, the endplates from the exercised muscles exhibited increased numbers of axonal sprouts and terminals than nonexercised muscles. These results demonstrate that denervated muscles exercised 4 days before reinnervation can preserve the structure of the endplate as well as enhance reinnervation and sprouting at these endplates after 11 days of denervation.

The effect of electrical stimulation on reinnervation of rat muscle: contractile properties and endplate morphometry

Denervated extensor digitorum longus muscles of Wistar rats were electrically stimulated in vivo for 4 days (2h per day) after peroneal nerve crush 1 cm from the muscle. Isometric contractile properties and endplate ultrastructure were measured on days 11 and 18. On day 11, the time to peak (116% of control) and 1/2-relaxation time (136% of control) for the twitch tensions of stimulated muscles measured in vivo were significantly less than those (127% and 157% of controls, respectively) of non-stimulated muscles. Peak twitch and tetanic tensions were not significantly different. The postsynaptic area of endplates for stimulated muscles were closer in size to controls than those for the non-stimulated ones. On day 18, no difference was found in the contractile responses between stimulated and non-stimulated groups. Similarly, the postsynaptic areas were the same for both groups. These results demonstrate that denervated muscle stimulated electrically for 4 days prior to reinnervation can preserve the structure of the endplate as well as accelerate recovery of normal function in reinnervated muscle fibers after 11 days of denervation.

Motor endplate involvement in the extraocular muscles of the myotonic rat

The motor endplates from the extraocular muscles of rats administered 20,25-diazacholesterol were examined by electron microscopy. Many anomalies were found at various levels of the junctional complex. Electron microscopy showed disrupted sole-plate nuclei, disruptions of the junctional sarcoplasm, atypical sarcoplasmic extensions, simplified postsynaptic areas, and interposition of Schwann cell cytoplasm between axonal terminal and muscle fiber with a reduplication of basement membrane, as well as atrophic and disrupted axonal terminals. These data indicate that the motor endplate is affected as well as the muscle fiber in myotonic dystrophy.

The effect of limb immobilization and stretch on the fine structure of the neuromuscular junction in rat muscle

Limb immobilization of rat plantaris muscle in the stretched position for 3 weeks led to increased postsynaptic areas of junctional folds and clefts per nerve terminals in both type I and type II muscle fibers. In addition, various ultrastructural alterations were evident in both types of end plates.

Structural alterations of the intramuscular nerves and junctional region in extraocular muscles of C57BL/Ks (db/db) diabetic mice

The extraocular muscles of the C57BL/Ks (db/db) diabetic mutant mouse were examined by electron microscopy. The intramuscular myelinated nerves and the junctional apparatus of the singly and multiply innervated muscle fibers were found to exhibit various anomalies. Lamellated inclusion bodies were found in many of the Schwann cells of the myelinated nerve fibers; intra-axonal inclusion bodies resembling polyglucosan bodies were also observed. Junctional abnormalities consisted of various types of inclusion bodies within the junctional sarcoplasm and within sole-plate nuclei; in addition, hypertrophied endplates were observed and often penetrated by networks of axonal terminal branches. At times, pseudopod-like extensions of the junctional sarcoplasm encompassed and made protracted synaptic contacts with the incoming axons.

Effects of passive exercise on neurogenic atrophy in rat skeletal muscle

Passive exercise treatment for 23 days produced a retardation of type II muscle fiber atrophy in denervated extensor digitorum longus muscle of rat compared with denervated-nontreated animals. The type I muscle fibers of both denervated groups were similar to that of control rats.

Neuromuscular plasticity following limb immobilization

The effects of immobilization on the ultrastructure of the rat neuromuscular junction of type I and type II muscle fibres were studied both qualitatively and quantitatively. Muscle fibre areas were measured as well. The plantaris muscle was immobilized in a shortened position by applying a plaster cast for three weeks. Immobilized muscles were then compared to normal litter mates. Both type I and type II immobilized muscle fibres atrophied. Endplates from type II muscle fibres exhibited greater amounts of degeneration than type I endplates. Degeneration consisted of nerve terminal disruption, exposed junctional folds, postsynaptic areas which contained little or no postjunctional folds, and subjunctional sarcoplasmic masses. In addition to degeneration, the type II endplates also exhibited regeneration in the same endplate consisting of small terminals associated with large expanses of junctional folds, several small terminals occurring within the same primary synaptic cleft, and several axons wrapped by the same Schwann cell. These observations suggest terminal axonal regeneration. Our results demonstrate that limb immobilization produces muscle atrophy as well as denervation-like changes at the neuromuscular junctions which leads to terminal axonal sprouting and an ultrastructural remodelling.

Endplate postsynaptic structure dependent upon muscle activity

The influence of contractile activity on the preservation of the denervated postsynaptic region of the endplate was quantitatively assessed by electron microscopy. The extensor digitorum longus muscle of rats were denervated for 21 days. Denervated animals were divided into two groups, those receiving electrical stimulation treatment (1 h/day for 21 days) and those left untreated. The postsynaptic area of clefts and folds in endplates of type I and II muscle fibers from controls and denervated-stimulated animals were found to be comparable in size whereas the postsynaptic areas in the denervated-non-stimulated muscles were significantly reduced. The results show that electrically-induced contractile activity plays a significant role in the maintenance of the postsynaptic region of the endplate.

Rat extraocular muscle. 2. Histochemical fibre types

A battery of histochemical stains was used to differentiate the component fibre populations in rat superior oblique muscle. Seven histochemical fibre types were identified and found to be comparable to those observed in a prior light and electron microscopic study of the muscle. The global region of the muscle contained three singly innervated fibre populations (pale, intermediate and red) and one of multiply innervated fibres. THe global singly innervated fibre populations produced a spectrum of fibre types with trichrome, succinate dehydrogenase and Sudan black. The overlying orbital surface layer contained two populations of singly innervated fibres and an additional population of multiply innervated fibres. All the singly innervated fibres (both global and orbital) exhibited a high mATPase activity at pH 10.4 and a low mATPase activity at pH 4.6. The global multiply innervated fibres had low mATPase activity at pH 10.4 and high mATPase activity at pH 4.6. The multiply innervated fibres of the orbital surface layer exhibited high mATPase activity at pH 10.4 and at pH 4.6. The global multiply innervated fibres are similar to the tonic fibres found in amphibian muscle, both histochemically and ultrastructurally. Based upon their histochemical reactivities with the various stains, the multiply innervated fibres of the orbital surface layer appear to be faster acting than the global multiply innervated fibres. Furthermore, it is postulated that the former have polyneuronal innervation and are capable of dual mATPase synthesis.

Rat extraocular muscle. 1. Three dimensional cytoarchitecture, component fibre populations and innervation

Rat superior oblique extraocular muscle was examined in serial sections by light and electron microscopy. By such analysis, it was possible to discriminate single versus multiply innervated fibres, characteristics of the internal structure of fibres, and topographical distribution of the respective fibre populations within the muscle. The superior oblique muscle was observed to consist of two distinguishable muscle portions; one portion originated proximally and the other muscle portion originated distally after passing through the trochlea tendon. Seven morphologically distinct fibre populations were discernible. Four populations, three singly innervated fibre populations and one multiply innervated fibre population, were localised in the global region; these differed in terms of diameter, mitochondrial richness, development of the sarcoplasmic reticulum and myofibrillar size. The orbital surface layer contained two singly innervated and one multiply innervated populations; all of these exhibited systematic morphological variability. The multiply innervated fibres displayed multiple, relatively superficial, neuromuscular junctions along their length, as well as end plate-like junctions which were apparently confined to the region of the singly innervated fibre innervation band, thus suggesting polyneuronal innervation. In the latter region, the multiply innervated fibres displayed morphological features characteristic of "twitch' fibres; away from this region these cells appeared to have morphological features typical of "tonic' fibres. In contrast, the global multiply innervated fibres were constant diameter and form along their length, and displayed only relatively superficial neuromuscular junctions.

Fiber composition of the superior rectus extraocular muscle of the rhesus macaque

The fiber composition of the superior rectus extraocular muscle of adult rhesus monkeys (Macaca mulatta) was examined in serial sections by light and electron microscopy as well as morphometry. Analyses allowed separation of singly versus multiply innervated fibers, and disclosed the morphology of these fibers and their topographical distribution within the muscle. Six morphologically distinct fiber types were found. The global layer of the muscle contains three singly innervated fibers (SIFs) and one multiply innervated fiber (MIF). The overlying orbital surface layer contains one SIF and one MIF, both showing morphological variation along their length. The MIFs of the orbital surface layer had not only multiple, relatively superficial endings along their length, but also endplatelike junctions in which the axonal terminals lie within synaptic clefts. These endplatelike junctions were confined to that region of the MIFs that had a morphology typical of "twitch" fibers; away from this region these MIFs had a morphology characteristic of "tonic" fibers. In contrast, the global MIFs showed constant morphology, and did not exhibit endplatelike endings.

Electrical stimulation effect on denervated skeletal myofibers in rats: a light and electron microscopic study

The purpose of the present study was to determine morphologically the effect of electrical stimulation on denervated rat extensor digitorum longus (EDL) muscle. Fifteen adult male rats were divided in to 3 groups: control, denervated-nonstimulated, and denervated-stimulated. Electrical stimulation treatment (1 hr/day for 24 days) began 4 days postsurgery. All animals were sacrificed 28 days after surgery; the EDL muscle was fixed in situ, removed, and processed for light and electron microscopic examination. Fibers from sections taken from the middle third of the muscle were differentiated into types I and II; fiber diameters were obtained and compared for each experimental group. Although both types atrophied following denervation, type I atrophied to a lesser extent than type II. Electrical stimulation was beneficial in retarding denervation atrophy for both types. Membrane-glycogen complexes were found on electron microscopy to be in high proportion in type II stimulated fibers but were observed infrequently in denervated nonstimulated muscles and were not apparent in control muscles. These glycogen arrays may be expressions of sarcoplasmic reticulum anabolic functions, indicating a high degree of regenerative metabolic activity in treated fibers. This study indicates that electrical stimulation as a method to induce muscle activity, can retard denervation atrophy.

Structural alterations of extraocular muscle associated with Apert's syndrome

An inferior oblique muscle from a patient with Apert's syndrome was examined by light and electron microscopy. Alterations in the muscle fibres, the myoneural junctions, and intramuscular nerves were observed. These data are not compatible with the widespread notion that motility disturbances in this syndrome are solely due to mechanical limitations.

Double-membrane arrays in type II fibers of mouse extraocular muscle

Double-membrane arrays were observed in singly innervated type II fibers of the global region of mouse superior rectus. These arrays were selectively confined to the endplate region of such cells. Close associations and continuities between the cisternae of the arrays with those of the intermyofibrillar sarcoplasmic reticulum suggest derivation of the former from the latter. These proliferations of the cellular smooth membranes might be related to the specialized functional requirements of the innervation site.

Morphological fiber types of retractor bulbi muscle in mouse and rat

Retractor bulbi muscles of mouse and rat were examined by light and electron microscopy. Two morphological fiber types were observed, analogous to Type I and Type II cells of skeletal musculature and comparable to fibers observed in the global region of the rectus extraocular muscles of these species.

Congenital total external ophthalmoplegia associated with infantile spinal muscular atrophy. Fine structure of extraocular muscle

A case of total congenital external ophthalmoplegia associated with infantile spinal muscular atrophy is presented. In the first 29 months of life, ophthalmoplegia has remained complete. Ultrastructure of lateral rectus extraocular muscle indicates a neurogenic process as the basis of the ophthalmoplegia. Light microscopy alone is insufficient to distinguish primary "myopathic" from "neurogenic" disease in external eye muscles.

Structural alterations of the junctional region in extraocular muscle of dystrophic mice. I. Modifications of sole-plate nuclei

Sole-plate nuclei of the C57Bl/6Jdy2j dystrophic mouse showed apparent selective susceptibility to various forms of structural alteration. Pyknosis and chromatin fragmentation were seen in addition to vacuolar and membranous nuclear inclusions. These were often associated with neuromuscular junctions with markedly reduced or virtually absent junctional folding. Membranous proliferations also occurred nearby sole-plate nuclei of such flattened junctions.

Structural alterations of the junctional region in extraocular muscle of dystrophic mice. II. Hypertrophy of the neuromuscular junctional apparatus

The fine structure of end-plate abnormalities was studied in the Bar harbor C57Bl/6jdy2j dystrophic mouse. A marked increase in area and volume of junctional sarcoplasm was often apparent. Such hypertrophied end-plates were often penetrated by networks of axonal terminal branches. At times, pseudopod-like extensions of the junctional sarcoplasm encompassed and made protracted synaptic contact with the incoming axon. Such apparent remodeling of the neuromuscular apparatus might represent a compensatory cellular response to decreased impulse transmission efficiency, as might result from a flattening of the postjunctional folding seen on abnormal muscle fibers in these animals.

Light and electron microscopic serial analysis of mouse extraocular muscle: morphology, innervation and topographical organization of component fiber populations

Mouse superior rectus extraocular muscle was examined in serial section by light and electron microscopy. By such analysis, it was possible to discriminate single versus multiple innervation, characteristics of internal cell morphology, and topographical distribution of the respective fiber populations within the muscle. Singly innervated (SIF) and multiply innervated fibers (MIF) were observed, both in an orbital surface layer and in the underlying global region of the muscle. Five morphologically distinct fiber types (three SIF and two MIF) were discriminable in terms of fiber diameter, mitochondrial richness, development of the sarcoplasmic reticulum, and myofibrillar size. Many fibers both SIF and MIF, terminated variously along the length of the muscle. The diameter of orbital MIF typically varied from one end of the fiber to the other by a factor of about three; the global MIF were of essentially constant diameter. The junctional complexity varied among the respective types of SIF. The MIF of both the global and orbital regions exhibited comparable ranges of complexity in their neuromuscular junctions.

Muscle fiber and motor end plate involvement in the extraocular muscles of the myotonic mouse

The extraocular muscles of the C57BL/6Jdy-2j myotonic mouse were studied by phase and electron microscopy. The most susceptible ocular muscle was the levator palpebrae; the other muscles manifested scattered abnormalities to varying degrees. Central nucleation and fiber splitting were prominent. Junctional abnormalities consisted of a reduction in post-junctional folding, excessive numbers of axonal terminals on hypertrophic fibers, and the presence of dense granules between axon and muscle. This study demonstrates the affection of both muscle fiber and motor end plate in mouse myotonic dystrophy.

Particle-free and glycogen-bearing double membrane arrays in extraocular muscle of rabbit

Smooth double membrane arrays were observed in apparently normal extraocular muscle. These were fully or partially glycogen bearing, or completely particle free. The respective structures were often closely associated. Comparable arrays have been reported in normal and pathologic muscle; in liver cells, particle-free and glycogen-bearing double membrane arrays are frequently seen under an assortment of abnormal conditions. The significance of such structures is not clear. The present observations suggest that particle-free arrays are related to those bearing glycogen and may thus be associated with anabolic functions.